WorldWideScience

Sample records for bone resorption

  1. [Pharmacology of bone resorption inhibitor].

    Science.gov (United States)

    Menuki, Kunitaka; Sakai, Akinori

    2015-10-01

    Currently, bone resorption inhibitor is mainly used for osteoporosis. A number of these agents have been developed. These pharmacological action are various. Bisphosphonate inhibit functions of the osteoclasts by inducing apoptosis. On the one hand, RANK-ligand inhibitor and selective estrogen receptor modulator inhibit formation of osteoclasts. It is important to understand these pharmacological action for the selection of the appropriate medicine. PMID:26529923

  2. Roles of hyaluronan in bone resorption

    Directory of Open Access Journals (Sweden)

    Prince Charles W

    2004-04-01

    Full Text Available Abstract Background Hyaluronan, an unsulfated glycosaminoglycan, while being closely linked to osteoclast function several years ago, has received little attention lately. Given recent new knowledge of hyaluronan's possible cell binding abilities, it is important to re-examine the role of this polysaccharide in bone homeostasis. Discussion Previously published data demonstrating a linkage between induction of hyaluronan synthesis and osteoclast-mediated bone resorption are reviewed. Suggestions are made involving the cell binding ability of hyaluronan and its potential to mediate osteoclast binding to bone surfaces and its potential to serve as a diffusion barrier and participate in the sealing zone required for osteoclast-mediated bone resorption. Summary This brief article summarizes previous studies linking HA to bone resorption and suggests roles for hyaluronan in the process of bone resorption.

  3. Circadian Clock Regulates Bone Resorption in Mice.

    Science.gov (United States)

    Xu, Cheng; Ochi, Hiroki; Fukuda, Toru; Sato, Shingo; Sunamura, Satoko; Takarada, Takeshi; Hinoi, Eiichi; Okawa, Atsushi; Takeda, Shu

    2016-07-01

    The circadian clock controls many behavioral and physiological processes beyond daily rhythms. Circadian dysfunction increases the risk of cancer, obesity, and cardiovascular and metabolic diseases. Although clinical studies have shown that bone resorption is controlled by circadian rhythm, as indicated by diurnal variations in bone resorption, the molecular mechanism of circadian clock-dependent bone resorption remains unknown. To clarify the role of circadian rhythm in bone resorption, aryl hydrocarbon receptor nuclear translocator-like (Bmal1), a prototype circadian gene, was knocked out specifically in osteoclasts. Osteoclast-specific Bmal1-knockout mice showed a high bone mass phenotype due to reduced osteoclast differentiation. A cell-based assay revealed that BMAL1 upregulated nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1 (Nfatc1) transcription through its binding to an E-box element located on the Nfatc1 promoter in cooperation with circadian locomotor output cycles kaput (CLOCK), a heterodimer partner of BMAL1. Moreover, steroid receptor coactivator (SRC) family members were shown to interact with and upregulate BMAL1:CLOCK transcriptional activity. Collectively, these data suggest that bone resorption is controlled by osteoclastic BMAL1 through interactions with the SRC family and binding to the Nfatc1 promoter. © 2016 American Society for Bone and Mineral Research. PMID:26841172

  4. Understanding coupling between bone resorption and formation

    DEFF Research Database (Denmark)

    Andersen, Thomas Levin; Abdelgawad, Mohamed Essameldim; Kristensen, Helene Bjørg;

    2013-01-01

    Bone remodeling requires bone resorption by osteoclasts, bone formation by osteoblasts, and a poorly investigated reversal phase coupling resorption to formation. Likely players of the reversal phase are the cells recruited into the lacunae vacated by the osteoclasts and presumably preparing these...... lacunae for bone formation. These cells, called herein reversal cells, cover >80% of the eroded surfaces, but their nature is not identified, and it is not known whether malfunction of these cells may contribute to bone loss in diseases such as postmenopausal osteoporosis. Herein, we combined...... histomorphometry and IHC on human iliac biopsy specimens, and showed that reversal cells are immunoreactive for factors typically expressed by osteoblasts, but not for monocytic markers. Furthermore, a subpopulation of reversal cells showed several distinctive characteristics suggestive of an arrested...

  5. Molecular and cellular basis of bone resorption.

    Science.gov (United States)

    Gruber, Reinhard

    2015-02-01

    Osteoclast research has an exciting history and a challenging future. More than 3 decades ago, it became evident that bone-resorbing osteoclasts are of hematopoietic origin and are ultimately linked to the "basic multicellular unit," where they team up with the other cell types, including bone-forming osteoblasts. Since 2 decades, we have learned about the signaling pathways controlling genes relevant for osteoclastogenesis and bone resorption. It took another decade until the hypothesized "osteoclast differentiation" factor was discovered and was translated into an approved pharmacologic strategy. Here, the focus is on another molecular target, cathepsin K, a cysteine protease being released by the osteoclast into the resorption compartment. Genetic deletion and pharmacological blocking of cathepsin K reduces bone resorption but with ongoing bone formation. This observation not only holds great promise to become a new pharmacologic strategy, but it also provides new insights into the coordinated work of cells in the "basic multicellular unit" and thus, bridges the history and future of osteoclast research. This article is a short primer on osteoclast biology for readers of the special issue on odanacatib, a cathepsin K inhibitor. PMID:25223736

  6. Bone Remodeling and Hydroxyapatite Resorption in Coated Primary Hip Prostheses

    OpenAIRE

    Tonino, Alphons J.; van der Wal, Bart C. H.; Heyligers, Ide C.; Grimm, Bernd

    2008-01-01

    Hydroxyapatite coatings for THA promote bone ongrowth, but bone and coating are exposed to stress shielding-driven osteoclastic resorption. We asked: (1) if the resorption of hydroxyapatite coating and bone ongrowth correlated with demographics; (2) if the resorption related to the stem level; and (3) what happens to the implant-bone interface when all hydroxyapatite coating is resorbed? We recovered 13 femoral components from cadaveric specimens 3.3 to 11.2 years after uneventful primary THA...

  7. Glucose-dependent insulinotropic polypeptide inhibits bone resorption in humans

    DEFF Research Database (Denmark)

    Nissen, Anne; Christensen, Mikkel; Knop, Filip K;

    2014-01-01

    BACKGROUND: In humans, the pronounced postprandial reduction in bone resorption (decreasing bone resorption markers by around 50%) has been suggested to be caused by gut hormones. Glucose-dependent insulinotropic polypeptide (GIP) is a peptide hormone secreted postprandially from the small intest...

  8. Bone resorption: an actor of dental and periodontal development?

    Science.gov (United States)

    Gama, Andrea; Navet, Benjamin; Vargas, Jorge William; Castaneda, Beatriz; Lézot, Frédéric

    2015-01-01

    Dental and periodontal tissue development is a complex process involving various cell-types. A finely orchestrated network of communications between these cells is implicated. During early development, communications between cells from the oral epithelium and the underlying mesenchyme govern the dental morphogenesis with successive bud, cap and bell stages. Later, interactions between epithelial and mesenchymal cells occur during dental root elongation. Root elongation and tooth eruption require resorption of surrounding alveolar bone to occur. For years, it was postulated that signaling molecules secreted by dental and periodontal cells control bone resorbing osteoclast precursor recruitment and differentiation. Reverse signaling originating from bone cells (osteoclasts and osteoblasts) toward dental cells was not suspected. Dental defects reported in osteopetrosis were associated with mechanical stress secondary to defective bone resorption. In the last decade, consequences of bone resorption over-activation on dental and periodontal tissue formation have been analyzed with transgenic animals (RANKTg and Opg−∕− mice). Results suggest the existence of signals originating from osteoclasts toward dental and periodontal cells. Meanwhile, experiments consisting in transitory inhibition of bone resorption during root elongation, achieved with bone resorption inhibitors having different mechanisms of action (bisphosphonates and RANKL blocking antibodies), have evidenced dental and periodontal defects that support the presence of signals originating bone cells toward dental cells. The aim of the present manuscript is to present the data we have collected in the last years that support the hypothesis of a role of bone resorption in dental and periodontal development. PMID:26594180

  9. Molecular Aspects of Bone Resorption in β-Thalassemia Major

    OpenAIRE

    Najmaldin Saki; Saeid Abroun; Fatemeh Salari; Fakher Rahim; Mohammad Shahjahani; Javad Mohammadi-Asl

    2016-01-01

    β-thalassemia is the most common single gene disorder worldwide, in which hemoglobin β-chain production is decreased. Today, the life expectancy of thalassemic patients is increased because of a variety of treatment methods; however treatment related complications have also increased. The most common side effect is osteoporosis, which usually occurs in early adulthood as a consequence of increased bone resorption. Increased bone resorption mainly results from factors such as delayed puberty, ...

  10. The role of synthetic biomaterials in resorptive alveolar bone regeneration

    Directory of Open Access Journals (Sweden)

    Kaličanin Biljana M.

    2007-01-01

    Full Text Available The alveolar bone tissue resorption defect has a significant role in dentistry. Because of the bone tissue deficit developed by alveolar resorption, the use of synthetic material CP/PLGA (calcium-phosphate/polylactide-co-gliycolide composite was introduced. Investigations were performed on rats with artificially produced resorption of the mandibular bone. The results show that the best effect on alveolar bone were attained by using nano-composite implants. The effect of the nanocomposite was ascertained by determining the calcium and phosphate content, as a basis of the hydroxyapatite structure. The results show that synthetic CP/PLGA nanocomposite alleviate the rehabilitation of weakened alveolar bone. Due to its osteoconductive effect, CP/PLGA can be the material of choice for bone substitution in the future.

  11. Bone resorption around pedicle screws after pedicle screw plate fixation

    International Nuclear Information System (INIS)

    To determine the frequency, level, distribution, onset, and pattern of progression of bone resorption that occurring around pedicle screws after pedicle screw plate fixation. Bone resorption around 902 pedicle screws was analyzed in post-operative, and follow-up radiographs obtained from 156 patients who underwent pedicle screw plate fixation. To determine the resorption degree, categorized arbitrarily as grade 1 (less than 1 mm), grade 2 (1mm or more, but less than 2 mm), or grade 3 (2mm or more), the width of radiolucent zones was measured. In 39 patients in whom resorption was graded 1, 2 or 3, the pattern of progression of 78 screws was evaluated. Resorption occurred around 78 (8.6%) screws in 39 (25%) patients, 26 of whom had more than on lesion. For 99% of screws, there was evidance of resorption within 12 weeks of pedicle screw plate fixation. During follow-up, 61.5% of screws (48/78) remained stable, while 38.5% (30 screws) showed progression to higher grades. The possibility of progression to a higher grade is less when the initial grade is lower. An understanding of the radiographic patterns of bone resorption is useful for monitoring a patient after pedicle screw plate fixation

  12. The chloride channel inhibitor NS3736 [corrected] prevents bone resorption in ovariectomized rats without changing bone formation

    DEFF Research Database (Denmark)

    Schaller, Sophie; Henriksen, Kim; Sveigaard, Christina;

    2004-01-01

    Chloride channel activity is essential for osteoclast function. Consequently, inhibition of the osteoclastic chloride channel should prevent bone resorption. Accordingly, we tested a chloride channel inhibitor on bone turnover and found that it inhibits bone resorption without affecting bone form...

  13. A novel approach to inhibit bone resorption

    DEFF Research Database (Denmark)

    Panwar, Preety; Søe, Kent; Guido, Rafael VC;

    2016-01-01

    pathways. The present study investigates the antiresorptive effect of an exosite inhibitor that selectively inhibits only the therapeutically relevant collagenase activity of CatK. EXPERIMENTAL APPROACH: Human osteoclasts and fibroblasts were used to analyse the effect of the exosite inhibitor, ortho...... RESULTS: DHT1 selectively inhibited the collagenase activity of CatK, without affecting the viability of osteoclasts. Both inhibitors abolished the formation of resorption trenches, with DHT1 having a slightly higher IC50 value than ODN. Maximal reductions of other resorption parameters by DHT1 and ODN...

  14. Peculiarities of the bone tissue resorption under microgravity conditions

    Science.gov (United States)

    Rodionova, N.; Oganov, V.; Polkovenko, O.; Nitsevich, T.

    The actual problem - peculiarities of resorptive processes in the spongiose of thingbones - we studied with the use of tranmissive electron microscopy in experiments on rats (American space station SLS-2) and on monkeys Macaca mulatt? (BION-11). Animals were onboard during 2 weeks. There was established, that the resorption happen with osteoclasts participation. They can create groups of cells. In the osteoclasts population we indicated not typical for the control (ground experiment) "giant" cells, which have on ultrathin sections 5-6 nuclei, many lysosomes, well developed "light" zone and "brush-border". The destruction of minera lized matrix in bone lacunas also happens by the way of osteolytic activity of osteocytes. Lysosome ferments of osteocytes are secreted by the eczocytosis. The osteocytic osteolysis, as well as the osteoclastic one can be seen as a physiological, gormon-dependent mechanism of resorption. The presence of a considerable number of neutrophiles, which enter in some zones of resorption is also typical. When these neutrophiles destruct, they release lysosomic ferments that dissolve the bone matrix. In some zones of resorption we noted the presence of the row from collagen fibrils, which loosed crystals , on mineralized matrix borders. The cell detritus is noted in zones of surface dissolving among crystallic conglomerates. It certificates the processes of osteogenic cells destruction that happen here. So, under the microgravity conditions in zones of adaptive remodeling of the spongiose the processes of the bone tissue resorption happen by some ways, namely: by the functional activization of osteoclasts; by the osteocytic osteolysis increasing; as a result of hydrolytic activity of neutrophiles, entering in these zones, and also by the local demineralization and further destruction of bone matrix surface zones.

  15. Acidification of the osteoclastic resorption compartment provides insight into the coupling of bone formation to bone resorption

    DEFF Research Database (Denmark)

    Karsdal, Morten A; Henriksen, Kim; Sørensen, Mette G;

    2005-01-01

    investigated the effect of inhibition of osteoclastic acidification in vivo by using the rat ovariectomy model withtwice daily oral dosing of NS3696 at 50 mg/kg for 6 weeks. We observed a 60% decrease in resorption (DPYR), increased tartrate-resistant acid phosphatase levels, and no effect on bone formation...

  16. Pharmacological diversity among drugs that inhibit bone resorption.

    Science.gov (United States)

    Russell, R Graham G

    2015-06-01

    Drugs that inhibit bone resorption ('anti-resorptives') continue to dominate the therapy of bone diseases characterized by enhanced bone destruction, including Paget's disease, osteoporosis and cancers. The historic use of oestrogens for osteoporosis led on to SERMs (Selective Estrogen Receptor Modulators, e.g. raloxifene and bazedoxifene). Currently the mainstay of treatment worldwide is still with bisphosphonates, as used clinically for over 40 years. The more recently introduced anti-RANK-ligand antibody, denosumab, is also very effective in reducing vertebral, non-vertebral and hip fractures. Odanacatib is the only cathepsin K inhibitor likely to be registered for clinical use. The pharmacological basis for the action of each of these drug classes is different, enabling choices to be made to ensure their optimal use in clinical practice. PMID:26048735

  17. Ischemic Stroke in Rats Enhances Bone Resorption in Vitro

    OpenAIRE

    Chung, Myung Eun; Lee, Jong In; Im, Sun; Park, Joo Hyun

    2011-01-01

    We hypothesized that the formation and differentialtion of osteoclasts are accelerated and the potential of bone resorption is increased in the hemiplegic bone marrow in the early stage of stroke. We randomly divided white female Sprague-Dawley (SD) rats (n = 30) into two groups, stroke (n = 15) and sham group (n = 15). On the 7th day after stroke, after cutting away the epiphyses of the femurs and tibias, diaphyseal channels were flushed using α-minimum essential medium (α-MEM) and bone marr...

  18. The Bone Resorption Inhibitors Odanacatib and Alendronate Affect Post-Osteoclastic Events Differently in Ovariectomized Rabbits

    OpenAIRE

    Jensen, Pia Rosgaard; Andersen, Thomas Levin; Pennypacker, Brenda L; Duong, Le T.; Delaissé, Jean-Marie

    2013-01-01

    Odanacatib (ODN) is a bone resorption inhibitor which differs from standard antiresorptives by its ability to reduce bone resorption without decreasing bone formation. What is the reason for this difference? In contrast with other antiresorptives, such as alendronate (ALN), ODN targets only the very last step of the resorption process. We hypothesize that ODN may therefore modify the remodeling events immediately following osteoclastic resorption. These events belong to the reversal phase and...

  19. Therapeutic inhibition of cathepsin K—reducing bone resorption while maintaining bone formation

    OpenAIRE

    Duong, Le T.

    2012-01-01

    Osteoporosis is a disease of high bone remodeling with an imbalance of bone resorption over bone formation, resulting in decreased bone mineral density and deterioration of bone microarchitecture. From the emerging understandings of the molecular and cellular regulators of bone remodeling, potential new targets for therapeutic intervention for this disease have been identified. Cathepsin K (CatK), a cysteine protease produced by osteoclasts, is the primary enzyme mediating the degradation of ...

  20. Disassociation of bone resorption and formation by GLP-2

    DEFF Research Database (Denmark)

    Henriksen, Dennis B; Alexandersen, Peter; Hartmann, Bolette;

    2007-01-01

    We have previously shown that a single subcutaneous injection of glucagon-like peptide-2 (GLP-2) at 10 p.m. in postmenopausal women results in a dose-dependent decrease in the nocturnal serum and urine concentrations of fragments derived from the degradation of the C-terminal telopeptide region of...... collagen type I (s-CTX and u-CTX) and u-DPD, markers of bone resorption. In contrast, bone formation, as assessed by serum osteocalcin and procollagen type I N-terminal propeptide (PINP), appeared to be unaffected by treatment with exogenous GLP-2. These effects were further investigated in a 14-day study....... The aim was to demonstrate that a parenteral formulation of GLP-2 is safe and well tolerated after repeated dosing in healthy postmenopausal women for 14 days. It was further investigated whether the effects on bone turnover markers were sustained throughout the study period. The study was a double...

  1. Echistatin is a potent inhibitor of bone resorption in culture.

    Science.gov (United States)

    Sato, M; Sardana, M K; Grasser, W A; Garsky, V M; Murray, J M; Gould, R J

    1990-10-01

    The venom protein, s-echistatin, originally derived from the saw-scaled viper Echis carinatus, was found to be a potent inhibitor of bone resorption by isolated osteoclasts. This Arg24-Gly25-Asp26-(RGD)-containing protein inhibited the excavation of bone slices by rat osteoclasts (IC50 = 0.1 nM). It also inhibited the release of [3H]proline from labeled bone particles by chicken osteoclasts (IC50 = 100 nM). By comparison, the tetrapeptide Arg-Gly-Asp-Ser (RGDS) inhibited resorption by rat or chicken osteoclasts with an IC50 of 0.1 mM while ala24-echistatin was inactive. Video microscopy showed that rat osteoclast attachment to substrate was more sensitive to s-echistatin than was the attachment of mononuclear cells or chicken osteoclasts. The difference in sensitivity of rat and chicken osteoclasts to s-echistatin may be due to differences between receptors on rat and chicken osteoclasts for s-echistatin. Antibody localization of echistatin on these cells showed much greater echistatin binding to rat osteoclasts than to chicken osteoclasts. Laser scanning confocal microscopy after immunohistochemical staining showed that s-echistatin binds to osteoclasts, that s-echistatin receptors are most abundant at the osteoclast/glass interface, and that s-echistatin colocalizes with vinculin. Confocal interference reflection microscopy of osteoclasts incubated with s-echistatin, demonstrated colocalization of s-echistatin with the outer edges of clusters of grey contacts at the tips of some lamellipodia. Identification of the echistatin receptor as an integrin was confirmed by colocalization of echistatin fluorescence with staining for an alpha-like subunit. Attachment of bone particles labeled with [3H]proline to chicken osteoclasts confirmed that the mechanism of action of echistatin was to inhibit osteoclast binding to bone presumably by disrupting adhesion structures. These data demonstrate that osteoclasts bind to bone via an RGD-sequence as an obligatory step in bone

  2. Automated method for measuring alveolar bone resorption by three-dimensional image processing

    International Nuclear Information System (INIS)

    This report describes a method for estimating regions of alveolar bone resorption and automatically measuring resorption depth using dental 3-D CT images by applying 3-D image processing techniques. The depth of alveolar bone resorption is an important index of the severity of periodontitis. Conventional methods for evaluating alveolar bone resorption have suffered from the limitations of not permitting inspection on the interproximal sides and not providing a 3-D description of resorption. In our proposed method, dental 3-D X-ray CT images are used to estimate the region of resorption and to automatically measure the resorption depth around the tooth of interest. Detailed information concerning the distribution of resorption can be obtained using this method. Regions of resorption are estimated using morphological operations and labeling. Limits are established by fitting convex hulls to the region of the target tooth before searching for the lowest points of resorption. The resorption depth is calculated as the distance between the cement-enamel junction and the lowest point of resorption. The experimental results and comparison of these results against measurements obtained by experts using cross-sectional CT images and the findings of clinical examination showed that the proposed method can be used to measure the resorption depth around the entire tooth automatically. (author)

  3. Bone resorption facilitates osteoblastic bone metastatic colonization by cooperation of insulin-like growth factor and hypoxia

    OpenAIRE

    Kuchimaru, Takahiro; Hoshino, Takuya; Aikawa, Tomoya; Yasuda, Hisataka; KOBAYASHI, Tatsuya; Kadonosono, Tetsuya; Kizaka-Kondoh, Shinae

    2014-01-01

    Bone metastasis is a multistep process that includes cancer cell dissemination, colonization, and metastatic growth. Furthermore, this process involves complex, reciprocal interactions between cancer cells and the bone microenvironment. Bone resorption is known to be involved in both osteolytic and osteoblastic bone metastasis. However, the precise roles of the bone resorption in the multistep process of osteoblastic bone metastasis remain unidentified. In this study, we show that bone resorp...

  4. The Bone Resorption Inhibitors Odanacatib and Alendronate Affect Post-Osteoclastic Events Differently in Ovariectomized Rabbits

    DEFF Research Database (Denmark)

    Jensen, Pia Rosgaard; Andersen, Thomas Levin; Pennypacker, Brenda L;

    2014-01-01

    Odanacatib (ODN) is a bone resorption inhibitor which differs from standard antiresorptives by its ability to reduce bone resorption without decreasing bone formation. What is the reason for this difference? In contrast with other antiresorptives, such as alendronate (ALN), ODN targets only the...

  5. A supra-cellular model for coupling of bone resorption to formation during remodeling: lessons from two bone resorption inhibitors affecting bone formation differently.

    Science.gov (United States)

    Jensen, Pia Rosgaard; Andersen, Thomas Levin; Pennypacker, Brenda L; Duong, Le T; Engelholm, Lars H; Delaissé, Jean-Marie

    2014-01-10

    The bone matrix is maintained functional through the combined action of bone resorbing osteoclasts and bone forming osteoblasts, in so-called bone remodeling units. The coupling of these two activities is critical for securing bone replenishment and involves osteogenic factors released by the osteoclasts. However, the osteoclasts are separated from the mature bone forming osteoblasts in time and space. Therefore the target cell of these osteoclastic factors has remained unknown. Recent explorations of the physical microenvironment of osteoclasts revealed a cell layer lining the bone marrow and forming a canopy over the whole remodeling surface, spanning from the osteoclasts to the bone forming osteoblasts. Several observations show that these canopy cells are a source of osteoblast progenitors, and we hypothesized therefore that they are the likely cells targeted by the osteogenic factors of the osteoclasts. Here we provide evidence supporting this hypothesis, by comparing the osteoclast-canopy interface in response to two types of bone resorption inhibitors in rabbit lumbar vertebrae. The bisphosphonate alendronate, an inhibitor leading to low bone formation levels, reduces the extent of canopy coverage above osteoclasts. This effect is in accordance with its toxic action on periosteoclastic cells. In contrast, odanacatib, an inhibitor preserving bone formation, increases the extent of the osteoclast-canopy interface. Interestingly, these distinct effects correlate with how fast bone formation follows resorption during these respective treatments. Furthermore, canopy cells exhibit uPARAP/Endo180, a receptor able to bind the collagen made available by osteoclasts, and reported to mediate osteoblast recruitment. Overall these observations support a mechanism where the recruitment of bone forming osteoblasts from the canopy is induced by osteoclastic factors, thereby favoring initiation of bone formation. They lead to a model where the osteoclast-canopy interface is

  6. Reduction of instability-induced bone resorption using bisphosphonates: high doses are needed in rats.

    OpenAIRE

    Åstrand, Jörgen; Aspenberg, Per

    2002-01-01

    Bone resorption associated with prosthetic loosening can be reduced by giving bisphosphonates since they bind to bone surfaces and inactivate osteoclasts when bisphosphonate-containing bone is resorbed. During loosening, an increase in osteoclastic activity can be triggered by mechanical instability, fluid pressure or wear particles. We used a rat model in which a titanium surface can be made to slide over a bone surface and cause instability-induced bone resorption. 111 rats were operated on...

  7. Erk1 positively regulates osteoclast differentiation and bone resorptive activity.

    Directory of Open Access Journals (Sweden)

    Yongzheng He

    Full Text Available The extracellular signal-regulated kinases (ERK1 and 2 are widely-expressed and they modulate proliferation, survival, differentiation, and protein synthesis in multiple cell lineages. Altered ERK1/2 signaling is found in several genetic diseases with skeletal phenotypes, including Noonan syndrome, Neurofibromatosis type 1, and Cardio-facio-cutaneous syndrome, suggesting that MEK-ERK signals regulate human skeletal development. Here, we examine the consequence of Erk1 and Erk2 disruption in multiple functions of osteoclasts, specialized macrophage/monocyte lineage-derived cells that resorb bone. We demonstrate that Erk1 positively regulates osteoclast development and bone resorptive activity, as genetic disruption of Erk1 reduced osteoclast progenitor cell numbers, compromised pit formation, and diminished M-CSF-mediated adhesion and migration. Moreover, WT mice reconstituted long-term with Erk1(-/- bone marrow mononuclear cells (BMMNCs demonstrated increased bone mineral density as compared to recipients transplanted with WT and Erk2(-/- BMMNCs, implicating marrow autonomous, Erk1-dependent osteoclast function. These data demonstrate Erk1 plays an important role in osteoclast functions while providing rationale for the development of Erk1-specific inhibitors for experimental investigation and/or therapeutic modulation of aberrant osteoclast function.

  8. LEPTIN REGULATION OF BONE RESORPTION BY THE SYMPATHETIC NERVOUS SYSTEM AND CART

    Science.gov (United States)

    Bone remodelling, the mechanism by which vertebrates regulate bone mass, comprises two phases, namely resorption by osteoclasts and formation by osteoblasts; osteoblasts are multifunctional cells also controlling osteoclast differentiation. Sympathetic signalling via beta2-adrenergic receptors (Adrb...

  9. In-Vivo Effect of Andrographolide on Alveolar Bone Resorption Induced by Porphyromonas gingivalis and Its Relation with Antioxidant Enzymes

    OpenAIRE

    Rami Al Batran; Fouad H. Al-Bayaty; Mazen M.Jamil Al-Obaidi

    2013-01-01

    Alveolar bone resorption is one of the most important facts in denture construction. Porphyromonas gingivalis (Pg) causes alveolar bone resorption, and morphologic measurements are the most frequent methods to identify bone resorption in periodontal studies. This study has aimed at evaluating the effect of Andrographolide (AND) on alveolar bone resorption in rats induced by Pg. 24 healthy male Sprague Dawley rats were divided into four groups as follows: normal control group and ...

  10. Local treatment of a bone graft by soaking in zoledronic acid inhibits bone resorption and bone formation. A bone chamber study in rats.

    OpenAIRE

    Belfrage Ola; Isaksson Hanna; Tägil Magnus

    2012-01-01

    ABSTRACT: BACKGROUND: Bone grafts are frequently used in orthopaedic surgery. Graft remodelling is advantageous but can occur too quickly, and premature bone resorption might lead to decreased mechanical integrity of the graft. Bisphosphonates delay osteoclastic bone resorption but may also impair formation of new bone. We hypothesize that these effects are dose dependent. In the present study we evaluate different ways of applying bisphosphonates locally to the graft in a bone...

  11. Effect of Kiwifruit on Bone Resorption in Ovariectomized Mice.

    Science.gov (United States)

    Katsumata, Shinichi; Wolber, Frances M; Tadaishi, Miki; Tousen, Yuko; Ishimi, Yoshiko; Kruger, Marlena C

    2015-01-01

    Kiwifruit is a good source of dietary components and has beneficial effects for health. In this study, we investigated the effects of two types of kiwifruit, green kiwifruit (GRK) and gold kiwifruit (GOK), on bone metabolism in ovariectomized (OVX) mice. Seven-week-old female Balb/c-strain mice were divided into four groups: sham-operated (sham) group, OVX group, and OVX mice that were fed a GRK-supplemented diet or GOK-supplemented diet. Freeze-dried GRK and GOK were prepared and added in the diet at a concentration of 3 g/100 g. After 9 wk, the mice were sacrificed, and the serum, uterus, and femurs were obtained. Final body weight did not differ significantly among the four groups. Compared to the sham group, uterine weight was significantly lower and serum C-terminal telopeptide of type I collagen (CTx) levels and receptor activator of NF-κB ligand (RANKL) mRNA expression of the whole femur were significantly higher in the OVX group. Compared to the OVX group, GRK, but not GOK, reduced serum CTx concentrations and RANKL mRNA expression of the whole femur without changes in uterine weight. These results suggest that the GRK inhibited bone resorption, which might be due to a decrease in RANKL mRNA expression in OVX mice. PMID:26440641

  12. Divalent cation ionophores stimulate resorption and inhibit DNA synthesis in cultured fetal rat bone

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo, J.A.; Raisz, L.G.

    1981-06-01

    Two divalent cation ionophores, A23187 and Ionomycin, which are selective for calcium, stimulated the resorption of fetal rat long bones in organ culture at 0.1 to 1 micromolar but not at higher concentrations. Both agents inhibited DNA synthesis at concentrations that stimulated resorption. These results might explain the differences in ionophore effects on bone previously reported, and they imply that cell replication is not required for osteoclast formation in fetal rat long bone cultures.

  13. [Effect of osthol on apoptosis and bone resorption of osteoclasts cultured in vitro].

    Science.gov (United States)

    Ming, Lei-Guo; Wang, Ming-Gang; Chen, Ke-Ming; Zhou, Jian; Han, Gui-Qiu; Zhu, Rui-Qing

    2012-02-01

    This study is to investigate the effect of osthol on osteoclasts' activity, bone resorption as well as apoptosis in vitro, and explore the mechanism of osthol in preventing osteoporosis. Osteoclasts were separated from long-limb bones of new born rabbits, cultured in 24-well plate with glass slices and bone slices, and treated by 1 x 10(-5) mol x L(-1) osthol. Osteoclasts were identified by observing live cells with phase contrast microscope, HE staining, TRAP staining and toluidine blue staining of bone resorption pits. The numbers of bone resorption pits were counted as well as the surface area of bone resorption on bone slice. Osteoclasts were stained with acridine orange to detect the cell apoptosis. The ratio of apoptotic osteoclasts was observed under fluorescence microscope. The gene expression of RANKL, OPG, TRAP and p-JNK1/2 protein expression were examined using real time PCR and Western blotting, respectively. Comparing with the control group without osthol, the rates of apoptotic osteoclasts increased obviously and the number and area of bone resorption pits decreased evidently with 1 x 10(-5) mol x L(-1) osthol. There is significant difference between control group and experiment group treated by 1 x 10(-5) mol x L(-1) osthol. Therefore, the osthol through RANK+RANKL/TRAF6/Mkk/JNK signal pathway inhibits the osteoclasts activity, enhances osteoclasts apoptotic and inhibits the bone resorption. PMID:22512027

  14. Control of bone resorption by semaphorin 4D is dependent on ovarian function.

    Directory of Open Access Journals (Sweden)

    Romain Dacquin

    Full Text Available Osteoporosis is one of the most common bone pathologies, which are characterized by a decrease in bone mass. It is well established that bone mass, which results from a balanced bone formation and bone resorption, is regulated by many hormonal, environmental and genetic factors. Here we report that the immune semaphorin 4D (Sema4D is a novel factor controlling bone resorption. Sema4D-deficient primary osteoclasts showed impaired spreading, adhesion, migration and resorption due to altered ß3 integrin sub-unit downstream signaling. In apparent accordance with these in vitro results, Sema4D deletion in sexually mature female mice led to a high bone mass phenotype due to defective bone resorption by osteoclasts. Mutant males, however, displayed normal bone mass and the female osteopetrotic phenotype was only detected at the onset of sexual maturity, indicating that, in vivo, this intrinsic osteoclast defect might be overcome in these mice. Using bone marrow cross transplantation, we confirmed that Sema4D controls bone resorption through an indirect mechanism. In addition, we show that Sema4D -/- mice were less fertile than their WT littermates. A decrease in Gnrh1 hypothalamic expression and a reduced number of ovarian follicles can explain this attenuated fertility. Interestingly, ovariectomy abrogated the bone resorption phenotype in Sema4D -/- mice, providing the evidence that the observed high bone mass phenotype is strictly dependent on ovarian function. Altogether, this study reveals that, in vivo, Sema4D is an indirect regulator of bone resorption, which acts via its effect on reproductive function.

  15. An automatic early stage alveolar-bone-resorption evaluation method on digital dental panoramic radiographs

    Science.gov (United States)

    Zhang, Min; Katsumata, Akitoshi; Muramatsu, Chisako; Hara, Takeshi; Suzuki, Hiroki; Fujita, Hiroshi

    2014-03-01

    Periodontal disease is a kind of typical dental diseases, which affects many adults. The presence of alveolar bone resorption, which can be observed from dental panoramic radiographs, is one of the most important signs of the progression of periodontal disease. Automatically evaluating alveolar-bone resorption is of important clinic meaning in dental radiology. The purpose of this study was to propose a novel system for automated alveolar-bone-resorption evaluation from digital dental panoramic radiographs for the first time. The proposed system enables visualization and quantitative evaluation of alveolar bone resorption degree surrounding the teeth. It has the following procedures: (1) pre-processing for a test image; (2) detection of tooth root apices with Gabor filter and curve fitting for the root apex line; (3) detection of features related with alveolar bone by using image phase congruency map and template matching and curving fitting for the alveolar line; (4) detection of occlusion line with selected Gabor filter; (5) finally, evaluation of the quantitative alveolar-bone-resorption degree in the area surrounding teeth by simply computing the average ratio of the height of the alveolar bone and the height of the teeth. The proposed scheme was applied to 30 patient cases of digital panoramic radiographs, with alveolar bone resorption of different stages. Our initial trial on these test cases indicates that the quantitative evaluation results are correlated with the alveolar-boneresorption degree, although the performance still needs further improvement. Therefore it has potential clinical practicability.

  16. The bone resorption inhibitors odanacatib and alendronate affect post-osteoclastic events differently in ovariectomized rabbits.

    Science.gov (United States)

    Jensen, Pia Rosgaard; Andersen, Thomas Levin; Pennypacker, Brenda L; Duong, Le T; Delaissé, Jean-Marie

    2014-02-01

    Odanacatib (ODN) is a bone resorption inhibitor which differs from standard antiresorptives by its ability to reduce bone resorption without decreasing bone formation. What is the reason for this difference? In contrast with other antiresorptives, such as alendronate (ALN), ODN targets only the very last step of the resorption process. We hypothesize that ODN may therefore modify the remodeling events immediately following osteoclastic resorption. These events belong to the reversal phase and include recruitment of osteoblasts, which is critical for connecting bone resorption to formation. We performed a histomorphometric study of trabecular remodeling in vertebrae of estrogen-deficient rabbits treated or not with ODN or ALN, a model where ODN, but not ALN, was previously shown to preserve bone formation. In line with our hypothesis, we found that ODN treatment compared to ALN results in a shorter reversal phase, faster initiation of osteoid deposition on the eroded surfaces, and higher osteoblast recruitment. The latter is reflected by higher densities of mature bone forming osteoblasts and an increased subpopulation of cuboidal osteoblasts. Furthermore, we found an increase in the interface between osteoclasts and surrounding osteoblast-lineage cells. This increase is expected to favor the osteoclast-osteoblast interactions required for bone formation. Regarding bone resorption itself, we show that ODN, but not ALN, treatment results in shallower resorption lacunae, a geometry favoring bone stiffness. We conclude that, compared to standard antiresorptives, ODN shows distinctive effects on resorption geometry and on reversal phase activities which positively affect osteoblast recruitment and may therefore favor bone formation. PMID:24085265

  17. [Reducing bone resorption by cathepsin K inhibitor and treatment of osteoporosis].

    Science.gov (United States)

    Watanabe, Reiko; Okazaki, Ryo

    2014-01-01

    Cathepsin K is a lysosomal cysteine protease, secreted from osteoclasts. It plays a major role in the osteoclastic bone resorption by cleaving type 1 collagen, the major bone matrix protein, under acidic pH. In cathepsin K knockout mice, bone mineral density (BMD) is increased, bone resorption is decreased without reduction in the number of osteoclast whereas bone formation is decreased. Based on these results, cathepsin K inhibitors have been developed for the treatment of osteoporosis. Odanacatib is one of them and is perhaps closest for launching. In phase 1 and 2 trials, it markedly reduced bone resorption with a transient reduction in bone formation, thus resulted in a robust increase in both trabecular and cortical BMD in osteoporotics. Currently, Odanacatib is in phase 3 fracture prevention trial, of which results are anticipated in 2014. PMID:24369281

  18. The diurnal rhythm of bone resorption in the rat. Effect of feeding habits and pharmacological inhibitors.

    OpenAIRE

    Mühlbauer, R C; Fleisch, H

    1995-01-01

    Prevention of low bone mass is important to reducing the incidence of osteoporotic fractures. This paper shows that, in rats, bone mass can be increased by feeding habits per se. Using six-hourly urinary excretion of [3H]tetracycline from prelabeled rats to monitor bone resorption, we previously found a peak of bone resorption following food administration. We now demonstrate that dividing the solid and liquid intake into portions blunts this peak and leads to a decrease in 24-h bone resorpti...

  19. Self-assembling bisphosphonates into nanofibers to enhance their inhibitory capacity on bone resorption

    Science.gov (United States)

    Tang, Anming; Qian, Yu; Liu, Shuang; Wang, Weijuan; Xu, Bing; Qin, An; Liang, Gaolin

    2016-05-01

    Osteoporosis (OP) is an important aging-related disease and the effective prevention/treatment of this disease remains challenging. Considering the acidic microenvironment of bone resorption lacunae, herein, we rationally designed two pamidronate (Pami)-derivative and alendronate (Alen)-derivative hydrogelators Pami-D and Alen-D which self-assemble into nanofibers to form supramolecular hydrogels under acidic conditions. Cell viability assay, osteoclastogenesis, osteoclastic gene expression, and in vitro bone resorption results indicated that both Pami-D and Alen-D have better inhibitory effects on osteoclastic formation and bone resorption than Pami and Alen, respectively. We anticipate that our new drugs Pami-D and Alen-D could ``smartly'' self-assemble and locally concentrate the drugs at bone resorption lacunae in vivo and subsequently prevent/treat osteoporosis more efficiently.Osteoporosis (OP) is an important aging-related disease and the effective prevention/treatment of this disease remains challenging. Considering the acidic microenvironment of bone resorption lacunae, herein, we rationally designed two pamidronate (Pami)-derivative and alendronate (Alen)-derivative hydrogelators Pami-D and Alen-D which self-assemble into nanofibers to form supramolecular hydrogels under acidic conditions. Cell viability assay, osteoclastogenesis, osteoclastic gene expression, and in vitro bone resorption results indicated that both Pami-D and Alen-D have better inhibitory effects on osteoclastic formation and bone resorption than Pami and Alen, respectively. We anticipate that our new drugs Pami-D and Alen-D could ``smartly'' self-assemble and locally concentrate the drugs at bone resorption lacunae in vivo and subsequently prevent/treat osteoporosis more efficiently. Electronic supplementary information (ESI) available: Experiment methods and details; syntheses and characterization of Pami-D and Alen-D; HPLC conditions; Fig. S1-S15, Schemes S1 and S2, Tables S1 and S2

  20. Response of Bone Resorption Markers to Aristolochia longa Intake by Algerian Breast Cancer Postmenopausal Women

    OpenAIRE

    Bachir Benarba; Boumedienne Meddah; Aicha Tir Touil

    2014-01-01

    Aristolochia longa is widely used in traditional medicine in Algeria to treat breast cancer. The aim of the present study was to investigate the response of bone resorption markers to A. longa intake by Algerian breast cancer postmenopausal women. According to the A. longa intake, breast cancer patients were grouped into A. longa group (Al) (n = 54) and non-A. longa group (non-Al) (n = 24). 32 women constituted the control group. Bone resorption markers (from urine) pyridinoline (PYD) and deo...

  1. Advanced glycation end products biphasically modulate bone resorption in osteoclast-like cells.

    Science.gov (United States)

    Li, Ziqing; Li, Chaohong; Zhou, Yuhuan; Chen, Weishen; Luo, Guotian; Zhang, Ziji; Wang, Haixing; Zhang, Yangchun; Xu, Dongliang; Sheng, Puyi

    2016-03-01

    Advanced glycation end products (AGEs) disturb bone remodeling during aging, and this process is accelerated in diabetes. However, their role in modulation of osteoclast-induced bone resorption is controversial, with some studies indicating that AGEs enhance bone resorption and others showing the opposite effect. We determined whether AGEs present at different stages of osteoclast differentiation affect bone resorption differently. Based on increased levels of tartrate-resistant acid phosphatase (TRAP) and cathepsin K (CTSK), we identified day 4 of induction as the dividing time of cell fusion stage and mature stage in RAW264.7 cell-derived osteoclast-like cells (OCLs). AGE-modified BSA (50-400 μg/ml) or control BSA (100 μg/ml) was then added at the beginning of each stage. Results showed that the presence of AGEs at the cell fusion stage reduced pit numbers, resorption area, and CTSK expression. Moreover, expression of receptor activator of nuclear factor-κB (RANK) as well as the number of TRAP-positive cells, nuclei per OCL, actin rings, and podosomes also decreased. However, the presence of AGEs at the mature stage enlarged the resorption area markedly and increased pit numbers slightly. Intriguingly, only the number of nuclei per OCL and podosomes increased. These data indicate that AGEs biphasically modulate bone resorption activity of OCLs in a differentiation stage-dependent manner. AGEs at the cell fusion stage reduce bone resorption dramatically, mainly via suppression of RANK expression in osteoclast precursors, whereas AGEs at the mature stage enhance bone resorption slightly, most likely by increasing the number of podosomes in mature OCLs. PMID:26670486

  2. MAPK11 in breast cancer cells enhances osteoclastogenesis and bone resorption

    OpenAIRE

    He, Zhimin; He, Jin; Liu, Zhiqiang(Institute of High Energy Physics, Beijing, 100049, People's Republic of China); Xu, Jingda; Yi, Sofia F.; Liu, Huan; Yang, Jing

    2014-01-01

    Breast cancer cells frequently metastasize to bone and induce osteolytic bone destruction in patients. These metastases cause severe bone pain, high risk of fractures and hypercalcemia, and are essentially incurable and fatal. Recent studies show that breast cancer cells in bone activate osteoclastogenesis and bone resorption. However the underlying mechanism is poorly understood. This study shows that the p38 MAPK (p38) isoform MAPK11 (p38β) is expressed in breast cancer cells. By using spec...

  3. Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

    DEFF Research Database (Denmark)

    Leeming, Diana J; Byrjalsen, Inger; Qvist, Per;

    2008-01-01

    BACKGROUND: Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover in...... breast and prostate cancer patients is associated with an increase in cartilage degradation and to test in vitro whether osteoclasts or cathepsin K alone generate CTXII from human bone. METHODS: The study included 132 breast and prostate cancer patient, where presence of bone metastases was graded...... according to the Soloway score. Total bone resorption (CTXItotal) and cartilage degradation (CTXII) were determined. RESULTS: Breast and prostate cancer patients with bone metastases revealed significant increased levels of CTXItotal at Soloway scores 1 and higher compared to patients without bone...

  4. Urine products of bone breakdown as markers of bone resorption and clinical usefulness of urinary hydroxyproline:an overview

    Institute of Scientific and Technical Information of China (English)

    Baris Simsek; (O)zgul Karacaer; inci Karaca

    2004-01-01

    Purpose The purpose of this study is to review the urine products of bone breakdown as markers of bone resorption and usefulness of urinary hydroxyproline. Data Related researches published in 1985 -2000 were systematically reviewed. Results Bone markers could be used for early diagnosis of bone metabolic diseases. Biochemical markers of bone resorption that reflect osteoclast activity and/or collagen degradation provide a new and potentially important clinical tool for the assessment and monitoring of bone metabolism. Assessment of bone resorption can be achieved with measurement of urinary hydroxylysine glycosides, urinary excretion of the collagen pyridinium cross-links, urinary excretion of type I collagen telopeptide breakdown products (cross-linked telopeptides) and urinary hydroxyproline. Conclusion Urinary hydroxyproline has been in use as a marker of bone resorption, but it lacks sensitivity and specificity. It is a modified aminoacid that is a metabolic product of collagen breakdown.Hydroxyproline may be released either free or with fragments of the collagen molecule attached during bone resorption, and it is also liberated by the breakdown of complement and nonskeletal collagen.

  5. Neural crest-mediated bone resorption is a determinant of species-specific jaw length.

    Science.gov (United States)

    Ealba, Erin L; Jheon, Andrew H; Hall, Jane; Curantz, Camille; Butcher, Kristin D; Schneider, Richard A

    2015-12-01

    Precise control of jaw length during development is crucial for proper form and function. Previously we have shown that in birds, neural crest mesenchyme (NCM) confers species-specific size and shape to the beak by regulating molecular and histological programs for the induction and deposition of cartilage and bone. Here we reveal that a hitherto unrecognized but similarly essential mechanism for establishing jaw length is the ability of NCM to mediate bone resorption. Osteoclasts are considered the predominant cells that resorb bone, although osteocytes have also been shown to participate in this process. In adults, bone resorption is tightly coupled to bone deposition as a means to maintain skeletal homeostasis. Yet, the role and regulation of bone resorption during growth of the embryonic skeleton have remained relatively unexplored. We compare jaw development in short-beaked quail versus long-billed duck and find that quail have substantially higher levels of enzymes expressed by bone-resorbing cells including tartrate-resistant acid phosphatase (TRAP), Matrix metalloproteinase 13 (Mmp13), and Mmp9. Then, we transplant NCM destined to form the jaw skeleton from quail to duck and generate chimeras in which osteocytes arise from quail donor NCM and osteoclasts come exclusively from the duck host. Chimeras develop quail-like jaw skeletons coincident with dramatically elevated expression of TRAP, Mmp13, and Mmp9. To test for a link between bone resorption and jaw length, we block resorption using a bisphosphonate, osteoprotegerin protein, or an MMP13 inhibitor, and this significantly lengthens the jaw. Conversely, activating resorption with RANKL protein shortens the jaw. Finally, we find that higher resorption in quail presages their relatively lower adult jaw bone mineral density (BMD) and that BMD is also NCM-mediated. Thus, our experiments suggest that NCM not only controls bone resorption by its own derivatives but also modulates the activity of mesoderm

  6. Endostatin inhibits VEGF-A induced osteoclastic bone resorption in vitro

    Directory of Open Access Journals (Sweden)

    Ilvesaro Joanna

    2006-07-01

    Full Text Available Abstract Background Endostatin is a C-terminal fragment of collagen XVIII which is a component of basement membranes with the structural properties of both collagens and proteoglycans. Endostatin has a major role in angiogenesis which is intimately associated with bone development and remodeling. Signaling between the endothelial cells and the bone cells, for example, may have a role in recruitment of osteoclastic precursor cells. Our study aims at exploring a possibility that endostatin, either as a part of basement membrane or as a soluble molecule, may control osteoclastogenesis and osteoclastic bone resorption in vitro. Methods Rat pit formation assay was employed in order to examine the effect of endostatin alone or in combination with vascular endothelial growth factor-A (VEGF-A on bone resorption in vitro. Effect of these agents on osteoclast differentiation in vitro was also tested. Osteoclastogenesis and the number of osteoclasts were followed by tartrate resistant acid phosphatase (TRACP staining and resorption was evaluated by measuring the area of excavated pits. Results Endostatin inhibited the VEGF-A stimulated osteoclastic bone resorption, whereas endostatin alone had no effect on the basal resorption level in the absence of VEGF-A. In addition, endostatin could inhibit osteoclast differentiation in vitro independent of VEGF-A. Conclusion Our in vitro data indicate that collagen XVIII/endostatin can suppress VEGF-A induced osteoclastic bone resorption to the basal level. Osteoclastogenesis is also inhibited by endostatin. The regulatory effect of endostatin, however, is not critical since endostatin alone does not modify the basal bone resorption.

  7. Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

    International Nuclear Information System (INIS)

    Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover in breast and prostate cancer patients is associated with an increase in cartilage degradation and to test in vitro whether osteoclasts or cathepsin K alone generate CTXII from human bone. The study included 132 breast and prostate cancer patient, where presence of bone metastases was graded according to the Soloway score. Total bone resorption (CTXItotal) and cartilage degradation (CTXII) were determined. Breast and prostate cancer patients with bone metastases revealed significant increased levels of CTXItotal at Soloway scores 1 and higher compared to patients without bone metastases (p < 0.001). CTXII was statistically elevated at score 3 and 4 (p < 0.01). CTXII/CTXItotal significantly decreased at score 3 and 4 (p < 0.001). Levels of CTXItotal, CTXII and CTXII/CTXItotal changed +900%, +130%, and -90%, respectively at Soloway score 4 compared to score 0. The in vitro experiments revealed that osteoclasts released CTXI fragments but not CTXII from bone specimens. The same was observed for cathepsin K. Data suggest that an uncoupling between bone resorption and cartilage degradation occurs in breast and lung cancer patient

  8. Assessment of global morphological and topological changes in trabecular structure under the bone resorption process

    Science.gov (United States)

    Sidorenko, Irina N.; Bauer, Jan; Monetti, Roberto; Baum, Thomas; Rummeny, Ernst J.; Eckstein, Felix; Matsuura, Maiko; Lochmueller, Eva-Maria; Zysset, Philippe K.; Raeth, Christoph W.

    2012-03-01

    Osteoporosis is a frequent skeletal disease characterised both by loss of bone mineral mass and deterioration of cancellous bone micro-architecture. It can be caused by mechanical disuse, estrogen deficiency or natural age-related resorption process. Numerical analysis of high-resolution images of the trabecular network is recognised as a powerful tool for assessment of structural characteristics. Using μCT images of 73 thoracic and 78 lumbar human vertebral specimens in vitro with isotropic resolution of 26μm we simulate bone atrophy as random resorption of bone surface voxels. Global morphological and topological characteristics provided by four Minkowski Functionals (MF) are calculated for two numerical resorption models with and without conservation of global topological connectivity of the trabecular network, which simulates different types of bone loss in osteoporosis, as it has been described in males and females. Diagnostic performance of morphological and topological characteristics as a function of relative bone loss is evaluated by a correlation analysis with respect to experimentally measured Maximum Compressive Strength (MCS). In both resorption models the second MF, which coincides with bone surface fraction BS/TV, demonstrates almost constant value of Pearson's correlation coefficient with respect to the relative bone loss ▵BV/TV. This morphological characteristic does not vary considerably under age-related random resorption and can be used for predicting bone strength in the elderly. The third and fourth MF demonstrate an increasing correlation coefficients with MCS after applying random bone surface thinning without preserving topological connectivity, what can be used for improvement of evaluation of the current state of the structure.

  9. A theory for bone resorption based on the local rupture of osteocytes cells connections: A finite element study

    OpenAIRE

    Ridha Hambli; Khalid H. Almitani; Abdessalem Chamekh; Hechmi Toumi; Tavares, João Manuel R.S.

    2015-01-01

    In this work, a bone damage resorption finite element model based on the disruption of the inhibitory signal transmitted between osteocytes cells in bone due to damage accumulation is developed and discussed. A strain-based stimulus function coupled to a damage-dependent spatialfunction is proposed to represent the connection between two osteocytes embedded in the bone tissue. The signal is transmitted to the bone surface to activate bone resorption. The proposed modelis based on the idea tha...

  10. Histomorphometric Evaluation of Anorganic Bovine Bone Coverage to Reduce Autogenous Grafts Resorption: Preliminary Results

    OpenAIRE

    C Maiorana; Beretta, M.; G B Grossi; Santoro, F.; A. Scott Herford; Nagursky, H; CICCIÙ, M.

    2011-01-01

    Physiologic resorption due to remodeling processes affects autogenous corticocancellous grafts in the treatment of atrophic jawbone alveolar ridges. Such a situation in the past made overgrafting of the recipient site mandatory to get enough bone support to dental implants in order to perform a prosthetic rehabilitation. Anorganic bovine bone, conventionally used to treat alveolar bone deficiencies in implant surgery, showed a high osteoconductive property thanks to its micro and macrostructu...

  11. Osteocyte Apoptosis Controls Activation of Intracortical Resorption in Response to Bone Fatigue

    OpenAIRE

    Cardoso, Luis; Herman, Brad C.; Verborgt, Olivier; Laudier, Damien; Majeska, Robert J.; Schaffler, Mitchell B.

    2008-01-01

    Osteocyte apoptosis is spatially and temporally linked to bone fatigue–induced microdamage and to subsequent intracortical remodeling. Specifically, osteocytes surrounding fatigue microcracks in bone undergo apoptosis, and those regions containing apoptotic osteocytes co-localize exactly with areas subsequently resorbed by osteoclasts. Here we tested the hypothesis that osteocyte apoptosis is a key controlling step in the activation and/or targeting of osteoclastic resorption after bone fatig...

  12. Quantification and visualization of alveolar bone resorption from 3D dental CT images

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Jiro; Mori, Kensaku; Kitasaka, Takayuki; Suenaga, Yasuhito [Nagoya University, Graduate School of Information Science, Nagoya (Japan); Yamada, Shohzoh; Naitoh, Munetaka [Aichi-Gakuin University, School of Dentistry, Nagoya (Japan)

    2007-06-15

    Purpose A computer aided diagnosis (CAD) system for quantifying and visualizing alveolar bone resorption caused by periodontitis was developed based on three-dimensional (3D) image processing of dental CT images. Methods The proposed system enables visualization and quantification of resorption of alveolar bone surrounding and between the roots of teeth. It has the following functions: (1) vertical measurement of the depth of resorption surrounding the tooth in 3D images, avoiding physical obstruction; (2) quantification of the amount of resorption in the furcation area; and (3) visualization of quantification results by pseudo-color maps, graphs, and motion pictures. The resorption measurement accuracy in the area surrounding teeth was evaluated by comparing with dentist's recognition on five real patient CT images, giving average absolute difference of 0.87 mm. An artificial image with mathematical truth was also used for measurement evaluation. Results The average absolute difference was 0.36 and 0.10 mm for surrounding and furcation areas, respectively. The system provides an intuitive presentation of the measurement results. Conclusion Computer aided diagnosis of 3D dental CT scans is feasible and the technique is a promising new tool for the quantitative evaluation of periodontal bone loss. (orig.)

  13. Dioscin inhibits osteoclast differentiation and bone resorption though down-regulating the Akt signaling cascades

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Xinhua; Zhai, Zanjing; Liu, Xuqiang; Li, Haowei [Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China); Ouyang, Zhengxiao [Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China); Department of Orthopaedics, Hunan Provincial Tumor Hospital and Tumor Hospital of Xiangya School of Medicine, Central South University, Changsha (China); Wu, Chuanlong [Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China); Liu, Guangwang [Department of Orthopaedic Surgery, The Central Hospital of Xuzhou, Affiliated Hospital of Medical Collage of Southeast University, Xuzhou (China); Fan, Qiming; Tang, Tingting [Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China); Qin, An, E-mail: dr.qinan@gmail.com [Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China); Dai, Kerong, E-mail: krdai@163.com [Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China)

    2014-01-10

    Highlights: •A natural-derived compound, dioscin, suppresses osteoclast formation and bone resorption. •Dioscin inhibits osteolytic bone loss in vivo. •Dioscin impairs the Akt signaling cascades pathways during osteoclastogenesis. •Dioscin have therapeutic value in treating osteoclast-related diseases. -- Abstract: Bone resorption is the unique function of osteoclasts (OCs) and is critical for both bone homeostasis and pathologic bone diseases including osteoporosis, rheumatoid arthritis and tumor bone metastasis. Thus, searching for natural compounds that may suppress osteoclast formation and/or function is promising for the treatment of osteoclast-related diseases. In this study, we for the first time demonstrated that dioscin suppressed RANKL-mediated osteoclast differentiation and bone resorption in vitro in a dose-dependent manner. The suppressive effect of dioscin is supported by the reduced expression of osteoclast-specific markers. Further molecular analysis revealed that dioscin abrogated AKT phosphorylation, which subsequently impaired RANKL-induced nuclear factor-kappaB (NF-κB) signaling pathway and inhibited NFATc1 transcriptional activity. Moreover, in vivo studies further verified the bone protection activity of dioscin in osteolytic animal model. Together our data demonstrate that dioscin suppressed RANKL-induced osteoclast formation and function through Akt signaling cascades. Therefore, dioscin is a potential natural agent for the treatment of osteoclast-related diseases.

  14. Dioscin inhibits osteoclast differentiation and bone resorption though down-regulating the Akt signaling cascades

    International Nuclear Information System (INIS)

    Highlights: •A natural-derived compound, dioscin, suppresses osteoclast formation and bone resorption. •Dioscin inhibits osteolytic bone loss in vivo. •Dioscin impairs the Akt signaling cascades pathways during osteoclastogenesis. •Dioscin have therapeutic value in treating osteoclast-related diseases. -- Abstract: Bone resorption is the unique function of osteoclasts (OCs) and is critical for both bone homeostasis and pathologic bone diseases including osteoporosis, rheumatoid arthritis and tumor bone metastasis. Thus, searching for natural compounds that may suppress osteoclast formation and/or function is promising for the treatment of osteoclast-related diseases. In this study, we for the first time demonstrated that dioscin suppressed RANKL-mediated osteoclast differentiation and bone resorption in vitro in a dose-dependent manner. The suppressive effect of dioscin is supported by the reduced expression of osteoclast-specific markers. Further molecular analysis revealed that dioscin abrogated AKT phosphorylation, which subsequently impaired RANKL-induced nuclear factor-kappaB (NF-κB) signaling pathway and inhibited NFATc1 transcriptional activity. Moreover, in vivo studies further verified the bone protection activity of dioscin in osteolytic animal model. Together our data demonstrate that dioscin suppressed RANKL-induced osteoclast formation and function through Akt signaling cascades. Therefore, dioscin is a potential natural agent for the treatment of osteoclast-related diseases

  15. Effect of odanacatib on root resorption and alveolar bone metabolism during orthodontic tooth movement.

    Science.gov (United States)

    Wei, X X; Chu, J P; Zou, Y Z; Ru, N; Cui, S X; Bai, Y X

    2015-01-01

    The aim of this study was to investigate the effect of local administration of odanacatib (ODN) on orthodontic root resorption and the status of alveolar bone metabolism in rat molars. All specimens were scanned using microcomputed tomography and then the raw images were reconstructed. The total volume of the root resorption craters of the 60 g-NS (normal saline) group was higher than in the 60 g-ODN group and the control group. In the 60 g-NS group, the bone volume fraction values of alveolar bone were significantly decreased compared with the other 2 groups. There were no significant differences in the bone volume fraction values of the tibiae among the 3 groups. The results of tartrate-resistant acid phosphatase-positive (TRAP+) numbers showed that there was no difference between the 60 g-NS group and the 60 g-ODN group. The expression of cathepsin K was decreased significantly in the 60 g-ODN group. These results indicate that ODN reduces orthodontics-induced external root resorption and increases alveolar bone metabolism. This may be because ODN inhibits the activity of odontoclasts, but maintains the quantity of odontoclasts and enhances bone formation. ODN promotes local alveolar bone metabolism, but does not affect systemic bone metabolism. PMID:26782444

  16. Time course of changes in bone resorption markers during pamidronate therapy in breast cancer patients with bone metastases

    Directory of Open Access Journals (Sweden)

    A. D. Petrova

    2014-07-01

    Full Text Available The paper gives the results of evaluating the time course of changes in the level of bone resorption markers (S-CTx and dPir in pami- dronate-treated patients with bone metastases from breast cancer. It shows the relationship of these markers to clinical and X-ray find- ings. The markers were not found to be of high clinical significance as a means for diagnosing bone metastases and estimating treat- ment trends.

  17. Tibolone inhibits bone resorption without secondary positive effects on cartilage degradation

    Directory of Open Access Journals (Sweden)

    Byrjalsen I

    2008-11-01

    Full Text Available Abstract Background Osteoarthritis is associated with increased bone resorption and increased cartilage degradation in the subchondral bone and joint. The objective of the present study was to determine whether Tibolone, a synthetic steroid with estrogenic, androgenic, and progestogenic properties, would have similar dual actions on both bone and cartilage turnover, as reported previously with some SERMS and HRT. Methods This study was a secondary analysis of ninety-one healthy postmenopausal women aged 52–75 yrs entered a 2-yr double blind, randomized, placebo-controlled study of treatment with either 1.25 mg/day (n = 36, or 2.5 mg/day Tibolone (n = 35, or placebo (n = 20, (J Clin Endocrinol Metab. 1996 Jul;81(7:2419–22 Second void morning urine samples were collected at baseline, and at 3, 6, 12, and 24 months. Urine CrossLaps® ELISA (CTX-I and Urine CartiLaps® ELISA (CTX-II was investigated as markers of bone resorption and cartilage degradation, respectively. Results Tibolone significantly (P Conclusion These data suggest uncoupling of the bone and cartilage effects of the synthetic steroid, Tibolone. Bone resorption was significantly decreased, whereas cartilage degradation was unchanged. These effects are in contrast to those observed some SERMs with effects on both bone and cartilage degradation. These effects may in part be described by the complicated pharmacology of Tibolone on testosterone, estrogen and progesterone receptors.

  18. Cytokine-mediated bone resorption is cytochrome P-450 dependent. Student Research Award 1998.

    Science.gov (United States)

    Young, N; Chole, R

    1999-12-01

    Localized bone loss leads to much of the morbidity of chronic otitis media. Although the cellular events of bone remodeling have been well established, their regulation remains poorly understood. Various cytokines, including tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma, used alone and in combination, are powerful inducers of bone resorption. One of the modulators of cytokine-induced bone resorption is nitric oxide (NO), a product of the action of NO synthase (NOS) on L -arginine to form NO. Cytochrome P-450, an enzyme that is similar to NOS both structurally and functionally, may also have a role in NO production in various cellular systems. The goal of this study was to elucidate a possible role of cytochrome P-450 in bone. In this study cytokine-induced bone resorption was blocked with cimetidine and clotrimazole, which are selective inhibitors of the cytochrome P-450 IIIA family and 7-ethoxyresorufin, a nonspecific cytochrome P-450 inhibitor. A concomitant reduction of NO was also observed. This effect may be explained by cytochrome P-450 being a preferred alternative pathway or providing an essential cofactor to NOS in bone. PMID:10580224

  19. Greater seasonal cycling of 25-hydroxyvitamin D is associated with increased parathyroid hormone and bone resorption

    NARCIS (Netherlands)

    Darling, A L; Hart, K H; Gibbs, M A; Gossiel, F; Kantermann, T; Horton, K; Johnsen, S; Berry, J L; Skene, D J; Eastell, R; Vieth, R; Lanham-New, S A

    2014-01-01

    SUMMARY: This analysis assessed whether seasonal change in 25-hydroxyvitamin D concentration was associated with bone resorption, as evidenced by serum parathyroid hormone and C-terminal telopeptide concentrations. The main finding was that increased seasonal fluctuation in 25-hydroxyvitamin D was a

  20. [Topics for basic research(osteoclast and bone resorption)in ASBMR 2015].

    Science.gov (United States)

    Udagawa, Nobuyuki

    2016-01-01

    This is a brief report summarizing topics in ASBMR 2015 held at Washington State Convention Center in Seattle on October 9-12th. In this paper, I report some topics from presentation of basic research(especially osteoclast and bone resorption)in ASBMR 2015. PMID:26728539

  1. Effect of glucagon-like peptide-2 exposure on bone resorption

    DEFF Research Database (Denmark)

    Askov-Hansen, Carsten; Jeppesen, Palle B; Lund, Pernille; Hartmann, Bolette; Holst, Jens Juul; Henriksen, Dennis B

    2013-01-01

    In healthy subjects, subcutaneous injections of GLP-2 have been shown to elicit dose-related decrease in the bone resorption marker, carboxy-terminal telopeptide of type I collagen (CTX), and have been proposed for the treatment of osteoporosis. This study investigated the relation between GLP-2 ...

  2. The Multifaceted Osteoclast; Far and Beyond Bone Resorption.

    Science.gov (United States)

    Drissi, Hicham; Sanjay, Archana

    2016-08-01

    The accepted function of the bone resorbing cell, osteoclast, has been linked to bone remodeling and pathological osteolysis. Emerging evidence points to novel functions of osteoclasts in controlling bone formation and angiogenesis. Thus, while the concept of a "clastokine" with the potential to regulate osteogenesis during remodeling did not come as a surprise, new evidence provided unique insight into the mechanisms underlying osteoclastic control of bone formation. The question still remains as to whether osteoclast precursors or a unique trap positive mononuclear cell, can govern any aspect of bone formation. The novel paradigm eloquently proposed by leaders in the field brings together the concept of clastokines and osteoclast precursor-mediated bone formation, potentially though enhanced angiogenesis. These fascinating advances in osteoclast biology have motivated this short review, in which we discuss these new roles of osteoclasts. J. Cell. Biochem. 117: 1753-1756, 2016. © 2016 Wiley Periodicals, Inc. PMID:27019318

  3. Neural crest-mediated bone resorption is a determinant of species-specific jaw length

    OpenAIRE

    Ealba, Erin L.; Jheon, Andrew H.; Hall, Jane; Curantz, Camille; Butcher, Kristin D.; Schneider, Richard A

    2015-01-01

    Precise control of jaw length during development is crucial for proper form and function. Previously we have shown that in birds, neural crest mesenchyme (NCM) confers species-specific size and shape to the beak by regulating molecular and histological programs for the induction and deposition of cartilage and bone. Here we reveal that a hitherto unrecognized but similarly essential mechanism for establishing jaw length is the ability of NCM to mediate bone resorption. Osteoclasts are conside...

  4. Inhibition of bone resorption by the cathepsin K inhibitor odanacatib is fully reversible.

    Science.gov (United States)

    Zhuo, Y; Gauthier, J-Y; Black, W C; Percival, M D; Duong, L T

    2014-10-01

    The cathepsin K (CatK) inhibitor odanacatib (ODN) is currently being developed for the treatment of osteoporosis. In clinical trials, efficacy and resolution of effect of ODN treatment on bone turnover biomarkers and accrued bone mass have been demonstrated. Here, we examine the effects of continuing treatment and discontinuation of ODN versus alendronate (ALN) on osteoclast (OC) function. First, accessibility and reversible engagement of active CatK in intracellular vesicles and resorption lacunae of actively resorbing OCs were demonstrated by the selective and reversible CatK inhibitors, BODIPY-L-226 (IC50=39nM) and L-873,724 (IC50=0.5nM). Next, mature human OCs on bone slices were treated with vehicle, ODN, or ALN for 2days, followed by either continuing with the same treatment, or replacement of the inhibitors by vehicle for additional times as specified per experimental conditions. Maintaining OCs on ODN or ALN significantly reduced CTx-I release compared to vehicle controls. However, only the treatment of OCs with ODN resulted in the formation of small shallow discrete resorption pits, retention of intracellular vesicles enriched with CatK and other lysosomal enzymes, increase in 1-CTP release and number of TRAP(+) OCs. Upon discontinuation of ODN treatment, OCs rapidly resumed bone resorption activity, as demonstrated by a return of OC functional markers (CTx-I, 1-CTP), cell number and size, morphology and number of resorption pits, and vesicular secretion of CatK toward the respective vehicle levels. As expected, discontinuation of ALN did not reverse the treatment-related inhibition of OC activity in the time frame of the experiment. In summary, this study demonstrated rapid kinetics of inhibition and reversibility of the effects of ODN on OC bone resorption, that differentiated the cellular mechanism of CatK inhibition from that of the bisphosphate antiresorptive ALN. PMID:25038310

  5. A theory for bone resorption based on the local rupture of osteocytes cells connections: A finite element study.

    Science.gov (United States)

    Ridha, Hambli; Almitani, Khalid H; Chamekh, Abdessalem; Toumi, Hechmi; Tavares, Joao Manuel R S

    2015-04-01

    In this work, a bone damage resorption finite element model based on the disruption of the inhibitory signal transmitted between osteocytes cells in bone due to damage accumulation is developed and discussed. A strain-based stimulus function coupled to a damage-dependent spatial function is proposed to represent the connection between two osteocytes embedded in the bone tissue. The signal is transmitted to the bone surface to activate bone resorption. The proposed model is based on the idea that the osteocyte signal reduction is not related to the reduction of the stimulus sensed locally by osteocytes due to damage, but to the difficulties for the signal in travelling along a disrupted area due to microcracks that can destroy connections of the intercellular network between osteocytes and bone-lining cells. To check the potential of the proposed model to predict the damage resorption process, two bone resorption mechano-regulation rules corresponding to two mechanotransduction approaches have been implemented and tested: (1) Bone resorption based on a coupled strain-damage stimulus function without ruptured osteocyte connections (NROC); and (2) Bone resorption based on a strain stimulus function with ruptured osteocyte connections (ROC). The comparison between the results obtained by both models, shows that the proposed model based on ruptured osteocytes connections predicts realistic results in conformity with previously published findings concerning the fatigue damage repair in bone. PMID:25640868

  6. Anthraquinone compounds from Morinda officinalis inhibit osteoclastic bone resorption in vitro.

    Science.gov (United States)

    Bao, Leilei; Qin, Luping; Liu, Lei; Wu, Yanbin; Han, Ting; Xue, Liming; Zhang, Qiaoyan

    2011-11-15

    The root of Morinda officinalis has been claimed to have a protective effect against bone loss in sciatic neurectomized and ovariectomized osteoporotic rats, and this protective effect is supposed to be attributed to anthraquinone compounds in the plant. In the present study, we investigated the effects of three anthraquinones isolated from M. officinalis, including 1, 3, 8-trihydroxy-2-methoxy-anthraquinone (1), 2-hydroxy-1-methoxy-anthraquinone (2) and rubiadin (3) on bone resorption activity in vitro and the mechanism on osteoclasts derived from rat bone marrow cells. Compound 1, 2 and 3 decreased the formation of bone resorption pits, the number of multinucleated osteoclasts, and the activity of tartrate resistant acid phosphates (TRAP) and cathepsin K in the coculture system of osteoblasts and bone marrow cells in the presence of 1, 25-dihydroxyvitamine D(3) and dexamethasone. They also enhanced the apoptosis of osteoclasts induced from bone marrow cells with M-CSF and RANKL. In addition, Compound 1, 2 and 3 improved the ratio of mRNA and protein expression of OPG and RANKL in osteoblasts, interfered with the JNK and NF-κB signal pathway, and reduced the expression of calcitonin receptor (CTR) and carbonic anhydrase/II (CA II) in osteoclasts induced from bone marrow cells with M-CSF and RANKL. These findings indicate that the anthraquinone compounds from M. officinalis are potential inhibitors of bone resorption, and may also serve as evidence to explain the mechanism of the inhibitory effects of some other reported anthraquinones on bone loss. PMID:21945525

  7. Atomic force microscopy of collagen structure in bone and dentine revealed by osteoclastic resorption

    International Nuclear Information System (INIS)

    Mineralised tissues such as bone consist of two material phases: collagen protein fibrils, secreted by osteoblasts, form model structures for subsequent deposition of mineral, calcium hydroxyapatite. Collagen and mineral are removed in a three-dimensional manner by osteoclasts during bone turnover in skeletal growth or repair. Bone active drugs have recently been developed for skeletal diseases, and there is revived interest in changes in the structure of mineralised tissues seen in disease and upon treatment. The resolution of atomic force microscopy and use of unmodified samples has enabled us to image bone and dentine collagen exposed by the natural process of cellular dissolution of mineralised matrix. The morphology of bone and dentine has been analysed when fully mineralised and after osteoclast-mediated bone resorption, and compared with results from other microscopy techniques. Banded type I collagen, with 66.5±1.4 nm axial D-periodicity and 62.2±7.0 nm diameter, has been identified within resorption lacunae in bone and 69.4±4.3 nm axial D-periodicity and 140.6±12.4 nm diameter in dentine substrates formed by human and rabbit osteoclasts, respectively. This observation suggests a route by which the material and morphological properties of bone collagen can be analysed in situ, compared with collagen from non-skeletal sites, and contrasted in diseases of medical importance, such as osteoporosis, where skeletal tissue is mechanically weakened

  8. Reduction of nocturnal rise in bone resorption by subcutaneous GLP-2

    DEFF Research Database (Denmark)

    Henriksen, Dennis B; Alexandersen, Peter; Byrjalsen, Inger;

    2004-01-01

    -CTX), a marker of bone resorption. In contrast, GLP-2 was found to have a neutral effect on bone formation, as assessed by serum osteocalcin. Since increased s-CTX levels are normally observed at night, we conducted bedtime studies in healthy postmenopausal women. The objective was to study the effect of...... GLP-2 injection on bone turnover given at bedtime. A total of 81 postmenopausal women were included in two randomised placebo-controlled studies. In conclusion, we found a dose-related reduction of s-CTX after injection of GLP-2 (P < 0.05) and osteocalcin levels was increased as compared to placebo (P...

  9. Bone resorption is decreased postprandially by intestinal factors and glucagon-like peptide-2 is a possible candidate

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Hartmann, Bolette; Gottschalck, Ida B;

    2007-01-01

    -bowel syndrome (SBS) or total gastrectomy in order to elucidate whether the signal for the meal-induced reduction of bone resorption is initiated from the stomach or the intestine. MATERIAL AND METHODS: Bone resorption was assessed from the serum concentration of collagen type I C-telopeptide cross-links (s...... and gastrectomy patients. GLP-2 concentrations increased significantly in all groups with the exception of the SBS plus colectomy group. CONCLUSIONS: An intestinal factor is responsible for the postprandial reduction in bone resorption, and our findings are compatible with such a function for GLP-2....

  10. Effect of calvarial burring on resorption of onlay cranial bone graft.

    Science.gov (United States)

    Hassanein, Aladdin H; Clune, James E; Mulliken, John B; Arany, Praveen R; Rogers, Gary F; Kulungowski, Ann M; Greene, Arin K

    2012-09-01

    Variable resorption occurs whenever calvarial bone graft is used for onlay cranioplasty. The recipient ectocortex may be burred to expose vessels and osteocytes to maximize healing. The purpose of this study was to determine whether abrading the recipient site improves the volume of onlay graft. The parietal bones of 17 rabbits were sectioned into split-thickness and full-thickness grafts. The right frontal cortex was abraded with a bur to punctate bleeding. Pairs of split-thickness (n = 48) or full-thickness (n = 20) grafts were onlayed to the burred right frontal bone and to the nonburred left frontal bone. Micro-computed tomography was used to determine graft volume immediately postoperatively and 16 weeks later. Histology, including tartrate-resistant acid phosphatase staining, was performed to quantify vascular channels and osteoclasts per high-power field 10 days postoperatively. Split-thickness graft volume decreased 58.0% when placed on the burred calvarial site, compared with grafts on the nonburred cortex (28.4%) (P = 0.01). Full-thickness grafts showed a similar trend: greater resorption (39.1%) when onlayed onto abraded calvaria compared with nonburred ectocortex (26.0%) (P = 0.11). Split-thickness graft orientation (cortical vs cancellous side in contact with the recipient site) did not affect resorption (P = 0.67). Onlay grafts placed on the burred recipient site had more vascular channels (11.8) and osteoclasts (5.7), compared with grafts over nonabraded cortex (3.4 and 4.2, respectively) (P < 0.05). Burring the recipient site cortex before onlay cranial bone grafting promotes resorption, possibly by increasing vascularization and osteoclastic activity. This technique cannot be recommended. PMID:22976644

  11. Epstein-Barr virus infection induces bone resorption in apical periodontitis via increased production of reactive oxygen species.

    Science.gov (United States)

    Jakovljevic, Aleksandar; Andric, Miroslav; Miletic, Maja; Beljic-Ivanovic, Katarina; Knezevic, Aleksandra; Mojsilovic, Slavko; Milasin, Jelena

    2016-09-01

    Chronic inflammatory processes in periapical tissues caused by etiological agents of endodontic origin lead to apical periodontitis. Apart from bacteria, two herpesviruses, Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) are recognized as putative pathogens in apical periodontitis. Although previous reports suggest the involvement of EBV in the pathogenesis of apical periodontitis, its exact role in periapical bone resorption has not yet been fully elucidated. We hypothesize that EBV infection in apical periodontitis is capable of inducing periapical bone resorption via stimulation of reactive oxygen species (ROS) overproduction. Increased levels of ROS induce expression of receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL). RANKL binding to receptor activator of nuclear factor κB (RANK) present on the surface of preosteoclasts induces their maturation and activation which consequently leads to bone resorption. The potential benefit of antiviral and antioxidant-based therapies in periapical bone resorption treatment remains to be assessed. PMID:27515196

  12. Effects of Neuropeptides and Mechanical Loading on Bone Cell Resorption in Vitro

    Directory of Open Access Journals (Sweden)

    Yeong-Min Yoo

    2014-04-01

    Full Text Available Neuropeptides such as vasoactive intestinal peptide (VIP and calcitonin gene-related peptide (CGRP are present in nerve fibers of bone tissues and have been suggested to potentially regulate bone remodeling. Oscillatory fluid flow (OFF-induced shear stress is a potent signal in mechanotransduction that is capable of regulating both anabolic and catabolic bone remodeling. However, the interaction between neuropeptides and mechanical induction in bone remodeling is poorly understood. In this study, we attempted to quantify the effects of combined neuropeptides and mechanical stimuli on mRNA and protein expression related to bone resorption. Neuropeptides (VIP or CGRP and/or OFF-induced shear stress were applied to MC3T3-E1 pre-osteoblastic cells and changes in receptor activator of nuclear factor kappa B (NF-κB ligand (RANKL and osteoprotegerin (OPG mRNA and protein levels were quantified. Neuropeptides and OFF-induced shear stress similarly decreased RANKL and increased OPG levels compared to control. Changes were not further enhanced with combined neuropeptides and OFF-induced shear stress. These results suggest that neuropeptides CGRP and VIP have an important role in suppressing bone resorptive activities through RANKL/OPG pathway, similar to mechanical loading.

  13. Dioscin inhibits osteoclast differentiation and bone resorption though down-regulating the Akt signaling cascades.

    Science.gov (United States)

    Qu, Xinhua; Zhai, Zanjing; Liu, Xuqiang; Li, Haowei; Ouyang, Zhengxiao; Wu, Chuanlong; Liu, Guangwang; Fan, Qiming; Tang, Tingting; Qin, An; Dai, Kerong

    2014-01-10

    Bone resorption is the unique function of osteoclasts (OCs) and is critical for both bone homeostasis and pathologic bone diseases including osteoporosis, rheumatoid arthritis and tumor bone metastasis. Thus, searching for natural compounds that may suppress osteoclast formation and/or function is promising for the treatment of osteoclast-related diseases. In this study, we for the first time demonstrated that dioscin suppressed RANKL-mediated osteoclast differentiation and bone resorption in vitro in a dose-dependent manner. The suppressive effect of dioscin is supported by the reduced expression of osteoclast-specific markers. Further molecular analysis revealed that dioscin abrogated AKT phosphorylation, which subsequently impaired RANKL-induced nuclear factor-kappaB (NF-κB) signaling pathway and inhibited NFATc1 transcriptional activity. Moreover, in vivo studies further verified the bone protection activity of dioscin in osteolytic animal model. Together our data demonstrate that dioscin suppressed RANKL-induced osteoclast formation and function through Akt signaling cascades. Therefore, dioscin is a potential natural agent for the treatment of osteoclast-related diseases. PMID:24333429

  14. Local treatment of a bone graft by soaking in zoledronic acid inhibits bone resorption and bone formation. A bone chamber study in rats

    Directory of Open Access Journals (Sweden)

    Belfrage Ola

    2012-12-01

    Full Text Available Abstract Background Bone grafts are frequently used in orthopaedic surgery. Graft remodelling is advantageous but can occur too quickly, and premature bone resorption might lead to decreased mechanical integrity of the graft. Bisphosphonates delay osteoclastic bone resorption but may also impair formation of new bone. We hypothesize that these effects are dose dependent. In the present study we evaluate different ways of applying bisphosphonates locally to the graft in a bone chamber model, and compare that with systemic treatment. Methods Cancellous bone grafts were placed in titanium chambers and implanted in the tibia of 50 male rats, randomly divided into five groups. The first group served as negative control and the grafts were rinsed in saline before implantation. In the second and third groups, the grafts were soaked in a zoledronic acid solution (0.5 mg/ml for 5 seconds and 10 minutes respectively before being rinsed in saline. In the fourth group, 8 μL of zoledronic acid solution (0.5 mg/ml was pipetted onto the freeze-dried grafts without rinsing. The fifth group served as positive control and the rats were given zoledronic acid (0.1 mg/kg systemically as a single injection two weeks after surgery. The grafts were harvested at 6 weeks and analysed with histomorphometry, evaluating the ingrowth distance of new bone into the graft as an equivalent to the anabolic osteoblast effect and the amount (bone volume/total volume; BV/TV of remaining bone in the remodelled graft as equivalent to the catabolic osteoclast effect. Results In all chambers, almost the entire graft had been revascularized but only partly remodelled at harvest. The ingrowth distance of new bone into the graft was lower in grafts soaked in zoledronic acid for 10 minutes compared to control (p = 0.007. In all groups receiving zoledronic acid, the BV/TV was higher compared to control. Conclusions This study found a strong inhibitory effect on bone resorption by

  15. μCT-Based, In Vivo Dynamic Bone Histomorphometry Allows 3D Evaluation of the Early Responses of Bone Resorption and Formation to PTH and Alendronate Combination Therapy

    Science.gov (United States)

    de Bakker, Chantal M. J.; Altman, Allison R.; Tseng, Wei-Ju; Tribble, Mary Beth; Li, Connie; Chandra, Abhishek; Qin, Ling; Liu, X. Sherry

    2015-01-01

    Current osteoporosis treatments improve bone mass by increasing net bone formation: anti-resorptive drugs such as bisphosphonates block osteoclast activity, while anabolic agents such as parathyroid hormone (PTH) increase bone remodeling, with a greater effect on formation. Although these drugs are widely used, their role in modulating formation and resorption is not fully understood, due in part to technical limitations in the ability to longitudinally assess bone remodeling. Importantly, it is not known whether or not PTH-induced bone formation is independent of resorption, resulting in controversy over the effectiveness of combination therapies that use both PTH and an anti-resorptive. In this study, we developed a μCT-based, in vivo dynamic bone histomorphometry technique for rat tibiae, and applied this method to longitudinally track changes in bone resorption and formation as a result of treatment with alendronate (ALN), PTH, or combination therapy of both PTH and ALN (PTH+ALN). Correlations between our μCT-based measures of bone formation and measures of bone formation based on calcein-labeled histology (r = 0.72 - 0.83) confirm the accuracy of this method. Bone remodeling parameters measured through μCT-based in vivo dynamic bone histomorphometry indicate an increased rate of bone formation in rats treated with PTH and PTH+ALN, together with a decrease in bone resorption measures in rats treated with ALN and PTH+ALN. These results were further supported by traditional histology-based measurements, suggesting that PTH was able to induce bone formation while bone resorption was suppressed. PMID:25554598

  16. Comparison of growth-induced resorption and denervation-induced resorption on the release of [3H]tetracycline, 45calcium, and [3H]collagen from whole bones of growing rats

    International Nuclear Information System (INIS)

    The major effect of immobilization during growth is a smaller bone mass induced by either an increased bone resorption or a decreased bone formation. Using a method of analyzing radioisotopic loss of [3H]tetracycline and [3H]collagen from bone prelabeled in vivo, we compared the amount of bone resorption due to immobilization with bone resorption induced by growth. One hind limb was denervated in growing male rats, 6 weeks of age, that had been chronically prelabeled with [3H]tetracycline, 45calcium, and [3H]proline. The total radioactivity of the whole femur and tibia/fibula from the denervated limb was compared with that from bones of the control limb at 0, 1, 2, 4, and 8 weeks after denervation. The effect of growth on bone formation was measured by net increases in bone length, volume, and mass of matrix and mineral. Experimental bones had a significantly smaller volume and mass. Bone resorption was much greater during growth modeling than during denervation. The additional bone resorption induced by denervation was a small fraction (one-fourth) of the resorption induced by growth. Denervation during growth resulted in less bone being formed due to a smaller gain in matrix and mineral mass as a result of a reduction in bone formation

  17. The dynamin inhibitor dynasore inhibits bone resorption by rapidly disrupting actin rings of osteoclasts.

    Science.gov (United States)

    Thirukonda, Gnanasagar J; Uehara, Shunsuke; Nakayama, Takahiro; Yamashita, Teruhito; Nakamura, Yukio; Mizoguchi, Toshihide; Takahashi, Naoyuki; Yagami, Kimitoshi; Udagawa, Nobuyuki; Kobayashi, Yasuhiro

    2016-07-01

    The cytoskeletal organization of osteoclasts is required for bone resorption. Binding of dynamin with guanosine triphosphate (GTP) was previously suggested to be required for the organization of the actin cytoskeleton. However, the role of the GTPase activity of dynamin in the organization of the actin cytoskeleton as well as in the bone-resorbing activity of osteoclasts remains unclear. This study investigated the effects of dynasore, an inhibitor of the GTPase activity of dynamin, on the bone-resorbing activity of and actin ring formation in mouse osteoclasts in vitro and in vivo. Dynasore inhibited the formation of resorption pits in osteoclast cultures by suppressing actin ring formation and rapidly disrupting actin rings in osteoclasts. A time-lapse image analysis showed that dynasore shrank actin rings in osteoclasts within 30 min. The intraperitoneal administration of dynasore inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced trabecular bone loss in mouse femurs. These in vitro and in vivo results suggest that the GTPase activity of dynamin is critical for the bone-resorbing activity of osteoclasts and that dynasore is a seed for the development of novel anti-resorbing agents. PMID:26063501

  18. Biocompatibility, resorption and biofunctionality of a new synthetic biodegradable membrane for guided bone regeneration.

    Science.gov (United States)

    Hoornaert, Alain; d'Arros, Cyril; Heymann, Marie-Francoise; Layrolle, Pierre

    2016-01-01

    Membranes for guided bone regeneration (GBR) were prepared from the synthetic biodegradable polymer poly-D,L-lactic/glycolic acid (PLGA). This GBR membrane has a bi-layered structure with a dense film to prevent gingival fibroblast ingrowth and ensure mechanical function, and a micro-fibrous layer to support colonization by osteogenic cells and promote bone regeneration. Hydrolysis and biodegradation were both studied in vitro through soaking in phosphate buffered saline (PBS) and in vivo by implantation in the subcutis of rats for 4, 8, 16, 26, 48 and 52 weeks. Histology revealed an excellent colonization of the micro-fibrous layer by cells with a minimal inflammatory reaction during resorption. GBR using the synthetic PLGA membrane was evaluated on critical-size calvaria defects in rats for 4 and 8 weeks. Radiographs, micro-computed tomography and histology showed bone regeneration with the PLGA membrane, while the defects covered with a collagen membrane showed a limited amount of mineralized bone, similar to that of the defect left empty. The biofunctionality of the PLGA membranes was also compared to collagen membranes in mandible defects in rabbits, associated or not with beta-tricalcium phosphate granules. This study revealed that the bi-layered synthetic membrane made of PLGA was safer, more biocompatible, and had a greater controlled resorption rate and bone regeneration capacity than collagen membranes. This new PLGA membrane could be used in pre-implantology and peri-odontology surgery. PMID:27509180

  19. Beneficial role of periosteum in distraction osteogenesis of mandible. Its preservation prevents the external bone resorption

    International Nuclear Information System (INIS)

    Distraction osteogenesis (DO) is a surgical process of new bone generation through the gradual extension of two segments of existing bone. DO is applied for maxillofacial surgeries to manage defects in mandibular continuity. Vertical DO with an oral device is often employed to augment the alveolar bone height for better implant anchorage for esthetic purposes or functional prosthetic requirements. To determine how the periosteum affects the vertical DO in mandibular reconstruction, we extracted the teeth and resected the alveolar parts of the mandible on both sides of dogs, along with removal of the surrounding periosteum in the right, but not left side. Three months later, box-shaped bone segments (vectors) were prepared from the resected alveolar part, and the segments were vertically elongated using a distraction device on both sides at 0.9 mm/day for one week. The extent of bone formation after distraction was determined with micro-focused computed tomography and by measuring incorporation of tetracycline and calcein with confocal laser scanning microscopy. During the initial two months after distraction, new bone formation was observed more prominently in the left side than in the right side of mandible with the periosteum. However, this difference was less clear during the bone-remodeling period. One notable change was the reduced height of the alveolar part of the right-side mandible, a sign of external bone resorption, observed in two out of three dogs at 6-month post-consolidation. These findings suggest that preservation of periosteum prevents the external bone resorption during the vertical DO of mandible. (author)

  20. 3H-tetracycline as a proxy for 41Ca for measuring dietary perturbations of bone resorption

    Science.gov (United States)

    Weaver, Connie; Cheong, Jennifer; Jackson, George; Elmore, David; McCabe, George; Martin, Berdine

    2007-06-01

    Our group is interested in evaluating early effects of dietary interventions on bone loss. Postmenopausal women lose bone following reduction in estrogen which leads to increased risk of fracture. Traditional means of monitoring bone loss and effectiveness of treatments include changes in bone density, which takes 6 months to years to observe effects, and changes in biochemical markers of bone turnover, which are highly variable and lack specificity. Prelabeling bone with 41Ca and measuring urinary 41Ca excretion with accelerator mass spectrometry provides a sensitive, specific, and rapid approach to evaluating effectiveness of treatment. To better understand 41Ca technology as a tool for measuring effective treatments on reducing bone resorption, we perturbed bone resorption by manipulating dietary calcium in rats. We used 3H-tetracycline (3H-TC) as a proxy for 41Ca and found that a single dose is feasible to study bone resorption. Suppression of bone resorption, as measured by urinary 3H-TC, by dietary calcium was observed in rats stabilized after ovariectomy, but not in recently ovariectomized rats.

  1. 3H-tetracycline as a proxy for 41Ca for measuring dietary perturbations of bone resorption

    International Nuclear Information System (INIS)

    Our group is interested in evaluating early effects of dietary interventions on bone loss. Postmenopausal women lose bone following reduction in estrogen which leads to increased risk of fracture. Traditional means of monitoring bone loss and effectiveness of treatments include changes in bone density, which takes 6 months to years to observe effects, and changes in biochemical markers of bone turnover, which are highly variable and lack specificity. Prelabeling bone with 41Ca and measuring urinary 41Ca excretion with accelerator mass spectrometry provides a sensitive, specific, and rapid approach to evaluating effectiveness of treatment. To better understand 41Ca technology as a tool for measuring effective treatments on reducing bone resorption, we perturbed bone resorption by manipulating dietary calcium in rats. We used 3H-tetracycline (3H-TC) as a proxy for 41Ca and found that a single dose is feasible to study bone resorption. Suppression of bone resorption, as measured by urinary 3H-TC, by dietary calcium was observed in rats stabilized after ovariectomy, but not in recently ovariectomized rats

  2. Study on bone resorption behavior of osteoclast under drug effect using {sup 41}Ca tracing

    Energy Technology Data Exchange (ETDEWEB)

    Dong Kejun [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Lu Liyan [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); CNNC Third Qinshan Nuclear Power Co. Ltd., Haiyan 314300 (China); He Ming; Ouyang Yinggen; Xue Yan; Li Chaoli; Wu Shaoyong [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Wang Xianggao [College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Shen Hongtao [College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China); Gao Jianjun [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China); Wang Wei [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); China National Nuclear Corporation, Beijing 100822 (China); Chen Dafu; Xing Yonggang [Beijing Research Institute of Traumatology and Orthopaedics, Beijing 100035 (China); Jian, Yuan [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Jiang Shan, E-mail: jiangs@ciae.ac.cn [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China)

    2013-01-15

    The mechanisms governing calcium fluxes during bone remodeling processes in Osteoporosis (OP) patients are poorly known. Understanding the changes of Osteoclasts (OC) during this dynamic transition is important to prevent and cure OP. The exploration of long-lived {sup 41}Ca (T{sub 1/2} = 1.04 Multiplication-Sign 10{sup 5} years) tracer combined with AMS measurements leads to the possibility of monitoring the bone resorption behavior of OC in OP patients. In this work, the behavior of OC with the administration of Strontium Ranelate (SR), a drug for OP, was studied by using {sup 41}Ca labeled hydroxyapatite (HAP) to simulate the bone. AMS on the HI-13 tandem accelerator at CIAE was used to determine trace amounts of {sup 41}Ca. The results show that the technique of {sup 41}Ca tracing with AMS can be used to quantitatively monitor the behavior of OC in bone resorption under the effects of drugs. Experimental details and preliminary results will be presented.

  3. The inhibitory effect of vitamin K on RANKL-induced osteoclast differentiation and bone resorption.

    Science.gov (United States)

    Wu, Wei-Jie; Kim, Min Seuk; Ahn, Byung-Yong

    2015-10-01

    To further understand the correlation between vitamin K and bone metabolism, the effects of vitamins K1, menaquinone-4 (MK-4), and menaquinone-7 (MK-7) on RANKL-induced osteoclast differentiation and bone resorption were comparatively investigated. Vitamin K2 groups (MK-4 and MK-7) were found to significantly inhibit RANKL-medicated osteoclast cell formation of bone marrow macrophages (BMMs) in a dose-dependent manner, without any evidence of cytotoxicity. The mRNA expression of specific osteoclast differentiation markers, such as c-Fos, NFATc1, OSCAR, and TRAP, as well as NFATc1 protein expression and TRAP activity in RANKL-treated BMMs were inhibited by vitamin K2, although MK-4 exhibited a significantly greater efficiency compared to MK-7. In contrast, the same dose of vitamin K1 had no inhibitory effect on RANKL-induced osteoclast cell formation, but increased the expression of major osteoclastogenic genes. Interestingly, vitamins K1, MK-4 and MK-7 all strongly inhibited osteoclastic bone resorption (p vitamins K1, MK-4 and MK-7 have anti-osteoporotic properties, while their regulation effects on osteoclastogenesis are somewhat different. PMID:26267519

  4. Influences of Fucoxanthin on Alveolar Bone Resorption in Induced Periodontitis in Rat Molars

    Science.gov (United States)

    Kose, Oguz; Arabaci, Taner; Yemenoglu, Hatice; Kara, Adem; Ozkanlar, Seckin; Kayis, Sevki; Duymus, Zeynep Yesil

    2016-01-01

    The aim of this study was to evaluate the effects of systemic fucoxanthin treatment on alveolar bone resorption in rats with periodontitis. Thirty rats were divided into control, experimental periodontitis (EP), and experimental periodontitis-fucoxanthin (EP-FUCO) groups. Periodontitis was induced by ligature for four weeks. After removal of the ligature, the rats in the EP-FUCO group were treated with a single dose of fucoxanthin (200 mg/kg bw) per day for 28 consecutive days. At the end of the study, all of the rats were euthanized and intracardiac blood and mandible tissue samples were obtained for biochemical, immunohistochemical, and histometric analyses. Fucoxanthin treatment resulted in a slight decrease in tumor necrosis factor-α, interleukin-1β, and interleukin-6 levels and a significant decrease in oxidative stress index. It was observed that fucoxanthin caused a significant reduction in receptor activator of nuclear factor kappa-β ligand (RANKL) levels and a statistically non-significant elevation in osteoprotegerin and bone-alkaline phosphatase levels. There were no significant differences in alveolar bone loss levels between the EP and EP-FUCO groups. This experimental study revealed that fucoxanthin provides a limited reduction in alveolar bone resorption in rats with periodontitis. One of the mechanisms underlying the mentioned limited effect might be related to the ability of fucoxanthin to inhibit oxidative stress-related RANKL-mediated osteoclastogenesis. PMID:27043583

  5. Bone Resorption Increases as Early as the Second Day in Head- Down Bed Rest

    Science.gov (United States)

    Heer, M.; Kamps, N.; Mika, C.; Boese, A.; Gerzer, R.

    Long-term bed rest and space mission studies have shown that immobilization as well as microgravity induce increased bone resorption while bone formation tends to decrease. In order to analyze the kinetics of short-term changes in bone turnover we studied in a randomized, strictly controlled crossover design the effects of 6 days 6° head-down tilt bed rest (HDT) in 8 male healthy subjects (mean body weight (BW): 70.1 +/- 1.88 kg; mean age: 25.5 +/- 1.04 years) in our metabolic ward. Two days before arriving in the metabolic ward the subjects started with a diet consisting of an energy content of 10 MJ/d, 2000 mg Calcium/d, 400 i.U. Vitamin D, 200 mEq Na+ and 50 ml water/kg BW/d. The diet was continued in the metabolic ward. The metabolic ward period (11days) was divided into 3 parts: 4 ambulatory days, 6 days either HDT or control and 1 recovery day. Continuous urine collection started on the first day in the metabolic ward to analyze calcium excretion and bone resorption markers, namely C-telopeptide (CTX) and N-telopeptide (NTX). On the 2nd ambulatory day in the metabolic ward and on the 5th day in HDT or control blood was drawn to analyze serum calcium, parathyroid hormone, and bone formation markers (bone Alkaline Phosphatase (bAP), Procollagen-I-Propeptide (P-I-CP). Both study phases were identical with respect to environmental conditions, study protocol and diet. Urinary calcium excretion was as early as the first day in immobilization increased (phuman subjects. Further studies are mandatory to investigate the underlying mechanisms and respective countermeasures.

  6. The Efect of Semelil (AngiparsW on Bone Resorption and Bone Formation Markers in Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Shirin Hasani-Ranjbar

    2012-01-01

    Full Text Available Background and purpose of the study: Diabetes mellitus has been recognized as a major risk factor for osteoporosis in which bone turnover is affected by different mechanisms. As the morbidity, mortality and financial cost related to osteoporosis are expected to rise in Iran in coming years, and considering the efficacy of AngiparsW for improvement of different ulcers which made it a new herbal drug in diabetic foot ulcer, there is a need toevaluate the effect of this new drug on different organs including bone resorption and bone formation markers.Methods: In this randomized, double- blind clinical trial, 61 diabetic patients were included. The subjects wererandomly divided into intervention and control groups. Subjects of intervention group received 100 mg of AngiparsW twice a day. Laboratory tests including bone resorption and bone formation markers were performed at baseline and after 3 months.Result: 31 patients in study group and 30 patients in control group finished the study. The mean age of the studypopulation and the mean disease duration was respectively 51.8 ± 6.2 and 7.5 ± 4.7 years with no significant differences between intervention and control patients. No statistically significant differences between patients and controls were observed in pyridinoline, osteocalcin, urine calcium, bone alkaline phosphatase and tumor necrosis factor (TNF-α. Only urine creatinine level significantly changed between two groups after 3 month of treatment (pvalue:0.029Conclusion: In conclusion, the findings of this study indicate that Semelil (AngiparsW had no beneficial or harmfuleffects on bone. It might be other effects of this new component on bone turnover process which need morestudies and more time to be discovered.

  7. The effect of semelil (angipars® on bone resorption and bone formation markers in type 2 diabetic patients

    Directory of Open Access Journals (Sweden)

    Hasani-Ranjbar Shirin

    2012-12-01

    Full Text Available Abstract Background and purpose of the study Diabetes mellitus has been recognized as a major risk factor for osteoporosis in which bone turnover is affected by different mechanisms. As the morbidity, mortality and financial cost related to osteoporosis are expected to rise in Iran in coming years, and considering the efficacy of Angipars® for improvement of different ulcers which made it a new herbal drug in diabetic foot ulcer, there is a need to evaluate the effect of this new drug on different organs including bone resorption and bone formation markers. Methods In this randomized, double- blind clinical trial, 61 diabetic patients were included. The subjects were randomly divided into intervention and control groups. Subjects of intervention group received 100 mg of Angipars® twice a day. Laboratory tests including bone resorption and bone formation markers were performed at baseline and after 3 months. Result 31 patients in study group and 30 patients in control group finished the study. The mean age of the study population and the mean disease duration was respectively 51.8 ± 6.2 and 7.5 ± 4.7 years with no significant differences between intervention and control patients. No statistically significant differences between patients and controls were observed in pyridinoline, osteocalcin, urine calcium, bone alkaline phosphatase and tumor necrosis factor (TNF-α. Only urine creatinine level significantly changed between two groups after 3 month of treatment (p-value: 0.029 Conclusion In conclusion, the findings of this study indicate that Semelil (Angipars® had no beneficial or harmful effects on bone. It might be other effects of this new component on bone turnover process which need more studies and more time to be discovered.

  8. Effect of RGD-insulin on activities of bone resorption and the possible mechanism in human osteoclast-like cells in vitro.

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective: In this study, we explored the mechanism of anti-bone resorption of RGD-insulin using osteoclastlike cells(OLCs) from giant cell tumor of bone as an in vitro model. Methods: The function of bone resorption was observed and the staining for tartrate-resistant acid

  9. Interleukin 1 synthesis by a transitional cell carcinoma: relationship to bone resorption and humoral hypercalcemia of malignancy

    International Nuclear Information System (INIS)

    A tumor cell line (TCCB) was isolated from a patient with transitional cell carcinoma, who had tumor-associated hypercalcemia. Culture supernatants from TCCB had significant bone resorption activity in a 45Ca release assay from fetal mouse long bones. Furthermore, TCCB supernatants possessed potent interleukin 1 (IL-1) activity in a mouse thymocyte assay. Histomorphometric analysis of fetal mouse long bones incubated with TCCB supernatants showed a 7 fold increase in osteoclasts and a significant decrease in bone mass as compared to control bones. IL-1 activity in culture supernatants from lipopolysaccharide-stimulated human monocytes comigrated with both IL-1 and bone resorption activities from TCCB tumor cells by gel chromatography on AcA-54 ultrogel. Furthermore, antisera against human IL-1 was shown to inhibit the Il-1 activity from both monocytes and TCCB tumor cells. In light of recent reports that IL-1 can cause bone resorption in vitro, these data suggest that the hypercalcemia of malignancy seen with certain solid tumors, may be the result of IL-1 release by the tumor which subsequently elevates serum calcium by induction of bone resorption

  10. The influence of tibial component fixation techniques on resorption of supporting bone stock after total knee replacement

    NARCIS (Netherlands)

    Chong, D.Y.; Hansen, U.N.; Venne, R. van der; Verdonschot, N.J.J.; Amis, A.A.

    2011-01-01

    Periprosthetic bone resorption after tibial prosthesis implantation remains a concern for long-term fixation performance. The fixation techniques may inherently aggravate the "stress-shielding" effect of the implant, leading to weakened bone foundation. In this study, two cemented tibial fixation ca

  11. Computational biomechanics of bone's responses to dental prostheses - osseointegration, remodeling and resorption

    International Nuclear Information System (INIS)

    Clinical and experimental studies showed that human bone has the ability to remodel itself to better adapt to its biomechanical environment by changing both its material properties and geometry. As a consequence of the rapid development and extensive applications of major dental restorations such as implantation and fixed partial denture (FPD), the effect of bone remodeling on the success of a dental restorative surgery is becoming critical for prosthetic design and pre-surgical assessment. This paper aims to provide a computational biomechanics framework to address dental bone's responses as a result of dental restoration. It explored three important issues of resorption, apposition and osseointegration in terms of remodeling simulation. The published remodeling data in long bones were regulated to drive the computational remodeling prediction for the dental bones by correlating the results to clinical data. It is anticipated that the study will provide a more predictive model of dental bone response and help develop a new design methodology for patient-specific dental prosthetic restoration.

  12. Computational biomechanics of bone's responses to dental prostheses - osseointegration, remodeling and resorption

    Science.gov (United States)

    Li, Wei; Rungsiyakull, Chaiy; Field, Clarice; Lin, Daniel; Zhang, Leo; Li, Qing; Swain, Michael

    2010-06-01

    Clinical and experimental studies showed that human bone has the ability to remodel itself to better adapt to its biomechanical environment by changing both its material properties and geometry. As a consequence of the rapid development and extensive applications of major dental restorations such as implantation and fixed partial denture (FPD), the effect of bone remodeling on the success of a dental restorative surgery is becoming critical for prosthetic design and pre-surgical assessment. This paper aims to provide a computational biomechanics framework to address dental bone's responses as a result of dental restoration. It explored three important issues of resorption, apposition and osseointegration in terms of remodeling simulation. The published remodeling data in long bones were regulated to drive the computational remodeling prediction for the dental bones by correlating the results to clinical data. It is anticipated that the study will provide a more predictive model of dental bone response and help develop a new design methodology for patient-specific dental prosthetic restoration.

  13. Interleukin-1-induced acute bone resorption facilitates the secretion of fibroblast growth factor 23 into the circulation.

    Science.gov (United States)

    Yamazaki, Miwa; Kawai, Masanobu; Miyagawa, Kazuaki; Ohata, Yasuhisa; Tachikawa, Kanako; Kinoshita, Saori; Nishino, Jin; Ozono, Keiichi; Michigami, Toshimi

    2015-05-01

    Fibroblast growth factor 23 (FGF23), a central regulator of phosphate and vitamin D metabolism, is mainly produced by osteocytes in bone and exerts its effects on distant organs. Despite its endocrine function, the mechanism controlling serum FGF23 levels is not fully understood. Here we tested the hypothesis that osteoclastic bone resorption may play a role in regulating circulating levels of FGF23, using a mouse model where injections of interleukin (IL)-1β into the subcutaneous tissue over the calvaria induced rapid bone resorption. A significant amount of FGF23 was detected in the extracts from mouse bones, which supports the idea that FGF23 stays in bone for a while after its production. IL-1β-induced bone resorption was associated with elevated serum FGF23 levels, an effect abolished by pre-treatment with pamidronate. Fgf23 expression was not increased in either the calvariae or tibiae of IL-1β-injected mice, which suggests that IL-1β facilitated the entry of FGF23 protein into circulation by accelerating bone resorption rather than increasing its gene expression. The direct effect of IL-1β on bone was confirmed when it increased FGF23 levels in the conditioned media of mouse calvariae in organ culture. Repeated treatment of the cultured calvariae with IL-1β led to a refractory phase, where FGF23 was not mobilized by IL-1β anymore. Consistent with the in vivo results, treatment with IL-1β failed to increase Fgf23 mRNA in isolated primary osteocytes and osteoblasts. These results suggest that FGF23 produced by osteocytes remains in bone, and that rapid bone resorption facilitates its entry into the bloodstream. PMID:24996526

  14. Assessment of bone formation and bone resorption in osteoporosis: a comparison between tetracycline-based iliac histomorphometry and whole body 85Sr kinetics

    International Nuclear Information System (INIS)

    Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to measurement imprecision alone. The exchange-corrected resorption rate correlated fairly well with iliac trabecular resorption surfaces, and using a volume referent rather than a surface referent for the histological index improved the statistical fit when patients with therapeutically accelerated bone turnover were included. A much better correlation was obtained by including osteoid volume acting as an independent predictor of bone resorption in a bivariate regression with a resorption surface index. The residual errors could then be accounted for by known measurement uncertainties. Whereas osteoid taking a double label closely predicted the kinetic rate of bone formation, further analysis suggested that osteoid that took no label or a single label was more closely related to bone resorption, presumably as a secondary result of the coupling of bone formation to bone resorption

  15. Dehydroepiandrosterone Inhibited the Bone Resorption through the Upregulation of OPG/RANKL

    Institute of Scientific and Technical Information of China (English)

    Yudong Wang; Ling Wang; Dajin Li; Wenjun Wang

    2006-01-01

    The plasma level of dehydroepiandrosterone (DHEA) is decreases gradually along with aging. The beneficial effects of DHEA as an anti-aging steroid, such as the stimulatory effect on immune system, anti-diabetes mellitus,anti-atherosclerosis, anti-dementia, anti-obesity and anti-osteoporosis have been demonstrated in experiment both in vitro and in vivo. It is important to investigate the effective mechanism of DHEA in therapeutics for postmenopausal osteoporosis. Having isolated and cultured osteoblasts (Obs) and osteoclasts (Ocs), we analysed the effect of DHEA on osteoblastic viability, regulation of DHEA on the expression of osteoprotegerin(OPG)/receptor activator of NF-κB ligand (RANKL) mRNA in Obs, and then observed the action of DHEA on bone resorption of Ocs in the presence or absence of Obs. The results showed that DHEA improved viability of Obs within the concentration range of 10-8-10-6 M, especially at the concentration of 10-7 M. DHEA could apparently increase the ratio of OPG/RANKL mRNA in Obs. In the presence of Obs, DHEA could decrease the number and area of absorption lacuna of specula. We concluded, therefore, only in the presence of Obs, DHEA could inhibit the bone resorption of Ocs, which may be mediated by OPG/RANKL of Obs.

  16. High Protein Intake Improves Insulin Sensitivity but Exacerbates Bone Resorption in Immobility (WISE Study)

    Science.gov (United States)

    Heer, Martina; Smith, Scott M.; Frings-Meuthen, Petra; Zwart, Sara R.; Baecker, Natalie

    2012-01-01

    Inactivity, like bed rest (BR), causes insulin resistance (IR) and bone loss even in healthy subjects. High protein intake seems to mitigate this IR but might exacerbate bone loss. We hypothesized that high protein intake (animal:vegetable protein ratio: 60:40), isocaloric, compared to the control group plus high potassium intake would prevent IR without affecting bone turnover. After a 20-day ambulatory adaptation to controlled confinement and diet, 16 women participated in a 60-day, 6 deg head-down-tilt BR and were assigned randomly to one of the two groups. Control subjects (CON, n=8) received 1g/kg body mass/d dietary protein. Nutrition subjects (NUT, n=8) received 1.45g/kg body mass/d dietary protein plus 7.2g branched chain amino acids per day during BR. All subjects received 1670 kcal/d. Bed rest decreased glucose disposal by 35% (pprotein intake prevented insulin resistance, but exacerbated bed rest induced increase in bone resorption markers C-telopeptide (> 30%) and Ntelopeptide (>20%) (both: pprotein intake. We conclude from these results that high protein intake might positively affect glucose tolerance, but might also foster bone loss. Further long-duration studies are mandatory before high protein intake for diabetic patients, who have an increased fracture risk, might be recommended.

  17. Inhibition of bone resorption by Tanshinone VI isolated from Salvia miltiorrhiza Bunge

    Directory of Open Access Journals (Sweden)

    V. Nicolin

    2010-05-01

    Full Text Available During the last decade, a more detailed knowledge of molecular mechanisms involved in osteoclastogenesis has driven research efforts in the development and screening of compound libraries of several small molecules that specifically inhibit the pathway involved in the commitment of the osteoclast precursor cells. Natural compounds that suppress osteoclast differentiation may have therapeutic value in treating osteoporosis and other bone erosive diseases such as rheumatoid arthritis or metastasis associated with bone loss. In ongoing investigation into anti-osteoporotic compounds from natural products we have analyzed the effect of Tanshinone VI on osteoclasts differentiation, using a physiologic three-dimensional osteoblast/bone marrow model of cell co-culture. Tanshinone VI is an abietane diterpene extracted from the root of Salvia miltiorrhiza Bunge (Labiatae, a Chinese traditional crude drug, ‘’Tan-Shen’’. Tashinone has been widely used in clinical practice for the prevention of cardiac diseases, arthritis and other inflammation-related disorders based on its pharmacological actions in multiple tissues. Although Tanshinone VI A has been used as a medicinal agent in the treatment of many diseases, its role in osteoclast-related bone diseases remains unknown. We showed previously that Tanshinone VI greatly inhibits osteoclast differentiation and suppresses bone resorption through disruption of the actin ring; subsequently, we intended to examine the precise inhibitory mechanism of Tanshinone VI on osteoclast differentiating factor. This study shows, for the first time, that Tanshinone VI prevents osteoclast differentiation by inhibiting RANKL expression and NFkB induction.

  18. From histology to micro-CT:Measuring and modeling resorption cavities and their relation to bone competence

    Institute of Scientific and Technical Information of China (English)

    Jef; Vanderoost; G; Harry; van; Lenthe

    2014-01-01

    The process of bone remodelling plays an essential role in the emergence and maintenance of bone geometry and its internal structure.Osteoclasts are one of the three main bone cell types that play a crucial role in the bone remodelling cycle.At the microstructural level,osteoclasts create bone deficits by eroding resorption cavities.Understanding how these cavities impair the mechanical quality of the bone is not only relevant in quantifying the impact of resorption cavities in healthy bone and normal aging,but maybe even more so in quantifying their role in metabolic bone diseases.Meta-bolic bone diseases and their treatment are both known to affect the bone remodelling cycle;hence,the bone mechanical competence can and will be affected.How-ever,the current knowledge of the precise dimensions of these cavities and their effect on bone competence is rather limited.This is not surprising considering the difficulties in deriving three-dimensional(3D)properties from two-dimensional(2D)histological sections.The measurement difficulties are reflected in the evalua-tion of how resorption cavities affect bone competence.Although detailed 3D models are generally being used to quantify the mechanical impact of the cavities,the representation of the cavities themselves has basicallybeen limited to simplified shapes and averaged cavityproperties.Qualitatively,these models indicate that cav-ity size and location are important,and that the effectof cavities is larger than can be expected from simplebone loss.In summary,the dimensions of osteoclastresorption cavities were until recently estimated from2D measures;hence,a careful interpretation of resorp-tion cavity dimensions is necessary.More effort needsto go into correctly quantifying resorption cavities usingmodern 3D imaging techniques like micro-computedtomography(micro-CT)and synchrotron radiation CT.Osteoclast resorption cavities affect bone competence.The structure-function relationships have been ana-lysed using

  19. The effects of icariine concentration on osteoclasts bone resorption induced by titanium particles in vitro

    OpenAIRE

    Zhang, Yiyuan; Lin, Yu; Xiao, Lili; Feng, Eryou; Wang, Wulian; Lin, Liqiong

    2015-01-01

    In artificial joint replacement, osteoclast bone resorption induced by wear debris of the implant is a main reason for aseptic loosening. To extend the life of the prosthesis, detailed mechanisms of aseptic loosening and the ways to prevent it should be explored. The aim of this study was to investigate the in vitro effect of icariine on the bone resorption of osteoclasts induced by titanium particles. Macrophage colony stimulating factor (M-CSF) and receptor activator of NF-kB ligand (RANKL)...

  20. Muramyl Dipeptide Enhances Lipopolysaccharide-Induced Osteoclast Formation and Bone Resorption through Increased RANKL Expression in Stromal Cells

    Directory of Open Access Journals (Sweden)

    Masahiko Ishida

    2015-01-01

    Full Text Available Lipopolysaccharide (LPS is bacterial cell wall component capable of inducing osteoclast formation and pathological bone resorption. Muramyl dipeptide (MDP, the minimal essential structural unit responsible for the immunological activity of peptidoglycans, is ubiquitously expressed by bacterium. In this study, we investigated the effect of MDP in LPS-induced osteoclast formation and bone resorption. LPS was administered with or without MDP into the supracalvariae of mice. The number of osteoclasts, the level of mRNA for cathepsin K and tartrate-resistant acid phosphatase (TRAP, the ratio of the bone destruction area, the level of tartrate-resistant acid phosphatase form 5b (TRACP 5b, and C-terminal telopeptides fragments of type I collagen as a marker of bone resorption in mice administrated both LPS and MDP were higher than those in mice administrated LPS or MDP alone. On the other hand, MDP had no effect on osteoclastogenesis in parathyroid hormone administrated mice. MDP enhanced LPS-induced receptor activator of NF-κB ligand (RANKL expression and Toll-like receptor 4 (TLR4 expression in vivo and in stromal cells in vitro. MDP also enhanced LPS-induced mitogen-activated protein kinase (MAPK signaling, including ERK, p38, and JNK, in stromal cells. These results suggest that MDP might play an important role in pathological bone resorption in bacterial infection diseases.

  1. Mandibular bone resorption in patients treated with tissue-integrated prostheses and in complete-denture wearers

    Energy Technology Data Exchange (ETDEWEB)

    Sennerby, L.; Carlsson, G.E.; Bergman, B.; Warfvinge, J.

    1988-01-01

    Mandibular bone resorption was studied in patients treated with tissue-integrated prostheses (TIP) and in complete-denture wearers by distance and area measurements on cephalometric radiographs. The area measurements were performed by means of a computer. Two TIP groups with short and long periods (average chi=2.4 and 23.9 years) of edentulousness, and wearing complete dentures before fixture installtion, were followed up to over 7-8 years. Mandibular bone resorption was remarkably small behind the distally positioned fixtures in comparison with the correspondings region in complete-denture wearers. Patients with complete dentures showed a continous resorption of the mandibular alveolar ridge over 21 years, even though there were great individual variations. The bone loss was most pronounced anteriorly and during the first 2 years after extraction of the residual teeth. It is concluded that treatment with tissue-integrated prostheses seems to reduce bone resorption in the mandible, probably owing to favorable load conditions and adequate stimulation of the bone.

  2. The effects of icariine concentration on osteoclasts bone resorption induced by titanium particles in vitro.

    Science.gov (United States)

    Zhang, Yiyuan; Lin, Yu; Xiao, Lili; Feng, Eryou; Wang, Wulian; Lin, Liqiong

    2015-09-01

    In artificial joint replacement, osteoclast bone resorption induced by wear debris of the implant is a main reason for aseptic loosening. To extend the life of the prosthesis, detailed mechanisms of aseptic loosening and the ways to prevent it should be explored. The aim of this study was to investigate the in vitro effect of icariine on the bone resorption of osteoclasts induced by titanium particles. Macrophage colony stimulating factor (M-CSF) and receptor activator of NF-kB ligand (RANKL) were used to generate osteoclasts from RAW264.7 precursors. The proliferation of RAW264.7 precursors in the presence of different doses of icariine was evaluated by MTT assay. The cells were treated with titanium particles, titanium particles with icariine and culture medium only (control), respectively. At 48 h after treatment, the expression level of receptor activator of NF-kB (RANK) was detected by ELISA, and messenger RNA (mRNA) levels of tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase 9 (MMP-9), carbonic anhydrase II (CAII) and Cathepsin K (CtsK) were determined by real-time polymerase chain reaction. Western blot was applied to analyze the expression levels of TRAP, RANK and CtsK. In addition, bone chips were cultured in the above conditions, and Toluidine blue staining was then employed to calculate the number and area of resorption pits in the bone chips. After treatment with icariine, expression level of RANK was significantly decreased in the RAW264.7 cell that induced by titanium particle and its cultural medium, mRNA and protein levels of TRAP, CAII, MMP-9 and CtsK were reduced as well. In addition, the numbers of bone resorption pits and areas on bone slices were both reduced by icariine challenging. Icariine could inhibit bone resorption of osteoclast induced by titanium particle, and it might be used as a promising drug for treating of aseptic loosening. PMID:26816641

  3. Impact of bone graft harvesting techniques on bone formation and graft resorption

    DEFF Research Database (Denmark)

    Saulacic, Nikola; Bosshardt, Dieter D; Jensen, Simon S;

    2015-01-01

    BACKGROUND: Harvesting techniques can affect cellular parameters of autogenous bone grafts in vitro. Whether these differences translate to in vivo bone formation, however, remains unknown. OBJECTIVE: The purpose of this study was to assess the impact of different harvesting techniques on bone fo...

  4. Low-Level Mechanical Vibrations can Reduce Bone Resorption and Enhance Bone Formation in the Growing Skeleton

    Energy Technology Data Exchange (ETDEWEB)

    Xie,L.; Jacobsen, J.; Busa, B.; Donahue, L.; Miller, L.; Rubin, C.; Judex, S.

    2006-01-01

    Short durations of extremely small magnitude, high-frequency, mechanical stimuli can promote anabolic activity in the adult skeleton. Here, it is determined if such signals can influence trabecular and cortical formative and resorptive activity in the growing skeleton, if the newly formed bone is of high quality, and if the insertion of rest periods during the loading phase would enhance the efficacy of the mechanical regimen. Eight-week-old female BALB/cByJ mice were divided into four groups, baseline control (n = 8), age-matched control (n = 10), whole-body vibration (WBV) at 45 Hz (0.3 g) for 15 min day{sup -1} (n = 10), and WBV that were interrupted every second by 10 of rest (WBV-R, n = 10). In vivo strain gaging of two additional mice indicated that the mechanical signal induced strain oscillations of approximately 10 microstrain on the periosteal surface of the proximal tibia. After 3 weeks of WBV, applied for 15 min each day, osteoclastic activity in the trabecular metaphysis and epiphysis of the tibia was 33% and 31% lower (P < 0.05) than in age-matched controls. Bone formation rates (BFR{center_dot}BS{sup -1}) on the endocortical surface of the metaphysis were 30% greater (P < 0.05) in WBV than in age-matched control mice but trabecular and middiaphyseal BFR were not significantly altered. The insertion of rest periods (WBV-R) failed to potentiate the cellular effects. Three weeks of either WBV or WBV-R did not negatively influence body mass, bone length, or chemical bone matrix properties of the tibia. These data indicate that in the growing skeleton, short daily periods of extremely small, high-frequency mechanical signals can inhibit trabecular bone resorption, site specifically attenuate the declining levels of bone formation, and maintain a high level of matrix quality. If WBV prove to be efficacious in the growing human skeleton, they may be able to provide the basis for a non-pharmacological and safe means to increase peak bone mass and, ultimately

  5. Azanitrile Cathepsin K Inhibitors: Effects on Cell Toxicity, Osteoblast-Induced Mineralization and Osteoclast-Mediated Bone Resorption.

    Directory of Open Access Journals (Sweden)

    Zhong-Yuan Ren

    Full Text Available The cysteine protease cathepsin K (CatK, abundantly expressed in osteoclasts, is responsible for the degradation of bone matrix proteins, including collagen type 1. Thus, CatK is an attractive target for new anti-resorptive osteoporosis therapies, but the wider effects of CatK inhibitors on bone cells also need to be evaluated to assess their effects on bone. Therefore, we selected, among a series of synthetized isothiosemicarbazides, two molecules which are highly selective CatK inhibitors (CKIs to test their effects on osteoblasts and osteoclasts.Cell viability upon treatment of CKIs were was assayed on human osteoblast-like Saos-2, mouse monocyte cell line RAW 264.7 and mature mouse osteoclasts differentiated from bone marrow. Osteoblast-induced mineralization in Saos-2 cells and in mouse primary osteoblasts from calvaria, with or without CKIs,; were was monitored by Alizarin Red staining and alkaline phosphatase activity, while osteoclast-induced bone resorption was performed on bovine slices.Treatments with two CKIs, CKI-8 and CKI-13 in human osteoblast-like Saos-2, murine RAW 264.7 macrophages stimulated with RANKL and mouse osteoclasts differentiated from bone marrow stimulated with RANKL and MCSF were found not to be toxic at doses of up to 100 nM. As probed by Alizarin Red staining, CKI-8 did not inhibit osteoblast-induced mineralization in mouse primary osteoblasts as well as in osteoblast-like Saos-2 cells. However, CKI-13 led to a reduction in mineralization of around 40% at 10-100 nM concentrations in osteoblast-like Saos-2 cells while it did not in primary cells. After a 48-hour incubation, both CKI-8 and CKI-13 decreased bone resorption on bovine bone slices. CKI-13 was more efficient than the commercial inhibitor E-64 in inhibiting bone resorption induced by osteoclasts on bovine bone slices. Both CKI-8 and CKI-13 created smaller bone resorption pits on bovine bone slices, suggesting that the mobility of osteoclasts was slowed

  6. Calcitonin receptors as markers for osteoclastic differentiation: correlation between generation of bone-resorptive cells and cells that express calcitonin receptors in mouse bone marrow cultures.

    Science.gov (United States)

    Hattersley, G; Chambers, T J

    1989-09-01

    The osteoclast is the cell that resorbs bone. It is known to derive from hemopoietic precursors, but analysis of lineage and regulation of differentiation has been hampered by lack of a specific marker that enables identification of cells of osteoclastic phenotype. Previously used markers, such as multinuclearity, that are specific for osteoclasts in bone become less specific in culture. Uniquely among bone and bone marrow cells, osteoclasts possess abundant calcitonin (CT) receptors. We therefore tested the correlation between the generation of bone-resorptive function and the formation of CT receptor-positive cells from hemopoietic tissue in vitro. Without 1,25-dihydroxy-vitamin D3 [1,25-(OH)2D3], a hormone that induces osteoclastic differentiation in vitro, bone marrow cultures showed very little bone resorption, and only small numbers of CT receptor-positive cells developed. When 1,25-(OH)2D3 was added to the cultures, CT receptor-positive cells developed within 1 day and reached a peak after 7 days. Bone resorption commenced within 2 days of hormone addition. There was a strong parallelism between the cumulative number of CT receptor-positive cells and the extent of bone resorption. The capacity of cultures to generate bone-resorptive activity and CT receptor-positive cells declined progressively when 1,25-(OH)2D3 was added to hemopoietic tissue after a 7- to 21-day hormone-free incubation period. The number of CT receptor-positive cells in these cultures correlated strongly (r = 0.96) with bone resorption. The behavior of these cultures suggests that 1,25-(OH)2D3 acts to induce terminal differentiation of osteoclast precursors present in the cultures, and that precursor cell numbers decreased with increasing time in vitro. All of the CT receptor-positive cells in control cultures and all of those seen shortly after 1,25-(OH)2D3 addition were mononuclear, despite considerable bone resorption; the majority of CT receptor-positive cells remained mononuclear

  7. Normal tempo of bone formation in Turner syndrome despite signs of accelerated bone resorption

    DEFF Research Database (Denmark)

    Cleemann, Line Hartvig; Holm, Kirsten Bagge; Kobbernagel, Hanne;

    2011-01-01

    Aims: To evaluate area bone mineral density (aBMD) and volumetric BMD (vBMD) by dual-energy X-ray absorptiometry, and relations to bone markers and hormones in adolescent women with Turner syndrome (TS). Methods: Cross-sectional study in TS patients (n = 37, 16.7 ± 3.4 years) and control group (n...

  8. Normal Tempo of Bone Formation in Turner Syndrome despite Signs of Accelerated Bone Resorption

    DEFF Research Database (Denmark)

    Cleemann, Line; Holm, Kirsten; Kobbernagel, Hanne;

    2011-01-01

    Aims: To evaluate area bone mineral density (aBMD) and volumetric BMD (vBMD) by dual-energy X-ray absorptiometry, and relations to bone markers and hormones in adolescent women with Turner syndrome (TS). Methods: Cross-sectional study in TS patients (n = 37, 16.7 ± 3.4 years) and control group (n...

  9. Biomechanical Loading Modulates Proinflammatory and Bone Resorptive Mediators in Bacterial-Stimulated PDL Cells

    Directory of Open Access Journals (Sweden)

    Andressa Vilas Boas Nogueira

    2014-01-01

    Full Text Available The present study aimed to evaluate in vitro whether biomechanical loading modulates proinflammatory and bone remodeling mediators production by periodontal ligament (PDL cells in the presence of bacterial challenge. Cells were seeded on BioFlex culture plates and exposed to Fusobacterium nucleatum ATCC 25586 and/or cyclic tensile strain (CTS of low (CTSL and high (CTSH magnitudes for 1 and 3 days. Synthesis of cyclooxygenase-2 (COX2 and prostaglandin E2 (PGE2 was evaluated by ELISA. Gene expression and protein secretion of osteoprotegerin (OPG and receptor activator of nuclear factor kappa-B ligand (RANKL were evaluated by quantitative RT-PCR and ELISA, respectively. F. nucleatum increased the production of COX2 and PGE2, which was further increased by CTS. F. nucleatum-induced increase of PGE2 synthesis was significantly (P<0.05 increased when CTSH was applied at 1 and 3 days. In addition, CTSH inhibited the F. nucleatum-induced upregulation of OPG at 1 and 3 days, thereby increasing the RANKL/OPG ratio. OPG and RANKL mRNA results correlated with the protein results. In summary, our findings provide original evidence that CTS can enhance bacterial-induced syntheses of molecules associated with inflammation and bone resorption by PDL cells. Therefore, biomechanical, such as orthodontic or occlusal, loading may enhance the bacterial-induced inflammation and destruction in periodontitis.

  10. A Stress Analysis on Abutment Teeth of Dowel Cemented Fixed Partial Dentures : On the effect of the resorption of alveoar bone

    OpenAIRE

    KATAOKA, SHIGERU; KOSAKA, SHIGERU; TSUCHIYA, SOHICHIRO; AMARI, MITSUHARU

    1995-01-01

    Stress in abutment teeth with cemented dowels and those with crown margins in fixed-fixed and cantilever bridges that resorp alveolar bone were analyzed by a two dimensional finite element method. Stress in all parts of the dentin in both bridges increased with the resorption of alveolar bone. Moreover, in th dentin and apex of the dowel in cantilever bridges, extreme stress when there were large amounts of resorption of alveolar bone, was seen. Therefore, in cantilevers bridges, cemented dow...

  11. The importance of assessing the rate of bone turnover and the balance between bone formation and bone resorption during daily teriparatide administration for osteoporosis: a pilot study.

    Science.gov (United States)

    Nakatoh, Shinichi

    2016-03-01

    This study aimed to examine the importance of simultaneously measuring bone formation and resorption markers during daily teriparatide administration. In 135 women with osteoporosis, bone mineral density (BMD) was measured at 0, 24, and 48 weeks after teriparatide administration. Bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase 5b were measured at 0, 4, 12, 24, 36, and 48 weeks. Subanalyses were performed in groups divided according to the BMD change at 48 weeks (increased and decreased groups), history of fragility fracture (acute and chronic groups), and treatment prior to teriparatide administration (alendronate, raloxifene, and naïve groups). The scatter diagram of multiple of median formation (MoMf) and multiple of median resorption (MoMr) showed that the distribution gradually spread to a high turnover by week 24. A significant correlation was observed between the rate of change in BMD at week 48 and the turnover rate [√(MoMf(2) + MoMr(2))] at week 0. Significant differences were observed in the turnover rate between the acute and chronic groups at weeks 0 and 4 and between the groups divided according to prior treatment from week 0 to 24. Because the assessment of either bone formation markers or bone resorption markers may result in erroneous data, it is necessary to assess them together during teriparatide treatment. The turnover rate at treatment initiation is a useful indicator to predict changes in BMD. When evaluating the turnover rate and balance (MoMf/MoMr), one should consider patient characteristics, including history of fragility fracture and prior treatment. PMID:26031934

  12. Does collagen trigger the recruitment of osteoblasts into vacated bone resorption lacunae during bone remodeling?

    DEFF Research Database (Denmark)

    Abdelgawad, Mohamed Essameldin; Søe, Kent; Andersen, Thomas Levin;

    2014-01-01

    Osteoblast recruitment during bone remodeling is obligatory to re-construct the bone resorbed by the osteoclast. This recruitment is believed to be triggered by osteoclast products and is therefore likely to start early during the remodeling cycle. Several osteoclast products with osteoblast...... recruitment potential are already known. Here we draw the attention on the osteoblast recruitment potential of the collagen that is freshly demineralized by the osteoclast. Our evidence is based on observations on adult human cancellous bone, combined with in vitro assays. First, freshly eroded surfaces where...... osteoblasts have to be recruited show the presence of non-degraded demineralized collagen and close cell-collagen interactions, as revealed by electron microscopy, while surface-bound collagen strongly attracts osteoblast lineage cells in a transmembrane migration assay. Compared with other extracellular...

  13. Inhibitory effects of French pine bark extract, Pycnogenol®, on alveolar bone resorption and on the osteoclast differentiation.

    Science.gov (United States)

    Sugimoto, Hideki; Watanabe, Kiyoko; Toyama, Toshizo; Takahashi, Shun-suke; Sugiyama, Shuta; Lee, Masaichi-Chang-il; Hamada, Nobushiro

    2015-02-01

    Pycnogenol(®) (PYC) is a standardized bark extract from French maritime pine (Pinus pinaster Aiton). We examined the inhibitory effects of PYC on alveolar bone resorption, which is a characteristic feature of periodontitis, induced by Porphyromonas gingivalis (P. gingivalis) and osteoclast differentiation. In rat periodontitis model, rats were divided into four groups: group A served as the non-infected control, group B was infected orally with P. gingivalis ATCC 33277, group C was administered PYC in the diet (0.025%: w/w), and group D was infected with P. gingivalis and administered PYC. Administration of PYC along with P. gingivalis infection significantly reduced alveolar bone resorption. Treatment of P. gingivalis with 1 µg/ml PYC reduced the number of viable bacterial cells. Addition of PYC to epithelial cells inhibited adhesion and invasion by P. gingivalis. The effect of PYC on osteoclast formation was confirmed by tartrate-resistant acid phosphatase staining. PYC treatment significantly inhibited osteoclast formation. Addition of PYC (1-100 µg/ml) to purified osteoclasts culture induced cell apoptosis. These results suggest that PYC may prevent alveolar bone resorption through its antibacterial activity against P. gingivalis and by suppressing osteoclastogenesis. Therefore, PYC may be useful as a therapeutic and preventative agent for bone diseases such as periodontitis. PMID:25336411

  14. Osteogenic protein 1 device increases bone formation and bone graft resorption around cementless implants

    DEFF Research Database (Denmark)

    Jensen, Thomas B; Overgaard, Søren; Lind, Martin;

    2002-01-01

    In each femoral condyle of 8 Labrador dogs, a non weight-bearing hydroxyapatite-coated implant was inserted surrounded by a 3 mm gap. Each gap was filled with bone allograft or ProOsteon with or without OP-1 delivered in a bovine collagen type I carrier (OP-1 device). 300 microg OP-1 was used in ...

  15. A digital subtraction radiography based tool for periodontal bone resorption analysis

    International Nuclear Information System (INIS)

    The aim of this paper was to describe an aided diagnosis scheme for periodontal bone resorption so that the dentist can make an early diagnosis of the periodontal disease and establish the best treatment plan to increase the success of healing. Three ways of displaying the results are provided: qualitative, simple quantitative and colored-percentage quantitative views. A total of 72 pairs of in vitro radiographic images were used. The main procedure registers the images perspective projection aimed to align them in rotation and translation, and is followed by the application of a contrast correction technique. The results from the subtraction were evaluated firstly by the comparison between the actual and the digital sizes corresponding to the holes made by drills in phantoms. The mean error was 4.2%. The method was also applied to actual tooth radiographic images and could detect clearly the effect of treatment of periodontal diseases. It is dependent on the reproducibility of the process of radiographs acquisition and digitization, but the calculated mean error allows to conclude its better efficacy compared to usual procedures in this field. (author)

  16. A digital subtraction radiography based tool for periodontal bone resorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schiabel, Homero; Rodrigues, Eveline B., E-mail: homero@sc.usp.br [University of Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Dept. of Electrical Engineering; Rubira-Bullen, Izabel R.F. [University of Sao Paulo (USP), Bauru, SP (Brazil). Bauru Dentistry School

    2011-07-01

    The aim of this paper was to describe an aided diagnosis scheme for periodontal bone resorption so that the dentist can make an early diagnosis of the periodontal disease and establish the best treatment plan to increase the success of healing. Three ways of displaying the results are provided: qualitative, simple quantitative and colored-percentage quantitative views. A total of 72 pairs of in vitro radiographic images were used. The main procedure registers the images perspective projection aimed to align them in rotation and translation, and is followed by the application of a contrast correction technique. The results from the subtraction were evaluated firstly by the comparison between the actual and the digital sizes corresponding to the holes made by drills in phantoms. The mean error was 4.2%. The method was also applied to actual tooth radiographic images and could detect clearly the effect of treatment of periodontal diseases. It is dependent on the reproducibility of the process of radiographs acquisition and digitization, but the calculated mean error allows to conclude its better efficacy compared to usual procedures in this field. (author)

  17. Portrayal and management of a rarely seen alveolar bone resorption pattern mimicking the Combination Syndrome: a clinical report

    OpenAIRE

    Piskin, Bulent; Sipahi, Cumhur; Emir, Faruk; Ayyıldız, Simel; Avsever, İsmail Hakan; Uyar, Alper

    2014-01-01

    ABSTRACTTreatment of severely resorbed edentulous alveolar ridges is still a challenging topic of prosthodontics. Combination Syndrome is one of the most remarkable intraoral manifestations of excessive alveolar bone resorption which may be observed at the denture wearing patients with complete edentulous maxilla and bilateral partial edentulous mandibula. Since its first recognition in 1972, the major symptoms and morphological features of the Combination Syndrome such as enlarged maxillary ...

  18. 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.

  19. Sequential analysis of biochemical markers of bone resorption and bone densitometry in multiple myeloma

    DEFF Research Database (Denmark)

    Abildgaard, Niels; Brixen, Kim; Eriksen, Erik Fink; Kristensen, Jens Erik; Nielsen, Johan Lanng; Heickendorff, Lene

    2004-01-01

    less informative. In Cox analysis, ICTP showed the highest predictive value, but should be replaced with NTx in patients with nephropathy. Pretreatment low lumbar BMD was predictive of early vertebral fractures. INTERPRETATION AND CONCLUSIONS: Sequential DEXA-scans showed heterogeneous local BMD...... changes, and our data do not support routine use of sequential DEXA-scans. However, lumbar DEXA-scans at diagnosis can identify patients with increased risk of early vertebral collapses. Sequential analyses of serum ICTP and urinary NTx are useful for monitoring bone damage....

  20. Inhibitory effects on bone resorption in postmenopausal osteoporosis model mice by delivery of serum calcium decreasing factor (caldecrin) gene

    International Nuclear Information System (INIS)

    Osteoporosis is a common condition in which decrease in the bone volume and strength occurs due to increased bone resorption. Caldecrin is a serine protease, with a molecular weight of 28kDa, and it is the causative factor of hypocalcemia frequently seen in acute pancreatitis. Recent reports have shown that caldecrin also acts to inhibit both differentiation of the osteoclasts and function of the mature osteoclasts. In this study, the osteoporosis model mice were used and bilateral ovariectomy was conducted in these mice. Effect of bone absorption was estimated after introducing genetically the pCaldecrin-IRES-hrGFP expressing vector into the femoral muscle by use of the hemagglutinating virus of Japan (HVJ)-liposomes. After the bilateral ovariectomy, serum calcium levels were raised and the bone mass of the femur was decreased. However, in the genetically introduced groups of the model mice, serum calcium levels were significantly lowered. Concomitantly, significant increase in bone density, trabecular width and number of trabecular was observed. Moreover, based on the histological findings, inhibition of bone resorption in the caldecrin-introduced osteoporosis model mice was confirmed. The present study indicates that caldecrin can be expected to become a novel cure for osteoporosis. (author)

  1. Osteoclastic resorption of bone-like apatite formed on a plastic disk as an in vitro assay system.

    Science.gov (United States)

    Matsuoka, H; Nakamura, T; Takadama, H; Yamada, S; Tamura, J; Okada, Y; Oka, M; Kokubo, T

    1998-11-01

    We have investigated the applicability of a simple and inexpensive osteoclastic assay system using bone-like apatite-coated polyethyleneterephthalate (PET) disks. A 1 microm thick apatite layer, uniform and homogeneous bone-mineral-like with no organic components, was made on PET disks using a biomimetic process. As substrates for an osteoclastic assay, these coated disks were compared with dentine as well as with bone-like or heat-treated apatite of various thicknesses on apatite- and wollastonite-containing glass ceramic (A-W GC) disks. The unfractionated bone cells, including osteoclasts, of a neonatal rabbit were seeded onto these substrates. By scanning electron microscopic examination, the resorption lacunae of the thick bone-like apatite clearly showed track-like shapes at various depths, similar to those of dentine although the border between the A-W GC and the apatite was unclear. In contrast, those of heat-treated apatite showed small and shallow shapes with irregular margins, quite different from those of dentine. By reducing the thickness of bone-like apatite to 1 microm as well as using PET as its substrate, the margins of the resorption lacunae became quite clear, and with the use of phase-contrast microscopy during culture, osteoclasts and resorption pits could be precisely observed. The resorbed area, easily measured with the aid of bright-field microscopy and an image analyzer, was found to have increased in a time-dependent manner and at the end of 4 days of culture was not statistically different from that of dentine. PMID:9773824

  2. STUDYING THE POSSIBILITIES OF THE INFRARED LASER WITH (λ904 FOR TREATMENT OF BONE RESORPTION OF DENTAL IMPLANTS IN PROCESS OF OSSEOINTEGRATION

    Directory of Open Access Journals (Sweden)

    Hristina Lalabonova

    2014-09-01

    Full Text Available The objective of this study is to establish the possibilities of the infrared laser with (λ 904 for treatment of bone resorptionof bone implants in the process of osseointegration. Material and methods: The osseointegration process of 167 implants was radiologically evaluated between the first and the second surgical stage. In nine was established bone resorption reaching the implant screw. For the treatment was used infrared laser with (λ 904 nm. Six procedures were performed, every other day, with a dose of 3-4 J/ cm2. Results: The x-ray tests done about three months after the treatment showed restoration of the bone resorption. Conclusion: In diagnosed bone resorption of implants in process of osseointegration, the application of infrared lasertherapy with (λ 904 nm, with protocol of six sessions every other day, with dose 3-4 J/ см2per session, recovers the bone structure.

  3. Calcitonin gene-related peptide stimulates stromal cell osteogenic differentiation and inhibits RANKL induced NF-κB activation, osteoclastogenesis and bone resorption

    OpenAIRE

    Wang, Liping; Shi, Xiaoyou; Zhao, Rong; Halloran, Bernard P.; Clark, David J; Jacobs, Christopher R; Kingery, Wade S.

    2009-01-01

    Previously we observed that capsaicin treatment in rats inhibited sensory neuropeptide signaling, with a concurrent reduction in trabecular bone formation and bone volume, and an increase in osteoclast numbers and bone resorption. Calcitonin gene-related peptide (CGRP) is a neuropeptide richly distributed in sensory neurons innervating the skeleton and we postulated that CGRP signaling regulates bone integrity. In this study we examined CGRP effects on stromal and bone cell differentiation an...

  4. Osteoclast cytosolic calcium, regulated by voltage-gated calcium channels and extracellular calcium, controls podosome assembly and bone resorption

    Science.gov (United States)

    Miyauchi, A.; Hruska, K. A.; Greenfield, E. M.; Duncan, R.; Alvarez, J.; Barattolo, R.; Colucci, S.; Zambonin-Zallone, A.; Teitelbaum, S. L.; Teti, A.

    1990-01-01

    The mechanisms of Ca2+ entry and their effects on cell function were investigated in cultured chicken osteoclasts and putative osteoclasts produced by fusion of mononuclear cell precursors. Voltage-gated Ca2+ channels (VGCC) were detected by the effects of membrane depolarization with K+, BAY K 8644, and dihydropyridine antagonists. K+ produced dose-dependent increases of cytosolic calcium ([Ca2+]i) in osteoclasts on glass coverslips. Half-maximal effects were achieved at 70 mM K+. The effects of K+ were completely inhibited by dihydropyridine derivative Ca2+ channel blocking agents. BAY K 8644 (5 X 10(-6) M), a VGCC agonist, stimulated Ca2+ entry which was inhibited by nicardipine. VGCCs were inactivated by the attachment of osteoclasts to bone, indicating a rapid phenotypic change in Ca2+ entry mechanisms associated with adhesion of osteoclasts to their resorption substrate. Increasing extracellular Ca2+ ([Ca2+]e) induced Ca2+ release from intracellular stores and Ca2+ influx. The Ca2+ release was blocked by dantrolene (10(-5) M), and the influx by La3+. The effects of [Ca2+]e on [Ca2+]i suggests the presence of a Ca2+ receptor on the osteoclast cell membrane that could be coupled to mechanisms regulating cell function. Expression of the [Ca2+]e effect on [Ca2+]i was similar in the presence or absence of bone matrix substrate. Each of the mechanisms producing increases in [Ca2+]i, (membrane depolarization, BAY K 8644, and [Ca2+]e) reduced expression of the osteoclast-specific adhesion structure, the podosome. The decrease in podosome expression was mirrored by a 50% decrease in bone resorptive activity. Thus, stimulated increases of osteoclast [Ca2+]i lead to cytoskeletal changes affecting cell adhesion and decreasing bone resorptive activity.

  5. Porphyromonas gingivalis GroEL induces osteoclastogenesis of periodontal ligament cells and enhances alveolar bone resorption in rats.

    Directory of Open Access Journals (Sweden)

    Feng-Yen Lin

    Full Text Available Porphyromonas gingivalis is a major periodontal pathogen that contains a variety of virulence factors. The antibody titer to P. gingivalis GroEL, a homologue of HSP60, is significantly higher in periodontitis patients than in healthy control subjects, suggesting that P. gingivalis GroEL is a potential stimulator of periodontal disease. However, the specific role of GroEL in periodontal disease remains unclear. Here, we investigated the effect of P. gingivalis GroEL on human periodontal ligament (PDL cells in vitro, as well as its effect on alveolar bone resorption in rats in vivo. First, we found that stimulation of PDL cells with recombinant GroEL increased the secretion of the bone resorption-associated cytokines interleukin (IL-6 and IL-8, potentially via NF-κB activation. Furthermore, GroEL could effectively stimulate PDL cell migration, possibly through activation of integrin α1 and α2 mRNA expression as well as cytoskeletal reorganization. Additionally, GroEL may be involved in osteoclastogenesis via receptor activator of nuclear factor κ-B ligand (RANKL activation and alkaline phosphatase (ALP mRNA inhibition in PDL cells. Finally, we inoculated GroEL into rat gingiva, and the results of microcomputed tomography (micro-CT and histomorphometric assays indicated that the administration of GroEL significantly increased inflammation and bone loss. In conclusion, P. gingivalis GroEL may act as a potent virulence factor, contributing to osteoclastogenesis of PDL cells and resulting in periodontal disease with alveolar bone resorption.

  6. Effects of long-term alendronate treatment on bone mineralisation, resorption parameters and biomechanics of single human vertebral trabeculae

    Directory of Open Access Journals (Sweden)

    M Krause

    2014-09-01

    Full Text Available Due to their well-established fracture risk reduction, bisphosphonates are the most frequently used therapeutic agent to treat osteoporosis. Bisphosphonates reduce fracture risk by suppressing bone resorption, but the lower bone turnover could have a negative impact on bone quality at the tissue level. Here, we directly assess the structural and mechanical characteristics of cancellous bone from the lumbar vertebrae (L5 in non-treated osteoporotic controls (n = 21, mid-term alendronate-treated osteoporotic patients (n = 6, and long-term alendronate-treated osteoporotic patients (n = 7. The strength and toughness of single trabeculae were evaluated, while the structure was characterised through measurements of microdamage accumulation, mineralisation distribution, and histological indices. The alendronate-treated cases had a reduced eroded surface (ES/BS, p < 0.001 and a higher bone mineralisation in comparison to non-treated controls (p = 0.037, which is indicative of low turnover associated with treatment. However, the amount of microdamage and the mechanical properties were similar among the control and treatment groups. As the tissue mineral density (TMD increased significantly with alendronate treatment compared to non-treated osteoporotic controls, the reduction in resorption cavities could counterbalance the higher TMD allowing the alendronate-treated bone to maintain its mechanical properties and resist microdamage accumulation. A multivariate analysis of the possible predictors supports the theory that multiple factors (e.g., body mass index, TMD, and ES/BS can impact the mechanical properties. Our results suggest that long-term alendronate treatment shows no adverse impact on mechanical cancellous bone characteristics.

  7. 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

  8. Tumor necrosis factor alpha and interleukin-1 stimulate bone resorption in vivo as measured by urinary [3H]tetracycline excretion from prelabeled mice

    International Nuclear Information System (INIS)

    Tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) have been shown to stimulate bone resorption in vitro. We have now investigated whether these cytokines also cause a similar action when administered in vivo. This was made possible by the adaptation of a newly developed technique that enables the continual assessment of bone resorption in vivo in mice by measuring urinary excretion of 3H from [3H]tetracycline-prelabeled animals. Experiments using maneuvers known to influence bone resorption, such as a change in dietary calcium or administration of parathyroid hormone or dichloromethylenebisphosphonate, indicate that the technique is reliable and sensitive in mice. Daily intravenous administration of either recombinant human or recombinant murine TNF-alpha, as well as subcutaneous administration of recombinant human IL-1 alpha, were found to stimulate bone resorption in a dose-dependent manner. The effect was maximal within 2 days. Thus, exogenous TNF-alpha and IL-1 alpha can stimulate bone resorption in vivo, suggesting that these cytokines may also exert a systemic effect on bone

  9. The Inhibitory Effects of Forsythia Koreana Extracts on the Metastatic Ability of Breast Cancer Cells and Bone Resorption by Osteoclasts

    Science.gov (United States)

    Kim, Yu Li; Lee, Sun Kyoung; Park, Kwang-Kyun; Chung, Won-Yoon

    2016-01-01

    Background: Breast cancer is the most common malignant disease in women. The patients with advanced breast cancer develop metastasis to bone. Bone metastasis and skeletal-related events by breast cancer are frequently associated with the invasiveness of breast cancer cells and osteoclasts-mediated bone resorption. Forsythia koreana is used in oriental traditional medicine to treat asthma, atopy, and allergic diseases. The aim of this study was to evaluate the inhibitory effects of F. koreana extracts on the invasion of breast cancer cells and bone resorption by osteoclasts. Methods: Cell viability was measured by an MTT assay and the migration and invasion of MDA-MB-231 cells were detected by a Boyden chamber assay. The formation of osteoclasts and pit was detected using tartrate-resistant acid phosphatase staining and calcium phosphate-coated plates, respectively. The activities of matrix metalloproteinases (MMPs) and cathepsin K were evaluated by gelatin zymography and a cathepsin K detection kit. Results: The fruit and leaf extracts of F. koreana significantly inhibited the invasion of MDA-MB-231 cells at noncytotoxic concentrations. The fruit extract of F. koreana reduced the transforming growth factor β1-induced migration, invasion and MMPs activities of MDA-MB-231 cells. In addition, the fruit, branch, and leaf extracts of F. koreana also inhibited the receptor activator of nuclear factor kappa-B ligand-induced osteoclast formation and osteoclast-mediated bone-resorbing activity by reducing the activities of MMPs and cathepsin K. Conclusions: The extracts of F. koreana may possess the potential to inhibit the breast cancer-induced bone destruction through blocking invasion of breast cancer cells, osteoclastogenesis, and the activity of mature osteoclasts. PMID:27390737

  10. Dynamic modeling of bone metastasis, microenvironment and therapy: Integrating parathyroid hormone (PTH) effect, anti-resorptive and anti-cancer therapy.

    Science.gov (United States)

    Coelho, Rui Moura; Lemos, João Miranda; Alho, Irina; Valério, Duarte; Ferreira, Arlindo R; Costa, Luís; Vinga, Susana

    2016-02-21

    Bone is a common site for the development of metastasis, as its microenvironment provides the necessary conditions for the growth and proliferation of cancer cells. Several mathematical models to describe the bone remodeling process and how osteoclasts and osteoblasts coupled action ensures bone homeostasis have been proposed and further extended to include the effect of cancer cells. The model proposed here includes the influence of the parathyroid hormone (PTH) as capable of triggering and regulating the bone remodeling cycle. It also considers the secretion of PTH-related protein (PTHrP) by cancer cells, which stimulates the production of receptor activator of nuclear factor kappa-B ligand (RANKL) by osteoblasts that activates osteoclasts, increasing bone resorption and the subsequent release of growth factors entrapped in the bone matrix, which induce tumor growth, giving rise to a self-perpetuating cycle known as the vicious cycle of bone metastases. The model additionally describes how the presence of metastases contributes to the decoupling between bone resorption and formation. Moreover, the effects of anti-cancer and anti-resorptive treatments, through chemotherapy and the administration of bisphosphonates or denosumab, are also included, along with their corresponding pharmacokinetics (PK) and pharmacodynamics (PD). The simulated models, available at http://sels.tecnico.ulisboa.pt/software/, are able to describe bone remodeling cycles, the growth of bone metastases and how treatment can effectively reduce tumor burden on bone and prevent loss of bone strength. PMID:26657065

  11. Release of titanium ions from an implant surface and their effect on cytokine production related to alveolar bone resorption

    International Nuclear Information System (INIS)

    Although interest in peri-implant mucositis and peri-implantitis has recently been increasing, the mechanisms driving these diseases remain unknown. Here, the effects of titanium ions on the inflammation and bone resorption around an implant were investigated. First, the accumulated amount of Ti ions released into gingival and bone tissues from an implant exposed to sodium fluoride solution was measured using inductively coupled plasma mass spectrometry. Next, the cellular responses in gingival and bone tissues to Ti ions and/or Porphyromonas gingivalis-lipopolysaccharide (P. gingivalis-LPS) were assessed using a rat model. More Ti ions were detected in the gingival tissues around an implant after treatment with sodium fluoride (pH 4.2) than in its absence, which suggests that the fluoride corroded the implant surface under salivary buffering capacity. The injection of Ti ions (9 ppm) significantly increased the mRNA expression and protein accumulation of chemokine (C–C motif) ligand 2, as well as the ratio of receptor activator of nuclear factor-κB ligand to osteoprotegerin, in rat gingival tissues exposed to P. gingivalis-LPS in a synergistic manner. In addition, the enhanced localization of toll-like receptor 4, which is an LPS receptor, was observed in gingival epithelium loaded with Ti ions (9 ppm). These data suggest that Ti ions may be partly responsible for the infiltration of monocytes and osteoclast differentiation by increasing the sensitivity of gingival epithelial cells to microorganisms in the oral cavity. Therefore, Ti ions may be involved in the deteriorating effects of peri-implant mucositis, which can develop into peri-implantitis accompanied by alveolar bone resorption

  12. Bone resorption following weight loss surgery is associated with treatment procedure and changes in secreted Wnt antagonists.

    Science.gov (United States)

    Hofsø, Dag; Bollerslev, Jens; Sandbu, Rune; Jørgensen, Anders; Godang, Kristin; Hjelmesæth, Jøran; Ueland, Thor

    2016-07-01

    To assess if altered bone turnover following bariatric surgery is related to metabolic consequences of the surgical procedure or weight loss. We evaluated serum markers reflecting bone turnover and metabolic pathways at baseline and after 1-year in a controlled non-randomized clinical trial comparing Roux-en-Y gastric bypass surgery (n = 74) with lifestyle intervention (n = 63) on obesity-related comorbidities. The decrease in body mass index (BMI) was larger in the surgery (-14.0 kg/m(2)) compared to lifestyle (-3.7 kg/m(2)). Markedly increased bone turnover was observed following surgery compared to lifestyle intervention and was correlated with change in BMI. Stepwise multivariable regression analysis revealed that group (β = 0.31, p < 0.01), and changes in BMI (β = -0.28, p < 0.01), dickkopf-1 (β = 0.20, p < 0.001) and sclerostin (β = 0.11, p < 0.05) were predictors of change in the bone resorption marker N-terminal telopeptide. Our data support that mechanisms related to the procedure itself and changes in secreted Wnt antagonists may contribute to increased bone turnover following bariatric surgery. PMID:26956843

  13. Enhancement of Osteoclastic Bone Resorption and Suppression of Osteoblastic Bone Formation in Response to Reduced Mechanical Stress Do Not Occur in the Absence of Osteopontin

    Science.gov (United States)

    Ishijima, Muneaki; Rittling, Susan R.; Yamashita, Teruhito; Tsuji, Kunikazu; Kurosawa, Hisashi; Nifuji, Akira; Denhardt, David T.; Noda, Masaki

    2001-01-01

    Reduced mechanical stress to bone in bedridden patients and astronauts leads to bone loss and increase in fracture risk which is one of the major medical and health issues in modern aging society and space medicine. However, no molecule involved in the mechanisms underlying this phenomenon has been identified to date. Osteopontin (OPN) is one of the major noncollagenous proteins in bone matrix, but its function in mediating physical-force effects on bone in vivo has not been known. To investigate the possible requirement for OPN in the transduction of mechanical signaling in bone metabolism in vivo, we examined the effect of unloading on the bones of OPN−/− mice using a tail suspension model. In contrast to the tail suspension–induced bone loss in wild-type mice, OPN−/− mice did not lose bone. Elevation of urinary deoxypyridinoline levels due to unloading was observed in wild-type but not in OPN−/− mice. Analysis of the mechanisms of OPN deficiency–dependent reduction in bone on the cellular basis resulted in two unexpected findings. First, osteoclasts, which were increased by unloading in wild-type mice, were not increased by tail suspension in OPN−/− mice. Second, measures of osteoblastic bone formation, which were decreased in wild-type mice by unloading, were not altered in OPN−/− mice. These observations indicate that the presence of OPN is a prerequisite for the activation of osteoclastic bone resorption and for the reduction in osteoblastic bone formation in unloaded mice. Thus, OPN is a molecule required for the bone loss induced by mechanical stress that regulates the functions of osteoblasts and osteoclasts. PMID:11157060

  14. Developmentally regulated monocyte recruitment and bone resorption are modulated by functional deletion of the monocytic chemoattractant protein-1 gene.

    Science.gov (United States)

    Graves, D T; Alsulaimani, F; Ding, Y; Marks, S C

    2002-08-01

    Tooth eruption involves the movement of a tooth from its site of development within the alveolar bone to its functional position in the oral cavity. Because this process is dependent upon monocytes and formation of osteoclasts, it represents an excellent model for examination of these processes under developmental regulation. We investigated the functional role of monocyte chemoattractant protein-1 (MCP-1) in monocyte recruitment and its impact on bone resorption by examining each parameter in MCP-1(-/-) mice as compared with wild-type controls during tooth eruption. The peak number of monocytes occurred on day 5 in the MCP-1(-/-) mice and on day 9 in the wild-type mice. The peak number of osteoclasts followed the same pattern, occurring sooner in the MCP-1(-/-) (day 5) than in wild-type mice (day 9). Consistent with this, MCP-1(-/-) mice had an accelerated rate of tooth eruption in the early phase when the teeth first entered the oral cavity as compared with the wild-type mice. However, there was accelerated eruption in the wild-type group in the later phase of tooth eruption. When examined at the molecular level, inducible nitric oxide synthase (iNOS) and interleukin-11 and -6 were expressed at considerably higher levels in the experimental group with accelerated tooth eruption. This is the first report identifying these factors as potential modulators of bone resorption that can accelerate the rate of tooth eruption. We conclude that, at early timepoints, monocyte recruitment occurs by MCP-1-independent mechanisms. However, at a later timepoint, MCP-1 may play a contributory role in the recruitment of monocytic cells, allowing the wild-type animals to catch up. PMID:12151080

  15. Effects of prostaglandin F2 alpha on bone formation and resorption in cultured neonatal mouse calvariae: Role of prostaglandin E2 production

    International Nuclear Information System (INIS)

    Although most studies show that prostaglandin E2 (PGE2) is the most potent and effective of the prostanoids in bone, recent data in cell culture suggest that PGF2 alpha may have unique effects, particularly on cell replication. The present study was undertaken to compare the effects of PGF2 alpha and PGE2 in cultured neonatal mouse parietal bones by simultaneous measurement of bone resorption as release of previously incorporated 45Ca, bone formation as incorporation of [3H]proline into collagenase-digestible (CDP) and noncollagen protein, and DNA synthesis as incorporation of [3H]thymidine. PGF2 alpha was less effective than PGE2 as a stimulator of bone resorption, and its effects were partially inhibited by indomethacin and markedly inhibited by glucocorticoids. In contrast, the resorptive response to PGE2 was unaffected by indomethacin and only partially inhibited by cortisol. PGF2 alpha had little effect on bone formation, in contrast to the biphasic effect of PGE2, which inhibited labeling of CDP in the absence of cortisol and stimulated CDP labeling in the presence of cortisol. PGF2 alpha increased thymidine incorporation into DNA, but the effect was smaller than that of PGE2 and was inhibited by indomethacin. These observations suggested that PGF2 alpha might act in part by stimulating PGE2 production. By RIA, PGE2 concentrations were increased in the medium of bones treated with PGF2 alpha, and this increase was blocked by indomethacin. By HPLC, bones prelabeled with [3H]arachidonic acid showed an increase in labeled PGE2 release, and RIA showed an increase in PGE2 after PGF2 alpha treatment. These results indicate that PGF2 alpha is a relatively weak agonist in bone compared to PGE2 and that some of the effects of PGF2 alpha on bone resorption, formation, and cell replication may be mediated by an increase in endogenous PGE2 production

  16. Nanogel-crosslinked nanoparticles increase the inhibitory effects of W9 synthetic peptide on bone loss in a murine bone resorption model

    Directory of Open Access Journals (Sweden)

    Sato T

    2015-05-01

    Full Text Available Toshimi Sato,1 Neil Alles,1,2 Masud Khan,1,3 Kenichi Nagano,1,4 Mariko Takahashi,1 Yukihiko Tamura,1 Asako Shimoda,5,6 Keiichi Ohya,1 Kazunari Akiyoshi,5,6 Kazuhiro Aoki1 1Department of Bio-Matrix (Pharmacology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan; 2Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka; 3Department of Dental Pharmacology, City Dental College and Hospital, Dhaka, Bangladesh; 4Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA; 5Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, 6ERATO Akiyoshi Bio-Nanotransporter Project, Japan Science and Technology Agency, Katsura Int’tech Center Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto, Japan Abstract: We investigated the biological activity of W9, a bone resorption inhibitor peptide, using NanoClik nanoparticles as an injectable carrier, where acryloyl group-modified cholesterol-bearing pullulan (CHPOA nanogels were crosslinked by pentaerythritol tetra (mercaptoethyl polyoxyethylene. Thirty 5-week-old male C57BL/6J mice were fed a low calcium diet and received once-daily subcutaneous injections of the carrier alone, W9 24 mg/kg/day alone, W9 24 mg/kg/day incorporated in cholesterol bearing pullulan (CHP nanogels, or W9 (8 and 24 mg/kg/day incorporated in NanoClik nanoparticles for 4 days (n=5. Mice that received a normal calcium diet with NanoClik nanoparticle injections without W9 were used as a control group. Radiological analyses showed that administration of W9 24 mg/kg/day significantly prevented low calcium-induced reduction of bone mineral density in the long bones and lumbar vertebrae, but only when the NanoClik nanoparticles were used as a carrier. Histomorphometric analyses of the proximal tibiae revealed that W9 24 mg/kg/day incorporated in NanoClik nanoparticles prevented the increase in bone resorption indices

  17. Dietary Zinc Reduces Osteoclast Resorption Activities and Increases Markers of Osteoblast Differentiation, Matrix Maturation, and Mineralization in the Long Bones of Growing Rats

    Science.gov (United States)

    The nutritional influence of zinc (Zn) on markers of bone extracellular matrix (ECM) resorption and mineralization was investigated in growing rats. Thirty male weanling rats were randomly assigned to consume AIN-93G based diets containing 2.5, 5, 7.5, 15, or 30 µg Zn/g diet for 24 d. Femur Zn incre...

  18. Effects of the natural and artificial menstrual cycle on the production of osteoprotegerin and the bone resorptive cytokines IL-1beta and IL-6

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Stilgren, L S; Rettmer, E;

    2003-01-01

    was similar in the two phases of HRT, but decreased nonsignificantly (p = 0.05) in the luteal phase in the premenopausal women. OPG levels did not exhibit any menstrual cycle-dependent changes. In conclusion, bone resorption is suppressed in the luteal phase through a mechanism that does not involve...

  19. Effects of a Mikania laevigata extract on bone resorption and RANKL expression during experimental periodontitis in rats

    Directory of Open Access Journals (Sweden)

    Bruno B. Benatti

    2012-06-01

    Full Text Available OBJECTIVES: The Mikania laevigata extract (MLE (popularly known in Brazil as "guaco" possesses anti-inflammatory properties. In the present study we tested the effects of MLE in a periodontitis experimental model in rats. We also investigated possible mechanisms underlying such effects. MATERIAL AND METHODS: Periodontal disease was induced by a ligature placed around the mandibular first molars of each animal. Male Wistar rats were divided into 4 groups: non-ligated animals treated with vehicle; non-ligated animals treated with MLE (10 mg/kg, daily; ligature-induced animals treated with vehicle and ligature-induced animals treated with MLE (10 mg/kg, daily. Thirty days after the induction of periodontal disease, the animals were euthanized and mandibles and gingival tissues removed for further analysis. RESULTS: Morphometric analysis of alveolar bone loss demonstrated that MLE-treated animals presented a decreased alveolar bone loss and a lower expression of the activator of nuclear factor-κB ligand (RANKL measured by immunohistochemistry. Moreover, gingival tissues from the MLE-treated group showed decreased neutrophil migration myeloperoxidase (MPO assay. CONCLUSIONS: These results indicate that MLE may be useful to control bone resorption during progression of experimental periodontitis in rats.

  20. Effects of rat serum containing Chinese herbal medicine Sangen Decoction on osteoclastogenesis and bone resorption of osteoclasts induced by polymethylmethacrylate particles

    OpenAIRE

    Shu-qiang Wang; Yong-qiang Chen

    2011-01-01

    Objective: To investigate the effects of Sangen Decoction, a compound Chinese herbal medicine, on osteoclastogenesis and bone resorption function of osteoclasts induced by polymethylmethacrylate particles in vitro.Methods: Macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) were used to induce differentiation of bone marrow-derived macrophages (BMMs) towards osteoclasts. BMMs and polymethylmethacrylate particles with ratio of 1︰3 were added ...

  1. A reversal phase arrest uncoupling the bone formation and resorption contributes to the bone loss in glucocorticoid treated ovariectomised aged sheep

    DEFF Research Database (Denmark)

    Andreasen, Christina Møller; Ding, Ming; Overgaard, Søren;

    2015-01-01

    had a complete absence of osteoid surfaces, and a 5-fold increase in the extent of eroded/reversal surfaces after 7months. Most of these reversal surfaces were actually arrested reversal surfaces, defined as reversal surfaces without the presence of neighbouring osteoid surfaces or osteoclasts, which...... is classically observed next to active reversal surfaces. As in humans, these arrested reversal surfaces had compared to active reversal surfaces a reduced canopy coverage, a significantly decreased cell density, and a decreased immunoreactivity for the osteoblastic markers osterix, runx2 and smooth...... muscle actin in the mononuclear reversal cells colonising the surfaces. In conclusion, glucocorticoid treatment of ovariectomised sheep induced a significant bone loss, caused by an arrest of the reversal phase, resulting in an uncoupling of the bone formation and resorption during the reversal phase, as...

  2. Can medio-lateral baseplate position and load sharing induce asymptomatic local bone resorption of the proximal tibia? A finite element study

    Directory of Open Access Journals (Sweden)

    Wong Pius

    2009-07-01

    Full Text Available Abstract Background Asymptomatic local bone resorption of the tibia under the baseplate can occasionally be observed after total knee arthroplasty (TKA. Its occurrence is not well documented, and so far no explanation is available. We report the incidence of this finding in our practice, and investigate whether it can be attributed to specific mechanical factors. Methods The postoperative radiographs of 500 consecutive TKA patients were analyzed to determine the occurrence of local medial bone resorption under the baseplate. Based on these cases, a 3D FE model was developed. Cemented and cementless technique, seven positions of the baseplate and eleven load sharing conditions were considered. The average VonMises stress was evaluated in the bone-baseplate interface, and the medial and lateral periprosthetic region. Results Sixteen cases with local bone resorption were identified. In each, bone loss became apparent at 3 months post-op and did not increase after one year. None of these cases were symptomatic and infection screening was negative for all. The FE analysis demonstrated an influence of baseplate positioning, and also of load sharing, on stresses. The average stress in the medial periprosthetic region showed a non linear decrease when the prosthetic baseplate was shifted laterally. Shifting the component medially increased the stress on the medial periprosthetic region, but did not significantly unload the lateral side. The presence of a cement layer decreases the stresses. Conclusion Local bone resorption of the proximal tibia can occur after TKA and might be attributed to a stress shielding effect. This FE study shows that the medial periprosthetic region of the tibia is more sensitive than the lateral region to mediolateral positioning of the baseplate. Medial cortical support of the tibial baseplate is important for normal stress transfer to the underlying bone. The absence of medial cortical support of the tibial baseplate may lead

  3. A supra-cellular model for coupling of bone resorption to formation during remodeling

    DEFF Research Database (Denmark)

    Jensen, Pia Rosgaard; Andersen, Thomas Levin; Pennypacker, Brenda L;

    2014-01-01

    canopy coverage above osteoclasts. This effect is in accordance with its toxic action on periosteoclastic cells. In contrast, odanacatib, an inhibitor preserving bone formation, increases the extent of the osteoclast-canopy interface. Interestingly, these distinct effects correlate with how fast bone...

  4. Correlation between Density and Resorption of Fresh-Frozen and Autogenous Bone Grafts

    OpenAIRE

    2014-01-01

    Trial Design. This analysis compared the outcome of fresh-frozen versus autologous bone block grafts for horizontal ridge augmentation in patients with Cawood and Howell class IV atrophies. Methods. Seventeen patients received autologous grafts and 21 patients received fresh-frozen bone grafts. Patients underwent CT scans 1 week and 6 months after surgery for graft volume and density analysis. Results. Two autologous and 3 fresh-frozen grafts failed. Autologous and fresh-frozen grafts lost, r...

  5. Progress on Action of Cathepsin K in Bone Resorption%组织蛋白酶K在骨吸收中的作用研究进展

    Institute of Scientific and Technical Information of China (English)

    王东; 顾建红; 刘宗平

    2014-01-01

    组织蛋白酶 K(Cathepsin K,CK)是一种溶酶体半胱氨酸蛋白酶,属于番木瓜蛋白酶超家族。在破骨细胞(osteoclast,OC)介导的骨吸收过程中有效降解骨组织中的基质蛋白,在骨吸收过程中发挥重要作用。研究 CK 在骨吸收中的重要性,为治疗骨代谢疾病开辟了新的途径。论文就组织蛋白酶 K 的结构和功能及在骨吸收过程中与破骨细胞的相互作用和表达水平的调控机制进行了阐述。%Cathepsin K is one of lysosomal cysteine proteases,belongs to the papaya protease superfamily,highly expressed in the process of bone resorption mediated by osteoclasts and degrade matrix proteins in bone tissue ef-fectively,plays a significant role in the process on bone resorption.Study of the importance of cathepsin k in bone resorption opened up a new approach to metabolic bone disease treatment.In this mini-review,we mainly focused on the structure and function of cathepsin K and the interaction with osteoclast,the regulation mechanisms of ex-pression levels in the process of bone resorption.

  6. Inhibition of Osteoclast Differentiation and Bone Resorption by Bisphosphonate-conjugated Gold Nanoparticles

    Science.gov (United States)

    Lee, Donghyun; Heo, Dong Nyoung; Kim, Han-Jun; Ko, Wan-Kyu; Lee, Sang Jin; Heo, Min; Bang, Jae Beum; Lee, Jung Bok; Hwang, Deok-Sang; Do, Sun Hee; Kwon, Il Keun

    2016-01-01

    In recent years, gold nanoparticles (GNPs) have been reported to affect the regeneration of bone tissue. The goal of this study was to improve bone tissue regeneration by using targeted GNPs. We fabricated a functionalized GNPs conjugated with alendronate (ALD), of the bisphosphonate group. Subsequently, the ALD, GNPs, and ALD conjugated GNPs (GNPs-ALD) were analyzed by ultraviolet-visible absorbance (UV-vis) spectrophotometer, Attenuated total reflectance Fourier transform infrared spectrometer (ATR-FTIR), and thermo gravimetric analysis (TGA). The prepared GNPs-ALD were used to investigate their inhibitory effects on the receptor activator of nuclear factor- κb ligand (RANKL)-induced osteoclastogenesis in bone marrow-derived macrophages (BMMs). Additionally, the GNPs-ALD were applied to ovariectomy (OVX)-induced osteoporotic mice and the experiments were evaluated. ALD was found to be successfully conjugated to the GNPs surface, and it displayed significant adhesion onto the bone surface. The in-vitro study indicated that the GNPs, ALD and GNPs-ALD suppressed osteoclast formation in a dose-dependent manner. Furthermore, in the OVX mouse model, the mice treated GNPs-ALD had higher bone density as compared to other OVX mice groups. The results from these tests indicated that GNPs-ALD can be useful agents for preventing and treating osteoporosis. PMID:27251863

  7. Microcracks and osteoclast resorption activity in vitro.

    Science.gov (United States)

    Rumpler, Monika; Würger, Tanja; Roschger, Paul; Zwettler, Elisabeth; Peterlik, Herwig; Fratzl, Peter; Klaushofer, Klaus

    2012-03-01

    During bone remodeling osteoclasts resorb bone, thus removing material, e.g., damaged by microcracks, which arises as a result of physiological loading and could reduce bone strength. Such a process needs targeted bone resorption exactly at damaged sites. Osteocytic signaling plays a key role in this process, but it is not excluded that osteoclasts per se may possess toposensitivity to recognize and resorb damaged bone since it has been shown that resorption spaces are associated with microcracks. To address this question, we used an in vitro setup of a pure osteoclast culture and mineralized substrates with artificially introduced microcracks and microscratches. Histomorphometric analyses and statistical evaluation clearly showed that these defects had no effect on osteoclast resorption behavior. Osteoclasts did not resorb along microcracks, even when resorption started right beside these damages. Furthermore, quantification of resorption on three different mineralized substrates, cortical bone, bleached bone (bone after partial removal of the organic matrix), and dentin, revealed lowest resorption on bone, significantly higher resorption on bleached bone, and highest resorption on dentin. The difference between native and bleached bone may be interpreted as an inhibitory impact of the organic matrix. However, the collagen-based matrix could not be the responsible part as resorption was highest on dentin, which contains collagen. It seems that osteocytic proteins, stored in bone but not present in dentin, affect osteoclastic action. This demonstrates that osteoclasts per se do not possess a toposensitivity to remove microcracks but may be influenced by components of the organic bone matrix. PMID:22271249

  8. Effect of 50 Hz sinusoidal electromagnetic field on 45Calcium uptake and bone resorption

    International Nuclear Information System (INIS)

    The hypothesis that exposure to weak exogenous electromagnetic field emulates physiological and strain related electrical currents which stimulate the bone formation, has been evaluated in this study. It was observed that a dose dependent increase in 45Ca levels in tibias of animals exposed to sinusoidal EMF full day for 30 days as compared to control animals

  9. Effects and Interaction of Icariin, Curculigoside, and Berberine in Er-Xian Decoction, a Traditional Chinese Medicinal Formula, on Osteoclastic Bone Resorption

    Directory of Open Access Journals (Sweden)

    Liming Xue

    2012-01-01

    Full Text Available Er-Xian decoction (EXD, a traditional Chinese medicine, has been reported to have a protective effect against bone loss in ovariectomized osteoporotic rats, and the inclusion of icariin (I, curculigoside (C, and berberine (B in EXD displays inhibitory effects on osteoclastic bone resorption. In the present paper, we investigated the interaction and effects of I, C, B, and their combination on bone resorption activity in vitro on osteoclasts derived from rat bone marrow cells. ICB synergistically decreased the formation of bone resorption pits, the number of multinucleated osteoclasts, and the activity of tartrate-resistant acid phosphatase (TRAP and showed antagonistic or additive effects on cathepsin K activity in the coculture system of osteoblasts and bone marrow cells in the presence of 1, 25-dihydroxyvitamin D3 and dexamethasone. The combination of ICB also enhanced the inhibitory effects on the formation of F-actin ring, a cytoskeleton structure of osteoclasts induced from bone marrow cells with macrophage colony stimulation factor (M-CSF and receptor activator of NF-κB ligand (RANKL. In addition, ICB synergistically improved the ratio of protein expression of osteoprotegerin (OPG and RANKL in osteoblasts and interfered with the mitogen-activated protein kinases (MAPKs pathway in osteoclast. These results clearly show that I, C, B, and their combination in EXD exert effects of mutual reinforcement. However, IBC does not show an intensified adverse effect in the ovariectomized murine model, as revealed by change in body and uterine weight, confirming the safety of EXD. These observations are in agreement with the rationality of the formula used in this paper.

  10. Human calcium metabolism including bone resorption measured with {sup 41}Ca tracer

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, S.P.H.T. [Lawrence Livermore National Lab., CA (United States); King, J.C. [California Univ., Berkeley, CA (United States). Dept. of Nutritional Science; Vieira, N.E. [National Inst. of Child Health and Human Development, Bethesda, MD (United States); Woodhouse, L.R. [California Univ., Berkeley, CA (United States). Dept. of Nutritional Science; Yergey, A.L. [National Inst. of Child Health and Human Development, Bethesda, MD (United States)

    1996-08-01

    Accelerator mass spectrometry is so sensitive to small quantities of {sup 41}Ca that it might be used as a tracer in the study of human calcium kinetics to generate unique kinds of data. In contrast with the use of other Ca isotopic tracers, {sup 41}Ca tracer can be so administered that the tracer movements between the various body pools achieve a quasi steady state. Resorbing bone may thus be directly measured. We have tested such a protocol against a conventional stable isotope experiment with good agreement.

  11. Can medio-lateral baseplate position and load sharing induce asymptomatic local bone resorption of the proximal tibia?: a finite element study

    OpenAIRE

    Wong Pius; Labey Luc; Truyens Evelyn; Innocenti Bernardo; Victor Jan; Bellemans Johan

    2009-01-01

    Abstract Background Asymptomatic local bone resorption of the tibia under the baseplate can occasionally be observed after total knee arthroplasty (TKA). Its occurrence is not well documented, and so far no explanation is available. We report the incidence of this finding in our practice, and investigate whether it can be attributed to specific mechanical factors. Methods The postoperative radiographs of 500 consecutive TKA patients were analyzed to determine the occurrence of local medial bo...

  12. Soy isoflavones do not affect bone resorption in postmenopausal women: A dose-response study using a novel approach with Ca-41

    OpenAIRE

    Cheong, J. M. K.; Martin, B R; Jackson, G.S.; Elmore, D.; McCabe, G. P.; Nolan, J R; Barnes, S.; Peacock, M.; Weaver, C. M.

    2007-01-01

    Introduction: The purpose of this 3-way crossover study was to identify the effective dose of soy protein isolate enriched with isoflavones for suppressing bone resorption in postmenopausal women using a novel, rapid assessment of antibone resorbing treatments. Methods: Thirteen postmenopausal women (>= 6 yr since menopause) were predosed with Ca-41 iv. After a 200-d baseline period, subjects were given 43 g soy p...

  13. VEGF-C, a Lymphatic Growth Factor, Is a RANKL Target Gene in Osteoclasts That Enhances Osteoclastic Bone Resorption through an Autocrine Mechanism*S⃞

    OpenAIRE

    Qian ZHANG; Guo, Ruolin; Lu, Yan; Zhao, Lan; Zhou, Quan; Schwarz, Edward M.; Huang, Jing; Chen, Di; Jin, Zheng-Gen; Boyce, Brendan F.; Xing, Lianping

    2008-01-01

    Osteoclasts are bone-resorbing cells, but they also secrete and respond to cytokines. Here, we test the hypothesis that osteoclasts secrete the lymphatic growth factor, VEGF-C, to increase their resorptive activity. Osteoclasts and osteoclast precursors were generated by culturing splenocytes with macrophage colony-stimulating factor and RANKL from wild-type, NF-κBp50-/-/p52-/-, and Src-/- mice. Expression of VEGFs was measured by real time reverse transcription-PC...

  14. 1,25-Dihydroxyvitamin D3 prevents bone loss of the secondary spongiosa in arthritic rats by an increase of bone formation and mineralization and inhibition of bone resorption

    OpenAIRE

    Oelzner, Peter; Petrow, Peter K; Wolf, Gunter; Bräuer, Rolf

    2014-01-01

    Background Active vitamin D metabolites have been shown to have protective effects in experimental arthritis especially when used as preventive treatment. However, because the direct effects of 1,25-dihydroxyvitamin D3 (1,25(OH) 2D3) on bone formation and resorption are very complex, the net effect of 1,25(OH)2D3 on histomorphometric parameters of bone turnover and mineralisation should be investigated. Therefore, we examined the influence of 1,25(OH)2D3 therapy on arthritis-induced alteratio...

  15. Comparison of the effects of stimulators and inhibitors of resorption on the release of lysosomal enzymes and radioactive calcium from fetal bone in organ culture

    International Nuclear Information System (INIS)

    The release of lysosomal enzymes, collagenase, and previously incorporated 45Ca from fetal rat long bones cultured in a chemically defined medium is compared. Parathyroid hormone (PTH) and prostaglandin E2 increased the release of β-glucuronidase, acetylglucosaminidase, and cathepsin D, but showed little effect on collagenase activity in the medium at 48 h. The dose-response relations for β-glucuronidase and 45Ca release were similar. However, the increase in lysosomal enzyme release was proportionally greater and occurred earlier than the increase in 45Ca release. PTH also caused a significant increase in total β-glucuronidase activity in bone plus medium. Several agents which stimulate 45Ca release at an optimal concentration, but not at a higher concentration, including dibutyryl cAMP, isobutylmethylxanthine, and the calcium ionophore, A23187, all increased lysosomal enzyme release at the concentration which increased 45Ca release. Three inhibitors of bone resorption (calcitonin, cortisol, and colchicine) blocked lysosomal enzyme release at the same time that 45Ca release decreased. When the bones escaped from calcitonin inhibition, both 45Ca and lysosomalenzyme release increased. While colchicine blocked both lysosomal enzymes and 45CA release, it actually increased the release of bone collagenase, and together with PTH or prostaglandin E2 caused a large increase in free collagenase activity in the medium. These data indicate that lysosomal enzyme release is closely linked to bone resorption and suggest that lysosomal enzymes may have a primary role in initiating resorption, perhaps by acting on noncollagenous matrix or tissue components before mineral removal and collagen degradation

  16. Effects of rat serum containing Chinese herbal medicine Sangen Decoction on osteoclastogenesis and bone resorption of osteoclasts induced by polymethylmethacrylate particles

    Directory of Open Access Journals (Sweden)

    Shu-qiang Wang

    2011-01-01

    Full Text Available Objective: To investigate the effects of Sangen Decoction, a compound Chinese herbal medicine, on osteoclastogenesis and bone resorption function of osteoclasts induced by polymethylmethacrylate particles in vitro.Methods: Macrophage colony stimulating factor (M-CSF and receptor activator of nuclear factor-κB ligand (RANKL were used to induce differentiation of bone marrow-derived macrophages (BMMs towards osteoclasts. BMMs and polymethylmethacrylate particles with ratio of 1︰3 were added to the 24-well plate and 96-well plate with bone slices respectively. A total of 50 male SD rats were divided into 5 groups randomly with each group containing 10 rats. After being treated with different drugs, serum samples of rats in each group were extracted, i.e., the blank serum, Western medicine (ibandronate serum and high-, medium-, and low-dose Sangen Decoction serum and were added to the medium respectively. The tartrate-resistant acid phosphatase (TRAP staining was used to identify the differentiation of BMMs and for counting of osteoclasts. Area of lacuna induced by osteoclast bone resorption on the bone slices was measured by computer image processing.Results: Numbers of osteoclasts of treatment groups were less than that of blank group by TRAP staining (P<0.05; numbers of osteoclasts of positive control group and high-dose Sangen Decoction group were much lower than those of medium- and low-dose Sangen Decoction groups (P<0.05, and no difference was found between Western medicine group and high-dose Sangen Decoction group (P>0.05. In bone resorption assay, area of lacuna of blank group was larger than those of treatment groups (P<0.05; areas of lacuna of Western medicine group and high-dose Sangen Decoction group were much smaller than those of medium- and low-dose Sangen Decoction groups (P<0.05, and no difference was found between Western medicine group and high-dose Sangen Decoction group (P>0.05.Conclusion: Sangen Decoction can inhibit

  17. The effect of semelil (angipars®) on bone resorption and bone formation markers in type 2 diabetic patients

    OpenAIRE

    Hasani-Ranjbar Shirin; Jouyandeh Zahra; Qorbani Mostafa; Hemmatabadi Mahbubeh; Larijani Bagher

    2012-01-01

    Abstract Background and purpose of the study Diabetes mellitus has been recognized as a major risk factor for osteoporosis in which bone turnover is affected by different mechanisms. As the morbidity, mortality and financial cost related to osteoporosis are expected to rise in Iran in coming years, and considering the efficacy of Angipars® for improvement of different ulcers which made it a new herbal drug in diabetic foot ulcer, there is a need to evaluate the effect of this new drug on diff...

  18. The Efect of Semelil (AngiparsW) on Bone Resorption and Bone Formation Markers in Type 2 Diabetic Patients

    OpenAIRE

    Shirin Hasani-Ranjbar; Zahra Jouyandeh; Mostafa Qorbani; Mahbubeh Hemmatabadi; Bagher Larijani

    2012-01-01

    Background and purpose of the study: Diabetes mellitus has been recognized as a major risk factor for osteoporosis in which bone turnover is affected by different mechanisms. As the morbidity, mortality and financial cost related to osteoporosis are expected to rise in Iran in coming years, and considering the efficacy of AngiparsW for improvement of different ulcers which made it a new herbal drug in diabetic foot ulcer, there is a need toevaluate the effect of this new drug on different org...

  19. A comparison of osteoclast-rich and osteoclast-poor osteopetrosis in adult mice sheds light on the role of the osteoclast in coupling bone resorption and bone formation

    DEFF Research Database (Denmark)

    Thudium, Christian S; Moscatelli, Ilana; Flores, Carmen; Thomsen, Jesper Skovhus; Brüel, Annemarie; Gudmann, Natasja Stæhr; Hauge, Ellen Margrethe; Karsdal, Morten A; Richter, Johan; Henriksen, Kim

    2014-01-01

    formation rate (54 %) in trabecular bone, while RANK KO recipients showed only minor trends compared to control recipients. We here show that maintaining non-resorbing osteoclasts, as opposed to reducing the osteoclasts, leads to increased bone formation, bone volume, and ultimately higher bone strength in......Osteopetrosis due to lack of acid secretion by osteoclasts is characterized by abolished bone resorption, increased osteoclast numbers, but normal or even increased bone formation. In contrast, osteoclast-poor osteopetrosis appears to have less osteoblasts and reduced bone formation, indicating......-poor adult osteopetrosis model. We used fetal liver HSCs from (1) oc/oc mice, (2) RANK KO mice, and (3) compared these to wt control cells. TRAP5b activity, a marker of osteoclast number and size, was increased in the oc/oc recipients, while a significant reduction was seen in the RANK KO recipients. In...

  20. Microcracks and Osteoclast Resorption Activity In Vitro

    OpenAIRE

    Rumpler, Monika; Würger, Tanja; Roschger, Paul; Zwettler, Elisabeth; Peterlik, Herwig; Fratzl, Peter; Klaushofer, Klaus

    2012-01-01

    During bone remodeling osteoclasts resorb bone, thus removing material, e.g., damaged by microcracks, which arises as a result of physiological loading and could reduce bone strength. Such a process needs targeted bone resorption exactly at damaged sites. Osteocytic signaling plays a key role in this process, but it is not excluded that osteoclasts per se may possess toposensitivity to recognize and resorb damaged bone since it has been shown that resorption spaces are associated with microcr...

  1. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost......-an ectodermal tissue layer (Malassez′s epithelium), a middle layer-composed by the collagen-mesodermal tissue layer, and an innermost root-close innervation layer. Abnormalities in one of these tissue layers are thought to cause inflammatory processes in the periodontal membrane comparable to inflammatory...

  2. Comparison of the effects of eldecalcitol with either raloxifene or bisphosphonate on serum tartrate resistant acid phosphatase-5b, a bone resorption marker, in postmenopausal osteoporosis

    Science.gov (United States)

    Takada, Junichi; Ikeda, Satoshi; Kusanagi, Tetsuya; Mizuno, Satoshi; Wada, Hiroshi; Iba, Kousuke; Yoshizaki, Takashi; Yamashita, Toshihiko

    2016-01-01

    Summary Objective This study analyzes whether concomitant raloxifene (RLX) or bisphosphonates (BP) plus eldecalcitol (ELD) has excessive suppressive effects on a bone resorption marker during the first 6 months of treatment in postmenopausal women in real-world setting. Methods 285 postmenopausal osteoporotic patients who had been treated with RLX or BP plus ELD were evaluated the bone resorption marker, serum tartrate resistant acid phosphatase-5b (TRACP-5b), during the first 6 months of treatment. Results In drug-naïve group (not received osteoporosis medications before the administration, n=70), the concomitant RLX or BP with ELD significantly decreased levels of TRACP-5b without severe suppression. In vitamin D switch group [RLX or BP plus alfacalcidol (ALF) and then switched to RLX or BP plus ELD, n=215], the replacing ALF with ELD further and significantly decreased TRACP-5b and tertile analyses based on baseline values were significantly decreased far more in the highest, compared with the lowest tertile in the ELD+RLX and ELD+BP groups. Conclusion ELD combined with RLX or BP administered for 6 months to postmenopausal women with osteoporosis who were drug-naïve or who had switched medications significantly reduced and maintained TRACP-5b values within the reference range. PMID:27252739

  3. Marginal bone resorption around dental implants placed in grafted sinuses; an up-to-30-month clinical and radiological follow-up

    International Nuclear Information System (INIS)

    Objective: To determine the relative success of two different bone grafting material - putty and powder forms of De-mineralised Bone Matrix (DBM) - used in sinus lift procedure. Methods: The retrospective study was conducted at the Department of Oral and Maxillofacial Surgery, Ankara University, Ankara, Turkey, and comprised data related to the patients referred for bilateral maxillary sinus augmentation between 2007 and 2010. During the period, 48 endoosseous implants were placed concurrently with the sinus augmentation in 12 patients. Marginal bone loss around the implants was measured at the time of loading, 12 and 30 months after the treatment. SPSS 11.5 was used for data analysis. Results: Of the 12 patients, 8 (66.6%) were females and 4 (33.3%) were males. All implants osseointegrated in both the putty and powder groups well without any significant clinical finding. The average volume of marginal bone resorption at implants for the putty side was 0.43+-0.22 mm, 0.8+-0.33 mm and 1.12+-0.49 mm at prosthetic loading, 12-month and 30-month follow-up, respectively. For the powder side, the corresponding numbers were 0.48+-0.32 mm, 0.82+-0.46 mm and 1.24+-0.57 mm. No statistically significant difference in bone loss between the two groups was observed (p >0.05). Conclusion: Both putty and powder forms of de-mineralised Bone Matrix showed satisfactory results and there was no significant difference in marginal bone loss around dental implants and survival rates. (author)

  4. Exceptional case of bone resorption in an osteo-odonto-keratoprosthesis. A scanning electron microscopy and X-ray microanalysis study.

    Science.gov (United States)

    Caiazza, S; Falcinelli, G; Pintucci, S

    1990-01-01

    This article reports the findings of investigations on an osteo-odonto-keratoprosthesis in an eye that was enucleated owing to severe complications 12 years after implantation. Scanning electron microscopy and electron probe X-ray microanalysis showed extensive resorption of the bone that was used as a supporting element in the kind of transcorneal prosthesis developed by Strampelli. The destructive process, in addition to surgical trauma, has been associated with the early and recurrent bacterial infections relating to the presence of Staphylococcus epidermidis. The need to control the occurrence of primary bacterial infections in traumatized tissues during operations as well as further infectious situations, given the enhanced antibiotic-resistence of bacteria, is emphasized. PMID:2297990

  5. Exceptional case of bone resorption in an osteo-odonto-keratoprosthesis. A scanning electron microscopy and X-ray microanalysis study

    Energy Technology Data Exchange (ETDEWEB)

    Caiazza, S.; Falcinelli, G.; Pintucci, S. (Istituto Superiore di Sanita, Rome (Italy))

    1990-01-01

    This article reports the findings of investigations on an osteo-odonto-keratoprosthesis in an eye that was enucleated owing to severe complications 12 years after implantation. Scanning electron microscopy and electron probe X-ray microanalysis showed extensive resorption of the bone that was used as a supporting element in the kind of transcorneal prosthesis developed by Strampelli. The destructive process, in addition to surgical trauma, has been associated with the early and recurrent bacterial infections relating to the presence of Staphylococcus epidermidis. The need to control the occurrence of primary bacterial infections in traumatized tissues during operations as well as further infectious situations, given the enhanced antibiotic-resistence of bacteria, is emphasized.

  6. Systemic effects of fluoxetine on the amount of tooth movement, root resorption, and alveolar bone remodeling during orthodontic force application in rat

    Directory of Open Access Journals (Sweden)

    Mehdi Rafiei

    2015-01-01

    Full Text Available Background: Antidepressant drugs such as fluoxetine are of the most commonly used drugs among the public. These drugs may impact the regulation of bone cell functioning, and thus affect orthodontic tooth movement. The aim of this study was to determine the effect of fluoxetine on tooth movements during orthodontic treatment in rats. Materials and Methods: In this study, 30 male rats were randomly assigned into two groups and injected with fluoxetine 10 mg/kg (experimental group and normal saline (control group for a period of 1-month intraperitoneally 5 times/week. Then, the rats were anesthetized and a nickel-titanium closed-coil spring was placed between the left maxillary first molar and left maxillary central incisors of all samples, and then fluoxetine (experimental group and normal saline (control group were injected for another 3 weeks by the same method. After measuring tooth movements, rats were sacrificed, and histomorphometric analyses were conducted and the obtained data were statistically analyzed using independent t-test and the significance was set at 0.05. Results: Following the fluoxetine injection, the mean amount of tooth movements in the experimental group was reduced compared to the control group, which was not statistically significant (P = 0.14. There was no significant difference between the two groups regarding bone apposition rate (P = 0.83, external root resorption rate (P = 0.1, and mean number of root resorption lacunae (P = 0.16. Conclusion: Within the limitations of this study, systemic use of fluoxetine may cause insignificant reduction of tooth movement rate in rats; however, this subject needs more evaluations.

  7. Dietary xylitol in the prevention of experimental osteoporosis:beneficial effects on bone resorption, structure and biomechanics

    OpenAIRE

    Mattila, P.

    1999-01-01

    Abstract Dietary xylitol supplementation increases bone calcium and phosphorus concentrations in healthy rats, as well as protects against the decrease of bone minerals and bone density during experimental osteoporosis. This suggests that dietary xylitol might have a favorable effect on the prevention of osteoporosis. However, before any conclusions can be drawn about the usefulness of a compound, studies including structural evaluation and biomechanical testing of ...

  8. Transforming growth factor-β synthesized by stromal cells and cancer cells participates in bone resorption induced by oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Ryosuke [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Kayamori, Kou [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Oue, Erika [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Sakamoto, Kei [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Harada, Kiyoshi [Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Yamaguchi, Akira, E-mail: akira.mpa@tmd.ac.jp [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan)

    2015-03-20

    Transforming growth factor beta (TGF-β) plays a significant role in the regulation of the tumor microenvironment. To explore the role of TGF-β in oral cancer-induced bone destruction, we investigated the immunohistochemical localization of TGF-β and phosphorylated Smad2 (p-Smad2) in 12 surgical specimens of oral squamous cell carcinoma (OSCC). These studies revealed TGF-β and p-Smad2 expression in cancer cells in all tested cases. Several fibroblasts located between cancer nests and resorbing bone expressed TGF-β in 10 out of 12 cases and p-Smad2 in 11 out of 12 cases. Some osteoclasts also exhibited p ∼ Smad2 expression. The OSCC cell line, HSC3, and the bone marrow-derived fibroblastic cell line, ST2, synthesized substantial levels of TGF-β. Culture media derived from HSC3 cells could stimulate Tgf-β1 mRNA expression in ST2 cells. Recombinant TGF-β1 could stimulate osteoclast formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264 cells. TGF-β1 could upregulate the expression of p-Smad2 in RAW264 cells, and this action was suppressed by the addition of a neutralizing antibody against TGF-β or by SB431542. Transplantation of HSC3 cells onto the calvarial region of athymic mice caused bone destruction, associated with the expression of TGF-β and p-Smad2 in both cancer cells and stromal cells. The bone destruction was substantially inhibited by the administration of SB431542. The present study demonstrated that TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction. - Highlights: • Cancer cell, fibroblastic cells, and osteoclasts at bone resorbing area by oral cancer exhibited TGF-β and p-Smad2. • TGF-β1 stimulated osteoclastogenesis induced by RAKL in RAW264 cell. • Xenograft model of oral cancer-induced bone resorption was substantially inhibited by SB431542. • TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC

  9. Transforming growth factor-β synthesized by stromal cells and cancer cells participates in bone resorption induced by oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Transforming growth factor beta (TGF-β) plays a significant role in the regulation of the tumor microenvironment. To explore the role of TGF-β in oral cancer-induced bone destruction, we investigated the immunohistochemical localization of TGF-β and phosphorylated Smad2 (p-Smad2) in 12 surgical specimens of oral squamous cell carcinoma (OSCC). These studies revealed TGF-β and p-Smad2 expression in cancer cells in all tested cases. Several fibroblasts located between cancer nests and resorbing bone expressed TGF-β in 10 out of 12 cases and p-Smad2 in 11 out of 12 cases. Some osteoclasts also exhibited p ∼ Smad2 expression. The OSCC cell line, HSC3, and the bone marrow-derived fibroblastic cell line, ST2, synthesized substantial levels of TGF-β. Culture media derived from HSC3 cells could stimulate Tgf-β1 mRNA expression in ST2 cells. Recombinant TGF-β1 could stimulate osteoclast formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264 cells. TGF-β1 could upregulate the expression of p-Smad2 in RAW264 cells, and this action was suppressed by the addition of a neutralizing antibody against TGF-β or by SB431542. Transplantation of HSC3 cells onto the calvarial region of athymic mice caused bone destruction, associated with the expression of TGF-β and p-Smad2 in both cancer cells and stromal cells. The bone destruction was substantially inhibited by the administration of SB431542. The present study demonstrated that TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction. - Highlights: • Cancer cell, fibroblastic cells, and osteoclasts at bone resorbing area by oral cancer exhibited TGF-β and p-Smad2. • TGF-β1 stimulated osteoclastogenesis induced by RAKL in RAW264 cell. • Xenograft model of oral cancer-induced bone resorption was substantially inhibited by SB431542. • TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC

  10. Long-term changes in the hormonal regulation of the bone tissue formation and resorption in participants of Chernobyl accident clean-up with high radiation exposure doses. Communication 2

    International Nuclear Information System (INIS)

    Systemic hormonal shifts, which can influence the processes of formation and resorption of the bone tissue both in the direction of osteopenic syndrome and normal bone mineral density are present in the participants of Chernobyl accident clean-up with a high exposure doses at long terms of the accident. Increased aging of the bone tissue in the participants of the clean-up vs the male population of Ukraine was revealed. The state of bone mineral density does not depend of the absorbed dose, age, and the concentration of the studied hormones

  11. Enhancement of Osteoclastic Bone Resorption and Suppression of Osteoblastic Bone Formation in Response to Reduced Mechanical Stress Do Not Occur in the Absence of Osteopontin

    OpenAIRE

    Ishijima, Muneaki; Rittling, Susan R; Yamashita, Teruhito; Tsuji, Kunikazu; Kurosawa, Hisashi; Nifuji, Akira; Denhardt, David T.; Noda, Masaki

    2001-01-01

    Reduced mechanical stress to bone in bedridden patients and astronauts leads to bone loss and increase in fracture risk which is one of the major medical and health issues in modern aging society and space medicine. However, no molecule involved in the mechanisms underlying this phenomenon has been identified to date. Osteopontin (OPN) is one of the major noncollagenous proteins in bone matrix, but its function in mediating physical-force effects on bone in vivo has not been known. To investi...

  12. A novel small-molecule PPI inhibitor targeting integrin αvβ3-osteopontin interface blocks bone resorption in vitro and prevents bone loss in mice.

    Science.gov (United States)

    Park, Doori; Park, Chan-Won; Choi, YoungJin; Lin, Jingjing; Seo, Dong-Hyun; Kim, Han-Sung; Lee, Soo Young; Kang, In-Cheol

    2016-08-01

    Small molecule-inhibition targeting protein-protein interaction (PPI) is now recognized as an emerging and challenging area in drug design. We developed a novel interactive drug discovery methodology known as Protein Chip technology (ProteoChip) as a cutting-edge PPI assay system applicable for unique PPI-targeting therapeutics integrated with computer-aided drug design (CADD). Here, we describe a novel small molecular PPI inhibitor, IPS-02001, which the blocks integrin αvβ3-osteopontin interface a novel PPI inhibitor identified by the interactive methodology of both ProteoChip- and CADD-based PPI assay. IPS-02001 (6,7-Dichloro-2,3,5,8-tetrahydroxy-1,4-naphthoquinone) was screened from different compound libraries (InterBioScreen, Commercial libraries) using an in silico structure-based molecular docking simulation method and a protein chip-based protein-protein interaction assay system. Additionally, integrin αvβ3, an adhesion receptor expressed in osteoclasts (OCs), was implicated in the regulation of OC function via regulation of the cytoskeletal organization of OCs. IPS-02001 blocked OC maturation from murine bone marrow-derived macrophages, as well as the resorptive function of OCs. Moreover, treatment with IPS-02001 impaired downstream signaling of integrin αvβ3 linked to Pyk2, c-Src, PLCγ2, and Vav3 and disrupted the actin cytoskeleton in mature OCs. Furthermore, IPS-02001 blocked RANKL-induced bone destruction by reducing the number of OCs and protected against ovariectomy-induced bone loss in mice. Thus, IPS-02001 may represent a promising new class of anti-resorptive drugs for treatment of bone diseases associated with increased OC function. PMID:27187277

  13. CCAAT/enhancer binding protein β-deficiency enhances type 1 diabetic bone phenotype by increasing marrow adiposity and bone resorption

    OpenAIRE

    Motyl, Katherine J.; Raetz, Michelle; Tekalur, Srinivasan Arjun; Schwartz, Richard C.; McCabe, Laura R.

    2011-01-01

    Bone loss in type 1 diabetes is accompanied by increased marrow fat, which could directly reduce osteoblast activity or result from altered bone marrow mesenchymal cell lineage selection (adipocyte vs. osteoblast). CCAAT/enhancer binding protein beta (C/EBPβ) is an important regulator of both adipocyte and osteoblast differentiation. C/EBPβ-null mice have delayed bone formation and defective lipid accumulation in brown adipose tissue. To examine the balance of C/EBPβ functions in the diabetic...

  14. Fortification of yogurts with vitamin D and calcium enhances the inhibition of serum parathyroid hormone and bone resorption markers: A double blind randomized controlled trial in women over 60 living in a community dwelling home

    OpenAIRE

    Bonjour, Jean-Philippe; Benoit, V.; Atkin, S; Walrand, S.

    2015-01-01

    Objective To evaluate whether fortification of yogurts with vitamin D and calcium exerts an additional lowering effect on serum parathyroid hormone (PTH) and bone resorption markers (BRM) as compared to iso-caloric and iso-protein dairy products in aged white women at risk of fragility fractures. Design A randomized double-blind controlled trial. Setting A community dwelling home. Participants Forty-eight women over 60 years (mean age 73.4). Intervention Consumption during 84 days of two 125 ...

  15. Effects of a herbal gel containing carvacrol and chalcones on alveolar bone resorption in rats on experimental periodontitis.

    Science.gov (United States)

    Botelho, Marco Antonio; Rao, Vietla Satyanarayana; Montenegro, Danusa; Bandeira, Mary Anne Menezes; Fonseca, Said Gonçalves Cruz; Nogueira, Nadia Accioly Pinto; Ribeiro, Ronaldo Albuquerque; Brito, Gerly Anne Castro

    2008-04-01

    Carvacrol and dimeric chalcones are the respective bioactive components of Lippia sidoides and Myracrodruon urundeuva, popular medicinal plants of Northeastern Brazil with proven antimicrobial and antiinflammatory properties. Periodontal disease is associated with inflammation and microbiological proliferation, thus the study aimed to investigate the effect of a topical gel based on carvacrol and chalcones in the experimental periodontal disease (EPD) in rats. Animals were treated with carvacrol and/or chalcones gel, immediately after EPD induction, three times a day for 11 days. Appropriate controls were included in the study. Animals were weighed daily. They were killed on day 11, the mandibles dissected and alveolar bone loss was measured. The periodontium were examined at histopathology and the neutrophil influx into the gingiva was assayed using myeloperoxidase activity. The bacterial flora were assessed through culture of the gingival tissue. Alveolar bone loss was significantly (p < 0.05) inhibited by combined carvacrol and chalcones gel, compared with the vehicle and non-treated groups. The treatment with the combined gel reduced tissue lesion at histopathology, decreased myeloperoxidase activity in gingival tissue and inhibited the growth of oral microorganisms as well as the weight loss. Carvacrol and chalcones combination gel has a beneficial effect upon EPD in this model. PMID:18338370

  16. [Calcitonin as an alternative treatment for root resorption].

    Science.gov (United States)

    Pierce, A; Berg, J O; Lindskog, S

    1989-01-01

    Inflammatory root resorption is a common finding following trauma and will cause eventual destruction of the tooth root if left untreated. This study examined the effects of intrapulpal application of calcitonin, a hormone known to inhibit osteoclastic bone resorption, on experimental inflammatory root resorption induced in monkeys. Results were histologically evaluated using a morphometric technique and revealed that calcitonin was an effective medicament for the treatment of inflammatory root resorption. It was concluded that this hormone could be a useful therapeutic adjunct in difficult cases of external root resorption. PMID:2576918

  17. Effect of osthol on apoptosis and bone resorption of osteoclasts cultured in vitro%蛇床子素对体外培养破骨细胞骨吸收及细胞凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    明磊国; 王鸣刚; 陈克明; 周建; 韩桂秋; 朱瑞清

    2012-01-01

    This study is to investigate the effect of osthol on osteoclasts' activity, bone resorption as well as apoptosis in vitro, and explore the mechanism of osthol in preventing osteoporosis. Osteoclasts were separated from long-limb bones of new born rabbits, cultured in 24-well plate with glass slices and bone slices, and treated by l×l0-5 mol·L-1 osthol. Osteoclasts were identified by observing live cells with phase contrast microscope, HE staining, TRAP staining and toluidine blue staining of bone resorption pits. The numbers of bone resorption pits were counted as well as the surface area of bone resorption on bone slice. Osteoclasts were stained with acridine orange to detect the cell apoptosis. The ratio of apoptotic osteoclasts was observed under fluorescence microscope. The gene expression of RANKL, OPG, TRAP and p-JNKl/2 protein expression were examined using real time PCR and Western blotting, respectively. Comparing with the control group without osthol, the rates of apoptotic osteoclasts increased obviously and the number and area of bone resorption pits decreased evidently with l×l0-5 mol·L-1 osthol. There is significant difference between control group and experiment group treated by l×l0-5 mol·L-1 osthol. Therefore, the osthol through RANK+RANKL/TRAF6/Mkk/JNK signal pathway inhibits the osteoclasts activity, enhances osteoclasts apoptotic and inhibits the bone resorption.%研究蛇床子素对破骨细胞骨吸收的影响及其分子机制.采用体外分离、培养兔破骨细胞,与盖玻片及骨磨片共同培养,使用1× 10-5 mol·L-1蛇床子素刺激破骨细胞,观察活体细胞并依据HE、TRAP、骨陷窝甲苯胺蓝染色鉴定破骨细胞;进行骨吸收陷窝和面积定量分析,吖啶橙染色统计凋亡细胞;real time PCR及Western blotting法检测相关基因和蛋白.与空白对照组比较,1×10-5 mol·L-1蛇床子素能够明显提高破骨细胞凋亡率并通过抑制RANKL和TRAP等相关基因及JNK1/2磷酸化水

  18. Prevention of bone growth defects, increased bone resorption and marrow adiposity with folinic acid in rats receiving long-term methotrexate.

    Directory of Open Access Journals (Sweden)

    Chia-Ming Fan

    Full Text Available The underlying pathophysiology for bone growth defects in paediatric cancer patients receiving high dose methotrexate chemotherapy remains unclear and currently there are no standardized preventative treatments for patients and survivors. Using a model in young rats, we investigated damaging effects of long-term treatment with methotrexate on growth plate and metaphyseal bone, and the potential protective effects of antidote folinic acid. This study demonstrated that chronic folinic acid supplementation can prevent methotrexate-induced chondrocyte apoptosis and preserve chondrocyte columnar arrangement and number in the growth plate. In the metaphysis, folinic acid supplementation can preserve primary spongiosa heights and secondary spongiosa trabecular volume by preventing osteoblasts from undergoing apoptosis and suppressing methotrexate-induced marrow adiposity and osteoclast formation. Systemically, plasma of folinic acid supplemented rats, in comparison to plasma from rats treated with MTX alone, contained a significantly lower level of IL-1β and suppressed osteoclast formation in vitro in normal bone marrow cells. The importance of IL-1β in supporting plasma-induced osteoclast formation was confirmed as the presence of an anti-IL-1β neutralizing antibody attenuated the ability of the plasma (from MTX-treated rats in inducing osteoclast formation. Findings from this study suggest that folinic acid supplementation during chronic methotrexate treatment can alleviate growth plate and metaphyseal damages and therefore may be potentially useful in paediatric patients who are at risk of skeletal growth suppression due to chronic methotrexate chemotherapy.

  19. Bone Markers

    Science.gov (United States)

    ... bone turnover: C-telopeptide (C-terminal telopeptide of type 1 collagen (CTx)) – a marker for bone resorption. It is ... resorption include: N-telopeptide (N-terminal telopeptide of type 1 collagen (NTx)) – a peptide fragment from the amino terminal ...

  20. Invasive cervical root resorption: Engineering the lost tissue by regeneration

    Directory of Open Access Journals (Sweden)

    Dexton Antony Johns

    2013-01-01

    Full Text Available Invasive cervical resorption (ICR is a localized resorptive process that commences on the surface of the root below the epithelial attachment and the coronal aspect of the supporting alveolar process, namely the zone of the connective tissue attachment′ early diagnosis, elimination of the resorption and restorative management are the keys to a successful outcome. Treatment done was a combined non-surgical root canal therapy, surgical treatment to expose the resorptive defect and the resorptive defect was filled up with reverse sandwich technique and finally the bony defect filled with platelet rich fibrin (PRF, hydroxylapatite and PRF membrane. Significant bone fill was obtained in our case after a 2 year follow-up period. This case report presents a treatment strategy that might improve the healing outcomes for patients with ICR.

  1. Frequency of the external resorptions of root apex

    Directory of Open Access Journals (Sweden)

    Opačić-Galić Vanja

    2004-01-01

    Full Text Available Root resorptions present a significant problem in endodontic therapy of the affected teeth and in dentistry in general. The objective of this study was to analyze, based on epidemiological and statistical research, the frequency of clinical incidence of pathological root resorptions in everyday practice related to localization, type of tooth, age and sex of patients. Radiographie documentation of patients treated from 1997 till 2002 at the Department of Conservative Dentistry and Endodontics, Faculty of Stomatology in Belgrade, was used as baseline for this study. Retroalveolar radiographs of teeth with visible signs of resorptions were singled out from 15654 patients' clinical records used for this study. The external resorptions were shown as radiolucent areas localized on various outer root surfaces, followed by significant or less significant resorption of lamina dura and alveolar bone. Out of all teeth analyzed in this study, 594 (3.79% showed some kind of resorption. The external resorptions were found to be more present in the upper jaw (55.10% and molars (50.30% than in the lower jaw (44.90% and single root teeth (49.70%, but in both cases without significant statistical differences. The most frequent localization of resorptions was root apex (82.44%. In regard to age, the most frequent resorptions were recorded in patients aged between 21 and 30 years (28.40%, and the lowest incidence was found in the youngest population (5.51%. The results also showed that resorptions were more frequent among the female population (59.04% than among the male population (40.96%. Based on these results, we may conclude that the external root resorptions are not a frequent clinical phenomenon. Proper and early diagnostics of such tissue pathology is one of the basic prerequisites for successful endodontic therapy of the affected root.

  2. The Microenvironment Matters: Estrogen Deficiency Fuels Cancer Bone Metastases

    OpenAIRE

    Wright, Laura E; Guise, Theresa A.

    2014-01-01

    Factors released during osteoclastic bone resorption enhance disseminated breast cancer cell progression by stimulating invasiveness, growth and a bone-resorptive phenotype in cancer cells. Post-menopausal bone loss may accelerate progression of breast cancer growth in bone, explaining the anti-cancer benefit of the bone-specific anti-resorptive agent zoledronic acid in the post-menopausal setting.

  3. Diets based on virgin olive oil or fish oil but not on sunflower oil prevent age-related alveolar bone resorption by mitochondrial-related mechanisms.

    Directory of Open Access Journals (Sweden)

    Pedro Bullon

    Full Text Available BACKGROUND/OBJECTIVES: Aging enhances frequency of chronic diseases like cardiovascular diseases or periodontitis. Here we reproduced an age-dependent model of the periodontium, a fully physiological approach to periodontal conditions, to evaluate the impact of dietary fat type on gingival tissue of young (6 months old and old (24 months old rats. METHODS/FINDINGS: Animals were fed life-long on diets based on monounsaturated fatty acids (MUFA as virgin olive oil, n-6 polyunsaturated fatty acids (n-6PUFA, as sunflower oil, or n-3PUFA, as fish oil. Age-related alveolar bone loss was higher in n-6PUFA fed rats, probably as a consequence of the ablation of the cell capacity to adapt to aging. Gene expression analysis suggests that MUFA or n-3PUFA allowed mitochondria to maintain an adequate turnover through induction of biogenesis, autophagy and the antioxidant systems, and avoiding mitochondrial electron transport system alterations. CONCLUSIONS: The main finding is that the enhanced alveolar bone loss associated to age may be targeted by an appropriate dietary treatment. The mechanisms involved in this phenomenon are related with an ablation of the cell capacity to adapt to aging. Thus, MUFA or n-3PUFA might allow mitochondrial maintaining turnover through biogenesis or autophagy. They might also be able to induce the corresponding antioxidant systems to counteract age-related oxidative stress, and do not inhibit mitochondrial electron transport chain. From the nutritional and clinical point of view, it is noteworthy that the potential treatments to attenuate alveolar bone loss (a feature of periodontal disease associated to age could be similar to some of the proposed for the prevention and treatment of cardiovascular diseases, a group of pathologies recently associated with age-related periodontitis.

  4. Selective cyclooxygenase-2 inhibition prevents bone resorption Inibidor seletivo de cicloxigenase-2 prevenindo reabsorção óssea

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Nassar

    2005-03-01

    Full Text Available The aim of the present work was to evaluate the effect of a selective cyclooxygenase-2 (COX-2 inhibitor (meloxicam on the alveolar bone loss progression in experimentally induced periodontitis. Forty (40 Wistar rats were separated into 8 experimental groups (n = 5. Cotton ligatures were placed at the gingival margin level of the lower right first molars of some rats. Four groups were treated for 5 or 15 days with an oral dose of 15 mg/kg of body weight/day of the selective COX-2 inhibitor. The other groups were used as positive control (sham or negative control in each experimental period. Standardized digital radiographs were taken after sacrifice at 5 and 15 days to measure the amount of bone loss at the mesial root surface of the first molar tooth in each rat. The treatment with meloxicam did not induce weight alteration or other visible systemic manifestations. One way analysis of variance (ANOVA indicated that groups treated with meloxicam, after 5 days, had significantly less alveolar bone loss (p O objetivo deste trabalho foi avaliar o efeito de um inibidor seletivo da cicloxigenase-2 (COX-2 (meloxicam na progressão da perda óssea alveolar durante o desenvolvimento da doença periodontal experimental induzida. Quarenta (40 ratos Wistar foram separados em 8 grupos experimentais (n = 5. Ligaduras de fio de algodão foram colocadas na margem gengival do primeiro molar inferior direito de alguns ratos. Quatro grupos foram tratados por 5 ou 15 dias com uma dose oral de 15 mg/kg de peso corporal/dia do inibidor seletivo de COX-2. Os outros grupos foram usados como controle positivo (sham e controle negativo dentro de cada período experimental. Radiografias digitais padronizadas foram realizadas para medir a perda óssea na região mesial do primeiro molar inferior de cada rato. O efeito do tratamento com meloxicam não induziu alteração de peso ou outras manifestações sistêmicas visíveis. A Análise de Variância (ANOVA indicou que os

  5. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I;

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling of...... aged bones....

  6. Ion transporters involved in acidification of the resorption lacuna in osteoclasts

    DEFF Research Database (Denmark)

    Henriksen, K.; Sorensen, M.G.; Jensen, V.K.; Nosjean, O.; Karsdal, M.A.; Dziegiel, Morten Hanefeld

    2008-01-01

    Osteoclasts possess a large amount of ion transporters, which participate in bone resorption; of these, the vacuolar-adenosine trisphosphatase (V-ATPase) and the chloride-proton antiporter ClC-7 acidify the resorption lacuna. However, whether other ion transporters participate in this process is ......, including carbonic anhydrase II, the NHEs, and potassium-chloride cotransporters, are all involved in resorption but do not seem to directly be involved in acidification of the lysosomes Udgivelsesdato: 2008/9......Osteoclasts possess a large amount of ion transporters, which participate in bone resorption; of these, the vacuolar-adenosine trisphosphatase (V-ATPase) and the chloride-proton antiporter ClC-7 acidify the resorption lacuna. However, whether other ion transporters participate in this process is...

  7. Root resorption following periodontally accelerated osteogenic orthodontics

    Directory of Open Access Journals (Sweden)

    Donald J Ferguson

    2016-01-01

    Full Text Available Background: Literature evidence suggests that root resorption, an adverse side effect of orthodontic therapy, may be decreased under conditions of alveolar osteopenia, a condition characterized by diminished bone density and created secondary to alveolar corticotomy (Cort surgery. Purpose: To compare root resorption of the maxillary central incisors following nonextraction orthodontic therapy with and without Cort surgery. Materials and Methods: The sample comprised two groups, with and without Cort and was matched by age and gender: Cort-facilitated nonextraction orthodontics with 27 subjects, 53 central incisors of mean age 24.8 ± 10.2 years, and conventional (Conv nonextraction orthodontics with 27 subjects, 54 incisors with mean age of 19.6 ± 8.8 years. All periapical radiographs were taken with the paralleling technique; total tooth lengths of the right and left central incisors were measured by projecting and enlarging the periapical radiographs exactly 8 times. Results: t-tests revealed a significant decrease in treatment time in the Cort group (6.3 ± 8.0 vs. 17.4 ± 20.2 months, P = 0.000. Pretreatment root lengths were not significantly different (P = 0.11, but Conv had significantly shorter roots at posttreatment when compared with Cort (P = 0.03. Significant root resorption (P < 0.01 occurred in both Cort (0.3 mm and Conv (0.7 mm, but the increment of change was significantly greater in Conv (P < 0.03. The variable SNA increased significantly in the Cort (P = 0.001 group and decreased significantly in the Conv group (P < 0.001. Conclusions: Based on the conditions of this study, it may be concluded that Cort-facilitated nonextraction orthodontic therapy results in less root resorption and enhanced alveolar support within a significantly reduced clinical service delivery time frame. Rapid orthodontic treatment and reduced apical root resorption are probably due to the transient osteopenia induced by the Cort surgery and inspired by

  8. Preeruptive intracoronal resorption observed in 13 patients

    DEFF Research Database (Denmark)

    Kjær, Inger; Steiniche, Kirsten; Kortegaard, Ulla; Pallisgaard, Carsten; Bille, Marie-Louise Bastholm; Seirup, Torben; Skjødt, Ole; Larsen, Helle Juul

    2012-01-01

    The literature on preeruptive intracoronal resorption is sparse, comprising mainly reports of single patients. This study includes 13 patients with preeruptive intracoronal resorption, forwarded for consultation regarding diagnostics and etiology. The purposes were to determine which teeth are af...

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

    OpenAIRE

    2015-01-01

    Bone tissue is continuously remodeled through the concerted actions of bone cells, which include bone resorption by osteoclasts and bone formation by osteoblasts, whereas osteocytes act as mechanosensors and orchestrators of the bone remodeling process. This process is under the control of local (e.g., growth factors and cytokines) and systemic (e.g., calcitonin and estrogens) factors that all together contribute for bone homeostasis. An imbalance between bone resorption and formation can res...

  10. 骨转换率对大鼠正畸牙齿移动量及牙根吸收的影响%The Rate of Teeth Movement and the Roots Resorption is Influenced by Bone Turnover in Rat Orthodontic Treatment Model

    Institute of Scientific and Technical Information of China (English)

    郑红; 殷丽华; 李秀华; 李静

    2012-01-01

    Objective: To study in a rat model, whether a state of high or low bone turnover had an effect on the incidence of root resorption induced by orthodontic treatment. Methods: Design performing orthodontic teeth movement in 30, 180 - 220 gram male rats with: high(n=10), low bone turnover (n= 10) , and normal (n= 10)groups. The high and low bone turnover groups were obtained by induction of hyperthyroidism and hypothyroidism, respectively. The upper left first molar was moved for 21 days. Bone markers were administered 15 and 2 days before killing. Results: The amount of teeth movement increased with longest tooth roots in high bone turnover group. Conclusion: Bone turnover affected the amount of teeth movement. High bone turnover increased the amount of teeth movement and decreased the the amount of teeth roots resorption.%目的:研究在不同骨转换率的条件下,大鼠牙齿移动过程中牙齿移动量及对牙根吸收的影响.方法:健康成年雄性威斯塔大鼠30只,体重180~220 g.随机分成3组:高骨转换率组,低骨转换率组,正常对照组.前2组通过20 d甲状腺片和丙硫氧嘧啶灌胃得到高骨转换率和低骨转换率组动物模型.左侧上颌第一磨牙加力21d.在处死动物前15d及2d添加骨标志物.拍X线片测量牙齿移动距离及牙根长度.结果:高骨转换率组的大鼠正畸牙齿移动的距离长,牙根最长.结论:骨转换率对正畸牙齿移动量及牙根吸收有影响.骨转换率高则大鼠牙齿移动量大,牙根吸收少,反之大鼠牙齿移动量小,牙根吸收多.

  11. Contaminant resorption during soil washing

    International Nuclear Information System (INIS)

    To evaluate the applicability of soil washing to a specific site requires some basic research in how contaminants are bound. Much can be learned from sequential extraction methodology based on micronutrient bioavailability studies wherein the soil matrix is chemically dissected to selectively remove particular fixation mechanisms independently. This procedure uses a series of progressively more aggressive solvents to dissolve the principle phases that make up a soil, however, the published studies do not appear to consider the potential for a contaminant released from one type of site to resorb on another site during an extraction. This physical model assumes no ion exchange or adsorption at sites either previously occupied by other ions, or exposed by the dissolution. Therefore, to make engineering use of the sequential extraction data, the release of contamination must be evaluated relative to the effects of resorption. Time release studies were conducted to determine the optimum duration for extraction to maximize complete destruction of the target matrix fraction while minimizing contaminant resorption. Tests with and without a potassium brine present to inhibit cesium resorption indicated extraction efficiency could be enhanced by as much as a factor of ten using the brine

  12. Orthopantomographic study of the alveolar bone level on periodontal disease

    International Nuclear Information System (INIS)

    The author had measured the alveolar bone level of periodontal disease on 50 cases of orthopantomogram to detect the degree of alveolar bone resorption of both sexes of Korean. The results were obtained as follows; 1. Alveolar bone resorption of mesial and distal portion was similar in same patient. 2. The order of alveolar bone resorption was mandibular anterior region, posterior region, canine and premolar region of both jaws. 3. The degree of alveolar bone destruction was severe in shorter root length than longer one. 4. The degree of alveolar bone resorption was severe in fourth decades.

  13. O papel do Fator de Necrose Tumoral Alfa (TNF-alfa no processo de erosão óssea presente no colesteatoma adquirido da orelha média The role of Tumor Necrosis Factor -Alpha (TNF- alpha in bone resorption present in middle ear cholesteatoma

    Directory of Open Access Journals (Sweden)

    Rodrigo Faller Vitale

    2007-02-01

    Full Text Available O colesteatoma adquirido da orelha média causa erosão óssea, com altas taxas de morbidade e mortalidade. O TNF-alfa (TNF-alfa lambda uma das principais citocinas envolvidas neste processo. OBJETIVO: Avaliar o papel do TNF-alfa na reabsorsão óssea e a ação dele no colesteatoma. MATERIAL E MÉTODOS: Foi realizado um levantamento e uma revisão crítica da literatura. RESULTADOS: Todos os autores estudados concordam com a importância do TNF-alfa no processo de reabsorção óssea presente no colesteatoma e com o grau de destruição observado. Diferentes trabalhos demonstraram que o TNF-alfa é capaz de provocar erosão óssea, através de diferentes vias de ação. Ele pode estimular a diferenciação e a maturação dos osteoclastos ou, ainda, agir na matriz óssea expondo-a à ação dos osteoclastos. Existe a possibilidade de inibir a ação do TNF-alfa, diminuindo seus efeitos e prevenindo a perda óssea em doenças como a artrite reumatóide. Não existe, entretanto, trabalhos específicos em colesteatoma. Não existe consenso sobre a sua localização. Estas diferenças, provavelmente, ocorrem devido à distribuição dos receptores. CONCLUSÃO: O TNF-alfa, presente no colesteatoma promove a reabsorsão óssea, juntamente com outras citocinas (RANKL e IL-1, estando relacionado com a presença de complicações.Cholesteatoma may cause bone erosion, with high morbidity and mortality rates. Tumor Necrosis Factor -Alpha (TNF-a is one of the main cytokines involved in this process. Our goal was to evaluate the role of TNF-a in Bone Resorption and its effect on cholesteatoma. MATERIAL AND METHODS: analysis and critical literature review. RESULTS: Different studies have demonstrated that TNF-a is capable of causing bone erosion. It may stimulate the differentiation and maturation of osteoclasts or it may act on the bone matrix, exposing it to the action of the osteoclasts. It is possible to inhibit TNF-a, reducing its effects and prevent

  14. The four mechanisms of dental resorption initiation

    Directory of Open Access Journals (Sweden)

    Alberto Consolaro

    2013-06-01

    Full Text Available The aim of this study is to present a classification with a clinical application for root resorption, so that diagnosis will be more objective and immediately linked to the source of the problem, leading the clinician to automatically develop the likely treatment plan with a precise prognosis. With this purpose, we suggest putting together all diagnosed dental resorptions into one of these four criteria: 1 Root resorption caused by cementoblast cell death, with preservation of the Malassez epithelial rests. 2 Root resorption by cementoblasts and Malassez epithelial rests death. 3 Dental resorption by odontoblasts cell death with preservation of pulp vitality. 4 Dental resorption by direct exposure of dentin to gingival connective tissue at the cementoenamel junction gaps.

  15. The four mechanisms of dental resorption initiation

    OpenAIRE

    Alberto Consolaro

    2013-01-01

    The aim of this study is to present a classification with a clinical application for root resorption, so that diagnosis will be more objective and immediately linked to the source of the problem, leading the clinician to automatically develop the likely treatment plan with a precise prognosis. With this purpose, we suggest putting together all diagnosed dental resorptions into one of these four criteria: 1) Root resorption caused by cementoblast cell death, with preservation of the Malassez e...

  16. Alendronate increases skeletal mass of growing rats during unloading by inhibiting resorption of calcified cartilage

    Science.gov (United States)

    Bikle, D. D.; Morey-Holton, E. R.; Doty, S. B.; Currier, P. A.; Tanner, S. J.; Halloran, B. P.

    1994-01-01

    Loss of bone mass during periods of skeletal unloading remains an important clinical problem. To determine the extent to which resorption contributes to the relative loss of bone during skeletal unloading of the growing rat and to explore potential means of preventing such bone loss, 0.1 mg P/kg alendronate was administered to rats before unloading of the hindquarters. Skeletal unloading markedly reduced the normal increase in tibial mass and calcium content during the 9 day period of observation, primarily by decreasing bone formation, although bone resorption was also modestly stimulated. Alendronate not only prevented the relative loss of skeletal mass during unloading but led to a dramatic increase in calcified tissue in the proximal tibia compared with the vehicle-treated unloaded or normally loaded controls. Bone formation, however, assessed both by tetracycline labeling and by [3H]proline and 45Ca incorporation, was suppressed by alendronate treatment and further decreased by skeletal unloading. Total osteoclast number increased in alendronate-treated animals, but values were similar to those in controls when corrected for the increased bone area. However, the osteoclasts had poorly developed brush borders and appeared not to engage the bone surface when examined at the ultrastructural level. We conclude that alendronate prevents the relative loss of mineralized tissue in growing rats subjected to skeletal unloading, but it does so primarily by inhibiting the resorption of the primary and secondary spongiosa, leading to altered bone modeling in the metaphysis.

  17. Deregulation of Bone Forming Cells in Bone Diseases and Anabolic Effects of Strontium-Containing Agents and Biomaterials

    OpenAIRE

    Shuang Tan; Binbin Zhang; Xiaomei Zhu; Ping Ao; Huajie Guo; Weihong Yi; Guang-Qian Zhou

    2014-01-01

    Age-related bone loss and osteoporosis are associated with bone remodeling changes that are featured with decreased trabecular and periosteal bone formation relative to bone resorption. Current anticatabolic therapies focusing on the inhibition of bone resorption may not be sufficient in the prevention or reversal of age-related bone deterioration and there is a big need in promoting osteoblastogenesis and bone formation. Enhanced understanding of the network formed by key signaling pathways ...

  18. Working pairs for resorption refrigerator

    International Nuclear Information System (INIS)

    The performances of three chemisorption working pairs operating under the resorption cycle were studied gravimetrically by comparing the desorbed and adsorbed mass of refrigerant in different operation conditions. All pairs used NH3 as refrigerant and MnCl2 in the main reactor, but each one used a different salt for the cooling effect production in the secondary reactor. These salts were NH4Cl or NaBr or BaCl2. The experimental results indicated that the degree of conversion in reaction between the NH3 and BaCl2 was inferior to 25% during cooling production at 0 oC or below, whereas the reactions with the other salts had conversions of at least 80%. When the systems operated with heat source temperature for the main reactor at 155 oC, heat sink temperature for both reactors at 30 oC, and cooling effect production temperature at 0 oC the coefficient of performance (COP) of the system using NH4Cl and the system using NaBr were similar and around 0.30; however, the former system had a specific cooling power (SCP) 5% higher than that of the latter system. Because the reaction in the system with NH4Cl was practically halted in a period much shorter than that used in the experiments, it is possible to expect that if the period of the cooling period was shortened, the difference between the SCP of those systems would be much higher. - Highlights: → The comparison of three different working pairs operating under resorption cycle was conducted. → The three working pairs were NH4Cl/MnCl2, NaBr/MnCl2, BaCl2/MnCl2, respectively. → The mass of refrigerant reacted in different situations were measured and compared. → Among the LTS studied, NH4Cl is the most suitable to be used in a resorption machine at 0 or below 0 oC.

  19. Osteoclasts secrete non-bone derived signals that induce bone formation

    DEFF Research Database (Denmark)

    Karsdal, Morten A; Neutzsky-Wulff, Anita V; Dziegiel, Morten Hanefeld;

    2008-01-01

    Bone turnover is a highly regulated process, where bone resorption in the normal healthy individual always is followed by bone formation in a manner referred to as coupling. Patients with osteopetrosis caused by defective acidification of the resorption lacuna have severely decreased resorption, in...... face of normal or even increased bone formation. This suggests that osteoclasts, not their resorptive activity, are important for sustaining bone formation. To investigate whether osteoclasts mediate control of bone formation by production of bone anabolic signals, we collected conditioned media (CM......) from human osteoclasts cultured on either bone or plastic, and tested their effects on bone nodule formation by osteoblasts. Both types of CM were shown to dose-dependently induce bone nodule formation, whereas non-conditioned osteoclast culture medium had no effects. These data show that osteoclasts...

  20. [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

  1. The Pathogenesis of the Bone Disease of Multiple Myeloma

    OpenAIRE

    Edwards, Claire M; Zhuang, Junling; Mundy, Gregory R.

    2008-01-01

    Multiple myeloma is a fatal hematologic malignancy associated with clonal expansion of malignant plasma cells within the bone marrow and the development of a destructive osteolytic bone disease. The principal cellular mechanisms involved in the development of myeloma bone disease are an increase in osteoclastic bone resorption, and a reduction in bone formation. Myeloma cells are found in close association with sites of active bone resorption, and the interactions between myeloma cells, and o...

  2. Estrogen directly attenuates human osteoclastogenesis, but has no effect on resorption by mature osteoclasts

    DEFF Research Database (Denmark)

    Sørensen, M G; Henriksen, K; Dziegiel, Morten Hanefeld;

    2006-01-01

    Estrogen deficiency arising with the menopause promotes marked acceleration of bone resorption, which can be restored by hormone replacement therapy. The inhibitory effects of estrogen seem to involve indirect cytokine- mediated effects via supporting bone marrow cells, but direct estrogen......-receptor mediated effects on the bone-resorbing osteoclasts have also been proposed. Little information is available on whether estrogens modulate human osteoclastogenesis or merely inhibit the functional activity of osteoclasts. To clarify whether estrogens directly modulate osteoclastic activities human CD14...... not affect bone resorption or TRACP activity. We investigated expression of the estrogen receptors, using immunocytochemistry and Western blotting. We found that ER-alpha is expressed in osteoclast precursors, whereas ER- beta is expressed at all stages, indicating that the inhibitory effect of...

  3. Prevention and management of external inflammatory resorption following trauma to teeth.

    Science.gov (United States)

    Abbott, P V

    2016-03-01

    External inflammatory resorption is one of the potential consequences of trauma to the teeth. It occurs when there has been loss of cementum due to damage to the external surface of the tooth root during trauma, plus the root canal system has become infected with bacteria. It is characterized by the radiographic appearance of loss of tooth substance with a radiolucency in the adjacent periodontal ligament and bone. The loss of cementum allows the intracanal bacteria and/or their endotoxins to reach the periodontal ligament more readily and this can lead to the development of the inflammatory resorptive process. External inflammatory resorption can ultimately lead to loss of the tooth if it is not managed in a timely manner. There are some injuries that are very likely to develop this type of resorption and a preventive approach can be adopted by commencing root canal treatment immediately as part of the emergency management of such cases. In cases where the resorptive process is already established, root canal treatment can arrest the resorption and encourage hard tissue repair. The use of a corticosteroid-antibiotic intracanal medicament has been shown to be particularly useful in the prevention and management of external inflammatory resorption. Calcium hydroxide should not be used as an immediate medicament because of its inherent toxicity and irritant properties but it is valuable as a subsequent medicament to encourage hard tissue repair where required. This review outlines the external inflammatory resorptive process and the management strategies that can be employed to prevent it from occurring, and to treat it if already present. PMID:26923450

  4. Odanacatib in postmenopausal women with low bone mineral density: a review of current clinical evidence

    OpenAIRE

    Zerbini, Cristiano A. F.; McClung, Michael R.

    2013-01-01

    Human bones are in a continuous process of remodeling that ensures renovation and maintenance of the skeletal mass. Bone remodeling has two phases that are normally coupled and balanced: bone resorption mediated by osteoclasts and bone formation mediated by osteoblasts. An increase in bone resorption over bone formation results in a progressive loss of bone mass and impairment of bone microarchitecture leading to osteoporosis and its associated fractures. Recent advances in the understanding ...

  5. Hypercalcemia and altered biochemical bone markers in post-bone marrow transplantation osteopetrosis: a case report and literature review.

    Science.gov (United States)

    Kulpiya, Alisa; Mahachoklertwattana, Pat; Pakakasama, Samart; Hongeng, Suradej; Poomthavorn, Preamrudee

    2012-08-01

    Autosomal recessive osteopetrosis is a rare disorder of bone resorption defect that results in generalized sclerotic bones and bone marrow failure. Allogeneic BMT is the only treatment for cure. One of the complications following a successful BMT is hypercalcemia that is a unique complication in this group of patients. We report a three-yr-old boy with osteopetrosis who developed hypercalcemia following the successful BMT. His maximal calcium level was 13.3 mg/dL. Markedly increased both bone formation and resorption markers were demonstrated along with hypercalcemia. These findings indicated an active donor-derived osteoclastic function and thus bone resorption following the successful donor engraftment in the patient. Treatment with hyperhydration, furosemide and bone resorption inhibitors, calcitonin, and bisphosphonate led to normalization of the serum calcium level. Bone resorption but not bone formation marker was persistently elevated despite having normocalcemia during a 16.5-month follow-up period. PMID:21323826

  6. [Decoronation: treatment protocol for ankylotic root resorption as a consequence of dental trauma].

    Science.gov (United States)

    Lin, S; Fuss, Z; Wigler, R; Karawani, M; Ashkenazi, M

    2013-10-01

    Severe dental traumatic injuries, such as the complete displacement of a tooth from its socket (Avulsion) or the displacement of a tooth within its socket (Intrusive Luxation), may result in extensive injury to the root surface. As a result, the root surface injury heals without cementum and there is fusion between the alveolar bone and the exposed dentin or anorganic exposed cementum, without any attachment apparatus between them. This phenomenon is known as "dento-alveolar ankylosis" and is accompanied by ankylotic resorption of the root. In a process that results subsequent to the ankylosis, the root surface resorbs, and this is part of the remodeling of the alveolar bone (ankylotic resorption). When the traumatic injury occurs at a young age, lateral and apical growth of the alveolar bone continues without continued physiological eruption of the tooth. As a result, the position of the ankylotic tooth does not change, and with time thetooth appears infra-occluded resulting in severe esthetic and functional consequences. Extraction of the ankylotic tooth is difficult and sometimes even impossible due to the rigid fusion between the bone and the tooth. In addition, attempted extraction of the ankylotic tooth may lead to fracture of the buccal plate and resorption of the alveolar bone. Retention of the ankylotic tooth may lead to damage in bone deposition in the verticaldimension, leading to difficulties in future prosthodonticrehabilitation, research-based information has been incorporated PMID:24660573

  7. [Multiple tooth resorption in an Italian greyhound].

    Science.gov (United States)

    Roux, P; Stich, H; Schawalder, P

    2011-06-01

    An Italian greyhound was presented three times during a two-year period for dental prophylaxis due to periodontal disease. Clinical examination revealed lesions on several teeth. Radiographs revealed extensive resorptive root lesions. On histological examination, the presence of odontoclasts and signs of boney remodeling of the roots confirmed the resorptive nature of the lesions. Given the extent of the lesions, and poor prognosis with conservative treatment alone, teeth affected by the most severe resorption were extracted at each visit using a flap technique combined with alveolar vestibular osteotomy. Dental resorptive lesions are rarely detected in the dog but may be more frequent than previously thought. The routine use of dental radiographs can be used to reveal these lesions in the dog. PMID:21638265

  8. Multiple tooth resorption in an Italian Greyhound

    International Nuclear Information System (INIS)

    An Italian greyhound was presented three times during a two-year period for dental prophylaxis due to periodontal disease. Clinical examination revealed lesions on several teeth. Radiographs revealed extensive resorptive root lesions. On histological examination, the presence of odontoclasts and signs of boney remodeling of the roots confirmed the resorptive nature of the lesions. Given the extent of the lesions, and poor prognosis with conservative treatment alone, teeth affected by the most severe resorption were extracted at each visit using a flap technique combined with alveolar vestibular osteotomy. Dental resorptive lesions are rarely detected in the dog but may be more frequent than previously thought. The routine use of dental radiographs can be used to reveal these lesions in the dog

  9. Immunology of root resorption: A literature review

    Directory of Open Access Journals (Sweden)

    Silva Luciano

    2008-01-01

    Full Text Available Root resorption seems to be related to a complex combination of mechanical factors and biological activity, which comprehends the role of immunologic structures including specialized cells. The aim of this research was to explain the development of the process - from mineralization to the destruction of hard tissues - and the possible relationship between root resorption and immunology, along with discussing current concepts described in the literature.

  10. Study of phase composition on resorption glass-ceramic соatings for titanium

    OpenAIRE

    Шадріна, Галина Миколаївна; Саввова, Оксана Вікторівна; Шемет, Дарина Юріївна

    2014-01-01

     The problem of long-term knitting of bioactive glass-ceramic calcium silicate-phosphate coatings for titanium with a bone that constitutes about 6 months today, using foreign implants of this kind is considered in the paper. The solution to this problem by providing an appropriate resorption level of glass-ceramic coatings due to reproducing a certain ratio of phase-forming components is proposed.The purpose of this work was to study the effect of phase composition on resorption of glass-cer...

  11. Eating disorders and bone.

    Science.gov (United States)

    Tomlinson, Dale; Morgan, Sarah L

    2013-01-01

    Low bone mineral density (BMD) is a frequent and often-overlooked consequence of eating disorders, in particular anorexia nervosa and eating disorders associated with the female athlete triad. The causes of low BMD are multifactorial and include low peak bone mass accrual, accelerated bone resorption, and changes in bone microarchitecture. Early diagnosis and interventions focused on nutritional rehabilitation and weight gain reduce the risk of further BMD deficits and fractures. PMID:24094471

  12. Cellular and Molecular Mechanisms of Bone Remodeling*

    OpenAIRE

    Raggatt, Liza J; Partridge, Nicola C

    2010-01-01

    Physiological bone remodeling is a highly coordinated process responsible for bone resorption and formation and is necessary to repair damaged bone and to maintain mineral homeostasis. In addition to the traditional bone cells (osteoclasts, osteoblasts, and osteocytes) that are necessary for bone remodeling, several immune cells have also been implicated in bone disease. This minireview discusses physiological bone remodeling, outlining the traditional bone biology dogma in light of emerging ...

  13. Apical root resorption in orthodontically treated adults.

    Science.gov (United States)

    Baumrind, S; Korn, E L; Boyd, R L

    1996-09-01

    This study analyzed the relationship in orthodontically treated adults between upper central incisor displacement measured on lateral cephalograms and apical root resorption measured on anterior periapical x-ray films. A multiple linear regression examined incisor displacements in four directions (retraction, advancement, intrusion, and extrusion) as independent variables, attempting to account for observed differences in the dependent variable, resorption. Mean apical resorption was 1.36 mm (sd +/- 1.46, n = 73). Mean horizontal displacement of the apex was -0.83 mm (sd +/- 1.74, n = 67); mean vertical displacement was 0.19 mm (sd +/- 1.48, n = 67). The regression coefficients for the intercept and for retraction were highly significant; those for extrusion, intrusion, and advancement were not. At the 95% confidence level, an average of 0.99 mm (se = +/- 0.34) of resorption was implied in the absence of root displacement and an average of 0.49 mm (se = +/- 0.14) of resorption was implied per millimeter of retraction. R2 for all four directional displacement variables (DDVs) taken together was only 0.20, which implied that only a relatively small portion of the observed apical resorption could be accounted for by tooth displacement alone. In a secondary set of univariate analyses, the associations between apical resorption and each of 14 additional treatment-related variables were examined. Only Gender, Elapsed Time, and Total Apical Displacement displayed statistically significant associations with apical resorption. Additional multiple regressions were then performed in which the data for each of these three statistically significant variables were considered separately, with the data for the four directional displacement variables. The addition of information on Elapsed Time or Total Apical Displacement did not explain a significant additional portion of the variability in apical resorption. On the other hand, the addition of information on Gender to the

  14. 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)

  15. Effects of smoking on resorption of the residual alveolar ridges in complete denture wearers

    Directory of Open Access Journals (Sweden)

    Marković Dubravka

    2003-01-01

    Full Text Available Introduction Based on literature data it is obvious that there is a connection between smoking and periodontal diseases. Alveolar bone loss increases with smoking. Tobacco smoking affects the proportion of subgingival bacterial flora by influencing oxidoreduction potential of dental plaque and thus making conditions for development of anaerobic bacteria. According to some researchers, smoking affects the mineral component of bone tissue. Orthopantomograms show higher level of alveolar bone loss in smokers than in nonsmokers with the same level of oral hygiene. The aim of this study was to establish if smoking affects alveolar bone loss in complete denture wearers. Material and methods Our clinical investigation included 60 patients of both sexes (30 smokers and 30 nonsmokers all complete dentures wearers. All patients met study criteria: jaw relation and smokers who smoke over 20 cigarettes per day. All subjects were interviewed, and after that orthopantomograms were made. They were used to calculate the degree of alveolar bone loss. Results The examined subjects were approximately of the same age. Mean age of smokers was 59.9 and nonsmokers 61.8. It was established that differences regarding resorption in men were not significant. The degree of resorption in women smokers and women nonsmokers was different, but differences were not significant. Discussion It has been proven that the number of cigarettes smoked per day is very important. It is considered that the risk of oral epithelial dysplasia increases when smoking more than 20 cigarettes per day. Considering our results regarding resorption of edentulous alveolar ridge in smokers and nonsmokers, we concluded that there were no significant differences. There are opinions in literature that smoking is not an etiological factor in resorption, but there are some opinions that smoking is connected with the degree of resorption in periodontium. The analyses of resorptive changes in edentulous

  16. Cortical thinning of clavicle bone in renal stone male patients

    International Nuclear Information System (INIS)

    Radiogrametry of the clavicle is the oldest direct method of bone mass measurement. It has offered a better understanding of the in-vivo changes of cortical bone mass during life which accounts for 80% of the skeleton. This study is aimed to find out the effect of bone resorption (bone thinning) on the formation of renal calculi, particularly clavicle bone resorption using radiogrametry method

  17. Extrinsic Mechanisms Involved in Age-Related Defective Bone Formation

    DEFF Research Database (Denmark)

    Trinquier, Anne Marie-Pierre Emilie; Kassem, Moustapha

    2011-01-01

    Context: Age-related bone loss is associated with progressive changes in bone remodeling characterized by decreased bone formation relative to bone resorption. Both trabecular and periosteal bone formation decline with age in both sexes, which contributes to bone fragility and increased risk of...

  18. Anti-Resorptive Activity of Anti-Hypertensive Agent ACEi in Older Men

    Science.gov (United States)

    Rianon, Nahid; Edwards, BeJier; Nhonthachit, Phetsamong; Messick, Amanda; Gagel, Robert; Smith, Scott M.

    2016-01-01

    Hypertension (HTN) is associated with bone loss due to activation of the renin- angiotensin system (RAS) which in turn affects bone turnover. Animal studies have shown decreased bone resorption (up to 19%) and increased bone mass (up to 2%) following treatment with RAStargeted antihypertensive medications (e.g., angiotensin converting enzyme inhibitors, ACEi). Cross-sectional human studies have documented greater femoral neck BMD in older hypertensive men and women treated with ACEi compared to those not-treated with ACEi (nor other RAS-targeted medications). These findings raise the potential for ACEi use in preventing, or at a minimum slowing bone loss due to age or even microgravity. Based on this, we conducted a cohort study to investigate if ACEi treatment would decrease bone resorption in humans. We investigated changes in serum CTX and P1NP in 10 hypertensive men (45 years or older) treated with (N=5) without (N=5) exposure to ACEi for 3-months. Lisinopril was the ACEi used, and dose was adjusted as deemed appropriate by the attending physicians. Participants did not have any known skeletal health problem and were not exposed to any bisphosphonates or hydrochlorothiazides. A small sample size prevented detailed statistical analysis and hence, we present a preliminary descriptive report of our findings. Participants' age was 57+/-7 years (mean +/-SD), baseline body mass index was 27+/-5 kg/sq m, serum concentration of 25-hydroxyvitamin D was 66+/-17 nmol/L and parathyroid hormone was 30+/-13 pg/ml. After Lisinopril treatment, men demonstrated a 10% decrease in the bone resorption marker C-terminal telopeptide (CTX) and 5% decrease in formation marker procollagen type 1 amino-terminal pro-peptide (P1NP). On the contrary, serum CTX increased 41% and P1NP increased 10% in those who were not treated with ACEi. This is the first human study to report reduction in bone resorptive activity following ACEi treatment for hypertension in older men. Our results indicates

  19. [Morphological analysis of bone dynamics and metabolic bone disease. Histomorphometric concepts of bone remodeling and modeling].

    Science.gov (United States)

    Takahashi, Hideaki E

    2011-04-01

    In tissue level turnover of bone cells, bone remodeling shows a sequential events of activation, resorption, reversal and formation. This may be observed as secondary osteons in the cortical bone and trabecular packets in the cancellous bone. Microcracks are repaired by targeted remodeling, and calcium is released by non-targeted remodeling. In macromodeling, a macroscopic size of a bone increases with growth, without changing its basic figure. In micromodelimg, a shift of trabecula, a minishift, is biomechnically controlled. New lamellar bone is added parallel to compressive and tensile force, and bone resorption occurs at the opposite surface of formation. In minimodeling new lamellar bone is formed with a sequence of activation, then directly formation, without scalloping at the cement line between newly formed bone and its basic bone. PMID:21447918

  20. Bone Metabolism in Anorexia Nervosa

    OpenAIRE

    Fazeli, Pouneh K.; Klibanski, Anne

    2014-01-01

    Anorexia nervosa (AN), a psychiatric disorder predominantly affecting young women, is characterized by self-imposed chronic nutritional deprivation and distorted body image. AN is associated with a number of medical co-morbidities including low bone mass. The low bone mass in AN is due to an uncoupling of bone formation and bone resorption, which is the result of hormonal adaptations aimed at decreasing energy expenditure during periods of low energy intake. Importantly, the low bone mass in ...

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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...

  3. The Effect of Ovariectomy and Orchiectomy on Orthodontic Tooth Movement and Root Resorption in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2015-12-01

    Full Text Available Statement of the Problem: Root resorption (RR after orthodontic tooth movement (OTM is known as a multifactorial complication of orthodontic treatments. Hormonal deficiencies and their effect on bone turnover are reported to have influences on the rate of tooth movement and root resorption. Purpose: This study was designed to evaluate the effect of female and male steroid sex hormones on tooth movement and root resorption. Materials and Method: Orthodontic appliances were placed on the right maxillary first molars of 10 ovariectomized female and 10 orchiectomized male Wistar rats as experimental groups and 10 female and 10 male healthy Wistar rats as control groups. NiTi closed-coil springs (9mm, Medium, 011"×.030", Ortho Technology®; Tampa, Florida were placed between the right incisors and the first right maxillary molars to induce tipping movement in the first molars with the application of a 60g force. After 21 days, the rats were sacrificed and tooth movement was measured by using a digital caliper (Guanglu, China. Orthodontic induced root resorption (OIRR was assessed by histomorphometric analysis after hematoxylin and eosin staining of sections of the mesial root. Results: The rate of tooth movement was significantly higher in all female rats, with the root resorption being lower in the experimental group. The rate of tooth movement in experimental male rats was significantly higher than the control group (p= 0.001 and the rate of root resorption was significantly lower in the experimental group (p= 0.001. Conclusion: It seems that alterations in plasma levels of estrogen, progesterone, and testosterone hormones can influence the rate of OTM and RR. The acceleration in tooth movement increased OTM and decreased RR.

  4. Use of Spongious Bone Chips and Fascia Temporalis in Alveolar Bone Defects

    OpenAIRE

    TÜZ, Hakan H.; AKAL, Ümit K.; CAMBAZOĞLU, Mine; KİŞNİŞCİ, Reha Ş.

    2004-01-01

    Graft materials are used for inducement of regeneration in bone defects. Organic and synthetic bone graft materials facilitate remodelation or healing of the bone and induce new bone formation in the area of bone resorption caused by pathological, traumatic, and physiological reasons. The aim of this study was to evaluate the effects of spongious allogenic bone graft and fascia temporalis membranous collagen tissue on the healing of bone defects clinically and radiologically. The study was c...

  5. Regional Aggressive Root Resorption Caused by Neuronal Virus Infection

    Directory of Open Access Journals (Sweden)

    Inger Kjær

    2012-01-01

    Full Text Available During orthodontic treatment, root resorption can occur unexplainably. No clear distinction has been made between resorption located within specific regions and resorption occurring generally in the dentition. The purpose is to present cases with idiopathic (of unknown origin root resorption occurring regionally. Two cases of female patients, 26 and 28 years old, referred with aggressive root resorption were investigated clinically and radiographically. Anamnestic information revealed severe virus diseases during childhood, meningitis in one case and whooping cough in the other. One of the patients was treated with dental implants. Virus spreading along nerve paths is a possible explanation for the unexpected resorptions. In both cases, the resorptions began cervically. The extent of the resorption processes in the dentition followed the virus infected nerve paths and the resorption process stopped when reaching regions that were innervated differently and not infected by virus. In one case, histological examination revealed multinuclear dentinoclasts. The pattern of resorption in the two cases indicates that innervation is a factor, which under normal conditions may protect the root surface against resorption. Therefore, the normal nerve pattern is important for diagnostics and for predicting the course of severe unexpected root resorption.

  6. ICTP in Bone Metastases of Lung Cancer

    OpenAIRE

    Franjević, Ana; Pavićević, Radomir; Bubanović, Gordana

    2011-01-01

    Bone metastases often appear in advanced stages of lung cancer. They are the result of modulation of bone metabolism by tumor cells that migrated into bone microenvironment and degraded bone organic matrix. Measurement of C-terminal telopeptide of type I collagen (ICTP) in the serum of subjects with lung cancer with and without bone metastases and healthy population is the way to explore bone resorption. In 343 subjects included in this research ICTP level was significantly higher...

  7. Bone formation following implantation of bone biomaterials into extraction sites

    OpenAIRE

    Molly, Liene; Vandromme, Heleen; Quirynen, Marc; Schepers, Evert; Adams, Jessica L; van Steenberghe, Daniel

    2008-01-01

    Background: Adequate bone volume is imperative for the osseointegration of endosseous implants, but post-extraction resorption and remodeling may challenge implant placement. The use of bone biomaterials has been advocated to fill extraction sites and to enhance primary implant stability during osseointegration. The objective of the case series was to evaluate bone formation histologically and biomechanically in extraction sites following implantation of three commercially available bone biom...

  8. Bone Biochemistry on the International Space Station

    Science.gov (United States)

    Smith, Scott M.; Heer, Martina; Zwart, Sara R.

    2016-01-01

    Bone biochemical measures provide valuable insight into the nature and time course of microgravity effects on bone during space flight, where imaging technology cannot be employed. Increased bone resorption is a hallmark of space flight, while markers of bone formation are typically unchanged or decreased. Recent studies (after the deployment to ISS of the advanced resistive exercise device, ARED), have documented that astronauts with good nutritional intake (e.g., maintenance of body mass), good vitamin D status, and exercise maintained bone mineral density. These data are encouraging, but crewmembers exercising on the ARED do have alterations in bone biochemistry, specifically, bone resorption is still increased above preflight levels, but bone formation is also significantly increased. While this bone remodeling raises questions about the strength of the resulting bone, however documents beneficial effects of nutrition and exercise in counteracting bone loss of space flight.

  9. Etiology and sequelae of root resorption.

    Science.gov (United States)

    Vlaskalic, V; Boyd, R L; Baumrind, S

    1998-06-01

    This article reviews the current status of investigation into apical root resorption within the context of orthodontic treatment. Treatment and patient factors that have traditionally been investigated are discussed, along with the results of current research in this area. The need for rethinking traditional research strategies in the quest for identifying both control and causative mechanisms is explored. Finally, proposals for key areas of future interest are highlighted. PMID:9680910

  10. External cervical resorption: clinical case report

    Directory of Open Access Journals (Sweden)

    Daniela Hansel

    2014-01-01

    Full Text Available External cervical resorption (ECR is an invasive type of resorption that begins below the gingival epithelium and affects mineralized tissues, e.g., cementum and dentin. Most authors refer to dental trauma, whitening agents, and orthodontic treatment as etiologic factors of ECR; clinical diagnosis is performed via inspection of the gingival groove and margin. In this scenario, cone beam computed tomography has become a highly valuable ancillary method, as it allows to assess the proximity between the resorption and the pulp cavity, and thus, plan treatment. This article describes, in the form of a clinical case report, the diagnosis and treatment of a case of ECR affecting tooth no. 11, classified as Class III according to Heitersay’s classification. Surgical approach, restoration and clinical follow-up over 2-years of follow-up are described. In view of the clinical and radiographic findings observed during follow-up, it can be concluded that treatment was successful in healing periodontal tissues, suggesting a good prognosis.

  11. Regulation of bone destruction in rheumatoid arthritis through RANKL-RANK pathways

    OpenAIRE

    2013-01-01

    Recent studies have demonstrated that osteoclasts, the primary cells responsible for bone resorption, are mainly involved in bone and joint destruction in rheumatoid arthritis (RA) patients. Recent progress in bone cell biology has revealed the molecular mechanism of osteoclast differentiation and bone resorption by mature osteoclasts. We highlight here the potential role of the receptor activator of nuclear factor κB ligand (RANKL)-RANK pathways in bone destruction in RA and review recent cl...

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

    OpenAIRE

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

    2015-01-01

    Bone remodeling is a lifelong process in vertebrates that relies on the correct balance between bone resorption by osteoclasts and bone formation by osteoblasts. Bone loss and fracture risk are implicated in inflammatory autoimmune diseases such as rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, and systemic lupus erythematosus. The network of inflammatory cytokines produced during chronic inflammation induces an uncoupling of bone formation and resorption, resulting...

  13. Effects of Tai Ji Exercise on Bone Structure and Function

    Institute of Scientific and Technical Information of China (English)

    Xu Hong; David Lawson

    2005-01-01

    To evaluated the effects of the 24 movements Tai Ji exercise on bone structure and function. Broadband Ultrsonic Attenuation (BUA) and velocity of sound (VOS), bone formation marker Osteocalcin (OSTN) and bone resorption markers urinary Pyridum crosslinks (PYR and D-PYR) were studied before and after four months of Tai Ji exercise. Improved bone structure and increased bone density in menopausal women were reflected by BUA results. The increased BUA appears to be associated with increased bone formation rather than decreased bone resorption.

  14. The use of biochemical markers of bone remodeling in multiple myeloma: a report of the International Myeloma Working Group

    DEFF Research Database (Denmark)

    Terpos, E; Dimopoulos, M A; Sezer, O; Roodman, D; Abildgaard, N; Vescio, R; Tosi, P; Garcia-Sanz, R; Davies, F; Chanan-Khan, A; Palumbo, A; Sonneveld, P; Drake, M T; Harousseau, J-L; Anderson, K C; Durie, B G M

    2010-01-01

    Lytic bone disease is a frequent complication of multiple myeloma (MM). Lytic lesions rarely heal and X-rays are of limited value in monitoring bone destruction during anti-myeloma or anti-resorptive treatment. Biochemical markers of bone resorption (amino- and carboxy-terminal cross-linking telo...

  15. Low bone turnover phenotype in Rett syndrome

    DEFF Research Database (Denmark)

    Roende, Gitte; Petersen, Janne; Ravn, Kirstine;

    2014-01-01

    Background:Patients with Rett syndrome (RTT) are at risk of having low bone mass and low-energy fractures.Methods:We characterised bone metabolism by both bone formation and resorption markers in blood in a RTT population of 61 girls and women and 122 well-matched healthy controls. Levels of N...

  16. Resorption of apatite-wollastonite containing glass-ceramic and beta-tricalcium phosphate in vivo.

    Science.gov (United States)

    Teramoto, Hidefumi; Kawai, Akira; Sugihara, Shinsuke; Yoshida, Aki; Inoue, Hajime

    2005-10-01

    Apatite-wollastonite containing glass ceramic is considered to be difficult to resorb, but we experienced the disappearance of the porous type of Apatite-wollastonite glass ceramic particles . In this study, the resorption of porous apatite-wollastonite glass-ceramic implanted in the femurs of rabbits was investigated, and the process was compared with beta-tricalcium phosphate, a resorbable ceramics. Porous apatite-wollastonite glass-ceramic (70, 80, and 90% porosity) and beta-tricalcium phosphate (75% porosity) were implanted in the femurs of Japanese white rabbits. Samples were harvested and examined 0, 4, 8, 12, 24 and 36 weeks after implantation. Quantitative analysis of the radiographic and histologic findings was performed with NIH Image software. Radiographic examination demonstrated that the radiopacity and size of the porous apatite-wollastonite glassceramic cylinders decreased gradually after implantation. Histologic examination revealed that the surface area of the apatite-wollastonite glass-ceramic cylinders decreased continuously, and approached 20% of the original area 36 weeks after implantation. However, the resorption rate of porous apatite-wollastonite glass-ceramic was slower than that of beta-tricalcium phosphate. Toluidine blue staining showed abundant new bone formation on the surface of the apatite-wollastonite glassceramic matrix. Considering its mechanical strength, gradual resorption characteristics, and good osteochonductive activity, porous apatite-wollastonite glass-ceramic appears to be a suitable artificial bone substitutes. PMID:16286959

  17. Resorption of apatite-wollastonite containing glass-ceramic and beta-tricalcium phosphate in vivo.

    Directory of Open Access Journals (Sweden)

    Teramoto,Hidefumi

    2005-10-01

    Full Text Available

    Apatite-wollastonite containing glass ceramic is considered to be difficult to resorb, but we experienced the disappearance of the porous type of Apatite-wollastonite glass ceramic particles . In this study, the resorption of porous apatite-wollastonite glass-ceramic implanted in the femurs of rabbits was investigated, and the process was compared with beta-tricalcium phosphate, a resorbable ceramics. Porous apatite-wollastonite glass-ceramic (70, 80, and 90% porosity and beta-tricalcium phosphate (75% porosity were implanted in the femurs of Japanese white rabbits. Samples were harvested and examined 0, 4, 8, 12, 24 and 36 weeks after implantation. Quantitative analysis of the radiographic and histologic findings was performed with NIH Image software. Radiographic examination demonstrated that the radiopacity and size of the porous apatite-wollastonite glassceramic cylinders decreased gradually after implantation. Histologic examination revealed that the surface area of the apatite-wollastonite glass-ceramic cylinders decreased continuously, and approached 20% of the original area 36 weeks after implantation. However, the resorption rate of porous apatite-wollastonite glass-ceramic was slower than that of beta-tricalcium phosphate. Toluidine blue staining showed abundant new bone formation on the surface of the apatite-wollastonite glassceramic matrix. Considering its mechanical strength, gradual resorption characteristics, and good osteochonductive activity, porous apatite-wollastonite glass-ceramic appears to be a suitable artificial bone substitutes.

  18. The Effect of An Angiogenic Cytokine on Orthodontically Induced Inflammatory Root Resorption

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2016-07-01

    Full Text Available Objective Orthodontically induced inflammatory root resorption (OIIRR is an undesirable sequel of tooth movement after sterile necrosis that takes place in periodontal ligament due to blockage of blood vessels following exertion of orthodontic force. This study sought to assess the effect of an angiogenic cytokine on OIIRR in rat model. Materials and Methods In this experimental animal study, 50 rats were randomly divided into 5 groups of 10 each: E10, E100 and E1000 receiving an injection of 10, 100 and 1000 ng of basic fibroblast growth factor (bFGF, respectively, positive control group (CP receiving an orthodontic appliance and injection of phosphate buffered saline (PBS and the negative control group (CN receiving only the anesthetic agent. A nickel titanium coil spring was placed between the first molar and the incisor on the right side of maxilla. Twenty-one days later, the rats were sacrificed. Histopathological sections were made to assess the number and area of resorption lacunae, number of blood vessels, osteoclasts and Howship’s lacunae. Data were statistically analyzed using ANOVA and Tukey’s honest significant difference (HSD test. Results Number of resorption lacunae and area of resorption lacunae in E1000 (0.97 ± 0.80 and 1. 27 ± 0.01×10-3, respectively were significantly lower than in CP (4.17 ± 0.90 and 2.77 ± 0.01×10-3, respectively, P=0.000. Number of blood vessels, osteoclasts and Howship’s lacunae were significantly higher in E1000 compared to CP (P<0.05. Conclusion Tooth movement as the outcome of bone remodeling is concomitant with the formation of sterile necrosis in the periodontal ligament following blocked blood supply. Thus, bFGF can significantly decrease the risk of root resorption by providing more oxygen and angiogenesis.

  19. Lack of Interleukin 1-beta Expression Following Orthodontic Induced Root Resorption

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2011-01-01

    Full Text Available Objective: To determine the effect of orthodontic tooth movement on the expression ofinterleukin-1β mRNA in rats using RT-PCR.Materials and Methods: Sample consisted of eighteen 8-week-old male Wistar rats. Theright maxillary first molar of each animal was protracted using an orthodontic protraction appliance.The left maxillary first molar received no treatment and was assigned as the controlgroup. On day 21, all rats were sacrifice and divided in two equal groups. The first group,group (A, was histologically evaluated for the presence and size of potential resorptive lacunae.The second group, group (B, was investigated using RT-PCR in order to determineIL-1β mRNA expression.Results: Measurements revealed that the mean tooth movement was 0.23 mm in group Aand 0.24 mm in group B. The mean depth of the resorptive lacunae was 0.17×10-11 mm2 inthe control group and 4.9×10-11 mm2 in the intervention group (control group: left maxillaryfirst molars; right maxillary first molars were divided to group A & B, histologic study of groupA assures the existence of resorptive lacunae and its extent relative to control group. Thedifference between the two groups was statistically significant (p<0.05. The RT-PCR evaluationshowed no significant differences in IL-1β mRNA expressions of resorptive lacunaebetween the treated and untreated groups.Conclusion: Although interleukin1-beta is the most potent stimulator of bone resorptionand mediator of inflammatory response, the present study showed that the IL-1beta mRNAwas not expressed more significantly in root resorption lacunae of the treated molars relativeto the control group.

  20. M-CSF potently augments RANKL-induced resorption activation in mature human osteoclasts.

    Directory of Open Access Journals (Sweden)

    Jason M Hodge

    Full Text Available Macrophage-CSF (M-CSF is critical for osteoclast (OC differentiation and is reported to enhance mature OC survival and motility. However, its role in the regulation of bone resorption, the main function of OCs, has not been well characterised. To address this we analysed short-term cultures of fully differentiated OCs derived from human colony forming unit-granulocyte macrophages (CFU-GM. When cultured on dentine, OC survival was enhanced by M-CSF but more effectively by receptor activator of NFκB ligand (RANKL. Resorption was entirely dependent on the presence of RANKL. Co-treatment with M-CSF augmented RANKL-induced resorption in a concentration-dependent manner with a (200-300% stimulation at 25 ng/mL, an effect observed within 4-6 h. M-CSF co-treatment also increased number of resorption pits and F-actin sealing zones, but not the number of OCs or pit size, indicating stimulation of the proportion of OCs activated. M-CSF facilitated RANKL-induced activation of c-fos and extracellular signal-regulated kinase (ERK 1/2 phosphorylation, but not NFκB nor nuclear factor of activated T-cells, cytoplasmic-1 (NFATc1. The mitogen-activated protein kinase kinase (MEK 1 inhibitor PD98059 partially blocked augmentation of resorption by M-CSF. Our results reveal a previously unidentified role of M-CSF as a potent stimulator of mature OC resorbing activity, possibly mediated via ERK upstream of c-fos.

  1. Myeloma bone disease: Pathophysiology and management

    OpenAIRE

    Silbermann, Rebecca; Roodman, G. David

    2013-01-01

    Multiple myeloma bone disease is marked by severe dysfunction of both bone formation and resorption and serves as a model for understanding the regulation of osteoblasts (OBL) and osteoclasts (OCL) in cancer. Myeloma bone lesions are purely osteolytic and are associated with severe and debilitating bone pain, pathologic fractures, hypercalcemia, and spinal cord compression, as well as increased mortality. Interactions within the bone marrow microenvironment in myeloma are responsible for the ...

  2. [Clinical usefulness of bone turnover markers in the management of osteoporosis].

    Science.gov (United States)

    Yano, Shozo

    2013-09-01

    Osteoporosis is a state of elevated risk for bone fracture due to depressed bone strength, which is considered to be the sum of bone mineral density and bone quality. Since a measure of bone quality has not been established, bone mineral density and bone turnover markers are the only way to evaluate bone strength. Bone turnover markers are classified into bone formation marker and resorption marker, which are correlated with the bone formation rate and resorption rate, respectively, and bone matrix-related marker. Bone is always metabolized; old tissue is resorbed by acids and proteases derived from osteoclasts, whereas new bone is produced by osteoblasts. Bone formation and resorption rates should be balanced (also called coupled). When the bone resorption rate exceeds the formation rate(uncoupled state), bone volume will be reduced. Thus, we can comprehend bone metabolism by measuring both formation and resorption markers at the same time. Increased fracture risk is recognized by elevated bone resorption markers and undercarboxylated osteocalcin, which reflects vitamin K insufficiency and bone turnover. These values and the time course give us helpful information to choose medicine suitable for the patients and to judge the responsiveness. If the value is extraordinarily high without renal failure, metabolic bone disorder or bone metastatic tumor should be considered. Bone quality may be assessed by measuring bone matrix-related markers such as homocystein and pentosidine. Since recent studies indicate that the bone is a hormone-producing organ, it is possible that glucose metabolism or an unknown mechanism could be assessed in the future. PMID:24369600

  3. Genistein supplementation increases bone turnover but does not prevent alcohol-induced bone loss in male mice

    Science.gov (United States)

    Chronic alcohol consumption results in bone loss through increased bone resorption and decreased bone formation. These effects can be reversed by estradiol (E2) supplementation. Soy diets are suggested to have protective effects on bone loss in men and women, as a result of the presence of soy prote...

  4. Generalized cervical root resorption associated with periodontal disease

    NARCIS (Netherlands)

    Beertsen, W; Piscaer, M; Van Winkelhoff, AJ; Everts, P. A. M.

    2001-01-01

    Background and description of case: The etiology and pathogenesis of generalized cervical root resorptions is not well understood. In the present report, a case of severe cervical root resorption involving 24 anterior and posterior teeth is presented. The lesions developed within a period of 2 years

  5. Conservative Nonsurgical Treatment of Class 4 Invasive Cervical Resorption: A Case Series.

    Science.gov (United States)

    Salzano, Stefano; Tirone, Federico

    2015-11-01

    External cervical resorption, also called invasive cervical resorption (ICR), is a pathological process difficult to diagnose that causes a progressive replacement of dentin by granulation tissue and results in complete tooth destruction. According to the literature, class 4 ICR can be expected to have success rates of 12.5% if treated. In this case series, we show nonsurgical conservative treatment of 4 patients affected by class 4 ICR. In 4 patients affected by class 4 ICRs, granulomatous tissue was orthograde removed with the help of an operating microscope and cone-beam computed tomographic imaging. The teeth were devitalized, the granulomatous tissue was mechanically removed, and the defects were filled with either mineral trioxide aggregate or Biodentine (Septodont, Saint-Maur-des-Fossés, France). After a follow-up period varying from 18 months for case 1 to 4 months for case 4, neither signs of periradicular bone rarefaction nor recurrence of resorption were observed. The teeth were asymptomatic, and conservative restorations appeared to be in excellent condition. Given the results achieved in this case series, it may be assumed that many class 4 ICRs could be successfully treated with the help of an operating microscope and cone-beam computed tomographic imaging. PMID:26395913

  6. External resorption presenting as an intracoronal radiolucent lesion in a pre-eruptive tooth.

    LENUS (Irish Health Repository)

    McNamara, C M

    1997-09-01

    A large intracoronal radiolucent lesion in an unerupted permanent molar was found during the routine assessment of a young male Caucasian prior to orthodontic treatment. The tooth was extracted. Histological examination indicated the lesion was caused by external resorption. The defect extended widely into the enamel and dentine, and was repaired in part by bone. The pulp chamber was not involved. The aetiology of these lesions is often obscure but in this case it appeared to have originated in the floor of two developmental pits on the occlusal surface of the tooth.

  7. Molecular Mechanisms of Bone Metastasis and Associated Muscle Weakness

    OpenAIRE

    Waning, David L.; Guise, Theresa A.

    2014-01-01

    Bone is a preferred site for breast cancer metastasis and leads to pathological bone loss due to increased osteoclast-induced bone resorption. The homing of tumor cells to the bone depends on the support of the bone microenvironment in which the tumor cells prime the pre-metastatic niche. The colonization and growth of tumor cells then depends on adaptations in the invading tumor cells to take advantage of normal physiological responses by mimicking bone marrow cells. This concerted effort by...

  8. Prevalent of root resorption of second molar adjustment the impacted third molar in prepiacal and panoramic radiographs

    Directory of Open Access Journals (Sweden)

    Mohammad Ebrahimi Saravi

    2013-10-01

    Full Text Available   Background and Aims: Impacted third molar reduces the bone level in the distal aspect of second molar, and sometimes it can lead to root resorption of the adjacent tooth. The purpose of this study was to determine this resorption using panoramic and periapical radiographs.   Materials and Methods: In this cross-sectional descriptive study 54 patient (28 men, 26 women above 15 years old with the average of 22 years in Oral and Maxillofacial Department of Tehran University were studied. A periapical radiography from the third molar and a panoramic radiograph were taken from each patient (Because of their routine use and evaluation of accuracy of panoramic compared with periapical, and the magnitude of the root resorption for the second molar was determined by 2 observers and written in a questionnaire. Data were analyzed using Fisher test.   Results: The prevalence of the root resorption of the second molar adjacent to the impacted third molar in the panoramic and the periapical radiographies, with respect to the limitation of the sample size were 46.3% and 31.5%, respectively, with 95% confidence(P>0.05. Most of these resorptions were in the cervical third of the second molar roots and in cases in which the third molars were mesially oriented or horizontal. There was also no significant difference between panoramic and periapical radiographs.   Conclusion: Due to the increased risk of the resorption of the second molar adjacent to the third molar, extraction of the impacted third molars, especiall y mesially oriented or horizontal ones are recommended.

  9. Using Micro-Computed Tomography to Evaluate the Dynamics of Orthodontically Induced Root Resorption Repair in a Rat Model

    Science.gov (United States)

    Yang, Fengxue; Wei, Shicheng; Dai, Hongwei

    2016-01-01

    Objective To observe dynamic changes in root resorption repair, tooth movement relapse and alveolar bone microstructure following the application of orthodontic force. Materials and Methods Forces of 20 g, 50 g or 100 g were delivered to the left maxillary first molars of fifteen 10-week-old rats for 14 days. Each rat was subjected to micro-computed tomography scanning at 0, 3, 7, 10, 14, 28 and 42 days after force removal. The root resorption crater volume, tooth movement relapse and alveolar bone microarchitecture were measured at each time point. Results From day 3 to day 14, the root resorption volume decreased significantly in each group. In the 20-g force group, the root resorption volume gradually stabilized after 14 days, whereas in the 50-g and 100-g force groups, it stabilized after 28 days. In all groups, tooth movement relapsed significantly from day 0 to day 14 and then remained stable. From day 3 to day 10, the 20-g group exhibited faster relapse than the 50-g and 100-g groups. In all groups, the structure model index and trabecular separation decreased slowly from day 0 to day 10 and eventually stabilized. Trabecular number increased slowly from day 0 to day 7 and then stabilized. Conclusions The initial stage of root resorption repair did not change significantly and was followed by a dramatic repair period before stabilizing. The most serious tooth movement relapse occurred immediately after the appliance was removed, and then the tooth completely returned to the original position. PMID:26930605

  10. [Bone metabolic markers and diagnosis of abnormal bone and calcium metabolism].

    Science.gov (United States)

    Fukunaga, M; Sone, T

    2001-07-01

    Bone metabolic markers increase in blood or urine, when bone formation or bone resorption accelerates. Reference values of bone metabolic markers are determined in male or female, and in pre- or post-menopause, respectively. Values of bone metabolic markers in most patients with primary osteoporosis were distributed within a reference value, mean+/-1.96 SD. When measured values exceeded a reference values, we should survey a possibility of abnormal calcium or bone metabolism such as primary hyperparathyroidism, renal osteodystrophy, hyperthyroidism and Paget's disease of bone or bone metastasis associated with malignant tumor. PMID:15775589

  11. Bone Metabolism on ISS Missions

    Science.gov (United States)

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

    2014-01-01

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

  12. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

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

  13. Receptor tyrosine kinase inhibition causes simultaneous bone loss and excess bone formation within growing bone in rats

    International Nuclear Information System (INIS)

    During postnatal skeletal growth, adaptation to mechanical loading leads to cellular activities at the growth plate. It has recently become evident that bone forming and bone resorbing cells are affected by the receptor tyrosine kinase (RTK) inhibitor imatinib mesylate (STI571, Gleevec (registered) ). Imatinib targets PDGF, ABL-related gene, c-Abl, c-Kit and c-Fms receptors, many of which have multiple functions in the bone microenvironment. We therefore studied the effects of imatinib in growing bone. Young rats were exposed to imatinib (150 mg/kg on postnatal days 5-7, or 100 mg/kg on postnatal days 5-13), and the effects of RTK inhibition on bone physiology were studied after 8 and 70 days (3-day treatment), or after 14 days (9-day treatment). X-ray imaging, computer tomography, histomorphometry, RNA analysis and immunohistochemistry were used to evaluate bone modeling and remodeling in vivo. Imatinib treatment eliminated osteoclasts from the metaphyseal osteochondral junction at 8 and 14 days. This led to a resorption arrest at the growth plate, but also increased bone apposition by osteoblasts, thus resulting in local osteopetrosis at the osteochondral junction. The impaired bone remodelation observed on day 8 remained significant until adulthood. Within the same bone, increased osteoclast activity, leading to bone loss, was observed at distal bone trabeculae on days 8 and 14. Peripheral quantitative computer tomography (pQCT) and micro-CT analysis confirmed that, at the osteochondral junction, imatinib shifted the balance from bone resorption towards bone formation, thereby altering bone modeling. At distal trabecular bone, in turn, the balance was turned towards bone resorption, leading to bone loss. - Research highlights: → 3-Day imatinib treatment. → Causes growth plate anomalies in young rats. → Causes biomechanical changes and significant bone loss at distal trabecular bone. → Results in loss of osteoclasts at osteochondral junction.

  14. High-dose therapy improved the bone remodelling compartment canopy and bone formation in multiple myeloma

    DEFF Research Database (Denmark)

    Hinge, Maja; Delaissé, Jean-Marie; Plesner, Torben; Clasen-Linde, Erik; Salomo, Morten; Levin Andersen, Thomas

    2015-01-01

    . Loss of this canopy has been associated with bone loss. This study addresses whether the bone remodelling in MM is improved by high-dose therapy. Bone marrow biopsies obtained from 20 MM patients, before and after first-line treatment with high-dose melphalan followed by autologous stem cell......Bone loss in multiple myeloma (MM) is caused by an uncoupling of bone formation to resorption trigged by malignant plasma cells. Increasing evidence indicates that the bone remodelling compartment (BRC) canopy, which normally covers the remodelling sites, is important for coupled bone remodelling...... transplantation, and from 20 control patients with monoclonal gammopathy of undetermined significance were histomorphometrically investigated. This investigation confirmed that MM patients exhibited uncoupled bone formation to resorption and reduced canopy coverage. More importantly, this study revealed that a...

  15. Frequency of the external resorptions of root apex

    OpenAIRE

    Opačić-Galić Vanja; Živković Slavoljub

    2004-01-01

    Root resorptions present a significant problem in endodontic therapy of the affected teeth and in dentistry in general. The objective of this study was to analyze, based on epidemiological and statistical research, the frequency of clinical incidence of pathological root resorptions in everyday practice related to localization, type of tooth, age and sex of patients. Radiographie documentation of patients treated from 1997 till 2002 at the Department of Conservative Dentistry and Endodontics,...

  16. Pathogen infection drives patterns of nutrient resorption in citrus plants.

    Science.gov (United States)

    Cao, Jirong; Cheng, Chunzhen; Yang, Junjie; Wang, Qibing

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen 'Candidatus Liberibacter asiaticus' grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of 'Ca. L. asiaticus' infection on nitrogen (N) and phosphorus (P) concentrations and resorption in different citrus species (i.e. Citrus reticulata, Citrus limon and Citrus maxima). HLB-pathogen infection had distinctive impacts on nutrient resorption in different species. P resorption efficiency substantially decreased in infected C. reticulata plants relative to the healthy plants in summer, which may account for the marked decrease in the average fruit yield. P resorption was more efficient in infected C. limon plants than in the healthy plants. However, for C. maxima plants, HLB had no significant effects on N:P ratio in live leaves and resorption efficiency as well as on fruit yield. Keeping efficient internal nutrient cycling can be a strategy of citrus species being tolerant to HLB. PMID:26419510

  17. Resorption Rate Tunable Bioceramic: Si, Zn-Modified Tricalcium Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Xiang Wei

    2006-08-09

    This dissertation is organized in an alternate format. Several manuscripts which have already been published or are to be submitted for publication have been included as separate chapters. Chapter 1 is a general introduction which describes the dissertation organization and introduces the human bone and ceramic materials as bone substitute. Chapter 2 is the background and literature review on dissolution behavior of calcium phosphate, and discussion of motivation for this research. Chapter 3 is a manuscript entitled ''Si,Zn-modified tricalcium phosphate: a phase composition and crystal structure study'', which was published in ''Key Engineering Materials'' [1]. Chapter 4 gives more crystal structure details by neutron powder diffraction, which identifies the position for Si and Zn substitution and explains the stabilization mechanism of the structure. A manuscript entitled ''Crystal structure analysis of Si, Zn-modified Tricalcium phosphate by Neutron Powder Diffraction'' will be submitted to Biomaterials [2]. Chapter 5 is a manuscript, entitled ''Dissolution behavior and cytotoxicity test of Si, Zn-modified tricalcium phosphate'', which is to be submitted to Biomaterials [3]. This paper discusses the additives effect on the dissolution behavior of TCP, and cytotoxicity test result is also included. Chapter 6 is the study of hydrolysis process of {alpha}-tricalcium phosphate in the simulated body fluid, and the phase development during drying process is discussed. A manuscript entitled ''Hydrolysis of {alpha}-tricalcium phosphate in simulated body fluid and phase transformation during drying process'' is to be submitted to Biomaterials [4]. Ozan Ugurlu is included as co-authors in these two papers due to his TEM contributions. Appendix A is the general introduction of the materials synthesis, crystal structure and preliminary dissolution result. A manuscript entitled

  18. The two faces of serotonin in bone biology

    OpenAIRE

    Ducy, Patricia; Karsenty, Gerard

    2010-01-01

    The serotonin molecule has some remarkable properties. It is synthesized by two different genes at two different sites, and, surprisingly, plays antagonistic functions on bone mass accrual at these two sites. When produced peripherally, serotonin acts as a hormone to inhibit bone formation. In contrast, when produced in the brain, serotonin acts as a neurotransmitter to exert a positive and dominant effect on bone mass accrual by enhancing bone formation and limiting bone resorption. The effe...

  19. Biochemical markers of bone turnover and their association with bone marrow lesions

    NARCIS (Netherlands)

    Hunter, D.J.; LaValley, M.; Li, J.; Bauer, D.C.; Nevitt, M.; Groot, J. de; Poole, R.; Eyre, D.; Guermazi, A.; Gale, D.; Totterman, S.; Felson, D.T.

    2008-01-01

    Introduction: Our objective was to determine whether markers of bone resorption and formation could serve as markers for the presence of bone marrow lesions (BMLs). Methods: We conducted an analysis of data from the Boston Osteoarthritis of the Knee Study (BOKS). Knee magnetic resonance images were

  20. 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)

  1. Decreased Bone Volume and Bone Mineral Density in the Tibial Trabecular Bone Is Associated with Per2 Gene by 405 nm Laser Stimulation

    OpenAIRE

    Yeong-Min Yoo; Myung-Han Lee; Ji Hyung Park; Dong-Hyun Seo; Sangyeob Lee; Byungjo Jung; Han Sung Kim; Kiho Bae

    2015-01-01

    Low-level laser therapy/treatment (LLLT) using a minimally invasive laser needle system (MILNS) might enhance bone formation and suppress bone resorption. In this study, the use of 405 nm LLLT led to decreases in bone volume and bone mineral density (BMD) of tibial trabecular bone in wild-type (WT) and Per2 knockout (KO) mice. Bone volume and bone mineral density of tibial trabecular bone was decreased by 405 nm LLLT in Per2 KO compared to WT mice at two and four weeks. To determine the reduc...

  2. In vitro osteoclast formation and resorption of silicon-substituted hydroxyapatite ceramics.

    Science.gov (United States)

    Friederichs, Robert J; Brooks, Roger A; Ueda, Masato; Best, Serena M

    2015-10-01

    Materials that participate in bone remodeling at the implant/tissue interface represent a modern tissue engineering approach with the aim of balancing implant resorption and nascent tissue formation. Silicon-substituted hydroxyapatite (SiHA) ceramics are capable of stimulating new bone formation, but little is known about their interaction with osteoclasts (OC). The effects of soluble silicate and SiHA on OCs were investigated in this study. Soluble silicate below 500 μM did not stimulate cell metabolism at 4 days or alter resorption area at 7 days on calcium phosphate discs. On sintered ceramics, OC numbers were similar on HA, Si0.3 HA (0.5 wt % Si) and Si0.5 HA (1.2 wt % Si) after 21 days in vitro, but actin ring sealing zone morphology on SiHA resembled that commonly found on bone or on carbonate-substituted hydroxyapatite (CHA). Smaller and thicker actin rings on SiHA as compared to HA were probably the result of altered surface chemistry and solubility differences. The more stable sealing zones and increased lattice solubility likely contributed to increased individual pit volumes observed on Si0.5 HA. The delayed formation of OCs on Si0.5 HA (lower numbers at day 14) excludes earlier differentiation as a possible mechanism of increased individual OC pit volumes at later times (day 21). Materials characterization of Si containing biomaterials remains paramount as the Si type and amounts can subsequently impact downstream OC behaviour in a complex manner. PMID:25847383

  3. USE OF PANORAMIC RADIOGRAPHS FOR EVALUATION OF MAXILLARY AND MANDIBULAR RESIDUAL RIDGE RESORPTION: IN VITRO STUDY

    Directory of Open Access Journals (Sweden)

    Priyanka

    2014-11-01

    Full Text Available : INTRODUCTION: Progressive ridge resorption is one of the main causes of loss of stability and retention of mandibular complete dentures. The location of the mental foramen can be identified easily on panoramic radiographs, and radiographic examinations are considered an important component of Prosthodontics diagnostic and treatment planning. Also the location of maxillary landmark is important to known how much resorption is there. Aim: To determine the average ratio of bone height with nearest constant anatomical landmarks in maxilla and in mandible. OBJECTIVE: To find out the association between radiographic findings & prosthodontics, such as measurements of the amount of resorption and the variation in the treatment planning of edentulous patients. METHODS: The subjects OPG was taken using standard radiographic procedural parameters. The measurement was done for distance ‘c’, ‘a’, ‘x’, ‘y’, ‘z’. Then the calculations from measurements were done to calculate the ratio of c/a, to calculate the ratio of x/y, to calculate the ratio of x/z. RESULT: The descriptive statistics was done. The C/a ratio mean is 2.71 ± 0.31. The X/Y ratio mean is 1.49 ± 0.34 and the X/Z ratio mean is 1.51 ± 0.24. CONCLUSION: This ratio can be assessed in edentulous patients and then there further treatment plan can be decided according to the ratio. The implant placement can be assessed by using the measurements in this study.

  4. The effect of photobiomodulation on root resorption during orthodontic treatment

    Directory of Open Access Journals (Sweden)

    Nimeri G

    2014-01-01

    Full Text Available Ghada Nimeri, Chung H Kau, Rachel Corona, Jeffery Shelly Department of Orthodontics, University of Alabama, Birmingham, AL, USA Abstract: Photobiomodulation is used to accelerate tooth movement during orthodontic treatments. The changes in root morphology in a group of orthodontic patients who received photobiomodulation were evaluated using the cone beam computed tomography technique. The device used is called OrthoPulse, which produces low levels of light with a near infrared wavelength of 850 nm and an intensity of 60 mW/cm2 continuous wave. Twenty orthodontic patients were recruited for these experiments, all with class 1 malocclusion and with Little's Irregularity Index (>2 mm in either of the arches. Root resorption was detected by measuring changes in tooth length using cone beam computed tomography. These changes were measured before the orthodontic treatment and use of low-level laser therapy and after finishing the alignment level. Little's Irregularity Index for all the patients was calculated in both the maxilla and mandible and patients were divided into three groups for further analysis, which were then compared to the root resorption measurements. Our results showed that photobiomodulation did not cause root resorption greater than the normal range that is commonly detected in orthodontic treatments. Furthermore, no correlation between Little's Irregularity Index and root resorption was detected. Keywords: photobiomodulation, root resorption, accelerate tooth movement, orthodontics, cone beam computed tomography

  5. Bone metabolism during pregnancy.

    Science.gov (United States)

    Salles, Jean Pierre

    2016-06-01

    During pregnancy, mineral concentrations, of calcium and phosphorus in particular, are maintained at a high level in fetal blood so that the developing skeleton may accrete adequate mineral content. The placenta actively transports minerals for this purpose. Maternal intestinal absorption increases in order to meet the fetal demand for calcium, which is only partly dependent on calcitriol. Mineral regulation is essentially dependent on parathyroid hormone (PTH) and PTH-related protein (PTHrP). The calcium-sensing receptor (CaSR) regulates PTH and PTHrP production. If calcium intake is insufficient, the maternal skeleton will undergo resorption due to PTHrP. After birth, a switch from fetal to neonatal homeostasis occurs through increase in PTH and calcitriol, and developmental adaptation of the kidneys and intestines with bone turnover contributing additional mineral to the circulation. Calcium absorption becomes progressively active and dependent on calcitriol. The postnatal skeleton can transiently present with osteoposis but adequate mineral diet usually allows full restoration. Cases of primary osteoporosis must be identified. Loss of trabecular mineral content occurs during lactation in order to provide calcium to the newborn. This programmed bone loss is dependent on a "brain-breast-bone" circuit. The physiological bone resorption during reproduction does not normally cause fractures or persistent osteoporosis. Women who experience fracture are likely to have other causes of bone loss. PMID:27157104

  6. Bone metabolism in anorexia nervosa.

    Science.gov (United States)

    Fazeli, Pouneh K; Klibanski, Anne

    2014-03-01

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

  7. Bone Metabolism in Anorexia Nervosa

    Science.gov (United States)

    Fazeli, Pouneh K.; Klibanski, Anne

    2014-01-01

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

  8. Odanacatib in postmenopausal women with low bone mineral density: a review of current clinical evidence.

    Science.gov (United States)

    Zerbini, Cristiano A F; McClung, Michael R

    2013-08-01

    Human bones are in a continuous process of remodeling that ensures renovation and maintenance of the skeletal mass. Bone remodeling has two phases that are normally coupled and balanced: bone resorption mediated by osteoclasts and bone formation mediated by osteoblasts. An increase in bone resorption over bone formation results in a progressive loss of bone mass and impairment of bone microarchitecture leading to osteoporosis and its associated fractures. Recent advances in the understanding of the molecular and cellular mechanisms involved in the remodeling process have allowed the development of new targets for osteoporosis treatment. Cathepsin K, a cysteine protease, is found in osteoclasts along the bone resorption surfaces and very efficiently degrades type I collagen, the major component of the organic bone matrix. Inhibition of cathepsin K reduces bone resorption but does not impair bone formation particularly at cortical sites. Odanacatib, a potent and highly selective cathepsin K inhibitor, showed prevention of bone loss without reduction of bone formation in preclinical and clinical trials (phase I and II). Odanacatib is currently in a phase III fracture outcome international trial for the treatment of postmenopausal osteoporosis. PMID:23904864

  9. Estrogen regulates the rate of bone turnover but bone balance in ovariectomized rats is modulated by prevailing mechanical strain

    Science.gov (United States)

    Westerlind, K. C.; Wronski, T. J.; Ritman, E. L.; Luo, Z. P.; An, K. N.; Bell, N. H.; Turner, R. T.

    1997-01-01

    Estrogen deficiency induced bone loss is associated with increased bone turnover in rats and humans. The respective roles of increased bone turnover and altered balance between bone formation and bone resorption in mediating estrogen deficiency-induced cancellous bone loss was investigated in ovariectomized rats. Ovariectomy resulted in increased bone turnover in the distal femur. However, cancellous bone was preferentially lost in the metaphysis, a site that normally experiences low strain energy. No bone loss was observed in the epiphysis, a site experiencing higher strain energy. The role of mechanical strain in maintaining bone balance was investigated by altering the strain history. Mechanical strain was increased and decreased in long bones of ovariectomized rats by treadmill exercise and functional unloading, respectively. Functional unloading was achieved during orbital spaceflight and following unilateral sciatic neurotomy. Increasing mechanical loading reduced bone loss in the metaphysis. In contrast, decreasing loading accentuated bone loss in the metaphysis and resulted in bone loss in the epiphysis. Finally, administration of estrogen to ovariectomized rats reduced bone loss in the unloaded and prevented loss in the loaded limb following unilateral sciatic neurotomy in part by reducing indices of bone turnover. These results suggest that estrogen regulates the rate of bone turnover, but the overall balance between bone formation and bone resorption is influenced by prevailing levels of mechanical strain.

  10. Gallium increases bone calcium and crystallite perfection of hydroxyapatite.

    Science.gov (United States)

    Bockman, R S; Boskey, A L; Blumenthal, N C; Alcock, N W; Warrell, R P

    1986-12-01

    Gallium, a group IIIa metal, is known to interact with hydroxyapatite as well as the cellular components of bone. In recent studies we have found gallium to be a potent inhibitor of bone resorption that is clinically effective in controlling cancer-related hypercalcemia as well as the accelerated bone resorption associated with bone metastases. To begin to elucidate gallium's mechanism of action we have examined its effects on bone mineral properties. After short-term (14 days) administration to rats, gallium nitrate produced measurable changes in bone mineral properties. Using atomic absorption spectroscopy, low levels of gallium were noted to preferentially accumulate in regions of active bone formation, 0.54 +/- .07 microgram/mg bone in the metaphyses versus 0.21 +/- .03 microgram/mg bone in the diaphyses, P less than 0.001. The bones of treated animals had increased calcium content measured spectrophotometrically. Rats injected with radiolabeled calcium during gallium treatment had greater 45-calcium content compared to control animals. By wide-angle X-ray analyses, larger and/or more perfect hydroxyapatite was observed. The combined effects of gallium on bone cell function and bone mineral may explain its clinical efficacy in blocking accelerated bone resorption. PMID:3026592

  11. RECENT ADVANCES IN PATHO-BIOLOGY OF MYELOMA BONE DISEASE: CLINICOPATHOLOGY AND LITERATURE OF REVIEW

    OpenAIRE

    Lohit Kumar; Bhubaneswar

    2016-01-01

    Bone disease is a hallmark of multiple myeloma, presenting as lytic lesions associated with bone pain, pathological fractures requiring surgery and/or radiation to bone, spinal cord compression and hypercalcaemia. Increased osteoclastic activity unaccompanied by a compensatory increase in osteoblast function, leading to enhanced bone resorption results in bone disease. The interaction of plasma cells with the bone marrow microenvironment has been shown to play a vital role. Also,...

  12. The Rho-GEF Kalirin regulates bone mass and the function of osteoblasts and osteoclasts

    OpenAIRE

    Huang, Su; Pierre P. Eleniste; Wayakanon, Kornchanok; Mandela, Prashant; Eipper, Betty A.; Mains, Richard E.; Allen, Matthew R; Bruzzaniti, Angela

    2013-01-01

    Bone homeostasis is maintained by the balance between bone resorption by osteoclasts and bone formation by osteoblasts. Dysregulation in the activity of the bone cells can lead to osteoporosis, a disease characterized by low bone mass and an increase in bone fragility and risk of fracture. Kalirin is a novel GTP-exchange factor protein that has been shown to play a role in cytoskeletal remodeling and dendritic spine formation in neurons. We examined Kalirin expression in skeletal tissue and f...

  13. In vitro study of the osteocytes response to hypoxia and their regulation of bone homeostasis

    OpenAIRE

    Montesi, Monica

    2014-01-01

    Bone remodelling is a fundamental mechanism for removing and replacing bone during adaptation of the skeleton to mechanical loads. Skeletal unloading leads to severe hypoxia (1%O2) in the bone microenvironment resulting in imbalanced bone remodelling that favours bone resorption. Hypoxia, in vivo, is a physiological condition for osteocytes, 5% O2 is more likely physiological for osteocytes than 20% O2, as osteocytes are embedded deep inside the mineralized bone matrix. Osteocytes are thought...

  14. Emerging strategies and therapies for treatment of Paget’s disease of bone

    OpenAIRE

    Brown, Jacques P.

    2011-01-01

    Laëtitia Michou, Jacques P BrownLaval University, Department of Medicine, CHUQ (CHUL) Research Centre and Division of Rheumatology, Quebec City, QC, CanadaAbstract: Paget’s disease of bone (PDB) is a progressive monostotic or polyostotic metabolic bone disease characterized by focal abnormal bone remodeling, with increased bone resorption and excessive, disorganized, new bone formation. PDB rarely occurs before middle age, and it is the second most frequent metabolic bone d...

  15. Immunoregulation of bone remodelling

    Science.gov (United States)

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

    2012-01-01

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

  16. Bone health in eating disorders.

    Science.gov (United States)

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

    2014-03-01

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

  17. Prevention and Treatment of Bone Metastases in Breast Cancer

    OpenAIRE

    Ripamonti Carla; Trippa Fabio; Barone Gloria; Maranzano Ernesto

    2013-01-01

    In breast cancer patients, bone is the most common site of metastases. Medical therapies are the basic therapy to prevent distant metastases and recurrence and to cure them. Radiotherapy has a primary role in pain relief, recalcification and stabilization of the bone, as well as the reduction of the risk of complications (e.g., bone fractures, spinal cord compression). Bisphosphonates, as potent inhibitors of osteoclastic-mediated bone resorption are a well-established, standard-of-care treat...

  18. Osteoporosis: Modern Paradigms for Last Century’s Bones

    OpenAIRE

    Kruger, Marlena C.; Wolber, Frances M.

    2016-01-01

    The skeleton is a metabolically active organ undergoing continuously remodelling. With ageing and menopause the balance shifts to increased resorption, leading to a reduction in bone mineral density and disruption of bone microarchitecture. Bone mass accretion and bone metabolism are influenced by systemic hormones as well as genetic and lifestyle factors. The classic paradigm has described osteoporosis as being a “brittle bone” disease that occurs in post-menopausal, thin, Caucasian women wi...

  19. Bone Substitutes for Peri-Implant Defects of Postextraction Implants

    OpenAIRE

    Pâmela Letícia Santos; Jéssica Lemos Gulinelli; Cristino da Silva Telles; Walter Betoni Júnior; Roberta Okamoto; Vivian Chiacchio Buchignani; Thallita Pereira Queiroz

    2013-01-01

    Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immed...

  20. The Effect of Inital-Phase Bone Remodeling on Implant Wound Healing.

    Science.gov (United States)

    Hsu, Yung-Ting; Oh, Tae-Ju; Rudek, Ivan; Wang, Hom-Lay

    2016-01-01

    This case series aimed to investigate the initial-phase bone remodeling during implant wound healing and to discuss the possible contributing factors. A total of 11 implants with polished collars were placed in premaxillary regions via flapless approach with the aid of computer technology. After 15 months of follow-up, the results suggested that the presence of polished collars triggered bone resorption via a bone remodeling mechanism. The overall vertical crestal resorption was 0.78 ± 0.46 mm on average. This initial-phase bone remodeling primarily occurred within the first 3 months postoperatively. The slightly exposed polished collar may not worsen crestal bone level. PMID:27560679

  1. Bone microenvironment-mediated resistance of cancer cells to bisphosphonates and impact on bone osteocytes/stem cells.

    Science.gov (United States)

    Alasmari, Abeer; Lin, Shih-Chun; Dibart, Serge; Salih, Erdjan

    2016-08-01

    Anti-resorptive bisphosphonates (BPs) have been clinically used to prevent cancer-bone metastasis and cancer-induced bone pathologies despite the fact that the phenotypic response of the cancer-bone interactions to BP exposure is "uncharted territory". This study offers unique insights into the interplay between cancer stem cells and osteocytes/osteoblasts and mesenchymal stem cells using a three-dimensional (3D) live cancer-bone interactive model. We provide extraordinary cryptic details of the biological events that occur as a result of alendronate (ALN) treatment using 3D live cancer-bone model systems under specific bone remodeling stages. While cancer cells are susceptible to BP treatment in the absence of bone, they are totally unaffected in the presence of bone. Cancer cells colonize live bone irrespective of whether the bone is committed to bone resorption or formation and hence, cancer-bone metastasis/interactions are though to be "independent of bone remodeling stages". In our 3D live bone model systems, ALN inhibited bone resorption at the osteoclast differentiation level through effects of mineral-bound ALN on osteocytes and osteoblasts. The mineral-bound ALN rendered bone incapable of osteoblast differentiation, while cancer cells colonize the bone with striking morphological adaptations which led to a conclusion that a direct anti-cancer effect of BPs in a "live or in vivo" bone microenvironment is implausible. The above studies were complemented with mass spectrometric analysis of the media from cancer-bone organ cultures in the absence and presence of ALN. The mineral-bound ALN impacts the bone organs by limiting transformation of mesenchymal stem cells to osteoblasts and leads to diminished endosteal cell population and degenerated osteocytes within the mineralized bone matrix. PMID:27155840

  2. Volumetric Measurement of Root Resorption following Molar Mini-Screw Implant Intrusion Using Cone Beam Computed Tomography

    Science.gov (United States)

    Li, Wen; Chen, Fei; Zhang, Feng; Ding, Wanghui; Ye, Qingsong; Shi, Jiejun; Fu, Baiping

    2013-01-01

    Objective Molar intrusion by mini-screw implantation can cause different degrees of root resorption. However, most methods (2-D and 3-D) used for evaluating root resorption have focused on the root length without considering 3-D resorption. The purpose of this study was to volumetrically evaluate root resorption using cone beam computed tomography(CBCT) after mini-screw implant intrusion. Materials and Methods 1. The volumes of 32 teeth were measured using CBCT and laser scanning to verify the accuracy of CBCT. 2. Twelve overerupted molars from adult patients were investigated in this study. After mini-screw implants were inserted into the buccal and palatal alveolar bones, 150 g of force was applied to the mini-screw implants on each side to intrude the molars. CBCT images of all patients were taken immediately prior to intrusion and after intrusion. The volumes of the roots were calculated using the Mimics software program. The differences between the pre-intrusion and post-intrusion root volumes were statistically evaluated with a paired-samples t-test. In addition, the losses of the roots were statistically compared with each other using one-way analysis of variance at the P0.05). The overerupted molars were significantly intruded (P<0.05), and the average intrusion was 3.30±1.60 mm. The differences between the pre-intrusion and post-intrusion root volumes were statistically significant for all of the roots investigated (P<0.05). The roots were sorted by volume loss in descending order as follows: mesiobuccal, palatal, and distobuccal. Statistical significance was achieved among the three roots. The average total resorption for each tooth was 58.39±1.54 mm3. Conclusion Volume measurement using CBCT was able to effectively evaluate root resorption caused by mini-screw intrusion. The highest volume loss was observed in the mesiobuccal root among the three roots of the investigated first molar teeth. PMID:23585866

  3. Regional aggressive root resorption caused by neuronal virus infection

    DEFF Research Database (Denmark)

    Kjær, Inger; Strøm, Carsten; Worsaae, Nils

    2012-01-01

    occurring regionally. Two cases of female patients, 26 and 28 years old, referred with aggressive root resorption were investigated clinically and radiographically. Anamnestic information revealed severe virus diseases during childhood, meningitis in one case and whooping cough in the other. One of the...

  4. Influence of Body Mass Index and the Time of Edentulousness on the Residual Alveolar Ridge Resorption in Complete Denture Wearers

    OpenAIRE

    Kovačić, Ivan; Čelebić, Asja; Knezović Zlatarić, Dubravka; Stipetić, Jasmina; Papić, Milan

    2003-01-01

    Alveolar bone loss (RRR) is a continous process following tooth extraction, more pronounced during the first few months after the tooth extraction than later. The RRR in the mandible is twice that of the maxilla during a 1-year period and the mandibular: maxillary resorption ratio increases further to 4:1. So far, the etiology of RRR has not been elucidated. It has been speculated that both systemic and local factors contribute. The aim of this study was to analyse the rate of ...

  5. Diabetes mellitus related bone metabolism and periodontal disease

    Institute of Scientific and Technical Information of China (English)

    Ying-Ying Wu; E Xiao; Dana T Graves

    2015-01-01

    Diabetes mellitus and periodontal disease are chronic diseases affecting a large number of populations worldwide. Changed bone metabolism is one of the important long-term complications associated with diabetes mellitus. Alveolar bone loss is one of the main outcomes of periodontitis, and diabetes is among the primary risk factors for periodontal disease. In this review, we summarise the adverse effects of diabetes on the periodontium in periodontitis subjects, focusing on alveolar bone loss. Bone remodelling begins with osteoclasts resorbing bone, followed by new bone formation by osteoblasts in the resorption lacunae. Therefore, we discuss the potential mechanism of diabetes-enhanced bone loss in relation to osteoblasts and osteoclasts.

  6. Evaluation of intracerebral hematoma resorption dynamics with computed tomography

    International Nuclear Information System (INIS)

    High mortality and severe grade of disability observed in patients after intracerebral hemorrhage provide efforts to improve diagnostics and therapy of the hemorrhagic cerebral stroke. An aim of this paper was an evaluation of blood resorption dynamics in patients with intracerebral hematoma, performed with computed tomography of the head and an analysis of clinical significance of this process. An examined group included 133 patients with intracerebral hematoma proven by a CT exam. In 97 patients resorption of the hematoma was measured, based on control scans taken on 15th and 30th day on average. Volume of the hemorrhagic foci was measured as well as the width of ventricles and the displacement of medial structures. The mean hematoma volume reached 11,59 ml after 15 days, and 3,16 m after 30 days (average decrease of the volume 0,67 ml/day). There was a significant difference in the rate of resorption between the first (0-15 days) and the second (15-30 days) observation period - 0,78 and 0,62 ml/day respectively. The dynamics of the process was dependent on volume and localization of the hematoma and independent of the grade of displacement and compression of the ventricles. The calculated mean rate of the hematomas resorption enables to schedule control examinations precisely. The significant differences of the dynamics of blood resorption depending on hematomas size and the independence of compression and displacement of ventricular system suggest, that the most important factor in therapeutic decision-making should be a clinical status of the patient. (author)

  7. A scanning electron microscopic study of the patterns of external root resorption under different conditions

    OpenAIRE

    Ravindran Sreeja; Chaudhary Minal; Tumsare Madhuri; Patil Swati; Wadhwan Vijay

    2009-01-01

    Objective: The aim of this study was to examine if there are qualitative differences in the appearance of external root resorption patterns of primary teeth undergoing physiologic resorption and permanent teeth undergoing pathological root resorption in different conditions. Material and Methods: A total of 40 teeth undergoing external root resorption in different conditions were divided into 4 groups and prepared for examination under scanning electron microscopy at magnifications ranging fr...

  8. Treatment of Internal Resorption with Mineral Trioxide Aggregates: A Case Report

    OpenAIRE

    Yadav, Pankaj; Rao, Yogesh; Jain, Anurag; Relhan, Nikhil; Gupta, Sandeep

    2013-01-01

    Tooth resorption is a common sequel which follows injuries or irritation to the periodontal ligament and/or tooth pulp. The course of tooth resorption involves an elaborate interaction among inflammatory cells, resorbing cells, and hard tissue structures. The key cells which are involved in resorption are multi–nucleated giant cells. Internal root resorptions are usually non–symptomatic and they are discovered occasionally through periapical radiographs, which reveal very defined and regular ...

  9. Bone Canopies in Pediatric Renal Osteodystrophy

    Science.gov (United States)

    Pereira, Renata C.; Andersen, Thomas L.; Friedman, Peter A.; Tumber, Navdeep; Salusky, Isidro B.; Wesseling-Perry, Katherine

    2016-01-01

    Pediatric renal osteodystrophy (ROD) is characterized by changes in bone turnover, mineralization, and volume that are brought about by alterations in bone resorption and formation. The resorptive and formative surfaces on the cancellous bone are separated from the marrow cavity by canopies consisting of a layer of flat osteoblastic cells. These canopies have been suggested to play a key role in the recruitment of osteoprogenitors during the process of bone remodeling. This study was performed to address the characteristics of the canopies above bone formation and resorption sites and their association with biochemical and bone histomorphometric parameters in 106 pediatric chronic kidney disease (CKD) patients (stage 2–5) across the spectrum of ROD. Canopies in CKD patients often appeared as thickened multilayered canopies, similar to previous reports in patients with primary hyperparathyroidism. This finding contrasts with the thin appearance reported in healthy individuals with normal kidney function. Furthermore, canopies in pediatric CKD patients showed immunoreactivity to the PTH receptor (PTHR1) as well as to the receptor activator of nuclear factor kappa-B ligand (RANKL). The number of surfaces with visible canopy coverage was associated with plasma parathyroid hormone (PTH) levels, bone formation rate, and the extent of remodeling surfaces. Collectively, these data support the conclusion that canopies respond to the elevated PTH levels in CKD and that they possess the molecular machinery necessary to respond to PTH signaling. PMID:27045269

  10. Wnt Signaling in Bone

    Science.gov (United States)

    Kubota, Takuo; Michigami, Toshimi; Ozono, Keiichi

    2010-01-01

    Wnt signaling is involved not only in embryonic development but also in maintenance of homeostasis in postnatal tissues. Multiple lines of evidence have increased understanding of the roles of Wnt signaling in bone since mutations in the LRP5 gene were identified in human bone diseases. Canonical Wnt signaling promotes mesenchymal progenitor cells to differentiate into osteoblasts. The canonical Wnt/β-catenin pathway possibly through Lrp6, a co-receptor for Wnts as well as Lrp5, in osteoblasts regulates bone resorption by increasing the OPG/RANKL ratio. However, endogenous inhibitors of Wnt signaling including sclerostin block bone formation. Regulation of sclerostin appears to be one of the mechanisms of PTH anabolic actions on bone. Since sclerostin is almost exclusively expressed in osteocytes, inhibition of sclerostin is the most promising design. Surprisingly, Lrp5 controls bone formation by inhibiting serotonin synthesis in the duodenum, but not by directly promoting bone formation. Pharmacological intervention may be considered in many components of the canonical Wnt signaling pathway, although adverse effects and tumorigenicity to other tissues are important. More studies will be needed to fully understand how the Wnt signaling pathway actually influences bone metabolism and to assure the safety of new interventions. PMID:23926379

  11. Single nucleotide polymorphisms in HIF-1α gene and residual ridge resorption (RRR) of mandible in Korean population.

    Science.gov (United States)

    Paek, J; Oh, Y; Kim, J; Lee, J-H

    2015-01-01

    Tooth extraction is a routine surgical procedure in dental treatment. As a wound healing process after tooth extraction, a saddle-shaped residual ridge forms due to bone formation in the extraction socket and localized bone resorption on the external surface of the jawbone. The residual ridge is subjected to continuous bone resorption with substantial differences among individuals. In some cases, it results in excessive bone atrophy, which complicates dental restorative treatment. This unique oral wound healing process may be influenced by factors that are specific to oral tissue. HIF expression is different in oral wound healing compared to that of skin wounds. The objective of this study was to examine a genetic association between SNP of the HIF-1α gene, which is known to have high genetic diversity, and the residual ridge resorption (RRR). Two hundred and two Korean subjects (70.80  ±  9.40 years) with partially or completely edentulous mandible were recruited, and edentulous mandibular bone height was measured following the protocol of the American College of Prosthodontists. The HIF-1α allele was directly sequenced in 24 subjects resulting in the variants over 5% frequency in 95% likelihood, whereas tag-SNPs were selected to perform analysis for the remaining population. Student's t-test and ANOVA were used for statistical analysis to examine the association between the SNPs and the RRR. Four novel variants were discovered, and a minor allele of rs11549467 was associated with the RRR of the subjects (p = 0.028). rs11549467 increases HIF-1α transactivity, enhancing angiogenesis and increasing new vessel formation. Thus, rs11549467 may play an important role in the disturbed bone remodeling balance resulting in RRR. Results of this study may be useful in developing novel genetic diagnostic tests and identifying Koreans susceptible to developing excessive jawbone atrophy after dental extraction. Most importantly, early screening using genetic information

  12. Osteoclasts from patients with autosomal dominant osteopetrosis type I caused by a T253I mutation in low-density lipoprotein receptor-related protein 5 are normal in vitro, but have decreased resorption capacity in vivo

    DEFF Research Database (Denmark)

    Henriksen, Kim; Gram, Jeppe; Høegh-Andersen, Pernille; Jemtland, Rune; Ueland, Thor; Dziegiel, Morten Hanefeld; Schaller, Sophie; Bollerslev, Jens; Karsdal, Morten A

    2005-01-01

    found attenuated resorptive response to T3 stimulation, despite a normal bone formation response, in alignment with the reduced number of osteoclasts in vivo. These data demonstrate that ADOI osteoclasts are normal with respect to all aspects investigated in vitro. We speculate that the mutations...

  13. Controlling dynamic mechanical properties and degradation of composites for bone regeneration by means of filler content

    NARCIS (Netherlands)

    Barbieri, Davide; de Bruijn, Joost D.; Luo, Xiaoman; Fare, Silvia; Grijpma, Dirk W.; Yuan, Huipin

    2013-01-01

    Bone tissue is a dynamic composite system that adapts itself, in response to the surrounding daily (cyclic) mechanical stimuli, through an equilibrium between growth and resorption processes. When there is need of synthetic bone grafts, the biggest issue is to support bone regeneration without causi

  14. Distribution of BMP6 in the alveolar bone during mouse mandibular molar eruption

    Czech Academy of Sciences Publication Activity Database

    Oralová, Veronika; Chlastáková, I.; Radlanski, R.J.; Matalová, Eva

    2014-01-01

    Roč. 55, 5-6 (2014), s. 357-366. ISSN 0300-8207 R&D Projects: GA ČR GCP302/12/J059 Institutional support: RVO:67985904 Keywords : bone morphogenetic protein * bone resorption * bone apposition Subject RIV: EA - Cell Biology Impact factor: 1.607, year: 2014

  15. [Bone health in patients with anorexia nervosa].

    Science.gov (United States)

    Suzuki, Mari Hotta

    2013-02-01

    Osteoporosis associated with anorexia nervosa (AN) is common, and tends to be severe, slow to recover from, and sometimes irreversible. The abnormal bone metabolism in severely emaciated AN patients involves both a reduction in bone formation and an increase in bone resorption. The annual change in lumbar bone mineral density (BMD) is significantly correlated with BMI at the entry. The critical BMI for a positive increase in BMD was 16.4±0.3 kg/m(2). Nutritional improvement with body weight gain is the most important goal of treatment for AN-related osteoporosis since it increases both serum levels of insulin-like growth factor-I, a potent osteogenic factor, and estradiol, a powerful bone resorption inhibitor. However, it is difficult for AN patients to accept weight gain. About 50% of AN patients are insufficient of vitamin D and 43% show an increase in plasma undercalboxylated osteocalcin, indicating a deficiency state of the vitamin K(2). Vitamin D(3) or vitamin K(2) (menatetrenone) can prevent further bone loss in severely emaciated AN patients. Recently, bone strength has been evaluated by both BMD and bone quality. Plasma levels of homocysteine, a marker of degradation of bone quality, have significantly positive correlation with their ages of AN patients. We must evaluate bone density as well as bone quality in AN patients. PMID:23354095

  16. Does methamphetamine affect bone metabolism?

    International Nuclear Information System (INIS)

    There is a close relationship between the central nervous system activity and bone metabolism. Therefore, methamphetamine (METH), which stimulates the central nervous system, is expected to affect bone turnover. The aim of this study was to investigate the role of METH in bone metabolism. Mice were divided into 3 groups, the control group receiving saline injections, and the 5 and 10 mg/kg METH groups (n = 6 in each group). All groups received an injection of saline or METH every other day for 8 weeks. Bone mineral density (BMD) was assessed by X-ray computed tomography. We examined biochemical markers and histomorphometric changes in the second cancellous bone of the left femoral distal end. The animals that were administered 5 mg/kg METH showed an increased locomotor activity, whereas those receiving 10 mg/kg displayed an abnormal and stereotyped behavior. Serum calcium and phosphorus concentrations were normal compared to the controls, whereas the serum protein concentration was lower in the METH groups. BMD was unchanged in all groups. Bone formation markers such as alkaline phosphatase and osteocalcin significantly increased in the 5 mg/kg METH group, but not in the 10 mg/kg METH group. In contrast, bone resorption markers such as C-terminal telopeptides of type I collagen and tartrate-resistant acid phosphatase 5b did not change in any of the METH groups. Histomorphometric analyses were consistent with the biochemical markers data. A significant increase in osteoblasts, especially in type III osteoblasts, was observed in the 5 mg/kg METH group, whereas other parameters of bone resorption and mineralization remained unchanged. These results indicate that bone remodeling in this group was unbalanced. In contrast, in the 10 mg/kg METH group, some parameters of bone formation were significantly or slightly decreased, suggesting a low turnover metabolism. Taken together, our results suggest that METH had distinct dose-dependent effects on bone turnover and that

  17. 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...

  18. Sclerostin Levels and Bone Turnover Markers in Adolescents with Anorexia Nervosa and Healthy Adolescent Girls

    OpenAIRE

    Faje, Alexander T.; Fazeli, Pouneh K.; Katzman, Debra K; Miller, Karen K.; Breggia, Anne; Rosen, Clifford J.; Mendes, Nara; Klibanski, Anne; Misra, Madhusmita

    2012-01-01

    Sclerostin, product of the SOST gene, is an important determinant of bone formation and resorption. Adolescents with anorexia nervosa (AN) have low bone density and decreased levels of bone turnover markers. However, sclerostin has not been examined in AN as a potential mediator of impaired bone metabolism. Our study objectives were to (i) assess associations of sclerostin with surrogate bone turnover markers in girls with AN and controls and (ii) examine effects of transdermal estradiol on s...

  19. Osteobiology: newest bone organ topics and the platelet-rich plasma treatment.

    OpenAIRE

    Ananias García Cardona; Gérgory Alfonso García; Ómar Ramón Mejía; Mario Vittorino Mejía; Dianney Clavijo Grimaldi; Ciro Alfonso Casadiego Torrado

    2007-01-01

    The bone is a dynamic tissue taht provides mechanical support, physical protection, storage site for minerals, and enables genesis movement. The bone biology (osteobiology) is regulated by the balance betqeen osteoblastic formation and osteoclatic resorption. the skeletal bone homeostasis is influenced by components of the bone marrow organ, neuroendocrine system and hemato-inmmune system. The purpose of this review is to describe the biodynamic of the bone organ, and actual terapeutics with ...

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

    OpenAIRE

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

    2011-01-01

    To maintain bone mass during bone remodelling, coupling is required between bone resorption and bone formation. This coordination is achieved by a network of autocrine and paracrine signalling molecules between cells of the osteoclast lineage and cells of the osteoblastic lineage. Mathematical modelling of signalling between cells of both lineages can assist in the interpretation of experimental data, clarify signalling interactions and help develop a deeper understanding of complex bone dise...

  1. The response of bone to unloading

    Science.gov (United States)

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

    1999-01-01

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

  2. Idiopathic Radiographic Apical Root Resorption in Wind Instrument Players.

    Science.gov (United States)

    Shafi, Imran; Welbury, Richard

    2015-12-01

    Root resorption of the permanent teeth involves an elaborate interaction among inflammatory cells resulting in loss of dental hard tissues. This report describes three clinical cases where idiopathic root resorption occurred in wind instrument playing patients. These patients produce adequate non-orthodontic forces, while playing their instruments, to expose their teeth to root resorbing force. Careful clinical monitoring of patients' teeth should be undertaken, as the additive effects of orthodontic treatment and musical habits are unknown. CPD/Clinical Relevance: This paper advises that questioning about wind instrument playing during case history-taking would be beneficial to clinicians. Furthermore, careful clinical monitoring of these patients' teeth during orthodontic treatment should be undertaken. PMID:26856005

  3. Bone pathology inpsoriatic arthritis

    Directory of Open Access Journals (Sweden)

    V. V. Badokin

    2007-10-01

    Full Text Available Objective. To study different variants of osteolysis in pts with psoriatic arthritis (PA and to reveal their relationship with other clinico-radiological features of joint damage. Material and methods. 370 pts with definite PA having different variants of joint damage were included. Radiological examination of bones and joints (in some cases large picture frame was performed. Morphological evaluation of synovial biopsies was done in 34 pts with PA and 10 pts with rheumatoid arthritis (RA. Results. Different types of osteolysis were revealed in 80 (21,6% pts. Osteolytic variant of joint damage was present in 29 pts. 33 pts had acral, 48 — intra-articular osteolysis and 16 - true bone atrophy. Frequency and intensity of bone resorption were associated with severity of PA. Acral osteolysis correlated with arthritis of distal interphalangeal joints and onychodystrophy. Intra-articular osteolysis was most often present in distal interphalangeal joints of hands and metacarpophalangeal joints (39,6% and 41,7% respectively. Characteristic feature of PA was combination of prominent resorption with formation of bone ankylosis and periosteal reaction. Ankylosis was present in 33,3% of pts with intra-articular osteolysis and in 60% of pts with combination of different osteolysis variants. Systemic reaction of microcirculation in synovial biopsies was most prominent in osteolytic variant: marked thickening of capillary and venule basal membrane with high level of acid phosphatase, increased capillary and precapillary blood flow with stasis features, vascular lymphocyte and macrophage infiltration, productive vasculitis with annular wall thickening, thrombovasculitis and villi deep layer sclerosis. Conclusion. Different variants of osteolysis show bone involvement in PA. Acral and intra- articular osteolysis association with bone ankylosis and periostitis proves their common pathogenetic entity.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Pathogen infection drives patterns of nutrient resorption in citrus plants

    OpenAIRE

    Jirong Cao; Chunzhen Cheng; Junjie Yang; Qibing Wang

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen ‘Candidatus Liberibacter asiaticus’ grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of ‘Ca. L. asiaticus’ infection on nit...

  6. A resorption cycle for the cogeneration of electricity and refrigeration

    International Nuclear Information System (INIS)

    Graphical abstract: A novel resorption cycle driven by low grade heat for cogeneration of electricity and refrigeration is studied. The cycle features in high exergy efficiency, very little or no ammonia liquid inside and simple structure. Highlights: ► A resorption cogeneration cycle for electricity and refrigeration is proposed. ► The cycle improved refrigeration COP by 10 times compared with Goswami cycle. ► The highest exergy efficiency of the cogeneration cycle is as high as 0.9. ► The cycle also features in safety and simple structure. - Abstract: This paper describes a novel resorption cycle driven by the low grade heat for the cogeneration of electricity and refrigeration, which is based on ammonia adsorption refrigeration technology. The presented cycle features a variable endothermic process which stands for higher adaptability if compared with the traditional Rankine cycle, very little or no ammonia liquid in the system which is a safety feature, solid adsorbents inside the beds, and simple structure for the fact of no rectifying equipment and circulation pumps required by the working fluids. This cycle can be utilised for the heat source with the temperature higher than 100 °C, and it has an electricity generation exergy efficiency of up to 0.69 and a refrigeration coefficient of performance (COP) of up to 0.77. If compared with the Goswami cycle, which is established based on the absorption Kalina cycle for the cogeneration of electricity and refrigeration, the novel resorption cycle kept the merit of the high exergy efficiency for electricity generation, meanwhile, it overcame the limitation of the low refrigeration coefficient of performance (COP) of Goswami cycle, and improved the COP by 10 times. The optimum overall exergy efficiency is as high as 0.9, which is 40–60% improved compared with the Goswami cycle under the same working conditions

  7. Multiple idiopathic external and internal resorption: Case report with cone-beam computed tomography findings

    Energy Technology Data Exchange (ETDEWEB)

    Celikten, Berkan; Uzuntas, Ceren Feriha; Kurt, Hakan [Faculty of Dentistry, Ankara University, Ankara (Turkmenistan)

    2014-12-15

    Root resorption is loss of dental hard tissue as a result of clastic activities. The dental hard tissue of permanent teeth does not normally undergo resorption, except in cases of inflammation or trauma. However, there are rare cases of tooth resorption of an unknown cause, known as 'idiopathic root resorption.' This report would discuss a rare case of multiple idiopathic resorption in the permanent maxillary and mandibular teeth of an otherwise healthy 36-year-old male patient. In addition to a clinical examination, the patient was imaged using conventional radiography and cone-beam computed tomography (CBCT). The examinations revealed multiple external and internal resorption of the teeth in all four quadrants of the jaws with an unknown cause. Multiple root resorption is a rare clinical phenomenon that should be examined using different radiographic modalities. Cross-sectional CBCT is useful in the diagnosis and examination of such lesions.

  8. Abnormal bone remodelling in inflammatory arthritis

    Science.gov (United States)

    Bogoch, Earl R.; Moran, Erica

    1998-01-01

    Osteopenia is responsible for substantial comorbidity in patients suffering from rheumatoid arthritis and is an important factor in the surgical management of joint disease. In animal models of bone loss stimulated by inflammatory arthritis, increased bone remodelling and altered microstructure of bone have been documented. The subchondral bone plate near the joint surface is narrow and perforated by vascular inflammatory invasion, and in the shaft the thin cortices are weakened by giant resorption defects. Biomechanical tests and a mathematical model of bone strength suggest that cortical defects, much larger than those found in normal osteonal remodelling, are principally responsible for the experimentally observed loss of strength. Similarly, these defects may explain the increased femoral fracture risk in rheumatoid arthritis. The osteoclast, the cell resorbing bone, is demonstrated in increased number and activity in rheumatoid arthritis and in animal models. Bisphosphonates, drugs that inhibit osteoclast function, have been shown experimentally to reduce both focal and generalized osteopenia and to prevent loss of bone strength. Bisphosphonates also protect articular cartilage from damage characteristic of inflammatory arthritis. The mechanism of chondroprotection may be prevention of subchondral bone resorption by the osteoclast and also an altered distribution of bone marrow cells. Thus, bisphosphonates, currently in clinical use for other bone metabolic diseases, appear to have potential as prophylaxis and treatment for osteopenia and joint damage in inflammatory arthritis. PMID:9711159

  9. Biochemical markers of bone metabolism reflect osteoclastic and osteoblastic activity in multiple myeloma

    DEFF Research Database (Denmark)

    Abildgaard, N; Glerup, H; Rungby, Jørgen;

    2000-01-01

    histomorphometric findings. MARKERS OF BONE FORMATION: Serum C-terminal propeptide of procollagen I (PICP) and serum bone-specific alkaline phosphatase (bAP) showed significant correlations with the dynamic parameters of bone formation (r=0.57-0.58), whereas serum osteocalcin and serum total AP did not. CYTOKINES......: Highly significant correlations were observed between marrow IL-6 and rates of bone resorption and activation frequency (r=0.76-0.82) and with serum ICTP (r=0.63). Minor, but also significant correlations were observed between the resorptive indices and IL-6sR and IL-1beta. The data indicate that...

  10. Bone Mineral Density in Patients with Growth Hormone Deficiency - Does a Gender Difference Exist?

    DEFF Research Database (Denmark)

    Hitz, Mette; Jensen, Jens-Erik Beck; Eskildsen, PC

    2006-01-01

    , phosphate, creatinine, PTH, vitamin D, IGF-1, markers of bone formation and bone resorption, and dual energy X-ray absorptiometry (DEXA), to determine BMD and BMC of the lumbar spine, hip, distal arm and total body, were performed in 34 patients with GHD (19 females) and 34 sex-, age- and weight...... identical BMD values at all regions. This gender difference was even more obvious when BMD values were expressed as Z-scores or as three-dimensional BMD of the total body. The bone formation and bone resorption markers, as well as calcium and vitamin D, were all at the same levels in GH-deficient and...

  11. Bone mineral density in patients with growth hormone deficiency: does a gender difference exist?

    DEFF Research Database (Denmark)

    Hitz, Mette Friberg; Jensen, Jens-Erik Beck; Eskildsen, Peter C

    2006-01-01

    , phosphate, creatinine, PTH, vitamin D, IGF-1, markers of bone formation and bone resorption, and dual energy X-ray absorptiometry (DEXA), to determine BMD and BMC of the lumbar spine, hip, distal arm and total body, were performed in 34 patients with GHD (19 females) and 34 sex-, age- and weight...... identical BMD values at all regions. This gender difference was even more obvious when BMD values were expressed as Z-scores or as three-dimensional BMD of the total body. The bone formation and bone resorption markers, as well as calcium and vitamin D, were all at the same levels in GH-deficient and...

  12. A histological evaluation on osteogenesis and resorption of methotrexate-loaded calcium phosphate cement in vivo

    International Nuclear Information System (INIS)

    In this study, we investigated the resorption of in vivo methotrexate-loaded calcium phosphate cement (MTX-CPC) implants and their effect on osteogenesis. MTX-CPC implants containing 1% methotrexate (MTX) (weight/weight) were preset and implanted into the femoral condyle of rabbits. Calcium phosphate cement (CPC) without MTX was used as the control. The femurs were harvested at day 1 and at 1, 3 and 6 months after implantation and radiological examination were performed. Decalcified sections were examined by hematoxylin and eosin (HE) staining, alkaline phosphatase (ALPase) immunohistochemistry and tartrate-resistant acid phosphatase (TRAPase) enzyme histochemistry. Then, we performed histomorphometric analysis, including determination of the percentage of newly formed bone and osteoblast and osteoclast counts. The results indicated that MTX-CPC implants were biocompatible, biodegradable and osteoconducive. However, MTX release from the implantation site inhibited osteogenesis in the initial period; this inhibition weakened with time, and no difference was observed between CPC and MTX-CPC at 6 months after implantation. Hence, MTX-CPC is an excellent material for filling defects and can be used for preparing effective drug delivery systems to achieve local control of invasive bone tumors.

  13. A histological evaluation on osteogenesis and resorption of methotrexate-loaded calcium phosphate cement in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Li Dong; Yang Zhiping; Li Xin; Li Zhenfeng; Li Jianmin [Department of Orthopedics, Qilu Hospital of Shandong University, Shandong (China); Yang Jingyan, E-mail: yangzhiping@medmail.com.c [Department of Pathology, 2nd Affiliated Hospital of Shandong University, Shandong (China)

    2010-04-15

    In this study, we investigated the resorption of in vivo methotrexate-loaded calcium phosphate cement (MTX-CPC) implants and their effect on osteogenesis. MTX-CPC implants containing 1% methotrexate (MTX) (weight/weight) were preset and implanted into the femoral condyle of rabbits. Calcium phosphate cement (CPC) without MTX was used as the control. The femurs were harvested at day 1 and at 1, 3 and 6 months after implantation and radiological examination were performed. Decalcified sections were examined by hematoxylin and eosin (HE) staining, alkaline phosphatase (ALPase) immunohistochemistry and tartrate-resistant acid phosphatase (TRAPase) enzyme histochemistry. Then, we performed histomorphometric analysis, including determination of the percentage of newly formed bone and osteoblast and osteoclast counts. The results indicated that MTX-CPC implants were biocompatible, biodegradable and osteoconducive. However, MTX release from the implantation site inhibited osteogenesis in the initial period; this inhibition weakened with time, and no difference was observed between CPC and MTX-CPC at 6 months after implantation. Hence, MTX-CPC is an excellent material for filling defects and can be used for preparing effective drug delivery systems to achieve local control of invasive bone tumors.

  14. Effects of low-level laser therapy on orthodontic tooth movement and root resorption after artificial socket preservation

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2014-01-01

    Full Text Available Background: Low- level laser therapy has been used to stimulate the orthodontic tooth movements (OTM previously. Furthermore, in the orthodontic treatments accompanying tooth extractions, the adjacent teeth move towards the extraction sites and close the space in some cases. Then, the adjacent tooth movements must be prevented in the treatments requiring space. Laser stimulates and at some doses decelerates tooth movement; it also improves healing process and enhances osteogenesis. Hence, it can prevent movement by osteogenesis adjacent to the tooth. The present study investigated the effects of low-level laser therapy on the OTM and root resorption following artificial socket preservation. Materials and Methods: In this experimental animal trial, 16 male albino rabbits were selected with similar characteristics and randomly divided in two groups. Under general anesthesia, an artificial socket, 8 mm in height, was created in the mesial aspect of the first premolars of the rabbits and filled with demineralized freeze dried bone allograft (DFDBA. The first premolars were connected to the incisors using nickel titanium coil springs. In experimental group, gallium-aluminum-arsenide (GaAlAs laser was irritated mesial to first premolar where artificial socket was created continuously (808 nm. The cycle was 10 days irritation, 14 days rest, 10 days irritation, 14 days rest (Biostimulation mode. Control group was not laser irradiated. All animals were sacrificed after 48 days and the distance between the distal aspect of the first premolars, and the mesial surface of the second premolars was measured with leaf gauge. The specimens underwent histological assessments. Integrity of root and its resorption was observed under microscope calibration. The size of resorption lacunae was calculated in mm 2 . Normality of data was proved according to Kolmogorov-Smirnov analysis, and Student′s t-test was done. P value less than 0.05 was considered as significant

  15. Vascularization of bone regeneration products in acute radiation sickness

    International Nuclear Information System (INIS)

    In 119 rabbits with acute radiation sickness the vascularization process in bone regeneration products was studied by microangiography. The formation of arteries and of bone structures was retarded in irradiated animals. The deficient formation of veins and capillaries did not cause conditions for venous blood circulation and resulted in a slow resorption of newly formed bone structures and gristle. That is one of the reasons for an extended healing process of fractures and for formation of false articulations in irradiated animals. (author)

  16. Contemporary Therapeutic Approaches Targeting Bone Complications in Prostate Cancer

    OpenAIRE

    Lee, Richard J.; Saylor, Philip J.; Smith, Matthew R.

    2010-01-01

    Skeletal complications are major causes of morbidity in patients with prostate cancer. Despite the osteoblastic appearance of prostate cancer bone metastases, elevated serum and urinary markers of bone resorption are indicative of high osteoclast activity. Increased osteoclast activity is independently associated with subsequent skeletal complications, disease progression, and death. Osteoclast-targeted therapies aim to reduce the risk for disease-related skeletal complications, bone metastas...

  17. Proteomics approaches for the studies of bone metabolism

    OpenAIRE

    Lee, Ji-Hyun; Cho, Je-Yoel

    2014-01-01

    Bone is an active tissue, in which bone formation by osteoblast is followed by bone resorption by osteoclasts, in a repeating cycle. Proteomics approaches may allow the detection of changes in cell signal transduction, and the regulatory mechanism of cell differentiation. LC-MS/MS-based quantitative methods can be used with labeling strategies, such as SILAC, iTRAQ, TMT and enzymatic labeling. When used in combination with specific protein enrichment strategies, quantitative proteomics method...

  18. Changes in biochemical bone markers during pregnancy and puerperium.

    OpenAIRE

    Yoon, B. K.; Lee, J.W.; Choi, D. S.; Roh, C. R.; Lee, J.H.

    2000-01-01

    To elucidate the changes in bone turnover during pregnancy and puerperium, we measured serially the levels of serum osteocalcin and urine deoxypyridinoline (Dpy) as markers of bone formation and bone resorption, respectively, in 22 healthy women with normal pregnancy. Nineteen non-pregnant women served as control. The Dpy levels increased significantly at 16 weeks of pregnancy and remained elevated thereafter. The levels of osteocalcin, however, were significantly decreased at 16 weeks of pre...

  19. Osteoblasts in Bone Physiology—Mini Review

    Directory of Open Access Journals (Sweden)

    Orit Rosenberg

    2012-04-01

    Full Text Available Bone structural integrity and shape are maintained by removal of old matrix by osteoclasts and in-situ synthesis of new bone by osteoblasts. These cells comprise the basic multicellular unit (BMU. Bone mass maintenance is determined by the net anabolic activity of the BMU, when the matrix elaboration of the osteoblasts equals or exceeds the bone resorption by the osteoclasts. The normal function of the BMU causes a continuous remodeling process of the bone, with deposition of bony matrix (osteoid along the vectors of the generated force by gravity and attached muscle activity. The osteoblasts are derived from mesenchymal stem cells (MSCs. Circulating hormones and locally produced cytokines and growth factors modulate the replication and differentiation of osteoclast and osteoblast progenitors. The appropriate number of the osteoblasts in the BMU is determined by the differentiation of the precursor bone-marrow stem cells into mature osteoblasts, their proliferation with subsequent maturation into metabolically active osteocytes, and osteoblast degradation by apoptosis. Thus, the two crucial points to target when planning to control the osteoblast population are the processes of cell proliferation and apoptosis, which are regulated by cellular hedgehog and Wnt pathways that involve humoral and mechanical stimulations. Osteoblasts regulate both bone matrix synthesis and mineralization directly by their own synthetic activities, and bone resorption indirectly by its paracrinic effects on osteoclasts. The overall synthetic and regulatory activities of osteoblasts govern bone tissue integrity and shape.

  20. Mutations in FAM20C Are Associated with Lethal Osteosclerotic Bone Dysplasia (Raine Syndrome), Highlighting a Crucial Molecule in Bone Development

    OpenAIRE

    Simpson, M. A. ; Hsu, R. ; Keir, L. S. ; Hao, J. ; Sivapalan, G. ; Ernst, L. M. ; Zackai, E. H. ; Al-Gazali, L. I. ; Hulskamp, G. ; Kingston, H. M. ; Prescott, T. E. ; Ion, A. ; Patton, M. A. ; Murday, V. ; George, A. 

    2007-01-01

    The generation and homeostasis of bone tissue throughout development and maturity is controlled by the carefully balanced processes of bone formation and resorption. Disruption of this balance can give rise to a broad range of skeletal pathologies. Lethal osteosclerotic bone dysplasia (or, Raine syndrome) is an autosomal recessive disorder characterized by generalized osteosclerosis with periosteal bone formation and a distinctive facial phenotype. Affected individuals survive only days or we...

  1. Short-Term Effects of Kefir-Fermented Milk Consumption on Bone Mineral Density and Bone Metabolism in a Randomized Clinical Trial of Osteoporotic Patients

    OpenAIRE

    Tu, Min-Yu; Chen, Hsiao-Ling; Tung, Yu-Tang; Kao, Chao-Chih; Hu, Fu-Chang; Chen, Chuan-Mu

    2015-01-01

    Milk products are good sources of calcium that may reduce bone resorption and help prevent bone loss as well as promote bone remodeling and increase bone formation. Kefir is a product made by kefir grains that degrade milk proteins into various peptides with health-promoting effects, including antithrombotic, antimicrobial and calcium-absorption enhancing bioactivities. In a controlled, parallel, double-blind intervention study over 6 months, we investigated the effects of kefir-fermented mil...

  2. Bone nutrients for vegetarians.

    Science.gov (United States)

    Mangels, Ann Reed

    2014-07-01

    The process of bone mineralization and resorption is complex and is affected by numerous factors, including dietary constituents. Although some dietary factors involved in bone health, such as calcium and vitamin D, are typically associated with dairy products, plant-based sources of these nutrients also supply other key nutrients involved in bone maintenance. Some research suggests that vegetarian diets, especially vegan diets, are associated with lower bone mineral density (BMD), but this does not appear to be clinically significant. Vegan diets are not associated with an increased fracture risk if calcium intake is adequate. Dietary factors in plant-based diets that support the development and maintenance of bone mass include calcium, vitamin D, protein, potassium, and soy isoflavones. Other factors present in plant-based diets such as oxalic acid and phytic acid can potentially interfere with absorption and retention of calcium and thereby have a negative effect on BMD. Impaired vitamin B-12 status also negatively affects BMD. The role of protein in calcium balance is multifaceted. Overall, calcium and protein intakes in accord with Dietary Reference Intakes are recommended for vegetarians, including vegans. Fortified foods are often helpful in meeting recommendations for calcium and vitamin D. Plant-based diets can provide adequate amounts of key nutrients for bone health. PMID:24898231

  3. Osteogenesis effect of guided bone regeneration combined with alveolar cleft grafting: assessment by cone beam computed tomography.

    Science.gov (United States)

    Xiao, W-L; Zhang, D-Z; Chen, X-J; Yuan, C; Xue, L-F

    2016-06-01

    Cone beam computed tomography (CBCT) allows for a significantly lower radiation dose than conventional computed tomography (CT) scans and provides accurate images of the alveolar cleft area. The osteogenic effect of guided bone regeneration (GBR) vs. conventional alveolar bone grafting alone for alveolar cleft defects was evaluated in this study. Sixty alveolar cleft patients were divided randomly into two groups. One group underwent GBR using acellular dermal matrix film combined with alveolar bone grafting using iliac crest bone grafts (GBR group), while the other group underwent alveolar bone grafting only (non-GBR group). CBCT images were obtained at 1 week and at 3 months following the procedure. Using Simplant 11.04 software, the bone resorption rate was calculated and compared between the two groups. The bone resorption rate from 1 week to 3 months following bone grafting without the GBR technique was 36.50±5.04%, whereas the bone resorption rate using the GBR technique was 31.69±5.50% (P=0.017). The application of autogenous iliac bone combined with the GBR technique for alveolar bone grafting of alveolar cleft patients can reduce bone resorption and result in better osteogenesis. PMID:26876144

  4. Bone Metabolism in Adolescents with Anorexia Nervosa

    Science.gov (United States)

    Misra, Madhusmita; Klibanski, Anne

    2013-01-01

    Adolescents with anorexia nervosa (AN) are at risk for low bone mass at multiple sites, associated with decreased bone turnover. Bone microarchitecture is also affected, with a decrease in bone trabecular volume and trabecular thickness, and an increase in trabecular separation. The adolescent years are typically the time when marked increases occur in bone mass accrual towards the attainment of peak bone mass, an important determinant of bone health and fracture risk in later life. AN often begins in the adolescent years, and decreased rates of bone mass accrual at this critical time are therefore also concerning for deficits in peak bone mass. Factors contributing to low bone density and decreased rates of bone accrual include alterations in body composition such as low BMI and lean body mass, and hormonal alterations such as hypogonadism, a nutritionally acquired resistance to growth hormone and low levels of IGF-1, relative hypercortisolemia, low levels of leptin, and increased adiponectin (for fat mass) and peptide YY. Therapeutic strategies include optimizing weight and menstrual recovery, and adequate calcium and vitamin D replacement. Oral estrogen-progesterone combination pills are not effective in increasing bone density in adolescents with AN. RhIGF-1 increases levels of bone formation markers in the short-term, while long-term effects remain to be determined. Bisphosphonates act by decreasing bone resorption, and are not optimal for use in adolescents with AN, in whom the primary defect is low bone formation. PMID:21301203

  5. Inhibitory effect of auranofin (I) and chloroquine (II) on bone degradation induced by the interleukin 1-like (IL-1-like) factor released from rheumatoid synovial tissue (RAST) in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Hodges, Y.; Maser, M.R.; Britton, M.C.; Multz, C.V.; Butler, E.; Chin, R.C.

    1986-03-01

    RAST, maintained in organ culture, releases two distinct types of bone resorptive factors and one co-resorptive factor. The first is prostaglandin E/sub 2/ (PGE/sub 2/), while the second is a protein with properties of IL-1. The co-resorptive factor collagenase, cannot induce bone resorption by itself, but augments the bone resorptive activity initiated by either PGE/sub 2/ or the IL-l-like factor. Bone resorptive activity was assessed by measuring the release of /sup 45/Ca from prelabelled rat fetal bones. We investigated the effects of five non-steroidal anti-inflammatory drugs (NSAIDs) and two disease-modifying anti-rheumatic drugs (DMARDs), (I) and (II), on bone degradation mediated by the IL-l-like factor. None of the NSAIDs tested inhibited bone degradation at 5 x 10/sup -5/ M. On the other hand, both (I) and (II) inhibited bone degradation 60 to 100% at 1 x 10/sup -6/ M and 8 x 10/sup -6/ M respectively. They can inhibit the action of IL-l-like factor on bone at therapeutically attainable concentrations. Additionally, both (I) and (II) block the release of collagenase from the organ culture of RAST with IC/sub 50/s of 5 x 10/sup -6/ M. This unique ability to inhibit collagenase release may contribute to their effectiveness is preventing bone loss in this test model.

  6. Inhibitory effect of auranofin (I) and chloroquine (II) on bone degradation induced by the interleukin 1-like (IL-1-like) factor released from rheumatoid synovial tissue (RAST) in vitro

    International Nuclear Information System (INIS)

    RAST, maintained in organ culture, releases two distinct types of bone resorptive factors and one co-resorptive factor. The first is prostaglandin E2 (PGE2), while the second is a protein with properties of IL-1. The co-resorptive factor collagenase, cannot induce bone resorption by itself, but augments the bone resorptive activity initiated by either PGE2 or the IL-l-like factor. Bone resorptive activity was assessed by measuring the release of 45Ca from prelabelled rat fetal bones. We investigated the effects of five non-steroidal anti-inflammatory drugs (NSAIDs) and two disease-modifying anti-rheumatic drugs (DMARDs), (I) and (II), on bone degradation mediated by the IL-l-like factor. None of the NSAIDs tested inhibited bone degradation at 5 x 10-5 M. On the other hand, both (I) and (II) inhibited bone degradation 60 to 100% at 1 x 10-6 M and 8 x 10-6 M respectively. They can inhibit the action of IL-l-like factor on bone at therapeutically attainable concentrations. Additionally, both (I) and (II) block the release of collagenase from the organ culture of RAST with IC50s of 5 x 10-6 M. This unique ability to inhibit collagenase release may contribute to their effectiveness is preventing bone loss in this test model

  7. Orthodontic treatment in patient with idiopathic root resorption: A case report

    Directory of Open Access Journals (Sweden)

    Diego Rey

    2015-02-01

    Full Text Available Multiple idiopathic external root resorption is a rare pathological condition usually detected as an incidental radiographic finding. External root resorption of permanent teeth is a multifactorial process related to several local and systemic factors. If an etiological factor cannot be identified for root resorption, the term "idiopathic" is applied. This report presents a case of multiple idiopathic apical root resorption. The condition was found in a young female patient seeking orthodontic treatment due to malocclusion. This kind of resorption starts apically and progresses coronally, causing a gradual shortening and rounding of the remaining root. Patients with this condition are not the ideal candidates for orthodontic treatment; however, the aim of this report is to describe an unusual case of idiopathic root resorption involving the entire dentition, and to present the orthodontic treatment of this patient. It describes the progress and completion of orthodontic therapy with satisfactory end results.

  8. Correlation of the Levels of the Bone Turnover Markers BAP and β-CTX with Bone Metastasis Progress in Lung Cancer Patients

    OpenAIRE

    Tang, Qiong; Zhao, Hui; JIA, RUI; Liu, Linlin

    2013-01-01

    Background and objective Bone metastasis is common in lung cancer patients. The β isomer of the C-terminal telopeptide of type I collagen (β-CTX) and bone-specific alkaline phosphates (BAP) are regarded as important bone turnover markers in bone resorption and formation. Thus, the aims of this study are to determine the correlation of these bone turnover markers with the extent of bone metastasis of lung cancer. Methods A total of 92 patients with bone metastasis of lung cancer from Tianjin U...

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Root resorption after dental traumas: classification and clinical, radiographic and histologic aspects

    OpenAIRE

    Bruno Oliveira de Aguiar Santos; Diego Santiago de Mendonça; Denise Lins de Sousa; José Jeová Siebra Moreira Neto; Rebeca Bastos Rocha de Araújo

    2011-01-01

    Introduction: One of the most common sequelae observed after dental trauma is root resorption. Objective: The aim of this study was to classify and discuss the external root resorption after a dental trauma, based on a literature review. Literature review: A bibliographic search was performed in the following databases: Medline, PubMed, and Lilacs, from 1997 to 2010. The following descriptors were used: Root resorption, Dental trauma and Classification. From a total of 152 articles found, 25...

  11. Management of Inflammatory Internal Root Resorption with Biodentine and Thermoplasticised Gutta-Percha

    OpenAIRE

    Girish Umashetty; Upendra Hoshing; Suvarna Patil; Nishant Ajgaonkar

    2015-01-01

    Internal root resorption is a chronic inflammatory process initiated within the pulp space with the loss of dentin. This condition demands a comprehensive understanding of the pathologic process, so as to identify the cause and arrest the resorptive phenomena. It is a rare occurrence, asymptomatic, with slow progression, detected through routine radiographic examination, where it appears as a radiolucent lesion. This paper reports a clinical case of inflammatory internal root resorption in th...

  12. Rapidly Assessing Changes in Bone Mineral Balance Using Natural Stable Calcium Isotopes

    Science.gov (United States)

    Morgan, J. L. L.; Gordon, G. W.; Romaniello, S. J.; Skulan, J. L.; Smith, S. M.; Anbar, A. D.

    2011-01-01

    We demonstrate that variations in the Ca isotope ratios in urine rapidly and quantitatively reflect changes in bone mineral balance. This variation occurs because bone formation depletes soft tissue of light Ca isotopes, while bone resorption releases that isotopically light Ca back into soft tissue. In a study of 12 individuals confined to bed rest, a condition known to induce bone resorption, we show that Ca isotope ratios shift in a direction consistent with net bone loss after just 7 days, long before detectible changes in bone density occur. Consistent with this interpretation, the Ca isotope variations track changes observed in N-teleopeptide, a bone resorption biomarker, while bone-specific alkaline phosphatase, a bone formation biomarker, is unchanged. Ca isotopes can in principle be used to quantify net changes in bone mass. Ca isotopes indicate an average loss of 0.62 +/- 0.16 % in bone mass over the course of this 30-day study. The Ca isotope technique should accelerate the pace of discovery of new treatments for bone disease and provide novel insights into the dynamics of bone metabolism.

  13. Reader's digest of the pathophysiology of bone metastases.

    Science.gov (United States)

    Gruber, Reinhard

    2012-09-01

    Bone metastases are a process originally proposed as the "seed and soil theory" in the eighteenth century. Tumor cell disseminating from patients with breast or prostate cancer typically use the bony environment to grow outside the primary tumor location. The severe clinical consequences of bone metastasis such as pain, fractures, and hypercalcemia result from a serious misbalance of bone turnover. Most bone metastases cause catabolic changes of bone turnover. The severity of bone resorption is associated with tumor growth, suggesting the existence of a vicious cycle that needs to be interrupted. Osteoblastic metastasis showing signs of osteosclerotic lesions are observed in prostate cancer. Understanding the pathophysiology of bone metastases and their detrimental consequence provide the scientific basis for therapeutic interventions at various levels including homing of tumors to bone, survival and growth of the tumor cell in the bone niche, and the mechanisms causing bone destruction. PMID:22797871

  14. In vitro model of bone to facilitate measurement of adhesion forces and super-resolution imaging of osteoclasts.

    Science.gov (United States)

    Deguchi, Takahiro; Alanne, Maria H; Fazeli, Elnaz; Fagerlund, Katja M; Pennanen, Paula; Lehenkari, Petri; Hänninen, Pekka E; Peltonen, Juha; Näreoja, Tuomas

    2016-01-01

    To elucidate processes in the osteoclastic bone resorption, visualise resorption and related actin reorganisation, a combination of imaging technologies and an applicable in vitro model is needed. Nanosized bone powder from matching species is deposited on any biocompatible surface in order to form a thin, translucent, smooth and elastic representation of injured bone. Osteoclasts cultured on the layer expressed matching morphology to ones cultured on sawed cortical bone slices. Resorption pits were easily identified by reflectance microscopy. The coating allowed actin structures on the bone interface to be visualised with super-resolution microscopy along with a detailed interlinked actin networks and actin branching in conjunction with V-ATPase, dynamin and Arp2/3 at actin patches. Furthermore, we measured the timescale of an adaptive osteoclast adhesion to bone by force spectroscopy experiments on live osteoclasts with bone-coated AFM cantilevers. Utilising the in vitro model and the advanced imaging technologies we localised immunofluorescence signals in respect to bone with high precision and detected resorption at its early stages. Put together, our data supports a cyclic model for resorption in human osteoclasts. PMID:26935172

  15. Peptide-induced de novo bone formation after tooth extraction prevents alveolar bone loss in a murine tooth extraction model.

    Science.gov (United States)

    Arai, Yuki; Aoki, Kazuhiro; Shimizu, Yasuhiro; Tabata, Yasuhiko; Ono, Takashi; Murali, Ramachandran; Mise-Omata, Setsuko; Wakabayashi, Noriyuki

    2016-07-01

    Tooth extraction causes bone resorption of the alveolar bone volume. Although recombinant human bone morphogenetic protein 2 (rhBMP-2) markedly promotes de novo bone formation after tooth extraction, the application of high-dose rhBMP-2 may induce side effects, such as swelling, seroma, and an increased cancer risk. Therefore, reduction of the necessary dose of rhBMP-2 which can still obtain sufficient bone mass is necessary by developing a new osteogenic reagent. Recently, we showed that the systemic administration of OP3-4 peptide, which was originally designed as a bone resorption inhibitor, had osteogenic ability both in vitro and in vivo. This study evaluated the ability of the local application of OP3-4 peptide to promote bone formation in a murine tooth extraction model with a very low-dose of BMP. The mandibular incisor was extracted from 10-week-old C57BL6/J male mice and a gelatin hydrogel containing rhBMP-2 with or without OP3-4 peptide (BMP/OP3-4) was applied to the socket of the incisor. Bone formation inside the socket was examined radiologically and histologically at 21 days after the extraction. The BMP/OP3-4-group showed significant bone formation inside the mandibular extraction socket compared to the gelatin-hydrogel-carrier-control group or rhBMP-2-applied group. The BMP/OP3-4-applied mice showed a lower reduction of alveolar bone and fewer osteoclast numbers, suggesting that the newly formed bone inside the socket may prevent resorption of the cortical bone around the extraction socket. Our data revealed that OP3-4 peptide promotes BMP-mediated bone formation inside the extraction socket of mandibular bone, resulting in preservation from the loss of alveolar bone. PMID:27118173

  16. Effect of Epimedium-derived Phytoestrogen on Bone Turnover and Bone Microarchitecture in OVX-induced Osteoporotic Rats

    Institute of Scientific and Technical Information of China (English)

    Songlin PENG; Renyun XIA; Huang FANG; Feng LI; Anmin CHEN; Ge ZHANG; Ling QIN

    2008-01-01

    To investigate the preventive effect of epimedium-defivod phytoestrogen (PE) on osteoporosis induced by ovariectomy (OVX) in rats, 11-month-old female Wistar rats were randomly di- vided into Sham, OVX and PE groups. One week after OVX, daily oral administration of PE (0.4 g·kg-1·day·-1) started in PE group, and rats in Sham and OVX groups were given vehicle accordingly. The administrations lasted for 12 weeks. The biological markers including serum osteocalcin (OC) and urinary deoxypyridinoline (DPD) for bone turnover were evaluated at the end of the 12th week. On the 13th week, all the rats were sacrificed. The right proximal tibiae were removed, subjected to micro CT for determination of trabeonlar bone structure and then bone histomorphometry was per- formed to assess bone remodeling. The OVX rats were in a high bone turnover status as evidenced by increased bone formation markers and bone resorption markers. Treatment with PE could suppress the high bone turnover rate in OVX rats. Micro CT data revealed that PE treatment could ameliorate the deterioration of the micro-architecture of proximal tibiae induced by OVX, as demonstrated by greater bone volume, increased trabecular thickness and less trahecular separation in PE group in comparison with OVX group. The static and dynamic parameters of bone histomorphometry indi- cated that there were significant increases in bone formation variables and significant decreases in bone resorption variables between PE and OVX groups. The findings suggest that PE has a beneficial effect on trabecular bone in OVX rat model and this effect is possibly associated with stimulation of bone formation as well as inhibition of bone resorption.

  17. Equilibrium-dependent bisphosphonate interaction with crystalline bone mineral explains the pharmacokinetics and osteonecrosis of the jaw in rats

    OpenAIRE

    Hokugo, Akishige; Sun, Shuting; Park, Sil; McKenna, Charles E.; Nishimura, Ichiro

    2012-01-01

    Bisphosphonates (BPs) are chemically stable analogs of pyrophosphate exhibiting strong affinity to bone and have been used for the treatment of diseases characterized by excessive bone resorption. Contrary to the widely accepted BP accumulation model in bone after repeated applications, we report here that an equilibrium-dependent BP-crystalline bone mineral interaction may better explain BP bio-distribution and anti-catabolic bone remodeling and may be relevant to the appearance of osteonecr...

  18. Rhus javanica Gall Extract Inhibits the Differentiation of Bone Marrow-Derived Osteoclasts and Ovariectomy-Induced Bone Loss

    Directory of Open Access Journals (Sweden)

    Tae-Ho Kim

    2016-01-01

    Full Text Available Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects of Rhus javanica (R. javanica extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts of R. javanica (eGr cocoons spun by Rhus javanica (Bell. Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr or 100% ethanolic extract (eeGr on ovariectomy- (OVX- induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks augmented the inhibition of femoral bone mineral density (BMD, bone mineral content (BMC, and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss.

  19. Management of external perforating root resorption by intentional replantation followed by Biodentine restoration

    Directory of Open Access Journals (Sweden)

    Preeti Jain Pruthi

    2015-01-01

    Full Text Available Resorption of tooth structures can occur as a result of physiological, pathological, and idiopathic factors. Early diagnosis and appropriate treatment can prevent its serious complications. This case report presents surgical endodontic management of a trauma-induced perforating external root resorption, which was diagnosed with the help of cone beam computed tomography. Following root canal treatment, intentional replantation of the tooth was performed so as to expose the opening of the resorption defect to allow for complete debridement and closure. Eighteen months follow-up showed arrest of root resorption, and progressive healing of the defect.

  20. Management of external perforating root resorption by intentional replantation followed by Biodentine restoration.

    Science.gov (United States)

    Pruthi, Preeti Jain; Dharmani, Umesh; Roongta, Ruchika; Talwar, Sangeeta

    2015-01-01

    Resorption of tooth structures can occur as a result of physiological, pathological, and idiopathic factors. Early diagnosis and appropriate treatment can prevent its serious complications. This case report presents surgical endodontic management of a trauma-induced perforating external root resorption, which was diagnosed with the help of cone beam computed tomography. Following root canal treatment, intentional replantation of the tooth was performed so as to expose the opening of the resorption defect to allow for complete debridement and closure. Eighteen months follow-up showed arrest of root resorption, and progressive healing of the defect. PMID:26604965

  1. Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil

    OpenAIRE

    José Luis Martínez-Sánchez

    2005-01-01

    In tropical forests with nutrient-rich soil tree’s nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, amo...

  2. 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

  3. A resorption refrigerator driven by low grade thermal energy

    International Nuclear Information System (INIS)

    Highlights: → A resorption refrigerator employing MnCl2-NH3 and NH4Cl-NH3 was designed and investigated. → The experiments were operated under different ambient temperatures from 20 to 35 oC. → The refrigerator provided simultaneously two cooling levels: at 0-6 oC and at -16 ∼ -14.5 oC. → With 3 h operation the total cooling capacity was 475 kJ per kg of NH4Cl salt. → The effective cooling production was 25-42% of the total cooling capacity. -- Abstract: A small refrigerator based on resorption technique, employed MnCl2 and NH4Cl as sorbent salts and ammonia as refrigerant, was presented for simultaneously cooling at 0-6 oC and freezing at -16 to -14.5 oC in this work. The cooling capacity of this device was investigated by measuring the mass amount of the ice generated during a certain period of 3 h operation, and the experiments were conducted at different ambient temperature ranging from 20 oC to 35 oC. The total cooling capacity was calculated 475 kJ per kg of NH4Cl salt, and the mean specific cooling power (SCP) was 43 W per kg of NH4Cl salt, the effective cooling production responsible for making ice accounted for 25-42% of the total cooling capacity depending on the different operating conditions studied in this work.

  4. Probiotic L. reuteri treatment prevents bone loss in a menopausal ovariectomized mouse model

    OpenAIRE

    Britton, Robert A.; Irwin, Regina; Quach, Darin; Schaefer, Laura; Zhang, Jing; Lee, Taehyung; Parameswaran, Narayanan; McCabe, Laura R.

    2014-01-01

    Estrogen deficiency is a major risk factor for osteoporosis that is associated with bone inflammation and resorption. Half of women over the age of 50 will experience an osteoporosis related fracture in their lifetime, thus novel therapies are needed to combat post-menopausal bone loss. Recent studies suggest an important role for gut-bone signaling pathways and the microbiota in regulating bone health. Given that the bacterium Lactobacillus reuteri ATCC PTA 6475 (L. reuteri) secretes benefic...

  5. Chronic radium intoxication: preliminary report of morphological and mineral changes in human bone

    International Nuclear Information System (INIS)

    Observations are presented on bone microradiograms from 44 radium patients. The data cover three basic categories of mineral changes: (1) increase in bone mineral resorption, (2) increase in bone mineral density and (3) increase in new bone tissue formation. The data show a trend of increasing amount of mineral change in all three categories as the cumulative rads, cumulative rad-years, and amount of radium intake increase

  6. 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 ...

  7. Bone Grafts

    Science.gov (United States)

    A bone graft transplants bone tissue. Surgeons use bone grafts to 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 ...

  8. In vitro study of osteoclastogenesis under simulated bone augmentation: The effects of bone-conditioned medium and saliva on osteoclastogenesis

    OpenAIRE

    Caballé Serrano, Jordi

    2015-01-01

    The present PhD thesis is a compendium of four publications broadening the knowledge on osteoclastogenesis under simulated bone augmentation, more especially about the effects of saliva and bone-conditioned medium on osteoclastogenesis. Resorption of bone grafts and host bone, can be a challenge especially when a bonny defect has to be regenerated or there is a lack of host bone due to a trauma, pathology, aging or tooth extraction among others. In the oral cavity, saliva is present and can r...

  9. Vitamin D and estrogen receptor-alpha genotype and indices of bone mass and bone turnover in Danish girls

    DEFF Research Database (Denmark)

    Cusack, S.; Mølgaard, C.; Michaelsen, K. F.;

    2006-01-01

    environmental factors. VDR genotypes had no effect on bone turnover markers. XX and PP ER alpha genotypes were associated (P <0.05) with reduced levels of urinary pyridinium cross-links, whereas serum osteocalcin was similar among genotypes. These findings suggest that the rate of bone resorption was influenced...... (VDR) (FokI, TaqI) and estrogen receptor-alpha (ER alpha) (PvuII, XbaI), and bone mineral density (BMD), bone mineral content (BMC), and markers of bone turnover in 224 Danish girls aged 11-12 years. BMD and BMC were measured by dual-energy X-ray absorptiometry. Serum osteocalcin, 25(OH)D, and...

  10. Calcium enriched mixture cement for primary molars exhibiting root perforations and extensive root resorption: report of three cases.

    Science.gov (United States)

    Tavassoli-Hojjati, Sara; Kameli, Somayeh; Rahimian-Emam, Sara; Ahmadyar, Maryam; Asgary, Saeed

    2014-01-01

    In primary molars with root perforations of endodontic origin, tooth extraction and space maintainer are recommended. Calcium-enriched mixture (CEM) cement is a new biomaterial demonstrating favorable sealability/biocompatibility. This report presents a novel treatment modality for cases of primary molar teeth with root perforations associated with a periodontal lesion due to extensive inflammatory root resorption, whereby CEM was used as a perforation repair/pulpotomy biomaterial. Three cases of primary molar root perforations due to inflammatory resorption were selected; all cases were associated with furcal lesions of endodontic origin. Pulp chambers were accessed/irrigated with NaOCl; the root canal orifices were filled with CEM and restored with stainless steel crowns. Clinical/radiographic examinations up to 17 months revealed that all teeth were functional and free of signs/symptoms of infection and all had complete bone healing. Further trials are suggested to confirm CEM use for management of root perforations in primary molars exhibiting root perforation. PMID:24717704

  11. Using Natural Stable Calcium Isotopes to Rapidly Assess Changes in Bone Mineral Balance Using a Bed Rest Model to Induce Bone Loss

    Science.gov (United States)

    Morgan, J. L. L.; Skulan, J. L.; Gordon, G. E.; Smith, Scott M.; Romaniello, S. J.; Anbar, A. D.

    2012-01-01

    Metabolic bone diseases like osteoporosis result from the disruption of normal bone mineral balance (BMB) resulting in bone loss. During spaceflight astronauts lose substantial bone. Bed rest provides an analog to simulate some of the effects of spaceflight; including bone and calcium loss and provides the opportunity to evaluate new methods to monitor BMB in healthy individuals undergoing environmentally induced-bone loss. Previous research showed that natural variations in the Ca isotope ratio occur because bone formation depletes soft tissue of light Ca isotopes while bone resorption releases that isotopically light Ca back into soft tissue (Skulan et al, 2007). Using a bed rest model, we demonstrate that the Ca isotope ratio of urine shifts in a direction consistent with bone loss after just 7 days of bed rest, long before detectable changes in bone mineral density (BMD) occur. The Ca isotope variations tracks changes observed in urinary N-teleopeptide, a bone resorption biomarker. Bone specific alkaline phosphatase, a bone formation biomarker, is unchanged. The established relationship between Ca isotopes and BMB can be used to quantitatively translate the changes in the Ca isotope ratio to changes in BMD using a simple mathematical model. This model predicts that subjects lost 0.25 0.07% ( SD) of their bone mass from day 7 to day 30 of bed rest. Given the rapid signal observed using Ca isotope measurements and the potential to quantitatively assess bone loss; this technique is well suited to study the short-term dynamics of bone metabolism.

  12. RECENT ADVANCES IN PATHO-BIOLOGY OF MYELOMA BONE DISEASE: CLINICOPATHOLOGY AND LITERATURE OF REVIEW

    Directory of Open Access Journals (Sweden)

    Lohit Kumar

    2016-03-01

    Full Text Available Bone disease is a hallmark of multiple myeloma, presenting as lytic lesions associated with bone pain, pathological fractures requiring surgery and/or radiation to bone, spinal cord compression and hypercalcaemia. Increased osteoclastic activity unaccompanied by a compensatory increase in osteoblast function, leading to enhanced bone resorption results in bone disease. The interaction of plasma cells with the bone marrow microenvironment has been shown to play a vital role. Also, interactions of myeloma cells with osteoclasts enhance myeloma growth and survival, and thereby create a vicious cycle leading to extensive bone destruction and myeloma cell expansion.

  13. 骨生化指标在骨肿瘤中的临床应用进展%Clinical application progress of bone biochemical markers in bone tumors

    Institute of Scientific and Technical Information of China (English)

    周定; 张琪琪; 胡勇

    2014-01-01

    Bone tumors refer to benign and malignant tumors which originate from mesenchymal stem cells and occur in bone tissues and their accessory structures. The pathogenesis and etiology of bone tumors still remain unclear, and the diagnosis methods of bone tumors are stagnating now. X-ray, computed tomography ( CT ) and magnetic resonance imaging ( MRI ) are important in diagnosing and evaluating bone tumors, but they cannot detect the lesions until the bone destruction reaches a certain degree. Isotope bone scan can detect the microscopic lesions of bone, whereas it is too expensive and the speciifcity is poor, with high false positive rates. At present, the golden standard for the diagnosis of bone tumors is the histopathological examination of bone. However, it is dififcult to achieve early diagnosis, and it is likely to miss the best treatment period. Every disease is inevitably accompanied by molecular biological changes in the body. Biochemical markers can promptly detect the property changes of bone tumor cells, including unlimited proliferation, apoptosis, active neoangiogenesis, inifltrative growth, metastatic growth and so on. Therefore, it is of great signiifcance for the diagnosis of bone tumors to detect appropriate biochemical markers in the patients. The normal bone metabolism is maintained by the dynamic balance of bone resorption and bone formation. When bone tumors occur, the balance will be disturbed. The bone biochemical markers which relfect bone resorption and bone formation are sensitive indicators of early abnormal bone metabolism. Recently, a large number of studies have explored the significance of bone biochemical markers in patients with bone tumors. The functions of bone biochemical markers in patients with bone tumors mainly include making an early detection of microscopic tumor lesions to start early treatment ( diagnostic effects ), evaluating the effects ( therapeutic monitoring ), evaluating the prognosis and predicting the risk of

  14. Bone remodeling during pregnancy and post-partum assessed by metal lead levels and isotopic concentrations.

    Science.gov (United States)

    Gulson, Brian; Taylor, Alan; Eisman, John

    2016-08-01

    Bone remodeling is normally evaluated using bone turnover markers/indices as indicators of bone resorption and formation. However, during pregnancy and post-partum, there have been inconsistent results between and within biomarkers for bone formation and resorption. These differences may relate to pregnancy-related changes in metabolism and/or hemodilution altering measured marker levels. An alternative approach to evaluating bone remodeling is to use the metal lead (Pb) concentrations and Pb isotopic compositions in blood. These measurements can also provide information on the amount of Pb that is mobilized from the maternal skeleton. Despite some similarities with accepted bone turnover markers, the Pb data demonstrate increased bone resorption throughout pregnancy that further continues post-partum independent of length of breast-feeding, dietary intake and resumption of menses. Furthermore the isotopic measurements are not affected by hemodilution. These data confirm calcium balance studies that indicate increased bone resorption throughout pregnancy and lactation. They also indicate potentially major public health implications of the transfer of maternal Pb burden to the fetus and new born. PMID:27233973

  15. Diet-induced obesity alters bone remodeling leading to decreased femoral trabecular bone mass in mice.

    Science.gov (United States)

    Cao, Jay J; Sun, Li; Gao, Hongwei

    2010-03-01

    Obesity-derived body mass may be detrimental to bone health through not well-defined mechanisms. In this study we determined changes in bone structure and serum cytokines related to bone metabolism in diet-induced obese mice. Mice fed a high-fat diet (HFD) had higher serum tartrate-resistant acid phosphatase (TRAP) and leptin but lower osteocalcin concentrations than those fed the normal-fat diet. The HFD increased multinucleated TRAP-positive osteoclasts in bone marrow compared to the control diet. Despite being much heavier, mice fed the HFD had lower femoral bone volume, trabecular number, and connectivity density and higher trabecular separation than mice on the control diet. These findings suggest that obesity induced by a HFD increases bone resorption that may blunt any positive effects of increased body weight on bone. PMID:20392249

  16. Crosstalk between cartilage and bone: when bone cytokines matter.

    Science.gov (United States)

    Funck-Brentano, Thomas; Cohen-Solal, Martine

    2011-04-01

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

  17. New bone implant material with calcium sulfate and Ti modified hydroxyapatite

    OpenAIRE

    A. Ślósarczyk; J. Czechowska; Z. Paszkiewicz; A. Zima

    2010-01-01

    (TiHA) to develop a novel bone cement. Results of previous studies showed that bioactive potential of titanium modified hydroxyapatite ceramics is higher than that of pure HA. Calcium sulfate hemihydrate is also considered as a safe, biocompatible material, however it has been criticized for its rapid resorption. Combination of these materials may result in new cement type material with surgical handiness and selective resorption.Design/methodology/approach: TiHA was obtained by a wet method....

  18. Expression of RANKL/OPG during bone remodeling in vivo

    International Nuclear Information System (INIS)

    Highlights: → This is the first study to determine the relationship between osteogenic differentiation and RANKL/OPG expression during bone remodeling in vivo. → The OPG expression peak occurred during the bone formation phase, whereas the marked elevation of RANKL expression was observed during the bone resorption phase. → Histological analysis showed that RANKL/OPG immunoreactivity was predominantly associated with bone marrow cells in the marrow cavity. → The present study confirmed that RANKL/OPG are key factors linking bone formation to resorption during the bone remodeling process. -- Abstract: The interaction between receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) plays a dominant role in osteoclastogenesis. As both proteins are produced by osteoblast lineage cells, they are considered to represent a key link between bone formation and resorption. In this study, we investigated the expression of RANKL and OPG during bone remodeling in vivo to determine the relationship between osteoclastogenic stimulation and osteoblastic differentiation. Total RNA was prepared from rat femurs after marrow ablation on days 0, 3, 6, and 9. The temporal activation patterns of osteoblast-related genes (procollagen α1 (I), alkaline phosphatase, osteopontin, and osteocalcin) were examined by Northern blot analysis. An appreciable increase in the expression of these osteoblast markers was observed on day 3. The peak increase in gene expression was observed on day 6 followed by a slight reduction by day 9. Real-time PCR analysis showed that the OPG mRNA expression was markedly upregulated on day 6 and slightly decreased on day 9. In contrast, RANKL mRNA expression was increased by more than 20-fold on day 9. The RANKL/OPG ratio, an index of osteoclastogenic stimulation, peaked on day 9. Histological analysis showed that RANKL and OPG immunoreactivity were predominantly associated with bone marrow cells. The expression of bone formation

  19. Human stem cell osteoblastogenesis mediated by novel glycogen synthase kinase 3 inhibitors induces bone formation and a unique bone turnover biomarker profile in rats

    International Nuclear Information System (INIS)

    Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/μCT imaging. GSK-3 inhibitors caused β-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28 days exposure in rats. After 7 days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH1–34 or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/μCT. GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption. - Highlights: • Wnt modulation with 3 novel GSK-3 inhibitors alters bone growth. • Human stem cell osteoblastogenesis and

  20. Human stem cell osteoblastogenesis mediated by novel glycogen synthase kinase 3 inhibitors induces bone formation and a unique bone turnover biomarker profile in rats

    Energy Technology Data Exchange (ETDEWEB)

    Gilmour, Peter S., E-mail: Peter.Gilmour@astrazeneca.com [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); O' Shea, Patrick J.; Fagura, Malbinder [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Pilling, James E. [Discovery Sciences, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Sanganee, Hitesh [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Wada, Hiroki [R and I IMed, AstraZeneca R and D, Molndal (Sweden); Courtney, Paul F. [DMPK, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Kavanagh, Stefan; Hall, Peter A. [Safety Assessment, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Escott, K. Jane [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom)

    2013-10-15

    Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/μCT imaging. GSK-3 inhibitors caused β-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28 days exposure in rats. After 7 days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH{sub 1–34} or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/μCT. GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption. - Highlights: • Wnt modulation with 3 novel GSK-3 inhibitors alters bone growth. • Human stem cell osteoblastogenesis

  1. Possible Role of Garlic Oil and Parsley Extract in Ameliorating Radiation-Induced Bone Loss in Female Rats

    International Nuclear Information System (INIS)

    To Investigate the possible protective effect of garlic oil and parsley extract against bone loss resulted in female virgin rats exposed to fractionated doses of gamma-radiation (1 Gy 3 times weekly for 5 weeks). Urinary calcium (U Ca), calcium to creatinine ratio (Ca/Cr), hydroxyproline and serum phosphorus were measured as bone resorption bio markers, while serum osteocalcine (OST) and serum alkaline phosphatase (ALP) were measured as bone formation bio markers. Furthermore, nitric oxide (NO) which represents the balance in bone remodeling was measured. Malondiadehyde level (MDA) as well as superoxide dismutase activity (SOD) was measured as oxidative stress bio markers. Female irradiated rats in the present study had significant increases in both bone resorption and bone formation bio markers after 6 weeks from the last exposure to gamma-radiation. Irradiated rats also had significant decreases in plasma NO indicating imbalance in bone remodeling as well as significant increase in oxidative stress bio markers. Daily treatment with garlic oil extracted in olive oil improved all measured parameters except OST level, while the vehicle used for garlic oil (extra virgin olive oil) significantly decreased bone resorption bio markers. Parsley extract induced normalization to all bone resorption and formation parameters measured in irradiated rats. Daily administration of garlic oil and parsley extract protected the bone from degeneration induced by exposure to fractionated doses of gamma radiation.

  2. Effect of epimedium pubescen flavonoid on bone mineral status and bone turnover in male rats chronically exposed to cigarette smoke

    Directory of Open Access Journals (Sweden)

    Gao Shu-guang

    2012-06-01

    Full Text Available Abstract Background Epimedii herba is one of the most frequently used herbs in formulas that are prescribed for the treatment of osteoporosis in China and its main constituent is Epimedium pubescen flavonoid (EPF. However, it is unclear whether EPF during chronic exposure to cigarette smoke may have a protective influence on the skeleton. The present study investigated the effect of EPF on bone mineral status and bone turnover in a rat model of human relatively high exposure to cigarette smoke. Methods Fifty male Wistar rats were randomized into five groups: controls, passive smoking groups and passive smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day in drinking water for 4 months. A rat model of passive smoking was prepared by breeding male rats in a cigarette-smoking box. Bone mineral content (BMC, bone mineral density (BMD, bone turnover markers, bone histomorphometric parameters and biomechanical properties were examined. Results Smoke exposure decreased BMC and BMD, increased bone turnover (inhibited bone formation and stimulated its resorption, affected bone histomorphometry (increased trabecular separation and osteoclast surface per bone surface; decreased trabecular bone volume, trabecular thickness, trabecular number, cortical thickness, bone formation rate and osteoblast surface per bone surface, and reduced mechanical properties. EPF supplementation during cigarette smoke exposure prevented smoke-induced changes in bone mineral status and bone turnover. Conclusion The results suggest that EPF can prevent the adverse effects of smoke exposure on bone by stimulating bone formation and inhibiting bone turnover and bone resorption.

  3. Elemental analysis by neutronic radioactivation for biocoral resorption and apatite formation versus time studies after implantation in vivo

    International Nuclear Information System (INIS)

    Previous works carried out on coral show the advantages presented by this bio material used in bony surgery. Its resorbability is due to its bio compatibility and chemical properties. In our laboratory, we have studied the physico-chemical properties, the ossification kinetics and the calcification mechanism of the bio coral. By nuclear radioactivation, we have determined the amounts of Ca, P, Mg, Sr in natural coral, and their variations versus time after implantation in the metaphysis femur. The analysis of these atomic elements allows the study of coral resorption and apatite formation kinetics in coral, in cortical and in spongy bone with two different animal species. (authors). 10 refs., 4 figs., 2 tabs

  4. Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil.

    Science.gov (United States)

    Martínez-Sánchez, José Luis

    2005-01-01

    In tropical forests with nutrient-rich soil tree's nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, among other physical and chemical characteristics, were analysed in 30 samples in the soil surface (10 cm) of three undisturbed forest plots at 'Estaci6n de Biologia Los Tuxtlas' on the east coast of Mexico (18 degrees 34' - 18 degrees 36' N, 95 degrees 04' - 95 degrees 09' W). N and P resorption proficiency were determined from senescing leaves in 11 dominant tree species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid. Soil was rich in total N (0.50%, n = 30) and extractable P (4.11 microg g(-1) n = 30). As expected, trees showed incomplete N (1.13%, n = 11) and P (0.11%, n = 1) resorption. With a more accurate method of nutrient resorption assessment, it is possible to prove that a forest community with a nutrient-rich soil can have low levels of N and P resorption. PMID:17354446

  5. Multiple external-internal resorptions as late effects of Thorium X (224Ra)

    International Nuclear Information System (INIS)

    Multiple external-internal resorptions are infrequent and are related to a variety of etiological factors. Thorium X (224Ra) is believed to cause the dental resorptive changes observed in two patients who had received a series of injections each containing 8 to 70 μC1 of 224Ra 25 years previously. (author)

  6. Identification of orthodontic patients at risk of severe apical root resorption.

    NARCIS (Netherlands)

    Artun, J.; Hullenaar, R. Van 't; Doppel, D.; Kuijpers-Jagtman, A.M.

    2009-01-01

    INTRODUCTION: Current information suggests that the major variation in orthodontic root resorption can be explained by differences in individual predisposition. Our aim was therefore to test the predictive value of the amount of maxillary incisor resorption about 6 and 12 months after bracket placem

  7. 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

  8. A resorption refrigerator driven by low grade thermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Bao, H.S. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, R.Z., E-mail: rzwang@sjtu.edu.c [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, L.W. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2011-06-15

    Highlights: {yields} A resorption refrigerator employing MnCl{sub 2}-NH{sub 3} and NH{sub 4}Cl-NH{sub 3} was designed and investigated. {yields} The experiments were operated under different ambient temperatures from 20 to 35 {sup o}C. {yields} The refrigerator provided simultaneously two cooling levels: at 0-6 {sup o}C and at -16 {approx} -14.5 {sup o}C. {yields} With 3 h operation the total cooling capacity was 475 kJ per kg of NH{sub 4}Cl salt. {yields} The effective cooling production was 25-42% of the total cooling capacity. -- Abstract: A small refrigerator based on resorption technique, employed MnCl{sub 2} and NH{sub 4}Cl as sorbent salts and ammonia as refrigerant, was presented for simultaneously cooling at 0-6 {sup o}C and freezing at -16 to -14.5 {sup o}C in this work. The cooling capacity of this device was investigated by measuring the mass amount of the ice generated during a certain period of 3 h operation, and the experiments were conducted at different ambient temperature ranging from 20 {sup o}C to 35 {sup o}C. The total cooling capacity was calculated 475 kJ per kg of NH{sub 4}Cl salt, and the mean specific cooling power (SCP) was 43 W per kg of NH{sub 4}Cl salt, the effective cooling production responsible for making ice accounted for 25-42% of the total cooling capacity depending on the different operating conditions studied in this work.

  9. Management of Inflammatory Internal Root Resorption with Biodentine and Thermoplasticised Gutta-Percha

    Science.gov (United States)

    Umashetty, Girish; Hoshing, Upendra; Patil, Suvarna; Ajgaonkar, Nishant

    2015-01-01

    Internal root resorption is a chronic inflammatory process initiated within the pulp space with the loss of dentin. This condition demands a comprehensive understanding of the pathologic process, so as to identify the cause and arrest the resorptive phenomena. It is a rare occurrence, asymptomatic, with slow progression, detected through routine radiographic examination, where it appears as a radiolucent lesion. This paper reports a clinical case of inflammatory internal root resorption in the premolar tooth. Because it is asymptomatic, internal root resorption needs an early diagnosis in order to institute the endodontic treatment before the process compromises the remaining mineralized structures of the tooth. Biodentine was used to reinforce the weaker structures in the root. Thermoplasticised gutta-percha was used to completely obturate the defect. Ten-month follow-up showed arrest of internal root resorption. PMID:26579316

  10. Management of External Invasive Cervical Resorption Tooth with Mineral Trioxide Aggregate: A Case Report

    Directory of Open Access Journals (Sweden)

    Anuja Ikhar

    2013-01-01

    Full Text Available Invasive cervical resorption is entirely uncommon entities and the etiology is poorly understood. A 19 year old patient presented with fractured upper left central incisor and sinus tract opening on the distobuccal aspect in cervical region. Radiographic examination shows irregular radiolucency over the coronal one-third and it extended externally towards the external invasive resorption. After sectional obturation, the defect was accessed surgically. The resorption area was chemomechanically debrided using irrigant solution. Fibre post placement using flowable composite resin and Mineral Trioxide Aggregate (MTA was used to fill the resorptive defect, and the coronal access was temporarily sealed. Composite restoration was subsequently replaced with ceramic crown after 4 years. Radiographs at 1 and 4 years showed adequate repair of the resorption and endodontic success. Clinically and radiographically the tooth was asymptomatic, and no periodontal pocket was found after a 4-year followup.

  11. Treatment of inflammatory root resorption using mineral trioxide aggregate: A case report

    Directory of Open Access Journals (Sweden)

    Roohollah Sharifi

    2014-01-01

    Full Text Available Introduction: This report presents a case to show inflammatory root resorption can be successfully treated by using mineral trioxide aggregate (MTA. Case Report: A central maxillary incisor of an eight-year-old boy was avulsed associated with crown fracture secondary to a fall. The tooth was stored in ice. Early attempts at pulpal revascularization of the replanted tooth proved unsuccessful. To stop inflammatory root resorption, long-term calcium hydroxide therapy was employed. Despite the use of calcium hydroxide, resorption continued. Subsequent to the failure of that treatment, MTA was used as a root canal filling material. At 20-month follow-up, the tooth was asymptomatic and had clinical signs of ankylosis but external inflammatory root resorption had stopped. Discussion: MTA may be considered as an alternative option for the treatment of continuous external inflammatory root resorption.

  12. Disruption of bone and skeletal muscle in severe burns

    Institute of Scientific and Technical Information of China (English)

    Gordon L Klein

    2015-01-01

    Severe burn injury triggers the body’s nonspecific adaptive responses to acute insult, including the systemic inflammatory and stress responses, as well as the sympathetic response to immobilization. These responses trigger inflammatory bone resorption followed by glucocorticoid-induced apoptosis of osteoblasts and probably osteocytes. Because these patients are catabolic, they suffer concomitant muscle wasting and negative nitrogen balance. The use of anabolic agents such as recombinant human growth hormone and oxandrolone results in improved bone mineral content and muscle strength after approximately 1 year. Use of bisphosphonates within the first 10 days of a severe burn completely blocks the resorptive bone loss and has the added advantage of appearing to preserve muscle protein from excessive breakdown. The mechanism for the protective effect on muscle is not currently known. However, if the effect of bisphosphonates on muscle can be confirmed, it raises the possibility that bone communicates with muscle.

  13. Short Anabolic Peptides for Bone Growth.

    Science.gov (United States)

    Amso, Zaid; Cornish, Jillian; Brimble, Margaret A

    2016-07-01

    Loss of bone occurs in the age-related skeletal disorder, osteoporosis, leading to bone fragility and increased incidence of fractures, which are associated with enormous costs and substantial morbidity and mortality. Recent data indicate that osteoporotic fractures are more common than other diseases, which usually attract public attention (e.g., heart attack and breast cancer). The prevention and treatment of this skeletal disorder are therefore of paramount importance. Majority of osteoporosis medications restore skeletal balance by reducing osteoclastic activity, thereby reducing bone resorption. These agents, however, do not regenerate damaged bone tissue, leaving limited options for patients once bone loss has occurred. Recently, attention has turned to bone-anabolic agents. Such agents have the ability to increase bone mass and strength, potentially reversing structural damage. To date, only one bone-anabolic drug is available in the market. The discovery of more novel, cost-effective bone anabolic agents is therefore a priority to treat those suffering from this disabling condition. Short peptides offer an important alternative for the development of novel bone-anabolic agents given their high target binding specificity, which translates into potent activity with limited side effects. This review summarizes attempts in the identification of bone-anabolic peptides, and their development for promoting bone growth. PMID:27297498

  14. 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 ...

  15. Artificial Gravity: Effects on Bone Turnover

    Science.gov (United States)

    Heer, M.; Zwart, S /R.; Baecker, N.; Smith, S. M.

    2007-01-01

    The impact of microgravity on the human body is a significant concern for space travelers. Since mechanical loading is a main reason for bone loss, artificial gravity might be an effective countermeasure to the effects of microgravity. In a 21-day 6 head-down tilt bed rest (HDBR) pilot study carried out by NASA, USA, the utility of artificial gravity (AG) as a countermeasure to immobilization-induced bone loss was tested. Blood and urine were collected before, during, and after bed rest for bone marker determinations. Bone mineral density was determined by DXA and pQCT before and after bed rest. Urinary excretion of bone resorption markers (n-telopeptide and helical peptide) were increased from pre-bed rest, but there was no difference between the control and the AG group. The same was true for serum c-telopeptide measurements. Bone formation markers were affected by bed rest and artificial gravity. While bone-specific alkaline phosphatase tended to be lower in the AG group during bed rest (p = 0.08), PINP, another bone formation marker, was significantly lower in AG subjects than CN before and during bed rest. PINP was lower during bed rest in both groups. For comparison, artificial gravity combined with ergometric exercise was tested in a 14-day HDBR study carried out in Japan (Iwase et al. J Grav Physiol 2004). In that study, an exercise regime combined with AG was able to significantly mitigate the bed rest-induced increase in the bone resorption marker deoxypyridinoline. While further study is required to more clearly differentiate bone and muscle effects, these initial data demonstrate the potential effectiveness of short-radius, intermittent AG as a countermeasure to the bone deconditioning that occurs during bed rest and spaceflight. Future studies will need to optimize not only the AG prescription (intensity and duration), but will likely need to include the use of exercise or other combined treatments.

  16. Progesterone and Bone: Actions Promoting Bone Health in Women

    Directory of Open Access Journals (Sweden)

    Vanadin Seifert-Klauss

    2010-01-01

    Full Text Available Estradiol (E2 and progesterone (P4 collaborate within bone remodelling on resorption (E2 and formation (P4. We integrate evidence that P4 may prevent and, with antiresorptives, treat women's osteoporosis. P4 stimulates osteoblast differentiation in vitro. Menarche (E2 and onset of ovulation (P4 both contribute to peak BMD. Meta-analysis of 5 studies confirms that regularly cycling premenopausal women lose bone mineral density (BMD related to subclinical ovulatory disturbances (SODs. Cyclic progestin prevents bone loss in healthy premenopausal women with amenorrhea or SOD. BMD loss is more rapid in perimenopause than postmenopause—decreased bone formation due to P4 deficiency contributes. In 4 placebo-controlled RCTs, BMD loss is not prevented by P4 in postmenopausal women with increased bone turnover. However, 5 studies of E2-MPA co-therapy show greater BMD increases versus E2 alone. P4 fracture data are lacking. P4 prevents bone loss in pre- and possibly perimenopausal women; progesterone co-therapy with antiresorptives may increase bone formation and BMD.

  17. Histologic diagnosis of metabolic bone diseases: bone histomorphometry

    Directory of Open Access Journals (Sweden)

    L. Dalle Carbonare

    2011-09-01

    Full Text Available Histomorphometry or quantitative histology is the analysis on histologic sections of bone resorption parameters, formation and structure. It is the only technique that allows a dynamic evaluation of the activity of bone modelling after labelling with tetracycline. Moreover, the new measurement procedures through the use of the computer allow an assessment of bone microarchitecture too. Histomorphometric bone biopsy is a reliable and well-tolerated procedure. Complications are reported only in 1% of the subjects (hematoma, pain, transient neuralgia. Histomorphometry is used to exclude or confirm the diagnosis of osteomalacia. It is employed in the evaluation of bone damage associated with particular treatments (for example, anticonvulsants or in case of rare bone diseases (osteogenesis imperfecta, systemic mastocytosis. It is also an essential approach when clinical, biochemical and other diagnostic data are not consistent. Finally, it is a useful method to understand the pathophysiologic mechanisms of drugs. The bone sample is taken at the level of iliac crest under local anesthesia. It is then put into methyl-metacrilate resin where the sections are prepared for the microscopic analysis of the various histomorphometric parameters.

  18. Root resorption after dental traumas: classification and clinical, radiographic and histologic aspects

    Directory of Open Access Journals (Sweden)

    Bruno Oliveira de Aguiar Santos

    2011-10-01

    Full Text Available Introduction: One of the most common sequelae observed after dental trauma is root resorption. Objective: The aim of this study was to classify and discuss the external root resorption after a dental trauma, based on a literature review. Literature review: A bibliographic search was performed in the following databases: Medline, PubMed, and Lilacs, from 1997 to 2010. The following descriptors were used: Root resorption, Dental trauma and Classification. From a total of 152 articles found, 25 were selected: 24 in English and 1 in Spanish. Classic articles were also used in our study. External root resorption after dental traumas can be divided into superficial, inflammatory and replacement. It can also be verified in primary dentition as physiological and atypical resorptions. Conclusion: Each type of resorption presents clinical features as well as radiographic and histological aspects. Therefore, the dentist should know these characteristics to perform an early diagnosis and appropriate treatment, minimizing the sequelae related to this problem. Moreover, in primary dentition, the differential diagnosis between physiological and pathological resorption is important to avoid over-treatment.

  19. The Effect of Estrogen on the Restoration of Bone Mass and Bone Quality in Ovariectomized Rats

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To evaluate the effect of estrogen on its ability to restore the bone mass and bone quality in ovariectomized rats by examining the changes of bone morphology and histomorphometry, 3month-old rats were divided randomly into 4 groups: normal control, ovariectomized (OVX), shamoperated (Sham-O) and OVX plus estrogen (OVX+E2). Treatment initiated from the day 8 weeks after operation and continued for 12 weeks. Bone morphology and histomorphometry were examined afterwards. Results showed that comparing to control group, the trabecular bone in OVX appeared thinner and reduced in the amount. The connectivity between trabecula was decreased and the structure disordered. The free-end of trabecula was increased. The cavity of bone marrow enlarged. After treatment with estrogen, above changes improved remarkably by different degree, although did not reach the normal face. The bone histomorphometry results damonstrated that estrogen treatment increased bone mass and the amount of trabecula by 129% and 132% respectively (P<0. 05). The activity of bone resorption decreased significantly and the rate of bone formation increased to 203 %. These results suggest that treatment of ovariectomized rats with estrogen can not only increase bone mass, also improve the bone structure and enhance the property of bone mechanics.

  20. Probiotic L. reuteri treatment prevents bone loss in a menopausal ovariectomized mouse model.

    Science.gov (United States)

    Britton, Robert A; Irwin, Regina; Quach, Darin; Schaefer, Laura; Zhang, Jing; Lee, Taehyung; Parameswaran, Narayanan; McCabe, Laura R

    2014-11-01

    Estrogen deficiency is a major risk factor for osteoporosis that is associated with bone inflammation and resorption. Half of women over the age of 50 will experience an osteoporosis related fracture in their lifetime, thus novel therapies are needed to combat post-menopausal bone loss. Recent studies suggest an important role for gut-bone signaling pathways and the microbiota in regulating bone health. Given that the bacterium Lactobacillus reuteri ATCC PTA 6475 (L. reuteri) secretes beneficial immunomodulatory factors, we examined if this candidate probiotic could reduce bone loss associated with estrogen deficiency in an ovariectomized (Ovx) mouse menopausal model. Strikingly, L. reuteri treatment significantly protected Ovx mice from bone loss. Osteoclast bone resorption markers and activators (Trap5 and RANKL) as well as osteoclastogenesis are significantly decreased in L. reuteri-treated mice. Consistent with this, L. reuteri suppressed Ovx-induced increases in bone marrow CD4+ T-lymphocytes (which promote osteoclastogenesis) and directly suppressed osteoclastogenesis in vitro. We also identified that L. reuteri treatment modifies microbial communities in the Ovx mouse gut. Together, our studies demonstrate that L. reuteri treatment suppresses bone resorption and loss associated with estrogen deficiency. Thus, L. reuteri treatment may be a straightforward and cost-effective approach to reduce post-menopausal bone loss. PMID:24677054

  1. Elevated Bone Turnover in an Infantile Patient with Mucolipidosis II; No Association with Hyperparathyroidism

    Science.gov (United States)

    Otomo, Takanobu; Yamamoto, Takehisa; Fujikawa, Yasuhiro; Shimotsuji, Tsunesuke; Ozono, Keiichi

    2011-01-01

    This present report concerns an infantile patient with mucolipidosis II, who showed transient cortical bone hyperostosis followed by severe osteopenia. The diagnosis of mucolipidosis II was made based on the leakage of lysosomal enzymes in serum and conditioned media of the patient's skin fibroblasts, low activity of lysosomal enzymes of the fibroblasts and mutation of c.2086_2089insC (p.L697fs) and c.3565C>T (p.R1189X) in the GNPTAB gene. Bone X-ray analysis demonstrated a periosteal reaction and elevated bone resorption at the age of 2 mo. Bone markers, including alkaline phosphatase, osteocalcin and urine deoxypyridinoline, also indicated a high turnover of bone metabolism; however, no apparent rickets-like changes and no increased levels of PTH were observed. Elevated bone resorption is possibly associated with the leakage of lysosomal enzyme from osteoclasts into bone matrices. Bone formation gradually reduced, and increased bone resorption persisted. This led to severe osteopenia at the age of 6 mo. Characteristic bone findings may contribute to early diagnosis of mucolipidosis II, but their pathogenesis remains to be clarified. PMID:23926388

  2. 1. Morphological Implication on Cellular Response to Mechanical Stress in Bone.

    Science.gov (United States)

    Amizuka, Norio

    2016-08-01

    In bone, there are 3 distinct cell types: an osteoblast, a bone forming cell; an osteocyte embedded in bone matrix as a consequence of being differentiated from an osteoblast; and an osteoclast, a multinucleated giant cell responsible for bone resorption. Bone is always remodeled by replacing old bone with new bone (bone remodeling), by which bone can maintain its stiffness and flexibility. However, in an osteoporotic state, the disrupted balance between bone resorption and formation results in not only markedly reduced bone mass, but also in disorganized geometry of trabecules, which can often give rise to a bone fracture. Osteocytes located in their lacunae insert their fine cytoplasmic processes into narrow passageways referred to as osteocytic canaliculi. Neighboring osteocytes connect to each other by means of a gap junction in their cytoplasmic processes. Therefore, osteocytes and their lacunae/canaliculi appear to form functional syncytium called osteocytic lacunar canalicular system (OLCS). The geometrical distribution of OLCS is poorly arranged in immature bone, while it appears well-arranged distribution in mature bone (cortical bone), in which molecular transports and sensing mechanical stress seems to be efficient, and therefore, may be able to respond to mechanical stress. In this seminar, I will introduce our recent findings on the morphology and function of OLCS which may respond to mechanical stress. PMID:27441762

  3. Estrogen-Related Receptors and the control of bone cell fate.

    Science.gov (United States)

    Carnesecchi, Julie; Vanacker, Jean-Marc

    2016-09-01

    Bone loss is naturally occurring in aging males and females and exacerbated in the latter after menopause, altogether leading to cumulative skeleton fragility and increased fracture risk. Two types of therapeutic strategies can be envisioned to counteract age- or menopause-associated bone loss, aiming at either reducing bone resorption exerted by osteoclasts or, alternatively, promoting bone formation by osteoblasts. We here summarize data suggesting that inhibition of the Estrogen-Related Receptors α and/or γ could promote bone formation and compensate for bone loss induced by ageing or estrogen-deficiency. PMID:26206717

  4. Biogeographic patterns of nutrient resorption from Quercus variabilis Blume leaves across China.

    Science.gov (United States)

    Sun, X; Kang, H; Chen, H Y H; Björn, B; Samuel, B F; Liu, C

    2016-05-01

    The variation in nutrient resorption has been studied at different taxonomic levels and geographic ranges. However, the variable traits of nutrient resorption at the individual species level across its distribution are poorly understood. We examined the variability and environmental controls of leaf nutrient resorption of Quercus variabilis, a widely distributed species of important ecological and economic value in China. The mean resorption efficiency was highest for phosphorus (P), followed by potassium (K), nitrogen (N), sulphur (S), magnesium (Mg) and carbon (C). Resorption efficiencies and proficiencies were strongly affected by climate and respective nutrients concentrations in soils and green leaves, but had little association with leaf mass per area. Climate factors, especially growing season length, were dominant drivers of nutrient resorption efficiencies, except for C, which was strongly related to green leaf C status. In contrast, green leaf nutritional status was the primary controlling factor of leaf nutrient proficiencies, except for C. Resorption efficiencies of N, P, K and S increased significantly with latitude, and were negatively related to growing season length and mean annual temperature. In turn, N, P, K and S in senesced leaves decreased with latitude, likely due to their efficient resorption response to variation in climate, but increased for Mg and did not change for C. Our results indicate that the nutrient resorption efficiency and proficiency of Q. variabilis differed strongly among nutrients, as well as growing environments. Our findings provide important insights into understanding the nutrient conservation strategy at the individual species level and its possible influence on nutrient cycling. PMID:26597338

  5. Quartz Resorption as a Geospeedometer in Peralkaline Rhyolites

    Science.gov (United States)

    Janebo, M.; Caricchi, L.; Rust, A.

    2010-12-01

    Magma ascent rate affects eruptive style and intensity as it determines time available for syn-eruptive crystallization, vesiculation and permeable gas loss. The width of hornblende reaction rims has previously been used to estimate ascent rates for eruptions of andesitic volcanoes. Reactions between quartz and the coexisting melt could provide a similar proxy for peralkaline silicic magmas. Mayor Island, a peralkaline rhyolitic volcano in New Zealand, was used as a case study to investigate the use of quartz resorption as a geospeedometer. During the last 130 ka, Mayor Island has exhibited a wide range of eruptions, both with regards to intensity and volume. Previous studies have determined the pre-eruptive temperature to be around 750°C and pressure to be 100-125 MPa, and proposed that the magma chamber is saturated in water (Barclay et al., 1996). Neither the composition of the magma (72-74 wt% SiO2) nor the water content (4.4 wt%) have changed significantly between the different styles of eruptions, and the wide range of eruptive style was therefore attributed to variations in the ascent rate. In general, the quartz phenocrysts from the effusive eruptions are rounded, whereas those from the explosive eruptions are euhedral. Scaillet and Macdonald (2001) established that there are realistic conditions for which quartz in peralkaline rhyolites goes from stable to unstable to stable again during decompression. In this study, the stability fields of quartz were determined for a Mayor Island magma composition using an externally heated cold-seal pressure vessel. The rate of quartz resorption was assessed by carrying out time-series experiments. The pre-eruptive conditions were determined to be about 700-750°C from feldspar thermometry and phase equilibria. The results indicate that the magma was water under-saturated and consequently stored at higher pressures than previously calculated. The time-series experiments imply that magma that erupt explosively did not

  6. Flavonoids isolated from Tridax procumbens (TPF) inhibit osteoclasts differentiation and bone resorption

    OpenAIRE

    Al Mamun, Md Abdullah; Islam, Kamrul; Khatun, Amina; Alam, M. Masihul; Al-Bari, Md. Abdul Alim; Alam, Md. Jahangir

    2015-01-01

    Background The Tridax procumbens flavonoids (TPF), are well known for their medicinal properties among local natives. The TPF are traditionally used for dropsy, anaemia, arthritis, gout, asthma, ulcer, piles, and urinary problems. It also used in treating gastric problems, body pain, and rheumatic pains of joints. The TPF have been reported to increase osteogenic functioning in mesenchymal stem cells. However, their effects on osteoclastogenesis remain unclear. The TPF isolated from T. procum...

  7. Camelliatannin D, a new inhibitor of bone resorption, from Camellia japonica.

    Science.gov (United States)

    Hatano, T; Han, L; Taniguchi, S; Okuda, T; Kiso, Y; Tanaka, T; Yoshida, T

    1995-11-01

    Camelliatannin D (1), a new complex tannin which inhibits Ca release from mouse calvaria, was isolated from the leaves and fruits of Camellia japonica L. (Theaceae). This tannin is the first example of complex tannin composed of a dimeric hydrolyzable tannin and a flavan-3-ol. PMID:8575042

  8. Glucocorticoid-Induced Changes in the Geometry of Osteoclast Resorption Cavities Affect Trabecular Bone Stiffness

    DEFF Research Database (Denmark)

    Vanderoost, Jef; Søe, Kent; Merrild, Ditte Marie Horslev;

    2012-01-01

    /BV, which is closely related to the shape of the cavities, highly determines the stiffness effect. The lumbar spine was the anatomic site most affected by the GC-induced changes on the shape of the cavities. These findings might explain the clinical observation that the prevalence of vertebral fractures...

  9. Study of some common biochemical bone turnover markers in postmenopausal women

    OpenAIRE

    Sachdeva, Ashuma; Seth, Shashi; Khosla, Anju Huria; Sachdeva, Sumit

    2005-01-01

    Markers of bone formation in serum include total and bone specific alkaline phosphatase, osteocalcin and Type 1 collagen carboxy terminal extension peptide. Bone resorption can be assessed by measuring plasma tartarate resistant acid phosphtase and urinary excretion of collagen degradation products: hydroxyproline, hydroxylysine glycosides and more recently the pyridinium crosslinks and associated peptides. We compared the excretion of hydroxyproline in women of reproductive age group to thos...

  10. [Regulation of bone metabolism in osteoporosis : novel drugs for osteoporosis in development].

    Science.gov (United States)

    Jakob, F; Genest, F; Baron, G; Stumpf, U; Rudert, M; Seefried, L

    2015-11-01

    Bone is continuously regenerated and remodeled as an adaptation to mechanical load. Bone mass and fracture resistance are maintained by a balanced equilibrium between bone formation and bone resorption. Regeneration and response to mechanical load are, however, impaired in osteoporosis and during aging. Bone resorption is enhanced by chronic inflammation while bone formation is altered by rising levels of inhibitors in the aging organism. Core molecular principles of the regulation of bone metabolism in health and disease have been characterized and developed as therapeutic targets. The receptor activator of nuclear factor kappaB ligand (RANKL) and osteoclast-derived protease cathepsin K are important regulators and effectors of osteoclast differentiation and bone resorption. Bone formation is stimulated by bone morphogenetic proteins (BMP) and via the parathyroid hormone receptor and the Wnt signaling pathway. The principles of osteoclast inhibition using bisphosphonates have now been known for almost three decades. Based on more recent knowledge RANKL and cathepsin K have been developed as new therapeutic targets to inhibit bone resorption. While denosumab, a RANKL antibody, has already been introduced into routine treatment strategies, the cathepsin K antagonist odanacatib is currently in the licensing process. Bone formation can also be stimulated by local administration of BMPs, by systemic treatment with the parathyroid hormone fragment teriparatide and by using antibodies targeting the Wnt inhibitor sclerostin. The latter are presently being tested in phase III clinical studies. In the near future a panel of traditional and novel treatment strategies will be available that will enable us to meet the individual clinical needs during aging and for the treatment of osteoporosis. PMID:26471379

  11. Biomechanical behaviour of cancellous bone on patellofemoral arthroplasty with journey prosthesis : a finite element study

    OpenAIRE

    Castro, André; Completo, António; Simões, José A.; Flores, Paulo

    2015-01-01

    Isolated patellofemoral (PF) arthritis of the knee is a common cause of anterior knee pain and disability. Patellofemoral arthroplasty (PFA) is a bone conserving solution for patients with PF degeneration. Failure mechanisms of PFA include growing tibiofemoral arthritis and loosening of components. The implant loosening can be associated with bone resorption, or fatigue-failure of bone by overload. This research work aims at determining the structural effects of the implantation of PF prosthe...

  12. Obesity-related changes in bone structural and material properties in hyperphagic OLETF rats and protection by voluntary wheel running

    Science.gov (United States)

    We conducted a study to examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. This was a 36-week study of sedentary, hyperphag...

  13. Bone and mineral metabolism in hyperthyroidism

    International Nuclear Information System (INIS)

    A 47Ca calcitonin study is described which is used in combination with a conventional balance study in 5 patients with hyperthyroidism both before and after therapy and in 1 control subject. The experimentally obtained data were analyzed according to Wendeberg and Dymling. The magnitude of the 47Ca loss through perspiration could not be determined. This fact can affect the rate of accretion but not the other parameters of calcium kinetics. A markedly flow of tracer into bone (inflow, internal disappearance, accretion, rate of accretion) and of calcium out of bone (resorption, outflow) was observed

  14. External root resorption: Different etiologies explained from the composition of the human root-close periodontal membrane

    Directory of Open Access Journals (Sweden)

    Inger Kjaer

    2013-01-01

    Full Text Available Introduction: This paper summarizes different conditions, which have a well-known influence on the resorption of tooth roots. It also highlights factors important for individual susceptibility to root resorption. Furthermore, the paper focuses on idiopathic root resorption where the provoking factor is not known. The Hypothesis: The several different disturbances causing root resorption can be either orthodontically provoked or acquired by trauma, virus or congenital diseases. It is presumed that all these conditions lead to inflammatory processes in the three main tissue layers, comprising the peri-root sheet. Evaluation of the Hypothesis: This paper explains how different etiologies behind root resorption and how different phenotypic traits in root resorption can be understood from immunohistochemical studies of the human periodontal membrane close to the root and thus, gain a new understanding of the phenomenon of root resorption.

  15. 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

  16. 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.

  17. [The interdisciplinary fixed restoration of an edentulous maxilla with a pronounced resorption of the alveolar crest. A case report. Part I: The immediate reconstruction].

    Science.gov (United States)

    Teubner, Eckart; Rohner, Dennis; Hammer, Beat; Pietrobon, Nic; Lorenzon, Andreas; Marinello, Carlo P

    2009-01-01

    Edentulous patients wearing a conventional complete denture often request a fixed restoration for functional, esthetical and/or psychosocial reasons. For these patients implant-supported fixed dental prostheses are a prosthetic means of choice. However, after years of edentulism often a marked resorption of the alveolar crest has taken place, asking for bone augmentation before implant placement. Thus, fixed implant reconstructions are time and cost intense and stressful for the patient. This case report documents the immediate fixed reconstruction in the edentulous maxilla after ridge augmentation with a cortical cancellous bone graft from the iliac crest and implant placement. A CAD/CAM-system was used for implant planning and the fabrication of a drilling guide. The prosthetic reconstruction was inserted immediately after implant placement. PMID:19485075

  18. Calcineurin/NFAT signaling in osteoblasts regulates bone mass.

    Science.gov (United States)

    Winslow, Monte M; Pan, Minggui; Starbuck, Michael; Gallo, Elena M; Deng, Lei; Karsenty, Gerard; Crabtree, Gerald R

    2006-06-01

    Development and repair of the vertebrate skeleton requires the precise coordination of bone-forming osteoblasts and bone-resorbing osteoclasts. In diseases such as osteoporosis, bone resorption dominates over bone formation, suggesting a failure to harmonize osteoclast and osteoblast function. Here, we show that mice expressing a constitutively nuclear NFATc1 variant (NFATc1(nuc)) in osteoblasts develop high bone mass. NFATc1(nuc) mice have massive osteoblast overgrowth, enhanced osteoblast proliferation, and coordinated changes in the expression of Wnt signaling components. In contrast, viable NFATc1-deficient mice have defects in skull bone formation in addition to impaired osteoclast development. NFATc1(nuc) mice have increased osteoclastogenesis despite normal levels of RANKL and OPG, indicating that an additional NFAT-regulated mechanism influences osteoclastogenesis in vivo. Calcineurin/NFATc signaling in osteoblasts controls the expression of chemoattractants that attract monocytic osteoclast precursors, thereby coupling bone formation and bone resorption. Our results indicate that NFATc1 regulates bone mass by functioning in both osteoblasts and osteoclasts. PMID:16740479

  19. Nonsurgical Endodontic Retreatment of Advanced Inflammatory External Root Resorption Using Mineral Trioxide Aggregate Obturation

    Directory of Open Access Journals (Sweden)

    Shivani Utneja

    2012-01-01

    Full Text Available Inflammatory external root resorption is one of the major complications after traumatic dental injury. In this case report, we describe treatment of a maxillary central incisor affected by severe, perforating external root resorption. An 18-year-old patient presented with a previously traumatized, root-filled maxillary central incisor associated with pain and sinus tract. Radiographic examination revealed periradicular lesion involving pathologic resorption of the apical region of the root and lateral root surface both mesially and distally. After removal of the root canal filling, the tooth was disinfected with intracanal triple antibiotic paste for 2 weeks. The antibiotic dressing was then removed, and the entire root canal was filled with mineral trioxide aggregate. The endodontic access cavity was restored with composite resin. After 18 months, significant osseous healing of the periradicular region and lateral periodontium had occurred with arrest of external root resorption, and no clinical symptoms were apparent.

  20. Resorption of radionuclides through the surface of thermal burns and problems of decontamination

    International Nuclear Information System (INIS)

    Resorption of sup(137)Cs, sup(89)Sr, sup(131)I, sup(241)Am during thermal burns of 1-3 degrees and choice of a decontamination method used simultaneously for decontamination and disinfection of burn wounds were studied. It is shown that a degree of burns effects in a certain form on skin penetrability: through burns of 1-2 degrees the resorption increases 1 5-3 times, through burns of the thir degree the resorption decreases slightly as compared to the resorption through intact skin. High efficiency of 3% soap solution for removing radionuclides from burn csurfae of skin has been established. For burns accompanied with the disturbance of epidermis integrality, when considerable absorption of radionuclides is possible, decontamination must be accomplished as soon and complete as possible

  1. Alveolar bone loss: mechanisms, potential therapeutic targets, and interventions.

    Science.gov (United States)

    Intini, G; Katsuragi, Y; Kirkwood, K L; Yang, S

    2014-05-01

    This article reviews recent research into mechanisms underlying bone resorption and highlights avenues of investigation that may generate new therapies to combat alveolar bone loss in periodontitis. Several proteins, signaling pathways, stem cells, and dietary supplements are discussed as they relate to periodontal bone loss and regeneration. RGS12 is a crucial protein that mediates osteoclastogenesis and bone destruction, and a potential therapeutic target. RGS12 likely regulates osteoclast differentiation through regulating calcium influx to control the calcium oscillation-NFATc1 pathway. A working model for RGS10 and RGS12 in the regulation of Ca(2+) oscillations during osteoclast differentiation is proposed. Initiation of inflammation depends on host cell-microbe interactions, including the p38 mitogen-activated protein kinase (MAPK) signaling pathway. Oral p38 inhibitors reduced lipopolysaccharide (LPS)-induced bone destruction in a rat periodontitis model but showed unsatisfactory safety profiles. The p38 substrate MK2 is a more specific therapeutic target with potentially superior tolerability. Furthermore, MKP-1 shows anti-inflammatory activity, reducing inflammatory cytokine biosynthesis and bone resorption. Multipotent skeletal stem cell (SSC) populations exist within the bone marrow and periosteum of long bones. These bone-marrow-derived SSCs and periosteum-derived SSCs have shown therapeutic potential in several applications, including bone and periodontal regeneration. The existence of craniofacial bone-specific SSCs is suggested based on existing studies. The effects of calcium, vitamin D, and soy isoflavone supplementation on alveolar and skeletal bone loss in post-menopausal women were investigated. Supplementation resulted in stabilization of forearm bone mass density and a reduced rate of alveolar bone loss over 1 yr, compared with placebo. Periodontal attachment levels were also well-maintained and alveolar bone loss suppressed during 24 wk of

  2. Instrumental and laboratory assessment of stressful remodelling processes in bone tissue at total hip replacement

    Directory of Open Access Journals (Sweden)

    E.V. Karjakina

    2010-06-01

    Full Text Available Research objective is to estimate stressful remodelling features of bone tissue according to the densitometry data and to the level of biochemical markers of bone resorption and formation in total hip replacement (THR. Bone tissue mineral density (BTMD, condition of calcium-phosphoric metabolism and biochemical markers of bone formation (osteocalcin and bone isoenzyme of alkaline phosphatase and resorption (С-terminal bodypeptide of the I type collagen have been determined in 52 patients with coxarthrosis of ll-lll stages with marked joint dysfunction before and after THR. The control group included 24 donors. The data were considered to be reliable when the probability index was р<0,05. The reliable (р<0,05 change of BTMD was determined only in 3-6 months after the operation, whereas the change of biochemical markers of remodeling had already been done after 1,5-3 months, allowing to define the group of patients with obvious negative bone balance: strong predominance of resorption processes without compensation of the subsequent adequate osteogenesis, that subsequently could lead to significant bone tissue deficiency in the area adjacent to the endoprosthesis. Changes of indices of calcium-phosphoric metabolism were not certain during the investigation term. ln conclusion it is to state that biochemical markers of remodeling in comparison with BTMD allow to estimate objectively features of adaptive bone tissue remodeling after THR in earlier periods and to define group of patients with sharp intensification of metabolism and obvious negative bone balance

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

    Science.gov (United States)

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

    2016-08-01

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

  4. Management of external invasive cervical resorption of tooth with Biodentine: A case report

    OpenAIRE

    Akash Kumar Baranwal

    2016-01-01

    Invasive cervical resorption (ICR) of a tooth is relatively uncommon and the etiology is not very clear. It is sometimes misdiagnosed and can lead to improper management or tooth loss. Correct diagnosis and proper management can result in a successful outcome. The treatment should aim toward the complete suppression of all resorbing tissues and the reconstruction of resorptive defect by the placement of a suitable filling material or some biological systems. One of the most significant develo...

  5. Inhibition of reactive oxygen species generation and downstream activation of the ERK/STAT3/RANKL signaling cascade in osteoblasts accounts for the protective effects of estradiol on ethanol-induced bone loss

    Science.gov (United States)

    Bone loss occurs with chronic ethanol (EtOH) consumption in males and cycling females as a result of increased bone resorption. We have demonstrated that in vivo estradiol treatment can reverse this effect. However, the molecular mechanisms of EtOH-induced bone loss and of estrogen protection are la...

  6. Bone changes in alcoholic liver disease

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Alcoholism has been associated with growth impairment,osteomalacia, delayed fracture healing, and asepticnecrosis (primarily necrosis of the femoral head), butthe main alterations observed in the bones of alcoholicpatients are osteoporosis and an increased risk offractures. Decreased bone mass is a hallmark of osteoporosis,and it may be due either to decreased bone synthesis and/or to increased bone breakdown. Ethanolmay affect both mechanisms. It is generally acceptedthat ethanol decreases bone synthesis, and most authorshave reported decreased osteocalcin levels (a "marker" ofbone synthesis), but some controversy exists regardingthe effect of alcohol on bone breakdown, and, indeed,disparate results have been reported for telopeptideand other biochemical markers of bone resorption.In addition to the direct effect of ethanol, systemicalterations such as malnutrition, malabsorption, liverdisease, increased levels of proinflammatory cytokines,alcoholic myopathy and neuropathy, low testosteronelevels, and an increased risk of trauma, play contributoryroles. The treatment of alcoholic bone disease should beaimed towards increasing bone formation and decreasingbone degradation. In this sense, vitamin D and calciumsupplementation, together with biphosphonates areessential, but alcohol abstinence and nutritional improvementare equally important. In this review we study thepathogenesis of bone changes in alcoholic liver diseaseand discuss potential therapies.

  7. Bone Metastasis from Renal Cell Carcinoma

    Science.gov (United States)

    Chen, Szu-Chia; Kuo, Po-Lin

    2016-01-01

    About one-third of patients with advanced renal cell carcinoma (RCC) have bone metastasis that are often osteolytic and cause substantial morbidity, such as pain, pathologic fracture, spinal cord compression and hypercalcemia. The presence of bone metastasis in RCC is also associated with poor prognosis. Bone-targeted treatment using bisphosphonate and denosumab can reduce skeletal complications in RCC, but does not cure the disease or improve survival. Elucidating the molecular mechanisms of tumor-induced changes in the bone microenvironment is needed to develop effective treatment. The “vicious cycle” hypothesis has been used to describe how tumor cells interact with the bone microenvironment to drive bone destruction and tumor growth. Tumor cells secrete factors like parathyroid hormone-related peptide, transforming growth factor-β and vascular endothelial growth factor, which stimulate osteoblasts and increase the production of the receptor activator of nuclear factor κB ligand (RANKL). In turn, the overexpression of RANKL leads to increased osteoclast formation, activation and survival, thereby enhancing bone resorption. This review presents a general survey on bone metastasis in RCC by natural history, interaction among the immune system, bone and tumor, molecular mechanisms, bone turnover markers, therapies and healthcare burden. PMID:27338367

  8. 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 ...

  9. External root resorption after orthodontic treatment: a study of contributing factors

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yun Hoa; Cho, Bong Hae [School of Dentistry, Pusan National University, Pusan (Korea, Republic of)

    2011-03-15

    The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. This study consisted of 163 patients who had completed orthodontic treatments and taken the pre- and post-treatment panoramic and lateral cephalometric radiographs. The length of tooth was measured from the tooth apex to the incisal edge or cusp tip on the panoramic radiograph. Overbite and overjet were measured from the pre- and post-treatment lateral cephalometric radiographs. The root resorption of each tooth and the factors of malocclusion were analyzed with an analysis of variance. A paired t test was performed to compare the mean amount of root resorption between male and female, between extraction and non-extraction cases, and between surgery and non-surgery groups. Correlation coefficients were measured to assess the relationship between the amount of root resorption and the age in which the orthodontic treatment started, the degree of changes in overbite and overjet, and the duration of treatment. Maxillary central incisor was the most resorbed tooth, followed by the maxillary lateral incisor, the mandibular central incisor, and the mandibular lateral incisor. The history of tooth extraction was significantly associated with the root resorption. The duration of orthodontic treatment was positively correlated with the amount of root resorption. These findings show that orthodontic treatment should be carefully performed in patients who need the treatment for a long period and with a pre-treatment extraction of teeth.

  10. External root resorption after orthodontic treatment: a study of contributing factors

    International Nuclear Information System (INIS)

    The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. This study consisted of 163 patients who had completed orthodontic treatments and taken the pre- and post-treatment panoramic and lateral cephalometric radiographs. The length of tooth was measured from the tooth apex to the incisal edge or cusp tip on the panoramic radiograph. Overbite and overjet were measured from the pre- and post-treatment lateral cephalometric radiographs. The root resorption of each tooth and the factors of malocclusion were analyzed with an analysis of variance. A paired t test was performed to compare the mean amount of root resorption between male and female, between extraction and non-extraction cases, and between surgery and non-surgery groups. Correlation coefficients were measured to assess the relationship between the amount of root resorption and the age in which the orthodontic treatment started, the degree of changes in overbite and overjet, and the duration of treatment. Maxillary central incisor was the most resorbed tooth, followed by the maxillary lateral incisor, the mandibular central incisor, and the mandibular lateral incisor. The history of tooth extraction was significantly associated with the root resorption. The duration of orthodontic treatment was positively correlated with the amount of root resorption. These findings show that orthodontic treatment should be carefully performed in patients who need the treatment for a long period and with a pre-treatment extraction of teeth.

  11. Low-dose hydrocortisone (HC) replacement therapy is associated with improved bone remodeling balance in hypopituitary subjects

    LENUS (Irish Health Repository)

    Behan, L A

    2011-06-01

    The effect of commonly used glucocorticoid replacement regimens on bone health in hypopituitary subjects is not well known. We aimed to assess the effect of 3 hydrocortisone (HC) replacement dose regimens on bone turnover in this group.10 hypopituitary men with severe ACTH deficiency were randomised in a crossover design to 3 HC dose regimens, Dose A (20mg mane, 10mg tarde), Dose B (10mg twice daily) and Dose C (10mg mane, 5mg tarde). Following 6 weeks of each regimen participants underwent fasting sampling of bone turnover markers.Data from matched controls were used to produce a Z score for subject bone formation and resorption markers and to calculate the bone remodeling balance (formation Z score-resorption Z score) and turnover index ((formation Z + resorption Z)\\/2). A positive bone remodeling balance with increased turnover is consistent with a favourable bone cycle. Data are expressed as median (range).The Pro Collagen Type 1 Peptide (PINP) bone formation Z-score was significantly increased in Dose C, (1.805 (-0.6-10.24)) compared to Dose A (0.035 (-1.0-8.1)) p<0.05 while there was no difference in the C-terminal crosslinking telopeptide (CTx) resorption Z score. The bone remodeling balance was significantly lower for dose A -0.02 (-1.05-4.12) compared to dose C 1.13 (0.13-6.4) (p<0.05). Although there was a trend to an increased bone turnover index with the lower dose regimen, this was not statistically significant.Low dose HC replacement (10mg mane\\/5 mg tarde) was associated with increased bone formation and improved bone remodeling balance which is associated with a more favourable bone cycle. This may have a long term beneficial effect on bone health.

  12. Bone Adaptation and Regeneration - New Developments

    Science.gov (United States)

    Klein-Nulend, Jenneke; Bacabac, Rommel Gaud

    Bone is a dynamic tissue that is constantly renewed and adapts to its local loading environment. Mechanical loading results in adaptive changes in bone size and shape that strengthen bone structure. The mechanisms for adaptation involve a multistep process called mechanotransduction, which is the ability of resident bone cells to perceive and translate mechanical energy into a cascade of structural and biochemical changes within the cells. The transduction of a mechanical signal to a biochemical response involves pathways within the cell membrane and cytoskeleton of the osteocytes, the professional mechansensor cells of bone. During the last decade the role of mechanosensitive osteocytes in bone metabolism and turnover, and the lacuno-canalicular porosity as the structure that mediates mechanosensing, is likely to reveal a new paradigm for understanding the bone formation response to mechanical loading, and the bone resorption response to disuse. Strain-derived fluid flow of interstitial fluid through the lacuno-canalicular porosity seems to mechanically activate the osteocytes, as well as ensures transport of cell signaling molecules, nutrients and waste products. Cell-cell signaling from the osteocyte sensor cells to the effector cells (osteoblasts or osteoclasts), and the effector cell response - either bone formation or resorption, allow an explanation of local bone gain and loss as well as remodeling in response to fatigue damage as processes supervised by mechanosensitive osteocytes. The osteogenic activity of cultured bone cells has been quantitatively correlated with varying stress stimulations highlighting the importance of the rate of loading. Theoretically a possible mechanism for the stress response by osteocytes is due to strain amplification at the pericellular matrix. Single cell studies on molecular responses of osteocytes provide insight on local architectural alignment in bone during remodeling. Alignment seems to occur as a result of the

  13. DLK1 is a novel regulator of bone mass that mediates estrogen deficiency-induced bone loss in mice

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Ditzel, Nicholas; Mahmood, Amer;

    2011-01-01

    Delta-like 1/fetal antigen 1 (DLK1/FA-1) is a transmembrane protein belonging to the Notch/Delta family that acts as a membrane-associated or a soluble protein to regulate regeneration of a number of adult tissues. Here we examined the role of DLK1/FA-1 in bone biology using osteoblast-specific Dlk...... the bone marrow by activated T cells. Interestingly, Dlk1(-/-) mice were significantly protected from ovx-induced bone loss compared with wild-type mice. Thus we identified Dlk1 as a novel regulator of bone mass that functions to inhibit bone formation and to stimulate bone resorption. Increasing DLK1...... production by T cells under estrogen deficiency suggests its possible use as a therapeutic target for preventing postmenopausal bone loss....

  14. 99mTc-MDP bone scintigraphy in the diagnosis of stress fracture of the metatarsal bones mimicking oligoarthritis

    Directory of Open Access Journals (Sweden)

    Jauković Ljiljana

    2008-01-01

    Full Text Available Background. Stress fractures are the injuries of soft tissues and bones caused by intensive and repeated stress on a bone. Repeated submaximal stress disturbs the balance between the processes of bone production and resorption that results in fracture. Case report. We presented a case of a patient with stress fracture of metatarsal bone. The patient was diagnosed and treated as having reactive oligoarthritis caused by Chlamydia trachomatis and administered antibiotics. Initial plain radiography was negative for bone fracture. Tc-99m bone scintigraphy suggested stress fracture of the second metatarsal. Plain radiography was became positive three weeks later, showing callus formation in the proximal part of the second metatarsal. Conclusion. Bone scintigraphy is a diagnostic test of choice in early diagnosis of stress fracture, and it is important to apply it timely in order to include the entire therapy and prevent complications, as well as to let a patient return to previous daily activites.

  15. Skeletal development of mice lacking bone sialoprotein (BSP--impairment of long bone growth and progressive establishment of high trabecular bone mass.

    Directory of Open Access Journals (Sweden)

    Wafa Bouleftour

    Full Text Available Adult Ibsp-knockout mice (BSP-/- display shorter stature, lower bone turnover and higher trabecular bone mass than wild type, the latter resulting from impaired bone resorption. Unexpectedly, BSP knockout also affects reproductive behavior, as female mice do not construct a proper "nest" for their offsprings. Multiple crossing experiments nonetheless indicated that the shorter stature and lower weight of BSP-/- mice, since birth and throughout life, as well as their shorter femur and tibia bones are independent of the genotype of the mothers, and thus reflect genetic inheritance. In BSP-/- newborns, µCT analysis revealed a delay in membranous primary ossification, with wider cranial sutures, as well as thinner femoral cortical bone and lower tissue mineral density, reflected in lower expression of bone formation markers. However, trabecular bone volume and osteoclast parameters of long bones do not differ between genotypes. Three weeks after birth, osteoclast number and surface drop in the mutants, concomitant with trabecular bone accumulation. The growth plates present a thinner hypertrophic zone in newborns with lower whole bone expression of IGF-1 and higher IHH in 6 days old BSP-/- mice. At 3 weeks the proliferating zone is thinner and the hypertrophic zone thicker in BSP-/- than in BSP+/+ mice of either sex, maybe reflecting a combination of lower chondrocyte proliferation and impaired cartilage resorption. Six days old BSP-/- mice display lower osteoblast marker expression but higher MEPE and higher osteopontin(Opn/Runx2 ratio. Serum Opn is higher in mutants at day 6 and in adults. Thus, lack of BSP alters long bone growth and membranous/cortical primary bone formation and mineralization. Endochondral development is however normal in mutant mice and the accumulation of trabecular bone observed in adults develops progressively in the weeks following birth. Compensatory high Opn may allow normal endochondral development in BSP-/- mice

  16. A new method of prefabricated vascularized allogenic bone grafts for maxillo-mandibular reconstruction

    International Nuclear Information System (INIS)

    Although there are various applications of allogenic bone grafts, a new technique of prevascularized lyophilized allogenic bone grafting for maxillo-mandibular reconstruction will be presented. Allogenic bone has been made by author's protocol for jaw defects as a powder, chip or block bone type. The author used lyophilized allogenic bone grafts for discontinuity defects as a block bone. In those cases, neovascularization and resorption of the allogenic bone were important factors for success of grafting. To overcome the problems, the author designed the technique of prefabricated vascularization of allogenic bone, which was lyophilized cranium, with an application of bovine BMP or not. Lyophilized cranial bone was designed for the defects and was put into the scalp. After confirming a hot spot via scintigram several months later, vascularized allogenic bone was harvested pedicled on the parietotemporal fascia based on the superficial temporal artery and vein. Vascularized allogenic cranial bone was rotated into the defect and fixed rigidly. Postoperatively, there was no severe resorption and functional disturbance of the mandible. In this technique, BMP seems to be an important role to help osteogenesis and neovascularization. Eight patients underwent prefabricated vascularization of allogenic bone grafts. Among them, four cases of reconstruction in mandibular discontinuity defects and one case of reconstruction in maxillectomy defect underwent this method, which will be presented with good results. This method may be an alternative technique of microvascular free bone graft

  17. Bone Metabolism in Adolescent Boys with Anorexia Nervosa

    Science.gov (United States)

    Misra, Madhusmita; Katzman, Debra K.; Cord, Jennalee; Manning, Stephanie J.; Mendes, Nara; Herzog, David B.; Miller, Karen K.; Klibanski, Anne

    2008-01-01

    Background: Anorexia nervosa (AN) is a condition of severe undernutrition associated with low bone mineral density (BMD) in adolescent females with this disorder. Although primarily a disease in females, AN is increasingly being recognized in males. However, there are few or no data regarding BMD, bone turnover markers or their predictors in adolescent AN boys. Hypotheses: We hypothesized that BMD would be low in adolescent boys with AN compared with controls associated with a decrease in bone turnover markers, and that the gonadal steroids, testosterone and estradiol, and levels of IGF-I and the appetite regulatory hormones leptin, ghrelin, and peptide YY would predict BMD and bone turnover markers. Methods: We assessed BMD using dual-energy x-ray absorptiometry and measured fasting testosterone, estradiol, IGF-I, leptin, ghrelin, and peptide YY and a bone formation (aminoterminal propeptide of type 1 procollagen) and bone resorption (N-telopeptide of type 1 collagen) marker in 17 AN boys and 17 controls 12–19 yr old. Results: Boys with AN had lower BMD and corresponding Z-scores at the spine, hip, femoral neck, trochanter, intertrochanteric region, and whole body, compared with controls. Height-adjusted measures (lumbar bone mineral apparent density and whole body bone mineral content/height) were also lower. Bone formation and resorption markers were reduced in AN, indicating decreased bone turnover. Testosterone and lean mass predicted BMD. IGF-I was an important predictor of bone turnover markers. Conclusion: AN boys have low BMD at multiple sites associated with decreased bone turnover markers at a time when bone mass accrual is critical for attainment of peak bone mass. PMID:18544623

  18. Bone-Forming Capabilities of a Newly Developed NanoHA Composite Alloplast Infused with Collagen: A Pilot Study in the Sheep Mandible

    Directory of Open Access Journals (Sweden)

    Charles Marin

    2013-01-01

    Full Text Available Lateral or vertical bone augmentation has always been a challenge, since the site is exposed to constant pressure from the soft tissue, and blood supply only exists from the donor site. Although, for such clinical cases, onlay grafting with autogenous bone is commonly selected, the invasiveness of the secondary surgical site and the relatively fast resorption rate have been reported as a drawback, which motivated the investigation of alternative approaches. This study evaluated the bone-forming capability of a novel nanoHA alloplast infused with collagen graft material made from biodegradable polylactic acid/polyglycolic acid versus a control graft material with the same synthesized alloplast without the nanoHA component and collagen infiltration. The status of newly formed bone and the resorption of the graft material were evaluated at 6 weeks in vivo histologically and three dimensionally by means of 3D microcomputed tomography. The histologic observation showed that newly formed bone ingrowth and internal resorption of the block were observed for the experimental blocks, whereas for the control blocks less bone ingrowth occurred along with lower resorption rate of the block material. The three-dimensional observation indicated that the experimental block maintained the external geometry, but at the same time successfully altered the graft material into bone. It is suggested that the combination of numerous factors contributed to the bone ingrowth and the novel development could be an alternative bone grafting choice.

  19. Activation of bone remodeling after fatigue: differential response to linear microcracks and diffuse damage.

    Science.gov (United States)

    Herman, B C; Cardoso, L; Majeska, R J; Jepsen, K J; Schaffler, M B

    2010-10-01

    Recent experiments point to two predominant forms of fatigue microdamage in bone: linear microcracks (tens to a few hundred microns in length) and "diffuse damage" (patches of diffuse stain uptake in fatigued bone comprised of clusters of sublamellar-sized cracks). The physiological relevance of diffuse damage in activating bone remodeling is not known. In this study microdamage amount and type were varied to assess whether linear or diffuse microdamage has similar effects on the activation of intracortical resorption. Activation of resorption was correlated to the number of linear microcracks (Cr.Dn) in the bone (R(2)=0.60, pmicrocracks in bone, does not result from sublamellar damage. These findings indicate that inability of diffuse microdamage to activate resorption may be due to lack of a focal injury response. Finally, we found that duration of loading does not affect the remodeling response. In conclusion, our data indicate that osteocytes activate resorption in response to linear microcracks but not diffuse microdamage, perhaps due to lack of a focal injury-induced apoptotic response. PMID:20633708

  20. Development, validation and characterization of a novel mouse model of Adynamic Bone Disease (ABD).

    Science.gov (United States)

    Ng, Adeline H; Willett, Thomas L; Alman, Benjamin A; Grynpas, Marc D

    2014-11-01

    The etiology of Adynamic Bone Disease (ABD) is poorly understood but the hallmark of ABD is a lack of bone turnover. ABD occurs in renal osteodystrophy (ROD) and is suspected to occur in elderly patients on long-term anti-resorptive therapy. A major clinical concern of ABD is diminished bone quality and an increased fracture risk. To our knowledge, experimental animal models for ABD other than ROD-ABD have not been developed or studied. The objectives of this study were to develop a mouse model of ABD without the complications of renal ablation, and to characterize changes in bone quality in ABD relative to controls. To re-create the adynamic bone condition, 4-month old female Col2.3Δtk mice were treated with ganciclovir to specifically ablate osteoblasts, and pamidronate was used to inhibit osteoclastic resorption. Four groups of animals were used to characterize bone quality in ABD: Normal bone controls, No Formation controls, No Resorption controls, and an Adynamic group. After a 6-week treatment period, the animals were sacrificed and the bones were harvested for analyses. Bone quality assessments were conducted using established techniques including bone histology, quantitative backscattered electron imaging (qBEI), dual energy X-ray absorptiometry (DXA), microcomputed tomography (microCT), and biomechanical testing. Histomorphometry confirmed osteoblast-related hallmarks of ABD in our mouse model. Bone formation was near complete suppression in the No Formation and Adynamic specimens. Inhibition of bone resorption in the Adynamic group was confirmed by tartrate-resistant acid phosphatase (TRAP) stain. Normal bone mineral density and architecture were maintained in the Adynamic group, whereas the No Formation group showed a reduction in bone mineral content and trabecular thickness relative to the Adynamic group. As expected, the No Formation group had a more hypomineralized profile and the Adynamic group had a higher mean mineralization profile that is

  1. Histologic and histomorphometric evaluation of the effect of lactoferrin combined with anorganic bovine bone on healing of experimentally induced bony defects on rabbit calvaria

    OpenAIRE

    Mojgan Paknejad; Amir Reza Rokn; Ali Akbar Sabur Yaraghi; Flora Elhami; Mohammad Javad Kharazifard; Neda Moslemi

    2012-01-01

    Background: Recent studies have shown that lactoferrin promotes the proliferation and differentiation of osteoblasts and inhibits osteoclast-mediated bone resorption. Anorganic bovine bone (ABB) graft has been extensively used as an osteoconductive material in the bone reconstructive surgeries. The purpose of this study was to examine whether the combination of lactoferrin with Bio-Oss would improve ossification in experimentally induced bone defects in rabbit calvaria. Materials and Meth...

  2. Osteoporosis: Modern Paradigms for Last Century's Bones.

    Science.gov (United States)

    Kruger, Marlena C; Wolber, Frances M

    2016-01-01

    The skeleton is a metabolically active organ undergoing continuously remodelling. With ageing and menopause the balance shifts to increased resorption, leading to a reduction in bone mineral density and disruption of bone microarchitecture. Bone mass accretion and bone metabolism are influenced by systemic hormones as well as genetic and lifestyle factors. The classic paradigm has described osteoporosis as being a "brittle bone" disease that occurs in post-menopausal, thin, Caucasian women with low calcium intakes and/or vitamin D insufficiency. However, a study of black women in Africa demonstrated that higher proportions of body fat did not protect bone health. Isoflavone interventions in Asian postmenopausal women have produced inconsistent bone health benefits, due in part to population heterogeneity in enteric bacterial metabolism of daidzein. A comparison of women and men in several Asian countries identified significant differences between countries in the rate of bone health decline, and a high incidence rate of osteoporosis in both sexes. These studies have revealed significant differences in genetic phenotypes, debunking long-held beliefs and leading to new paradigms in study design. Current studies are now being specifically designed to assess genotype differences between Caucasian, Asian, African, and other phenotypes, and exploring alternative methodology to measure bone architecture. PMID:27322315

  3. Collagen-derived markers of bone metabolism in osteogenesis imperfecta

    DEFF Research Database (Denmark)

    Lund, A M; Hansen, M; Kollerup, Gina Birgitte; Juul, A; Teisner, Børge; Skovby, F

    1998-01-01

    )] were measured in 78 osteogenesis imperfecta (OI) patients to investigate bone metabolism in vivo and relate marker concentrations to phenotype and in vitro collagen I defects, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). PICP and PINP were generally low, and the...... in vivo findings correlated with in vitro results of collagen I SDS-PAGE. Bone turnover is reduced in OI children and mildly affected OI adults, whereas bone resorption is elevated in severely affected adults. These findings may prove helpful for diagnosis and decision-making regarding therapy in OI....

  4. External apical root resorption in maxillary incisors in orthodontic patients: associated factors and radiographic evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Nanekrungsan, Kamonporn [Dept. of Dentistry, Overbrook Hospital, Chiang Rai (Thailand); Patanaporn, Virush; Janhom, Apirum; Korwanich, Narumanus [Dept. of Chiang Mai University, Chiang Mai (Thailand)

    2012-09-15

    This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. The periapical radiographs of 564 teeth showed that the average root resorption was 1.39{+-}1.27 (8.24{+-}7.22%) and 1.69{+-}1.14 mm (10.16{+-}6.78%) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

  5. External apical root resorption in maxillary incisors in orthodontic patients: associated factors and radiographic evaluation

    International Nuclear Information System (INIS)

    This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. The periapical radiographs of 564 teeth showed that the average root resorption was 1.39±1.27 (8.24±7.22%) and 1.69±1.14 mm (10.16±6.78%) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

  6. New insights into the physiology of bone regulation: the role of neurohormones.

    Science.gov (United States)

    Zofková, I; Matucha, P

    2014-01-01

    Bone metabolism is regulated by interaction between two skeletal cells - osteoclasts and osteoblasts. Function of these cells is controlled by a number of humoral factors, including neurohormones, which ensure equilibrium between bone resorption and bone formation. Influence of neurohormones on bone metabolism is often bimodal and depends on the tissue, in which the hormone is expressed. While hypothalamic beta-1 and beta-2-adrenergic systems stimulate bone formation, beta-2 receptors in bone tissue activate osteoclatogenesis and increases bone resorption. Chronic stimulation of peripheral beta-2 receptors is known to quicken bone loss and alter the mechanical quality of the skeleton. This is supported by the observation of a low incidence of hip fractures in patients treated with betablockers. A bimodal osteo-tropic effect has also been observed with serotonin. While serotonin synthetized in brain has osteo-anabolic effects, serotonin released from the duodenum inhibits osteoblast activity and decreases bone formation. On the other hand, both cannabinoid systems (CB1 receptors in the brain and CB2 in bone tissue) are unambiguously osteo-protective, especially with regard to the aging skeleton. Positive (protective) effects on bone have also been shown by some hypophyseal hormones, such as thyrotropin (which inhibits bone resorption) and adrenocorticotropic hormone and oxytocin, both of which stimulate bone formation. Low oxytocin levels have been shown to potentiate bone loss induced by hypoestrinism in postmenopausal women, as well as in girls with mental anorexia. In addition to reviewing neurohormones with anabolic effects, this article also reviews neurohormones with unambiguously catabolic effects on the skeleton, such as neuropeptide Y and neuromedin U. An important aim of research in this field is the synthesis of new molecules that can stimulate osteo-anabolic or inhibiting osteo-catabolic processes. PMID:24702491

  7. Defective microtubule-dependent podosome organization in osteoclasts leads to increased bone density in Pyk2−/− mice

    Science.gov (United States)

    Gil-Henn, Hava; Destaing, Olivier; Sims, Natalie A.; Aoki, Kazuhiro; Alles, Neil; Neff, Lynn; Sanjay, Archana; Bruzzaniti, Angela; De Camilli, Pietro; Baron, Roland; Schlessinger, Joseph

    2007-01-01

    The protein tyrosine kinase Pyk2 is highly expressed in osteoclasts, where it is primarily localized in podosomes. Deletion of Pyk2 in mice leads to mild osteopetrosis due to impairment in osteoclast function. Pyk2-null osteoclasts were unable to transform podosome clusters into a podosome belt at the cell periphery; instead of a sealing zone only small actin rings were formed, resulting in impaired bone resorption. Furthermore, in Pyk2-null osteoclasts, Rho activity was enhanced while microtubule acetylation and stability were significantly reduced. Rescue experiments by ectopic expression of wild-type or a variety of Pyk2 mutants in osteoclasts from Pyk2−/− mice have shown that the FAT domain of Pyk2 is essential for podosome belt and sealing zone formation as well as for bone resorption. These experiments underscore an important role of Pyk2 in microtubule-dependent podosome organization, bone resorption, and other osteoclast functions. PMID:17846174

  8. Defective microtubule-dependent podosome organization in osteoclasts leads to increased bone density in Pyk2(-/-) mice.

    Science.gov (United States)

    Gil-Henn, Hava; Destaing, Olivier; Sims, Natalie A; Aoki, Kazuhiro; Alles, Neil; Neff, Lynn; Sanjay, Archana; Bruzzaniti, Angela; De Camilli, Pietro; Baron, Roland; Schlessinger, Joseph

    2007-09-10

    The protein tyrosine kinase Pyk2 is highly expressed in osteoclasts, where it is primarily localized in podosomes. Deletion of Pyk2 in mice leads to mild osteopetrosis due to impairment in osteoclast function. Pyk2-null osteoclasts were unable to transform podosome clusters into a podosome belt at the cell periphery; instead of a sealing zone only small actin rings were formed, resulting in impaired bone resorption. Furthermore, in Pyk2-null osteoclasts, Rho activity was enhanced while microtubule acetylation and stability were significantly reduced. Rescue experiments by ectopic expression of wild-type or a variety of Pyk2 mutants in osteoclasts from Pyk2(-/-) mice have shown that the FAT domain of Pyk2 is essential for podosome belt and sealing zone formation as well as for bone resorption. These experiments underscore an important role of Pyk2 in microtubule-dependent podosome organization, bone resorption, and other osteoclast functions. PMID:17846174

  9. Conservative management of external root resorption after tooth reimplantation: a 3-year follow-up.

    Science.gov (United States)

    Ionta, Franciny Querobim; de Oliveira, Gabriela Cristina; de Alencar, Catarina Ribeiro Barros; Gonçalves, Priscilla Santana Pinto; Alcalde, Murilo Priori; Minotti, Paloma Gagliardi; Machado, Maria Aparecida de Andrade Moreira; Rios, Daniela

    2016-01-01

    The aim of this case report is to describe the treatment of a 9-year-old patient who suffered external root resorption of the permanent maxillary left lateral incisor following reimplantation of the avulsed left central and lateral incisors. Sixteen days after reimplantation and splinting of the incisors in a hospital emergency department, the patient was brought to the pediatric department of a dental school for further treatment. Root canal access was created in the maxillary left lateral and central incisors, and calcium hydroxide paste was used as intracanal dressing. At the 5-month follow-up, a radiograph revealed extensive external root resorption, a communicating root canal, and a periodontal lesion affecting the left lateral incisor. Management of the root resorption included obturation of the apical third of the canal with gutta percha and the middle third with mineral trioxide aggregate (MTA). At the 3-year recall examination, the patient was asymptomatic, and no mobility or soft tissue alterations were observed clinically. There was no radiographic sign that resorption had progressed. Despite the success of treatment, observation is still required. The use of MTA may be considered an alternative treatment for external root resorption after tooth reimplantation. The technique may allow tooth preservation in children until skeletal growth and development are completed and implant treatment may be considered. PMID:27367632

  10. The clinical meaning of external cervical resorption in maxillary canine: transoperative dental trauma

    Directory of Open Access Journals (Sweden)

    Alberto Consolaro

    2014-12-01

    Full Text Available External Cervical Resorption in maxillary canines with pulp vitality is frequently associated with dental trauma resulting from surgical procedures carried out to prepare the teeth for further orthodontic traction. Preparation procedures might surgically manipulate the cementoenamel junction or cause luxation of teeth due to applying excessive force or movement tests beyond the tolerance limits of periodontal ligament and cervical tissue structures. Dentin exposure at the cementoenamel junction triggers External Cervical Resorption as a result of inflammation followed by antigen recognition of dentin proteins. External Cervical Resorption is painless, does not induce pulpitis and develops slowly. The lesion is generally associated with and covered by gingival soft tissues which disguise normal clinical aspects, thereby leading to late diagnosis when the process is near pulp threshold. Endodontic treatment is recommended only if surgical procedures are rendered necessary in the pulp space; otherwise, External Cervical Resorption should be treated by conservative means: protecting the dental pulp and restoring function and esthetics of teeth whose pulp will remain in normal conditions. Unfortunately, there is a lack of well-grounded research evincing how often External Cervical Resorption associated with canines subjected to orthodontic traction occurs.

  11. Receptor activator of nuclear factor-κB ligand and osteoprotegerin: maintaining the balance to prevent bone loss

    OpenAIRE

    Trouvin, Anne-Priscille; Goëb, Vincent

    2010-01-01

    Bone remodeling requires a precise balance between resorption and formation. It is a complex process that involves numerous factors: hormones, growth factors, vitamins, and cytokines, and notably osteoprotegerin (OPG) and receptor activator for nuclear factor-κB (RANK) ligand. The signaling pathway OPG/RANK/RANKL is key to regulation for maintaining the balance between the activity of osteoblasts and osteoclasts in order to prevent bone loss and ensure a normal bone turnover. In this review, ...

  12. Short-term aluminum administration in the rat. Effects on bone formation and relationship to renal osteomalacia.

    OpenAIRE

    Goodman, W G; Gilligan, J; Horst, R.

    1984-01-01

    Aluminum may be pathogenic in the osteomalacia observed in some patients receiving hemodialysis. To study the early effects of Al on bone growth, bone formation, mineralization, and resorption were measured during short-term Al exposure in the tibial cortex of pair-fed control (C, n = 10), aluminum-treated (AL, n = 9), subtotally nephrectomized control (NX-C, n = 7), and subtotally nephrectomized aluminum-treated (NX-AL, n = 8) rats using double tetracycline labeling of bone. Animals received...

  13. A short-term clinical study of marginal bone level change around microthreaded and platform-switched implants

    OpenAIRE

    Yun, Hee-Jung; Park, Jung-Chul; Yun, Jeong-Ho; Jung, Ui-Won; Kim, Chang-Sung; Choi, Seong-Ho; Cho, Kyoo-Sung

    2011-01-01

    Purpose The marginal bone levels around implants following restoration are used as a reference for evaluating implant success and survival. Two design concepts that can reduce crestal bone resorption are the microthread and platform-switching concepts. The aims of this study were to analyze the placement of microthreaded and platform-switched implants and their short-term survival rate, as well as the level of bone around the implants. Methods The subjects of this study were 27 patients (79 i...

  14. Effect of spaceflight on periosteal bone formation in rats

    Science.gov (United States)

    Wronski, T. J.; Morey, E. R.

    1983-01-01

    Male Wistar rats were placed in orbit for 18.5 days aboard the Soviet COSMOS 1129 biological satellite. Tetracycline was administered before and after spaceflight to label areas of bone formation. An inhibition of periosteal bone formation occurred during spaceflight in the tibial and humeral diaphyses, but this defect was corrected during the postflight period. The increased extent of arrest lines at these skeletal sites suggested that periosteal bone formation may have even ceased during spaceflight. The rib exhibited a small but nonsignificant decrease in periosteal bone formation. Endosteal bone resorption was not affected markedly by spaceflight conditions. The observed inhibition of periosteal bone formation may be a result of mechanical unloading, but endocrine factors cannot be ruled out.

  15. Bone Cancer

    Science.gov (United States)

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

  16. Bone Cancer

    Science.gov (United States)

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

  17. Bone Diseases

    Science.gov (United States)

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

  18. Resorption of impacted teeth as a marker of squamous cell carcinoma infiltrating the mandible

    OpenAIRE

    Colin Liew; Nicolas Dulguerov; Donald Murray Walker; Sathesh Balasundram

    2013-01-01

    The invasion of the mandible by oral squamous cell carcinoma has been firmly demonstrated by anatomical and histological studies.Although squamous cell carcinomas may induce resorption of the roots of standing teeth, there have been no reports of them also causing resorption of the crowns of teeth. A 73-year-old patient presented with an invading buccal squamous cell carcinoma. Radiological investigations showed tumour invasion of the dentate region of the left mandible and resorption of the...

  19. Understanding the local actions of lipids in bone physiology.

    Science.gov (United States)

    During, Alexandrine; Penel, Guillaume; Hardouin, Pierre

    2015-07-01

    The adult skeleton is a metabolically active organ system that undergoes continuous remodeling to remove old and/or stressed bone (resorption) and replace it with new bone (formation) in order to maintain a constant bone mass and preserve bone strength from micro-damage accumulation. In that remodeling process, cellular balances--adipocytogenesis/osteoblastogenesis and osteoblastogenesis/osteoclastogenesis--are critical and tightly controlled by many factors, including lipids as discussed in the present review. Interest in the bone lipid area has increased as a result of in vivo evidences indicating a reciprocal relationship between bone mass and marrow adiposity. Lipids in bones are usually assumed to be present only in the bone marrow. However, the mineralized bone tissue itself also contains small amounts of lipids which might play an important role in bone physiology. Fatty acids, cholesterol, phospholipids and several endogenous metabolites (i.e., prostaglandins, oxysterols) have been purported to act on bone cell survival and functions, the bone mineralization process, and critical signaling pathways. Thus, they can be regarded as regulatory molecules important in bone health. Recently, several specific lipids derived from membrane phospholipids (i.e., sphingosine-1-phosphate, lysophosphatidic acid and different fatty acid amides) have emerged as important mediators in bone physiology and the number of such molecules will probably increase in the near future. The present paper reviews the current knowledge about: (1°) bone lipid composition in both bone marrow and mineralized tissue compartments, and (2°) local actions of lipids on bone physiology in relation to their metabolism. Understanding the roles of lipids in bone is essential to knowing how an imbalance in their signaling pathways might contribute to bone pathologies, such as osteoporosis. PMID:26118851

  20. Critical appraisal of denosumab in the treatment and prevention of postmenopausal osteoporosis and bone loss in patients undergoing hormone ablation

    Directory of Open Access Journals (Sweden)

    David L Kendler

    2010-09-01

    Full Text Available David L Kendler1, Kenneth Shawn Davison21Prohealth Clinical Research, University of British Columbia, Vancouver, British Columbia, Canada; 2Department of Medicine, Division of Immunology and Rheumatology, Laval University, Quebec, CanadaAbstract: Antiresorptive therapies are the mainstay for treating patients with excessively high rates of bone resorption. The receptor activator of nuclear factor-κB (RANK ligand (RANKL, secreted by osteoblasts, binds to the RANK receptor on the surface of preosteoclasts and osteoclasts to elicit osteoclast formation, survival, and activity. Osteoprotegerin, also secreted by the osteoblast, acts as a decoy RANK receptor reducing RANKL binding to RANK and reducing bone resorption. Denosumab, a fully human monoclonal antibody, has a high affinity and specificity for RANKL. Denosumab rapidly decreases bone resorption and increases bone mineral density (BMD at the lumbar spine, total hip, femoral neck, and one-third radius sites. In head-to-head trials, denosumab increased BMD and decreased bone resorption to a significantly greater degree than alendronate. In postmenopausal osteoporotic women, denosumab decreased the risk of vertebral fracture (68%, nonvertebral fracture (20%, and hip fracture (40% over 36 months, compared to placebo. In patients with iatrogenic hypogonadism, denosumab rapidly decreased markers of bone resorption and increased BMD. In men treated with GnRH agonist for prostate cancer, treatment with denosumab led to a 62% decreased risk of new vertebral fracture over 3 years, as compared to placebo. In all trials completed to date, comparable adverse events have been observed in both denosumab and placebo or treatment groups.Keywords: medication adherence, fracture, bone mineral density, bone turnover markers

  1. Bone mineral density and markers of bone turnover in patients with renal transplantation and regular hemodialysis

    Directory of Open Access Journals (Sweden)

    Samir M. Ibrahim,. Khalid H Abdel-Mageed, Magdi M El-Sharkawy

    2002-09-01

    Full Text Available Background: Decreased bone mineral density (BMD is a known complication for the uremic state antedating dialysis / renal transplantation (RTx. The issue of stabilized versus continued decrease of BMD especially on long-term basis, continues to be unresolved. Patients and Methods: !"#"hemodialysis (HD-#" $% " &'( &'(-group had been evaluated for metabolic bone changes by calcium homeostasis parameters (serum calcium, phosphorus, alkaline phosphatase "ALP" and vitamin D "calcitriol", markers of bone formation (bone alkaline phosphatase "BAP", osteocalcin "OC", N-terminal propeptide of collagen type I "PINP", bone resorption markers (pyridoline "PYL" and deoxypyridoline "DPYL", and intact parathyroid hormone (iPTH. Also, BMD had been assessed by dual energy x-ray absorptiometry (DEXA twice, at inclusion time and * ! "" Results: comparing both groups regarding calcium homeostasis, markers of bone turnover and iPTH showed non significant difference. However, there was a significant drop of BMD (as evidenced by T-score at follow up in the HD group, compared to stabilization of T-score for the RTx-group. Furthermore, annual T-score change was significantly more in HD-group, compared to RTx-group. Results also showed that, the best marker correlating with T-score annual changes and iPTH to be PINP. Irrespective of normal calcium homeostasis parameters, low BMD is a prevalent disorder among patients on regular HD and renal transplants.Conclusion: Follow up for * ! " %+ ,- ." % """"!to continued bone loss in patients on regular HD. This could raise recommendation for calcium and calcitriol supplementation, especially in the predialysis period, early post transplantation period, and continued guided replacement for those on maintenance HD. Serum PINP showed best correlations with BMD changes and iPTH and could be considered a reliable marker reflecting bone formation in those patients. Keywords: hemodialysis, renal transplantation, markers of bone

  2. The development of post-traumatic cyst-like lesions in bone

    International Nuclear Information System (INIS)

    Cyst-like lesions in the radius and tibia were observed in two children as a post-fracture event. The pathogenesis of these lesions is discussed. Cut sections from anatomic specimens display extensive hemorrhage in subperiosteal as well as endosteal and trabecular bone. Cysts arising from hemorrhagic resorption in various locales may explain the occasional atypical appearance of these lesions. (orig.)

  3. Influence of radiation resorption on criteria of the existence of local thermodynamic equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Denisova, N.V.; Preobrazhenskii, N.G.; Sevast' yanenko, V.G.

    1986-12-01

    The emission of radiation from a plasma volume upsets the Boltzmann equilibrium. A number of authors have proposed criteria for approximate testing of the existence of local thermodynamic equilibrium on the basis of collision and radiation processes. However, those criteria give excessive values, because they do not take into account radiation resorption, which can moderate the test conditions. The present article is concerned with the influence of radiation resorption on the criterion of the existence of local thermodynamic equilibrium in a low-temperature plasma. The domain of existence of local thermodynamic equilibrium (in the sense of Saha-Boltzmann equilibrium) is calculated for electric arcs.

  4. Histomorphological evaluation of Compound bone of Granulated Ricinus in bone regeneration in rabbits

    International Nuclear Information System (INIS)

    Histological evaluation is an effective method in the behavioral description of the qualitative and quantitative implanted materials. The research validated the performance of Compound bone of Granulated Ricinus on bone regeneration with the histomorphological analysis results. Were selected 30 rabbits, females, divided into 3 groups of 10 animals (G1, G2, G3) with a postoperative time of 45, 70 and 120 days respectively. Each animal is undergone 2 bone lesions in the ilium, one implemented in the material: Compound bone of Granulated Ricinus and the other for control. After the euthanasia, the iliac bone was removed, identified and subjected to histological procedure. The evaluation histological, histomorphological results were interpreted and described by quantitative and qualitative analysis based facts verified in the three experimental groups evaluating the rate of absorption of the material in the tissue regeneration, based on the neo-bone formation. The histomorphologic results classified as a material biocompatible and biologically active. Action in regeneration by bone resorption occurs slowly and gradually. Knowing the time and rate of absorption and neo-formation bone biomaterial, which can be determined in the bone segment applicable in the clinical surgical area.

  5. Calcium phosphate cement delivering zoledronate decreases bone turnover rate and restores bone architecture in ovariectomized rats

    International Nuclear Information System (INIS)

    Patients sustaining bony fractures frequently require the application of bone graft substitutes to fill the bone defects. In the meantime, anti-osteoporosis drugs may be added in bone fillers to treat osteoporosis, especially in postmenopausal women and the elderly. The effects of zoledronate-impregnated calcium phosphate cement (ZLN/CPC) on ovariectomized (OVX) rats were evaluated. OVX rats were implanted with ZLN/CPC, containing 0.025 mg ZLN in the greater omentum. Afterward the clinical sign of toxicity was recorded for eight weeks. The rats were sacrificed and blood samples were collected for hematology and serum bone turnover markers analyses. The four limbs of the rats were harvested and micro-computer tomography (micro-CT) scanning and bone ash analyses were performed. No clinical toxicity was observed in the treated rats. Compared to the OVX rats, levels of bone resorption markers (fragments of C-telopeptides of type I collagen) and bone formation markers (alkaline phosphatase and osteocalcin) decreased significantly in the treated rats. Osteopontin, which mediates the anchoring of osteoclasts to the mineral matrix of bones, also decreased significantly. Micro-CT scanning and histologic examinations of the distal femoral metaphyses showed that the cancellous bone architectures were restored, with a concomitant decrease in bone porosity. The bone mineral content in the bone ashes also increased significantly. This study indicates that ZLN-impregnated CPC reduces bone turnover rate and restores bone architecture in OVX rats. CPC may be an appropriate carrier to deliver drugs to treat osteoporosis, and this approach may also reduce rates of post-dosing symptoms for intravenous ZLN delivery. (paper)

  6. Impact of treatments for postmenopausal osteoporosis (bisphosphonates, parathyroid hormone, strontium ranelate, and denosumab) on bone quality: a systematic review.

    Science.gov (United States)

    Gallacher, S J; Dixon, T

    2010-12-01

    The objective of this systematic review was to examine the influence of treatments for postmenopausal osteoporosis (parathyroid hormone [PTH], bisphosphonates, strontium ranelate, and denosumab) on bone quality and discuss the clinical implications. Most bone-quality data for PTH is from teriparatide. Teriparatide results in a rapid increase in bone-formation markers, followed by increases in bone-resorption markers, opening an "anabolic window," a period of time when PTH is maximally anabolic. Teriparatide reverses the structural damage seen in osteoporosis and restores the structure of trabecular bone. It has a positive effect on cortical bone, and any early increases in cortical porosity appear to be offset by increases in cortical thickness and diameter. Bisphosphonates are antiresorptive agents which reduce bone turnover, improve trabecular microarchitecture, and mineralization. Concerns have been raised that the prolonged antiresorptive action of bisphosphonates may lead to failure to repair microdamage, resulting in microcracks and atypical fragility. Strontium ranelate is thought to have a mixed mode of action, increasing bone formation and decreasing bone resorption. Strontium ranelate improves cortical thickness, trabecular number, and connectivity, with no change in cortical porosity. Denosumab exerts rapid, marked, and sustained effects on bone resorption, resulting in falls in the markers of bone turnover. Evidence from bone-quality studies suggests that treatment-naive women, aged 60-65 years, with very low BMD T scores may benefit from PTH as primary therapy to improve bone substrate and build bone. Post-PTH treatment with bisphosphonates will maintain improvements in bone quality and reduce the risk of fracture. PMID:20872215

  7. Bone Plasticity in Response to Exercise Is Sex-Dependent in Rats

    OpenAIRE

    Vicente, Wagner S.; Dos Reis, Luciene M.; Graciolli, Rafael G.; Graciolli, Fabiana G.; Dominguez, Wagner V; Wang, Charles C.; Fonseca, Tatiana L.; Velosa, Ana P.; Roschel, Hamilton; Teodoro, Walcy R; Gualano, Bruno; Jorgetti, Vanda

    2013-01-01

    Purpose To characterize the potential sexual dimorphism of bone in response to exercise. Methods Young male and female Wistar rats were either submitted to 12 weeks of exercise or remained sedentary. The training load was adjusted at the mid-trial (week 6) by the maximal speed test. A mechanical test was performed to measure the maximal force, resilience, stiffness, and fracture load. The bone structure, formation, and resorption were obtained by histomorphometric analyses. Type I collagen (C...

  8. Role of periodontal pathogenic bacteria in RANKL-mediated bone destruction in periodontal disease

    OpenAIRE

    Kajiya, Mikihito; Giro, Gabriela; Taubman, Martin A.; Han, Xiaozhe; Marcia P.A. Mayer; Kawai, Toshihisa

    2010-01-01

    Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal bacteria in the onset and progression of periodontal disease (PD) are well documented. However, the mechanism underlying the engagement of periodontal bacteria in RANKL-mediated alveolar bone resorption remains unclear. Therefore, this review article addresses three critical subjects. First, ...

  9. The iliac bone or osteocutaneous transplant pedicled to the deep circumflex iliac artery. II. Clinical application.

    Science.gov (United States)

    Bitter, K; Schlesinger, S; Westerman, U

    1983-12-01

    10 patients received a bone or osteocutaneous transplant pedicled to the deep circumflex iliac artery (DCIA) after in-continuity resection of the mandible. 9 grafts healed primarily and were stable after a period of time corresponding to that needed in fractured bones. No infection or resorption occurred. In one case, varicosity made the vessel preparation impossible. Indications, reliability and pitfalls of this method are outlined and discussed in this paper. PMID:6361188

  10. Use of multiple acoustic wave modes for assessment of long bones: Model study

    OpenAIRE

    Tatarinov, Alexey; Sarvazyan, Noune; Sarvazyan, Armen

    2005-01-01

    Multiple acoustic wave mode method has been proposed as a new modality in axial bone QUS. The new method is based on measurement of ultrasound velocity at different ratio of wavelength to the bone thickness, and taking into account both bulk and guided waves. It allows assessment of changes in both the material properties related to porosity and mineralization as well as the cortical thickness influenced by resorption from inner layers, which are equally important in diagnostics of osteoporos...

  11. Significant Association Between Bone-Specific Alkaline Phosphatase and Vascular Calcification of the Hand Arteries in Male Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Eiji Ishimura

    2014-09-01

    Full Text Available Background/Aims: Bone-specific alkaline phosphatase (BAP hydrolyzes pyrophosphate, which inhibits vascular calcification. We examined association between serum BAP and vascular calcification of male hemodialysis patients. Methods: Hand roentgenography of 167 male maintenance hemodialysis patients was conducted, and visible vascular calcification of the hand arteries was evaluated. Serum levels of 3 bone formation markers (BAP, osteocalcin, and N-terminal propeptide of type I collagen and 2 bone resorption markers (C-terminal telopeptide of type I collagen, and cross-linked N-telopeptide of type I collagen were measured, along with serum intact parathyroid hormone (PTH. Results: Of 167 patients, visible vascular calcification was seen in 37 patients. Among the bone formation and resorption markers, serum BAP was significantly higher in patients with vascular calcification than in those without (pConclusions: Higher serum BAP, but not other bone markers, is significantly associated with the presence of vascular calcification in male hemodialysis patients.

  12. Effect of simvastatin on bone markers in osteopenic women: a placebo-controlled, dose-ranging trial [ISRCTN85429598

    Directory of Open Access Journals (Sweden)

    Morse Megan

    2002-02-01

    Full Text Available Abstract Background Hydroxymethylglutaryl coenzyme A reductase inhibitors increase new bone formation in vitro and in rodents. Results of epidemiologic analyses evaluating the association between use of these cholesterol-lowering drugs, bone mineral density and fracture have been mixed. Methods Women (n = 24 with osteopenia, assessed by broad band ultrasound attenuation, were randomized to simvastatin 20 mg, 40 mg or identical-appearing placebo for 12 weeks. Fasting lipid profiles and biochemical markers of bone formation (bone-specific alkaline phosphatase and resorption (N-telopeptides and C-terminal propeptide of type 1 collagen were measured at baseline, 6 and 12 weeks. Results Plasma low density lipoprotein-cholesterol concentration fell 7%, 39% (p Conclusion Among osteopenic women, treatment with simvastatin for 12 weeks did not affect markers of bone formation or resorption.

  13. The effect of infliximab, a monoclonal antibody against TNF-alpha, on disc herniation resorption - A randomized controlled study

    NARCIS (Netherlands)

    Autio, Reijo A.; Karppinen, Jaro; Niinimaki, Jaakko; Ojala, Risto; Veeger, Nic; Korhonen, Timo; Hurri, Heikki; Tervonen, Osmo

    2006-01-01

    Study Design. Randomized, controlled study. Objective. To evaluate the effect of infliximab on herniated nucleus pulposus (HNP) resorption. Summary of Background Data. Although the effects of tumor necrosis factor alpha (TNF-alpha) on HNP resorption are not fully understood, TNF-alpha appears to be

  14. A possible association between early apical resorption of primary teeth and ectodermal characteristics of the permanent dentition

    DEFF Research Database (Denmark)

    Bille, M L B; Kvetny, M J; Kjaer, I

    2008-01-01

    apical resorption in the primary dentition. Panoramic radiographs of 12 children (7 boys and 5 girls) aged 6 years 4 months to 8 years 9 months with unexpected early apical resorption of primary teeth were identified from a dental archive of 588 patients. After written request, follow-up radiographs were...

  15. Future human bone research in space

    Science.gov (United States)

    LeBlanc, A.; Shackelford, L.; Schneider, V.

    1998-01-01

    Skylab crewmembers demonstrated negative calcium (Ca) balance reaching about -300 mg/day by flight day 84. Limited bone density (BMD) measurements documented that bone was not lost equally from all parts of the skeleton. Subsequent BMD studies during long duration Russian flights documented the regional extent of bone loss. These studies demonstrated mean losses in the spine, femur neck, trochanter, and pelvis of about 1%-1.6% with large differences between individuals as well as between bone sites in a given individual. Limited available data indicate postflight bone recovery occurred in some individuals, but may require several years for complete restoration. Long duration bedrest studies showed a similar pattern of bone loss and calcium balance (-180 mg/day) as spaceflight. During long duration bedrest, resorption markers were elevated, formation markers were unchanged, 1,25 vitamin D (VitD) and calcium absorption were decreased, and serum ionized Ca was increased. Although this information is a good beginning, additional spaceflight research is needed to assess architectural and subregional bone changes, elucidate mechanisms, and develop efficient as well as effective countermeasures. Space research poses a number of unique problems not encountered in ground-based laboratory research. Therefore, researchers contemplating human spaceflight research need to consider a number of unique problems related to spaceflight in their experimental design.

  16. Bone Health in Patients with Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Vit Zikan

    2011-01-01

    Full Text Available Multiple sclerosis (MS is a gait disorder characterized by acute episodes of neurological defects leading to progressive disability. Patients with MS have multiple risk factors for osteoporotic fractures, such as progressive immobilization, long-term glucocorticoids (GCs treatment or vitamin D deficiency. The duration of motor disability appears to be a major contributor to the reduction of bone strength. The long term immobilization causes a marked imbalance between bone formation and resorption with depressed bone formation and a marked disruption of mechanosensory network of tightly connected osteocytes due to increase of osteocyte apoptosis. Patients with higher level of disability have also higher risk of falls that combined with a bone loss increases the frequency of bone fractures. There are currently no recommendations how to best prevent and treat osteoporosis in patients with MS. However, devastating effect of immobilization on the skeleton in patients with MS underscores the importance of adequate mechanical stimuli for maintaining the bone structure and its mechanical competence. The physical as well as pharmacological interventions which can counteract the bone remodeling imbalance, particularly osteocyte apoptosis, will be promising for prevention and treatment of osteoporosis in patients with MS.

  17. Application of Petri Nets in Bone Remodeling

    Directory of Open Access Journals (Sweden)

    Lingxi Li

    2009-07-01

    Full Text Available Understanding a mechanism of bone remodeling is a challenging task for both life scientists and model builders, since this highly interactive and nonlinear process can seldom be grasped by simple intuition. A set of ordinary differential equations (ODEs have been built for simulating bone formation as well as bone resorption. Although solving ODEs numerically can provide useful predictions for dynamical behaviors in a continuous time frame, an actual bone remodeling process in living tissues is driven by discrete events of molecular and cellular interactions. Thus, an event-driven tool such as Petri nets (PNs, which may dynamically and graphically mimic individual molecular collisions or cellular interactions, seems to augment the existing ODE-based systems analysis. Here, we applied PNs to expand the ODE-based approach and examined discrete, dynamical behaviors of key regulatory molecules and bone cells. PNs have been used in many engineering areas, but their application to biological systems needs to be explored. Our PN model was based on 8 ODEs that described an osteoprotegerin linked molecular pathway consisting of 4 types of bone cells. The models allowed us to conduct both qualitative and quantitative evaluations and evaluate homeostatic equilibrium states. The results support that application of PN models assists understanding of an event-driven bone remodeling mechanism using PN-specific procedures such as places, transitions, and firings.

  18. Divergent resorbability and effects on osteoclast formation of commonly used bone substitutes in a human in vitro-assay.

    Directory of Open Access Journals (Sweden)

    Johannes Keller

    Full Text Available Bioactive bone substitute materials are a valuable alternative to autologous bone transplantations in the repair of skeletal defects. However, clinical studies have reported varying success rates for many commonly used biomaterials. While osteoblasts have traditionally been regarded as key players mediating osseointegration, increasing evidence suggests that bone-resorbing osteoclasts are of crucial importance for the longevity of applied biomaterials. As no standardized data on the resorbability of biomaterials exists, we applied an in vitro-assay to compare ten commonly used bone substitutes. Human peripheral blood mononuclear cells (PBMCs were differentiated into osteoclasts in the co-presence of dentin chips and biomaterials or dentin alone (control for a period of 28 days. Osteoclast maturation was monitored on day 0 and 14 by light microscopy, and material-dependent changes in extracellular pH were assessed twice weekly. Mature osteoclasts were quantified using TRAP stainings on day 28 and their resorptive activity was determined on dentin (toluidin blue staining and biomaterials (scanning electron microscopy, SEM. The analyzed biomaterials caused specific changes in the pH, which were correlated with osteoclast multinuclearity (r = 0.942; p = 0.034 and activity on biomaterials (r = 0.594; p = 0.041. Perossal led to a significant reduction of pH, nuclei per osteoclast and dentin resorption, whereas Tutogen bovine and Tutobone human strikingly increased all three parameters. Furthermore, natural biomaterials were resorbed more rapidly than synthetic biomaterials leading to differential relative resorption coefficients, which indicate whether bone substitutes lead to a balanced resorption or preferential resorption of either the biomaterial or the surrounding bone. Taken together, this study for the first time compares the effects of widely used biomaterials on osteoclast formation and resorbability in an unbiased approach that may now aid

  19. IL-1 & IL-6 in Bone: Local Translators in Cell-to-Cell Communications

    Directory of Open Access Journals (Sweden)

    Sri Angky Soekanto

    2015-10-01

    Full Text Available Interleukin-1 (IL-1 and interleukin-6 (IL-6 which are produced in bone marrow cells and bone cells play an important roles as local mediators between cells in the bone microenvironment. These interleukin of osteotropic cytokines have important regulatory roles in many organ processes, such as embryogenesis, angiogenesis, tumorigenesis, wound healing, and immune responses. The major targets of these cytokines in the bone is progenitor cells, and in particular, hematopoietic precursors of osteoclasts, are strongly influenced by these cytokines. Proliferation and differentiation of osteoblasts are modulated by IL-1 and IL-6 through autocrine and/or paracrine mechanisms. IL-1 and IL-6 both have the action on bone formation and resorption in normal and pathologic bone turnover. However, it seems almost impossible to clearly elucidate their roles. Further investigation are needed to give more information on the role of osteotropic cytokines in bone cell function that will advance bone research.

  20. Management of a massive resorptive lesion with multiple perforations in a molar: case report.

    Science.gov (United States)

    Borkar, Swati; de Noronha de Ataide, Ida

    2015-05-01

    Internal resorption is usually asymptomatic. Large resorption defects may result in penetration of the root dentin leading to perforation. In this case report, we describe the diagnosis and nonsurgical repair of a large resorptive lesion with multiple perforations in a mandibular first molar using cone-beam computed tomographic technology. The 3 different root perforations were located in the mesial root and repaired using Biodentine (Septodont, Saint-Maur des Fossés, France). The mesial root weakened from resorption was reinforced by replacing the lost root dentin with calcium silicate-based cement and placement of a glass fiber post. The 18-month follow-up confirmed remineralization of the osseous defect and asymptomatic function of the tooth. A further follow-up at 43 months revealed retention of the tooth and absence of root fracture. Usually, a tooth with multiple perforations and such a severe tooth material loss would have been destined for extraction. However, with contemporary diagnostic techniques such as cone-beam computed tomography and use of advanced biomaterials and root reinforcement methods, such teeth can be salvaged. PMID:25728818

  1. On the assessment of radionuclide resorption from the gastro-intestinal tract of the blood

    International Nuclear Information System (INIS)

    A comparison of the resorption rates measured for the radionuclides Ce, Co, Pu, Ru, Sr and Zn as well as the vitamin B12 with the recommendations for calculation given by the SSK showed that the values used by the SSK partly are too low by orders of magnitude. The dose factors therefore no longer correspond to the international level of science. (DG)

  2. 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

  3. Polyethylene particles from a hip simulator cause (45Ca release from cultured bone.

    Directory of Open Access Journals (Sweden)

    Wang KY

    2001-12-01

    Full Text Available Periprosthetic osteolysis is a dominant factor in the success or failure of total hip prostheses. Polyethylene wear debris has been implicated in the process of bone resorption and subsequent implant loosening. The present study is the first to examine the effect of ultra high molecular weight polyethylene (UHMWPE wear debris produced by a hip simulator on calvarial bone resorption in vitro. (45Ca release was measured in cultured mouse calvarial bone samples. Although short-term exposure to UHMWPE particles (2 h decreased (45Ca release, longer-term exposure for 1-2 days increased release in a dose-dependent manner. After one-day exposure to 7.5 x 10(6 particles per mL, 18% more (45Ca was released from cultured calvarial bone than from control samples. It was concluded that UHMWPE wear particles either directly or indirectly stimulated osteoclasts to activate bone resorption. Polyethylene wear debris contributes to the osteolytic process at the bone-implant interface.

  4. The Periosteal Bone Surface is Less Mechano-Responsive than the Endocortical

    Science.gov (United States)

    Birkhold, Annette I.; Razi, Hajar; Duda, Georg N.; Weinkamer, Richard; Checa, Sara; Willie, Bettina M.

    2016-03-01

    Dynamic processes modify bone micro-structure to adapt to external loading and avoid mechanical failure. Age-related cortical bone loss is thought to occur because of increased endocortical resorption and reduced periosteal formation. Differences in the (re)modeling response to loading on both surfaces, however, are poorly understood. Combining in-vivo tibial loading, in-vivo micro-tomography and finite element analysis, remodeling in C57Bl/6J mice of three ages (10, 26, 78 week old) was analyzed to identify differences in mechano-responsiveness and its age-related change on the two cortical surfaces. Mechanical stimulation enhanced endocortical and periosteal formation and reduced endocortical resorption; a reduction in periosteal resorption was hardly possible since it was low, even without additional loading. Endocortically a greater mechano-responsiveness was identified, evident by a larger bone-forming surface and enhanced thickness of formed bone packets, which was not detected periosteally. Endocortical mechano-responsiveness was better conserved with age, since here adaptive response declined continuously with aging, whereas periosteally the main decay in formation response occurred already before adulthood. Higher endocortical mechano-responsiveness is not due to higher endocortical strains. Although it is clear structural adaptation varies between different bones in the skeleton, this study demonstrates that adaptation varies even at different sites within the same bone.

  5. Modalities for Visualization of Cortical Bone Remodeling: The Past, Present, and Future.

    Science.gov (United States)

    Harrison, Kimberly D; Cooper, David M L

    2015-01-01

    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 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 of 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 architecture." 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." PMID:26322017

  6. A radiographic study of solitary bone cysts

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the clinical, radiographic and histopathologic features of 23 cases of solitary bone cyst by means of the analysis of radiographs and biopsy specimens in 23 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chunbuk National University. The obtained results were as follows; 1. The incidence of solitary bone cyst was almost equal in males (52.2%) and in females(42.8%) and the prevalent age of the solitary bone cyst were the second decade (47.8%) and the third decade (21.7%). 2. In the signs and symptoms of solitary bone cyst, pain or tenderness revealed in 17.4%, swelling revealed in 13.0%, pain and swelling revealed in 21.7%, paresthesia revealed in 4.4% and 43.5% were a symptom and the tooth vitality involved in the solitary bone cyst, 76.5% were posterior and 23.5% were either positive or negative. 3. In the location of the solitary bone cyst, 47.8% present posterior region, 21.7% present anterior region, 21.6% present anterior and posterior region, 4.4% present condylar process area. 4. In the hyperostotic border of the solitary bone cyst, 47.8% were seen entirely, 21.8% were seen partially, and 30.4% were not seen. 5. In the change of tooth, 59.1% were loss of the alveolar lamina dura, 13.6% were root resorption 4.55% were tooth displacement, 4.55% were root resorption and tooth displacement. 6. In the change of cortical bone of the solitary bone cyst, 39.1% were intact and 60.9% were thinning and expansion of cortical bone. 7. In the histopathologic findings of 9 cases, 33.3% were thin connective tissue wall, 11.1% were thickened myxo-fibromatous wall, 55.6% were thickened myxofibromatous wall with dysplastic bone formation.

  7. Effects of obesity on bone metabolism

    Directory of Open Access Journals (Sweden)

    Cao Jay J

    2011-06-01

    Full Text Available Abstract Obesity is traditionally viewed to be beneficial to bone health because of well-established positive effect of mechanical loading conferred by body weight on bone formation, despite being a risk factor for many other chronic health disorders. Although body mass has a positive effect on bone formation, whether the mass derived from an obesity condition or excessive fat accumulation is beneficial to bone remains controversial. The underline pathophysiological relationship between obesity and bone is complex and continues to be an active research area. Recent data from epidemiological and animal studies strongly support that fat accumulation is detrimental to bone mass. To our knowledge, obesity possibly affects bone metabolism through several mechanisms. Because both adipocytes and osteoblasts are derived from a common multipotential mesenchymal stem cell, obesity may increase adipocyte differentiation and fat accumulation while decrease osteoblast differentiation and bone formation. Obesity is associated with chronic inflammation. The increased circulating and tissue proinflammatory cytokines in obesity may promote osteoclast activity and bone resorption through modifying the receptor activator of NF-κB (RANK/RANK ligand/osteoprotegerin pathway. Furthermore, the excessive secretion of leptin and/or decreased production of adiponectin by adipocytes in obesity may either directly affect bone formation or indirectly affect bone resorption through up-regulated proinflammatory cytokine production. Finally, high-fat intake may interfere with intestinal calcium absorption and therefore decrease calcium availability for bone formation. Unraveling the relationship between fat and bone metabolism at molecular level may help us to develop therapeutic agents to prevent or treat both obesity and osteoporosis. Obesity, defined as having a body mass index ≥ 30 kg/m2, is a condition in which excessive body fat accumulates to a degree that adversely

  8. Osteoporosis and adynamic bone in chronic kidney disease.

    Science.gov (United States)

    Cannata-Andía, Jorge B; Rodriguez García, Minerva; Gómez Alonso, Carlos

    2013-01-01

    Among the chronic kidney disease-mineral bone disease (CKD-MBD) disorders, osteoporosis and adynamic bone are highly prevalent, and they have been consistently associated with low bone mass, bone fractures, vascular calcifications and greater mortality in general and CKD populations. Despite the fact that osteoporosis and adynamic bone have similar clinical outcomes, they have different pathogeneses and clinical management. In osteoporosis, there is a lack of balance between bone formation and bone resorption, and less new bone is formed to replace bone losses. Osteoporosis is defined by the World Health Organization as "a disease characterized by low bone mineral density and micro architectural deterioration leading to low bone strength and increased risk of fractures." In the general population, there is a good correlation between dual-energy X-ray absorptiometry measurements and bone fractures, but this is not the case with CKD patients. Despite the fact that we have a great number of active antiosteoporotic drugs, the experience in CKD patients is limited. Adynamic bone is suspected based on biochemical parameters, mainly parathyroid hormone (PTH) and bone alkaline phosphatase, but it needs to be proven using a bone biopsy, where a low or zero bone formation rate and a reduction or absence of osteoblasts and osteoclasts should be found. The clinical management of adynamic bone has important limitations and currently does not allow taking many active measures. Treatment is mainly based on the prevention of risk factors known to induce PTH oversuppression, such as aluminium and calcium load and very high doses of vitamin D receptor activators. Due to the limitations in the treatment of both conditions, prevention plays a key role in the management of these disorders. PMID:23023723

  9. A Bone Anabolic Effect of RANKL in a Murine Model of Osteoporosis Mediated Through FoxP3+ CD8 T Cells.

    Science.gov (United States)

    Buchwald, Zachary S; Yang, Chang; Nellore, Suman; Shashkova, Elena V; Davis, Jennifer L; Cline, Anna; Ko, Je; Novack, Deborah V; DiPaolo, Richard; Aurora, Rajeev

    2015-08-01

    TNF-α and IL-17 secreted by proinflammatory T cells (T(EFF)) promote bone erosion by activating osteoclasts. We previously demonstrated that in addition to bone resorption, osteoclasts act as antigen-presenting cells to induce FoxP3 in CD8 T cells (Tc(REG)). The osteoclast-induced regulatory CD8 T cells limit bone resorption in ovariectomized mice (a murine model of postmenopausal osteoporosis). Here we show that although low-dose receptor activator of NF-κB ligand (RANKL) maximally induces Tc(REG) via Notch signaling pathway to limit bone resorption, high-dose RANKL promotes bone resorption. In vitro, both TNF-α and IL-17, cytokines that are abundant in ovariectomized animals, suppress Tc(REG) induction by osteoclasts by repressing Notch ligand expression in osteoclasts, but this effect can be counteracted by addition of RANKL. Ovariectomized mice treated with low-dose RANKL induced Tc(REG) that suppressed bone resorption, decreased T(EFF) levels, and increased bone formation. High-dose RANKL had the expected osteolytic effect. Low-dose RANKL administration in ovariectomized mice lacking CD8 T cells was also osteolytic, confirming that Tc(REG) mediate this bone anabolic effect. Our results show that although RANKL directly stimulates osteoclasts to resorb bone, it also controls the osteoclasts' ability to induce regulatory T cells, engaging an important negative feedback loop. In addition to the conceivable clinical relevance to treatment of osteoporosis, these observations have potential relevance to induction of tolerance and autoimmune diseases. PMID:25656537

  10. 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 ...

  11. The effects of twelve weeks of bed rest on bone histology, biochemical markers of bone turnover, and calcium homeostasis in eleven normal subjects

    Science.gov (United States)

    Zerwekh, J. E.; Ruml, L. A.; Gottschalk, F.; Pak, C. Y.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    This study was undertaken to examine the effects of 12 weeks of skeletal unloading on parameters of calcium homeostasis, calcitropic hormones, bone histology, and biochemical markers of bone turnover in 11 normal subjects (9 men, 2 women; 34 +/- 11 years of age). Following an ambulatory control evaluation, all subjects underwent 12 weeks of bed rest. An additional metabolic evaluation was performed after 12 days of reambulation. Bone mineral density declined at the spine (-2.9%, p = 0.092) and at the hip (-3.8%, p = 0.002 for the trochanter). Bed rest prompted a rapid, sustained, significant increase in urinary calcium and phosphorus as well as a significant increase in serum calcium. Urinary calcium increased from a pre-bed rest value of 5.3 mmol/day to values as high as 73 mmol/day during bed rest. Immunoreactive parathyroid hormone and serum 1,25-dihydroxyvitamin D declined significantly during bed rest, although the mean values remained within normal limits. Significant changes in bone histology included a suppression of osteoblastic surface for cancellous bone (3.1 +/- 1.3% to 1.9 +/- 1.5%, p = 0.0142) and increased bone resorption for both cancellous and cortical bone. Cortical eroded surface increased from 3.5 +/- 1.1% to 7.3 +/- 4.0% (p = 0.018) as did active osteoclastic surface (0.2 +/- 0.3% to 0.7 +/- 0.7%, p = 0.021). Cancellous eroded surface increased from 2.1 +/- 1.1% to 4.7 +/- 2.2% (p = 0.002), while mean active osteoclastic surface doubled (0.2 +/- 0.2% to 0.4 +/- 0.3%, p = 0.020). Serum biochemical markers of bone formation (osteocalcin, bone-specific alkaline phosphatase, and type I procollagen extension peptide) did not change significantly during bed rest. Urinary biochemical markers of bone resorption (hydroxyproline, deoxypyridinoline, and N-telopeptide of type I collagen) as well as a serum marker of bone resorption (type I collagen carboxytelopeptide) all demonstrated significant increases during bed rest which declined toward normal

  12. Microgravity Induces Pelvic Bone Loss through Osteoclastic Activity, Osteocytic Osteolysis, and Osteoblastic Cell Cycle Inhibition by CDKN1a/p21

    OpenAIRE

    Blaber, Elizabeth A.; Dvorochkin, Natalya; Lee, Chialing; Alwood, Joshua S.; Yousuf, Rukhsana; Pianetta, Piero; Globus, Ruth K.; Burns, Brendan P.; Almeida, Eduardo A.C.

    2013-01-01

    Bone is a dynamically remodeled tissue that requires gravity-mediated mechanical stimulation for maintenance of mineral content and structure. Homeostasis in bone occurs through a balance in the activities and signaling of osteoclasts, osteoblasts, and osteocytes, as well as proliferation and differentiation of their stem cell progenitors. Microgravity and unloading are known to cause osteoclast-mediated bone resorption; however, we hypothesize that osteocytic osteolysis, and cell cycle arres...

  13. Icariin attenuates titanium-particle inhibition of bone formation by activating the Wnt/β-catenin signaling pathway in vivo and in vitro

    OpenAIRE

    Junhua Wang; Yunxia Tao; Zichuan Ping; Wen Zhang; Xuanyang Hu; Yijun Wang; Liangliang Wang; Jiawei Shi; Xiexing Wu; Huilin Yang; Yaozeng Xu; Dechun Geng

    2016-01-01

    Wear-debris-induced periprosthetic osteolysis (PIO) is a common clinical condition following total joint arthroplasty, which can cause implant instability and failure. The host response to wear debris promotes bone resorption and impairs bone formation. We previously demonstrated that icariin suppressed wear-debris-induced osteoclastogenesis and attenuated particle-induced osteolysis in vivo. Whether icariin promotes bone formation in a wear-debris-induced osteolytic site remains unclear. Her...

  14. Bone mineral density after implantation of a femoral neck hip prosthesis – a prospective 5 year follow-up

    OpenAIRE

    Steens, Wolfram; Boettner, Friedrich; Bader, Rainer; Skripitz, Ralf; Schneeberger, Alberto

    2015-01-01

    Background Bone resorption in the proximal femur due to stress shielding has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to prospectively investigate the in vivo changes of bone-mineral density as a parameter of bone remodeling around a short, femoral neck prosthesis over the first 5 years following implantation. T...

  15. Bone biology, signaling pathways, and therapeutic targets for osteoporosis.

    Science.gov (United States)

    Iñiguez-Ariza, Nicole M; Clarke, Bart L

    2015-10-01

    Major advances have occurred recently in the treatment of osteoporosis in recent years. Most patients are currently treated with bisphosphonates, denosumab, raloxifene, or teriparatide, and in some countries, strontium ranelate. Strontium ranelate and calcitonin have recently had their use restricted due to cardiovascular concerns and malignancy, respectively. The available agents have generally provided excellent options that effectively reduce fracture risk. New targets are being sought based on appreciation of the bone biology and signaling pathways involved in bone formation and resorption. These agents will directly target these signaling pathways, and further expand the options available for treatment of osteoporosis. PMID:26255682

  16. 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 ...

  17. Receptor-Activator of Nuclear KappaB Ligand Expression as a New Therapeutic Target in Primary Bone Tumors

    Science.gov (United States)

    Yamagishi, Tetsuro; Kawashima, Hiroyuki; Ogose, Akira; Ariizumi, Takashi; Sasaki, Taro; Hatano, Hiroshi; Hotta, Tetsuo; Endo, Naoto

    2016-01-01

    The receptor-activator of nuclear kappaB ligand (RANKL) signaling pathway plays an important role in the regulation of bone growth and mediates the formation and activation of osteoclasts. Osteoclasts are involved in significant bone resorption and destruction. Denosumab is a fully human monoclonal antibody against RANKL that specifically inhibits osteoclast differentiation and bone resorption. It has been approved for use for multiple myeloma and bone metastases, as well as for giant cell tumor of bone. However, there is no previous report quantitatively, comparing RANKL expression in histologically varied bone tumors. Therefore, we analyzed the mRNA level of various bone tumors and investigated the possibility of these tumors as a new therapeutic target for denosumab. We examined RANKL mRNA expression in 135 clinical specimens of primary and metastatic bone tumors using real-time PCR. The relative quantification of mRNA expression levels was performed via normalization with RPMI8226, a human multiple myeloma cell line that is recognized to express RANKL. Of 135 cases, 64 were also evaluated for RANKL expression by using immunohistochemistry. Among all of the tumors investigated, RANKL expression and the RANKL/osteoprotegerin ratio were highest in giant cell tumor of bone. High RANKL mRNA expression was observed in cases of aneurysmal bone cyst, fibrous dysplasia, osteosarcoma, chondrosarcoma, and enchondroma, as compared to cases of multiple myeloma and bone lesions from metastatic carcinoma. RANKL-positive stromal cells were detected in six cases: five cases of GCTB and one case of fibrous dysplasia. The current study findings indicate that some primary bone tumors present new therapeutic targets for denosumab, particularly those tumors expressing RANKL and those involving bone resorption by osteoclasts. PMID:27163152

  18. Mechanisms inducing low bone density in Duchenne muscular dystrophy in mice and humans.

    Science.gov (United States)

    Rufo, Anna; Del Fattore, Andrea; Capulli, Mattia; Carvello, Francesco; De Pasquale, Loredana; Ferrari, Serge; Pierroz, Dominique; Morandi, Lucia; De Simone, Michele; Rucci, Nadia; Bertini, Enrico; Bianchi, Maria Luisa; De Benedetti, Fabrizio; Teti, Anna

    2011-08-01

    Patients affected by Duchenne muscular dystrophy (DMD) and dystrophic MDX mice were investigated in this study for their bone phenotype and systemic regulators of bone turnover. Micro-computed tomographic (µCT) and histomorphometric analyses showed reduced bone mass and higher osteoclast and bone resorption parameters in MDX mice compared with wild-type mice, whereas osteoblast parameters and mineral apposition rate were lower. In a panel of circulating pro-osteoclastogenic cytokines evaluated in the MDX sera, interleukin 6 (IL-6) was increased compared with wild-type mice. Likewise, DMD patients showed low bone mineral density (BMD) Z-scores and high bone-resorption marker and serum IL-6. Human primary osteoblasts from healthy donors incubated with 10% sera from DMD patients showed decreased nodule mineralization. Many osteogenic genes were downregulated in these cultures, including osterix and osteocalcin, by a mechanism blunted by an IL-6-neutralizing antibody. In contrast, the mRNAs of osteoclastogenic cytokines IL6, IL11, inhibin-βA, and TGFβ2 were increased, although only IL-6 was found to be high in the circulation. Consistently, enhancement of osteoclastogenesis was noted in cultures of circulating mononuclear precursors from DMD patients or from healthy donors cultured in the presence of DMD sera or IL-6. Circulating IL-6 also played a dominant role in osteoclast formation because ex vivo wild-type calvarial bones cultured with 10% sera of MDX mice showed increase osteoclast and bone-resorption parameters that were dampen by treatment with an IL-6 antibody. These results point to IL-6 as an important mediator of bone loss in DMD and suggest that targeted anti-IL-6 therapy may have a positive impact on the bone phenotype in these patients. PMID:21509823

  19. Novel Receptor-Based Countermeasures to Microgravity-Induced Bone Loss

    Science.gov (United States)

    OMalley, Bert W.

    1999-01-01

    The biological actions mediated by the estrogen receptor (ER), vitamin D receptor (VDR) and Ca(sup 2+) (sub o) -sensing receptor (CaR) play key roles in the normal control of bone growth and skeletal turnover that is necessary for skeletal health. These receptors act by controlling the differentiation and/or function of osteoblasts and osteoclasts, and other cell types within the bone and bone marrow microenvironment. The appropriate use of selective ER modulators (SERMS) which target bone, vitamin D analogs that favor bone formation relative to resorption, and CaR agonists may both stimulate osteoblastogenesis and inhibit osteoclastogenesis and the function of mature osteoclasts, should make it possible to prevent the reduction in bone formation and increase in bone resorption that normally contribute to the bone loss induced by weightlessness. Indeed, there may be synergistic interactions among these receptors that enhance the actions of any one used alone. Therefore, we proposed to: 1) assess the in vitro ability of novel ER, VDR and CaR agonists, alone or in combination, to modulate osteoblastogenesis and mature osteoblast function under conditions of 1g and simulated microgravity; 2) assess the in vitro ability of novel ER, VDR and CaR agonists, alone or in combination, to modulate osteoclastogenesis and bone resorption under conditions of lg and simulated microgravity; and 3) carry out baseline studies on the skeletal localization of the CaR in normal rat bone as well as the in vivo actions of our novel ER- and VDR-based therapeutics in the rat in preparation for their use, alone or in combination, in well-established ground-based models of microgravity and eventually in space flight.

  20. Bone disease in haemoglobin disorders

    Directory of Open Access Journals (Sweden)

    Ersi Voskaridou

    2013-03-01

    Full Text Available Bone disease represents a prominent cause of morbidity in patients with thalassaemia and other haemoglobin disorders. The delay in sexual maturation, the presence of diabetes and hypothyroidism, the parathyroid gland dysfunction, the haemolytic anaemia, the progressive marrow expansion, the iron toxicity on osteoblasts, the iron chelators, and the deficiency of growth hormone or insulin growth factors have been identified as major causes of osteoporosis in thalassaemia. Adequate hormonal replacement, effective iron chelation, improvement of hemoglobin levels, calcium and vitamin D administration, physical activity, and smoking cessation are the main to-date measures for the management of the disease. During the last decade, novel pathogenetic data suggest that the reduced osteoblastic activity, which is believed to be the basic mechanism of bone loss in thalassemia, is accompanied by a comparable or even greater increase in bone resorption. Therefore, potent inhibitors of osteoclast activation, such as the aminobisphosphonates, arise as key drugs for the management of osteoporosis in thalassaemia patients and other haemoglobin disorders.

  1. Delayed Cranioplasty: Outcomes Using Frozen Autologous Bone Flaps.

    Science.gov (United States)

    Hng, Daniel; Bhaskar, Ivan; Khan, Mumtaz; Budgeon, Charley; Damodaran, Omprakash; Knuckey, Neville; Lee, Gabriel

    2015-09-01

    Reconstruction of skull defects following decompressive craniectomy is associated with a high rate of complications. Implantation of autologous cryopreserved bone has been associated with infection rates of up to 33%, resulting in considerable patient morbidity. Predisposing factors for infection and other complications are poorly understood. Patients undergoing cranioplasty between 1999 and 2009 were identified from a prospectively maintained database. Records and imaging were reviewed retrospectively. Demographics, the initial craniectomy and subsequent cranioplasty surgeries, complications, and outcomes were recorded. A total of 187 patients underwent delayed cranioplasty using autologous bone flaps cryopreserved at -30°C following decompressive craniectomy. Indications for craniectomy were trauma (77.0%), stroke (16.0%), subarachnoid hemorrhage (2.67%), tumor (2.14%), and infection (2.14%). There were 64 complications overall (34.2%), the most common being infection (11.2%) and bone resorption (5.35%). After multivariate analysis, intraoperative cerebrospinal fluid (CSF) leak was significantly associated with infection, whereas longer duration of surgery and unilateral site were associated with resorption. Cranioplasty using frozen autologous bone is associated with a high rate of infective complications. Intraoperative CSF leak is a potentially modifiable risk factor. Meticulous dissection during cranioplasty surgery to minimize the chance of breaching the dural or pseudodural plane may reduce the chance of bone flap. PMID:26269726

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

    Science.gov (United States)

    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.

  3. Long-term hormone replacement therapy preserves bone mineral density in Turner syndrome

    DEFF Research Database (Denmark)

    Cleemann, Line; Hjerrild, Britta E; Lauridsen, Anna L;

    2009-01-01

    non-dominant forearm. Bone formation and resorption markers, sex hormones, IGF1, and maximal oxygen uptake. RESULTS: At follow-up, forearm BMD, radius ultradistal BMD, and hip BMD remained unchanged, radius 1/3 BMD declined (0.601+/-0.059 vs 0.592+/-0.059, P=0.03), while spine BMD increased (0.......972+/-0.139 vs 1.010+/-0.144, P<0.0005). Bone formation markers did not change over time in TS. Bone resorption markers decreased over time in TS. Testosterone, IGF1, and maximal oxygen uptake was significantly reduced in TS. CONCLUSION: Longitudinal changes in BMD in TS were slight. BMD can be maintained at...

  4. Relation between body composition and biochemical markers of bone turnover among early postmenopausal women

    DEFF Research Database (Denmark)

    Hla, M M; Davis, J W; Ross, P D;

    2000-01-01

    We studied the associations between body composition and biochemical markers of bone formation and resorption among 1600 postmenopausal women, ages 45-59. Multiple regression analyses were performed to examine the independent associations of fat mass, muscle strength (quadriceps strength), height......, and whole body bone mineral content (BMC) with biochemical markers of bone formation (serum osteocalcin) and resorption (urinary type I collagen crosslinked N-telopeptides [NTX]). Per interquartile range (IQR) (the difference between 75th and 25th percentiles) increase in fat mass and whole body BMC......, the mean levels of osteocalcin decreased by 3% and 13%, respectively; NTX decreased by 5 and 21%. Fat mass and whole-body BMC were also significantly associated with decreases in the average of osteocalcin and NTX Z-scores. By contrast, the mean levels of serum osteocalcin increased by 2 and 11...

  5. Shell bone histology of the long-necked chelid Yaminuechelys (Testudines: Pleurodira) from the late Cretaceous—early Palaeocene of Patagonia with comments on the histogenesis of bone ornamentation

    Science.gov (United States)

    Jannello, Juan Marcos; Cerda, Ignacio A.; de la Fuente, Marcelo S.

    2016-04-01

    Yaminuechelys is a long-necked chelid turtle whose remains have been recovered from outcrops of the Santonian-Maastrichtian and Danian of South America. With the purpose of providing data about shell sculpturing origin and palaeoecology, the bone histology of several shell elements (including neural, costal, peripheral and plastral plates) of Yaminuechelys is described herein. Histological analysis reveals that Yaminuechelys shares with Chelidae the presence of interwoven structural fibre bundles in the external cortex, and parallel-fibred bone of the internal cortex. The presence of resorption lines in several samples indicates that the particular ornamentation of the external surfaces originated, at least in part, by focalized resorption and new bone deposition. This mechanism for ornamentation origin and maintenance is here described for the first time in a turtle. Compactness of the shell bones is consistent with an aquatic habitat, which supports previous hypothesis based on palaeoenvironmental and morphological data.

  6. Bone histomorphometric analysis in a patient with anorexia nervosa.

    Science.gov (United States)

    Hiramatsu, Rikako; Ubara, Yoshifumi; Suwabe, Tatsuya; Hoshino, Junichi; Sumida, Keiichi; Hasegawa, Eiko; Yamanouchi, Masayuki; Hayami, Noriko; Sawa, Naoki; Takaichi, Kenmei

    2013-09-01

    A 34-year-old Japanese woman with anorexia nervosa (AN) of a body mass index (BMI) of 11.0 kg/cm(2) was admitted to our hospital for assessment of renal dysfunction with a serum creatinine of 1.8 mg/dL and hypokalemia (3.0 mEq/L). Renal biopsy showed chronic interstitial fibrosis with hypertrophy of the juxtaglomerular apparatus. Iliac crest biopsy was performed because of a severe decrease in bone mineral density. It showed active resorption at the periosteal and endosteal surfaces of cortical bone by numerous osteoclasts, as well as bone island formation in cancellous bone due to marked decrease of trabecular connections. A dynamic study using double labeling showed that mineralization of cancellous bone adjacent to cortical bone occurred between the first and second labelings, but did not occur between the second labeling and osteoid formation during the 28-day period before biopsy, which implied that the mineralization was related to promotion of food intake after hospitalization, while the lack of mineralization was due to poor food intake outside hospital. Empty lacunae that indicated the death of osteocytes were seen. Because her bone mass and kidney injury improved after weight gain and normokalemia were achieved by a highly nutritious diet, malnutrition with hypokalemia may have a negative influence on bone formation due to impaired mineralization and may activate bone resorption by osteoclasts secondary to the formation of empty lacunae. This is the first report about the histological features of premenopausal osteoporosis in a patient with AN and kidney injury. PMID:23726962

  7. Bone tumor

    Science.gov (United States)

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

  8. Preimplant preparation of the extraction alveolus with the deproteinized bovine bone and calcium-sulphate

    Directory of Open Access Journals (Sweden)

    Brković Božidar

    2006-01-01

    Full Text Available Background. Different materials are used to prevent the resorption of alveolar bone. The aim of this report was to show the radiographical and histological results prior to implant insertion, when a deproteinized bovine bone mineral (BioOss and calcium-sulphate were placed into the extraction socket immediately after the tooth removal. Case report. A 22-year-old woman was scheduled for the removal of the second lower molar when the extraction socket was filled with BioOss covered with calcium-sulphate as a resorbable membrane. Primary closure of the surgical site was performed. Radiography was done 4 and 12 months later. One year after the surgery, when the implant was inserted, a biopsy of the new regenerated bone was obtained for the histological evaluation. The lamellar bone was evident using both materials. The resorption of BioOss was slow and the connective tissue was observed. Conclusion. Both materials had biocompatible and oseoconductive properties. One year after the grafting procedure, we observed the lamellar bone and partial resorption of BioOss, while calciumsulphate showed no significant effect as a resorbable membrane.

  9. The fate of allogenic radiation sterilized bone grafts controlled by the electron spin resonance spectrometry

    International Nuclear Information System (INIS)

    The normal fate of bone grafts is their resorption and substitution by the own host's bone tissue. This phenomenon described as creeping substitution process was controlled using biopsies from the grafted region in allogenic experimental system. Electron spin resonance (ESR) spectrometry was used for independent evaluation of resorption and substitution processes. The measurements were based on the process of induction in the hydroxyapatite (HA) crystals of bone mineral of stable paramagnetic centers which can be detected by ESR spectrometry. The loss of total amount of spins connected with the paramagnetic centers expressed in percent describes the kinetics of resorption. The changes in the concentration of spins due to the ''dilution'' of spins implanted with the graft by the nonirradiated ingrowing host's own bone describe the kinetics of the substitution process. Allogenic bone of calvaria was grafted orthotopically into rabbits after lyophilization and radiation sterilization with a dose of 3.5 Mrads. The process of graft's rebuilding was evaluated using the described ESR method. The application of the described technique in the human clinic is possible. (author)

  10. [Histomorphometric analysis of the bones of rats on board the Kosmos 1667 biosatellite].

    Science.gov (United States)

    Kaplanskiĭ, A S; Durnova, G N; Sakharova, Z F; Il'ina-Kakueva, E I

    1987-01-01

    Bones of the rats flown on Cosmos-1667 were examined histologically and histomorphometrically. It was found that 7-day exposure to weightlessness led to osteoporosis in the spongy matter of proximal metaphyses of tibia and, although to a lesser extent, in the spongiosa of lumbar vertebrae whereas no signs of osteoporosis were seen in the spongy matter of iliac bones. Osteoporosis in the spongy matter of the above bones developed largely due to the inhibition of bone neoformation, which was indicated by a decrease in the number and activity of osteoblasts. Increased bone resorption (as shown by a greater number and activity of osteoclasts) was observed only in the spongy matter of tibial metaphyses. It is emphasized that a reduction of the number of highly active osteoblasts in spongy bones is one of the early signs of inhibition of bone neoformation and development of osteoporosis. PMID:3695333

  11. Short-Term Effects of TNF Inhibitors on Bone Turnover Markers and Bone Mineral Density in Rheumatoid Arthritis.

    Science.gov (United States)

    Orsolini, Giovanni; Adami, Giovanni; Adami, Silvano; Viapiana, Ombretta; Idolazzi, Luca; Gatti, Davide; Rossini, Maurizio

    2016-06-01

    TNFα inhibitors (TNFαI) exert positive effects on disease activity in rheumatoid arthritis (RA). Bone involvement is a major determinant of functional impairment in this disease. Here we investigated the short-term effects of TNFαI therapy on bone metabolism and density. We studied 54 patients with RA starting a TNFαI biologic drug, in whom any factor known to interfere with bone metabolism was excluded or rigorously accounted for. We measured at baseline and after 6-month therapy bone turnover markers: N-propeptide of type I collagen (P1NP), and bone alkaline phosphates for bone formation and serum C-terminal telopeptide of type I collagen (CTX) for bone resorption. We also evaluated bone mineral density (BMD) at hip and lumbar by dual-energy X-ray absorptiometry. All bone markers rose significantly and these changes were not dependent on steroid dosage. A significant decrease in femoral neck BMD was also observed. These results indicate that TNFαI therapy in RA over 6 months is associated with an early increase in bone turnover and a decline in hip BMD. PMID:26887973

  12. The impact of skeletal unloading on bone formation

    Science.gov (United States)

    Bikle, Daniel D.; Sakata, Takeshi; Halloran, Bernard P.

    2003-01-01

    Skeletal unloading leads to decreased bone formation and decreased bone mass. Bone resorption is uncoupled from bone formation, contributing to the bone loss. During space flight bone is lost principally from the bones most loaded in the 1 g environment. Determining the mechanism(s) by which loading of bone is sensed and translated into a signal(s) controlling bone formation remains the holy grail in this field. It seems likely that matrix/cell interactions will underlie much of the mechanocoupling. Integrins are a prime mediator of such interactions. The role for systemic hormones such as PTH, GH and 1,25(OH)2D compared to locally produced factors such as IGF-I, PTHrP, BMPs and TGF beta in modulating the cellular response to load remains unclear. Our studies demonstrate that skeletal unloading leads to resistance to the anabolic actions of IGF-I on bone as a result of failure of IGF-I to activate its own signaling pathways. This is associated with a reduction in integrin expression, suggesting crosstalk between these two pathways. As the mechanism(s) by which bone responds to changes in mechanical load with changes in bone formation is further elucidated, applications of this knowledge to other etiologies of osteoporosis are likely to develop. Skeletal unloading provides a perturbation in bone mineral homeostasis that can be used to understand the mechanisms by which bone mineral homeostasis is maintained, and that such understanding will lead to effective treatment for disuse osteoporosis in addition to preventive measures for the bone loss that accompanies space travel.

  13. Bone fatigue and its implications for injuries in racehorses.

    Science.gov (United States)

    Martig, S; Chen, W; Lee, P V S; Whitton, R C

    2014-07-01

    Musculoskeletal injuries are a common cause of lost training days and wastage in racehorses. Many bone injuries are a consequence of repeated high loading during fast work, resulting in chronic damage accumulation and material fatigue of bone. The highest joint loads occur in the fetlock, which is also the most common site of subchondral bone injury in racehorses. Microcracks in the subchondral bone at sites where intra-articular fractures and palmar osteochondral disease occur are similar to the fatigue damage detected experimentally after repeated loading of bone. Fatigue is a process that has undergone much study in material science in order to avoid catastrophic failure of engineering structures. The term 'fatigue life' refers to the numbers of cycles of loading that can be sustained before failure occurs. Fatigue life decreases exponentially with increasing load. This is important in horses as loads within the limb increase with increasing speed. Bone adapts to increased loading by modelling to maintain the strains within the bone at a safe level. Bone also repairs fatigued matrix through remodelling. Fatigue injuries develop when microdamage accumulates faster than remodelling can repair. Remodelling of the equine metacarpus is reduced during race training and accelerated during rest periods. The first phase of remodelling is bone resorption, which weakens the bone through increased porosity. A bone that is porous following a rest period may fail earlier than a fully adapted bone. Maximising bone adaptation is an important part of training young racehorses. However, even well-adapted bones accumulate microdamage and require ongoing remodelling. If remodelling inhibition at the extremes of training is unavoidable then the duration of exposure to high-speed work needs to be limited and appropriate rest periods instituted. Further research is warranted to elucidate the effect of fast-speed work and rest on bone damage accumulation and repair. PMID:24528139

  14. Etiology and prevention of external cervical root resorption associated to teeth bleaching

    Directory of Open Access Journals (Sweden)

    Eliane Mendes da SILVA

    2010-03-01

    Full Text Available Introduction and objective: Esthetic dentistry has been prioritizedand the desire for whiter teeth has been increasingly present in dental offices, since whiter teeth tend to indicate health, beauty, youth and a more attractive smile. Teeth bleaching is a conservative method widely used to restore the original color of darkened teeth. However, possible relations with the external cervical root resorption have concerned many researchers and clinicians. Literature review: There are many mechanisms that can activate the external cervical root resorption, such as: chemical and physical action of the bleaching materials used, morphology of the cementoenamel junction associated to the immune system, material concentration, traumas and bleaching technique used. Conclusion: Therefore, considering many factors that are still not conclusive, preventing deleterious effects on teeth and support structures, care must be taken when choosing bleaching agent and bleaching technique, as well as when selecting each case, beyond a proper restoration after teeth bleaching.

  15. Interdisciplinary Approach for Management of Iatrogenic Internal Root Resorption: A Case Report.

    Science.gov (United States)

    Ramazani, Mohsen; Asgary, Saeed; Zarenejad, Nafiseh; Mehrani, Javad

    2016-01-01

    For management of a symptomatic maxillary lateral incisor with dull pain on chewing, suppurative sinus tract, defective metal-ceramic crown and iatrogenic internal root resorption, an interdisciplinary approach was taken. Two-visit nonsurgical treatment with calcium-enriched mixture (CEM) cement, replacement of metal-ceramic crown with all-ceramic crown and corrective periodontal plastic surgery were included in the treatment plan. Six-month and one-year follow-ups revealed complete resolution of signs and symptoms and radiographic healing. This case report highlights the importance of adequate cooling during crown preparation to preserve the pulp vitality and prevent internal resorptive lesions and also the profound sealing ability and biocompatibility of CEM cement. PMID:26843882

  16. Orthodontic camouflage via total arch movement in a Class II with idiopathic condylar resorption

    Directory of Open Access Journals (Sweden)

    Ji-Sung Jang

    2014-01-01

    Full Text Available Idiopathic condylar resorption (ICR, also known as idiopathic condylysis or condylar atrophy, is multifactorial pathology leading to severe mandibular retrognathism. The etiology has been shown to be multifactorial, such as avascular necrosis, traumatic injuries, hormone and autoimmune disease and it is largely difficult to distinguish the exact cause in each individual. In spite of the remarkable morphological alteration, surgical intervention is not readily recruited due to the possibility of recurrence of resorption. In order to restore balanced facial profile and occlusion. In this report, we present a camouflage treatment for skeletal Class II with ICR and facial asymmetry involving total arch movement, for the improvement facial profile and reconstruction of occlusion.

  17. Management of external invasive cervical resorption of tooth with Biodentine: A case report.

    Science.gov (United States)

    Baranwal, Akash Kumar

    2016-01-01

    Invasive cervical resorption (ICR) of a tooth is relatively uncommon and the etiology is not very clear. It is sometimes misdiagnosed and can lead to improper management or tooth loss. Correct diagnosis and proper management can result in a successful outcome. The treatment should aim toward the complete suppression of all resorbing tissues and the reconstruction of resorptive defect by the placement of a suitable filling material or some biological systems. One of the most significant developments of the past decade, i.e. the operating microscope used for surgical endodontics, helps the surgeon to assess pathological changes more precisely and to remove pathological lesions with far greater precision, thus minimizing tissue damage. The aim of this article was to show the management of maxillary left central incisor diagnosed with external ICR using Biodentine under dental operatory microscope (DOM). PMID:27217649

  18. Management of external invasive cervical resorption of tooth with Biodentine: A case report

    Directory of Open Access Journals (Sweden)

    Akash Kumar Baranwal

    2016-01-01

    Full Text Available Invasive cervical resorption (ICR of a tooth is relatively uncommon and the etiology is not very clear. It is sometimes misdiagnosed and can lead to improper management or tooth loss. Correct diagnosis and proper management can result in a successful outcome. The treatment should aim toward the complete suppression of all resorbing tissues and the reconstruction of resorptive defect by the placement of a suitable filling material or some biological systems. One of the most significant developments of the past decade, i.e. the operating microscope used for surgical endodontics, helps the surgeon to assess pathological changes more precisely and to remove pathological lesions with far greater precision, thus minimizing tissue damage. The aim of this article was to show the management of maxillary left central incisor diagnosed with external ICR using Biodentine under dental operatory microscope (DOM.

  19. Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil

    Directory of Open Access Journals (Sweden)

    José Luis Martínez-Sánchez

    2005-09-01

    Full Text Available In tropical forests with nutrient-rich soil tree’s nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, among other physical and chemical characteristics, were analysed in 30 samples in the soil surface (10 cm of three undisturbed forest plots at ‘Estación de Biología Los Tuxtlas’ on the east coast of Mexico (18°34’ - 18°36’ N, 95°04’ - 95°09’ W. N and P resorption proficiency were determined from senescing leaves in 11 dominant tree species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid. Soil was rich in total N (0.50%, n = 30 and extractable P (4.11 µg g-1, n = 30. As expected, trees showed incomplete N (1.13%, n = 11 and P (0.11%, n = 11 resorption. With a more accurate method of nutrient resorption assessment, it is possible to prove that a forest community with a nutrient-rich soil can have low levels of N and P resorption. Rev. Biol. Trop. 53(3-4: 353-359. Epub 2005 Oct 3.En las selvas tropicales con suelos fértiles se ha observado que la reabsorción de nutrientes de los arboles de las hojas seniles no siempre es baja. Esta falta de consistencia en el resultado es talvez debida en parte a la metodología de reabsorción de nutrientes utilizada. El objetivo de este estudio fue analizar la reabsorción final de N y P de arboles de la selva húmeda tropical en un suelo rico en nutrientes. La hipótesis planteada fue que en un suelo rico en nutrientes los arboles presentarían una baja reabsorción final de

  20. Management of external invasive cervical resorption of tooth with Biodentine: A case report

    Science.gov (United States)

    Baranwal, Akash Kumar

    2016-01-01

    Invasive cervical resorption (ICR) of a tooth is relatively uncommon and the etiology is not very clear. It is sometimes misdiagnosed and can lead to improper management or tooth loss. Correct diagnosis and proper management can result in a successful outcome. The treatment should aim toward the complete suppression of all resorbing tissues and the reconstruction of resorptive defect by the placement of a suitable filling material or some biological systems. One of the most significant developments of the past decade, i.e. the operating microscope used for surgical endodontics, helps the surgeon to assess pathological changes more precisely and to remove pathological lesions with far greater precision, thus minimizing tissue damage. The aim of this article was to show the management of maxillary left central incisor diagnosed with external ICR using Biodentine under dental operatory microscope (DOM). PMID:27217649