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Sample records for mononucleated macrophage resorption

  1. Macrophage depletion abates Porphyromonas gingivalis-induced alveolar bone resorption in mice.

    PubMed

    Lam, Roselind S; O'Brien-Simpson, Neil M; Lenzo, Jason C; Holden, James A; Brammar, Gail C; Walsh, Katrina A; McNaughtan, Judith E; Rowler, Dennis K; Van Rooijen, Nico; Reynolds, Eric C

    2014-09-01

    The role of the macrophage in the immunopathology of periodontitis has not been well defined. In this study, we show that intraoral inoculation of mice with Porphyromonas gingivalis resulted in infection, alveolar bone resorption, and a significant increase in F4/80(+) macrophages in gingival and submandibular lymph node tissues. Macrophage depletion using clodronate-liposomes resulted in a significant reduction in F4/80(+) macrophage infiltration of gingival and submandibular lymph node tissues and significantly (p < 0.01) less P. gingivalis-induced bone resorption compared with controls in BALB/c and C57BL/6 mice. In both mouse strains, the P. gingivalis-specific IgG Ab subclass and serum cytokine [IL-4, IL-10, IFN-γ, and IL-12 (p70)] responses were significantly (p < 0.01) lower in the macrophage-depleted groups. Macrophage depletion resulted in a significant reduction in the level of P. gingivalis infection, and the level of P. gingivalis infection was significantly correlated with the level of alveolar bone resorption. M1 macrophages (CD86(+)), rather than M2 macrophages (CD206(+)), were the dominant macrophage phenotype of the gingival infiltrate in response to P. gingivalis infection. P. gingivalis induced a significant (p < 0.01) increase in NO production and a small increase in urea concentration, as well as a significant increase in the secretion of IL-1β, IL-6, IL-10, IL-12 (p70), eotaxin, G-CSF, GM-CSF, macrophage chemoattractant protein-1, macrophage inflammatory protein-α and -β, and TNF-α in isolated murine macrophages. In conclusion, P. gingivalis infection induced infiltration of functional/inflammatory M1 macrophages into gingival tissue and alveolar bone resorption. Macrophage depletion reduced P. gingivalis infection and alveolar bone resorption by modulating the host immune response.

  2. Evidence that Resorption of Bone by Rat Peritoneal Macrophages Occurs in an Acidic Environment

    NASA Technical Reports Server (NTRS)

    Blair, H. C.

    1985-01-01

    Skeletal loss in space, like any form of osteoporosis, reflects a relative imbalance of the activities of cells resorbing (degrading) or forming bone. Consequently, prevention of weightlessness induced bone loss may theoretically be accomplished by (1) stimulating bone formation or (2) inhibiting bone resorption. This approach, however, requires fundamental understanding of the mechanisms by which cells form or degrade bone, information not yet at hand. An issue central to bone resorption is the pH at which resorption takes place. The pH dependent spectral shift of a fluorescent dye (fluorescein isothiocyanate) conjugated to bone matrix was used to determine the pH at the resorptive cell bone matrix interface. Devitalized rat bone was used as the substrate, and rat peritoneal macrophages were used as the bone resorbing cells. The results suggest that bone resorption is the result of generation of an acidic microenvironment at the cell matrix junction.

  3. Evidence that Resorption of Bone by Rat Peritoneal Macrophages Occurs in an Acidic Environment

    NASA Technical Reports Server (NTRS)

    Blair, H. C.

    1985-01-01

    Skeletal loss in space, like any form of osteoporosis, reflects a relative imbalance of the activities of cells resorbing (degrading) or forming bone. Consequently, prevention of weightlessness induced bone loss may theoretically be accomplished by (1) stimulating bone formation or (2) inhibiting bone resorption. This approach, however, requires fundamental understanding of the mechanisms by which cells form or degrade bone, information not yet at hand. An issue central to bone resorption is the pH at which resorption takes place. The pH dependent spectral shift of a fluorescent dye (fluorescein isothiocyanate) conjugated to bone matrix was used to determine the pH at the resorptive cell bone matrix interface. Devitalized rat bone was used as the substrate, and rat peritoneal macrophages were used as the bone resorbing cells. The results suggest that bone resorption is the result of generation of an acidic microenvironment at the cell matrix junction.

  4. Macrophage-osteoclast differentiation and bone resorption in osteoarthrotic subchondral acetabular cysts.

    PubMed

    Sabokbar, A; Crawford, R; Murray, D W; Athanasou, N A

    2000-06-01

    A macrophage infiltrate is commonly found in enlarging subchondral cysts in osteoarthrosis (OA) and the surrounding bone. To determine whether osteoclast differentiation by these cells contributes to the increase in the number of osteoclasts and bone resorption that accompanies OA cyst enlargement, we isolated macrophages from the wall of OA cysts and co-cultured them with osteoblast-like UMR106 cells in the presence or absence of 1,25(OH)2D3 and M-CSE After 14 days of incubation, co-cultures of UMR106 cells and cyst-derived macrophages showed evidence of osteoclast differentiation by expression of TRAP, VNR and formation of numerous lacunar pits. We found that, unlike osteoclast precursors in monocyte and other tissue macrophage populations, the addition of M-CSF to medium is not required for osteoclast differentiation. Our findings suggest that macrophage-osteoclast differentiation is one means whereby the osteolysis associated with the enlargement of OA cysts could be effected.

  5. The effect of the bleaching agent sodium perborate on macrophage adhesion in vitro: implications in external cervical root resorption.

    PubMed

    Jiménez-Rubio, A; Segura, J J

    1998-04-01

    The purpose of this study was to investigate the in vitro effect of sodium perborate, which is used as a bleaching agent in the treatment of discolored pulpless teeth, on substrate adherence capacity of macrophages. Inflammatory macrophages were obtained from Wistar rats and resuspended in RPMI-1640 medium. As a test of macrophage adhesion, the adherence capacity of macrophages to a plastic surface was determined. Assays were conducted in Eppendorf tubes for 15 min of incubation at 37 degrees C in a humidified atmosphere of 5% CO2. The adherence index was calculated. Results showed that sodium perborate decreased in a dose-dependent manner and decreased significantly (p < 0.05) the adherence index of rat peritoneal macrophages. Sodium perborate was less potent than sodium hypochlorite and eugenol in inhibiting macrophage adhesion. The inhibitory effect of sodium perborate on macrophage adhesion further supports the concept that this agent is not implicated in external cervical root resorption associated with intracoronal bleaching.

  6. Fisetin antagonizes cell fusion, cytoskeletal organization and bone resorption in RANKL-differentiated murine macrophages.

    PubMed

    Kim, Yun-Ho; Kim, Jung-Lye; Lee, Eun-Jung; Park, Sin-Hye; Han, Seon-Young; Kang, Soon Ah; Kang, Young-Hee

    2014-03-01

    Osteoclastogenesis is comprised of several stage s including progenitor survival, differentiation to mononuclear preosteoclasts, cell fusion to multinuclear mature osteoclasts, and activation to osteoclasts with bone resorbing activity. Botanical antioxidants are now being increasingly investigated for their health-promoting effects on bone. This study investigated that fisetin, a flavonol found naturally in many fruits and vegetables, suppressed osteoclastogenesis by disturbing receptor activator of nuclear factor (NF)-κB ligand (RANKL)-mediated signaling pathway and demoting osteoclastogenic protein induction. Nontoxic fisetin at ≤10 μM inhibited the induction of RANK, tumor necrosis factor receptor associated factor 6 (TRAF6) and the activation of NF-κB in RANKL-stimulated RAW 264.7 macrophages. In RANKL-differentiated osteoclasts cell fusion protein of E-cadherin was induced, which was dampened by fisetin. The formation of tartrate-resistance acid phosphatase-positive multinucleated osteoclasts was suppressed by adding fisetin to RANKL-exposed macrophages. It was also found that fisetin reduced actin ring formation and gelsolin induction of osteclasts enhanced by RANKL through disturbing c-Src-proline-rich tyrosine kinase 2 signaling. Fisetin deterred preosteoclasts from the cell-cell fusion and the organization of the cytoskeleton to seal the resorbing area and to secret protons for bone resorption. Consistently, the 5 day-treatment of fisetin diminished RANKL-induced cellular expression of carbonic anhydrase II and integrin β3 concurrently with a reduction of osteoclast bone-resorbing activity. Therefore, fisetin was a natural therapeutic agent retarding osteoclast fusion and cytoskeletal organization such as actin rings and ruffled boarder, which is a property of mature osteoclasts and is required for osteoclasts to resorb bone. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. CX3CR1hi Monocyte/Macrophages Support Bacterial Survival and Experimental Infection-Driven Bone Resorption.

    PubMed

    Steinmetz, Orit; Hoch, Shifra; Avniel-Polak, Shani; Gavish, Keren; Eli-Berchoer, Luba; Wilensky, Asaf; Nussbaum, Gabriel

    2016-05-01

    Porphyromonas gingivalis,an anaerobic bacterium strongly linked to infection-driven inflammatory bone erosion, thrives within a highly inflamed milieu and disseminates to distant sites, such as atherosclerotic plaque. We examined the role of monocyte/macrophages in determining the outcome of infection with P. gingivalis. Surprisingly, transient monocyte/macrophage depletion led to greatly improved clearance of P. gingivalis. The chemokine receptors CCR2 and CX3CR1 play a major role in monocyte recruitment and differentiation to Ly6C(hi) vs CX3CR1(hi) subsets, respectively. To determine the contribution of particular monocyte/macrophage subsets to bacterial survival, we challenged chemokine receptor knockout mice and found that P. gingivalis clearance is significantly improved in the absence of CX3CR1. CX3CR1(hi) monocyte/macrophages promote P. gingivalis survival by downregulating neutrophil phagocytosis. Furthermore, CX3CR1 knockout mice resist bone resorption in the oral cavity following challenge with P. gingivalis Our findings provide an explanation for bacterial coexistence alongside an activate neutrophil infiltrate.

  8. Mesenchymal dental pulp cells attenuate dentin resorption in homeostasis.

    PubMed

    Zheng, Y; Chen, M; He, L; Marão, H F; Sun, D M; Zhou, J; Kim, S G; Song, S; Wang, S L; Mao, J J

    2015-06-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone-derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  9. Mesenchymal Dental Pulp Cells Attenuate Dentin Resorption in Homeostasis

    PubMed Central

    Zheng, Y.; Chen, M.; He, L.; Marão, H.F.; Sun, D.M.; Zhou, J.; Kim, S.G.; Song, S.; Wang, S.L.

    2015-01-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone–derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  10. Ascorbic acid stimulates the resorption of canine articular cartilage induced by a factor derived from activated rabbit macrophages.

    PubMed

    Dean, D D; Sellers, A; Howell, D S; Kerwar, S S; Woessner, J F

    1985-01-01

    Articular cartilage explants from the knees of mongrel dogs release 5-10% of their proteoglycan content spontaneously when cultured for 4 days in serum-free modified Bigger's medium. A factor synthesized and secreted by lipopolysaccharide-stimulated rabbit macrophages can stimulate this release of proteoglycan by 2 to 3-fold. The release of proteoglycan in response to macrophage factor is maximal in the presence of 1.5-50 micrograms/ml L-ascorbic acid. In the absence of ascorbate, or with high levels of ascorbate (150 micrograms/ml), the effect of the factor is diminished by 50%. D-isoascorbate, reduced glutathione, or dithiothreitol cannot substitute for L-ascorbate in producing this effect, while dehydroascorbate can.

  11. Mononucleated Blood Cell Populations Display Different Abilities To Transmit Prion Disease by the Transfusion Route

    PubMed Central

    Douet, Jean-Yves; Lacroux, Caroline; Litaise, Claire; Lugan, Séverine; Corbière, Fabien; Arnold, Mark; Simmons, Hugh; Aron, Naima; Costes, Pierrette; Tillier, Cécile; Cassard, Hervé

    2016-01-01

    ABSTRACT Previous experiments carried out in a sheep scrapie model demonstrated that the transfusion of 200 μl of prion-infected whole blood has an apparent 100% efficacy for disease transmission. These experiments also indicated that, despite the apparent low infectious titer, the intravenous administration of white blood cells (WBC) resulted in efficient disease transmission. In the study presented here, using the same transmissible spongiform encephalopathy (TSE) animal model, our aim was to determine the minimal number of white blood cells and the specific abilities of mononucleated cell populations to transmit scrapie by the transfusion route. Our results confirmed that the transfusion of 100 μl, but not 10 μl, of fresh whole blood collected in asymptomatic scrapie-infected donor sheep can transmit the disease. The data also show that the intravenous administration of 105 WBCs is sufficient to cause scrapie in recipient sheep. Cell-sorted CD45R+ (predominantly B lymphocytes), CD4+/CD8+ (T lymphocytes), and CD14+ (monocytes/macrophages) blood cell subpopulations all were shown to contain prion infectivity by bioassays in ovine PrP transgenic mice. However, while the intravenous administration of 106 CD45+ or CD4+/8+ living cells was able to transmit the disease, similar numbers of CD14+ cells failed to infect the recipients. These data support the contention that mononucleated blood cell populations display different abilities to transmit TSE by the transfusion route. They also represent an important input for the risk assessment of blood-borne prion disease transmission and for refining the target performance of leukoreduction processes that currently are applied to mitigate the transmission risk in transfusion medicine. IMPORTANCE Interindividual variant Creutzfeldt-Jakob disease (vCJD) transmission through blood and blood-derived products is considered a major public health issue in transfusion medicine. Over the last decade, TSE in sheep has emerged as a

  12. Effects of vitamin D binding protein-macrophage activating factor (DBP-MAF) infusion on bone resorption in two osteopetrotic mutations.

    PubMed

    Schneider, G B; Benis, K A; Flay, N W; Ireland, R A; Popoff, S N

    1995-06-01

    Osteopetrosis is a heterogeneous group of bone diseases characterized by an excess accumulation of bone and a variety of immune defects. Osteopetrosis (op) and incisors absent (ia) are two nonallelic mutations in the rat which demonstrated these skeletal defects as a result of reduced bone resorption. Osteopetrotic (op) rats have severe sclerosis as a result of reduced numbers of osteoclasts which are structurally abnormal. The sclerosis in ia rats is not as severe as in op mutants; they have elevated numbers of osteoclasts, but they are also morphologically abnormal, lacking a ruffled border. Both of these mutations have defects in the inflammation-primed activation of macrophages. They demonstrate independent defects in the cascade involved in the conversion of vitamin D binding protein (DBP) to a potent macrophage activating factor (DBP-MAF). Because this factor may also play a role in the pathogenesis of osteoclastic dysfunction, the effects of ex vivo-generated DBP-MAF were evaluated on the skeletal system of these two mutations. Newborn ia and op rats and normal littermate controls were injected with DBP-MAF or vehicle once every 4 days from birth until 2 weeks of age, at which time bone samples were collected to evaluate a number of skeletal parameters. DBP-MAF treated op rats had an increased number of osteoclasts and the majority of them exhibited normal structure. There was also reduced bone volume in the treated op animals and an associated increased cellularity of the marrow spaces. The skeletal sclerosis was also corrected in the ia rats; the bone marrow cavity size was significantly enlarged and the majority of the osteoclasts appeared normal with extensive ruffled borders.

  13. Osteoclasts differentiate from resident precursors in an in vivo model of synchronized resorption: a temporal and spatial study in rats.

    PubMed

    Baroukh, B; Cherruau, M; Dobigny, C; Guez, D; Saffar, J L

    2000-11-01

    Osteoclasts differentiate from mononucleated precursors expressing monocyte markers, which gradually evolve to preosteoclasts expressing the osteoclast phenotype. Although the role of osteogenic cells in these changes has been well documented in vitro, their contribution in vivo has not been established. In this study, a synchronized wave of resorption was activated along the mandibular periosteum. The periosteum adjacent to the bone surface studied was separated by a computer-assisted technique into an osteogenic alkaline phosphatase-positive compartment and an outer nonosteogenic compartment. Specific markers (nonspecific esterase [NSE], tartrate-resistant acid phosphatase [TRAP], and ED1 antibody, a marker of the monocyte-macrophage lineage) were used to follow osteoclast differentiation quantitatively as a function of time after activation of resorption, from day 0 to day 4 (peak of resorption in this model). Local cell proliferation was assessed in parallel. Between day 0 and day 3, the thickness of the osteogenic compartment decreased by 50% (p < 0.0002). In the osteogenic compartment, proliferating cell numbers fell by 80% at 12 day, NSE(+) cells (located farthest from the bone surface) increased 3. 9-fold on day 4 vs. day 0 (p < 0.005), ED1(+) cells decreased between day 0 and day 2 (p < 0.02) before returning to their initial value, and TRAP(+) cells increased 2.7-fold between day 1 and day 3 (p < 0.0005). Resorption was absent in the site studied on day 0, but on day 4 there were 20.5 osteoclast nuclei per millimeter of bone surface. The cell ratio changed from 30.3 NSE(+) and ED1(+) (some of which were also TRAP(+)) cells per millimeter on day 0 to 37.6 mononucleated cells plus 20.5 osteoclast nuclei on day 4. In the nonosteogenic compartment, an entry of ED1(+)/NSE(-) was observed on 12 day (+23 cells, p < 0.02 vs. day 0). This was followed by a return of ED1(+) cell numbers to the control level on day 1, and a transient increase in NSE(+) cells (+47

  14. Mononucleated Blood Cell Populations Display Different Abilities To Transmit Prion Disease by the Transfusion Route.

    PubMed

    Douet, Jean-Yves; Lacroux, Caroline; Litaise, Claire; Lugan, Séverine; Corbière, Fabien; Arnold, Mark; Simmons, Hugh; Aron, Naima; Costes, Pierrette; Tillier, Cécile; Cassard, Hervé; Andréoletti, Olivier

    2016-01-13

    Previous experiments carried out in a sheep scrapie model demonstrated that the transfusion of 200 μl of prion-infected whole blood has an apparent 100% efficacy for disease transmission. These experiments also indicated that, despite the apparent low infectious titer, the intravenous administration of white blood cells (WBC) resulted in efficient disease transmission. In the study presented here, using the same transmissible spongiform encephalopathy (TSE) animal model, our aim was to determine the minimal number of white blood cells and the specific abilities of mononucleated cell populations to transmit scrapie by the transfusion route. Our results confirmed that the transfusion of 100 μl, but not 10 μl, of fresh whole blood collected in asymptomatic scrapie-infected donor sheep can transmit the disease. The data also show that the intravenous administration of 10(5) WBCs is sufficient to cause scrapie in recipient sheep. Cell-sorted CD45R(+) (predominantly B lymphocytes), CD4(+)/CD8(+) (T lymphocytes), and CD14(+) (monocytes/macrophages) blood cell subpopulations all were shown to contain prion infectivity by bioassays in ovine PrP transgenic mice. However, while the intravenous administration of 10(6) CD45(+) or CD4(+)/8(+) living cells was able to transmit the disease, similar numbers of CD14(+) cells failed to infect the recipients. These data support the contention that mononucleated blood cell populations display different abilities to transmit TSE by the transfusion route. They also represent an important input for the risk assessment of blood-borne prion disease transmission and for refining the target performance of leukoreduction processes that currently are applied to mitigate the transmission risk in transfusion medicine. Interindividual variant Creutzfeldt-Jakob disease (vCJD) transmission through blood and blood-derived products is considered a major public health issue in transfusion medicine. Over the last decade, TSE in sheep has emerged as a

  15. Multiple external root resorption.

    PubMed

    Yusof, W Z; Ghazali, M N

    1989-04-01

    Presented is an unusual case of multiple external root resorption. Although the cause of this resorption was not determined, several possibilities are presented. Trauma from occlusion, periodontal and pulpal inflammation, and resorption of idiopathic origin are all discussed as possible causes.

  16. Fusiform cells in the cambium of Kalopanax pictus are exclusively mononucleate.

    PubMed

    Kitin, Peter; Sano, Yuzou; Funada, Ryo

    2002-03-01

    While it is generally accepted that most plant cells are mononucleate, it has been argued with some vehemence that fusiform cambial cells can be multinucleate. The controversy has not been resolved since to date, studies by conventional microscopy and transmission electron microscopy have failed to confirm unambiguously whether cambial cells are mononucleate or multinucleate. In this study, semi-thin sections of epoxy-embedded specimens and thick slices of cambial tissues from the hardwood Kalopanax pictus were analysed by confocal laser scanning microscopy. Tangential sections of cambium, regardless of the thickness of the section, are likely to contain portions of cells in several adjacent layers of cells and, at the lower resolution of conventional microscopy, several adjacent cells can appear to be a single cell with more than one nucleus. The higher resolution in the third dimension of confocal microscopy allowed clearly adjacent layers of cells in the cambium to be distinguished and the number of nuclei per cell to be determined. In this tree, the cambial cells were mononucleate in all cases.

  17. [Evaluation of the survival of bone marrow mononucleate cells transplanted in a rat model of striatal lesion with quinolinic acid].

    PubMed

    Alberti-Amador, E; García-Miniet, R; Serrano-Sánchez, T; Blanco-Lezcano, L; Martínez-Marti, L; Mendoza-Mari, Y; Rosillo-Martí, J C; Castillo-Díaz, L; de la Cuétara-Bernal, K

    Transplant is one of the alternatives available for the treatment of neurodegenerative diseases aimed at replacing the cells lost during the course of the disease. One promising source of cells for the development of transplants could be the mononucleate cells from bone marrow. AIMS. The purpose of this study was to study the capacity of bone marrow mononucleate cells to survive the transplant process, and to search for a method that enables tracking of these cells in vivo once they have been implanted. Bone marrow mononucleate cells were extracted from the femur of rats by means of a Ficoll-Hypaque gradient. The cells under study were modified genetically with an adenovirus that expresses the PFV or which are marked with Hoechst dye. The marked cells were implanted in the striatum of rats with lesions caused by quinolinic acid. The viability of the genetically modified cells was low, whereas that of the cells marked with Hoechst dye was above 90%. The implanted cells survived the transplant at least a month and dispersed away from the site of entry towards the corpus callosum and cortex. We consider that the use of Hoechst dye offers more advantages for tracking these cells in vivo. Mononucleate cells have a number of characteristics that allow them to be included as candidate sources of cells for the treatment of neurodegenerative diseases.

  18. Tooth resorption part II - external resorption: Case series.

    PubMed

    Fernandes, Marina; de Ataide, Ida; Wagle, Rahul

    2013-03-01

    External tooth resorption usually follows trauma to the periodontal ligament. It can be classified into five categories based on its clinical and histological manifestations. Calcium hydroxide has long been used as an intracanal medicament to slow down the resorption process due to its alkaline pH. A combination of both external and internal resorptions can also occur on the same tooth, making the management more complex. Five case reports of external resorption have been presented in this article along with pertinent review of literature. Successful management was possible in two cases, while extractions had to be advised in 3 cases due to advanced nature of the lesions.

  19. Tooth resorption part I - pathogenesis and case series of internal resorption

    PubMed Central

    Fernandes, Marina; de Ataide, Ida; Wagle, Rahul

    2013-01-01

    Resorption is a pathologic process that often eludes the clinician with its varied etiologic factors and diverse clinical presentations. The key cells involved in tooth resorption are odontoclasts which are multinucleated cells that produce resorption lacunae. Resorption can be classified as internal and external resorption. Internal resorption has been described as a rare occurrence as compared to external resorption. This article describes the pathogenesis of tooth resorption and various forms of internal resorption along with some clinical cases. Early diagnosis is the key factor in the successful management of resorptive lesions. PMID:23349568

  20. Tooth resorption part I - pathogenesis and case series of internal resorption.

    PubMed

    Fernandes, Marina; de Ataide, Ida; Wagle, Rahul

    2013-01-01

    Resorption is a pathologic process that often eludes the clinician with its varied etiologic factors and diverse clinical presentations. The key cells involved in tooth resorption are odontoclasts which are multinucleated cells that produce resorption lacunae. Resorption can be classified as internal and external resorption. Internal resorption has been described as a rare occurrence as compared to external resorption. This article describes the pathogenesis of tooth resorption and various forms of internal resorption along with some clinical cases. Early diagnosis is the key factor in the successful management of resorptive lesions.

  1. Macrophage activation and muscle remodeling at myotendinous junctions after modifications in muscle loading.

    PubMed Central

    St Pierre, B. A.; Tidball, J. G.

    1994-01-01

    Modifications in muscle loading have been reported previously to result in increased numbers of mononucleated cells and changes in myofibril organization at myotendinous junctions (MTJs). The goals of this study were to determine the identity of those mononucleated cells and to examine the relationships between changes in their structure, location, and number with structural aspects of remodeling at MTJs experiencing modified loading. Soleus muscles from rats subjected to 10 days of hindlimb suspension were analyzed 0, 2, 4, and 7 days after return to weight bearing. Immunohistochemistry showed that ED1+, ED2+ and Ia+ macrophages were present at the MTJ and microtendon of control muscle. After reloading, ED2+ macrophages increased in number and size at MTJs and microtendons, indicating their activation. ED1+ cells showed no change in size or number whereas Ia+ cells were increased in size at day 7 of reloading. Electron microscopic observations showed that mononucleated cells near MTJs of control or suspended muscle were not highly active in protein synthesis or secretion. However, in reloaded muscle, mononucleated cells were found to be in close proximity to MTJs and to contain a high concentration of organelles associated with protein secretion. During these stages of reloading, extensive remodeling of myofibril-membrane associations occurred and nascent sarcomeres appeared in the MTJ regions of muscle fibers. Immunohistochemistry showed that during these stages of nascent sarcomere formation, there was renewed expression of developmental myosin heavy chain at MTJs, with this heavy chain appearing most prominently at the MTJ at day 7 of reloading. The activation and increased numbers of macrophages at MTJs and the close apposition of secretory cells to the MTJ membrane during remodeling lead us to propose that macrophage-derived factors may influence remodeling of MTJs in muscles experiencing modified loading. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

  2. Responses of peripheral blood mononucleated cells from non-celiac gluten sensitive patients to various cereal sources.

    PubMed

    Valerii, Maria Chiara; Ricci, Chiara; Spisni, Enzo; Di Silvestro, Raffaella; De Fazio, Luigia; Cavazza, Elena; Lanzini, Alberto; Campieri, Massimo; Dalpiaz, Alessandro; Pavan, Barbara; Volta, Umberto; Dinelli, Giovanni

    2015-06-01

    Non-celiac gluten sensitivity (NCGS) is still an undefined syndrome whose triggering mechanisms remain unsettled. This study aimed to clarify how cultured peripheral blood mononucleated cells (PBMC) obtained from NCGS patients responded to contact with wheat proteins. Results demonstrated that wheat protein induced an overactivation of the proinflammatory chemokine CXCL10 in PBMC from NCGS patients, and that the overactivation level depends on the cereal source from which proteins are obtained. CXCL10 is able to decrease the transepithelial resistance of monolayers of normal colonocytes (NCM 460) by diminishing the mRNA expression of cadherin-1 (CDH1) and tight junction protein 2 (TJP2), two primary components of the tight junction strands. Thus, CXCL10 overactivation is one of the mechanisms triggered by wheat proteins in PBMC obtained from NCGS patients. This mechanism is activated to a greater extent by proteins from modern with respect to those extracted from ancient wheat genotypes.

  3. Invasive Cervical Resorption: A Review

    PubMed Central

    Kandalgaonkar, Shilpa D; Gharat, Leena A; Tupsakhare, Suyog D; Gabhane, Mahesh H

    2013-01-01

    Invasive cervical resorption is a relatively uncommon form of external root resorption exhibiting no external signs. The resorptive condition is often detected by routine radiographic examination. The clinical features vary from a small defect at the gingival margin to a pink coronal discoloration of the tooth crown resulting in ultimate cavitation of the overlying enamel which is painless unless pulpal or periodontal infection supervenes. Radiographic features of lesions vary from well-delineated to irregularly bordered mottled radiolucencies, and these can be confused with dental caries. A characteristic radiopaque line generally separates the image of the lesion from that of the root canal, because the pulp remains protected by a thin layer of predentin until late in the process. Histopathologically, the lesions contain fibrovascular tissue with resorbing clastic cells adjacent to the dentin surface. More advanced lesions display fibro-osseous characteristics with deposition of ectopic bonelike calcifications both within the resorbing tissue and directly on the dentin surface. How to cite this article: Kandalgaonkar SD, Gharat LA, Tupsakhare SD, Gabhane MH. Invasive Cervical Resorption: A Review. J Int Oral Health 2013;5(6):124-30 . PMID:24453457

  4. Detection of AIDS Virus in Macrophages in Brain Tissue from AIDS Patients with Encephalopathy

    NASA Astrophysics Data System (ADS)

    Koenig, Scott; Gendelman, Howard E.; Orenstein, Jan M.; Canto, Mauro C.; Pezeshkpour, Gholam H.; Yungbluth, Margaret; Janotta, Frank; Aksamit, Allen; Martin, Malcolm A.; Fauci, Anthony S.

    1986-09-01

    One of the common neurological complications in patients with the acquired immune deficiency syndrome (AIDS) is a subacute encephalopathy with progressive dementia. By using the techniques of cocultivation for virus isolation, in situ hybridization, immunocytochemistry, and transmission electron microscopy, the identity of an important cell type that supports replication of the AIDS retrovirus in brain tissue was determined in two affected individuals. These cells were mononucleated and multinucleated macrophages that actively synthesized viral RNA and produced progeny virions in the brains of the patients. Infected brain macrophages may serve as a reservoir for virus and as a vehicle for viral dissemination in the infected host.

  5. Root resorption after orthodontic treatment: a review.

    PubMed

    Jatania, Archana; Shivalinga, B M; Kiran, Jyothi

    2012-01-01

    Root resorption that occurs in permanent teeth is an unwanted process and is considered pathologic. Although apical root resorption occurs in individuals who have never experienced orthodontic tooth movement, the incidence among treated individuals is seen to be significantly higher. Some resorption occurs in most orthodontic patients, but because of repair the changes are difficult to detect with radiographic examination and therefore are clinically insignificant. This article gives a review of the various types of root resorption, the etiological factors, the biology and the identification of root resorption.

  6. Clinical technique for invasive cervical root resorption

    PubMed Central

    Silveira, Luiz Fernando Machado; Silveira, Carina Folgearini; Martos, Josué; Piovesan, Edno Moacir; César Neto, João Batista

    2011-01-01

    This clinical case report describes the diagnosis and treatment of an external invasive cervical resorption. A 17-year-old female patient had a confirmed diagnosis of invasive cervical resorption class 4 by cone beam computerized tomography. Although, there was no communication with the root canal, the invasive resorption process was extending into the cervical and middle third of the root. The treatment of the cervical resorption of the lateral incisor interrupted the resorptive process and restored the damaged root surface and the dental functions without any esthetic sequelae. Both the radiographic examination and computed tomography are imperative to reveal the extent of the defect in the differential diagnosis. PMID:22144822

  7. Contaminant resorption during soil washing

    SciTech Connect

    Gombert, D.

    1993-10-01

    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.

  8. Probing of Actinobacillus pleuropneumoniae ApxIIIA toxin-dependent cytotoxicity towards mammalian peripheral blood mononucleated cells

    PubMed Central

    Vanden Bergh, Philippe GAC; Zecchinon, Laurent LM; Fett, Thomas; Desmecht, Daniel

    2008-01-01

    Background Actinobacillus pleuropneumoniae, the causative bacterial agent of porcine pleuropneumonia, produces Apx toxins which belong to RTX toxin family and are recognized as the major virulence factors. So far, their target receptor(s) has not been identified and the disease cytopathogenesis remains poorly understood. Production of an active Apx toxin and characterization of its toxic activity constitute the premises necessary to the description of its interaction with a potential receptor. From this point of view, we produced an active recombinant ApxIIIA toxin in order to characterize its toxicity on peripheral blood mononucleated cells (PBMCs) isolated from several species. Findings Toxin preparation exercises a strong cytotoxic action on porcine PBMCs which is directly related to recombinant ApxIIIA since preincubation with polymyxin B does not modify the cytotoxicity rate while preincubation with a monospecific polyclonal antiserum directed against ApxIIIA does. The cell death process triggered by ApxIIIA is extremely fast, the maximum rate of toxicity being already reached after 20 minutes of incubation. Moreover, ApxIIIA cytotoxicity is species-specific because llama, human, dog, rat and mouse PBMCs are resistant. Interestingly, bovine and caprine PBMCs are slightly sensitive to ApxIIIA toxin too. Finally, ApxIIIA cytotoxicity is cell type-specific as porcine epithelial cells are resistant. Conclusion We have produced an active recombinant ApxIIIA toxin and characterized its specific cytotoxicity on porcine PBMCs which will allow us to get new insights on porcine pleuropneumonia pathogenesis in the future. PMID:19046441

  9. Dendritic Cell-Mediated In Vivo Bone Resorption

    PubMed Central

    Maitra, Radhashree; Follenzi, Antonia; Yaghoobian, Arash; Montagna, Cristina; Merlin, Simone; Cannizzo, Elvira S.; Hardin, John A.; Cobelli, Neil; Stanley, E. Richard; Santambrogio, Laura

    2013-01-01

    Osteoclasts are resident cells of the bone that are primarily involved in the physiological and pathological remodeling of this tissue. Mature osteoclasts are multinucleated giant cells that are generated from the fusion of circulating precursors originating from the monocyte/macrophage lineage. During inflammatory bone conditions in vivo, de novo osteoclastogenesis is observed but it is currently unknown whether, besides increased osteoclast differentiation from undifferentiated precursors, other cell types can generate a multinucleated giant cell phenotype with bone resorbing activity. In this study, an animal model of calvaria-induced aseptic osteolysis was used to analyze possible bone resorption capabilities of dendritic cells (DCs). We determined by FACS analysis and confocal microscopy that injected GFP-labeled immature DCs were readily recruited to the site of osteolysis. Upon recruitment, the cathepsin K-positive DCs were observed in bone-resorbing pits. Additionally, chromosomal painting identified nuclei from female DCs, previously injected into a male recipient, among the nuclei of giant cells at sites of osteolysis. Finally, osteolysis was also observed upon recruitment of CD11c-GFP conventional DCs in Csf1r–/– mice, which exhibit a severe depletion of resident osteoclasts and tissue macrophages. Altogether, our analysis indicates that DCs may have an important role in bone resorption associated with various inflammatory diseases. PMID:20581147

  10. Bone resorptive activity of human peripheral blood mononuclear cells after fusion with polyethylene glycol.

    PubMed

    Manrique, Edwin; Castillo, Luz M; Lazala, Oswaldo; Guerrero, Carlos A; Acosta, Orlando

    2017-03-01

    The bone remodeling process occurs through bone formation by osteoblasts and bone resorption by osteoclasts, a process involving the contribution of endocrine and nervous systems. The mechanisms associated to differentiation and proliferation of osteoclasts and osteoblasts are considered a potential therapeutic target for treating some erosive bone diseases. The aim of the present study is to explore the feasibility of generating active osteoclast-like cells from peripheral blood mononuclear cells (PBMCs) following polyethylene glycol (PEG)-induced fusion. PEG-fused PBMCs showed TRAP(+)-multinucleated cells and bone resorption activity, and were also positive for osteoclast markers such as carbonic anhydrase II, calcitonin receptor, vacuolar ATPase, and cathepsin K, when examined by reverse transcription-polymerase chain reaction, immunochemistry and Western blotting. TRAP expression and bone resorptive activity were higher in whole PEG-fused PBMCs than in separated T lymphocytes, B lymphocytes or monocytes. Both TRAP expression and bone resorptive activity were also higher in osteogenesis imperfecta patients compared to PEG-fused PBMCs from healthy individuals. PEG-induced fusion was more efficient in inducing TRAP and bone resorptive activities than macrophage colony-stimulating factor or dexamethasone treatment. Bone resorptive activity of PEG-fused PMBCs was inhibited by bisphosphonates. Evidence is provided that the use of PEG-based cell fusion is a straightforward and amenable method for studying human osteoclast differentiation and testing new therapeutic strategies.

  11. COMPUTED TOMOGRAPHY OF TOOTH RESORPTION IN CATS.

    PubMed

    Lang, Linda G; Wilkinson, Thomas E; White, Tammy L; Farnsworth, Raelynn K; Potter, Kathleen A

    2016-09-01

    Tooth resorption is the most common dental disease in cats and can be a source of oral pain. The current clinical gold standard for diagnosis includes a combination of oral exam and dental radiography, however early lesions are not always detected. Computed tomography (CT) of the skull, including the dental arches, is a commonly performed diagnostic procedure, however the appearance of tooth resorption on CT and the diagnostic ability of CT to detect tooth resorption have not been evaluated. The purpose of this prospective, descriptive, diagnostic accuracy study was to characterize the CT appearance of tooth resorption in a sample of affected cats and to evaluate the sensitivity and specificity of CT for tooth resorption compared to the clinical gold standard of oral exam and intraoral dental radiography. Twenty-eight cat cadaver specimens were recruited for inclusion. Each specimen was evaluated using oral exam, intraoral dental radiography, and computed tomography (four different slice thicknesses). Each tooth was evaluated for the presence or absence of tooth resorption. Teeth with lesions and a subset of normal teeth were evaluated with histopathology. On CT, tooth resorption appeared as irregularly marginated hypoattenuating defects in the mineral attenuating tooth components, most commonly involving the root or cementoenamel junction. Sensitivity for CT detection of tooth resorption was fair to poor (42.2-57.7%) and specificity was good to excellent (92.8-96.3%). Findings from this study indicated that CT has high specificity but low sensitivity for detection of tooth resorption in cats.

  12. In vitro expression of hard metal dust (WC-Co) - responsive genes in human peripheral blood mononucleated cells

    SciTech Connect

    Lombaert, Nooemi Lison, Dominique; Van Hummelen, Paul; Kirsch-Volders, Micheline

    2008-03-01

    Hard metals consist of tungsten carbide (WC) and metallic cobalt (Co) particles and are important industrial materials produced for their extreme hardness and high wear resistance properties. While occupational exposure to metallic Co alone is apparently not associated with an increased risk of cancer, the WC-Co particle mixture was shown to be carcinogenic in exposed workers. The in vitro mutagenic/apoptogenic potential of WC-Co in human peripheral blood mononucleated cells was previously demonstrated by us. This study aimed at obtaining a broader view of the pathways responsible for WC-Co induced carcinogenicity, and in particular genotoxicity and apoptosis. We analyzed the profile of gene expression induced in vitro by WC-Co versus control (24 h treatment) in human PBMC and monocytes using microarrays. The most significantly up-regulated pathways for WC-Co treated PBMC were apoptosis and stress/defense response; the most down-regulated was immune response. For WC-Co treated monocytes the most significantly up- and down-regulated pathways were nucleosome/chromatin assembly and immune response respectively. Quantitative RT-PCR data for a selection of the most strongly modulated genes (HMOX1, HSPA1A, HSPA1L, BNIP3, BNIP3L, ADORA2B, MT3, PLA2G7, TNFAIP6), and some additionally chosen apoptosis related genes (BCL2, BAX, FAS, FASL, TNF{alpha}), confirmed the microarray data after WC-Co exposure and demonstrated limited differences between the Co-containing compounds. Overall, this study provides the first analysis of gene expression induced by the WC-Co mixture showing a large profile of gene modulation and giving a preliminary indication for a hypoxia mimicking environment induced by WC-Co exposure.

  13. Incomplete cytokinesis and re-fusion of small mononucleated Hodgkin cells lead to giant multinucleated Reed-Sternberg cells.

    PubMed

    Rengstl, Benjamin; Newrzela, Sebastian; Heinrich, Tim; Weiser, Christian; Thalheimer, Frederic B; Schmid, Frederike; Warner, Kathrin; Hartmann, Sylvia; Schroeder, Timm; Küppers, Ralf; Rieger, Michael A; Hansmann, Martin-Leo

    2013-12-17

    Multinucleated Reed-Sternberg (RS) cells are pathognomonic for classical Hodgkin lymphoma (HL), and their presence is essential for diagnosis. How these giant tumor cells develop is controversial, however. It has been postulated that RS cells arise from mononucleated Hodgkin cells via endomitosis. Conversely, continuous single-cell tracking of HL cell lines by long-term time-lapse microscopy has identified cell fusion as the main route of RS cell formation. In contrast to growth-induced formation of giant Hodgkin cells, fusion of small mononuclear cells followed by a size increase gives rise to giant RS cells. Of note, fusion of cells originating from the same ancestor, termed re-fusion, is seen nearly exclusively. In the majority of cases, re-fusion of daughter cells is preceded by incomplete cytokinesis, as demonstrated by microtubule bonds among the cells. We confirm at the level of individual tracked cells that giant Hodgkin and RS cells have little proliferative capacity, further supporting small mononuclear Hodgkin cells as the proliferative compartment of the HL tumor clone. In addition, sister cells show a shared propensity for re-fusion, providing evidence of early RS cell fate commitment. Thus, RS cell generation is related neither to cell fusion of unrelated Hodgkin cells nor to endomitosis, but rather is mediated by re-fusion of daughter cells that underwent mitosis. This surprising finding supports the existence of a unique mechanism for the generation of multinuclear RS cells that may have implications beyond HL, given that RS-like cells are frequently observed in several other lymphoproliferative diseases as well.

  14. Incomplete cytokinesis and re-fusion of small mononucleated Hodgkin cells lead to giant multinucleated Reed–Sternberg cells

    PubMed Central

    Rengstl, Benjamin; Newrzela, Sebastian; Heinrich, Tim; Weiser, Christian; Thalheimer, Frederic B.; Schmid, Frederike; Warner, Kathrin; Hartmann, Sylvia; Schroeder, Timm; Küppers, Ralf; Rieger, Michael A.; Hansmann, Martin-Leo

    2013-01-01

    Multinucleated Reed–Sternberg (RS) cells are pathognomonic for classical Hodgkin lymphoma (HL), and their presence is essential for diagnosis. How these giant tumor cells develop is controversial, however. It has been postulated that RS cells arise from mononucleated Hodgkin cells via endomitosis. Conversely, continuous single-cell tracking of HL cell lines by long-term time-lapse microscopy has identified cell fusion as the main route of RS cell formation. In contrast to growth-induced formation of giant Hodgkin cells, fusion of small mononuclear cells followed by a size increase gives rise to giant RS cells. Of note, fusion of cells originating from the same ancestor, termed re-fusion, is seen nearly exclusively. In the majority of cases, re-fusion of daughter cells is preceded by incomplete cytokinesis, as demonstrated by microtubule bonds among the cells. We confirm at the level of individual tracked cells that giant Hodgkin and RS cells have little proliferative capacity, further supporting small mononuclear Hodgkin cells as the proliferative compartment of the HL tumor clone. In addition, sister cells show a shared propensity for re-fusion, providing evidence of early RS cell fate commitment. Thus, RS cell generation is related neither to cell fusion of unrelated Hodgkin cells nor to endomitosis, but rather is mediated by re-fusion of daughter cells that underwent mitosis. This surprising finding supports the existence of a unique mechanism for the generation of multinuclear RS cells that may have implications beyond HL, given that RS-like cells are frequently observed in several other lymphoproliferative diseases as well. PMID:24302766

  15. Variation in nutrient resorption by desert shrubs

    USDA-ARS?s Scientific Manuscript database

    Plant nutrient resorption prior to leaf senescence is an important nutrient conservation mechanism for aridland plant species. However, little is known regarding the phylogenetic and environmental factors influencing this trait. Our objective was to compare nitrogen and phosphorus resorption in a ...

  16. Macrophage fusion factor elicited from BGG-sensitized lymphocytes.

    PubMed Central

    Warfel, A. H.; Hadden, J. W.

    1978-01-01

    Lymphocytes obtained from rabbit lymph nodes sensitized to bovine gamma globulin produce in vitro the lymphokine macrophage fusion factor (MFF) which mediates the fusion of approximately 100% of normal alveolar and oil-induced peritoneal macrophages. Giant cells (GC) of Langhans and foreign body type form large syncytia containing as many as several hundred nuclei per cell. Nuclei of GC appear more spherical and larger than those of the normal mononucleated macrophages, and they possess several prominent nucleoli. Giant cells of peritoneal macrophage origin show enhanced intracytoplasmic vacuolization. Normal macrophages cultured as a monolayer in MFF-rich supernatants form cell clusters which progressively fuse during the 24-hour incubation period. A signoid dose-response curve was obtained for cell fusion with MFF-rich supernatants possessing high titers, ie, the latter supernatants undiluted partially inhibited macrophage fusion. MIF-like activity was detected in MFF-rich supernatants as well as a factor(s) which inhibited 3H-thymidine uptake by giant cells. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:362945

  17. Root resorption during orthodontic tooth movements.

    PubMed

    Ramanathan, C; Hofman, Z

    2009-12-01

    The aim of the study was to compare the extent of maxillary incisor root resorption during different orthodontic tooth movements using three different techniques, namely the basal intrusion arch, the three component arch, and levelling of the upper dental arch with the straightwire appliance. The radiographs of 49 subjects (20 males and 29 females) with a mean age of 14.5 years were taken at two time points: in groups 1 and 2 after the levelling phase and in group 3 immediately after placement of the archwire (T1) and in all groups after a period of 6 months (T2). The amount of root resorption of the central incisors was determined at T2. The average incisor resorption was different in the three groups, with group 2 (three component arch) showing greater resorption (0.46 mm) than groups 1 (basal arch) and 3 (straightwire) of 0.26 and 0.25 mm, respectively. Analysis of variance (ANOVA) demonstrated that differences in root resorption in the three groups were not significant. Wilcoxon paired test showed that the root resorption occurring between T1 and T2 in the three groups was not significant. There was also no significant difference among the rates of resorption in the three groups. Grouping the subjects on the basis of the extent of root resorption and the biomechanics used showed differences in the percentage of subjects with the least (<0.5 mm) and greatest (0.5-0.9 mm) amounts of root resorption between the three groups. This again showed that the technique of three component intrusion arch resulted in the greatest increase in root resorption.

  18. Invasive cervical resorption--a periodontist's perspective.

    PubMed

    Evans, R I

    2000-10-01

    Invasive cervical resorption (ICR) is a relatively uncommon, insidious, resorptive lesion starting subgingivally at the cervical root surface of a tooth. ICR is of uncertain aetiology, although damage to the cervical periodontal attachment to the tooth appears to be a prerequisite. For the most part the lesion is asymptomatic so early detection can be difficult. Nevertheless, if less than a third of the root of the tooth is affected by an ICR lesion treatment of the resorptive tissue using the chemical escharotic agent trichloracetic acid, with or without surgical access, followed by curettage of the lesion and restoration of the defect with glass ionomer cement, is generally successful.

  19. Osteoarthritis, osteoarthrosis, and idiopathic condylar resorption.

    PubMed

    Mercuri, Louis G

    2008-05-01

    The term "osteoarthritis" has classically been defined as a low-inflammatory arthritic condition. The term "osteoarthrosis," a synonym for osteoarthritis in the medical orthopedic literature, has recently come to be identified in the dental/temporomandibular joint (TMJ) disorders literature with any noninflammatory arthritic condition that results in similar degenerative changes as in osteoarthritis. The term "idiopathic condylar resorption," also known as "progressive condylar resorption," is described as a dysfunctional remodeling of the TMJ manifested by morphologic change, decreased ramal height, progressive mandibular retrusion in the adult, or decreased mandibular growth in the juvenile. This article discusses the diagnosis and management of osteoarthritic TMJ disorders and idiopathic condylar resorption.

  20. Skeletal muscle-melanocyte association during tadpole tail resorption in a tropical frog, Clinotarsus curtipes Jerdon (Anura, Ranoidea).

    PubMed

    Divya, Lekha; Beyo, Reston S; Sreejith, Parameswaran; Akbarsha, Mohammad A; Oommen, Oommen V

    2010-05-01

    We tested the hypothesis that melanin has a role as a molecule within the thyroid-mediated cascade. Light microscopic and ultrastructural changes in the skeletal muscle during tail resorption in tadpoles of the tropical frog Clinotarsus curtipes Jerdon (Anura: Ranoidea) were observed. Light microscopic analysis at metamorphic stage XVIII showed a melanized epidermis. A gradual migration of melanocytes from the epidermis to the dermis and filopodia of melanocytes pervading the skeletal muscle preceded tail resorption. The invasion of melanocytes into the muscle bundles coincided with the breakdown of the muscle bundles into sarcolytes and the arrival of macrophages at this site. This would suggest that the melanocyte-sarcolyte association signals the arrival of macrophages at these sites as metamorphosis progressed. Melanophages, macrophages with melanin granules, were observed at the climax stage of XXIII. The sarcolytes and the melanin granules were phagocytosed by macrophages so as to completely cleanse the exocytic muscle debris and the melanin granules. The presence of large melanomacrophage centers in the tadpole liver at metamorphic climax suggests that these phagocytic macrophages were further processed in the liver and, likely, in the spleen. It is proposed that melanin, a byzantine molecule, has a role in the cascade of events leading to tail resorption in anuran tadpoles. (c) 2010 Elsevier GmbH. All rights reserved.

  1. External multiple invasive cervical resorption with subsequent arrest of the resorption.

    PubMed

    Mattar, Rinaldo; Pereira, Sanivia Aparecida de Lima; Rodor, Rovena Carneiro; Rodrigues, Denise Bertulucci Rocha

    2008-10-01

    A rare, the uncommon, case of multiple invasive cervical resorption (MICR) with subsequent arrest of the resorption involving eight teeth of the mandible (tooth 46 to tooth 32) is presented. This case is noteworthy because of the characteristics of its clinical evolution. There have only been a few cases in the literature were found presenting involvement of such a large number of teeth. Furthermore, no reports on cases of MICR with arrest of the resorption, as described in this report, were found.

  2. Management of Perforating Idiopathic Internal Root Resorption.

    PubMed

    Abdullah, Dalia; Eziana Hussein, Farah; Abd Ghani, Huwaina

    2017-01-01

    This case report describes the endodontic treatment of an idiopathic perforated internal root resorption. A 24-year-old male Malay patient presented with internal root resorption of two of his anterior teeth. The medical history was non-contributory and he had no history of traumatic injury or orthodontic treatment. Cone-beam computed tomography (CBCT) determined the nature, location and severity of the resorptive lesion. Non-surgical root canal treatment of tooth #22 and combined non-surgical and surgical approach for tooth #11 were carried out using mineral trioxide aggregate (MTA) as the filling material. The clinical and radiographic examination three years after completion of treatment revealed evidences of periapical healing. The appropriate diagnosis and the treatment of internal root resorption allowed good healing of these lesions and maintained the tooth in function for as long as possible.

  3. Apical root resorption in orthodontically treated adults.

    PubMed

    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

  4. Increased levels of sodium chloride directly increase osteoclastic differentiation and resorption in mice and men.

    PubMed

    Wu, L; Luthringer, B J C; Feyerabend, F; Zhang, Z; Machens, H G; Maeda, M; Taipaleenmäki, H; Hesse, E; Willumeit-Römer, R; Schilling, A F

    2017-08-29

    To better understand the association between high salt intake and osteoporosis, we investigated the effect of sodium chloride (NaCl) on mice and human osteoclastogenesis. The results suggest a direct, activating role of NaCl supplementation on bone resorption. High NaCl intake is associated with increased urinary calcium elimination and parathyroid hormone (PTH) secretion which in turn stimulates the release of calcium from the bone, resulting in increased bone resorption. However, while calciuria after NaCl loading could be shown repeatedly, several studies failed to reveal a significant increase in PTH in response to a high-sodium diet. Another possible explanation that we investigated here could be a direct effect of high-sodium concentration on bone resorption. Mouse bone marrow macrophage and human peripheral blood mononuclear cells (PBMC) driven towards an osteoclastogenesis pathway were cultivated under culture conditions mimicking hypernatremia environments. In this study, a direct effect of increased NaCl concentrations on mouse osteoclast differentiation and function was observed. Surprisingly, in a human osteoclast culture system, significant increases in the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts, calcitonin receptor (CTR)-positive osteoclasts, nuclear factor-activated T cells c1 (NFATc1) gene expression, and areal and volumetric resorptions were observed for increasing concentrations of NaCl. This suggests a direct, activating, cell-mediated effect of increased concentrations of NaCl on osteoclasts. The reported that enhanced bone resorption after high-sodium diets may not only be secondary to the urinary calcium loss but may also be a direct, cell-mediated effect on osteoclastic resorption. These findings allow us to suggest an explanation for the clinical findings independent of a PTH-mediated regulation.

  5. Macrophage Polarization.

    PubMed

    Murray, Peter J

    2017-02-10

    Macrophage polarization refers to how macrophages have been activated at a given point in space and time. Polarization is not fixed, as macrophages are sufficiently plastic to integrate multiple signals, such as those from microbes, damaged tissues, and the normal tissue environment. Three broad pathways control polarization: epigenetic and cell survival pathways that prolong or shorten macrophage development and viability, the tissue microenvironment, and extrinsic factors, such as microbial products and cytokines released in inflammation. A plethora of advances have provided a framework for rationally purifying, describing, and manipulating macrophage polarization. Here, I assess the current state of knowledge about macrophage polarization and enumerate the major questions about how activated macrophages regulate the physiology of normal and damaged tissues.

  6. Sinusoidal electromagnetic fields promote bone formation and inhibit bone resorption in rat femoral tissues in vitro.

    PubMed

    Zhou, Jian; Ma, Xiao-Ni; Gao, Yu-Hai; Yan, Juan-Li; Shi, Wen-Gui; Xian, Cory J; Chen, Ke-Ming

    2016-01-01

    Effects of sinusoidal electromagnetic fields (SEMFs) on bone metabolism have not yet been well defined. The present study investigated SEMF effects on bone formation and resorption in rat femur bone tissues in vitro. Cultured femur diaphyseal (cortical bone) and metaphyseal (trabecular bone) tissues were treated with 50 Hz 1.8 mT SEMFs 1.5 h per day for up to 12 days and treatment effects on bone formation and resorption markers and associated gene expression were examined. Treatment with SEMFs caused a significant increase in alkaline phosphatase (ALP) activity and inhibited the tartrate-resistant acid phosphatase (TRACP) activity in the femoral diaphyseal or metaphyseal tissues. SEMFs also significantly increased levels of mRNA expression of osterix (OSX), insulin-like growth factor (IGF-1) and ALP in the bone tissues. SEMF treatment decreased glucose content and increased lactic acid contents in the culture conditioned medium. In addition, treatment with SEMFs decreased mRNA expression levels of bone resorption-related genes TRACP, macrophage colony stimulating factor (M-CSF) and cathepsin K (CTSK) in the cultured bone tissues. In conclusion, the current study demonstrated that treatment with 1.8 mT SEMFs at 1.5 h per day promoted bone formation, increased metabolism and inhibited resorption in both metaphyseal and diaphyseal bone tissues in vitro.

  7. Equine odontoclastic tooth resorption and hypercementosis.

    PubMed

    Staszyk, Carsten; Bienert, Astrid; Kreutzer, Robert; Wohlsein, Peter; Simhofer, Hubert

    2008-12-01

    A poorly described, painful disorder of incisor and canine teeth, variably causing periodontitis, with resorptive or proliferative changes of the calcified dental tissues, has recently been documented in aged horses. No plausible aetiopathogenesis for this syndrome has been recorded. Eighteen diseased teeth from eight horses were examined grossly and microscopically and showed the presence of odontoclastic cells by tartrate resistant acid phosphatase (TRAP) staining. A chronological sequence of odontoclastic resorption followed by hypercementosis was demonstrated and, consequently, the term equine odontoclastic tooth resorption and hypercementosis (EOTRH) is proposed for this disorder. EOTRH shares many features with similar dental syndromes described in humans and cats. An aetiological hypothesis proposes mechanical stress of the periodontal ligament as the initiating factor.

  8. Understanding External Cervical Resorption in Vital Teeth.

    PubMed

    Mavridou, Athina M; Hauben, Esther; Wevers, Martine; Schepers, Evert; Bergmans, Lars; Lambrechts, Paul

    2016-12-01

    The aim of this study was to investigate the 3-dimensional (3D) structure and the cellular and tissue characteristics of external cervical resorption (ECR) in vital teeth and to understand the phenomenon of ECR by combining histomorphological and radiographic findings. Twenty-seven cases of vital permanent teeth displaying ECR were investigated. ECR diagnosis was based on clinical and radiographic examination with cone-beam computed tomographic imaging. The extracted teeth were further analyzed by using nanofocus computed tomographic imaging, hard tissue histology, and scanning electron microscopy. All examined teeth showed some common characteristics. Based on the clinical and experimental findings, a 3-stage mechanism of ECR was proposed. At the first stage (ie, the initiation stage), ECR was initiated at the cementum below the gingival epithelial attachment. At the second stage (ie, the resorption stage), the resorption invaded the tooth structure 3-dimensionally toward the pulp space. However, it did not penetrate the pulp space because of the presence of a pericanalar resorption-resistant sheet. This layer was observed to consist of predentin, dentin, and occasionally reparative mineralized (bonelike) tissue, having a fluctuating thickness averaging 210 μm. At the last advanced stage (ie, the repair stage), repair took place by an ingrowth and apposition of bonelike tissue into the resorption cavity. During the reparative stage, repair and remodeling phenomena evolve simultaneously, whereas both resorption and reparative stages progress in parallel at different areas of the tooth. ECR is a dynamic and complex condition that involves periodontal and endodontic tissues. Using clinical, histologic, radiographic, and scanning microscopic analysis, a better understanding of the evolution of ECR is possible. Based on the experimental findings, a 3-stage mechanism for the initiation and growth of ECR is proposed. Copyright © 2016 American Association of

  9. External cervical resorption: diagnostic and treatment tips

    PubMed Central

    Consolaro, Alberto

    2016-01-01

    ABSTRACT External cervical resorption is caused, almost exclusively, by dental trauma - especially those characterized by concussion - and is a dental disease to be diagnosed and treated accurately by endodontists. However, the vast majority of the cases is initially diagnosed by an orthodontist, due to the imaging possibilities in standardized documentations. Among the causes of external cervical resorption, it is common to mistakenly attribute it to orthodontic treatment, traumatic occlusion or even to chronic inflammatory periodontal disease. External cervical resorption is associated to dental trauma in several situations mentioned in this paper. In old cases, and eventually still nowadays, it may have been induced by internal tooth bleaching, which is increasingly less frequent in endodontically treated teeth. There are some tips to be followed and some care that must be taken during the diagnosis and treatment of external cervical resorption clinical cases. The present study lists foundations that will allow the professional to perform safely and accurately in each specific case. Some of these tips and care measures are of orthodontic nature. PMID:27901225

  10. Thyroxine Induced Resorption of Xenopus Laevis Tail Tissue in Vitro.

    ERIC Educational Resources Information Center

    Scadding, Steven R.

    1984-01-01

    A simple method of studying thyroxine-induced resorption of tadpole tails in vitro is described. This procedure demonstrates that resorption is dependent on thyroxine and requires protein synthesis. It introduces students to the use of tissue culture methods. (Author)

  11. Thyroxine Induced Resorption of Xenopus Laevis Tail Tissue in Vitro.

    ERIC Educational Resources Information Center

    Scadding, Steven R.

    1984-01-01

    A simple method of studying thyroxine-induced resorption of tadpole tails in vitro is described. This procedure demonstrates that resorption is dependent on thyroxine and requires protein synthesis. It introduces students to the use of tissue culture methods. (Author)

  12. ON THE MECHANISMS OF BONE RESORPTION

    PubMed Central

    Vaes, Gilbert

    1968-01-01

    Bone resorption, characterized by the solubilization of both the mineral and the organic components of the osseous matrix, was obtained in tissue culture under the action of parathyroid hormone (PTH). It was accompanied by the excretion of six lysosomal acid hydrolases, which was in good correlation with the progress of the resorption evaluated by the release of phosphate, calcium 45 or hydroxyproline from the explants; there was no increased excretion of two nonlysosomal enzymes, alkaline phosphatase, and catalase. Balance studies and experiments with inhibitors of protein synthesis indicated that the intracellular stores of the acid hydrolases excreted were maintained by new synthesis. The release was not due to a direct disruption of the lysosomal membrane by PTH; it is presumed to result from an exocytosis of the whole lysosomal content and to involve mechanisms similar to those controlling the secretion of this content into digestive vacuoles. The resorbing explants acidified their culture fluids at a faster rate and released more lactate and citrate than the controls; this release was in good correlation, in the PTH-treated cultures, with the resorption of the bone mineral, but the amount of citrate released was considerably smaller than that of lactate. The acid released could account for the resorption of the mineral. It is proposed, as a working hypothesis, that the acid hydrolases of the lysosomes are active in the resorption of the organic matrix of bone and that acid, originating possibly from the stimulation of glycolysis, cares for the concomitant solubilization of bone mineral while also favoring the hydrolytic action of the lysosomal enzymes. PMID:5699937

  13. Inhibited osteoclastic bone resorption through alendronate treatment in rats reduces severe osteoarthritis progression.

    PubMed

    Siebelt, M; Waarsing, J H; Groen, H C; Müller, C; Koelewijn, S J; de Blois, E; Verhaar, J A N; de Jong, M; Weinans, H

    2014-09-01

    Osteoarthritis (OA) is a non-rheumatoid joint disease characterized by progressive degeneration of extra-cellular cartilage matrix (ECM), enhanced subchondral bone remodeling, osteophyte formation and synovial thickening. Alendronate (ALN) is a potent inhibitor of osteoclastic bone resorption and results in reduced bone remodeling. This study investigated the effects of pre-emptive use of ALN on OA related osteoclastic subchondral bone resorption in an in vivo rat model for severe OA. Using multi-modality imaging we measured effects of ALN treatment within cartilage and synovium. Severe osteoarthritis was induced in left rat knees using papain injections in combination with a moderate running protocol. Twenty rats were treated with subcutaneous ALN injections and compared to twenty untreated controls. Animals were longitudinally monitored for 12weeks with in vivo μCT to measure subchondral bone changes and SPECT/CT to determine synovial macrophage activation using a folate-based radiotracer. Articular cartilage was analyzed at 6 and 12weeks with ex vivo contrast enhanced μCT and histology to measure sulfated-glycosaminoglycan (sGAG) content and cartilage thickness. ALN treatment successfully inhibited subchondral bone remodeling. As a result we found less subchondral plate porosity and reduced osteophytosis. ALN treatment did not reduce subchondral sclerosis. However, after the OA induction phase, ALN treatment protected cartilage ECM from degradation and reduced synovial macrophage activation. Surprisingly, ALN treatment also improved sGAG content of tibia cartilage in healthy joints. Our data was consistent with the hypothesis that osteoclastic bone resorption might play an important role in OA and may be a driving force for progression of the disease. However, our study suggest that this effect might not solely be effects on osteoclastic activity, since ALN treatment also influenced macrophage functioning. Additionally, ALN treatment and physical activity

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

    PubMed

    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.

  15. Stoichiometric patterns in foliar nutrient resorption across multiple scales

    USGS Publications Warehouse

    Reed, Sasha C.; Townsend, Alan R.; Davidson, Eric A.; Cleveland, Cory C.

    2012-01-01

    *Nutrient resorption is a fundamental process through which plants withdraw nutrients from leaves before abscission. Nutrient resorption patterns have the potential to reflect gradients in plant nutrient limitation and to affect a suite of terrestrial ecosystem functions. *Here, we used a stoichiometric approach to assess patterns in foliar resorption at a variety of scales, specifically exploring how N : P resorption ratios relate to presumed variation in N and/or P limitation and possible relationships between N : P resorption ratios and soil nutrient availability. *N : P resorption ratios varied significantly at the global scale, increasing with latitude and decreasing with mean annual temperature and precipitation. In general, tropical sites (absolute latitudes < 23°26′) had N : P resorption ratios of < 1, and plants growing on highly weathered tropical soils maintained the lowest N : P resorption ratios. Resorption ratios also varied with forest age along an Amazonian forest regeneration chronosequence and among species in a diverse Costa Rican rain forest. *These results suggest that variations in N : P resorption stoichiometry offer insight into nutrient cycling and limitation at a variety of spatial scales, complementing other metrics of plant nutrient biogeochemistry. The extent to which the stoichiometric flexibility of resorption will help regulate terrestrial responses to global change merits further investigation.

  16. Etiology and sequelae of root resorption.

    PubMed

    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.

  17. Titanium particles that have undergone phagocytosis by macrophages lose the ability to activate other macrophages.

    PubMed

    Xing, Zhiqing; Schwab, Luciana P; Alley, Carie F; Hasty, Karen A; Smith, Richard A

    2008-04-01

    Titanium particles derived from the wear of the orthopaedic implant surfaces can activate macrophages to secrete cytokines and stimulate osteoclastic bone resorption, causing osteolysis around orthopaedic implants. However, what happens to the titanium particles after being phagocytosed by macrophages is not known. We prepared titanium particles (as received, clean, and LPS-coated), and exposed them to macrophages in culture. Free particles were washed away after 24 h and the intracellular particles were kept in culture for additional 48 h until being harvested by lysing the cells. Particles that had been cell treated or noncell treated were examined by scanning electronic microscopy to analyze the shape, size, and concentration of the particles. The cell treated and noncell treated particles were exposed to macrophages in culture with a particle to cell ratio of 300:1. After 18 h, the levels of TNF-alpha in culture medium and the viability of the cells were examined. Clean particles did not stimulate TNF-alpha secretion by macrophages, while LPS-coated particles dramatically increased that response. Phagocytosis by macrophages did not change the shape and size of the particles, but depleted the ability of the particles to stimulate TNF-alpha secretion by macrophages. This indicates that macrophages are capable of rendering titanium particles inactive without degrading the particles, possibly by altering the surface chemistry of the particles.

  18. Idiopathic external root resorption associated to hypercalciuria.

    PubMed

    Llena-Puy, M C; Amengual-Lorenzo, J; Forner-Navarro, L

    2002-01-01

    Although external root resorption (ERR) is a physiological process in deciduous dentition, it is very infrequent in permanent dentition - where the phenomenon is related to the existence of inadequate occlusal forces, periodontal pathology and microtraumatisms, etc. However, in many cases root resorption cannot be attributed to any concrete cause; such cases are defined as idiopathic external root resorption (IERR). Epidemiological studies have found that the underlying cause can only be established in 5% of all ERR. The present study describes three cases of IERR with different degrees of involvement and associated to mild calciuria and a history of nephrolithiasis. Hypercalciuria with normal blood calcium levels is usually idiopathic and exhibits a familial trait, with a prevalence of 20-40 cases per 1,000 individuals in adults. A form of hypercalciuria associated to nephrolithiasis with a mutation of the CLCN5 gene has been identified, involving low molecular weight proteinuria - though this mutation has not been uniformly demonstrated in most cases of idiopathic hypercalciuria. The peculiarity of the cases described in the present study is attributable to the coexistence of IERR with normocalcemic hypercalciuria and nephrolithiasis - thus pointing to the need for in-depth evaluation of the possible association of these three clinical situations.

  19. Histological and Immunohistochemical Evaluation of Autologous Cultured Bone Marrow Mesenchymal Stem Cells and Bone Marrow Mononucleated Cells in Collagenase-Induced Tendinitis of Equine Superficial Digital Flexor Tendon

    PubMed Central

    Crovace, Antonio; Lacitignola, Luca; Rossi, Giacomo; Francioso, Edda

    2010-01-01

    The aim of this study was to compare treatment with cultured bone marrow stromal cells (cBMSCs), bone marrow Mononucleated Cells (BMMNCs), and placebo to repair collagenase-induced tendinitis in horses. In six adult Standardbred horses, 4000 IU of collagenase were injected in the superficial digital flexor tendon (SDFT). Three weeks after collagenase treatment, an average of either 5.5 × 106 cBMSCs or 1.2 × 108 BMMNCs, fibrin glue, and saline solution was injected intralesionally in random order. In cBMSC- and BMMNCS-treated tendons, a high expression of cartilage oligomeric matrix protein (COMP) and type I collagen, but low levels of type III collagen were revealed by immunohistochemistry, with a normal longitudinally oriented fiber pattern. Placebo-treated tendons expressed very low quantities of COMP and type I collagen but large numbers of randomly oriented type III collagen fibers. Both cBMSC and BMMNCS grafts resulted in a qualitatively similar heling improvement of tendon extracellular matrix, in terms of the type I/III collagen ratio, fiber orientation, and COMP expression. PMID:20445779

  20. OCLI-023, a Novel Pyrimidine Compound, Suppresses Osteoclastogenesis In Vitro and Alveolar Bone Resorption In Vivo

    PubMed Central

    Kim, Ju Ang; Lee, Doohyun; Kim, Nam Doo; Shin, Hong-In; Bae, Yong Chul; Park, Eui Kyun

    2017-01-01

    An abnormal increase in osteoclast differentiation and activation results in various bone-resorptive diseases, including periodontitis, rheumatoid arthritis, and osteoporosis. Chemical compounds containing pyrimidine ring have been shown to regulate a variety of biological processes. Therefore, in order to identify an antiresorptive agent, we synthesized a series of pyrimidine ring-containing chemical compounds, and found that OCLI-023 suppressed the differentiation and activation of osteoclasts in vitro. OCLI-023 directly inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced differentiation of bone marrow macrophages into osteoclasts, without a cytotoxic response. OCLI-023 also downregulated the RANKL-induced mRNA expression of osteoclast markers as well as inhibited the formation of actin rings and resorption pits. OCLI-023 attenuated the RANKL-induced activation of c-Jun N-terminal kinase and nuclear factor kappa-light-chain-enhancer of activated B cell signaling pathways. In a mouse model of periodontitis, ligature induced an increase of distance between cementoenamel junction (CEJ) and alveolar bone crest (ABC) in the second molar, and OCLI-023 significantly reduced it. Histological analysis showed ligature-induced increase of osteoclast numbers was also significantly reduced by OCLI-023. These data demonstrated the inhibitory effect of OCLI-023 on osteoclast differentiation and activity of osteoclasts in vitro, as well as on ligature-induced bone loss in vivo, and OCLI-023 can be proposed as a novel anti-resorptive compound. PMID:28085946

  1. The cell biology and role of resorptive cells in diseases: A review.

    PubMed

    Babaji, Prashant; Devanna, Raghu; Jagtap, Kiran; Chaurasia, Vishwajit Rampratap; Jerry, Jeethu John; Choudhury, Basanta Kumar; Duhan, Dinesh

    2017-01-01

    Resorptive cells are responsible for the resorption of mineralized matrix of hard tissues. Bone-resorbing cells are called osteoclasts; however, they can resorb mineralized dental tissues or calcified cartilage and then they are called odontoclasts and chondroclasts, respectively. Resorptive cells form when mononuclear precursors derived from a monocyte-macrophage cell lineage are attracted to certain mineralized surfaces and subsequently fuse and adhere onto them for exerting their resorbing activity. These cells are responsible for degradation of calcified extracellular matrix composed of organic molecules and hydroxyapatite. The activity of these cells can be observed in both physiological and pathological processes throughout life and their activity is mainly required in bone turnover and growth, spontaneous and induced (orthodontic) tooth movement, tooth eruption, and bone fracture healing, as well as in pathological conditions such as osteoporosis, osteoarthritis, and bone metastasis. In addition, they are responsible for daily control of calcium homeostasis. Clastic cells also resorb the primary teeth for shedding before the permanent teeth erupt into the oral cavity.

  2. Artemisia capillaris Alleviates Bone Loss by Stimulating Osteoblast Mineralization and Suppressing Osteoclast Differentiation and Bone Resorption.

    PubMed

    Lee, Chung-Jo; Shim, Ki-Shuk; Ma, Jin Yeul

    2016-01-01

    Artemisia capillaris has been used to treat jaundice and relieve high liver-heat in traditional medicine. In this study, we found that the administration of a water extract from A. capillaris (WEAC) to the receptor activator of nuclear factor kappa-B ligand (RANKL)-induced bone loss model significantly prevents osteoporotic bone loss, increasing bone volume/trabecular volume by 22% and trabecular number by 24%, and decreasing trabecular separation by 29%. WEAC stimulated in vitro osteoblast mineralization from primary osteoblasts in association with increasing expression of osterix, nuclear factor of activated T cells cytoplasmic 1, and activator protein-1, as well as phosphorylation of extracellular signal-regulated kinase. In contrast to the anabolic effect of WEAC, WEAC significantly suppressed in vitro osteoclast formation from bone marrow macrophages by inhibiting the RANKL signaling pathways and bone resorption by downregulating the expression of resorption markers. Therefore, this study demonstrated that WEAC has a beneficial effect on bone loss through the regulation of osteoblast mineralization, as well as osteoclast formation and bone resorption. These results suggest that A. capillaris may be a promising herbal candidate for therapeutic agents to treat or prevent osteoporotic bone diseases.

  3. Lectin-mediated effects on bone resorption in vitro: a morphological and functional study

    SciTech Connect

    Popoff, S.N.

    1986-01-01

    Lectins have been used to study the structure and function of a variety of cells and tissues. The authors used 4 different lectins, concanavalin A (con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA) and peanut agglutinin (PNA) as in vitro biological probes to study the osteoclast, a multinucleated bone cell that is widely accepted as the primary effector cell responsible for normal bone resorption. They evaluated the effects of each of these lectins on osteoclastic bone resorbing activity and then examined mechanisms that may be responsible for the activation and/or inhibition of osteoclastic activity. Using con A and hemocyanin, a marker molecule used to visualize cell-bound con A via scanning electron microscopy, they demonstrated that osteoclasts have specific con A binding sites on their cell surface. They conducted a series of /sup 45/Ca bone release assays demonstrating that con A has a dose-dependent biphasic effect on bone resorption; stimulation at low concentrations and inhibition at higher concentrations. The findings suggest that the specificity of lectin binding to cell surface receptors may play an important role in the induction of altered cell function. Recently, cells of the mononuclear phagocyte system have been proposed as surrogates of less readily available osteoclasts. They used a macrophage-devitalized bone culture system to evaluate the effects of con A and SBA on the attachment of macrophages to bone and their subsequent functional activity. The results showed that con A, but not SBA, alters the morphology and function of macrophages on a devitalized bone surface. The results support the hypothesis that certain, specific saccharides regulate the interaction between macrophages and bone.

  4. [The question of root resorption. Is the risk of root resorption related to the typology of the face?].

    PubMed

    Bacon, W; Reziciner, V; Tschill, P

    1989-01-01

    The mechanisms involved in root resorption are of the same nature than those leading to bone resorption. The state of calcification and the local conditions in the microenvironment are responsible for the different responses of alveolar bone and root with regard to calcified matrix resorption. Root resorption is commonly observed in association with impacted cuspids, acute chronical trauma, inflammatory or idiopathic conditions. Root resorption is more frequent in females and is independent on facial typology or orthodontic technique. Critical conditions to root integrity are often associated with heavy forces and periodontal ligament disruption. Root anatomy may also be a predisposing factor to resorption. Systematic radiological examination is the only way to control the onset of a root resorption process in orthodontic therapy.

  5. Resorption of Autogenous Bone Graft in Cranioplasty: Resorption and Reintegration Failure

    PubMed Central

    Lee, Si Hoon; Lee, Uhn; Park, Cheol Wan; Lee, Sang Gu; Kim, Woo Kyung

    2014-01-01

    Objective Re-implantation of autologous skull bone has been known to be difficult because of its propensity for resorption. Moreover, the structural characteristics of the area of the defect cannot tolerate physiologic loading, which is an important factor for graft healing. This paper describes our experiences and results with cranioplasty following decompressive craniectomy using autologous bone flaps. Methods In an institutional review, the authors identified 18 patients (11 male and 7 female) in whom autologous cranioplasty was performed after decompressive craniectomy from January 2008 to December 2011. We examined the age, reasons for craniectomy, size of the skull defect, presence of bony resorption, and postoperative complications. Results Postoperative bone resorption occurred in eight cases (44.4%). Among them, two experienced symptomatic breakdown of the autologous bone graft that required a second operation to reconstruct the skull contour using porous polyethylene implant (Medpor®). The incidence of bone resorption was more common in the pediatric group and in those with large cranial defects (>120 cm2). No significant correlation was found with sex, reasons for craniectomy, and cryopreservation period. Conclusion The use of autologous bone flap for reconstruction of a skull defect after decompressive craniectomy is a quick and cost-effective method. But, the resorption rate was greater in children and in patients with large skull defects. As a result, we suggest compressive force of the tightened scalp, young age, large skull defect, the gap between bone flap and bone edge and heat sterilization of autologous bone as risk factors for bone resorption. PMID:27169026

  6. Toll-Like Receptor 2 Stimulation of Osteoblasts Mediates Staphylococcus Aureus Induced Bone Resorption and Osteoclastogenesis through Enhanced RANKL

    PubMed Central

    Kassem, Ali; Lindholm, Catharina; Lerner, Ulf H

    2016-01-01

    Severe Staphylococcus aureus (S. aureus) infections pose an immense threat to population health and constitute a great burden for the health care worldwide. Inter alia, S. aureus septic arthritis is a disease with high mortality and morbidity caused by destruction of the infected joints and systemic bone loss, osteoporosis. Toll-Like receptors (TLRs) are innate immune cell receptors recognizing a variety of microbial molecules and structures. S. aureus recognition via TLR2 initiates a signaling cascade resulting in production of various cytokines, but the mechanisms by which S. aureus causes rapid and excessive bone loss are still unclear. We, therefore, investigated how S. aureus regulates periosteal/endosteal osteoclast formation and bone resorption. S. aureus stimulation of neonatal mouse parietal bone induced ex vivo bone resorption and osteoclastic gene expression. This effect was associated with increased mRNA and protein expression of receptor activator of NF-kB ligand (RANKL) without significant change in osteoprotegerin (OPG) expression. Bone resorption induced by S. aureus was abolished by OPG. S. aureus increased the expression of osteoclastogenic cytokines and prostaglandins in the parietal bones but the stimulatory effect of S. aureus on bone resorption and Tnfsf11 mRNA expression was independent of these cytokines and prostaglandins. Stimulation of isolated periosteal osteoblasts with S. aureus also resulted in increased expression of Tnfsf11 mRNA, an effect lost in osteoblasts from Tlr2 knockout mice. S. aureus stimulated osteoclastogenesis in isolated periosteal cells without affecting RANKL-stimulated resorption. In contrast, S. aureus inhibited RANKL-induced osteoclast formation in bone marrow macrophages. These data show that S. aureus enhances bone resorption and periosteal osteoclast formation by increasing osteoblast RANKL production through TLR2. Our study indicates the importance of using different in vitro approaches for studies of how S

  7. IL-37 inhibits lipopolysaccharide-induced osteoclast formation and bone resorption in vivo.

    PubMed

    Saeed, Jafari; Kitaura, Hideki; Kimura, Keisuke; Ishida, Masahiko; Sugisawa, Haruki; Ochi, Yumiko; Kishikawa, Akiko; Takano-Yamamoto, Teruko

    2016-07-01

    IL-37 is a newly defined member of the IL-1 cytokine family. It has been reported that IL-37 inhibited innate immunity and inflammatory responses in autoimmune diseases and tumors. IL-37 also inhibited Lipopolysaccharide (LPS)-induced immunological reaction. LPS is a bacterial cell wall component that is capable of inducing osteoclast formation and pathological bone resorption. However, there is no study to investigate the effect of IL-37 on LPS-induced osteoclast formation and bone resorption. The purpose of this study is to investigate the effect of IL-37 in LPS-induced osteoclast formation and bone resorption. LPS was administrated with or without IL-37 by subcutaneous injection on mice calvariae. The number of osteoclasts, the level of tartrate-resistant acid phosphatase (TRAP) and cathepsin K mRNA, the ratio of the bone resorption pits and the level of C-terminal telopeptide fragments of type I collagen cross-Links as a marker of bone resorption in mice administrated both LPS and IL-37 were lower than that in mice administrated LPS alone. Real-time RT-PCR was performed to analyze osteoclast related cytokines RANKL, TNF-α and IL-1β mRNA levels in vivo. RANKL, TNF-α and IL-1β mRNAs were increased in the LPS alone administrated mice as compared with PBS administrated groups. On the other hand, RANKL, TNF-α and IL-1β mRNAs were inhibited in the IL-37 and LPS administrated mice as compared with LPS alone administrated group. In vitro analysis, there was no effect of IL-37 in RANKL-induced osteoclast formation, TNF-α-induced osteoclast formation and cell viability from bone marrow macrophages as osteoclast precursor and LPS-induced RANKL expression from stromal cells. These results indicated that IL-37 inhibited LPS-induced osteoclast formation and bone resorption via inhibition of LPS-induced osteoclast related cytokines, but might not directly inhibit osteoclast formation on osteoclast precursor and RANKL expression on stromal cells. Copyright © 2016

  8. Nitric oxide promotes infectious bone resorption by enhancing cytokine-stimulated interstitial collagenase synthesis in osteoblasts.

    PubMed

    Lin, Sze-Kwan; Kok, Sang-Heng; Kuo, Mark Yen-Ping; Lee, Ming-Shu; Wang, Chih-Chiang; Lan, Wan-Hong; Hsiao, Michael; Goldring, Steven R; Hong, Chi-Yuan

    2003-01-01

    This experiment was undertaken to determine the role of macrophage-derived nitric oxide (NO) in mediating lipopolysaccharide (LPS)-induced bone resorption by using an in vitro co-culture system and an in vivo model of infectious bone resorption. Our results demonstrated that LPS stimulated the expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-a mRNAs and nitrite synthesis in the J774 mouse macrophage cell line but not in the UMR-106 (rat) and MC3T3-E1 (mouse) osteoblast cell lines. Conditioned media (CM) from LPS-stimulated J774 triggered only low to moderate levels of iNOS mRNAs in MC3T3-E1 and a trivial effect in UMR-106. On the other hand, CM induced matrix metalloproteinase-1 (MMP-1) gene expression in both osteoblast cell lines. The NOS inhibitor N(G)-monomethyl-L-arginine (L-NMMA) did not alter this effect in MC3T3-E1 and UMR-106, whereas TNF-a antibody diminished the CM-induced MMP-1 gene expression in both cell lines. Interestingly, SNAP, a NO donor, although by itself is not a MMP-1 stimulator for UMR-106, augmented the TNF-alpha-stimulated MMP-1 mRNA production in UMR-106. In a J774/UMR-106 co-culture system, LPS stimulated significant MMP-1 gene expression in UMR-106, and this upregulation was abolished by L-NMMA and TNF-alpha antibodies. Immunohistochemical analysis in a rat model of infectious bone resorption (periapical lesion) showed co-distributions of iNOS+ macrophages and MMP-1+ osteoblasts around the osteolytic areas. Administration of L-NMMA markedly reduced the extent of bone loss and the percentage of MMP-1-synthesizing osteoblasts. These data suggest that NO derived from macrophages after LPS stimulation may enhance bone loss by augmenting the cytokine-induced MMP-1 production in osteoblasts.

  9. Amelogenesis Imperfecta with Coronal Resorption: Report of Three Cases.

    PubMed

    Bhatia, Shannu K; Hunter, M Lindsay; Ashley, Paul F

    2015-12-01

    Intracoronal resorption of the permanent dentition in cases of amelogenesis imperfecta (AI) is a rare finding which poses an added complication to the already complex management of this condition. This paper presents three cases of AI associated with delayed eruption of permanent teeth in which asymptomatic intracoronal resorption occurred. CPD/Clinical Relevance: This paper highlights the fact that teeth affected with amelogenesis imperfecta may undergo asymptomatic intracoronal resorption which is only identifiable radiographically.

  10. Contact microradiographic analysis of feline tooth resorptive lesions.

    PubMed

    Ohba, S; Kiba, H; Kuwabara, M; Yoshida, H; Koide, F; Takeishi, M

    1993-04-01

    Feline tooth resorptive lesions were studied using contact microradiographic analysis of ground sections. Contact microdiagram films were developed with a PIAS-imaging device, and decalcification patterns were evaluated, revealing a clear boundary between normal tissue and the resorptive area, which was different from the image of dental caries in humans. By contrasting analysis, decalcification signs appearing in human caries were not observed in feline resorptive lesions.

  11. Radiographic changes associated with tooth resorption type 2 in cats.

    PubMed

    Mihaljevic, Susann-Yvonne; Kernmaier, Alice; Mertens-Jentsch, Svea

    2012-01-01

    The aim of this retrospective study was to follow the progression of radiographic changes in intentionally retained roots of teeth affected with tooth resorption type 2 in cats. Emphasis was placed on assessment of degree of resorption as well as the occurrence of inflammatory changes in tooth roots. The results confirm that crown amputation is an adequate treatment in cats for teeth affected by type 2 resorption.

  12. Hypergravity suppresses bone resorption in ovariectomized rats

    NASA Astrophysics Data System (ADS)

    Ikawa, Tesshu; Kawaguchi, Amu; Okabe, Takahiro; Ninomiya, Tadashi; Nakamichi, Yuko; Nakamura, Midori; Uehara, Shunsuke; Nakamura, Hiroaki; Udagawa, Nobuyuki; Takahashi, Naoyuki; Nakamura, Hiroaki; Wakitani, Shigeyuki

    2011-04-01

    The effects of gravity on bone metabolism are unclear, and little has been reported about the effects of hypergravity on the mature skeleton. Since low gravity has been shown to decrease bone volume, we hypothesized that hypergravity increases bone volume. To clarify this hypothesis, adult female rats were ovariectomized and exposed to hypergravity (2.9G) using a centrifugation system. The rats were killed 28 days after the start of loading, and the distal femoral metaphysis of the rats was studied. Bone architecture was assessed by micro-computed tomography (micro-CT) and bone mineral density was measured using peripheral quantitative CT (pQCT). Hypergravity increased the trabecular bone volume of ovariectomized rats. Histomorphometric analyses revealed that hypergravity suppressed both bone formation and resorption and increased bone volume in ovariectomized rats. Further, the cell morphology, activity, proliferation, and differentiation of osteoclasts and osteoblasts exposed to hypergravity were evaluated in vitro. Hypergravity inhibited actin ring formation in mature osteoclasts, which suggested that the osteoclast activity was suppressed. However, hypergravity had no effect on osteoblasts. These results suggest that hypergravity can stimulate an increase in bone volume by suppressing bone resorption in ovariectomized rats.

  13. Cytokine expression in feline osteoclastic resorptive lesions.

    PubMed

    DeLaurier, A; Allen, S; deFlandre, C; Horton, M A; Price, J S

    2002-01-01

    Feline osteoclastic resorptive lesions (FORL) of the teeth are common in cats, and lead to pain, destruction of the periodontal ligament, and tooth loss. The expression of interleukin (IL)-1 beta and IL-6 mRNA was higher in teeth with FORL than in normal teeth (P<0.01 and P<0.001, respectively), but no such differences were found between pathological and normal gingival tissue samples. There were no differences between teeth affected with FORL and normal teeth in respect of the expression of receptor activator of NF kappa B ligand (RANKL) mRNA or osteoprotegerin (OPG) mRNA. However, OPG mRNA expression was higher in gingival tissue associated with teeth affected with FORL than in normal gingival tissue (P<0.05), whereas the reverse was true of RANKL mRNA expression (P<0.05). OPG mRNA expression was significantly higher in teeth than in femoral and alveolar bone (P<0.001). RANKL and OPG mRNAs were detected in all tissues examined. The data suggest that the elevated expression of IL-l beta and IL-6 mRNA plays a role in the mediation of osteoclast activity in advanced FORL. In contrast, OPG and RANKL do not appear to regulate osteoclasts in advanced disease. The results also suggest that OPG and RANKL mRNA play a role in mediating inflammatory responses in gingival cells, and that OPG has an inhibiting effect on tooth resorption.

  14. Root resorption in bicuspid intrusion. A scanning electron microscope study.

    PubMed

    Harry, M R; Sims, M R

    1982-07-01

    Apical root surfaces covered by cellular cementum are rapidly subjected to resorption under orthodontic loads of varying magnitude and duration. Within the experimental parameters employed, the intrusive forces applied to the teeth produced a striking increase in root resorption compared with the control teeth. The amount of resorption increased markedly with the duration of the force, and to a lesser extent with the magnitude of the appliance activation. After 70 days, cellular cementum repair accompanied the continuing resorption. Little variation was detected in the susceptibility of different patients to root resorption in the experimental teeth. The same intrusive load applied for the same duration to similar teeth produced a corresponding degree of root resorption in various individuals. On the other hand, there were individual differences in the amount of resorption on untreated control teeth. There is a need to extent our understanding of the periodontal ligament and its associated tissues which provide the basis for our professional services. Clearly, root resorption and the capacity for repair are orthodontic facts of life. In the current climate of technological innovation great emphasis has been given to cephalometrics and appliance mechanics, which provide the orthodontist with the clinical stimulus of visual and tactile involvement. This paper is presented as a contribution to our knowledge of the unseen biological consequences which accompany that orthodontic treatment.

  15. Effect of bisphosphonates and gallium on dentin resorption in vitro.

    PubMed

    Liewehr, F R; Craft, D W; Primack, P D; Kulild, J C; Turgeon, D K; Sutherland, D E; Schuster, G S; Pashley, D H

    1995-02-01

    Replacement resorption may follow the replantation of an avulsed tooth. Currently there is no effective treatment for replacement resorption. The purpose of this study was to investigate the effect of bisphosphonates and gallium nitrate, which have been shown to reduce bone resorption, on cells which resorb dentin. Osteoclast-like cells were obtained by culturing cells from prenatal chick tibeas. These cells were seeded onto slices of human dentin which had been soaked in either saline (control), or solutions of 10(-5) M 1-hydroxyethylidene-1, 1-bisphosphonic acid (EHBP), 10(-6) M dichloromethylene bisphosphonic acid (Cl2MBP), or 10(-6) M gallium nitrate. Resorption was measured by counting the number of resorptive lacunae produced by the cells. Results indicated that the experimental groups did not differ significantly from each other, but each exhibited significantly reduced resorption compared with saline controls (p < 0.01). These results suggested that the experimental treatment reduced dentinal resorption by the osteoclast-like cells, and that these agents might be useful to prevent or at least postpone replacement resorption in avulsed teeth.

  16. Negative effects of fertilization on plant nutrient resorption.

    PubMed

    Yuan, Z Y; Chen, Han Y H

    2015-02-01

    Plants in infertile habitats are thought to have a high rate of nutrient resorption to enable them reuse nutrients more efficiently than those in fertile habitats. However, there is still much debate on how plant nutrient resorption responds to nutrient availability. Here we used a meta-analysis from a global data set of 9703 observations at 306 sites from 508 published articles to examine the effects of nitrogen (N) and phosphorus (P) fertilization on plant foliar N and P concentrations and resorption efficiency. We found that N fertilization enhanced N concentration in green leaves by 27% and P fertilization enhanced green-leaf P by 73% on average. The N and P concentrations in senesced leaves also increased with respective nutrient fertilization. Resorption efficiencies (percentage of nutrient recovered from senescing leaves) of both N and P declined in response to respective nutrient fertilization. Combined N and P fertilization also had negative effects on both N and P resorption efficiencies. Whether nutrient resorption efficiency differs among plant growth types and among ecosystems, however, remains uncertain due to the limited sample sizes when analyzed by plant growth types or ecosystem types. Our analysis indicates that fertilization decreases plant nutrient resorption and the view that nutrient resorption is a critical nutrient conservation strategy for plants in nutrient-poor environments cannot be abandoned. The response values to fertilization presented in our analysis can help improve biogeochemical models.

  17. Tooth resorption in the Swedish Eurasion lynx (Lynx lynx).

    PubMed

    Pettersson, Ann

    2010-01-01

    The etiology of tooth resorption in the domestic cat remains unknown. The high prevalence and progressive nature of the disease complicates defining healthy control groups. In order to evaluate the possible influence of various life style changes on the prevalence of tooth resorption, healthy control groups are a prerequisite. This paper presents a prevalence study for tooth resorption in a free-ranging wild felidae population. Skulls from 46 free-ranging Eurasian lynx (Lynx lynx) were examined. The age of the animals had previously been estimated based on cementum annuli in the maxillary right canine tooth. The dental examination included both dental probing and radiographic imaging. Complicated fractures of the canine teeth were found in 9/46 (19.5%) skulls. In one fractured canine, apical root resorption and periapical lucency was detected. The root resorption was attributed to inflammatory resorption as a consequence of the initial dental trauma and necrotic pulp. No signs of tooth resorption were found in the remaining teeth. Supernumerary roots were detected in 18/46 skulls (39.1 %). Supernumerary "peg" teeth caudal to the mandibular first molar tooth were detected in 6/46 (13.0%) skulls. Although further studies on dental ultra-structure are needed, the Swedish Eurasian lynx may, in the future, be useful as a healthy comparative model for studies on the etiopathogenesis of tooth resorption in the domestic cat.

  18. Clinical Management of Two Root Resorption Cases in Endodontic Practice

    PubMed Central

    2016-01-01

    Root resorption is a pathological process involving loss of hard dental tissues. It may occur as a consequence of dental trauma, orthodontic treatment, and bleaching, and occasionally it accompanies periodontal disease. Although the mechanism of resorption process is examined in detail, its etiology is not fully understood. Wide open apical foramen is more difficult to manage and the root canal may often overfill. In this report we present two cases of root resorption and describe means for its clinical management. We conclude that useful measure of a success or failure in managing root resorption is the persistence of the resorption process. It is a clear sign of an active ongoing inflammatory process and shows the clinical need for retreatment. PMID:27648314

  19. Clinical Management of Two Root Resorption Cases in Endodontic Practice.

    PubMed

    Mincik, Jozef; Urban, Daniel; Timkova, Silvia

    2016-01-01

    Root resorption is a pathological process involving loss of hard dental tissues. It may occur as a consequence of dental trauma, orthodontic treatment, and bleaching, and occasionally it accompanies periodontal disease. Although the mechanism of resorption process is examined in detail, its etiology is not fully understood. Wide open apical foramen is more difficult to manage and the root canal may often overfill. In this report we present two cases of root resorption and describe means for its clinical management. We conclude that useful measure of a success or failure in managing root resorption is the persistence of the resorption process. It is a clear sign of an active ongoing inflammatory process and shows the clinical need for retreatment.

  20. Feline tooth resorption in a colony of 109 cats.

    PubMed

    Girard, N; Servet, E; Biourge, V; Hennet, P

    2008-09-01

    The aim of the present study was to evaluate the prevalence of clinical and/or radiographic tooth resorption in a standardized population of 109 healthy cats fed dry diets, with specific emphasis on the mapping and typing of the lesions, as well as the influence of variables including breed, sex, and age. Prevalence of tooth resorption was significantly higher in pure-breed cats (70.0%) compared with mixed-breed cats (38.0%). A total of 290 tooth resorption lesions were diagnosed radiographically. For all lesions, 60.0% were Type 2 compared to 40.0% Type 1. There was an increased frequency of tooth resorption observed in older mixed breed-cats and female pure-breed cats. In conclusion, the current study demonstrated a strong breed influence (pure-breed vs. mixed-breed) on the prevalence of tooth resorption, as well as an uneven oral distribution with regard to mapping and typing characteristics.

  1. [Resorption of hydrocyanic acid from linseed].

    PubMed

    Schulz, V; Löffler, A; Gheorghiu, T

    1983-01-01

    Resorption of hydrocyanic acid after ingestion of linseed was investigated in 20 healthy volunteers and 5 patients. The persons investigated took a single dose of 30 g or of 100 g of linseed or they received throughout several weeks 15 g. t.i.d. One volunteer also took for purposes of comparison bitter almonds or potassium cyanide. Before, during and after the periods of ingestion plasma levels of hydrocyanic acid and of thiocyanate were normal. During long-term trials urinary excretion of thiocyanate was monitored regularly. Intake of linseed even in extremely high dosages never caused significant rises of plasma thiocyanate levels; this, however, was the case after intake of bitter almonds or potassium cyanide. Thus, it can be excluded, that intoxication by hydrocyanic acid can be caused by linseed. Long-term intake of linseed however, raised plasma levels of thiocyanate significantly; at the same time urinary excretion of thiocyanate increased.

  2. ['Door de beugel': resorption at dental elements].

    PubMed

    Leunisse, M; Barendrecht, D S

    2015-09-01

    A twenty-year-old man was referred to an orthodontist for orthodontic re-treatment of dental element 32 by his dentist and a periodontist. At the buccal surface of the dental element a significant gingival resorption had occurred and the root of the element was located outside of the processus alveolaris buccally. This case will be presented at the thematic tour 'Door de beugel: team up' on 27 October 2015, which is organised by the Nederlandse Vereniging van Tandartsen (Dutch Dentists' Society) and will be held at 4 different locations in the Netherlands. Readers of the Nederlands Tijdschrift voor Tandheelkunde get an exclusive preview of the case. The treatment of choice will be published in the December 2015 issue.

  3. Ectopic bone regeneration by human bone marrow mononucleated cells, undifferentiated and osteogenically differentiated bone marrow mesenchymal stem cells in beta-tricalcium phosphate scaffolds.

    PubMed

    Ye, Xinhai; Yin, Xiaofan; Yang, Dawei; Tan, Jian; Liu, Guangpeng

    2012-07-01

    Tissue engineering approaches using the combination of porous ceramics and bone marrow mesenchymal stem cells (BMSCs) represent a promising bone substitute for repairing large bone defects. Nevertheless, optimal conditions for constructing tissue-engineered bone have yet to be determined. It remains unclear if transplantation of predifferentiated BMSCs is superior to undifferentiated BMSCs or freshly isolated bone marrow mononucleated cells (BMNCs) in terms of new bone formation in vivo. The aim of this study was to investigate the effect of in vitro osteogenic differentiation (β-glycerophosphate, dexamethasone, and l-ascorbic acid) of human BMSCs on the capability to form tissue-engineered bone in unloaded conditions after subcutaneous implantation in nude mice. After isolation from human bone marrow aspirates, BMNCs were divided into three parts: one part was seeded onto porous beta-tricalcium phosphate ceramics immediately and transplanted in a heterotopic nude mice model; two parts were expanded in vitro to passage 2 before cell seeding and in vivo transplantation, either under osteogenic conditions or not. Animals were sacrificed for micro-CT and histological evaluation at 4, 8, 12, 16, and 20 weeks postimplantation. The results showed that BMSCs differentiated into osteo-progenitor cells after induction, as evidenced by the altered cell morphology and elevated alkaline phosphatase activity and calcium deposition, but their clonogenicity, proliferating rate, and seeding efficacy were not significantly affected by osteogenic differentiation, compared with undifferentiated cells. Extensive new bone formed in the pores of all the scaffolds seeded with predifferentiated BMSCs at 4 weeks after implantation, and maintained for 20 weeks. On the contrary, scaffolds containing undifferentiated BMSCs revealed limited bone formation only in 1 out of 6 cases at 8 weeks, and maintained for 4 weeks. For scaffolds with BMNCs, woven bone was observed sporadically only in one

  4. A practical approach for the validation of sterility, endotoxin and potency testing of bone marrow mononucleated cells used in cardiac regeneration in compliance with good manufacturing practice.

    PubMed

    Soncin, Sabrina; Lo Cicero, Viviana; Astori, Giuseppe; Soldati, Gianni; Gola, Mauro; Sürder, Daniel; Moccetti, Tiziano

    2009-09-08

    Main scope of the EU and FDA regulations is to establish a classification criterion for advanced therapy medicinal products (ATMP). Regulations require that ATMPs must be prepared under good manufacturing practice (GMP). We have validated a commercial system for the determination of bacterial endotoxins in compliance with EU Pharmacopoeia 2.6.14, the sterility testing in compliance with EU Pharmacopoeia 2.6.1 and a potency assay in an ATMP constituted of mononucleated cells used in cardiac regeneration. For the potency assay, cells were placed in the upper part of a modified Boyden chamber containing Endocult Basal Medium with supplements and transmigrated cells were scored. The invasion index was expressed as the ratio between the numbers of invading cells relative to cell migration through a control insert membrane. For endotoxins, we used a commercially available system based on the kinetic chromogenic LAL-test. Validation of sterility was performed by direct inoculation of TSB and FTM media with the cell product following Eu Ph 2.6.1 guideline. The calculated MVD and endotoxin limit were 780x and 39 EU/ml respectively. The 1:10 and 1:100 dilutions were selected for the validation. For sterility, all the FTM cultures were positive after 3 days. For TSB cultures, Mycetes and B. subtilis were positive after 5 and 3 days respectively. The detection limit was 1-10 colonies. A total of four invasion assay were performed: the calculated invasion index was 28.89 +/- 16.82% (mean +/- SD). We have validated a strategy for endotoxin, sterility and potency testing in an ATMP used in cardiac regeneration. Unlike pharmaceutical products, many stem-cell-based products may originate in hospitals where personnel are unfamiliar with the applicable regulations. As new ATMPs are developed, the regulatory framework is likely to evolve. Meanwhile, existing regulations provide an appropriate structure for ensuring the safety and efficacy of the next generation of ATMPs. Personnel

  5. Novel use of a Dektak 150 surface profiler unmasks differences in resorption pit profiles between control and Charcot patient osteoclasts.

    PubMed

    Petrova, Nina L; Petrov, Peter K; Edmonds, Michael E; Shanahan, Catherine M

    2014-04-01

    We hypothesized that newly formed osteoclasts from patients with acute Charcot osteoarthropathy can resorb surfaces of bone more extensively compared with controls. Peripheral blood monocytes, isolated from eight Charcot patients and nine controls, were cultured in vitro on 24-well plates and bovine bone discs in duplicate with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor κβ ligand (RANKL). Osteoclast formation was assessed by tartrate-resistant acid phosphatase staining (TRAcP) at day 17. Resorption was measured at day 21 after toluidine blue staining by two methods: (1) area of resorption at the surface by image analysis (%) and (2) area of resorption under the surface (μm(2)) measured by a Dektak 150 Surface Profiler. Ten 1,000 μm-long scans were performed per disc. Pits were classified as unidented, bidented, and multidented according to their shape. Although the number of newly formed TRAcP positive multinucleated cells (>3 nuclei) was similar in M-CSF + RANKL-treated cultures between controls and Charcot patients, the latter exhibited increased resorbing activity. The area of resorption on the surface by image analysis was significantly greater in Charcot patients compared with controls (21.1 % [14.5-26.2] vs. 40.8 % [35.4-46.0], median [25-75th percentile], p < 0.01), as was the area of resorption under the surface (2.7 x 10(3) μm(2) [1.6 x 10(3)- 3.9 x 10(3)] vs. 8.3 x 10(3) μm (2) [5.6 x 10(3)- 10.6 x 10(3), [corrected] p < 0.01) after profilometry. In Charcot patients pits were deeper and wider and more frequently presented as multidented pits. This application of the Dektak 150 Surface Profiler revealed novel differences in resorption pit profile from osteoclasts derived from Charcot patients compared with controls. Resorption in Charcot patients was mediated by highly aggressive newly formed osteoclasts from monocytes eroding large and deep areas of bone.

  6. Orthodontic aligners and root resorption: A systematic review.

    PubMed

    Elhaddaoui, Rajae; Qoraich, Halima Saadia; Bahije, Loubna; Zaoui, Fatima

    2017-03-01

    Root resorption is one of the leading problems in orthodontic treatment. Most earlier studies have assessed the incidence and severity of root resorption following orthodontic treatment using fixed appliances as well as associated factors. However, few studies have assessed these parameters in the context of orthodontic treatment using thermoplastic splints or aligners. The aim of this systematic review was to assess the incidence and severity of root resorption following orthodontic treatment using aligners and associated factors. A comparative analysis was also made with fixed multi-bracket treatments. The data bases consulted were: Medline, Embase, EBSCO Host, Cochrane Library and Science Direct. Our search included meta-analyses, randomized and non-randomized controled trials, cohort studies and descriptive studies published before December 2015 and evidencing a connection with the incidence and severity of root resorption following orthodontic treatment using aligners alone or compared with fixed multi-bracket treatments. Among the 93 selected references, only 3 studies met our selection criteria. The incidence of root resorption ranged between 0 and 46%, of which 6% were severe cases. Relative to fixed multi-bracket non-extraction treatments to correct the same malocclusions, the incidence of resorption ranged between 2% and 50%, of which 22% were severe cases. In both techniques, the incidence of resorption was higher for the maxillary incisors and was not influenced by either age or sex. In malocclusion cases not requiring extractions, orthodontic aligner treatment is possibly associated with a lower incidence of resorption than fixed multi-bracket treatment. Further research encompassing extraction cases is needed to better assess the incidence and severity of root resorption following the use of these removable appliances. Copyright © 2016 CEO. Published by Elsevier Masson SAS. All rights reserved.

  7. Tumour macrophages as potential targets of bisphosphonates

    PubMed Central

    2011-01-01

    Tumour cells communicate with the cells of their microenvironment via a series of molecular and cellular interactions to aid their progression to a malignant state and ultimately their metastatic spread. Of the cells in the microenvironment with a key role in cancer development, tumour associated macrophages (TAMs) are among the most notable. Tumour cells release a range of chemokines, cytokines and growth factors to attract macrophages, and these in turn release numerous factors (e.g. VEGF, MMP-9 and EGF) that are implicated in invasion-promoting processes such as tumour cell growth, flicking of the angiogenic switch and immunosuppression. TAM density has been shown to correlate with poor prognosis in breast cancer, suggesting that these cells may represent a potential therapeutic target. However, there are currently no agents that specifically target TAM's available for clinical use. Bisphosphonates (BPs), such as zoledronic acid, are anti-resorptive agents approved for treatment of skeletal complication associated with metastatic breast cancer and prostate cancer. These agents act on osteoclasts, key cells in the bone microenvironment, to inhibit bone resorption. Over the past 30 years this has led to a great reduction in skeletal-related events (SRE's) in patients with advanced cancer and improved the morbidity associated with cancer-induced bone disease. However, there is now a growing body of evidence, both from in vitro and in vivo models, showing that zoledronic acid can also target tumour cells to increase apoptotic cell death and decrease proliferation, migration and invasion, and that this effect is significantly enhanced in combination with chemotherapy agents. Whether macrophages in the peripheral tumour microenvironment are exposed to sufficient levels of bisphosphonate to be affected is currently unknown. Macrophages belong to the same cell lineage as osteoclasts, the major target of BPs, and are highly phagocytic cells shown to be sensitive to

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

    PubMed

    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 < 0.01) in a dose dependent manner. These results suggest that vitamins K1, MK-4 and MK-7 have anti-osteoporotic properties, while their regulation effects on osteoclastogenesis are somewhat different.

  9. Multiple idiopathic external apical root resorption: A rare case report

    PubMed Central

    Bansal, Parul; Nikhil, Vineeta; Kapur, Sonali

    2015-01-01

    Multiple idiopathic external apical root resorption (MIEARR) is a relatively rare condition affecting multiple teeth in a dentition. As the condition is nonsymptomatic, a case is usually detected as an incidental radiographic finding. However, it may cause pain and mobility in severe cases. It is sometimes self-limiting or sometimes may progress to tooth loss. This paper presents a case of external apical root resorption involving multiple teeth in which etiology was not identified, so idiopathic root resorption was considered as a diagnosis of exclusion. PMID:25657532

  10. Prevalence of dental resorptive lesions in Swedish cats.

    PubMed

    Pettersson, A; Mannerfelt, T

    2003-09-01

    Ninety-six, randomly selected Swedish cats were evaluated for the presence of dental resorptive lesions. All cats were examined while receiving general anesthesia. Diagnosis was based on oral examination and full-mouth, intraoral dental radiographs. Information concerning age, sex, vaccination status, eating habits, food type, environment (indoor or outdoor housing), oral, discomfort, dental care, and medical treatment was recorded. Hematologic samples included analysis for FeLV, FIV, and calcivirus. Of the cats examined in this study, 32% had gross or radiographic signs of dental resorptive lesions. There was a positive relationship between the occurrence of dental resorptive lesions and increasing age.

  11. Experiment K-317: Bone resorption in rats during spaceflight

    NASA Technical Reports Server (NTRS)

    Cann, C. E.; Adachi, R. R.

    1981-01-01

    Direct measurement of bone resorption in flight and synchronous control rats is described. Continuous tracer administration techniques were used, with replacement of dietary calcium with isotopically enriched Ca40 and measurement by neutron activation analysis of the Ca48 released by the skeleton. There is no large change in bone resorption in rats. Based on the time course of changes, the measured 20-25% decrease in resorption is probably secondary to a decrease in total body calcium turnover. The excretion of sodium, potassium and zinc all increase during flight, sodium and potassium to a level 4-5 times control values.

  12. Experiment K-317: Bone resorption in rats during spaceflight

    NASA Technical Reports Server (NTRS)

    Cann, C. E.; Adachi, R. R.

    1981-01-01

    Direct measurement of bone resorption in flight and synchronous control rats is described. Continuous tracer administration techniques were used, with replacement of dietary calcium with isotopically enriched Ca40 and measurement by neutron activation analysis of the Ca48 released by the skeleton. There is no large change in bone resorption in rats. Based on the time course of changes, the measured 20-25% decrease in resorption is probably secondary to a decrease in total body calcium turnover. The excretion of sodium, potassium and zinc all increase during flight, sodium and potassium to a level 4-5 times control values.

  13. Effect of Pasteurella multocida toxin on bone resorption in vitro.

    PubMed Central

    Felix, R; Fleisch, H; Frandsen, P L

    1992-01-01

    Pasteurella multocida toxin (PMT), which is the primary etiologic factor in the pathogenesis of progressive atrophic rhinitis in pigs, was found to stimulate bone resorption in vitro. This stimulation was observed both in cultures of murine calvaria by measuring the release of calcium and of the lysosomal enzyme beta-glucuronidase and in murine long bone cultures by measuring the release of calcium. Both systems showed the same dose response curve, with the maximal effect at a concentration of 5 ng/ml. The effect on calvaria was studied in more detail. PMT increased bone resorption 24 h after its addition and always had to be present to express an effect. Calcitonin was able to inhibit this increase of resorption completely, and inhibitors of prostaglandin synthesis suppressed it partially. Although the data show an effect of PMT on bone tissue, the results do not exclude an action on cells in the nasal cavity, which could indirectly stimulate bone resorption. PMID:1452328

  14. Osteoclastic resorption of biomimetic calcium phosphate coatings in vitro.

    PubMed

    Leeuwenburgh, S; Layrolle, P; Barrère, F; de Bruijn, J; Schoonman, J; van Blitterswijk, C A; de Groot, K

    2001-08-01

    A new biomimetic method for coating metal implants enables the fast formation of dense and homogeneous calcium phosphate coatings. Titanium alloy (Ti6Al4V) disks were coated with a thin, carbonated, amorphous calcium phosphate (ACP) by immersion in a saturated solution of calcium, phosphate, magnesium, and carbonate. The ACP-coated disks then were processed further by incubation in calcium phosphate solutions to produce either crystalline carbonated apatite (CA) or octacalcium phosphate (OCP). The resorption behavior of these three biomimetic coatings was studied using osteoclast-enriched mouse bone-marrow cell cultures for 7 days. Cell-mediated degradation was observed for both carbonated apatite and octacalcium phosphate coatings. Numerous resorption lacunae characteristic of osteoclastic resorption were found on carbonated apatite after cell culture. The results showed that carbonated apatite coatings are resorbed by osteoclasts in a manner consistent with normal osteoclastic resorption. Osteoclasts also degraded the octacalcium phosphate coatings but not by classical pit formation.

  15. Cyclic hydrostatic pressure and particles increase synthesis of 1,25-dihydroxyvitamin D3 by human macrophages in vitro.

    PubMed

    Evans, C E; Mylchreest, S; Mee, A P; Berry, J L; Andrew, J G

    2006-01-01

    1,25-Dihydroxyvitamin D(3) has a pivotal role in bone resorption and osteoclast activity. As activated macrophages are known to synthesise 1,25-dihydroxyvitamin D(3), this study examined whether pressure modulated its synthesis. Pressure and particles have been shown to increase synthesis of pro-resorptive cytokines and other factors by cultured macrophages. Human peripheral blood macrophages were isolated, cultured and exposed to pressure (similar to that found in the human joint) and/or particles. Synthesis of 1,25-dihydroxyvitamin D(3) by macrophages was assayed using high pressure liquid chromatography and in situ hybridization. Synthesis of 1,25-dihydroxyvitamin D(3) but not 24,25-dihydroxyvitamin D(3) was increased in macrophages under pressure. In situ hybridization demonstrated an increase in 1alpha-hydroxylase expression in response to pressure or particles and simultaneous exposure to both stimuli generated higher expression of 1alpha-hydroxylase. In conclusion, this is the first study to demonstrate that mechanical loading, in the form of pressure, stimulates 1,25-dihydroxyvitamin D(3) synthesis in human macrophages. These findings have implications for the in vivo situation, as they suggest that 1,25-dihydroxyvitamin D(3) could be one factor stimulating osteoclastic bone resorption in pathologies, such as arthritis or implant loosening, where intra-articular or intra-osseous pressure is raised or where wear particles interact with macrophages.

  16. Artesunate Inhibits RANKL-induced Osteoclastogenesis and Bone Resorption In Vitro and Prevents LPS-induced Bone Loss In Vivo.

    PubMed

    Wei, Cheng-Ming; Liu, Qian; Song, Fang-Ming; Lin, Xi-Xi; Su, Yi-Ji; Xu, Jiake; Huang, Lin; Zong, Shao-Hui; Zhao, Jin-Min

    2017-03-15

    Osteoclasts are multinuclear giant cells responsible for bone resorption in lytic bone diseases such as osteoporosis, arthritis, periodontitis, and bone tumors. Due to the severe side-effects caused by the currently available drugs, a continuous search for novel bone-protective therapies is essential. Artesunate (Art), the water-soluble derivative of artemisinin has been investigated owing to its anti-malarial properties. However, its effects in osteoclastogenesis have not yet been reported. In this study, Art was shown to inhibit the nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis, the mRNA expression of osteoclastic-specific genes, and resorption pit formation in a dose-dependent manner in primary bone marrow-derived macrophages cells (BMMs). Furthermore, Art markedly blocked the RANKL-induced osteoclastogenesis by attenuating the degradation of IκB and phosphorylation of NF-κB p65. Consistent with the in vitro results, Art inhibited lipopolysaccharide (LPS)-induced bone resorption by suppressing the osteoclastogenesis. Together our data demonstrated that Art inhibits RANKL-induced osteoclastogenesis by suppressing the NF-κB signaling pathway and that it is a promising agent for the treatment of osteolytic diseases. This article is protected by copyright. All rights reserved.

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

    PubMed Central

    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

  18. Cell-based resorption assays for bone graft substitutes.

    PubMed

    Zhang, Ziyang; Egaña, José T; Reckhenrich, Ann K; Schenck, Thilo Ludwig; Lohmeyer, Jörn A; Schantz, Jan Thorsten; Machens, Hans-Günther; Schilling, Arndt F

    2012-01-01

    The clinical utilization of resorbable bone substitutes has been growing rapidly during the last decade, creating a rising demand for new resorbable biomaterials. An ideal resorbable bone substitute should not only function as a load-bearing material but also integrate into the local bone remodeling process. This means that these bone substitutes need to undergo controlled resorption and then be replaced by newly formed bone structures. Thus the assessment of resorbability is an important first step in predicting the in vivo clinical function of bone substitute biomaterials. Compared with in vivo assays, cell-based assays are relatively easy, reproducible, inexpensive and do not involve the suffering of animals. Moreover, the discovery of RANKL and M-CSF for osteoclastic differentiation has made the differentiation and cultivation of human osteoclasts possible and, as a result, human cell-based bone substitute resorption assays have been developed. In addition, the evolution of microscopy technology allows advanced analyses of the resorption pits on biomaterials. The aim of the current review is to give a concise update on in vitro cell-based resorption assays for analyzing bone substitute resorption. For this purpose models using different cells from different species are compared. Several popular two-dimensional and three-dimensional optical methods used for resorption assays are described. The limitations and advantages of the current ISO degradation assay in comparison with cell-based assays are discussed.

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

    PubMed Central

    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

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

    PubMed

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

    2015-09-30

    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.

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

    PubMed

    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 (RANK (Tg) 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.

  2. Bone resorption and remodeling in murine collagenase-induced osteoarthritis after administration of glucosamine

    PubMed Central

    2011-01-01

    Introduction Glucosamine is an amino-monosaccharide and precursor of glycosaminoglycans, major components of joint cartilage. Glucosamine has been clinically introduced for the treatment of osteoarthritis but the data about its protective role in disease are insufficient. The goal of this study was to investigate the effect of long term administration of glucosamine on bone resorption and remodeling. Methods The effect of glucosamine on bone resorption and remodeling was studied in a model of collagenase-induced osteoarthritis (CIOA). The levels of macrophage-inflammatory protein (MIP)-1α, protein regulated upon activation, normal T-cell expressed, and secreted (RANTES), soluble receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor (TNF)-α, and interleukin (IL)-6, 4 and 10 in synovial fluid were measured by enzyme-linked immunosorbent assay (ELISA). Cell populations in synovial extracts and the expression of RANKL, of receptors for TNF-α (TNF-αR) and interferon γ (IFN-γR) on clusters of differentiation (CD) three positive T cells were analyzed by flow cytometry. Transforming growth factor (TGF)-β3, bone morphogenetic protein (BMP)-2, phosphorylated protein mothers against decapentaplegic homolog 2 (pSMAD-2), RANKL and Dickkopf-1 protein (DKK-1) positive staining in CIOA joints were determined by immunohistochemistry. Results The administration of glucosamine hydrochloride in CIOA mice inhibited loss of glycosaminoglycans (GAGs) and proteoglycans (PGs) in cartilage, bone erosion and osteophyte formation. It decreased the levels of soluble RANKL and IL-6 and induced IL-10 increase in the CIOA joint fluids. Glucosamine limited the number of CD11b positive Ly6G neutrophils and RANKL positive CD3 T cells in the joint extracts. It suppressed bone resorption via down-regulation of RANKL expression and affected bone remodeling in CIOA by decreasing BMP-2, TGF-β3 and pSMAD-2 expression and up-regulating DKK-1 joint levels. Conclusions

  3. In vivo resorption of a biodegradable polyurethane foam, based on 1,4-butanediisocyanate: a three-year subcutaneous implantation study.

    PubMed

    van Minnen, B; van Leeuwen, M B M; Kors, G; Zuidema, J; van Kooten, T G; Bos, R R M

    2008-06-15

    Degradable polyurethanes (PUs), based on aliphatic diisocyanates, can be very useful in tissue regeneration applications. Their long-term in vivo degradation has not been extensively investigated. In this study a biodegradable PU with copolyester soft segments of DL-lactide/epsilon-caprolactone and hard segments synthesized from 1,4-butanediisocyanate was evaluated with regard to tissue response during degradation and, ultimately, the resorption of the material. Highly porous PU foam discs were subcutaneously implanted in rats and rabbits for intervals up to 3 years. A copolymer foam of DL-lactide and epsilon-caprolactone served as a control. The foams, the surrounding tissues and the draining lymph nodes were evaluated with light and electron microscopy. In the first stages of degradation the number of macrophages and giant cells increased. As the resorption stage set in their numbers gradually decreased. Electron microscopy showed macrophages containing pieces of PU. The size of the intracellular PU particles diminished and cells containing these remnants gradually disappeared after periods from 1 to 3 years. After 3 years an occasional, isolated macrophage with biomaterial remnants could be traced in both PU and copolymer explants. Single macrophages with biomaterial remnants were observed in the lymph nodes between 39 weeks and 1.5 years following implantation. It is concluded that the PU foam is biocompatible during degradation. After 3 years PU samples had been resorbed almost completely. These results indicate that the PU foam can be safely used as a biodegradable implant.

  4. Physiologic root resorption in primary teeth: molecular and histological events.

    PubMed

    Harokopakis-Hajishengallis, Evlambia

    2007-03-01

    Root resorption is a physiologic event for the primary teeth. It is still unclear whether odontoclasts, the cells which resorb the dental hard tissue, are different from the osteoclasts, the cells that resorb bone. Root resorption seems to be initiated and regulated by the stellate reticulum and the dental follicle of the underlying permanent tooth via the secretion of stimulatory molecules, i.e. cytokines and transcription factors. The primary root resorption process is regulated in a manner similar to bone remodeling, involving the same receptor ligand system known as RANK/RANKL (receptor activator of nuclear factor-kappa B/ RANK Ligand). Primary teeth without a permanent successor eventually exfoliate as well, but our current understanding on the underlying mechanism is slim. The literature is also vague on how resorption of the pulp and periodontal ligament of the primary teeth occurs. Knowledge on the mechanisms involved in the physiologic root resorption process may enable us to delay or even inhibit exfoliation of primary teeth in those cases that the permanent successor teeth are not present and thus preservation of the primary teeth is desirable.

  5. Deciduous canine and permanent lateral incisor differential root resorption.

    PubMed

    Davies, K R; Schneider, G B; Southard, T E; Hillis, S L; Wertz, P W; Finkelstein, M; Hogan, M M

    2001-10-01

    When a permanent maxillary canine erupts apical to the permanent lateral incisor and the deciduous canine, resorption typically takes place only on the deciduous canine root. An understanding of this differential resorption could provide insight into the reasons for excessive iatrogenic root resorption during orthodontic tooth movement. The purpose of the present study was to examine the response of roots of permanent lateral incisors and deciduous canines to simulated resorption, and to acid and enzyme attack, reflecting the physiologic environment of an erupting permanent canine. Groups of maxillary permanent lateral incisor and deciduous canine roots were exposed to 5 combinations of Ten Cate demineralizing solution, Ten Cate demineralizing solution with EDTA, and a Type I collagenase solution. Sections of the roots were examined under a polarized light microscope. Analysis of variation of the resulting root lesions demonstrated that the lesion depths for deciduous canines were greater than those for permanent lateral incisors when averaged across 4 of the conditions (F(1,24) = 7.49, P =.0115). On average, deciduous canine roots demonstrated lesions 10% deeper than did permanent lateral incisor roots. We concluded that when deciduous canine and permanent lateral incisor roots are subjected to acid and enzyme attack, reflecting the physiologic environment of an erupting permanent canine, significantly deeper demineralized lesions are seen in the deciduous roots compared with the permanent roots. This finding may partially explain the differential root resorption during permanent tooth eruption.

  6. Commercial Honeybush (Cyclopia spp.) Tea Extract Inhibits Osteoclast Formation and Bone Resorption in RAW264.7 Murine Macrophages—An in vitro Study

    PubMed Central

    Visagie, Amcois; Kasonga, Abe; Deepak, Vishwa; Moosa, Shaakirah; Marais, Sumari; Kruger, Marlena C.; Coetzee, Magdalena

    2015-01-01

    Honeybush tea, a sweet tasting caffeine-free tea that is indigenous to South Africa, is rich in bioactive compounds that may have beneficial health effects. Bone remodeling is a physiological process that involves the synthesis of bone matrix by osteoblasts and resorption of bone by osteoclasts. When resorption exceeds formation, bone remodeling can be disrupted resulting in bone diseases such as osteoporosis. Osteoclasts are multinucleated cells derived from hematopoietic precursors of monocytic lineage. These precursors fuse and differentiate into mature osteoclasts in the presence of receptor activator of NF-kB ligand (RANKL), produced by osteoblasts. In this study, the in vitro effects of an aqueous extract of fermented honeybush tea were examined on osteoclast formation and bone resorption in RAW264.7 murine macrophages. We found that commercial honeybush tea extract inhibited osteoclast formation and TRAP activity which was accompanied by reduced bone resorption and disruption of characteristic cytoskeletal elements of mature osteoclasts without cytotoxicity. Furthermore, honeybush tea extract decreased expression of key osteoclast specific genes, matrix metalloproteinase-9 (MMP-9), tartrate resistant acid phosphatase (TRAP) and cathepsin K. This study demonstrates for the first time that honeybush tea may have potential anti-osteoclastogenic effects and therefore should be further explored for its beneficial effects on bone. PMID:26516894

  7. Substance P stimulates bone marrow stromal cell osteogenic activity, osteoclast differentiation, and resorption activity in vitro

    PubMed Central

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

    2009-01-01

    Introduction SP is a neuropeptide distributed in the sensory nerve fibers that innervate the medullar tissues of bone, as well as the periosteum. Previously we demonstrated that inhibition of neuropeptide signaling after capsaicin treatment resulted in a loss of bone mass and we hypothesized that SP contributes to bone integrity by stimulating osteogenesis. Materials and Methods Osteoblast precursors (bone marrow stromal cells, BMSCs) and osteoclast precursors (bone marrow macrophages, BMMs) derived from C57BL/6 mice were cultured. Expression of the SP receptor (NK1) was detected by using immunocytochemical staining and PCR. Effects of SP on proliferation and differentiation of BMSCs were studied by measuring BrdU incorporation, gene expression, alkaline phosphatase activity, and osteocalcin and Runx2 protein levels with EIA and western blot assays, respectively. Effects of SP on BMMs were determined using a BrdU assay, counting multinucleated cells staining positive for tartrate-resistant acid phosphatase (TRAP+), measuring pit erosion area, and evaluating RANKL protein production and NF-κB activity with ELISA and western blot. Results The NK1 receptor was expressed in both BMSCs and BMMs. SP stimulated the proliferation of BMSCs in a concentration-dependent manner. Low concentrations (10−12 M) of SP stimulated alkaline phosphatase and osteocalcin expression, increased alkaline phosphatase activity, and up-regulated Runx2 protein levels, and higher concentrations of SP (10−8 M) enhanced mineralization in differentiated BMSCs. SP also stimulated BMSCs to produce RANKL, but at concentrations too low to evoke osteoclastogenesis in co-culture with macrophages in the presence of SP. SP also activated NF-κB in BMMs and directly facilitate RANKL induced macrophage osteoclastogenesis and bone resorption activity. Conclusions NK1 receptors are expressed by osteoblast and osteoclast precursors and SP stimulates osteoblast and osteoclast differentiation and function in

  8. Kcnn4 Is a Regulator of Macrophage Multinucleation in Bone Homeostasis and Inflammatory Disease

    PubMed Central

    Kang, Heeseog; Kerloc’h, Audrey; Rotival, Maxime; Xu, Xiaoqing; Zhang, Qing; D’Souza, Zelpha; Kim, Michael; Scholz, Jodi Carlson; Ko, Jeong-Hun; Srivastava, Prashant K.; Genzen, Jonathan R.; Cui, Weiguo; Aitman, Timothy J.; Game, Laurence; Melvin, James E.; Hanidu, Adedayo; Dimock, Janice; Zheng, Jie; Souza, Donald; Behera, Aruna K.; Nabozny, Gerald; Cook, H. Terence; Bassett, J.H. Duncan; Williams, Graham R.; Li, Jun; Vignery, Agnès; Petretto, Enrico; Behmoaras, Jacques

    2014-01-01

    Summary Macrophages can fuse to form osteoclasts in bone or multinucleate giant cells (MGCs) as part of the immune response. We use a systems genetics approach in rat macrophages to unravel their genetic determinants of multinucleation and investigate their role in both bone homeostasis and inflammatory disease. We identify a trans-regulated gene network associated with macrophage multinucleation and Kcnn4 as being the most significantly trans-regulated gene in the network and induced at the onset of fusion. Kcnn4 is required for osteoclast and MGC formation in rodents and humans. Genetic deletion of Kcnn4 reduces macrophage multinucleation through modulation of Ca2+ signaling, increases bone mass, and improves clinical outcome in arthritis. Pharmacological blockade of Kcnn4 reduces experimental glomerulonephritis. Our data implicate Kcnn4 in macrophage multinucleation, identifying it as a potential therapeutic target for inhibition of bone resorption and chronic inflammation. PMID:25131209

  9. Association between non-enzymatic glycation, resorption, and microdamage in human tibial cortices.

    PubMed

    Ural, Ani; Janeiro, Colleen; Karim, Lamya; Diab, Tamim; Vashishth, Deepak

    2015-03-01

    To better understand the association between different components of bone quality, we investigated the relationship among in vivo generated non-enzymatic glycation, resorption, and microdamage. The results showed negative correlation between advanced glycation end-products (AGEs) and resorption independent of age highlighting the interaction between these parameters that may lead to bone fragility. Changes in the quality of bone material contribute significantly to bone fragility. In order to establish a better understanding of the interaction of the different components of bone quality and their influence on bone fragility, we investigated the relationship between non-enzymatic glycation, resorption, and microdamage generated in vivo in cortical bone using bone specimens from the same donors. Total fluorescent advanced glycation end-products (AGEs) were measured in 96 human cortical bone samples from 83 donors. Resorption pit density, average resorption pit area, and percent resorption area were quantified in samples from 48 common donors with AGE measurements. Linear microcrack density and diffuse damage were measured in 21 common donors with AGE and resorption measurements. Correlation analyses were performed between all measured variables to establish the relationships among them and their variation with age. We found that average resorption pit area and percent resorption area decreased with increasing AGEs independently of age. Resorption pit density and percent resorption area demonstrated negative age-adjusted correlation with diffuse damage. Furthermore, average resorption pit area, resorption pit density, and percent resorption area were found to decrease significantly with age. The current study demonstrated the in vivo interrelationship between the organic constituents, remodeling, and damage formation in cortical bone. In addition to the age-related reduction in resorption, there is a negative correlation between AGEs and resorption independent of age

  10. Bone resorption and mineral excretion in rats during spaceflight

    NASA Technical Reports Server (NTRS)

    Cann, C. E.; Adachi, R. R.

    1983-01-01

    Bone resorption was measured directly in flight and synchronous control rats during COSMOS 1129. Continuous tracer administration techniques were used, with replacement of dietary calcium with isotopically enriched Ca-40 and measurement by neutron activation analysis of the Ca-48 released by the skeleton. There is no large change in bone resorption in rats at the end of 20 days of spaceflight as has been found for bone formation. Based on the time course of changes, the measured 20-25 percent decrease in resorption is probably secondary to a decrease in total body calcium turnover. The excretion of sodium, potassium, and zinc all increase during flight, sodium and potassium to a level four to five times control values.

  11. Management of Root Resorption Using Chemical Agents: A Review

    PubMed Central

    Mohammadi, Zahed; C. Cehreli, Zafer; Shalavi, Sousan; Giardino, Luciano; Palazzi, Flavio; Asgary, Saeed

    2016-01-01

    Root resorption (RR) is defined as the loss of dental hard tissues because of clastic activity inside or outside of tooth the root. In the permanent dentition, RR is a pathologic event; if untreated, it might result in the premature loss of the affected tooth. Several hypotheses have been suggested as the mechanisms of root resorption such as absence of the remnants of Hertwig's epithelial root sheath (HERS) and the absence of some intrinsic factors in cementum and predentin such as amelogenin or osteoprotegerin (OPG). It seems that a barrier is formed by the less-calcified intermediate cementum or the cementodentin junction that prevents external RR. There are several chemical strategies to manage root resorption. The purpose of this paper was to review several chemical agents to manage RR such as tetracycline, sodium hypochlorite, acids (citric acid, phosphoric acid, ascorbic acid and hydrochloric acid), acetazolamide, calcitonin, alendronate, fluoride, Ledermix and Emdogain. PMID:26843869

  12. In Vitro Osteoclastogenesis and Bone Resorption are Increased During Spaceflight

    NASA Astrophysics Data System (ADS)

    Di Benedetto, A.; Camerino, C.; Tamma, R.; Colaianni, G.; Greco, G.; Strippoli, M.; Vergari, R.; Grano, A.; Zallone, A.

    2008-06-01

    During space exploration, astronauts are exposed to the microgravity environment, which has an immediate impact on many biological systems. Osteoporosis-like bone mass loss is one of the most significant effects of microgravity, ranging around 1-2% reduction per month in flight. An uncoupling of bone remodeling could be responsible for this process. Human data showed a 38% decrease in bone formation serum markers and up to 78% increase in bone resorption markers during flights. We investigated the biological role of osteoclasts in microgravity-induced bone loss and participated to FOTON M3 ESA Mission in September 2007. We studied osteoclast differentiation from mouse-derived isolated monocyte precursors and bone resorption by mature osteoclast, and found that microgravity directly stimulates osteoclastogenesis and increases bone resorption. These evidences indicate osteoclast as a direct target of mechanical forces and further address future studies to the understanding the cellular and molecular mechanisms of osteoclast behavior in microgravity.

  13. Podosome organization drives osteoclast-mediated bone resorption

    PubMed Central

    Georgess, Dan; Machuca-Gayet, Irma; Blangy, Anne; Jurdic, Pierre

    2014-01-01

    Osteoclasts are the cells responsible for physiological bone resorption. A specific organization of their most prominent cytoskeletal structures, podosomes, is crucial for the degradation of mineralized bone matrix. Each podosome is constituted of an F-actin-enriched central core surrounded by a loose F-actin network, called the podosome cloud. In addition to intrinsic actin dynamics, podosomes are defined by their adhesion to the extracellular matrix, mainly via core-linking CD44 and cloud-linking integrins. These properties allow podosomes to collectively evolve into different patterns implicated in migration and bone resorption. Indeed, to resorb bone, osteoclasts polarize, actively secrete protons, and proteases into the resorption pit where these molecules are confined by a podosome-containing sealing zone. Here, we review recent advancements on podosome structure and regulatory pathways in osteoclasts. We also discuss the distinct functions of different podosome patterns during the lifespan of a single osteoclast. PMID:24714644

  14. Bone resorption and mineral excretion in rats during spaceflight

    NASA Technical Reports Server (NTRS)

    Cann, C. E.; Adachi, R. R.

    1983-01-01

    Bone resorption was measured directly in flight and synchronous control rats during COSMOS 1129. Continuous tracer administration techniques were used, with replacement of dietary calcium with isotopically enriched Ca-40 and measurement by neutron activation analysis of the Ca-48 released by the skeleton. There is no large change in bone resorption in rats at the end of 20 days of spaceflight as has been found for bone formation. Based on the time course of changes, the measured 20-25 percent decrease in resorption is probably secondary to a decrease in total body calcium turnover. The excretion of sodium, potassium, and zinc all increase during flight, sodium and potassium to a level four to five times control values.

  15. Peculiarities of the bone tissue resorption under microgravity conditions

    NASA Astrophysics Data System (ADS)

    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.

  16. Two-photon laser scanning microscopy as a useful tool for imaging and evaluating macrophage-, IL-4 activated macrophage- and osteoclast-based in vitro degradation of beta-tricalcium phosphate bone substitute material.

    PubMed

    Duarte Campos, Daniela F; Vogt, Michael; Lindner, Markus; Kirsten, Armin; Weber, Michael; Megens, Remco T A; Pyta, Jürgen; Zenke, Martin; Van Zandvoort, Marc; Fischer, Horst

    2014-02-01

    Two-photon microscopy is an innovative technology that has high potential to combine the examination of soft and hard tissues in vitro and in vivo. Calcium phosphates are widely used substitutes for bone tissue engineering, since they are degradable and consequently replaced by newly formed tissue. It is well known that osteoclasts are responsible for the resorption processes during bone remodelling. We hypothesize that also macrophages are actively involved in the resorption process of calcium phosphate scaffolds and addressed this question in in vitro culture systems by two-photon laser scanning microscopy. Beta-tricalcium phosphate specimens were incubated with (1) macrophages, (2) interleukin-4 activated macrophages, and (3) osteoclasts for up to 21 days. Interestingly, macrophages degraded beta-tricalcium phosphate specimens in an equivalent fashion compared to osteoclasts and significantly more than IL-4 activated macrophages. An average of ~32% of the macrophages was partially filled with ceramic material while this was 18% for osteoclasts and 9% for IL-4 activated macrophages. For the first time by applying two-photon microscopy, our studies show the previously unrecognized potential of macrophages to phagocytose ceramic material, which is expected to have implication on osteoconductive scaffold design. Copyright © 2013 Wiley Periodicals, Inc.

  17. Apical External Root Resorption and Repair in Orthodontic Tooth Movement: Biological Events

    PubMed Central

    Thomadakis, George; Fourie, Jeanine; Lemmer, Johan

    2016-01-01

    Some degree of external root resorption is a frequent, unpredictable, and unavoidable consequence of orthodontic tooth movement mediated by odontoclasts/cementoclasts originating from circulating precursor cells in the periodontal ligament. Its pathogenesis involves mechanical forces initiating complex interactions between signalling pathways activated by various biological agents. Resorption of cementum is regulated by mechanisms similar to those controlling osteoclastogenesis and bone resorption. Following root resorption there is repair by cellular cementum, but factors mediating the transition from resorption to repair are not clear. In this paper we review some of the biological events associated with orthodontically induced external root resorption. PMID:27119080

  18. Apical External Root Resorption and Repair in Orthodontic Tooth Movement: Biological Events.

    PubMed

    Feller, Liviu; Khammissa, Razia A G; Thomadakis, George; Fourie, Jeanine; Lemmer, Johan

    2016-01-01

    Some degree of external root resorption is a frequent, unpredictable, and unavoidable consequence of orthodontic tooth movement mediated by odontoclasts/cementoclasts originating from circulating precursor cells in the periodontal ligament. Its pathogenesis involves mechanical forces initiating complex interactions between signalling pathways activated by various biological agents. Resorption of cementum is regulated by mechanisms similar to those controlling osteoclastogenesis and bone resorption. Following root resorption there is repair by cellular cementum, but factors mediating the transition from resorption to repair are not clear. In this paper we review some of the biological events associated with orthodontically induced external root resorption.

  19. [Impacted teeth and the six incarnations of resorption].

    PubMed

    Becker, Adrian; Chaushu, Stella

    2015-12-01

    There are six distinct types of resorption of dental hard tissue that occur in association with unerupted and impacted permanent teeth. These pathologic entities differ markedly from one another in terms of their aetiology, their treatment and their prognosis. In several of them, the continued existence of the affected tooth may be in danger while in others, conservative treatment may halt the resorption process and provide for a successful outcome. The treatment approach is specific for each type and is entirely dependant on the diagnosis. This presentation will discuss prevalence, aetiology, presenting symptoms and clinical signs, radiographic features, histopathology, differential diagnosis, treatment and prognosis in relation to each of the conditions.

  20. Macrophage phenotypes in atherosclerosis.

    PubMed

    Colin, Sophie; Chinetti-Gbaguidi, Giulia; Staels, Bart

    2014-11-01

    Initiation and progression of atherosclerosis depend on local inflammation and accumulation of lipids in the vascular wall. Although many cells are involved in the development and progression of atherosclerosis, macrophages are fundamental contributors. For nearly a decade, the phenotypic heterogeneity and plasticity of macrophages has been studied. In atherosclerotic lesions, macrophages are submitted to a large variety of micro-environmental signals, such as oxidized lipids and cytokines, which influence the phenotypic polarization and activation of macrophages resulting in a dynamic plasticity. The macrophage phenotype spectrum is characterized, at the extremes, by the classical M1 macrophages induced by T-helper 1 (Th-1) cytokines and by the alternative M2 macrophages induced by Th-2 cytokines. M2 macrophages can be further classified into M2a, M2b, M2c, and M2d subtypes. More recently, additional plaque-specific macrophage phenotypes have been identified, termed as Mox, Mhem, and M4. Understanding the mechanisms and functional consequences of the phenotypic heterogeneity of macrophages will contribute to determine their potential role in lesion development and plaque stability. Furthermore, research on macrophage plasticity could lead to novel therapeutic approaches to counteract cardiovascular diseases such as atherosclerosis. The present review summarizes our current knowledge on macrophage subsets in atherosclerotic plaques and mechanism behind the modulation of the macrophage phenotype.

  1. Metabolism Supports Macrophage Activation

    PubMed Central

    Langston, P. Kent; Shibata, Munehiko; Horng, Tiffany

    2017-01-01

    Macrophages are found in most tissues of the body, where they have tissue- and context-dependent roles in maintaining homeostasis as well as coordinating adaptive responses to various stresses. Their capacity for specialized functions is controlled by polarizing signals, which activate macrophages by upregulating transcriptional programs that encode distinct effector functions. An important conceptual advance in the field of macrophage biology, emerging from recent studies, is that macrophage activation is critically supported by metabolic shifts. Metabolic shifts fuel multiple aspects of macrophage activation, and preventing these shifts impairs appropriate activation. These findings raise the exciting possibility that macrophage functions in various contexts could be regulated by manipulating their metabolism. Here, we review the rapidly evolving field of macrophage metabolism, discussing how polarizing signals trigger metabolic shifts and how these shifts enable appropriate activation and sustain effector activities. We also discuss recent studies indicating that the mitochondria are central hubs in inflammatory macrophage activation. PMID:28197151

  2. Autogenous bone harvesting and grafting in advanced jaw resorption: morbidity, resorption and implant survival.

    PubMed

    Nkenke, Emeka; Neukam, Friedrich W

    2014-01-01

    To analyse the morbidity arising from autogenous bone graft harvesting, graft resorption and implant survival in grafted sites. Only comparative clinical trials on the harvest of autogenous bone grafts were selected. Studies were excluded if they compared autogenous bone grafts to bone substitutes or vascularised free bone grafts. A total of 24 studies were included in the review. Six intraoral or distant donor sites were identified. The highest level of evidence was reached by a randomised controlled trial. The mandibular ramus was the source of bone that was preferred by the patients. From this intraoral donor site bone was harvested under local anaesthesia on an outpatient basis. Patients' acceptance of chin bone harvesting was low. It led to a considerable morbidity that included pain, superficial skin sensitivity disorders and wound healing problems at the donor site. Patients even preferred iliac crest bone harvesting over bone harvesting from the chin, although this distant donor site required general anaesthesia and a hospital stay. The harvest of posterior iliac crest block led to less morbidity than the harvest of anterior iliac crest block grafts. When only cancellous bone was needed, percutaneous bone harvesting from the iliac crest led to less morbidity than an open approach to the iliac crest. Dependent on the required graft structure and amount of bone needed, ramus grafts, block bone grafts from the posterior iliac crest and cancellous bone grafts harvested with a trephine from the anterior iliac crest should be chosen.

  3. Development of fusogenic glass surfaces that impart spatiotemporal control over macrophage fusion: Direct visualization of multinucleated giant cell formation.

    PubMed

    Faust, James J; Christenson, Wayne; Doudrick, Kyle; Ros, Robert; Ugarova, Tatiana P

    2017-06-01

    Implantation of synthetic material, including vascular grafts, pacemakers, etc. results in the foreign body reaction and the formation of multinucleated giant cells (MGCs) at the exterior surface of the implant. Despite the long-standing premise that fusion of mononucleated macrophages results in the formation of MGCs, to date, no published study has shown fusion in context with living specimens. This is due to the fact that optical-quality glass, which is required for the majority of live imaging techniques, does not promote macrophage fusion. Consequently, the morphological changes that macrophages undergo during fusion as well as the mechanisms that govern this process remain ill-defined. In this study, we serendipitously identified a highly fusogenic glass surface and discovered that the capacity to promote fusion was due to oleamide contamination. When adsorbed on glass, oleamide and other molecules that contain long-chain hydrocarbons promoted high levels of macrophage fusion. Adhesion, an essential step for macrophage fusion, was apparently mediated by Mac-1 integrin (CD11b/CD18, αMβ2) as determined by single cell force spectroscopy and adhesion assays. Micropatterned glass further increased fusion and enabled a remarkable degree of spatiotemporal control over MGC formation. Using these surfaces, we reveal the kinetics that govern MGC formation in vitro. We anticipate that the spatiotemporal control afforded by these surfaces will expedite studies designed to identify the mechanism(s) of macrophage fusion and MGC formation with implication for the design of novel biomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Management of Internal Root Resorption on Permanent Teeth

    PubMed Central

    Bonte, Eric; Bayet, François; Lasfargues, Jean-Jacques

    2013-01-01

    Internal root resorption (IRR) is a particular category of pulp disease characterized by the loss of dentine as a result of the action of clastic cells stimulated by pulpal inflammation. This review article explains the etiology, the prevalence of IRR, and, in addition to the clinical data, the contribution of the three-dimensional imaging (CBCT) to the diagnosis, the clinical decision, and the therapeutic management of IRR. The authors discussed the various therapeutic options including the orthograde or retrograde fillings of the root canal resorption area. Root canal treatment remains the treatment of choice of internal root resorption as it removes the granulation tissue and blood supply of the clastic cells. The authors describe with different clinical cases the modern endodontic techniques including optical aids, ultrasonic improvement of chemical debridement, and the use of alternative materials such as calcium silicate combined with thermoplastic filling (warm gutta-percha). In these conditions, the prognosis of the conservative treatment of internal resorptions, even if root walls are perforated, is good. PMID:24348560

  5. Root resorption and orthodontic treatment. Review of the literature.

    PubMed

    Pizzo, G; Licata, M E; Guiglia, R; Giuliana, G

    2007-01-01

    The aim of this paper was to provide a systematic review of the literature on the root resorption caused by orthodontic treatment. Original papers on this subject, published in English from January 2000 until December 2005, were located in the MEDLINE/PubMed database. Other sources were taken from the references of the selected papers. Root resorption is the most common sequela of the orthodontic treatment. It is an inflammatory process that leads to an ischemic necrosis localized in the periodontal ligament when the orthodontic force is applied. The onset and progression of root resorption are associated with risk factors related to the orthodontic treatment such as the duration of treatment, the magnitude of the force applied, the direction of the tooth movement, the method of force application (continuous versus intermittent), the orthodontic movement. Patient-related risk factors are the individual susceptibility on a genetic basis, some systemic diseases, anomalies in root morphology, dental trauma, and previous endodontic treatment. The prevention of root resorption during the orthodontic treatment may be performed controlling the risk factors. The periodic radiographic control during the treatment is necessary in order to detect the occurrence of root damages and quickly reassess the treatment goals.

  6. Volumetric evaluation of fat resorption after breast lipofilling.

    PubMed

    Ho Quoc, C; Taupin, T; Guérin, N; Delay, E

    2015-12-01

    The fat transfer or the lipofilling is a technique that had a major impact on the breast surgery results. We have been using this technique since 1998 as an adjuvant in breast reconstruction. The transferred fat is partially resorbed in the first three months after fat grafting. Literature shows that fat resorption varies from 30 to 80% and the experimental studies register a variation between 50 and 90%. The difficulty of the lipomodeling consists in anticipating the fat resorption rate in order to obtain breast symmetry. The purpose of this article is to evaluate the resorption rate of the transferred fat in the reconstructed breast by means of volumetric imaging 3 months after fat grafting. A prospective study was undertaken including breast reconstructions with total autologous latissimus dorsi. All the surgical procedures have been done by the same surgeon (1st author). It focused on the second stage of breast reconstruction: the lipofilling. We registered the average harvested volumes, the volumes obtained after centrifugation and the transferred volumes for every reconstructed breast. The intramuscular volume in the reconstructed breast was measured by volumetric imaging on the third day after lipofilling (D3) and three months after lipofilling (M3). The volumetry was performed by using an after treatment console SIEMENS (SOMATOM definition AS 2*64 barettes). The average intramuscular volume was registered at D3 and M3. The average volume difference was calculated in order to obtain the exact resorption rate. This prospective study was undertaken on 32 reconstructed breasts by total autologous latissimus dorsi flap. The average age was 52 years, the average BMI was 24.7 kg/m(2). The average harvested fat volume for the breast lipofilling was 560 cc and the volume obtained after centrifugation was evaluated at about 371 cc, the average fat volume transferred being 291 cc. The volumetric study showed that intramuscular volume at D3 was measured at 284 cc and

  7. ASSOCIATION BETWEEN NON-ENZYMATIC GLYCATION, RESORPTION, AND MICRODAMAGE IN HUMAN TIBIAL CORTICES

    PubMed Central

    Karim, Lamya; Diab, Tamim; Vashishth, Deepak

    2015-01-01

    Purpose/Introduction Changes in the quality of bone material contribute significantly to bone fragility. In order to establish a better understanding of the interaction of the different components of bone quality and their influence on bone fragility we investigated the relationship between non-enzymatic glycation, resorption, and microdamage generated in vivo in cortical bone using bone specimens from the same donors. Methods Total fluorescent advanced glycation end-products (AGEs) were measured in 96 human cortical bone samples from 83 donors. Resorption pit density, average resorption pit area, and percent resorption area were quantified in samples from 48 common donors with AGE measurements. Linear microcrack density and diffuse damage were measured in 21 common donors with AGE and resorption measurements. Correlation analyses were performed between all measured variables to establish the relationships among them and their variation with age. Results We found that average resorption pit area and percent resorption area decreased with increasing AGEs independently of age. Resorption pit density and percent resorption area demonstrated negative age-adjusted correlation with diffuse damage. Furthermore, average resorption pit area, resorption pit density, and percent resorption area were found to decrease significantly with age. Conclusions The current study demonstrated the in vivo interrelationship between the organic constituents, remodeling, and damage formation in cortical bone. In addition to the age-related reduction in resorption, there is a negative correlation between AGEs and resorption independent of age. This inverse relationship indicates that AGEs alter the resorption process and/or accumulate in the tissue as a result of reduced resorption and may lead to bone fragility by adversely affecting fracture resistance through altered bone matrix properties. PMID:25326375

  8. Gallium modulates osteoclastic bone resorption in vitro without affecting osteoblasts

    PubMed Central

    Verron, Elise; Masson, Martial; Khoshniat, Solmaz; Duplomb, Laurence; Wittrant, Yohann; Baud'huin, Marc; Badran, Zahi; Bujoli, Bruno; Janvier, Pascal; Scimeca, Jean-Claude; Bouler, Jean-Michel; Guicheux, Jérôme

    2010-01-01

    Background and purpose: Gallium (Ga) has been shown to be effective in the treatment of disorders associated with accelerated bone loss, including cancer-related hypercalcemia and Paget's disease. These clinical applications suggest that Ga could reduce bone resorption. However, few studies have studied the effects of Ga on osteoclastic resorption. Here, we have explored the effects of Ga on bone cells in vitro. Experimental approach: In different osteoclastic models [osteoclasts isolated from long bones of neonatal rabbits (RBC), murine RAW 264.7 cells and human CD14-positive cells], we have performed resorption activity tests, staining for tartrate resistant acid phosphatase (TRAP), real-time polymerase chain reaction analysis, viability and apoptotic assays. We also evaluated the effect of Ga on osteoblasts in terms of proliferation, viability and activity by using an osteoblastic cell line (MC3T3-E1) and primary mouse osteoblasts. Key results: Gallium dose-dependently (0–100 µM) inhibited the in vitro resorption activity of RBC and induced a significant decrease in the expression level of transcripts coding for osteoclastic markers in RAW 264.7 cells. Ga also dramatically reduced the formation of TRAP-positive multinucleated cells. Ga down-regulated in a dose-dependant manner the expression of the transcription factor NFATc1. However, Ga did not affect the viability or activity of primary and MC3T3-E1 osteoblasts. Conclusions and implications: Gallium exhibits a dose-dependent anti-osteoclastic effect by reducing in vitro osteoclastic resorption, differentiation and formation without negatively affecting osteoblasts. We provide evidence that this inhibitory mechanism involves down-regulation of NFATc1 expression, a master regulator of RANK-induced osteoclastic differentiation. PMID:20397300

  9. Heptamethoxyflavone, a citrus flavonoid, suppresses inflammatory osteoclastogenesis and alveolar bone resorption.

    PubMed

    Matsumoto, Chiho; Inoue, Hiroki; Tominari, Tsukasa; Watanabe, Kenta; Hirata, Michiko; Miyaura, Chisato; Inada, Masaki

    2015-01-01

    We examined the effects of heptamethoxyflavone (HMF), a citrus flavonoid on inflammatory bone resorption. HMF suppressed the osteoclast formation and PGE2 production induced by IL-1. In mouse calvarial organ cultures, HMF attenuated the bone resorption elicited by LPS. HMF suppressed bone resorption in the mandibular alveolar bone. HMF may protect against inflammatory bone loss such as periodontal disease.

  10. Angiopoietin-Like 4 Is Over-Expressed in Rheumatoid Arthritis Patients: Association with Pathological Bone Resorption

    PubMed Central

    Swales, Catherine; Athanasou, Nicholas A.; Knowles, Helen J.

    2014-01-01

    Introduction Osteoclasts are responsible for the bone loss associated with rheumatoid arthritis (RA). The secreted adipokine angiopoietin-like 4 (ANGPTL4) specifically increases osteoclast-mediated bone resorption. We have investigated expression of ANGPTL4 and its regulatory transcription factor, hypoxia-inducible factor-1 alpha (HIF-1α), in osteoclasts and other cells within rheumatoid synovium. We have also examined whether circulating levels of ANGPTL4 differ in RA patients compared with that in normal controls or patients with osteoarthritis (OA). Results Immunohistochemical analysis revealed that bone-apposing osteoclasts within the rheumatoid synovium express both ANGPTL4 and HIF-1α. ANGPTL4 was also strongly expressed in synovial lining cells, endothelial cells, stromal cells, CD68+ macrophages and plasma cells within RA synovium. Little ANGPTL4 was evident in normal synovial tissue. This reflected the over-expression of HIF-1α in rheumatoid versus normal synovial tissue. The concentration of ANGPTL4 was higher in both the serum and the synovial fluid of RA patients than in patients with OA or normal controls. High serum ANGPTL4 associated with elevated levels of the serum marker of bone resorption, receptor activator for nuclear factor κB ligand (RANKL). Conclusions Over-expression of ANGPTL4 in multiple cell types within the rheumatoid synovium potentially provides a local pool of ANGPTL4 to stimulate osteoclast-mediated bone resorption in RA. Additionally, correlation of high serum ANGPTL4 with circulating RANKL suggests that ANGPTL4 may represent a novel marker for bone destruction in RA. PMID:25289668

  11. Seasonal Variation of Nutrient Resorption in Nine Canopy Trees of a Wet Tropical Forest

    NASA Astrophysics Data System (ADS)

    Wood, T. E.; Lawrence, D.

    2006-12-01

    Withdrawal of nutrients at the time of leaf abscission (nutrient resorption) is a nutrient conserving mechanism that could play an important role in stand-level nutrient economy. Currently data on nutrient resorption in wet tropical forests and on how this process varies temporally are sparse. We evaluated the N and P resorption efficiency of nine rain forest canopy tree species in both wet and dry season months. In addition, we measured short-term (bi-weekly) variation in nutrient resorption in the two dominant tree species, Pentaclethra macroloba and Laetia procera, over a 4-month period. We hypothesized that nutrient resorption would be more efficient during the dry season months and that resorption would be low during periods of high rainfall. Contrary to expectations, P resorption efficiency was higher in the wet season for four of the nine canopy tree species, while N resorption did not differ seasonally. The low dry season P resorption efficiency found in this study may be the result of drought stress during short periods of low rainfall, leading to incomplete nutrient resorption from senescing leaves. Nutrient resorption also varied significantly over the short-term. Both P and N resorption efficiency increased in P. macroloba and L. procera as the wet season progressed. The variability in resorption was not related to rainfall or temperature. Instead, the senesced leaf concentrations were a simple proportion of green leaf nutrient concentrations, with short punctuated periods of high resorption efficiency that may be reflective of species-specific phenological events, such as fruit and leaf production. The different timing of the seasonal increase in nutrient resorption between L. procera and P. macroloba supports this hypothesis, deserving of further study.

  12. Macrophage elastase kills bacteria within murine macrophages.

    PubMed

    Houghton, A McGarry; Hartzell, William O; Robbins, Clinton S; Gomis-Rüth, F Xavier; Shapiro, Steven D

    2009-07-30

    Macrophages are aptly positioned to function as the primary line of defence against invading pathogens in many organs, including the lung and peritoneum. Their ability to phagocytose and clear microorganisms has been well documented. Macrophages possess several substances with which they can kill bacteria, including reactive oxygen species, nitric oxide, and antimicrobial proteins. We proposed that macrophage-derived proteinases may contribute to the antimicrobial properties of macrophages. Macrophage elastase (also known as matrix metalloproteinase 12 or MMP12) is an enzyme predominantly expressed in mature tissue macrophages and is implicated in several disease processes, including emphysema. Physiological functions for MMP12 have not been described. Here we show that Mmp12(-/-) mice exhibit impaired bacterial clearance and increased mortality when challenged with both gram-negative and gram-positive bacteria at macrophage-rich portals of entry, such as the peritoneum and lung. Intracellular stores of MMP12 are mobilized to macrophage phagolysosomes after the ingestion of bacterial pathogens. Once inside phagolysosomes, MMP12 adheres to bacterial cell walls where it disrupts cellular membranes resulting in bacterial death. The antimicrobial properties of MMP12 do not reside within its catalytic domain, but rather within the carboxy-terminal domain. This domain contains a unique four amino acid sequence on an exposed beta loop of the protein that is required for the observed antimicrobial activity. The present study represents, to our knowledge, the first report of direct antimicrobial activity by a matrix metallopeptidase, and describes a new antimicrobial peptide that is sequentially and structurally unique in nature.

  13. Arthroplasty implant biomaterial particle associated macrophages differentiate into lacunar bone resorbing cells.

    PubMed Central

    Pandey, R; Quinn, J; Joyner, C; Murray, D W; Triffitt, J T; Athanasou, N A

    1996-01-01

    OBJECTIVE: To study the pathogenesis of aseptic loosening: in particular, to determine whether macrophages responding to particles of biomaterials commonly used in arthroplasty surgery for arthritis are capable of differentiating into osteoclastic bone resorbing cells, and the cellular and hormonal conditions required for this to occur. METHODS: Biomaterial particles (polymethylmethacrylate, high density polyethylene, titanium, chromium-cobalt, stainless steel) were implanted subcutaneously into mice. Macrophages were isolated from the foreign body granulomas that resulted, cultured on bone slices and coverslips, and assessed for both cytochemical and functional evidence of osteoclast differentiation. RESULTS: Tartrate resistant acid phosphatase (TRAP) negative macrophages isolated from granulomas containing particles of all types of biomaterial composition were capable of differentiating into TRAP positive cells capable of extensive lacunar bone resorption (assessed by scanning electron microscopy). The presence of both UMR106 rat osteoblast-like cells and 1,25-dihydroxy vitamin D3 was necessary for this to occur. CONCLUSION: All implant materials produce wear particles that are the focus of a heavy foreign body macrophage response in the fibrous membrane between a loose implant component and the host bone undergoing resorption. These findings underline the importance of biomaterial wear particle generation and the macrophage response to different types of biomaterial wear particles in the pathogenesis of aseptic loosening. Images PMID:8694579

  14. Cardiomyocyte­-specific expression of the nuclear matrix protein, CIZ1, stimulates production of mono-nucleated cells with an extended window of proliferation in the postnatal mouse heart

    PubMed Central

    Bageghni, Sumia A.; Frentzou, Georgia A.; Drinkhill, Mark J.; Mansfield, William; Coverley, Dawn

    2017-01-01

    ABSTRACT Myocardial injury in mammals leads to heart failure through pathological cardiac remodelling that includes hypertrophy, fibrosis and ventricular dilatation. Central to this is inability of the mammalian cardiomyocyte to self-renew due to entering a quiescent state after birth. Modulation of the cardiomyocyte cell-cycle after injury is therefore a target mechanism to limit damage and potentiate repair and regeneration. Here, we show that cardiomyocyte-specific over-expression of the nuclear-matrix­-associated DNA replication protein, CIZ1, extends their window of proliferation during cardiac development, delaying onset of terminal differentiation without compromising function. CIZ1-expressing hearts are enlarged, but the cardiomyocytes are smaller with an overall increase in number, correlating with increased DNA replication after birth and retention of an increased proportion of mono-nucleated cardiomyocytes into adulthood. Furthermore, these CIZ1 induced changes in the heart reduce the impact of myocardial injury, identifying CIZ1 as a putative therapeutic target for cardiac repair. PMID:27934662

  15. Pharmacological diversity among drugs that inhibit bone resorption.

    PubMed

    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.

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

    PubMed

    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.

  17. Experimental study of diamond resorption during mantle metasomatism

    NASA Astrophysics Data System (ADS)

    Fedorchuk, Yana; Schmidt, Max W.; Liebske, Christian

    2014-05-01

    Many of kimberlite-derived diamonds are partially dissolved to various degree but show similar resorption style. This resorption style has been observed in experiments with aqueous fluid at the conditions corresponding to kimberlite emplacement (1-2 GPa). At the same time, each diamond population has more than ten percent of diamond crystals with several drastically different resorption styles, which have not been observed in experiments, and may represent partial dissolution of diamonds during metasomatism in different mantle domains. Metasomatic processes modify the composition of subcratonic mantle, may trigger the formation of kimberlite magma, and result in the growth and partial dissolution of diamonds. Composition of metasomatic agents as constrained from studies of the reaction rims on mantle minerals (garnet, clinopyroxene) and experimental studies vary between carbonatitic melt, aqueous silicate melt, and CHO fluid. However, complex chemical pattern of mantle minerals and estimates of redox regime in subcratonic mantle allow different interpretations. Here we explore diamond dissolution morphology as an indicator of the composition of mantle metasomatic agents. Towards this end we examine diamond dissolution morphologies developed in experiments at the conditions of mantle metasomatism in different reacting media and compare them to the mantle-derived dissolution features of natural diamonds. The experiments were conducted in multi-anvil (Walker-Type) apparatus at 6 GPa and 1200-1500oC. Dissolution morphology of natural octahedral diamond crystals (0.5 mg) was examined in various compositions in synthetic system MgO-CaO- SiO2-CO2-H2O. The runs had the following phases present: solid crystals with fluid (various ratio of H2O-CO2-SiO2, and in the air), carbonate melt, carbonate-silicate melt, and carbonate melt with CHO fluid. Experiments produced three different styles of diamond resorption. In the presence of a fluid phase with variable proportions of H2O

  18. Further evidence for direct pro-resorptive actions of FSH.

    PubMed

    Sun, Li; Zhang, Zhiyuan; Zhu, Ling-Ling; Peng, Yuanzhen; Liu, Xuan; Li, Jianhua; Agrawal, Manasi; Robinson, Lisa J; Iqbal, Jameel; Blair, Harry C; Zaidi, Mone

    2010-03-26

    We confirm that FSH stimulates osteoclast formation, function and survival to enhance bone resorption. It does so via the activation of a pertussis toxin-sensitive G(i)-coupled FSH receptor that we and others have identified on murine and human osteoclast precursors and mature osteoclasts. FSH additionally enhances the production of several osteoclastogenic cytokines, importantly TNFalpha, likely within the bone marrow microenvironment, to augment its pro-resorptive action. FSH levels in humans rise before estrogen falls, and this hormonal change coincides with the most rapid rates of bone loss. On the basis of accumulating evidence, we reaffirm that FSH contributes to the rapid peri-menopausal and early post-menopausal bone loss, which might thus be amenable to FSH blockade.

  19. Bone resorption and complications in alveolar distraction osteogenesis.

    PubMed

    Ettl, Tobias; Gerlach, Till; Schüsselbauer, Thomas; Gosau, Martin; Reichert, Torsten E; Driemel, Oliver

    2010-10-01

    Distraction osteogenesis presents an alternative procedure for augmentation of atrophic alveolar bone prior to inserting dental implants. The aim of this retrospective study was to evaluate complications of this method with specific focus on bone resorption during the consolidation period and the follow-up period after dental implant insertion into distracted bone. Thirty partially edentulous patients underwent a total of 36 vertical alveolar distractions with an extraosseous distraction system. Eleven devices were placed in the maxilla and 25 in the mandible. Eighty-two dental implants were inserted after a mean consolidation period of 4.5 months. Treatment results were evaluated by means of panoramic radiographs for distraction follow-up and periapical radiographs for implant follow-up. The mean length of the transport segment was 19 mm. The average alveolar height achieved was 6.4 mm with a mean resorption of 1.8 mm (21.1%) at the time of dental implant insertion. Main problems comprised oral displacement of the transport segment (n = 15) and inadequate soft tissue extension (n = 13). Eighty-two dental implants were inserted with an overall survival rate of 95.1% after 45.8 months. For periimplant marginal bone, an average resorption of 3.5 mm was recorded 50.4 months after implant insertion. Although alveolar distraction osteogenesis seems to be an effective tool to treat vertical defects of the alveolar ridge, it is not an uncomplicated procedure. A combination with vestibular augmentation of autogenous bone grafts should be considered. Overcorrection of 20% may compensate bone relapse during the consolidation period of the distracted alveolar bone. Further bone resorption after dental implantation is common.

  20. Root resorption related to orthodontics and other factors: a review of the literature.

    PubMed

    Rupp, R

    1995-09-01

    Each patient (and parents or guardian) should be clearly informed that there is a real possibility of one or more teeth undergoing root resorption during orthodontic procedures. They should sign an Information and Consent Form arranged by the dentist that they understand these risks before treatment is begun. Open bite cases possess significantly great degrees of resorption. Since trauma is closely associated with root resorption, the patient (and parents or guardian) should be questioned concerning previous traumatic occurrences that involved blows or accidents involving the teeth. Periapical radiographs are an important part of orthodontic records. They are useful to compare pretreatment and posttreatment root resorption. Maxillary incisors are affected more frequently and to a greater degree than the rest of the teeth during active treatment. Also, root resorption of the upper incisors during the initial 6-9 months of treatment with fixed appliances gives a high risk for continued resorption during the subsequent treatment. Therefore, it would be prudent to take periapical radiographs periodically during treatment. When root resorption is detected during active treatment, a decision must be made as to whether to continue, modify or discontinue the treatment. Extremely heavy forces should be avoided, since they have been shown to produce greater resorption activity. The ectopic eruption of canines causes a significant number of resorptions in lateral incisors. Habits adversely affect root resorption and should be eliminated if possible. Pathological lesions increase the risk of resorption. Periodontal disease increases the risk of resorption. The practitioner contemplating doing orthodontics should be cognizant of the above factors in evaluating the risk of root resorption. Patients (and parents or guardians) should be made clearly aware that any type of orthodontic treatment carries with it the risk of root tip blunting or resorption during orthodontic therapy.

  1. Nutrient resorption of two evergreen shrubs in response to long‑term fertilization in a bog.

    PubMed

    Wang, Meng; Murphy, Meaghan T; Moore, Tim R

    2014-02-01

    Plant resorption of multiple nutrients during leaf senescence has been established but stoichiometric changes among N, P and K during resorption and after fertilization are poorly understood. We anticipated that increased N supply would lead to further P limitation or co-limitation with N or K [i.e. P-(co)limitation], decrease N resorption and increase P and K resorption, while P and K addition would decrease P and K resorption and increase N resorption. Furthermore, Ca would accumulate while Mg would be resorbed during leaf senescence, irrespective of fertilization. We investigated the effect of N, P and K addition on resorption in two evergreen shrubs (Chamaedaphne calyculata and Rhododendron groenlandicum) in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada. In general, N addition caused further P-(co)limitation, increased P and K resorption efficiency but did not affect N resorption. P and K addition did not shift the system to N limitation and affect K resorption, but reduced P resorption proficiency. C. calyculata resorbed both Ca and Mg while R. groenlandicum resorbed neither. C. calyculata showed a higher resorption than R. groenlandicum, suggesting it is better adapted to nutrient deficiency than R. groenlandicum. Resorption during leaf senescence decreased N:P, N:K and K:P ratios. The limited response of N and K and the response of P resorption to fertilization reflect the stoichiometric coupling of nutrient cycling, which varies among the two shrub species; changes in species composition may affect nutrient cycling in bogs.

  2. Resorptive tooth root lesions in the Malayan tapir (Tapirus indicus).

    PubMed

    Da Silva, Mari-Ann O; Kortegaard, Hanne E; Choong, Siew Shean; Arnbjerg, Jens; Bertelsen, Mads F

    2011-03-01

    Facial abscessation and osteomyelitis due to dental disease is commonly seen in the Malayan tapir (Tapirus indicus), but little is known about the prevalence or etiology of these lesions. To determine the prevalence of dental ailments, 56 skulls and mandibles of deceased Malayan tapirs were visually and radiographically evaluated. Dental lesions were scored according to severity, and individuals were classified according to their age (juvenile/ young adult/adult) and origin (captive/free ranging). All of the lesions identified were of a resorptive nature. seemingly originating at the cementoenamel junction and burrowing towards the center of the tooth. Overall, 27% of the investigated skulls presented radiolucent dental lesions. The prevalence among captive animals was 52% (13/25), while only 6% (2/31) of the free-ranging tapirs had dental lesions. The second, third, and fourth premolars and first molar were the teeth most commonly affected, and the mandibular teeth were more often involved than the maxillary dentition. This study demonstrates a high prevalence of resorptive dental lesions in captive Malayan tapirs and provides a strong indication that age and captivity are significant risk factors in the development of these lesions. Dental disease, Malayan tapir, radiology, resorptive lesions, Tapirus indicus.

  3. Bone Resorption Is Regulated by Circadian Clock in Osteoblasts.

    PubMed

    Takarada, Takeshi; Xu, Cheng; Ochi, Hiroki; Nakazato, Ryota; Yamada, Daisuke; Nakamura, Saki; Kodama, Ayumi; Shimba, Shigeki; Mieda, Michihiro; Fukasawa, Kazuya; Ozaki, Kakeru; Iezaki, Takashi; Fujikawa, Koichi; Yoneda, Yukio; Numano, Rika; Hida, Akiko; Tei, Hajime; Takeda, Shu; Hinoi, Eiichi

    2016-12-07

    We have previously shown that endochondral ossification is finely regulated by the Clock system expressed in chondrocytes during postnatal skeletogenesis. Here we show a sophisticated modulation of bone resorption and bone mass by the Clock system through its expression in bone-forming osteoblasts. Brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 (Bmal1) and Period1 (Per1) were expressed with oscillatory rhythmicity in the bone in vivo, and circadian rhythm was also observed in cultured osteoblasts of Per1::luciferase transgenic mice. Global deletion of murine Bmal1, a core component of the Clock system, led to a low bone mass, associated with increased bone resorption. This phenotype was recapitulated by the deletion of Bmal1 in osteoblasts alone. Co-culture experiments revealed that Bmal1-deficient osteoblasts have a higher ability to support osteoclastogenesis. Moreover, 1α,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ]-induced receptor activator of nuclear factor κB ligand (Rankl) expression was more strongly enhanced in both Bmal1-deficient bone and cultured osteoblasts, whereas overexpression of Bmal1/Clock conversely inhibited it in osteoblasts. These results suggest that bone resorption and bone mass are regulated at a sophisticated level by osteoblastic Clock system through a mechanism relevant to the modulation of 1,25(OH)2 D3 -induced Rankl expression in osteoblasts. © 2016 American Society for Bone and Mineral Research.

  4. Conservative Management of Invasive Cervical Resorption: A Case Report

    PubMed Central

    Umer, Fahad; Adnan, Samira; Raza Khan, Farhan

    2013-01-01

    Invasive cervical resorption is a condition that affects the root surface area below the epithelial attachment. Multiple treatment modalities are advocated, involving exposure of the invasive defect, removal of the granulation tissue and sealing with various restorative materials. This report demonstrates conservative treatment of a patient presenting with peri-apical periodontitis in upper right central and lateral incisors, along with Class II invasive resorption defect cervically on the mesial aspect of the central incisor, as a result of trauma. As the patient was not willing for any surgical intervention, only ortho-grade root canal treatment was carried out in both teeth, with Calcium hydroxide as intra-canal medicament. At three year follow-up, the patient remains asymptomatic demonstrating radiographic evidence of infilling of defect with bone-like tissue. Within the limitations of this report, it was seen that this conservative method for halting the progression of invasive cervical resorption could be under taken in patients who are un-willing for surgical intervention or in whom surgery is contra-indicated. PMID:25512757

  5. Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

    SciTech Connect

    Nie, Shaobo; Xu, Jiawei; Zhang, Chenghua; Xu, Chen; Liu, Ming; Yu, Degang

    2016-01-29

    Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

  6. Botryllus schlosseri (Tunicata) whole colony irradiation: Do senescent zooid resorption and immunological resorption involve similar recognition events

    SciTech Connect

    Rinkevich, B.; Weissman, I.L. )

    1990-02-01

    The colonial tunicate Botryllus schlosseri undergoes cyclic blastogenesis where feeding zooids are senescened and resorbed and a new generation of zooids takes over the colony. When non-identical colonies come into direct contact, they either reject each other or fuse. Fusion is usually followed by the resorption of one of the partners in the chimera (immunological resorption). The striking morphological similarities between the two resorption phenomena suggest that both may involve tissue destruction following self-nonself recognition events. Here we attempt to modify these two events by whole colony gamma irradiation assays. Three sets of experiments were performed: (1) different doses of whole colony irradiation for determination of irradiation effects (110 colonies); (2) pairs of irradiated-nonirradiated isografts of clonal replicates for the potential of reconstruction of the irradiated partners (23 pairs); (3) chimeras of irradiated-nonirradiated partners for analysis of resorption hierarchy. Mortality increased with the irradiation dose. All colonies exposed to more than 5,000 rads died within 19 days, while no colony died below 2,000 rads. The average mortality periods, in days, for doses of 6,000-8,000, 5,000, and 2,500-4,000 rads were 14.4 +/- 3.1 (n = 24), 19.8 +/- 6.0 (n = 15), and 19.6 + 5.1 (n = 22), respectively. Younger colonies (3-6 months old) may survive radiation better than older ones (more than 13 months). Many morphological alterations were recorded in irradiated colonies: ampullar contraction and/or dilation, accumulation of pigment cells within ampullae, abnormal bleeding from blood vessels, sluggish blood circulation, necrotic zones, reduction in bud number, and irregularities in zooid and system structures. With doses of 3,000-4,000 rads and above, irradiation arrested the formation of new buds and interrupted normal takeover.

  7. Macrophages in Synovial Inflammation

    PubMed Central

    Kennedy, Aisling; Fearon, Ursula; Veale, Douglas J.; Godson, Catherine

    2011-01-01

    Synovial macrophages are one of the resident cell types in synovial tissue and while they remain relatively quiescent in the healthy joint, they become activated in the inflamed joint and, along with infiltrating monocytes/macrophages, regulate secretion of pro-inflammatory cytokines and enzymes involved in driving the inflammatory response and joint destruction. Synovial macrophages are positioned throughout the sub-lining layer and lining layer at the cartilage–pannus junction and mediate articular destruction. Sub-lining macrophages are now also considered as the most reliable biomarker for disease severity and response to therapy in rheumatoid arthritis (RA). There is a growing understanding of the molecular drivers of inflammation and an appreciation that the resolution of inflammation is an active process rather than a passive return to homeostasis, and this has implications for our understanding of the role of macrophages in inflammation. Macrophage phenotype determines the cytokine secretion profile and tissue destruction capabilities of these cells. Whereas inflammatory synovial macrophages have not yet been classified into one phenotype or another it is widely known that TNFα and IL-l, characteristically released by M1 macrophages, are abundant in RA while IL-10 activity, characteristic of M2 macrophages, is somewhat diminished. Here we will briefly review our current understanding of macrophages and macrophage polarization in RA as well as the elements implicated in controlling polarization, such as cytokines and transcription factors like NFκB, IRFs and NR4A, and pro-resolving factors, such as LXA4 and other lipid mediators which may promote a non-inflammatory, pro-resolving phenotype, and may represent a novel therapeutic paradigm. PMID:22566842

  8. Responses of plant nutrient resorption to phosphorus addition in freshwater marsh of Northeast China.

    PubMed

    Mao, Rong; Zeng, De-Hui; Zhang, Xin-Hou; Song, Chang-Chun

    2015-01-29

    Anthropogenic activities have increased phosphorus (P) inputs to most aquatic and terrestrial ecosystems. However, the relationship between plant nutrient resorption and P availability is still unclear, and much less is known about the underlying mechanisms. Here, we used a multi-level P addition experiment (0, 1.2, 4.8, and 9.6 g P m(-2) year(-1)) to assess the effect of P enrichment on nutrient resorption at plant organ, species, and community levels in a freshwater marsh of Northeast China. The response of nutrient resorption to P addition generally did not vary with addition rates. Moreover, nutrient resorption exhibited similar responses to P addition across the three hierarchical levels. Specifically, P addition decreased nitrogen (N) resorption proficiency, P resorption efficiency and proficiency, but did not impact N resorption efficiency. In addition, P resorption efficiency and proficiency were linearly related to the ratio of inorganic P to organic P and organic P fraction in mature plant organs, respectively. Our findings suggest that the allocation pattern of plant P between inorganic and organic P fractions is an underlying mechanism controlling P resorption processes, and that P enrichment could strongly influence plant-mediated biogeochemical cycles through altered nutrient resorption in the freshwater wetlands of Northeast China.

  9. Responses of plant nutrient resorption to phosphorus addition in freshwater marsh of Northeast China

    NASA Astrophysics Data System (ADS)

    Mao, Rong; Zeng, De-Hui; Zhang, Xin-Hou; Song, Chang-Chun

    2015-01-01

    Anthropogenic activities have increased phosphorus (P) inputs to most aquatic and terrestrial ecosystems. However, the relationship between plant nutrient resorption and P availability is still unclear, and much less is known about the underlying mechanisms. Here, we used a multi-level P addition experiment (0, 1.2, 4.8, and 9.6 g P m-2 year-1) to assess the effect of P enrichment on nutrient resorption at plant organ, species, and community levels in a freshwater marsh of Northeast China. The response of nutrient resorption to P addition generally did not vary with addition rates. Moreover, nutrient resorption exhibited similar responses to P addition across the three hierarchical levels. Specifically, P addition decreased nitrogen (N) resorption proficiency, P resorption efficiency and proficiency, but did not impact N resorption efficiency. In addition, P resorption efficiency and proficiency were linearly related to the ratio of inorganic P to organic P and organic P fraction in mature plant organs, respectively. Our findings suggest that the allocation pattern of plant P between inorganic and organic P fractions is an underlying mechanism controlling P resorption processes, and that P enrichment could strongly influence plant-mediated biogeochemical cycles through altered nutrient resorption in the freshwater wetlands of Northeast China.

  10. Age-Related Effects of Advanced Glycation End Products (Ages) in Bone Matrix on Osteoclastic Resorption.

    PubMed

    Yang, Xiao; Gandhi, Chintan; Rahman, Md Mizanur; Appleford, Mark; Sun, Lian-Wen; Wang, Xiaodu

    2015-12-01

    Advanced glycation end products (AGEs) accumulate in bone extracellular matrix as people age. Previous studies have shown controversial results regarding the role of in situ AGEs accumulation in osteoclastic resorption. To address this issue, this study cultured human osteoclast cells directly on human cadaveric bone slices from different age groups (young and elderly) to warrant its relevance to in vivo conditions. The cell culture was terminated on the 3rd, 7th, and 10th day, respectively, to assess temporal changes in the number of differentiated osteoclasts, the number and size of osteoclastic resorption pits, the amount of bone resorbed, as well as the amount of matrix AGEs released in the medium by resorption. In addition, the in situ concentration of matrix AGEs at each resorption pit was also estimated based on its AGEs autofluorescent intensity. The results indicated that (1) osteoclastic resorption activities were significantly correlated with the donor age, showing larger but shallower resorption pits on the elderly bone substrates than on the younger ones; (2) osteoclast resorption activities were not significantly dependent on the in situ AGEs concentration in bone matrix, and (3) a correlation was observed between osteoclast activities and the concentration of AGEs released by the resorption. These results suggest that osteoclasts tend to migrate away from initial anchoring sites on elderly bone substrate during resorption compared to younger bone substrates. However, such behavior is not directly related to the in situ concentration of AGEs in bone matrix at the resorption sites.

  11. A Single Dose of the Anti-Resorptive Peptide Human Calcitonin Paradoxically Augments Particle- and Endotoxin-Mediated Pro-Inflammatory Cytokine Production In Vitro.

    PubMed

    Jablonski, H; Wedemeyer, C; Bachmann, H S; Schlagkamp, M; Bernstein, A; Jäger, M; Kauther, M D

    2016-09-01

    The peptide hormone calcitonin (CT) is known to inhibit bone resorption and has previously been shown also to prevent particle-induced osteolysis, the leading cause of revision arthroplasty. In the present study, the influence of human CT on the initial inflammatory response to particulate wear debris or bacterial endotoxins, ultimately leading to osteoclast-mediated bone resorption, was analysed in human THP-1 macrophage-like cells. The cells were activated with either ultra-high molecular weight polyethylene (UHMWPE) particles or bacterial lipopolysaccharides (LPS) in order to simulate an osteolysis-associated inflammatory response. The cells were simultaneously treated with human CT (10(-9) M). Cytokine production of tumour necrosis factor (TNF)-α was quantified on both RNA and protein levels while interleukins (IL)-1β and IL-6 were measured as secreted protein only. Stimulation of the cells with either particles or LPS led to a dose- and time-dependent increase of TNF-α mRNA production and protein secretion of TNF-α, IL-1β, and IL-6. Application of CT mostly enhanced cytokine production as elicited by UHMWPE particles while a pronounced transient inhibitory effect on LPS-induced inflammation became evident at 24 h of incubation. Human CT displayed ambivalent effects on the wear- and LPS-induced production of pro-inflammatory cytokines. Thereby, the peptide primarily upregulated particle-induced inflammation while LPS-induced cytokine secretion was temporarily attenuated in a distinct manner. It needs to be evaluated whether the pro- or anti-inflammatory action of CT contributes to its known anti-resorptive effects. Thus, the therapeutic potential of the peptide in the treatment of either particle- or endotoxin-mediated bone resorption could be determined. © Georg Thieme Verlag KG Stuttgart · New York.

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

    PubMed Central

    Rey, Diego; Smit, Rosana Martínez; Gamboa, Liliana

    2015-01-01

    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. PMID:25741832

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

    PubMed Central

    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 outlines. Many techniques and materials have been used to fill internal resorptive defects. Among them, Mineral Trioxide Aggregates (MTAs) have satisfactory properties, which include: biocompatibility, a favourable sealing ability, mechanical strength and a capacity to promote a periradicular tissue healing. Thus, a Mineral Trioxide Aggregate (MTA) repair of a maxillary left central incisor tooth with an inflammatory resorptive defect, in the middle third of the root canal, has been reported here. PMID:24298543

  14. Traumatic injury to permanent tooth resulting in complete root resorption: a case report.

    PubMed

    Niikuni, Naoko; Seki, Nobuyuki; Sato, Kieko; Nasu, Daisuke; Shirakawa, Tetsuo

    2007-12-01

    When a tooth is avulsed and replanted following traumatic dental injury, complications such as replacement and inflammatory resorption may occur. Ultimately, resorption may result in loss of the tooth. This case report describes a traumatic injury to a permanent tooth resulting in complete root resorption within a short period, which required surgery. In the present case, improper treatment measures such as dry condition of the avulsed tooth before replantation and extra-oral retrograde root canal filling may have led to rapid complete root resorption. Even if it is impossible to avoid resorption completely, the overall knowledge of both dentists and patients regarding traumatic dental injuries should be improved to delay the progress of resorption.

  15. Macrophages and CSF-1

    PubMed Central

    Jones, Christina V; Ricardo, Sharon D

    2013-01-01

    Recent focus on the diversity of macrophage phenotype and function signifies that these trophic cells are no longer of exclusive interest to the field of immunology. As key orchestrators of organogenesis, the contribution of macrophages to fetal development is worthy of greater attention. This review summarizes the key functions of macrophages and their primary regulator, colony-stimulating factor (CSF)-1, during development; highlighting trophic mechanisms beyond phagocytosis and outlining their roles in a range of developing organ systems. Advances in the understanding of macrophage polarization and functional heterogeneity are discussed from a developmental perspective. In addition, this review highlights the relevance of CSF-1 as a pleiotropic developmental growth factor and summarizes recent experimental evidence and clinical advancements in the area of CSF-1 and macrophage manipulation in reproduction and organogenic settings. Interrogation of embryonic macrophages also has implications beyond development, with recent attention focused on yolk sac macrophage ontogeny and their role in homeostasis and mediating tissue regeneration. The regulatory networks that govern development involve a complex range of growth factors, signaling pathways and transcriptional regulators arising from epithelial, mesenchymal and stromal origins. A component of the organogenic milieu common to the majority of developing organs is the tissue macrophage. These hemopoietic cells are part of the mononuclear phagocyte system regulated primarily by colony-stimulating factor (CSF)-1 1, 2. There is a resurgence in the field of CSF-1 and macrophage biology; where greater understanding of the heterogeneity of these cells is revealing contributions to tissue repair and regeneration beyond the phagocytic and inflammatory functions for which they were traditionally ascribed 3–6. The accumulation of macrophages during tissue injury is no longer viewed as simply a surrogate for disease

  16. RANKL Is a Mediator of Bone Resorption in Idiopathic Hypercalciuria

    PubMed Central

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

    2008-01-01

    Background and objectives: This study aimed to determine the expression of osteoprotegerin, receptor activator of nuclear factor κB ligand, interleukin-1α, transforming growth factor-β, and basic fibroblast growth factor in stone-forming patients with idiopathic hypercalciuria. Design, setting, participants, & measurements: Immunohistochemical analysis was performed in undecalcified bone samples previously obtained from 36 transiliac bone biopsies of patients who had idiopathic hypercalciuria and whose histomorphometry had shown lower bone volume, increased bone resorption, and prolonged mineralization lag time. Results: Bone expression of receptor activator of nuclear factor κB ligand and osteoprotegerin was significantly higher in patients with idiopathic hypercalciuria versus control subjects. Transforming growth factor-β immunostaining was lower in patients with idiopathic hypercalciuria than in control subjects and correlated directly with mineralization surface. Interleukin-1α and basic fibroblast growth factor staining did not differ between groups. Receptor activator of nuclear factor κB ligand bone expression was significantly higher in patients who had idiopathic hypercalciuria and exhibited higher versus normal bone resorption. Conclusion: A higher expression of receptor activator of nuclear factor κB ligand in bone tissue suggests that increased bone resorption in patients with idiopathic hypercalciuria is mediated by receptor activator of nuclear factor κB ligand. Osteoprotegerin bone expression might have been secondarily increased in an attempt to counteract the actions of receptor activator of nuclear factor κB ligand. The low bone expression of transforming growth factor-β could contribute to the delayed mineralization found in such patients. PMID:18480302

  17. TGF-β and Physiological Root Resorption of Deciduous Teeth

    PubMed Central

    Shimazaki, Emi; Karakida, Takeo; Yamamoto, Ryuji; Kobayashi, Saeko; Fukae, Makoto; Yamakoshi, Yasuo; Asada, Yoshinobu

    2016-01-01

    The present study was performed to examine how transforming growth factor β (TGF-β) in root-surrounding tissues on deciduous teeth regulates the differentiation induction into odontoclasts during physiological root resorption. We prepared root-surrounding tissues with (R) or without (N) physiological root resorption scraped off at three regions (R1–R3 or N1–N3) from the cervical area to the apical area of the tooth and measured both TGF-β and the tartrate-resistant acid phosphatase (TRAP) activities. The TGF-β activity level was increased in N1–N3, whereas the TRAP activity was increased in R2 and R3. In vitro experiments for the receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-mediated osteoclast differentiation revealed that proteins from N1–N3 and R1–R3 enhanced the TRAP activity in RAW264 cells. A genetic study indicated that the mRNA levels of TGF-β1 in N1 and N2 were significantly increased, and corresponded with levels of osteoprotegerin (OPG). In contrast, the expression level of RANKL was increased in R2 and R3. Our findings suggest that TGF-β is closely related to the regulation of OPG induction and RANKL-mediated odontoclast differentiation depending on the timing of RANKL and OPG mRNA expression in the root-surrounding tissues of deciduous teeth during physiological root resorption. PMID:28035998

  18. Root Resorption a 6-Year Follow-up Case Report

    PubMed Central

    Dias, Caroline; Closs, Luciane; Barletta, Fernando; Reston, Eduardo; Tovo, Maximiano F; Lambert, Paula

    2015-01-01

    This paper describes the clinical course of a pediatric patient developing cervical external root resorption (CERR). An 11-year old male patient had sustained dental trauma and was diagnosed with crown fracture affecting the incisal and middle thirds of the maxillary right permanent central incisor and the maxillary right permanent lateral incisor with pulp exposure and CERR after 24 months. Diagnosis and treatment of CERR are a challenge for dental practitioners. In this case, preservation of natural dentition is shown as a successful treatment in a 6-year follow-up. PMID:25870717

  19. Conservative management of progressive external inflammatory root resorption after traumatic tooth intrusion.

    PubMed

    Ghafoor, Robia

    2013-05-01

    Intrusive luxation is one of the most severe types of dental trauma. The risk of development of inflammatory or replacement root resorption is high if not timely managed. Endodontic intervention is required soon after the occurrence of trauma, in an attempt to prevent or delay inflammatory root resorption. This case report emphasized timely referral for endodontic management of intruded tooth to prevent inflammatory root resorption.

  20. Glutamine Modulates Macrophage Lipotoxicity.

    PubMed

    He, Li; Weber, Kassandra J; Schilling, Joel D

    2016-04-12

    Obesity and diabetes are associated with excessive inflammation and impaired wound healing. Increasing evidence suggests that macrophage dysfunction is responsible for these inflammatory defects. In the setting of excess nutrients, particularly dietary saturated fatty acids (SFAs), activated macrophages develop lysosome dysfunction, which triggers activation of the NLRP3 inflammasome and cell death. The molecular pathways that connect lipid stress to lysosome pathology are not well understood, but may represent a viable target for therapy. Glutamine uptake is increased in activated macrophages leading us to hypothesize that in the context of excess lipids glutamine metabolism could overwhelm the mitochondria and promote the accumulation of toxic metabolites. To investigate this question we assessed macrophage lipotoxicity in the absence of glutamine using LPS-activated peritoneal macrophages exposed to the SFA palmitate. We found that glutamine deficiency reduced lipid induced lysosome dysfunction, inflammasome activation, and cell death. Under glutamine deficient conditions mTOR activation was decreased and autophagy was enhanced; however, autophagy was dispensable for the rescue phenotype. Rather, glutamine deficiency prevented the suppressive effect of the SFA palmitate on mitochondrial respiration and this phenotype was associated with protection from macrophage cell death. Together, these findings reveal that crosstalk between activation-induced metabolic reprogramming and the nutrient microenvironment can dramatically alter macrophage responses to inflammatory stimuli.

  1. Glutamine Modulates Macrophage Lipotoxicity

    PubMed Central

    He, Li; Weber, Kassandra J.; Schilling, Joel D.

    2016-01-01

    Obesity and diabetes are associated with excessive inflammation and impaired wound healing. Increasing evidence suggests that macrophage dysfunction is responsible for these inflammatory defects. In the setting of excess nutrients, particularly dietary saturated fatty acids (SFAs), activated macrophages develop lysosome dysfunction, which triggers activation of the NLRP3 inflammasome and cell death. The molecular pathways that connect lipid stress to lysosome pathology are not well understood, but may represent a viable target for therapy. Glutamine uptake is increased in activated macrophages leading us to hypothesize that in the context of excess lipids glutamine metabolism could overwhelm the mitochondria and promote the accumulation of toxic metabolites. To investigate this question we assessed macrophage lipotoxicity in the absence of glutamine using LPS-activated peritoneal macrophages exposed to the SFA palmitate. We found that glutamine deficiency reduced lipid induced lysosome dysfunction, inflammasome activation, and cell death. Under glutamine deficient conditions mTOR activation was decreased and autophagy was enhanced; however, autophagy was dispensable for the rescue phenotype. Rather, glutamine deficiency prevented the suppressive effect of the SFA palmitate on mitochondrial respiration and this phenotype was associated with protection from macrophage cell death. Together, these findings reveal that crosstalk between activation-induced metabolic reprogramming and the nutrient microenvironment can dramatically alter macrophage responses to inflammatory stimuli. PMID:27077881

  2. Macrophage activation and polarization.

    PubMed

    Martinez, Fernando Oneissi; Sica, Antonio; Mantovani, Alberto; Locati, Massimo

    2008-01-01

    Macrophages are widely distributed immune system cells that play an indispensable role in homeostasis and defense. They can be phenotypically polarized by the microenvironment to mount specific functional programs. Polarized macrophages can be broadly classified in two main groups: classically activated macrophages (or M1), whose prototypical activating stimuli are IFNgamma and LPS, and alternatively activated macrophages (or M2), further subdivided in M2a (after exposure to IL-4 or IL-13), M2b (immune complexes in combination with IL-1beta or LPS) and M2c (IL-10, TGFbeta or glucocorticoids). M1 exhibit potent microbicidal properties and promote strong IL-12-mediated Th1 responses, whilst M2 support Th2-associated effector functions. Beyond infection M2 polarized macrophages play a role in resolution of inflammation through high endocytic clearance capacities and trophic factor synthesis, accompanied by reduced pro-inflammatory cytokine secretion. Similar functions are also exerted by tumor-associated macrophages (TAM), which also display an alternative-like activation phenotype and play a detrimental pro-tumoral role. Here we review the main functions of polarized macrophages and discuss the perspectives of this field.

  3. Root resorption of maxillary incisors retracted with and without skeletal anchorage.

    PubMed

    Barros, Sérgio Estelita; Janson, Guilherme; Chiqueto, Kelly; Baldo, Vitor Oliveira; Baldo, Taiana Oliveira

    2017-02-01

    Our objective was to compare root resorption degree of the maxillary central incisors retracted with and without skeletal anchorage. This nonrandomized historical control study included 37 patients requiring maximum anterior retraction and treated with extraction of 2 maxillary premolars. Group 1 consisted of 22 patients (11 male, 11 female) in whom anterior retraction was performed without skeletal anchorage, and group 2 included 15 patients (3 male, 12 female) treated with skeletally anchored anterior retraction. Periapical radiographs were used to evaluate root resorption degree by a scoring system. The groups were compared regarding the resorption score and resorption degree distribution with the Mann-Whitney U test, chi-square test, and Z test on proportions. There was no statistically significant intergroup difference regarding root resorption, but the number of patients with severe and extreme root resorption degrees was significantly greater in group 2. Although the root resorption degree of the skeletal anchorage group was not significantly different from the group without skeletal anchorage, the number of patients with severe to extreme resorption in the first group was significantly greater. Therefore, careful clinical monitoring of skeletally anchored anterior retraction is needed, especially when there are known root resorption predisposing factors. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

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

    PubMed Central

    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

  5. Biogeographic patterns of nutrient resorption from Quercus variabilis Blume leaves across China.

    PubMed

    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.

  6. Primary tooth radicular resorption as a consequence of self-corrected ectopic eruption: 2 unusual cases.

    PubMed

    Guzeler, Irem; Sara, Sezgi; Cehreli, Zafer C; Uysal, Serdar; Musselman, Robert J

    2011-01-01

    Resorption of the distal root of primary second molars is a common consequence of ectopically erupting permanent first molars. Here, we report 2 unusual cases of primary molar root resorption caused by reversible (self-correcting) ectopic eruption of premolar and canine teeth. In both cases, severe pathological resorption of the mesial roots of primary molars was detected on routine dental radiographs, and the affected molars remained asymptomatic until exfoliation. The purpose of this paper was, using 2 case studies, to highlight the possibility of primary root resorption as a sequel of self-corrected ectopic eruption in locations not frequently diagnosed or reported.

  7. NOD1 in the modulation of host-microbe interactions and inflammatory bone resorption in the periodontal disease model.

    PubMed

    Chaves de Souza, João Antônio; Frasnelli, Sabrina Cruz Tfaile; Curylofo-Zotti, Fabiana de Almeida; Ávila-Campos, Mário Julio; Spolidório, Luis Carlos; Zamboni, Dario Simões; Graves, Dana T; Rossa, Carlos

    2016-12-01

    Periodontitis is a chronic inflammatory condition characterized by destruction of non-mineralized and mineralized connective tissues. It is initiated and maintained by a dysbiosis of the bacterial biofilm adjacent to teeth with increased prevalence of Gram-negative microorganisms. Nucleotide-binding oligomerization domain containing 1 (NOD1) is a member of the Nod-like receptors (NLRs) family of proteins that participate in the activation of the innate immune system, in response to invading bacteria or to bacterial antigens present in the cytoplasm. The specific activating ligand for NOD1 is a bacterial peptidoglycan derived primarily from Gram-negative bacteria. This study assessed the role of NOD1 in inflammation-mediated tissue destruction in the context of host-microbe interactions. We used mice with whole-genome deletion of the NOD1 gene in a microbe-induced periodontitis model using direct injections of heat-killed Gram-negative or Gram-negative/Gram-positive bacteria on the gingival tissues. In vitro experiments using primary bone-marrow-derived macrophages from wild-type and NOD1 knockout mice provide insight into the role of NOD1 on the macrophage response to Gram-negative and Gram-negative/Gram-positive bacteria. Microcomputed tomography analysis indicated that deletion of NOD1 significantly aggravated bone resorption induced by Gram-negative bacteria, accompanied by an increase in the numbers of osteoclasts. This effect was significantly attenuated by the association with Gram-positive bacteria. In vitro, quantitative PCR arrays indicated that stimulation of macrophages with heat-killed Gram-negative bacteria induced the same biological processes in wild-type and NOD1-deficient cells; however, expression of pro-inflammatory mediators was increased in NOD1-deficient cells. These results suggest a bone-sparing role for NOD1 in this model. © 2016 John Wiley & Sons Ltd.

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

    PubMed Central

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

    2015-01-01

    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, diabetes mellitus, hypothyroidism, ineffective hematopoiesis as well as hyperplasia of the bone marrow, parathyroid gland dysfunction, toxic effect of iron on osteoblasts, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) deficiency. These factors disrupt the balance between osteoblasts and osteoclasts by interfering with various molecular mechanisms and result in decreased bone density. Given the high prevalence of osteopenia and osteoporosis in thalassemic patients and complexity of their development process, the goal of this review is to evaluate the molecular aspects involved in osteopenia and osteoporosis in thalassemic patients, which may be useful for therapeutic purposes. PMID:26199898

  9. Notch signaling promotes osteoclast maturation and resorptive activity

    PubMed Central

    Ashley, Jason W; Ahn, Jaimo; Hankenson, Kurt D

    2015-01-01

    The role of Notch signaling in osteoclast differentiation is controversial with conflicting experimental evidence indicating both stimulatory and inhibitory roles. Differences in experimental protocols and in vivo versus in vitro models may explain the discrepancies between studies. In this study, we investigated cell autonomous roles of Notch signaling in osteoclast differentiation and function by altering Notch signaling during osteoclast differentiation using stimulation with immobilized ligands Jagged1 or Delta-like1 or by suppression with γ-secretase inhibitor DAPT or transcriptional inhibitor SAHM1. Stimulation of Notch signaling in committed osteoclast precursors resulted in larger osteoclasts with a greater number of nuclei and resorptive activity whereas suppression resulted in smaller osteoclasts with fewer nuclei and suppressed resorptive activity. Conversely, stimulation of Notch signaling in osteoclast precursors prior to induction of osteoclastogenesis resulted in fewer osteoclasts. Our data support a mechanism of context-specific Notch signaling effects wherein Notch stimulation inhibits commitment to osteoclast differentiation, but enhances the maturation and function of committed precursors. PMID:25914241

  10. Equine Odontoclastic Tooth Resorption and Hypercementosis: Histopathologic Features.

    PubMed

    Smedley, R C; Earley, E T; Galloway, S S; Baratt, R M; Rawlinson, J E

    2015-09-01

    Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a painful progressive condition of older horses that involves multiple teeth, including canines and incisors. EOTRH is uncommonly recognized by veterinary pathologists and in some cases may be misdiagnosed as cementoblastoma. The cause is unknown. The goals of this study were to describe the histopathologic features of EOTRH in 17 affected horses from the United States and to increase awareness of this condition. Samples ranged from affected tooth to the entire rostral mandible and maxilla. Affected teeth exhibited cemental hyperplasia and lysis. The marked proliferation of cementum in severe cases caused bulbous enlargement of the intra-alveolar portions of affected teeth. Several teeth contained necrotic debris, bacteria, and plant material in the regions of cemental lysis. All horses exhibited dentinal lysis in at least affected tooth, and several contained necrotic debris in these regions. Endodontic disease was often present with inflammation, lysis, necrotic debris, fibrosis, and/or a thin rim of atubular mineralized tissue in the pulp cavity. Periodontal disease was a common feature that was primarily characterized by moderate lymphoplasmacytic inflammation. Resorption with secondary hypercementosis appears to begin on the external surface of the teeth rather than within the pulp cavity. Distinguishing EOTRH from other diseases requires a complete history that includes the number and location of affected teeth, a gross description of regional hard/soft tissue health, and radiographic findings.

  11. Gadolinium induces macrophage apoptosis.

    PubMed

    Mizgerd, J P; Molina, R M; Stearns, R C; Brain, J D; Warner, A E

    1996-02-01

    Gadolinium (Gd) suppresses reticuloendothelial functions in vivo by unknown mechanisms. In vitro exposure of rat alveolar macrophages to GdCl3.6H20 caused cell death, as measured by trypan blue permeability, in both dose- and time-dependent fashions. Even a 10-min exposure to Gd caused significant cell death by 24 h. The morphology of Gd-treated cells, pyknosis and karyorrhexis prior to loss of membrane integrity, suggested apoptosis. Upon flow cytometric examination, Gd-treated propidium iodide-excluding cells demonstrated light scatter changes characteristic of apoptotic cells (decreased forward and increased right angle scatter). Gel electrophoresis of DNA from Gd-treated macrophages clearly showed the ladder pattern unique to apoptotic cells. Electron-dense structures containing Gd were observed via electron spectroscopic imaging within phagosomes and also within nuclei (associated with condensed chromatin). Gadolinium, endocytosed by macrophages and distributed to nuclei, causes apoptosis of macrophages in vitro.

  12. Physiological roles of macrophages.

    PubMed

    Gordon, Siamon; Martinez-Pomares, Luisa

    2017-04-01

    Macrophages are present in mammals from midgestation, contributing to physiologic homeostasis throughout life. Macrophages arise from yolk sac and foetal liver progenitors during embryonic development in the mouse and persist in different organs as heterogeneous, self-renewing tissue-resident populations. Bone marrow-derived blood monocytes are recruited after birth to replenish tissue-resident populations and to meet further demands during inflammation, infection and metabolic perturbations. Macrophages of mixed origin and different locations vary in replication and turnover, but are all active in mRNA and protein synthesis, fulfilling organ-specific and systemic trophic functions, in addition to host defence. In this review, we emphasise selected properties and non-immune functions of tissue macrophages which contribute to physiologic homeostasis.

  13. A preliminary investigation of short-term cytokine  expression in gingival crevicular fluid secondary to high-level orthodontic forces and the associated root resorption: case series analytical study.

    PubMed

    Ahuja, Rajiv; Almuzian, Moahmmed; Khan, Alamgir; Pascovici, Dana; Dalci, Oyku; Darendeliler, M Ali

    2017-12-01

    Orthodontically induced iatrogenic root resorption (OIIRR) is an unavoidable inflammatory process. Several factors claimed to be related to the severity of OIIRR. Orthodontic forces cause micro-trauma to the periodontal ligament and activate a cascade of cellular events associated with local periodontal inflammation. The purpose of this split-mouth study were (1) to investigate the changes in cytokine profile in the gingival crevicular fluid (GCF) secondary to heavy orthodontic forces and (2) to compare the cytokine expression between participants showing high and low root resorption. Eight participants requiring maxillary first premolar extractions involved in this study. The teeth on the tested side (TS) received 225 g of controlled buccal tipping force for 28 days, while the contralateral teeth act as a control (CS). GCF was collected from both TS and CS teeth at 0 h (prior to application of force) and 3 h, 1 day, 3 days, 7 days and 28 days after the application of force, and analysed with multiplex bead immunoassay to determine the cytokine levels. Statistically significant temporal increase was found in the TS teeth for tumour necrosis factor alpha (TNF-α) at 3 h and 28 days (p = 0.01). Interleukin 7 (IL-7) significantly peaked at the 28th day. Comparing cytokine profile for participants with high and low root resorption (>0.35 and <0.15 mm(3), respectively), the levels of GM-CSF was significantly greater in low root resorption cases (p < 0.05). The amounts of root resorption which craters on mesial, distal surfaces and middle third region were significant in the TS teeth (p < 0.05). IL-7 and TNF-α (pro-resorptive cytokine) increased significantly secondary to a high-level of orthodontic force application. Significantly high levels of granulocyte macrophage colony-stimulating factor (anti-resorptive cytokine) were detected in mild root resorption cases secondary to high-level orthodontic force application. A future long

  14. Measuring autophagy in macrophages.

    PubMed

    Harris, James; Hanrahan, Orla; De Haro, Sergio A

    2009-11-01

    Macroautophagy is a conserved intracellular homeostatic mechanism for the degradation of cytosolic constituents. Autophagy can promote cell survival by providing essential amino acids from the breakdown of macromolecules during periods of nutrient deprivation, and can remove damaged or excess organelles, such as mitochondria and peroxisomes. More recently, autophagy has been shown to play an important role in innate and adaptive immune responses to pathogenic bacteria in macrophages and dendritic cells. This unit presents protocols for the measurement of autophagy in macrophages.

  15. Relationship between the relative limitation and resorption efficiency of nitrogen vs phosphorus in woody plants.

    PubMed

    Han, Wenxuan; Tang, Luying; Chen, Yahan; Fang, Jingyun

    2013-01-01

    Most previous studies have ascribed variations in the resorption of a certain plant nutrient to its corresponding environmental availability or level in tissues, regardless of the other nutrients' status. However, given that plant growth relies on both sufficient and balanced nutrient supply, the nutrient resorption process should not only be related to the absolute nutrient status, but also be regulated by the relative limitation of the nutrient. Here, based on a global woody-plants dataset from literature, we test the hypothesis that plants resorb proportionately more nitrogen (or phosphorus) when they are nitrogen (or phosphorus) limited, or similar proportions of nitrogen (N) and phosphorus (P) when co-limited by both nutrients (the relative resorption hypothesis). Using the N:P ratio in green foliage as an indicator of nutrient limitation, we found an inverse relationship between the difference in the proportionate resorption of N vs P and this foliar N:P ratio, consistent across species, growth-forms, and vegetation-types globally. Moreover, according to the relative resorption hypothesis, communities with higher/lower foliar N:P (more likely P/N limited) tend to produce litter with disproportionately higher/lower N:P, causing a worsening status of P/N availability; this positive feedback may somehow be counteracted by several negative-feedback mechanisms. Compared to N, P generally shows higher variability in resorption efficiency (proportion resorbed), and higher resorption sensitivity to nutrient availability, implying that the resorption of P seems more important for plant nutrient conservation and N:P stoichiometry. Our findings elucidate the nutrient limitation effects on resorption efficiency in woody plants at the global scale, and thus can improve the understanding of nutrient resorption process in plants. This study also suggests the importance of the foliar N:P ratio as a key parameter for biogeochemical modeling, and the relative resorption

  16. Pulmonary Macrophage Transplantation Therapy

    PubMed Central

    Suzuki, Takuji; Arumugam, Paritha; Sakagami, Takuro; Lachmann, Nico; Chalk, Claudia; Sallese, Anthony; Abe, Shuichi; Trapnell, Cole; Carey, Brenna; Moritz, Thomas; Malik, Punam; Lutzko, Carolyn; Wood, Robert E.; Trapnell, Bruce C.

    2014-01-01

    SUMMARY Bone marrow transplantation is an effective cell therapy but requires myeloablation, which increases infection-risk and mortality. Recent lineage-tracing studies documenting that resident macrophage populations self-maintain independent of hematologic progenitors prompted us to consider organ-targeted, cell-specific therapy. Here, using GM-CSF receptor-β deficient (Csf2rb−/−) mice that develop a myeloid cell disorder identical to hereditary pulmonary alveolar proteinosis (hPAP) in children with CSF2RA/CSF2RB mutations, we show that pulmonary macrophage transplantation (PMT) of either wild-type or Csf2rb-gene-corrected macrophages without myeloablation was safe, well-tolerated, and that one administration corrected the lung disease, secondary systemic manifestations, normalized disease-related biomarkers, and prevented disease-specific mortality. PMT-derived alveolar macrophages persisted for at least one year as did therapeutic effects. Results identify mechanisms regulating alveolar macrophage population size in health and disease, indicate that GM-CSF is required for phenotypic determination of alveolar macrophages, and support translation of PMT as the first specific therapy for children with hPAP. PMID:25274301

  17. The Elusive Antifibrotic Macrophage

    PubMed Central

    Adhyatmika, Adhyatmika; Putri, Kurnia S. S.; Beljaars, Leonie; Melgert, Barbro N.

    2015-01-01

    Fibrotic diseases, especially of the liver, the cardiovascular system, the kidneys, and the lungs, account for approximately 45% of deaths in Western societies. Fibrosis is a serious complication associated with aging and/or chronic inflammation or injury and cannot be treated effectively yet. It is characterized by excessive deposition of extracellular matrix (ECM) proteins by myofibroblasts and impaired degradation by macrophages. This ultimately destroys the normal structure of an organ, which leads to loss of function. Most efforts to develop drugs have focused on inhibiting ECM production by myofibroblasts and have not yielded many effective drugs yet. Another option is to stimulate the cells that are responsible for degradation and uptake of excess ECM, i.e., antifibrotic macrophages. However, macrophages are plastic cells that have many faces in fibrosis, including profibrotic behavior-stimulating ECM production. This can be dependent on their origin, as the different organs have tissue-resident macrophages with different origins and a various influx of incoming monocytes in steady-state conditions and during fibrosis. To be able to pharmacologically stimulate the right kind of behavior in fibrosis, a thorough characterization of antifibrotic macrophages is necessary, as well as an understanding of the signals they need to degrade ECM. In this review, we will summarize the current state of the art regarding the antifibrotic macrophage phenotype and the signals that stimulate its behavior. PMID:26618160

  18. Macrophage polarization in pathology.

    PubMed

    Sica, Antonio; Erreni, Marco; Allavena, Paola; Porta, Chiara

    2015-11-01

    Macrophages are cells of the innate immunity constituting the mononuclear phagocyte system and endowed with remarkable different roles essential for defense mechanisms, development of tissues, and homeostasis. They derive from hematopoietic precursors and since the early steps of fetal life populate peripheral tissues, a process continuing throughout adult life. Although present essentially in every organ/tissue, macrophages are more abundant in the gastro-intestinal tract, liver, spleen, upper airways, and brain. They have phagocytic and bactericidal activity and produce inflammatory cytokines that are important to drive adaptive immune responses. Macrophage functions are settled in response to microenvironmental signals, which drive the acquisition of polarized programs, whose extremes are simplified in the M1 and M2 dichotomy. Functional skewing of monocyte/macrophage polarization occurs in physiological conditions (e.g., ontogenesis and pregnancy), as well as in pathology (allergic and chronic inflammation, tissue repair, infection, and cancer) and is now considered a key determinant of disease development and/or regression. Here, we will review evidence supporting a dynamic skewing of macrophage functions in disease, which may provide a basis for macrophage-centered therapeutic strategies.

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

    PubMed

    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.

  20. Soil nutrient availability and reproductive effort drive patterns in nutrient resorption in Pentachlethra macroloba

    Treesearch

    K. L. Tully; Tana Wood; A. M. Schwantes; D. Lawrence

    2013-01-01

    The removal of nutrients from senescing tissues, nutrient resorption, is a key strategy for conserving nutrients in plants. However, our understanding of what drives patterns of nutrient resorption in tropical trees is limited. We examined the effects of nutrient sources (stand-level and tree-level soil fertility) and sinks (reproductive effort) on nitrogen (N) and...

  1. Effect of bisphosphonates on root resorption after tooth replantation - a systematic review.

    PubMed

    Najeeb, Shariq; Siddiqui, Fahad; Khurshid, Zohaib; Zohaib, Sana; Zafar, Muhammad Sohail; Ansari, Shazia Akbar

    2017-04-01

    Replantation of avulsed teeth may lead to root resorption. Bisphosphonates (BPs), a class of drugs of used to treat resorptive diseases of the bone such as osteoporosis and Paget's disease, have been observed to exert an antiresorptive effect on periodontal bone as well. The antiresorptive properties of BPs could prove them useful in preventing root resorption of replanted avulsed teeth. The aim of this systematic review was to analyze and summarize the currently available literature concerning the use of BPs in preventing root resorption of avulsed teeth. PubMed/MEDLINE, Google Scholar, ISI Web of Knowledge, and Embase databases were searched using keywords 'bisphosphonate', 'replantation', and 'tooth'. Quality assessment of each study was carried out. In addition, general characteristics and outcomes of each study were summarized. After exclusion of 116 irrelevant articles, 10 animal studies were included in this review. The majority of the studies suggest that surface application of zoledronate or alendronate reduces root resorption of replanted teeth in animal models. Surface treatment with etidronate had no significant effect on root resorption, and intracanal etidronate accelerated resorption. Surface application of zoledronate and alendronate reduces root resorption of replanted teeth in animal models. However, the efficacy of intracanal usage of BPs is still debatable. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. [The role of pulp in the root resorption of primary teeth without permanent tooth germs].

    PubMed

    Lin, Bi-chen; Yang, Jie; Zhao, Yu-ming; Ge, Li-hong

    2011-03-01

    To investigate the role of pulp in the root resorption of primary teeth without permanent tooth germs. The animal model without permanent tooth germs was established by surgery in Beagle dog. The root resorption was observed by taking periapical radiographs periodically. The samples of mandibular bone and pulp at different resorption stages were collected. The distribution of odontoclasts and the activating factor was analyzed by histological staining and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). The role of pulp in the root resorption of primary teeth was tested by early pulpectomy. In the root resorption of primary molars without permanent teeth germs, a large number of odontoclasts were present on the pulpal surface of the root canal. Semi-quantification RT-PCR showed that the ratios of the expression of receptor activator of NF-κB ligand (RANKL) mRNA and β-actin in the pulp of permanent teeth and primary teeth without permanent teeth germ during different periods of root resorption are 0.1314, 0.1901, 0.2111 and 0.6058 (P > 0.05). The root resorption of primary teeth without permanent teeth germs in test groups was about 5 weeks later than that of control group. The pulp of primary tooth played an important role in the root resorption of primary tooth without permanent tooth germ.

  3. Macrophage polarization in inflammatory diseases.

    PubMed

    Liu, Yan-Cun; Zou, Xian-Biao; Chai, Yan-Fen; Yao, Yong-Ming

    2014-01-01

    Diversity and plasticity are two hallmarks of macrophages. M1 macrophages (classically activated macrophages) are pro-inflammatory and have a central role in host defense against infection, while M2 macrophages (alternatively activated macrophages) are associated with responses to anti-inflammatory reactions and tissue remodeling, and they represent two terminals of the full spectrum of macrophage activation. Transformation of different phenotypes of macrophages regulates the initiation, development, and cessation of inflammatory diseases. Here we reviewed the characters and functions of macrophage polarization in infection, atherosclerosis, obesity, tumor, asthma, and sepsis, and proposed that targeting macrophage polarization and skewing their phenotype to adapt to the microenvironment might hold great promise for the treatment of inflammatory diseases.

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

    PubMed Central

    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

  5. Histological characterization of bleaching-induced external root resorption in dogs.

    PubMed

    Rotstein, I; Friedman, S; Mor, C; Katznelson, J; Sommer, M; Bab, I

    1991-09-01

    External root resorption occasionally develops after intracoronal bleaching with hydrogen peroxide. In this study, an experimental model was established to study thermocatalytic bleaching-induced root resorption in dogs. Histological examination after 6 months revealed that 18% of the teeth had root resorption lesions. The lesions could be divided into three types. In type I, root excavations were associated with a dense inflammatory cell infiltrate. Type II lesions were characterized by granulation tissue formation. In type III, the lesions were filled with reparative cementum. The three types probably represent different phases of one process. Calcium hydroxide had no effect on the occurrence or type of resorption. The instability of hydrogen peroxide and the presence of inflammatory resorption lesions 6 months postoperatively suggest hydrogen peroxide-induced toxic radicals or denaturants as potential irritants.

  6. Sharp curvature of premolar resulting in external apical root resorption of the neighbouring molar.

    PubMed

    Ulusoy, Ozgür İlke Atasoy

    2011-01-01

    This case report describes an external apical root resorption resulted from the unusual root morphology of the neighbouring tooth. A 28-year-old female was referred to the department of endodontics with a complaint of intense pain in her maxillary second premolar tooth. The clinical and radiographical evaluation revealed an external apical resorption in the mesial root of the maxillary first molar, which shows close proximity to the severely curved root of the premolar. A successful root canal treatment of the premolar was performed using anticurvature filing method. However, molar tooth received no curative treatment. One-year followup of the apical external resorption did not show any progression. External apical root resorption affecting single permanent tooth may be induced from the pressure exerted during the eruption of the adjacent tooth with unusual root morphology. The preferred approach for the management of such apical resorption cases includes long-term observation and no curative treatment.

  7. Reactive dentures: a novel approach to decrease residual ridge resorption

    PubMed Central

    Reddy, Kesava K; Prasanna, Renuka G S; Sundaresh, K J; Mallikarjuna, Rachappa

    2013-01-01

    The need for reduction of traumatic forces transmitted through the prosthesis has long been recognised and studies have shown that either a soft acrylic resin/silicone rubber can serve as a stress distributor and absorb some of the forces applied to the teeth. These dentures permit reaction to impacting forces which allows independent movement of one or more teeth in function unlike the conventional dentures. A completely edentulous patient with adequate inter-ridge distance was selected for the case, the dentures with soft liner placed between the patient's teeth and denture base were fabricated. This report presents a completely new technique to reduce the ridge resorption and facilitate patient comfort. PMID:23576651

  8. Osseointegration of hydroxyapatite and remodeling-resorption of tricalciumphosphate ceramics.

    PubMed

    Draenert, Miriam; Draenert, Alice; Draenert, Klaus

    2013-04-01

    Cancellous bone defects surrounded by still intact bone structures never heal. Ceramics offer a solution providing osteoconductive scaffolds. The purpose of the study is to evaluate whether structured β-TCP and HA implants can reconstruct cancellous bone defects, which role micro- and macro-porosity, stiffness and surface area play; finally the indication for both materials based on its resorbability. 10 German Shepard dogs were operated on both tibial heads implanting shell-like fully interconnected ceramic cylinders, using a wet grinding hollow drill coated with diamonds. β-TCP was compared with HA. A polychromatic sequential labelling with 4 different fluorochromes controlled bone formation dynamics. Non-decalcifying histology after perfusion fixation and vessel casting was performed. μ-CT was combined with high resolution microradiography and histology on thin ground crossections. The stages after 6 weeks, 2, 3, 4 months and 15 months were evaluated. In spite of osseointegration of HA and β-TCP, the osseointegration of both materials was completely different. Both shell-like bone void fillers were osseointegrated in a sandwich-like manner. HA yielded primarily a reinforcement of the recipient's cancellous-bone bed and full osseointegration after 4 months, whereas β-TCP-implants were fully osseointegrated after 6 weeks. HA did not show signs of resorption. The resorption of the β-TCP resulted during remodelling. The final stage showed restitution "ad integrum" of the β-TCP defects with a physiological architecture, whereas HA was integrated in the cancellous bone construction providing 600 μm measuring macropores showing osteoinductive properties. Copyright © 2013 Wiley Periodicals, Inc.

  9. Integrating Immunometabolism and Macrophage Diversity

    PubMed Central

    Artyomov, Maxim; Sergushichev, Alexey; Schilling, Joel D.

    2017-01-01

    Macrophages are heterogeneous cells that play a key role in inflammatory and tissue reparative responses. Over the past decade it has become clear that shifts in cellular metabolism are important determinants of macrophage function and phenotype. At the same time, our appreciation of macrophage diversity in vivo has also been increasing. Factors such as cell origin and tissue localization are now recognized as important variables that influence macrophage biology. Whether different macrophage populations also have unique metabolic phenotypes has not been extensively explored. In this article, we will discuss the importance of understanding how macrophage origin can modulate metabolic programming and influence inflammatory responses. PMID:27771140

  10. Nutrient limitation results in juvenile hormone-mediated resorption of previtellogenic ovarian follicles in mosquitoes.

    PubMed

    Clifton, Mark E; Noriega, Fernando G

    2011-09-01

    Juvenile hormone (JH) is a central hormonal regulator of previtellogenic development in female Aedes aegypti mosquitoes. JH levels are low at eclosion and increase during the first day after adult emergence. This initial rise in JH is essential for female reproductive maturation. After previtellogenic maturation is complete, the mosquito enters a 'state-of-arrest' during which JH synthesis continues at a slower pace and further ovary development is repressed until a blood meal is taken. By examining the relationships between juvenile hormone, follicular resorption and nutrition in A. aegypti, we were able to define a critical role of JH during the previtellogenic resting stage. The rate of follicular resorption in resting stage mosquitoes is dependent on nutritional quality. Feeding water alone caused the rate of follicular resorption to reach over 20% by day 7 after emergence. Conversely, feeding a 20% sucrose solution caused resorption to remain below 5% during the entire experimental period. Mosquitoes fed 3% sucrose show rates of resorption intermediate between water and 20% sucrose and only reached 10% by day 7 after emergence. Follicular resorption is related to JH levels. Ligated abdomens separated from a source of JH (the corpora allata) showed an increase in resorption comparable to similarly aged starved mosquitoes (16%). Resorption in ligated abdomens was reduced to 6% by application of methoprene. The application of methoprene was also sufficient to prevent resorption in intact mosquitoes starved for 48 h (14% starved vs. 4% starved with methoprene). Additionally, active caspases were localized to resorbing follicles indicating that an apoptotic cell-death mechanism is responsible for follicular resorption during the previtellogenic resting stage. Taken together, these results indicate that JH mediates reproductive trade-offs in resting stage mosquitoes in response to nutrition.

  11. Nutrient limitation results in juvenile hormone-mediated resorption of previtellogenic ovarian follicles in mosquitoes

    PubMed Central

    Clifton, Mark E.; Noriega, Fernando G.

    2011-01-01

    Juvenile hormone (JH) is a central hormonal regulator of previtellogenic development in female Aedes aegypti mosquitoes. JH levels are low at eclosion and increase during the first day after adult emergence. This initial rise in JH is essential for female reproductive maturation. After previtellogenic maturation is complete, the mosquito enters a ‘state-of-arrest’ during which JH synthesis continues at a slower pace and further ovary development is repressed until a blood meal is taken. By examining the relationships between juvenile hormone, follicular resorption and nutrition in A. aegypti, we were able to define a critical role of JH during the previtellogenic resting stage. The rate of follicular resorption in resting stage mosquitoes is dependent on nutritional quality. Feeding water alone caused the rate of follicular resorption to reach over 20% by day 7 after emergence. Conversely, feeding a 20% sucrose solution caused resorption to remain below 5% during the entire experimental period. Mosquitoes fed 3% sucrose show rates of resorption intermediate between water and 20% sucrose and only reached 10% by day 7 after emergence. Follicular resorption is related to JH levels. Ligated abdomens separated from a source of JH (the corpora allata) showed an increase in resorption comparable to similarly aged starved mosquitoes (16%). Resorption in ligated abdomens was reduced to 6% by application of methoprene. The application of methoprene was also sufficient to prevent resorption in intact mosquitoes starved for 48 hours (14% starved vs. 4% starved with methoprene). Additionally, active caspases were localized to resorbing follicles indicating that an apoptotic cell-death mechanism is responsible for follicular resorption during the previtellogenic resting stage. Taken together, these results indicate that JH mediates reproductive trade-offs in resting stage mosquitoes in response to nutrition. PMID:21708165

  12. Macrophage Responses to Hypoxia

    PubMed Central

    Lewis, Claire; Murdoch, Craig

    2005-01-01

    The presence of multiple areas of hypoxia (low oxygen tension) is a hallmark feature of human and experimental tumors. Monocytes are continually recruited into tumors, differentiate into tumor-associated macrophages (TAMs), and then accumulate in these hypoxic areas. A number of recent studies have shown that macrophages respond to the levels of hypoxia found in tumors by up-regulating such transcription factors as hypoxia-inducible factors 1 and 2, which in turn activate a broad array of mitogenic, proinvasive, proangiogenic, and prometastatic genes. This could explain why high numbers of TAMs correlate with poor prognosis in various forms of cancer. In this review, we assess the evidence for hypoxia activating a distinct, protumor phenotype in macrophages and the possible effect of this on the growth, invasion, angiogenesis, and immune evasion of tumors. We also discuss current attempts to selectively target TAMs for destruction or to use them to deliver gene therapy specifically to hypoxic tumor sites. PMID:16127144

  13. Macrophages and iron metabolism

    PubMed Central

    Soares, Miguel P.; Hamza, Iqbal

    2016-01-01

    Iron is a transition metal that due to its inherent ability to exchange electrons with a variety of molecules is essential to support life. In mammals, iron exists mostly in the form of heme, enclosed within an organic protoporphyrin ring and functioning primarily as a prosthetic group in proteins. Paradoxically, free iron also has the potential to become cytotoxic when electron exchange with oxygen is unrestricted and catalyzes the production of reactive oxygen species. These biological properties demand that iron metabolism is tightly regulated such that iron is available for core biological functions whilst preventing its cytotoxic effects. Macrophages play a central role in establishing this delicate balance. Here, we review the impact of macrophages on heme-iron metabolism and, reciprocally, how heme-iron modulates macrophage function. PMID:26982356

  14. [Macrophages in asthma].

    PubMed

    Medina Avalos, M A; Orea Solano, M

    1997-01-01

    Every time they exist more demonstrations of the paper than performs the line monocytes-macrophage in the patogenesis of the bronchial asthma. The mononuclear phagocytes cells, as the alveolar macrophages, also they can be activated during allergic methods. The monocytes macrophages are possible efficient inductors of the inflammation; this due to the fact that they can secrete inflammatory mediators, between those which are counted the pre-forming granules of peptides, metabolites of oxidation activation, activator of platelets activator and metabolites of the arachidonic acid. The identification of IL-1 in the liquidate of the bronchial ablution of sick asthmatic, as well as the identification of IL-1 in the I bronchioalveolar washing of places of allergens cutaneous prick, supports the activation concept mononuclear of phagocytic cells in allergic sufferings.

  15. Monocyte and macrophage heterogeneity.

    PubMed

    Gordon, Siamon; Taylor, Philip R

    2005-12-01

    Heterogeneity of the macrophage lineage has long been recognized and, in part, is a result of the specialization of tissue macrophages in particular microenvironments. Circulating monocytes give rise to mature macrophages and are also heterogeneous themselves, although the physiological relevance of this is not completely understood. However, as we discuss here, recent studies have shown that monocyte heterogeneity is conserved in humans and mice, allowing dissection of its functional relevance: the different monocyte subsets seem to reflect developmental stages with distinct physiological roles, such as recruitment to inflammatory lesions or entry to normal tissues. These advances in our understanding have implications for the development of therapeutic strategies that are targeted to modify particular subpopulations of monocytes.

  16. Deletion of calponin 2 in macrophages attenuates the severity of inflammatory arthritis in mice.

    PubMed

    Huang, Qi-Quan; Hossain, M Moazzem; Sun, Wen; Xing, Lianping; Pope, Richard M; Jin, J-P

    2016-10-01

    Calponin is an actin cytoskeleton-associated protein that regulates motility-based cellular functions. Three isoforms of calponin are present in vertebrates, among which calponin 2 encoded by the Cnn2 gene is expressed in multiple types of cells, including blood cells from the myeloid lineage. Our previous studies demonstrated that macrophages from Cnn2 knockout (KO) mice exhibit increased migration and phagocytosis. Intrigued by an observation that monocytes and macrophages from patients with rheumatoid arthritis had increased calponin 2, we investigated anti-glucose-6-phosphate isomerase serum-induced arthritis in Cnn2-KO mice for the effect of calponin 2 deletion on the pathogenesis and pathology of inflammatory arthritis. The results showed that the development of arthritis was attenuated in systemic Cnn2-KO mice with significantly reduced inflammation and bone erosion than that in age- and stain background-matched C57BL/6 wild-type mice. In vitro differentiation of calponin 2-null mouse bone marrow cells produced fewer osteoclasts with decreased bone resorption. The attenuation of inflammatory arthritis was confirmed in conditional myeloid cell-specific Cnn2-KO mice. The increased phagocytotic activity of calponin 2-null macrophages may facilitate the clearance of autoimmune complexes and the resolution of inflammation, whereas the decreased substrate adhesion may reduce osteoclastogenesis and bone resorption. The data suggest that calponin 2 regulation of cytoskeleton function plays a novel role in the pathogenesis of inflammatory arthritis, implicating a potentially therapeutic target. Copyright © 2016 the American Physiological Society.

  17. Resorption controls bone anabolism driven by parathyroid hormone (PTH) receptor signaling in osteocytes.

    PubMed

    Rhee, Yumie; Lee, Eun-Young; Lezcano, Virginia; Ronda, Ana C; Condon, Keith W; Allen, Matthew R; Plotkin, Lilian I; Bellido, Teresita

    2013-10-11

    The contribution of remodeling-based bone formation coupled to osteoclast activity versus modeling-based bone formation that occurs independently of resorption, to the anabolic effect of PTH remains unclear. We addressed this question using transgenic mice with activated PTH receptor signaling in osteocytes that exhibit increased bone mass and remodeling, recognized skeletal effects of PTH elevation. Direct inhibition of bone formation was accomplished genetically by overexpressing the Wnt antagonist Sost/sclerostin; and resorption-dependent bone formation was inhibited pharmacologically with the bisphosphonate alendronate. We found that bone formation induced by osteocytic PTH receptor signaling on the periosteal surface depends on Wnt signaling but not on resorption. In contrast, bone formation on the endocortical surface results from a combination of Wnt-driven increased osteoblast number and resorption-dependent osteoblast activity. Moreover, elevated osteoclasts and intracortical/calvarial porosity is exacerbated by overexpressing Sost and reversed by blocking resorption. Furthermore, increased cancellous bone is abolished by Wnt inhibition but further increased by blocking resorption. Thus, resorption induced by PTH receptor signaling in osteocytes is critical for full anabolism in cortical bone, but tempers bone gain in cancellous bone. Dissecting underlying mechanisms of PTH receptor signaling would allow targeting actions in different bone compartments, enhancing the therapeutic potential of the pathway.

  18. Resorption Controls Bone Anabolism Driven by Parathyroid Hormone (PTH) Receptor Signaling in Osteocytes*

    PubMed Central

    Rhee, Yumie; Lee, Eun-Young; Lezcano, Virginia; Ronda, Ana C.; Condon, Keith W.; Allen, Matthew R.; Plotkin, Lilian I.; Bellido, Teresita

    2013-01-01

    The contribution of remodeling-based bone formation coupled to osteoclast activity versus modeling-based bone formation that occurs independently of resorption, to the anabolic effect of PTH remains unclear. We addressed this question using transgenic mice with activated PTH receptor signaling in osteocytes that exhibit increased bone mass and remodeling, recognized skeletal effects of PTH elevation. Direct inhibition of bone formation was accomplished genetically by overexpressing the Wnt antagonist Sost/sclerostin; and resorption-dependent bone formation was inhibited pharmacologically with the bisphosphonate alendronate. We found that bone formation induced by osteocytic PTH receptor signaling on the periosteal surface depends on Wnt signaling but not on resorption. In contrast, bone formation on the endocortical surface results from a combination of Wnt-driven increased osteoblast number and resorption-dependent osteoblast activity. Moreover, elevated osteoclasts and intracortical/calvarial porosity is exacerbated by overexpressing Sost and reversed by blocking resorption. Furthermore, increased cancellous bone is abolished by Wnt inhibition but further increased by blocking resorption. Thus, resorption induced by PTH receptor signaling in osteocytes is critical for full anabolism in cortical bone, but tempers bone gain in cancellous bone. Dissecting underlying mechanisms of PTH receptor signaling would allow targeting actions in different bone compartments, enhancing the therapeutic potential of the pathway. PMID:23963454

  19. Oral status and prosthetic factors related to residual ridge resorption in elderly subjects.

    PubMed

    Xie, Q; Närhi, T O; Nevalainen, J M; Wolf, J; Ainamo, A

    1997-10-01

    Our earlier studies on edentulous elderly subjects have shown associations of severe resorption in the mandibular residual ridge with female gender and systemic diseases. The aim of this study was to examine whether other factors also were related to residual ridge resorption (RRR). Among 177 edentulous elderly subjects effects on RRR were investigated with regard to history of edentulousness and denture-wearing, the condition of the dentures and soft tissues, dental status of the opposing jaw, and oral hygiene habits. No significant association was found between degree of resorption and duration of edentulousness in either the mandible or the maxilla. RRR was related to denture quality (P < 0.05); however, severe resorption was not. In the maxilla previous use of removable partial dentures was a factor contributing to the resorption (odds ratio (OR), 2.4); flabby ridge was related to the severity of the resorption (OR, 2.4). This study showed local factors related to RRR more often in the maxilla than in the mandible, thus suggesting that severe resorption in the mandible is influenced more by systemic factors than by those investigated in this study.

  20. Root resorption of primary molars without successor teeth. An experimental study in the beagle dog.

    PubMed

    Lin, Bi-Chen; Zhao, Yu-Ming; Yang, Jie; Ge, Li-Hong

    2012-04-01

    Tooth agenesis is a common craniofacial congenital malformation in humans, but little is known about the mechanisms of root resorption in this condition. The purpose of this study was to investigate the mechanisms of root resorption in primary molars without successors. An animal model without permanent tooth germs was established by surgery in beagles. The times of onset of primary molar root resorption, with and without successors, were compared. The distribution of immune cells, odontoclasts, and their activating factors were determined by histochemistry and immunohistochemistry. Root resorption of primary mandibular molars without successors began later than physiological resorption. In primary molars without permanent germs, odontoclasts and immune cells were present mainly in the apical pulp at the start of root resorption, whereas in control teeth receptor activator of nuclear factor-κB ligand (RANKL)-positive cells were found mainly in the region of the periodontal ligament. CD14(+) and CD3(+) cells were found in both the pulp and the periodontal ligament region. These results suggest that the dental pulp of primary molars, as well as immune cells, may play an important role in root resorption in primary molars without permanent tooth germs.

  1. Severe root resorption resulting from orthodontic treatment: Prevalence and risk factors

    PubMed Central

    Maués, Caroline Pelagio Raick; do Nascimento, Rizomar Ramos; Vilella, Oswaldo de Vasconcellos

    2015-01-01

    OBJECTIVE: To assess the prevalence of severe external root resorption and its potential risk factors resulting from orthodontic treatment. METHODS: A randomly selected sample was used. It comprised conventional periapical radiographs taken in the same radiology center for maxillary and mandibular incisors before and after active orthodontic treatment of 129 patients, males and females, treated by means of the Standard Edgewise technique. Two examiners measured and defined root resorption according to the index proposed by Levander et al. The degree of external apical root resorption was registered defining resorption in four degrees of severity. To assess intra and inter-rater reproducibility, kappa coefficient was used. Chi-square test was used to assess the relationship between the amount of root resorption and patient's sex, dental arch (maxillary or mandibular), treatment with or without extractions, treatment duration, root apex stage (open or closed), root shape, as well as overjet and overbite at treatment onset. RESULTS: Maxillary central incisors had the highest percentage of severe root resorption, followed by maxillary lateral incisors and mandibular lateral incisors. Out of 959 teeth, 28 (2.9%) presented severe root resorption. The following risk factors were observed: anterior maxillary teeth, overjet greater than or equal to 5 mm at treatment onset, treatment with extractions, prolonged therapy, and degree of apex formation at treatment onset. CONCLUSION: This study showed that care must be taken in orthodontic treatment involving extractions, great retraction of maxillary incisors, prolonged therapy, and/or completely formed apex at orthodontic treatment onset. PMID:25741825

  2. Scanning electron microscopic description of cellular activity and mineral changes in feline odontoclastic resorptive lesions.

    PubMed

    Gauthier, O; Boudigues, S; Pilet, P; Aguado, E; Heymann, D; Daculsi, G

    2001-12-01

    The cellular activity and changes in mineral composition of dental tissues involved in feline odontoclastic resorptive lesions were investigated. Teeth with at least 1 lesion (n = 10) were extracted from 10 different cats that were presented primarily for chronic gingivostomatitis and/or severe periodontal disease. Scanning electron microscopic methods were used to determine the presence of resorptive cells in 8 teeth while 2 teeth were evaluated for pathologic changes in dental mineral composition. Observations were complicated by the presence of organic wear on the dental surfaces, however resorptive cells could be clearly identified in feline odontoclastic resorptive lesions. Resorptive cells had morphologic features indicative of "osteoclast-like" cells or odontoclasts. Resorptive cell activity created a resorption area of darker dentin continuous with physiologic dentin. The darker dentin area seemed poorly mineralized and showed a significantly lower calcium/phosphorous ratio compared with adjacent physiologic denting in 1 tooth. A significantly higher level of magnesium combined with available carbonate ions may have increased the solubility in areas of darker dentin.

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

    PubMed Central

    Xue, Liming; Jiao, Lei; Wang, Yin; Nie, Yan; Han, Ting; Jiang, Yiping; Rahman, Khalid; Zhang, Qiaoyan; Qin, Luping

    2012-01-01

    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. PMID:23243450

  4. Identification of factors associated with pathological root resorption in traumatized primary teeth.

    PubMed

    Cardoso, Mariane; Rocha, Maria José de Carvalho

    2008-06-01

    The aim of this study was to determine the factors associated with the development of pathological root resorptions in traumatized primary teeth. Based on Dental Reports on Traumatism from the Assistance Program for the Traumatized Patient, 90 children were selected. Among these children, 45 did not present pathological root resorption, while 45 did (23 replacement root resorptions and 22 external inflammatory root resorptions). Possible factors associated with the development of the pathological resorption include: (i) over 18 months or over 52 months of age, (ii) complicated trauma, and (iii) presence of more than one trauma in the same tooth. Using the chi-squared test, it was verified that trauma recurrence was considered to be a factor associated with the development of pathological root resorption (chi(2) = 3.636; P < 0.05). Through the univaried logistic regression test, it was revealed that children with trauma recurrence present a 2.6 times higher chance of developing pathological root resorptions when compared with children that did not report trauma recurrence. Through the univaried logistic regression test, it was also observed that the association of two or three factors caused the chances of pathological root resorption development to increase by 3.8 times in 18-month-old children or older (95% CI: 1.5-9.7) and by 5.1 times in 52-month-old children or older (95% CI: 1.5-17). Trauma recurrence in the same primary tooth is associated with pathological root resorption, and the interaction among two or three factors increases the chance of developing such sequelae.

  5. Evaluation of simulated external root resorptions with digital radiography and digital subtraction radiography.

    PubMed

    Ono, Evelise; Medici Filho, Edmundo; Faig Leite, Horacio; Tanaka, Jefferson Luis Oshiro; De Moraes, Mari Eli Leonelli; De Melo Castilho, Julio Cezar

    2011-03-01

    Root resorption can cause damage in orthodontic patients. Digital subtraction radiography (DSR) is a useful resource for the detection of mineral losses. The purpose of this study was to compare the efficacy of digital radiography (DR) and DSR in detecting simulated external root resorption. Examiner agreement between the 2 techniques was also evaluated. Root resorptions of various sizes were simulated on the apical and lingual aspects of 49 teeth from 9 dry human mandibles. The teeth were radiographed in standardized conditions. The radiographs were registered with Regeemy Image Registration and Mosaicking (version 0.2.43-RCB, DPI-INPE, São José dos Campos, São Paulo, Brazil) and subtracted with Image Tool (University of Texas Health Science Center at San Antonio). The subtracted images and the digital radiographs were evaluated by 3 oral radiologists. No statistically significant differences were found for the methods in the detection of apical root resorptions, independently from lesion size, and of lingual resorptions of 1.2 mm or greater. DSR was significantly better than DR for detection of lingual resorptions up to 1 mm. Resorptions less than 0.5 mm were not precisely detected by either method. DSR provided better intraexaminer and interexaminer agreement than did DR. Both methods are precise for detection of apical root resorptions as small as 0.5 mm and lingual resorptions of 1 mm or more. However, DSR frequently performed better than did DR. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  6. Distribution of mast cells and macrophages and expression of interleukin-6 in periapical cysts.

    PubMed

    Bracks, Igor Vieira; Armada, Luciana; Gonçalves, Lúcio Souza; Pires, Fábio Ramôa

    2014-01-01

    Mast cells and macrophages are important components of the inflammatory infiltrate found in inflammatory periapical diseases. Several cytokines participate in the mechanisms of inflammation, tissue repair, and bone resorption associated with periapical cysts. The aim of the present study was to evaluate the distribution of mast cells and macrophages and the expression of interleukin-6 (IL-6) in periapical cysts. Thirty periapical cysts were selected for the study, and clinical, demographic, and gross information from the cases was obtained from the laboratory records. Five-micrometer sections stained with hematoxylin-eosin were reviewed for analysis of the microscopic features of the cysts, and 3-μm sections on silanized slides were used for immunohistochemical reactions with anti-tryptase, anti-CD68, and anti-IL-6. There was no statistically significant difference in the mean number of mast cells and macrophages when comparing superficial and deep regions of the fibrous capsule of the cysts. Mean number of mast cells on the superficial region of the fibrous capsule was higher in cysts showing intense superficial inflammation and exocytosis. Macrophages were more commonly found in areas showing IL-6 expression, and IL-6 was less expressed in deep regions of the fibrous capsule in cysts showing greater gross volume. The results reinforced the participation of mast cells and macrophages in the pathogenesis of periapical cysts and suggested that IL-6 is not the major bone resorption mediator in larger periapical cysts. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Elevation of pro-inflammatory cytokine levels following anti-resorptive drug treatment is required for osteonecrosis development in infectious osteomyelitis

    PubMed Central

    Morita, Mayu; Iwasaki, Ryotaro; Sato, Yuiko; Kobayashi, Tami; Watanabe, Ryuichi; Oike, Takatsugu; Nakamura, Satoshi; Keneko, Yosuke; Miyamoto, Kana; Ishihara, Kazuyuki; Iwakura, Yoichiro; Ishii, Ken; Matsumoto, Morio; Nakamura, Masaya; Kawana, Hiromasa; Nakagawa, Taneaki; Miyamoto, Takeshi

    2017-01-01

    Various conditions, including bacterial infection, can promote osteonecrosis. For example, following invasive dental therapy with anti-bone resorptive agents, some patients develop osteonecrosis in the jaw; however, pathological mechanisms underlying these outcomes remain unknown. Here, we show that administration of anti-resorptive agents such as the bisphosphonate alendronate accelerates osteonecrosis promoted by infectious osteomyelitis. Potent suppression of bone turnover by these types of agents is considered critical for osteonecrosis development; however, using mouse models we found that acceleration of bone turnover by teriparatide injection did not prevent osteonecrosis but rather converted osteoclast progenitors to macrophages expressing inflammatory cytokines, which were required for osteonecrosis development. In fact, we demonstrate that TNFα-, IL-1α/β- or IL-6-deficient mice as well as wild-type mice administered a TNFα-inhibitor were significantly resistant to development of osteonecrosis accompanying infectious myelitis, even under bisphosphonate treatment. Our data provide new insight into mechanisms underlying osteonecrosis and suggest new ways to prevent it. PMID:28387378

  8. Quartz Resorption as a Geospeedometer in Peralkaline Rhyolites

    NASA Astrophysics Data System (ADS)

    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

  9. Cone beam CT assisted re-treatment of class 3 invasive cervical resorption

    PubMed Central

    Krishnan, Unni; Moule, Alex J; Alawadhi, Abdulwahab

    2015-01-01

    Invasive cervical root resorption is an uncommon external root resorption which initiates at the cervical aspect of the tooth. This case report involves a case of cervical root resorption which was initially misdiagnosed and managed as cervical root caries. It was later diagnosed with cone beam CT and the lesion microsurgically removed and restored with resin modified glass ionomer cement. The importance of increasing awareness of this uncommon pathology and the role of cone beam CT in mapping the extent of the lesion is emphasised. PMID:25795743

  10. Mandibular resorption in progressive systemic sclerosis: a report of three cases.

    PubMed

    Auluck, A; Pai, K M; Shetty, C; Shenoi, S D

    2005-11-01

    Progressive systemic sclerosis is a generalized collagen disorder, which is characterized by fibrosis that involves skin, muscles and other organ systems like the gastrointestinal tract, lungs, heart and kidneys. Its oral manifestations include features like restricted mouth opening, widening of periodontal ligament space, pseudoankylosis, malocclusion and mandibular resorption. Mandibular resorption in systemic sclerosis is relatively uncommon and is reported only in 10% of cases. The purpose of reporting these three cases is to highlight the importance of screening all patients with advanced systemic sclerosis with panoramic radiographs. Panoramic radiographs are essential for early detection of resorption in the mandible to prevent possible consequences like pathological fractures, osteomyelitis and neuropathies.

  11. Wormhole Travel for Macrophages.

    PubMed

    Okabe, Yasutaka; Medzhitov, Ruslan

    2016-04-21

    Leukocyte recruitment is generally achieved by rapid migration of inflammatory cells out of circulation, through modified blood vessels, and into affected tissues. Now, Wang and Kubes show that macrophages can be rapidly recruited from body cavities to the liver, via a non-vascular route, where they help to coordinate tissue repair. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Intracellular fragmentation of bone resorption products by reactive oxygen species generated by osteoclastic tartrate-resistant acid phosphatase.

    PubMed

    Halleen, J M; Räisänen, S; Salo, J J; Reddy, S V; Roodman, G D; Hentunen, T A; Lehenkari, P P; Kaija, H; Vihko, P; Väänänen, H K

    1999-08-13

    Tartrate-resistant acid phosphatase (TRAP) is highly expressed in bone-resorbing osteoclasts and activated macrophages. It has been suggested that a redox-active iron in the binuclear iron center of TRAP could have the capacity to react with hydrogen peroxide to produce highly destructive reactive oxygen species (ROS). Here we show that TRAP can generate ROS in vitro and that cells over-expressing TRAP produce higher amounts of intracellular ROS than their parent cells. We further demonstrate that these ROS can be targeted to destroy collagen and other proteins. In resorbing osteoclasts, TRAP was found in transcytotic vesicles transporting matrix degradation products through the cell, suggesting that TRAP-facilitated fragmentation of endocytosed material takes place in a specific cellular compartment. These results suggest that bone matrix degradation occurs not only extracellularly in the resorption lacunae but also intracellularly in the transcytotic vesicles. We propose that proteins containing redox-active iron could represent a novel mechanism of physiological fragmentation of organic molecules. This mechanism could be important in tissue remodeling and as a defense mechanism of phagocytosing cells.

  13. Dual Effect of Chrysanthemum indicum Extract to Stimulate Osteoblast Differentiation and Inhibit Osteoclast Formation and Resorption In Vitro

    PubMed Central

    Baek, Jong Min; Cheon, Yoon-Hee; Park, Sun-Hyang; Ahn, Sung-Jun; Yoon, Kwon-Ha; Oh, Jaemin; Lee, Myeung Su

    2014-01-01

    The risk of bone-related diseases increases due to the imbalance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively. The goal in the development of antiosteoporotic treatments is an agent that will improve bone through simultaneous osteoblast stimulation and osteoclast inhibition without undesirable side effects. To achieve this goal, numerous studies have been performed to identify novel approaches using natural oriental herbs to treat bone metabolic diseases. In the present study, we investigated the effect of Chrysanthemum indicum extract (CIE) on the differentiation of osteoclastic and osteoblastic cells. CIE inhibited the formation of TRAP-positive mature osteoclasts and of filamentous-actin rings and disrupted the bone-resorbing activity of mature osteoclasts in a dose-dependent manner. CIE strongly inhibited Akt, GSK3β, and IκB phosphorylation in RANKL-stimulated bone marrow macrophages and did not show any effects on MAP kinases, including p38, ERK, and JNK. Interestingly, CIE also enhanced primary osteoblast differentiation via upregulation of the expression of alkaline phosphatase and the level of extracellular calcium concentrations during the early and terminal stages of differentiation, respectively. Our results revealed that CIE could have a potential therapeutic role in bone-related disorders through its dual effects on osteoclast and osteoblast differentiation. PMID:25530776

  14. Changing a limb muscle growth program into a resorption program

    PubMed Central

    Cai, Liquan; Das, Biswajit; Brown, Donald D.

    2007-01-01

    Summary Transgenic Xenopus laevis tadpoles that express a dominant negative form of the thyroid hormone receptor (TRDN) controlled by the cardiac actin muscle promoter (pCar) develop with very little limb muscle. Under the control of the tetracycline system the transgene can be induced at will by adding doxycycline to the rearing water. Pre existing limb muscle fibers begins to disintegrate within 2 days after up-regulation of the TRDN transgene. The muscle cells do not die even after weeks of transgene exposure when the myofibrils have degenerated completely and the tadpole is nearing death. A micro array analysis after 2 weeks of exposure to the transgene identified 25 muscle genes whose expression was altered in such a way that they might cause the muscle phenotype. These candidate genes are normally activated in growing limb muscle but they are repressed by the TRDN transgene. Several of these genes have been implicated in mammalian myopathies. However, the expression of only one of these genes, calsequestrin, is down regulated in 48 hrs and therefore might initiate the degeneration. Calsequestrin is one of several affected genes that encode proteins involved in calcium sequestration, transport and utilization in muscle suggesting that uncontrolled calcium influx into the growing limb muscle fibers causes rhabdomyolysis. Many of the same genes that are down regulated in the tail at the peak of metamorphic climax just before it is resorbed are suppressed in the transgenic limb muscle in effect turning the limb growth program into a tail resorption program. PMID:17234173

  15. [Temporomandibular joint septic arthritis with secondary condylar resorption].

    PubMed

    Constant, M; Nicot, R; Maes, J-M; Raoul, G; Ferri, J

    2016-09-01

    Septic arthritis are serious infections rarely observed for the temporomandibular joint. They are mainly hematogenous or transmitted by contiguity. Our patient presents the case of an infection of the temporomandibular joint by maxillary sinusitis of dental origin further complicated by cerebral abscess and empyema. Initial treatment consisted of an endonasal and intraoral drainage, intravenous empirical antibiotic therapy, a close clinicoradiological monitoring, and rehabilitation following a long-term active physiotherapy. Furthermore, the patient reported the onset of a dental articulation disorder with a left side premature contact and right lateral open bite, corresponding to a significant left condylar resorption. This infectious disease is very rare for temporomandibular location; however, its general and functional outcome is determined by the precocity of the treatment. It is important to know the diagnosis and the associated symptoms even if they are not very specifically described. It is essential to consider the diagnosis when facing atypical pain of the temporomandibular joint associated with trismus. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Transcriptional Regulation and Macrophage Differentiation.

    PubMed

    Hume, David A; Summers, Kim M; Rehli, Michael

    2016-06-01

    Monocytes and macrophages are professional phagocytes that occupy specific niches in every tissue of the body. Their survival, proliferation, and differentiation are controlled by signals from the macrophage colony-stimulating factor receptor (CSF-1R) and its two ligands, CSF-1 and interleukin-34. In this review, we address the developmental and transcriptional relationships between hematopoietic progenitor cells, blood monocytes, and tissue macrophages as well as the distinctions from dendritic cells. A huge repertoire of receptors allows monocytes, tissue-resident macrophages, or pathology-associated macrophages to adapt to specific microenvironments. These processes create a broad spectrum of macrophages with different functions and individual effector capacities. The production of large transcriptomic data sets in mouse, human, and other species provides new insights into the mechanisms that underlie macrophage functional plasticity.

  17. Macrophage in chronic kidney disease

    PubMed Central

    Flaquer, Maria; Cruzado, Josep M.

    2016-01-01

    Chronic kidney disease (CKD) has become a major health problem worldwide. This review describes the role of macrophages in CKD and highlights the importance of anti-inflammatory M2 macrophage activation in both renal fibrosis and wound healing processes. Furthermore, the mechanisms by which M2 macrophages induce renal repair and regeneration are still under debate and currently demand more attention. The M1/M2 macrophage balance is related to the renal microenvironment and could influence CKD progression. In fact, an inflammatory renal environment and M2 plasticity can be the major hurdles to establishing macrophage cell-based therapies in CKD. M2 macrophage cell-based therapy is promising if the M2 phenotype remains stable and is ‘fixed’ by in vitro manipulation. However, a greater understanding of phenotype polarization is still required. Moreover, better strategies and targets to induce reparative macrophages in vivo should guide future investigations in order to abate kidney diseases. PMID:27994852

  18. Macrophage polarization in kidney diseases.

    PubMed

    Tian, Shaojiang; Chen, Shi-You

    Macrophage accumulation associates closely with the degree of renal structural injury and renal dysfunction in human kidney diseases. Depletion of macrophages reduces while adoptive transfer of macrophages worsens inflammation in animal models of the renal injury. However, emerging evidence support that macrophage polarization plays a critical role in the progression of a number of kidney diseases including obstructive nephropathy, ischemia-reperfusion injury, glomerulonephritis, diabetic nephropathy, and other kidney diseases. In this mini-review, we briefly summarize the macrophage infiltration and polarization in these inflammatory and fibrotic kidney diseases, discussing the results mostly from studies in animal models. In view of the critical role of macrophage in the progression of these diseases, manipulating macrophage phenotype may be a potential effective strategy to treat various kidney diseases.

  19. The role of a posteriorly inclined condylar neck in condylar resorption after orthognathic surgery.

    PubMed

    Hwang, S J; Haers, P E; Sailer, H F

    2000-04-01

    Recently, it has been reported that a posteriorly inclined condylar neck is associated with condylar resorption following orthognathic surgery, although its role in resorption remains unknown. By cephalometric screening of 240 patients with Angle Class II occlusion 2 years after orthognathic surgery, 11 patients with postoperative condylar resorption were identified. The preoperative posterior inclination of the condylar neck and the surgical risk factors mentioned in the literature, particularly surgically induced counterclockwise rotation of the mandibular proximal segment were evaluated. In all 11 cases, the condylar neck was clearly inclined posteriorly. Counterclockwise rotation of the proximal segment was also observed in all cases, and it amounted to 6.7 degrees (2.5-12 degrees) on average. The contributing role of a posteriorly inclined condylar neck in connection with surgical mandibular movement in postoperative condylar resorption is discussed.

  20. Bone resorption under chin implants: The orthodontist's role in its diagnosis and management.

    PubMed

    Polo, Mario

    2017-01-01

    Alloplastic chin implants have been a valuable treatment modality for the correction of microgenia. Their use has provided satisfactory esthetic results by improving facial balance. However, bone resorption under these implants can occur. Case reports of 4 patients with the incidental radiographic finding of the presence of chin implants are presented. All 4 subjects had lateral cephalograms and panoramic x-rays taken as part of their orthodontic evaluation. One had a normal mandibular symphyseal contour, and 3 had bone resorption under the implants. One subject had severe resorption. In addition to panoramic and cephalometric x-rays, the subject with severe resorption also had magnetic resonance imaging and computerized tomography as part of the evaluation workup.

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

    PubMed Central

    Benarba, Bachir; Meddah, Boumedienne; Tir Touil, Aicha

    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 deoxypyridinoline (DPD) were determined by HPLC. Serum and urinary creatinine, uric acid, and urea were measured. 1 g of A. longa intake resulted in significant rise of renal serum markers and a pronounced increase of bone resorption markers. The intake of A. longa roots is detrimental for kidney function and resulted in high bone resorption, maybe due to the reduction in renal function caused by the aristolochic acids contained in the roots. PMID:24876833

  2. Mineral trioxide aggregate repair of a perforating internal resorption in a mandibular molar.

    PubMed

    Meire, Maarten; De Moor, Roeland

    2008-02-01

    Internal resorption is a rare condition in permanent teeth that poses difficulties for treatment. The challenge is complicated further if the resorption extends beyond the confines of the root. This article describes treatment of a perforating internal resorption in the mesial root of a second lower molar, with adjacent destruction of the alveolar bone. After cleaning the root canal space and the resorption lacuna by mechanical instrumentation, irrigation, and interim calcium hydroxide dressing, the defect was filled with mineral trioxide aggregate, and the canals were obturated conventionally with gutta percha and epoxy resin sealer. At a 2-year follow-up examination, no clinical abnormalities were found, and complete resolution of the alveolar bone lesion and establishment of a new periodontal ligament were observed.

  3. WHI-131 Promotes Osteoblast Differentiation and Prevents Osteoclast Formation and Resorption in Mice.

    PubMed

    Cheon, Yoon-Hee; Kim, Ju-Young; Baek, Jong Min; Ahn, Sung-Jun; Jun, Hong Young; Erkhembaatar, Munkhsoyol; Kim, Min Seuk; Lee, Myeung Su; Oh, Jaemin

    2016-02-01

    The small molecule WHI-131 is a potent therapeutic agent with anti-inflammatory, antiallergic, and antileukemic potential. However, the regulatory effects of WHI-131 on osteoblast and osteoclast activity are unclear. We examined the effects of WHI-131 on osteoblast and osteoclast differentiation with respect to bone remodeling. The production of receptor activator of nuclear factor kappa-B ligand (RANKL) by osteoblasts in response to interleukin (IL)-1 or IL-6 stimulation decreased by 56.8% or 50.58%, respectively, in the presence of WHI-131. WHI-131 also abrogated the formation of mature osteoclasts induced by IL-1 or IL-6 stimulation. Moreover, WHI-131 treatment decreased RANKL-induced osteoclast differentiation of bone marrow-derived macrophages, and reduced the resorbing activity of mature osteoclasts. WHI-131 further decreased the mRNA and protein expression levels of c-Fos and nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) by almost twofold, and significantly downregulated the mRNA expression of the following genes: tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), DC-STAMP, OC-STAMP, ATP6v0d2, and cathepsin K (CtsK) compared with the control group. WHI-131 further suppressed the phosphorylation of protein kinase B (Akt) and degradation of inhibitor of kappa B (IκB); Ca(2+) oscillation was also affected, and phosphorylation of the C-terminal Src kinase (c-Src)-Bruton agammaglobulinemia tyrosine kinase (Btk)-phospholipase C gamma 2 (PLCγ2) (c-Src-Btk-PLCg2 calcium signaling pathway) was inhibited following WHI-131 treatment. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway was activated by WHI-131, accompanied by phosphorylation of STAT3 Ser727 and dephosphorylation of STAT6. In osteoblasts, WHI-131 caused an approximately fourfold increase in alkaline phosphatase activity and Alizarin Red staining intensity. Treatment with WHI-131 increased the mRNA expression

  4. Evidence for multiple bone resorption-stimulating factors produced by normal human keratinocytes in culture.

    PubMed

    Fried, R M; Voelkel, E F; Rice, R H; Levine, L; Tashjian, A H

    1988-06-01

    Conditioned medium from cultured normal human foreskin keratinocytes enhanced the release of calcium from neonatal mouse calvaria in organ culture. Unfractionated keratinocyte-conditioned medium (KCM) stimulated bone resorption in a dose-dependent manner, but it did not increase the concentration of prostaglandin E2 (PGE2) in the bone culture medium until a maximal dose of KCM for resorption was used. Furthermore, inhibitors of PGE2 synthesis, indomethacin, ibuprofen, and piroxicam, did not inhibit KCM-induced calcium release. High concentrations of KCM increased cAMP production by calvaria in the presence of isobutylmethylxanthine, but the increase was small compared with that produced by a dose of bovine PTH that caused a similar level of bone resorption. The bone resorption-stimulating activity of KCM was not lost after incubation at 56 C for 60 min, but it was lost after heating at 100 C for 10 min. Fractionation of KCM by gel filtration chromatography revealed two distinct peaks of bone resorption-stimulating activity. One peak, KCMI, caused a significant increase in bone resorption at 2 micrograms protein/ml. KCMI did not increase medium PGE2, and inhibition of PGE2 synthesis in bone had no effect on KCMI-induced bone resorption. KCMI failed to increase cAMP production by human osteosarcoma SaOS-2 cells. Another peak, KCMII, caused a dose-dependent increase in bone resorption, and a significant increase in medium calcium was noted at a 20-fold lower concentration (0.1 microgram protein/ml) than with KCMI. In contrast to KCMI, the increase in bone resorption stimulated by KCMII was accompanied by a parallel increase in the production of PGE2, and inhibition of PGE2 synthesis completely inhibited the bone resorption-stimulating activity of KCMII. KCMII also caused an increase in cAMP production by SaOS-2 cells. We conclude that KCM contains at least two distinct bone resorption-stimulating factors, one of which acts via a PG-mediated mechanism and the other by

  5. Nutrient resorption in shrubs growing by design, and by default in Chihuahuan Desert arroyos.

    PubMed

    Killingbeck, K; Whitford, W

    2001-08-01

    In the northern stretches of the Chihuahuan Desert, the margins of ephemeral stream channels called arroyos support a unique vegetation dominated by a guild of winter-deciduous shrubs. To explore the dynamics of nutrient conservation in this assemblage of arroyo shrubs, we measured nitrogen (N) and phosphorus (P) resorption efficiency and proficiency in six species of shrubs growing in arroyos in southern New Mexico. Collectively, these six species were no more efficient or proficient at resorbing N and P from senescing leaves than shrubs growing in other environments. Resorption efficiency averaged 53% and 50% for N and P, respectively, and resorption proficiency averaged 0.80% and 0.06% for N and P, respectively. However, resorption varied significantly between species specifically restricted in their distribution to riparian habitats (obligate riparian species), and those that were not. The two obligate riparian species combined (Brickellia laciniata, Chilopsis linearis) were significantly more efficient and proficient at resorbing N than the non-obligate riparian species combined (Fallugia paradoxa, Flourensia cernua, Prosopis glandulosa, Rhus microphylla). Additionally, both Brickellia and Chilopsis were individually significantly more proficient at resorbing N than any of the other four species. The dichotomy in resorption between obligate riparian species and those that were not may have been the result of the interplay between hydrology, geomorphology, and biology. Because arroyos move in space as the movement of water erodes banks and changes channel location, some plants are found along arroyos only because the arroyos have moved to them. These plants (plants growing by default) may be less well adapted to arroyo margins than obligate riparian species (plants growing by design). Significant differences in resorption between obligate and non-obligate riparian species suggested that evolutionary history and habitat specificity may be added to the list of

  6. Convergent responses of nitrogen and phosphorus resorption to nitrogen inputs in a semiarid grassland

    USGS Publications Warehouse

    Lü, Xiao-Tao; Reed, Sasha; Yu, Qiang; He, Nian-Peng; Wang, Zheng-Wen; Han, Xing-Guo

    2013-01-01

    Human activities have significantly altered nitrogen (N) availability in most terrestrial ecosystems, with consequences for community composition and ecosystem functioning. Although studies of how changes in N availability affect biodiversity and community composition are relatively common, much less remains known about the effects of N inputs on the coupled biogeochemical cycling of N and phosphorus (P), and still fewer data exist regarding how increased N inputs affect the internal cycling of these two elements in plants. Nutrient resorption is an important driver of plant nutrient economies and of the quality of litter plants produce. Accordingly, resorption patterns have marked ecological implications for plant population and community fitness, as well as for ecosystem nutrient cycling. In a semiarid grassland in northern China, we studied the effects of a wide range of N inputs on foliar nutrient resorption of two dominant grasses, Leymus chinensis and Stipa grandis. After 4 years of treatments, N and P availability in soil and N and P concentrations in green and senesced grass leaves increased with increasing rates of N addition. Foliar N and P resorption significantly decreased along the N addition gradient, implying a resorption-mediated, positive plant–soil feedback induced by N inputs. Furthermore, N : P resorption ratios were negatively correlated with the rates of N addition, indicating the sensitivity of plant N and P stoichiometry to N inputs. Taken together, the results demonstrate that N additions accelerate ecosystem uptake and turnover of both N and P in the temperate steppe and that N and P cycles are coupled in dynamic ways. The convergence of N and P resorption in response to N inputs emphasizes the importance of nutrient resorption as a pathway by which plants and ecosystems adjust in the face of increasing N availability.

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

    NASA Astrophysics Data System (ADS)

    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

  8. Nutrient resorption patterns of plant functional groups in a tropical savanna: variation and functional significance.

    PubMed

    Ratnam, Jayashree; Sankaran, Mahesh; Hanan, Niall P; Grant, Rina C; Zambatis, Nick

    2008-08-01

    Green and senesced leaf nitrogen (N) and phosphorus (P) concentrations of different plant functional groups in savanna communities of Kruger National Park, South Africa were analyzed to determine if nutrient resorption was regulated by plant nutritional status and foliar N:P ratios. The N and P concentrations in green leaves and the N concentrations in senesced leaves differed significantly between the dominant plant functional groups in these savannas: fine-leaved trees, broad-leaved trees and grasses. However, all three functional groups reduced P to comparable and very low levels in senesced leaves, suggesting that P was tightly conserved in this tropical semi-arid savanna ecosystem. Across all functional groups, there was evidence for nutritional control of resorption in this system, with both N and P resorption efficiencies decreasing as green leaf nutrient concentrations increased. However, specific patterns of resorption and the functional relationships between nutrient concentrations in green and senesced leaves varied by nutrient and plant functional group. Functional relationships between N concentrations in green and senesced leaves were indistinguishable between the dominant groups, suggesting that variation in N resorption efficiency was largely the result of inter-life form differences in green leaf N concentrations. In contrast, observed differences in P resorption efficiencies between life forms appear to be the result of both differences in green leaf P concentrations as well as inherent differences between life forms in the fraction of green leaf P resorbed from senescing leaves. Our results indicate that foliar N:P ratios are poor predictors of resorption efficiency in this ecosystem, in contrast to N and P resorption proficiencies, which are more responsive to foliar N:P ratios.

  9. Osteoclasts on bone and dentin in vitro: mechanism of trail formation and comparison of resorption behavior.

    PubMed

    Rumpler, M; Würger, T; Roschger, P; Zwettler, E; Sturmlechner, I; Altmann, P; Fratzl, P; Rogers, M J; Klaushofer, K

    2013-12-01

    The main function of osteoclasts in vivo is the resorption of bone matrix, leaving behind typical resorption traces consisting of pits and trails. The mechanism of pit formation is well described, but less is known about trail formation. Pit-forming osteoclasts possess round actin rings. In this study we show that trail-forming osteoclasts have crescent-shaped actin rings and provide a model that describes the detailed mechanism. To generate a trail, the actin ring of the resorption organelle attaches with one side outside the existing trail margin. The other side of the ring attaches to the wall inside the trail, thus sealing that narrow part to be resorbed next (3–21 lm). This 3D configuration allows vertical resorption layer-by-layer from the surface to a depth in combination with horizontal cell movement. Thus, trails are not just traces of a horizontal translation of osteoclasts during resorption. Additionally, we compared osteoclastic resorption on bone and dentin since the latter is the most frequently used in vitro model and data are extrapolated to bone. Histomorphometric analyses revealed a material-dependent effect reflected by an 11-fold higher resorption area and a sevenfold higher number of pits per square centimeter on dentin compared to bone. An important material-independent aspect was reflected by comparable mean pit area (μm²) and podosome patterns. Hence, dentin promotes the generation of resorbing osteoclasts, but once resorption has started, it proceeds independently of material properties. Thus, dentin is a suitable model substrate for data acquisition as long as osteoclast generation is not part of the analyses.

  10. Identification of dentine sialoprotein in gingival crevicular fluid during physiological root resorption and orthodontic tooth movement.

    PubMed

    Kereshanan, Shalene; Stephenson, Pamela; Waddington, Rachel

    2008-06-01

    Root resorption is an unwanted effect of orthodontic tooth movement. Analysis of dentine proteins in gingival crevicular fluid (GCF) is a potentially safer method of quantifying root resorption compared with conventional radiographic methods. This study aimed to identify and quantify the dentine-specific matrix protein, dentine sialoprotein (DSP), released into GCF during physiological root resorption and orthodontic tooth movement. GCF was collected using micropipettes from 50 second primary molar sites undergoing physiological root resorption in 9- to 14-year olds [coronal group (Rc) with advanced resorption (n = 33) and apical group (Ra) with minimal resorption (n = 17)] and 20 subjects aged 8-14 years with erupted mandibular second premolars (control group). In addition, GCF was collected from 20 patients undergoing treatment with fixed appliances at two time points, immediately prior to orthodontic intervention (T0) and 12 weeks following commencement of fixed appliance therapy (T1). GCF samples were analysed for DSP using an immunoassay and levels semi-quantified using image analysis. To determine differences between the means of the various experimental and control groups, data based on the relative optical density volumes, were statistically analysed using a parametric t-test. DSP was raised in sites that were undergoing physiological resorption compared with the non-resorbing controls (P < 0.05). Notably, DSP was detected in some control samples. There was no difference in DSP levels for the Rc or Ra groups. DSP was also raised in GCF samples of teeth at 12 weeks following commencement of fixed appliance therapy (P < 0.001). The results highlight the potential for measuring DSP in GCF as a biomarker to monitor root resorption. Dentine is likely to be the major source for DSP in GCF, although alternative origins of bone and cementum are possible.

  11. Macrophage infection models for Mycobacterium tuberculosis.

    PubMed

    Johnson, Benjamin K; Abramovitch, Robert B

    2015-01-01

    Mycobacterium tuberculosis colonizes, survives, and grows inside macrophages. In vitro macrophage infection models, using both primary macrophages and cell lines, enable the characterization of the pathogen response to macrophage immune pressure and intracellular environmental cues. We describe methods to propagate and infect primary murine bone marrow-derived macrophages and J774 and THP-1 macrophage-like cell lines. We also present methods on the characterization of M. tuberculosis intracellular survival and the preparation of infected macrophages for imaging.

  12. The effect of resorption cavities on bone stiffness is site dependent.

    PubMed

    Vanderoost, Jef; van Lenthe, G Harry

    2014-01-01

    Resorption cavities formed during the bone remodelling cycle change the structure and thus the mechanical properties of trabecular bone. We tested the hypotheses that bone stiffness loss due to resorption cavities depends on anatomical location, and that for identical eroded bone volumes, cavities would cause more stiffness loss than homogeneous erosion. For this purpose, we used beam-shell finite element models. This new approach was validated against voxel-based FE models. We found an excellent agreement for the elastic stiffness behaviour of individual trabeculae in axial compression (R(2) = 1.00) and in bending (R(2)>0.98), as well as for entire trabecular bone samples to which resorption cavities were digitally added (R(2) = 0.96, RMSE = 5.2%). After validation, this new method was used to model discrete cavities, with dimensions taken from a statistical distribution, on a dataset of 120 trabecular bone samples from three anatomical sites (4th lumbar vertebra, femoral head, iliac crest). Resorption cavities led to significant reductions in bone stiffness. The largest stiffness loss was found for samples from the 4th lumbar vertebra, the lowest for femoral head samples. For all anatomical sites, resorption cavities caused significantly more stiffness loss than homogeneous erosion did. This novel technique can be used further to evaluate the impact of resorption cavities, which are known to change in several metabolic bone diseases and due to treatment, on bone competence.

  13. Role of carbonic anhydrase in bone resorption induced by prostaglandin E2 in vitro

    NASA Technical Reports Server (NTRS)

    Hall, G. E.; Kenny, A. D.

    1985-01-01

    The possible role of carbonic anhydrase in bone resorption induced by prostaglandin E2 (PGE2) was studied using an in vitro neonatal mouse calvarial culture system. PGE2 (10 to the -6th M) was effective in stimulating resorption, as assessed by calcium release into culture media. This enhanced resorption was accompanied by significant increases in calvarial carbonic anhydrase activity over control values at 48 and 96 h. At 48 h, bones treated with PGE2 had 20 percent more carbonic anhydrase activity than controls. By 96 h, treated bones contained 79 percent more carbonic anhydrase activity than controls. PGE2-induced bone resorption was inhibited by the carbonic anhydrase inhibitor acetazolamide in a dose-dependent fashion from 10 to the -5th to 10 to the -4th M with 77 percent inhibition observed at 10 to the -4th M. The acetazolamide analogue CL 13,850 (N-t-butylacetazolamide), which does not inhibit carbonic anhydrase, failed to inhibit PGE2-induced resorption. These results are consistent with the hypothesis that carbonic anhydrase is a necessary component of the osteoclastic bone resorptive mechanism.

  14. CBCT evaluation of multiple idiopathic internal resorptions in permanent molars: case report

    PubMed Central

    2014-01-01

    Background Internal inflammatory root resorption is a rare condition in permanent teeth, which requires the presence of necrotic and infected pulp tissue within the coronal portion of the root canal system as well as inflamed pulp tissue apical to the resorptive defect. The aetiology of internal root resorption is not completely understandable, trauma and chronic pulpitis are considered the main risk factors. Case presentation We report a rare case of the multiple idiopathic resorption in the permanent maxillary and mandibular molars in a healthy 33-year-old female patient. In addition to clinical examination the patient was imaged using conventional radiography techniques and cone beam computed tomography (CBCT).The patient had recurrent throbbing pain in her # 46. The radiographic examination including “panoramic radiography and CBCT” revealed that radiographic evidence of internal resorption in #37 #36 #35 #34 #33 #47 #46 #45 #44 #43 #16 #15 #14 #13 and also including in unerupted #17, #26, #27, #28 teeth. The definitive diagnosis was made with the histopathological examination of the extracted tooth. Conclusions Internal root resorption is a rare clinical process that should be examined using different radiographic modalities. CBCT seems to be useful in evaluation of the lesions with superior diagnostic performance. PMID:24739085

  15. Radiographic and micro-computed tomographic imaging of lipopolysaccharide-mediated bone resorption.

    PubMed

    Nason, Robert; Lee, Dong H; Jung, Jae Y; Chole, Richard A

    2009-05-01

    Chronic otitis media and cholesteatomas cause hearing loss as a result of bony erosion. This bone resorption is known to be more aggressive when cholesteatomas become infected. The most common organism isolated from both diseases is the gram-negative bacterium Pseudomonas aeruginosa. Lipopolysaccharide (LPS), a major virulence factor found in the gram-negative bacterial cell wall, is well known to incite inflammatory bone resorption. The mechanisms underlying this process, however, are poorly understood. In this study, we developed a mouse model of calvarial osteolysis in which resorption was reliably imaged by plain radiography and micro-computed tomography (micro-CT). A murine calvarial model was developed to study bone resorption induced by P aeruginosa LPS. Calvariae from wild-type and knockout mice used in this model were imaged by plain radiography and micro-CT. A high degree of correlation between plain radiography and micro-CT was identified (R2 = 0.8554). Furthermore, maximal LPS-induced bone resorption required functioning toll-like receptor (TLR) 2, TLR4, and myeloid differentiation factor 88 (MyD88). We have developed a successful model of inflammatory osteolysis in which plain radiography can reliably delineate induced bone resorption. In vivo, we have shown that P aeruginosa LPS signals via TLR2, as well as TLR4 through MyD88.

  16. Effects of intrusion combined with anterior retraction on apical root resorption.

    PubMed

    Martins, Décio Rodrigues; Tibola, Douglas; Janson, Guilherme; Maria, Fábio Rogério Torres

    2012-04-01

    This study evaluated the influence of intrusion mechanics combined with anterior retraction on root resorption of the maxillary incisors. A sample of 56 patients was divided into two groups: group 1 comprised 28 patients (12 females and 16 males), presenting with an increased overjet and deep overbite (6.48 and 4.78 mm, respectively) treated with reverse curve of Spee intrusion mechanics and group 2 comprised 28 patients (12 females and 16 males) with an increased overjet of 5.67 mm and a normal overbite of 1.12 mm. The initial mean ages for groups 1 and 2 were 13.41 and 13.27 years, respectively. Pre- (T1) and post- (T2) treatment periapical radiographs were used to evaluate root resorption. The groups were compared using the Mann-Whitney U-test. Correlation between root resorption and tooth movement was investigated with Spearman's correlation coefficient. The subjects in group 1 had statistically greater root resorption (P < 0.05) than those in group 2. The initial overbite severity and the amount of correction had significant positive correlations with root resorption (r = 0.324 and r = 0.320, respectively). The combination of anterior retraction with intrusive mechanics causes more root resorption than anterior retraction of the maxillary incisors alone.

  17. External root resorption after orthodontic treatment: a study of contributing factors

    PubMed Central

    Jung, Yun-Hoa

    2011-01-01

    Purpose The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. Materials and Methods 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. Results 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. Conclusion 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. PMID:21977469

  18. TNF-induced osteoclastogenesis and inflammatory bone resorption are inhibited by transcription factor RBP-J

    PubMed Central

    Zhao, Baohong; Grimes, Shannon N.; Hu, Xiaoyu

    2012-01-01

    Tumor necrosis factor (TNF) plays a key role in the pathogenesis of inflammatory bone resorption and associated morbidity in diseases such as rheumatoid arthritis and periodontitis. Mechanisms that regulate the direct osteoclastogenic properties of TNF to limit pathological bone resorption in inflammatory settings are mostly unknown. Here, we show that the transcription factor recombinant recognition sequence binding protein at the Jκ site (RBP-J) strongly suppresses TNF-induced osteoclastogenesis and inflammatory bone resorption, but has minimal effects on physiological bone remodeling. Myeloid-specific deletion of RBP-J converted TNF into a potent osteoclastogenic factor that could function independently of receptor activator of NF-κB (RANK) signaling. In the absence of RBP-J, TNF effectively induced osteoclastogenesis and bone resorption in RANK-deficient mice. Activation of RBP-J selectively in osteoclast precursors suppressed inflammatory osteoclastogenesis and arthritic bone resorption. Mechanistically, RBP-J suppressed induction of the master regulator of osteoclastogenesis (nuclear factor of activated T cells, cytoplasmic 1) by attenuating c-Fos activation and suppressing induction of B lymphocyte–induced maturation protein-1, thereby preventing the down-regulation of transcriptional repressors such as IRF-8 that block osteoclast differentiation. Thus, RBP-J regulates the balance between activating and repressive signals that regulate osteoclastogenesis. These findings identify RBP-J as a key upstream negative regulator of osteoclastogenesis that restrains excessive bone resorption in inflammatory settings. PMID:22249448

  19. Bone resorption in incompletely impacted mandibular third molars and acute pericoronitis

    PubMed Central

    Yamaoka, Minoru; Ono, Yusuke; Takahashi, Masahiro; Doto, Ryosuke; Yasuda, Kouichi; Uematsu, Takashi; Furusawa, Kiyofumi

    2009-01-01

    Acute pericoronitis (AP) arises frequently in incompletely impacted mandibular third molars, but it remains unknown whether bone resorption in aging is associated with acute inflammation of the third molar. We conducted an experiment to compare the ratio of bone resorption to root length in the distal surface of the second molar (A), the proximal surface (B), and distal surface (C) in mesio-angular, incompletely impacted third molars in 27 young and 58 older adults with AP and 77 young and 79 older adults without a history of AP. Bone resorption in A, B, and C in older adults with AP demonstrated a significantly higher ratio when compared to those without AP, whereas there was no difference between those with and without AP in young adults except for B in women. However, there were no differences between bone resorption in B with AP in young and older women, and between bone resorption in C with AP in young and older adults. These indicate that AP and bone resorption are associated with incompletely impacted mandibular third molars in older adults. PMID:23674899

  20. Bone resorption in incompletely impacted mandibular third molars and acute pericoronitis.

    PubMed

    Yamaoka, Minoru; Ono, Yusuke; Takahashi, Masahiro; Doto, Ryosuke; Yasuda, Kouichi; Uematsu, Takashi; Furusawa, Kiyofumi

    2009-01-01

    Acute pericoronitis (AP) arises frequently in incompletely impacted mandibular third molars, but it remains unknown whether bone resorption in aging is associated with acute inflammation of the third molar. We conducted an experiment to compare the ratio of bone resorption to root length in the distal surface of the second molar (A), the proximal surface (B), and distal surface (C) in mesio-angular, incompletely impacted third molars in 27 young and 58 older adults with AP and 77 young and 79 older adults without a history of AP. Bone resorption in A, B, and C in older adults with AP demonstrated a significantly higher ratio when compared to those without AP, whereas there was no difference between those with and without AP in young adults except for B in women. However, there were no differences between bone resorption in B with AP in young and older women, and between bone resorption in C with AP in young and older adults. These indicate that AP and bone resorption are associated with incompletely impacted mandibular third molars in older adults.

  1. Role of carbonic anhydrase in bone resorption induced by prostaglandin E2 in vitro

    NASA Technical Reports Server (NTRS)

    Hall, G. E.; Kenny, A. D.

    1985-01-01

    The possible role of carbonic anhydrase in bone resorption induced by prostaglandin E2 (PGE2) was studied using an in vitro neonatal mouse calvarial culture system. PGE2 (10 to the -6th M) was effective in stimulating resorption, as assessed by calcium release into culture media. This enhanced resorption was accompanied by significant increases in calvarial carbonic anhydrase activity over control values at 48 and 96 h. At 48 h, bones treated with PGE2 had 20 percent more carbonic anhydrase activity than controls. By 96 h, treated bones contained 79 percent more carbonic anhydrase activity than controls. PGE2-induced bone resorption was inhibited by the carbonic anhydrase inhibitor acetazolamide in a dose-dependent fashion from 10 to the -5th to 10 to the -4th M with 77 percent inhibition observed at 10 to the -4th M. The acetazolamide analogue CL 13,850 (N-t-butylacetazolamide), which does not inhibit carbonic anhydrase, failed to inhibit PGE2-induced resorption. These results are consistent with the hypothesis that carbonic anhydrase is a necessary component of the osteoclastic bone resorptive mechanism.

  2. In vitro degradation and in vivo resorption of dicalcium phosphate cement based grafts.

    PubMed

    Sheikh, Zeeshan; Zhang, Yu Ling; Grover, Liam; Merle, Géraldine E; Tamimi, Faleh; Barralet, Jake

    2015-10-01

    There are two types of DCP: dihydrated (brushite) and anhydrous (monetite). After implantation, brushite converts to hydroxyapatite (HA) which resorbs very slowly. This conversion is not observed after implantation of monetite cements and result in a greater of resorption. The precise mechanisms of resorption and degradation however of these ceramics remain uncertain. This study was designed to investigate the effect of: porosity, surface area and hydration on in vitro degradation and in vivo resorption of DCP. Brushite and two types of monetite cement based grafts (produced by wet and dry thermal conversion) were aged in phosphate buffered saline (PBS) and bovine serum solutions in vitro and were implanted subcutaneously in rats. Here we show that for high relative porosity grafts (50-65%), solubility and surface area does not play a significant role towards in vitro mass loss with disintegration and fragmentation being the main factors dictating mass loss. For grafts having lower relative porosity (35-45%), solubility plays a more crucial role in mass loss during in vitro ageing and in vivo resorption. Also, serum inhibited dissolution and the formation of HA in brushite cements. However, when aged in PBS, brushite undergoes phase conversion to a mixture of octacalcium phosphate (OCP) and HA. This phase conversion was not observed for monetite upon ageing (in both serum and PBS) or in subcutaneous implantation. This study provides greater understanding of the degradation and resorption process of DCP based grafts, allowing us to prepare bone replacement materials with more predictable resorption profiles.

  3. Pre-treatment radiographic features predict root resorption of treated impacted maxillary central incisors.

    PubMed

    Ho, K H; Liao, Y F

    2012-08-01

    To determine independent predictors of root resorption for surgical-orthodontic treatment of impacted maxillary central incisors. The Department of Dentistry at Show Chwan Hospital, Changhua, Taiwan. Eighty patients with unilateral osseous-impacted maxillary central incisors receiving a surgical-orthodontic treatment. This is a retrospective observational study. Root resorption and its predictors were abstracted from patients' charts, pre-treatment cephalometric radiographs, and post-treatment periapical radiographs. Predictors included demographics, treatment duration, crown angle, crown height, crown depth, and root dilacerations. The patients' mean age was 9.2 ± 2.3 years (6.4-20.6 years), and 60% were females. Impacted maxillary central incisors had greater root resorption than naturally erupted contralateral incisors (Δ = -2.8 mm, p < 0.001). Independent predictors of root resorption for impacted maxillary central incisors were shown by linear regression analysis to be crown height (β = -0.2, p < 0.01), crown depth (β = -0.3, p = 0.001), treatment duration (β = 0.2, p < 0.01), and root dilacerations (β = 3.1, p = 0.001). Impacted maxillary central incisors had greater root resorption during surgical-orthodontic treatment than their naturally erupted contralateral incisors. Predictors of a greater root resorption were highly and deeply impacted incisors, longer treatment, and root dilacerations. These predictors may help to inform patient and family counseling before treatment. © 2012 John Wiley & Sons A/S.

  4. Cone beam computed tomography study of apical root resorption induced by Herbst appliance

    PubMed Central

    SCHWARTZ, João Paulo; RAVELI, Taísa Boamorte; ALMEIDA, Kélei Cristina de Mathias; SCHWARTZ-FILHO, Humberto Osvaldo; RAVELI, Dirceu Barnabé

    2015-01-01

    Objective This study evaluated the frequency of root resorption during the orthodontic treatment with Herbst appliance by Cone Beam Computed Tomography (CBCT). Material and Methods The sample comprised 23 patients (11 men, 12 women; mean ages 15.76±1.75 years) with Class II division 1 malocclusion, treated with Herbst appliance. CBCT was obtained before treatment (T0) and after Herbst treatment (T1). All the dental roots, except third molars, were evaluated, and apical root resorption was determined using the axial guided navigation method. Paired t-tests and Wilcoxon T Test were used to compare the dependent samples in parametric and nonparametric cases, respectively. Chi-Square Test with Yates’ correction was used to evaluate the relationship between apical root resorption and gender. Results were considered at a significance level of 5%. Results Apical resorption was detected by CBCT in 57.96% of 980 roots that underwent Herbst appliance treatment. All patients had minimal resorption and there was no statistical significance between the genders. Conclusion CBCT three-dimensional evaluation showed association between Herbst appliance and minimal apical root resorption, mostly in the anchoring teeth, without clinical significance. PMID:26537718

  5. Why not to treat the tooth canal to solve external root resorptions? Here are the principles!

    PubMed Central

    Consolaro, Alberto; Bittencourt, Graziella

    2016-01-01

    ABSTRACT This paper aims at exposing the foundations or reasons why, in cases of external tooth resorption, including those of orthodontic origin, one should not perform a root canal to treat it. That should be done only to teeth with contamination or pulp necrosis, to remove the periapical inflammation induced by microbial products. When facing cases of external tooth resorption, one's conduct must always respect the following sequence of steps: first of all, identifying the cause accurately; then, planning the therapeutic approach and, finally, adopting the conducts in a very well-founded way. The situations in which endodontic treatment is recommended for tooth resorptions are those when there are: a) pulp necrosis with microbial contamination, b) aseptic pulp necrosis, c) developing calcific metamorphosis of the pulp and d) diagnosis of internal resorption. It is not possible, through the pulp, to control the resorption process that is taking place in the external part, after all, the causes are acting in the periodontal ligament. There is no evidence that justifies applying endodontic treatment, by means of root canal, to control external resorption processes, when the pulp shows vitality. PMID:28125136

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Imaging macrophages with nanoparticles

    NASA Astrophysics Data System (ADS)

    Weissleder, Ralph; Nahrendorf, Matthias; Pittet, Mikael J.

    2014-02-01

    Nanomaterials have much to offer, not only in deciphering innate immune cell biology and tracking cells, but also in advancing personalized clinical care by providing diagnostic and prognostic information, quantifying treatment efficacy and designing better therapeutics. This Review presents different types of nanomaterial, their biological properties and their applications for imaging macrophages in human diseases, including cancer, atherosclerosis, myocardial infarction, aortic aneurysm, diabetes and other conditions. We anticipate that future needs will include the development of nanomaterials that are specific for immune cell subsets and can be used as imaging surrogates for nanotherapeutics. New in vivo imaging clinical tools for noninvasive macrophage quantification are thus ultimately expected to become relevant to predicting patients' clinical outcome, defining treatment options and monitoring responses to therapy.

  8. Macrophage polarization following chitosan implantation.

    PubMed

    Vasconcelos, Daniela P; Fonseca, Ana C; Costa, Madalena; Amaral, Isabel F; Barbosa, Mário A; Águas, Artur P; Barbosa, Judite N

    2013-12-01

    Macrophages are a key cell in the host response to implants and can be polarized into different phenotypes capable of inducing both detrimental and beneficial outcomes in tissue repair and remodeling, being important in tissue engineering and regenerative medicine. The objective of this study was to evaluate the macrophage response to 3D porous chitosan (Ch) scaffolds with different degrees of acetylation (DA, 5% and 15%). The M1/M2 phenotypic polarization profile of macrophages was investigated in vivo using a rodent air-pouch model. Our results show that the DA affects the macrophage response. Ch scaffolds with DA 5% induced the adhesion of lower numbers of inflammatory cells, being the M2 the predominant phenotypic profile among the adherent macrophages. In the inflammatory exudates F4/80(+)/CD206(+) cells (M2 macrophages) appeared in higher numbers then F4/80(+)/CCR7(+) cells (M1 macrophages), in addition, lower levels of pro-inflammatory cytokines together with higher levels of anti-inflammatory cytokines were found. Ch scaffolds with DA 15% showed opposite results, since M1 were the predominant macrophages both adherent to the scaffold and in the exudates, together with high levels of pro-inflammatory cytokines. In conclusion, Ch scaffolds with DA 5% induced a benign M2 anti-inflammatory macrophage response, whereas Ch scaffolds with DA 15% caused a macrophage M1 pro-inflammatory response.

  9. Epigenomics of macrophages.

    PubMed

    Gosselin, David; Glass, Christopher K

    2014-11-01

    Macrophages play essential roles in tissue homeostasis, pathogen elimination, and tissue repair. A defining characteristic of these cells is their ability to efficiently adapt to a variety of abruptly changing and complex environments. This ability is intrinsically linked to a capacity to quickly alter their transcriptome, and this is tightly associated with the epigenomic organization of these cells and, in particular, their enhancer repertoire. Indeed, enhancers are genomic sites that serve as platforms for the integration of signaling pathways with the mechanisms that regulate mRNA transcription. Notably, transcription is pervasive at active enhancers and enhancer RNAs (eRNAs) are tightly coupled to regulated transcription of protein-coding genes. Furthermore, given that each cell type possesses a defining enhancer repertoire, studies on enhancers provide a powerful method to study how specialization of functions among the diverse macrophage subtypes may arise. Here, we review recent studies providing insights into the distinct mechanisms that contribute to the establishment of enhancers and their role in the regulation of transcription in macrophages.

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

    SciTech Connect

    Wei, Xiang

    2006-01-01

    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 ''Resorption rate tunable bioceramic: Si and Zn-modified tricalcium phosphate'' was published in

  11. Osteointegration and Resorption of Intravertebral and Extravertebral Calcium Phosphate Cement.

    PubMed

    Klein, Roman; Tetzlaff, Ralf; Weiss, Christel; Schäfer, Meike-Kristina; Tanner, Michael; Wiedenhöfer, Bernd; Grafe, Ingo; Meeder, Peter-Jürgen; Noeldge, Gerd; Nawroth, Peter P; Kasperk, Christian

    2017-04-01

    Eleven patients with painful osteoporotic vertebral fractures who underwent kyphoplasty using calcium phosphate (CaP) cement were followed up for 1 week, 1, 2, and 3 years in a monocentric, nonrandomized, noncontrolled retrospective trial. This study investigates long-term radiomorphologic features of intraosseous CaP cement implants and of extraosseous CaP cement leakages for up to 3 years after implantation by kyphoplasty. Kyphoplasty is frequently used for the treatment of painful osteoporotic fractures. Of the materials available, CaP is frequently used as a filling material. Resorption of this material is frequently observed, although clinical outcome is comparable with other cements. Kyphoplasty utilizing CaP cement was performed in 11 patients with painful osteoporotic vertebral fractures. All patients received a pharmacological antiosteoporosis treatment consisting of calcium, vitamin D, and a standard dose of oral bisphosphonates. Radiomorphologic measurements, pain, and mobility were assessed. Intraosseous and extraosseous CaP cement volumes decreased significantly over 3 years. However, vertebral stability as determined by a constant vertebral body height and the sagittal index was not impaired. Pain improved significantly 2 years after implantation and the mobility scores 1 year after kyphoplasty at least until the third year. Intravertebral CaP cement implants are resorbed slowly over time without jeopardizing stability and clinical outcomes most likely because of a slowly progressing osseous replacement. Extraosseous CaP cement material because of leakages during the kyphoplasty procedure is almost completely resorbed as early as 2 years after the leakage occurred. Therefore, CaP cement is an important alternative to PMMA-based cement materials utilized for kyphoplasty of osteoporotic vertebral fractures.

  12. Foliar nutrient resorption patterns of four functional plants along a precipitation gradient on the Tibetan Changtang Plateau.

    PubMed

    Zhao, Guangshuai; Shi, Peili; Wu, Jianshuang; Xiong, Dingpeng; Zong, Ning; Zhang, Xianzhou

    2017-09-01

    Nutrient resorption from senesced leaves as a nutrient conservation strategy is important for plants to adapt to nutrient deficiency, particularly in alpine and arid environment. However, the leaf nutrient resorption patterns of different functional plants across environmental gradient remain unclear. In this study, we conducted a transect survey of 12 communities to address foliar nitrogen (N) and phosphorus (P) resorption strategies of four functional groups along an eastward increasing precipitation gradient in northern Tibetan Changtang Plateau. Soil nutrient availability, leaf nutrient concentration, and N:P ratio in green leaves ([N:P]g) were linearly correlated with precipitation. Nitrogen resorption efficiency decreased, whereas phosphorus resorption efficiency except for sedge increased with increasing precipitation, indicating a greater nutrient conservation in nutrient-poor environment. The surveyed alpine plants except for legume had obviously higher N and P resorption efficiencies than the world mean levels. Legumes had higher N concentrations in green and senesced leaves, but lowest resorption efficiency than nonlegumes. Sedge species had much lower P concentration in senesced leaves but highest P resorption efficiency, suggesting highly competitive P conservation. Leaf nutrient resorption efficiencies of N and P were largely controlled by soil and plant nutrient, and indirectly regulated by precipitation. Nutrient resorption efficiencies were more determined by soil nutrient availability, while resorption proficiencies were more controlled by leaf nutrient and N:P of green leaves. Overall, our results suggest strong internal nutrient cycling through foliar nutrient resorption in the alpine nutrient-poor ecosystems on the Plateau. The patterns of soil nutrient availability and resorption also imply a transit from more N limitation in the west to a more P limitation in the east Changtang. Our findings offer insights into understanding nutrient

  13. Ultrasound stimulation attenuates resorption of tooth root induced by experimental force application.

    PubMed

    Inubushi, Toshihiro; Tanaka, Eiji; Rego, Emanuel B; Ohtani, Junji; Kawazoe, Aki; Tanne, Kazuo; Miyauchi, Mutsumi; Takata, Takashi

    2013-04-01

    Root resorption is an adverse outcome of orthodontic tooth movement. However, there have been no available approaches for the protection and repair of root resorption. The aim of this study was to evaluate the effects of low-intensity pulsed ultrasound (LIPUS) on root resorption during experimental tooth movement and the effects of LIPUS in the RANKL/OPG mechanism in osteoblasts and cementoblasts in vitro. Twenty four Wistar strain male rats of 12-week-old were used in this study. The upper first molars were subjected to experimental movement in the mesial direction for 1-3weeks. Through the experimental periods, the right upper first maxillary molar was exposed to LIPUS (LIPUS group) every day for 1, 2 or 3weeks. The nature of root resorption was observed and then quantified by histomorphometric analysis. In the 2weeks period, significantly greater amount of tooth movement was observed in the LIPUS group (p<0.05). In addition, LIPUS group showed less root resorption lacunae and lower number of odontoclasts. In the period of 3weeks, LIPUS group presented significantly shorter length of root resorption lacunae and smaller amount of root resorption area (p<0.01). The number of odontoclasts and osteoclasts was also significantly lower in the LIPUS group (p<0.01 and p<0.05, respectively). However, no significant differences could be found regarding the amount of tooth movement. It is shown that LIPUS exposure significantly reduced the degree of root resorption during tooth movement without interrupting tooth movement. In vitro experiments showed that MC3T3-1 constitutively expressed higher levels of RANKL and RANTES mRNA comparing to OCCM-30. However, OPG mRNA expression was much higher in OCCM-30. LIPUS stimulation significantly increased the mRNA expression of RANKL in MC3T3-E1 at 4 (p<0.01) and 12h (p<0.05), although OPG mRNA expression was not affected by LIPUS. In contrast, the expression of RANKL and OPG mRNAs were both significantly increased by LIPUS in OCCM-30

  14. Evolutionary Aspects of Macrophages Polarization.

    PubMed

    Edholm, Eva-Stina; Rhoo, Kun Hyoe; Robert, Jacques

    2017-01-01

    Macrophages constitute a heterogeneous population of myeloid cells that are essential for maintaining homeostasis and as a first line of innate responders controlling and organizing host defenses against pathogens. Monocyte-macrophage lineage cells are among the most functionally diverse and plastic cells of the immune system. They undergo specific activation into functionally distinct phenotypes in response to immune signals and microbial products. In mammals, macrophage functional heterogeneity is defined by two activation states, M1 and M2, which represent two polar ends of a continuum exhibiting pro-inflammatory and tissue repair activities, respectively. While the ancient evolutionary origin of macrophages as phagocytic defenders is well established, the evolutionary roots of the specialized division of macrophages into subsets with polarized activation phenotypes is less well defined. Accordingly, this chapter focuses on recent advances in the understanding of the evolution of macrophage polarization and functional heterogeneity with a focus on ectothermic vertebrates.

  15. The macrophages in rheumatic diseases

    PubMed Central

    Laria, Antonella; Lurati, Alfredomaria; Marrazza, Mariagrazia; Mazzocchi, Daniela; Re, Katia Angela; Scarpellini, Magda

    2016-01-01

    Macrophages belong to the innate immune system giving us protection against pathogens. However it is known that they are also involved in rheumatic diseases. Activated macrophages have two different phenotypes related to different stimuli: M1 (classically activated) and M2 (alternatively activated). M1 macrophages release high levels of pro-inflammatory cytokines, reactive nitrogen and oxygen intermediates killing microorganisms and tumor cells; while M2 macrophages are involved in resolution of inflammation through phagocytosis of apoptotic neutrophils, reduced production of pro-inflammatory cytokines, and increased synthesis of mediators important in tissue remodeling, angiogenesis, and wound repair. The role of macrophages in the different rheumatic diseases is different according to their M1/M2 macrophages phenotype. PMID:26929657

  16. Bioelectric modulation of macrophage polarization

    NASA Astrophysics Data System (ADS)

    Li, Chunmei; Levin, Michael; Kaplan, David L.

    2016-02-01

    Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells’ resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

  17. Macrophage Cryptococcus interactions: an update

    PubMed Central

    Mansour, Michael K.; Reedy, Jennifer L.; Tam, Jenny M.; Vyas, Jatin M.

    2014-01-01

    Cryptococcus species are fungal pathogens that are a leading cause of mortality. Initial inoculation is through the pulmonary route and, if disseminated, results in severe invasive infection including meningoencephalitis. Macrophages are the dominant phagocytic cell that interacts with Cryptococcus. Emerging theories suggest that Cryptococcus microevolution in macrophages is linked to survival and virulence within the host. In addition, Cryptococcus elaborates virulence factors as well as usurps host machinery to establish macrophage activation states that are permissive to intracellular survival and replication. In this review, we provide an update of the recent findings pertaining to macrophage interaction with Cryptococcus and focus on new avenues for biomedical research. PMID:24660045

  18. Macrophages in homeostatic immune function

    PubMed Central

    Jantsch, Jonathan; Binger, Katrina J.; Müller, Dominik N.; Titze, Jens

    2014-01-01

    Macrophages are not only involved in inflammatory and anti-infective processes, but also play an important role in maintaining tissue homeostasis. In this review, we summarize recent evidence investigating the role of macrophages in controlling angiogenesis, metabolism as well as salt and water balance. Particularly, we summarize the importance of macrophage tonicity enhancer binding protein (TonEBP, also termed nuclear factor of activated T-cells 5 [NFAT5]) expression in the regulation of salt and water homeostasis. Further understanding of homeostatic macrophage function may lead to new therapeutic approaches to treat ischemia, hypertension and metabolic disorders. PMID:24847274

  19. Bioelectric modulation of macrophage polarization.

    PubMed

    Li, Chunmei; Levin, Michael; Kaplan, David L

    2016-02-12

    Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells' resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

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

    PubMed Central

    Sipola, Annina; Nelo, Katri; Hautala, Timo; Ilvesaro, Joanna; Tuukkanen, Juha

    2006-01-01

    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. PMID:16839420

  1. Prevalence and types of tooth resorption in dogs with oral tumors.

    PubMed

    Nemec, Ana; Arzi, Boaz; Murphy, Brian; Kass, Philip H; Verstraete, Frank J M

    2012-07-01

    To determine the prevalence and types of tooth resorption in dogs with oral tumors and to compare findings with those for control dogs. 101 dogs with oral tumors and 128 control dogs that did not have oral tumors and for which dental radiographs were available. Exclusion criteria for dogs included systemic disease, long-term administration of anti-inflammatory drugs, traumatic occlusion, severe semigeneralized or generalized periodontitis, and endodontic disease. For each dog with an oral tumor, histologic sections of biopsy specimens of tumors were examined. Dental radiographic images of dogs were examined, and the presence and type of tooth resorption were determined for each tooth. Statistical analyses were performed to compare data regarding prevalence of tooth resorption. Teeth at tumor sites in dogs with nonodontogenic tumors were significantly more frequently affected with external inflammatory resorption, compared with teeth at tumor sites in dogs with odontogenic tumors. Teeth at sites distant from tumors in dogs with oral tumors were 3.2 times as likely to have external surface resorption (OR, 3.2; 95% confidence interval, 1.3 to 7.9) and 83.4 times as likely to have external inflammatory resorption (OR, 83.4; 95% confidence interval, 9.7 to 719.6) as teeth in control dogs. Resorption of teeth at tumor sites and at sites distant from tumors was common in dogs with oral tumors. Results of the present study will contribute to an understanding of the complex effects of oral tumors on local and distant hard tissues.

  2. External apical root resorption in maxillary incisors in orthodontic patients: associated factors and radiographic evaluation

    PubMed Central

    Patanaporn, Virush; Janhom, Apirum; Korwanich, Narumanus

    2012-01-01

    Purpose 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. Materials and Methods 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. Results 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. Conclusion 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. PMID:23071964

  3. Intracanal bisphosphonate does not inhibit replacement resorption associated with delayed replantation of monkey incisors.

    PubMed

    Thong, Yo Len; Messer, Harold H; Zain, Rosnah Binti; Saw, Lip Hean; Yoong, Lai Thong

    2009-08-01

    Progressive replacement resorption following delayed replantation of avulsed teeth has proved to be an intractable clinical problem. A wide variety of therapeutic approaches have failed to result in the predictable arrest of resorption, with a good long-term prognosis for tooth survival. Bisphosphonates are used in the medical management of a range of bone disorders and topically applied bisphosphonate has been reported to inhibit root resorption in dogs. This study evaluated the effectiveness of a bisphosphonate (etidronate disodium) as an intracanal medicament in the root canals of avulsed monkey teeth, placed before replantation after 1 h of extraoral dry storage. Incisors of six Macaca fascicularis monkeys were extracted and stored dry for 1 h. Teeth were then replanted after canal contamination with dental plaque (negative control) or after root canal debridement and placement of etidronate sealed in the canal space. A positive control of calcium hydroxide placed 8-9 days after replantation was also included. All monkeys were sacrificed 8 weeks later and block sections were prepared for histomorphometric assessment of root resorption and periodontal ligament status. Untreated teeth showed the greatest extent of root resorption (46% of the root surface), which was predominantly inflammatory in nature. Calcium hydroxide treated teeth showed the lowest overall level of resorption (<30% of the root surface), while the bisphosphonate-treated group was intermediate (39%). Ankylosis, defined as the extent of the root surface demonstrating direct bony union to both intact and resorbed root surface, was the lowest in the untreated control group (15% of the root surface), intermediate in the calcium hydroxide group (27%) and the highest in the bisphosphonate group (41%). Bony attachment to the tooth root was divided approximately equally between attachment to intact cementum and to previously resorbed dentin. Overall, bisphosphonate resulted in a worse outcome than

  4. Root resorption after experimental tooth movement using superelastic forces in the rat.

    PubMed

    Noda, Koji; Arai, Chihiro; Nakamura, Yoshiki

    2010-12-01

    The purpose of this study was to assess the rate of root resorption in relation to different magnitudes of continuous force during experimental tooth movement using nickel-titanium (NiTi) alloy wire. Four force magnitudes of 0.8, 1.6, 4, and 8 g were applied to the upper first molars of 75 male Wistar rats (300-320 g, 10-week-old) for 1, 7, 14, 21, and 28 days and compared with a control group without an orthodontic appliance. Light microscopic images of the compressed periodontal ligament (PDL) were processed by computer, and the ratio of the root resorption lacuna length to root surface length without the lacuna was analysed and statistically compared using Tukey-Kramer multiple comparison honestly significant difference test. The experimental groups with 4 and 8 g force showed undermining bone resorption with degenerating tissue and marked root resorption, the 1.6 g group showed only root resorption, while the 0.8 g group was similar to the control. Comparison of the ratios showed that the 0.8 g group was similar to the control with no significant difference. The ratio on day 28 in the 1.6 g group was larger than that in the 0.8 g and control groups, while on days 14, 21, and 28, the ratios in the 4 and 8 g groups were larger than those in the control (P < 0.01); these two experimental groups showed the same significant differences. It is suggested that significant root resorption occurs when the force magnitude exceeds 1.6 g in the rat upper first molar during tipping tooth movement by continuous force, and the amount of root resorption increases with serial force magnitudes from 0.8 to 4 g.

  5. Regenerative Endodontic Procedures for Traumatized Teeth after Horizontal Root Fracture, Avulsion, and Perforating Root Resorption.

    PubMed

    Saoud, Tarek Mohamed A; Mistry, Sonali; Kahler, Bill; Sigurdsson, Asgeir; Lin, Louis M

    2016-10-01

    Traumatic injury to the teeth can cause horizontal root fractures and inflammatory root resorptions (external and internal). Traditionally, traumatized teeth with horizontal root fractures resulting in pulp necrosis and inflammatory root resorptions are treated with conventional root canal therapy. A 15-year-old boy had a history of traumatic injury to mature tooth #8 resulting in horizontal root fracture and pulp necrosis of the coronal fragment. A 7-year-old girl suffered an avulsion injury to immature tooth #9, which developed inflammatory replacement resorption and subsequently root fractured 15 months later. Another 16-year-old boy also suffered a history of traumatic injury to mature tooth #8, resulting in perforating root resorption. All teeth were treated with regenerative endodontic procedures using chemomechanical debridement, calcium hydroxide/triple antibiotic paste dressing, EDTA rinse, induction of periapical bleeding into the canal space, and a coronal mineral trioxide aggregate plug. In the tooth presenting with horizontal root fracture, only the coronal fragment was treated to preserve pulp vitality in the apical fragment for possible pulp tissue regeneration. After regenerative endodontic procedures, clinical signs/symptoms subsided, and inflammatory osteolytic lesions resolved in all traumatized teeth. Two teeth were followed for 19 months and 1 tooth for 5 years. At the last review of the teeth with horizontal root fractures, the first case showed healing by calcified tissue and the second case showed healing by fibrous connective and hard tissue. Tooth with perforating root resorption demonstrated a decrease in size of the resorptive defect. Based on these case reports, regenerative endodontic procedures have the potential to be used to treat traumatized teeth with horizontal root fracture and inflammatory root resorption. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. From molds and macrophages to mevalonate: a decade of progress in understanding the molecular mode of action of bisphosphonates.

    PubMed

    Rogers, M J

    2004-12-01

    Although bisphosphonates were first used as therapeutic agents to inhibit bone resorption in the early 1970s, their mode of action at the molecular level has only become fully clear within the last few years. One of the reasons for this lack of understanding was the difficulty in isolating large numbers of pure osteoclasts for biochemical studies. In the last decade, the identification of appropriate surrogate models that reflected the antiresorptive potencies of bisphosphonates, such as Dictyostelium slime molds and macrophages, helped overcome this problem and proved to be instrumental in elucidating the molecular pathways by which these compounds inhibit osteoclast-mediated bone resorption. This brief review summarizes our current understanding of these pathways.

  7. Identification of Leukocyte Subpopulations Responsible for the Production of Osteoclast Activating Factor and their Role in Bone Resorption.

    DTIC Science & Technology

    1980-12-31

    Identification of Leukocyte Subpopulat ions Respoi�Zhfor theae 31 FVFI0VŜ Production of 40steoclast Activating FactorO and their Role in 6. Bone Resorption #a...17a. Descriptors M W o i t Bone Resorption Lymphokines Osteoclast Activating Factor 17b. Identifiers/Open-Ended Terms Isolation and Purification LL... RESORPTION Charles E. Hawley, Colonel, Dental Corps Division of Oral Biology United States Army Institute of Dental Research Washington, D. C. 20012 31

  8. Early detection and staging of spontaneous embryo resorption by ultrasound biomicroscopy in murine pregnancy

    PubMed Central

    2014-01-01

    Background Embryo resorption is a major problem in human medicine, agricultural animal production and in conservation breeding programs. Underlying mechanisms have been investigated in the well characterised mouse model. However, post mortem studies are limited by the rapid disintegration of embryonic structures. A method to reliably identify embryo resorption in alive animals has not been established yet. In our study we aim to detect embryos undergoing resorption in vivo at the earliest possible stage by ultra-high frequency ultrasound. Methods In a longitudinal study, we monitored 30 pregnancies of wild type C57BI/6 mice using ultra-high frequency ultrasound (30-70 MHz), so called ultrasound biomicroscopy (UBM). We compared the sonoembryology of mouse conceptuses under spontaneous resorption and neighbouring healthy conceptuses and correlated the live ultrasound data with the respective histology. Results The process of embryo resorption comprised of four stages: first, the conceptus exhibited growth retardation, second, bradycardia and pericardial edema were observed, third, further development ceased and the embryo died, and finally embryo remnants were resorbed by maternal immune cells. In early gestation (day 7 and 8), growth retardation was characterized by a small embryonic cavity. The embryo and its membranes were ill defined or did not develop at all. The echodensity of the embryonic fluid increased and within one to two days, the embryo and its cavity disappeared and was transformed into echodense tissue surrounded by fluid filled caverns. In corresponding histologic preparations, fibrinoid material interspersed with maternal granulocytes and lacunae filled with maternal blood were observed. In later stages (day 9–11) resorption prone embryos were one day behind in their development compared to their normal siblings. The space between Reichert’s membrane and inner yolk sac membrane was enlarged The growth retarded embryos exhibited bradycardia and

  9. Early detection and staging of spontaneous embryo resorption by ultrasound biomicroscopy in murine pregnancy.

    PubMed

    Flores, Luis E; Hildebrandt, Thomas B; Kühl, Anja A; Drews, Barbara

    2014-05-10

    Embryo resorption is a major problem in human medicine, agricultural animal production and in conservation breeding programs. Underlying mechanisms have been investigated in the well characterised mouse model. However, post mortem studies are limited by the rapid disintegration of embryonic structures. A method to reliably identify embryo resorption in alive animals has not been established yet. In our study we aim to detect embryos undergoing resorption in vivo at the earliest possible stage by ultra-high frequency ultrasound. In a longitudinal study, we monitored 30 pregnancies of wild type C57BI/6 mice using ultra-high frequency ultrasound (30-70 MHz), so called ultrasound biomicroscopy (UBM). We compared the sonoembryology of mouse conceptuses under spontaneous resorption and neighbouring healthy conceptuses and correlated the live ultrasound data with the respective histology. The process of embryo resorption comprised of four stages: first, the conceptus exhibited growth retardation, second, bradycardia and pericardial edema were observed, third, further development ceased and the embryo died, and finally embryo remnants were resorbed by maternal immune cells. In early gestation (day 7 and 8), growth retardation was characterized by a small embryonic cavity. The embryo and its membranes were ill defined or did not develop at all. The echodensity of the embryonic fluid increased and within one to two days, the embryo and its cavity disappeared and was transformed into echodense tissue surrounded by fluid filled caverns. In corresponding histologic preparations, fibrinoid material interspersed with maternal granulocytes and lacunae filled with maternal blood were observed. In later stages (day 9-11) resorption prone embryos were one day behind in their development compared to their normal siblings. The space between Reichert's membrane and inner yolk sac membrane was enlarged The growth retarded embryos exhibited bradycardia and ultimately cessation of heart

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

    PubMed Central

    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 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

  11. RIP140 in monocytes/macrophages regulates osteoclast differentiation and bone homeostasis

    PubMed Central

    Lee, Bomi; Iwaniec, Urszula T.; Turner, Russell T.; Lin, Yi-Wei; Clarke, Bart L.; Gingery, Anne

    2017-01-01

    Osteolytic bone diseases, such as osteoporosis, are characterized by diminished bone quality and increased fracture risk. The therapeutic challenge remains to maintain bone homeostasis with a balance between osteoclast-mediated resorption and osteoblast-mediated formation. Osteoclasts are formed by the fusion of monocyte/macrophage-derived precursors. Here we report, to our knowledge for the first time, that receptor-interacting protein 140 (RIP140) expression in osteoclast precursors and its protein regulation are crucial for osteoclast differentiation, activity, and coupled bone formation. In mice, monocyte/macrophage–specific knockdown of RIP140 (mϕRIP140KD) resulted in a cancellous osteopenic phenotype with significantly increased bone resorption and reduced bone formation. Osteoclast precursors isolated from mϕRIP140KD mice had significantly increased differentiation potential. Furthermore, conditioned media from mϕRIP140KD primary osteoclast cultures significantly suppressed osteoblast differentiation. This suppressive activity was effectively and rapidly terminated by specific Syk-stimulated RIP140 protein degradation. Mechanistic analysis revealed that RIP140 functions primarily by inhibiting osteoclast differentiation through forming a transcription-suppressor complex with testicular receptor 4 (TR4) to repress osteoclastogenic genes. These data reveal that monocyte/macrophage RIP140/TR4 complexes may serve as a critical transcription regulatory complex maintaining homeostasis of osteoclast differentiation, activity, and coupling with osteoblast formation. Accordingly, we propose a potentially novel therapeutic strategy, specifically targeting osteoclast precursor RIP140 protein in osteolytic bone diseases. PMID:28405613

  12. The amino bisphosphonate ibandronate prevents calciphylaxis in the rat at doses that inhibit bone resorption.

    PubMed

    Price, P A; Omid, N; Than, T N; Williamson, M K

    2002-10-01

    The present experiments were carried out to test the hypothesis that there is a common underlying biochemical mechanism that accounts for the different kinds of soft tissue calcification observed in animals that are treated with toxic doses of vitamin D. In previous studies we showed that lethal doses of vitamin D cause extensive calcification of arteries, lungs, kidneys, and cartilage, and that doses of the amino bisphosphonate ibandronate that inhibit bone resorption completely inhibit each of these soft tissue calcifications and prevent death. In the present experiments we have examined the effect of ibandronate on an entirely different type of calcification, the calciphylaxis induced by administration of a challenger to rats previously treated with sub-lethal doses of vitamin D. These studies show that ibandronate doses that inhibit bone resorption completely inhibit artery calcification as well as, in the same rat, the calciphylactic responses to either subcutaneous injection of 300 mg FeCl3 or intrascapular epilation. Since the vitamin D-treated animals had dramatically increased levels of bone resorption, and concurrent treatment with ibandronate normalized resorption, these results support the hypothesis that soft tissue calcifications in the vitamin D-treated rat may be linked to bone resorption. The ability of ibandronate to inhibit all vitamin D-associated calcifications in the rat cannot be explained by an effect of ibandronate on serum calcium, since serum calcium remained 30% above control levels in the vitamin D-treated animals that also received ibandronate.

  13. Longitudinal in vivo imaging of bone formation and resorption using fluorescence molecular tomography.

    PubMed

    Lambers, F M; Stuker, F; Weigt, C; Kuhn, G; Koch, K; Schulte, F A; Ripoll, J; Rudin, M; Müller, R

    2013-02-01

    Bone research often focuses on anatomical imaging of the bone microstructure, but in order to gain better understanding in how bone remodeling is modulated through interventions also bone formation and resorption processes should be investigated. With this in mind, the purpose of this study was to establish a longitudinal in vivo imaging approach of bone formation and resorption using fluorescence molecular tomography (FMT). In this study the reproducibility, accuracy and sensitivity of FMT for bone imaging were assessed by performing longitudinal measurements with FMT and comparing it to in vivo micro-computed tomography on a set of control mice, and mice in which load-adaptation was induced in the sixth caudal vertebra. The precision error for FMT measurements, expressed as coefficient of variation, was smaller than 16%, indicating acceptable reproducibility. A correlation was found between bone resorption measured with FMT and bone resorption rate measured with in vivo micro-computed tomography only over the first 14days (R=0.81, p<0.01), but not between bone formation measured with FMT and bone formation rate measured with in vivo micro-CT. Bone formation measured by FMT was 89-109% greater (p<0.05) for mice subjected to mechanical loading than control mice. Bone resorption was 5-8% lower, but did not reach a significant difference between groups, indicating moderate sensitivity for FMT. In conclusion, in vivo FMT in mouse tail bones is feasible but needs to be optimized for monitoring load adaptation in living mice.

  14. The clinical meaning of external cervical resorption in maxillary canine: transoperative dental trauma

    PubMed Central

    Consolaro, Alberto; Cardoso, Mauricio de Almeida; de Almeida, Carolina Dornelas C. M.; Souza, Ingrid Araújo Oliveira; Capelloza, Leopoldino

    2014-01-01

    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. PMID:25628076

  15. The clinical meaning of external cervical resorption in maxillary canine: transoperative dental trauma.

    PubMed

    Consolaro, Alberto; Cardoso, Mauricio de Almeida; de Almeida, Carolina Dornelas C M; Souza, Ingrid Araújo Oliveira; Capelloza Filho, Leopoldino

    2014-01-01

    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.

  16. External cervical resorption: an analysis using cone beam and microfocus computed tomography and scanning electron microscopy.

    PubMed

    Gunst, V; Mavridou, A; Huybrechts, B; Van Gorp, G; Bergmans, L; Lambrechts, P

    2013-09-01

    To provide a three-dimensional representation of external cervical resorption (ECR) with microscopy, stereo microscopy, cone beam computed tomography (CT), microfocus CT and scanning electron microscopy (SEM). External cervical resorption is an aggressive form of root resorption, leading to a loss of dental hard tissues. This is due to clastic action, activated by a damage of the covering cementum and stimulated probably by infection. Clinically, it is a challenging situation as it is characterized by a late symptomatology. This is due to the pericanalar protection from a resorption-resistant sheet, composed of pre-dentine and surrounding dentine. The clastic activity is often associated with an attempt to repair, seen by the formation of osteoid tissue. Cone beam CT is extremely useful in the diagnoses and treatment planning of ECR. SEM analyses provide a better insight into the activity of osteoclasts. The root canal is surrounded by a layer of dentine that is resistant to resorption. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  17. The effects of the cathepsin K inhibitor odanacatib on osteoclastic bone resorption and vesicular trafficking.

    PubMed

    Leung, P; Pickarski, M; Zhuo, Y; Masarachia, P J; Duong, L T

    2011-10-01

    Odanacatib (ODN) is a selective, potent and reversible inhibitor of cathepsin K (CatK) that inhibits bone loss in postmenopausal osteoporosis. Evidence from osteoclast (OC) formation from bone marrow of CatK(-/-) mice or human OC progenitors treated with ODN, demonstrated that CatK inhibition has no effect on osteoclastogenesis or survival of OCs. Although having no impact on OC activation, ODN reduces resorption activity as measured by CTx release (IC(50)=9.4 nM) or resorption area (IC(50)=6.5 nM). While untreated cells generate deep trail-like resorption lacunae, treated OCs form small discrete shallow pits. ODN leads to significant accumulation of intracellular vesicles intensely stained for CatK and TRAP. CatK (+) vesicles localize toward the basolateral and functional secretory membranes of the polarized OC and TRAP(+) vesicles evenly distribute in the cytoplasm, suggesting that ODN disrupts multiple vesicular trafficking pathways. Intracellular levels of both precursor and mature TRAP were increased by 2-fold and the pre-pro and mature CatK by 6- and 2-fold in ODN-treated OCs compared to untreated controls. ODN treated OC accumulates labeled degraded bone matrix proteins in CatK containing vesicles. In summary, ODN treatment inhibits bone resorption by blocking degradation of demineralized collagen in the resorption lacunae, and retarding transcytosis for further processing of degraded proteins. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Periodontal ligament hydrostatic pressure with areas of root resorption after application of a continuous torque moment.

    PubMed

    Hohmann, Ansgar; Wolfram, Uwe; Geiger, Martin; Boryor, Andrew; Sander, Christian; Faltin, Rolf; Faltin, Kurt; Sander, Franz Guenter

    2007-07-01

    To evaluate the risk of root resorption, individual finite element models (FEMs) of extracted human maxillary first premolars were created, and the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models was simulated. A continuous lingual torque of 3 Nmm and 6 Nmm respectively was applied in vivo to the aforementioned teeth. After extraction, FEMs of these double-rooted teeth were created based on high-resolution microcomputed tomographics (micro CT, voxel size: 35 microns). This high volumetric resolution made the recognition of very small resorption lacunae possible. Scanning electron micrographs of the root surfaces were created as well. This enabled the investigation of advantages and disadvantages of the different imaging techniques from the viewpoint of the examination of root resorption. Using the FEMs, the same loading conditions as applied in vivo were simulated. The results of clinical examination and simulations were compared using the identical roots of the teeth. The regions that showed increased hydrostatic pressure (>0.0047 MPa) correlated well with the locations of root resorption for each tooth. Increased torque resulted in increased high-pressure areas and increased magnitudes of hydrostatic pressure, correlating with the experiments. If hydrostatic pressure exceeds typical human capillary blood pressure in the PDL, the risk of root resorption increases.

  19. Conservative management of external root resorption after tooth reimplantation: a 3-year follow-up.

    PubMed

    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.

  20. Changes in Autumnal Leaf Reflectance Measurements of Deciduous Trees in Relation to Nitrogen Resorption Efficiencies

    NASA Astrophysics Data System (ADS)

    Wheeler, K. I.; Levia, D. F., Jr.; Vargas, R.

    2016-12-01

    During autumn, leaves play a significant and influential role in a forested ecosystem's hydrologic and biogeochemical cycles. Starting at pre-senescence, trees resorb essential nutrients, such as nitrogen and phosphorus, in order to maintain nutrient levels throughout the winter and into spring growth. Initial spring growth is almost exclusively dependent on nutrients resorbed before abscission. Climate change is expected to impact nutrient resorption and thus the need exists to be able to monitor changes in nutrient resorption. Spectrophotometry has been successfully used to identify pigment concentrations in senescing leaves, but current nitrogen metrics have not been reproducible. These metrics focus on reflectance values at key wavelengths and relationships between wavelengths in order to attempt to deduce the nitrogen concentration. We are interested, though, if the patterns of change in the leaf reflectance signatures throughout the fall can be used to compare resorption efficiencies. During 2015 and 2016, chlorophyll concentrations and light reflectance signatures were routinely measured for leaves of Fagus grandifolia (American beech), Liriodendron tulipifera (yellow poplar), and Betula lenta (sweet birch) trees throughout senescence. Leaves from each tree were collected both in August and post-abscission and analyzed for nitrogen concentrations using a CNHS Elementar Cube. Patterns in the light reflectance data were analyzed using Kohonen's self-organizing maps. Preliminary data suggests that the temporal leaf reflectances for each tree maps closer to those of trees with similar resorption efficiencies, thus potentially providing a method to non-destructively monitor nitrogen resorption efficiencies.

  1. Calmodulin interacts with Rab3D and modulates osteoclastic bone resorption

    PubMed Central

    Zhu, Sipin; Chim, Shek Man; Cheng, Taksum; Ang, Estabelle; Ng, Benjamin; Lim, Baysie; Chen, Kai; Qiu, Heng; Tickner, Jennifer; Xu, Huazi; Pavlos, Nathan; Xu, Jiake

    2016-01-01

    Calmodulin is a highly versatile protein that regulates intracellular calcium homeostasis and is involved in a variety of cellular functions including cardiac excitability, synaptic plasticity and signaling transduction. During osteoclastic bone resorption, calmodulin has been reported to concentrate at the ruffled border membrane of osteoclasts where it is thought to modulate bone resorption activity in response to calcium. Here we report an interaction between calmodulin and Rab3D, a small exocytic GTPase and established regulator osteoclastic bone resorption. Using yeast two-hybrid screening together with a series of protein-protein interaction studies, we show that calmodulin interacts with Rab3D in a calcium dependent manner. Consistently, expression of a calcium insensitive form of calmodulin (i.e. CaM1234) perturbs calmodulin-Rab3D interaction as monitored by bioluminescence resonance energy transfer (BRET) assays. In osteoclasts, calmodulin and Rab3D are constitutively co-expressed during RANKL-induced osteoclast differentiation, co-occupy plasma membrane fractions by differential gradient sedimentation assay and colocalise in the ruffled border as revealed by confocal microscopy. Further, functional blockade of calmodulin-Rab3D interaction by calmidazolium chloride coincides with an attenuation of osteoclastic bone resorption. Our data imply that calmodulin- Rab3D interaction is required for efficient bone resorption by osteoclasts in vitro. PMID:27897225

  2. Tibial plateau fracture after anterior cruciate ligament reconstruction: Role of the interference screw resorption in the stress riser effect.

    PubMed

    Thaunat, Mathieu; Nourissat, Geoffroy; Gaudin, Pascal; Beaufils, Philippe

    2006-06-01

    We report a case of tibial plateau fracture after previous anterior cruciate ligament (ACL) reconstruction using patellar tendon autograft and bioabsorbable screws 4 years previously. The fracture occurred through the tibial tunnel. The interference screw had undergone complete resorption and the tunnel widening had increased. The resorption of the interference screw did not simultaneously promote and foster the growth of surrounding bone tissue. Therefore, the area of reactive tissue left by the screw resorption in an enlarged bone tunnel may lead to vulnerability of the tibial plateau. Stress risers would occur following ACL reconstruction if either resorption is not complete or bony integration is not complete.

  3. Biology of Bony Fish Macrophages

    PubMed Central

    Hodgkinson, Jordan W.; Grayfer, Leon; Belosevic, Miodrag

    2015-01-01

    Macrophages are found across all vertebrate species, reside in virtually all animal tissues, and play critical roles in host protection and homeostasis. Various mechanisms determine and regulate the highly plastic functional phenotypes of macrophages, including antimicrobial host defenses (pro-inflammatory, M1-type), and resolution and repair functions (anti-inflammatory/regulatory, M2-type). The study of inflammatory macrophages in immune defense of teleosts has garnered much attention, and antimicrobial mechanisms of these cells have been extensively studied in various fish models. Intriguingly, both similarities and differences have been documented for the regulation of lower vertebrate macrophage antimicrobial defenses, as compared to what has been described in mammals. Advances in our understanding of the teleost macrophage M2 phenotypes likewise suggest functional conservation through similar and distinct regulatory strategies, compared to their mammalian counterparts. In this review, we discuss the current understanding of the molecular mechanisms governing teleost macrophage functional heterogeneity, including monopoetic development, classical macrophage inflammatory and antimicrobial responses as well as alternative macrophage polarization towards tissues repair and resolution of inflammation. PMID:26633534

  4. Origins of Brain Tumor Macrophages.

    PubMed

    De Palma, Michele

    2016-12-12

    The ontogeny of brain-tumor-associated macrophages is poorly understood. New findings indicate that both resident microglia and blood-derived monocytes generate the pool of macrophages that infiltrate brain tumors of either primary or metastatic origin. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Embryonic resorption in context to intragestational corpus luteum regression: a longitudinal ultrasonographic study in the European brown hare (Lepus europaeus PALLAS, 1778).

    PubMed

    Schroeder, K; Drews, B; Roellig, K; Goeritz, F; Hildebrandt, T B

    2013-09-15

    Embryonic resorption is frequently observed in polytocous mammals. Often it occurs as partial litter resorption affecting only single conceptuses of a whole litter. The aim of the study was to describe the incidence and morphology of embryonic resorption in the European brown hare (Lepus europaeus). In 154 pregnancies viable conceptuses, conceptuses undergoing resorption and CL of pregnancy were ultrasonographically monitored during the entire gestation period. Resorptions were classified into (1) "pre-implantation resorptions," (2) "peri-implantation resorptions," and (3) "post-implantation resorptions." The incidence of resorption in the pre-implantation period was 9%, in the peri-implantation period 9%, and in the post-implantation period 24%. Post-implantation resorptions were found up to late pregnancy stages when fetal development was already in progress. The highest daily incidence of resorption was on Day 8 of the 42-day pregnancy. In 91% of the cases, the regression of one CL was observed, while an embryo was undergoing resorption at the same time. The number of resorptions did not significantly differ from the number of CL in regression during gestation, suggesting an interesting one-resorption-to-one-regression relationship. The ultrasonographic appearance of the luteal regression during pregnancy was similar to the morphology characteristic for postpartal luteolysis. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Macrophage podosomes go 3D.

    PubMed

    Van Goethem, Emeline; Guiet, Romain; Balor, Stéphanie; Charrière, Guillaume M; Poincloux, Renaud; Labrousse, Arnaud; Maridonneau-Parini, Isabelle; Le Cabec, Véronique

    2011-01-01

    Macrophage tissue infiltration is a critical step in the immune response against microorganisms and is also associated with disease progression in chronic inflammation and cancer. Macrophages are constitutively equipped with specialized structures called podosomes dedicated to extracellular matrix (ECM) degradation. We recently reported that these structures play a critical role in trans-matrix mesenchymal migration mode, a protease-dependent mechanism. Podosome molecular components and their ECM-degrading activity have been extensively studied in two dimensions (2D), but yet very little is known about their fate in three-dimensional (3D) environments. Therefore, localization of podosome markers and proteolytic activity were carefully examined in human macrophages performing mesenchymal migration. Using our gelled collagen I 3D matrix model to obligate human macrophages to perform mesenchymal migration, classical podosome markers including talin, paxillin, vinculin, gelsolin, cortactin were found to accumulate at the tip of F-actin-rich cell protrusions together with β1 integrin and CD44 but not β2 integrin. Macrophage proteolytic activity was observed at podosome-like protrusion sites using confocal fluorescence microscopy and electron microscopy. The formation of migration tunnels by macrophages inside the matrix was accomplished by degradation, engulfment and mechanic compaction of the matrix. In addition, videomicroscopy revealed that 3D F-actin-rich protrusions of migrating macrophages were as dynamic as their 2D counterparts. Overall, the specifications of 3D podosomes resembled those of 2D podosome rosettes rather than those of individual podosomes. This observation was further supported by the aspect of 3D podosomes in fibroblasts expressing Hck, a master regulator of podosome rosettes in macrophages. In conclusion, human macrophage podosomes go 3D and take the shape of spherical podosome rosettes when the cells perform mesenchymal migration. This work

  7. Plasma fluctuation in estradiol-17β and bone resorption markers around parturition in dairy cows.

    PubMed

    Devkota, Bhuminad; Takahashi, Masahiro; Sato, Saori; Sasaki, Kouya; Ueki, Atsushi; Osawa, Takeshi; Takahashi, Masahiro; Yamagishi, Norio

    2015-07-01

    Blood samples were obtained sequentially from 10 dairy cows around the time of parturition to assess plasma fluctuations in estradiol-17β (E2) levels in association with those of several bone resorption markers. Plasma E2 concentration increased sharply a few days prepartum and decreased quickly after parturition. In terms of bone resorption markers, the plasma level of tartrate-resistant acid phosphatase isoform 5b (TRAP5b) rose significantly, commencing 1 week prepartum, and was maintained at this level to a few days postpartum. The plasma concentration of carboxyterminal collagen cross-links of type-I collagen (CTx) increased significantly after parturition. These observations suggest that osteoclast-mediated bone resorption was activated after parturition when plasma E2 concentrations decreased.

  8. Plasma fluctuation in estradiol-17β and bone resorption markers around parturition in dairy cows

    PubMed Central

    DEVKOTA, Bhuminad; TAKAHASHI, Masahiro; SATO, Saori; SASAKI, Kouya; UEKI, Atsushi; OSAWA, Takeshi; TAKAHASHI, Masahiro; YAMAGISHI, Norio

    2015-01-01

    Blood samples were obtained sequentially from 10 dairy cows around the time of parturition to assess plasma fluctuations in estradiol-17β (E2) levels in association with those of several bone resorption markers. Plasma E2 concentration increased sharply a few days prepartum and decreased quickly after parturition. In terms of bone resorption markers, the plasma level of tartrate-resistant acid phosphatase isoform 5b (TRAP5b) rose significantly, commencing 1 week prepartum, and was maintained at this level to a few days postpartum. The plasma concentration of carboxyterminal collagen cross-links of type-I collagen (CTx) increased significantly after parturition. These observations suggest that osteoclast-mediated bone resorption was activated after parturition when plasma E2 concentrations decreased. PMID:25755022

  9. Nonsurgical management of a large periapical lesion associated with an immature tooth displaying external inflammatory resorption

    PubMed Central

    Fernandes, Marina; de Ataide, Ida

    2015-01-01

    Immature nonvital teeth can often be associated with periapical lesions. Presence of external inflammatory resorption can complicate the treatment plan. A 21-year-old female patient presented with a large periapical lesion in relation to teeth 11 and 12. Tooth 11 was an immature tooth undergoing external inflammatory resorption. Aspiration through the root canal was carried out to evacuate the purulent fluid in the periapical lesion. Triple antibiotic paste was then placed as an intracanal medicament for a period of 2 weeks, followed by calcium hydroxide therapy for a period of 2 months. Mineral trioxide aggregate was then placed as an apical barrier to a thickness of about 4 mm. Obturation of the remainder of the canal space was done after 48 h. Complete periapical healing was evident after 1 year and 6 months. Nonsurgical healing of a large periapical lesion associated with an immature tooth displaying external inflammatory resorption can be successfully achieved. PMID:26180425

  10. Anti-resorptive osteonecrosis of the jaws: facts forgotten, questions answered, lessons learned.

    PubMed

    Carlson, Eric R; Schlott, Benjamin J

    2014-05-01

    Osteonecrosis of the jaws associated with bisphosphonate and other anti-resorptive medications (ARONJ) has historically been a poorly understood disease process in terms of its pathophysiology, prevention and treatment since it was originally described in 2003. In association with its original discovery 11 years ago, non-evidence based speculation of these issues have been published in the international literature and are currently being challenged. A critical analysis of cancer patients with ARONJ, for example, reveals that their osteonecrosis is nearly identical to that of cancer patients who are naive to anti-resorptive medications. In addition, osteonecrosis of the jaws is not unique to patients exposed to anti-resorptive medications, but is also seen in patients with osteomyelitis and other pathologic processes of the jaws. This article represents a review of facts forgotten, questions answered, and lessons learned in general regarding osteonecrosis of the jaws. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Severe root resorption of the upper central incisors as a consequence of playing the flute.

    PubMed

    Seres, Laszlo; Vetro, Eva; Perenyi, Janos; Kocsis, Andras

    2017-10-01

    This study presents a case of severe root resorption of the maxillary central incisors in an 18-year-old woman who was referred for orthodontic treatment of irregular dental arches. A detailed history revealed that she used to play the block flute on an everyday basis during childhood. Against all warnings, she continued to firmly press her teeth into the mouthpiece of the instrument. Impressions of the upper central incisors were clearly visible on the instrument. Although it is well known that excessive occlusal forces can result in root resorption, to the authors' knowledge, this case involves one of the first reported occurrences of extensive root resorption that was most likely caused by playing a wind instrument during childhood. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. External cervical resorption case report and a brief review of literature

    PubMed Central

    Ahmed, Nizar; Gopalakrishnan; Mony, Bejoy; Parthasarthy, Harinath

    2014-01-01

    External cervical resorption (ECR) is the loss of dental hard tissue as a result of odontoclastic action; it usually begins on the cervical region of the root surface of the teeth. The etiology, predisposing factors, diagnosis, and management of ECR have been reviewed here. Effective management and appropriate treatment can only be carried out if the true nature and exact location of the ECR lesion are known. This paper reports on the management of a case of external cervical root resorption (ECRR), which involved root canal treatment and removal of the resorbing area of the affected tooth as well as filling the resorbed area with mineral trioxide aggregate (MTA) and resin-modified glass ionomer filling material (RMGIC). The defect was filled with bone graft material and guided tissue regeneration (GTR) membrane. This case highlights the importance of using MTA and successful management of cervical resorption with a stable uneventful clinical recovery. PMID:24678232

  13. Oral pain due to severe pre-eruptive intracoronal resorption in permanent tooth.

    PubMed

    Brunet-Llobet, Ll; Lahor-Soler, E; Miranda-Rius, J

    2014-09-01

    Pre-eruptive intracoronal resorption is a dental lesion located within the dentin. This defect is usually discovered incidentally on routine dental radiographs. Occasionally this process may be associated with oral pain in advanced lesions. This case report describes a 12-year-old boy whose chief complaint was a diffuse oral pain due to a severe pre-eruptive intracoronal resorption in a permanent second molar. The previous radiographs, taken at the age of nine years, showed no evidence of the lesion. After surgical exposure, a pulp-like tissue under the crown was removed and analyzed; subsequently the tooth was extracted due to extensive resorption. A follow-up of the unerupted third molar, still in formation process, allowed to see that it was favourably positioned for replacing the extracted molar.

  14. Nonsurgical management of a large periapical lesion associated with an immature tooth displaying external inflammatory resorption.

    PubMed

    Fernandes, Marina; de Ataide, Ida

    2015-01-01

    Immature nonvital teeth can often be associated with periapical lesions. Presence of external inflammatory resorption can complicate the treatment plan. A 21-year-old female patient presented with a large periapical lesion in relation to teeth 11 and 12. Tooth 11 was an immature tooth undergoing external inflammatory resorption. Aspiration through the root canal was carried out to evacuate the purulent fluid in the periapical lesion. Triple antibiotic paste was then placed as an intracanal medicament for a period of 2 weeks, followed by calcium hydroxide therapy for a period of 2 months. Mineral trioxide aggregate was then placed as an apical barrier to a thickness of about 4 mm. Obturation of the remainder of the canal space was done after 48 h. Complete periapical healing was evident after 1 year and 6 months. Nonsurgical healing of a large periapical lesion associated with an immature tooth displaying external inflammatory resorption can be successfully achieved.

  15. Mechanical Failure Begins Preferentially Near Resorption Cavities in Human Vertebral Cancellous Bone Under Compression

    PubMed Central

    Slyfield, C.R.; Tkachenko, E.V.; Fischer, S.E.; Ehlert, K.M.; Yi, I. H.; Jekir, M. G.; O’Brien, R. G.; Keaveny, T.M.; Hernandez, C.J.

    2012-01-01

    Summary The amount of bone turnover in the body has been implicated as a factor that can influence fracture risk and bone strength. Here we test the idea that remodeling cavities promote local tissue failure by determining if microscopic tissue damage (microdamage) caused by controlled loading in vitro is more likely to form near resorption cavities. Specimens of human vertebral cancellous bone (L4, 7 male and 2 female, age 70 ± 10, mean ± SD) were loaded in compression to the yield point, stained for microscopic tissue damage and submitted to three-dimensional fluorescent imaging using serial milling (image voxel size 0.7 × 0.7 × 5.0 µm). We found the resulting damage volume per bone volume (DV/BV) was correlated with percent eroded surface (p < 0.01, r2 = 0.65), demonstrating that whole specimen measures of resorption cavities and microdamage are related. Locations of microdamage were more than two times as likely to have a neighboring resorption cavity than randomly selected sites without microdamage (relative risk 2.39, 95% confidence interval of relative risk: 2.09 – 2.73), indicating a spatial association between resorption cavities and microdamage at the local level. Individual microdamage sites were 48,700 (40,100; 62,700) µm3 in size (median, 25th and 75th percentiles). That microdamage was associated with resorption cavities when measured at the whole specimen level as well as at the local level provides strong evidence that resorption cavities play a role in mechanical failure processes of cancellous bone and therefore have the potential to influence resistance to clinical fracture. PMID:22426306

  16. Impacted maxillary canines and root resorption of adjacent teeth: A retrospective observational study.

    PubMed

    Guarnieri, R; Cavallini, C; Vernucci, R; Vichi, M; Leonardi, R; Barbato, E

    2016-11-01

    The prevalence of impacted maxillary canine is reported to be between 1% and 3%. The lack of monitoring and the delay in the treatment of the impacted canine can cause different complications such as: displacement of adjacent teeth, loss of vitality of neighbouring teeth, shortening of the dental arch, follicular cysts, canine ankylosis, recurrent infections, recurrent pain, internal resorption of the canine and the adjacent teeth, external resorption of the canine and the adjacent teeth, combination of these factors. An appropriate diagnosis, accurate predictive analysis and early intervention are likely to prevent such undesirable effects. The objective is to evaluate, by means of a retrospective observational study, the possibility of carrying out a predictive analysis of root resorption adjacent to the impacted canines by means of orthopantomographs, so as to limit the prescription of additional 3D radiography. 120 subjects with unilateral or bilateral maxillary impacted canine were examined and 50 patients with 69 impacted maxillary canine (22 male, 28 female; mean age: 11.7 years) satisfied the inclusion criteria of the study. These patients were subjected to a basic clinical and radiographic investigation (orthopantomographs and computerized tomography). All panoramic films were viewed under standardized conditions for the evaluation of two main variables: maxillary canine angulations (a, b, g angles) and the overlapping between the impacted teeth and the lateral incisor (Analysis of Lindauer). Binary logistic regression was used to estimate the likelihood of resorbed lateral incisors depending on sector location and angle measurements. Results indicated that b angle has the greatest influence on the prediction of root resorption (predictive value of b angle = 76%). If β angle <18° and Lindauer = I, the probability of resorption is 0.06. Evaluation of b angle and superimposition lateral incisor/impacted canine analysed on orthopantomographs could be one of

  17. Local Mechanical Stimuli Regulate Bone Formation and Resorption in Mice at the Tissue Level

    PubMed Central

    Schulte, Friederike A.; Ruffoni, Davide; Lambers, Floor M.; Christen, David; Webster, Duncan J.; Kuhn, Gisela; Müller, Ralph

    2013-01-01

    Bone is able to react to changing mechanical demands by adapting its internal microstructure through bone forming and resorbing cells. This process is called bone modeling and remodeling. It is evident that changes in mechanical demands at the organ level must be interpreted at the tissue level where bone (re)modeling takes place. Although assumed for a long time, the relationship between the locations of bone formation and resorption and the local mechanical environment is still under debate. The lack of suitable imaging modalities for measuring bone formation and resorption in vivo has made it difficult to assess the mechanoregulation of bone three-dimensionally by experiment. Using in vivo micro-computed tomography and high resolution finite element analysis in living mice, we show that bone formation most likely occurs at sites of high local mechanical strain (p<0.0001) and resorption at sites of low local mechanical strain (p<0.0001). Furthermore, the probability of bone resorption decreases exponentially with increasing mechanical stimulus (R2 = 0.99) whereas the probability of bone formation follows an exponential growth function to a maximum value (R2 = 0.99). Moreover, resorption is more strictly controlled than formation in loaded animals, and ovariectomy increases the amount of non-targeted resorption. Our experimental assessment of mechanoregulation at the tissue level does not show any evidence of a lazy zone and suggests that around 80% of all (re)modeling can be linked to the mechanical micro-environment. These findings disclose how mechanical stimuli at the tissue level contribute to the regulation of bone adaptation at the organ level. PMID:23637993

  18. Tannerella forsythia GroEL induces inflammatory bone resorption and synergizes with interleukin-17.

    PubMed

    Jung, Y-J; Choi, Y-J; An, S-J; Lee, H-R; Jun, H-K; Choi, B-K

    2016-08-03

    Tannerella forsythia is a major periodontal pathogen, and T. forsythia GroEL is a molecular chaperone homologous to human heat-shock protein 60. Interleukin-17 (IL-17) has been implicated in the pathogenesis of periodontitis and several systemic diseases. This study investigated the potential of T. forsythia GroEL to induce inflammatory bone resorption and examined the cooperative effect of IL-17 and T. forsythia GroEL on inflammatory responses. Human gingival fibroblasts (HGFs) and periodontal ligament (PDL) fibroblasts were stimulated with T. forsythia GroEL and/or IL-17. Gene expression of IL-6, IL-8, and cyclooxygenase-2 (COX-2) and concentrations of IL-6, IL-8, and prostaglandin E2 (PGE2 ) were measured by real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. After stimulation of MG63 cells with T. forsythia GroEL and/or IL-17, gene expression of osteoprotegerin (OPG) was examined. After subcutaneous injection of T. forsythia GroEL and/or IL-17 above the calvaria of BALB/c mice, calvarial bone resorption was assessed by micro-computed tomography and histological examination. Tannerella forsythia GroEL induced IL-6 and IL-8 production in HGFs and PDL cells, and IL-17 further promoted IL-6 and IL-8 production. Both T. forsythia GroEL and IL-17 synergistically increased PGE2 production and inhibited OPG gene expression. Calvarial bone resorption was induced by T. forsythia GroEL injection, and simultaneous injection of T. forsythia GroEL and IL-17 further increased bone resorption. These results suggest that T. forsythia GroEL is a novel virulence factor that can contribute to inflammatory bone resorption caused by T. forsythia and synergizes with IL-17 to exacerbate inflammation and bone resorption.

  19. Potential and realized nutrient resorption in serpentine and non-serpentine chaparral shrubs and trees.

    PubMed

    Drenovsky, Rebecca E; Koehler, Catherine E; Skelly, Kathryn; Richards, James H

    2013-01-01

    Low-nutrient adapted species have numerous mechanisms that aid in nutrient conservation. Hypothetically, species adapted to nutrient-poor soils should have tighter internal nutrient recycling, as evidenced by greater resorption. However, literature results are mixed. We suggest methodological factors may limit our understanding of this process. We hypothesized that plants adapted to serpentine soils would be more proficient in resorbing N and P than plants adapted to non-serpentine soils, although there would be differences among functional groups within each soil type. For six growing seasons, we sampled senescent leaf tissue from the dominant and co-dominant shrubs and trees found in serpentine and non-serpentine chaparral communities in the California Coast Range. Our study also explicitly included congener pairs found on both soil types. Most species were highly N proficient, but species adapted to serpentine soils were more P proficient. Surprisingly, two of the three potential N-fixing species were also highly N proficient. Evergreen Quercus congeners were more N proficient than their deciduous congener pairs, although there was no difference in P resorption proficiency. Overall, large inter-annual variation was observed among most species sampled, but at least in some years, maximum potential resorption likely was reached. However, climate (temperature and precipitation) was not strongly correlated with either N or P resorption proficiency. Our data suggest that controlling for phylogeny can aid in interpretation of resorption patterns. More importantly, our study clearly shows that resorption patterns can only be discerned through long-term datasets, of which few exist in the literature.

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

    PubMed Central

    Seifi, Massoud; Ezzati, Baharak; Saedi, Sara; Hedayati, Mehdi

    2015-01-01

    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. PMID:26636117

  1. Lithium chloride attenuates root resorption during orthodontic tooth movement in rats.

    PubMed

    Wang, Yu; Gao, Shang; Jiang, Huan; Lin, Peng; Bao, Xingfu; Zhang, Zhimin; Hu, Min

    2014-02-01

    Root resorption is a common side effect of orthodontic treatment. In the current study, lithium chloride (LiCl), a Wnt signaling activator, was examined to determine its effect on root resorption. In total, 10 Sprague Dawley rats were randomly allocated into the experimental group (EG) and control group (CG). Each group consisted of five subjects. By using closed nickel-titanium coil springs, a 50-g force was applied between the upper incisors and the maxillary right first molars in order to mimic orthodontic biomechanics in the EG and CG for 14 days. During the 14 days, the EG rats were gavage-fed 200 mg/kg LiCl every 48 h. Next, digital radiographs were captured using a micro-computational tomography scanner. The movement of the maxillary first molars and the root resorption area ratio were measured electronically on the digital radiographs. The outcomes were analyzed using ANOVA. Following 14 days of experimental force application, all rats had spaces of varying sizes between the first and second right maxillary molars. The average distance measured in the CG was slightly higher than in the EG, however, the difference was not found to be statistically significant (P=0.224). Root resorption craters were observed in the groups following the experiment. Rough cementum areas were observed on the mesial surface of the distobuccal and distopalatal roots. The mean root resorption area ratio of CG was significantly greater than EG (P<0.05). Results of the present study indicate that LiCl can attenuate orthodontically induce root resorption during orthodontic tooth movement. The effect of LiCl on tooth movement is insignificant.

  2. A novel approach to inhibit bone resorption: exosite inhibitors against cathepsin K

    PubMed Central

    Panwar, Preety; Søe, Kent; Guido, Rafael VC; Bueno, Renata V C; Delaisse, Jean‐Marie

    2016-01-01

    Background and Purpose Cathepsin K (CatK) is a major drug target for the treatment of osteoporosis. Potent active site‐directed inhibitors have been developed and showed variable success in clinical trials. These inhibitors block the entire activity of CatK and thus may interfere with other 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‐dihydrotanshinone (DHT1), and the active site inhibitor, odanacatib (ODN), on bone resorption and TGF‐ß1 degradation. Cell cultures, Western blot, light and scanning electron microscopy as well as energy dispersive X‐ray spectroscopy, molecular modelling and enzymatic assays were used to evaluate the inhibitors. Key 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 were comparable, respectively 41% and 33% for total resorption surface, 46% and 48% for resorption depths, and 83% and 61% for C‐terminal telopetide fragment (CTX) release. DHT1 did not affect the turnover of fibrosis‐associated TGF‐ß1 in fibroblasts, whereas 500 nM ODN was inhibitory. Conclusions and Implications Our study shows that an exosite inhibitor of CatK can specifically block bone resorption without interfering with other pathways. PMID:26562357

  3. Effects of Activated Macrophages on Nocardia asteroides

    PubMed Central

    Filice, Gregory A.; Beaman, Blaine L.; Remington, Jack S.

    1980-01-01

    The mechanism(s) of host resistance against Nocardia asteroides has not been well defined. Since disease due to N. asteroides frequently occurs in patients with impaired cell-mediated immunity, we studied the interaction of N. asteroides with activated and control mouse peritoneal macrophages. Activated macrophages were from mice infected with Toxoplasma gondii or injected with Corynebacterium parvum. N. asteroides in the early stationary phase (>99% in the coccobacillary form) was used for challenge of macrophage monolayers. Growth of two strains of N. asteroides was markedly inhibited in activated macrophages, whereas N. asteroides grew well in control macrophages. Quantitation of macrophage-associated N. asteroides indicated that activated macrophages killed 40 to 50% of N. asteroides within 6 h (P < 0.002). In control macrophage preparations, it appeared as if Nocardia filaments extended from within macrophages to the outside, and many of these filaments appeared to have extended to and then grown through neighboring macrophages. In activated macrophage preparations, Nocardia remained in the coccobacillary form in most macrophages. Control macrophage monolayers were almost completely overgrown with and destroyed by Nocardia 20 h after challenge, whereas activated macrophage monolayers remained intact. Nocardia that grew in control macrophages were not acid-alcohol fast or only weakly so, whereas the few Nocardia that grew in activated macrophages were strongly acid-alcohol fast. Our results indicate that activated macrophages may be important in host defense against N. asteroides. Images Fig. 1 PMID:6991421

  4. Dissolved water distribution in vesicular magmatic glass records both decompressive bubble growth and quench resorption

    NASA Astrophysics Data System (ADS)

    McIntosh, I. M.; Llewellin, E.; Humphreys, M.; Nichols, A. R.; Burgisser, A.; Schipper, C.

    2013-12-01

    Water distribution in magma varies over the lifetime of an eruption due to a variety of processes, including decompressive degassing of the melt, cooling during the quench from melt to glass, and post-emplacement hydration under ambient conditions. Correct interpretation of water distributions in erupted pyroclasts can therefore offer crucial insights into the dynamics of eruption mechanisms and emplacement histories. Volcanic eruptions are driven by the nucleation and growth of bubbles in magma. Bubbles grow as volatile species in the melt, of which water is volumetrically the most important, diffuse down a concentration gradient towards and across the bubble wall. On cooling, the melt quenches to glass, preserving the spatial distribution of water concentration around the bubbles (now vesicles). We use Backscatter Scanning Electron Microscopy (BSEM), Secondary Ion Mass Spectrometry (SIMS) and Fourier Transform Infra-Red spectroscopy (FTIR) to measure the spatial distribution of water around vesicles in experimentally-vesiculated samples. We find that, contrary to expectation, the total water concentration increases (by up to 2 wt.%) in the ~30 microns closest to the vesicle wall. Our samples record significant resorption of water back into the melt around bubbles during the quench process, a process which represents ';regassing' of the magma. We propose that the observed total water resorption profiles result from the increase in the equilibrium solubility of water as temperature decreases during the quench to glass, and that this resorption locally overprints the pre-existing concentration total water profile resulting from bubble growth during decompression. This resorption occurs over the very short timescales of rapid experimental quench (3-10 seconds) resulting in strongly disequilibrium water speciation. Water re-enters the melt as molecular water leading to enrichment in molecular water around vesicles, while the distribution of hydroxyl groups remains

  5. Information for the diagnosis and treatment of root resorption due to tooth replantation.

    PubMed

    Manfrin, Thais Mara; Poi, Wilson Roberto; Panzarini, Sonia Regina; Sonoda, Celso Koogi; Coradazzi, Luis Francisco; Giovanini, Ellen Greves

    2008-01-01

    A favorable prognosis after tooth avulsion depends on some variables, such as the extra-alveolar period and storage medium. Vitality of the periodontal ligament cells is considered a critical factor for a successful outcome without root resorption. The dental surgeon is provided with clinical information and radiographic findings to establish a diagnosis and may rely on current available guidelines. Once trauma has occurred, treatment must be quick and effective, and periodic follow-up must be performed. Clinical, radiographic, and histologic characteristics for each type of root resorption due to tooth replantation are presented, with the aim to provide information for the diagnosis and treatment of healing complications.

  6. Metabolic Reprograming in Macrophage Polarization

    PubMed Central

    Galván-Peña, Silvia; O’Neill, Luke A. J.

    2014-01-01

    Studying the metabolism of immune cells in recent years has emphasized the tight link existing between the metabolic state and the phenotype of these cells. Macrophages in particular are a good example of this phenomenon. Whether the macrophage obtains its energy through glycolysis or through oxidative metabolism can give rise to different phenotypes. Classically activated or M1 macrophages are key players of the first line of defense against bacterial infections and are known to obtain energy through glycolysis. Alternatively activated or M2 macrophages on the other hand are involved in tissue repair and wound healing and use oxidative metabolism to fuel their longer-term functions. Metabolic intermediates, however, are not just a source of energy but can be directly implicated in a particular macrophage phenotype. In M1 macrophages, the Krebs cycle intermediate succinate regulates HIF1α, which is responsible for driving the sustained production of the pro-inflammatory cytokine IL1β. In M2 macrophages, the sedoheptulose kinase carbohydrate kinase-like protein is critical for regulating the pentose phosphate pathway. The potential to target these events and impact on disease is an exciting prospect. PMID:25228902

  7. Vascular expression of the chemokine CX3CL1 promotes osteoclast recruitment and exacerbates bone resorption in an irradiated murine model.

    PubMed

    Han, Ki Hoon; Ryu, Jae Won; Lim, Kyung-Eun; Lee, Soo-Han; Kim, Yuna; Hwang, Chang Sun; Choi, Je-Yong; Han, Ki Ok

    2014-04-01

    Circulating osteoclast precursor cells highly express CX3C chemokine receptor 1 (CX3CR1), which is the only receptor for the unique CX3C membrane-anchored chemokine, fractalkine (CX3CL1). An irradiated murine model was used to evaluate the role of the CX3CL1-CX3CR1 axis in osteoclast recruitment and osteoclastogenesis. Ionizing radiation (IR) promoted the migration of circulating CD11b+ cells to irradiated bones and dose-dependently increased the number of differentiated osteoclasts in irradiated bones. Notably, CX3CL1 was dramatically upregulated in the vascular endothelium after IR. IR-induced production of CX3CL1 by skeletal vascular endothelium promoted chemoattraction of circulating CX3CR1+/CD11b+ cells and triggered homing of these osteoclast precursor cells toward the bone remodeling surface, a specific site for osteoclast differentiation. CX3CL1 also increased the endothelium-derived expression of other chemokines including stromal cell-derived factor-1 (CXCL12) and macrophage inflammatory protein-2 (CXCL2) by activating the hypoxia-inducible factor-1 α pathway. These effects may further enhance osteoclastogenesis. A series of in vivo experiments confirmed that knockout of CX3CR1 in bone marrow-derived cells and functional inhibition of CX3CL1 using a specific neutralizing antibody significantly ameliorated osteoclastogenesis and prevented bone loss after IR. These results demonstrate that the de novo CX3CL1-CX3CR1 axis plays a pivotal role in osteoclast recruitment and subsequent bone resorption, and verify its therapeutic potential as a new target for anti-resorptive treatment.

  8. The Type II Collagen N-propeptide, PIIBNP, inhibits cell survival and bone resorption of osteoclasts via integrin-mediated signaling

    PubMed Central

    Hayashi, Shinya; Wang, Zhepeng; Bryan, Jennifer; Kobayashi, Chikashi; Faccio, Roberta; Sandell, Linda J.

    2011-01-01

    Objective Type IIB procollagen is characteristic of cartilage, comprising 50% of the extracellular matrix. The NH2-propeptide of type IIB collagen, PIIBNP, can kill tumor cells via binding to integrins αVβ3 and αVβ5. As osteoclasts rely on αVβ3 integrins for function in bone erosion, we sought to determine whether PIIBNP could inhibit osteoclast function. Methods We undertook in vitro and in vivo experiments to evaluate both osteoblast and osteoclast function in the presence of recombinant PIIBNP. Adhesion of osteoclasts to PIIBNP was analyzed by staining of attached cells with crystal violet. PIIBNP-induced cell death was evaluated by cell counting Trypan Blue stained cells. The mechanism of cell death was evaluated by DNA fragmentation, TUNEL staining and western blotting to detect cleaved caspases. To determine the role of αVβ3 integrin, osteoclasts were pretreated with αV or β3 integrin specific siRNA before the treatment with PIIBNP. To explore PIIBNP function in vivo, a lipopolysaccharide-induced mouse calvaria lysis model was employed. Results Osteoclasts adhered to PIIBNP via an RGD-mediated mechanism. When osteoclasts were plated on extracellular matrix proteins, PIIBNP induced apoptosis of osteoclasts via caspase 3/8 activation. Osteoblasts and macrophages were not killed. Reduction of αV or β3 integrin levels on osteoclasts by siRNA reduced cell death in a dose-dependent manner. In vivo, PIIBNP could inhibit bone resorption. Conclusion We conclude that PIIBNP can inhibit osteoclast survival and bone resorption via signal transduction through the αVβ3 integrins. Because of this property and the cell specificity, we propose that PIIBNP may play a role in vivo in protecting cartilage from osteoclast invasion and also could be a new therapeutic strategy for decreasing bone loss. PMID:21708300

  9. Macrophage heterogeneity and tissue lipids.

    PubMed

    Gordon, Siamon

    2007-01-01

    Macrophages are present as resident cells in adipose tissue, and blood monocytes are recruited in increased numbers to sites of lipid accumulation in atherosclerosis, a modified form of inflammation in the arterial wall. Recent findings reported by 3 separate groups in this issue of the JCI provide evidence for distinct monocyte subsets, differential chemokine receptor usage, and phenotypic modulation of macrophages in murine models of genetic and high-fat diet-induced disease (see the related articles beginning on pages 175, 185, and 195). These studies raise prospects for selective therapeutic targets to ameliorate macrophage hyperinflammatory responses, while sparing host defense and repair mechanisms.

  10. The Effect of Root Coating with Titanium on Prevention of Root Resorption in Avulsed Teeth: An Animal Study

    PubMed Central

    Heydari, Azar; Tahmasbi, Soodeh; Badiee, Mohammadreza; Izadi, SeyedSadra; Mashhadi Abbas, Fatemeh; Mokhtari, Sepideh

    2016-01-01

    Introduction: Tooth avulsion is a real dental emergency. If immediate replantation is not performed, the avulsed tooth may be lost due to inflammatory or replacement resorption. This animal study aimed to evaluate the bone response to the titanium coating of the root surface as an artificial barrier, and prevention of resorption of avulsed teeth. Methods and Materials: This experimental study was conducted on four male dogs. The dogs were randomly divided into two groups for assessment at two and eight weeks. Four teeth were extracted in each animal. The root surfaces of the test group were coated with a titanium layer using the Electron Beam Deposition system. After 24 h, replantation of the teeth was performed. Two animals were sacrificed after two weeks and the remaining dogs were killed after eight weeks. The presence of inflammation, inflammatory resorption, replacement resorption, periodontal regeneration, periapical granuloma and ankylosis were evaluated through histological analyses. Results: Inflammatory root resorption was not present in any tooth except one tooth in the coated group after eight weeks. Replacement resorption was noted just in three of the non-coated teeth after two weeks and two teeth after eight weeks. The McNemar's test revealed that the frequency of replacement resorption in the non-coated group was significantly higher than the coated group (P=0.031). Conclusion: Based on the results of this study, it seems that coating the root surfaces of avulsed teeth with titanium may control the replacement root resorption. PMID:27790261

  11. Novel treatment of equine odontoclastic tooth resorption and hypercementosis of incisor teeth in a 22-year-old Arabian mare.

    PubMed

    Grier-Lowe, Candace K; Anthony, James

    2015-08-01

    Equine odontoclastic tooth resorption and hypercementosis is a rarely reported condition in the incisor and canine teeth of older horses. Histologically, there is internal and external resorption of the tooth with formation of excessive cementum. Once lesions become infected or supragingival this condition is very painful. The clinical manifestation, diagnosis and treatment of hypercementosis in an Arabian mare are described.

  12. Amiloride‐sensitive fluid resorption in NCI‐H441 lung epithelia depends on an apical Cl− conductance

    PubMed Central

    Korbmacher, Jonas P.; Michel, Christiane; Neubauer, Daniel; Thompson, Kristin; Mizaikoff, Boris; Frick, Manfred; Dietl, Paul; Wittekindt, Oliver H.

    2014-01-01

    Abstract Proper apical airway surface hydration is essential to maintain lung function. This hydration depends on well‐balanced water resorption and secretion. The mechanisms involved in resorption are still a matter of debate, especially as the measurement of transepithelial water transport remains challenging. In this study, we combined classical short circuit current (ISC) measurements with a novel D2O dilution method to correlate ion and water transport in order to reveal basic transport mechanisms in lung epithelia. D2O dilution method enabled precise analysis of water resorption with an unprecedented resolution. NCI‐H441 cells cultured at an air–liquid interface resorbed water at a rate of 1.5 ± 0.4 μL/(h cm2). Water resorption and ISC were reduced by almost 80% in the presence of the bulk Cl− channel inhibitor 5‐nitro‐2‐(3‐phenylpropylamino)benzoic acid (NPPB) or amiloride, a specific inhibitor of epithelial sodium channel (ENaC). However, water resorption and ISC were only moderately affected by forskolin or cystic fibrosis transmembrane regulator (CFTR) channel inhibitors (CFTRinh‐172 and glybenclamide). In line with previous studies, we demonstrate that water resorption depends on ENaC, and CFTR channels have only a minor but probably modulating effect on water resorption. However, the major ENaC‐mediated water resorption depends on an apical non‐CFTR Cl− conductance. PMID:24744880

  13. Macrophages and the Viral Dissemination Super Highway

    PubMed Central

    Klepper, Arielle; Branch, Andrea D

    2016-01-01

    Monocytes and macrophages are key components of the innate immune system yet they are often the victims of attack by infectious agents. This review examines the significance of viral infection of macrophages. The central hypothesis is that macrophage tropism enhances viral dissemination and persistence, but these changes may come at the cost of reduced replication in cells other than macrophages. PMID:26949751

  14. Novel Use of PRF and PDT in the Management of Trauma Induced Root Resorption and Infrabony Defect

    PubMed Central

    Yadav, Neha; Nawal, Ruchika Roongta; Talwar, Sangeeta; Lamba, Arundeep Kaur

    2015-01-01

    Root resorption is a common squeal of traumatic injury to the dentition. Its progression can be minimized by early diagnosis and appropriate treatment. This case report presents the diagnosis and management of a case of trauma induced trio of apical root resorption, intraradicular root resorption and infrabony defect in maxillary central incisor. The main aim in treating such cases of resorption is to limit the inflammatory response at the periapical region so as to halt the resorptive process. To allow faster regeneration of the periodontal tissues, Platelet rich fibrin (PRF), a second generation platelet concentrate was used as an apical matrix over which MTA plug was given. The periodontal defect was managed with the help of localized antimicrobial photodynamic therapy (aPDT). PMID:26155584

  15. Novel Use of PRF and PDT in the Management of Trauma Induced Root Resorption and Infrabony Defect.

    PubMed

    Pruthi, Preeti Jain; Yadav, Neha; Nawal, Ruchika Roongta; Talwar, Sangeeta; Lamba, Arundeep Kaur

    2015-05-01

    Root resorption is a common squeal of traumatic injury to the dentition. Its progression can be minimized by early diagnosis and appropriate treatment. This case report presents the diagnosis and management of a case of trauma induced trio of apical root resorption, intraradicular root resorption and infrabony defect in maxillary central incisor. The main aim in treating such cases of resorption is to limit the inflammatory response at the periapical region so as to halt the resorptive process. To allow faster regeneration of the periodontal tissues, Platelet rich fibrin (PRF), a second generation platelet concentrate was used as an apical matrix over which MTA plug was given. The periodontal defect was managed with the help of localized antimicrobial photodynamic therapy (aPDT).

  16. Investigation of bone resorption within a cortical basic multicellular unit using a lattice-based computational model

    PubMed Central

    Buenzli, P R; Pivonka, P; Smith, D W; Cummings, P T

    2017-01-01

    In this paper we develop a lattice-based computational model focused on bone resorption by osteoclasts in a single cortical basic multicellular unit (BMU). Our model takes into account the interaction of osteoclasts with the bone matrix, the interaction of osteoclasts with each other, the generation of osteoclasts from a growing blood vessel, and the renewal of osteoclast nuclei by cell fusion. All these features are shown to strongly influence the geometrical properties of the developing resorption cavity including its size, shape and progression rate, and are also shown to influence the distribution, resorption pattern and trajectories of individual osteoclasts within the BMU. We demonstrate that for certain parameter combinations, resorption cavity shapes can be recovered from the computational model that closely resemble resorption cavity shapes observed from microCT imaging of human cortical bone. PMID:22100414

  17. Macrophages Facilitate Electrical Conduction in the Heart.

    PubMed

    Hulsmans, Maarten; Clauss, Sebastian; Xiao, Ling; Aguirre, Aaron D; King, Kevin R; Hanley, Alan; Hucker, William J; Wülfers, Eike M; Seemann, Gunnar; Courties, Gabriel; Iwamoto, Yoshiko; Sun, Yuan; Savol, Andrej J; Sager, Hendrik B; Lavine, Kory J; Fishbein, Gregory A; Capen, Diane E; Da Silva, Nicolas; Miquerol, Lucile; Wakimoto, Hiroko; Seidman, Christine E; Seidman, Jonathan G; Sadreyev, Ruslan I; Naxerova, Kamila; Mitchell, Richard N; Brown, Dennis; Libby, Peter; Weissleder, Ralph; Swirski, Filip K; Kohl, Peter; Vinegoni, Claudio; Milan, David J; Ellinor, Patrick T; Nahrendorf, Matthias

    2017-04-20

    Organ-specific functions of tissue-resident macrophages in the steady-state heart are unknown. Here, we show that cardiac macrophages facilitate electrical conduction through the distal atrioventricular node, where conducting cells densely intersperse with elongated macrophages expressing connexin 43. When coupled to spontaneously beating cardiomyocytes via connexin-43-containing gap junctions, cardiac macrophages have a negative resting membrane potential and depolarize in synchrony with cardiomyocytes. Conversely, macrophages render the resting membrane potential of cardiomyocytes more positive and, according to computational modeling, accelerate their repolarization. Photostimulation of channelrhodopsin-2-expressing macrophages improves atrioventricular conduction, whereas conditional deletion of connexin 43 in macrophages and congenital lack of macrophages delay atrioventricular conduction. In the Cd11b(DTR) mouse, macrophage ablation induces progressive atrioventricular block. These observations implicate macrophages in normal and aberrant cardiac conduction. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Isolation and Differentiation of Murine Macrophages.

    PubMed

    Rios, Francisco J; Touyz, Rhian M; Montezano, Augusto C

    2017-01-01

    Macrophages play a major role in inflammation, wound healing, and tissue repair. Infiltrated monocytes differentiate into different macrophage subtypes with protective or pathogenic activities in vascular lesions. In the heart and vascular tissues, pathological activation promotes cardiovascular inflammation and remodeling and there is increasing evidence that macrophages play important mechanisms in this environment. Primary murine macrophages can be obtained from: bone marrow by different treatments (granulocyte-macrophage colony-stimulating factor-GM-CSF, macrophage colony-stimulating factor-M-CSF or supernatant of murine fibroblast L929), peritoneal cavity (resident or thioglycolate elicit macrophages), from the lung (alveolar macrophages) or from adipose tissue. In this chapter we describe some protocols to obtain primary murine macrophages and how to identify a pure macrophage population or activation phenotypes using different markers.

  19. The Macrophage Switch in Obesity Development

    PubMed Central

    Castoldi, Angela; Naffah de Souza, Cristiane; Câmara, Niels Olsen Saraiva; Moraes-Vieira, Pedro M.

    2016-01-01

    Immune cell infiltration in (white) adipose tissue (AT) during obesity is associated with the development of insulin resistance. In AT, the main population of leukocytes are macrophages. Macrophages can be classified into two major populations: M1, classically activated macrophages, and M2, alternatively activated macrophages, although recent studies have identified a broad range of macrophage subsets. During obesity, AT M1 macrophage numbers increase and correlate with AT inflammation and insulin resistance. Upon activation, pro-inflammatory M1 macrophages induce aerobic glycolysis. By contrast, in lean humans and mice, the number of M2 macrophages predominates. M2 macrophages secrete anti-inflammatory cytokines and utilize oxidative metabolism to maintain AT homeostasis. Here, we review the immunologic and metabolic functions of AT macrophages and their different facets in obesity and the metabolic syndrome. PMID:26779183

  20. Effect of gingival fibroblasts and ultrasound on dogs' root resorption during orthodontic treatment

    PubMed Central

    Crossman, Jacqueline; Hassan, Ali H; Saleem, Ali; Felemban, Nayef; Aldaghreer, Saleh; Fawzi, Elham; Farid, Mamdouh; Abdel-Ghaffar, Khaled; Gargoum, Ausama; El-Bialy, Tarek

    2017-01-01

    Objectives: To investigate the effect of using osteogenic induced gingival fibroblasts (OIGFs) and low intensity pulsed ultrasound (LIPUS) on root resorption lacunae volume and cementum thickness in beagle dogs that received orthodontic tooth movement. Materials and Methods: Seven beagle dogs were used, from which gingival cells (GCs) were obtained and were induced osteogenically to produce OIGFs. Each third and fourth premolar was randomly assigned to one of the five groups, namely, LIPUS, OIGFs, bone morphogenetic protein-2 (BMP-2), OIGFs + LIPUS, and control. All groups received 4 weeks of bodily tooth movement, then LIPUS-treated groups received LIPUS for 20 min/day for 4 weeks, and OIGFs groups received an injection of OIGFs near the root apex. Microcomputed tomography analysis was used to calculate root resorption lacunae volume and histomorphometric analysis was performed to measure the cementum thickness of each root at 3 root levels on compression and tension sides. Results: There was no significant difference in resorption volume between the treatment groups. OIGFs + LIPUS increased cementum thickness (P > 0.05) in third premolars near the apex, and LIPUS increased cementum thickness (P > 0.05) in fourth premolars near the apex. Furthermore, BMP2 increased cementum thickness at the coronal third at the compression side. Conclusion: OIGFs, LIPUS, and BMP-2 can be potential treatments for orthodontically induced root resorption, however, improvements in experimental design and treatment parameters are required to further investigate these repair modalities. PMID:28197400

  1. Effects of moisture and nitrogen stress on gas exchange and nutrient resorption in Quercus rubra seedlings

    Treesearch

    K. Francis Salifu; Douglass F. Jacobs

    2008-01-01

    The effects of simulated soil fertility at three levels (poor, medium, and rich soils) and moisture stress at two levels (well watered versus moisture stressed) on gas exchange and foliar nutrient resorption in 1+0 bareroot northern red oak (Quercus rubra) seedlings were evaluated. Current nitrogen (N) uptake was labeled with the stable isotope

  2. Potentiation of osteoclast bone-resorption activity by inhibition of nitric oxide synthase.

    PubMed Central

    Kasten, T P; Collin-Osdoby, P; Patel, N; Osdoby, P; Krukowski, M; Misko, T P; Settle, S L; Currie, M G; Nickols, G A

    1994-01-01

    We have examined the effects of modulating nitric oxide (NO) levels on osteoclast-mediated bone resorption in vitro and the effects of nitric oxide synthase (NOS) inhibitors on bone mineral density in vivo. Diaphorase-based histochemical staining for NOS activity of bone sections or highly enriched osteoclast cultures suggested that osteoclasts exhibit substantial NOS activity that may account for basal NO production. Chicken osteoclasts were cultured for 36 hr on bovine bone slices in the presence or absence of the NO-generating agent sodium nitroprusside or the NOS inhibitors N-nitro-L-arginine methyl ester and aminoguanidine. Nitroprusside markedly decreased the number of bone pits and the average pit area in comparison with control cultures. On the other hand, NOS inhibition by N-nitro-L-arginine methyl ester or aminoguanidine dramatically increased the number of bone pits and the average resorption area per pit. In a model of osteoporosis, aminoguanidine potentiated the loss of bone mineral density in ovariectomized rats. Aminoguanidine also caused a loss of bone mineral density in the sham-operated rats. Inhibition of NOS activity in vitro and in vivo resulted in an apparent potentiation of osteoclast activity. These findings suggest that endogenous NO production in osteoclast cultures may regulate resorption activity. The modulation of NOS and NO levels by cells within the bone microenvironment may be a sensitive mechanism for local control of osteoclast bone resorption. Images PMID:7513424

  3. Lutein, a carotenoid, suppresses osteoclastic bone resorption and stimulates bone formation in cultures.

    PubMed

    Tominari, Tsukasa; Matsumoto, Chiho; Watanabe, Kenta; Hirata, Michiko; Grundler, Florian M W; Inada, Masaki; Miyaura, Chisato

    2017-02-01

    Lutein, a member of the xanthophyll family of carotenoids, suppressed IL-1-induced osteoclast differentiation and bone resorption. The survival of mature osteoclasts was also suppressed by lutein in cultures. When lutein was added to the cultures of osteoblasts, lutein enhanced the formation of mineralized bone nodules by elevating BMP2 expression and inhibiting sclerostin expression. Lutein may be beneficial for bone health.

  4. All washed out? Foliar nutrient resorption and leaching in senescing switchgrass

    USDA-ARS?s Scientific Manuscript database

    Ideal bioenergy feedstocks are low in nutrients that act as anti-quality factors during conversion processes. Research has shown that delaying harvest of temperate perennial grasses until late winter reduces nutrient content, primarily due to end-season resorption, but also indicates a role for foli...

  5. [Total alloplastic temporomandibular joint reconstruction combined with orthodontic treatment in a patient with idiopathic condylar resorption].

    PubMed

    Chung, Chooryung J; Choi, Yoon-Jeong; Kim, In-Sil; Huh, Jong-Ki; Kim, Hyung-Gon; Kim, Kyung-Ho

    2012-09-01

    This case report describes the successful treatment of an adult patient with skeletal Class II open-bite malocclusion secondary to idiopathic condylar resorption. Total alloplastic joint reconstruction and counterclockwise rotation of the maxillomandibular complex combined with orthodontic treatment provided a satisfying outcome with maximum functional and esthetic improvement.

  6. Total alloplastic temporomandibular joint reconstruction combined with orthodontic treatment in a patient with idiopathic condylar resorption.

    PubMed

    Chung, Chooryung J; Choi, Yoon-Jeong; Kim, In-Sil; Huh, Jong-Ki; Kim, Hyung-Gon; Kim, Kyung-Ho

    2011-09-01

    This case report describes the successful treatment of an adult patient with skeletal Class II open-bite malocclusion secondary to idiopathic condylar resorption. Total alloplastic joint reconstruction and counterclockwise rotation of the maxillomandibular complex combined with orthodontic treatment provided a satisfying outcome with maximum functional and esthetic improvement.

  7. Impairment of osteoclastic bone resorption in rapidly growing female p47phox knockout mice

    USDA-ARS?s Scientific Manuscript database

    Bone formation is dependent on the activity and differentiation of osteoblasts; whereas resorption of preexisting mineralized bone matrix by osteoclasts is necessary not only for bone development but also for regeneration and remodeling. Bone remodeling is a process in which osteoblasts and osteocla...

  8. Focus Ion Beam/Scanning Electron Microscopy Characterization of Osteoclastic Resorption of Calcium Phosphate Substrates.

    PubMed

    Diez-Escudero, Anna; Espanol, Montserrat; Montufar, Edgar B; Di Pompo, Gemma; Ciapetti, Gabriela; Baldini, Nicola; Ginebra, Maria-Pau

    2017-02-01

    This article presents the application of dual focused ion beam/scanning electron microscopy (FIB-SEM) imaging for preclinical testing of calcium phosphates with osteoclast precursor cells and how this high-resolution imaging technique is able to reveal microstructural changes at a level of detail previously not possible. Calcium phosphate substrates, having similar compositions but different microstructures, were produced using low- and high-temperature processes (biomimetic calcium-deficient hydroxyapatite [CDHA] and stoichiometric sintered hydroxyapatite, respectively). Human osteoclast precursor cells were cultured for 21 days before evaluating their resorptive potential on varying microstructural features. Alternative to classical morphological evaluation of osteoclasts (OC), FIB-SEM was used to observe the subjacent microstructure by transversally sectioning cells and observing both the cells and the substrates. Resorption pits, indicating OC activity, were visible on the smoother surface of high-temperature sintered hydroxyapatite. FIB-SEM analysis revealed signs of acidic degradation on the grain surface under the cells, as well as intergranular dissolution. No resorption pits were evident on the surface of the rough CDHA substrates. However, whereas no degradation was detected by FIB sections in the material underlying some of the cells, early stages of OC-mediated acidic degradation were observed under cells with more spread morphology. Collectively, these results highlight the potential of FIB to evaluate the resorptive activity of OC, even in rough, irregular, or coarse surfaces where degradation pits are otherwise difficult to visualize.

  9. Osteoclastogenesis and Osteoclastic Resorption of Tricalcium Phosphate: Effect of Strontium and Magnesium Doping

    PubMed Central

    Roy, Mangal; Bose, Susmita

    2012-01-01

    Bone substitute materials are required to support the remodeling process, which consists of osteoclastic resorption and osteoblastic synthesis. Osteoclasts, the bone resorbing cells, generate from differentiation of hemopoietic mononuclear cells. In the present study we have evaluated the effects of 1.0 wt% strontium (Sr) and 1.0 wt% magnesium (Mg) doping in beta-tricalcium phosphate (β-TCP) on the differentiation of mononuclear cells into osteoclast-like cells and its resorptive activity. In vitro osteoclast-like cell formation, adhesion, and resorption were studied using osteoclast precursor RAW 264.7 cell, supplemented with receptor activator of nuclear factor κβ ligand (RANKL). Osteoclast-like cell formation was noticed on pure and Sr doped β-TCP samples at day 8 which was absent on Mg doped β-TCP samples indicating decrease in initial osteoclast differentiation due to Mg doping. After 21 days of culture, osteoclast-like cell formation was evident on all samples with osteoclastic markers such as actin ring, multiple nuclei, and presence of vitronectin receptor αvβ3 integrin. After osteoclast differentiation, all substrates showed osteoclast-like cell mediated degradation, however; significantly restricted for Mg doped β-TCP samples. Our present results indicated substrate chemistry controlled osteoclast differentiation and resorptive activity which can be used in designing TCP based resorbable bone substitutes with controlled degradation properties. PMID:22566212

  10. Localized idiopathic root resorption in the primary dentition: Review of the literature and a case report

    PubMed Central

    Nasehi, Atefeh; Mazhari, Fatemeh; Mohtasham, Nooshin

    2015-01-01

    Idiopathic root resorption (IRR) is an infrequent condition that is usually found as an accidental finding on radiography. A significant number of cases of IRR in permanent dentition have been presented but are rarely reported in primary dentition. The aim of this case report is to present a case of localized IRR in a 7-year-old boy. The patient was referred because of increased mobility of the left mandibular primary second molar. On radiographic evaluation, severe root resorption of that tooth, and mild root resorption of the right mandibular primary second molar were evident; the patient was caries-free. The left affected tooth was lost, and after placing a band and loop space maintainer, the patient was followed for 18 months. A patient with an abnormal pattern of root resorption, especially in the primary dentition, should alert the clinician to rule out the known important local and systemic factors. The exact causes of and treatments for IRR continue to be discovered. PMID:26929703

  11. Treatment with Potassium Bicarbonate Lowers Calcium Excretion and Bone Resorption in Older Men and Women

    USDA-ARS?s Scientific Manuscript database

    Bicarbonate has been implicated in bone health in older subjects on acid-producing diets in short-term studies. The objective of this study was to determine the effects of potassium bicarbonate and its components on changes in bone resorption and calcium excretion over 3 months in older men and wom...

  12. Inhibitory effects of IL-12 on experimental tooth movement and root resorption in mice.

    PubMed

    Yoshimatsu, Masako; Kitaura, Hideki; Fujimura, Yuji; Kohara, Haruka; Morita, Yukiko; Eguchi, Toshiko; Yoshida, Noriaki

    2012-01-01

    Interleukin (IL)-12 is an important cytokine for innate and adaptive immunity. We previously reported that IL-12 inhibits tumour necrosis factor (TNF)-α-mediated osteoclast formation by inducing apoptosis. We also reported that TNF-α plays an important role in mechanical loading-induced osteoclast formation and bone resorption during orthodontic tooth movement. In this study, we investigated the effects of IL-12 on mechanical tooth movement in mice. A Ni-Ti closed coil spring was inserted between the upper incisors and the upper left first molar in mice. IL-12 was injected locally adjacent to the first molar every other day during the experimental period, at doses varying from 0 to 1.5μg/day. After 12 days, the animals were killed and their jaws were processed for histological evaluation using tartrate-resistant acid phosphatase (TRAP) and TdT-mediated dUTP-biotin nick end-labelling (TUNEL) staining, and measurements of the root resorption area. In the IL-12-treated mice, tooth movement and root resorption appeared to be reduced. In TUNEL-stained sections, many apoptotic cells were recognized on the pressure side in the IL-12-treated mice. Our findings suggest that IL-12 inhibits not only mechanical tooth movement, but also root resorption during orthodontic tooth movement. These findings may arise through apoptosis induced by IL-12. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Element uptake, accumulation, and resorption in leaves of mangrove species with different mechanisms of salt regulation

    Treesearch

    E. Medina; W. Fernandez; F. Barboza

    2015-01-01

    Element uptake from substrate and resorption capacity of nutrients before leaf shedding are frequently species-specific and difficult to determine in natural settings. We sampled populations of Rhizophora mangle (salt-excluding species) and Laguncularia racemosa (salt-secreting species) in a coastal lagoon in the upper section of the Maracaibo strait in western...

  14. [Topics for basic research(osteoclast and bone resorption)in ASBMR 2016.

    PubMed

    Udagawa, Nobuyuki

    This is a brief report summarizing topics in ASBMR 2016 held at Georgia World Congress Center in Atlanta on September 16-19th. In this paper, I report some topics from presentation of basic research(especially osteoclast and bone resorption)in ASBMR 2016.

  15. Evidence of Increased Bone Resorption in Neurofibromatosis Type 1 Using Urinary Pyridinium Crosslink Analysis

    PubMed Central

    STEVENSON, DAVID A.; SCHWARZ, ELISABETH L.; VISKOCHIL, DAVID H.; MOYER-MILEUR, LAURIE J.; MURRAY, MARY; FIRTH, SEAN D.; D’ASTOUS, JACQUES L.; CAREY, JOHN C.; PASQUALI, MARZIA

    2011-01-01

    Although neurofibromatosis type 1 (NF1) is a neuro-cutaneous disorder, skeletal abnormalities such as long-bone dysplasia, scoliosis, sphenoid wing dysplasia, and osteopenia are observed. To investigate the role of bone resorption as a mechanism for the bony abnormalities, we selected urinary pyridinium crosslinks (collagen degradation products excreted in urine) as a measure of bone resorption in NF1. Bone resorption was evaluated by quantitative assessment of the urinary excretion of pyridinium crosslinks [pyridinoline (Pyd) and deoxypyridinoline (Dpd)]. Total (free plus peptide-bound) pyridinium crosslinks from the first morning urines from 59 NF1 children (ages 5–19) were extracted and analyzed (17 children with a localized skeletal dysplasia, and 42 without). The data were compared with a healthy reference population without NF1 (n = 99). Multivariate analyses, controlling for age showed statistically significant increases for Dpd (p < 0.001) and the Dpd/Pyd ratio (p < 0.001) in NF1 individuals with and without a skeletal dysplasia. NF1 children have an increase in the urinary excretion of pyridinium crosslinks, reflecting increased bone resorption. The effects of NF1 haploinsufficiency likely contribute to abnormal bone remodeling, either directly or indirectly by aberrant Ras signaling, potentially predisposing NF1 individuals to localized skeletal defects. PMID:18317233

  16. Experimental orthodontic tooth movement and extensive root resorption: periodontal and pulpal changes.

    PubMed

    Tripuwabhrut, Polbhat; Brudvik, Pongsri; Fristad, Inge; Rethnam, Sivakami

    2010-12-01

    Previous studies have reported changes both in dental pulp and in periodontal ligament (PDL) following orthodontic tooth movement. However, pulpal changes following extensive root resorption after orthodontic tooth movement have not been studied in detail. The aim of this study was therefore to evaluate inflammatory changes, both in the dental pulp and in the compressed PDL, after experimentally induced extensive root resorption. Extensive root resorption was induced in rats by the activation and re-activation of orthodontic force, with a short intervening period of no force application. The distribution of immune cells, nerve fibres and blood vessels was studied immunohistochemically using antibodies against CD68-immunoreactive (IR) cells, major histocompatibility complex (MHC) class II Ia-expressing cells, CD43-IR cells, protein gene product 9.5 (PGP 9.5), and laminin. In the compressed PDL of experimental first molars, significantly increased density of CD68-IR cells and MHC class II Ia-expressing cells were found, whereas the density of CD43-IR cells were unchanged when compared with control second molars. In the compressed PDL, there was an increased density of blood vessels, but no sprouting of nerve fibres. In the dental pulp, however, no increased density of immune cells or sprouting of nerve fibres was recorded. In conclusion, inflammation after extensive root resorption was confined to the compressed PDL, whereas the dental pulp was unaffected.

  17. Strontium ranelate improved tooth anchorage and reduced root resorption in orthodontic treatment of rats.

    PubMed

    Kirschneck, Christian; Wolf, Michael; Reicheneder, Claudia; Wahlmann, Ulrich; Proff, Peter; Roemer, Piero

    2014-12-05

    The anchorage mechanisms currently used in orthodontic treatment have various disadvantages. The objective of this study was to determine the applicability of the osteoporosis medication strontium ranelate in pharmacologically induced orthodontic tooth anchorage. In 48 male Wistar rats, a constant orthodontic force of 0.25 N was reciprocally applied to the upper first molar and the incisors by means of a Sentalloy(®) closed coil spring for two to four weeks. 50% of the animals received strontium ranelate at a daily oral dosage of 900 mg per kilogramme of body weight. Bioavailability was determined by blood analyses. The extent of tooth movement was measured both optometrically and cephalometrically (CBCT). Relative alveolar gene expression of osteoclastic markers and OPG-RANKL was assessed by qRT-PCR and root resorption area and osteoclastic activity were determined in TRAP-stained histologic sections of the alveolar process. Compared to controls, the animals treated with strontium ranelate showed up to 40% less tooth movement after four weeks of orthodontic treatment. Gene expression and histologic analyses showed significantly less osteoclastic activity and a significantly smaller root resorption area. Blood analyses confirmed sufficient bioavailability of strontium ranelate. Because of its pharmacologic effects on bone metabolism, strontium ranelate significantly reduced tooth movement and root resorption in orthodontic treatment of rats. Strontium ranelate may be a viable agent for inducing tooth anchorage and reducing undesired root resorption in orthodontic treatment. Patients under medication of strontium ranelate have to expect prolonged orthodontic treatment times.

  18. The relationship between apical root resorption and orthodontic tooth movement in growing subjects.

    PubMed

    Xu, Tianmin; Baumrind, S

    2002-07-01

    To investigate the relationship between apical root resorption and orthodontic tooth movement in growing subjects. 58 growing subjects were collected randomly into the study sample and another 40 non-treated cases were used as control. The apical resoption of the upper central incisors was measured on periapical film and the incisor displacement was measured on lateral cephalogram. Using multiple linear regression analysis to examine the relationship between root resoption and the displacement of the upper incisor apex in each of four direction (retraction, advancement, intrusion and extrusion). The statistically significant negative association were found between resorption and both intrusion (P < 0.001) and extrusion (P < 0.05), but no significant association was found between resorption and both retraction and advancement. The regression analysis implied an average of 2.29 mm resorption in the absence of apical displacement. The likelihood that the magnitude of displacement of the incisor root is positively associated with root resoption in the population of treated growing subjects is very small.

  19. ROS sets the stage for macrophage differentiation.

    PubMed

    Covarrubias, Anthony; Byles, Vanessa; Horng, Tiffany

    2013-08-01

    While M1 macrophages are highly pro-inflammatory and microbicidal, M2 macrophages and the related tumor associated macrophages (TAMs) regulate tissue remodeling and angiogenesis and can display immunomodulatory activity. In July issue of Cell Research, Zhang et al. show that ROS production, critical for the activation and functions of M1 macrophages, is necessary for the differentiation of M2 macrophages and TAMs, and that antioxidant therapy blocks TAM differentiation and tumorigenesis in mouse models of cancer.

  20. Voxel size and measures of individual resorption cavities in three-dimensional images of cancellous bone.

    PubMed

    Tkachenko, Evgeniy V; Slyfield, Craig R; Tomlinson, Ryan E; Daggett, Justin R; Wilson, David L; Hernandez, Christopher John

    2009-09-01

    Cavities formed by osteoclasts on the surface of cancellous bone during bone remodeling (resorption cavities) are believed to act as stress risers and impair cancellous bone strength and stiffness. Although resorption cavities are readily detected as eroded surfaces in histology sections, identification of resorption cavities in three-dimensional images of cancellous bone has been rare. Here we use sub-micrometer resolution images of rat lumbar vertebral cancellous bone obtained through serial milling (n=5) to determine how measures of the number and surface area of resorption cavities are influenced by image resolution. Three-dimensional images of a 1 mm cube of cancellous bone were collected at 0.7x0.7x5.0 microm/voxel using fluorescence based serial milling and uniformly coarsened to four other resolutions ranging from 1.4x1.4x5.0 to 11.2x11.2x10 microm/voxel. Cavities were identified in the three-dimensional image as an indentation on the cancellous bone surface and were confirmed as eroded surfaces by viewing two-dimensional cross-sections (mimicking histology techniques). The number of cavities observed in the 0.7x0.7x5.0 microm/voxel images (22.0+/-1.43, mean+/-SD) was not significantly different from that in the 1.4x1.4x5.0 microm/voxel images (19.2+/-2.59) and an average of 79% of the cavities observed at both of these resolutions were coincident. However, at lower resolutions, cavity detection was confounded by low sensitivity (<20%) and high false positive rates (>40%). Our results demonstrate that when image voxel size exceeds 1.4x1.4x5.0 microm/voxel identification of resorption cavities by bone surface morphology is highly inaccurate. Experimental and computational studies of resorption cavities in three-dimensional images of cancellous bone may therefore require images to be collected at resolutions of 1.4 microm/pixel in-plane or better to ensure consistent identification of resorption cavities.

  1. Impacted maxillary canines and root resorption of adjacent teeth: A retrospective observational study

    PubMed Central

    Cavallini, Costanza; Vernucci, Roberto; Vichi, Maurizio; Leonardi, Rosalia; Barbato, Ersilia

    2016-01-01

    Background The prevalence of impacted maxillary canine is reported to be between 1% and 3%. The lack of monitoring and the delay in the treatment of the impacted canine can cause different complications such as: displacement of adjacent teeth, loss of vitality of neighbouring teeth, shortening of the dental arch, follicular cysts, canine ankylosis, recurrent infections, recurrent pain, internal resorption of the canine and the adjacent teeth, external resorption of the canine and the adjacent teeth, combination of these factors. An appropriate diagnosis, accurate predictive analysis and early intervention are likely to prevent such undesirable effects. The objective is to evaluate, by means of a retrospective observational study, the possibility of carrying out a predictive analysis of root resorption adjacent to the impacted canines by means of orthopantomographs, so as to limit the prescription of additional 3D radiography. Material and Methods 120 subjects with unilateral or bilateral maxillary impacted canine were examined and 50 patients with 69 impacted maxillary canine (22 male, 28 female; mean age: 11.7 years) satisfied the inclusion criteria of the study. These patients were subjected to a basic clinical and radiographic investigation (orthopantomographs and computerized tomography). All panoramic films were viewed under standardized conditions for the evaluation of two main variables: maxillary canine angulations (a, b, g angles) and the overlapping between the impacted teeth and the lateral incisor (Analysis of Lindauer). Binary logistic regression was used to estimate the likelihood of resorbed lateral incisors depending on sector location and angle measurements. Results Results indicated that b angle has the greatest influence on the prediction of root resorption (predictive value of b angle = 76%). If β angle <18° and Lindauer = I, the probability of resorption is 0.06. Conclusions Evaluation of b angle and superimposition lateral incisor

  2. Inhibition of osteoclast bone resorption activity through osteoprotegerin-induced damage of the sealing zone.

    PubMed

    Song, Ruilong; Gu, Jianhong; Liu, Xuezhong; Zhu, Jiaqiao; Wang, Qichao; Gao, Qian; Zhang, Jiaming; Cheng, Laiyang; Tong, Xishuai; Qi, Xinyi; Yuan, Yan; Liu, Zongping

    2014-09-01

    Bone remodeling is dependent on the dynamic equilibrium between osteoclast-mediated bone resorption and osteoblast-mediated osteogenesis. The sealing zone is an osteoclast-specific cytoskeletal structure, the integrity of which is critical for osteoclast-mediated bone resorption. To date, studies have focused mainly on the osteoprotegerin (OPG)‑induced inhibition of osteoclast differentiation through the OPG/receptor activator of the nuclear factor kappa-B ligand (RANKL)/RANK system, which affects the bone resorption of osteoclasts. However, the effects of OPG on the sealing zone have not been reported to date. In this study, the formation of the sealing zone was observed by Hoffman modulation contrast (HMC) microscopy and confocal laser scanning microscopy. The effects of OPG on the existing sealing zone and osteoclast-mediated bone resorption activity, as well as the regulatory role of genes involved in the formation of the sealing zone were examined by immunofluorescence staining, HMC microscopy, quantitative reverse transcription polymerase chain reaction (RT-qPCR), western blot analysis and scanning electron microscopy. The sealing zone was formed on day 5, with belt-like protuberances at the cell edge and scattered distribution of cell nuclei, but no filopodia. The sealing zone was intact in the untreated control group. However, defects in the sealing zone were observed in the OPG-treated group (20 ng/ml) and the structure was absent in the groups treated with 40 and 80 ng/ml OPG. The podosomes showed a scattered or clustered distribution between the basal surface of the osteoclasts and the well surface. Furthermore, resorption lacunae were not detected in the 20 ng/ml OPG-treated group, indicating the loss of osteoclast-mediated bone resorption activity. Treatment with OPG resulted in a significant decrease in the expression of Arhgef8/Net1 and DOCK5 Rho guanine nucleotide exchange factors (RhoGEFs), 10 of 18 RhoGTPases (RhoA, RhoB, cdc42v1, cdc42v2

  3. Implications of garnet resorption for the Lu-Hf garnet geochronometer: Makhevinekh Lake Pluton aureole, Labrador

    NASA Astrophysics Data System (ADS)

    Kelly, E. D.; Carlson, W. D.; Connelly, J.

    2009-12-01

    In the contact aureole of the Makhevinekh Lake Pluton (MLP), Labrador, garnet resorption caused redistribution of Lu and loss of Hf, creating spuriously young Lu-Hf ages. Resetting of the Lu-Hf system by contact metamorphic heating is not primarily responsible for progressively younger ages toward the MLP; instead, ages depend upon the degree of garnet resorption and the original core-to-rim Lu zoning. Garnet grew during granulite-facies regional metamorphism at 1850 Ma. At 1322 Ma, garnet rims were replaced by coronas of opx + crd during contact metamorphism. Garnet-rutile and garnet-ilmenite Lu-Hf geochronology using bulk garnet separates yields ages younging from 1878 ±22 Ma at 4025 m from the contact to 1397 ±8 Ma at 450 m from the contact. Toward the contact, garnet Lu/Hf ratios increase and garnet crystals are progressively more resorbed. Concentrations of Lu measured by LA-ICP-MS along radial traverses on central sections through relict garnets decrease gently away from the cores but rise steeply within 50-200 microns of the edge of the relict garnet. Enrichments of Lu in rims of relict garnets demonstrate strong partitioning of Lu into garnet during resorption and limited intracrystalline diffusion of Lu during contact metamorphism. Hf distributions could not be measured, but considering the strong incompatibility of Hf with garnet, it is likely that all Hf in resorbed portions of the garnets was lost from the crystals. We hypothesize that Lu-Hf ages in the aureole are controlled predominantly by retention of Lu and loss of Hf during garnet resorption. We tested this hypothesis with a simple numerical model in which we treat a population of garnets of uniform size with identical original Lu growth zoning. The model simulates: (1) Lu-Hf decay for a specified period before resorption; (2) retention of Lu and loss of Hf from the rim during instantaneous resorption; and (3) Lu-Hf decay during a specified period after resorption. We varied the volume fraction

  4. Macrophage activation in human diseases.

    PubMed

    Schultze, Joachim L; Schmieder, Astrid; Goerdt, S

    2015-08-01

    It is becoming increasingly accepted that macrophages play a crucial role in many diseases associated with chronic inflammation, including atherosclerosis, obesity, diabetes, cancer, skin diseases, and even neurodegenerative diseases. It is therefore not surprising that macrophages in human diseases have gained significant interest during the last years. Molecular analysis combined with more sophisticated murine disease models and the application of genome-wide technologies has resulted in a much better understanding of the role of macrophages in human disease. We highlight important gain of knowledge during the last years for tumor-associated macrophages, and for macrophages in atherosclerosis, obesity and wound healing. Albeit these exciting findings certainly pave the way to novel diagnostics and therapeutics, several hurdles still need to be overcome. We propose a general outline for future research and development in disease-related macrophage biology based on integrating (1) genome-wide technologies, (2) direct human sampling, and (3) a dedicated use of in vivo model systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Combined effects of nitrogen addition and litter manipulation on nutrient resorption of Leymus chinensis in a semi-arid grassland of northern China.

    PubMed

    Li, X; Liu, J; Fan, J; Ma, Y; Ding, S; Zhong, Z; Wang, D

    2015-01-01

    Plant growth in semi-arid ecosystems is usually severely limited by soil nutrient availability. Alleviation of these resource stresses by fertiliser application and aboveground litter input may affect plant internal nutrient cycling in such regions. We conducted a 4-year field experiment to investigate the effects of nitrogen (N) addition (10 g N·m(-2) ·year(-1)) and plant litter manipulation on nutrient resorption of Leymus chinensis, the dominant native grass in a semi-arid grassland in northern China. Although N addition had no clear effects on N and phosphorus (P) resorption efficiencies in leaves and culms, N fertilisation generally decreased leaf N resorption proficiency by 54%, culm N resorption proficiency by 65%. Moreover, N fertilisation increased leaf P resorption proficiency by 13%, culm P resorption proficiency by 20%. Under ambient or enriched N conditions, litter addition reduced N and P resorption proficiencies in both leaves and culms. The response of P resorption proficiency to litter manipulation was more sensitive than N resorption proficiency: P resorption proficiency in leaves and culms decreased strongly with increasing litter amount under both ambient and enriched N conditions. In contrast, N resorption proficiency was not significantly affected by litter addition, except for leaf N resorption proficiency under ambient N conditions. Furthermore, although litter addition caused a general decrease of leaf and culm nutrient resorption efficiencies under both ambient and enriched N conditions, litter addition effects on nutrient resorption efficiency were much weaker than the effects of litter addition on nutrient resorption proficiency. Taken together, our results show that leaf and non-leaf organs of L. chinensis respond consistently to altered soil N availability. Our study confirms the strong effects of N addition on plant nutrient resorption processes and the potential role of aboveground litter, the most important natural fertiliser in

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    Seifi, Massoud; Lotfi, Ali; Badiee, Mohammad Reza; Abdolazimi, Zahra; Amdjadi, Parisa; Bargrizan, Majid

    2016-01-01

    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. PMID:27551674

  8. tBHQ Suppresses Osteoclastic Resorption in Xenogeneic-Treated Dentin Matrix-Based Scaffolds.

    PubMed

    Sun, Jingjing; Li, Jie; Li, Hui; Yang, Hefeng; Chen, Jinlong; Yang, Bo; Huo, Fangjun; Guo, Weihua; Tian, Weidong

    2017-09-01

    Extracellularmatrix (ECM)-based scaffolds are important for their potential therapeutic application. Treated dentin matrix (TDM), a kind of ECM, seeded with allogeneic dental follicle stem cells (TDM/aDFC) provides a suitable inductive microenvironment for tooth root regeneration. Considering the limited sources, xenogeneic TDM (xTDM) is a possible alternative to allogeneic TDM; however, xTDM-based scaffold presents severe osteolysis and resorption lacunae causing regenerated tooth root failure. Immune response-induced excessive osteoclastogenesis plays a critical role in xenogeneic scaffold osteolysis and resorption. The impact of antioxidant, tert-butylhydroquinone (tBHQ), on xTDM/aDFCs-induced osteoclastogenesis and osteoclastic resorption in vivo and in vitro are investigated. tBHQ upregulates heme oxygenase-1 release and downregulates high mobility group box 1 mRNA expression. mRNA expression of other osteoclast-related genes including nuclear factor-kappa Bp65, receptor activator of nuclear factor kappa-B, nuclear factor of activated T-cells cytoplasmic 1, cathepsin K, and integrin β3, also decreases significantly. Furthermore, tBHQ-treated xTDM/aDFCs scaffolds implanted into rhesus macaques show reduced osteolysis and osteoclastic resorption by microcomputed tomography and tartrate-resistant acid phosphatase staining. tBHQ-induced suppression of xTDM/aDFC-induced osteoclastogenesis and osteoclastic resorption presents a new strategy for the regeneration of biological tooth root and could be applied to the regeneration of other complex tissues and organs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Human and feline invasive cervical resorptions: the missing link?--Presentation of four cases.

    PubMed

    von Arx, Thomas; Schawalder, Peter; Ackermann, Mathias; Bosshardt, Dieter D

    2009-06-01

    This report describes 4 patients presenting with multiple teeth affected by invasive cervical resorption (ICR). The cases came to our attention between 2006 and 2008; previously, no cases of multiple ICR (mICR) had been reported in Switzerland. Characteristics common to all 4 cases included progression of disease over time, similar clinical and radiographic appearance of lesions, and obscure etiology. The histologically assessed teeth showed a similar pattern of tooth destruction, with resorptive lesions being confined to the cervical region. Howship's lacunae and multinucleated, tartrate-resistant acid phosphatase-positive odontoclasts were detected. None of the teeth presented with internal resorption. The positive pulp sensitivity corresponded to the histologic findings, indicating that the pulp tissue resisted degradation even in advanced stages of resorptive lesions. Although mICR is rare in humans, a similar disease known as feline odontoclastic resorptive lesions (FORL) is common in domestic, captive, and wild cats. The etiology of FORL, like that of mICR, remains largely unknown. Because FORL has been associated with feline viruses, we asked our mICR patients whether they had had contact with cats, and interestingly, all patients reported having had direct (2 cases) or indirect (2 cases) contact. In addition, blood samples were taken from all patients for neutralization testing of feline herpes virus type 1 (FeHV-1). Indeed, the sera obtained were able to neutralize (2 cases) or partly inhibit (2 cases) replication of FeHV-1, indicating transmission of feline viruses to humans. Future studies on mICR (and FORL) should evaluate the possible role of a (feline) virus as an etiologic (co-)factor in this disease.

  10. Structural requirements for the action of parathyroid hormone-related protein (PTHrP) on bone resorption by isolated osteoclasts

    SciTech Connect

    Evely, R.S.; Bonomo, A.; Schneider, H.G.; Moseley, J.M.; Gallagher, J.; Martin, T.J. )

    1991-01-01

    Parathyroid hormone-related protein (PTHrP) plays a major role in the syndrome of humoral hypercalcemia of malignancy (HHM) by its actions on bone and kidney. In this study an isolated osteoclast bone resorption assay was used to investigate the actions of this peptide and the structure-activity relationships for its resorption effect. As with PTH, neither synthetic nor recombinant PTHrP preparations stimulated resorption within highly purified osteoclast populations. Resorption was stimulated only in the presence of contaminating osteoblasts or in cocultures with the osteoblast-like cell line UMR-106. In the presence of osteoblasts PTHrP-(1-34) and PTHrP-(1-84) stimulated bone resorption in a dose-dependent manner with a potency comparable to that of PTH-(1-34) on a molar basis. The biologic activity of the PTHrP was shown to reside in the first 34 amino acids, and within that region the structural requirements for promotion of osteoclastic resorption resembled closely those for promotion of cyclic AMP formation in osteoblast-like cells. Using emulsion autoradiography with iodinated PTHrP-(1-34) and PTHrP-(1-84) on mixed bone cell preparations from neonatal rats, specific binding was demonstrated only to osteoblasts, not to osteoclasts. These results clearly demonstrate that PTHrP is a potent stimulator of bone resorption and that these effects are, like those of PTH, mediated by initial actions upon cells of the osteoblast lineage.

  11. Morphine enhances macrophage apoptosis.

    PubMed

    Singhal, P C; Sharma, P; Kapasi, A A; Reddy, K; Franki, N; Gibbons, N

    1998-02-15

    Laboratory data indicate that morphine decreases the numbier of peritoneal and alveolar macrophages (Mphi) and compromises their phagocytic capability for immune complexes and bacteria. We hypothesize that morphine decreases the number of, as well as compromises the phagocytic capability of, Mphi by programming their death. We studied the effect of morphine on Mphi apoptosis in vivo as well as in vitro. Peritoneal Mphi harvested from morphine-treated rats showed DNA fragmentation. Morphine enhanced murine Mphi (J 774.16) apoptosis in a dose-dependent manner. Human monocytes treated with morphine showed a classic ladder pattern in gel electrophoretic and end-labeling studies. Morphine promoted nitric oxide (NO) production both under basal and LPS-activated states. N(G)-nitro-L-arginine methyl ester (L-NAME) and N(G)-monomethyl-L-arginine monoacetate (L-NMMA), inhibitors of NO synthase, attenuated the morphine-induced generation of NO by Mphi. Morphine also enhanced Mphi mRNA expression of inducible NO synthase (iNOS). Since morphine-induced Mphi apoptosis was inhibited by L-NAME and L-NMMA, it appears that morphine-induced Mphi apoptosis may be mediated through the generation of NO. Morphine promoted the synthesis of Bax and p53 proteins by Mphi. Moreover, IL-converting enzyme (ICE)-1 inhibitor attenuated morphine-induced Mphi apoptosis. These studies suggest that morphine activates the induction phase of the apoptotic pathway through accumulation of p53. The effector phase of morphine-induced apoptosis appears to proceed through the accumulation of Bax and activation of ICE-1. The present study provides a basis for a hypothesis that morphine may be directly compromising immune function by promoting Mphi apoptosis in patients with opiate addiction.

  12. Three-dimensional analysis of alveolar bone resorption by image processing of 3-D dental CT images

    NASA Astrophysics Data System (ADS)

    Nagao, Jiro; Kitasaka, Takayuki; Mori, Kensaku; Suenaga, Yasuhito; Yamada, Shohzoh; Naitoh, Munetaka

    2006-03-01

    We have developed a novel system that provides total support for assessment of alveolar bone resorption, caused by periodontitis, based on three-dimensional (3-D) dental CT images. In spite of the difficulty in perceiving the complex 3-D shape of resorption, dentists assessing resorption location and severity have been relying on two-dimensional radiography and probing, which merely provides one-dimensional information (depth) about resorption shape. However, there has been little work on assisting assessment of the disease by 3-D image processing and visualization techniques. This work provides quantitative evaluation results and figures for our system that measures the three-dimensional shape and spread of resorption. It has the following functions: (1) measures the depth of resorption by virtually simulating probing in the 3-D CT images, taking advantage of image processing of not suffering obstruction by teeth on the inter-proximal sides and much smaller measurement intervals than the conventional examination; (2) visualizes the disposition of the depth by movies and graphs; (3) produces a quantitative index and intuitive visual representation of the spread of resorption in the inter-radicular region in terms of area; and (4) calculates the volume of resorption as another severity index in the inter-radicular region and the region outside it. Experimental results in two cases of 3-D dental CT images and a comparison of the results with the clinical examination results and experts' measurements of the corresponding patients confirmed that the proposed system gives satisfying results, including 0.1 to 0.6mm of resorption measurement (probing) error and fairly intuitive presentation of measurement and calculation results.

  13. Reconsideration of macrophage and dendritic cell classification.

    PubMed

    Kadowaki, Takeshi; Shimada, Misato; Inagawa, Hiroyuki; Kohchi, Chie; Hirashima, Mitsuomi; Soma, Gen-Ichiro

    2012-06-01

    It is well known that the activation of innate immune cells, especially antigen-presenting cells such as macrophages and dendritic cells, can ameliorate or exacerbate various diseases, including cancer. Currently, the macrophages and dendritic cells are categorized into several groups by their cell surface and intracellular molecules. However, the detailed classification of the differences between macrophages and dendritic cells has still not been established. Here, we summarized and reviewed the previous studies on the classification of macrophages and dendritic cells. In addition, the previous classification of monocytes, macrophages and dendritic cells is discussed based on our findings of macrophage activation, which has both conventional and plasmacytoid dendritic cell phenotype.

  14. Bisphosphonates alendronate and ibandronate inhibit artery calcification at doses comparable to those that inhibit bone resorption.

    PubMed

    Price, P A; Faus, S A; Williamson, M K

    2001-05-01

    The present experiments were carried out to test the hypothesis that artery calcification is linked to bone resorption by determining whether the selective inhibition of bone resorption with the bisphosphonates alendronate and ibandronate will inhibit artery calcification. Artery calcification was first induced by treatment of 42-day-old male rats with warfarin, a procedure that inhibits the gamma-carboxylation of matrix Gla protein and has been shown to cause extensive calcification of the artery media within 2 weeks. These experiments revealed that ibandronate (0.05 mg. kg(-1). d(-1)) and alendronate (0.1 mg x kg(-1) x d(-1)) completely inhibited calcification of all arteries and heart valves examined after 2 and 4 weeks of warfarin treatment. A 10-fold lower dose of alendronate reduced artery calcification by 50% (P<0.005). These bisphosphonate doses are comparable to those that inhibit bone resorption in rats of this age. More rapid artery calcification was induced by treatment with warfarin together with high doses of vitamin D, a procedure that causes extensive artery calcification by 84 hours. Alendronate and ibandronate again completely inhibited calcification of all arteries and heart valves examined. The subcutaneous doses of alendronate and ibandronate necessary to inhibit artery calcification are comparable to the daily subcutaneous doses of these drugs that have previously been shown to inhibit bone resorption in rats of the same age, with 50% inhibition of artery calcification at 20 microg alendronate x kg(-1) x d(-1) and at 1 microg ibandronate x kg(-1) x d(-1) x Bisphosphonate treatment did not affect serum calcium and phosphate, and so the inhibition of artery calcification cannot be due to a simple lowering of the serum calcium phosphate ion product. We conclude that bisphosphonates inhibit the calcification of arteries and heart valves at doses comparable to the doses that inhibit bone resorption. These results support the hypothesis that artery

  15. Bovine parathyroid hormone enhances osteoclast bone resorption by modulating V-ATPase through PTH1R

    PubMed Central

    LIU, SHUANGXIN; ZHU, WEIPING; LI, SIJIA; MA, JIANCHAO; ZHANG, HUITAO; LI, ZHONGHE; ZHANG, LI; ZHANG, BIN; LI, ZHUO; LIANG, XINLING; SHI, WEI

    2016-01-01

    The vacuolar-type H+ adenosine triphosphatase (V-ATPase) plays an important role in cellular acidification and bone resorption by osteoclasts. However, the direct effect of bovine parathyroid hormone (bPTH) on V-ATPase has not yet been elucidated. The aim of the present study was to assess the effects of bPTH on V-ATPase and osteoclasts. Osteoclasts from bone marrow (BM)-derived monocytes of C57BL/6 mice were cultured with or without bPTH. The mRNA and protein expression levels of the V-ATPase a3-subunit and d2-subunit (by RT-qPCR and western blot analysis), V-ATPase activity (using the V type ATPase Activity Assay kit) and the bone resorption function of osteoclasts (by bone resorption assay) were examined following treatment with various concentrations of bPTH (0.1, 1.0, 10 and 100 ng/ml) alone or with bPTH and its inhibitor, bafilomycin A1. Furthermore, the expression of parathyroid hormone (PTH) receptors in osteoclasts was also detected. The results revealed that the mRNA and protein expression levels of V-ATPase a3-subunit and d2-subunit increased in a dose-dependent manner, paralleling the level of bPTH present. In addition, an increase in the concentration of bPTH was accompanied by the increased resorption capability of osteoclasts, whereas bone resorption was inhibited in the presence of bafilomycin A1. In addition, we confirmed the existence of parathyroid hormone 1 receptor (PTH1R) in osteoclasts using three different methods (RT-qPCR, western blot analysis and immunofluorescence staining). We found that bPTH enhanced the bone resorption capability of osteoclasts by modulating the expression of V-ATPase subunits, intracellular acidification and V-ATPase activity. Thus, we propose that PTH has a direct effect on osteoblasts and osteoclasts, and that this effect is mediated through PTH1R, thus contributing to bone remodeling. PMID:26647715

  16. Effect of LED-mediated-photobiomodulation therapy on orthodontic tooth movement and root resorption in rats.

    PubMed

    Ekizer, Abdullah; Uysal, Tancan; Güray, Enis; Akkuş, Derya

    2015-02-01

    The aim of this experimental study was to evaluate the effects of light-emitting diode-mediated-photobiomodulation therapy (LPT), on the rate of orthodontic tooth movement (TM) and orthodontically induced root resorption, in rats. Twenty male 12-week-old Wistar rats were separated into two groups (control and LPT) and 50 cN of force was applied between maxillary left molar and incisor with a coil spring. In the treatment group, LPT was applied with an energy density of 20 mW/cm(2) over a period of 10 consecutive days directly over the movement of the first molar teeth area. The distance between the teeth was measured with a digital caliper on days 0 (T0), 10 (T1), and 21 (T2) on dental cast models. The surface area of root resorption lacunae was measured histomorphometrically using digital photomicrographs. Mann-Whitney U and Wilcoxon tests were used for statistical evaluation at p < 0.05 level. TM during two different time intervals (T1-T0 and T2-T1) were compared for both groups and a statistically significant difference was found in the LPT group (p = 0.016). The TM amount at the first time period (1.31 ± 0.36 mm) was significantly higher than the second time period (0.24 ± 0.23 mm) in the LPT group. Statistical analysis showed significant differences between two groups after treatment/observation period (p = 0.017). The magnitude of movement in the treatment group was higher (1.55 ± 0.33 mm) compared to the control group (1.06 ± 0.35 mm). Histomorphometric analysis of root resorption, expressed as a percentage, showed that the average relative root resorption affecting the maxillary molars on the TM side was 0.098 ± 0.066 in the LPT group and 0.494 ± 0.224 in the control group. Statistically significant inhibition of root resorption with LPT was determined (p < 0.001) on the TM side. The LPT method has the potential of accelerating orthodontic tooth movement and inhibitory effects on orthodontically induced

  17. Chlorogenic acid inhibits osteoclast differentiation and bone resorption by down-regulation of receptor activator of nuclear factor kappa-B ligand-induced nuclear factor of activated T cells c1 expression.

    PubMed

    Kwak, Sung Chul; Lee, Cheol; Kim, Ju-Young; Oh, Hyun Mee; So, Hong-Seob; Lee, Myeung Su; Rho, Mun Chual; Oh, Jaemin

    2013-01-01

    Excessive osteoclastic bone resorption plays a critical role in inflammation-induced bone loss such as rheumatoid arthritis and periodontal bone erosion. Therefore, identification of osteoclast targeted-agents may be a therapeutic approach to the treatment of pathological bone loss. In this study, we isolated chlorogenic acid (CGA) from fructus of Gardenia jasminoides to discover anti-bone resorptive agents. CGA is a polyphenol with anti-inflammatory and anti-oxidant activities, however, its effects on osteoclast differentiation is unknown. Thus, we investigated the effect of CGA in receptor activator of nuclear factor-kappa B (NF-κB) ligand (RANKL)-induced osteoclast differentiation and RANKL signaling. CGA dose-dependently inhibited RANKL-mediated osteoclast differentiation in bone marrow macrophages (BMMs) without any evidence of cytotoxicity. CGA inhibited the phosphorylation of p38, Akt, extracellular signal-regulated kinase (ERK), and inhibitor of nuclear factor-kappa B (IκB), and IκB degradation by RANKL treatment. CGA suppressed the mRNA expression of nuclear factor of activated T cells c1 (NFATc1), TRAP and OSCAR in RANKL-treated bone marrow macrophages (BMMs). Also, overexpression of NFATc1 in BMMs blocked the inhibitory effect of CGA on RANKL-mediated osteoclast differentiation. Furthermore, to evaluate the effects of CGA in vivo, lipopolysaccharide (LPS)-induced bone erosion study was carried out. CGA remarkably attenuated LPS-induced bone loss based on micro-computed tomography and histologic analysis of femurs. Taken together, our findings suggest that CGA may be a potential treatment option for osteoclast-related diseases with inflammatory bone destruction.

  18. Viral Determinants of HIV-1 Macrophage Tropism

    PubMed Central

    Duncan, Christopher J. A.; Sattentau, Quentin J.

    2011-01-01

    Macrophages are important target cells for HIV-1 infection that play significant roles in the maintenance of viral reservoirs and other aspects of pathogenesis. Understanding the determinants of HIV-1 tropism for macrophages will inform HIV-1 control and eradication strategies. Tropism for macrophages is both qualitative (infection or not) and quantitative (replication capacity). For example many R5 HIV-1 isolates cannot infect macrophages, but for those that can the macrophage replication capacity can vary by up to 1000-fold. Some X4 viruses are also capable of replication in macrophages, indicating that cellular tropism is partially independent of co-receptor preference. Preliminary data obtained with a small number of transmitted/founder viruses indicate inefficient macrophage infection, whereas isolates from later in disease are more frequently tropic for macrophages. Thus tropism may evolve over time, and more macrophage tropic viruses may be implicated in the pathogenesis of advanced HIV-1 infection. Compartmentalization of macrophage-tropic brain-derived envelope glycoproteins (Envs), and non-macrophage tropic non-neural tissue-derived Envs points to adaptation of HIV-1 quasi-species in distinct tissue microenvironments. Mutations within and adjacent to the Env-CD4 binding site have been identified that determine macrophage tropism at the entry level, but post-entry molecular determinants of macrophage replication capacity involving HIV-1 accessory proteins need further definition. PMID:22163344

  19. Inhibition of osteoclast differentiation and bone resorption by rotenone, through down-regulation of RANKL-induced c-Fos and NFATc1 expression.

    PubMed

    Kwak, Han Bok; Lee, Byeong Ki; Oh, Jaemin; Yeon, Jeong-Tae; Choi, Sik-Won; Cho, Hae Joong; Lee, Myeung Su; Kim, Jeong-Joong; Bae, Ji-Myung; Kim, Seong Hwan; Kim, Hun Soo

    2010-03-01

    Osteoclasts are responsible for bone erosion in diseases as diverse as osteoporosis, periodontitis, and rheumatoid arthritis. Natural plant-derived products have received recent attention as potential therapeutic and preventative drugs in human disease. The effect of rotenone in RANKL-induced osteoclast differentiation was examined in this study. Rotenone inhibited RANKL-mediated osteoclast differentiation in bone marrow macrophages (BMMs) in a dose-dependent manner without any evidence of cytotoxicity. The mRNA expression of c-Fos, NFATc1, TRAP, and OSCAR in RANKL-treated BMMs was inhibited by rotenone treatment. Rotenone strongly inhibited p38 and ERK phosphorylation and I-kappaB degradation in RANKL-stimulated BMMs, and did not inhibit JNK phosphorylation. Further, RANKL-induced c-Fos and NFATc1 protein expression was suppressed by rotenone. Rotenone additionally inhibited the bone resorptive activity of differentiated osteoclasts. A lipopolysaccharide (LPS)-induced bone erosion study was also performed to assess the effects of rotenone in vivo. Mice treated with rotenone demonstrated marked attenuation of bone erosion based on Micro CT and histologic analysis of femurs. These results collectively suggested that rotenone demonstrated inhibitory effects on osteoclast differentiation in vitro and suppressed inflammatory bone loss in vivo. Rotenone may therefore serve as a useful drug in the prevention of bone loss.

  20. Macrophage Heterogeneity in Respiratory Diseases

    PubMed Central

    Boorsma, Carian E.; Draijer, Christina; Melgert, Barbro N.

    2013-01-01

    Macrophages are among the most abundant cells in the respiratory tract, and they can have strikingly different phenotypes within this environment. Our knowledge of the different phenotypes and their functions in the lung is sketchy at best, but they appear to be linked to the protection of gas exchange against microbial threats and excessive tissue responses. Phenotypical changes of macrophages within the lung are found in many respiratory diseases including asthma, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis. This paper will give an overview of what macrophage phenotypes have been described, what their known functions are, what is known about their presence in the different obstructive and restrictive respiratory diseases (asthma, COPD, pulmonary fibrosis), and how they are thought to contribute to the etiology and resolution of these diseases. PMID:23533311

  1. Study on bone resorption behavior of osteoclast under drug effect using 41Ca tracing

    NASA Astrophysics Data System (ADS)

    Kejun, Dong; Liyan, Lu; Ming, He; Yinggen, Ouyang; Yan, Xue; Chaoli, Li; Shaoyong, Wu; Xianggao, Wang; Hongtao, Shen; Jianjun, Gao; Wei, Wang; Dafu, Chen; Yonggang, Xing; Jian, Yuan; Shan, Jiang

    2013-01-01

    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 41Ca (T1/2 = 1.04 × 105 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 41Ca labeled hydroxyapatite (HAP) to simulate the bone. AMS on the HI-13 tandem accelerator at CIAE was used to determine trace amounts of 41Ca. The results show that the technique of 41Ca 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.

  2. Ameloblastic fibroma of the mandible associated with root resorption and unerupted teeth: a case report.

    PubMed

    Dimitrakopoulos, Ioannis; Psomaderis, Konstantinos; Zaramboukas, Thomas

    2008-06-01

    Ameloblastic fibroma (AF) is an uncommon benign odontogenic mixed tumor. A case of an AF associated with unerupted and missing teeth is presented. A 13-year-old girl was referred for evaluation of a painless swelling of her right mandible. The most remarkable finding was the resorption of the proximal root of the permanent first molar. The lesion was completely enucleated. Follow-up showed satisfactory bony healing, and the resorbed root was completely surrounded by a continuous layer of intact lamina dura. In most cases, the patient presents to the clinician complaining of an unerupted tooth at the posterior area of the mandible. The most remarkable finding in our case, however, was the coexisting root resorption. This finding could indicate a more aggressive form of AF. AF has a very good prognosis. Malignant transformation is extremely rare.

  3. Brief communication: Identification of bone formation and resorption surfaces by reflected light microscopy.

    PubMed

    Martinez-Maza, Cayetana; Rosas, Antonio; Nieto-Diaz, Manuel

    2010-10-01

    Developmental and evolutionary changes in craniofacial morphology are a central issue in paleoanthropology, but the underlying bone growth processes have been scarcely studied. Relevant knowledge on bone growth dynamics can be obtained from the spatial distribution of bone formation and resorption activities. Determining these patterns from the valuable samples typically used in anthropology and palaeoanthropology necessarily implies nondestructive procedures. In this work, we present a methodology based on the analysis of high-resolution replicas by reflected light microscopy, describing how microfeatures related to bone formation and resorption activities are recognized on both recent and fossil bone surfaces. The proposed method yields highly similar images to those obtained with scanning electron microscope and has proven its utility in an analysis of a large sample of extant and extinct hominoids.

  4. Management of external invasive cervical resorption of tooth with Biodentine: A case report

    PubMed Central

    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

  5. Management of external invasive cervical resorption of tooth with Biodentine: A case report.

    PubMed

    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).

  6. Bone resorption and/or osteogenesis of the mandible in implanto-orthognathic reconstructive surgery.

    PubMed

    Bütow, K W; Duvenage, J G; Dintcheva, P M; Benninghoff, W

    2000-11-01

    Over a period of 18-48 months, the bone resorption, or bone deposition (osteogenesis) of the mandible, in the supero-inferior dimension, was evaluated in patients who had had implanto-orthognathic reconstructive surgery (IORS). It entails the combination of three different types of surgical involvement for the reconstruction of the atrophic (class V), and severely atrophic (class VI) mandibular alveolar ridge (Bütow and Duvenage, 1993). This type of surgical reconstruction combines orthognathic osteotomy, interpositional bone grafting and the immediate placement of osseointegrated implants by means of a trans-mucoperiosteal approach. Evaluation of the mandibular IORS over the long-term, has proven that not only is there minimal resorption, but that osteogenesis of the alveolar ridge occurs.

  7. Heterotopic new bone formation causes resorption of the inductive bone matrix

    SciTech Connect

    Nilsson, O.S.; Persson, P.E.; Ekelund, A. )

    1990-08-01

    The bone matrix of growing rats was labeled by multiple injections of 3H-proline, and demineralized bone matrix (DBM) was prepared. The DBM was allotransplanted heterotopically into growing rats. New bone formation was induced in and around the implants. The new bone formation was accompanied by a decrease in the content of 3H; 20 and 30 days after implantation, 72% and 46%, respectively, of the activity remained in the implants. Daily injections of indomethacin (2 mg/kg) inhibited calcium uptake by about 20% at 20 and 30 days and inhibited the release of 3H from the DBM to a similar degree. Heterotopic bone induction by DBM is accompanied by matrix resorption, and inhibition of the new bone formation decreases the resorption of DBM.

  8. Effects of matrix metalloproteinase inhibitors on bone resorption and orthodontic tooth movement.

    PubMed

    Holliday, L S; Vakani, A; Archer, L; Dolce, C

    2003-09-01

    Matrix metalloproteinases are involved in the regulation of bone remodeling. The hypothesis that matrix metalloproteinase inhibitors may be useful for experimentally limiting orthodontic tooth movement, a process involving perturbations of normal bone remodeling, was tested. General matrix metalloproteinase inhibitors limited the resorption of bone slices by mouse marrow cultures stimulated by calcitriol, parathyroid hormone, and basic-fibroblast growth factor. Pre-coating dentin slices with short arginine-glycine aspartic acid (RGD) peptides, but not arginine-glycine-glutamic acid (RGE) controls, restored bone resorption in the presence of matrix metalloproteinase inhibitors. Orthodontic tooth movement was inhibited by local delivery of Ilomastat, a general matrix metalloproteinase inhibitor, with the use of ethylene-vinyl-acetate (ELVAX) 40, a non-biodegradable, non-inflammatory sustained-release polymer. This study shows that orthodontic tooth movement can be inhibited with the use of matrix metalloproteinase inhibitors, and suggests a mechanistic link between matrix metalloproteinase activity and the production of RGD peptides.

  9. Monocyte-to-Macrophage Differentiation

    PubMed Central

    Chang, Mary Y.; Chan, Christina K.; Braun, Kathleen R.; Green, Pattie S.; O'Brien, Kevin D.; Chait, Alan; Day, Anthony J.; Wight, Thomas N.

    2012-01-01

    Although monocyte- and macrophage-derived molecules are known to promote extracellular matrix (ECM) disruption and destabilization, it is less appreciated that they also synthesize molecules contributing to ECM formation, stabilization, and function. We have identified and characterized the synthesis of proteoglycans and related proteins, some not previously known to be associated with macrophages. Proteoglycan extracts of [35S]sulfate- and 35S-trans amino acid-radiolabeled culture media from THP-1 monocytes induced to differentiate by treatment with phorbol myristate acetate revealed three major proteins of ∼25, 90, and 100 kDa following chondroitin ABC lyase digestion. The 25-kDa protein was predominant for monocytes, whereas the 90- and 100-kDa proteins were predominant for macrophages. Tandem mass spectrometry identified (i) the 25-kDa core protein as serglycin, (ii) the 90-kDa core protein as inter-α-inhibitor heavy chain 2 (IαIHC2), and (iii) the 100-kDa core as amyloid precursor-like protein 2 (APLP2). Differentiation was also associated with (i) a >500-fold increase in mRNA for TNF-stimulated gene-6, an essential cofactor for heavy chain-mediated matrix stabilization; (ii) a >800-fold increase in mRNA for HAS2, which is responsible for hyaluronan synthesis; and (iii) a 3-fold increase in mRNA for versican, which interacts with hyaluronan. Biochemical evidence is also presented for an IαIHC2-APLP2 complex, and immunohistochemical staining of human atherosclerotic lesions demonstrates similar staining patterns for APLP2 and IαIHC2 with macrophages, whereas serglycin localizes to the underlying glycosaminoglycan-rich region. These findings indicate that macrophages synthesize many of the molecules participating in ECM formation and function, suggesting a novel role for these molecules in the differentiation of macrophages in the development of atherosclerosis. PMID:22351750

  10. Effect of Nanocrystalline Hydroxyapatite Socket Preservation on Orthodontically Induced Inflammatory Root Resorption

    PubMed Central

    Seifi, Massoud; Arayesh, Ali; Shamloo, Nafise; Hamedi, Roya

    2015-01-01

    Objective Orthodontically induced inflammatory root resorption (OIIRR) is considered to be an important sequel associated with orthodontic tooth movement (OTM). OTM after Socket preservation enhances the periodontal condition before orthodontic space closure. The purpose of this study is to investigate the histologic effects of NanoBone®, a new highly nonsintered porous nano-crystalline hydroxyapatite bone on root resorption following OTM. Materials and Methods This experimental study was conducted on four male dogs. In each dog, four defects were created at the mesial aspects of the maxillary and mandibular first premolars. The defects were filled with NanoBone®. We used the NiTi closed coil for mesial movement of the first premolar tooth. When the experimental teeth moved approximately halfway into the defects, after two months, the animals were sacrificed and we harvested the area of interest. The first premolar root and adjacent tissues were histologically evaluated. The three-way ANOVA statistical test was used for comparison. Results The mean root resorption in the synthetic bone substitute group was 22.87 ± 11.25×10-4mm2 in the maxilla and 21.41 ± 11.25×10-4mm2 in the mandible. Statistically, there was no significant difference compared to the control group (p>0.05). Conclusion The use of a substitution graft in the nano particle has some positive effects in accessing healthy periodontal tissue following orthodontic procedures without significant influence on root resorption (RR). Histological evaluation in the present study showed osteoblastic activity and remodeling environment of nanoparticles in NanoBone®. PMID:25685742

  11. Effect of nanocrystalline hydroxyapatite socket preservation on orthodontically induced inflammatory root resorption.

    PubMed

    Seifi, Massoud; Arayesh, Ali; Shamloo, Nafise; Hamedi, Roya

    2015-01-01

    Orthodontically induced inflammatory root resorption (OIIRR) is considered to be an important sequel associated with orthodontic tooth movement (OTM). OTM after Socket preservation enhances the periodontal condition before orthodontic space closure. The purpose of this study is to investigate the histologic effects of NanoBone®, a new highly nonsintered porous nano-crystalline hydroxyapatite bone on root resorption following OTM. This experimental study was conducted on four male dogs. In each dog, four defects were created at the mesial aspects of the maxillary and mandibular first premolars. The defects were filled with NanoBone®. We used the NiTi closed coil for mesial movement of the first premolar tooth. When the experimental teeth moved approximately halfway into the defects, after two months, the animals were sacrificed and we harvested the area of interest. The first premolar root and adjacent tissues were histologically evaluated. The three-way ANOVA statistical test was used for comparison. The mean root resorption in the synthetic bone substitute group was 22.87 ± 11.25×10(-4)mm(2) in the maxilla and 21.41 ± 11.25×10(-4)mm(2) in the mandible. Statistically, there was no significant difference compared to the control group (p>0.05). The use of a substitution graft in the nano particle has some positive effects in accessing healthy periodontal tissue following orthodontic procedures without significant influence on root resorption (RR). Histological evaluation in the present study showed osteoblastic activity and remodeling environment of nanoparticles in NanoBone®.

  12. Low-Level Laser Action on Orthodontically Induced Root Resorption: Histological and Histomorphometric Evaluation

    PubMed Central

    Vasconcelos, Eliziane Cossetin; Henriques, Jose Fernando Castanha; Sousa, Marinês Vieira Silva; de Oliveira, Rodrigo Cardoso; Consolaro, Alberto; Pinzan, Arnaldo; Henriques, Fernanda Pinelli; Bronfman, aroline Nemetz

    2016-01-01

    Introduction: Studies have been conducted to develop a means of preventing, controlling or reducing orthodontically induced root resorption. Phototherapy has demonstrated effectiveness as an anti-inflammatory and, considering the inflammatory origin of this pathology, this study evaluated the effects of laser on root resorption. Methods: The research was conducted among 54 80-day-old male Wistar rats, with weights of 280 ± 40 g. Phototherapy consisted of a diode laser (Ga-Al-As), calibrated with a wavelength of 808 nm, an output power of 100 mW, 2.1 J or 96 J of energy and area of 0.0028 cm2. The application was continuous, punctual and with contact. The left first maxillary molar was moved by a super-elastic closed spring with a pre-calibrated and constant force of 25 g. The specimens were irradiated every 48 hours, totaling three or six times, depending on the group to which they belonged. Euthanasia was made in the 7th or 10th day after the onset of movement. The histological and histomorphometric examination was performed with sections of 6 μm stained with hematoxylin and eosin (H&E). Results: Considering the dosimetry studied, when compared the subgroups with the same time of movement, 7 or 10 days, the low-level laser (LLL) has no statistically significant effect on the root resorption. As expected, differences were found between groups with different time of movement. Conclusion: Based on the result, this dosimetry does not seem to be clinically recommended to avoid or reduce inflammatory root resorption, but it also does not induce any root surface alteration. PMID:28144433

  13. Gallium a unique anti-resorptive agent in bone: Preclinical studies on its mechanisms of action

    SciTech Connect

    Bockman, R.; Adelman, R.; Donnelly, R.; Brody, L.; Warrell, R. ); Jones, K.W. )

    1990-01-01

    The discovery of gallium as a new and unique agent for the treatment of metabolic bone disorders was in part fortuitous. Gallium is an exciting new therapeutic agent for the treatment of pathologic states characterized by accelerated bone resorption. Compared to other therapeutic metal compounds containing platinum or germanium, gallium affects its antiresorptive action without any evidence of a cytotoxic effect on bone cells. Gallium is unique amongst all therapeutically available antiresorptive agents in that it favors bone formation. 18 refs., 1 fig.

  14. Efficacy of XP-endo Finisher File in Removing Calcium Hydroxide from Simulated Internal Resorption Cavity.

    PubMed

    Keskin, Cangül; Sariyilmaz, Evren; Sariyilmaz, Öznur

    2017-01-01

    The aim of this study was to evaluate the effect of supplementary use of XP-endo Finisher file, passive ultrasonic activation (PUI), EndoActivator (EA), and CanalBrush (CB) on the removal of calcium hydroxide (CH) paste from simulated internal resorption cavities. The root canals of 110 extracted single-rooted teeth with straight canals were prepared up to size 50. The specimens were split longitudinally, and standardized internal resorption cavities were prepared with burs. The cavities and root canals were filled with CH paste. The specimens were divided into 5 groups as follows: XP-endo Finisher, EA, PUI, CB, and syringe irrigation (SI). The root canals were irrigated with 5.25% NaOCl and 17% EDTA for 2 minutes, respectively. Apart from the SI group, both solutions were activated by using tested techniques for 1 minute. The quantity of CH remnants on resorption cavities was scored. Data were analyzed by using Kruskal-Wallis H and Mann-Whitney U tests. XP-endo Finisher and PUI removed significantly more CH than SI, EA, and CB (P < .05), showing no significant difference between them (P > .05). Differences among SI, EA, and CB were also non-significant (P > .05). None of the tested techniques render the simulated internal resorption cavities free of CH debris. XP-endo Finisher and PUI were superior to SI, CB, and EA. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Pre-Eruptive Intracoronal Resorption (PEIR): Literature Review and Case Report.

    PubMed

    Omar, Samah; Choi, Jessica; Nelson, Bonnie; Shin, Michelle; Chen, Jung-Wei

    2015-05-01

    Pre-eruptive intracoronal resorption (PEIR) are lesions that are often located in the occlusal portion of the crown in unerupted teeth. The etiology and pathology of these lesions remain unclear and most go undetected until later stages of development. Prognosis is dependent on early detection, and conservative treatment is recommended. This report reviews the etiology, prevalence, diagnosis and treatment of PEIR and describes a case of a permanent second molar with PEIR diagnosed in an 11-year-old patient.

  16. [Current possibilities of correcting subchondral bone resorption as a major pathogenetic factor for progressive osteoarthrosis].

    PubMed

    Naumov, A V

    2014-01-01

    The paper considers the current pathogenesis, by choosing the actual targets of pharmacotherapy with available drugs. It reflects the cytokine mechanisms responsible for lesion of the synovial membranes, cartilage, and subchondral bone. Particular emphasis is laid on the role of chondroitin sulfate, glucosamine, vitamin D3 as drugs that affect the key components of pathogenesis, including the volume of resorptive cavities in the subchondral bone.

  17. Low dose of propranolol down-modulates bone resorption by inhibiting inflammation and osteoclast differentiation

    PubMed Central

    Rodrigues, WF; Madeira, MFM; da Silva, TA; Clemente-Napimoga, JT; Miguel, CB; Dias-da-Silva, VJ; Barbosa-Neto, O; Lopes, AH; Napimoga, MH

    2012-01-01

    BACKGROUND AND PURPOSE Bones are widely innervated, suggesting an important role for the sympathetic regulation of bone metabolism, although there are controversial studies. We investigated the effects of propranolol in a model of experimental periodontal disease. EXPERIMENTAL APPROACH Rats were assigned as follows: animals without ligature; ligated animals receiving vehicle and ligated animals receiving 0.1, 5 or 20 mg·kg−1 propranolol. After 30 days, haemodynamic parameters were measured by cardiac catheterization. Gingival tissues were removed and assessed for IL-1β, TNF-α and cross-linked carboxyterminal telopeptides of type I collagen (CTX) by elisa, or intercellular adhesion molecule 1 (ICAM-1), receptor activator of NF-κ B ligand (RANKL) and osteoprotegerin (OPG) by Western blot analysis. Sections from the mandibles were evaluated for bone resorption. Also, we analysed the ability of propranolol to inhibit osteoclastogenesis in vitro. RESULTS Propranolol at 0.1 and 5 mg·kg−1 reduced the bone resorption as well as ICAM-1 and RANKL expression. However, only 0.1 mg·kg−1 reduced IL-1β, TNF-α and CTX levels as well as increased the expression of OPG, but did not alter any of the haemodynamic parameters. Propranolol also suppressed in vitro osteoclast differentiation and resorptive activity by inhibiting the nuclear factor of activated T cells (NFATc)1 pathway and the expression of tartrate-resistant acid phosphatase (TRAP), cathepsin K and MMP-9. CONCLUSIONS AND IMPLICATIONS Low doses of propranolol suppress bone resorption by inhibiting RANKL-mediated osteoclastogenesis as well as inflammatory markers without affecting haemodynamic parameters. PMID:21950592

  18. Low dose of propranolol down-modulates bone resorption by inhibiting inflammation and osteoclast differentiation.

    PubMed

    Rodrigues, W F; Madeira, M F M; da Silva, T A; Clemente-Napimoga, J T; Miguel, C B; Dias-da-Silva, V J; Barbosa-Neto, O; Lopes, A H; Napimoga, M H

    2012-04-01

    Bones are widely innervated, suggesting an important role for the sympathetic regulation of bone metabolism, although there are controversial studies. We investigated the effects of propranolol in a model of experimental periodontal disease. Rats were assigned as follows: animals without ligature; ligated animals receiving vehicle and ligated animals receiving 0.1, 5 or 20 mg·kg(-1) propranolol. After 30 days, haemodynamic parameters were measured by cardiac catheterization. Gingival tissues were removed and assessed for IL-1β, TNF-α and cross-linked carboxyterminal telopeptides of type I collagen (CTX) by elisa, or intercellular adhesion molecule 1 (ICAM-1), receptor activator of NF-κ B ligand (RANKL) and osteoprotegerin (OPG) by Western blot analysis. Sections from the mandibles were evaluated for bone resorption. Also, we analysed the ability of propranolol to inhibit osteoclastogenesis in vitro. Propranolol at 0.1 and 5 mg·kg(-1) reduced the bone resorption as well as ICAM-1 and RANKL expression. However, only 0.1 mg·kg(-1) reduced IL-1β, TNF-α and CTX levels as well as increased the expression of OPG, but did not alter any of the haemodynamic parameters. Propranolol also suppressed in vitro osteoclast differentiation and resorptive activity by inhibiting the nuclear factor of activated T cells (NFATc)1 pathway and the expression of tartrate-resistant acid phosphatase (TRAP), cathepsin K and MMP-9. Low doses of propranolol suppress bone resorption by inhibiting RANKL-mediated osteoclastogenesis as well as inflammatory markers without affecting haemodynamic parameters. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  19. Mapping nutrient resorption efficiencies of subarctic cryptogams and seed plants onto the Tree of Life

    PubMed Central

    Lang, Simone I; Aerts, Rien; van Logtestijn, Richard S P; Schweikert, Wenka; Klahn, Thorsten; Quested, Helen M; van Hal, Jurgen R; Cornelissen, Johannes H C

    2014-01-01

    Nutrient resorption from senescing photosynthetic organs is a powerful mechanism for conserving nitrogen (N) and phosphorus (P) in infertile environments. Evolution has resulted in enhanced differentiation of conducting tissues to facilitate transport of photosynthate to other plant parts, ultimately leading to phloem. Such tissues may also serve to translocate N and P to other plant parts upon their senescence. Therefore, we hypothesize that nutrient resorption efficiency (RE, % of nutrient pool exported) should correspond with the degree of specialization of these conducting tissues across the autotrophic branches of the Tree of Life. To test this hypothesis, we had to compare members of different plant clades and lichens within a climatic region, to minimize confounding effects of climatic drivers on nutrient resorption. Thus, we compared RE among wide-ranging basal clades from the principally N-limited subarctic region, employing a novel method to correct for mass loss during senescence. Even with the limited numbers of species available for certain clades in this region, we found some consistent patterns. Mosses, lichens, and lycophytes generally showed low REN (<20%), liverworts and conifers intermediate (40%) and monilophytes, eudicots, and monocots high (>70%). REP appeared higher in eudicots and liverworts than in mosses. Within mosses, taxa with more efficient conductance also showed higher REN. The differences in REN among clades broadly matched the degree of specialization of conducting tissues. This novel mapping of a physiological process onto the Tree of Life broadly supports the idea that the evolution of conducting tissues toward specialized phloem has aided land plants to optimize their internal nitrogen recycling. The generality of evolutionary lines in conducting tissues and nutrient resorption efficiency needs to be tested across different floras in different climatic regions with different levels of N versus P availability. PMID:25360262

  20. Apoptosis of the reduced enamel epithelium and its implications for bone resorption during tooth eruption.

    PubMed

    Park, Su-Jin; Bae, Hyun-Sook; Cho, Young-Sik; Lim, Soon-Ryun; Kang, Seung-Ae; Park, Joo-Cheol

    2013-02-01

    Bone remodeling, the selective deposition and resorption of bone, is an important cause of tooth eruption. During tooth eruption, reduced enamel epithelia of the enamel organ interact with follicle cells to recruit osteoclasts for bone remodeling. However, little is known about the relationship between cellular activity of reduced enamel epithelium and bone resorption during tooth eruption. The purpose of this study was to investigate the effect of apoptosis in reduced enamel epithelium on osteoclastogenesis and its implications for bone resorption. We have analyzed erupting mandibular molars in mice by TdT-mediated dUTP-biotin nick end labeling assay, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemistry. TRAP-positive cells were detected in the osteoclasts near both the buccal and lingual sides of tooth socket at postnatal day 0 (PN0). They significantly increased until PN3 and decreased thereafter as the tooth erupted. Interestingly, apoptosis was barely detected in the reduced enamel epithelium at PN3 but clearly at PN7. A few apoptotic cells were also investigated within the dental follicle surrounding developing tooth at PN7 and PN10. We observed apoptotic osteoblast-lineage cells along the inner margin of alveolar bone facing the buccal cusp and at the base of the bony crypt at PN3 decreasing until PN10. In contrast, expression levels of bone sialoprotein increased at PN10 compared to levels at PN3. These results suggest that apoptosis of reduced enamel epithelium resulted in a reduction of osteoclast activity and of bone resorption mediated by dental follicle during tooth eruption.

  1. Comparison of growth-induced resorption and denervation-induced resorption on the release of (/sup 3/H)tetracycline, /sup 45/calcium, and (/sup 3/H)collagen from whole bones of growing rats

    SciTech Connect

    Klein, L.; Heiple, K.G.; Stromberg, B.V.

    1983-01-01

    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 (/sup 3/H)tetracycline and (/sup 3/H)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 (/sup 3/H)tetracycline, /sup 45/calcium, and (/sup 3/H)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.

  2. Meta-Analysis of Correlations Between Marginal Bone Resorption and High Insertion Torque of Dental Implants.

    PubMed

    Li, Haoyan; Liang, Yongqiang; Zheng, Qiang

    2015-01-01

    To evaluate correlations between marginal bone resorption and high insertion torque value (> 50 Ncm) of dental implants and to assess the significance of immediate and early/conventional loading of implants under a certain range torque value. Specific inclusion and exclusion criteria were used to retrieve eligible articles from Ovid, PubMed, and EBSCO up to December 2013. Screening of eligible studies, quality assessment, and data extraction were conducted in duplicate. The results were expressed as random/fixed-effects models using weighted mean differences for continuous outcomes with 95% confidence intervals. Initially, 154 articles were selected (11 from Ovid, 112 from PubMed, and 31 from EBSCO). After exclusion of duplicate articles and articles that did not meet the inclusion criteria, six clinical studies were selected. Assessment of P values revealed that correlations between marginal bone resorption and high insertion torque were not statistically significant and that there was no difference between immediately versus early/conventionally loaded implants under a certain range of torque. None of the meta-analyses revealed any statistically significant differences between high insertion torque and conventional insertion torque in terms of effects on marginal bone resorption.

  3. Risedronate decreases bone resorption and improves low back pain in postmenopausal osteoporosis patients without vertebral fractures.

    PubMed

    Ohtori, Seiji; Akazawa, Tsutomu; Murata, Yasuaki; Kinoshita, Tomoaki; Yamashita, Masaomi; Nakagawa, Koichi; Inoue, Gen; Nakamura, Junichi; Orita, Sumihisa; Ochiai, Nobuyasu; Kishida, Shunji; Takaso, Masashi; Eguchi, Yawara; Yamauchi, Kazuyo; Suzuki, Munetaka; Aoki, Yasuchika; Takahashi, Kazuhisa

    2010-02-01

    Elderly postmenopausal women who have osteoporosis sometimes experience low back pain, however, the relationship between low back pain and osteoporosis in the absence of vertebral fractures remains unclear. We examined the relationship between bone mineral density (BMD), bone resorption and low back pain in elderly female patients who did not have osteoporotic vertebral fractures. The average BMD was 0.675 g/cm(2) when assessed by dual-energy X-ray absorptiometry (DEXA). Patients were excluded from the study if they had vertebral fractures revealed by radiography, CT scans or MRI. Bisphosphonate (risedronate) was administered for 4 months. The visual analogue scale (VAS) pain score, Roland Morris Disability Questionnaire (RDQ), Short Form-36 (SF-36) questionnaire, BMD and N-terminal telopeptide of type I collagen (NTx; a marker for bone resorption) were examined before and after treatment. DEXA did not increase significantly, but serum and urinary NTx were decreased (-51.4% and -62.0%, respectively) after 4 months of risedronate treatment (p<0.01). The assessment was repeated using the VAS score, RDQ and SF-36, which revealed an improvement after risedronate treatment (p<0.01). A decrease in serum and urinary NTx was associated with improvement of low back pain, suggesting that despite the absence of vertebral fractures, bone resorption due to osteoporosis may cause low back pain. Copyright 2009 Elsevier Ltd. All rights reserved.

  4. Effects of nonylphenol on rates of tail resorption and metamorphosis in Rana catesbeiana tadpoles.

    PubMed

    Christensen, Jennie R; Richardson, John S; Bishop, Christine A; Pauli, Bruce; Elliott, John

    2005-04-09

    Nonylphenol (NP) is a persistent, lipophilic, and toxic chemical that can be endocrine disrupting (estrogenic) at sublethal concentrations. Since amphibian metamorphosis is a hormone-driven process and a delicate balance of hormone levels is required for successful metamorphosis, exposure of larval amphibians to NP might disrupt metamorphic processes. This study tested whether NP exposure influenced rate of metamorphic progression and tail resorption in bullfrog (Rana catesbeiana) tadpoles. Premetamorphic bullfrog tadpoles were exposed for 7 d to one of 3 nominal concentrations of NP (234 microg/L, 468 microg/L, or 936 microg/L) with or without the addition of exogenous 3,3',5-triiodothyronine (T3). In the absence of exogenous T3, NP significantly increased the rate of tail growth (as measured by tail length) at 936 microg/L. There was no significant effect of NP alone on tail width, limb development, or the process of cranial transformation. When T3 was added to the treatments, increasing NP concentrations were associated with a significant decrease in the rate of cranial transformation, and at the highest dose, the rate of tail resorption was significantly lower than in the controls. Overall, NP had an inhibitory effect on the rate of bullfrog tadpole metamorphic progression and tail resorption.

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

    SciTech Connect

    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

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  7. Apoptosis in pulp elimination during physiological root resorption in human primary teeth.

    PubMed

    Rodrigues, Luciana Villela; Vasconcelos, Anilton César; Campos, Pedro Alves; Brant, Juliana Massote Caldeira

    2009-01-01

    Pulp samples of 50 healthy human teeth with indication for extraction were examined to evaluate the role of apoptosis in pulp elimination during physiological root resorption. Two groups were formed: a test group (n=30) composed of pulp samples of primary teeth with physiological root resorption and a control group (n=20) composed of pulp samples of permanent maxillary third molars. Morphological evidence of apoptosis as well as in situ detection of cellular DNA fragmentation by TUNEL assay and detection of internucleosomal pattern of fragmentation of the genomic DNA by electrophoresis were observed. The apoptotic index of the primary tooth group was significantly higher than that of the permanent tooth group (51.01 +/- 0.52 versus 25.32 +/- 0.68) (p<0.001). TUNEL reaction showed intense and diffuse labeling in the pulp samples of primary teeth, which were discrete in the controls. Intense DNA internucleosomal fragmentation, a specific pattern for apoptosis, was observed in primary tooth pulps DNA by electrophoresis, in the permanent tooth pulps this pattern fragmentation of the genomic DNA for apoptosis were not present. These results seem to indicate a role of apoptosis in pulp elimination during the physiological root resorption of human primary teeth.

  8. Oxidative Stress and Bone Resorption Interplay as a Possible Trigger for Postmenopausal Osteoporosis

    PubMed Central

    Cervellati, Carlo; Bonaccorsi, Gloria; Cremonini, Eleonora; Romani, Arianna; Fila, Enrica; Castaldini, Maria Cristina; Ferrazzini, Stefania; Giganti, Melchiorre; Massari, Leo

    2014-01-01

    The underlying mechanism in postmenopausal osteoporosis (PO) is an imbalance between bone resorption and formation. This study was conducted to investigate whether oxidative stress (OxS) might have a role in this derangement of bone homeostasis. In a sample of 167 postmenopausal women, we found that increased serum levels of a lipid peroxidation marker, hydroperoxides, were negatively and independently associated with decreased bone mineral density (BMD) in total body (r = −0.192, P < 0.05), lumbar spine (r = −0.282, P < 0.01), and total hip (r = −0.282, P < 0.05), as well as with increased bone resorption rate (r = 0.233, P < 0.05), as assessed by the serum concentration of C-terminal telopeptide of type I collagen (CTX-1). On the contrary, the OxS marker failed to be correlated with the serum levels of bone-specific alkaline phosphatase (BAP), that is, elective marker of bone formation. Importantly, multiple regression analysis revealed that hydroperoxides is a determinant factor for the statistical association between lumbar spine BMD and CTX-1 levels. Taken together, our data suggest that OxS might mediate, by enhancing bone resorption, the uncoupling of bone turnover that underlies PO development. PMID:24524081

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

    PubMed Central

    Leeming, Diana J; Byrjalsen, Inger; Qvist, Per; Koizumi, Mitsuru; Lynnerup, Niels; Fregerslev, Michael; Sørensen, Mette G; Christiansen, Claus; Karsdal, Morten A

    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 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. Conclusion Data suggest that an uncoupling between bone resorption and cartilage degradation occurs in breast and lung cancer patient. PMID:18588674

  10. Interleukin-10 inhibits bone resorption: a potential therapeutic strategy in periodontitis and other bone loss diseases.

    PubMed

    Zhang, Qian; Chen, Bin; Yan, Fuhua; Guo, Jianbin; Zhu, Xiaofeng; Ma, Shouzhi; Yang, Wenrong

    2014-01-01

    Periodontitis and other bone loss diseases, decreasing bone volume and strength, have a significant impact on millions of people with the risk of tooth loss and bone fracture. The integrity and strength of bone are maintained through the balance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively, so the loss of bone results from the disruption of such balance due to increased resorption or/and decreased formation of bone. The goal of therapies for diseases of bone loss is to reduce bone loss, improve bone formation, and then keep healthy bone density. Current therapies have mostly relied on long-term medication, exercise, anti-inflammatory therapies, and changing of the life style. However there are some limitations for some patients in the effective treatments for bone loss diseases because of the complexity of bone loss. Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine, and recent studies have indicated that IL-10 can contribute to the maintenance of bone mass through inhibition of osteoclastic bone resorption and regulation of osteoblastic bone formation. This paper will provide a brief overview of the role of IL-10 in bone loss diseases and discuss the possibility of IL-10 adoption in therapy of bone loss diseases therapy.

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

    NASA Technical Reports Server (NTRS)

    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.

  12. Impact of bone lead and bone resorption on plasma and whole blood lead levels during pregnancy.

    PubMed

    Téllez-Rojo, Martha María; Hernández-Avila, Mauricio; Lamadrid-Figueroa, Héctor; Smith, Donald; Hernández-Cadena, Leticia; Mercado, Adriana; Aro, Antonio; Schwartz, Joel; Hu, Howard

    2004-10-01

    The authors tested the hypotheses that maternal bone lead burden is associated with increasing maternal whole blood and plasma lead levels over the course of pregnancy and that this association is modified by rates of maternal bone resorption. A total of 193 Mexican women were evaluated (1997-1999) in the first, second, and third trimesters of pregnancy. Whole blood lead and plasma lead levels were measured in each trimester. Urine was analyzed for cross-linked N-telopeptides (NTx) of type I collagen, a biomarker of bone resorption. Patella and tibia lead levels were measured at 4 weeks postpartum. The relation between whole blood, plasma, and bone lead and NTx was assessed using mixed models. Plasma lead concentrations followed a U-shape, while NTx levels increased significantly during pregnancy. In a multivariate model, the authors observed a significant and positive interaction between NTx and bone lead when plasma lead was used as the outcome variable. Dietary calcium intake was inversely associated with plasma lead. Results for whole blood lead were similar but less pronounced. These results confirm previous evidence that bone resorption increases during pregnancy, with a consequential significant release of lead from bone, constituting an endogenous source of prenatal exposure. They also provide a rationale for testing strategies (e.g., nutritional supplementation with calcium) aimed at decreasing prenatal lead exposure.

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

    PubMed

    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. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Embryonic resorption and polycyclic aromatic hydrocarbons: putative immune-mediated mechanisms.

    PubMed

    Detmar, Jacqui; Jurisicova, Andrea

    2010-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are released into the environment as a result of incomplete fossil fuel combustion from industrial furnaces, wood-burning stoves, and automobile exhaust fumes; however, the primary source of human exposure to these compounds is cigarette smoke. Embryonic and fetal loss after treatment with high doses of PAHs have been well documented in animal studies; however, few studies have addressed the reproductive consequences of long-term, low-level exposure to these chemicals. We previously reported that low doses of PAHs administered to ICR mice over a period of 9 weeks prior to conception resulted in early embryonic resorptions, whereby treated dams lost approximately 50% of their litter. During the course of these studies, we observed greater numbers of infiltrating uterine natural killer (uNK) cells into the placenta of PAH-exposed conceptuses. While exposure to high levels of PAHs has been shown to be immunosuppressive, increasing evidence suggests that chronic, low-dose exposure to PAHs may stimulate immune cells. Thus, we hypothesized that low-dose, chronic PAH exposure in our mouse model is mediating embryonic resorption by hyperstimulating maternal immune cells. In this review of the literature, we outline the rationale of our argument and present preliminary data, focussing upon PAH-mediated alterations in uNK cell dynamics and how these changes may be linked to early embryonic resorptions.

  15. Resorptive remodeling in maxillary anterior region after bimaxillary surgery for skeletal Class III deformities.

    PubMed

    Lee, Paul; Kim, Yong-Il; Kim, Seong-Sik; Park, Soo-Byung; Son, Woo-Sung

    2015-12-01

    The aim of this retrospective study was to evaluate bony remodelling in the anterior region of the maxilla after bimaxillary surgery for skeletal Class III deformities preoperatively, immediately postoperatively, and 6 months postoperatively. For accurate analysis, cone-beam computed tomographic (CT) images of 29 patients (12 men and 17 women; mean age 22 (range 19 to 44) years) were used. The nasopalatine canal, unaffected by the maxillary Le Fort I osteotomy, was used for the reference points (posterosuperior, midpoint, and posteroinferior). The changes in the distance from each of the points on the nasopalatine canal to the corresponding anterior border of the maxilla were measured and analysed at the 3 stages (p<0.05). Bony resorption was apparent during the postoperative period, and the mean resorption was -1.13 (1.53) mm at the posterosuperior level, -0.92 (0.83) mm at the midpoint, and -0.83 (0.88) mm at the posteroinferior level (p<0.01). These findings show that there had been resorptive remodelling postoperatively in the anterior maxillary region after bimaxillary surgery with superior maxillary movement, which suggests that the postoperative change in the position of point A is affected by operative movement as well as by postoperative relapse and bony remodelling. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2015-12-22

    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.

  17. Double 'pink tooth' associated with extensive internal root resorption after orthodontic treatment: a case report.

    PubMed

    Silveira, Frank F; Nunes, Eduardo; Soares, Janir A; Ferreira, Cynthia L; Rotstein, Ilan

    2009-06-01

    Advanced internal resorption affecting the crown of teeth may result in the appearance of a 'pink tooth', which, when located in the root canal, can perforate the external root surface. Therapeutically, this condition represents a clinical challenge and normally requires a combined endodontic and surgical focus. Presented herein are cases of double 'pink tooth' which appeared at different times after orthodontic treatment. In the most severe case, upon radiographic examination and computed tomography, the maxillary right central incisor presented an internal resorption, extending from the pulp chamber to the root middle third. After pulp removal, the debridement of the defect was performed using a 2.5% sodium hypochlorite solution, a #80 Kerr file, and an ultrasonic tip ST-17, aided by a surgical microscope. During the cleaning process, various sites of periodontal communication were identified. Upon controlling the hemorrhaging, the root canal was completely filled with White mineral trioxide aggregate. Within the 3-month follow-up treatment, a pink spot appeared on the maxillary left central incisor, which received conventional root canal therapy. Clinically and radiographically, over 18 months of follow up, both cases responded favorably to the proposed treatments. Therefore, it is important to monitor the patient due to the fact that pulp and periodontal sequelae can develop at varied moments after orthodontic treatment. Furthermore, with the current technology and biomaterials, it is possible to resolve cases with extensive internal perforating resorption through endodontic treatment.

  18. Effect of low-intensity pulsed ultrasound on orthodontically induced root resorption in beagle dogs.

    PubMed

    Al-Daghreer, Saleh; Doschak, Michael; Sloan, Alastair J; Major, Paul W; Heo, Giseon; Scurtescu, Cristian; Tsui, Ying Y; El-Bialy, Tarek

    2014-06-01

    We investigated the effect of low-intensity pulsed ultrasound (LIPUS) on orthodontically induced inflammatory root resorption in vivo. Ten beagle dogs were treated with an orthodontic appliance to move the mandibular fourth premolars bodily. The orthodontic movement was carried out for 4 wk with a continuous force of 1 N/side; using a split-mouth model, LIPUS was applied daily for 20 min. Fourth premolar and surrounding periodontal tissue were evaluated with micro-computed tomography and hematoxylin and eosin and tartrate-resistant acid phosphatase staining. We calculated the number, volume and distribution of root resorption lacunae and their percentage relative to total root volume, orthodontic tooth movement and periodontal ligament space. There was no significant difference in orthodontic tooth movement between the two sides. LIPUS significantly reduced the number of orthodontically induced inflammatory root resorption initiation areas by 71%, reduced their total volume by 68% and reduced their volume relative to the affected root total volume by 70%. LIPUS induced the formation of a precementum layer, thicker cementum and reparative cellular cementum.

  19. Bone growth on and resorption of calcium phosphate coatings obtained by pulsed laser deposition.

    PubMed

    Clèries, L; Fernández-Pradas, J M; Morenza, J L

    2000-01-01

    Three different calcium phosphate coatings of crystalline hydroxyapatite (HA), alpha- and beta-tricalcium phosphate (alpha+beta-TCP), or amorphous calcium phosphate (ACP) obtained by pulsed laser deposition on Ti-6Al-4V were incubated in a potentially osteogenic primary cell culture (rat bone marrow) in order to evaluate the amount and mode of mineralized bone matrix formation after 2 weeks with special emphasis on the type of interfacial structure that was created. Evaluation techniques included fluorescence labeling and scanning electron microscopy. The resistance to cellular resorption by osteoclasts was also studied. Bone matrix delaminated from the ACP coatings, while it remained on the HA and the alpha+beta-TCP coatings even after fracturing. A cementlike line was seen as the immediate contiguous interface with the nondegrading dense HA surface and with the surface of the remaining porous beta-TCP coating. Highly dense and crystalline HA coatings do not dissolve but are capable of establishing a strong bond with the bone matrix grown on top. Chemical and mechanical bonding were considered in this case. Cellular resorption was practically not observed on the HA coatings, but it was observed on the alpha+beta-TCP coatings. Resorption took place as dissolution that was due to the acidic microenvironment.

  20. Interleukin-10 Inhibits Bone Resorption: A Potential Therapeutic Strategy in Periodontitis and Other Bone Loss Diseases

    PubMed Central

    Guo, Jianbin; Zhu, Xiaofeng; Ma, Shouzhi; Yang, Wenrong

    2014-01-01

    Periodontitis and other bone loss diseases, decreasing bone volume and strength, have a significant impact on millions of people with the risk of tooth loss and bone fracture. The integrity and strength of bone are maintained through the balance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively, so the loss of bone results from the disruption of such balance due to increased resorption or/and decreased formation of bone. The goal of therapies for diseases of bone loss is to reduce bone loss, improve bone formation, and then keep healthy bone density. Current therapies have mostly relied on long-term medication, exercise, anti-inflammatory therapies, and changing of the life style. However there are some limitations for some patients in the effective treatments for bone loss diseases because of the complexity of bone loss. Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine, and recent studies have indicated that IL-10 can contribute to the maintenance of bone mass through inhibition of osteoclastic bone resorption and regulation of osteoblastic bone formation. This paper will provide a brief overview of the role of IL-10 in bone loss diseases and discuss the possibility of IL-10 adoption in therapy of bone loss diseases therapy. PMID:24696846

  1. Macrophage Heterogeneity and Plasticity: Impact of Macrophage Biomarkers on Atherosclerosis

    PubMed Central

    Martínez, María Sofía; Palmar, Jim; Bautista, Jordan; Chávez-Castillo, Mervin; Gómez, Alexis; Bermúdez, Valmore

    2015-01-01

    Cardiovascular disease (CVD) is a global epidemic, currently representing the worldwide leading cause of morbidity and mortality. Atherosclerosis is the fundamental pathophysiologic component of CVD, where the immune system plays an essential role. Monocytes and macrophages are key mediators in this aspect: due to their heterogeneity and plasticity, these cells may act as either pro- or anti-inflammatory mediators. Indeed, monocytes may develop heterogeneous functional phenotypes depending on the predominating pro- or anti-inflammatory microenvironment within the lesion, resulting in classic, intermediate, and non-classic monocytes, each with strikingly differing features. Similarly, macrophages may also adopt heterogeneous profiles being mainly M1 and M2, the former showing a proinflammatory profile while the latter demonstrates anti-inflammatory traits; they are further subdivided in several subtypes with more specialized functions. Furthermore, macrophages may display plasticity by dynamically shifting between phenotypes in response to specific signals. Each of these distinct cell profiles is associated with diverse biomarkers which may be exploited for therapeutic intervention, including IL-10, IL-13, PPAR-γ, LXR, NLRP3 inflammasomes, and microRNAs. Direct modulation of the molecular pathways concerning these potential macrophage-related targets represents a promising field for new therapeutic alternatives in atherosclerosis and CVD. PMID:26491604

  2. Technological advances in endodontics: treatment of a mandibular molar with internal root resorption using a reciprocating single-file system.

    PubMed

    de Souza, Samir Noronha; Marques, André Augusto Franco; Sponchiado-Júnior, EmÍlio Carlos; Roberti Garcia, Lucas da Fonseca; da Frota, Matheus Franco; de Carvalho, Fredson Márcio Acris

    2017-01-01

    The field of endodontics has become increasingly successful due to technological advances that allow clinicians to solve clinical cases that would have been problematic a few years ago. Despite such advances, endodontic treatment of teeth with internal root resorption remains challenging. This article presents a clinical case in which a reciprocating single-file system was used for endodontic treatment of a mandibular molar with internal root resorption. Radiographic examination revealed the presence of internal root resorption in the distobuccal root canal of the mandibular right first molar. A reciprocating single-file system was used for root canal instrumentation and final preparation, and filling was obtained through a thermal compaction technique. No painful symptoms or periapical lesions were observed in 12 months of follow-up. The results indicate that a reciprocating single-file system is an adequate alternative for root canal instrumentation, particularly in teeth with internal root resorption.

  3. Pulp-dentine complex changes and root resorption during intrusive orthodontic tooth movement in patients prescribed nabumetone.

    PubMed

    Villa, Paula A; Oberti, Giovanni; Moncada, Cesar A; Vasseur, Olga; Jaramillo, Alejandro; Tobón, Diego; Agudelo, Jaime A

    2005-01-01

    Pulpitis, external root resorption, and pain may be experienced during orthodontic movement. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been suggested to control these changes. The purpose of this study was to observe pulp-dentinal reactions, root resorption, tooth pain, and tooth movement after the application of a 4-ounce intrusive orthodontic force to human maxillary first premolars in patients given the NSAID nabumetone. Thirty-four maxillary first premolars were evaluated. A placebo was prescribed to 17 patients after an intrusive force was activated and reactivated for an 8-week period on the right side. The same procedure was repeated on the left side after patients were given nabumetone. Pulp-dentinal reactions and external root resorption were evaluated by histology. Pain and movement were also evaluated. Nabumetone was found to be useful in reducing pulpitis, external root resorption, and pain caused by intrusive orthodontic movement, without altering tooth movement in response to the application of orthodontic force.

  4. Macrophages and HIV-1: An Unhealthy Constellation.

    PubMed

    Sattentau, Quentin J; Stevenson, Mario

    2016-03-09

    Lentiviruses have a long-documented association with macrophages. Abundant evidence exists for in vitro and, in a tissue-specific manner, in vivo infection of macrophages by the primate lentiviruses HIV-1 and SIV. However, macrophage contribution to aspects of HIV-1 and SIV pathogenesis, and their role in viral persistence in individuals on suppressive antiretroviral therapy, remains unclear. Here we discuss recent evidence implicating macrophages in HIV-1-mediated disease and highlight directions for further investigation.

  5. Dakin Solution Alters Macrophage Viability and Function

    DTIC Science & Technology

    2014-07-18

    macrophage adhesion , phagocytosis, and generation of reactive oxygen species was examined. Macrophage polarization following DS exposure was...concentrations. For controls, cells in DMEMwere washedwith PBS and exposed to a neutralizing agent as described previously. 2.6. Macrophage adhesion ...assay Macrophage adhesion assays were performed as previously described with minor modifications [33]. Briefly, cell suspen sions of 2.5e5.0 106 cells

  6. Measurement of macrophage growth and differentiation

    PubMed Central

    Chitu, Violeta; Yeung, Yee-Guide; Yu, Wenfeng; Nandi, Sayan

    2011-01-01

    This unit provides protocols for measuring the abundance and growth of macrophage precursors in agar cultures and the proliferation of isolated mature macrophages in vitro, by either direct cell counting or by DNA measurement. Methods for the immunohistochemical identification of macrophages and the determination of their proliferative status in vivo by immunofluorescence are also included. It also describes methods for characterization of macrophage differentiation through the immunofluorescence analysis of cell surface expression of CSF-1 receptor. PMID:21400680

  7. A Comparison of pical Root Resorption in Incisors after Fixed Orthodontic Treatment with Standard Edgewise and Straight Wire (MBT) Method

    PubMed Central

    Zahed Zahedani, SM; Oshagh, M; Momeni Danaei, Sh; Roeinpeikar, SMM

    2013-01-01

    Statement of Problem: One of the major outcomes of orthodontic treatment is the apical root resorption of teeth moved during the treatment. Identifying the possible risk factors, are necessary for every orthodontist. Purpose: The aim of this study was to compare the rate of apical root resorption after fixed orthodontic treatment with standard edgewise and straight wire (MBT) method, and also to evaluate other factors effecting the rate of root resorption in orthodontic treatments. Materials and Method: In this study, parallel periapical radiographs of 127 patients imaging a total of 737 individual teeth, were collected. A total of 76 patients were treated by standard edgewise and 51 patients by straight wire method. The periapical radiographs were scanned and then the percentage of root resorption was calculated by Photoshop software. The data were analyzed by Paired-Samples t-test and the Generalized Linear Model adopting the SPSS 15.0. Results: In patients treated with straight wire method (MBT), mean root resorption was 18.26% compared to 14.82% in patients treated with standard edgewise technique (p< .05). Male patients had higher rate of root resorption,statistically significant (p< .05). Age at onset of treatment, duration of treatment, type of dental occlusion, premolar extractions and the use of intermaxillary elastics had no significant effect on the root resorption in this study. Conclusion: Having more root resorption in the straight wire method and less in the standard edgewise technique can be attributed to more root movement in pre-adjusted MBT technique due to the brackets employed in this method. PMID:24724131

  8. Alendronate binds to tooth root surfaces and inhibits progression of feline tooth resorption: a pilot proof-of-concept study.

    PubMed

    Mohn, Kenneth L; Jacks, Thomas M; Schleim, Klaus Dieter; Harvey, Colin E; Miller, Bonnie; Halley, Bruce; Feeney, William P; Hill, Susan L; Hickey, Gerry

    2009-01-01

    Tissue distribution, bioavailability, and efficacy of alendronate in preventing progression of resorption of teeth were evaluated in cats. [Butyl-4-14C-]-alendronate accumulates on subgingival tooth and alveolar bone surfaces adjacent to vascularized tissue resulting in concentration of the drug around tooth roots. Three cats were treated with a 0.03 mg/kg i.v. bolus of [butyl-4-14C-]-alendronate followed by blood, urine, and feces collection and euthanasia 24-hours later. Drug tissue distribution was accessed by autoradiography and sample combustion. To assess bioavailability, 12 cats were administered alendronate orally (3.0 or 9.0 mg/kg in water or 9.0 mg/kg in tuna water) and urine was collected for 24-hours. In these formulations, alendronate oral bioavailability in cats was approximately 3%. In addition, 10 cats with radiographic evidence of pre-existing tooth resorption (14 affected teeth) were treated with vehicle or 3.0 mg/kg alendronate per os once weekly for 22-weeks and, then, 9.0 mg/kg per os twice weekly for 27-weeks in a random, masked study. Radiographic area of resorption was measured and progression scored every 3 to 4-months. In placebo-treated cats, resorption progressed in five of six teeth (+ 97% average increase in area of resorption), whereas progression of resorption was seen in only three of eight affected teeth in alendronate-treated cats with a -22% average change (decrease) in area (P < 0.01 difference in number of teeth showing progression; P < 0.001 difference in area of resorption). Alendronate accumulated preferentially on subgingival tooth surfaces and adjacent alveolar bone and, at a dose of 9 mg/kg twice weekly, effectively slowed or arrested the progression of resorption.

  9. Monocyte and macrophage biology: an overview.

    PubMed

    Rees, Andrew J

    2010-05-01

    This review provides an overview of the current understanding of the biology of monocytes and macrophages. It focuses on four rapidly advancing areas that underpin recent conceptual advances, namely: (1) the bone marrow origins of monocytes and macrophages, (2) monocyte heterogeneity, (3) the early inflammatory consequences of tissue injury, and (4) current concepts of macrophage activation and their limitations.

  10. Tissue macrophage identity and self-renewal.

    PubMed

    Gentek, Rebecca; Molawi, Kaaweh; Sieweke, Michael H

    2014-11-01

    Macrophages are cellular components of the innate immune system that reside in virtually all tissues and contribute to immunity, repair, and homeostasis. The traditional view that all tissue-resident macrophages derive from the bone marrow through circulating monocyte intermediates has dramatically shifted recently with the observation that macrophages from embryonic progenitors can persist into adulthood and self-maintain by local proliferation. In several tissues, however, monocytes also contribute to the resident macrophage population, on which the local environment can impose tissue-specific macrophage functions. These observations have raised important questions: What determines resident macrophage identity and function, ontogeny or environment? How is macrophage proliferation regulated? In this review, we summarize the current knowledge about the identity, proliferation, and turnover of tissue-resident macrophages and how they differ from freshly recruited short-lived monocyte-derived cells. We examine whether macrophage proliferation can be qualified as self-renewal of mature differentiated cells and whether the concepts and molecular pathways are comparable to self-renewal mechanisms in stem cells. Finally, we discuss how improved understanding of macrophage identity and self-renewal could be exploited for therapeutic intervention of macrophage-mediated pathologies by selectively targeting freshly recruited or resident macrophages. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Comparison between the lengths of individual osteoid seams and resorption cavities in human iliac crest cancellous bone.

    PubMed

    Yamaguchi, K; Croucher, P I; Compston, J E

    1993-10-01

    The current concept of bone remodelling is based on the belief that bone resorption and formation are coupled both in time and space; this implies that the surface extent of bone eroded in a bone remodelling unit would approximate to the surface extent of the osteoid seam formed subsequently. The greater total surface extent of osteoid as opposed to erosion is generally attributed to the longer life-span of bone formation, but no comparison of the length of eroded surface and osteoid seam within individual bone remodelling units has been reported. In this study we have compared the length of individual osteoid seams, resorption cavities and bone structural units in iliac crest trabecular bone obtained from normal subjects and from patients with renal osteodystrophy. Values for osteoid seam and bone packet length were significantly greater than resorption cavity length in both the normal and patient groups (P < 0.001), the ratio of osteoid seam and eroded length being similar in the two groups (1:0.44 and 1:0.40, respectively). These results indicate that the discrepancy between total osteoid and eroded surface extent cannot be wholly explained on the basis of a longer formation life-span. Possible additional explanations include underestimation of eroded surface by light microscopic techniques, initiation of bone formation within a cavity before the completion of resorption, the presence of arrested resorption cavities, non-random distribution of resorption cavities on the trabecular surface and bone formation on quiescent bone surfaces.

  12. Stage-dependent stoichiometric homeostasis and responses of nutrient resorption in Amaranthus mangostanus to nitrogen and phosphorus addition

    PubMed Central

    Peng, Huiyuan; Chen, Yahan; Yan, Zhengbing; Han, Wenxuan

    2016-01-01

    Stoichiometric homeostasis is the ability of plants remaining their element composition relatively stable regardless of changes in nutrient availability, via various physiological mechanisms. Nutrient resorption is one of such key mechanisms, but whether and how nitrogen and phosphorus homeostasis and resorption in plants would change with growth-stages under variable nutrient supply was unclear. A nitrogen (N) and phosphorus (P) fertilizer addition experiment was conducted to evaluate the dynamics of N and P homeostasis and resorption efficiency during different growth-stages of Amaranthus mangostanus in a greenhouse. The homeostasis regulation coefficient of green-leaf P varied significantly, while that of green-leaf N maintained relatively stable across growth stages. Moreover, homeostasis regulation coefficient of N was higher at seedling stage but lower at flowering stage than that of P at corresponding stages, suggesting that the growth of A. mangostanus may switch from being more N- to P-limited from vegetative to reproductive stage. N resorption efficiency (NRE) was higher and P resorption efficiency (PRE) was lower at flowering than seed-filling stage. The nutrient dynamics displayed here suggested contrasting nutrient homeostasis and resorption responses of plants to environmental nutrient availability across growth stages. These findings can improve the understanding of nutrition maintenance mechanism of plants during their growth. PMID:27849041

  13. Inhibition of Osteoclastogenesis and Bone Resorption in vitro and in vivo by a prenylflavonoid xanthohumol from hops

    PubMed Central

    Li, Jing; Zeng, Li; Xie, Juan; Yue, Zhiying; Deng, Huayun; Ma, Xueyun; Zheng, Chunbing; Wu, Xiushan; Luo, Jian; Liu, Mingyao

    2015-01-01

    Excessive RANKL signaling leads to superfluous osteoclast formation and bone resorption, is widespread in the pathologic bone loss and destruction. Therefore, targeting RANKL or its signaling pathway has been a promising and successful strategy for this osteoclast-related diseases. In this study, we examined the effects of xanthohumol (XN), an abundant prenylflavonoid from hops plant, on osteoclastogenesis, osteoclast resorption, and RANKL-induced signaling pathway using both in vitro and in vivo assay systems. In mouse and human, XN inhibited osteoclast differentiation and osteoclast formation at the early stage. Furthermore, XN inhibited osteoclast actin-ring formation and bone resorption in a dose-dependent manner. In ovariectomized-induced bone loss mouse model and RANKL-injection-induced bone resorption model, we found that administration of XN markedly inhibited bone loss and resorption by suppressing osteoclast activity. At the molecular level, XN disrupted the association of RANK and TRAF6, resulted in the inhibition of NF-κB and Ca2+/NFATc1 signaling pathway during osteoclastogenesis. As a results, XN suppressed the expression of osteoclastogenesis-related marker genes, including CtsK, Nfatc1, Trap, Ctr. Therefore, our data demonstrated that XN inhibits osteoclastogenesis and bone resorption through RANK/TRAF6 signaling pathways. XN could be a promising drug candidate in the treatment of osteoclast-related diseases such as postmenopausal osteoporosis. PMID:26620037

  14. Role of exopolysaccharide in Aggregatibacter actinomycetemcomitans-induced bone resorption in a rat model for periodontal disease.

    PubMed

    Shanmugam, Mayilvahanan; Gopal, Prerna; El Abbar, Faiha; Schreiner, Helen C; Kaplan, Jeffrey B; Fine, Daniel H; Ramasubbu, Narayanan

    2015-01-01

    Aggregatibacter actinomycetemcomitans a causative agent of periodontal disease in humans, forms biofilm on biotic and abiotic surfaces. A. actinomycetemcomitans biofilm is heterogeneous in nature and is composed of proteins, extracellular DNA and exopolysaccharide. To explore the role played by the exopolysaccharide in the colonization and disease progression, we employed genetic reduction approach using our rat model of A. actinomycetemcomitans-induced periodontitis. To this end, a genetically modified strain of A. actinomycetemcomitans lacking the pga operon was compared with the wild-type strain in the rat infection model. The parent and mutant strains were primarily evaluated for bone resorption and disease. Our study showed that colonization, bone resorption/disease and antibody response were all elevated in the wild-type fed rats. The bone resorption/disease caused by the pga mutant strain, lacking the exopolysaccharide, was significantly less (P < 0.05) than the bone resorption/disease caused by the wild-type strain. Further analysis of the expression levels of selected virulence genes through RT-PCR showed that the decrease in colonization, bone resorption and antibody titer in the absence of the exopolysaccharide might be due to attenuated levels of colonization genes, flp-1, apiA and aae in the mutant strain. This study demonstrates that the effect exerted by the exopolysaccharide in A. actinomycetemcomitans-induced bone resorption has hitherto not been recognized and underscores the role played by the exopolysaccharide in A. actinomycetemcomitans-induced disease.

  15. Role of carbonic anhydrase in bone resorption induced by 1,25 dihydroxyvitamin D3 in vitro

    NASA Technical Reports Server (NTRS)

    Hall, G. E.; Kenny, A. D.

    1985-01-01

    The calvaria of 5-to-6-day-old mice treated with 1 x 10 to the -8th M of 1,25(OH)2D3 in vitro for 48 hours are examined in order to study the function of carbonic anhydrase in bone resorption. Calcium concentrations in the culture were measured to assess bone resorption. It is observed that 1,25(OH)2D3 effectively stimulates bone resorption in vitro and the resorption is dose-dependent. The effects of azetazolamide on 1,25(OH)2D3-induced bone resorption are investigated. The data reveal that 1,25(OH)2D3-induced calcium release is associated with an increase in the carbonic anhydrase activity of bone, and bone alkaline phosphatase activity is decreased and acid phosphatase activity is increased in response to 1,25(OH)2D3. A two-fold mechanism for 1,25(OH)2D3-induced bone resorption is proposed; the first mechanism is an indirect activation of osteoclasts and the second involves an interaction between hormone and osteoclast precursors.

  16. Inhibition of Osteoclastogenesis and Bone Resorption in vitro and in vivo by a prenylflavonoid xanthohumol from hops.

    PubMed

    Li, Jing; Zeng, Li; Xie, Juan; Yue, Zhiying; Deng, Huayun; Ma, Xueyun; Zheng, Chunbing; Wu, Xiushan; Luo, Jian; Liu, Mingyao

    2015-12-01

    Excessive RANKL signaling leads to superfluous osteoclast formation and bone resorption, is widespread in the pathologic bone loss and destruction. Therefore, targeting RANKL or its signaling pathway has been a promising and successful strategy for this osteoclast-related diseases. In this study, we examined the effects of xanthohumol (XN), an abundant prenylflavonoid from hops plant, on osteoclastogenesis, osteoclast resorption, and RANKL-induced signaling pathway using both in vitro and in vivo assay systems. In mouse and human, XN inhibited osteoclast differentiation and osteoclast formation at the early stage. Furthermore, XN inhibited osteoclast actin-ring formation and bone resorption in a dose-dependent manner. In ovariectomized-induced bone loss mouse model and RANKL-injection-induced bone resorption model, we found that administration of XN markedly inhibited bone loss and resorption by suppressing osteoclast activity. At the molecular level, XN disrupted the association of RANK and TRAF6, resulted in the inhibition of NF-κB and Ca(2+)/NFATc1 signaling pathway during osteoclastogenesis. As a results, XN suppressed the expression of osteoclastogenesis-related marker genes, including CtsK, Nfatc1, Trap, Ctr. Therefore, our data demonstrated that XN inhibits osteoclastogenesis and bone resorption through RANK/TRAF6 signaling pathways. XN could be a promising drug candidate in the treatment of osteoclast-related diseases such as postmenopausal osteoporosis.

  17. Antimicrobial proteins of murine macrophages.

    PubMed Central

    Hiemstra, P S; Eisenhauer, P B; Harwig, S S; van den Barselaar, M T; van Furth, R; Lehrer, R I

    1993-01-01

    Three murine microbicidal proteins (MUMPs) were purified from cells of the murine macrophage cell line RAW264.7 that had been activated by gamma interferon. Similar proteins were also present in nonactivated RAW264.7 cells, in cells of the murine macrophage cell line J774A.1, and in resident and activated murine peritoneal macrophages. MUMP-1, MUMP-2, and MUMP-3 killed Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Mycobacterium fortuitum, and Cryptococcus neoformans in vitro. MUMP-1 resembled an H1 histone but was unusual because its N-terminal residue (serine) was not N acetylated. Although MUMP-2 was N terminally blocked, its high lysine/arginine ratio and its reactivity with an antibody to H1 histones suggested that it also belonged to the H1 histone family. MUMP-3 was identical to histone H2B in 30 of 30 amino-terminal residues. Although the antimicrobial properties of histones have been recognized for decades, this is the first evidence that such proteins may endow the lysosomal apparatus of macrophages with nonoxidative antimicrobial potential. Other MUMPs, including some with a more restricted antimicrobial spectrum and one that appeared to be induced in RAW264.7 cells after gamma interferon stimulation, were noted but remain to be characterized. Images PMID:8514411

  18. Murine macrophages response to iron.

    PubMed

    Polati, Rita; Castagna, Annalisa; Bossi, Alessandra Maria; Alberio, Tiziana; De Domenico, Ivana; Kaplan, Jerry; Timperio, Anna Maria; Zolla, Lello; Gevi, Federica; D'Alessandro, Angelo; Brunch, Ryan; Olivieri, Oliviero; Girelli, Domenico

    2012-12-05

    Macrophages play a critical role at the crossroad between iron metabolism and immunity, being able to store and recycle iron derived from the phagocytosis of senescent erythrocytes. The way by which macrophages manage non-heme iron at physiological concentration is still not fully understood. We investigated protein changes in mouse bone marrow macrophages incubated with ferric ammonium citrate (FAC 10 μM iron). Differentially expressed spots were identified by nano RP-HPLC-ESI-MS/MS. Transcriptomic, metabolomics and western immunoblotting analyses complemented the proteomic approach. Pattern analysis was also used for identifying networks of proteins involved in iron homeostasis. FAC treatment resulted in higher abundance of several proteins including ferritins, cytoskeleton related proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) at the membrane level, vimentin, arginase, galectin-3 and macrophage migration inhibitory factor (MIF). Interestingly, GAPDH has been recently proposed to act as an alternative transferrin receptor for iron acquisition through internalization of the GAPDH-transferrin complex into the early endosomes. FAC treatment also induced the up-regulation of oxidative stress-related proteins (PRDX), which was further confirmed at the metabolic level (increase in GSSG, 8-isoprostane and pentose phosphate pathway intermediates) through mass spectrometry-based targeted metabolomics approaches. This study represents an example of the potential usefulness of "integarated omics" in the field of iron biology, especially for the elucidation of the molecular mechanisms controlling iron homeostasis in normal and disease conditions. This article is part of a Special Issue entitled: Integrated omics.

  19. Modulating macrophage response to biomaterials

    NASA Astrophysics Data System (ADS)

    Zaveri, Toral

    Macrophages recruited to the site of biomaterial implantation are the primary mediators of the chronic foreign body response to implanted materials. Since foreign body response limits performance and functional life of numerous implanted biomaterials/medical devices, various approaches have been investigated to modulate macrophage interactions with biomaterial surfaces to mitigate this response. In this work we have explored two independent approaches to modulate the macrophage inflammatory response to biomaterials. The first approach targets surface integrins, cell surface receptors that mediate cell adhesion to biomaterials through adhesive proteins spontaneously adsorbed on biomaterial surfaces. The second approach involves surface modification of biomaterials using nanotopographic features since nanotopography has been reported to modulate cell adhesion and viability in a cell type-dependent manner. More specifically, Zinc Oxide (ZnO) nanorod surface was investigated for its role in modulating macrophage adhesion and survival in vitro and foreign body response in vivo. For the first approach, we have investigated the role of integrin Mac-1 and RGD-binding integrins in the in-vivo osteolysis response and macrophage inflammatory processes of phagocytosis as well as inflammatory cytokine secretion in response to particulate biomaterials. We have also investigated the in vivo foreign body response (FBR) to subcutaneously implanted biomaterials by evaluating the thickness of fibrous capsule formed around the implants after 2 weeks of implantation. The role of Mac-1 integrin was isolated using a Mac-1 KO mouse and comparing it to a WT control. The role of RGD binding integrins in FBR was investigated by coating the implanted biomaterial with ELVAX(TM) polymer loaded with Echistatin which contains the RGD sequence. For the in-vivo osteolysis study and to study the in-vitro macrophage response to particulate biomaterials, we used the RGD peptide encapsulated in ELVAX

  20. Actions of Interferons on Macrophages.

    DTIC Science & Technology

    1986-06-20

    bactericidal activities of macrophages, and (c) possible immunomodulatory activities, it is conceivable that IFNs produced during listeriosis may function in...resistance. A goal of our research is to determine t-he functions of each IFN in resistance to a nonviral infectious disease, using murine listeriosis

  1. [The resorption of carbon dioxide from the pneumoperitoneum in laparoscopic cholecystectomy].

    PubMed

    Blobner, M; Felber, A R; Gögler, S; Feussner, H; Weigl, E M; Jelen, G; Jelen-Esselborn, S

    1993-05-01

    Laparoscopic cholecystectomy is claimed to be a minimally invasive procedure, but uptake of carbon dioxide (CO2) from the pneumoperitoneum (CO2-PP) can cause clinically relevant hypercapnia. In this prospective study, CO2 resorption during laparoscopic cholecystectomy was investigated. METHODS. In 30 patients (ASA I and II) total intravenous anesthesia was performed with propofol and fentanyl. Controlled ventilation was started with a tidal volume of 10 ml/kg min, a respiratory rate of 10/min, and FiO2 = 0.4 using an Engström Erica ventilator. When end-tidal CO2 (PeCO2) rose to 42 mmHg the respiratory rate was increased. In addition to standard monitoring, intra-abdominal pressure (IAP) was measured. Minute volume (VI), CO2 elimination (VCO2), oxygen uptake (VO2), and the respiratory quotient (RQ) were registered by indirect calorimetry from the Erica Metabolic Monitor. The CO2 resorption (delta VCO2) was calculated from the equation: delta VCO2(Mi) = VCO2(Mi) RQ(M1)VO2(Mi). (i = 1; 2; ...;5) All values are medians (interquartile range) or ranges. All parameters were compared at five measuring points that are characteristic for laparoscopic cholecystectomy: M1 baseline, 30 min after induction of anaesthesia, M2 10 min after starting CO2 insufflation, M3 while mobilising the gallbladder from the liver bed, M4 while extracting the gallbladder from the abdominal cavity, and M5 10 min after desufflating the CO2-PP (spontaneous breathing). RESULTS. A typical pattern of VCO2 was observed (Fig. 1). Baseline VCO2 was 165 (145-180) ml/min, PeCO2 was 33 (31-35) mmHg, and VI was 6.0 (6.0-7.0) l/min. After insufflation of CO2 to an IAP of between 14 and 20 mmHg, an increase in VCO2 to 201 (179-222) ml/min was registered (P < 0.05). During mobilisation of the gallbladder, the IAP was between 12 and 18 mmHg and no further increase in VCO2 (200 (179-229) ml/min) was observed. During extraction of the gallbladder from the abdominal cavity, the CO2-PP deflated and IAP dropped to 1

  2. Cherubism mice also deficient in c-Fos exhibit inflammatory bone destruction executed by macrophages that express MMP14 despite the absence of TRAP+ osteoclasts.

    PubMed

    Kittaka, Mizuho; Mayahara, Kotoe; Mukai, Tomoyuki; Yoshimoto, Tetsuya; Yoshitaka, Teruhito; Gorski, Jeffrey P; Ueki, Yasuyoshi

    2017-09-15

    Currently, it is believed that osteoclasts positive for tartrate-resistant acid phosphatase (TRAP +) are the exclusive bone-resorbing cells responsible for focal bone destruction in inflammatory arthritis. Recently, a mouse model of cherubism (Sh3bp2(KI/KI) ) with a homozygous gain-of-function mutation in the SH3-domain binding protein 2 (SH3BP2) was shown to develop auto-inflammatory joint destruction. Here, we demonstrate that Sh3bp2(KI/KI) mice also deficient in the FBJ osteosarcoma oncogene (c-Fos) still exhibit noticeable bone erosion at the distal tibia even in the absence of osteoclasts at 12 weeks old. Levels of serum ICTP, a marker of bone resorption generated by matrix metalloproteinases (MMPs), were elevated, while levels of serum CTX, another resorption marker produced by cathepsin K, were not increased. Collagenolytic MMP levels were increased in the inflamed joints of the Sh3bp2(KI/KI) mice deficient in c-Fos. Resorption pits contained a large number of F4/80+ macrophages and genetic depletion of macrophages rescued these erosive changes. Importantly, administration of NSC405020, an MMP14 inhibitor targeted to the hemopexin (PEX) domain, suppressed bone erosion in c-Fos-deficient Sh3bp2(KI/KI) mice. After activation of the NF-κB pathway, M-CSF-dependent macrophages from c-Fos-deficient Sh3bp2(KI/KI) mice expressed increased amounts of MMP14 compared to wild-type macrophages. Interestingly, RANKL-deficient Sh3bp2(KI/KI) mice failed to show notable bone erosion, while c-Fos deletion did restore bone erosion to the RANKL-deficient Sh3bp2(KI/KI) mice, suggesting that osteolytic transformation of macrophages requires both loss-of-function of c-Fos and gain-of-function of SH3BP2 in this model. These data provide the first genetic evidence that cells other than osteoclasts can cause focal bone destruction in inflammatory bone disease and suggest that MMP14 is a key mediator conferring pathological bone-resorbing capacity on c-Fos-deficient Sh3bp2(KI

  3. The journey from stem cell to macrophage

    PubMed Central

    Pittet, Mikael J.; Nahrendorf, Matthias; Swirski, Filip K.

    2014-01-01

    Essential protectors against infection and injury, macrophages can also contribute to many common and fatal diseases. Here we discuss the mechanisms that control different types of macrophage activities in mice. We follow the cells’ maturational pathways over time and space, and elaborate on events that influence the type of macrophage eventually settling a particular destination. The nature of the precursor cells, developmental niches, tissues, environmental cues, and other connecting processes appear to contribute to the identity of macrophage type. Together, the spatial and developmental relationships of macrophages comprise a topo-ontogenic map that can guide our understanding of their biology. PMID:24673186

  4. Isolation and Differentiation of Human Macrophages.

    PubMed

    Rios, Francisco J; Touyz, Rhian M; Montezano, Augusto C

    2017-01-01

    Macrophage subtypes display protective or pathogenic activities in vascular lesions. They recognize and engulf modified lipids, accumulate in the arterial intima, contributing to the atherosclerosis development. In the heart, vascular tissues and perivascular adipose tissues, there is increasing evidence that macrophages play a role in endothelial dysfunction, vascular inflammation and remodeling. In this chapter we describe protocols to isolate human monocytes from peripheral blood mononuclear cell and how to differentiate them into macrophages by using growth factors (granulocyte-macrophage colony-stimulating factor-GM-CSF or colony-stimulating factor-M-CSF) or by different cell culture medium concentration. We also describe how to indentify different macrophage activation phenotypes.

  5. Identification of polarized macrophage subsets in zebrafish

    PubMed Central

    Nguyen-Chi, Mai; Laplace-Builhe, Béryl; Travnickova, Jana; Luz-Crawford, Patricia; Tejedor, Gautier; Phan, Quang Tien; Duroux-Richard, Isabelle; Levraud, Jean-Pierre; Kissa, Karima; Lutfalla, Georges

    2015-01-01

    While the mammalian macrophage phenotypes have been intensively studied in vitro, the dynamic of their phenotypic polarization has never been investigated in live vertebrates. We used the zebrafish as a live model to identify and trail macrophage subtypes. We generated a transgenic line whose macrophages expressing tumour necrosis factor alpha (tnfa), a key feature of classically activated (M1) macrophages, express fluorescent proteins Tg(mpeg1:mCherryF/tnfa:eGFP-F). Using 4D-confocal microscopy, we showed that both aseptic wounding and Escherichia coli inoculation triggered macrophage recruitment, some of which started to express tnfa. RT-qPCR on Fluorescence Activated Cell Sorting (FACS)-sorted tnfa+ and tnfa− macrophages showed that they, respectively, expressed M1 and alternatively activated (M2) mammalian markers. Fate tracing of tnfa+ macrophages during the time-course of inflammation demonstrated that pro-inflammatory macrophages converted into M2-like phenotype during the resolution step. Our results reveal the diversity and plasticity of zebrafish macrophage subsets and underline the similarities with mammalian macrophages proposing a new system to study macrophage functional dynamic. DOI: http://dx.doi.org/10.7554/eLife.07288.001 PMID:26154973

  6. Identification of polarized macrophage subsets in zebrafish.

    PubMed

    Nguyen-Chi, Mai; Laplace-Builhe, Béryl; Travnickova, Jana; Luz-Crawford, Patricia; Tejedor, Gautier; Phan, Quang Tien; Duroux-Richard, Isabelle; Levraud, Jean-Pierre; Kissa, Karima; Lutfalla, Georges; Jorgensen, Christian; Djouad, Farida

    2015-07-08

    While the mammalian macrophage phenotypes have been intensively studied in vitro, the dynamic of their phenotypic polarization has never been investigated in live vertebrates. We used the zebrafish as a live model to identify and trail macrophage subtypes. We generated a transgenic line whose macrophages expressing tumour necrosis factor alpha (tnfa), a key feature of classically activated (M1) macrophages, express fluorescent proteins Tg(mpeg1:mCherryF/tnfa:eGFP-F). Using 4D-confocal microscopy, we showed that both aseptic wounding and Escherichia coli inoculation triggered macrophage recruitment, some of which started to express tnfa. RT-qPCR on Fluorescence Activated Cell Sorting (FACS)-sorted tnfa(+) and tnfa(-) macrophages showed that they, respectively, expressed M1 and alternatively activated (M2) mammalian markers. Fate tracing of tnfa(+) macrophages during the time-course of inflammation demonstrated that pro-inflammatory macrophages converted into M2-like phenotype during the resolution step. Our results reveal the diversity and plasticity of zebrafish macrophage subsets and underline the similarities with mammalian macrophages proposing a new system to study macrophage functional dynamic.

  7. Macrophages in tissue repair, regeneration, and fibrosis

    PubMed Central

    Wynn, Thomas A.; Vannella, Kevin M.

    2016-01-01

    Inflammatory monocytes and resident tissue macrophages are key regulators of tissue repair, regeneration, and fibrosis. Following tissue injury, monocytes and macrophages undergo marked phenotypic and functional changes to play critical roles during the initiation, maintenance, and resolution phases of tissue repair. Disturbances in macrophage function can lead to aberrant repair, with uncontrolled inflammatory mediator and growth factor production, deficient generation of anti-inflammatory macrophages, or failed communication between macrophages and epithelial cells, endothelial cells, fibroblasts, and stem or tissue progenitor cells all contributing to a state of persistent injury, which may lead to the development of pathological fibrosis. In this review, we discuss the mechanisms that instruct macrophages to adopt pro-inflammatory, pro-wound healing, pro-fibrotic, anti-inflammatory, anti-fibrotic, pro-resolving, and tissue regenerating phenotypes following injury, and highlight how some of these mechanisms and macrophage activation states could be exploited therapeutically. PMID:26982353

  8. Inhibiting macrophage proliferation suppresses atherosclerotic plaque inflammation.

    PubMed

    Tang, Jun; Lobatto, Mark E; Hassing, Laurien; van der Staay, Susanne; van Rijs, Sarian M; Calcagno, Claudia; Braza, Mounia S; Baxter, Samantha; Fay, Francois; Sanchez-Gaytan, Brenda L; Duivenvoorden, Raphaël; Sager, Hendrik; Astudillo, Yaritzy M; Leong, Wei; Ramachandran, Sarayu; Storm, Gert; Pérez-Medina, Carlos; Reiner, Thomas; Cormode, David P; Strijkers, Gustav J; Stroes, Erik S G; Swirski, Filip K; Nahrendorf, Matthias; Fisher, Edward A; Fayad, Zahi A; Mulder, Willem J M

    2015-04-01

    Inflammation drives atherosclerotic plaque progression and rupture, and is a compelling therapeutic target. Consequently, attenuating inflammation by reducing local macrophage accumulation is an appealing approach. This can potentially be accomplished by either blocking blood monocyte recruitment to the plaque or increasing macrophage apoptosis and emigration. Because macrophage proliferation was recently shown to dominate macrophage accumulation in advanced plaques, locally inhibiting macrophage proliferation may reduce plaque inflammation and produce long-term therapeutic benefits. To test this hypothesis, we used nanoparticle-based delivery of simvastatin to inhibit plaque macrophage proliferation in apolipoprotein E deficient mice (Apoe(-/-) ) with advanced atherosclerotic plaques. This resulted in rapid reduction of plaque inflammation and favorable phenotype remodeling. We then combined this short-term nanoparticle intervention with an eight-week oral statin treatment, and this regimen rapidly reduced and continuously suppressed plaque inflammation. Our results demonstrate that pharmacologically inhibiting local macrophage proliferation can effectively treat inflammation in atherosclerosis.

  9. Inhibiting macrophage proliferation suppresses atherosclerotic plaque inflammation

    PubMed Central

    Tang, Jun; Lobatto, Mark E.; Hassing, Laurien; van der Staay, Susanne; van Rijs, Sarian M.; Calcagno, Claudia; Braza, Mounia S.; Baxter, Samantha; Fay, Francois; Sanchez-Gaytan, Brenda L.; Duivenvoorden, Raphaël; Sager, Hendrik B.; Astudillo, Yaritzy M.; Leong, Wei; Ramachandran, Sarayu; Storm, Gert; Pérez-Medina, Carlos; Reiner, Thomas; Cormode, David P.; Strijkers, Gustav J.; Stroes, Erik S. G.; Swirski, Filip K.; Nahrendorf, Matthias; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

    2015-01-01

    Inflammation drives atherosclerotic plaque progression and rupture, and is a compelling therapeutic target. Consequently, attenuating inflammation by reducing local macrophage accumulation is an appealing approach. This can potentially be accomplished by either blocking blood monocyte recruitment to the plaque or increasing macrophage apoptosis and emigration. Because macrophage proliferation was recently shown to dominate macrophage accumulation in advanced plaques, locally inhibiting macrophage proliferation may reduce plaque inflammation and produce long-term therapeutic benefits. To test this hypothesis, we used nanoparticle-based delivery of simvastatin to inhibit plaque macrophage proliferation in apolipoprotein E–deficient mice (Apoe−/−) with advanced atherosclerotic plaques. This resulted in the rapid reduction of plaque inflammation and favorable phenotype remodeling. We then combined this short-term nanoparticle intervention with an 8-week oral statin treatment, and this regimen rapidly reduced and continuously suppressed plaque inflammation. Our results demonstrate that pharmacologically inhibiting local macrophage proliferation can effectively treat inflammation in atherosclerosis. PMID:26295063

  10. Radiographic comparison of apical root resorption after orthodontic treatment between bidimensional and Roth straight-wire techniques

    PubMed Central

    Zawawi, Khalid H; Malki, Ghadah A

    2014-01-01

    Objective: The aim of this study was to compare the amount of root resorption after orthodontic treatment between the bidimensional and the Roth straight-wire techniques. Another objective was to compare the amount of root resorption in the whole sample studied and record the prevalence of root resorption. Materials and Methods: The sample consisted of 40 patients (age ranged between 11 and 18 years) with Angle Class II division 1 malocclusions, treated nonextraction. Twenty patients were treated with bidimensional technique and 20 with a 0.018-inch Roth straight-wire technique. Root lengths of the maxillary incisors were measured on pre- and post-treatment periapical radiographs. Results: The results demonstrated that the bidimensional and Roth straight-wire groups showed significant root resorption after treatment, 1.11 (0.17) and 0.86 (0.05), respectively, P < 0.001. When comparing the amount of root shortening between the bidimensional and Roth straight-wire groups, there was no significant difference between the mean change from pre- to post-treatment between bidimensional group (mean = 1.00 ± 1.34) and Roth straight-wire group (mean = 0.88 ± 0.86), P = 0.63. Considering the whole sample, there was no root resoprtion in 32.5% of the analysed teeth. There was only mild resorption in 56.2%, moderate in 8.8% and severe in only 2.5% of the teeth. Conclusions: Treatment with the bidimensional technique did not produce an increase in the amount of root resorption. The prevalence and amount of root resorption was similar between bidimensional and Roth straight-wire techniques. PMID:25426453

  11. Expression of adhesion molecules during tooth resorption in feline teeth: a model system for aggressive osteoclastic activity.

    PubMed

    Shigeyama, Y; Grove, T K; Strayhorn, C; Somerman, M J

    1996-09-01

    Tooth resorption, a common feline dental problem, is often initiated at the cemento-enamel junction and hence is called cat 'neck' lesion. Studies have demonstrated that osteoclasts/odontoclasts are increased and activated at resorption sites, and that areas of resorption are partly repaired by formation of tissues resembling bone, cementum, and possibly dentin. However, the cellular/molecular mechanisms/factors involved in resorption and repair are unknown. In this study of tissues from cats with 'neck' lesions, we used specific antibodies and immunohistochemical analyses to examine adhesion molecules associated with mineralized tissues, bone sialoprotein (BSP) and osteopontin (OPN), and a cell-surface receptor linked with these molecules, alpha v beta 3, for their localization in these lesions. In addition, to determine general cellular activity during repair, we performed in situ hybridization using a type I collagen riboprobe. Results showed OPN localized to resorption fronts and reversal lines, while BSP was localized to reversal lines. However, some osteoclasts and odontoblasts "sat" on mineralized surfaces not associated with OPN. The cell-surface receptor, alpha v beta 3, was localized to surfaces of osteoclasts/odontoclasts. Type I collagen mRNA was expressed where osteoblasts attempted to repair mineralized tissue. In contrast, odontoblasts did not express mRNA for type I collagen. This study suggests that osteoclastic resorption is the predominant activity in 'neck' lesions and that this activity was accompanied, at least in part, by increased concentrations of OPN and an associated integrin, alpha v beta 3, at resorption sites. Lack of collagen expression by odontoblasts indicates that odontoblasts do not play an active role in attempts at repair.

  12. Obesity phenotypes and resorption percentage after breast autologous fat grafting: Rule of low-grade inflammation

    PubMed Central

    Gentile, Pietro; Sarlo, Francesca; De Angelis, Barbara; De Lorenzo, Antonio; Cervelli, Valerio

    2016-01-01

    Background: One of the main reasons why the breast fat grafting was questioned is that there may be lipofilling resorption. In the literature, the resorption rate reported over the 1st year is highly variable (20–90%). Objective: The aim of this work was to identify the biochemical and clinical parameters, which increase fat graft maintenance in breast reconstruction. Materials and Methods: A sample of 19 patients was treated with fat grafting mixed with platelet-rich plasma. A complete screening of anthropometry, body composition, and blood biochemical parameters was assessed using the standardized equipment. Pre- and post-operative evaluation was performed, which included a complete clinical examination, photographic assessment, nuclear magnetic resonance imaging of the soft tissue, and ultrasound. The follow-up period was 2 years. Results: The authors divided the results into two types of patients: “responder” and “not a responder.” In the “responder” group patients with normal weight, gynoid fat distribution, obese, with normal blood biochemical parameters, and atherogenic indices but with high preoperative values of platelet-to-lymphocyte ratio (PLR) (174.49) and neutrophil-lymphocyte ratio (NLR) (2.65) showed a greater increase of fat graft maintenance at 6 and 12 months after the last lipofilling session. In the “not responder group” patients with overweight, android fat distribution, obese, high values of atherogenic indices, but with normal preoperative NLR and PLR ratios showed a lower fat graft maintenance at 6 and 12 months. Conclusion: We assume, the problem of fat resorption may be resolved by analysis of body composition and by examine the predictive role of preoperative markers of low-grade inflammation. PMID:27656603

  13. An inverse modeling strategy and a computer program to model garnet growth and resorption

    NASA Astrophysics Data System (ADS)

    Lanari, Pierre; Giuntoli, Francesco

    2017-04-01

    GrtMod is a computer program that allows numerical simulation of the pressure-temperature (P-T) evolution of garnet porphyroblasts based on the composition of successive growth zones preserved in natural samples. For each garnet growth stage, a new reactive bulk composition is optimized, allowing for resorption and/or fractionation of the previously crystalized garnet. The successive minimizations are performed using a heuristic search method and an objective function that quantify the amount by which the predicted garnet composition deviates from the measured values. The automated strategy of GrtMod includes a two stages optimization and one refinement stage. In this contribution, we will present several application examples. The new strategy provides quantitative estimates of the optimal P-T conditions whereas it was generally derived in a qualitatively way by using garnet isopleth intersections in equilibrium phase diagrams. GrtMod can also be used to model the evolution of the reactive bulk composition along any P-T trajectories. The results for typical MORB and metapelite compositions demonstrate that fractional crystallization models are required to derive accurate P-T information from garnet compositional zoning. GrtMod can also be used to retrieve complex garnet histories involving several stages of resorption. For instance, it has been used to model the P-T condition of garnet growth in grains from the Sesia Zone (Western Alps). The compositional variability of successive growth zones is characterized using standardized X-ray maps and the program XMapTools. Permian garnet cores crystalized under granulite facies conditions (T > 800°C and P = 6 kbar), whereas Alpine garnet rims grew at eclogite facies conditions (650°C and 16 kbar) involving several successive episodes of resorption. The model predicts that up to 50 vol% of garnet was dissolved before a new episode of garnet growth.

  14. Bone resorption is affected by follicular phase length in female rotating shift workers.

    PubMed Central

    Lohstroh, Pete N; Chen, Jiangang; Ba, Jianming; Ryan, Louise M; Xu, Xiping; Overstreet, James W; Lasley, Bill L

    2003-01-01

    Stressors as subtle as night work or shift work can lead to irregular menstrual cycles, and changes in reproductive hormone profiles can adversely affect bone health. This study was conducted to determine if stresses associated with the disruption of regular work schedule can induce alterations in ovarian function which, in turn, are associated with transient bone resorption. Urine samples from 12 rotating shift workers from a textile mill in Anqing, China, were collected in 1996-1998 during pairs of sequential menstrual cycles, of which one was longer than the other (28.4 vs. 37.4 days). Longer cycles were characterized by a prolonged follicular phase. Work schedules during the luteal-follicular phase transition (LFPT) preceding each of the two cycles were evaluated. All but one of the shorter cycles were associated with regular, forward phase work shift progression during the preceding LFPT. In contrast, five longer cycles were preceded by a work shift interrupted either by an irregular shift or a number of "off days." Urinary follicle-stimulating hormone levels were reduced in the LFPT preceding longer cycles compared with those in the LFPT preceding shorter cycles. There was greater bone resorption in the follicular phase of longer cycles than in that of shorter cycles, as measured by urinary deoxypyridinoline. These data confirm reports that changes in work shift can lead to irregularity in menstrual cycle length. In addition, these data indicate that there may be an association between accelerated bone resorption in menstrual cycles and changes of regularity in work schedule during the preceding LFPT. PMID:12676625

  15. The presence of TNF-alpha and TNFR1 in aseptic root resorption. A preliminary study.

    PubMed

    Curl, Linda; Sampson, Wayne

    2011-11-01

    It is hypothesised that osteoprotegerin (OPG), as an osteoclast antagonist, may offer molecular control over the process of orthodontic root resorption. Previous work investigating OPG in a rat periodontal ligament (PDL) ankylosis model found no inhibitory effect on osteoclasts and odontoclasts when given at a recommended dosage of 2.5 mg/kg. It was considered that traumatically-induced PDL inflammation produces mediators and cytokines with the ability to stimulate clast cell differentiation and counter the effects of OPG. The present study investigated the presence of Tumour Necrosis Factor Alpha (TNF-alpha) and its receptor Tumour Necrosis Factor Receptor 1 (TNFR1) in a PDL sterile inflammatory model. Dry ice was applied for 15 minutes to the upper right first molar crown of eighteen, 8-week-old, male Sprague-Dawley rats of which 9 were injected with OPG at a dose of 2.5 mg/kg of body weight at the time of freezing. After 7 days, the rats were sacrificed and each maxilla processed for immunohistochemical identification of TNF-alpha and TNFR1. Results showed the presence of root resorption in varying amounts and locations in both experimental and control rats. Reparative processes appeared greater in the OPG-treated rats, often with the presence of an ankylotic union. Immunolabelling showed the presence of TNF-alpha and TNFR1 in the sterile inflammation located mainly in the interradicular PDL area. More definitive labelling appeared in OPG-treated rats. The results indicated that TNF-alpha, and its receptor TNFR1, by their presence, may modify OPG effectiveness by offering an alternative pathway for osteoclast formation, which counters the anti-resorptive effects of OPG.

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

    PubMed Central

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

    1994-01-01

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

  17. Oral contraceptives moderately effect bone resorption markers and serum-soluble interleukin-6 receptor concentrations.

    PubMed

    Zittermann, A; Rühl, J; Berthold, H K; Sudhop, T; van der Ven, H; Reinsberg, J; Stehle, P

    2002-01-01

    This study investigated the effect of ethinylestradiol(EE2)-containing oral contraceptives on mineral and bone metabolism and on serum soluble-interleukin-6-receptor (sIL-6R) during the menstrual cycle. Twelve women, aged 24.3 +/- 2.9 years, were examined. Blood and 24-hour and fasting urine samples were obtained during one menstrual cycle between cycle day 3-5 (t(1)), cycle day 10-12 (t(2)), cycle day 24-26 (t(3)), and again on day 3-5 of the next cycle (t(4)). EE2 intake was 0 mg at t(1), 30 mg at t(2), 30 mg at t(3) and 0 mg at t(4). Fasting renal phosphorus and calcium excretions were slightly reduced at t(2) and t(3) compared with t(1) and t(4) (P < 0.05-0.001). Moreover, renal excretion of the bone resorption marker C-Teleopeptide was at t(3) reduced by 26% compared with t(1)(P < 0.01) and by 13% compared with t(4)(P > 0.05). Fasting sIL-6R levels were 16.5% lower at t(2) and 12% lower at t(3) than at t(4) (P < 0.01 and P < 0.05). sIL-6R was correlated with total deoxypyridinoline excretion (r = +0.35; P < 0.05) and with fasting renal excretions of calcium (r = +0.36; P < 0.05) and phosphorus (r = +0.29; P < 0.05). In summary, our data suggest that in young women, cyclic monthly oral contraceptive intake is associated with small, but significant variations in bone resorption processes and in serum sIL-6R levels. Results are a further indication that monthly fluctuations of bone resorption in young women are mediated by sex hormones and that osteoclastic activity is stimulated by cytokines in vivo.

  18. Effectiveness of elcatonin for alleviating pain and inhibiting bone resorption in patients with osteoporotic vertebral fractures.

    PubMed

    Tanaka, Shinya; Yoshida, Akira; Kono, Shinjiro; Oguma, Tadanori; Hasegawa, Kyoichi; Ito, Manabu

    2016-11-09

    Elderly patients with osteoporotic vertebral fractures often experience severe pain that reduces their quality of life (QOL). Calcitonin, a bone resorption inhibitor, has been reported to alleviate pain in such patients; however, few clinical studies have demonstrated this effect. The objective of this study was to compare changes in pain scores, activities of daily living (ADL), QOL, bone resorption, bone mineral density (BMD), and fracture healing among patients with new vertebral fractures who received different treatment modalities. We conducted an open-label, multicenter, randomized, parallel control group study comprising 107 female patients ≥55 years old with acute back pain from vertebral fracture. All subjects received either intramuscular injections of elcatonin, a derivative of calcitonin, or an oral nonsteroidal antiinflammatory drug (NSAID) combined with an active vitamin D3 (VD3) analogue for 6 months. The pain was assessed using a visual analogue scale, and ADL and QOL were assessed using questionnaires. BMD was measured using dual-energy X-ray absorptiometry. A two-tailed significance level of 5% was used. The elcatonin IM group had significantly higher QOL score at 2 weeks and later, and significantly lower VAS and ADL scores than those in the NSAID + VD3 group at 1 month and later. The elcatonin IM group had significantly reduced TRACP-5b levels compared with those in the NSAID + VD3 group at 3 months and later and significantly higher percent changes in BMD than the NSAID + VD3 group. These results suggest that elcatonin significantly alleviated pain, inhibited bone resorption, and improved ADL, QOL, and BMD compared with NSAID + VD3.

  19. Changes in markers of bone formation and resorption in a bed rest model of weightlessness

    NASA Technical Reports Server (NTRS)

    Lueken, S. A.; Arnaud, S. B.; Taylor, A. K.; Baylink, D. J.

    1993-01-01

    To study the mechanism of bone loss in physical unloading, we examined indices of bone formation and bone resorption in the serum and urine of eight healthy men during a 7 day -6 degrees head-down tilt bed rest. Prompt increases in markers of resorption--pyridinoline (PD), deoxypyridinoline (DPD), and hydroxyproline (Hyp)/g creatinine--during the first few days of inactivity were paralleled by tartrate-resistant acid phosphatase (TRAP) with significant increases in all these markers by day 4 of bed rest. An index of formation, skeletal alkaline phosphatase (SALP), did not change during bed rest and showed a moderate 15% increase 1 week after reambulation. In contrast to SALP, serum osteocalcin (OC) began increasing the day preceding the increase in Hyp, remained elevated for the duration of the bed rest, and returned to pre-bed rest values within 5 days of reambulation. Similarly, DPD increased significantly at the onset of bed rest, remained elevated for the duration of bed rest, and returned to pre-bed rest levels upon reambulation. On the other hand, the other three indices of resorption, Hyp, PD, and TRAP, remained elevated for 2 weeks after reambulation. The most sensitive indices of the levels of physical activity proved to be the noncollagenous protein, OC, and the collagen crosslinker, DPD. The bed rest values of both these markers were significantly elevated compared to both the pre-bed rest values and the post-bed rest values. The sequence of changes in the circulating markers of bone metabolism indicated that increases in serum OC are the earliest responses of bone to head-down tilt bed rest.

  20. Esculetin inhibits cartilage resorption induced by interleukin 1α in combination with oncostatin M

    PubMed Central

    Elliott, S; Rowan, A; Carrere, S; Koshy, P; Catterall, J; Cawston, T

    2001-01-01

    OBJECTIVE—To determine if a new inhibitor, esculetin (EST), can block resorption of cartilage.
METHODS—Interleukin 1α (IL1α, 0.04-5 ng/ml) and oncostatin M (OSM, 0.4-50 ng/ml) were used to stimulate the release of proteoglycan and collagen from bovine nasal cartilage and human articular cartilage in explant culture. Proteoglycan and collagen loss were assessed by dimethylmethylene blue and hydroxyproline assays, respectively. Collagenase levels were measured by assay of bioactivity and by enzyme linked immunosorbent assay (ELISA). The effects of EST on the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the transformed human chondrocyte cell line T/C28a4 were assessed by northern blot analysis. TIMP-1 protein levels were assayed by ELISA. The effect of EST on the MMP-1 promoter was assessed using a promoter-luciferase construct in transient transfection studies.
RESULTS—EST inhibited proteoglycan and collagen resorption in a dose dependent manner with significant decreases seen at 66 µM and 100 µM EST, respectively. Collagenolytic activity was significantly decreased in bovine nasal cartilage cultures. In human articular cartilage, EST also inhibited IL1α + OSM stimulated resorption and decreased MMP-1 levels. TIMP-1 levels were not altered compared with controls. In T/C28a4 chondrocytes the IL1α + OSM induced expression of MMP-1, MMP-3, and MMP-13 mRNA was reduced to control levels by 250 µM EST. TIMP-1 mRNA levels were unaffected by EST treatment. All cytokine stimulation of an MMP-1 luciferase-promoter construct was lost in the presence of the inhibitor.
CONCLUSION—EST inhibits degradation of bovine nasal cartilage and human articular cartilage stimulated to resorb with IL1α + OSM.

 PMID:11156550

  1. Inhibition of bone resorption and growth of breast cancer in the bone microenvironment.

    PubMed

    Buijs, Jeroen T; Que, Ivo; Löwik, Clemens W G M; Papapoulos, Socrates E; van der Pluijm, Gabri

    2009-02-01

    Breast cancer frequently metastasizes to bone, where tumor cells induce osteoclasts to locally destroy bone. During bone resorption, growth factors are locally released that may support bone metastatic growth. Differently from most other tissues, drugs that can limit local turnover, such as bisphosphonates and osteoprotegerin (OPG), are available for bone. We examined the hypothesis that inhibition of bone resorption by two different mechanisms may also affect the growth of cancer cells in bone. For this, we tested the effects of high doses of OPG and zoledronic acid (ZOL) on progression of MDA-231-B/Luc+ breast cancer cells in the bone microenvironment using whole body bioluminescent reporter imaging (BLI). Both treatments significantly inhibited the development of radiographically detectable osteolytic lesions. Histologic examination corroborated the radiographic findings, showing that both treatments preserved the integrity of bone trabeculae and prevented bone destruction (significantly higher trabecular bone volumes vs. vehicle). However, whereas practically no TRAcP-positive osteoclasts were observed in tibiae preparations of animals treated with Fc-OPG, TRAcP-positive osteoclasts were still present in the animals treated with ZOL. Intra-bone tumor burden was reduced with ZOL and Fc-OPG treatment. Although there appeared to be a trend for less overall total tumor burden upon treatment with both compounds, this was not significant as assessed by BLI and histomorphometric analysis due to the extramedullary growth of cancer cells which was not affected by these treatments. Collectively, anti-resorptive agents with different mechanisms of action - ZOL and OPG - significantly reduced cancer-induced osteolysis and intra-osseous tumor burden, but failed to restrain local tumor growth. However, interference with the bone micro-environmental growth support could still be of therapeutic relevance when given to patients early in the course of bone metastatic disease.

  2. Cadmium effects on bone metabolism: accelerated resorption in ovariectomized, aged beagles.

    PubMed

    Sacco-Gibson, N; Chaudhry, S; Brock, A; Sickles, A B; Patel, B; Hegstad, R; Johnston, S; Peterson, D; Bhattacharyya, M

    1992-04-01

    The purpose of this study was to evaluate, in an animal whose skeleton is comparable to humans, the combined effects of estrogen depletion and Cd exposure on bone resorption by monitoring skeletal release of 45Ca and to determine whether Cd-induced bone resorption occurred independent of osteotropic hormone changes and renal dysfunction. Cd exposure following ovariectomy or sham surgery was for 7 months: 1 month by oral ingestion of capsules (1, 5, 15, 50 ppm) and 6 months via drinking water (15 ppm). Serum and fecal 45Ca were increased at 1 week following ovariectomy (OV) (54 +/- 9% and 122 +/- 40%, respectively), but this response was attenuated by 2 weeks. Five of seven exposed dogs had increased serum and fecal 45Ca during the 50-ppm Cd capsule period (15-40% and 15-190%, respectively). Serum 45Ca levels in OV/+Cd dogs showed a significant and consistent increase within 1 week of initiating each of three separate Cd.H2O exposure cycles. Blood Cd levels increased over time from 2 to 15 micrograms/l, coinciding with the elevated serum 45Ca concentrations. No correlation was observed between serum 45Ca increases and parathyroid hormone, 1,25-(OH)2-vitamin D, or calcitonin. No effects of ovariectomy and/or Cd were observed in total serum Ca, calciotropic hormone concentrations, serum or urinary phosphorus and creatinine, creatinine clearance, or urinary specific gravity. Urinary Cd concentrations ranged from 7 to 50 micrograms/l in exposed dogs but were not detectable in nonexposed dogs. Urinary protein concentrations showed no differences between groups. Cd increased bone resorption (skeletal 45Ca release) in ovariectomized and sham-operated dogs without renal dysfunction or calciotropic hormone interaction. Based on our results, Cd is an exogenous factor which exacerbates bone mineral loss in postmenopausal osteoporosis.

  3. In vivo loading increases mechanical properties of scaffold by affecting bone formation and bone resorption rates.

    PubMed

    Roshan-Ghias, Alireza; Lambers, Floor M; Gholam-Rezaee, Mehdi; Müller, Ralph; Pioletti, Dominique P

    2011-12-01

    A successful bone tissue engineering strategy entails producing bone-scaffold constructs with adequate mechanical properties. Apart from the mechanical properties of the scaffold itself, the forming bone inside the scaffold also adds to the strength of the construct. In this study, we investigated the role of in vivo cyclic loading on mechanical properties of a bone scaffold. We implanted PLA/β-TCP scaffolds in the distal femur of six rats, applied external cyclic loading on the right leg, and kept the left leg as a control. We monitored bone formation at 7 time points over 35 weeks using time-lapsed micro-computed tomography (CT) imaging. The images were then used to construct micro-finite element models of bone-scaffold constructs, with which we estimated the stiffness for each sample at all time points. We found that loading increased the stiffness by 60% at 35 weeks. The increase of stiffness was correlated to an increase in bone volume fraction of 18% in the loaded scaffold compared to control scaffold. These changes in volume fraction and related stiffness in the bone scaffold are regulated by two independent processes, bone formation and bone resorption. Using time-lapsed micro-CT imaging and a newly-developed longitudinal image registration technique, we observed that mechanical stimulation increases the bone formation rate during 4-10 weeks, and decreases the bone resorption rate during 9-18 weeks post-operatively. For the first time, we report that in vivo cyclic loading increases mechanical properties of the scaffold by increasing the bone formation rate and decreasing the bone resorption rate.

  4. Reduced bone formation and relatively increased bone resorption in absorptive hypercalciuria.

    PubMed

    Heller, H J; Zerwekh, J E; Gottschalk, F A; Pak, C Y C

    2007-04-01

    Absorptive hypercalciuria (AH), a common stone-forming condition characterized biochemically by intestinal hyperabsorption of calcium and hypercalciuria may be associated with bone loss. In AH type I (AH-1), hypercalciuria persists despite restriction in dietary calcium intake. We therefore hypothesized that the skeleton may contribute to the hypercalciuria in this subgroup of patients. Histomorphometric analysis of iliac crest biopsies were performed on nine stone-formers with AH-1 and on nine matched normal subjects. After stabilization on a stone-prevention diet, calcium homeostasis in the stone formers was then evaluated on inpatient constant metabolic diet before and after short-term blockade of bone resorption by alendronate (10 mg daily, 17 days total). Compared with controls, the stone-formers had lower indices of bone formation (osteoblast surface/bone surface 1.8+/-2.1 vs 3.0+/-1.5%, P=0.04; wall thickness 35.8+/-6.9 vs 47.2+/-7.6%, P=0.001) and relatively higher bone resorption (osteoclast surface/bone surface 0.4+/-0.2 vs 0.2+/-0.2%, P=0.05). In the stone-formers, a short-term course of alendronate treatment corrected fasting urinary calcium (0.14+/-0.06 to 0.06+/-0.04 mg Ca/mg Cr, P=0.001) and marginally reduced 24-h urinary calcium by 48 mg/day (P=0.06). Increased intestinal calcium absorption and hypercalciuria persisted, but estimated calcium balance improved (P=0.007). Our results suggest that the hypercalciuria of AH-1 originates primarily from intestinal hyperabsorption of calcium, but bone resorption in excess of bone formation may contribute.

  5. Changes in markers of bone formation and resorption in a bed rest model of weightlessness

    NASA Technical Reports Server (NTRS)

    Lueken, S. A.; Arnaud, S. B.; Taylor, A. K.; Baylink, D. J.

    1993-01-01

    To study the mechanism of bone loss in physical unloading, we examined indices of bone formation and bone resorption in the serum and urine of eight healthy men during a 7 day -6 degrees head-down tilt bed rest. Prompt increases in markers of resorption--pyridinoline (PD), deoxypyridinoline (DPD), and hydroxyproline (Hyp)/g creatinine--during the first few days of inactivity were paralleled by tartrate-resistant acid phosphatase (TRAP) with significant increases in all these markers by day 4 of bed rest. An index of formation, skeletal alkaline phosphatase (SALP), did not change during bed rest and showed a moderate 15% increase 1 week after reambulation. In contrast to SALP, serum osteocalcin (OC) began increasing the day preceding the increase in Hyp, remained elevated for the duration of the bed rest, and returned to pre-bed rest values within 5 days of reambulation. Similarly, DPD increased significantly at the onset of bed rest, remained elevated for the duration of bed rest, and returned to pre-bed rest levels upon reambulation. On the other hand, the other three indices of resorption, Hyp, PD, and TRAP, remained elevated for 2 weeks after reambulation. The most sensitive indices of the levels of physical activity proved to be the noncollagenous protein, OC, and the collagen crosslinker, DPD. The bed rest values of both these markers were significantly elevated compared to both the pre-bed rest values and the post-bed rest values. The sequence of changes in the circulating markers of bone metabolism indicated that increases in serum OC are the earliest responses of bone to head-down tilt bed rest.

  6. Macrophage physiology in the eye.

    PubMed

    Chinnery, Holly R; McMenamin, Paul G; Dando, Samantha J

    2017-04-01

    The eye is a complex sensory organ composed of a range of tissue types including epithelia, connective tissue, smooth muscle, vascular and neural tissue. While some components of the eye require a high level of transparency to allow light to pass through unobstructed, other tissues are characterized by their dense pigmentation, which functions to absorb light and thus control its passage through the ocular structures. Macrophages are present in all ocular tissues, from the cornea at the anterior surface through to the choroid/sclera at the posterior pole. This review will describe the current understanding of the distribution, phenotype, and physiological role of ocular macrophages, and provide a summary of evidence pertaining to their proposed role during pathological conditions.

  7. Immunosuppressive effects of macrophage antiserum

    PubMed Central

    Panijel, Jacques; Cayeux, Philippe

    1968-01-01

    Heterologous anti-macrophage serum (MAS) specifically destroys or damages macrophages in vitro. The treatment of mice by MAS results in various immunosuppressive effects: the latter are studied using phage ΦX174 and two pathogenic viruses (EMC virus and Yellow fever virus). It is shown that these effects depend both on the infectious capacity and on the dose of the particulate antigens injected. In the case of phage, MAS greatly inhibits the secondary response obtained by performing the antigenic challenge after a primary stimulation which is itself too weak for producing antibodies. In the case of the pathogenic viruses, the effects of MAS depend on whether the treatment was carried out before or after the intraperitoneal injection of virus. The implications of these results for studying the primary and the secondary responses are discussed. ImagesFIG. 1 PMID:4298549

  8. Macrophages: Their Emerging Roles in Bone

    PubMed Central

    Sinder, Benjamin P; Pettit, Allison R; McCauley, Laurie K

    2016-01-01

    Macrophages are present in nearly all tissues and are critical for development, homeostasis, and regeneration. Resident tissue macrophages of bone, termed osteal macrophages, are recently classified myeloid cells that are distinct from osteoclasts. Osteal macrophages are located immediately adjacent to osteoblasts, regulate bone formation, and play diverse roles in skeletal homeostasis. Genetic or pharmacological modulation of macrophages in vivo results in significant bone phenotypes, and these phenotypes depend on which macrophage subsets are altered. Macrophages are also key mediators of osseous wound healing and fracture repair, with distinct roles at various stages of the repair process. A central function of macrophages is their phagocytic ability. Each day, billions of cells die in the body and efferocytosis (phagocytosis of apoptotic cells) is a critical process in both clearing dead cells and recruitment of replacement progenitor cells to maintain homeostasis. Recent data suggest a role for efferocytosis in bone biology and these new mechanisms are outlined. Finally, although macrophages have an established role in primary tumors, emerging evidence suggests that macrophages in bone support cancers which preferentially metastasize to the skeleton. Collectively, this developing area of osteoimmunology raises new questions and promises to provide novel insights into pathophysiologic conditions as well as therapeutic and regenerative approaches vital for skeletal health. PMID:26531055

  9. Dual origin of mouse spleen macrophages

    PubMed Central

    1984-01-01

    The present study concerns the isolation, characterization, origin, and kinetics of spleen macrophages. The spleen was first perfused in situ to remove monocytes from the vascular bed and then dissected and treated with collagenase. The macrophages in the cell suspension thus obtained were characterized morphologically and cytochemically and then quantitated. The spleen cell suspension was incubated for 24 h in Leighton tubes to obtain an enriched glass-adherent population of macrophages for characterization and [3H]thymidine-labeling studies. Almost all of the adhering macrophages were esterase positive, had Fc and C3b receptors, and ingested EIgG and opsonized bacteria. In vitro labeling with [3H]thymidine showed that approximately 5% of the mononuclear phagocytes in the spleen synthesize DNA and must be considered to be dividing cells. The course of the number of labeled monocytes and macrophages after a single injection of [3H]thymidine indicates migration of monocytes into the spleen, where they become macrophages. Calculation of the influx of monocytes into the spleen and of the local production of macrophages by DNA-synthesizing mononuclear phagocytes showed that under steady-state conditions, 55% of the population of spleen macrophages is supplied by monocyte influx and 45% by local production. This means that there is a dual origin of spleen macrophages. The mean turnover time calculated with the value for the efflux of spleen macrophages is 6.0 d. PMID:6491600

  10. Pathophysiological relevance of macrophage subsets in atherogenesis.

    PubMed

    Liberale, Luca; Dallegri, Franco; Montecucco, Fabrizio; Carbone, Federico

    2017-01-05

    Macrophages are highly heterogeneous and plastic cells. They were shown to play a critical role in all stages of atherogenesis, from the initiation to the necrotic core formation and plaque rupture. Lesional macrophages primarily derive from blood monocyte, but local macrophage proliferation as well as differentiation from smooth muscle cells have also been described. Within atherosclerotic plaques, macrophages rapidly respond to changes in the microenvironment, shifting between pro- (M1) or anti-inflammatory (M2) functional phenotypes. Furthermore, different stimuli have been associated with differentiation of newly discovered M2 subtypes: IL-4/IL-13 (M2a), immune-complex (M2b), IL-10/glucocorticoids (M2c), and adenosine receptor agonist (M2d). More recently, additional intraplaque macrophage phenotypes were also recognized in response to CXCL4 (M4), oxidized phospholipids (Mox), haemoglobin/haptoglobin complexes (HA-mac/M(Hb)), and heme (Mhem). Such macrophage polarization was described as a progression among multiple phenotypes, which reflect the activity of different transcriptional factors and the cross-talk between intracellular signalling. Finally, the distribution of macrophage subsets within different plaque areas was markedly associated with cardiovascular (CV) vulnerability. The aim of this review is to update the current knowledge on the role of macrophage subsets in atherogenesis. In addition, the molecular mechanisms underlying macrophage phenotypic shift will be summarised and discussed. Finally, the role of intraplaque macrophages as predictors of CV events and the therapeutic potential of these cells will be discussed.

  11. Macrophages: Their Emerging Roles in Bone.

    PubMed

    Sinder, Benjamin P; Pettit, Allison R; McCauley, Laurie K

    2015-12-01

    Macrophages are present in nearly all tissues and are critical for development, homeostasis, and regeneration. Resident tissue macrophages of bone, termed osteal macrophages, are recently classified myeloid cells that are distinct from osteoclasts. Osteal macrophages are located immediately adjacent to osteoblasts, regulate bone formation, and play diverse roles in skeletal homeostasis. Genetic or pharmacological modulation of macrophages in vivo results in significant bone phenotypes, and these phenotypes depend on which macrophage subsets are altered. Macrophages are also key mediators of osseous wound healing and fracture repair, with distinct roles at various stages of the repair process. A central function of macrophages is their phagocytic ability. Each day, billions of cells die in the body and efferocytosis (phagocytosis of apoptotic cells) is a critical process in both clearing dead cells and recruitment of replacement progenitor cells to maintain homeostasis. Recent data suggest a role for efferocytosis in bone biology and these new mechanisms are outlined. Finally, although macrophages have an established role in primary tumors, emerging evidence suggests that macrophages in bone support cancers which preferentially metastasize to the skeleton. Collectively, this developing area of osteoimmunology raises new questions and promises to provide novel insights into pathophysiologic conditions as well as therapeutic and regenerative approaches vital for skeletal health. © 2015 American Society for Bone and Mineral Research.

  12. Turbo methanol extract inhibits bone resorption through regulation of T cell function.

    PubMed

    Balakrishnan, Babita; Indap, Madhavi M; Singh, Surya P; Krishna, C Murali; Chiplunkar, Shubhada V

    2014-01-01

    Marine organisms have bioactive potential which has tremendous pharmaceutical promise. Emerging evidence highlights the importance of the interplay between bone and the immune system of which T lymphocytes and their product act as key regulators of bone resorption. In the present investigation we have analyzed the anti-osteoporotic effect of turbo methanol extract (TME) in the reversal of bone resoprtion. Forty-two female Swiss albino mice were used and randomly assigned into sham-operated group (sham) and six ovariectomized (OVX) subgroups, i.e. OVX with vehicle (OVX) that received daily oral administration of water ad libitum; OVX with estradiol (2mg/kg/day); and OVX with different doses of TME i.e. TME 100mg/kg, TME 50mg/kg, TME 25mg/kg and TME 12.5mg/kg. Oral administration of TME or estradiol started on the second week after ovariectomy for a period of 4weeks. We observed that the administration of TME increased the trabeculation in tibia and reduced the atrophy in the uterus. TME significantly decreased the serum alkaline phosphatase (ALP) and acid phosphatase (ACP) activity in OVX mice. Micro CT analysis revealed that the TME administration preserved the bone volume, connectivity density, trabecular number, trabecular thickness and trabecular separation in OVX mice. Bone mineralization was measured in different groups of mice by Raman spectroscopy. Reversal of bone resorption was observed in TME treated group of mice. To further investigate the mechanism of action of TME, we analyzed the T lymphocyte proliferation and profiles of cytokine TNFα and sRANKL in TME treated ovariectomized mice. Decrease in the elevation of T cell subsets was observed after the supplementation with TME. The extract significantly lowered the T cell proliferation responses to mitogens, phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io) and phytohemagglutinin (PHA). A marked reduction in TNFα and sRANKL secretion in serum and TNFα in cell free supernatants of activated T

  13. Mineral metabolism in isolated mouse long bones: Opposite effects of microgravity on mineralization and resorption

    NASA Technical Reports Server (NTRS)

    Veldhuijzen, Jean Paul; Vanloon, Jack J. W. A.

    1994-01-01

    An experiment using isolated skeletal tissues under microgravity, is reported. Fetal mouse long bones (metatarsals) were cultured for 4 days in the Biorack facility of Spacelab during the IML-1 (International Microgravity Laboratory) mission of the Space Shuttle. Overall growth was not affected, however glucose consumption was significantly reduced under microgravity. Mineralization of the diaphysis was also strongly reduced under microgravity as compared to the on-board 1 g group. In contrast, mineral resorption by osteoclasts was signficantly increased. These results indicate that these fetal mouse long bones are a sensitive and useful model to further study the cellular mechanisms involved in the changed mineral metabolism of skeletal tissues under microgravity.

  14. Distance between implants has a potential impact of crestal bone resorption.

    PubMed

    Danza, Matteo; Zollino, Ilaria; Avantaggiato, Anna; Lucchese, Alessandra; Carinci, Francesco

    2011-07-01

    Around dental implants exists a "biologic width" of few millimeters that have to be preserved in order to not have adverse effect on soft and hard tissues around implant. Because the minimum distance between adjacent implants has not been determined yet, we therefore, decided to perform a retrospective study on a series of spiral family implants (SFIs) to verify the minimum inter-implants' distance that has an impact on crestal bone resorption. Fifty-nine implants were investigated with a mean follow-up of 14 months. Implant diameter was 3.75, 4.2, 5 and 6 mm in 11 (18.6%), 29 (49.2%), 17 (28.8%) and 2 (3.4%) SFIs. Implant length was shorter than 13 mm, equal to 13 mm and 16 mm in 23 (39%), 23 (39%) and 13 (22%) SFIs. Implants were inserted to replace 13 incisors (22%), 7 cuspids (11.9%), 30 premolars (50.8%) and 9 molars (15.3%). Twenty-seven fixtures were inserted in post-extractive sockets and the remaining 32 in healed bone; 36 (61%) were immediately loaded. In addition to the above mentioned implant-related factors, several host- and surgery-factors were investigated. Independent samples T-test, univariate and multivariate analysis were used to detect those variables associated with the clinical outcome. Data were evaluated with a two steps statistical analysis (i.e. univariate and multivariate) after having grouped implants in two series: those with an implant-implant distance less of 1.8 mm and those with an implant-implants distance greater than 1.8 mm. In univariate analysis, post-extractive implants and number of prosthetic units were statistically significant. In multivariate analysis, only post-extractive implants have a significant adverse effect on crestal bone resorption. Adjacent implants inserted with a distance lower and higher than 1.8 mm have difference in crestal bone resorption but this difference is not statistically significant in a short period follow up. This could due to the specific implant used that has a reverse conical neck

  15. Distance between implants has a potential impact of crestal bone resorption

    PubMed Central

    Danza, Matteo; Zollino, Ilaria; Avantaggiato, Anna; Lucchese, Alessandra; Carinci, Francesco

    2011-01-01

    Objectives Around dental implants exists a “biologic width” of few millimeters that have to be preserved in order to not have adverse effect on soft and hard tissues around implant. Because the minimum distance between adjacent implants has not been determined yet, we therefore, decided to perform a retrospective study on a series of spiral family implants (SFIs) to verify the minimum inter-implants’ distance that has an impact on crestal bone resorption. Materials and Methods Fifty-nine implants were investigated with a mean follow-up of 14 months. Implant diameter was 3.75, 4.2, 5 and 6 mm in 11 (18.6%), 29 (49.2%), 17 (28.8%) and 2 (3.4%) SFIs. Implant length was shorter than 13 mm, equal to 13 mm and 16 mm in 23 (39%), 23 (39%) and 13 (22%) SFIs. Implants were inserted to replace 13 incisors (22%), 7 cuspids (11.9%), 30 premolars (50.8%) and 9 molars (15.3%). Twenty-seven fixtures were inserted in post-extractive sockets and the remaining 32 in healed bone; 36 (61%) were immediately loaded. In addition to the above mentioned implant-related factors, several host- and surgery-factors were investigated. Independent samples T-test, univariate and multivariate analysis were used to detect those variables associated with the clinical outcome. Results Data were evaluated with a two steps statistical analysis (i.e. univariate and multivariate) after having grouped implants in two series: those with an implant-implant distance less of 1.8 mm and those with an implant-implants distance greater than 1.8 mm. In univariate analysis, post-extractive implants and number of prosthetic units were statistically significant. In multivariate analysis, only post-extractive implants have a significant adverse effect on crestal bone resorption. Conclusions Adjacent implants inserted with a distance lower and higher than 1.8 mm have difference in crestal bone resorption but this difference is not statistically significant in a short period follow up. This could due to

  16. Effects of Nitrogen Addition on Nitrogen Resorption in Temperate Shrublands in Northern China

    PubMed Central

    Zhang, Jianhua; Li, He; Shen, Haihua; Chen, Yahan; Fang, Jingyun; Tang, Zhiyao

    2015-01-01

    Nutrient resorption from senescing leaves is a key mechanism of nutrient conservation for plants. The nutrient resorption efficiency is highly dependent on leaf nutrient status, species identity and soil nutrient availability. Nitrogen is a limiting nutrient in most ecosystems, it is widely reported that nitrogen resorption efficiency (NRE) was highly dependent on the soil nitrogen availability and vary with N deposition. The effects of nitrogen deposition on NRE and nitrogen concentration in green and senescing leaves have been well established for forests and grasslands; in contrast, little is known on how plants in shrublands respond to nitrogen deposition across the world. In this study, we conducted a two-year nitrogen addition manipulation experiment to explore the responses of nitrogen concentration in green and senescing leaves, and NRE of seven dominant species, namely, Vitex negundo, Wikstroemia chamaedaphne, Carex rigescens and Cleistogenes chinensis from the Vitex negundo community, and Spirea trilobata, Armeniaca sibirica, V. negundo, C. rigescens and Spodiopogon sibiricus from the Spirea trilobata community, to nitrogen deposition in two typical shrub communities of Mt. Dongling in northern China. Results showed that NRE varied remarkably among different life forms, which was lowest in shrubs, highest in grasses, and intermediate in forbs, implying that shrubs may be most capable of obtaining nitrogen from soil, grasses may conserve more nitrogen by absorption from senescing leaves, whereas forbs may adopt both mechanisms to compete for limited nitrogen supply from the habitats. As the N addition rate increases, N concentration in senescing leaves ([N]s) increased consistent from all species from both communities, that in green leaves ([N]g) increased for all species from the Vitex negundo community, while no significant responses were found for all species from the Spirea trilobata community; NRE decreased for all species except A. sibirica from the

  17. Effects of Nitrogen Addition on Nitrogen Resorption in Temperate Shrublands in Northern China.

    PubMed

    Zhang, Jianhua; Li, He; Shen, Haihua; Chen, Yahan; Fang, Jingyun; Tang, Zhiyao

    2015-01-01

    Nutrient resorption from senescing leaves is a key mechanism of nutrient conservation for plants. The nutrient resorption efficiency is highly dependent on leaf nutrient status, species identity and soil nutrient availability. Nitrogen is a limiting nutrient in most ecosystems, it is widely reported that nitrogen resorption efficiency (NRE) was highly dependent on the soil nitrogen availability and vary with N deposition. The effects of nitrogen deposition on NRE and nitrogen concentration in green and senescing leaves have been well established for forests and grasslands; in contrast, little is known on how plants in shrublands respond to nitrogen deposition across the world. In this study, we conducted a two-year nitrogen addition manipulation experiment to explore the responses of nitrogen concentration in green and senescing leaves, and NRE of seven dominant species, namely, Vitex negundo, Wikstroemia chamaedaphne, Carex rigescens and Cleistogenes chinensis from the Vitex negundo community, and Spirea trilobata, Armeniaca sibirica, V. negundo, C. rigescens and Spodiopogon sibiricus from the Spirea trilobata community, to nitrogen deposition in two typical shrub communities of Mt. Dongling in northern China. Results showed that NRE varied remarkably among different life forms, which was lowest in shrubs, highest in grasses, and intermediate in forbs, implying that shrubs may be most capable of obtaining nitrogen from soil, grasses may conserve more nitrogen by absorption from senescing leaves, whereas forbs may adopt both mechanisms to compete for limited nitrogen supply from the habitats. As the N addition rate increases, N concentration in senescing leaves ([N]s) increased consistent from all species from both communities, that in green leaves ([N]g) increased for all species from the Vitex negundo community, while no significant responses were found for all species from the Spirea trilobata community; NRE decreased for all species except A. sibirica from the

  18. Spontaneous resorption of calcification at the long head of the biceps tendon

    PubMed Central

    Amri, Adriansyah; Nakai, Sho; Hara, Michiharu; Yamanaka, Issei; Hamawaki, Jun-ichi

    2015-01-01

    Calcific tendinitis of the long head of the biceps tendon is a rare cause of shoulder pain. Calcium deposits are often spontaneously resorbed or reduced in size in the rotator cuff tendons, which represent the most common sites of calcific tendinitis around the shoulder. To our knowledge, no case of spontaneous resorption of calcification in the long head of the biceps tendon has been reported in the literature. Here, we report one such case and describe its successful treatment using a conservative approach. PMID:27582978

  19. Extreme root resorption associated with induced tooth movement: A protocol for clinical management

    PubMed Central

    Consolaro, Alberto; Furquim, Laurindo Zanco

    2014-01-01

    Cases in which teeth have only the cervical third remaining from orthodontically induced external root resorption, cast the following doubts: 1) What care should be taken to keep these teeth in mouth with the least risk possible? 2) What care should be taken with regards to reading of imaging exams, particularly in terms of accurately determining cervical root and bone loss? 3) Why is not endodontic treatment recommended in these cases? The present study aims at shedding light on the aforementioned topics so as to induce new insights into the theme. PMID:25715713

  20. Odontoclastic resorptive lesion of a mandibular right first molar in a cougar.

    PubMed

    Mendoza, K A; Marretta, S M; Klippert, L S

    2000-12-01

    A two-year old neuteral/male cougar (Felis concolor) was presented because of abnormal eating habits and an irregularity of the mandibular right first molar that was noted by the caretaker. Oral examination and dental radiographs showed a lesion consistent with odontoclastic resorption of the mandibular right first molar, and a crown fracture and dilacerated root of the maxillary right first incisor. Exodontic therapy was performed on both teeth. The caretaker reported no problems associated with the patient's oral cavity 10-months following treatment.

  1. Root resorption associated with an impacted mesiodens: a surgical and endodontic approach to treatment.

    PubMed

    Zmener, Osvaldo

    2006-10-01

    This article describes a case of root resorption of a maxillary non-vital immature incisor associated with an impacted and angulated mesiodens. The impacted tooth was surgically removed and the compromised incisor was subsequently endodontically treated. Over a period of 27 months the tooth was medicated with repeated applications of calcium hydroxide. Radiographically after 18 months, an incomplete hard tissue barrier was observed with full apical closure at the conclusion of 27 months of treatment. Once the patient was comfortable after surgical removal of the mesiodens, the tooth was asymptomatic and remained so for the duration of the treatment and after definitive restorative work had been completed.

  2. Extreme root resorption associated with induced tooth movement: a protocol for clinical management.

    PubMed

    Consolaro, Alberto; Furquim, Laurindo Zanco

    2014-01-01

    Cases in which teeth have only the cervical third remaining from orthodontically induced external root resorption, cast the following doubts: 1) What care should be taken to keep these teeth in mouth with the least risk possible? 2) What care should be taken with regards to reading of imaging exams, particularly in terms of accurately determining cervical root and bone loss? 3) Why is not endodontic treatment recommended in these cases? The present study aims at shedding light on the aforementioned topics so as to induce new insights into the theme.

  3. Increased bone resorption in moderate smokers with low body weight: the Minos study.

    PubMed

    Szulc, P; Garnero, P; Claustrat, B; Marchand, F; Duboeuf, F; Delmas, P D

    2002-02-01

    Tobacco was found to be a risk factor for osteoporosis, mainly in postmenopausal women. We studied the effect of smoking on bone mineral density (BMD) and bone turnover in a cohort of 719 men, aged 51-85 yr, composed of 83 current smokers, 405 former smokers, and 231 men who never smoked. Most current and former smokers were moderate smokers (median, 10 cigarettes/d). Current smokers were younger, thinner, and drank more coffee and more alcoholic beverages. After adjustment for age, body weight, alcohol intake, and caffeine intake, current and former smokers had similar BMD, except at the forearm. Former smokers had lower BMD compared with never-smokers at most skeletal sites. Men who had smoked more than 7120 packs (third quartile) had lower BMD of total hip (P < 0.01) and distal forearm (P = 0.03) compared with men in the 2 lower tertiles. In the 3 groups, levels of bone formation markers did not differ. After adjustment for confounding variables, levels of urinary markers of bone resorption (beta-isomerized C-terminal telopeptide, free and total deoxypyridinoline) were higher in the current smokers than in former smokers and never-smokers. Concentrations of T, total 17beta-E2, and androstenedione were higher, whereas that of 25-hydroxyvitamin D was lower, in current smokers. When men were divided accordin