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OBJECTIVES: Botulinum toxin is used in human in repeatedly masticatory muscles injections. A single BTX injection in animal induces mandibular bone loss with a muscle enthesis hypertrophic metaplasia. Our aim was to evaluate mandibular bone changes after unilateral repeated injections of BTX in adult rats. STUDY DESIGN: Mature male rats were randomized into 3 groups: one, two or three injections. Each rat received injections in right masseter and temporalis muscles. The left side was the control side. Microcomputed tomography was used to perform 2D and 3D analyses. RESULTS: Bone loss was evidenced on the right sides of alveolar and condylar bone. Alveolar bone volume increased in both control left side and injected right side whereas condylar bone volume remained constant in all groups, for both sides. Enthesis bone hypertrophic metaplasias were evidenced on the BTX injected sides without any modification with the number of injections. CONCLUSION: BTX repeated injections in masticatory muscles lead to major mandibular condylar and alveolar bone loss that does not worsen. They lead to the occurrence of an enthesis bone proliferation that is not dependent on the number of injections. These results are an argument for the safety of BTX injections in masticatory muscles in human.
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McDonald and colleagues reported osteoclast-related dynamic mechanisms that lead, by fission, to osteomorphs; motile, fusion-competent cells capable of forming bone-resorbing osteoclasts. scRNA-seq analyses revealed that osteomorphs are transcriptionally distinct from osteoclasts and macrophages and might be implicated in rare and common bone diseases in humans.
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Resorción Ósea , Huesos , Animales , Huesos/citología , Humanos , Macrófagos/citología , Ratones , Osteoclastos/citología , Medicina de PrecisiónRESUMEN
The use of resorbable devices for osteosynthesis has become a subject of interest. Nacre has been proposed as a resorbable and osteoconductive material favoring bone apposition without triggering an inflammatory reaction. We compared the in vivo osseointegration and erosion of nacre screws in an animal model with titanium screws. Implantation of similar nacre and titanium screws was performed in the femoral condyles of adult rats. Animals (n = 41) were randomized in four groups sacrificed at day one, 1, 6, and 12 months. Microcomputed tomography (microCT) allowed 3D morphometry of erosion of nacre. Osseointegration was measured as the volume of trabecular bone bone volume/tissue volume (BV/TV) in a standardized volume of interest around each screw. Undecalcified bone histology was also done. Gross examination revealed a similar clinical osseointegration for titanium and nacre screws. A progressive erosion of nacre screws, but no erosion of titanium screws, was observed in microCT. The volume of nacre screws progressively decreased over time whereas no modification occurred for titanium. For titanium screws, BV/TV remained stable throughout the study. For nacre screws, the BV/TV decrease was not statistically different. A significant difference was found between nacre and titanium screws at 6 months but not at 12 months. The screw heads, outside the bone shaft, were not eroded even after 12 months. Erosion of nacre occurred during the entire study period, only within the bone shaft in direct contact with bone marrow. Bone apposition was observed on nacre surfaces without signs of erosion. Nacre is a promising biomaterial in maxillofacial surgery.
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Tornillos Óseos , Fémur , Fijación Interna de Fracturas , Nácar/química , Oseointegración , Ostreidae/química , Animales , Modelos Animales de Enfermedad , Fémur/lesiones , Fémur/cirugía , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
ß-TCP is a resorbable bony biomaterial but its biodegradation mechanisms in vivo remains unclear. Osteoclast can resorb ß-TCP but a role for macrophages has also been suggested by in vivo studies. However no in vitro study has clearly evidenced the action of macrophages in the resorption process. We prepared flat ß-TCP tablets with a smooth surface to investigate the in vitro capability of murine (RAW 264.7) and human macrophage cells (PBMCs) to resorb the biomaterial. In parallel, these cells were differentiated into multinucleated osteoclasts with M-CSF and RANK-L. The action of these cells was evaluated by scanning electron microscopy and Raman microspectroscopy after a 21 day culture on the tablets. Human macrophages and osteoclasts derived from PBMCs appeared able to resorb ß-TCP by forming resorption pits at the surface of the flat tablets. RAW macrophages were unable to resorb ß-TCP but they exhibited this possibility when they have been differentiated into osteoclasts. These cells can engulf ß-TCP grains in their cytoplasm as evidenced by light and TEM microscopy with production of carbonic anhydrase (revealed by the immunogold technique in TEM). The resorbed areas were characterized by severe degradation of the grains showing speckled and stick-like aspects indicating a chemical corrosion. The effect was maximal at the grain boundaries which have a slightly different chemical composition. Changes in the Raman spectrum were observed between the resorbed and un-resorbed ß-TCP suggesting crystal modifications. In contrast, un-differentiated murine macrophages were not able to chemically attack ß-TCP and no resorption pit was observed. RAW cell is not a representative model of the macrophage-biomaterial interactions that occur in human. This in vitro study evidences that both human osteoclasts and macrophages represent active cell populations capable to resorb ß-TCP.
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Fosfatos de Calcio/metabolismo , Macrófagos/metabolismo , Osteoclastos/metabolismo , Animales , Materiales Biocompatibles/metabolismo , Transporte Biológico , Células Cultivadas , Humanos , Macrófagos/química , Macrófagos/citología , Ratones , Microscopía Electrónica de Rastreo , Osteoclastos/química , Osteoclastos/citología , Espectrometría RamanRESUMEN
Sinus elevation is a common procedure to increase bone volume in the atrophic maxilla to allow placement of dental implants. Autogenous bone is the gold standard but is limited in quantity and causes morbidity at the donor site. ß-TCP is a synthetic biomaterial commonly used in that purpose. It appears to induce a poor inflammatory response. This study aimed to evaluate the degree of edema of the sinus mucosa after sinus lift surgery according to the type of biomaterial. Forty sinuses (20 patients) were included retrospectively and divided into 2 groups according to the biomaterial that was used: synthetic biomaterial (BTCP group), natural bone (BONE group). A control group (CTRL group) was constituted by the non-grafted maxillary sinuses. Twelve measurements per sinus were realized on pre- and post-operative computed tomography and averaged to provide the sinus membrane thickness value (SM.Th). SM.Th was thicker post-operatively in the BTCP and BONE groups in comparison with the CTRL group and in comparison with pre-operative measurements. No difference was found post operatively between the BTCP and BONE groups. We found that a synthetic biomaterial (ß-TCP) induced the same degree of edema, and thus of inflammation, as natural bone. It constitutes therefore an interesting alternative to autogenous bone for maxillary sinus lifts.
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Sustitutos de Huesos/efectos adversos , Trasplante Óseo/efectos adversos , Fosfatos de Calcio/efectos adversos , Fosfatos de Calcio/química , Sinusitis Maxilar/etiología , Elevación del Piso del Seno Maxilar/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Materiales Biocompatibles/efectos adversos , Sustitutos de Huesos/química , Trasplante Óseo/métodos , Implantación Dental Endoósea/efectos adversos , Implantación Dental Endoósea/métodos , Implantes Dentales/efectos adversos , Femenino , Humanos , Inflamación/etiología , Inflamación/patología , Masculino , Seno Maxilar/efectos de los fármacos , Seno Maxilar/patología , Sinusitis Maxilar/patología , Persona de Mediana Edad , Estudios Retrospectivos , Elevación del Piso del Seno Maxilar/métodosRESUMEN
Noninvasive diagnostic by imaging combined with a contrast agent (CA) is by now the most used technique to get insight into human bodies. X-ray and magnetic resonance imaging (MRI) are widely used technologies providing complementary results. Nowadays, it seems clear that bimodal CAs could be an emerging approach to increase the patient compliance, accessing different imaging modalities with a single CA injection. Owing to versatile designs, targeting properties, and high payload capacity, nanocarriers are considered as a viable solution to reach this goal. In this study, we investigated efficient superparamagnetic iron oxide nanoparticle (SPION)-loaded iodinated nano-emulsions (NEs) as dual modal injectable CAs for X-ray imaging and MRI. The strength of this new CA lies not only in its dual modal contrasting properties and biocompatibility, but also in the simplicity of the nanoparticulate assembling: iodinated oily core was synthesized by the triiodo-benzene group grafting on vitamin E (41.7% of iodine) via esterification, and SPIONs were produced by thermal decomposition during 2, 4, and 6 h to generate SPIONs with different morphologies and magnetic properties. SPIONs with most anisotropic shape and characterized by the highest r2/ r1 ratio once encapsulated into iodinated NE were used for animal experimentation. The in vivo investigation showed an excellent contrast modification because of the presence of the selected NEs, for both imaging techniques explored, that is, MRI and X-ray imaging. This work provides the description and in vivo application of a simple and efficient nanoparticulate system capable of enhancing contrast for both preclinical imaging modalities, MRI, and computed tomography.
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Medios de Contraste , Yodo , Imagen por Resonancia Magnética/métodos , Nanopartículas de Magnetita , Tomografía Computarizada por Rayos X/métodos , Animales , Medios de Contraste/química , Medios de Contraste/farmacocinética , Medios de Contraste/farmacología , Emulsiones , Células HeLa , Humanos , Yodo/química , Yodo/farmacocinética , Yodo/farmacología , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapéutico , RatonesRESUMEN
OBJECTIVES: Pathogenesis of bisphosphonate-related osteonecrosis of the jaws (BRONJ) is not fully explained. An antiangiogenic effect of bisphosphonates (BPs) or an altered bone quality have been advocated. The aims of the present study were to analyze alveolar mandibular vascularization and bone quality in rats with BRONJ. MATERIALS AND METHODS: Thirty-eight Sprague-Dawley rats were randomized into two groups: zoledronic acid (ZA), n = 27, and control (CTRL) n = 11. The ZA group received a weekly IV injection of ZA (100 µg/kg) during 10 weeks. The CTRL group received saline. After 6 weeks, extraction of the right mandibular molars was performed. Rats were sacrificed after 14 weeks. Microtomography characterized bone lesions and vascularization after injection of a radio-opaque material. Raman microspectroscopy evaluated bone mineralization. RESULTS: Fifty-five percent of ZA rats presented bone exposure and signs of BRONJ. None sign was found at the left hemimandible in the ZA group and in the CTRL group. Vascular density appeared significantly increased in the right hemimandibles of the CTRL group compared to the left hemimandibles. Vascularization was reduced in the ZA group. A significantly increased of the mineral-to-amide ratio was found in the alveolar bone of ZA rats by Raman microspectroscopy. CONCLUSIONS: In a rat model of BRONJ, microtomography evidenced osteonecrosis in BRONJ. Raman spectroscopy showed an increased mineralization. Vascularization after tooth extraction was impaired by ZA. CLINICAL RELEVANCE: Prolonged BP administration caused an increase in the mineralization and a quantitative reduction of the vascularization in the alveolar bone; both factors might be involved concomitantly in the BRONJ pathophysiology.
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Osteonecrosis de los Maxilares Asociada a Difosfonatos , Conservadores de la Densidad Ósea , Difosfonatos , Mandíbula , Ácido Zoledrónico , Animales , Ratas , Osteonecrosis de los Maxilares Asociada a Difosfonatos/patología , Conservadores de la Densidad Ósea/toxicidad , Calcificación Fisiológica , Difosfonatos/toxicidad , Mandíbula/irrigación sanguínea , Distribución Aleatoria , Ratas Sprague-Dawley , Espectrometría Raman , Ácido Zoledrónico/toxicidadRESUMEN
Muscle and bone masses are highly correlated and muscles impose large loads on bone. Muscle wasting that accompanies bone loss has been poorly investigated. 21 female mice were spread into seven groups. At day 0, 18 mice received Botulinum toxin (BTX) injection in the quadriceps muscle to induce paralysis of the right hind limb; the left contralateral side was used as control. Mice were sacrificed at 7, 14, 21, 28, 56 and 90 days post-injection. A remaining group was sacrificed at day 0. Trabecular bone volume was determined by microcomputed tomography (microCT) at the distal femur and tibia proximal metaphyses on both sides. Limbs were immersed in an HgCl2 solution allowing muscle visualization by microCT. On 2D sections, the cross-sectional areas and form-factors were measured for the quadriceps at mid-thigh and gastrocnemius at mid-leg and these muscles were dissected and weighed. Bone volume decreased in the paralysed side. Bone loss was maximal at 56 days followed by recuperation at 90 days. The cross-sectional areas of gastrocnemius and quadriceps were significantly lower in the paralysed limb from 7 days; the decrease was maximum at 21 days for the gastrocnemius and 28 days for the quadriceps. No difference in form-factors was found between the two limbs. Similar results were obtained with the anatomical method and significant correlations were obtained between the two methods. Quantitative analysis of muscle loss and recovery was possible by microCT after using a metallic contrast agent. Loss of bone secondary to muscle wastage induced by BTX and recovery showed a parallel evolution for bone and muscles.
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Densidad Ósea/efectos de los fármacos , Huesos/efectos de los fármacos , Toxinas Botulínicas/toxicidad , Músculo Esquelético/efectos de los fármacos , Tiempo , Animales , Enfermedades Óseas Metabólicas , Hueso Esponjoso/efectos de los fármacos , Femenino , Fémur/efectos de los fármacos , Ratones , Atrofia Muscular/tratamiento farmacológico , Microtomografía por Rayos X/métodosRESUMEN
AIM: Using multi-slice computed tomography (MSCT), Barrier et al. described the disappearance at the posterior auricular surface of a "central line" (CL) and "juxtalinear cells" (JLCs) belonging to a trabecular bundle, and a trabecular density gradient around the CL that decreased with age. The aim of our study was to use micro-CT to test these findings, referring to the concept of Ascadi and Nemeskeri. METHODOLOGY: The coxal bones of fifteen males were used; age was known. CLs were identified on MSCT-sections using Barrier's method (64 detectors, 0.6 mm slice thickness, 0.1 mm overlap) with two different software programs (Synapse®, Amira®). Then, CLs were researched on microCT slices (pixel size: 36 µm). Three volumes of interest were defined (around, above, and below CL), and 3D morphometric parameters of the trabecular microarchitecture (particularly BV/TV and DA) were calculated. Two-tailed statistical analyses were performed attempting to correlate these parameters with age at death. RESULTS: CLs and JLCs were observed on micro-CT slices, but with moderate agreement between both imaging techniques. Their presence was not correlated with the age of the subjects. Around the CL, BV/TV decreased significantly with age; DA was negatively correlated with BV/TV and had a tendency to increase with age. Between areas above and below the CL, there was a BV/TV gradient and both BV/TVs decreased in parallel with age. CONCLUSION: Our findings regarding the contribution of micro-CT to the evaluation of trabecular bone could be a promising research approach for application in a larger study population.
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Determinación de la Edad por el Esqueleto/métodos , Hueso Esponjoso/diagnóstico por imagen , Huesos Pélvicos/diagnóstico por imagen , Microtomografía por Rayos X , Adulto , Antropología Forense , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Tomografía Computarizada MultidetectorRESUMEN
Sinus lift elevation restores bone mass at the maxilla in edentulate patients before the placement of dental implants. It consists of opening the lateral side of the sinus and grafting beta-tricalcium phosphate granules (ß-TCP) under the olfactory membrane. Bone biopsies were obtained in five patients after 60 weeks. They were embedded undecalcified in poly(methyl methacrylate) (pMMA); blocks were analyzed by nanocomputed tomography (nanoCT); specific areas were studied by Raman microspectroscopy. Remnants of ß-TCP were osseointegrated and covered with mineralized bone; osteoid tissue was also filling the inner porosity. Macrophages having engulfed numerous ß-TCP grains were observed in marrow spaces. ß-TCP was identified by nanoCT as osseointegrated particles and as granules in the cytoplasm of macrophages. Raman microspectroscopy permitted to compare the spectra of ß-TCP and bone in different areas. The ratio of the ~820 cm-1 band of pMMA (-CH2 groups) on the ν1 phosphate band at 960 cm-1 reflected tissue hydration because water was substituted by MMA during histological processing. In bone, the ratio of the ~960 cm-1 phosphate to the amide 1 band and the ratio ν2 phosphate band by the 1240-1250 amide III band reflect the mineralization degree. Specific bands of ß-TCP were found in osseointegrated ß-TCP granules and in the grains phagocytized by the macrophages. The hydration degree was maximal for ß-TCP phagocytized by macrophages. Raman microspectroscopy associated with nanoCT is a powerful tool in the analysis of the biomaterial degradation and osseointegration.
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Materiales Biocompatibles/uso terapéutico , Trasplante Óseo/métodos , Fosfatos de Calcio/uso terapéutico , Implantación Dental Endoósea/métodos , Seno Maxilar/cirugía , Implantes Dentales , Humanos , Arcada Parcialmente Edéntula , Seno Maxilar/diagnóstico por imagen , Nanotecnología , Oseointegración/efectos de los fármacos , Espectrometría Raman , Tomografía Computarizada por Rayos XRESUMEN
It is not clear why patients with an indolent form of multiple myeloma (MM) develop into an aggressive form with poor prognostic. We investigated the effect of a dietary calcium deficiency on tumor growth, osteolysis and gene expression in the 5T2MM murine model. Two groups of C57BL/KaLwRij mice received 5T2MM cells and started a diet with normal (0.8%; "normal-Ca-MM") or low calcium content (0.05%; "low-Ca-MM"). Two control groups (without 5T2MM cells) received either a normal or low calcium diet (normal-Ca and low-Ca groups). Tumor growth, osteolysis and marrow gene expression of the Wnt pathway, RANKL and MIP-1α were monitored at 6, 8 and 10 weeks (w) after cell injection. In low-Ca mice, serum level of PTH was higher after 10w; microCT showed trabecular bone loss and decrease of cortical thickness at the tibia. A higher M-protein level was evidenced at 10w and 4 mice developed paraplegia at 8/9w in low-Ca-MM group only. Numerous cortical perforations of the tibia were observed in MM groups with a marked decrease in cortical thickness in low-Ca-MM. At 6w, osteoclast number from the endosteum was significantly higher in low-Ca-MM compared to normal-Ca MM. This observation was not found at 8 and 10w. MicroCT of the lumbar vertebrae showed dramatic bone destruction in the low-Ca-MM group. qPCR revealed no difference in RANKL expression whereas differences were obtained in the expression of Lrp5/Lrp6 and MIP-1α from 6w. A low calcium diet induced higher bone destruction in the tibia and vertebra associated with an earlier decrease in bone formation level and a higher increase in bone resorption level at early time in the MM development.
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Calcio/deficiencia , Hueso Esponjoso/patología , Vértebras Lumbares/patología , Mieloma Múltiple/patología , Osteólisis/patología , Tibia/patología , Animales , Remodelación Ósea/fisiología , Calcio de la Dieta , Línea Celular Tumoral , Modelos Animales de Enfermedad , Humanos , Hiperparatiroidismo/patología , Ratones , Ratones Endogámicos C57BL , Microtomografía por Rayos XRESUMEN
In man, botulinum toxin type A (BTX) is injected in masticatory muscles for several indications such as trismus, bruxism, or masseter hypertrophy. Bone changes in the mandible following BTX injections in adult animal have therefore became a subject of interest. The aim of this study was to analyze condylar and alveolar bone changes following BTX unilateral injections in masseter and temporal muscles in adult rats. Mature male rats (n = 15) were randomized into 2 groups: control (CTRL; n = 6) and BTX group (n= 9). Rats of the BTX group received a single injection of BTX into right masseter and temporal muscles. Rats of the CTRL group were similarly injected with saline solution. Rats were sacrificed 4 weeks after injections. Masticatory muscles examination and microcomputed tomography (microCT) were performed. A significant difference of weight was found between the 2 groups at weeks 2, 3 and 4 (p < 0.05). Atrophy of the right masseter and temporal muscles was observed in all BTX rats. MicroCT analysis showed significant bone loss in the right alveolar and condylar areas in BTX rats. Decrease in bone volume reached -20% for right alveolar bone and -35% for right condylar bone. A hypertrophic bone metaplasia at the digastric muscle enthesis was found on every right hemimandible in the BTX group and none in the CTRL group. BTX injection in masticatory muscles leads to a significant and major mandible bone loss. These alterations can represent a risk factor for fractures in human. The occurrence of a hypertrophic bone metaplasia at the Mus Digastricus enthesis may constitute an etiological factor for tori.
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Toxinas Botulínicas/farmacología , Cóndilo Mandibular/patología , Músculos Masticadores/efectos de los fármacos , Osteoporosis/patología , Animales , Masculino , Ratas , Ratas Sprague-Dawley , Microtomografía por Rayos XRESUMEN
Among biomaterials used for filling bone defects, beta-tricalcium phosphate (ß-TCP) is suitable in non-bearing bones, particularly in dental implantology, oral and maxillofacial surgery. When ß-TCP granules are placed in a bone defect, they occupy the void 3D volume. Little is known about the 3D arrangement of the granules, which depends on the nature and size of the granules. The aim of this study was to examine the 3D architecture of porous ß-TCP granules. Granules were prepared with different concentrations of ß-TCP powder in slurry (10, 11, 15, 18, 21, and 25 g of ß-TCP powder in distilled water). Granules were prepared by the polyurethane foam method. They were analyzed by nano-computed tomography (nanoCT) and compared with scanning electron microscopy (SEM). Commercial granules of hydroxyapatite-ß-TCP prepared by the same methodology were also used. The outer and inner architectures of the granules were shown by nanoCT which evidenced macroporosity, internal porosity and microporosity between the sintered grains. Macroporosity was reduced at high concentration and conversely, numerous concave surfaces were observed. Internal porosity, related to the sublimation of the polyurethane foam, was present in all the granules. Microporosity at the grain joints was evidenced by SEM and on 2D nanoCT sections. Granules presented a heterogeneous aspect due to the different mineralization degree of the sintered powder grains in the ß-TCP granules; the difference between hydroxyapatite and ß-TCP was also evidenced. NanoCT is an interesting method to analyze the fine morphology of biomaterials with a resolution close to synchrotron and better than microcomputed tomography.
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Sustitutos de Huesos , Fosfatos de Calcio , Química Farmacéutica , Durapatita , Imagenología Tridimensional , Microscopía Electrónica de Rastreo , Poliuretanos , Porosidad , Microtomografía por Rayos XRESUMEN
Multiple myeloma is due to the proliferation of malignant plasma cells which increase the number of osteoclasts leading to trabecular and cortical bone osteolysis. The 5T2MM murine model reproduces the human disease and microcomputed tomography is a precise tool to investigate bone loss. Bisphosphonates (zoledronic acid or pamidronate) are used in preventing osteolysis. However, loss of cortical bone in not possible to quantify by histomorphometry on histological sections or microCT images. Osteolysis was studied in mice grafted with the 5THL subline to see if one drug was more active after 10 weeks. Mice were distributed into 4 groups: control, untreated, treated with pamidronate or with zoledronic acid. The left femurs were embedded undecalcified and sectioned at 7 µm. The right tibias and femurs were analyzed by microCT and trabecular morphometric parameters were obtained. Cortical bone osteolysis was analyzed by developing a new algorithm to unwrap microCT sections of the cortices, allowing measurement of the number of perforations, porosity and mean perforation area. The bisphosphonates had no significant effect on the tumor growth as evidence by the absence of effect on the M-protein level. Cortical perforations were evidenced on histological sections and their number seemed to be reduced by both bisphosphonates. MicroCT was used to quantify the trabecular bone: a bone loss was evidenced in the untreated myeloma group and both bisphosphonates appeared equal to preserve trabecular mass. However, the number and size of cortical perforations cannot be determined on 3D models. Unwrapping microCT images provided flat images allowing a precise determination of cortical perforations. Pamidronate did not reduce the number and size of cortical perforations but significantly reduced porosity. Zoledronic acid appeared significantly superior and considerably reduced all parameters. Unwrapping microCT image is a new method allowing the measurement of cortical perforations in bone malignancies, a parameter that cannot be measured correctly on 2D histological sections.
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Conservadores de la Densidad Ósea/administración & dosificación , Difosfonatos/administración & dosificación , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/patología , Osteólisis/patología , Microtomografía por Rayos X/métodos , Animales , Modelos Animales de Enfermedad , Monitoreo de Drogas/métodos , Ratones , Resultado del TratamientoRESUMEN
Microparticles (MPs) released from the plasma membrane play a role in tumor progression. Involvement of MPs in myeloma (MM) has been poorly investigated. Because of the strong interaction of MM cells with bone microenvironment, we hypothesized an implication of MPs in MM using a murine model. Forty-four mice were injected with 5THL-MM cells and compared with 14 non-injected mice. Blood was collected at the early and end stages of MM development (EMM and LMM) to characterize the circulating MPs. At LMM, MPs were isolated from bone marrow (BM) of long bones of 22 mice, after centrifugation. Electron microscopy immunohistochemistry and Western blotting using CD138 were performed on BM-derived MPs. At EMM, MPs circulating level was significantly lower versus controls. In LMM, a significant increase of the total MP number from plasma was observed versus controls. Characterization of circulating MPs showed an increase of leukocyte- and erythrocyte-derived MPs. In LMM, serum M-protein was correlated with circulating MP number. BM-derived MPs increased in LMM and expressed CD138. Anti-CD138 coupled with nanobeads localized at the MP surface. There is evidence of an association between increase of MPs and MM development; the results underscore the participation of plasma cell-derived MPs originating from BM.
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Micropartículas Derivadas de Células/ultraestructura , Mieloma Múltiple/patología , Células Plasmáticas/ultraestructura , Animales , Western Blotting , Células de la Médula Ósea , Modelos Animales de Enfermedad , Inmunohistoquímica , Ratones , Microscopía Electrónica , Plasma/citologíaRESUMEN
OBJECTIVE: To characterize the nuclear changes induced in vitro by thiazolidinediones (TZDs) in a murine pluripotent mesenchymal cell line. STUDY DESIGN: The C3H10T1/2 cell line, which can differentiate either in osteoblast or in adipocyte, was cultured in the presence of pioglitazone (5 microM) or rosiglitazone (0.5 microM) for 6, 8 and 9 days (D). Quantitative real-time polymerase chain reaction analysis evaluated the expression of key genes of the adipocytic or osteoblastic differentiation (PPARgamma[peroxisome proliferatoractivated receptor gamma], Runx2 [runt-related transcription factor 2] and alkaline phosphatase). Cells were stained with Oil Red O for lipids, and chromatin was counter-stained with hematoxylin. Cells were photographed at x 1,000 magnification and analyzed with texture analysis software. Nuclear area, mean gray level and run-length parameters were calculated. RESULTS: PPARgamma was significantly expressed from D6 (normalized ratio > 7) in TZD groups (ratio >27 at D9). No significant differences were found for either Runx2 or alkaline phosphatase expression versus control at D6 or D9. Cells cultured with TZDs began to differentiate into adipocytes with numerous lipid droplets which appeared at D6. Nuclear area decreased suddenly at D6 for both TZDs, and the mean gray level increased. Run-length parameters changed significantly due to chromatin compaction. CONCLUSION: TZDs provoked differentiation of C3H10T1/2 into adipocytes, leading to inactivation of genes that were highly compacted into heterochromatin.
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Adipogénesis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Núcleo Celular/efectos de los fármacos , Heterocromatina/efectos de los fármacos , Células Madre Pluripotentes/efectos de los fármacos , Tiazolidinedionas/farmacología , Adipocitos/citología , Adipocitos/fisiología , Adipogénesis/fisiología , Fosfatasa Alcalina/genética , Animales , Diferenciación Celular/fisiología , Línea Celular , Núcleo Celular/patología , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Expresión Génica/efectos de los fármacos , Expresión Génica/fisiología , Heterocromatina/patología , Hipoglucemiantes/farmacología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/fisiología , Ratones , PPAR gamma/genética , Fenotipo , Pioglitazona , Células Madre Pluripotentes/citología , Células Madre Pluripotentes/fisiología , RosiglitazonaRESUMEN
OBJECTIVE: Bone implants are now widely used to replace missing teeth. Bone grafting (sinus lift) is a very useful way to increase the bone volume of the maxilla in patients with bone atrophy. There is a 6- to 9-month delay for the receiver grafted site to heal before the implants can be placed. Computed tomography is a useful method to measure the amount of remaining bone before implantation and to evaluate the quality of the receiver bone at the end of the healing period. Texture analysis is a non-invasive method useful to characterize bone microarchitecture on X-ray images. PATIENTS AND METHODS: Ten patients in which a sinus lift surgery was necessary before implantation were analyzed in the present study. All had a bone reconstruction with a combination of a biomaterial (beta tricalcium phosphate) and autograft bone harvested at the chin. Computed tomographic images were obtained before grafting (t0), at mid-interval (t1, 4.2 ± 0.7 months) and before implant placement (t2, 9.2 ± 0.6 months). Texture analysis was done with the run-length method. RESULTS: A significant increase of texture parameters at t1 reflected a gain of homogeneity due to the graft and the beginning of bone remodeling. At t2, some parameters remained high and corresponded to the persistence of bone trabeculae while the resorption of biomaterials was identified by other parameters which tended to return to pregraft values. CONCLUSION: Texture analysis identified changes during the healing of the receiver site. CLINICAL RELEVANCE: The method is known to correlate with microarchitectural changes in bone and could be a useful approach to characterized osseointegrated grafts.
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Pérdida de Hueso Alveolar/cirugía , Remodelación Ósea , Atención Dental para Enfermos Crónicos , Seno Maxilar/diagnóstico por imagen , Osteoporosis/patología , Elevación del Piso del Seno Maxilar , Implantes Absorbibles , Adulto , Anciano , Anciano de 80 o más Años , Sustitutos de Huesos , Fosfatos de Calcio , Femenino , Humanos , Masculino , Maxilar/patología , Persona de Mediana Edad , Procedimientos Quirúrgicos Preprotésicos Orales , Oseointegración , Osteoporosis/diagnóstico por imagen , Estadísticas no Paramétricas , Tomografía Computarizada por Rayos XRESUMEN
Pseudoxanthoma elasticum in humans and dystrophic cardiac calcification in mice are heritable disorders characterized by dystrophic calcification of soft connective tissues related to the defective function of the ABCC6 (human)/Abcc6 (mouse) transporter. Of particular interest is the finding of calcified vibrissae in Abcc6(-/-) mice, which facilitates the study of dystrophic calcification by histological techniques. We aimed to determine whether mice prone to dystrophic cardiac calcification (C3H/HeOuJ and DBA/2J strains) presented similar vibrissae changes and to evaluate the value of microcomputed tomography to quantify the extent of mystacial vibrissae calcifications. These calcifications were absent in DBA/2J and C57BL/6J control mice. In both Abcc6(-/-) and C3H/HeOuJ mice, calcifications progressed in a caudal-rostral direction with aging. However, the calcification process was delayed in C3H/HeOuJ mice, indicating an incomplete expression of the calcification phenotype. We also found that the calcification process in the cephalic region was not limited to mystacial vibrissae but was also present in other periorbital sensorial vibrissae. The vibrissae calcification was circular and encompassed the medial region of the vibrissae capsule, adjacent to the ring and cavernous sinuses (the areas adjacent to blood and lymphatic vessels). Collectively, our findings confirm that Abcc6 acts as an inhibitor of spontaneous chronic mineralization and that microcomputed tomography is a valuable noninvasive tool for the assessment of the calcification phenotype in Abcc6-deficient mice.
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Transportadoras de Casetes de Unión a ATP/genética , Calcinosis/diagnóstico por imagen , Transportadoras de Casetes de Unión a ATP/fisiología , Animales , Calcinosis/genética , Calcinosis/patología , Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/metabolismo , Colorimetría/métodos , Progresión de la Enfermedad , Femenino , Humanos , Ratones , Ratones Endogámicos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos , Fenotipo , Seudoxantoma Elástico/diagnóstico por imagen , Seudoxantoma Elástico/metabolismo , Cráneo/diagnóstico por imagen , Vibrisas/metabolismo , Vibrisas/patología , Microtomografía por Rayos X/métodosRESUMEN
BACKGROUND: Angiogenesis contributes to proliferation and metastatic dissemination of cancer cells. Anatomy of blood vessels in tumors has been characterized with 2D techniques (histology or angiography). They are not fully representative of the trajectories of vessels throughout the tissues and are not adapted to analyze changes occurring inside the bone marrow cavities. METHODOLOGY/PRINCIPAL FINDINGS: We have characterized the vasculature of bone metastases in 3D at different times of evolution of the disease. Metastases were induced in the femur of Wistar rats by a local injection of Walker 256/B cells. Microfil®, (a silicone-based polymer) was injected at euthanasia in the aorta 12, 19 and 26 days after injection of tumor cells. Undecalcified bones (containing the radio opaque vascular casts) were analyzed by microCT, and a first 3D model was reconstructed. Bones were then decalcified and reanalyzed by microCT; a second model (comprising only the vessels) was obtained and overimposed on the former, thus providing a clear visualization of vessel trajectories in the invaded metaphysic allowing quantitative evaluation of the vascular volume and vessel diameter. Histological analysis of the marrow was possible on the decalcified specimens. Walker 256/B cells induced a marked osteolysis with cortical perforations. The metaphysis of invaded bones became progressively hypervascular. New vessels replaced the major central medullar artery coming from the diaphyseal shaft. They sprouted from the periosteum and extended into the metastatic area. The newly formed vessels were irregular in diameter, tortuous with a disorganized architecture. A quantitative analysis of vascular volume indicated that neoangiogenesis increased with the development of the tumor with the appearance of vessels with a larger diameter. CONCLUSION: This new method evidenced the tumor angiogenesis in 3D at different development times of the metastasis growth. Bone and the vascular bed can be identified by a double reconstruction and allowed a quantitative evaluation of angiogenesis upon time.
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Angiografía , Neoplasias Óseas/irrigación sanguínea , Neoplasias Óseas/secundario , Imagenología Tridimensional/métodos , Microtomografía por Rayos X , Animales , Neoplasias Óseas/diagnóstico por imagen , Fémur/irrigación sanguínea , Fémur/diagnóstico por imagen , Fémur/patología , Ratas , Ratas Sprague-Dawley , Elastómeros de Silicona , Factores de TiempoRESUMEN
Young mice overexpressing Runx2 specifically in cells of the osteoblastic lineage failed to gain bone mass and exhibited a dramatic increase in bone resorption, leading to severe osteopenia and spontaneous vertebral fractures. The objective of the current study was to determine whether treatment with a bisphosphonate (risedronate, Ris), which reduces fractures in postmenopausal as well as in juvenile osteoporosis, was able to improve bone quality and reduce vertebral fractures in mice overexpressing Runx2. Four-week-old female Runx2 mice received Ris at 2 and 10 µg/kg subcutaneously twice a week for 12 weeks. Runx2 and wild-type mice received vehicle (Veh) as control. We measured the number of new fractures by X-ray and bone mineral density (BMD) by DEXA. We evaluated bone quality by histomorphometry, micro-CT, and Fourier transform infrared imaging (FTIRI). Ris at 20 µg/kg weekly significantly reduced the average number of new vertebral fractures compared to controls. This was accompanied by significantly increased BMD, increased trabecular bone volume, and reduced bone remodeling (seen in indices of bone resorption and formation) in the vertebrae and femoral metaphysis compared to Runx2 Veh. At the femur, Ris also increased cortical thickness. Changes in collagen cross-linking seen on FTIRI confirmed that Runx2 mice have accelerated bone turnover and showed that Ris affects the collagen cross-link ratio at both forming and resorbing sites. In conclusion, young mice overexpressing Runx2 have high bone turnover-induced osteopenia and spontaneous fractures. Ris at 20 µg/kg weekly induced an increase in bone mass, changes in bone microarchitecture, and decreased vertebral fractures.