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OBJECTIVE: To assess the influence of unilateral open disc repositioning surgery (ODRS) of the temporomandibular joint (TMJ) on the internal derangement (ID) of the contralateral joint. METHODS: Patients with bilateral ID of TMJ who underwent unilateral ODRS were enrolled and followed-up for one year. They were divided into two groups based on the contralateral disease: the anterior disc displacement with reduction (ADDWR) and without reduction (ADDWoR). Postoperative evaluation included clinical and MRI evaluation. Indices measured were unilateral intermaxillary distance (UID), visual analogue scale (VAS), disc length (DL), condylar height (CH), and disc-condyle angle (DCA). Paired t tests were used to compare the clinical and MRI indices between different time points. RESULTS: Ninety-six patients were enrolled, including 47 in the ADDWR group and 49 in the ADDWoR group. One-year post-surgery, ODRS led to significant increases in MMO, DL, and CH, and decrease in VAS and DCA on the operated side (P < 0.05). In ADDWR group, UID, DL, and CH increased significantly, and VAS decreased (P < 0.05), with no significant change in DCA (P > 0.05). In ADDWoR group, clinical and MRI variables worsened slightly, except for UID, which remained unchanged (P > 0.05). CONCLUSIONS: ODRS is a promising method for correcting TMJ ID and may improve condition of ADDWR and decrease progress of ADDWoR at the contralateral joint. Preoperative bilateral TMJ evaluation is essential for better outcomes. CLINICAL RELEVANCE: ODRS can effectively treat TMJ ID and produce adaptive changes in the contralateral ID, for which continuous monitoring of the contralateral joint is essential.
Asunto(s)
Imagen por Resonancia Magnética , Disco de la Articulación Temporomandibular , Trastornos de la Articulación Temporomandibular , Humanos , Femenino , Masculino , Estudios Prospectivos , Trastornos de la Articulación Temporomandibular/cirugía , Trastornos de la Articulación Temporomandibular/diagnóstico por imagen , Adulto , Disco de la Articulación Temporomandibular/cirugía , Disco de la Articulación Temporomandibular/diagnóstico por imagen , Resultado del Tratamiento , Luxaciones Articulares/cirugía , Luxaciones Articulares/diagnóstico por imagen , Persona de Mediana Edad , Dimensión del Dolor , AdolescenteRESUMEN
Bacterial infection and poor osseointegration are two critical issues that need to be solved for long-term use of titanium implants. As such, Sr/Ag-containing TiO2 microporous coatings were prepared on a Ti alloy surface in the current study via a single-step microarc oxidation technique. The coatings showed both good cytocompatibility in vitro and biosafety in vivo. Sr/Ag incorporation brought no significant change in the surface micromorphology and physicochemical properties, but endowed the coating with strong osteogenic activity and long-term antibacterial capability in vitro. Furthermore, the osteogenic and antibacterial capability of the coating was also confirmed in vivo. In a rat osseointegration model, new bone formation, implant-bone contact, removal torque and bone mineralization were all significantly increased in the M-Sr/Ag group when compared with those in group M, although they were slightly lower than those in group M-Sr. In a periimplantitis model, no rats suffered infection in the M-Sr/Ag group after 3 months of osseointegration and 5 weeks of bacterial inoculation period, when compared to 100% and 75% infection rates in M and M-Sr groups, respectively. In addition, active bone remodeling and many mesenchymal cells were observed in the M-Sr group, suggesting good bone regeneration potential in Sr-containing coatings in the case of controlled periimplantitis. Overall, the Sr/Ag-containing TiO2 microporous coating is valuable for preventing periimplantitis and improving implant reosseointegration, and is therefore promising for long-term and high quality use of titanium implants.
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Periimplantitis , Titanio , Humanos , Titanio/farmacología , Titanio/química , Osteogénesis , Materiales Biocompatibles Revestidos/farmacología , Materiales Biocompatibles Revestidos/química , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
Strontium (Sr) is the most common element introduced into TiO2 coatings to strengthen the osteogenic property of titanium implants. However, the optimal Sr content and its effect on osteogenic and physicochemical properties of the coatings need to be clarified. In the current study, TiO2 microporous coatings with different contents of Sr (9.64-21.25 wt %) and silver (Ag) (0.38-0.75 wt %) were prepared via micro-arc oxidation technique. Sr contents did not change physicochemical properties of the coatings, including surface microstructure, micropore size and distribution, phase composition, roughness and hydrophilicity. Meanwhile, higher Sr contents (18.23-21.25 wt %) improved cytocompatibility, proliferation and alkaline phosphatase (ALP) activity of preosteoblasts, even the coatings underwent 30 days' PBS immersion. Furthermore, higher Sr contents facilitated preosteoblast growth and spreading, which are essential for their proliferation and osteogenic differentiation. Therefore, it is promising to incorporate higher Sr content (18.23-21.25 wt %) within TiO2 microporous coatings to improve their osteogenic capability.
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Materiales Biocompatibles Revestidos , Osteogénesis , Materiales Biocompatibles Revestidos/farmacología , Materiales Biocompatibles Revestidos/química , Estroncio/farmacología , Estroncio/química , Titanio/farmacología , Titanio/química , Propiedades de SuperficieRESUMEN
Due to the good biocompatibility and ideal mechanical property, titanium implants have been widely used in dental clinic and orthopedic surgery. However, bacteria induced infection can cause per-implant inflammation and decrease the success rate of implant surgery. Therefore, developing antimicrobial techniques is essential to successful application of titanium implants. Many surface antimicrobial techniques, including antimicrobial coating and surface modifications, have been explored and they always exert antimicrobial effect by reducing bacterial adhesion, inhibiting their metabolism, or destructing cell structure. In this paper, different surface antimicrobial techniques and their recent research progress are reviewed to provide a brief insight on this area.
RESUMEN
Titanium (Ti) and Ti alloys are widely used biomaterials, but they lack osteogenic capability for rapid bone integration. To improve osseointegration of Ti implants, TiO2 nanotubes were prepared using the anodizing oxidation technique, and strontium (Sr) combined with icariin (ICA) was loaded on TiO2 nanotube coatings. Cell adhesion and proliferation of MC3T3-E1 cells, alkaline phosphatase (ALP) activity, mineralization of extracellular matrix, and bone formation around titanium implants in ovariectomized rats, were examined separately. The results showed that compared with pure Ti, TiO2 and Sr-loaded TiO2 coatings, the coatings loaded with both Sr and ICA showed better effect on cell adhesion and proliferation, higher ALP activity and more red-stained mineralized nodules. Furthermore, more bone was formed around implants loaded with both Sr and ICA in osteoporotic rats. Therefore, coating with Sr and ICA is valuable for clinical application to strengthen the osseointegration of titanium implants, especially in osteoporotic patients.
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Flavonoides/farmacología , Nanotubos/química , Osteogénesis/efectos de los fármacos , Estroncio/farmacología , Titanio/química , Animales , Densidad Ósea , Interfase Hueso-Implante , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Femenino , Flavonoides/química , Flavonoides/farmacocinética , Liofilización , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Osteogénesis/fisiología , Osteoporosis/fisiopatología , Osteoporosis/terapia , Ovariectomía , Prótesis e Implantes , Ratas Sprague-Dawley , Estroncio/química , Estroncio/farmacocinéticaRESUMEN
Ti and Ti alloys are bioinert materials and two frequent problems associated with them are bacterial infection and lack of osteogenic potential for rapid bone integration. To overcome the problems, the present study incorporated strontium (Sr) and silver (Ag) simultaneously into porous TiO2 coatings through a single-step technique, micro-arc oxidation (MAO). Incorporation of Sr and Ag brought no significant changes to coating micromorphology and physicochemical properties, but endowed TiO2 coatings with both strong antibacterial activity and osteogenic ability. Antibacterial activity increased with Ag contents in the coatings. When Ag content reached 0.58 wt%, the coating showed both excellent short-term (100.0%) and long-term (77.6%) antibacterial activities. Sr/Ag-containing coatings with 18.23 wt% Sr and 0.58 wt% Ag also presented good cytocompatibility for preosteoblast adhesion and proliferation, and promoted preosteoblast osteogenic differentiation both short-termly and long-termly. However, higher Ag content (1.29 wt%) showed toxic effects to preosteoblasts. In summary, MAO is a simple and effective way to incorporate Sr and Ag into porous TiO2 coatings and Sr/Ag-containing TiO2 coating with 18.5 wt% Sr and 0.58 wt% Ag has both good osteogenic activity and strong antibacterial capability short-termly and long-termly. Therefore, such coatings are valuable for clinical application to strengthen osseointegration and long-term high quality use of titanum implants.
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Antibacterianos/farmacología , Materiales Biocompatibles Revestidos/farmacología , Osteogénesis/efectos de los fármacos , Plata/farmacología , Estroncio/farmacología , Titanio/farmacología , Adhesión Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular , Fenómenos Químicos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Pruebas de Sensibilidad Microbiana , Osteoblastos/efectos de los fármacos , Osteoblastos/ultraestructura , Oxidación-Reducción , Porosidad , Staphylococcus aureus/efectos de los fármacos , Propiedades de Superficie , Difracción de Rayos XRESUMEN
Various bone substitutes have been applied in sinus augmentation (SA) to overcome insufficient bone height at the posterior maxilla region caused by pneumatized sinus and severe alveolar bone resorption after teeth loss. However, their effectiveness in SA needs to be further elucidated. In this study, strontium-doped brushite (Sr-DCPD), a new bone substitute, together with bovine-derived hydroxyapatite (bHA) and synthetic hydroxyapatite (sHA) was used in rabbit maxillary SA with simultaneous implant installation. The sinus space-keeping capacity, resorption rate, osteoconductivity, and mechanical properties of regenerated bone, were evaluated by micro-computed tomography (CT), histological analysis, and mechanical testing. Sr-DCPD exhibited the best osteoconductivity and new bone formation (<4 weeks), but its final bone regeneration and removal torque of implants at week 12 were the lowest, mainly due to its poor space-keeping capacity and fast resorption. bHA exhibited the best space-keeping capacity and slowest resorption rate, but relative lower final bone volume and mechanical properties, while sHA showed good space-keeping capacity, slower resorption rate, and the best final bone formation and mechanical properties. sHA was most effective for SA and bHA was also an acceptable bone substitute; however, Sr-DCPD was least effective and not suitable in SA by itself.
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Materiales Biocompatibles , Sustitutos de Huesos/química , Fosfatos de Calcio/farmacología , Durapatita/farmacología , Elevación del Piso del Seno Maxilar/métodos , Estroncio/farmacología , Animales , Conducción Ósea , Regeneración Ósea/efectos de los fármacos , Resorción Ósea , Fosfatos de Calcio/química , Bovinos , Durapatita/química , Humanos , Masculino , Seno Maxilar/cirugía , Fenómenos Mecánicos , Persona de Mediana Edad , Osteogénesis/efectos de los fármacos , Prótesis e Implantes , Conejos , Estroncio/química , Microtomografía por Rayos XRESUMEN
Calcium/calmodulin-dependent protein kinases (CaMKs) are a group of important molecules mediating calcium signal transmission and have been proved to participate in osteoclastogenesis regulation. CaMKII, a subtype of CaMKs is expressed during osteoclast differentiation, but its role in osteoclastogenesis regulation remains controversial. In the present study, we identified that both mRNA and protein levels of CaMKII (δ) were upregulated in a time-dependent manner during osteoclast differentiation. CaMKII (δ) gene silencing significantly inhibited osteoclast formation, bone resorption, and expression of osteoclast-related genes, including nuclear factor of activated T cells c1 (NFATc1), tartrate-resistant acid phosphatase (TRAP), and c-Src. Furthermore, CaMKII (δ) gene silencing downregulated phosphorylation of mitogen-activated protein kinases (MAPKs), including JNK, ERK, and p38, which were transiently activated by RANKL. Specific inhibitors of ERK, JNK, and p38 also markedly inhibited expression of osteoclast-related genes, osteoclast formation, and bone resorption like CaMKII (δ) gene silencing. Additionally, CaMKII (δ) gene silencing also suppressed RANKL-triggered CREB phosphorylation. Collectively, these data demonstrate the important role of CaMKII (δ) in osteoclastogenesis regulation through JNK, ERK, and p38 MAPKs and CREB pathway.
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Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Osteoclastos/metabolismo , Osteogénesis , Transducción de Señal , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Resorción Ósea/genética , Resorción Ósea/patología , Diferenciación Celular/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Silenciador del Gen/efectos de los fármacos , Ratones , Osteoclastos/citología , Osteoclastos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Ligando RANK/farmacología , Células RAW 264.7 , Transducción de Señal/efectos de los fármacos , Fosfatasa Ácida Tartratorresistente/metabolismo , Factores de TiempoRESUMEN
Pulp stones were denaturation of pulp tissue, which were usually found in the pulp chamber. Generally, they were associated with caries and pulposis, and the occurrence of pulp stone increased with age. Pulp stones were frequently found by radiographic examination, and appeared as radiopaque lesions which were round or ovoid in shape. We reported an unusual case of multiple pulp stones with normal clinical crowns in a young female patient and analyzed the possible etiology.
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Calcificaciones de la Pulpa Dental/diagnóstico , Caries Dental , Cavidad Pulpar , Femenino , HumanosRESUMEN
Osteoporosis deteriorates jaw bone quality and may compromise early implant osseointegration and early implant loading. The influence of lowmagnitude, highfrequency (LMHF) vibration on periimplant bone healing and implant integration in osteoporotic bones remains poorly understood. LMHF loading via wholebody vibration (WBV) for 8 weeks has previously been demonstrated to significantly enhance bonetoimplant contact, periimplant bone fraction and implant mechanical properties in osteoporotic rats. In the present study, LMHF loading by WBV was performed in osteoporotic rats, with a loading duration of 4 weeks during the early stages of bone healing. The results indicated that 4week LMHF loading by WBV partly reversed the negative effects of osteoporosis and accelerated early periimplant osseointegration in ovariectomized rats.
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Conservadores de la Densidad Ósea/uso terapéutico , Oseointegración/efectos de los fármacos , Vibración/uso terapéutico , Animales , Densidad Ósea/efectos de los fármacos , Femenino , Osteogénesis/efectos de los fármacos , Osteoporosis/tratamiento farmacológico , Ovariectomía/métodos , Prótesis e Implantes , Ratas , Ratas Sprague-Dawley , Tibia/efectos de los fármacos , Titanio/farmacologíaRESUMEN
PURPOSE: To investigate the current status and problems of bilingual teaching on stomatology in China. METHODS: Three database, including CNKI, Wanfang database and VIP were used to retrieve the articles of bilingual teaching on stomatology from January 2001 to December 2012. RESULTS: Fifty articles were included in this study and the following items, publishing time, foundation support, journals, authors and author affiliation, the course, teaching effects, research classification and main components of the articles were analyzed. The problems remained were also discussed. CONCLUSIONS: The level of current bilingual teaching on stomatology in China is low and great efforts are needed to make it better. Supported by Research Fund of Hebei United University(Z201333).
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Educación en Odontología , Medicina Oral , Edición , China , Humanos , MultilingüismoRESUMEN
BACKGROUND: Resorption of grafted bone and delayed osseointegration of implants are main problems associated with alveolar bone augmentation in dental implantology, especially for patients with osteoporosis. The aim of this study is to investigate the early healing response of implants to systemic treatment of zoledronic acid (ZA) in autogenous grafted iliac bone of osteoporotic rabbits. METHODS: Ovariectomy (OVX) or sham operation was performed in 46 rabbits, and osteoporotic changes were verified in animals receiving OVX 3 months later. The remaining animals were divided into three groups (n = 12): sham, OVX, and OVX with ZA treatment (ZA group). Autogenous iliac bone grafting was performed in bilateral tibiae, and hydroxyapatite-coated titanium implants were simultaneously placed into the grafted bone. The animals were sacrificed 2 and 8 weeks later for examination. RESULTS: At both time points, systemic treatment of ZA efficiently promoted bone healing of implants in grafted bone, and all histologic and microcomputed tomography bone indices, including mineralized bone volume, implant-bone contact ratio, connectivity density, trabecular thickness, and trabecular number, were significantly increased in the ZA group compared with the OVX-only group (P <0.01); implant-bone contact rates in the ZA group were even restored to levels similar to those of sham-operated animals (P >0.05). Furthermore, biomechanical testing demonstrated that removal torque of implants was significantly increased in the ZA group compared with the OVX group (P <0.01). CONCLUSION: Systemic treatment with ZA could efficiently promote early bone healing of implants in autogenous grafted bone of osteoporotic rabbits by increasing early osseointegration and fixation of implants.
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Conservadores de la Densidad Ósea/uso terapéutico , Trasplante Óseo/métodos , Materiales Biocompatibles Revestidos/química , Implantes Dentales , Difosfonatos/uso terapéutico , Durapatita/química , Imidazoles/uso terapéutico , Osteoporosis/tratamiento farmacológico , Absorciometría de Fotón , Animales , Autoinjertos/trasplante , Densidad Ósea/efectos de los fármacos , Calcificación Fisiológica/efectos de los fármacos , Femenino , Ilion/cirugía , Oseointegración/efectos de los fármacos , Ovariectomía/métodos , Conejos , Estrés Mecánico , Tibia/cirugía , Factores de Tiempo , Torque , Sitio Donante de Trasplante/cirugía , Cicatrización de Heridas/efectos de los fármacos , Microtomografía por Rayos X/métodos , Ácido ZoledrónicoRESUMEN
OBJECTIVE: To investigate the effect of zoledronate acid on osteoclast differentiation and gene expression of calmodulin (CAM) and calmodulin-dependent protein kinase (CAMK)II. METHODS: Receptor activation of nuclear factor κB ligand (RANKL) was used to induce differentiation of RAW264.7 cells into osteoclasts in vitro. The cells were divided into two groups, group A and group B. Both groups were treated with RANKL for 5 days, whereas group B was also treated with zoledronate for the last 2 days.Osteoclastogenesis and gene expression of CAM and CAMK II were examined. RESULTS: In group B, the number of new-generated osteoclasts (≥3 nuclei), number and size of dentin resorption lacunaes were (23 ± 3) , (19 ± 2) and (4951 ± 223) µm(2) respectively, which were significantly lower than those [(44 ± 3) , (46 ± 1) and (13 331 ± 248) µm(2)] in group A (P < 0.01).mRNA and protein level of CAM and CAMK II were also significantly down-regulated in group B when compared with group A (P < 0.01) and the decrease was 26.7% and 37.2% respectively for CAM, 57.0% and 76.1% respectively for CAMK II. CONCLUSIONS: Zoledronate acid could significantly inhibit formation and resorption function of osteoclasts. CAM and CAMKII may be involved in the inhibition process.
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Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Calmodulina/metabolismo , Diferenciación Celular , Difosfonatos/farmacología , Imidazoles/farmacología , Osteoclastos , Animales , Conservadores de la Densidad Ósea/farmacología , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/genética , Calmodulina/genética , Línea Celular , Macrófagos/citología , Macrófagos/efectos de los fármacos , Ratones , Osteoclastos/citología , Osteoclastos/metabolismo , ARN Mensajero/metabolismo , Receptor Activador del Factor Nuclear kappa-B/farmacología , Ácido ZoledrónicoRESUMEN
OBJECTIVE: To study the effects of glial cell derived neurotrophic factor (GDNF) on regeneration of facial nerve defects by autogenous facial vein conduit. METHODS: Thirty-six rabbits were used in this study and 10 mm-length facial nerve defects were made on both sides of all animals. The nerve gaps were bridged using autogenous posterior facial vein graft of the same side. The animals received injection of either saline (group A, n=16) or GDNF (group B, n=16) into the veins. Nerve function was evaluated by evoking nerve action potential immediately after operation and 4, 8 and 16 weeks after operation. Regenerated nerve samples were harvested at 4, 8, and 16 weeks after operation and processed for histology and transmitting electron microscopic examination (TEM). RESULTS: Action potential did not exist immediately after operation but it was evoked at 4, 8, and 16 weeks in both groups. At 4 and 8 weeks after operation, the amplitude and width of action potential were significantly higher in group B than group A (P < 0.01), except wave width at 4 weeks, which showed no significant differences, while the latency period was significantly shorter in group B than that in group A (P < 0.01). At 16 weeks, action potential was similar between two groups, except wave amptitude, which was higher in group B than group A (P < 0.01). Morphologic and TEM examinations showed more matured myelinated nerve fibers and active Schwann's cells in group B when compared group A during the whole regeneration process. CONCLUSION: GDNF can promote nerve regeneraat early stage during reconstruction of facial nerve defects by autogenous facial vein conduit and combination of GDNF and autogenous vein graft provides a valuable method for clinical reconstruction of facial nerve defects.
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Nervio Facial , Regeneración Nerviosa , Animales , Factores de Crecimiento Nervioso , Neuroglía , Conejos , RegeneraciónRESUMEN
OBJECTIVE: To investigate the influences of experimental osteoporosis (OP) on bone healing of autologous iliac crest graft around dental implants in rabbits. METHODS: Twenty Japanese rabbits were randomly divided into two groups. Bilaterally ovariectomy was performed on experimental group and control group received sham-operation. Twelve weeks later, femoral bones were examined for bone mineral density (BMD) to verify OP status. Then bone defects were made in the proximal metaphysis of the tibiae and autologous iliac crest grafts with simultaneous implant placement were performed. The animals were killed at 8 and 12 weeks after bone graft surgery. Undecalcified sections were prepared and examined histologically and histomorphometrically. RESULTS: Osteoporotic status caused by ovariectomy was verified by significantly decreased BMD in experimental group (P < 0.001). At 8 and 12 weeks after bone graft surgery, osseointegration was observed in both groups. However, thickness of cortical bone (TCB), bone volume in cancellous area (BVC), implant-bone contact rate (IBCR) at bone graft area all significantly decreased in experimental group when compared with control group (P < 0.01). Newly formed bone was also less in experimental group than that in control group. CONCLUSION: Although experimental OP may not delay osseointegration of dental implants in autologous iliac crest graft, it certainly promotes resorption of bone grafts, decreases cancellous bone volume and implant-bone contact rate. Therefore it may be an important risk factor for patients receiving autologous bone graft with simultaneous implant placement.
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Trasplante Óseo , Implantes Dentales , Ilion/trasplante , Oseointegración , Osteoporosis/patología , Animales , Femenino , Ovariectomía , ConejosRESUMEN
OBJECTIVE: To study the response of rat bone marrow mesenchymal stem cells (MSCs) to a single period of mechanical strain and expression patterns of transforming growth factor-beta (TGF-beta) and insulin-like growth factor-II (IGF-II) after mechanical stretch. METHODS: Bone marrow MSCs were isolated from SD rats and cultured in vitro. A four-point bending apparatus were used to perform a single period of mechanical strain (2000 microepsilon, 40 min) on MSCs. Cellular proliferation and alkaline phosphatase (ALP) activity of MSCs were examined and gene expression patterns of TGF-beta and IGF-II were detected by SYBR green quantitative real-time RT-PCR. RESULTS: Cell proliferation, ALP activity and expression of TGF-beta and IGF-II were all significantly up-regulated in stretched MSCs when compared with their controls. The mRNA levels of TGF-beta and IGF-II got top increase immediately after mechanical loading and increased about 51.44 and 8.92 folds, respectively, when compared with control cells. Expression of TGF-beta and IGF-II decreased with time and returned to control level at 12 h after mechanical stimulus, despite of a small increase at 6 h. CONCLUSION: The mechanical stretch can promote MSCs proliferation, up-regulate its ALP activity and induce a time-dependent expression increase of TGF-beta and IGF-II which in turn result in osteogenic differentiation of MSCs. Mechanical stimulus is a key stimulator for osteogenic differentiation of MSCs and vital for bone formation in distraction osteogenesis.
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Factor II del Crecimiento Similar a la Insulina , Factor de Crecimiento Transformador beta , Animales , Células de la Médula Ósea , Diferenciación Celular , Proliferación Celular , Células Madre Mesenquimatosas , Osteogénesis , Osteogénesis por Distracción , ARN Mensajero , Ratas , Ratas Sprague-Dawley , SomatomedinasRESUMEN
AIM: Understanding the response of mesenchymal stem cells (MSCs) to mechanical strain and their consequent gene expression patterns will broaden our knowledge of the mechanobiology of distraction osteogenesis. METHODOLOGY: In this study, a single period of cyclic mechanical stretch (0.5 Hz, 2,000 microepsilon) was performed on rat bone marrow MSCs. Cellular proliferation and alkaline phosphatase (ALP) activity was examined. The mRNA expression of six bone-related genes (Ets-1, bFGF, IGF-II, TGF-beta, Cbfa1 and ALP) was detected using real-time quantitative RT-PCR. RESULTS: The results showed that mechanical strain can promote MSCs proliferation, increase ALP activity, and up-regulate the expression of these genes. A significant increase in Ets-1 expression was detected immediately after mechanical stimulation, but Cbfa1 expression became elevated later. The temporal expression pattern of ALP coincided perfectly with Cbfa1. CONCLUSION: The results of this study suggest that mechanical strain may act as a stimulator to induce differentiation of MSCs into osteoblasts, and that these bone-related genes may play different roles in the response of MSCs to mechanical stimulation.
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Células de la Médula Ósea/fisiología , Células Madre Mesenquimatosas/fisiología , Osteogénesis por Distracción , Fosfatasa Alcalina/análisis , Animales , Antígenos de Superficie/análisis , Fenómenos Biomecánicos , Técnicas de Cultivo de Célula , Diferenciación Celular/fisiología , Proliferación Celular , Subunidad alfa 1 del Factor de Unión al Sitio Principal/análisis , Factor 2 de Crecimiento de Fibroblastos/análisis , Factor II del Crecimiento Similar a la Insulina/análisis , Osteoblastos/fisiología , Células Madre Pluripotentes/fisiología , Proteína Proto-Oncogénica c-ets-1/análisis , Ratas , Estrés Mecánico , Factor de Crecimiento Transformador beta/análisis , Regulación hacia Arriba/fisiologíaRESUMEN
OBJECTIVE: To evaluate autogenous vein grafts and inside-out vein grafts as conduits for the defects repair in the rabbit facial nerves. METHODS: The 10 mm segments of buccal division of facial nerve were transected for 48 rabbits in this study. Then the gaps were immediately repaired by autogenous vein grafts or inside-out vein grafts in different groups. All the animals underwent the whisker movement test and electrophysiologic test during the following 16 weeks at different time points postoperatively. Subsequently, the histological examination was performed to observe the facial nerve regeneration morphologically. RESULTS: At 8 weeks after operation, the facial nerve regeneration has significant difference between the experimental group and the control group in electrophysiologic test and histological observation. However, at the end of this study, 16 weeks after operation, there was no significant difference between inside-out vein grafts and standard vein grafts in enhancing peripheral nerve regeneration. CONCLUSION: This study suggest that both kinds of vein grafts play positive roles in facial nerve regeneration after being repaired immediately, but the autogenous inside-out vein grafts might accelerate and facilitate axonal regeneration as compared with control.
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Traumatismos del Nervio Facial/cirugía , Venas/trasplante , Animales , Axones/fisiología , Nervio Facial/fisiología , Nervio Facial/cirugía , Masculino , Regeneración Nerviosa/fisiología , Conejos , Trasplante Autólogo/métodosRESUMEN
OBJECTIVE: To study the effect of recombinant pAd-BMP-7 on osteogenic differentiation of rat bone marrow mesenchymal stem cells (MSC). METHODS: Recombinant pAd-bone morphogenetic protein (BMP) 7 was constructed and the titer of recombinant adenovirus was determined. pAd-BMP-7 and pAdTrack-CMV were used to transfect rat MSC. Transfection efficiency was measured by fluorescent microscope and BMP-7 expression was detected by RT-PCR and immunocytochemical analysis. The MSC were then randomly divided into 3 groups: group A received pAd-BMP-7 transfection, group B was transfected with pAdTrack-CMV, and group C received pAdTrack-CMV transfection plus bone supplements. Osteogenic differentiation of MSC was evaluated by examination of mineralization nodes formation. RESULTS: The titer of pAd-BMP-7 reached about 2.0 x 10(15) pfu/L and transfection efficiency of exogenous gene was nearly 99% at day 2. The expression of exogenous gene sustained about 5 to 7 weeks, with a higher level during first 3 weeks. After transfection, transcription of BMP-7 and expression of BMP-7 protein were also verified in MSC. Compared with the negative results in group B, mineralization nodes were formed in both group A and group C. However, group A showed better formation of mineralization nodes than group C (P < 0.01). CONCLUSIONS: The results of this study indicated that recombinant pAd-BMP-7 can successfully transfect rat MSC and accelerate their osteogenic differentiation. The technique explored in this study provides a unique and valuable gene engineering approach for reconstruction of craniofacial bone defects.
Asunto(s)
Adenoviridae/genética , Células de la Médula Ósea/citología , Proteína Morfogenética Ósea 7/genética , Células Madre Mesenquimatosas/citología , Animales , Proteína Morfogenética Ósea 7/metabolismo , Diferenciación Celular , Células Cultivadas , Vectores Genéticos , Ratas , TransfecciónRESUMEN
OBJECTIVE: To explore the response of rat bone marrow mesenchymal stem cells (MSCs and calvarial osteoblasts to mechanical strain and the consequent changes of cytoskeleton F-actin. METHODS: Bone marrow MSCs and calvarial osteoblasts were isolated from SD rats and cultured in vitro. Mechanical stretch was performed on passage 3 cells at 2 000 microepsilon for 0, 2, 6 and 12 hours using four-point bending system. The response of cells and the distribution of F-actin were observed using fluorescent staining under laser scanning confocal microscope and the morphological parameters were quantified using image analysis software Laserpix. RESULTS: Under mechanical stretch, the fluorescent staining decreased obviously at both MSCs and osteoblasts, and F-actin filaments were rearranged and became tenuous, thinner, and abnormally distributed. The outline of nucleus became unclear and apoptotic changes were observed at some of both cells. Cellular size decreased more significantly in MSCs than in osteoblasts. Quantity analysis showed that total area of cells, total fluorescent density and green fluorescent density (F-actin) were all significantly decreased in MSCs (P < 0.05 or P < 0.01), and total fluorescent density, green fluorescent density and red fluorescent density (nuclei) did also in osteoblasts (P < 0.05 or P < 0.01). CONCLUSION: Mechanical stretch caused extensive response on both MSCs and osteoblasts which led to the rearrangement of F-actin filament and apoptosis in some of these cells. MSCs were more sensitive to mechanical strain than osteoblasts.