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The Hedgehog (Hh) signalling pathway is essential for cellular proliferation and differentiation during embryonic development. Gain and loss of function of Hh signalling are known to result in an array of craniofacial malformations. To determine the critical period for Hh pathway antagonist-induced frontal bone hypoplasia, we examined patterns of dysmorphology caused by Hh signalling inhibition. Pregnant mice received a single oral administration of Hh signalling inhibitor GDC-0449 at 100 mg•kg or 150 mg•kg body weight at preselected time points between embryonic days (E)8.5 and 12.5. The optimal teratogenic concentration of GDC-0449 was determined to be 150 mg•kg. Exposure between E9.5 and E10.5 induced frontal bone dysplasia, micrognathia and limb defects, with administration at E10.5 producing the most pronounced effects. This model showed decreased ossification of the frontal bone with downregulation of Hh signalling. The osteoid thickness of the frontal bone was significantly reduced. The amount of neural crest-derived frontal bone primordium was reduced after GDC-0449 exposure owing to a decreased rate of cell proliferation and increased cell death.
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Animals , Female , Mice , Pregnancy , Administration, Oral , Anilides , Pharmacology , Bone Diseases, Developmental , Cell Proliferation , Physiology , Frontal Bone , Congenital Abnormalities , Hedgehog Proteins , Limb Deformities, Congenital , Micrognathism , Osteogenesis , Pyridines , Pharmacology , Signal TransductionABSTRACT
Objective@#To classify the morphology of mandible posterior region and provide reference for the planning of dental implantation.@*Methods@#Cone beam CT data of 208 patients were collected. The CT data were imported into CS 3D imaging V3 software and then the morphology of mandible posterior region were analyzed. The types of premolar and molar mandible cross-section morphology were recorded, classified and analyzed.@*Results@#The results showed that type A (vertical type) (79%-96%) was the most common in the premolars, whereas type B (inclined type) (36%-37%) and type C (lingual inverted concave) (30%-54%) were the most common types in the molars, followed type D (absorption severe type) (2%-5%). There was a statistically significant differences in tooth positions (P<0.001), tooth deficiency aspect (P<0.001) and different side (P=0.013), different age (P<0.001), and different gender (P=0.007).@*Conclusions@#Using cone beam CT to determine the morphology of mandible may be a reference for the planning of dental implantation.
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Objective@#To analysis teratogenic effect of GDC-0449 to fetus and set up the animal model of GDC-0449 induced oromandibular limb hypogenesis in mouse for further research of its pathogenesis.@*Methods@#Twenty-seven pregnant Institute of Cancer Research (ICR) mice were randomly divided into: control group, embryonic day 8.5 (E8.5) exposed groups, E9.5 exposed groups, E10.5 exposed groups, E11.5 exposed groups, E12.5 exposed groups, E13.5 exposed groups, E14.5 exposed groups and E15.5 exposed groups. Each group had 3 mice. Exposed groups were treated with the Hedgehog pathway antagonist GDC-0449 at a single dose 150 mg/kg by oral gavage from E8.5 to E15.5. At E16.5, embryonic phenotypes were analyzed in detail by stereo microscope and histology. After establish an optimal dysmorphogenic concentration, 6 pregnant ICR mice were randomly divided into control group and the optimal group, embryonic phenotypes were analyzed by whole-mount skeletal staining and micro-computed tomography at E18.5.@*Results@#The mice were exposed to GDC-0449 on E11.5 and E12.5 had a high incidence of cleft palate. GDC-0449 exposed between E9.5 and E10.5 caused craniofacial and limb dysmorphology, including micrognathia, microglossia, ectrodactylia, partial anodontia and cleft palate. Most interestingly, these are extremely similar to oromandibular limb hypogenesis syndrome.@*Conclusions@#The results of this study indicate that GDC-0449 can be used to induce micrognathia, microglossia, ectrodactylia, partial anodontia and cleft palate. This work established a novel mouse model for oromandibular limb hypogenesis.
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Objective To explore the association of anti-mullerian hormone(AMH)in seminal plasma and serum with sperm counts and energy for male.Methods For 215 cases of healthy male selected from our reproductive clinic,with women′s reason for infertility,seminal plasma and serum AMH were detected,as semen parameters(sperm density,living rate,vitality and malformation rate),6 items of serum sex hormone.In seminal plasma and serum AMH respectively as the dependent variable,using multiple line-ar regression model to explore its quantitative relation with semen parameters and sex hormone levels.Results 215 cases were en-rolled,aged 34.28±5.70 years,while the median of the seminal plasma AMH was 0.47,quartile 0.05-3.09 pmol/ejaculation.The median of the serum AMH was 53.07,quartile 32.32 -72.20 pmol/L.Through multiple linear regression analysis,after adjusted by age and BMI,the seminal plasma of AMH and total number of sperm,sperm concentration,dynamic motility,total sperm activi-ty,serum inhibin B were positively correlated(P 0.05);Serum AMH negatively correlated with serum FSH,with serum inhibin B positively(P 0.05).Conclu-sion The seminal plasma of AMH were positively correlated with sperm concentration,sperm counts,sperm vitality,with the asso-ciation for serum AMH not yet found.
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BACKGROUND:Occlusal stimulation is essential for mandible function and remodeling, but there is stil a lack of clear understanding about the effect of occlusal stimulation on the bone remodeling in the process of bone defect repair using bone grafts. OBJECTIVE:To analyze the possible regulative effect of occlusal stimulation on bone remodeling in the process of bone defect repair using colagen substitutes. METHODS:Standard models of bone defects were respectively established in left mandible and parietal bone area of adult Sprague-Dawley rats. Then the bone defects area were filed with colagen and bone meal. The differences of two bone defects areas were observed by X-ray, hematoxylin-eosin staining, Gomori staining, tartrate-resistant acid phosphatase staining and bone morphogenetic protein 2 immunohistochemical staining at the 12th week after operation. RESULTS AND CONCLUSION: New bone formation was visible in the bone defect regions of the mandible and parietal bone. The amount of lamelar bone formation and the degree of mineralization of the new bone were significantly increased in the parietal bone defect compared with the mandibular bone defect area, indicating the bone remodeling in the parietal bone defect area was better than that in the mandible bone defect area. The integral absorbance values of tartrate-resistant acid phosphatase and bone morphogenetic protein 2 in the parietal bone defect area were lower than those in the mandibular bone defect area, indicating that the viabilities of osteoblasts and osteoclasts in the parietal bone defect area were lower than those in the mandible bone defect area. These results demonstrate that occlusal stimulation may delay the bone remodeling during the repair of mandibular bone defects by regulating bone mineralization and maturation.
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BACKGROUND: There is a close relationship between innervations and bone formation and bone mass maintenance in the extraction sockets. OBJECTIVE:To study the possible effect of denervations on the regulation of new bone formation and bone mass maintenance in the extraction sockets. METHODS:The unilateral inferior nerve of dogs was sectioned to establish an animal denervation model. The normal side was used as control. After model establishment, the premolars of denervated side and normal side were extracted. Histological method was used to test new bone formation and bone mass maintenance in the extraction sockets at the 2nd, 4th, 8th and 12th weeks after tooth extraction. RESULTS AND CONCLUSION:The percentage of new bone areas in the extraction sockets was significantly lower in the experiment group than the control group at weeks 2, 4, 8 after tooth extraction (P < 0.01). The height difference between the buccal and lingual alveolar ridge was higher in the experimental group than the control group at weeks 2, 4, 8, 12 after tooth extraction (P < 0.05 or P < 0.01). These findings indicate that denervation is closely related with new bone formation and bone mass maintenance in the extraction sockets.
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BACKGROUND: Consummate innervation plays an important role in bone formation. Nerve injury can impact normal bone metabolism, whereas bone regeneration depends on nerve regeneration in the innervation site to some degrees. Modified implant surface structure or usage of growth factors in local region can promote osseointegretion.OBJECTIVE: To retrospectively analyze effects of nervous system dominance bone metabolism and denervation on bone remodeling, innervated establishment and osseoperception during osseointegration following implantation.METHODS: The first author retrieved Pubmed database (http://www.ncbi.nlm.nih.gov/PubMed) and Wanfang database (http://www.wanfangdata.com.cn) (1990/2008) for publications of effects of nervous system dominance bone metabolism and denervation on bone remodeling, innervated establishment and osseoperception during osseointegration following implantation,with the key words of "bone metabolism, innervation, osseointegrationosseoperception" . Articles of repetitive contents were excluded. A total of 54 literatures were primarily obtained. According to inclusion criteria, 28 literatures were selected for summary.RESULTS AND CONCLUSION: Signals derived from the nervous system exert potent effects on osteoclast and osteoblast function. A ubiquitous innervation of all periosteal surfaces exists and its disruption affects bone remodeling. Several neuropeptides, neurohormones, nerotransmitters and their receptors are detectable in bone, and make it clear that nervous system is involved in bone metabolism and regeneration. Establishment of innervation of soft and hard tissue around implants may play an important role in osseointegration and osseoperception. Further studies will be required to explore the basic of anatomy,neurophysiology and neuropathology, which forms osseoperception.
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Platelet-rich plasma is a volume of autogenous plasma with a high platelet concentration. Platelet-rich gel which is polymerized from platelet-rich plasma becomes a hot topic in the repairing of jaw bones in oral and dentofacial surgery. Presently, the mechanism of platelet-rich gel in enhancement of bone defect repair has not been clarified. Generally, we believed that the unifiation of blood platelet degranulation released many high-concentration growth factor during polymerization stimulated bone formation and accelerated bone repair. In addition, the application of platelet-rich gel has some problems. Thus, wide application of platelet-rich gel in tissue engineering deserves further studies. With the development, platelet-rich gel should be widely used in bone tissue engineering.
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This study sought to elucidate the function of NO during the signal transduction wherein fluid shear stress regulates the proliferation and differentiation of osteoblast cells. The isolated rat osteoblast-like cells were exposed to fluid shear stress 12 dyn/cm2 for 5, 10, 15, 30, 60 and 120 min respectively with the use of a flow chamber. The NO release was examined. After the exposure to fluid shear stress, the NO synthesis of rat primary osteoblast-like cells increased significantly (P<0.05) when compared with the control. After 60 minutes of exposure, the release of NO began to increase significantly (P<0.05), but no significant increase as such was seen in the control (P>0.05). NO synthesis may be one of the signal transduction pathways which transduce the fluid shear stress into osteoblast cells. In early stage, it may be induced by cNOS and in late stage by iNOS.
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Animals , Rats , Cell Differentiation , Cell Proliferation , Cells, Cultured , Nitric Oxide , Nitric Oxide Synthase , Metabolism , Osteoblasts , Cell Biology , Metabolism , Shear Strength , Signal Transduction , Stress, MechanicalABSTRACT
Objective:To establish a tongue cancer cell line that stably overexpresses nm23-H1.Methods:The reconstructed plasmid, pCMV-BamH1-Neo-nm23-H1, was transfected into bacteria and amplified. The plasmid was identified by electrophoresis on a 10 g/L agarose gel and stained with ethidium bromide and then transfected to the cell line of Tca8113 by lipofectin strategy and was selected by G418 for 5 weeks. The stable expression of nm23-H1 was identified by immunofluorescence,Western-blotting and flow cytometer.Results:Restriction endonuclease Bam H1 examination showed that 986 bp of nm23-H1 was in pCMV-Bam-Neo vector. 5 weeks after transfection positive clones were obtained and the transfected cells were proliferated to confluent.Immunohistochemical examination,Western blot and flow cytometry showed that nm23-H1 expression was increased in the transfected cells.Conclusion:A tongue cancer cell line expressing nm23-H1 is established.
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Objective To study the mechanism of increased sensitivity to cisplatin by nm23-H1.Methods The plasmid,pCMV-BamH1-Neo-nm23-H1,was transfected to cell line Tca8113 by lipofection strategy and was selected by G418 for 5 weeks.The stable products of nm23-H1 gene were identified by Immunohistofluorescence and Western-blotting.Using MTT and flow cytometer,we detected the changes of cell mortality rate,apoptosis and mitochondrial membrane potential.Results We successfully established the cell line of stable overexpression of nm23-H1.In vitro,the cell mortality rate and apoptosis were increased significantly in stable expression cell line of nm23-H1,compared with those in Tca8113 cell line of non-transfection;this effect could be inhibited by oubain which is an inhibitor of Na(+)/K(+)-ATPase.Mitochondrial membrane potential was decreased significantly in stable expression cell line of nm23-H1.Conclusion Nm23-H1 can increase the sensitivity of cisplatin on Tca8113 cell line;The mechanism may be the mitochondrial membrane potential is decreased by nm23-H1 so that intracellular platinum are increased to finally cause the apoptosis and necrosis of cells.