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AIM: To observe the effects of Helicobacter pylori (Hp) on the apoptosis of human gingival tissue.METHODS: Gingival tissue samples were taken from 30 patients without chronic periodontitis, and Hp was detected by conventional PCR.The apoptosis of the gingivival cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to analyze the correlation between Hp infection and apoptosis of the gingival tissues.RESULTS: The Hp positive detections were 12 in the 30 patients without periodontitis, so the positive rate of Hp in the gingival tissue samples was 40%.The gingival tissue showed a large number of apoptotic cells in Hp positive group, and less apoptotic cells in Hp negative group.The apoptotic index in Hp positive group (0.498±0.092) was significantly higher than that in normal group (0.207±0.053) (P<0.05).CONCLUSION: Hp might play a role in the apoptosis of gingival tissues.
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Objective:To investigate the synergistic effect and mechanism of the combined application of recombinant human bone morphogenetic protein-2(rhBMP-2) and basic fibroblast growth factor (bFGF).Methods:24KM male mice were randomly divided into6 groups with4 mice in each group, namely,GroupA(control group),GroupB(only treated with collagen),GroupC(treated with 2 ng bFGF+collagen),GroupD(treated with4 μg rhBMP-2+collagen),GroupE(treated with4 μg rhBMP-2+2 ng bFGF+collagen) andGroupF(treated with4 μg rhBMP-2+4 ng bFGF+collagen). The composites were implanted into the intermuscular septum of hind legs mice; whereas in control group, intermuscular septum of mice was separated and no implantation was performed. General observation, detection of concentration of calcium content, micro computed tomography (Micro-CT), three-dimensional reconstruction scan, measurement of bone mineral density(BMD), bone volume fraction(BVF) and trabecular thickness(Tb.Th), as well as histological observation withHE staining andALP andCD34 immumohistochemical staining were performed.Results:Ectopic osteogenesis was found inGroupsD,E andF mice.The difference in concentration of calcium contentswas statistically significant betweenGroupsD andE(P0.05).Micro-CT and three-dimensional reconstruction revealed continuous newborn bone substance in external surface of ectopic bone formation, and the center of bone formation did not show obvious substantial filling by bone substance.The differences in BMD,BVF andTb.Th were statistically significant betweenGroupsD andE orF(P<0.01 or <0.05). HE staining showed that inGroupsD,E andF, newborn bone substance was mainly located at the edge of ectopic bone formation, and the bone formation inGroupsE andF was better than that in GroupD.ALP andCD34 immumohistochemical staining revealed the positive expression mainly at the edge of ectopic bone formation, and area of positiveexpression inGroupsE andF was larger than that inGroupsD.Conclusions:rhBMP-2 possesses the capacity to induce ectopic osteogenesis independently, but bFGF does not have this ability; the combined application of rhBMP-2 and bFGF can enhance the synergetic effect on inducing ectopic osteogenesis.
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[ABSTRACT]AIM:Toinvestigatetheapplicabilityanddegradabilityoftheantigen-extractedxenogeneicbone carrying recombinant human bone morphogenetic protein 2 ( rhBMP-2) as a scaffold in repairing the mandibular defect in vivo.METHODS:New Zealand rabbits (n=28) with 28 mandibular defects were divided into 3 groups at random:anti-gen-extracted xenogeneic cancellous bone /rhBMP-2 group (group A), antigen-extracted xenogeneic cancellous bone group ( group B ) and blank control group ( group C ) .Twelve bone defects each in group A and group B were classified into 3 time points (4, 8 and 12 weeks).Observation in general, X-ray test and hematoxylin and eosin staining and bone density measurement were conducted on each rabbit in group A and group B .Four bone defects were classified into group C .Ob-servation in general , X-ray test and hematoxylin and eosin staining were also conducted on each rabbit in group C .RE-SULTS:The X-ray showed that the implanted materials were degraded after a period of time , and were replaced by autoge-nous bone.At the 12th week, the implanted materials in group A were entirely degraded and replaced by autogenous bone . The bone density measurement showed that the bone density was enhanced after implantation .At the 12th week, there was an obvious difference between group A and group B .The hematoxylin and eosin staining showed there were more neovascu-larization, new fibrosis and new bone formation in group A than those in group B .The implanted material in group A de-graded much faster than that in group B .The significant difference in the new bone area ratio between the 2 groups among all weeks was observed .CONCLUSION: An antigen-extracted xenogeneic cancellous bone has good biocompatibility , which can act as a scaffold in bone repairment .It is the carrier of rhBMP-2 to continue the bone formation .Therefore, anti-gen-extracted xenogeneic cancellous bone is a kind of good material for bone repairment .
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BACKGROUND: Traditional solid bone can not receive satisfied effects in repairing irregular bone defects in oral maxillofacial surgery due to uneven distribution of cells and growth factors. Therefore, it is a research direction to prepare injectable tissue engineering bone.OBJECTIVE: To explore the effects of chitosan/β-tricalcium phosphate/recombinant human bone morphogenetic protein-2(CS/β-TCP/rhBMP-2) composite on mandibular defect repair.DESIGN, TIME AND SETTING: A randomized controlled animal experiment. The experiment was performed atthe animal laboratory, Medical College of Jinnan University from May 2008 to March 2009.MATERIALS: The injectable tissue engineering bone was prepared by using complex of liquid CS and solid β-TCP as scaffold materials, and combined with freeze-dried rhBMP-2.METHODS: Twenty-four New Zealand white rabbits were prepared for double sides mandibular defect models, and randomized into 4 groups: ①CS/p-TCP/rhBMP-2 group: 1 mL CS/β-TCP/rhBMP-2 complex was injected into the defects.②CS/β-TCP group:0.5 mL CS/β-TCP complex was injected into defects. ③Autograft bone group: repairing the defects with sclerotin of the iliac crest.④Blank control group: no implantation. MAIN OUTCOME MEASURES: At weeks 2, 4 and 8 after surgery, the material degradation and new bone formation were evaluated with, haematoxylin-eosin staining, and electron microscope; the bone mineral density was detected by dual energy X-ray absorptiometry (DXA) to determine bone formation rate and quality.RESULTS: ①Gross observation demonstrated that the size and thickness of osteotylus in CS/β-TCP/rhBMP-2 group was equivalent with the autograft group, which were greater than that of the other groups.②Histologicalobservation demonstrated that there were more bone matrixes in the CS/β-TCP/rhBMP-2 group and autograft group than that in the CS/β-TCP group and blank control group at each time points. ③Scanning electron microscope image suggested that at 8 weeks after operation, the bone bed and the materials in CS/β-TCP/rhBMP-2 group were connected with bone, and the gap was diminished. The degradation of the materials was so obvious that the complete structure of materials could not be found. ⑤DXA detection appealed that the bone density of each group was gradually increased with time prolonged. The quantities of bone density in CS/β-TCP/rhBMP-2 group in weeks 2, 4 and 8 were significantly higher than CS/β-TCP group and blankcontrol group (P < 0.05).CONCLUSION: ①CS/β-TCP/rhBMP-2 has good biocompatibility, degradability and the capacity of bone guidance and bone induction. ②CS/β-TCP can be served as a promising carrier for BMP-2, which is a potential degradable biological material for repairing bone defects.
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AIM: To examine the microsatellite instability (MSI) and loss of heterozygosity (LOH) in head and neck squamous cell carcinomas (HNSCC). METHODS: 36 cases of HNSCC were analyzed with 15 microsatellite markers from chromosome 3,5,6,8,9,13,17 and 18. RESULTS: Among the 36 cases of HNSCC, 27.8%(10/36)of samples showed MSI in one to eight microsatellite markers. High frequent MSI occurred at D17S520(22.9%), D6S105(16 7%)and D8S264(13 9%). LOH was detected on the site of 9p21-p22 and 3p14. No correlations were found between allelic instability and grade or stage of the tumor. CONCLUSION: Our data suggest that MSI is a common genetic change in HNSCC. Tumor suppressor genes related to HNSCC may harbor at chromosome 9p21-p22 and 3p14 regions. [
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AIM:This study aims to screen the differentially expressed genes related to the pathogenesis of ameloblastoma by cDNA microarray.METHODS:The total RNAs were isolated from ameloblastoma and tooth germ,respectively.The RNAs were purified by oligotex.Both the mRNAs from two kinds of tissues were reversely transcribed to cDNA with the incorporation of fluorescent-labelled dUTP to prepare the hybridization probes.The mixed probes were hybridized to cDNA microarray.Tumor-related genes were screened through the analysis of fluroescent intensity.RESULTS:722 genes exhibited significant changes in expression levels in the ameloblastoma in comparison with tooth germs tissues.240 genes were overexpressed more than doubled(92 genes were more than 3-fold),and 482 genes were underexpressed to below 0.5 of the control level.CONCLUSION:Microarray technique facilitates large scale and rapid identification of potential target genes of ameloblastoma.
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AIM: The purpose of this study was to investigate the effects of rhBMP-2/collagen composite on bone regeneration during expansion of the interparietal suture in the rats. METHODS: 32 10-week old SD rats were divided into groups consisting of 8 rats each. They were comprised of normal control group, expansion control group and the treatment group, the two treatment groups were covered with atelo-typeⅠcollagen and rhBMP-2/collagen composite on the suture before subjected to the expansion force. The bone regeneration in the interparietal suture was estimated by histological method, the osteocalcin content was measured by radioimmonoassay and the calcium content was determined by atomic absorption spectrophotometer. RESULTS: The bone regeneration was more active in the suture after giving an expanding force than in the suture without any intervention. Even bone bridge was formed in the rhBMP-2/collagen composite group. Both the osteocalcin content and calcium content were much higher in the rhBMP-2/collagen composite group than in other three groups (P