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BACKGROUND: In recent years, the development of tissue engineering has provided a new approach for the treatment of periodontal bone defect. Tissue engineering therapy includes seed cells, scaffolds and growth factors. Platelet gel contains a large number of platelet growth factors, and collagen is often used for the preparation of scaffold materials. Therefore, the platelet gel and collagen biologically active composite membrane can provide scaffolds and growth factors for the defect bone. OBJECTIVE: To investigate the effect of autologous platelet gel-collagen biologically active composite membrane on the repair of periodontal bone defect in rats. METHODS: Forty-two Wistar rats (Shanghai Xipuer-Bikai Experimental Animal Co., Ltd., China) were selected. (1) Collagen was cut into 5 mm×2 mm size, and 10 mL of whole blood was extracted from 6 rats to obtain platelet-rich plasma. Autologous platelet gel-collagen composite membrane was prepared by adding bovine thrombin, calcium chloride and collagen in a certain proportion. Platelets in whole blood and in platelet-rich plasma were detected. The levels of platelet derived growth factor AB, transforming growth factor-β, basic fibroblast growth factor and vascular endothelial growth factor in whole blood and platelet-rich plasma were detected by ELISA. (2) The models of mandibular periosteal defect were established in 36 rats (the size of the bone defect was 5 mm×2 mm, and the root surface cementum was removed) , and randomly divided into two groups. Autologous platelet gel-collagen group placed the autologous platelet gel-collagen composite membrane in the bone defect, and the control group did not place any materials. The hematoxylin-eosin staining of periodontal tissues of rats in each group was analyzed at 2, 4 and 8 weeks after surgery. Rate of new born, new centumum formation, new alveolar bone formation, and new periodontal ligament tissue formation height were measured. The expression of bone morphogenetic protein-2 was detected by immunohistochemical staining. RESULTS AND CONCLUSION: (1) The mean platelet count in platelet-rich plasma was 4.78 times as high as the whole blood, indicating that the number of platelets increased significantly after prepared into platelet-rich plasma (P < 0.05) . The levels of platelet derived growth factor AB, transforming growth factor-β, basic fibroblast growth factor and vascular endothelial growth factor in platelet-rich plasma were 3.10, 3.45, 7.17 and 5.45 times of the whole blood, respectively (P < 0.05) . (2) The results of hematoxylin-eosin staining observed that the rate of new born, new centumum formation, new alveolar bone formation, and new periodontal ligament tissue formation height at 2 weeks in the autologous platelet gel-collagen group showed no significant difference from the control group (P> 0.05) . At 4 and 8 weeks, all above indexes in the autologous platelet gel-collagen group were significantly higher than those in the control group (P < 0.05) . (3) Results of immunohistochemical staining revealed that at 2 weeks, bone morphogenetic protein-2 in the autologous platelet gel-collagen group began to express, and the expression of bone morphogenetic protein-2 was highest at 4 weeks (P < 0.05) , and the positive expression was weakened at 8 weeks (P> 0.05) . (4) Our results clarify that autologous platelet gel-collagen bioactive composite membrane can significantly promote the regeneration of new tooth, which is associated with the expression of bone morphogenetic protein-2, and reduce the repair time after periodontal tissue defect.
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Objective To investigate the effect of supratemporalis approach scalp coronal incision for treating craniomaxillofacial fracture.Methods Fifty-two cases of traditional coronal scalp approach were retrospectively analyzed for understanding the facial nerve damage situation.Then 30 cases a.dopted the supratemporalis approach scalp coronal incision and the facial nerve damage situation was recorded.The follow-up observation lasted for 6-24 months.Results The facial contour,mouth opening and occlusion function recovered well after the operation in all 82 cases.Eight cases of temporary facial nerve injury were observed in the traditional approach group.No case of facial nerve injury occurred in the supratemporalis approach group(P＜0.05).Conclusion The supratemporalis approach scalp coronal incision can effectively avoid the facial nerve injuries.
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Objective:To construct an adeno-associated vector expressing Snail "tough decoy" (TUD).Methods:The nucleotide sequence of Snail gene were obtained from GenBank,then 2 cDNAs were designed and synthesized coding expression of small hairpin RNAs for Snail genes.The pAAV-U6-shRNA-Snail-TUD-EGFP expression vector was constructed by molecular biological techniques.Then pAAV-U6-shRNA-Snail-TUD-EGFP was co-transfected with Helper Free adeno-associated virus system pAAV-RC and pAAV-Helper into AAV-293 cell line to form rAAY-U6-shRNA-Snail-TUD(shRNA-Snail).The silencing effect of shRNA-Snail in Tca8113 and Cal-27 cells was detected by RT-PCR.The titer of the virus was measured.The expression level of green fluorescent protein in AAV-293 cells was monitored by the fluorescent microscopy.Results:The result of gene sequencing showed that shRNA-Snail was successful constructed in pAAV-U6-shRNA-Snail-TUD-EGFP vector.The titer of the recombined virus was 4.4 × 1010/ml.The Snail mRNA and protein expression level was significantly reduced in Tca8113 and Cal-27 cells by rAAY-U6-shRNA-Snail-TUD-EGFP transfection.Conclusion:rAAY-U6-shRNA-Snail-TUD-EGFP may inhibite Snail gene expression in cells.
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Objective:To study the cytotoxicity of PHEMA /CPC composite hydrogel.Methods:L929 cells were cultured by RP-MI1 640 with 1 0% fetal bovine serum(blank control),with PHEMA /CPC extraction(experimental group),high density polyethy-lene(HDPE)extracts(negative control)and 5% DMSO(positive control)for 24,48 and 72 h respectively.The cell proliferation was examined by MTT assay.Cell apoptosis was detected by flow cytometry and Annexin V-FITC /PI kit.Results:The A value of positive control group decreased with the increase of culture time(P 0.05).The cytotoxicity of the experimental group was grade Ⅰ.That of other groups increased with the increase of culture time. Cell apoptosis(%)in PHEMA /CPC composite hydrogel group and blank group was 4.21 ±0.30 and 4.89 ±0.39 respectively(P>0.05).Conclusion:Injectable PHEMA /CPC composite hydrogel has no cytotoxicity and no effect on cell apoptosis.
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<p><b>OBJECTIVE</b>To study the effect of high glucose and mannitol (osmotic control) on receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis and Notch2 expression using bone marrow macrophages (BMMs) from mice. Furthermore, the effect of Notch2 activation on RANKL-induced osteoclastogenesis with high glucose concentration was explored.</p><p><b>METHODS</b>Preosteoclasts were cultured and exposed to sustained high glucose (0, 5, 10, 20, 40 mmol x L(-1)) levels to mimic diabetic conditions. Osteoclast formation was analyzed using tartrate resistant acid phosphatase (TRAP) assay. Expression of Notch2 gene was analyzed using real-time polymerase chain reaction. Constitutively over-expressed active Notch2, via stable transfection of exogenous ICN2 (intracellular fragment of Notch2) in preosteoclasts and the effect of Notch2 over expression on osteoclastogenesis was analyzed using Western blotting and TRAP staining.</p><p><b>RESULTS</b>The osteoclast number with 20 mmol x L(-1) glucose (110.3 +/- 6.8) and 40 mmol x L(1) glucose (72.0 +/- 8.0) was significantly less than the group with 20mmol x L(-1) mannitol (152.7 +/- 7.0) and 40 mmol x L(-1) mannitol (157.0 +/- 12.5). The relative gene expression of Notch2 with 20 mmol x L(-1) glucose (1.65 +/- 0.23) and 40 mmol x L(-1) glucose (1.10 +/- 0.11) was significantly less than the group with 20 mmol x L(-1) mannitol (2.82 +/- 0.28) and 40 mmol x L(-1) mannitol (2.42 +/- 0.27) (P < 0.05). The osteoclast number after Notch2 activation (ICN2-OE) with 20 mmol x L(-1) glucose (206.7+/- 7.8) and 40 mmol x L(-1) glucose (178.3 +/- 11.5) was significantly more than the control group (EMPTY) (102.3 +/- 8.7 and 76.0 +/- 10.1 respectively) ( P < 0.05).</p><p><b>CONCLUSION</b>Notch2 signaling activation may promote osteoclastogenesis under high glucose concentration.</p>
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Animals , Mice , Blotting, Western , Cell Differentiation , Cells, Cultured , Glucose , In Vitro Techniques , Macrophages , Osteoclasts , RANK Ligand , TransfectionABSTRACT
0.05), except PYM-AMS of 1.130 mg/ml and PYM of 300 ?g/ml at 24 h.In the same group and at the same exposure time,higher dose of the corresponding agents showed higher growth inhibition ratio(P0.05).At the same doses 48 h exposure of PYM-AMS or PYM gave higher apoptosis rate than 24 h exposure(P
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Objective: To evaluate the effect of pingyangmycin-albumin microspheres (PYM-AMS) on the modality of endothelial cells. Methods:In the in vitro study blood vessle endothelial cells of ECV 304 cell line were exposed to PYM-AMS(containing PYM at 150 ?g/ml),AMS and PYM(150 ?g/ml) for 24,48,72 and 96 h respectively. In the in vivo study,24 Japanese white rabbits were divided into 4 groups using randomized block design. PYM+9 g/L NaCl,PYM+soyabean oil, PYM-AMS+soyabean oil(PYM at 5 mg/ml) were injected into the central auricular arteries of the animals(0.26 ml/per ear), then these vessels were examined histologically 2, 7, 14, 21 days after injection respectively. The mophorlogy of the cells was observed by light microscope and electron microscope.Results:In vitro, a great part of cells were swollen and cell number decreased in PYM and PYM-AMS group. But there was no change in AMS group.In vivo, the endothelial cells had no significant changes in PYM+9 g/L NaCl group.In PYM+soyabean oil group, at the 2nd day, the endothelial cells were a little bit swollen. At the 7th day, some endothelial cells were dropped off. At the 21st day, a few of endothelial cells were proliferative. In PYM-AMS group, at the 2nd day, the endothelial cells were a little bit swollen and small vessels were embolized by PYM-AMS. At the 7th day, the endothelial cells were swollen. At the 14th day, the endothelial cells were proliferative and the wall of the central auricular artery had more layers. The lumen of the central artery became smaller, while the surface of PYM-AMS was absorbed. At the 21st day, the wall of the central auricular artery was proliferative and the artery became sclerostenosed. The PYM-AMS was obviously absorbed, while the wall of small vein was proliferative, too. Conclusion:PYM-AMS and PYM may injure blood vessel endothelial cells, the effect of PYM-AMS is more obvious than pingyangmycin.