Objective To establish a three-dimensional finite element model of rapid canine tooth movement by reducing resistance and distracting procedures,and to discuss canine distal movement and force distribution of periodontium,and to provide theory basis for its clinical application.Methods Through 64-slice spiral scanning,temporomandibular joint (TMJ),the mandible,lower jaw denture section phantom DICOM data were obtained.Mimics software,Geomagic Studio 8.0 software,Unigraphics NX software,and Ansys11.0 software were mixed,and the three-dimensional finite element model were established under the conventional condition to move the canine (model 1 ),rapid canine movement through distracting osteggenesis of the periodontal ligament (model 2),rapid canine movement tooth movement through reducing resistance and distracting method (model 3),the strength were carried on three kind of models and the canine,the pericementum,the tooth socket bone stress distribution were observed.Results The biggest displacements on those three models occured in canine crown on 1/3,biggest displacement quantity:model 3 ＞model 2 ＞model 1,and the canine crown displacement reduced gradually from crown to the root point; in the model 1 most greatly equivalent stress mainly concentrated in the middle of distal alveolar crest,but in the models 2 and 3 most greatly equivalent stress centralism area shifted liguodistal alveolar crest.Conclusions In the process of canine distal movement,reducing bone resistance,can accelerate the tooth moving speed effectively and simultaneously,the canine has distal motion tendency.While under the action of force,the canine tends to move ligually with the canine distal movement,and thus appropriate measures should be taken to prevent canine lingual rotation in clinical work.

Colorectal cancer is currently the third most common cancer worldwide,and there are still half of the patients undergoing recurrence and metastasis after surgical treatment,so it is necessary for colorectal cancer patients to receive radiation therapy routinely.Due to the side effects brought by radiotherapy,it is of great importance to solve how to minimize the radiation dose in radiation therapy and improve radiation sensitivity.In recent years,people discovered that microRNAs can not only be involved in the origins of colorectal cancer and progress,but also play a increasingly important role in cancer radiosensitivity.MicroRNAs can regulate tumor radiosensitivity by influencing tumor microenvironment and function on target genes.DNA damage response caused by radiation includes the activation of ATM,histone modification and chromatin remodeling,cell cycle arrest,damage repair and apoptosis.microRNAs can regulate tumor radiosensitivity through above processes.This review focuses on the mechanism of microRNAs in affecting DNA damage repair and prospects the future of microRNAs in influencing the sensitivity of cancer radiotherapy in clinical application.

Objective To analyze the application and funding for projects in radiation oncology from National Natural Science Foundation of China ( NNSFC ) from 2006 to 2015. Methods To collect the funding information in radiation oncology from NNSFC from 2006 to 2015, a computerized search was performed in the ISIS system using a subject code of H1610 and a keyword of radiation oncology. Analyses were performed in distribution of research fields, the geographical distribution of applicants, and the properties of institutes/universities the applicants were affiliated with. Results In the last decade, a total of 435 projects in the field of radiation oncology were funded with 180 million yuan. Most projects were funded by general, youth, and regional foundation, which covered the highest proportion of NNSFC. For a single project, the amounts of funding from general, youth, and regional foundations were 530, 220, and 400 thousand yuan, respectively. The institutes/universities the NNSFC?funded projects were affiliated with were located quite close to each other. The top 10 institutes/universities in terms of the number of NNSFC?funded projects covered 53% of projects. In all projects, 88% studied basic science, which covered many hot topics in oncology including biological effects of radiotherapy, microenvironment, and stem cells. A small number ( 12%) of projects focused on physics. Top 3 cancers in terms of the number of projects and the amount of funding were lung cancer, nasopharyngeal carcinoma, and esophagus cancer. Conclusions In the last decade, the field of radiation oncology has stable increases in the number of NNSFC?funded projects and the amount of funding. The NNSFC?funded research teams are unevenly distributed, most of which are located in East China. The most popular topic in basic science studies is about biological effects of radiotherapy.

BACKGROUND: Connexin 43 (Cx43) plays an important role in occurrence and development of osteoarthritis. However, the specific mechanisms involved remain unclear. OBJECTIVE: To verify the possibility of the dominant position of Cx43 in connexin family in osteoarthritis by detecting the expression of Cx43 in articular cartilage and chondrocyte cell line, and to construct shRNA lentivirus vector of Cx43 gene and establish a stable transfer cell line of chondrocyte (SW1353). METHODS: Animal models of osteoarthritis were established in six C57BL/6 mice by anterior cruciate ligament transection. The differences of Cx43 expression between osteoarthritic and normal knees were investigated by immunohistochemistry. Expression of Cx43 mRNA in chondrocyte (SW1353) was detected by RT-PCR, and the expression levels of Cx37, Cx40, Cx45 and Cx46 in SW1353 cells were detected as control. Cx43 were connected to the lentiviral vector carrying the EGFP gene, to reconstruct the lentiviral vector plasmid. The viral particles were generated by co-transfection of 293T cells with Cx43-shRNA. After transfection of Cx43-shRNA lentiviral vector into chondrocytes (SW1353), the expression level of Cx43 was detected by western blot assay and RT-PCR. The study protocol was approved by the Ethics Committee of State Key Laboratory of Oral Diseases, approved No. SKLODLL2013A172. RESULTS AND CONCLUSION: The expression level of Cx43 was significantly increased in the articular cartilage of osteoarthritic knees. The expression level of Cx43 mRNA was significantly higher than that of Cx37, Cx40, Cx45 and Cx46 in chondrocytes (SW1353). In SW1353 cells, Cx43 occupied the dominant position in connexin family. Cx43 shRNA lentiviral vector could inhibit the expression of Cx43 mRNA in SW1353 cells. The stably transfected SW1353 cell line was screened, laying a foundation for verifying the role of Cx43 in osteoarthritis.

ObjectiveTo explore the pathological effect of Anti-stenosis No.1 which had effect of vivid Qi and promoting blood flow,eliminate sputum and circulating collaterals on restenosis after carotid artery angioplasty in experimental rats.Methods48 rats were randomly divided into the blank group,the hyperlipid group,the small-dose group and the large-dose group.Restenosis model in carotid artery after angioplasty was built by high-dose cholesterol diet and three times balloon injury.Chinese herbs were administered for three months.Lumen area,intimal area,media area and intimal area/media area in the restenosis region were calculated.ResultsLumen area and intimal area were very more significantly changed in the hyperlipid group,the small-dose group,and the large-dose group compared to the blank group(P<0.01).Media area and intimal area/media area were very more significantly changed in the hyperlipid group and the small-dose group compared to the blank group(P<0.01).There was no significant difference in the large-dose group.Compared to hyperlipid group,lumen area significantly increased in the large-dose group(P<0.01)),intimal area significantly decreased in the small-and large-dose groups(P<0.05),and media area significantly decreased in the large-dose group(P<0.01).There was a significant difference in media area between the small-and large-dose groups(P<0.05).ConclusionAnti-stenosis No.1 can significantly inhibit restenosis by inhibiting intimal and media hyperplasty,and the effect is dose dependent.

Objective To investigate the relationship of extracellular regulated protein kinases activation and neural cells autophagy in rats after subarachnoid hemorrhage.Methods One hundred twenty male SD rats were randomly divided into sham operated group,SAH group,ERK1/2 inhibitor U0126 group,autophagy inducer rapamycin (Rap) group.The animal models were established by injecting the autologous blood into cisterna magna twice.U0126 (5μ g/μL) and Rap (10nmol/μL) were injected into lateral ventricles in U0126 group and Rap group 30min before SAH.The morphology of hippocampal nerve cells were examined by using light microscopy.The expression levels of phosphorylated ERK 1/2 (p-ERK 1/2),ERK 1/2mRNA and autophagy markers (Beclin-1 and Beclin-1 mRNA、LC3-Ⅱ and LC3mRNA) in the hippocampus were detected by using inmunohistochemistry and real-time fluorescence quantitative PCR.Result Compared with sham group,the rate of dead nerve cells,the mRNA levels of ERK1/2,Beclin-1 and LC3 as well as the levels of the p-ERK1/2,Beclin-1 and LC3-Ⅱ increased in SAH group (P＜0.05).Compared with SAH group,the rate of dead nerve cells increased(P＜0.05),the ERK1/2 mRNA,Beclin-1 mRNA and LC3 mRN A,and p-ERK1/2,Beclin-landLC3-Ⅱ in U0126 group decreased(P＜0.05);the rate of dead nerve cells decreased (P＜0.05),the Beclin-1 mRNA and LC3 mRNA,the Beclin-1and LC3-Ⅱ level increased in Rap group(P＜0.05),but ERK 1/2 mRNA and p-ERK 1/2 remained unchanged (P＞0.05).Conclusion Activation of the ERK1/2 signaling pathway after SAH,can induce nerve cells death by increasing Beclin-1 and LC3-Ⅱ expressions.

Objective To investigate the effect of MAPK activation on autophagy in the hippocampus of rats with subarachnoid hemorrhage.Methods A total of 100 male SD rats were divided into 5 groups randomly:sham operated group,SAH group,inhibitor U0126 group,inhibitor SB203580 group,SP600125 group.The animal model was established by injecting the autologous blood into cisterna magna twice.The morphological changes of hippocampus nerve cells of rat brain were detected with HE.The mRNA levels of ERK1/2,p38MAPK,JNK and LC3 in hippocampus were detected with quantitative real time PCR and the expression of phosphorylated ERK1/2,phosphorylated p38MAPK,phosphorylated JNK and LC3-Ⅱ in hippocampus of rat brain were detected by immunohistochemistry.Results Compared with the Sham group,the survival rate of neurons in SAH group decreased (6 h:(84.982 ± 5.723) ％,24 h:(74.383± 9.860) ％,48 h:(62.860± 10.820) ％,72 h:(52.260± 10.960) ％) (all P＜0.05).The levels of ERK1/2 mRNA,p38MAPK mRNA,JNK mRNA and LC3 mRNA in hippocampus increased (all P＜ 0.05) and the expression of p-ERK1/2,p-p38MAPK,p-JNK,LC3-Ⅱ proteins increased(all P＜0.05).Compared with the SAH group,the survival rate of neurons in U0126 group was decreased (6 h:(71.620±6.542) ％,24 h:(66.221±7.742)％,48 h:(55.208±8.802) ％,72 h:(46.242±7.782) ％),and the ERK1/2 and LC3 in hippocampus decreased both in mRNA level and in protein level(all P＜0.05).Compared with the SAH group,the survival rate of neurons in SB203580 groups was increased (6 h:(89.082±6.602)％,24 h:(85.840±9.726) ％,48 h:(74.96± 10.916) ％,72 h:(69.211 ± 10.745) ％),and the p38MAPK,LC3-Ⅱ in hippocampus decreased at both mRNA and protein levels (all P＜0.05).Compared with the SAH group,the survival rate of neurons in SP600125 groups was increased (6 h:(91.620± 7.542) ％,24 h:(86.221 ± 10.742) ％,48 h:(75.208±11.802) ％,72 h:(70.242± 11.782) ％).The expression of JNK was decreased while the LC3-Ⅱ was increased in hippocampus (P＜0.05).Conclusion MAPK activation is involved in the autophagy of hippocampal neurons after SAH,in which ERK1/2 activation plays a positive role in the regulation of autophagy in hippocampal neurons after SAH,while p38MAPK and JNK activation plays a negative role in autophagy.

Objective Carbon/carbon ( C/C) composites are a potential material for bone repair .To improve the hydrophilicity and biological activity of C/C composites , polydopamine coating was prepared on the surface of C /C composites.Methods By changing the coating time and coating environment ( oxygen or air atmosphere ), a series of polydopamine coating samples were prepared . The water contact angle test , scanning electron microscope , energy dispersive spectrometer , atomic force microscope and protein adsorption test were used to characterize the properties of different samples.Then, the data were analyzed to optimize preparation conditions .Results When the concentration of dopamine was 2.0 g/L,and the coating time was 30 min (oxygen atmosphere) +11.5 h (air atmosphere), the water contact angle was decreased from 64.0°(blank sample) to 25.9°, suggesting that the hydrophilicity was improved greatly . The results of the scanning electron microscope , energy dispersive spectrometer and atomic force microscope showed that the coating was uniform and dense .The amount of protein adsorption per sample was 0.2817 mg.Conclusion The polydopamine coating on the C/C composites improves its hydrophilicity and biological activity , which indicates that the polydopamine coated C/C composites will be a new potential material for bone tissue repair .

ObjectiveTo observe the effect of indomethacin on the migration of breast cancer cell line MCF-7 in vitro and investigate the mechanism involved.MethodsThe migration of MCF-7 cell line stimulated with or without indomethacin were tested using transwell plates consisting upper and lower chambers separated by Millipore polycarbonate membrance filters with 8 μm pore sizes; the levels of chemokine receptor 4(CXCR4),cyclooxygenase(COX-2),epidermal growth factor receptor(EGFR) and vascular endothelial growth factor(VEGF)expression in MCF-7 cell line were detected by flow cytometry,Real-time PCR and ELISA,respectively.Results Indomethacin decreased the migration ability of MCF-7 cell line significandy.CXCR4 membrane expression was significantly reduced in a time-dose dependent manner,and CXCR4,COX-2 and EGFR mRNA levels were significantly downregulated after indomethacin stimulation.However,exposure to indometahcin had no major effect on VEGF production of cells.ConclusionThe downregulation of CXCR4,COX-2 and EGFR expression might be the primary mechanism involved in the inhibitory effect of indomethacin on the migration of MCF-7 cell line.

BACKGROUND:Peridental membrane distraction osteogenesis exerts the functions at peridental membrane and leads to tooth movement. Alveolar bone distraction osteogenesis produces tooth movement through the displacement of the whole bone plate.
OBJECTIVE:To establish three-dimensional finite element model of upper and lower jaw of healthy adults under three different conditions, and to compare the stress distribution and distal movement of the models using three-dimensional finite element analysis method.
METHODS:Model 1:three-dimensional finite element model of the canine under normal conditions using a
variety of software;Model 2:three-dimensional finite element model of the canine after distracting osteggenesis of the periodontal ligament;Model 3, three-dimensional finite element model of the canine after reducing resistance and distracting osteggenesis of the alveolar bone. The force loadings were stimulated among these models.
RESULTS AND CONCLUSION:The biggest displacements on those three models occurred in canine crown on 1/3, and the displacement quantity on canine was model 2>model 3>model 1. The biggest equivalent stress concentrated in distal alveolar crest, and the equivalent stress was model 2