Since enrolling oral medical undergraduates, under the guiding ideology of “culti-vating applied medical personnel for grass roots”, Xi 'an Medical University has kept trying to find effective measures to strengthen tooth carving training. It has made full use of resources and advan-tages of oral professional technology, cleared the aim, significance, content and form of tooth carving training, paid attention to linking up tooth carving skill and oral clinical courses, then formed a set of distinctive tooth carving experimental teaching mode by strengthening teacher training, innovating pra-ctice teaching methods, making teaching models, carrying out opening experiment, designing com-prehensive experiment examination methods, and actively taking part in skill competitions, and so on.

Dental Care ; Plasma Gases

Objective To explore the effects of low-dose X-ray irradiation effects on ischemic flap survival and its possible mechanism.Methods From June, 2014 to December, 2014, 80 SD rats were include in the study, the rats were randomly divided into 2 groups: the experimental group A and control group B.There were 40 rats in each group.The ischemic flaps with the size of 9 cm × 3 cm were designed on the back of the rats.The pedicle of the flaps was near to the tail.A sterile biological isolating membrane was placed under the flap to block the blood supply between muscular layer and flaps.The flaps were intermittently sutured into their original position.The group A was immediately received single and local irradiation of 0.2 Gy after surgery, The group B was not treated.On days 1 to 14 after operation,general observation,HE staining and the western blot of the flaps were performed to calculate the survival vate of the flaps, observe neovascularization and determin the content of VEGF and MMP-9, respectively.Results On the third, seventh and fourteenth days, survival rates of the flaps in the experimental group [(66.46 ± 4.37)％, (44.30 ± 3.86)％, (32.20 ± 4.22)％, respectively] were higher than the control group [(43.15 ± 5.03)％, (27.71 ± 3.20)％, (16.40 ± 5.34)％, respectively] after inspection, there were statistically significant differences between these indices (P ＜ 0.01), HE staining of the flaps in the experimental group were seen in the fibroblast infiltration and neovascularization were higher than that of control group, and experimental group within the lumen of blood vessels were arranged in order, the groups were visible tissue edema obviously control, neovascularization in small numbers, the lumen was irregular.On the third and seventh days, MVD rates of the flaps in the experimental group (85.54 ± 6.12, 44.32 ± 3.56, respectively) were higher than the control group (49.35 ± 4.75,18.75 ± 2.89,respectively) after inspection, there were statistically significant differences between these indices (P ＜ 0.01).VEGF and MMP-9 protein content in the flap for the seventh day in the experimental group were significantly higher than that of the control group.Conclusion Low-dose X-ray irradiation can promote the survival rate of ischemic flap, the mechanism may be related to the expression of VEGF and MMP-9 increased and promoted angiogenesis of the flaps after low-dose X-ray irradiation.

Objective To investigate the effect ofnarrow-band ultraviolet-B(NB-UVB)(311 nm)on dendrite formation in B16 melanoma cells.Methods B16 melanoma cells were irradiated with various doses of NB-UVB(0,25,50,100,200,300 mJ/cm2).Atier additional culture of varying durations,irradiated cells were harvested and subjected to the observation of morphological changes and cell cytoskeleton F-actin microfilaments by phase contrast microscopy and laser scanning confocal microscopy(LSCM).respectively,and to the detection of cell proliferation bv MTT colorimetric assay.Pull down assay was performed to detect the activity of GTP-RhoAA and GTP-Rac1 in B16 cells before and after UVB irradiation.Results Twenty-four hours after irradiation with UVB of 100 mJ/cm2.an increase was observed in the cell body of B16 cells which appeared in sphericity,as well as in the number of dendrites(P＜0.01)which showed a branch-like appearance.compared with non-irradiated cells which had 2-3 dendrites and obscure branches.LSCM revealed that F-actin microfilaments in B16 cells were well organized with clear textures before irradiation;after irradiation wim NB-UVB of 100 mJ/cm2.stress fibers were disassembled and disrupted and the texture became unclear,which was observed as early as 30 minutes and became more and more evident,and at 6 hours the stress fibers displayed a clumping appearance with obscure textures.Following the irradiation with NB-UVB of 100 mJ/cm2,the expression level of GTP-Rac 1 protein increased at l 5 minutes,and.at 30minutes,reached 2 times of that observed in nonirradiated cells,then decreased a liale,but still remained elevated at 60 minutes and 120 minutes,compared to unirradiated cells;meanwhile.the level of GTP-RhoA dropped a little at 30 minutes,then gradually increased and,at 120 minutes.reached 1.6 times of that observed in unirradiated cells.Conclusion Narrow-band UVB(311 nm)can promote dendrite formation.likely via regulating the expression of GTP-Racl and GTP-RhoA in B16 melanoma cells.

Objective To establish the gas chromatographic(GC) fingerprint of oleic acid of Whitmania pigra Whitman for its quality control. Methods Ten batches of Whitmania pigra from different sources and processed by different methods were analyzed with Agilent 6890N gas chromatography detector on DB-WAX(30 mm × 0.32 mm × 0.25μm)column at the vaporizing temperature of 270℃, column temperature of 130℃and flame ionization detector (FID) temperature of 280℃. We used a software of Similarity Evaluation System for Chromatographic Fingerprint of TCM(Version of 2004A) published by Chinese Pharmacopoeia Commission to calculate GC similarity. Results Oleic acid content of Whitmania pigra processed by different methods had significant differences (F2,7 = 7.350, P = 0.019). The oleic acid content of samples dried after washing with clean water significantly differed from that of the samples processed by alumen or the slices dried naturally(P = 0.021, P= 0.009). The similarity of the fingerprints was in the range of 0.458 - 0.998. The similarity of samples from Lipu of Guangxi Province was the lowest. Conclusion The fingerprints of most of the samples have very high similarity. The established GC fingerprints can be used to effectively identify the qualified or inferior Whitmania pigra products, which will provide some reference for the quality control of Whitmania pigra.

Objective To study the effects of Guhong injection on the expression of vascular endothelial growth factor (VEGF) in the cortex 14 days after cerebral ischemia-reperfusion. Methods 30 male Sprague-Dawley rats were divided into sham group (n=6), ischemia group (n=6), aceglutamide injection group (n=6), Honghua injection group (n=6) and Guhong injection group (n=6). The middle cerebral arteries of all the rats were occluded for 2 hours and reperfusion, except the sham group. Drugs were administered once a day 24 hours after reperfusion. The expression of VEGF in cortex was detected with enzyme-linked immunosorbent assay (ELISA) 14 days after reperfusion. Results The expression of VEGF decreased in the ischemia group compared with the sham group (P<0.001), and it increased both in the aceglutamide and Guhong injection groups compared with the ischemia group (P<0.05). Conclusion Guhong injection can significantly increase the expression of VEGF in the cortex 14 days after ischemia-reperfusion, which may be one of the ways for neuro-protection.

Anti-Bacterial Agents ; therapeutic use ; Drainage ; External Fixators ; Female ; Fracture Fixation ; methods ; Fracture Fixation, Internal ; adverse effects ; Fractures, Open ; surgery ; Humans ; Male ; Microsurgery ; Soft Tissue Injuries ; surgery ; Surgical Flaps ; Surgical Wound Infection ; therapy ; Tibial Fractures ; surgery ; Treatment Outcome

Objective To study effect of bufalin on invasion and metastasis of gastric cancer cells and related mechanism.Methods AGS human gastric cancer cell line was used for in vitro experiments.Cultured cells were treated by negative control group,bufalin group and oxaliplatin group.Cell proliferation was determined by MTT.Invasion and metastasis were observed by Wound-Healing Assay and Transwell Assay.Expression levels of E-cadherin,matrix metalloproteinases (MMP)-2,MMP-9 were detected by Western blotting.Results Bufalin was found to significantly inhibit the proliferation of AGS cells in a dose and time dependent manner.Wound-Healing Assay and Transwell Assay showed that as compared with the blank control group,bufalin inhibited invasion and metastasis of AGS cells (P＜ 0.05),but there was no statistically significant difference between bufalin group and oxaliplatin group (P＞0.05).Western blotting showed the expression of E-cadherin was increased in bufalin group as compared with the blank control group while the expression levels of MMP-9 and MMP-2 were down-regulated (P＜0.05),but there was no statistically significant difference between bufalin group and oxaliplatin group (P＞ 0.05).Conclusion Bufalin has anti-cancer activity on gastric cancer cells,and it has the ability of inhibiting cancer cell invasion and metastasis,and regulating the expression of some related gene.

OBJECTIVETo explore the inhibitory effect of angiotensin (1-7) on hepatic sinusoid angiogenesis using a rat model of hepatic fibrosis.

METHODSEighteen male Wistar rats were randomly divided into three equal groups for sham operation (untreated/uninduced control group), bile duct ligation (BDL) (untreated model group), or BDL with angiotensin (1-7) treatment (treated model group). Histological analysis was used to assess the liver fibrosis score, by hematoxylin-eosin staining, and the level of fibrosis, by Masson's trichrome staining. Immunohistochemistry, western blotting, and immunofluorescence were used to assess the expression of the angiogenesis markers vWF, VEGFA, and CD31.

RESULTSCompared with the untreated/uninduced control group, the untreated BDL model group showed remarkably higher fibrosis score, area of the type I collagen expression, and expression levels of vWF, VEGFA, and CD31. However, the angiotensin (1-7)-treatment protected against the BLD-related changes, as evidenced by decreased robustness and down-regulation of the corresponding indicators. Moreover, the expression level of VEGFA was highly correlated to the expression level of vWF (r = 0.956, P = 0.000).

CONCLUSIONBDL-induced hepatic fibrosis is accompanied by significant increases in angiogenesis-related factors, but angiotensin (1-7) treatment may inhibit hepatic sinusoid angiogenesis during the liver fibrosis process.

Angiotensin I ; therapeutic use ; Animals ; Bile Ducts ; surgery ; Hepatic Veins ; pathology ; Ligation ; Liver Cirrhosis, Experimental ; drug therapy ; pathology ; Male ; Neovascularization, Pathologic ; drug therapy ; Peptide Fragments ; therapeutic use ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Rats ; Rats, Wistar ; Vascular Endothelial Growth Factor A ; metabolism ; von Willebrand Factor ; metabolism

OBJECTIVETo obtain highly purified tetanus toxin fragment C (TTC) with good immunogenicity.

METHODSThe gene fragment encoding TTC was amplified from Clostridium tetani plasmid DNA by PCR, inserted into the vector pET43.1a (+) and expressed in E. coli BL21(DE3)plysS. After purification using Ni2+-chelate affinity chromatography, the expressed fusion protein was digested by thrombin and the resultant TTC protein was purified with Ni2+-chelate affinity chromatography followed by identification with SDS-PAGE and Western blotting. The purifed TTC protein was then used to immunize mice to test its immunogenecity.

RESULTSThe 1373-bp gene fragment encoding TTC was obtained, and the constructed recombinant expression vector pET43.1a (+)-TTC was successfully expressed in E. coli BL21(DE3)plysS. SDS-PAGE identified a recombinant fusion protein with relative molecular mass (Mr) of 117 000, which accounted for 22% of the total bacterial protein. The TTC protein with Mr of 50 000 was obtained after purification of the thrombin digestion products of the fusion protein, with a purity reaching 95.5%. Both the fusion protein and TTC protein could be recognized by anti-tetanus toxin antibody as shown by Western blotting. The titer of the anti-serum from mice immunized with the TTC protein was 1:25 600, and the anti-serum could specifically bind to tetanus toxin.

CONCLUSIONHighly purified and immunogenetic TTC protein has been successfully obtained, which provides a good model antigen for studying antigen presentation and immune responses in vivo.

Cloning, Molecular ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Peptide Fragments ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Tetanus Toxin ; biosynthesis ; genetics ; immunology ; Tetanus Toxoid ; immunology