Prognostic evaluation of the labial bone plate after anterior maxillary repair with immediate implant combined with immediate restoration / 中国组织工程研究

BACKGROUND: The immediate implantation in the anterior maxillary region is in a high risk of aesthetic complications. OBJECTIVE: To assess the prognosis of the labial bone plate after anterior maxillary repair with immediate implant combined with immediate restoration. METHODS: Thirty-two patients with single failed tooth in the anterior maxillary region were subjected to implantation of ZIMMER implants immediately after minimally invasive extraction. Good primary stability was achieved and immediate restoration was carried out. Final restoration was finished after 6-12 months of osteosynthesis and gingival shaping. The loading situation of the labial bone plate was recorded at 6 months post operation. RESULTS AND CONCLUSION: Final restoration was finished with normal loading in all the patients. No bleeding and swelling of the gingiva was recorded. The horizontal absorption of the labial bone plate at the upper margin, 5 mm and 10 mm below the upper margin was (-2.12±0.05), (-1.54±0.04), and (-1.01±0.06) mm, respectively. Therefore, absorption of the labial bone plate with varying degrees exists after anterior maxillary repair with immediate implant combined with immediate restoration.

Expression and purification of human amelogenin mature peptide in Escherichia coli / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To establish the expression and purification route for human amelogenin mature peptide in Escherichia coli and obtain the purified amelogenin (AMG) mature peptide.</p><p><b>METHODS</b>Recombined plasmid pGEX-4T-1-AMG was transformed to Escherichia coli BL21. After expression, AMG was purified with glutathione S-transferase fusion protein purification system (GSTrapFF) column.</p><p><b>RESULTS</b>Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting hybridization results showed that 45,000 GST-AMG fusing protein and 19,000 target AMG mature peptide were obtained successfully.</p><p><b>CONCLUSIONS</b>pGEX-4T-1-AMG-BL21 system is used successfully to express and purify human AMG mature peptide.</p>

Effects of simvastatin on the immune-related genes of mouse osteoblasts / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of immune-related genes during osteogenesis stimulated by simvastatin.</p><p><b>METHODS</b>After treated with simvastatin, the expression of immune-related genes of mouse osteoblast was examined with gene chip (BiostarM-140s).</p><p><b>RESULTS</b>There were 16 differently expressed genes related to immune function, with nine down-regulated genes and seven up-regulated genes.</p><p><b>CONCLUSIONS</b>After treated with simvastatin, expression of inflammation related genes is down-regulated and inflammation inhibitor genes is up-regulated in mouse osteoblasts.</p>

Effects of Simvastatin on osteoblast activity of human periodontal ligament cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the effects of Simvastatin on the osteoblast activity of human periodontal ligament (PDL) cells.</p><p><b>METHODS</b>The third passage human PDL were cultured in conditional mineralization medium with different concentrations of Simvastatin. The cells were divided into A group (0 mol/L), B group (1 x 10(-9) mol/L), C group (1 x 10(-8) mol/L), D group (1 x 10(-7) mol/L) and E group (1 x 10(-6) mol/L). Alkaline phosphatase (ALP) activity, osteopontin (OPN) and capability of mineralization were measured.</p><p><b>RESULTS</b>Differentiation osteoblast and mineralization of human PDL were improved in all treatment groups with different concentrations of Simvastatin (1 x 10(-9), 1 x 10(-8), 1 x 10(-7), 1 x 10(-6) mol/L). Compared with control group, statistically significant differences were found in 1 x 10(-8) mol/L, 1 x 10(-7) mol/L and 1 x 10(-6) mol/L groups (P<0.05). The maximum effect was observed at the concentration of 1 x 10(-7) mol/L.</p><p><b>CONCLUSION</b>Optimal concentration of Simvastatin can improve the osteoblastic activity of human PDL.</p>

Clinical application of maxillary sinus lift with Summers osteotome / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To introduce and evaluate the procedure and the effect of maxillary sinus lift with closed technique by Summers osteotome, bone grafting and simultaneous implant placement.</p><p><b>METHODS</b>66 cases with severely resorbed alveolar bone in maxillary posterior region received sinus lift with Summers osteotome, simultaneously bone grafting and implants placement. The final restoration was finished at 6 months postoperatively.</p><p><b>RESULTS</b>The operation procedure were eventless in the 66 cases, the sinus floor were elevated by 2-5 mm, three-dimensional reconstruction of the CT scan pictures showed the smooth dome profile of the lifting sites and no signs of laceration on the membrane, and there were no maxillary antritis after operation. After 6 months, no significantly bone graft resorption and good osseointegration were noticed in X-ray imaging. The final restoration was finished at this time. 12-24 months after the restoration, all implants inserted were remain, the hard and soft tissue were healthy, prosthesis were stable and functioned. X-ray showed good osseointegration in the lifting sites, the vertical resorption around the implants were less than 1 mm.</p><p><b>CONCLUSION</b>With properly use of Summers osteotome, scraps of the bone in the implant sockets can be pushed into the sinus, these autogenous bone scraps were in favor of the osseogenesis and the sinus floor can be easily elevated by the method with very infrequent complications. It enlarged indication of dental implants and avoided operation of harvesting autogenous bone in other site. The method is simple and valuable to clinical application.</p>

Expression and purification of human amelogenin in Escherichia coli / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish the expression and purification route for the gene encoding human amelongenin (AMG) mature peptide in Escherichia coli (E. coli).</p><p><b>METHODS</b>Recombined plasmid pGEX-4T-1/AMG was identified by double endonuclease digestion electrophoretogram and DNA sequence analysis. The recombined plasmid was transformed to E. coli BL21. The inducing time, isopropyl-beta-D-thiogalactopyranoside (IPTG) concentration and inducing temperature were optimized for the express system. Under the optimized condition, the target fusing protein in superatant, periplasm, plasm and inclusion body was analyzed separately. A great amount of target fusing protein was found in the dissoluble protein. AMG fusing protein was purified by the GSTrapFF affinity column.</p><p><b>RESULTS</b>Double endonuclease digestion electrophoretogram and DNA sequence analysis were done to identify the recombined vector pGEX-4T-1/AMG. The results were consistent with the anticipation. The optimum inducing time was 14.5 hours. The optimum IPTG concentration was 1.0 mmol/L. The optimum inducing temperature was 20 degrees C. Under this condition, the target protein was expressed to a maximum. Plentiful target protein was expressed in plasm and inclusion body under the optimized condition. A mount of plasm protein was obtained and purified by the GSTrapFF affinity column. The purified liquid was collected and analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PACE). The protein electrophoresis map showed that AMG fusing protein was purified successfully. After twice elution, high pure fusing protein was obtained.</p><p><b>CONCLUSION</b>pGEX-4T-1/AMG system is used successfully to express human AMG fusing protein.</p>

A single tetracycline-regulated vector devised for controlled insulin gene expression / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To construct a single plasmid vector mediating doxycycline-inducible recombined human insulin gene expression in myotube cell line.</p><p><b>METHODS</b>An expression cassette of rtTAnls driven by promoter of human cytomegalovirus and a furin-cuttable recombined human insulin expression cassette driven by a reverse poly-tetO DNA motif were cloned into a single plasmid vector (prTR-tetO-mINS). The prTR-tetO-mINS and pLNCX were co-transfected into a myotube cell line (C2C12) and pLNCX vector were used as a control. After selection with G418, the transfected cells were induced with doxycycline at concentrations of 0, 2, and 10 microg/mL. RT-PCR was used to determine expression levels of recombinant insulin mRNA at the 5th day. Insulin production in cell cultures medium (at different incubation time) and cell extracts (at the 7th day) were analyzed with human pro/insulin RIA kits.</p><p><b>RESULTS</b>Immune reactive insulin (IRI) level in cell medium was found increased at 24 hours of doxycycline incubation, and still increased at the 5th day. After withdrawn of doxycycline, IRI decreased sharply and was at baseline three days later. IRI and human insulin mRNA levels were positively related to different levels of doxycycline. A 25-fold increase in IRI was found against background expression at the 7th day.</p><p><b>CONCLUSION</b>Human insulin expression can be successfully regulated by doxycycline and the background was very low. This single tet-on insulin expression system may provide a new approach to a controlled insulin gene therapy in skeletal muscle.</p>