Objective:To evaluate the effects of platform switching and platform matching system on the marginal bone resorption a-round implant.Methods:Randomized controlled trials (RCTs)that compared marginal bone loss around platform-switched implants with platform matched prostheses were selected from PubMed,EMbase,CBM,CNKI and other electronic databases supplemented by hand search and retrospective collection of literature published or unpublished between 1 991 -201 4.The literature based on inclusion and exclusion criteria was screened by 2 revieweres independently,the quality of the included studies was evaluated,the data were extracted using RevMan 5.2 software for Meta-analysis.Results:1 4 studies with 1 331 implants were included.Meta-analysis showed that peri-implant bone resorption in the platform switching group was significantly less than that in the platform matching group[MD =-0.51 ,95% CI:(-0.72 -0.30),P <0.01 ].Subgroup analysis showed that the implant-abutment diameter difference >0.45 mm (unilateral)was more favorable to implant marginal bone preservation.Conclusion:The present data suggest that platform-switched technology is more conducive to implant bone preservation than platform-matched method.

Objective:To evaluate the effect of different polishing instruments on the microstructure of composite resin.Methods:Specimens of 5 kinds of resins were randomly divided into three groups and were polished with Astropol(group A),Sof-Lex(group B) and Super-snap(group C)respectively(n=3 for each resin).Specimens of natural enamel surface were used as the controls(group D).The surface roughness(Ra)and microstructure of the specimens were evaluated by an atomic force microscope(AFM).Results:Ra value in group A was lower than that in group B(P=0.015);Z350 XT resin obtained the lowest Ra value among the 5 kinds of resin specimens(P<0.05).All of the resin specimens had similar average Ra after polishing procedure(P>0.05).Conclusion:Astropol polishing instrument is better than Sof-Lex;Z350 XT has better polish performance.The three polishing instruments are ef-fective in polishing the 5 composite resins.

Objective To evaluate laparoscopic resection of gastric stromal tumors. Methods Clinical data of 20 patients undergoing laparoscopic resection of gastric stromal tumors from June 2003 to October 2007 were retrospectively analyzed. Result Laparoscopic wedge resection was completed successfully in all 20 patients with a mean operating time of(60±34) min, and without major complications. The mean hospital stay was (6.0±2.6) days. During a follow-up period from 10 to 22 months there was no recurrence. Conclusions Laparoscopic wedge resection is safe, effective, and minimally invasive for treating gastric stromal tumors.

Objective To investigate the feasibility and effectiveness of laparoscopic splenoctomy (LS)in patients with idiopathic thrombocytopenic purpura(ITP). Methods Clinical data of 17 ITP cases undergoing LS between Augest 2003 and December 2006 were analyzed retrospectively. Remits LS was Successfully conducted in all 17 cases without converting to open surgery with an average intraoperative blood loss of 120 ml in each case.There was no postoperative bleeding,fistula and infection.The platelet count increased rapidly in one week.After stopping glucocorticoid treatment for one month.15 cases achieved complete response(88.2%)and 2 caSes had partial response(11.8%).Fbllow-up of 3～43 months found no recurrence. Conclusions Use of LS for ITP is safe,feasible and effective.

Objective To evaluate the clinical results of total laparoscopic hepatectomy for hepatolithiasis. Methods The clinical data of 72 patients with intrahepatic lithiasis receiving total laparoscopic hepatectomy in our hospital from July 2005 to April 2009 were retrospectively analyzed. Results The mean age of the 72 patients was (43. 8±21.7) yrs (16-65 yrs). For laparoscopic hepatectomy, it was anatomical left liver resection in 34 patients, anatomical resection of left lateral liver in 19 and resection of S6 in 16. The operative duration was (262.5± 115.5)min (125-320 min). The median intraoperative blood loss was 150 ml (50-400 ml). The occurring rate of postoperative complications was 12.50 %. Complications included bile duct infection in 8 patients, bile leakage in 6, gastroparesis in 1,postoperative early inflammatory ileus in 1 and subcapsular fluid collection of liver in 1. All the complications were cured by non-surgical means. Conclusion In the era of minimally invasive surgery, total laparoscopic hepatectomy has gradually become the prominent treatment for hepatolithiasis.

Objective To evaluate the histological response and the clinical value in laparescopic colorectal surgery combined with preoperative regional intra-arterial chemotherapy(PRAC). Methods In cases of rectal cancer and fiver metastases selective regional intra-arterial chemotherapy and iodinated oil embolism was carried out in 23 cases of colorectal carcinoma. After 1 to 11 days laparoseopic radical resection was done, specimens were sent for histopathological examination. We analyzed the correlation between tumor differentiation and TNM stage, compared the effect of PRAC with PRAC + embolism by the criteria of histological response of chemotherapy. χ2-test was used to compare interclass correlation.Results The histological effect in the 23 cases of PRAC level 0 was in 2 cases, level Ⅰ in 7 cases, level Ⅱ in 10 cases, and level Ⅲ in 2 cases. The overall effective rate was 91% (21/23). In the 15 cases with lymph node metastases, the effective rate was 87% (13/15). There was no significant statistic correlation between tumor differentiation or TNM stage and histological response. PRAC associated embolism had a better histological response compared to PRAC alone. Conclusions Preoperative regional intra-arterial chemotherapy had marked therapeutic effect on histological response to the colorectal carcinoma patients of various tumor differentiations and TNM stage, especially combining with the embolism to rectal cancer could improve the efficacy.

Adiponectin is an adipocyte-derived secretory protein. It was found to be associated with insulin resistance, inflammation and arteriosclerosis. To further study the biological function and expression of adiponection in vivo, adipoenctin gene knock-out and LacZ gene knock-in mouse model was constructed. Gene targeting strategy was designed to replace part of exon 2 and exon 3 of adiponectin gene with full length LacZ gene in frame with remaining upstream ATG and signal peptide sequence of exon 2. The targeting vector (Adipo-LacZ-XpPNT) was constructed and verified by restriction enzyme digestion and sequencing. CJ7 ES cells were transfected with targeting vector linearized by NotⅠ digestion, selected in the medium containing both G418 and ganciclovoir. Resistant clones were screened by PCR and further confirmed by Southern blot for correct homologous recombinants. Chimera mice were obtained by routing microinjection of homologous recombined ES cells into blastocysts. After mating, mice heterozygous and further homozygous for adiponectin knockout and LacZ gene knock-in were established. Expression of both endogenous adiponectin and exogenous LacZ gene in mouse tissues and sera were detected by RT-PCR, Northern-blot, Western blot and ELISA. The results show that adiponectin was disrupted at both mRNA and protein levels. LacZ gene is expressed exclusively in adipose tissue of mutant mice. Its expression profile is identical to endogenous adiponection. Unexpectedly, LacZ activity could not be detected in both adipose tissue and serum although LacZ protein can be detected in adipose tissue but not in serum of mutant mice. In conclusion, mice homozygous for adiponectin knockout and LacZ gene knock-in have been successfully constructed. Mutant mice display LacZ expression profile identical to endogenous adiponectin albeit neither LacZ activity nor protein can be detected in serum of mutant mice.

OBJECTIVETo investigate the effect of TiO₂nanotube arrays covalently modified by recombinant human bone morphogenetic protein- 2(rhBMP- 2) on the early bioactivity of mesenchymal stem cells (MSC) in vitro and to provide experimental evidence for the biochemical modification of titanium implants.

METHODSIn the experiment group, double titanium nanotube arrays were prepared by anodization, and were chemically grafted with rhBMP- 2. Mechanically polished pure titanium was used as blank control group, and titanium dioxide nanotubes was used as negative control A group, and titanium dioxide nanotubes + carbonyldiimidazole as negative control B group. Field emission scanning electron microscope (FE- SEM) and X- ray photoelectron spectroscopy (XPS) were used to detect the morphology and physicochemical properties of the experiment group, blank control group and the negative control group. Cell adhesion on the specimen surface of the experiment group, blank control group and negative control group on the 1st day was tested. Cell proliferation on the 1st, 3rd and 5th day and alkaline phosphatase activity on the 5th, 7th and 11th day was also tested.

RESULTSFE- SEM showed that the surface of titanium nanotubes loaded with rhBMP- 2 possessed visible miliary particulate matter. XPS showed that nitrogen peak in the group of titanium nanotubes loaded with rhBMP-2 was significantly greater that those in the other groups. FE- SEM showed that the cells on the surface of the experimental group on the 1st day spread well, better than those in the control group and negative control group. Cell proliferation activity on the 1st day in different groups was not obvious (P>0.05), the A value of the experimental group on the 3rd and 5th day (3.295 ± 0.153, 3.823 ± 0.059) were significantly higher than those in the control group (2.479 ± 0.064, 3.131 ± 0.096) and negative control A group (2.715 ± 0.075, 3.371 ± 0.047) and negative control B group (2.756 ± 0.132, 3.637 ± 0.047) (P<0.05). Alkaline phosphatase activity on the 5th, 7th and 11th day in the experimental group (0.0477 ± 0.0287, 0.0615 ± 0.0016, 0.0667 ± 0.0018) were better than those in the control group, negative control A group and negative control B group (P<0.05).

CONCLUSIONSTitanium nanotube arrays can be loaded with rhBMP-2 by biochemical methods and have good biocompatibility.

Alkaline Phosphatase ; metabolism ; Bone Morphogenetic Protein 2 ; pharmacology ; Cell Adhesion ; Cell Proliferation ; Humans ; Materials Testing ; Mesenchymal Stromal Cells ; Microscopy, Electron, Scanning ; Nanotubes ; chemistry ; ultrastructure ; Photoelectron Spectroscopy ; Recombinant Proteins ; pharmacology ; Surface Properties ; Titanium ; chemistry ; Transforming Growth Factor beta ; pharmacology

Sorghum (Sorghum bicolor L.) was one of the most important crops in the world next to wheat, rice, maize, soybean and barley. Using the callus derived from immature inflorescence as the recipients, we efficiently transformed sorghum varieties 115, ICS21B and 5-27 with the insecticidal Bacillus thuringiensis (Bt) cry1Ab gene carried in the T-DNA of binary vectors which contained hygromycin resistance gene and gus gene via Agrobacterium tumefaciens. After gradient selection with hygromycin, a total of 21 independent transgenic plant lines, 52 transgenic plants were regenerated, and the average stably transformation efficiency was 1.9%. The integration and transcription of cry1Ab gene in transgenic sorghum was confirmed by PCR analysis, Southern blotting and RT-PCR analysis. The Bt proteins were expressed in most transgenic plants with different level from plant to plant by Western blotting and ELISA assay. According to insect bioassay in laboratory, the transgenic plants with a relatively high level of Bt gene expression displayed insect-resistance to pink rice borer (Sesamina inferens).
Agrobacterium tumefaciens ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Endotoxins ; genetics ; metabolism ; Hemolysin Proteins ; genetics ; metabolism ; Pest Control, Biological ; Plants, Genetically Modified ; genetics ; Sorghum ; genetics ; Transformation, Genetic

Objective : To explore the optimal pulse width of ultra-short pulse Er : YAG laser for improving dentin bonding strength． Methods : Forty isolated third molars were prepared in the shape of wedge defect in the neck，and the coronal plane was taken．The samples were randomly divided into 5 groups : group G0 was blank group，and groups G1-G4 were treated with 30 MJ，20 Hz Er : YAG laser，and the pulse width was set to 30，40，50 and 60 μs， respectively．The morphology of dentin surface was observed by scanning electron microscopy (SEM) ，and the ratio of calcium to phosphorus was detected by energy dispersive X-ray spectroscopy ( EDX) ．The shear bond strength ( SBS) of each group and the fracture form under the type microscope were tested by the universal mechanical tes- ting machine．The effect of different pulse width on improving dentin bonding strength was evaluated. Results : SEM observation showed that the stained layer was removed after laser treatment with different pulse widths，and the den- tin tubules were opened to different degrees．The calcium-phosphorus ratio of dentin after laser treatment increased， and the difference of calcium-phosphorus ratio in G2 group was statistically significant (P＜0. 05) ．The mean value of SBS after the cold and hot cycle experiment was G2 ＞G3 ＞G1 ＞G4 ＞G0，and the difference between G2 group and G0 group，G1 group，G3 group and G4 group are statistically significant (P ＜0. 05 ) ．The difference between group G0 and groups G1，G2，G3 and G4 was statistically significant (P＜0. 05) ．The main fracture forms of each group were type 1 and type 3． Conclusion The 30 MJ，20 Hz Er : YAG laser pulse width of 40 μs can significantly improve the bond strength of dentin.