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Objective To investigate expression of slug and E-cadherin in pancreatic cancer tissues and determine the inhibitory effects of anti-Slug, an anti-sense plasmid, on the invasion of pancreatic cancer cell lines in vitro. Methods Slug and E-cadherin protein and mRNA was analyzed by IHP and RT-PCR in 36 cases of pancreatic cancer. Then anti-Slug plasmid was transfected into herin and Slug expression. The inhibitory effects of anti-sense Slug were also detected by Transwell motility assay and Matrigel invasion assay. Results The expression of Slug and mRNA in metastatic pancreatic cancer tissue was higher than that in non-metastatic tissue. E-cadherin and mRNA was lower in metastasis tissues(P＜0.05). The inverse relationships were further observed by transient transfection of anti-Slug into SW1990H4 cells. The downregulated expression of Slug and re-expression of E-cadherin were found. The Slug mRNA levels were 0.985±0.016,0.973±0.014, 0. 554±0. 011 after 0, 48 h of transfection of anti-sense Slug, and that of E-cadherin were 0.120±0.001, 0.360±0.002, 0. 727±0. 006, respectively. The diference was significant between different time points (P＜0.05). The Slug mRNA levels were 0. 206±0.017, 0.968±0.015, and that of E-cadherin were 0. 18±0.002,0.727±0.006 after stable transfection of anti-sense Slug, and control plasmid, respectively. The diference was significant (P＜0.05). The motility activity(393±28, 352±24, 96 ±13 )and the invasion activity (223 ± 69, 202 ± 64, 65 ±19) of1 antisense Slug transfectant cells were significantly decreased as compared with those of control cells (P＜0.05). Conclusions Higher expression of slug and lower expression of E-cadherin is related to the invasion and metastasis in pancreatic cancer. A reverse corelation of E-cadherin and Slug expression exists in pancreatic cancer. Slug is possibly a potential target for cancer gene therapy blocking invasion and metastasis in human pancreatic cancer.
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Objective To explore mechanical property changes of methyl vinyl silicone rubber modified by ferric nanoparticles and its dispersed phase.Methods Mechanical properties such as Shore A hardness,tensile strength,elongation at break,tearing rate of permanent deformation and tearing strength of pre-prepared ironic nanoparticle enhanced silicone rubber and carbon-coated ferric particle reinforced silicone rubber were tested according to national standards.A thermal field emission scanning electron microscope (TFE-SEM) was used to investigate the morphology of both surface and fracture of the composite materials and to observe the dispersion of ferric nanoparticles in them.Results Mean values of Shore A hardness,tensile strength,elongation at break,tearing permanent deformation rate and tear strength of modified composites increased with the increasing amounts of ferric nanoparticles,however,when the quota of ironic nanoparticles in the composite formula were greater than 17 phr,carbon-coated ferric nanoparticles more than 19 phr,the mean values of tensile strength of two composites stopped increasing and presented the declining trend.When the quota of ferric nanoparticles in the formula exceeding 15 phr,the mean values of elongation at break and tear strength began to decrease in the formula ratio of silicone rubber/ferric nanoparticles up to 85:15,while the Shore A hardness of samples increased all the way.Ferric nanoparticles dispersed evenly on the surface of composites.Nanopowder aggregation in the fracture surface of both composites could be observed at the formula ratio of 85:15 of silicone rubber/iron nanoparticle and 87:13 of silicone rubber/carbon-coated iron specimen.Conclusion Effect of iron nanapareticles and carbon-coated ferric nanoparticles on the mechanical properties of the reinforced methyl vinyl silicone rubber depends on the nanoparticle size,additive amount and agglomeration.
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BACKGROUND:Recently,with the rapid development of material science and bioscience,the technology of dental implant has made great progress,especially the immediate implant technology.But the size and shape of implant are usually not fit for tooth extraction wound,so it is an important factor that leads to failure when implant and tooth extraction wound can not form close tangency.Guided bone regeneration or bone grafting materials are usually used to solve this problem.OBJECTIVE:To study the effects of nano-hydroxyapatite/collogen (nHAC) with recombinant human bone morphogenetic protein-2(rhBMP-2) and titanium (Ti) membrane on repairing peripheral bone defects of instant implant.DESIGN,TIME AND SETTING:A randomized,controlled animal study was performed at the Central Laboratory,the Fourth Military Medical University of Chinese PLA between January 2005 and January 2006.MATERIALS:Ti screw implants (diameter 2 mm,length 10 mm,and pitch 0.4 mm) without the part that went through gum were offered by Nonferrous Metal Academy in Baoji,China.The nonabsorbable Ti membranes (2 cm×2 cm) were offered by Zhongbang Biomaterial Limited Company in Xi'an,China.The nHAC materials were gifted by professor Cui Fu-zhai from Material Science and Engineering Department of Tsinghua University and fabricated into 0.5 mm×0.5 mm×0.5 mm small blocks.rhBMP-2 was offered by the Academy of Military Medical Sciences in Beijing,China.rhBMP-2 was dissolved with hydrochloric carbamidine and then nHAC was immersed in it.Vacuumization,freeze-drying,and Ekibon degermation were followed.Each gram of nHAC compounds required approximately 1 mg rhBMP-2.METHODS:Four healthy purebred male dogs were included in this study.According to the methods to repair bone defects rhBMP-2+Ti membrane,nHAC composited with rhBMP-2 was implanted,covering Ti membrane.Six defects were made on the mandible on each side.MAIN OUTCOME MEASURES:At 6 and 12 weeks after implantation,new bone formation and the correlation of new bone to Ti implant were investigated by radiography,bone density measurement and histological examinations.RESULTS:All the bone wounds were full of new bone at 12 weeks,the Ti implants were steady and the osseointegration was good.In the nHAC+rhBMP-2 and nHAC+rhBMP-2+Ti membrane groups,new bone formed and maturated earlier.In the nHAC +Ti membrane,blank control,and nHAC + rhBMP-2 +Ti membrane groups,new bone formed well below Ti membrane and the alveolar crest was plump.In the nHAC + rhBMP-2 +Ti membrane group,new bone formed earliest with the most quantity and the alveolar crest was the plumpest.By 12 weeks,the bone density had achieved the same level as the autologous cancellous bone transplantation,but the alveolar crest was plumper compared to the positive control group.In addition,bone mass was much more.Bone formed slowest in the blank control group and fastest in the positive control group with the crest of ridge being slightly absorbed.CONCLUSION:nHAC is a new good bone graft material in repairing peripheral bone defects of instant implant,especially compositing with rhBMP-2 and/or Ti membrane.A round method to repair the surrounding bone defect of instant implant should be selected according to the specific situation in the clinic.
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Objective To observe effects of Genistein and 5fluorouracil(5-FU) on human colon carcinoma cell line Colo320.Methods The MTT assay and median-effect principle were used.Results The two drugs were antagonistic at higher concentrations and synergistic at lower concentrations,The sequence and time of drug administration can influence the effects of the two drugs on Colo320.Conclusion The two drugs were cooperated at lower concentrations and antagonistic at higher concentrations.The sequence and time of drug administration were also important for their effects on the cells.
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Objective To determine the susceptibility of yeasts and to explore the antifungal m echanismof Lisea cubeba oil,so as to provide evidence for the development of antifungal medicinal herbs.Methods The minimuminhibitory concentrations(MIC)of Lisea cubeba oil and fluconazole were determined by broth microdilution method according to the National Com mittee on Clinical Laboratory Standards(NCCLS)reference method for broth dilution antifungal susceptibility testing of yeasts.Ultra-structur al changes of C.krusei were observed by electron microscopy before and after Lisea cubeba oil treatment.Results Five previously identified quality control(QC)strains(Candida albicans,Candida tropical is,Candida glabrata,Candida parapsilosis,Candida krusei)were susceptible to Lisea cubeba oil,their MICs were 14.14?3.64?g /mL,23.22?2.85?g /mL,31.24?2.88?g /mL,76.19?4.40?g /mL,28.30?2.54?g /mL,respectively.After treatmen t with Lisea cubeba oil the mor-phology and ultrastructure of Candida krusei showed obvious changes:their cell wall and cytoplasmic membrane ruptured;intracellar components dissolved;organellae swollen and di ssolved.There were no changes observed in the morphology and ultrastructure of C.krusei treated with fluconazole.Conclusions The data indicate that Lisea cubeba oil has antifungal effect not only on C.albican and other medically important Candida spp.,but also on fluconazole resistant isolates such as C.krusei and thus has great clinical importan ce.The antifungal mechanismof Lisea cubeba oil may be that the structure of cell w all and cell membrane of C.krusei being inhibited.