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find Keyword "polymer" 66 results
  • Experimental Study on Changes of Expression of AFP mRNA in Human Hepatocellular Carcinoma Tissues after Oral Xeloda Therapy

    【Abstract】Objective To explore the changes of expression of AFP mRNA in human hepatocellular carcinoma (HCC) tissues after oral Xeloda therapy.Methods Total RNA was extracted from HCC tissue samples collect after operation and nested reverse transcription polymerase chain reaction (RT-nested PCR) assay was performed to determine the expression of AFP mRNA in this study.Results The final product of AFP mRNA amplified by RT-PCR was 174 bp and by RT-nested PCR was 101 bp. The AFP mRNA is positive in 12 of 21 patients (positive rate 57.14%) amplified by RT-nested PCR assay in Xeloda treatment group which is much lower than control group: 18 of 20 patients (positive rate 90.00%),P<0.05.The serum AFP value of Xeloda treatment group 〔(23.2±12.8) μg/L〕 is much lower than that of control group 〔(39.6±24.3) μg/L〕 four weeks after operation (P<0.05). However, There was no difference between two groups in serum AFP value before operation.Conclusion Xeloda can effectively suppress the expression of AFP mRNA in human HCC tissues and lower it’s product serum AFP value.The clinical application of Xeloda in HCC patients deserve further study.

    Release date:2016-08-28 04:44 Export PDF Favorites Scan
  • THE ALTERNATION OF AFP-mRNA DETECTED IN BLOOD DURING LIVER RESECTION FOR HEPATOCELLULAR CARCINOMA AND ITS SIGNIFICANCE

    【Abstract】Objective To investigate whether liver resection for hepatocellular carcinoma (HCC) causes dissemination of liver tumor cells into blood circulation. Methods Fourteen patients with HCC, but without evidences of metastasis, were enrolled for the study. Blood samples of peripheral blood before skin incision and after abdominal wall suture, and of hepatic venous blood and portal venous blood after liver parenchyma dissection, were obtained. AFPmRNA was detected by reverse transcription polymerase chain reaction assays, the change of the level of its expression during operation was assessed by semi-quantitative analysis. Results The rate of its expression before and after operation in peripheral blood, and during operation in portal venous blood and in hepatic venous was 42.9%, 35.7%, 42.9% and 57.1% respectively. There were no differences between them. However, the level of its expression in hepatic venous blood was significantly higher than others (P<0.05). Conclusion Liver resection for HCC induces releases of cells from the liver, probably including tumor cells, into blood circulation.

    Release date:2016-08-28 05:30 Export PDF Favorites Scan
  • OVEREXPRESSION OF THE MDRl GENE EXPRESSION IN HUMAN PRIMARY HEPATOCELLU-LAR CARCINOMAS

    We have devised a highly sensitive, specific, and quantitative assay for multidrug resistance (mdr1) mRNA expression based on the reverse transcription-polymerase chain reaction (RT-PCR). mdr1 mRNA levels were detected in 30 human primary hepatocellular carcinoma (PHC) tissue and adjacent liver tissue. Five of the patients had received chemotherapy before hepatectomy. The results show that the level of expression of mdr1 gene is higher in tumor tissue than in adjacent liver tissue. mdr1 gene is overexpressed in PHC after chemotherapy. Furthermore, mdr1 gene expression in the treated tumor adjacent liver tissue is higher than that in untreated tumor adjacent liver tissue. Our results indicated that overexpression of mdr1 gene may be responsible for the intrinsic and acquired drug resistance of PHC.

    Release date:2016-08-29 03:25 Export PDF Favorites Scan
  • Measurement of the Forkhead Box P3 Gene Expression Levels in Esophageal Squamous Cell Carcinoma by Realtime Quantitative Reverse Transcriptionpolymerase Chain Reaction

    Objective To detect the expression of forkhead box P3 (FOXP3 )gene in esophageal squamous cell carcinoma(ESCC) and provide a new basis for immunotherapy of esophageal cancer. Methods Based on fluorescent TaqMan methodology, a realtime quantitative reverse transcription polymerase chain reaction (RT-PCR) for detecting the expression of FOXP3 was set up. In this method, a cloning vector pMD 18-T-FOXP3 was constructed as a standard plasmid. The specific expression of FOXP3 in 42 patients with ESCC and 30 healthy controls were measured by using GeneAmp 7500 Sequence Detection Systems. Results FOXP3 mRNA copy number in ESCC was significantly higher than that in healthy control tissue [(72.20±23.10)×104copy/μg RNA vs.(0.68±0.34)×104 copy/μg RNA;Plt;0.05]. Conclusion A realtime quantitative RT-PCR method for detecting the expression of FOXP3 gene in ESCC has been successfully established. The expression level of FOXP3 is increased in ESCC compare with healthy controls.

    Release date:2016-08-30 06:05 Export PDF Favorites Scan
  • Decellularized Xenogenic Valve Scaffolds Coated with Biodegradable Polymer for Heart Valve Tissue Engineering

    Objective To study and test novel hybrid valves in vitro and in vivo, and provide basis for clinical use in future. Methods The hybrid valves were fabricated from decellularized porcine aortic valves coated with poly (3-hydroxybutyrate-co-3hydroxyhexanoate, PHBHHx).(1)In the mechanical test in vitro, the uniaxial tensile biomechanics test of the fresh (n=12), uncoated (n=12) and hybrid valve leaflets (n=12) were investigated. (2)In study in vivo, hybrid valves(n=5) implanted in pulmonary position in sheep without cardiopulmonary bypass. Uncoated grafts (n=5) used as control. The specimens of the hybrid or uncoated valve in sheep were explanted and examined by scanning electron microscopy, histology, calcium content and immunofluorescence staining 18 weeks after surgery. Results The mechanical test in vitro revealed that coating with PHBHHx increased maximal tensile strength of hybrid valves compared with the fresh and uncoated state (P<0.05). The results in vivo indicated the hybrid valves maintained original shape and softness. Immunofluorescence staining for CD31 confirmed that the surface of hybrid valve was covered by confluent CD31+ cells.The interstitium of hybrid valve indicated that smooth muscle actin (SMA)+ cells population were similar to native valvular tissue. The calcium content of hybrid valve was significantly lower than that of uncoated valve leaflets (P<0.05). Conclusion Decellularized porcine aortic valves coated with PHBHHx have good biological and biomechanical characteristics. The hybrid valve may provide superior valve replacement with current techniques.

    Release date:2016-08-30 06:09 Export PDF Favorites Scan
  • CycloRGD Peptide Regulates the Expression of Integrin αVβ3 Gene of Myofibroblast on the Decellularized Scaffolds

    Objective To observe whether Cyclo-RGDfK (Arg-Gly-Asp-D-Phe-Lys) could enhance the adhesion of myofibroblast to decellularized scaffolds and upregulate the expression of Integrin αVβ3 gene. Methods Myofibroblast from the rat thoracic aorta was acquired by primary cell culture. The expression of Vimentin and α-smooth muscle actin(α-SMA) has been detected by immunoflurescent labeling. Decellularized valves have been randomly divided into three groups (each n=7). Group A (blank control): valves do not receive any pretreatment; Group B: valves reacted with linking agent NEthylN(3dimethylaminopropyl)carbodiimide hydrochloride (EDC) for 36 hours before being seeded; Experimental group: Cyclo-RGD peptide has been covalently immobilized onto the surface of scaffolds by linking agent EDC. The fifth generation of myofibroblast has been planted on the scaffolds of each group. The adhesion of myofibroblast to the scaffolds was evaluated by HE staining and electron scanning microscope. The expression of Integrin αVβ3 was quantified by halfquantitative reverse transcriptionpolymerase china reaction (RT-PCR). Results We can see that myofibroblast has exhibited b positive staining for Vimentin and α-SMA. Besides, it has been shown that the expression of Integrin αVβ3 was much higher in the experimental group than that of the group A and group B(Plt;0.05). There was no statistically difference in group A and group B (P=0.900). Conclusion RGD pretreatment does enhance the adhesive efficiency of seeding cells to the scaffolds and this effect may be related to the upregulation of Integrin αVβ3.

    Release date:2016-08-30 06:09 Export PDF Favorites Scan
  • hVEGF165/pcDNA3. 1 Expression in Neonate Mice Myocardial Cells

    Objective To investigate the transfection and expression of recombinant plasmid human vascular endothelial growth factor 165/pcDNA3. 1 (hVEGF165/pcDNA3. 1) in myocardial cells, and to build foundation for gene therapy and cell therapy of coronary artery disease (CAD). Methods Myocardial cells were cultured in vitro and transfected by hVEGF165/pcDNA3.1 with liposome; then transient expressed protein was detected by reverse transcriptase-polymerase chain reaction (RT-PCR), immunochemistry and Western blotting. Results A strap as hVEGF165 was obtained by RT-PCR, the protein of hVEGF165 was found in myocardial cells by immunochemistry and in supernatant by Western blotting. Conclusion The recombinant plasmid hVEGFI65/pcDNA3. 1 can be expressed in myocardial cells, and may be used in studying CAD by gene therapy and cell transplantation.

    Release date:2016-08-30 06:22 Export PDF Favorites Scan
  • NOVEL ARTIFICIAL LAMINA FOR PREVENTION OF EPIDURAL ADHESIONS AFTER POSTERIOR CERVICAL LAMINECTOMY

    Objective To evaluate the application of artificial lamina of multi-amino-acid copolymer (MAACP)/nano-hydroxyapatite (n-HA) in prevention of epidural adhesion and compression of scar tissue after posterior cervical laminectomy. Methods Fifteen 2-year-old male goats [weighing, (30 ± 2) kg] were randomly divided into experimental group (n=9) and control group (n=6). In the experimental group, C4 laminectomy was performed, followed by MAACP/n-HA artificial lamina implantations; in the control group, only C4 laminectomy was performed. At 4, 12, and 24 weeks after operation, 2, 2, and 5 goats in the experimental group and 2, 2, and 2 goats in the control group were selected for observation of wound infection, artificial laminar fragmentation and displacement, and its shape; Rydell’s degree of adhesion criteria was used to evaluate the adhesion degree between 2 groups. X-ray and CT images were observed; at 24 weeks after operation, CT scan was used to measure the spinal canal area and the sagittal diameter of C3, C4, and C5 vertebrea, 2 normal goats served as normal group; and MRI was used to assess adhesion and compression of scar tissue on the dura and the nerve root. Then goats were sacrificed and histological observation was carried out. Results After operation, the wound healed well; no toxicity or elimination reaction was observed. According to Rydell’s degree of adhesion criteria, adhesion in the experimental group was significantly slighter than that in the control group (Z= — 2.52, P=0.00). X-ray and CT scan showed that no dislocation of artificial lamina occurred, new cervical bone formed in the defect, and bony spinal canal was rebuilt in the experimental group. Defects of C4 vertebral plate and spinous process were observed in the control group. At 24 weeks, the spinal canal area and sagittal diameter of C4 in the experimental group and normal group were significantly larger than those in the control group (P lt; 0.05), but no significant difference was found between experimental group and normal group (P gt; 0.05). MRI showed cerebrospinal fluid signal was unobstructed and no soft tissue projected into the spinal canal in the experimental group; scar tissue projected into the spinal canal and the dura were compressed by scar tissue in the control group. HE staining and Masson trichrome staining showed that artificial lamina had no obvious degradation with high integrity, some new bone formed at interface between the artificial material and bone in the experimental group; fibrous tissue grew into defect in the control group. Conclusion The MAACP/n-HA artificial lamina could maintaine good biomechanical properties for a long time in vivo and could effectively prevent the epidural scar from growing in the lamina defect area.

    Release date:2016-08-31 04:07 Export PDF Favorites Scan
  • PROGRESS AND PROSPECT OF SYNTHETIC BIODEGRADABLE POLYMERS FOR BONE REPAIR AND RECONSTRUCTION

    Objective To review the latest researches of synthetic biodegradable polymers for bone repair and reconstruction, to predict the progress of bone substitute materials and bone tissue engineering scaffolds in future. Methods The l iterature concerning synthetic biodegradable polymers as bone substitute materials or bone tissue engineering scaffolds was collected and discussed. Results Al i phatic polyester, polyanhydride, polyurethane and poly (amino acids) were the most extensively studied synthetic biodegradable polymers as bone substitutes and the scaffolds. Each polymer was of good biological safety and biocompatibil ity, and the degradation products were nontoxic to human body. The mechanical properties and degradation rate of the polymers could be adjusted by the type or number of the monomers anddifferent synthetic methods. Therefore, the polymers with suitable mechanical strength and degradation rate could be produced according to the different requirements for bone grafting. Prel iminary studies in vivo showed their favorable capacity for bone repair. Conclusion The synthetic biodegradable polymers, especially the copolymers, composite materials and those carrying bone growth factors are expected to be the most promising and ideal biomaterials for bone repair and reconstruction.

    Release date:2016-08-31 05:47 Export PDF Favorites Scan
  • DIFFERENT ADHESION RATE OF SHEEP BMSCs ON COPOLYMERS OF 3-HYDROXYBUTYRATE AND 3-HYDROXYVALERATE BEFORE AND AFTER PHOTOGRAFTING MODIFICATION IN VITRO

    【Abstract】 Objective To evaluate the biocompatibil ity of the sheep BMSCs cultured on the surface of photografting modified copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate(PHBV). Methods BMSCs were isolated from bone marrow of the posterior il iac crest of a 6-month old sheep by whole marrow adherent culture method. The 3rd passage BMSCs were seeded onto modified PHBV and conventional PHBV films, or three-dimension scaffolds. Cell-adhesion rates were calculated by hemocytometer at 1, 2 and 6 hours after seeded. Cell morphology was examined by scanning electron microscope when the BMSCs were cultured for 3 days, 1 week and 3 weeks. Cell cycle was analyzed by flow cytometry at 5 days after seeded. The content of protein in BMSCs was determined by BCA assay and the content of DNA was quantified by Hoechst 33258 assay at 4, 8 and 12 days after seeded. Results At 1 hour after seeded, cell-adhesion rate on modified PHBV films (52.7% ± 6.0%) was significantlyhigher than that of conventional PHBV films (37.5% ± 5.3%) (P lt; 0.05); At 2 and 6 hours after seeded, cell-adhesion rate of modified PHBV films was similar to that of PHBV films (P gt; 0.05). The surface of modified PHBV film was rougher. In the early culture stage, more cells adhered to modified PHBV and the cells displayed much greater spreading morphology. Furthermore, ECM on modified PHBV were richer. There were no significant differences between the trial team and the control on the cell cycle and the content of DNA and protein of BMSCs (P gt; 0.05). Conclusion Photografting modification on PHBV can promote BMSCs’ adhesion and enhance their biocompatibil ity.

    Release date:2016-09-01 09:09 Export PDF Favorites Scan
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