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find Keyword "polymer" 67 results
  • A STUDY ON THE GENOMIC VARIANT IN MATCHED ADENOCINOMA AND NON-TUMOR GASTRIC TISSUE BY ARBITRARILY PRIMER POLYMERASE CHAIN REACTION

    Objective To identify and isolate the variant gene associated with gastric adenocarcinoma and clone the fragment of variant gene.Methods By arbitrarily primer polymerase chain reaction (AP-PCR), DNA samples from 5 matched gastric adenocarcinoma and non-tumor gastric tissues were analysed. Results The produced AP-PCR profiles were different in each matched gastric adenocarcinoma and non-tumor gastric tissue. One differentiated amplified DNA fragments PW2.2 from a matched gastric adenocarcinoma were cloned. The result of Southern blot hybridization with PW2.2 as a probe showing that this fragment was also found in some other gastric adenocarcinoma samples. Conclusion AP-PCR fingerprinting assay can be used to identify and clone the variant genes associated with gastric adenocarcinoma.

    Release date:2016-09-08 02:00 Export PDF Favorites Scan
  • A STUDY ON IN VITRO FORCEVASCULARIZATION AND IN VIVO VASCULARIZATION OF POROUS POLYLACTIC/GLYCOLIC ACID COPOLYMER SCAFFOLDS WITH INTERNAL NETWORK CHANNELS

    Objective To study the influence of in vitro force-vascularization on in vivo vascularization of porous polylactic glycolic acid copolymer(PLGA) scaffolds with internal network channels (PPSINC). Methods After the in vitro forcevascula ization of PPSINCs covered with microvessel endothelial cells (MVEC) of mice, they were divided into two groups: the force-vascularization group (group A) and the control group with only PSINCs (group B). All the PPSINCs were planted in the mesentery of 12 mice for 2 and 4 weeks, the PPSINCs were cut out, the vascular ization of PPSINCs was investigated by histology and immunohistochemistry, and the vascularization area of the histologic section of the PPSINCswas measured with the computer-assistant image analysis system. Result After the in vitro forcevascularization of PPSINCs, the MVEC of the mice sticking on the channel wall could be seen. After the scaffold was im planted into the mice for 2 weeks, the vascularization area of the histologic section of PPSINCs (VA) in group A (2 260.91±242.35 μm2) was compared with that in group B (823.64±81.29 μm2),and the difference was sig nificant in statistics(P<0.01).The VA for 4 weeks in group A (17 284.36 ±72.67 μm2) was compared with that in group B (17 041.14±81.51 μm2), and the difference was not significant in statistics(P>0.05).The area of the actin positivestaining (AA) in the histologi c section of PPSINCs for 2 weeks’ implantation in group A (565.22±60.58 μm2) was compared with that in group B (205.91±16.25 μm2), and the difference was signi ficant in statistics(P<0.01). After the implantation for 4 weeks, the VA in group A (4 321.09±19.82 μm2) was compared with group B (4 260.28±27.17 μm2), and the difference was not significant in statistics(P>0.05). Conclusion The PPSINC is a good simple scaffold model of vasculariazation. The in vitro force-vascularization can increase the in vivo vascularization of PPSINCs in the early stage.

    Release date:2016-09-01 09:25 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
  • The therapeutic effect of poly tetrahydrofurfuryl-co-lactic acid on rhegmatogenous retinal detachment

    Objective To observe the therapeutic effect of poly tetrahydrofurfuryl co-lactic acid(copolymer C4) as the biodegradable vitreous substitutes on rhegmatogenous retinal detachment.Methods Vitreoretinal surgery with copolymer C4 tamponades was performed on 32 pigmented rabbits (64eyes) with rhegmatogenous retinal detachment. The rate of reattached retina and the post operative cornplications were observed.Results Three months after the operation, reattached retina was found in 96. 4%, glaucoma in 5.5%, cataract in 10.9%, and copolymer emulsion in 10.2% of all the eyes.Conclusion copolymer C4 may withstand the retinal tear effectively for 3 months, and can be a valuable vitreous substitutes. (Chin J Ocul Fundus Dis,2004,20:27-28)

    Release date:2016-09-02 05:58 Export PDF Favorites Scan
  • Construction of controllable polyethylene glycol bioactive coating with hemocompatibility from the surface of modified glass substrate

    A diblock copolymer, poly(ethylene glycol) methacrylate-block-glycidyl methacrylate (PEGMA-GMA), was prepared on glass substrate by surface-initiated atom transfer radical polymerization (SI-ATRP), and endothelial specific peptide Arg-Glu-Asp-Val (REDV) was immobilized at the end of the PEGMA-GMA polymer brush by ring opening reaction through the rich epoxy groups in the GMA. The structure and hydrophilicity of the polymer brushes were characterized by static water contact angle, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The results showed that the REDV modified copolymer brushes were successfully constructed on the glass substrates. The REDV peptide immobilized onto surface was quantitatively characterized by ultraviolet–visible spectroscopy (UV-VIS). The blood compatibility of the coating was characterized by recalcification time and platelet adhesion assay. The results showed that the polymer coating had good blood compatibility. The multifunctional active polymer coating with PEGMA and peptide produced an excellent prospect in surface construction with endothelial cells selectivity.

    Release date:2019-04-15 05:31 Export PDF Favorites Scan
  • Vascular endothelial growth factor/polylactide-polyethyleneglycol-polylactic acid copolymer/basic fibroblast growth factor mixed microcapsules in promoting angiogenic differentiation of rat bone marrow mesenchymal stem cells in vitro

    ObjectiveTo observe the effect of vascular endothelial growth factor/polylactide-polyethyleneglycol-polylactic acid copolymer/basic fibroblast growth factor (VEGF/PELA/bFGF) mixed microcapsules in promoting the angiogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) in vitro. MethodsThe BMSCs were isolated by the method of whole bone marrow adherent, and sub-cultured. The passage 3 BMSCs were identified by Wright-Giemsa staining and flow cytometry, and used for subsequent experiments. VEGF/PELA/bFGF (group A), PELA/bFGF (group B), VEGF/PELA (group C), and PELA (group D) microcapsules were prepared. The biodegradable ability and cytotoxicity of PELA microcapsule were determined, and the slow-released ability of VEGF/PELA/bFGF mixed microcapsules was measured. The passage 3 BMSCs were co-cultured with the extracts of groups A, B, C, and D, separately. At 1, 3, 7, 14, and 20 days after being cultured, the morphological changes of induced BMSCs were recorded. At 21 days, the induced BMSCs were tested for DiI-labeled acetylated low density lipoprotein (Dil-ac-LDL) and FITC-labeled ulex europaeus agglutinin I (FITC-UEA-I) uptake ability. The tube-forming ability of the induced cells on Matrigel was also verified. The differences of the vascularize indexes in nodes, master junctions, master segments, and tot.master segments length in 4 groups were summarized and analyzed. ResultsThe isolated and cultured cells were identified as BMSCs. The degradation time of PELA was more than 20 days. There was no significant effect on cell viability under co-culture conditions. At 20 days, the cumulative release of VEGF in the mixed microcapsules exceeded 95%, and the quantity of bFGF exceeded 80%. The morphology of cells in groups A, B, and C were changed. The cells in groups A and B showed the typical change of cobble-stone morphology. The numbers of double fluorescent labeled cells observed by fluorescence microscope were the most in group A, and decreases from group B and group C, with the lowest in group D. The cells in groups A and B formed a grid-like structure on Matrigel. Quantitative analysis showed that the differences in the number of nodes, master junctions, master segments, and tot.master segments length between groups A, B and groups C, D were significant (P<0.05). The number of nodes and the tot.master segments length of group A were more than those of group B (P<0.05). There was no significant differences in the number of master junctions and master segments between group A and group B (P>0.05). ConclusionVEGF/PELA/bFGF mixed microcapsules have significantly ability to promote the angiogenic differentiation of rat BMSCs in vitro.

    Release date:2019-01-25 09:40 Export PDF Favorites Scan
  • Progress in medical treatment of ovarian cancer

    The mortality rate of ovarian cancer is the highest among female reproductive tract malignancies. Although most patients have undergone recurrent treatments such as surgery, chemotherapy, and targeted therapy, the recurrence rate is still high. The exploration of scholars in this field has never stopped. In recent years, remarkable achievements have been made in the medical treatment of ovarian cancer. The research of poly adenosinediphosphate-ribose polymerase, immunotherapy (immunocheckpoint inhibitor monotherapy, immune checkpoint inhibitor combined with other drugs) and anti-angiogenic drugs have provided new methods for the treatment of this disease, and throughout the whole process of ovarian cancer treatment. This paper summarizes this, and aims to provide a reference for the clinical treatment of ovarian cancer.

    Release date:2021-04-15 05:32 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
  • Detection of Hepatocellular Carcinoma Cells Using SSX1 mRNA as Tumor Specific Marker

    【Abstract】ObjectiveTo discuss the possibility and clinical significance of SSX-1 mRNA used as specific marker for examining HCC cells in peripheral blood of HCC patients. MethodsUsing the RT-PCR method, the SSX1 mRNA of the peripheral blood was examined in 25 cases of HCC patients and 20 non-HCC patients. The same method was used to detect the expression of SSX-1 mRNA in the tumor tissues, para-tumor tissues, cirrhosis tissues and normal hepatic tissues. A randomized sample was extracted for DNA sequencing from positive electrophoresis expression samples of SSX-1 to examine the reliability of results. ResultsThe expression rates of SSX-1 mRNA were 60%(15/25) and 40%(10/25) respectively in tumor tissues of HCC and the corresponding peripheral blood. SSX-1 mRNA were not expressed in para-tumor tissues,cirrhosis tissues and normal hepatic tissues. The DNA sequence -confirmed that the RTPCR products were true target cDNA. No relationships were found between the expression of SSX-1 gene and clinical characteristics, such as age, sex, tumor size, TNM stage, extent of differentiation and serum AFP level (Pgt;0.05). However, in 33%(3/9) patients with normal serum AFP (lt;20 μg/L), specific expression of SSX1 mRNA was observed. ConclusionHigh specific expression of SSX-1 mRNA is observed in the peripheral blood of patients with HCC, it suggests that applying it as a tumor marker to detect HCC cells in peripheral blood is an adjuvant diagnostic tool. The expression of SSX-1 mRNA in the peripheral blood is observed in the group HCC patients whose serum AFP (lt;20 μg/L) are normal, which suggests that applying both SSX-1 mRNA and AFP as tumor markers together might be useful to improve the diagnostic accuracy for HCC.

    Release date:2016-09-08 11:53 Export PDF Favorites Scan
  • Culture and identification of adult human parathyroid cells

    Objective To investigate the reliability of culture method of adult human parathyroid cells. Methods Adult human parathyroid tissue was digested by collagenase, then the original generation of cells were cultured and passaged, and their morphological changes were observed and recorded every other day. Part of the passaged cells were observed through electron microscope and its supernatant parathyroid hormone (PTH) was assayed. Meanwhile, the other part of cells were tested the parathyroid markers, including PTH, calcium-sensing receptor (CaSR) and glial cells missing-2 (GCM-2) by PCR. Results Abundant cytoplasm, mitochondria, endoplasmic reticulum and Golgi apparatus from the seventh day's passaged cells were observed by the electron microscopy, as well as, some secretory granules existing in both cytoplasm and intercellular lacuna. Also, the PTH from supernate was detected, and parathyroid specific markers, such as CaSR, PTH, and GCM2 were positive. Conclusions These trials demonstrated the adult human parathyroid cells could be harvested by collagenase digestion and the cultured. Furthermore, the cells remained good shape and kept functioning, making it a potential source for allogeneic cell transplantation to the treatment of permanent hypoparathyroidism.

    Release date:2017-01-18 08:04 Export PDF Favorites Scan
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