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find Keyword "Polymer" 33 results
  • Joint Detection of hTERT mRNA and GGT mRNA-H Expressions in Peripheral Blood of Small Hepatocellular Carcinoma Patients and Its Clinical Significance

    ObjectiveTo investigate the expressions and clinical significance of human telomerase reverse transcriptase (hTERT) mRNA and γglutamyl transpeptidase mRNA-H (GGT mRNA-H) in the peripheral blood of small hepatocellular carcinoma (HCC) patients. MethodsThe expressions of hTERT mRNA and GGT mRNA-H were detected in the peripheral blood of thirty patients with small HCC by RT-PCR, eighteen patients with benign liver diseases, and twelve normal volunteers. ResultsThe positive rate of hTERT mRNA and GGT mRNA-H expression in patients with small HCC were 80.0% (24/30) and 46.7%(14/30), respectively. In patients with hepatitic cirrhosis the positive rate of hTERT mRNA expression was 33.3% (6/18), while the expression of GGT mRNA was not detected. Both the expressions of hTERT mRNA and GGT mRNA-H were negative in all normal volunteers. The combination analysis of hTERT mRNA and GGT mRNA-H expression achieved positive rate of 86.7% in the diagnosis of small HCC, which was significantly higher than the positive rate of AFP (26.7%), Plt;0.05. ConclusionThe hTERT mRNA and GGT mRNA-H are significantly expressed in small HCC patients, the combination analysis of hTERT mRNA and GGT mRNA-H seems to be useful in the early diagnosis of small HCC.

    Release date:2016-09-08 10:46 Export PDF Favorites Scan
  • Mutation and Expression of β-Catenin Gene in Breast Hyperplasia and Breast Cancer

    Objective To investigate the role of β-catenin gene in breast tumorigenesis by detecting mutation and expression of β-catenin gene in breast hyperplasia and breast cancer. Methods Mutation and expression of β-catenin gene in 42 breast cancer, 15 simple hyperplasia and 15 atypical hyperplasia were detected by polymerase chain reaction-single strand conformation polymorphism and immunohistochemistry. Results Normal expression of β-catenin occurred in tissue of breast simple hyperplasia. The rate of abnormal expression of β-catenin in tissue of breast atypical hyperplasia and breast cancer were 26.7% (4/15) and 59.5% (25/42), respectively, which were higher than that of simple hyherplasia tissue (P<0.05). And there was a markedly difference between the atypical hyperplasia tissue and breast cancer tissue (P<0.05). Mutation of β-catenin gene wasn’t detected in this three kinds of tissues. Conclusion Abnormal expression of β-catenin plays an important role in human breast tumorigenesis, reason of abnormal expression of β-catenin isn’t mutation of β-catenin gene. Expression of β-catenin can be regulated by other mechanisms.

    Release date:2016-08-28 04:08 Export PDF Favorites Scan
  • CONTRAST STUDY ON DIAGNOSIS OF LYMPH NODES METASTASIS BY CONVENTIONAL PATHOLOGY AND GENETIC DETECTION

    Objective To evaluate the potential of specific mRNA marker keratin 19(K19) to detect micrometastasis by reverse transcriptase polymerase chain reaction (RT-PCR) .Methods One hundred and ninty four regional lymph nodes harvested from 6 cases of benign diseases, 4 cases of breast carcinoma, 5 cases of gastric carcinoma and 12 cases of colorectal carcinoma patients were examined by conventional pathology and amplifying tissue specific K19 mRNA by RT-PCR separately, then the two methods were compared with each other. Results None of the 34 lymph nodes which were pathological metastasis-negative from benign diseases expressed K19 mRNA by RT-PCR, all of the 28 regional lymph nodes which were pathological metastasis-positive from malignant cases showed trains of K19 mRNA by RT-PCR. Of the 132 lymph nodes which were pathological metastasis-negative from malignant cases, 11 lymph nodes were detected with micrometastasis by genetic diagnosis.Conclusion Genetic diagnosis of lymph node micrometastasis is more sensitive than conventional pathology and has diagnostic value and merits further study.

    Release date:2016-08-28 05:30 Export PDF Favorites Scan
  • mRNA EXPRESSION OF nm23-H1 GENE IN HUMAN LIVER TUMOR ASSAYED BY REVERSE TRANSCRIPTIONPOLYMERASE CHAIN REACTION

    To investigate the mRNA expression of nm23-H1 gene in human liver tumor. In tumor and corresponding nontumoral liver specimens from 20 patients, nm23-H1 mRNA were examined by reverse transcriptionpolymerase chain reaction (RT-PCR) method with specific primers. Results: The primers designed in this study could amplified nearly entire coding sequence of nm23-H1 gene. All the samples showed positive expression of nm23-H1 mRNA, indicating there was no expression loss or obvious alteration. Conclusions: The achievement of RT-PCR method lays foundation for quantitative gaugement of nm23-H1 mRNA in liver tumor.

    Release date:2016-08-29 09:20 Export PDF Favorites Scan
  • A STUDY ON BACTERIAL DNA IN CHOLESTERAL GALLSTONES AND ITS CLINICAL SIGNIFICANCE BY NP-PCR

    The aim of the this study was to search for bacterial DNA sequences in cholesterol gallstones with negative bacterial culture by NP-PCR technique. Bacterial gene fragments were amplified in vitro from DNA which were extracted from cholesterol gallstones in gallbladder for identifying the existence of bacteria. The gallbladder gallstones of 30 patients were analysed. Bacterial DNA was found in the stones of 26 patients, indicating that most cholesterol gallstones harbor bacterial DNA.

    Release date:2016-08-29 03:19 Export PDF Favorites Scan
  • Artificial Coronary Vascular Stents Fabrication Using Biodegradable Material Compounds of PLA/PGA-co-Chitosan

    Abstract: The first generation scaffolds of bare metal stents (BMS) and the second generation of drug eluting stents (DES) have been widely used in the treatment of coronary heart diseases. However, long term incidences of major adverse cardiovascular events and revascularization treatments are still high because of in-stent re-stenosis and thrombosis. These may be caused by chronic inflammations and vascular wall damages due to persistent metal stents stimulation. What’s more, the eluting drugs within metal stents could also disturb normal growth of vascular endothelial cell, intima, tunica media, smooth muscle and epimysium. Therefore, in order to meet these demands several fully biodegradable scaffolds and drug carried stents have been manufactured using polymers polyester, polycarbonate and polyphosphate, etc. Among them, the security and histo-and hemo-compatibilities of coronary scaffolds made from poly-lactic acid (PLA), poly-glycolic acid(PGA), chitosan as coating, poly-caprolactone (PCL) and other copolymer like poly-lactic-co-glycolic acid (PLGA) have been testified to be sound. Nevertheless, there exist several different shortages for these stents such as tensile strength deficiency and slow degradation. PLA is hard and brittle with slow degradation, while PGA is soft with insufficient support force and fast degradation. Whether stents degrade too fast or too slow, they could not supply sufficient strength and effective support after implantation, and also they may cause target vascular injuries and elastic shrink inducing restenosis and thrombosis in long terms. Using optimized molar ratio component of PLA and PGA with chitosan coating, we can get sound composite materials with better biocompatibility, moderate degradation (approximately 3 - 6 months of completedegradation), adequate mechanical strength, lower inflammatory response and good range of extension, and establish an experiment ground for fully biodegradable vascular scaffolds fabrication.

    Release date:2016-08-30 05:50 Export PDF Favorites Scan
  • APPLICATION OF COLLAGEN COMPOSITE SCAFFOLD IN VASCULAR TISSUE ENGINEERING

    Objective To review the appl ication of collagen and biodegradable polymer composite scaffolds in vascular tissue engineering, and describe the multi-layering vascular scaffolds of collagen-based material in recent years. Methods The l iterature concerning collagen composite scaffold production for scaffold of vascular tissue engineering was extensively reviewed and summarized. Results As one of the structural proteins in natural blood vessel, collagen is widely used in vascular tissue engineering because of good biocompatibil ity, biodegradabil ity, and cell recognition signal. The vascular scaffolds with biological activity and good mechanical properties can be made by collagen-polymer composite materials. In addition, the structure and function of the natural blood vessel can be better simulated by multi-layering vascularscaffolds. Conclusion Collagen-polymer composite material is the hot spot in the research of vascular scaffolds, and multilayering vascular scaffolds have a brill iant future.

    Release date:2016-08-31 05:44 Export PDF Favorites Scan
  • EXPERIMENTAL STUDY IN RABBIT ON REPAIR OF RADIAL BONE DEFECT BY BIOACTIVE DEGRADABLE POLYMER

    OBJECTIVE: To investigate the availability of bone defect repair by degradable porous polycaprolactam (PCL) as the carrier of bone morphogenetic protein (BMP). METHODS: Three different kinds of bone substitutes, including decalcified bone matrix, PCL-BMP compounds and simple PCL, were implanted into the radial bone defects in 36 rabbits, and in the other 12 rabbits the bone defects were left untreated as control. X-ray examination, X-ray morphometry, histological and electron microscopic observation were performed at different time after operation. RESULTS: The quantity of new bone formation in PCL-BMP group was prior to that in simple PCL group. The pattern and speed of bone defect repair in PCL-BMP group were similar to those in decalcified bone matrix. Electron microscopic observation showed that the PCL-BMP group degraded faster than simple PCL group, which was more suitable for bone repair. CONCLUSION: PCL is a good carrier of BMP with potential for clinical use.

    Release date:2016-09-01 10:21 Export PDF Favorites Scan
  • THE RYR1 GENOTYPE OF CHINESE INBRED PIGS

    OBJECTIVE: Porcine stress syndrome (PSS) is one kind of molecular genetics defect diseases of pig which will cause malignant hyperthermia syndrome (MHS) and is the first index should be excluded in screening of a pig species for xenotransplantation. It was reported that mutation of pig rynodine receptor(RYR1) gene is the main reason for PSS. In this study, RYR1 genotypes of the Chinese Banna mini pig inbred line and inbreeding closed colony Wuzhishan pig were investigated with polymerase chain reaction-restriction endonuclease fragment length polymorphism (PCR-RFLP) technique. METHODS: Antevenocaval whole blood samples were collected from 50 Banna mini-pig inbred-line(BMI), 15 inbreeding Wuzhishan pig (WZSP) and 25 Neijiang pigs (NJP) as negative control, the primer were designed and synthesized, PCR reaction was conducted following the sequence of 94 degrees C (1 min), 58 degrees C (1 min) and 72 degrees C (1 min) for 30 cycles. The PCR products were digested with restriction endonuclease HhaI and then electrophoresis check. RESULTS: A 659 bp DNA fragment was amplified with these two primers, the HALNN sample fragment was cut into fragments as 493 bp and 166 bp individually after the digestion, indicates no point mutation at site 1,843 in RYR1 gene in all tested BMI pig and WZSP. Namely, the RYR1 genotype of 50 cases of BMI and 15 cases of WZSP were HALNN, therefore their phenotype is PSS negative. CONCLUSION: It indicates that the genotype of Banna mini pig inbred line and inbreeding Wuzhishan pig are HALNN therefore PSS absolutely negative, the group penetrance is 0. This is consistent with experimental observation. It suggests that Banna mini pig inbred line and inbreeding Wuzhishan pig may be the alternative donor for xenotransplantation.

    Release date:2016-09-01 10:27 Export PDF Favorites Scan
  • Polymorphisms in HLA-DQB1 promoter and coding regions in Chinese Han patients with Vogt-Koyanagi-Harada syndrome

      Objective To investigate the genetic interaction of HLA-DQB1 promoter and coding alleles in the pathogenesis of Vogt-Koyanagi-Harada syndrome (VKH). Methods Eighty-eight Chinese Han patients with VKH and eighty-eight non-VKH normal controls were enrolled in this study. DNA was extracted from white blood cells of the subjects by phenolchloroform method. Thirteen alleles were genotyped by polymerase chain reaction-sequence-specific primers (PCR-SSP), polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and clone-sequencing was applied to determine the polymorphisms of the promoter and coding regions of HLA-DQB1 gene. Chromas and Bioedit software were used to analyze the sequences of the promoter of HLA-DQB1. Chi-square test and Fisher exact test were the statistical methods. Relationships among single nucleotide polymorphism (SNP) in the promoter and coding region were analyzed. Results Twelve of thirteen already known HLA-DQB1 alleles were genotyped by PCR-SSP in VKH patients. The most frequent allele in VKH patients was HLA-DQB10401 (0.318, 56∶176) which was significantly higher in patients than that in normal controls (0.045, 8∶176) (chi;2=44.00, P=0.000, OR=9.8). So was for HLA-DQB10303 (0.068 vs. 0.006, chi;2=9.67, P=0.002, OR=12.81). In contrast, the frequency of HLA-DQB10601 (0.017 vs.0.096, chi;2=10.39, P=0.001, OR=0.16) and HLA-DQB10302 (0.062 vs. 0.193,chi;2=13.48, P=0.000, OR=0.28) in VKH patients were significantly lower than normal controls. Twelve SNP were found in all subjects. The frequency of C allele at position -189C/A in VKH patients was significantly higher than that in controls (0.324 vs. 0.074, chi;2=45.92, P=0.000). However, the frequency of G allele at position -227G/A in VKH patients was significantly lower than that in the normal controls (0.011 vs. 0.108, chi;2=15.63,P=0.000). The frequency of combination of susceptible alleles in promoter and coding area (-189C and HLA-DQB10401) in VKH patients was statistically higher than that in controls, the frequency of combination of resistant alleles in control (-227G and HLA-DQB10601) was higher than that in VKH patients. Conclusions The specific interactions of SNP in the promoter and coding alleles of HLA-DQB1 are associated with the pathogenesis of VKH.

    Release date:2016-09-02 05:41 Export PDF Favorites Scan
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