Polymorphism of angiotensin-converting enzyme gene I/D of broad jumpers / 重庆医学

Objective To explore the characteristic of ACE gene I/D polymorphism in Han broad jumpers .Methods Distribu‐tion of ACE gene I/D polymorphism for broad jumpers was analyzed by PCR ,DNA sequencing ,Hardy‐Weinberg and SPSS ,and the results were compared with that of normal people .Results There were II ,DD and ID in gene ACE 16 ,and the Hard‐Weinberg re‐sults showed that the subjects were group representative .The ACE DD genotype and D allele in broad jumpers was statistically higher than normal controls (P<0 .05) .Conclusion The results suggest that ACE DD genotype and D allele are associated with training sensitivity of broad jumpers and could be the molecular marker for athletes choosing genetically .

Effects of CXCR7-shRNA lentiviral vector on the growth and invasiveness of human hepatoma carcinoma cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of CXCR7 knock-down by CXCR7-shRNA lentiviral vector on the proliferation and invasion of human hepatoma carcinoma cells in vitro.</p><p><b>METHODS</b>CXCR7-shRNA lentiviral vector was transfected into hepatocellular carcinoma HCCLM3 cells. The changes in mRNA and protein expression of CXCR7 in the transfected cells were investigated using real-time PCR and Western blotting, respectively, and MTT assay was employed to assess the cell proliferation changes. In vitro adhesion assay and transwell chamber test were used to observe the adhesion and invasiveness of HCCLM3 cells, respectively.</p><p><b>RESULTS</b>Transfection of HCCLM3 cells with CXCR7-shRNA lentiviral vector resulted in a significantly decreased expression of CXCR7 at both mRNA and protein levels (P<0.01) and obvious suppression of the cell proliferative activity (P<0.05). CXCR7-shRNA also significantly suppressed the invasiveness and adhesion of HCCLM3 cells (P<0.01).</p><p><b>CONCLUSION</b>CXCR7 knock-down can significantly inhibit the proliferation and invasiveness of human hepatoma carcinoma cells in vitro, suggesting the value of CXCR7 as a potential target for hepatoma carcinoma therapy.</p>

Application of OMIM in medical genetics teaching and its reflection / 中华医学教育探索杂志

With the rapid development of medical genetics,online Medelian inheritance in man (OMIM) manifests a more and more important role in medical genetics teaching.Using the educational form combining ‘ classroom teaching,review writing and seminar’,‘ Query and use of OMIM ’was introduced into the education of medical genetics.Reality practice revealed that this educational practice maintained advanced and timely status of knowledge and deeply activated self-studying and independent thinking ability of students.

Effect of basic amino acid on acid accumulation during poly(D,L-lactide-co-glycol ide)degradation in vitro○ / 中国组织工程研究

BACKGROUND:Poly(D,L-lactide-co-glycolide)(PLGA)may produce lactic acid and glycolic acid when PLGA degrades,thus leading to the acid accumulation and inducing the inflammatory reaction locally.OBJECTIVE:To investigate the effect of lysine,histidine and arginine on regulating the acid accumulation of PLGA copolymer during the degradation.DESIGN:Repeated measurement and experiment.TIME AND SETTING:The experiments were performed in the College of Bioengineering.Chongqing University from July 2006 to August 2007.MATERIALS:PILGA(80:20)was produced by Sigma(USA);Lysine,histidine and arginine(purlty>99%)were purchased from Sigma(USA);Chitosan(deacetylation degree:85%)was purchased from Chengdu Kelong Chemical Reagent Factory;Algin(viscosity:1.05-1.15)was purchased from Tianiin Damao Chemical Reagent Factory.METHODS:Lysine,histidine and arginine were added into PLGA with the proportion of 5%(w/v)and 10%(w/v)respectively.The resultant film sample was put into a bottle with tri-distilled-water for 2-month degradation at 37℃.The pH value of degradation solution was detected by pH meter;Each film sample was taken out and lyophilized 12 hours to get its dry weight and calculate mass loss ratio.Each variety of the solution was sampled three specimens,the average pH value,average initial weight and average finial weight of these three specimens were taken as the indices at each sampling time point,respectively.Accordingly,the regulation effect of basic amino acid was comparexl with that of algin,chitosan and NaHCO3.MAIN OUTCOME MEASURES:The changes of pH value of degradation solution;the mass loss ratio of the composite.RESULTS:Each basic additive could relieve the acid accumulation,among them,NaHCO3 was the strongest,while algin and chitosan showed a lowest capacity,basic amino acid was moderate;The suitable regulation effect could be achieved at a level of 5%lysine.CONCLUSION:Basic amino acid can effectively regulate the acid accumulation after PLGA degrades,and the optimal concentration of lysine is 5%.

Study on biomechanical properties of several scaffold materials for tissue engineering / 中国组织工程研究

BACKGROUND:It is still a research focus on constructing substitution of the human tissues and organs, or producing the alliance for grafting by engineering methods in tissue engineering. Among these researches, it is pivotal to choose appropriate materials. The prepared scaffolds should have suitable tensile strength and mechanical toughness to withstand the various outside forces without being damaged. So, it is very necessary to evaluate the biomechanical properties of candidated materials in tissue engineering, which can supply the references for selecting materials for tissue scaffolds and their designation.OBJECTIVE: To investigate the biomechanical properties of nine kinds of scaffold materials, in order to supply a biomechanical basis for the selection and design of scaffold materials for tissue engineering.DESIGN: A repetitive measurement study.SETTING: College of Bioengineering, Chongqing University.MATERIALS: The materials involved in this study were poly (DL-lactic-co - glycolic acid) (PLGA), sodium polymannuronate, gelatine, chitosan, collagen, acellular porcine dermis (APD), acellular vascular matrix (AVM),APD-PLGA, AVM-PLGA, modified gelatine and chitosan.METHODS: All the experiments related to this study were completed in the Biorheology laboratory of the College of Bioengineering, Chongqing University from April 2006 to March 2007. The nine materials above were prepared, gelatine and chitosan were modified. Stress-strain testing was performed at 10 mm per minute by a material testing machine (INSTRON 1011, USA). The Yang's modulus was calculated in the range of 0.005 to 0.02, the ultimate strain and stress were also obtained.MAIN OUTCOME MEASURES: The ultimate strain, ultimate stress and Yang's modulus of the nine materials were analyzed.polymannuronate ＞ AVM-PLGA ＞ collagen ＞ gelatine (P ＜ 0.05). The rate of burst straining of chitosan and PLGA were greater than those of other materials, 133% and 276% respectively (P ＜ 0.05). In addition, after being combined with ultimate stresses of APD and APD-PLGA were greater than that of other materials, i.e., their burst strengths were greater than those of other materials. The data also indicated that the burst strength of APD-PLGA was a little greater than that of APD (P ＞ 0.05). The burst strengths of gelatin, chitosan, and collagen were similar at the range of 7.67 to 9.51 MPa (P ＞ 0.05). The burst strengths of collagen and sodium polymannuronate were from 1.16 to 1.40 MPa, which were the least among all the materials. At the same time, being combined with PLGA, the burst strength of AVM-PLGA greatest, i.e., its rigidity was the greatest. The rigidity of APD was the least. After combined with PLGA, the rigidity of AVM and APD were increased (P ＜ 0.05), and corresponded with PLGA (P＞ 0.05). Except for gelatin, the order of rigidity in the materials was AVM-PLGA ＞ PLGA ＞ APD-PLGA ＞ AVM ＞ chitosan ＞ sodium polymannuronate ＞ collagen ＞ APD.CONCLUSION: AVM and APD have good biomechanical properties, which are very different from the water-soluble collagen. It is promising to improve the biomechanical properties of sodium polymannuronate, gelatin and chitosan by the complex of PLGA.