Expression and characterization of mesophilic GH1 β-glucosidase CdBglA from acidophilic Cuniculiplasma divulgatum / 生物工程学报

β-glucosidase has important applications in food, pharmaceutics, biomass conversion and other fields, exploring β-glucosidase with strong adaptability and excellent properties thus has received extensive interest. In this study, a novel glucosidase from the GH1 family derived from Cuniculiplasma divulgatum was cloned, expressed, and characterized, aiming to find a better β-glucosidase. The amino acid sequences of GH1 family glucosidase derived from C. divulgatum were obtained from the NCBI database, and a recombinant plasmid pET-30a(+)-CdBglA was constructed. The recombinant protein was induced to express in Escherichia coli BL21(DE3). The enzymatic properties of the purified CdBglA were studied. The molecular weight of the recombinant CdBglA was 56.0 kDa. The optimum pH and temperature were 5.5 and 55 ℃, respectively. The enzyme showed good pH stability, 92.33% of the initial activity could be retained when treated under pH 5.5-11.0 for 1 h. When pNPG was used as a substrate, the kinetic parameters Km, Vmax and Kcat/Km were 0.81 mmol, 291.99 μmol/(mg·min), and 387.50 s-1 mmol-1, respectively. 90.33% of the initial enzyme activity could be retained when CdBglA was placed with various heavy metal ions at a final concentration of 5 mmol/L. The enzyme activity was increased by 28.67% under 15% ethanol solution, remained unchanged under 20% ethanol, and 43.68% of the enzyme activity could still be retained under 30% ethanol. The enzyme has an obvious activation effect at 0-1.5 mol/L NaCl and can tolerate 0.8 mol/L glucose. In conclusion, CdBglA is an acidic and mesophilic enzyme with broad pH stability and strong tolerance to most metal ions, organic solvents, NaCl and glucose. These characteristics may facilitate future theoretical research and industrial production.

The study of hemodynamic mechanism of a novel endovascular stent on complicated abdominal aortic aneurysms / 中华胸心血管外科杂志

Objective:To detect the hemodynamic mechanism of the novel endovascular stent on complicated abdominal aortic aneurysms by Computational Fluid Dynamics(CFD) firstly, and then compare the effect of the novel endovascular stent and the streamliner multilayer flow modulator(SMFM) stent.Methods:All medical images were obtained by computed tomography. A semiautomatic segmentation protocol within Mimics(v17.0; Materialise, Leuven, Belgium) was used to extract the threedimensional aortic aneurysms. The stents was generated numerically and fitted along the aortic aneurysms. The lumen volume represented the fluid domain that was discretised in smaller volumes, which defined a mesh within the ICEM software(Ansys ICEM CFD v15.0). Hemodynamic analysis was performed with software Fluent 16.0.Results:Both kinds of stents can change the pattern of flow distribution. Compared with SMFM, the novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall.What’s more, the flow velocity of the branch artery was accelerated by the novel endovascular stent.Conclusion:The novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall, and acceleratethe the flow velocity of the branch artery.

The study of hemodynamic mechanism of a novel endovascular stent on complicated abdominal aortic aneurysms / 中华胸心血管外科杂志

Objective@#To detect the hemodynamic mechanism of the novel endovascular stent on complicated abdominal aortic aneurysms by Computational Fluid Dynamics(CFD) firstly, and then compare the effect of the novel endovascular stent and the streamliner multilayer flow modulator(SMFM) stent.@*Methods@#All medical images were obtained by computed tomography. A semiautomatic segmentation protocol within Mimics(v17.0; Materialise, Leuven, Belgium) was used to extract the threedimensional aortic aneurysms. The stents was generated numerically and fitted along the aortic aneurysms. The lumen volume represented the fluid domain that was discretised in smaller volumes, which defined a mesh within the ICEM software(Ansys ICEM CFD v15.0). Hemodynamic analysis was performed with software Fluent 16.0.@*Results@#Both kinds of stents can change the pattern of flow distribution. Compared with SMFM, the novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall.What’s more, the flow velocity of the branch artery was accelerated by the novel endovascular stent.@*Conclusion@#The novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall, and acceleratethe the flow velocity of the branch artery.

Prognostic value of plasma big endothelin-1 in patients with moderate to severe chronic ischemic mitral insufficiency after mitral valvuloplasty / 中华胸心血管外科杂志

Objective Big endothelin-1(big ET-1) is associated with the prognosis of various cardiovascular diseases. This study is to explore the predictive value of plasma big ET-1 level for long-term outcome after mitral valvuloplasty in patients with moderate to severe chronic ischemic mitral insufficiency .Methods A total of 142 consecutive patients with moderate to severe chronic ischemic mitral regurgitation who underwent coronary artery bypass grafting and mitral valvuloplasty were enrolled at our center from January 2009 to December 2015.The clinical baseline data were collected and recorded.All patients were followed up.The mortalities and major adverse cardiovascular and cerebrovascular events during the follow-up period were re-corded.Results A total of 142 patients were enrolled, with mean age of(59.4 ±8.3) years.During(51.9 ±22.6) months follow-up, 19 cases(13.4％) died and 35 cases(24.6％) had major adverse cardiovascular and cerebrovascular events.Uni-variate and multivariate Cox regression analysis showed that big ET-1 was an independent risk factor for all-cause mortality (HR=3.970, 95％CI:1.535-10.268) and major adverse cardiovascular and cerebrovascular events(HR=2.754, 95％CI:1.238-6.129).In addition, left ventricular ejection fraction, pulmonary hypertension and stroke history were independent risk factors for all-cause mortality , while left ventricular ejection fraction , stroke history were independent risk factors for major adverse cardiovascular and cerebrovascular events.Conclusion Long-term outcomes of simultaneous coronary artery bypass grafting and mitral valvuloplasty for moderate to severe ischemic mitral insufficiency are satisfactory and big ET-1 is an inde-pendent risk factor for long-term outcomes of these patients.

Characteristics of monoclonal antibody against glycophorin A of human erythrocyte / 医学研究生学报

Objectives: To study and prepare monoclonal antibody against glycophorin A of human erythrocyte(GPA McAb).This antibody is a key reagent in preparation of bispecific antibodies for rapid whole-blood immunoassay.　Methods: BALB/c mice received GPA antigen injection. Hybridoma was produced by traditional techniques. Hybridoma was determined with ELISA and indirect agglutination(IA) method.　Results: All 3 GPA McAb reacted with GPA, and they did not autoagglutenate with four types of red cells(type A,B,O,AB).Of the 3 McAb-GPA, two antibodies were IgG1,one IgG2 subtypes. Two IgG1 McAb-GPA can be used in making bispecific antibody in preparation of rapid whole-blood immunoassay.　Conclusions: Immunogenity of GPA was enhanced after coupling with the native serum albumin of the immunized animal, and high titer GPA McAb could be easily obtained. This result is important in making bispecific antibodies in preparation of rapid whole-blood immunoassay.