Aim To investigate the effects of Astragalus Mongholicus Bunge Lectin (AMML) on tumor cells proliferation,cell cycle and apoptosis by using human leukemia cell line (K562 cells).Methods The antiproliferation effect of AMML on K562 cells was detected by the colorimetric MTT assay.The apoptosis induced by AMML on K562 cells was explored by means of cell morphological and flow cytometry.Results AMML showed strong inhibiton of the growth of K562 cells in a time-and concentration-dependence. After incubation of K562 cells with AMML at a concentration of 60 mg?L-1 for 72 h,the inhibition ratio was 89%.Morphological observation showed that AMML-treated K562 cells displayed outstanding apoptosis characteristics,such as nuclear fragmentation,chromatin condensation. AMML induced significant cell cycle arrest at S phase in K562 cells,and the apoptosis of K562 cells was confirmed by flow cytometry.Conclusion AMML can inhibit the growth of K562 cells through S arrest and induce the apoptosis of K562 cells. Thus,AMML may be valuable for the treatment of cancer.

Objective To isolate and purify a lectin from the roots of Astragalus membranaceus.Methods The protein was purified using a combination of 20%—60% ammonium sulfate fraction and ConA-Sepharose 4B affinity chromatography.Results The purified protein appeared as a single band with molecular mass of 3.15?104 on SDS-PAGE and the relative molecular mass was estimated by gel filtration on a calibrated Superdex 75 column with apparent molecular weight of 3.35?104.This lectin was a glycoprotein with a neutral carbohydrate content of 10.7%.Conclusion A lectin is isolated and purified from the roots of A.membranaceus for the first time.It is a monomer glycoprotein and its specific activity is 391.9 U/mg.

Objective To investigate the incidence, imaging and clinical characteristics in elderly patients with coronary artery ectasia (CAE). Methods A retrospective analysis was conducted on patients with CAE who underwent coronary angiography between January 2006 and December 2012. According to age, the enrolled patients were divided into two groups (elderly group, age≥ 65 years; non-elderly group, age < 65 years). The clinical feature, imaging characteristics and the 5-year survival rate of the two groups were compared.Results The preva-lence of CAE in elderly patients was 0.33%. Patients in elderly group were found to have significantly higher proportion of female (30.1%vs. 10.1%,P< 0.001), three-vessel disease (60.5%vs. 45.2%,P = 0.003) and localized ectasia (55.0%vs. 40.2%,P = 0.003). In addition, body mass index (20.90 ± 2.71 kg/m2vs. 22.31 ± 2.98 kg/m2,P < 0.001) and percentage of current smokers (45.0%vs. 64.6%,P < 0.001) were significantly lower in elderly group. Cumulative survival curves demonstrated reduced 5-year cumulative survival at the follow-up in the elderly group compared with the non-elderly group (88.0%vs. 96.0%,P = 0.002). But the 5-year event free survival rate failed to show a significant difference between the two groups (31.0%vs. 35.0%,P= 0.311).ConclusionThe prevalence of CAE in elderly patients was 0.33%, which was about 1/3 of the entire numbers of CAE patients. There were significant differences between the elderly and the non-elderly patients with CAE in terms of coronary artery disease risk factors and coronary artery ectatic characteristics. CAE might be asso-ciated with increased mortality risk in the elderly.

Directed evolution was used to improve the performance of beta-1,3-1,4-glucanase (designated as PtLicl6A) from Paecilomyces thermophila J18 under acidic condition. A mutant library was constructed by error-prone PCR and DNA shuffling, and positive clones were screened by Congo red staining. More than 1 500 mutants were selected. One mutant (PtLic16AM1) exhibited an optimal activity at pH 5.5, while the optimal pH of the wild-type enzyme was 7.0. The mutant PtLic16AM1 kept the high specific activity and thermotolerence of the wild-type enzyme. Sequence analysis revealed that the mutant enzyme has four sense substitutions which caused four amino acid substitutions - namely T58S, Y110N, G195E and D221G.. Homology modeling showed that among the four amino acid substitutions, Y110N was near the active site of the enzyme, while the other three was distant. T58S and G195E may play key roles in the change of optimal pH. This study provided a new perspective of obtaining applicable 3-1,3-1,4-glucanase for industrial use.
Catalysis ; Directed Molecular Evolution ; methods ; Endo-1,3(4)-beta-Glucanase ; biosynthesis ; genetics ; metabolism ; Enzyme Stability ; Hot Temperature ; Hydrogen-Ion Concentration ; Mutant Proteins ; metabolism ; Mutation ; Paecilomyces ; classification ; enzymology ; genetics ; Protein Engineering ; methods

Objective To evaluate and compare the analytical performances and application values of three nucleic acid extraction methods for quantification of plasma Epstein-Barr Virus ( EBV ) DNA. Methods It used silica membrane spin column , boiling and automated magnetic bead method to extract viral nucleic acid in parallel , and combined real-time fluorescence quantitative PCR assays for quantitative EBV-DNA quantification.The performances of three methods were determined and compared by using the third-party reference materials , and the clinical values were analyzed by pairing detecting 100 NPC patients and 100 healthy subjects in pair .Results The accuracy and imprecision of three methods were all in line with requirements , and the results of clinical samples were linearly correlated . But actually the reproducibility and intermediate imprecision of the magnetic bead method were smaller and stable than those of the spin column method and the boiling method ( all <3％);the limit of detection for the magnetic bead method was 3.334 ×101 IU/ml, better than that of spin column method (4.159 ×101 IU/ml) and boiling method (8.511 ×101 IU/ml);the linear range of the magnetic bead method was 5.4 ×101 -5.4 ×105 IU/ml, slightly wider than that of the boiling method (5.4 ×102 -5.4 ×105 IU/ml); the ability of anti -Hb interference ability of magnetic bead method is better than that of boiling method ;and the positive rate and the mean viral load of the NPC samples measured with the magnetic bead method were significantly higher (95％, 8.342 ×103 IU/ml) than those measured with the spin column method (84％, 4.707 ×103 IU/ml) and the boiling method (78％, 2.571 ×103 IU/ml) ( P all<0.05).Conclusion The automated magnetic bead nucleic acid extraction method offered better analytical performance and higher clinical value for EBV DNA quantification in plasma .