In the process of evolution, pathogenic Streptococcus pyogenes secretes an immunoglobulin G-degrading enzyme IdeS which can specifically cleave the hinge region of immunoglobulin G in order to escape the immune response against the host. On the one hand, IdeS can be used for IgG fingerprinting as a tool enzyme combined with mass spectrometry technology. On the other hand, IdeS can be used to treat the antibody-responsive diseases produced by autoimmunity as a therapeutic protein. In this study, the backbone of plasmid pCold was used to construct two expression vectors of recombinant protein IdeS, which were heterologously expressed in Escherichia coli Shuffle T7. After purification by affinity chromatography, the recombinant IdeS activity was detected and their activity differences between the two were compared. Among them, the yield of the recombinant IdeS containing the His6-tag at the N-terminus was 4 mg·L^-1, and the cleavage reaction with antibody IgG1 at 1∶200 (m/m) at 37 ℃ for 30 min could complete. However, the yield of the recombinant IdeS containing both the N-terminal His6 tag and the C-terminal silica affinity tag (silica bing peptide, SiBP) is 1.5 mg·L^-1, and the degradation reaction with antibody IgG1 at 1∶20 (m/m) at 37 ℃ for 30 min could reach the end. The C-terminal fusion peptide has a great influence on the yield and activity of IdeS, which is not conducive to subsequent application in drug development. Above all, the recombinant IdeS containing the His6-tag at the N-terminus expressed by this system has high activity and can fully meet the needs of antibody drug development and mapping analysis of IgG.

Objective:To investigate the effect of metformin and arsenic trioxide on KG1a cells proliferation of acute myeloid leukemia and its possible mechanism.Methods:CCK-8 method was used to detect the killing effect of metformin,arsenic trioxide and combined application on KG1a cells.Annexin V-FITC/P1 Dual Stain Flow Cytometry was used to detect the effect of combined application on apoptosis of KG1 a cells.Western blot was used to detect the expression of intracellular apoptosis-,autophagy-related protein.Results:Metformin and arsenic trioxide alone or in combination could inhibit the proliferation of KG1 a cells and induce apoptosis of KG1 a cells,and the proliferation inhibition rate and apoptosis rate in the combined drug group were higher than those in the drug group alone(P＜0.05).The combination of drugs induced upregulation of Caspase 8 protein and P62 protein expression and was higher than that in the drug group alone(P＜0.05).Conclusion:Metformin can synergize with arsenic trioxide to kill KG1a cells,and its mechanism of action may be related to inducing apoptosis and enhancing autophagy.

Adult ; Aged ; Female ; Humans ; Lung Neoplasms ; blood ; genetics ; Male ; Middle Aged ; Mutation ; Tumor Suppressor Protein p53 ; blood ; genetics

Objective To summarize the experience of hybrid repair performed in high risk patients with dissection involving the aortic arch.Methods From Sep.2007 to Mar.2015,hybrid repair was performed in 33 high risk patients with dissection involving the aortic arch including acute (n =8),subacute (n =15),or chronic (n =10) cases.Descripitive statistics were computed for continuous and categorical variables.Results There were 22 male and 11 female patients with a mean age of(69 ± 10) years,and ASA Physical Status Ⅲ-Ⅳ.Simultaneous (n =27) and staged (n =5,mean interval 5.0 ± 1.3 days)endovascular repair were performed via femoral artery.The technical success rate was 100％.The average hospital stay was (16 ±6) days.One case died of cerebral infraction.There were two with strokes,one with pneumonia and two with renal failure as complications.Median follow-up was 47 months (3-66 months).There were four deaths with two were related to aortic artery.Endoleak was found in 3 during follow-up.One type Ⅰ endoleak was cured after remedy hybrid repair.Conclusions Hybrid repair performed in patients at high risk with dissection involving the aortic arch is less invasive with favorable medium and long-term outcomes.

Background Ultraviolet irradiation promotes cellular apoptosis by affecting the mitochondrial transmembrane potential,including human lens epithelial cells (LECs).Gene associated with retinoid-interferoninduced mortality-19 (GRIM-19),a cell death regulatory protein,is essential for the assembly and function of mitochondrial complex Ⅰ.However,whether LECs apoptosis induced by ultraviolet irradiation is related to GRIM-19 is still unclear.Objective The purpose of this study was to investigate the relationship between the apoptosis of human LECs caused by ultraviolet with GRIM-19 expression in vitro.Methods Human LEC line(SRA01/04)was cultured in α-MEM containing 10％ fetal bovine serum.The cells were exposed to ultraviolet ray at doses of 0,30,60,90,120 or 150 mJ/cm2 when cell growth reached the logarithmic phase and 80％ confluency.The rate of apoptosis of the cells was assayed using flow cytometry,and the level of expression and relative amount of GRIM-19 protein (GRIM-19/β-actin) were detected by Western blot.The relationship between apoptosis and the GRIM-19/β-actin value among the different treatment groups was compared using One-way ANOVA,and the correlation of LECs apoptosis rate and GRIM-19 expression level was assessed by Pearson linear analysis.Results A significant difference was found in the apoptosis rate among the different treatment groups(F=149.32,P＜0.01).Compared with the 0 mJ/cm2 ultraviolet irradiation group,the apoptosis rate of LECs was significantly increased in the 60,90,120 and 150 mJ/cm2 ultraviolet irradiation groups (q =17.02,-25.20,-29.41,-8.61,P ＜ 0.01).The expression of the GRIM-19 protein in the LECs suspension was enhanced by ultraviolet irradiation at 60,90,120 and 150 mJ/cm2.The relative expression of the GRIM-19 protein (GRIM-19/β-actin) was significantly different among the various groups (F=6.87,P＜0.05),and the GRIM-19/β-actin values in the 60,90,120,150 mJ/cm2 ultraviolet irradiation groups were elevated in comparison with the un-irradiated group(2.01±0.76,2.98± 1.80,3.97± 1.61,2.42± 1.28 vs.0.56±0.23),which showed statistically significant differences (q =4.12,-5.04,-7.09,-3.85,P ＜ 0.01).In addition,a positive correlation was seen between the rate of apoptosis and the expression of the GRIM-19 protein(r=0.71,P＜0.01).Conclusions GRIM-19 is expressed in normal human LECs.The apoptosis of human LECs accompanies the up-regulation of GRIM-19.The expression of GRIM-19 in LECs increases with ultraviolet irradiation in a doseindependent manner.

Background Epithelial-myofibroblast transition (EMT) of human lens epithelial cells (LECs) induced by transforming growth factor-β2 (TGF-β2) is the main mechanism in the pathogenesis of posterior capsular opacification(PCO).Seeking an effective drug capable of inhibiting this process is important for the prevention and treatment of PCO.Objective The purpose of this study was to investigate the inhibitory effect of rapamycin (RAPA)on the proliferation of human LECs and TGF-β2-induced EMT.Methods Human LEC strain(SRA01/04)was cultured in DMEM with high glucose and 10％ fetal bovine serum.The cells were consequently cultured in serumfree DMEM with 5 mg/L TGF-β2,TGF-β2+10 mg/L RAPA,TGF-β2 + 100 mg/L RAPA,TGF-β2 + 1000 mg/L RAPA or TGF-β2 +10 000 mg/L RAPA for 72 hours,and SRA01/04 cultured in serum-free DMEM were used as control.The proliferation rate(A490)of SRA01/04 in the different groups was detected using the MTT assay and the rate of inhibition of RAPA was calculated.The expressions of the α-smooth muscle actin(α-SMA) and E-cadherin(E-cad)mRNA and protein were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot,respectively.The changes in the expression of α-SMA and E-cad in SRA01/04 were evaluated by Western blot 24,48 and 72 hours after TGF-β2 +400 mg/L RAPA treatment.Results The A490 value of SRA01/04 was 0.680±0.020,0.550±0.013,0.480±0.014,0.400±0.011 and 0.200±0.019 in the control group,TGF-β2 group,TGF-β2 + 10 mg/LRAPA group,TGF-β2 + 100 mg/L RAPA group,TGF-β2 + 1000 mg/L RAPA and TGF-β2 + 10 000 mg/L RAPA group,respectively,showing a gradually declining trend in SRA01/04 rate of proliferation with increasing RAPA concentrations (F =101.920,P =0.000).RT-PCR and Western blot assay showed that the relative expression levels of α-SMA mRNA (α-SMA mRNA/β-actin mRNA)and protein (α-SMA/β-actin)in the cells were significantly increased in the TGF-β2 treatment group.However,with exposure to RAPA,the relative expression levels of α-SMA mRNA and protein were significantly lowered with increasing RAPA concentrations,but the expression levels of E-cad mRNA and protein were raised (α-SMA mRNA:F =294.660,P =0.000 ; α-SMA protein:F =346.950,P =0.000 ; E-cad mRNA:F =264.250,P =0.000 ; E-cad protein:F =317.327,P =0.000).In addition,after exposure to 400 mg/L RAPA,the expression levels of α-SMA protein gradually reduced and those of E-cad protein gradually increased with increasing treatment durations,showing significant differences among the different time points (α-SMA:F =693.864,P =0.000 ;E-cad:F=369.286,P =0.000).Conclusions RAPA can inhibit the proliferation of SRA01/04 in vitro and arrest EMT of SRA01/04 induced by TGF-β2 in a dose-and time-dependent manner.

Total 1188 subjects aged 35-74 in an urban community of Beijing were recruited by a multistage stratified random sampling procedure. Dental caries were examined by three dentists independently. The prevalence of dental crown caries was 79. 6% (DF), that of DMFS was 24. 39% and the root caries index (RCI) was 3.5% in this group. 22. 3% of the examinees required treatment for the crown caries and 26. 0% for root caries. Bivariate correlation analysis showed that DMFS was significantly correlated with RCI (P <0. 01 ), and there was no significant difference of DMFS and RCI between males and females. The study indicates that dental caries is a common health problem in adults and elderly population of urban Beijing, and the development of community oral health service system is necessary.

Objective:To investigate the radiosensitizing effect of three flavonoids on ovarian cancer SKOV3 cells under hypoxia. Methods:The SKOV3 cells were divided into normoxic group and hypoxic group. The hypoxic SKOV3 cellular model in vitro was es-tablished and tested by measuring the expression profile of HIF-1αprotein in SKOV3 cells. Colony-forming assay was used to detect the radiosensitivity of normoxic and hypoxic SKOV3 cells. The cytotoxicity and radiosensitizing effects of flavonoids were evaluated on the basis of cell death and MTT assay. Results:The Western blot results showed that the gray intensity ratio of HIF-1α/β-Actin in hypoxia group was significantly higher than that in normoxia group (1. 068>0. 117). Radiosensitivity of hypoxic SKOV3 cells in hypoxia group was significantly lower than that in normoxia group. The survival rate of SKOV3 cells was decreased with the increase of concentration. When the concentration was increased, D0 and Dqin chrysin group and quercetin group were significantly decreased (P<0. 01), and SER was increased (P<0. 05). SER showed no significant difference in breviscapine group (P>0. 05). The overall radiobiological parameters of hypoxia group were higher than those of normoxia group. Conclusion: Hypoxia can induce the expression of HIF-1α in SKOV3 cells, which results in the decrease of radiosensitivity. Chrysin and quercetin can enhance the radiosensitivity of SKOV3 cells, and the enhancement is significant under hypoxia, while breviscapine is without such effect. The radiosensitizing effect may be achieved by the level decrease of HIF-1α in SKOV3 cells and inhibition of DNA damage repair.

Objective To prepare triamcinolone acetonide acetate(TAA)thermosensitive hydrogel for intra-articular injection,and to investigate its release in vitro. Methods TAA suspending thermosensitive hydrogel was prepared by using poly lactic-co-glycolic acid(PLGA)-polyethylene glycol(PEG)-PLGA as gel matrices,xanthan gum as suspending agent and NaCl as flocculant. It was evaluated preliminarily by determining its contents and its in vitro release. Results The best compositions for preparation of TAA suspending thermosensitive hydrogel were 25% PLGA-PEG-PLGA,0.05% xanthan gum, 0.9% NaCl and 4 mg·mL-1 TAA.The gelation temperature was 35.3 ℃ .The average recovery was(98.98±0.31)%. By the method of membraneless dissolution,the accumulative drug release was up to 83. 31% at 16 days. The drug release followed Ritger-Peppas methematical model. Conclusion The TAA thermosensitive hydrogel with obviously sustained release is expected to become a new drug delivery system for intra-articular injection.

OBJECTIVE:To optimize the formulation of Methotrexate thermosensitive hydrogels,and to study the in vitro re-lease property of it. METHODS:Taking PLGA-PEG-PLGA as matrix and mannitol as viscosity modifiers,Methotrexate thermosen-sitive hydrogels were prepared. Using the absolute value of the deviation of gelation temperature between 35 ℃,its formulation was optimized by orthogonal test using the concentrations of PLGA-PEG-PLGA,methotrexate and mannitol as factors. The dialysis bag method was used to investigate accumulative release rate of Methotrexate thermosensitive hydrogels and methotrexate solution within 336 h in vitro. RESULTS:The optimal formulation was as PLGA-PEG-PLGA of 20%,methotrexate of 0.10% and mannitol of 0.10%;gelation temperature were 35.1,35.0,35.0℃. The average drug-loading rate was more than 90%. 12 d accumulative re-lease rate was more than 90%(r=3). Methotrexate solution has been substantially completely relased within 240 h. CONCLU-SIONS:Methotrexate thermosensitive hydrogels with sustained-release are prepared successfully,and the preparation technology is simple and practical.