Objective:To obtain a polyvalent single-chain variable fragment（scFv）against West Nile virus through PEGylation in order to improve its antigen-binding ability and neutralizing activity.Methods:A scFv carrying a C-terminal cysteine residue（scFvC）was constructed by introducing Cys into the C-terminal of scFv against West Nile virus. Then the multimerization of scFvC was achieved by targeting the thiol group of Cys with maleimide-activated polyethylene glycol. ELISA was used to detect the antigen-binding activity of the multivalent scFvC. Pseudovirus-based neutralization assay was used to evaluate the neutralizing activity of the multivalent scFvC in vitro. One-way analysis of variance was used for statistical analysis. Results:The PEGylated scFvC multimers showed higher antigen-binding ability than the monomeric scFvC. In the pseudovirus-based neutralization assay，both monomeric scFvC and PEGylated scFvC multimers showed good neutralizing activity compared with the control group（ P<0.000 1）. Moreover，the PEGylated scFvC multimers showed a more effective ability to block the pseudovirus infection in target cells（ P<0.05），suggesting that the PEGylated scFvC multimers could enhance their function in vitro through avidity effect. Conclusion:In this study，a scFvC targeting West Nile virus is successfully constructed and its polyvalent form is generated through PEGylation，which improves the antigen-binding and neutralizing activity of the parental scFv.

Objective:To obtain a polyvalent single-chain variable fragment（scFv）against West Nile virus through PEGylation in order to improve its antigen-binding ability and neutralizing activity.Methods:A scFv carrying a C-terminal cysteine residue（scFvC）was constructed by introducing Cys into the C-terminal of scFv against West Nile virus. Then the multimerization of scFvC was achieved by targeting the thiol group of Cys with maleimide-activated polyethylene glycol. ELISA was used to detect the antigen-binding activity of the multivalent scFvC. Pseudovirus-based neutralization assay was used to evaluate the neutralizing activity of the multivalent scFvC in vitro. One-way analysis of variance was used for statistical analysis. Results:The PEGylated scFvC multimers showed higher antigen-binding ability than the monomeric scFvC. In the pseudovirus-based neutralization assay，both monomeric scFvC and PEGylated scFvC multimers showed good neutralizing activity compared with the control group（ P<0.000 1）. Moreover，the PEGylated scFvC multimers showed a more effective ability to block the pseudovirus infection in target cells（ P<0.05），suggesting that the PEGylated scFvC multimers could enhance their function in vitro through avidity effect. Conclusion:In this study，a scFvC targeting West Nile virus is successfully constructed and its polyvalent form is generated through PEGylation，which improves the antigen-binding and neutralizing activity of the parental scFv.

Objective:To evaluate the efficacy and safety of dienogest (DNG) in the treatment of refractory endometriosis-associated pain (REAP).Methods:In this study, REAP was defined according to the following criteria: (1) the pain duration was ≥12 months and visual analogue scale (VAS)≥60 mm; (2) the previous treatments with over two medicines like oral contraceptives and levonorgestrel-releasing intrauterine system failed to achieve satisfactory relief of pain, with VAS reduction less than 50%; with gonadotropin-releasing hormone agonist or mifepristone, the pain could be controlled temporarily, but it recurred after discontinuation of medicines; (3) the pain could not be relieved by surgery or even repeated surgeries. In the present study, 48 patients with REAP were treated with DNG 2 mg/day orally and the clinical outcomes were retrospectively analyzed. The VAS scores, levels of CA 125, estradiol, FSH, LH and changes in the size of endometriotic lesions before and after treatment were compared respectively. The side effects were also analyzed. Results:The average duration of DNG treatment was (20.1±12.8) months. After 3 months of medication, the VAS score was significantly reduced from (77.9±15.8) mm to (20.8±10.7) mm ( P<0.01), and CA 125 level was significantly reduced from (95±139) kU/L to (38±45) kU/L ( P<0.05). The effects were maintained with continuation of DNG treatment. Endometriotic lesions tended to shrink, after 12 months of DNG treatment, the size of ovarian endometriomas was reduced significantly from (3.1±1.0) cm to (1.9±1.2) cm ( P<0.05). The mean level of estradiol was maintained at 124.82-221.04 pmol/L and levels of FSH and LH did not change significantly during the treatment. The major side effect was irregular bleeding (75%, 36/48). Conclusions:DNG could effectively relieve REAP and is a well-tolerated therapy. It may supply an alternative option for patients with REAP.

Objective To construct a lentiviral vector delivering the Nicastrin (NCT) gene-targeted short hairpin RNA (shRNA) and determine gene-silencing efficiency of the vector in the human immortalized keratinocyte cell line HaCaT,and to construct a NCT gene-silenced HaCaT cell model to lay an experimental foundation for subsequently studying effects of NCT gene silencing on biological behavior of keratinocytes.Methods Three NCT gene-targeted shRNAs were designed and inserted into the pGLV3/ H1/GFP + Puro vector to construct three recombinant plasmids,which were then confirmed by sequencing.Recombinant plasmids combined with lentivirus packaging plasmids were co-transfected into 293T cells to obtain lentivirus particles,and the virus titer was determined.Cultured HaCaT cells were divided into 3 groups:blank group receiving no treatment,negative control group infected with the empty vector LV3-shNC,interference groups infected with lentivirus NCT-shRNA1,-shRNA2,-shRNA3,respectively.Flow cytometry was performed to determine transfection efficiency,and real-time fluorescence-based quantitative PCR (qRT-PCR) and Western blot analysis were conducted to determine efficiency of target gene silencing in HaCaT cells,so as to select the most efficient interference sequence.Results Sequencing analysis indicated that recombinant lentiviral vector NCT-shRNA was constructed successfully.After co-transfection of recombinant plasmids and lentivirus packaging plasmids into 293T cells,the titer of recombinant lentivirus particles was about 109 TU/ml.Flow cytometry showed that the transfection efficiency was greater than 95％.qRT-PCR revealed that the NCT mRNA expression was obviously down-regulated in the interference group compared with the negative control group,and NCT-shRNA1 was the most efficient sequence with interference efficiency being 75％.Western blot analysis showed that the inhibition rate of NCT protein expression was 71.7％ in the shRNA1 group compared with the negative control group.Conclusion The most efficient NCT-shRNA interference sequence is screened out,and the recombinant lentiviral vector NCT-shRNA and an NCT gene-silenced HaCaT cell model are both constructed successfully.

OBJECTIVE:To evaluate the economics of azithromycin vs. amocillin clavulante in the treatment of lower respirato-ry tract infections. METHODS:System evaluation was adopted to retrieve the randomized controlled trials(RCT)about azithromy-cin(test group)vs. amoxicillin clavulanate(control group)in the treatment of lower respiratory tract infections. Information was col-lected and Meta-analyses were performed. On this basis and short-term decision tree model,cost factors were added to conduct the pharmacoeconomics by the principle of PICO of Treeage Pro 2011 edition software. RESULTS:Totally 18 RCT were enrolled,in-volving 3 365 patients. Results of Meta-analysis showed that there were no significant differences in the effective rate [RR=0.93, 95%CI(0.55,1.55),P=0.77] and incidence of adverse reactions [RR=0.79,95%CI(0.62,1.0),P=0.05] between 2 groups. The av-erage treatment cost in test group and control group was respectively 790.4 yuan and 884.4 yuan,and cost-effectiveness ratio was respectively 216.0 and 245.7,and the incremental cost-effectiveness ratio(ICER)was -1 392.59. CONCLUSIONS:Azithromycin has similar efficacy and safety to amoxicillin clavulanate in the treatment of lower respiratory tract infection,however,azithromy-cin has better cost-effectiveness.