ObjectiveTo construct a stable monoclonal human embryonic kidney 293 （HEK293） cell line expressing recombinant human coagulation factor Ⅶ （rhFⅦ） and evaluate the expression level and procoagulant bioactivity of rhFⅦ. MethodsThe plasmid pCDNA3.1-EGFP-FⅦ was transfected into HEK293 cells to verify the effectiveness of the transfection system. The plasmid pCDNA3.1-FⅦ was transfected into HEK293 cells， and monoclonal stable transfected cell lines were selected using geneticin （G418）. The transcription of the FⅦ gene was identified by reverse transcription polymerase chain reaction （RT-PCR）. The expression level of rhFⅦ in the supernatant of the monoclonal stable transfected cell line was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot. The concentration of rhFⅦ was determined by enzyme-linked immunosorbent assay （ELISA）， and the procoagulant activity of rhFⅦ was measured by human coagulation factor Ⅶ potency assay. ResultsHEK293 cells transfected with pcDNA3.1-EGFP-FⅦ showed green fluorescence， indicating that rhFⅦ was successfully expressed in the supernatant of HEK293 cells after transient transfection with pcDNA3.1-FⅦ. The monoclonal stable transfected cell line was obtained by G418 screening. RT-PCR identified that the FⅦ gene was integrated into the genome of the monoclonal stable transfected cell line. The cell viability was good as detected by Cell Counting Kit-8， and a single band of rhFⅦ was obtained by purification of the cell supernatant. The highest rhFⅦ expression was （1.27±0.09） mg/L， and the highest procoagulant activity was （380.29±13.80）%. ConclusionThe monoclonal HEK293 cell lines which can express rhFⅦ protein efficiently and stably with excellent procoagulant bioactivity is successfully screened.

Objective: To perform transient transfection of recombinant human Factor X(rhFX) into HEK293 cells,to optimize transfection parameters,to develop a high-yield in vitro expression system for rhFX production,and to assess the biological activity of expressed rhFX. Methods: The eukaryotic expression vector pcDNA3. 1-EGFP-FX was constructed by inserting the F10 gene into pcDNA3. 1-EGFP and subsequently transfected into HEK293cells to validate the transfection system efficiency. The recombinant expression vector pcDNA3. 1-FX was generated through ligation of the F10 gene fragment with pcDNA3. 1, followed by liposome-mediated transfection into HEK293 cells. The expression of rhFX in the cell supernatant was analyzed by Western blot and sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE). Transfection conditions were systematically optimized,and rhFX concentration was quantified by enzyme-linked immunosorbent assay(ELISA). The coagulation bioactivity of rhFX was evaluated through prothrombin time(PT) assay and chromogenic substrate method. Results: rhFX was successfully expressed in the supernatant of HEK293 cells. rhFX was successfully expressed in the supernatant of HEK293 cells. The highest expression level of rhFX was achieved on the third day after transfection when the cell density was 80% and the ratio of plasmid DNA to polyethyleneimine(PEI) transfection reagent was 1 ∶ 2.Triplicate ELISA measurements demonstrated a maximum rhFX concentration of 5. 20 ng/mL in the supernatant.The prothrombin time(PT) of rhFX-containing supernatant was significantly shorter(P 50) of etoxaban was determined to be 1. 449 nmol/L using the chromogenic substrate method based on rhFX,which was in the same order of magnitude as the reported 0. 78 nmol/L in the literature. Conclusion HEK293cells successfully express biologically active recombinant human Factor X(rhFX) protein,laying a foundation for advancing the development of rhFX-based therapeutics.

BACKGROUND:Stem cell transplantation is a new way to prevent and cure intervertebral disc degeneration.However,whether the transplanted stem cells can survive,proliferate,differentiate,and restore the function of nucleus pulposus cells after transplantation,is the key and difficult point to overcome. OBJECTIVE:To explore the effects of Bushenhuoxue decoction on survival,proliferation,and nucleus pulposus-like differentiation of adipose-derived stem cells. METHODS:A Transwell chamber was used to construct a co-culture model of human adipose-derived stem cells and human degenerative nucleus pulposus cells.The experiment was divided into control group,model group,drug-containing serum group,and drug-free serum group.Except for the control group,the co-culture system of other groups was treated with 50 μmol/L tert-butyl hydrogen peroxide for 24 hours.The drug-containing serum group and drug-free serum group were treated with DMEM low-glucose complete culture medium containing drug-containing serum of Bushenhuoxue decoction or drug-free serum with 20％volume fraction for 48 hours.The sublayer adipose-derived stem cells were taken.Toluidine blue staining was used to detect proteoglycan synthesis levels.Real-time PCR method was used to detect mRNA expression of type Ⅱ collagen,proteoglycan and SRY-box transcription factor 9.The protein expression of SOX9 was detected by western blot assay.Lactate dehydrogenase assay was used to detect cytotoxicity.Flow cytometry was used to detect reactive oxygen species,and β-galactosidase staining was used to detect cell senescence. RESULTS AND CONCLUSION:(1)Compared with the control group,the proportion of necrotic cells in the model group increased;toluidine blue staining became lighter,and the expression levels of type Ⅱ collagen,proteoglycan,SOX9 mRNA and SOX9 protein decreased(P<0.05).Compared with the model group,the drug-containing serum of Bushenhuoxue decoction could significantly reduce cell injury and promote the expression of type Ⅱ collagen,proteoglycan,SOX9 mRNA,and SOX9 protein(P<0.05),but the improvement in the drug-free serum group was not significant(P>0.05).(2)Compared with the control group,the contents of cytotoxicity,reactive oxygen species,and cell senescence in the model group were significantly increased.Compared with the model group,the microenvironment of the coculture system was significantly improved by drug-containing serum of Bushenhuoxue decoction(P<0.05),while drug-free serum had no significant effect on the microenvironment of the co-culture system(P>0.05).(3)The results show that Bushenhuoxue decoction can promote the survival,proliferation,and nucleus pulposus-like differentiation of adipose-derived stem cells.

Objective:To investigate whether murine peroxidase reductase-5(mPRDX5)has anti-tumor activity in mice,so as to further confirm the anti-tumor activity and mechanism of recombinant peroxidase reductase-5.Methods:High purity mPRDX5 was obtained by heterologous expression and purification in vitro.Pancreatic cancer Pan02 cells were inoculated subcutaneously on the left axillary back of mice to establish a tumor bearing mouse model.Mice were randomly divided into PBS(solvent control)group,GEM(gemcitabine)50.0 mg/kg group and mPRDX5 10.0 mg/kg group,with 10 mice in each group,and the tumor related indexes were detected in mice.Results:Compared with PBS group,weight of tumor-bearing mice in GEM group was decreased obviously,while weight of mPRDX5 group was increased to a certain extent.Tumor growth was good in PBS group,according to tumor volume,com-pared with PBS group,tumor growth inhibition rates in D7 were 87.07%in GEM group and 52.82%in mPRDX5 10.0 mg/kg group,re-spectively;according to tumor weight,compared with PBS group,GEM group and mPRDX5 10.0 mg/kg group had tumor growth inhibi-tion rates of 95.39%and 48.33%in D7,respectively.Polarization state of macrophages in tumor tissues of mice in PBS group and mPRDX5 group was analyzed,and it was found that compared with PBS group,M1 macrophages expressing CD86 in tumor tissues of mice in mPRDX5 group were significantly increased,while M2 macrophages expressing CD206 were significantly decreased.Conclu-sion:mPRDX5 has significant anti-pancreatic cancer activity in mice,and the activity is exerted by promoting M1-type polarization of macrophages in the tumor microenvironment.

Objective To investigate the characteristics of nosocomial infection of carbapenem resistant En-terobacteriaceae ,then to study the risk factors and prognosis of patients ,as to provide evidence for effective control of CRE hospital infection .Methods A retrospective epidemiology study was conducted of CRE infec-ted patients from January 2016 to June 2017 .This was a 1∶2 matched case-control study of patients with in-fection due to carbapenem resistant Enterobacteriaceae and randomly select 218 patients with non CRE infec-tion in the same hospital as control group ,then the risk factors of CRE infection were investigate .Results A-mong the 109 cases CRE infection patients ,the most common bacteria were Klebsiella pneumoniae ,Enter-obacter cloacae and Escherichia coli .The CRE strains were more sensitive to minocycline than other common antibiotics ,the resistance rate to other antibiotics was more than 40% .Univariate analysis showed that ICU staying time more than 7 d ,using beta lactamase inhibitors and carbapenem antibiotics ,combination therapy and mechanical ventilation were the potential risk factors of CRE nosocomial infection .The non conditional multivariate Logistic regression analysis showed that Check in ICU more than 7 d (OR＝ 4 .981 ,95% CI 2 .451-10 .122 ) ,the use of containing beta lactamase inhibitor antibiotics (OR＝ 3 .718 ,95% CI 2 .162-6 .394) ,use of carbapenem antibiotics (OR＝3 .232 ,95% CI 1 .879-5 .561) ,and mechanical ventilation (OR＝5 .26 ,95% CI 2 .576-10 .742) were independent risk factors of CRE nosocomial infection .The nosocomial in- fection CRE strain was with highly antibiotic resistance rate ,and the average hospitalization time and mortality were significantly higher than those of the control group .Conclusion The carbapenem resistant Enterobacte-riaceae infection had multiple independent risk factors ,strengthening of these independent risk factor control can effectively prevent the spread of CRE isolates infection .

The crude extracts of the fermentation broth from a marine sediment-derived actinomycete strain, Saccharothrix sp. 10-10, showed significant antibacterial activities against drug-resistant pathogens. A genome-mining PCR-based experiment targeting the genes encoding key enzymes involved in the biosynthesis of secondary metabolites indicated that the strain 10-10 showed the potential to produce tetracenomycin-like compounds. Further chemical investigation of the cultures of this strain led to the identification of two antibiotics, including a tetracenomycin (Tcm) analogs, Tcm X (1), and a tomaymycin derivative, oxotomaymycin (2). Their structures were identified by spectroscopic data analysis, including UV, 1D-NMR, 2D-NMR and MS spectra. Tcm X (1) showed moderate antibacterial activities against a number of drug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) pathogens, with the MIC values in the range of 32-64 microg x mL(-1). In addition, 1 also displayed significant cytotoxic activities against human cancer cell lines, including HL60 (leukemia), HepG2 (liver), and MCF-7 (breast) with the IC 50 values of 5.1, 9.7 and 18.0 micromol x L(-1), respectively. Guided by the PCR-based gene sequence analysis, Tcm X (1) and oxotomaymycin (2) were identified from the genus of Saccharothrix and their 13C NMR data were correctly assigned on the basis of 2D NMR spectroscopic data analysis for the first time.

In the last decade, along with the development of taxonomy research in marine-derived actinobacteria, more and more halogenated natural products were discovered from marine actinobacteria. Most of them showed good biological activity and unique structure compared to those from land. The special halogenation mechanism in some compounds' biosynthesis has drawn great attention. So in this review, we focus on the halogenated natural products from marine actinobacteria and their halogenation mechanisms.

Glycosylation, one of the most common and important reactions in biological systems, results in diverse functions and is often found in biologically active small-molecule natural products produced by microorganisms. Furthermore, sugar moieties are generally critical for their activities. Alternating the sugar structures thus provides the potentials for enhancing the biological activities of natural products, which evokes researchers to study the sugar biosynthetic machinery and its application in the modification of sugar moieties with an aim of generating unnaturally glycosylated natural product drugs with better activities. This review will briefly outline current studies on sugar biosynthesis and glycosyltransferase, with a few selected experiments designed to alter natural-product sugar structures.

Objective To evaluate the relationship between the lung volume (LV) in inspiration and expiration,pulmonary function tests(PFT),and other CT measurements of emphysema index (EI) and mean lung density (MLD) in patients with chronic obstructive pulmonary disease (COPD).Methods Seventy-six patients with COPD were included.Three-dimension analysis was performed to obtain the following CT parameters on the inspiratory and expiratory phases:EI,MLD,LV.The ratios and differencesof MLD and LV between the two phases were calculated(ΔMLD,ΔLV,MLDex/in,LVexin).Not only the linear correlations between the lung volume parameters and PFT but also the correlations of lung volume parameters with the other CT parameters were tested by the Spearman rank correlation test and multivariant step wise regression.Results LVex/in had negative correlations with forced expiratory volume in 1 second ％ predicted [FEV1 ％,(54.32 ± 7.11)] and the ratio of forced expiratory volume in 1 second to forced vital capacity [FEV1/FVC,(49.12 ±8.01)％] (r =-0.69,-0.56,P ＜0.01),but it had the positive correlation with the ratio of residual volume to total lung capacity [RV/TLC,(58.03 ± 8.55) ％,Spearman coefficients 0.66,P ＜ 0.01].LV/exin (0.67 ± 0.12) was positively correlated with MLDex/in (0.89 ± 0.04,r =0.88,P ＜0.01).The further multivariate step wise regression denonstrated that EI,LV and MLD could introduce a regression equation with R2 =0.77 and 0.73,respectively (P ＜ 0.01).Conclusions There is an association between LVex/in and the parameters of routine PFT,which can reflect the collapsibility of lung.Moreover,LVex/in can be considered to be equivalent to MLDex/in.Taking into account the impact of scanning parameters on MLDex/in,LVex/in may play a complementary role in the assessment of pulmonary function.

A novel near-infrared (NIR) diffuse correlation spectroscopy (DCS) has recently been developed for noninvasive monitoring of tumor blood flow during photodynamic therapy (PDT).DCS offers several attractive new features for tumor blood flow measurement such as noninvasiveness,portability,low cost,high temporal resolution and relatively large penetration depth.DCS technology has been utilized for continuous measurement of tumor blood flow before,during and after PDT in both animals and humans.The ultimate goal is to predict treatment outcomes from the measured tumor hemodynamic responses to PDT.