To provide suggestions for perfecting essential drug centralized bidding and purchasing system. Methods:Using literature method to analyze comparatively essential drug bidding purchasing implement plans of 30 provinces in China. Results:Bidding mode in most provinces was double envelope system. Most evaluation methods did not distinguish the quality level, while there were great differences among provincial evaluation standard and scores of economic, technical and business bidding. Conclusion: To explore scientific and reasonable evaluation standard, it needs to establish an authoritative evaluation system for reference, choose the objective index as far as possible and properly increase the amount of bidding manufacturer.

Background Human retinal pigment epithelial (RPE) cell transplantation treating retinal degenerative diseases is a researching topic,and the source of human RPE cells is a key problem.Many biological carriers can be used for the preparation of RPE cell layer.However,some advantages,such as cytotoxicity,lack of stability and immunologic reaction etc.are still existed.To study an ideal biological carrier is very important.Objective This experimental was to determine the effects of amniotic membrane on the proliferation and differentiation of human RPE cells and the possibility as a scaffold for RPE cell transplantation.Methods ARPE19 cell line cells were cultured and passaged in DMEM/F12 medium with 10％ fetal bovine serum,and 8-12generation of cells were used.The cells were divided into two groups.One group of cells were incubated on the denuded amniotic membrane,and the other group of cells were cultured in the medium (control group).MTT was performed to detect the A492 value of RPE cells for the evaluation of cell proliferation ability 24,48,72,96 hours after culture.Cell morphology was compared by histopathological examination 3 weeks after culture.The mRNA expression of pigment epithelium-derived factor (PEDF),N-cadherin,β-catenin and cell connection related proteins in the cells of both groups were assayed using reverse transcription polymerase chain reaction (RT-PCR).Ultrastructure of the cells was observed under the transmission and scan electronic microscope 3 weeks after culture.Results The number of ARPE-19 cells cultured on denuded amniotic membrane was decreased significantly in comparison with the normal culture plate(F=41.760,P =0.000).Histopatholy also showed that the cell density on amniotic membrane was lower than of normal cells on plate surface.Moreover,the expression level of claudin 1 mRNA,N-cadherin mRNA and PEDF mRNA were significantly up-regulated in denuded amniotic membrane group in comparison with control group (t=15.828,P=0.000 ;t=6.839,P=0.002 ;t=14.667,P=0.000),but the expression of Connexin 43 mRNA was down-regulated in denuded amniotic membrane group compared with control group(t=3.358,P=0.024).Ultrastructural examination revealed that ARPE-19 cells cultured on amniotic membrane exhibited a polygonal epithelial phenotype with cilium on the apical side,however,the cells cultured on normal culture plate displayed fusiform shape and uneven thickness.Conclusions Amniotic membrane plays a promoting effect on the differentiation of ARPE-19 cells and a inhibitory effect on the proliferation of ARPE-19 cells,suggesting that amniotic membrane might be an useful scaffold for the preparation of functionally mature RPE cells for clinical transplantation.

Traditional herbal medicines, Panax ginseng, Panax quinquefolium and Panax notoginseng, attract our attention for their extensive and powerful pharmacological activities. Ginsenosides are the main active constituents of these medicinal herbs. The related glycosyltransferases involved in ginsenoside biosynthesis are the key enzymes which catalyze the last important step. Modification of ginsenoside aglycones by glycosyltransferases produces the complexity and diversity of ginsenosides, which have more extensive pharmacological activity. At present, ginsenoside aglycones and compound K have been obtained by synthetic biology. As the last step of ginsenoside biosynthesis, glycosylation of ginsenoside aglycones has been studied intensively in recent years. This review summarizes the basic strategies and research advances in studies on glycosyltransferases involved in ginsenoside biosynthesis, which is expected to lay the theoretical foundation for the in-depth research of biosynthetic pathway of ginsenosides and their production by synthetic biology.
Biosynthetic Pathways ; Ginsenosides ; biosynthesis ; Glycosyltransferases ; metabolism ; Panax ; chemistry ; Plants, Medicinal ; chemistry ; Synthetic Biology

Objective To evaluate risk factors for central venous catheter-related bloodstream infection(CRBSI)in intensive care unit(ICU)patients by Meta analysis. Methods Literatures about risk factors of CRBSI in ICU pa-tients were retrieved from databases of Cochrane Library,PubMed,Embase,CBM,CNKI,and WanFang Data,RevMan 5.3 software was used for Meta analysis.Results There are 12 literatures in accordance with the inclusion criteria,with a total sample size of 14 422 cases,5 cohort studies and 7 case-control studies,the Newcastle-Ottawa Scale(NOS)scores were 4-6 points. According to Meta analysis,duration of indwelling catheter(WMD,12.25 [95%CI,5.55-18.94]),multi-cavity catheter(OR,3.52[95% CI,1.46-8.52]),femoral vein catheterization (OR,2.44[95%CI,1.34-4.46]),parenteral nutrition(O R,2.47[95% CI,1.18-5.21]),length of stay in ICU(WMD,10.01[95%CI,4.17-15.85]),APACHE II score(WMD,4.46[95%CI,1.25-7.66]),and dia-betes mellitus(OR,1.83[95% CI,1.08-3.09])were significantly different in each group(all P<0.05). Conclusion Risk factors for CRBSI in ICU patients are duration of indwelling catheter,multi-cavity catheter,femo-ral vein catheterization,parenteral nutrition,length of stay in ICU,APACHE II score,and diabetes mellitus. However,due to the limitation of methodological quality of included studies,more strictly designed and large sam-ple prospective studies are needed to verify the result.

Pichia pastoris is one of the most important systems used in the field of molecular biology for the expression of recombinant proteins. The system has advantages of high expression, high stability, high secretion, easy high-density fermentation and low cost. Many factors affect the expression of recombinant protein, such as gene copy number, codon usage preference, type of promoter, molecular chaperones, glycosylation, signal peptide and fermentation process. In this review, research advances of the above aspects are summarized, which lay a foundation for improving the expression of recombinant proteins in P. pastoris.
Fermentation ; Gene Dosage ; Glycosylation ; Molecular Chaperones ; Pichia ; metabolism ; Promoter Regions, Genetic ; Protein Sorting Signals ; Recombinant Proteins ; biosynthesis

Lanosterol synthase is encoded by the erg7 gene and catalyzes the cyclization of 2, 3-oxidosqualene, which is a rate-limiting step of the inherent mevalonate (MVA)/ergosterol metabolic pathway in Saccharomyces cerevisiae. The intermediate 2, 3-oxidosqualene is also the precursor of triterpenoids. Therefore, the cyclization of 2, 3-oxidosqualene is the key branch point of ergosterol and triterpenoids biosynthesis. Down-regulation of 2, 3-oxidosqualene metabolic flux to ergosterol in S. cerevisiae may redirect the metabolic flux toward the triterpenoid synthetic pathway reconstructed by the synthetic biology approach. To construct erg7 knockout cassette harboring the loxP-Marker-loxP element, long primers were designed, which were homologous to the sequences of both erg7 ORF and plasmid pUG66. The cassette was transformed into diploid wild strain INVSc1 by LiAc/SS Carrier DNA/PEG method and then erg7 gene haploid deficient mutant was obtained by homologous recombination. The results of semiquantitative PCR and real-time quantitative PCR revealed that erg7 expression level in erg7 gene haploid deficient mutant is one time lower than that in wild strain. The results of TLC and HPLC showed that the ergosterol content in deficient mutant decreased to 42% of that in wild strain.
Chromatography, High Pressure Liquid ; DNA Primers ; Down-Regulation ; Ergosterol ; metabolism ; Haploidy ; Intramolecular Transferases ; genetics ; Polymerase Chain Reaction ; Saccharomyces cerevisiae ; genetics ; Squalene ; analogs & derivatives ; metabolism

Objective To investigate the role of inflammatory cytokines in the pathogenesis of chronic non-bacterial prostatitis/chronic pelvic pain syndrome (CAP/CPPS) patients. Methods The 38 cases with CAP/CPPS patients (18 cases of CAP and 20 cases of CPPS) and 20 cases of healthy controls were selected. The differential expressions of 40 kinds of inflammatory cytokines were detec-ted by antibody arrays in prostate fluid. Results The inflammatory cytokines which increased more than 1.5 times expression have been found. There were seven kinds in CAP including monocyte che-moattractant protein (MCP)-1, solution tumor necrosis factor receptor Ⅱ(s TNF R Ⅱ), platelet-de-rived growth faetor-BB (PDGF-BB), interleukin (IL)-β, IL-11、IL-6、MCP-2 and five kinds in CPPS groups including MCP-1、PDGF-BB、MCP-2、s TNF R Ⅱ、It-11 respectively, compared with healthy control group. The cluster analysis results showed that protein expression of Monocyte chemoattrac-tant protein 1 (MCP-1)and platelet-derived growth factor BB (PDGF-BB) were significantly increased in CAP (3.47 and 2.07 times) and CPPS (2.25 and 2.19 times) compared with healthy control group and were the final polymerization of inflammatory cytokines. The protein expression of interleukin 1 β (IL-1 β), MCP-1 and soluble tumor necrosis factor Ⅱ (s TNF R Ⅱ) in CAP group was increased more than 1.85,1.55,1.67 times compared with CPPS group. Conclusions Elevated expression of inflammatory cytokines may play an important role in the course of CAP/CPPS disease. The extent of the inflammatory response of CAP was higher than CPPS. The inflammatory factors of MCP-1 and PDGF-BB could serve as a novel diagnostic marker.

Objective To investigate the diagnostic value of texture analysis derived from conventional MR imaging in differentiating benign and malignant breast lesions. Methods Thirty-six patients with malignant breast lesion and 33 patients with benign breast lesion were retrospectively analyzed in our study. All patients underwent conventional MR imaging including axial T1WI, T2WI, and contrast-enhanced T1WI before surgery. Texture features were calculated from manually drawn ROIs by using MaZda software. The feature selection methods included mutual information (MI), Fishers coefficient, classification error probability combined with average correlation coefficients (POE + ACC) and the combination of the above three methods(FPM). These methods were used to identify the most significant texture features in discriminating benign breast lesion from malignant breast lesion. The statistical methods including raw data analysis (RDA), principal component analysis (PCA), linear discriminant analysis (LDA) and nonlinear discriminant analysis (NDA) were used to distinguish malignant breast lesion from benign breast lesion. The results were shown by misclassification rate. Results In the three kinds of sequences, the texture features for differentiating malignant breast lesion and benign breast lesion were mainly from T2WI which had the lowest misclassification rate 4.35%(3/69). The misclassification rates of the feature selection methods were similar in MI, Fisher coefficient and POE+ACC (15.94%to 56.52%for MI;17.39%to 56.52%for Fisher coefficient and 17.39%to 56.52%for POE+ACC). However, the misclassification rate of the combination of the three methods (4.35%to 53.62%for FPM) was lower than that of any other kind of method. In the statistical methods, NDA (4.35% to 27.54%) had lower misclassification rate than RDA (33.33% to 56.52%), PCA (33.33% to 53.62%) and LDA (15.94% to 44.93%). Conclusion Texture analysis of conventional MR imaging can provide reliably objective basis for differentiating benign from malignant breast lesions.

Objective To explore the temporal and spatial expression pattern of tenascin-c(tnc) and tenascin-w(tnw) in zebrafish early development,to further explore the role of tenacsin in zebrafish embryo development,and the association between them.Methods Zebrafish embryos at 2 hours post fertilization(hpf),4 hpt,8 hpt,10 hpf,24 hpt,48 hpr,72 hpf and 7 days post fertilization(dpf) were collected to extract RNA for reverse transcription-polymerase chain reaction(RT-PCR) and fix the embryos at different stages for in situ hybridization.Temporal and spatial expression pattern of tnc and tnw on different stages of zebrafish early development was observed.Results tnc and tnw all expressed in zebrafish from 24 hpf to 7 dpf,but did not expressed from 2 hpf to 10 hpf.Tnc expressed at pharyngeal arch,notochord,somite in 24 hpf,then weakly expressed at somite,but highly expressed at otic vesicle,pectoral fin and hindbrain in 48 hpf,and tnc was expressed at hindbrain,pharyngeal and notochord and disappeared at somite and pectoral.tnw expressed at hindbrain,midbrain and otic vesicle in 24 hpf,expressed at somite,notochord,hindbrain,otic vesicle and pharyngeal in 48 hpf.In 72 hpf,tnw expressed weakly at somite and notochord.Conclusions Zebrafish tnc and tnw have special temporal and spatial expression pattern,and share partial overlapping expression pattern.

Objective To explore the expression pattern of tenascin-c(tnc)gene in zebrafish embryo abnormal development which was induced by ethanol,and to further understand the function of tnc gene in embryo develepment.Methods Zebrafish were treated with ethanol at different concentration from 100 to 500 mmol/L,and embryos at 24 and 48 hours were collected and fixed,then tnc expression pattern was observed by in situ hybridization and reverse transcriptase-polymerase chain reaction(RT-PCR).Results The result of RT-PCR showed that ethanol at 100 and 200 mmol/L could increase the expression of tnc,while the result of in situ hybridization showed that,while ethanol at 300 mmol/L and above decrease the expression of tnc in presumptive position at 24 hours,and ethanol at 100 mmol/L and above caused increase expression of tnc in zebrafish heart.Conclusions tnc is increased when treated with 100 and 200 mmol/L ethanol and is presented in the abnormal development of hearts of zebrafish,which can promote the normal development of embryos in some degrees.The expression pattern of tnc in pathologic state is highly conserved in all vertebrate,and in adult and embryos as well.