Objective To observe the relation between the changes of plasma TpP and D-dimer in patients with acute cerebral infarction( ACI).Methods D-dimer and thrombus precursor protein (TpP) levels in plasma of 55 cases with ACI during early phase and 25 normal healthy subjects were detected,and 24/55 cases were measured dynamically. D-dimer levels were detected by automated latex D-dimer immunoassay. Plasma TpP level was determined using a new assay,the TpP_ TM(USA),which is based on an ELISA method.Results There was significant difference(P

Objective:To investigate the role of NOD-like receptor protein 3 (NLRP3) in the regulation of phagocytosis in Vibrio vulnificus ( V. vulnificus)-infected macrophages. Methods:Expression profiles of phagocytosis-related genes in PBS- and V. vulnificus-infected J774A.1 cells were analyzed by RNA-Seq. NLRP3-knockout (NLRP3 KO) J774A.1 cells were constructed using CRISPR-Cas9 gene-editing system. The phagocytosis of V. vulnificus and pHrodo RED-labelled Escherichia coli ( E. coli) bioparticles in parental and NLRP3 KO J774A.1 cells was detected by flow cytometry. Real-time PCR was performed to measure the expression of Fgr2 b gene at mRNA level in PBS- and V. vulnificus-treated parental and NLRP3 KO J774A.1 cells. Results:The expression of 18 phagocytosis-related genes was upregulated in V. vulnificus-infected J774A.1 cells than in PBS-treated J774A.1 cells ( P<0.05). There was a 5 bp deletion in the exon 2 of NLRP3 gene in NLRP3 KO J774A.1 cells, resulting in frameshift mutation and complete loss of NLRP3 expression. NLRP3 KO J774A.1 cells exhibited enhanced phagocytosis of V. vulnificus and pHrodo RED-labelled E. coli bioparticles than parental J774A.1 cells ( P<0.05). Besides, the expression of Fgr2 b gene at mRNA level was significantly increased in V. vulnificus-infected NLRP3 KO J774A.1 cells than in parental J774A.1 cells ( P<0.05). Conclusions:The phagocytosis of V. vulnificus in macrophages could be negatively regulated by NLRP3, which was possibly mediated through the regulation of Fgr2 b gene expression.

Objective To study the role of Vibrio vulnificus cytolysin(rVvhA) induced THP-1 apoptosis and calcium influx.Methods CCK-8 cell proliferation kit,Fluo3/AM staining and AnnexinV/PI staining were performed to identify the apoptosis and calcium influx induced by rVvhA in THP-1 cells.Results rVvhA could induce THP-1 apoptosis and up-regulate the cellular calcium concentration.BAPTAAM could enhance the calcium influx induced by rVvhA in THP-1.Conclusion rVvhA had cytotoxic to THP-1 cells by inducing apoptosis and triggering extracellular calcium influx.

Objective To employ Borrelia burgdorferi( B. burgdorferi) , a culturable and genetical-ly transformable spirochete, as a surrogate system to study Treponema pallidum ( T. pallidum) gene function. Methods Bioinformatic analysis revealed that the T. pallidum gene tp0111 encodes the putative sigma factor RpoN. We constructed a B. burgdorferi shuttle vector harboring tp0111. The shuttle vector was then trans-formed into the B. burgdorferi rpoN mutant strain. The phenotype of the resulting B. burgdorferi strain was then determined. Results We successfully constructed the B. burgdorferi rpoN mutant carrying the T. palli-dum gene tp0111. We found that tp0111 could partially complement the B. burgdorferi rpoN mutant. Con-clusion This work provides the first experimental evidence showing that tp0111 is the rpoN gene of T. palli-dum. It also demonstrates that B. burgdorferi can be used as a surrogate system for studying T. pallidum gene function.

Objective To investigate the distribution of ompA gnne in 15 Chinese reference standard strains belonging to 15 serogroups of Leptospira interrogate, and to express recombinant OmpA ( rOmpA ) and to identify immunogenicity and immunoprotection of rOmpA. Methods Genomic DNAs from different leptospiral strains were extracted by phenol-chloroform method. Entire ompA gene fragments from the strains were amplified by PCR and then sequenced after T-A cloning. A prokaryotic expression system of ompA gene from L. interrogans strain 56601 was constructed, and the expression and yield of rOmpA were determined by SOS-PAGE plus Bio-Rad Agarose Image Analyser. Rabbits were immunized with rOmpA for obtaining antiserum, and immunodiffusion test was used to measure the antiserum's titer. Western blot assay was performed to determine the immunoreaetivity of rOmpA with the antiserum against rOmpA and antiserum against whole cell of L. interrogans strain 56601, while mi-croscopic agglutination test (MAT) was applied to detect the cross agglutination to the 15 L. interrogans strains. A leptospire adhering cell model and a leptospire infecting guinea pigs model were used to determine the adhesion-bloc-king effect of rOmpA antiserum and immunoprotection of rOmpA. Results All the 15 L. interrogans strains, but not L. biflexa strain Patoe Ⅰ , had sequence conserved ompA genes. The yield of rOmpA was approximate 20% of the total bacterial proteins, rOmpA could induce rabbits to produce antibody and immunodiffusion titer of the anti-serum was 1:4. Both antisera against rOmpA and against whole cell of L. interrogans strain 56601 were able to pro-duce positive Western blot signs to rOmpA, and the former offered 1 : 20-1 : 320 MAT titers to the 15 L. interrogans strains. 1: 10-1:160 dilutions of rOmpA antiserum could efficiently block L. interrogans strain 56601 adhering to J774A. 1 cells, and 100 μg and 200 μg rOmpA displayed 50.0% and 75.0% immunoprotective rates in the infee-ted guinea pigs. Conclusion ompA gene only exists in genomes of different pathogenic L. interrogans serogroups. rOmpA has relatively stronger antigenicity, cross immunoreactivity and certain immunoprotection, implying that this recombinant protein may be used as a candidate antigen for developing universal genetic engineering vaccine of L. interrogans.

Objective To investigate the molecular and cell signal transduction mechanisms by Lactobacillus cell wall extract(LCWE)inducing human-β-defensin-2(hBD-2)expression in human vaginal epithelial cells.Methods The induction of hBD-2 in human vaginal epithelial cells(WZV-1)by LCWE was observed using real-time PCR and Western blot.After stimulating WZV-1.the activation of NF-κB and p38MAPK signaling pathways were determined by Western blot.The induction of hBD-2 in WZV-1 cells by LCWE was observed with signaling pathways inhibitors of NF-κB and p38MAPK using real-time PCR and Western blot.Results The results showed that LCWE significantly upregulated hBD-2 expression in the time and dose-dependent manner.The maximal stimulatory effect of LCWE on the expression of hBD-2mRNA in WZV-1 cells were observed at the concentration of 50μg/ml after treatment for 8 h.After stimulation by 50μg/ml LCWE,Western blot analysis demonstrated that the phosphorylation of p38MAPK increased at 0.5 h significantly,peaked at 1 h,moreover the concentration of NF-κB in nucleus increased at 0.5 h significantly(P<0.05),peaked at 2 h.Blocking with inhibitor of NF-κB and(or)p38MAPK pathways results in decreased levels of HBD-2 expression.Conclusion These findings suggest that p38MAPK and NF-κB pathways play the important roles in induction of hBD-2 expression by LCWE in human vagihal epithelial cells.

Experiment examination plays an important role in evaluation of clinical microbiology experiment teaching.Standardized experiment examination system of clinical microbiology is a fair,objective and scientific assessment of students' learning effect and an important mean to evaluate teaching quality.The standardized experimental evaluation system includes organization,standardized examination contents,standardized procedures and operations,standardized invigilation and record,standardized scoring criteria,correction and prevention measures.

Objective To investigate the correlation between Streptococcus pneumoniae (S.pneumoniae) StkP kinase and drug resistance and to analyze the binding ability of StkP extracellular region (EC-StkP) to β-lactam antibiotics.Methods A stkP gene knockout (ΔstkP) mutant was constructed from S.pneumoniae strain ATCC6306 by insertional inactivation method.E-test was performed to detect the minimum inhibitory concentrations (MIC) of penicillin (PCN) and cefotaxime (CTX) against ΔstkP mutant and its wild-type strain.Bioinformatic softwares were used to predict the EC-StkP of S.pneumonia strain ATCC6306,to generate the three-dimensional structure model of EC-StkP and to analyze the correlation between the structure and functions of EC-StkP.PCR was performed to amplify the extracellular segment of stkP (EC-stkP) gene and the product of it was sequenced after T-A cloning.A prokaryotic expression system of EC-stkP gene was constructed.SDS-PAGE in combination with a gel image analysis system was used to detect the expression of the recombinant EC-StkP (EC-rStkP).The expressed EC-rStkP was extracted by Ni-NTA affinity chromatography.The binding abilities of EC-rStkP to PCN and CTX were detected by isothermal titration calorimetry (VT-ITC) and surface plasmon resonance (Biacore).Results S.pneumonia strain ATCC6306 was sensitive to PCN (MIC=0.06 μg/ml) and CTX (MIC=0.12 μg/ml),but its ΔstkP mutant was resistant to the two antibiotics (PCN MIC=16 μg/ml,CTX MIC=32 μg/ml).The 295 aa segment was predicted as the extracellular region at C-end of StkP of S.pneumoniae strain ATCC6306,containing four penicillin-binding proteins and Ser/Thr kinase-associated (PASTA) domains.The cloned EC-stkP segment and the EC-stkP segment in GenBank shared 99.6% similarity in nucleotide sequence and 100% in amino acid sequence.The constructed prokaryotic expression system for EC-stkP gene expressed EC-rStkP in soluble form.Both PCN and CTX could bind to EC-rStkP and CTX was better than PCN in term of binding ability.Conclusion The stkP gene of S.pneumonia is closely related to drug resistance and the encoded protein,Ser/Thr kinase StkP,can recognize and bind to β-lactam antibiotics.

Objective To construct a mutant strain of Streptococcus pneumoniae ( S.pneumoniae) with ciaH gene-knockout (ΔciaH) and to analyze the correlation between the ciaH gene and the bacterial re-sistance against β-lactam antibiotics.Methods The ciaH gene segament of S.pneumoniae strain ATCC6306 was amplified by PCR.The PCR product was sequenced after T-A cloning.A suicide plasmid pEVP3ciaH was constructed for the deletion of ciaH gene and then transformed into the ATCC 6306 strain by using the CaCl2 method .The mutant strain of S.pneumonia strain ATCC6306 with ciaH gene-knockout (ΔciaH) was genera-ted through homologous recombination , insertion inactivation and amphemycin screening , which was further identified by PCR , sequencing analysis and laser confocal microscopy .Double agar dilution method was used to detect the minimal inhibitory concentrations ( MICs ) of penicillin G ( PCN ) and cefotaxime ( CTX ) against theΔciaH mutant strain and the wild type strain .The differences between the MICs were further ana-lyzed.The changes of ciaH gene expression at mRNA level after treatment with 1/4 MIC of PCN or CTX were detected by real-time fluorescent quantitative RT-PCR ( qRT-PCR ) .Results The ciaH gene in the genomic DNA of the generated ΔciaH mutant strain was inactivated by insertion as indicated by PCR and se-quencing analysis .Results of the immunofluorescence assay showed that the ΔciaH mutant strain did not ex-press the CiaH protein .The MICs of PCN and CTX against the ΔciaH mutant strain were 32 μg/ml and 64μg/ml, respectively, which were significantly higher than that of the wild type strain (0.06 μg/ml and 1μg/ml) (P<0.01).The expression of ciaH gene at mRNA level was significantly elevated after treatment S.pneumoniae ATCC6306 strain with 1/4 MIC PCN or CTX (P<0.01).Conclusion The CiaH protein in the CiaH/CiaR two-component signaling system is involved in the resistance of S.pneumoniae against β-lac-tam antibiotics.

Objective To construct a prokaryotic expression system for expressing the phosphatase-encoding gene phpP in StkP/PhpP signaling couple in Streptococcus pneumonia ( S.pneumoniae) strains, and to further understand the phosphatase activity of the recombinant protein rPhpP.Methods The entire phpP gene of S.pneumoniae strain ATCC6306 was amplified by PCR.The PCR products were sequenced.A prokaryotic ex-pression system for expressing the phpP gene was constructed by the genetic engineering technique.The ex-pressed protein rPhpP and the solubility of rPhpP were assessed by SDS-PAGE and gel image analyzer.Ni-NTA affinity chromatography was performed to purify rPhpP.The changes of phpP gene transcription after the treat-ment with sublethal dosages of penicillin and cefotaxime were determined by real-time fluorescent quantitative RT-PCR.The functional domain in the sequence of the phpP gene and its type was analyzed by bioinformatic softwares.The activity of rPhpP in hydrolyzing the substrate of PP2C phosphotase was measured with Serine/Threonine Phosphotase Assay Kit.The enzyme kinetic parameters of rPhpP were calculated.Results The se-quence of the cloned phpP gene was identical with that reported in GenBank.The rPhpP in soluble form was ex-pressed in the constructed prokaryotic expression system.An increased expression of phpP gene at mRNA level was induced by sublethal dosage of penicillin or cefotaxime.The domain of PP2Cc type phosphatase was detec-ted in the sequence of phpP gene.The purified rPhpP protein could hydrolyze phosphopeptides [ RRA ( pT) VA], a substrate of PP2C type phosphatase, in a dose-dependent manner with Km and Kcat values of 277.35μmol/L and 0.71 S-1 ,respectively.Conclusion The protein encoded by phpP gene of S.pneumoniae was a PP2C type phosphatase.The expression of phpP gene could be enhanced by sublethal dosage of penicillin or ce-fotaxime.