Objective To construct the recombinant plasmid with a human peptide antibiotic hPAB-? gene and to make it expressed in E. coli. Methods To replace the CNBr cleavage site in plasmid pFAST-hPAB-? (CNBr), a pair of primers containing the hydroxylamine cleavage site were designed, and the amplified PCR fragments were cloned into pFAST-HTa plasmid to produce pFAST-hPAB-? (HA), which was then transformed into E. coli DH10B. The constructed plasmid was identified by Ehe Ⅰ/Hind Ⅲ digestion and direct DNA sequencing. An Ehe Ⅰ/Hind Ⅲ digested fragment from pFAST-hPAB-? (HA) was subcloned into pQE32-CP to construct pQE32-CP-hPAB-?, which was transformed into E. coli JM109. The bacteria containing the expression plasmid were induced to express the fusion protein by IPTG. SDS-PAGE was carried out to analyze the molecular weight, expression quantity and expression form of the target fusion protein. After captured by Ni-NTA affinity column, the fusion protein was subjected to hydroxylamine cleavage analysis. Results An expected 230bp fragment was obtained by digesting pFAST-hPAB-? with Ehe Ⅰ/Hind Ⅲ. After this fragment was cloned into pQE32-CP, the recombinant plasmid was confirmed to contain the correct target sequence by DNA sequencing. The recombinant plasmid pQE32-CP-hPAB-? could express a desired protein with a relative molecular weight about 27kD, and its expression level reached 43 percent of the total bacterial proteins. The inclusion bodies were lysed by 8mol/L urea, and the fusion protein could then be captured by Ni-NTA column and cleaved by 2mol/L hydroxylamine at pH9.0. Conclusion The recombinant plasmid pQE32-CP-hPAB-? has been successfully constructed, and it can express the desired hPAB-? fusion protein in E. coli JM109 at high level. These results provide the foundation for future research.

Objective To observe the clinical effect of combination of clopidogrel and simvastatin on coro-nary heart disease and transient ischemic attack(TIA). Methods 76 patients with coronary heart disease and TIA were randomly divided into test group (n=40) and control group (n=36). The control group was treated with en-teric-coated aspirin 50 mg×2 every night after supper, and the test group was treated with clopidogrel 25 mg×2 and simvastatin 10 mg×2 every night before sleep. Liver and kidney function, blood coagulation function and blood lipids were measured before treatment and after. 1 year followed-up. Results The effective rate was 95.0% (38/40) in test group and 55.5% (20/36) in control group(χ2=6.45,P<0.01). LDL-C was (3.18±1.24) mmol/L and (2.60±1.03)mmol/L(t=2.67,P<0.01),TC was(5.18±1.24) mmol/L and (4.02±2.18) mmol/L(t= 4.91, P<0.01),TG was (1.50±1.02) mmol/L and (1.30±1.03) mmol/L(t=1.02, P>0.05), respectively in test group before and after treatment. However, there was no statistical difference in LDL-C, TC and TG (t=0.17, 0.00,0.52,0.57,P>0.05 for each) in control group. The two groups showed no difference after treatment (t= 1.51,2.55,0.57, P>0.05 for each). Conclusions Glopidogrel combined with simvastatin capsules is safe in pre-vention of TIA attack.

Objective To identify the nanobaeteria in prostate fluid of patients with CPPS.Methods Expressed prostatic secretion(EPS)and urine specimens were collected by Meares-Stamey way from CPPS patients(n=100)and normal controls(n=100).The specimens were cultured and nanobacteria was identified by indirect immunofluoreseenee staining with rnonoelonal antibody.The morphological features were observed by using transmission electron microscopy(TEM). Results The positive rate of nanobaeteria in the EPS cdture of CPPS patients and controls were 43% and 5% respectively,with significant statistical difference(X2=39.58,P＜0.01).By TEM,the sizes of NB ranged from 100 to 500 nm and appeared eoccoid-ccccobacillary shape. Conclusion Nanobaeteria infection may exist in EPS of CPPS patients.

Medical microbiology is an important basic subject in medical colleges.In view of the multifarious and abstract nature of the specialized course and the dull atmosphere in classroom teaching,we have adopted a doggerel teaching method in order to enliven the classroom atmosphere and improve the class teaching quality.After long-term teaching practice,it's been proved that the proper use of doggerel in classroom teaching can not only refresh boring theory and enhance students' learning interesting,but also simplify the complicated context and improve their memorizing ability and learning efficiency,posing a significant impact on the teaching effects of medical microbiology.

Objectives: To design the mutants of peptide antibiotics hPAB ? based on its molecular structure. Methods: The three dimension structure of hPAB ? was constructed by protein homology modeling method. The mutant molecules were designed and generated by PCR and inserted into pQE CP4 expression plasmid. The recombinant plasmids were identified by PCR and DNA sequencing and then transformed into Escherichia coli JM109 to express target fusion proteins. Results:Peptide hPAB ? shows one ? helical and three ? sheet in its structure. Its ? helical regions seem play a key role in the formation of active oligomer. Aside from positioning Thr 7 and Lys 10 into contact positions, the orientation of the ? helix is conserved about the oligome core, forming a ridge around it. Additionally, the dipoles of the helices would overlap to create a positively charged region near the core. These dipoles may be offset, however, by the presence of Asp 4 at the base of the helix. Two mutant molecules, hPAB ? 38 and hPAB ? 34, were designed by deleting N or/and C terminal 2～5 amino acid residues based on hPAB ? structure. The recombinant plasmids containing the mutants gene can express interest fusion proteins in E. coli JM109 successfully. Conclusions: Design, cloning and expression of the mutants of peptide antibiotics hPAB ? lay down the foundation for screening of the mutant of shorter peptide chain and having high or same antimicrobial activity.

Objective:To screen and clone a carrier molecule for the expression of small bioactive peptides at high levels. Methods: A carrier molecule, PaP3.30, was screened out from the genome of Pseudomonas aeruginosa phage PaP3 and its gene was cloned by PCR method and inserted into pQE 32 expression plasmid, this recombinant plasmid was named pQE PaP30. The peptide antibiotics hPAB ? gene was then inserted into pQE PaP30 and induced to express the fusion protein in Escherichia coli . The ability of PaP3.30 to express other bioactive peptides was evaluated by fusing 6 different origins, varies in sizes and isoelectric points selected peptides to it. Results: After fused to PaP3.30, the peptide antibiotics hPAB ? could express as fusion protein above 30% of total bacterial proteins. Six selected peptides were also expressed by the level of 35%～44% total bacterial proteins when fused to carrier molecule, PaP3.30. Conclusion: The new carrier molecular, PaP3.30, is versatile in the expression of small bioactive peptides.

Innovation education was introduced in medical microbiology teaching practice,including updating the innovative education concept,reforming teaching methods and means,constructing the teaching content system and practice platform adapting to innovation education.

Objective To investigate the role of a transcription factor p 53 in dengue virus infec-tion.Methods A plasmid expressing siRNA specific for p 53 gene was constructed and then used to prepare HepG2 cell line with a suppressed expression of p 53 protein.The expression of p53 protein was detected by Western blot assay .A wild type control group and a siRNA group were set up by infecting wildtype HepG 2 cells and p53 low expressing HepG2 cells with type 2 dengue viruses,respectively.The virus titers in two dif-ferent cells were determined by plaque forming assay using Vero cells .Indirect immunofluorescence assay was performed to detect virus multiplication .The apoptosis of virus infected cells were analyzed by flow cytome-try.ELISA was performed to analyze the levels of IFN-βsecreted by infected cells from two groups .Results Compared with wildtype control group ,the cells in siRNA group showed a suppressed expression of p 53 pro-tein,suggesting that the HepG2 cell line with low p53 protein expression was successfully established .The vi-rus titer in supernatants of the cells from siRNA group was about 100-fold higher than that of wildtype control group at 24 hours after viral infection .Fluorescence activated cell sorting analysis showed that the numbers of green fluorescence labeled cells were remarkably increased in siRNA group .We speculated that p53 protein might play a role in the inhibition of dengue virus infection as indicated by the observed results .The numbers of apoptotic cells showed no significant difference between two groups .However,the level of IFN-βsecreted by wildtype HepG2 cells was six times higher than that of the cells in siRNA group .Conclusion p53 pro-tein might inhibit dengue virus infection through the activation of type Ⅰ interferon signaling pathway rather than enhance cell apoptosis .

Objective: To screen the best genetic engineering bacterium for the production of peptide antibiotic hPAB-? and evaluate its fermentation level in bottle. Methods:After analysis of the interest fusion protein expression levels of 8 recombinant bacteria containing 1-8 copies of human peptide antibiotic hPAB-? expressing plasmid respectively,2-5 copies expressing bacteria were chosen for the further study of their bacteria yield,expression forms of the target protein, dissolution of the inclusion bodies and the efficiency of fusion protein purification by affinity chromatography, then the best engineering bacterium with the certain copies of interest peptide expressing plasmid was screened out and its optimal fermentation parameters in bottle were also studied. Results:The recombinant bacterium transformed by 3 copies of interest peptide expressing plasmid was the best candidate for its bacteria yield (3.153 g/L) and fusion protein expression level (27.7%) were the highest among 1-8 copies candidates. The inclusion bodies of 3 copies target fusion protein could be easily dissolved by 8 mol/L urea and captured by Ni-NTA column. The elution of the fusion protein could be directly cleaved to monomer by adding 2 mol/L hydroxylamine, adjusting pH to 9.0 and incubating at 45℃ for 2 h. The optimal fermentation conditions of the selected recombinant bacteria were: culture the organisms with modified M9-CAA media at 37℃ and 160 r/min to (A 600 )≈2.5, then add IPTG to the final concentration 100 ?mol/L to induce the expression of target fusion protein for 5 h. Conclusion:The engineering bacterium containing 3 copies interest peptide recombinant expressing plasmid is the best candidate for the production of peptide antibiotic hPAB-?,and its fermentation parameters are confirmed.

Objective To investigate the binding ability of the terminase large subunit of Pseudomonas aeruginosa bacteriophage PaP3 to the cos site. Methods The gene tls was amplified from the genome of bacteriophage PaP3 by PCR and subcloned into pMD18-T vector. Then the gene tls cut down from the vector was inserted into the plasmid pQE31 which could give a 6-His tag at the N-terminal of the expressed protein. The recombinant vector pQE-tls was transformed to E.coli. JM109, after induction with IPTG, the expressed bacteria were resuspended and sonicated, then after centrifugation, the inclusion body was obtained. The inclusion body was dissolved with lysis buffer, then the tagged protein was purified by Ni-NTA affinity chromatography and renatured by dialysis. Finally the DNA-binding ability of the fusion protein rTLS was determined by EMSA. Results The expression plasmid pQE31-tls was successfully constructed, and the target protein yield was up to 30% of the total bacterial proteins. After purification and renaturation, the fusion protein rTLS can partially bind the cos fragment. Conclusion The fusion protein rTLS was successfully expressed, purified and renatured. The rTLS has the specific DNA-binding activity. The present work lays the foundation for the further research of the gene tls.