BACKGROUND: Diabetic wound healing remains a major challenge due to the impaired functionality of angiogenesis by persistent hyperglycemia. Mesenchymal stem cell exosomes are appropriate candidates for regulating the formation of angiogenesis in tissue repair and regeneration. Here, we explored the effects of exosomes derived from human amniotic mesenchymal stem cell (hAMSC-Exos) on the biological activities of human umbilical vein endothelial cells (HUVECs) treated with high glucose and on diabetic wound healing and investigate lncRNAs related to angiogenesis in hAMSC-Exos. METHODS: hAMSCs and hAMSC-Exos were isolated and identified by flow cytometry or western blot. A series of functional assays such as cell counting kit-8, scratching, transwell and tube formation assays were performed to evaluate the potential effect of hAMSC-Exos on high glucose-treated HUVECs. The effect of hAMSC-Exos on diabetic wound healing were tested by measuring wound closure rates and immunohistochemical staining of CD31. Subsequently, the lncRNAs profiles in hAMSC-Exos and hAMSCs were examined to screen the lncRNAs related to angiogenesis. RESULTS: The isolated hAMSC-Exos had a size range of 30–150 nm and were positive for CD9, CD63 and CD81. The hAMSC-Exos facilitate the functional properties of high glucose-treated HUVECs including the proliferation, migration and the angiogenic activities as well as wound closure and angiogenesis in diabetic wound. hAMSC-Exos were enriched lncRNAs that related to angiogenesis, including PANTR1, H19, OIP5-AS1 and NR2F1-AS1. CONCLUSION Our findings demonstrated hAMSC-Exos facilitate diabetic wound healing by angiogenesis and contain several exosomal lncRNAs related to angiogenesis, which may represent a promising strategy for diabetic wound healing.

Phenol-soluble modulins (PSMs) are a novel family of small amphipathic, alpha-heli-cal peptides with strong surfactant-like properties. PSMs have multiple roles in staphylococcal pathogenesis and are considered as important virulence-associated factors. They may cause lysis of many eukaryotic cells, such as human neutrophils,erythrocytes and dendritic cells;induce the expression of pro-inflammatory cyto-kines;facilitate the structuring and detachment of biofilms;influence the expression of other genes. This re-view summarizes the classification,structure,regulatory effect on gene expression and biological function of PSMs. The potential avenues to target PSMs for drug development against staphylococcal infections are also evaluated in this paper.

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.

China ; epidemiology ; History, 19th Century ; History, 20th Century ; Humans ; Mycobacterium bovis ; Tuberculosis ; epidemiology ; history ; prevention & control

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 .

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 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.

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.