Small non-coding RNA (sRNA) is a kind of newly discovered 50 nt~500 nt small RNAs that do not encode proteins. To date, more than 150 sRNA have been found in bacteria. The small RNA acting by base-pairing with target mRNAs, resulting in post-transcriptionally regulating gene expression, is important regulators in the bacterial response to stress, virulence and metabolism. At present, researches of sRNA mainly based on bioinformatical prediction and molecular biological experiments. The sRNA that obtained through these methods needs confirmation in laboratory, and then study of its functions through a variety of experimental methods.

Quantitative specific detection of Staphylococcus aureus is based on recombinant lysostaphin and ATP bioluminescence. To produce recombinant lysostaphin, the lysostaphin gene was chemically synthesized and inserted it into prokaryotic expression vector pQE30, and the resulting expression plasmid pQE30-Lys was transformed into E. coli M15 for expressing lysostaphin with IPTG induction. The recombinant protein was purified by Ni(2+)-NTA affinity chromatography. Staphylococcus aureus was detected by the recombinant lysostaphin with ATP bioluminescence, and plate count method. The results of the two methods were compared. The recombinant lysostaphin was successfully expressed, and a method of quantitative specific detection of S. aureus has been established, which showed a significant linear correlation with the colony counting. The detection method developed has good perspective to quantify S. aureus.
Adenosine Triphosphate ; chemistry ; Chromatography, Affinity ; Escherichia coli ; Luminescent Measurements ; methods ; Lysostaphin ; chemistry ; Recombinant Proteins ; chemistry ; Staphylococcus aureus ; isolation & purification

Bacteriolysis ; physiology ; Bacteriophages ; genetics ; isolation & purification ; physiology ; England ; Gram-Negative Bacteria ; virology ; Humans ; International Cooperation

Objective To assess value of serum level of ischemia modified albumin (IMA) in diagnosis for myocardial ischemia of coronary artery disease (CAD). Methods Seventy-two patients with clinically suspected myocardial ischemia of CAD admitted to The First People's Hospital of Hangzhou during November 2009 to May 2010 ready for undergoing coronary angiography, the gold standard for diagnosis of CAD, were randomly selected for the study. The patients were divided into CAD and non-CAD groups based on their coronary angiography. Serum level of IMA was determined with cobalt-albumin binding ( ACB) assay before coronary angiography, which served as diagnostic standard for CAD. Logistic regression analysis method was used to evaluate varied levels of IMA with area under the receiver operating characteristic curve (AUCROC) in diagnosis for myocardial ischemia of CAD. Results Mean level of IMA was (97 ±24) U/ml and (81 ±15) U/ml for CAD group (n =51) and non-CAD group (n =21), respectively. Sensitivity and specificity of a cut-off value of IMA 83.69 U/ml in diagnosis for myocardial ischemia of CAD was 80 percent and 57 percent, respectively, with a predictive value of a positive test 82 percent and that of a negative test 55 percent, respectively, from AUCROC. Logistic regression analysis demonstrated that both hypertension (P=0. 022, 6 = 1.421, OR=4. 141) and level of IMA (P=0.003, b= 1.780, OR=5.928) were independent predictors for CAD. Conclusions Sensitivity, specificity and predictive value of a positive test of the level of IMA are relatively high in diagnosis for myocardial ischemia of CAD, which is an independent predictor of it.

Although previous publications suggest the 2009 pandemic influenza A(H1N1)virus was reassorted from swine viruses of North America and Eurasia, the immediate ancestry still remains elusive due to the big evolutionary distance between the 2009 H1N1 virus and the previously isolated strains. Since the unveiling of the2009 H1N1 influenza, great deal of interest has been drawn to influenza, consequently a large number of influenza virus sequences have been deposited into the public sequence databases. Blast analysis demonstrated that the recently submitted 2007 South Dakota avian influenza virus strains and other North American avian strains contained genetic segments very closely related to the 2009 H1N1 virus, which suggests these avian influenza viruses are very close relatives of the 2009 H1N1 virus. Phylogenetic analyses also indicate that the2009 H1N1 viruses are associated with both avian and swine influenza viruses circulating in North America. Since the migrating wild birds are preferable to pigs as the carrier to spread the influenza viruses across vast distances, it is very likely that birds played an important role in the inter-continental evolution of the 2009 H1N1virus. It is essential to understand the evolutionary route of the emerging influenza virus in order to find a way to prevent further emerging cases. This study suggests the close relationship between 2009 pandemic virus and the North America avian viruses and underscores enhanced surveillance of influenza in birds for understanding the evolution of the 2009 pandemic influenza.

Anti-Bacterial Agents ; pharmacology ; Bacterial Infections ; therapy ; Bacteriophages ; physiology ; Drug Resistance, Bacterial ; drug effects ; Humans ; Probiotics ; pharmacology ; therapeutic use

Objective:To investigate the clinical characteristics of elderly patients with coronavirus disease 2019(COVID-19), in order to provide scientific evidence for the diagnosis and treatment of COVID-19 in elderly patients.Methods:Clinical data of 102 patients with COVID-19 admitted to the B11 East Ward of the Zhongfaxincheng campus and the E1-3 ward of the Guanggu Campus of Tongji Hospital affiliated to Huazhong University of Science and Technology in Wuhan from 1 February 2020 to 28 February 2020 were retrospectively collected and analyzed.Patients were categorized into 2 groups: the elderly group(≥60 years old)and the young and middle-aged group(<60 years old). Differences in epidemiological features, demographics, clinical symptoms, laboratory results and imaging findings between the two groups were retrospectively analyzed.Results:Among 102 patients with COVID-19, 58 were in the elderly group(≥60 years old), with a median age of 67.0(63.8, 71.0)years old, and 44 in the young and middle-aged group(<60 years old), with a median age of 47.5(38.0, 51.8)years old.There was no significant difference in gender ratio between the two groups( χ2=0.033, P=0.855). Of 102 patients, 42.0%(21/50)had close contact with an infected person, 14.0%(7/50)were from infection clusters, and 18.0%(9/50)had suspected hospital-acquired infections.Fever and cough remained the most common symptoms, but gastrointestinal symptoms such as nausea, poor appetite, diarrhea and muscle cramps were also warning signs.Fatigue and cough were the most common presenting symptoms in elderly male patients.Bilateral patchy infiltrates(57.9%, 22/38)and ground-glass opacities(42.1%, 16/38)were the main imaging features and 42.1%(16/38)patients had multiple areas of the lungs involved.Over 50% patients had increased levels of blood glucose, D-dimer, fibrinogen, C-reactive protein, procalcitonin, multiple cytokines and neutrophil-to-lymphocyte ratio, as well as decreased levels of albumin, hemoglobin, hematocrit, lymphocytes and serum calcium.Compared with the young and middle-aged group, the elderly group had higher rates of abnormality in levels of D-dimer and serum calcium( χ2=7.067 and 4.166, P=0.008 and 0.041). Conclusions:Fever and cough are the most common symptoms in elderly patients with COVID-19.Elderly patients with COVID-19 have multiple abnormalities in clinical laboratory test results, which show a certain level of specificity compared with young and middle-aged patients.

OBJECTIVETo investigate the effects of culture supernatant of human amnion mesenchymal stem cells (hAMSCs-CS) on biological characteristics of human fibroblasts.

METHODS(1) hAMSCs were isolated from deprecated human fresh amnion tissue of placenta and then sub-cultured. The morphology of hAMSCs on culture day 3 and hAMSCs of the third passage were observed with inverted phase contrast microscope. (2) Two batches of hAMSCs of the third passage were obtained, then the expression of vimentin of cells was observed with immunofluorescence method, and the expression of cell surface marker CD90, CD73, CD105, and CD45 was detected by flow cytometer. (3) hAMSCs-CS of the third passage at culture hour 72 were collected, and the content of insulin-like growth factor Ⅰ (IGF-Ⅰ), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and basic fibroblast growth factor (bFGF) were detected by enzyme-linked immunosorbent assay. (4) Human fibroblasts were isolated from deprecated human fresh prepuce tissue of circumcision and then sub-cultured. Human fibroblasts of the third passage were used in the following experiments. Cells were divided into blank control group and 10%, 30%, 50%, and 70% hAMSCs-CS groups according to the random number table (the same grouping method below), with 48 wells in each group. Cells in blank control group were cultured with DMEM/F12 medium containing 2% fetal bovine serum (FBS), while cells in the latter 4 groups were cultured with DMEM/F12 medium containing corresponding volume fraction of hAMSCs-CS and 2% FBS. The proliferation activity of cells was detected by cell counting kit 8 and microplate reader at culture hour 12, 24, 48, and 72, respectively, and corresponding volume fraction of hAMSCs-CS which causing the best proliferation activity of human fibroblasts was used in the following experiments. (5) Human fibroblasts were divided into blank control group and 50% hAMSCs-CS group and treated as in (4), with 4 wells in each group, at post scratch hour (PSH) 0 (immediately after scratch), 12, 24, 48, and 72, the migration distance of cells was observed and measured with inverted phase contrast microscope. (6) Human fibroblasts were grouped and treated as in (5), with 3 battles in each group, and apoptosis rate of cells was detected by flow cytometer. Data were processed with analysis of variance of factorial design, analysis of variance for repeated measurement, one-way analysis of variance, LSD test, and t test.

RESULTS(1) On culture day 3, most hAMSCs were in large form, and spindle-shaped with much prominences like fibroblasts or in flat polygonal shape. hAMSCs of the third passage were spindle-shaped. The expression of vimentin of hAMSCs of the third passage was strongly positive, and the expressions of surface markers CD90, CD73, and CD105 of the cells were positive, while the expression of CD45 of the cells was negative. (2) The content of IGF-Ⅰ, VEGF, EGF, and bFGF in hAMSCs-CS were respectively (11.7±1.0), (316±68), (6.1±0.4), and (1.49±0.05) pg/mL. (3) At culture hour 12-72, the proliferation activity of human fibroblasts in each hAMSCs-CS group was significantly higher than that in blank control group (with P values below 0.01), and the proliferation activity of human fibroblasts in 50% hAMSCs-CS group was the highest. (4) The width of scratch in two groups was nearly the same at PSH 0. The migration distance of cells in 50% hAMSCs-CS group was significantly longer than that in blank control group at PSH 12-72 (with P values below 0.01). (5) The apoptosis rate of human fibroblasts in blank control group was (16.2±2.4)%, which was significantly higher than that in 50% hAMSCs-CS group [(7.4±3.6)%, t=6.710, P<0.01].

CONCLUSIONShAMSCs-CS can promote proliferation and migration of human fibroblasts and inhibit the apoptosis of human fibroblasts.

Amnion ; cytology ; Apoptosis ; Cell Movement ; Cell Proliferation ; Cells, Cultured ; Culture Media, Conditioned ; chemistry ; Enzyme-Linked Immunosorbent Assay ; Epidermal Growth Factor ; metabolism ; Female ; Fibroblast Growth Factor 2 ; metabolism ; Fibroblasts ; cytology ; drug effects ; Flow Cytometry ; Humans ; Insulin-Like Growth Factor I ; metabolism ; Male ; Mesenchymal Stromal Cells ; chemistry ; Pregnancy ; Vascular Endothelial Growth Factor A ; metabolism

To use the designed restriction enzyme assisted mutagenesis technique to perform rapid site-directed mutagenesis on double-stranded plasmid DNA. The target amino acid sequence was reversely translated into DNA sequences with degenerate codons, resulting in large amount of silently mutated sequences containing various restriction endonucleases (REs). Certain mutated sequence with an appropriate RE was selected as the target DNA sequence for designing mutation primers. The full-length plasmid DNA was amplified with high-fidelity Phusion DNA polymerase and the amplified product was 5' phosphorylated by T4 polynucleotide kinase and then self-ligated. After transformation into an E. coli host the transformants were rapidly screened by cutting with the designed RE. With this strategy we successfully performed the site-directed mutagenesis on an 8 kb plasmid pcDNA3.1-pIgR and recovered the wild-type amino acid sequence of human polymeric immunoglobulin receptor (pIgR). A novel site-directed mutagenesis strategy based on DREAM was developed which exploited RE as a rapid screening measure. The highly efficient, high-fidelity Phusion DNA polymerase was applied to ensure the efficient and faithful amplification of the full-length sequence of a plasmid of up to 8 kb. This rapid mutagenesis strategy avoids using any commercial site-directed mutagenesis kits, special host strains or isotopes.
Amino Acid Sequence ; Base Sequence ; DNA ; genetics ; DNA Restriction Enzymes ; genetics ; DNA-Directed DNA Polymerase ; genetics ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; methods ; Plasmids ; Receptors, Polymeric Immunoglobulin ; genetics

Objective To induce a novel temperate bacteriophage from staphylococcus haemolyticus strain SA98,observe the morphology and size,complete the whole genome sequencing,analyse the structure of genome and evolutionary relationship.Methods The mitomycin C was used to induce the temperate phage from staphylococcushaemolyticus strain SA98,the induced phage was observed by transmission electron microscopy after be concentrated and purified.The genome DNA was extracted and high through sequenced.The feature of whole genome and evolutionary relationship was analyzed.Results A temperate phage IME-SA4 was successfully induced from staphylococcus haemolyticus strain SA98.Transmission electron microscopy analysis indicated that IME-SA4 had an isometric head and a non-contractile long tail.The whole genome of IME-SA4 was long as 41 843 bp,and the whole genome blast result indicated IME-SA4 shared only 13％ homology with most related strain phiRS7.Conclusions A novel staphylococcus haemolyticus temperate phage with low homology with other staphylococcusphages was successfully induced from staphylococcus haemolyticus strain SA98.The research of its morphology,whole genome sequencing and comparative genome analysis make the foundation for further study of staphylococcus phages' properties and practical application.