Objective To explore the inhibition of fusing antimicrobial peptides humanβ-defensin 3 and carbohydrate binding do-main on Staphylococcus aureus N315 and Staphylococcus epidermidis 35984.Methods The direct bactericidal test and other molec-ular biology methods were adopted to detect the inhibition role on Staphylococcus aureus strain N315 and Staphylococcus epidermi-dis strain 35984 and the influence on the key genes expression.Results The direct bactericidal test demonstrated that antimicrobial peptides hBD3 and hBD3-CBD had significantly inhibitory effects on staphylococcus aureus N315 and staphylococcus epidermidis 35984;the inhibitory effects of hBD3-CBD was stronger than that of hBD3;the stability of the inhibitory effects of hBD3-CBD also stronger than that of hBD3.In the key gene expression test,there were significant inhibitions on the agr and mecA gene expressions in Staphylococcus aureus N315 and Staphylococcus epidermidis 35984 by hBD3-CBD.At the same time,hBD3-CBD could inhibit the icaA gene expression and promote icaR gene expression in Staphylococcus epidermidis 35984,which indicated that hBD3-CBD could inhibit the biofilm formation of Staphylococcus epidermidis.Conclusion The fusion strategy of antimicrobial peptide has very important significance for improving the antibacterial efficacy of antimicrobial peptides and brings more hope in their future applications.

Objective · To isolate phages which can fight against extended-spectrum β-lactamase (ESBLs)-producing Escherichia coli (E. coli), and provide basic research for establishment of E. coli phage library and treatment of bacterial infection. Methods · Samples collected from sewage were co-cultured with 93 ESBLs-producing E. coli strains. A phage named JDEC001 was isolated by double agar overlay plaque assay. The biological characteristics, complete genome sequence and comparative genome analyses of JDEC001 were studied respectively. Results · JDEC001 belongs to the lytic phage as a member of the Caudovirales order, Podoviridae family. It has high activity at pH from 5 to 11 and with temperature from 0 to 39 ℃ .Whole-genome sequencing of JDEC001 demonstrated double-stranded DNA genome of 38745 bp with GC content of 49.93%, which encoded 46 open reading frames. The comparative genomics also showed that there was no virulent genes or antibiotic resistant genes in its genome. Conclusion · The phage JDEC001 against ESBLs-producing E. coli was isolated and purified, with good stability in a broad range of pH and temperature.

We used reverse transcriptase polymerase chain reaction (RT-PCR) and rapid amplification of cDNA end (RACE) techniques to obtain the full-length cDNA of beta-mannanase (EC 3.2.1.78) from Armillariella tabescens EJLY2098 (an edible fungus). Sequence analysis of the 1481 bp full-length cDNA encoding 445 amino acid residues indicated that the gene contained two structural domains, cellulose-binding domains (CBD) and glycoside hydrolase family 5 (GHF5) domains, other than the conserved beta-mannanase domain. Thus, we classified this gene as a member of glycoside hydrolase family 5. Next, we cloned a 1308 bp fragment encoding the beta-mannanase mature peptide (re-atMAN47) into the expression vector pPICZalphaA and expressed it in Pichia pastoris. The yield was 440 mg/L. Enzyme activity reached a maximum of 1.067 IU/mL after 72 h of methanol induction. The re-atMAN47 had an optimal temperature of 60 degrees C and an optimal pH of 5.5. It manifested broad thermostability from 30 degrees C-65 degrees C, and was stable between pH 4.5-7.0. This study represents the first record of a beta-mannanase from Armillariella tabescens EJLY2098 and provides a new source of carbohydrate hydrolysis enzyme with good biosafety, thermostability and wide pH stability. It is a good approach for the industrial needs of feed, food and pharmaceutical manufacturers.
Armillaria ; classification ; enzymology ; genetics ; Cloning, Molecular ; Enzyme Stability ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Sequence Analysis, DNA ; beta-Mannosidase ; biosynthesis ; chemistry ; genetics

Objective To evaluate the effects of different concentrations of desflurane on the electrophysiological stability of hearts in female patients.Methods Forty female patients,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,aged 20-50 yr,weighing 45-77 kg,scheduled for elective surgery with general anesthesia,were divided into 2 groups (n =20 each) using a random number table method:0.6 MAC group (group D1) and 1.3 MAC group (group D2).The intravenous access was opened after admission to the operating room,midazolam 0.1 mg/kg,vecuronium 0.1 mg/kg,fentanyl 3 μg/kg and etomidate 0.3 mg/kg were injected intravenously,and mechanical ventilation was performed after tracheal intubation.The concentrations of desflurane reached 0.6 and 1.3 MAC in D1 and D2 groups,respectively.Twelve-lead electrocardiograms were collected before anesthesia induction (T1),at 5 min after intubation (T2) and at 20 min after reaching the set concentration of desflurane (T3).The QT interval and Tpe interval were measured,the QTc interval,Tp-e/QT ratio and index of cardiac electrophysiological balance were calculated,and the development of arrhythmia was also observed.Results The QT interval and QTc interval were significantly longer,and the Tp-e/QT ratio was lower at T3 than at T1,2 in two groups (P＜ 0.05).There was no significant difference in QT interval,Tp-e/QT ratio or index of cardiac electrophysiological balance at each time point between two groups (P＞0.05).No arrhythmia was found in neither group.Conclusion The clinical concentration of desflurane affects the electrophysiological stability of hearts to some extent in female patients without causing arrhythmia.

Objective:To evaluate the effect of electroacupuncture postconditioning on the expression of microRNA-1 (miRNA-1) in rats with arrhythmias induced by myocardial ischemia-reperfusion (I/R).Methods:Twenty-four clean-grade healthy adult male Sprague-Dawley rats, aged 2-3 months, weighing 280-320 g, were divided into 3 groups ( n=8 each) using a random number table method: sham operation group (S group), I/R group and electroacupuncture postconditioning group (EP group). The model of myocardial reperfusion arrhythmia was established by ligating the left anterior descending branch of coronary artery for 30 min followed by 30-min reperfusion in anesthetized rats.The artery was only isolated without ligation after thoracotomy in group S. Bilateral Neiguan acupoints were stimulated for 30 min starting from the time point immediately after reperfusion in EP group.The occurrence of arrhythmia during reperfusion was recorded.The rats were sacrificed at 30 min of reperfusion, and hearts were removed for examination of the pathological changes of the myocardium and for determination of miRNA-1 expression (by quantitative real-time polymerase chain reaction) and expression of Kir2.1 and connexin 43 (Cx43) (by Western blot). Results:Compared with S group, the incidence of arrhythmia was significantly increased, the expression of miRNA-1 was up-regulated, and the expression of Kir2.1 and Cx43 was down-regulated in I/R and EP groups ( P<0.05). Compared with I/R group, the incidence of arrhythmia was significantly decreased, the expression of miRNA-1 was down-regulated, and the expression of Kir2.1 and Cx43 was up-regulated in EP group ( P<0.05). The pathological changes of myocardium were accentuated in I/R and EP groups when compared with S group, and the pathological changes were significantly attenuated in EP group when compared with I/R group. Conclusion:The mechanism by which electroacupuncture postconditioning reduces the occurrence of reperfusion arrhythmia is related to up-regulation of Kir2.1 and Cx43 expression after down-regulation of miRNA-1 expression in rats.

Objective To explore the neuroprotective effect of curcumin(Cur)on Parkinson's disease model and its mechanism.Methods Sprague-Dawley rats were randomly divided into the control(CON)group,the model(PD)group,and the low-,medium-,and highdose curcumin(Cur)groups,with ten rats in each group.Lipopolysaccharide was injected into the substantia nigra to establish a Parkinson's disease model.Rats in the Cur groups were administered Cur intraperitoneally at doses of 20 mg/kg,40 mg/kg,and 60 mg/kg daily for 21 days.α-synuclein(α-syn),nuclear transcription factor κB proteins(NF-κB,IKBα,p-NF-κB,p-IKBα)and the activation levels of astrocytes were detected in rat brain tissues by immunohistochemistry(IHC).mRNA levels of pro-inflammatory cytokines(TNF-α,IL-β,IFN-γ,IL-6),inducible nitric oxide synthase(iNOS),cyclooxygenase-2(COX-2),NADPH oxidase complex(gp47phox,gp91phox,gp67phox),and apoptosis-related factors(Bax,Bcl-2,Caspase-3,and Caspase-9)were measured by quantitative reverse transcription polymerase chain reaction(qRT-PCR).The rotarod and pole climbing tests were used to evaluate the motor coordination of the rats.Results Compared to the CON group,PD rats showed significantly increased levels of α-syn,p-NF-κB,p-IKBα proteins,activation of astrocytes,TNF-α,IL-β,IFN-γ,IL-6,iNOS,COX-2,Bax,Caspase-3,Caspase-9,gp47phox,gp91phox and gp67phox mRNA levels(P<0.05);while the Bcl-2 level was significantly decreased(P<0.05).Compared with the PD group,the medium-and high-dose Cur treatment groups inhibited the aggregation of α-syn protein,reduced the activation of the NF-κB pathway,and the expression of inflammatory and apoptosis-related factors(P<0.05).Moreover,medium and high doses of Cur significantly improved the motor coordination in rats,and compared with the PD group,the performance of rotarod and pole climbing tests was significantly improved(P<0.05).Conclusion cur may inhibit the aggregation of α-syn by suppressing neuroinflammation and oxidative stress responses,thereby improving motor coordination in Parkinson's disease rats and exerting neuroprotective effects.