In vitro antibacterial activity of triclosan in combination with different antibacterial agents against triclosan-resistant multidrug-resistant Acinetobacter baumannii / 中华微生物学和免疫学杂志

Objective To investigate the in vitro antibacterial activity of triclosan combined with different antibacterial agents against triclosan-resistant multidrug-resistant Acinetobacter baumannii ( A. bau-mannii) . Methods A total of 626 A. baumannii strains were collected from the First Affiliated Hospital of Wenzhou Medical University from 2016 to 2017. The sensitivity of these A. baumannii strains to common an-tibiotics was detected by VITEK 2-compact automatical microbiological analyzer and the minimum inhibitory concentrations ( MIC) of triclosan were detected by agar dilution method. Checkerboard method was used to detect the changes in MIC values of triclosan against 16 triclosan-resistant multidrug-resistant A. baumannii strains after it was used in combination with four external ointments, including gentamicin, erythromycin, chloramphenicol and kanamycin, and three common antibiotics of imipenem, meropenem and ciprofloxacin, respectively. Fractional inhibitory concentration index ( FICI) was used to evaluate the joint bacteriostatic effects. Results Among the 626 A. baumannii strains, 17 were resistant to triclosan with a drug resistance rate of 2. 7％ (17/626). These triclosan-resistant strains had high MIC values for ciprofloxacin, imipenem,ceftazidime and other commonly used clinical antibiotic and most of them were multidrug-resistant. After tri-closan was used in combination with seven different antibacterial drugs, the MIC values of all drugs de-creased to various degrees compared with those when they were used alone. Triclosan in combination with gentamicin, chloramphenicol and ciprofloxacin showed synergistic effects on 62. 5％, 56. 25％ and 62. 5％of the 16 strains and additive effects on 37. 5％, 43. 75％ and 37. 5％, respectively. When it was used in combination with erythromycin, kanamycin, imipenem and meropenem, synergistic effects on 37. 5％, 25％, 12. 5％ and 12. 5％, additive effects on 37. 5％, 56. 25％, 62. 5％ and 62. 5％, and indifferent effects on 25％, 18. 75％, 25％ and 25％ of the strains were detected, respectively. No antagonistic effect was found between triclosan and any of the above antibiotics. Conclusions Triclosan combined with genta-micin, chloramphenicol and ciprofloxacin had better in vitro antibacterial effects against the triclosan-resist-ant multidrug-resistant A. baumannii strains in this study with synergistic and additive effects. Some indiffer-ent effects were found between triclosan and kanamycin, erythromycin, imipenem and meropenem, but no antagonistic effects were detected.

In vitro antibacterial activity of triclosan in combination with different antibacterial agents against triclosan-resistant multidrug-resistant Acinetobacter baumannii / 中华微生物学和免疫学杂志

Objective@#To investigate the in vitro antibacterial activity of triclosan combined with different antibacterial agents against triclosan-resistant multidrug-resistant Acinetobacter baumannii (A.baumannii).@*Methods@#A total of 626 A. baumannii strains were collected from the First Affiliated Hospital of Wenzhou Medical University from 2016 to 2017. The sensitivity of these A. baumannii strains to common antibiotics was detected by VITEK 2-compact automatical microbiological analyzer and the minimum inhibitory concentrations (MIC) of triclosan were detected by agar dilution method. Checkerboard method was used to detect the changes in MIC values of triclosan against 16 triclosan-resistant multidrug-resistant A. baumannii strains after it was used in combination with four external ointments, including gentamicin, erythromycin, chloramphenicol and kanamycin, and three common antibiotics of imipenem, meropenem and ciprofloxacin, respectively. Fractional inhibitory concentration index (FICI) was used to evaluate the joint bacteriostatic effects.@*Results@#Among the 626 A. baumannii strains, 17 were resistant to triclosan with a drug resistance rate of 2.7% (17/626). These triclosan-resistant strains had high MIC values for ciprofloxacin, imipenem, ceftazidime and other commonly used clinical antibiotic and most of them were multidrug-resistant. After triclosan was used in combination with seven different antibacterial drugs, the MIC values of all drugs decreased to various degrees compared with those when they were used alone. Triclosan in combination with gentamicin, chloramphenicol and ciprofloxacin showed synergistic effects on 62.5%, 56.25% and 62.5% of the 16 strains and additive effects on 37.5%, 43.75% and 37.5%, respectively. When it was used in combination with erythromycin, kanamycin, imipenem and meropenem, synergistic effects on 37.5%, 25%, 12.5% and 12.5%, additive effects on 37.5%, 56.25%, 62.5% and 62.5%, and indifferent effects on 25%, 18.75%, 25% and 25% of the strains were detected, respectively. No antagonistic effect was found between triclosan and any of the above antibiotics.@*Conclusions@#Triclosan combined with gentamicin, chloramphenicol and ciprofloxacin had better in vitro antibacterial effects against the triclosan-resistant multidrug-resistant A. baumannii strains in this study with synergistic and additive effects. Some indifferent effects were found between triclosan and kanamycin, erythromycin, imipenem and meropenem, but no antagonistic effects were detected.

Resistance mechanisms and molecular epidemiology of chlorhexidine acetate-resistant Klebsiella pneu-moniae clinical isolates / 中华微生物学和免疫学杂志

Objective To investigate the chlorhexidine acetate-resistance in Klebsiella pneumoniae ( K. pneumoniae) clinical isolates and to analyze the possible mechanisms and molecular epidemiology of re-sistant isolates. Methods A total of 332 K. pneumoniae clinical isolates were collected in the First Affilia-ted Hospital of Wenzhou Medical University in 2015. Standard agar dilution was used to screen chlorhexidine acetate-resistant isolates. The minimum inhibition concentrations ( MIC) of chlorhexidine acetate to resistant isolates with and without the presence of carbonyl cyanide m-chlorophenyl hydrazone ( CCCP) , which was an efflux pump inhibitor, were analyzed. Efflux pump genes of cepA, qacE and qacΔE1 that carried by and ex-pressed in those isolates were detected by polymerase chain reaction ( PCR) and quantitative real-time PCR ( RT-qPCR) , respectively. The biofilm formation ability was measured by crystal violet staining. The homol-ogy among the chlorhexidine acetate-resistant isolates was investigated with multilocus sequence typing ( MLST) and pulsed-field gel electrophoresis ( PFGE) . Results Twenty-five K. pneumoniae strains were re-sistant to chlorhexidine acetate. The MIC values of chlorhexidine acetate for them were reduced by at least four-fold in the presence of CCCP. Strains carrying the genes of cepA, qacE and qacΔE1 accounted for 100％, 40％ and 40％, respectively. The expression of the efflux pump genes in the chlorhexidine acetate-resistant isolates was higher than that in the susceptible isolates. The biofilm formation ability of the chlo-rhexidine acetate-resistant isolates was better than that of the susceptible isolates. Furthermore, negative, weak-positive and positive biofilm formation ability was observed in four ( 16％) , 20 ( 80％) and one (4％) strains, respectively. The results of MLST and PFGE showed that the 25 chlorhexidine acetate-resist-ant isolates belonged to 19 different sequence types ( ST) with diverse PFGE patterns. Conclusions This study suggested that active efflux was the main mechanism of chlorhexidine acetate resistance in K. pneumoni-ae. The 25 chlorhexidine acetate-resistant K. pneumoniae strains possessed different biofilm formation ability and shared low homology.

In vitro antibiotic effects of drug combinations against colistin-heteroresistant Acinetobacter baumannii / 中华微生物学和免疫学杂志

Objective@#To evaluate the in vitro antibiotic effects of colistin combined with meropenem, levofloxacin or fosfomycin against colistin-heteroresistant Acinetobacter baumannii (A.baumannii).@*Methods@#A total of 576 A. baumannii clinical isolates were collected from the First Affiliated Hospital of Wenzhou Medical University from 2014 to 2015. Minimal inhibitory concentrations (MICs) of colistin against A. baumannii were detected by broth dilution method. Colistin-heteroresistant A. baumannii isolates were screened using population analysis profiles (PAPs). MICs of colistin combined with meropenem, levofloxacin or fosfomycin, and the four drugs used alone against colistin-heteroresistant A. baumannii were detected by checkerboard method and broth dilution method. Fractional inhibitory concentration index (FICI) was calculated to evaluate antibiotic effects.@*Results@#None of the 576 A. baumannii isolates was resistant to colistin as indicated by the broth dilution method. Nine colistin-heteroresistant A. baumannii isolates were identified using PAPs. Compared with the MICs of colistin used alone, the MICs of colistin used in combination with meropenem, levofloxacin or fosfomycin against colistin-heteroresistant isolates were all decreased. Colistin-meropenem combination showed synergistic (55.6%), additive (33.3%) and indifferent effects (11.1%), but no antagonistic effect. Colistin-levofloxacin combination showed synergistic (55.6%), additive (22.2%) and indifferent effects (22.2%), but no antagonistic effect. Colistin-fosfomycin combination showed synergistic (77.8%) and additive (22.2%) effects, but no indifferent or antagonistic effect.@*Conclusion@#In vitro use of colistin in combination with meropenem, levofloxacin or fosfomycin has synergistic and additive antibacterial effects against colistin-heteroresistant A. baumannii. Combinations of colistin-meropenem and colistin-levofloxacin have fewer indifferent effects and no antagonistic effect.

Effect of Notch1 signaling pathway activation on pancreatic cancer cell proliferation in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of activation of Notch1 signaling pathway by Notch intracellular domain (NICD) plasmid transfection on pancreatic cancer cell proliferation and explore the underlying mechanism.</p><p><b>METHODS</b>The transfection rates were observed under microscope with fluorescence stimulation, and mRNA expression levels of Hes1 were detected by real-time PCR. Cell proliferation changes were evaluated by CCK-8 after NICD and control plasmid transfection in pancreatic cancer cells. Caspase 3 activity was examined using a caspase 3 detection kit.</p><p><b>RESULTS</b>The transfection rates of NICD plasmid were up to 80% by fluorescence stimulation observation. Hes1 expression was significantly increased after NICD plasmid transfection, suggesting the activation of Notch1 signaling pathway. NICD plasmid transfection significantly promoted cancer cell proliferation compared to control plasmid transfeciton. The activities of caspase 3 were obviously decreased after NICD plasmid transfection in 3 pancreatic cancer cell lines.</p><p><b>CONCLUSION</b>Activation of Notch1 signaling pathway by NICD plasmid transfection can promote the proliferation of pancreatic cancer cells by inhibiting the apoptosis pathway.</p>

Discussion on information system construction for postgraduate administration in affiliated clinical hospital / 中华医学教育探索杂志

Postgraduate administration is faced with new challenge in the affiliated clinical hospital because of the increasing quantity of postgraduates.The paper analyzed the characteristics of postgraduate administration and the status quo of information system construction in the affiliated clinical hospital and proposed the ideas of constructing information system for postgraduate administration from three aspects including system-frame,system-function and system-management.The purpose of the study was to provide reference for improving quality of postgraduate administration.

Comparative analysis of double-blind review and open review of Ph.D candidates' thesis / 中华医学科研管理杂志

Improvement of the review of dissertation for doctoral degree is important for the training of qualified doctors.Current practice includes double-blind review and open review.This paper compares and analyses the outcome of the two kinds of reviews and found that double-blind review is more objective that the other(the mean of open review score is 96.39±2.069,the mean of double-blind review score is 85.18±6.635.P=0.001,P＜0.01).In the end some suggestions are proposed to improve the double-blind review system.

Problems in Ph.D education revealed by Double-blind review of Ph.D candidates' dissertation and counter-measures / 中华医学科研管理杂志

The paper analysed the double-blind review result of Ph.D candidates' dissertation at Peking University People's Hospital.Rigor deficiency and inadequate knowledge about the research subjects were identified as the main problems.In the end some suggestions were proposed from two aspects,namely,full-process management of Ph.D training and supervisor-team construction.

~1H-MRS study of brain metabolic disorder in patients with cyanosed congenital heart disease / 中华放射学杂志

Objective To study the metabolic alteration in the brain of patients with cyanosed congenital heart disease (CCHD) by using 1H magnetic resonance spectroscopy ( 1H MRS) and discover the pathophysiology of chronic hypoxic brain, which will help to diagnose and treat this disease completely. Methods Twenty five patients with CCHD and 25 controls were performed PRESS 1H MRS and MRI, The areas under the resonance of metabolites were measured, the ratios of the other metabolites to Cr were calculated and compared. Results In patients with CCHD, the mean value of NAA/ Cr was significantly lower than that in controls ( P 0.05). Conclusion 1H MRS can detect brain metabolic changes in patients with cyanosed congenital heart disease in vivo noninvasively and can detect the metabolism disorder of the energy and amino acid, so the pathophysiology of this disease can be understood.