1.The relationship of resistance mechanism of two strains of Enterobacteriaceae resistant to carbapenems isolated from a single specimen
Deshi SHI ; Haifeng SHAO ; Weiping WANG ; Mei HUANG ; Xiaowen ZHANG
Chinese Journal of Microbiology and Immunology 2011;31(5):417-420
Objective To investigate the relationship of resistance mechanisms of a Klebsiella pneumoniae strain and a Morganella morganii strain resistance to carbapenems isolated from a single specimen. Methods Sensibility of antimicrobial agents was detected by agar dilution method. Specific PCR and DNA sequence analysis were performed to detect resistance genes. Plasmid feature was detected by plasmid conjugation and electrophoresis analysis. Genetic environment around blaKPC was analyzed with sequencing. The changes of outer membrane permeability were analyzed with electrophoresis of outer membrane proteins. Results blaKPC-2 was detected in 2 original isolates strains and their transconjugants. Carbapenem-resistance was successfully transfered by conjugation experiments. blaKPC-2 was located on dissimilar plasmids, but genetic environment around blaKPC-2 was the same sequence. The Morganella morganii isolate showed a loss of 38 ×103 OMPs and an additional 36 ×103 OMPs appearance, while the Klebsiella pneumoniae isolate showed a loss of OMPK36. Conclusion blaKPC-2 was detected in 2 isolates. This gene encoded by two plasmids with different sizes was located on the same composite transposon. The lack of outer membrane proteins could also play an important role causing isolates to exhibite resistance to carbapenems.
2.Study on the molecular mechanism of carbapenem-resistant Escherichia coli
Shougang KUAI ; Haifeng SHAO ; Weiping WANG ; Ming FAN ; Mei HUANG
Chinese Journal of Microbiology and Immunology 2010;30(9):829-833
Objective To investigate the molecular epidemiology and mechanism of carbapenem resistance of Escherichia coli collected from intensive care units(ICUs)of general surgery.Methods Agardilution were carried out to confirmed the drug-susceptibility,pulsed-field gel electrophoresis(PFGE)were performed to analyze the molecular epidcmiology of carbapenem-resistance isolates.Specific PCR,DNA sequencing,conjugation experiments,plasmids extraction,plasmid transformation assays and SDS-PAGE of outer membrane proteins(OMPs)were carried to confirm genotype of carbapenemase and its transmission mechanism.Results PFGE showed the isolates belonged to 10 clonotype,and all the clinical isolates were resistant to β-lactams including imipenem and meropenem,but uncertain to aminoglycosides,specific PCR and DNA sequencing revealed that all isolates encoded carbapenem-hydrolyzing enzyme gene,KPC-2.Plasmid DNA extraction and plasmid transformation assays from some isolates comfirmed that KPC-2 encoded on a 56 kb plasmid.SDS-PAGE analysis confirmed that there are alterations in OMPs of Escherichia coli.Conclusion Escherichia coli isolates with carbapenem resistance are collected from our hospital,production of KPC-2 carbapenemase mainly contributed to reduced susceptibility of carbapenem in Escherichia coli,the alterations in OMPs may as a cofactor in high-level drug-resistance in Escherichia coli.
3.Prognostic effects of continuous renal replacement therapy on multiple organ dysfunction complicated with acute kidney injury
Haifeng MEI ; Jilu YE ; Zhiyun ZHU ; Zongmin LIANG
Journal of Chinese Physician 2014;16(5):623-626
Objective To investigate the prognostic effects of continuous renal replacement therapy on multiple organ dysfunction complicated with acute kidney injury.Methods Fifty nine patients who were diagnosed with multiple organ dysfunction syndrome (MODS) complicated with acute kidney injury (AKI) and underwent continuous renal replacement therapy (CRRT) were selected and grouped according to the Kidney Disease Improving Global Outcomes (KDIGO) staging.Their clinical data before CRRT were collected.The patients were grouped according to the Intensive Care Unit (ICU) prognosis,namely death and survival.The differences between two groups were analyzed.The multinomial logistic regression analysis was performed to explore the prognostic factors.Results With the increase of KDIGO stage,the Acute Physiology And Chronic Health Evaluation Ⅱ (APACHEII) score,Sequential Organ Failure Assessment (SOFA) score,the need for vasoactive drugs,and the number of cases with oliguria and ICU mortality rates showed an increasing trend,and those differences were statistically significant (P < 0.05).After multivariate analysis,KDIGO Ⅲ stage,the number of failed organs,oliguria,and the mean daily fluid balance were independent risk factors of death in patients who were diagnosed with MODS complicated with AKI and underwent CRRT.Conclusions The KDIGO classification plays an important role in predicting the prognosis of patients with MODS complicated with AKI in need of CRRT.The number of failed organs,oliguria,and the mean daily fluid balance are also the risk factors for prognosis.
4.Clinical characteristics and management of recurrent retinal detachment in silicone oil tamponade eyes
Qing BAO ; Jia CHEN ; Yiqiao XING ; Lei DU ; Haifeng MEI
Recent Advances in Ophthalmology 2017;37(6):576-578
Objective To explore the characteristics and surgical managements of recurrent retinal detachment in silicone oil tamponade eyes.Methods The records of consecutive series of 134 patients (134 eyes) with recurrent retinal detachment in silicone oil tamponade eyes from January 2012 to December 2015 in our hospital were reviewed retrospectively,the vitrectomy combined with silicone oil replacement or scleral buckling procedure were performed.The follow-up time was 6 months,the surgical efficient was evaluated.Results 101 eyes underwent vitrectomy combined with silicone oil replacement.Retina was completely reattached in 79 eyes,and vitrectomy was reperformed in the left 22 eyes,the successful rate was 78.2% (79/101);The visual acuity improved in 16 eyes,unchanged in 56 eyes,decreased in 29 eyes;The intraocular pressure of 31 eyes increased more than 25 mmHg (1 kPa =7.5 mmHg).33 eyes underwent scleral buckling procedure.Retina was completely reattached in 23 eyes,and vitrectomy combined with silicone oil replacement was performed in the left l0 eyes,the successful rate was 69.7% (23/33);The visual acuity improved in 5 eyes,unchanged in 16 eyes,decreased in 12 eyes;The intraocular pressure of 14 eyes increased more than 25 mmHg.Conelusion For limited retinal detachment caused by inferior or peripheral holes,proliferative vitreoretinopathy in the A or B-class,the refractive medium does not affect the fundus examination,scleral buckling surgery is preferred;For the hole in the posterior pole or extensive retinal detachment caused by giant retinal holes,proliferation or retinal fixed fold formation,vitrectomy combined with silicone oil replacement is a better option.
5.Matrix-assisted laser desorption ionization-time of flight mass spectrometry for rapid identification of clinical isolates
Haiyan XI ; Ying WANG ; Mei HUANG ; Linghui LI ; Ming FAN ; Haifeng SHAO ; Weiping WANG ; Xiaojun LI
Journal of Medical Postgraduates 2015;(4):416-419
Objective Laboratory tests of yeast, with their disadvantages of long identification, complicated operation, and low positive rate, cannot meet the needsof rapid diagnosis and timely treatment.This studyinvestigated the feasibility ofapplying matrix-assisted laser desorption ionization-time of flight mass spectrometry ( MALDI-TOF-MS) in rapid identification and clinical isolationof yeast strains. Methods A total of 120 clinical non-repetitive isolates were collected from clinical culture samples and identified by MALDI-TOF-MS and VITEK 2-Compact/API, respectively.The discordant results were resolved by ITS gene sequencing. Results Of the 120 yeast isolates analyzed, 117 (97.5%) were correctly identified at the species level by MALDI-TOF-MS, 1(0.8%) misidenti-fied, and 2 ( 1.7%) unidentified.ITS gene sequencing of the 3 isolates showed the coincidence rate to be 0( 0/3) for MALDI-TOF-MS and Vitek 2-Compact/API. Conclusion MALDI-TOF-MScan be used as a rapid, accurate, and inexpensive tool for the identification of clinical yeast strains.
6.Study on the Mechanism of Quinolone Resistance in Pseudomonas Aeruginosa
Ying WANG ; Mei HUANG ; Haiyan XI ; Linghui LI ; Lining SHI ; Weiping WANG ; Haifeng SHAO
Journal of Modern Laboratory Medicine 2014;(6):18-20,24
Objective 30 Pseudomonasaeruginosa mechanism of resistance to quinolones.Methods For the determination of ciprofloxacin MIC by agar dilution method.Used PCR on DNA gyrase and topoisomerase Ⅳ,resistance genes gyrA,gyrB, parC and parE were amplified,and BLAST,to determine whether there was resistance to bits mutation point;using pulsed-field gel electrophoresis (PFGE)of these 30 strains homology analysis.Results The 28 bacterial strains gyrA gene ampli-fied fragment of 137 points were C→T mutation causes T83I;17 strains gyrB gene amplified fragment of 351 G→C lead to G466A;parC gene amplification 21 bacteria fragment 277 point increase with C→U mutation causes S87L change two differ-ent strains parE gene locus C→U mutation A425V and A473V cause change.PFGE results:30 Pseudomonas aeruginosa could be divided into six clones,Aclone 4,B clone 7,C clone 3,D clone 14,and two other single clones.Conclusion The tar-get mutant strains closely related to the epidemic clone type,the same changes in the same pop-type strains of drug targets, and proportional to the level of ciprofloxacin MICs value,the more the number of mutated genes,MICs value higher.GyrA gene most prone to mutation,the mutation was also the first to be discovered,more than any other target of the mutation mutations on binding of drugs and targets that would be the focus of concern.
7.Discussion on the Problems of Vitek 2 Compact Advanced Expert System to Identify Carbapenemase Phenotypes in Isolates of Enterobacteriaceae
Ying WANG ; Fangfang CHEN ; Mei HUANG ; Haiyan XI ; Ming FAN ; Haifeng SHAO ; Weiping WANG
Journal of Modern Laboratory Medicine 2017;32(4):101-103,106
Objective To explore the accuracy of Vitek 2 compact advanced expert system (AES) in indicating and analyze the carbapenemases-resisting Enterobacteriaceae phenotypes,and further investigate the methods to make up the AES.Methods 28 Enterobacteriaceae strains with Imipenem-Nonsusceptible by Vitek 2 compact,but AES suggested all production of carbapenemases were isolated.And imipenem susceptibility was determined by the disk diffusion method.Modified Hodge test (MHT) and the metallo-β-1actamase was detected by the double disk synergy method.Resistance genes were detected by the PCR amplification.Results ESBLs gene was amplified from all 28 selected strains,16 of which was detected KPC gene,and no strain of metallo-β-1actamases-producing bacteria.With carbapenemase gene detection as the gold standard,the accuracy of AES was 57.1%.Disc diffusion method detection accuracy rate of imipenem was 100%,and for 100% of MHT accuracy.PCR amplification,MHT and the disk diffusion displayed the same result in detecting carbapenemases,but different with AES (x2 =10.08,P<0.05).Conclusion The indications of the presence of carbapenemases using AES was not completely correct with a certain false-positive,and it is necessary to take other methods,such as disk diffusion or MHT methods,and improve the reliability of medicine-sensitivity tests.
8.Triptolide downregulates Rac1 and the JAK/STAT3 pathway and inhibits colitis-related colon cancer progression.
Zhipeng WANG ; Haifeng JIN ; Ruodan XU ; Qibing MEI ; Daiming FAN
Experimental & Molecular Medicine 2009;41(10):717-727
Triptolide, a diterpenoid triepoxide from the traditional Chinese medicinal herb Tripterygium wilfordii Hook. f., is a potential treatment for autoimmune diseases as well a possible anti-tumor agent. It inhibits proliferation of coloretal cancer cells in vitro and in vivo. In this study, its ability to block progress of colitis to colon cancer, and its molecular mechanism of action are investigated. A mouse model for colitis-induced colorectal cancer was used to test the effect of triptolide on cancer progression. Treatment of mice with triptolide decreased the incidence of colon cancer formation, and increased survival rate. Moreover, triptolide decreased the incidence of tumors in nude mice inoculated with cultured colon cancer cells dose-dependently. In vitro, triptolide inhibited the proliferation, migration and colony formation of colon cancer cells. Secretion of IL6 and levels of JAK1, IL6R and phosphorylated STAT3 were all reduced by triptolide treatment. Triptolide prohibited Rac1 activity and blocked cyclin D1 and CDK4 expression, leading to G1 arrest. Triptolide interrupted the IL6R-JAK/STAT pathway that is crucial for cell proliferation, survival, and inflammation. This suggests that triptolide might be a candidate for prevention of colitis induced colon cancer because it reduces inflammation and prevents tumor formation and development.
Animals
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Cell Transformation, Neoplastic/*drug effects
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Colitis/complications
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Colonic Neoplasms/chemically induced/*drug therapy/metabolism/pathology
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Dextran Sulfate/toxicity
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Dimethylhydrazines/toxicity
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Diterpenes/*administration & dosage
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Epoxy Compounds/administration & dosage
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Humans
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Interleukin-6/biosynthesis
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Janus Kinases/metabolism
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Male
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Mice
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Mice, Inbred BALB C
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Mice, Inbred ICR
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Mice, Nude
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Neoplasm Transplantation
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Phenanthrenes/*administration & dosage
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STAT3 Transcription Factor/metabolism
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Signal Transduction/*drug effects
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Tumor Burden/drug effects
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rac1 GTP-Binding Protein/*biosynthesis
9.Complement 3-complement 3a receptor pathway and neurodegenerative diseases
Zhi ZHANG ; Yiwen MEI ; Xin CHEN ; Haifeng SHU ; Yongqin KUANG
Chinese Journal of Neuromedicine 2021;20(10):1059-1063
Neurodegenerative disease is a kind of degenerative diseases of the central nervous system that seriously endanger human health. The complement 3 (C3)-complement 3a receptor (C3aR) pathway is one of the important pathways for classical complement cascade activation. A large number of studies have shown that the C3-C3aR pathway can mediate and regulate the interaction of astrocyte-microglia axis in neurons, resulting in function changes in central nervous system. In addition, studies in recent years have found that the C3-C3aR pathway is closely related to the occurrence and progress of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, stroke, and epilepsy. This article reviews the progress of C3-C3aR pathway and discuss the role of C3-C3aR pathway in several important neurodegenerative diseases, and it provides a new idea fo treatment of these diseases.
10.Detection of the diagnosis about primary hepatocellular carcinoma with the AFP-IgM immune complexes in serum
Jingting JIANG ; Changping WU ; Jun WU ; Xihu QIN ; Dacheng SUN ; Mei JI ; Bin XU ; Haifeng DENG ; Mingyang LU ; Guoping ZHOU ; Min LI ; Xiao ZHENG ; Jian LIU ; Liangrong SHI ; Xu NING ; Nilssonehle PETER
Chinese Journal of Laboratory Medicine 2008;31(7):789-792
Objective To evaluate the significance of AFP-IgM, this is one of new tumor markers, in the diagnosis of primary hepatocellular carcinoma (PHC). Methods The contents of AFP-IgM and AFP in serum of 103 healthy subjects, 74 patients suffered primary hepatic carcinoma, 27 patients affected by liver cirrhosis and 63 patients affected by chronic hepatitis were detected by means of enzyme linked immunosorbent assay and electrochemiluminescence. No-PHC is comprised of liver cirrhosis,chronic hepatitis and health subjects as control group. Results The area under ROC curve of AFP was larger than that of AFP-IgM (0.85 vs 0.72, Z=3.21) and the best cut-off value of AFP-IgM and AFP was 3×105-AU/L and 10 ug/L respectively, which was determined by ROC curve. Under the cut-off value, the sensitivity of AFP- lgM and AFP for PHC were 64.9% and 79.7%, and the specificity were 75.6% and 80.3%, yet their efficacies were similar. However, for early diagnosis of liver cancer (stage Ⅰ and Ⅱ), the area under ROC curve of AFP-IgM was larger than that of AFP (0.91 vs 0.82,Z=1.73). The sensitivity of AFP-IgM andAFP were 94.4% and 72. 2%, and the specificity were 81.9% and 79.9%. The differences of AFP-IgMand AFP for early diagnosis of liver cancer were statistically significant. When both of the test results combined AFP-IgM with AFP are positive, it can be diagnosed as liver cancer. The specificity of combineddetermination of the two forms was 89.1%, and the efficacy was 79. 0%. Conclusions Both of thesensitivity and specificity of the AFP-IgM test were higher than that of the AFP for early diagnosis of livercancer. We also found that combined determination of the two forms significantly increased the specificityand the positive predictive value for the diagnosis of PHC, thus AFP-IgM was of especially significance forearly diagnosis of liver cancer.