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ABSTRACT: The purpose of this study was to examine the carbapenemase-encoding resistance genes and analyze homologous of multidrug-resistant Acinetobacter baumannii (MRAB) isolates from nosocomial infections. Seventy-six A. baumannii strains were collected from inpatients and object surface of devices in intensive care units from May 2008 to February 2011. Antibiotic susceptibility testing of 18 antimicrobial agents was performed. The presence of carbapenemase-encoding resistance genes was investigated by polymerase chain reaction. Genotyping and dendrogram analysis of A. baumannii strains from nosocomial infections were performed using the DiversiLab System. All of the 76 clinical A. baumannii isolates were shown multidrug resistance. The bla(OXA-23) gene was identified in the 76 MRAB strains, while bla(OXA-24), bla(OXA-58), VIM, IMP-1, IMP-4, SIM, and blaNDM-1 were absent in all. Twenty-four A. baumannii strains from the samples with nosocomial infections were classified into four unrelated groups and nine patterns. In conclusion, production of bla(OXA-23) in MRAB is one of the molecular mechanisms responsible for carbapenem resistance. The MRAB strains from unrelated groups show different drug resistance, but the homologous strains also have different drug resistance. Homologous analysis can provide scientific evidence for evaluation of epidemic status of nosocomial infection caused by MRAB.
Microbial drug resistance (Larchmont, N.Y.) 07/2012; · 1.99 Impact Factor
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ABSTRACT: To establish a protein fingerprint database of Salmonella paratyphi A by surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS).
Thirty-six clinical bacterial isolates and 96 control bacteria isolates were collected and identified using 16S rDNA sequencing. Bacterial proteins were detected by SELDI-TOF-MS, and all protein fingerprints were analyzed by ProteinChip and Biomarker Wizard software. The analysis results were used to set up a classification tree model by means of BioMarker Patterns software. At the same time, the data were tested by a blinded validation.
In the range of M(r); 3 000-20 000, we obtained 104 protein peaks, of which 90 were of statistical significance (P<0.01). A protein peak with mass-to-charge ratio(M/Z) 10 061.7 was chosen to establish the classification tree model of Salmonella paratyphi A, and the sensitivity and specificity of Salmonella paratyphi A diagnosis was 100% as shown by the blinded validation.
The classification tree model of Salmonella paratyphi A can be not only established using SELDI-TOF-MS technology, but also used for the rapid identification of Salmonella paratyphi A.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 06/2012; 28(6):576-9.
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ABSTRACT: Statins are being widely used for the therapy and prevention of several types of tumors, including human chronic myelogenous leukemia, but the underlying molecular mechanisms still remain unknown. Therefore, inhibition of cell proliferation, apoptosis and involved molecules were investigated in K562 cells after incubation with simvastatin.The results showed that simvastatin diminished K562 cell proliferation and induced apoptosis. At the same time, the level of reactive oxygen species (ROS) and intracellular calcium concentration increased. Furthermore, nitric oxide (NO) content and inducible NO synthase (iNOS) mRNA expression were significantly higher in the simvastatin-treated group than in the corresponding control group. The elevated ROS level and intracellular calcium concentration, enhanced mRNA expression of iNOS and total NO content might be responsible for the apoptotic and anti-proliferative effects of simvastatin in K562 cells.
Pharmacology 10/2009; 84(4):191-5. · 1.79 Impact Factor
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ABSTRACT: Staphylococcus aureus (S. aureus), a vital nosocomial pathogen, is responsible for several diseases. With the increasing isolation rate in clinical specimens, rapid identification of this bacterial species is required. But present identification via conventional methods is time-consuming and lacks accuracy. The purpose of the current study was to evaluate the use of surface enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF MS) for rapid identification of S. aureus. A total of 120 clinical isolates of S. aureus and 153 non-S. aureus species were identified by conventional methods, and the species nature of all staphylococci was further confirmed by 16S rDNA sequencing. All strains observed were analyzed by SELDI-TOF MS. An identification model for S. aureus was developed and validated by an artificial neural network. The model based on 6 protein peaks exhibited a sensitivity of 98.4% and specificity of 98.6%. This strategy has the potential for rapid identification of S. aureus.
Journal of microbiological methods 03/2009; 77(2):202-6. · 2.43 Impact Factor
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ABSTRACT: To explore the apoptotic effect of simvastatin on K562 cells through Caspase-12 activation.
Morphological changes of apoptotic cells were observed by Hoechst33258 fluorescent staining under fluorescent microscope; Apoptosis rate of cells was determined with annexin V-FITC/PI double staining by flow cytometry; Intracellular calcium concentration ([ca2+]i) was measured by Laser Scanning Confocal Microscope(LSCM); The expression levels of GRP78 and Calpain gene mRNA were determined by RT-PCR; The expression levels of Caspase-3,-6,-7,-9,-12 and GRP78 proteins were evaluated by Western blot.
Typical morphological changes of K562 apoptosis cells were observed post 72 hours treated with 10, 20, 30 micromol/L simvastatin. The apoptotic rates of K562 cells were (12.41 +/- 0.32)%, (19.08 +/- 0.26)% and (23.41 +/- 0.36)%, respectively. The fluorescent intensities were 43 +/- 2.9, 54 +/- 2.7 and 64 +/- 2.6, respectively in K562 cells treated with 10, 20, 30 micromol/L simvastatin, which represented the increase of [ca2+]i The expression levels of GRP78 and Calpain gene mRNA were up-regulated. And the cleavage and activation of Caspase-3,-6,-7,-9,-12 and upregulation of GRP78 expression were demonstrated by Western blot detection for the treated cells.
Caspase-12 is a important pathway of apoptosis in cells and participates simvastatin-induced apoptosis in K562 cells.
Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 12/2008; 39(6):900-4.
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ABSTRACT: Statins, a family of 3-hydroxy-3-methylglutaryl CoA (HMG CoA) reductase inhibitors, are being investigated for the therapy and prevention of cancers. Here we aimed to investigate the effects of simvastatin on chronic myelogenous leukemia (CML) cells in vitro and in vivo, and to elucidate the mechanisms.
Cell proliferation and cell cycle were measured after K562 cells were incubated with simvastatin, and differentially expressed genes were determined by oligonucleotide microarray. Changes of 2 genes obtained by oligonucleotide microarray were validated by real-time RT-PCR, and immunohistochemistry was performed to determine expression of proliferating cell nuclear antigen (PCNA). Finally, a xenograft tumor model was constructed to evaluate the effects of simvastatin in vivo.
Simvastatin could inhibit K562 cell proliferation, and the inhibition rate was approximately 30% after treatment with 20 mumol/l simvastatin for 48 h. Cell cycle was arrested in G(1) phase, as shown by flow cytometry results. Fifteen downregulated, 9 upregulated cell cycle-related genes and decreased PCNA protein were observed in the presence of simvastatin. Furthermore, simvastatin exhibited impairment of xenograft tumor growth in nude mice and also blocked cell cycle in G(1) phase.
Simvastatin can inhibit CML cell proliferation in vitro and in vivo, and its mechanisms might be involved in cell cycle regulation.
Chemotherapy 10/2008; 54(6):438-46. · 1.82 Impact Factor
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ABSTRACT: To explore the apoptotic effect of simvastatin on K562 cells through endoplasmic reticulum stress, morphological change of apoptotic cells was observed by Hoechst33258 fluorescent staining under fluorescent microscope. Apoptosis rate of cells was determined with annexinV-FITC/PI double staining by flow cytometry; Intracellular calcium concentration ([Ca2+]i) was measured by laser scanning confocal microscope (LSCM); The expression levels of glucose regulated protein 78 (GRP78) and calpain gene mRNA were determined by RT-PCR; The expression levels of caspase-3, -6, -7, -9, -12, calpain and GRP78 proteins were evaluated by Western blotting. In this study, K562 cells treated with simvastatin for 72 h exhibited typical morphological change of apoptosis cells. After 72 h exposed to 10, 20, 30 micromol x L(-1) simvastatin, the apoptotic rates of K562 cells were 12.41%, 19.08% and 23.41%, respectively. Simvastatin induced the increase of [Ca2+]i in K562 cells, fluorescent intensities were 43, 54, and 64, respectively. The expression levels of GRP78 and calpain gene mRNA were up-regulated. The cleavage and activation of caspase-3, -6, -7, -9, -12 and upregulation of GRP78 expression were determined by Western blotting. These findings suggest that endoplasmic reticulum is an important pathway of apoptosis in cells and participates simvastatin-induced apoptosis in K562 cells. It is implied that simvastatin may be suitable for clinical usage in the treatment of myeloma patients.
Yao xue xue bao = Acta pharmaceutica Sinica 05/2008; 43(4):371-7.
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ABSTRACT: To develop a Fab antibody against platelet GPIIb/IIIa.
A mouse anti-human GPIIb/IIIa monoclonal antibody (mAb) P140 was selected by the indirect immunofluorescence assay (IFA) and platelet aggregation inhibition test. The Fd and light chain genes were cloned from the hybridoma cells secreting the mAb P140. The genes of P140 Fab were inserted into plasmid p3MH to construct recombinant expression plasmid p3MH/P140kappa-Fd. After digestion with the restriction enzyme, the recombinant plasmid was transformed into E.coli XLI-Blue. The expressed product was purified by TALON metal affinity resin. Purified P140 Fab was characterized by SDS-PAGE, ELISA, Western blot and platelet aggregation inhibition test.
SDS-PAGE analysis showed that relative molecular mass (M(r)) of P140 Fab was 47x10(3). The results of ELISA, Western blot and platelet aggragation inhibition test indicated that P140 Fab could specifically bind to platelet and inhibit platelet aggragation in dose-dependent manner. The mean value of IC(50) was 16.85 mg/L.
A soluble anti-platelet GPIIb/IIIa antibody P140 Fab was prepared successfully, which lays the foundation for further clinical application.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 10/2004; 20(5):563-7.
