1.Auto-induction of PcoI-PcoR Quorum-sensing System in Pseudomonas fluorescens 2P24
Xiao-Gang WU ; Cheng-Mei FU ; Li-Qun ZHANG ;
Microbiology 2008;0(07):-
PcoI-PcoR is a quorum-sensing (QS) system influencing the biofilm formation and rhizosphere colonization in Pseudomonas fluorescens 2P24. The expression of the pcoI, a N-acyl-homoserne lactone (AHL) biosynthase gene, is under the regulation of a number of chromosomal factors, such as the GacS-GacA two-component system. In this paper, we investigated the upstream regulators that influence the transcription of pcoI gene using a chromosomal pcoI-lacZ fusion reporter strain PM203. Cosmids containing genomic DNA of the wild-type strain 2P24 were introduced into the reporter strain PM203 (gacA—, pcoI-lacZ) to screen positive transcriptional regulators of pcoI gene. One of them named pP32-24, which contained a 5-kb Pst I functional fragment was selected. Further analysis identified that the pcoI was the gene responsible for the increase of the pcoI-lacZ expression. The expression of pcoI-lacZ reporter was alsoimproved in both PM101 (pcoI-lacZ) and its gacAmutant PM203 after addition of exogenous AHL, indicating that the expression of pcoI is positively regulated by AHL (autoinduction) in strain 2P24. In addition, deletion mutagenesis and complementation experiments demonstrated that the transcriptional regulator PcoR positively controlled the expression of pcoI and the formation of biofilm. These results suggest that, in strain 2P24, the expression of PcoI-PcoR QS system is auto-inducted, and the transcriptional factor PcoR is involved in the regulation of pcoI transcription and the biofilm formation.
2.Analysis of related factors of diabetes foot ulcer amputation
Shimin FU ; Qingfeng CHENG ; Shuhua DENG ; Ying SONG ; Mei MEI ; Zhiping LIU
Chongqing Medicine 2017;46(23):3198-3200
Objective To explore related factors of amputation in patients with diabetes foot ulcer(DFU) and provide the evidence of reducing amputation rate.Methods A total of 307 inpatients with DFU in this hospital from October 2013 to December 2015 were collected and divided into amputation group(n=28) and non-amputation group(n=279).The clinical data and laboratory data were treated with single variable analysis and multivariate Logistic regression analysis.Results Single variable analysis showed that hospitalization time,hyper-sensitive C-reactive(hs-CRP) and fibrinogen(FIB) level were significantly increased in amputation group(P<0.05) when compared with non-amputation group,and the hemoglobin (Hb) level,high-density lipoprotein cholesterol(HDL) and serum albumin (ALB) level in amputation group were markedly lower than in non-amputation group(P<0.05).Amputation rate was significantly different among different Wagner grades (P=0.000).Multivariate Logistic regression analysis showed that hospitalization time,Wagner grade were independent risk factors of amputation in patients with DFU,OR values were 1.024(95%CI:1.009-1.039) and 2.779 (95%CI:1.753-4.404),respectively.While HDL was a protective factor of amputation in patient with DFU (OR=0.161;95%CI:0.036-0.729).Conclusion The higher the rank of Wanger in DFU patients are,the longer hospital stay and the higher amputation risk become.HDL is the protective factor of DFU amputation.
3.Design of method comparison and bias estimation of multi tests on multi instruments
Ling QIU ; Xin-Qi CHENG ; Li LIU ; Fu-Cheng LIU ; Qian LIU ; Zeng-Mei GE ;
Chinese Journal of Laboratory Medicine 2003;0(09):-
Objective To design an experiment for method-comparison and bias estimation of multi tests on multi instruments.Methods According to the procedure described by the NCCLS approved guideline EP9-A and improving the method of sample collection,we took 8 patient mixing samples each day to analyze all comparison tests on 11 auto-chemistry analyzer within following 5 days.The duplicates were assessed within the same run.The coefficient of correlation and average bias% were calculated,and the system errors at medical decided levels were assessed.Results Taking ALT as an example,the coefficients of correlation were between 0.994-1.000,and the average bias% were between-0.460%-4.927%,SE at 40U/L was-1.510-1.834 and SE at 300 U/L was-3.101-9.188.Conclusion In all tests that joined the comparison among the different instruments,28 tests were acceptable,2 tests were acceptable after modifying the coefficients,and AMY and LIP were not acceptable.
4.Nasal Colonization by Opportunistic Pathogens among Health Care Workers:A Survey
Fu QIAO ; Yi XIE ; Weijia YIN ; Mei KANG ; Xiaojing GUO ; Huili CHEN ; Cheng TAN
Chinese Journal of Nosocomiology 2004;0(10):-
OBJECTIVE To investigate the prevalence of nasal colonization among health care workers(HCWs).METHODS Nasal swabs from 93 ICU workers and 98 other clinical workers were cultured and isolated and the tests of antibiotic susceptibility were performed by using paper diffusion method.RESULTS In total,214 isolates of 8 species from 191 health care workers were recovered,of which 187 isolates were coagulase-negative Staphylococcus(CNS)(the carriage rate of 93.71%) and 8 isolates were Staphylococcus aureus(the carriage rate of 4.19%).While the total Gram-negative bacteria carriage rate was 14.14%(27 isolates).The most frequent CNS species were S.epidermidis and S.haemolyticus.The antibiotic susceptibility profiles of S.aureus and CNS differed sharply: all 8 S.aureus strains were resistant to penicillin but were fully susceptible to oxacillin,in contrast,most of CNS were resistant to both penicillin and oxacillin.The carriage rate of CNS(60.2%)and Gram-negative bacteria(26.9%)in HCWs of ICU were higher than other HCWs(P
5.Therapeutic effects of ginsenosides on ischemic kidney with acute renal failure
Xiang-Mei CHEN ; Feng LI ; Qing-Li CHENG ; Ying ZHANG ; Bo FU ;
Chinese Journal of Clinical Pharmacology and Therapeutics 1999;0(04):-
Aim To investigate the therapeutic effects of ginsenosides on ischemic kidneys withacute renal failure. Methods Ischemic and reperfused (I/ R) rat model of acute renalfailure was established by clipping right renal artery of the rat for one hour and thenremoving the left kidney. After reperfusion for 24 hours the serum BUN, Scr, ET-1 andNO were detected and the renal pathologic changes were observed. Results The levelsof serum BUN, Scr were significantly decreased in the treatment group as comparedwith those in the I/R group (P 0. 05); The tubular lesions in the treatment group were obviously ameliorated ascompared with those in the I/ R group (P
6.Relative bioavailablity of cefaclor effervescent tabletsin human volunteers
Fu-Rong QIU ; Jin-Mei JI ; Bo CHENG ; Zhao-Hong ZENG ; Hua SUN ; Guo-Guang MAO ;
Chinese Journal of Clinical Pharmacology and Therapeutics 2000;0(02):-
Aim To study relative bioavailablity of cefaclor effervescent tablets in healthy volunteers. Methods According to the crossover design, A volunteers were each orally given a single does of the 0.75 g cefaclor effervescent tablets and cefaclor capsules with an interval of 5 days between the two formulations.The plasma concentrations of the drug were determined by RP-HPLC.Pharmacokinetic parameters were obtained by ATPK programe,and calculated on the basis of open single compartment model.Results After a single oral dose, the peak levels in plasma averaged Cmax(31.27?5.81)?g?ml-1 and(30.56?5.25) ?g?ml-1 at (0.58?0.12)h and(0.73?0.17)h and AUC0~4(35.48?4.65) ?g?h?ml-1 and (35.89?2.90) ?g?h?ml-1 for tablet and capsule,respectively. Conclusion The result shows that two formulations are bioequivalence.
7.Pharmacokinetics of epirubicin hydrochloride long-circulating thermosensitive liposomes in rat plasma.
Yan WU ; Fu-cheng ZHANG ; Cheng WU ; Xing-guo MEI ; Wan-liang LÜ
Acta Pharmaceutica Sinica 2010;45(3):365-370
To develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of epirubicin hydrochloride (EPI) in rat plasma, daunorubicin hydrochloride was used as internal standard. The plasma samples were deproteinated with methanol, and separation was performed on a reversed-phase CAPCELL PAK C18 column (3.0 mm x 50 mm, 3 microm). The mobile phase contained methanol-0.1% formic acid (80:20). Detection was carried out by multiple reaction monitoring on a HP1200-6410 QQQ LC/MS system. Different preparations of EPI solution, EPI-LIP (EPI-liposome) and EPI-LTSL (EPI-thermosensitive liposome) was administered in rats by i.v with the same dosage (12 mg kg(-1)). The pharmacokinetic model and parameters were fitted and calculated by the DAS ver2.0 software. The calibration curve was linear in the range of 0.01-50 microg mL(-1). The limit of quantification was 0.01 microg mL(-1). RSDs of intra- and interbatch precisions were all less than 11.9%. The average extract recovery was 89.3% and 92.1%, respectively. The pharmacokinetics of EPI in rats with all preparations were fitted to three compartments, which all fast distributed and slowly eliminated. The t1/2 alpha, t1/2 beta, t1/2 gamma, AUC(0-infinity), and MRT(0-infinity) of EPI-LTSL group were 7.5, 1.3, 12.6, 12.9, 3.7 times those of EPI solution group; and 1.6, 1.4, 12.3, 2.9, 2.6 times those of EPI-LIP group. Moreover, the CL of the latter two groups was about 13.4 times of the former EPI-LTSL group. EPI-LTSL can significantly improve AUC and prolong the circulation time of EPI in rat plasma.
Animals
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Antibiotics, Antineoplastic
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administration & dosage
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blood
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pharmacokinetics
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Area Under Curve
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Chromatography, Liquid
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Drug Carriers
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Epirubicin
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administration & dosage
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blood
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pharmacokinetics
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Liposomes
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blood
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pharmacokinetics
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Male
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Rats
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Rats, Sprague-Dawley
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Reproducibility of Results
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Sensitivity and Specificity
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Tandem Mass Spectrometry
8.Effect of ionization on the expression of hypoxia-inducible factor-1alpha and VEGF in hepatocellular carcinoma HepG2 cells under anoxic condition.
Hui-hua CHENG ; Zhi-chao FU ; Feng-mei WANG
Journal of Southern Medical University 2008;28(2):284-287
OBJECTIVETo investigate the effect of ionization on the expression of hypoxia-inducible factor-1alpha and vascular endothelial growth factor (VEGF) in human hepatocellular carcinoma HepG2 cells under anoxic condition, and search for an effective method for improving the radiosensitivity of the tumor cells.
METHODSHepG2 cells were divided into 4 groups, namely the control group, hypoxia group, ionization radiation group, and hypoxia and radiation group, with corresponding treatments. The cell apoptosis was detected by fluorescence microscope, and the cell viability analyzed by MTT assay. The expressions of HIF-1alpha and VEGF mRNAs were detected by RT-PCR.
RESULTSA few apoptotic cells were found in hypoxia group, but significant apoptosis occurred in the radiation group; fewer apoptotic cells were observed in the hypoxia and radiation group than in the hypoxia group. The viable cell fraction increased in the order of the control group>hypoxia group> hypoxia plus radiation group> radiation group (P<0.05), and the expression of HIF-1alpha mRNA increased in the order of hypoxia plus radiation group>hypoxia group>radiation group (P<0.05), and no significant difference was found in the radiation group and control group. The expression of VEGF mRNA increased in the order of hypoxia plus radiation group> hypoxia group>radiation group>control group (P<0.05).
CONCLUSIONThe expression of HIF-1alpha may protect the hepatocellular carcinoma cells from damages by radiation in hypoxic condition, and HIF-1alpha decreases the radiosensitivity of the cells possibly by inducing VEGF expression.
Apoptosis ; Carcinoma, Hepatocellular ; metabolism ; radiotherapy ; Cell Hypoxia ; Cell Survival ; Hep G2 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; radiation effects ; Radiation, Ionizing ; Vascular Endothelial Growth Factor A ; metabolism ; radiation effects
9.Effects of sericine on TGF-beta1/Smad3 signal pathway of diabetic mephropathy rats kidney.
Cheng-Jun SONG ; Xiu-Mei FU ; Jian LI ; Zhi-Hong CHEN
Chinese Journal of Applied Physiology 2011;27(1):102-105
OBJECTIVETo observe the effects of color silk cocoon extraction-sericine on transforming growth factor-beta1 (TGF-beta1) and Smad3 protein expression in kidney of diabetic nephropathy (DN) rats.
METHODS60 male SD rats were randomly divided into 5 groups (n = 12): normal control group, DN model group, sericine treatment group, metformin group and sericine prevention group. The rats in model group, sericine treatment group, metformin group and sericine prevention group were all established DN rats model by intraperitoneally injected streptozotocin (STZ). Blood glucose > or = 16.7 mmol/L was taken as standard to judge if the rats model were successfully established. After the rats model were successfully established, the rats in sericine treatment group were lavaged with sericine (2.4 g/(kg x d), 35 d). The rats in metformin group were lavaged with metformin (55.33 mg/(kg x d), 35 d). The rats in sericine prevention group were lavaged with the same dose sericine for 35 d before injecting STZ. The blood glucose and kidney weight/body weight of rats in each group were respectively detected. Immunohistochemical staining was used to observe the expression of TGF-beta1 and Western blot to detect the expression of Smad3 in kidney.
RESULTSCompared with normal control rats: the blood glucose, kidney weight/body weight, TGF-beta1 and Smad3 expression in kidney of rats in model group increased obviously (P < 0.01). The blood glucose, TGF-beta1 and Smad3 expression in kidney of rats in sericin treatment group, sericin prevention group and metformin group were significantly lower than that of model group (P < 0.01). Moreover, there were no obvious differences between sericin treatment group, sericin prevention group and metformin group (P > 0.05). The kidney weight/body weight of rats in sericin treatment group, sericin prevention group and metformin group were significantly lower than that of model group (P < 0.01). Moreover, the kidney weight/body weight of rats in sericin treatment group and sericin prevention group were obviously lower than that of metformin group (P < 0.05).
CONCLUSIONSericin can inhibit activation of TGF-beta1/Smad3 signal pathway in kidney of DN rats, lighten glomerulosclerosis and renal interstitial fibrosis, so has protective and preventive effects on kidney injury of DN rats. Moreover, the therapeutical and preventive effects of sericin on DN are similar with metformin.
Animals ; Bombyx ; chemistry ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Nephropathies ; drug therapy ; Kidney ; metabolism ; Male ; Materia Medica ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects ; Smad3 Protein ; metabolism ; Transforming Growth Factor beta1 ; metabolism
10.Functional significance of TGF-beta1 signal transduction pathway in oral squamous cell carcinoma.
Xiu-mei WANG ; Cheng-min LIU ; Cheng-ren ZHANG ; Xu-guang XU ; Song-bin FU
Chinese Journal of Oncology 2009;31(1):28-32
OBJECTIVEThe aim of this study was to investigate the expression of transforming growth factor-beta1 (TGF-beta1) and its signaling pathway molecules in oral squamous cell carcinoma (OSCC) and analyze the association between these factors and genesis and metastasis of OSCC.
METHODSThe express of TGF-beta1, TbetaRI, TbetaRII and Smad4, a pivotal downstream molecule of its signaling, in 10 normal oral mucosa tissues and 108 OSCC was detected by SP immunohistochemistry, and thier correlation with genesis and metastasis of OSCC were assessed.
RESULTSThe expressions of TbetaRII and Smad4 were lower in the tumors (34.3%, 38.9%) than those in the normal oral epithelium (80.0%, 100.0%, P < 0.05). The positive expression rates of TGF-beta1 and TbetaRI in the normal oral epithelium and OSCC were not significantly different (P > 0.05). There was an inverse correlation between TGF-beta1, Smad4, TbetaRII, TbetaRI expression and clinical stages (P < 0.01). The expression of TGF-beta1 was related with histological differentiation and tumor localization (P < 0.05). There was a relationship beteween Smad4 expression and histological differentiation and lymph node metastasis (P < 0.05). The expression of TbetaRII in the samples with lymph node metastasis was less than that in the ones without lymph node metastasis (P < 0.01), although there was no association between expression of TbetaRII and lymph node metastasis status.
CONCLUSIONThere is an important relationship between the abnormal TGF-beta1/Smad4 signal pathway and genesis and development of OSCC, while the low expressed Smad4 and TbetaRII may promote the metastasis of OSCC.
Carcinoma, Squamous Cell ; metabolism ; pathology ; Cell Membrane ; metabolism ; Cytoplasm ; metabolism ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; Mouth Neoplasms ; metabolism ; pathology ; Neoplasm Staging ; Protein-Serine-Threonine Kinases ; metabolism ; Receptors, Transforming Growth Factor beta ; metabolism ; Signal Transduction ; Smad4 Protein ; metabolism ; Transforming Growth Factor beta1 ; metabolism