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Radiotherapy is one of the most commonly used and effective method to treat malignant tumors in clinical practice. However, there are still some limitations including high radiotherapy doses, harmful side effects on normal tissues, and radiation resistance of tumor cells. Therefore, seeking safe and effective radiotherapy sensitizers to improve radiation sensitivity of tumor cells has been focused for a long time. Histone deacetylase inhibitors (HDACIs), as a kind of epigenetic modifiers, can regulate the sensitivity of tumor cells to ionizing radiation and ultraviolet radiation in addition to the inherent anticancer characteristics. This article reviewed the molecular mechanisms of HDACIs in enhancing radiation sensitivity and by selectively killing tumor cells.
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BACKGROUND/AIMS@#To evaluate cellular immune function in systemic lupus erythematosus (SLE) patients over 60 years old, the association between antinuclear antibody (ANA) titers and the ratio of CD4âº/CD8⺠was analyzed in this study. The distribution of ANAs and extractable nuclear antibodies (ENAs) in a healthy elderly population was also investigated.@*METHODS@#Serum ANA titers were assayed by indirect immunofluorescence (IIF) and the CD4âº/CD8⺠T-cell ratio was determined by flow cytometry in 76 SLE patients and 30 healthy control individuals. IIF of cytoplasm and nuclear and nucleolar staining were performed on samples taken from 286 healthy elderly individuals. ENA levels were determined using a strip enzyme immunoassay among patients that tested positive for ANAs.@*RESULTS@#ANA titers were negative in the 30 control individuals, but were positive in the 76 SLE patients. Based on ANA titers, the SLE patients were stratified to low (≤ 1:320), medium (1:640 to 1:1,280), and high (≥ 1:2,560) titer groups. The average CD4âº/CD8⺠ratio of the SLE group was significantly lower than that of the control group. Among the 286 healthy elderly volunteers, 59 (20.63%) tested positive for ANAs. A homogeneous pattern was present in 47.46% of those 59 patients and a granule pattern in the karyoplasm was present in 33.90%. Furthermore, of the 59 patients, ENAs immunoassay was positive in 18 (30.51%); Sjogren syndrome-related antigen A (SSA)/52 kd and Sjogren syndrome antigen B (SSB)/La were the two major antibodies.@*CONCLUSIONS@#The significantly lower CD4âº/CD8⺠ratio among SLE patients over 60 years old is associated with deregulated immune responses and the development of SLE. A low ANA titer (1:160) is common in healthy elders, emphasizing the importance of considering age when determining if the evaluation of ANA titers is to be included in autoimmune disease diagnosis.
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Objective@#To investigate the association of D-dimer (DD) level on admission with the hospital length of stay (LOS) for the children with community-acquired pneumonia (CAP). @*Methods@#The children diagnosed as CAP hospitalized in the Second Hospital of Tianjin Medical University from December 2016 to December 2017 were studied. The clinical and biological variables were retrieved via electronic medical record system. Binary logistic regression model and Cox proportional risk model were constructed to estimate the assosiation of DD level with hospital length of stay(LOS). @*Results@#A total of 413 children met the inclusion criteria. Their median of LOS was 7 days (range from 3 to 21 days). The median of DD level on admission was 510.87 ng/mL and tertiles were 400 ng/mL and 712.23 ng/mL. In logistic regression model, both the high (＞712.23 ng/mL) and middle (400-712.23 ng/mL) DD level groups were in more risk for hospital stay of more than 7 days in comparison with the low DD level group (＜400). The OR values were 3.335 (95%CI:1.973-5.637, P＜0.001) and 2.015 (95%CI:1.195-3.398, P=0.009) respectively. Consistently, in Cox model high level of DD was associated with low probability of discharge (HR=0.652, 95%CI: 0.486-0.874, P=0.004 ), suggesting more risk of prolonged LOS in contrast to the low DD level group. @*Conclusion@#The DD level on admission should be independently associated with the hospital length of stay, suggesting the consideration of DD levels may be helpful for clinical management of the hospitalized children with CAP.
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Objective To detect the expression levels of insulin-like growth factor 1 (IGF-1) and leptin (LP) in serum of patients with colorectal cancer, and to analyze its clinical significance. Methods Seventy-three patients with colorectal cancer, 37 patients with benign colorectal cancer and 40 healthy subjects were enrolled. Serum IGF-1 and LP levels of all the subjects were measured. A two-year follow-up study of colorectal patients was performed to observe the occurrence of lymph node metastasis. Logistic regression was used to analyze the factors affecting lymph node metastasis in colorectal cancer patients. The area under the receiver operating characteristic curve (AUC) was used to analyze the diagnostic value of IGF-1 and LP for colorectal cancer and recurrence. Results The serum IGF-1 concentration in colorectal cancer was significantly lower than that in the control group (P<0.05), but there was no significant difference between the patients with benign lesions (P>0.05). The serum LP level of colorectal cancer was significantly higher than that of benign lesions and control group (P<0.05). Both IGF-1 and LP have certain diagnostic value for colorectal cancer, and the combined test and efficacy of the two methods are higher than those of the separate test (P<0.05). The two-year recurrence rate of colorectal cancer patients was 16.43％, and the patient age (≥40 years old), TNM grade (Ⅲ～Ⅳgrade), tumor diameter (≥4 cm), vascular infiltration and deep muscle infiltration in the recurrent patients were significantly higher than that in the untreated patients (all P<0.05). In the cancer metastasis patients, the level of serum IGF-1 and LP was significantly lower and higher than that in non-metastatic patients, respectively (all P<0.05). Vascular infiltration, deep myometrial invasion, low IGF-1 levels, and high LP levels were independent predictors of recurrence in colorectal cancer patients, and the combined predictive AUC of the above four factors was 0.956 (95％CI:0.9881～0.990). Conclusions In patients with colorectal cancer, IGF-1 level is low and LP level is high, which is closely related to cancer recurrence.
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Objective To develop a competitive immunoassay for quantitative determination of total immunoglobin E (tIgE) in human serum based on light-initiated chemiluminescent assay (LICA).Methods The LICA-tIgE assay was performed by incubating serum samples or calibrator with anti-human IgE antibody-coated chemiluminescet beads,biotinylated human IgE and streptavidin-coated sensitizer beads.The working conditions of this assay were optimized,analytical performance was detected and the correlation of tIgE results between LICA and Beckman Coulter IMMAGE 800 was evaluated.Results The precision of intra-assay and inter-assay (coefficient of variation) ranged from 5.50％ to 7.73％ and 6.45％ to 9.90％,respectively.The functional sensitivity of this assay was 12.65 IU/mL.The recovery rates measured by adding IgE calibrators to human sera with different IgE concentrations were ranged from 104.15％ to 109.37％.The disturbing rates measured by adding total bilirubin,hemoglobin and triacylglycerol to human sera with different IgE concentrations were ranged from-4.49％ to 8.46％.Also,the tIgE results of 111 patients measured by LICA correlated well with those by Beckman Coulter IMMAGE 800 (r2 =0.959).Conclusion LICA developed in this study for detecting tIgE of human serum showed effective perfomance and could meet the basic requirements of clinical diagnostic reagents.
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Platelets are anuclear cell fragments derived from megakaryocytes, playing a critical role in hemostasis and thrombosis through adhesion,activation,release and aggregation. Antiplatelet therapy represents as the cornerstone of secondary prophylaxis of cardiovascular diseases. Increasing evidences sup-port the emerging role of platelets in innate immunity and inflammation and their involvement in the patho-physiological processes of sepsis, atherosclerosis, autoimmune diseases and tumors. Anti-inflammatory and anti-tumor effects of aspirin and P2Y12 receptor antagonist have been reported in clinical trials, suggesting that antiplatelet therapy may have a broad prospect in application. In this review,we focused on the molecu-lar mechanism of platelet involved in immunity and inflammation. In addition,recent findings of antiplatelet therapy for sepsis,atherosclerosis and tumors were discussed.
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Objective To investigate the hysteromyoma treated with the gonadotropin releasing hormone agonist(GnRH-a)and the impact on immunologic function.Methods 130 cases selected from the patients with hysteromyoma enrolled from January 2016 to December 2016 in hospital have been randomly divided into two groups.The control group has been treated with mifepristone while the study group GnRH-a.Results The sizes of uterus and myoma of both groups have no significant difference before treatment.After treatment, both of them are significantly improved, and those of the study group is significantly smaller than that of the control group(P<0.05).The levels of serum sex hormone and immunologic function of both groups have no significant difference before treatment.They are both improved after treatment, and the study group is significantly better than the control group(P<0.05).Conclusion Applying GnRH-a therapy to the patients with uterine myoma benefits for improving the therapeutic effect, which can improve the serum sex hormone levels and immunologic function.
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Objective To investigate the relationship between serum uric acid level and the severity of pregnancy induced hypertension (PIH) in pregnant women with hypertension.MethodsFrom January 2016 to July 2016 in our hospital for treatment of 100 cases of patients with pregnancy induced hypertension, as PIH group, divided into severe hypertension group (33 cases), moderate PIH group (33 cases) and mild PIH group (34 cases), then select 100 cases of normal pregnant women normal pregnancy group.The serum uric acid levels were measured and the results were analyzed.ResultsThe average serum uric acid levels in PIH group (359.75+89.23) mol/L was significantly higher than the control group (188.24+54.54) mol/L in PIH group, the average level of serum uric acid in severe, moderate and mild degree is decreasing, respectively (449.32+81.11), (352.89+76.41), (288.76+59.58) mol/L, a statistically significant difference between the groups (P<0.05).ConclusionThe detection of serum uric acid level in pregnant women can effectively determine the degree of pregnancy induced hypertension in pregnant.
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Objective To investigate the adhesion levels in uropathogenic Escherichia coli with various degree of drug resistance.Methods One hundred strains of Escherichia coli isolated from urine specimen were collected from patients admitted to 4 Grade A tertiary hospitals in Tianjin during March 2012 to October 2015.Escherichia coli were divided into drug sensitive group and drug resistant group by drug sensitivity tests with 50 strains in each group.The expressions of fimH,fimA,fimB genes of type I fimbriae and papA,papB,papC,papGII genes of P fimbriae were detected by polymerase chain reaction(PCR)and real-time fluorescence quantitative RCR (RT-PCR),respectively.Adhesion ability of type I fimbriae and P fimbriae were tested by yeast cell adhesion test and erythrocyte agglutination test.Chi square test and t(Z) test were used to analyze the data.Results The positive rate of papGII in drug resistant group (42.0%) was significantly higher than that in the drug sensitive group (16.0%)(χ2 =8.208,P 0.05).The expression levels of fimH,fimB and papC genes in the sensitive group were higher than those in the resistant group(Z =3.427,t =5.182 and 8.120,all P <0.05).The adhesion ability of strains carrying type I fimbriae in sensitive group was stronger than that of resistant group (χ2 =5.769,P <0.05).Conclusions The decline in adhesion ability of type I fimbriae in drug resistant E.coli strains is possibly associated with the adaptive cost of bacteria,the transcription and deficiency of other genes encoded by fim and pap gene cluster will also affect the adhesion function of type I pili and type P pili.
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Objective To select valuable biomarkers for diagnosis and predicting outcome of sepsis-related acute respiratory distress syndrome(ARDS) from D-dimmer (DD),yon Willebrand factor (vWF),platelet (PLT),N terminal-pro brain natriuretic peptide (NT-ProBNP),interleukin-6 (IL-6),interleukin-8 (IL-8) and surfactant protein D (SP-D).Methods A total of 48 sepsis accompanied with ARDS patients and 40 sepsis patients were prospectively studied with comparison.The clinical characteristics of all the patients were recorded in detail.The blood samples were obtained within 24 hours of ICU admission.The concentration or activity of the seven biomarkers was quantitatively assayed and the results were recorded.To select the most valuable biomarkers as clinical indices,diagnosis model and death predictive model were constructed by Logistic regression.Results Among the seven candidate biomarkers,SP-D,vWF and IL-8 showed the most value.Their area under the receiver operator characteristic curve (ROC) were 0.758 (P ＜ 0.01),0.783 (P ＜ 0.01) and 0.747 (P ＜ 0.01) respectively,and raised to 0.847 (P ＜ 0.001) when the three biomarkers were combined.IL-8,age greater than or equal to 60 years and APACHE Ⅱ score greater than or equal to 20 were related to ARDS death with 12.138(lnIL-8)(P=0.022),6.157(P=0.040) and7.415(P=0.014) of OR values respectively.Conclusion SP-D,vWF,IL-8 should be valuable for early prediction of sepsis-induced ARDS and the diagnostic accuracy raised through combined utilization.IL-8 may be predictable for prognosis of sepsis related ARDS and the comprehensive evaluation combining clinical indices with IL-8 should be suggested in clinical practice.
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Objective To study drug resistance of carbapenem-resistant Klebsiella pneumonia ( CRKP) in neonates hospitalized in the neonatal unit , and to identify the risk factors for CRKP colonization in neonates .Methods Totally 108 neonates with Klebsiella pneumonia colonization admitted in Department of Neonates , the Second Hospital of Tianjin Medical University during January 2012 and June 2014 were enrolled in the study , including 23 cases with CRKP colonization ( case group ) and 85 cases with carbapenem-sensitive Klebsiella pneumonia (CSKP) colonization (control group).Chi-square test and fisher exact test were used to compare the differences in resistance to 21 antibiotics between CRKP and CSKP . Univariate analysis and Logistic regression analysis were performed to identify the risk factors for CRKP colonization in neonates .Results All of the CRKP strains were resistant to penicillins , cephalosporins and SMZco, and 95.7% and 87.0% of the CRKP strains were resistant to meropenem and imipenem , respectively.All of the CRKP strains were susceptible to amikacin , gentamicin, ciprofloxacin and tetracycline, but were highly resistant to the rest 16 antibiotics compared with CSKP strains (all P<0.05). Univariate analysis showed that 14 factors were associated with CRKP colonization: exposure to cefoxitin (χ2 =20.053, P<0.01), sputum suction (χ2 =15.817, P<0.01), gastrointestinal decompression (χ2 =10.731, P<0.01), nasogastric feeding (χ2 =15.146, P<0.01), invasive procedure (χ2 =22.572, P<0.01), birth weight (χ2 =6.026, P<0.05), frequency of sampling for CRKP/CSKP (χ2 =18.577, P<0.01), hypertension of pregnancy (χ2 =8.698, P<0.01), premature birth (χ2 =4.904, P<0.05), prenatal hospitalization experience (χ2 =8.396, P<0.01), adequacy for gestational age (χ2 =7.295, P<0.05), gestational age (χ2 =7.294, P<0.05), rupture of membranes (χ2 =9.397, P<0.01), length of hospitalization (χ2 =14.649, P<0.01) and admission to the neonatal intensive care unit (NICU) (OR=11.050, P<0.01).Multivariate Logistic regression analysis showed that hypertension of pregnancy (OR=9.718, P<0.01), rupture of membranes ( <24 h) (OR=6.640, P<0.01) and admission to NICU ( OR=4.119, P<0.05) were independent risk factors for CRKP colonization .Conclusions CRKP strains are highly resistant to most antibiotics .Preventing hypertension of pregnancy and rupture of membranes , and monitoring bacterial resistance in NICU may help to reduce the occurrence of CRKP colonization and dissemination .
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BACKGROUND:Silver nanoparticles (AgNPs) show strong antibacterial effect and are not easy to have drug resistance. But the antibacterial mechanisms of AgNPs have not been wel developed. OBJECTIVE:To explain the antibacterial mechanisms of AgNPs. METHODS:We investigated the influence of Ti, TiO2 and TiO2 containing AgNPs onEscherichia coliand Staphylococcus aureus by bacterial inhibition ring test. Escherichia coli was cultured in LB liquid medium with 0, 5, 10 mg/L AgNPs. We measured the absorbance value of bacterial culture. DNA gel electrophoresis was used to study the effect of AgNPs onEscherichia coliDNA. Then we researched the character of apoptosis on Escherichia coli by Annexin V and PI staining, using flow cytometry. RESULTS AND CONCLUSION:The inhibiting effect of Ti and TiO2 onEscherichia coliandStaphylococcus aureus was not obvious. But the inhibition rings of TiO2 containing AgNPs to bacteria appeared. The absorbance value of Escherichia coliculture was reduced whenEscherichia coliwas co-cultured with AgNPs. And this decrease tendency was in direct proportion with AgNPs concentration. AgNPs reduced the amount of DNA of Escherichia coli and this tendency was directly proportional with AgNPs concentration. TheEscherichia coli apoptosis rate induced by AgNPs was increased and this tendency was positively correlated to the AgNPs concentration. These results indicate that AgNPs can induce bacterial apoptosis to influence the growth of bacteria.
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Objective To investigate dynamic changes of plasma D-dimer, C-reactive protein (CRP) and fasting plas?ma glucose (FBG) levels in elderly patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) combined with type 2 diabetes mellitus. Methods AECOPD group (n=65) was used as A group, AECOPD combined with type 2 diabetes mellitus group (n=65) was used as B group. Levels of D-dimer, CRP and FBG were observed and compared between two groups in the first day, the 3rd day, the 7th day and the 14th day after hospital admission. The correlation be?tween D-dimer, CRP and FBG was analyzed. Logistic regression analysis was used to estimate the factors affecting increased plasma levels of D-dimer. Results Levels of D-dimer, CRP and FBG were significantly higher in B group than those of A group in the first day, the 3rd day, the 7th after hospital admission (P<0.01). Values of D-dimer and CRP were declined ob?viously in A group in the 7th day after hospital admission, but in B group they were declined obviously until the 14th day. There was no significant difference in FBG of A group. The level of FBG was significantly decreased in B group. There was a positive correlation between D-dimer, CRP and FBG (P<0.05). Logistic regression analysis showed that CRP, FBG, p(O2) and age were the influence factors for the increased levels of D-dimer. Conclusion In elderly patients with AECOPD com?bined with type 2 diabetes mellitus, we should pay attention to anti-inflammatory and controlling blood sugar, and the dy?namic monitoring levels of D-dimer, which helps to improve the prognosis for patients with AECOPD, and reduce mortality.
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Objective To investigate the diagnostic value of combined copeptin, cardiac troponin I (cTnI) and high sen?sitive cardiac troponin T (hs-TnT) in determination of acute myocardial infarction (AMI). Methods A total of 152 patients with AMI were selected as AMI group and 143 healthy examinees during the same period were selected as control group. (1) The levels of copeptin, cTnI and hs-TnT were detected at 0, 4, 6 and 12 h in two groups. (2) The combined detection of cop/cTnI and cop/hs-TnT were studied. The positive rates of these items were evaluated at different time points of AMI. ( 3) The diagnostic sensitivity, specificity and accuracy of different cardiac biomarkers for AMI were compared. Results (1) There were significant differences in copeptin at 0, 4, 6 and 12 h between two groups (P<0.05). There were no significant differ?ences in cTnI and hs-TnT between two groups. (2) cop/cTnI and cop/hs-TnT combined detection showed better positive rates than those of copeptin, cTnI or hs-TnT detection alone. (3) In addition, the combined detection of cop/cTnI and cop/cTnI improved significantly the diagnostic sensitivity of AMI. Compared to cop/cTnI combination, cop/hs-TnT combination detec?tion showed better diagnostic sensitivity, specificity and accuracy for AMI. Conclusion The combined detection of cop/cTnI and cop/hs-TnT are very helpful for early diagnosis of AMI, which shows a very good diagnostic value in clinical application.
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Objective To examine the detection rate of 30 known virulence factors (VFs) of extraintestinal pathogenic Escherichia coli(ExPEC), and to investigates the epidemiology of ExPEC in elderly nosocomial infection. Methods A to?tal of 140 ExPEC clinical isolates from elderly nosocomial patients in hospitals in Tianjin were investigated. Multiplex PCR was performed to detect the 30 virulence factors among the E.coli strains and the detection rate of virulence factors for Ex?PEC were compared between isolates from different sites of infection.Fifty E. coli strains were shown to carry fimH gene that was amplified and sequenced. These sequences were used besides3 references strains (CFT037、UTI89 and K-12 ) to detect SNPs of fimH gene using DNAMAN Version 6.0.3.93 these 53 fimH sequences were used for genotyping and building dendrogram by MEGA4 software. Results In ExPEC, the following virulence factor genes, fimH, traT, fyuA, iutA and kpsMT II, had a higher detection rate than those of the rest . The following virulence factor genes, kpsMT II, K5, papC, pa?pEF ,papG allele II (Internal), papA, cnf1 (CNF), sfa/focDE and rfc had a a higher detectionrate from non-urine origin sam?ples than those from urine origin samples. fimH SNPs analysis of the 50 clinical isolated samples and 3 references samples showed 60 SNPs at 57 polymorphic sites. The fimH SNPs analysis classified the 53 strains into 25 genotype. The genetic fin?gerprintings of 11 isolates were exactly the same. Conclusion Many kinds of virulence factors can be found in ExPEC of el?derly nosocomial infection. The ExPEC strain isolated from non-urine origin had a stronger pathogenicity than those from urine-origin specimens. fimH SNPs analysis is suitable for molecular epidemiological investigation of ExPEC in hospital.
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Objective To investigate the effect of fimH gene on type 1 fimbriae adhesion of uropathogenic Escherichia coli (UPEC) and the gene variations between type 1 fimbriae adhesion positive and negative bacteria.Methods A total of 171 UPEC strains (not catheter associated) were collected from the Second Hospital of Tianjin Medical University,Tianjin First Center Hospital,and Tianjin Children's Hospital during January 2012 and January 2013.fimH gene was detected by PCR technique,and type 1 fimbriae adhesion was detected by yeast agglutination test.RT-PCR was used to exterminate gene transcript factor impacting on adhesion.Chi-square and Yates' chi-squared tests were performed to comparefimH gene sequences between the adhesion positive and negative bacteria.Results Among 171 UPEC strains,142 (83％) werefimH gene positive,and type 1 fimbriae was expressed in 98 strains (57％).All adhesion positive strains carriedfimH gene.Among 44 strains with positivefimH gene and negative adhesion RT-PCR revealed thatfimH gene did not transcript in 8 strains (18％).The sequencing results showed that gene mutation on the 51 st amino acid site was more prevalent in the adhesion positive group compared with the negative group (x2 =6.64,P =0.010).In adhesion,mutations on the 190th and 219th amino acid sites were observed in 6 strains and 7 strains of negative group,respectively; while not observed in the adhesion positive group (x2 =4.69 and 5.87,P ＜ 0.05).Negative adhesion in other 23 strains was not attributed to single nucleotide polymorphism.Conclusion Adhesion function of type 1 fimbriae mignt be affected by mutation and deletion offimH gene.Three key site mutations may also affect the adhesion function of type 1 fimbriae.Besides fimH gene,there may be other genes that can affect the adhesion function of type 1 fimbriae.
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Objective To study the relationship between Escherichia coli (E.coli.) phylogenetic groups and the antimicrobial resistance in elderly patients with urinary tract infections.Methods 133 Escherichia coli were collected from elderly patients with urinary tract infections in 3 general hospitals in Tianjin.Kirby Bauer method was used to test susceptibility of E.coli.to four antibiotics.Escherichia coli DNA was extracted by boiling method.Phylogenetic groups (A,B1,B2 and D) of the E.coli was isolated by the two-step triplex-PCR.Results In all the strains,levofloxacin resistance rate was the highest (54.1％,72 strains),piperacillin/tazobactam resistance rate was the lowest (15.0％,20 strains) (Z=51.57,P＜0.01).The detection rates of Escherichia coli phylogenetic group A,B1,B2 and D were 24.8％ (33 strains),15.0％ (20 strains),18.0％ (24 strains),42.1％(56 strains) (Z=31.2,P＜0.01).Levofloxacin-sensitive strains were more common in Escherichia coli phylogenetic group B2 strains,and there was a significant difference in the strain number between the resistant and sensitive strains [29.5％ (18/61) vs.8.3％ (6/72),x2 =10.01,P＜0.01].Levofloxacin-resistant strains were more common in Escherichia coli phylogenetic group D strains,and there was a significant difference in the strain number between the resistant and sensitive strains [31.1％ (19/61) and 51.4 ％ (37/72),x2 =5.55,P＜0.05].There was no significant relationship between the Escherichia coli phylogenetic groups and the other three antibiotic resistance (all P＞0.05).Conclusions The detection rates of group D are the highest in the Escherichia coli phylogenetic groups,and it has a relationship with levofloxacin resistant.The antimicrobial resistance can be estimated by phylogenetic analysis in elderly patients with E.coli urinary tract infections.
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Objective To study genotypes,antibiotic resistance and epidemiology of extendedspectrum β-lactamases (ESBL)-producing Shigella isolated in Tianjin,and to discuss the relationship between ESBL-producing Shigella and drug-resistance plasmid.Methods A total of 136 Shigella spp.were isolated from stool specimens of patients with diarrhea who presented mainly with bloody purulent stool from Tianjin Children's Hospital,Tianjin Medical University No.2 Hospital and Tianjin No.1 Central Hospital between May 2009 and September 2010.Suspicious ESBL-producing isolates were screened by K-B disc diffusion method. The conjugation experiment was performed in the confirmed ESBL-producing strains and antibiotic resistance was compared between clinical strains and transconjugants to confirm the plasmid-mediated resistance. The genotypes of these isolates were detected by polymerase chain reaction (PCR) using universal primers for TEM,SHV,CTX-M-1 group,CTX-M-2 group,CTX-M-9 group,respectively.Intergenic consensus PCR (ERIC-PCR) was employed to understand the molecular homology of the ESBL-producing isolates. The data were analyzed by x2 test.ResultsESBL were identified in 14.7％ (20/136) of Shigella isolates,but no AmpC enzyme were detected.Among all the Shigella isolates,16 strains were genotype CTX-M-14,4 were genotype CTX-M-15.The strains with CTX-M ESBL were resistant to multiple antibiotics,while 100％ sensitive to imipenem.The transconjugant test of 18 ESBL-producing isolates were positive,and these conjugations were only resistant to β-lactamases. Conclusions CTX-M type is the common genotype of ESBL-producing Shigella isolates in Tianjin. ESBL-producing is the main cause of multiple resistance to β-lactams.The transmission of CTX-M producing strains is mainly mediated by plasmids.
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Objective To investigate expression of polysaccharides biosynthetic genes in biofilm formation in Pseudomonas aeruginosa PAO1. Methods Real-time RT-PCR was used to quantify mRNA to analyze their mRNA level during planktonic growth and biofilm cells. Results Analysis of the relative ex-pression levels indicated that the level of transcripts of planktonic pslA, algD, pelA was significantly lower than that of biofilms sessile growth in all other form bacteria. The levels of transcripts of pslA, algD, pelA were the highest at the first day of biofilms development. Conclusion From the observations in the present study, transcripts of the pslA, algD, pelA involved biofilm development.
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Objective To establish a new method to measure alkaline phosphatase (ALP) activity using disodium p-acetylphenylphosphate (PAP-PNa2) as substrate.Methods Experimental parameters were set up with continuous-monitoring procedures on a semiautomatic analyzer.Results The wavelength of maximum absorption of PAP was 325 nm,and the Km of ALP was 0.376 mmol/L.The molecular extinction coefficient of PAP at 340 nm was 23 390 L?mol-1?cm-1 and the concentration of citrate buffer was 0.438 mol/L.In the measurement,the optimum pH was 10.4,and the optimum concentration of substrate was 5.0 mmol/L.The delay time was 60 sec and the time keeping the linear reaction was 15 min,and the linear range was 0~1 110 U/L.The measurement was not interfered by the hemoglobin