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Sample records for cdta

  1. To Design High CMRR, High Slew rate Instrumentation Amplifier using OTA and CDTA for Biomedical Application

    Directory of Open Access Journals (Sweden)

    Shruti Jain

    2013-09-01

    Full Text Available In today’s world operational amplifier is used in lot of application. The techniques for achieving high slew rate and high CMRR is by cascading the transistors. This paper focus is on understanding of Operational Trans conductance Amplifier (OTA and Current Differencing Trans conductance Amplifier (CDTA with its application as Instrumentation Amplifier (IA for Biomedical application. We have designed Instrumentation Amplifier using CDTA to obtain high common mode rejection ratio (CMRR, high slew rate in comparison with OTA using PSPICE software.

  2. A new functional site W115 in CdtA is critical for Aggregatibacter actinomycetemcomitans cytolethal distending toxin.

    Directory of Open Access Journals (Sweden)

    Lu Li

    Full Text Available Aggregatibacter actinomycetemcomitans, a specific pathogen of localized aggressive periodontitis, produces a cytolethal distending toxin (CDT that arrests eukaryotic cells irreversibly in G0/G1 or G2/M phase of the cell cycle. Although structural studies show that the aromatic patch region of CdtA plays an important role in its biological activity, the functional sites of CdtA have not been firmly established. In this study, site-specific mutagenesis strategy was employed for cdtA point mutations construction so as to examine the contributions of individual amino acids to receptor binding and the biological activity of holotoxin. The binding ability was reduced in CdtA(Y181ABC holotoxin and the biological function of CDT was not weaken in CdtA(Y105ABC, CdtA(Y125ABC, CdtA(F109ABC and CdtA(S106NBC holotoxin suggesting that these sites were not critical to CDT. But the binding activity and cell cycle arrest ability of holotoxin complexes were inhibited in CdtA(W115GBC. And this site did not affect the holotoxin assembly by size exclusion chromatography. Therefore, W115 might be a critical site of CdtA binding ability. These findings suggest that the functional sites of CdtA are not only in the aromatic patch region. W115, the new functional site is critical for receptor binding and cell cycle arrest, which provides potential targets for pharmacological disruption of CDT activity.

  3. Single CDTA-Based Current Mode All-Pass Filter and Its Applications

    Directory of Open Access Journals (Sweden)

    Neeta Pandey

    2011-01-01

    Full Text Available This paper presents a single current difference transconductance amplifier (CDTA based all-pass current mode filter. The proposed configuration makes use of a grounded capacitor which makes it suitable for IC implementation. Its input impedance is low and output impedance is high, hence suitable for cascading. The circuit does not use any matching constraint. The nonideality analysis of the circuit is also given. Two applications, namely, a quadrature oscillator and a high Q band pass filter are developed with the proposed circuit. The functionality of the circuit is verified with SPICE simulation using 0.35  m TSMC CMOS technology parameters.

  4. Demineralization effect of EDTA, EGTA, CDTA and citric acid on root dentin: a comparative study Efeito do EDTA, EGTA, CDTA e ácido cítrico na desmineralização da dentina radicular: estudo comparativo

    Directory of Open Access Journals (Sweden)

    Simone Maria Galvão Sousa

    2005-09-01

    Full Text Available The purpose of this study was to biochemically compare the decalcifying effects of 1% EDTA (pH 7.4, 1% EGTA (pH 7.4, 1% CDTA (pH 7.4, 1% citric acid solutions (pH 1.0 and 7.4 and saline solution (control on root dentin. Forty-eight single-rooted teeth were used in this study. The canals were instrumented by the step-back technique and the roots were randomly divided into six equal experimental groups (n = 8 according to the irrigating agent tested. A total of 30 µL of each solution was pipetted into the root canal and allowed to set undisturbed for 5 minutes. After this time, 15 µL of the solutions were removed from each canal using a Hamilton syringe and placed in a container with 5 mL of deionised water. The µg/mL concentration of calcium ion (Ca2+ extracted from the root canal samples was determined using inductively coupled plasma-atomic emission spectrometry (ICP-AES. Data were analysed by means of the Kruskal-Wallis and Mood's median tests. Citric acid solution at pH 1.0 removed more calcium than at pH 7.4 and than the other chelating solutions tested (p 0.05. These results indicate that citric acid at pH 1.0 is a good alternative as an irrigating solution to remove the smear layer and facilitate the biomechanical procedures.Este trabalho teve como objetivo comparar o efeito desmineralizante do EDTA (pH 7,4, EGTA (pH 7,4, CDTA (pH 7,4, ácido cítrico (pH 1,0 e 7,4 e da solução salina (controle sobre a dentina radicular. Todas as soluções teste foram preparadas na concentração de 1%. Quarenta e oito dentes unirradiculares recém-extraídos foram utilizados neste experimento. Após a instrumentação dos canais radiculares pela técnica "step-back", as raízes foram aleatoriamente divididas em 6 grupos experimentais (n = 8 de acordo com a solução teste utilizada na irrigação final. Em cada grupo, 30 µL da solução teste foram pipetados no interior de cada canal radicular e mantidos estáveis por 5 minutos. Decorrido esse per

  5. Complejos de V(III en solución acuosa con el ácido aminopolicarboxílico CDTA

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    Lino Hernández

    2011-12-01

    Full Text Available Electromotive forces measurements emf (H were employed to study the formation of the Vanadium(III complexes with the aminopolycarboxylic acid trans-1,2-diaminocyclohexane-N,N,N',N'-tetraethanoic (CDTA, H4L in aqueous solution at 25 °C in 3.0mol.L-1 KCl as the ionic media. The analysis of the potentiometric data by means of the least-squares computational program LETAGROP, indicates the formation of significant quantities of the complexes [VHL], [VL]- and [V(OHL]2- together with their respective stability constants of each complex. In addition to the LETAGROP analysis UV-Vis spectrophotometric measurements were done in order to make a qualitative characterization of the complexes formed in aqueous solution

  6. CDT-a entropic theory of quantum gravity

    DEFF Research Database (Denmark)

    Ambjørn, Jan; Görlich, A.; Jurkiewicz, J.;

    2010-01-01

    High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Lattice (hep-lat)......High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Lattice (hep-lat)...

  7. Multiplex PCR method for detection of Clostridium difficile tcdA, tcdB, cdtA, and cdtB and internal in-frame deletion of tcdC.

    Science.gov (United States)

    Persson, Søren; Jensen, Joan N; Olsen, Katharina E P

    2011-12-01

    A multiplex PCR method was developed for the detection of Clostridium difficile toxin genes tcdA, tcdB, ctdA, and cdtB and the major in-frame deletion types (18, 39, and 54 bp) of tcdC. The method has high specificity for PCR ribotype 027 and may identify other C. difficile strains of clinical and epidemiological importance. PMID:21976756

  8. PCR detection of Clostridium difficile triose phosphate isomerase (tpi), toxin A (tcdA), toxin B (tcdB), binary toxin (cdtA, cdtB), and tcdC genes in Vhembe District, South Africa.

    Science.gov (United States)

    Samie, Amidou; Obi, Chikwelu L; Franasiak, Jason; Archbald-Pannone, Laurie; Bessong, Pascal O; Alcantara-Warren, Cirle; Guerrant, Richard L

    2008-04-01

    Specific polymerase chain reaction (PCR) protocols were used to determine the prevalence of toxigenic Clostridium difficile in Vhembe, South Africa. Of 322 stool samples collected, toxigenic C. difficile was found in 23 (7.1%) cases and was significantly associated with diarrhea 20 (11.4%) compared with 3 (2%) in non-diarrheal samples (chi(2) = 426, P = 0.001), intestinal inflammation in 18 (12.1%) compared with 5 (2.9%) in lactoferrin-negative samples (chi(2) = 10.194, P = 0.001), and occult blood in 19 (16%) compared with 4 (2%) in occult blood-negative samples (chi(2) = 22.157, P difficile was more common among individuals > 50 years of age (20%), followed by those between 30 and 39 years of age (19%) and was not associated with HIV infections (chi(2) = 0.289, P = 0.591). Co-infection with other pathogens was common. Multivariate analysis indicated that toxigenic C. difficile was associated with E. bieneusi (P = 0.028), C. parvum (P = 0.007), and Enteroaggregative Escherichia coli (EAEC) (P = 0.007) in diarrheal samples. This study confirms the usefulness of PCR methodologies in the detection of toxigenic C. difficile and suggests that C. difficile is responsible for a small, but underappreciated, proportion of diarrheal cases in the region, and further study is warranted in this area. PMID:18385352

  9. Clostridium difficile binary toxin CDT

    OpenAIRE

    Gerding, Dale N.; Johnson, Stuart; Rupnik, Maja; Aktories, Klaus

    2013-01-01

    Binary toxin (CDT) is frequently observed in Clostridium difficile strains associated with increased severity of C. difficile infection (CDI). CDT belongs to the family of binary ADP-ribosylating toxins consisting of two separate toxin components: CDTa, the enzymatic ADP-ribosyltransferase which modifies actin, and CDTb which binds to host cells and translocates CDTa into the cytosol. CDTb is activated by serine proteases and binds to lipolysis stimulated lipoprotein receptor. ADP-ribosylatio...

  10. Potentiometric studies on stepwise biligand complex formation La(III), Pr(III) or Nd(III)-cyclo hexane-1, 2-diaminotetraacetic acid-hydroxy acid

    International Nuclear Information System (INIS)

    Potentiometric studies of the interaction between 1:1 Ln(III)-CDTA binary chelate (where Ln(III) = La(III), Pr(III) or Nd(III); CDTA = cyclohexane-1,2-diamino-N,N,N',N'-tetracetic acid) with certain hydroxy acids such as glycollic (GA), lactic (LA) and malic (MEA) are described. The nature of the titration curves indicates the stepwise addition of the secondary ligand to the initially formed 1:1, M(III)-CDTA binary complex. Formation constants (Ksub(MAL)) of the resulting biligand chelates have been determined at 30 +- 10 and 35 +- 10C and also thermodynamic functions (viz. ΔG,ΔH and ΔS). The order of stability in terms of metal ions has been found to be La(III) LA > GA. (author)

  11. PCR detection of seven virulence and toxin genes of Campylobacter jejuni and Campylobacter coli isolates from Danish pigs and cattle and cytolethal distending toxin production of the isolates

    DEFF Research Database (Denmark)

    Bang, Dang Duong; Nielsen, E.M.; Scheutz, F.;

    2003-01-01

    Aims: To study the prevalence of seven virulence and toxin genes, and cytolethal distending toxin (CDT) production of Campylobacter jejuni and C. coli isolates from Danish pigs and cattle. Methods and Results: The presence of the cadF, ceuE, virB11, flaA, cdtA, cdtB, cdtC and the cdt gene cluster...

  12. Determination of free Gd3+ as a cyclohexanediaminetetraacetic acid complex by reversed-phase HPLC in ionic gadolinium(III) chelates

    International Nuclear Information System (INIS)

    A reversed-phase HPLC method to analyze free Gd3+ in ionic Gd chelates, Gd(EDTA)-, Gd(DPTA)2-, and Gd(DOTA)-, was developed. In the method, free Gd3+ was complexed with cyclohexanediaminetetraacetic acid (CDTA). Either the complexation was carried out before analysis or CDTA was added to the buffered mobile phase (pH 7.4, Tris-HCI) to complex the free metal in the chelate sample. The complex Gd(CDTA)- was separated from the ionic chelate by high-performance liquid chromatography on a C18 reversed-phase Nucleosil column. A fluorescence detection method with 280-and 310-nm excitation and emission wavelengths, respectively, was used for monitoring. The recoverability, the linearity, and the limit of detection (LOD) of the method were determined. The method was evaluated in terms of thermodynamic and kinetic properties of Gd(CDTA)-, Gd(EDTA)-, Gd(DTPA)2-, and Gd(DOTA)-. The LOD for Gd3+ in the ionic chelates was 39 ng. 27 refs., 4 figs., 3 tabs

  13. Solution stabilities of some mixed ligand complexes of UO22+ and Th4+ with complexones and salicylic acids

    International Nuclear Information System (INIS)

    Formation constants (log Ksub(MAL)sup(MA)) of mixed ligands complexes (MAL), where M = UO22+ or Th4+, A = IMDA, NTA, HEDTA, EDTA, CDTA or DTPA, L = salicylic acid (SA) or 5-sulphosalicylic acid (SSA), have been determined by pH titrations using Irving-Rossotti approach at 25oC and at I =0.2 (mol dm-3, KNO3). The solution stabilities exhibit the sequence (i) Th4+>UO22+, (ii) IMDA>NTA>HEDTA>EDTA>CDTA>DTPA, and (iii) SA>SSA with respect to metal ions, primary ligands and secondary ligands, respectively. The formation constants log Ksub(ML)sup(M) and log Ksub(ML2)sup(ML) have also been determined. The Δlog K values have been found to be negative-increasing numerically with the negative charge on the deprotonated primary ligand (An-). (author). 17 refs., 1 tab

  14. Recombinant Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin Proteins Are Required To Interact To Inhibit Human Cell Cycle Progression and To Stimulate Human Leukocyte Cytokine Synthesis

    OpenAIRE

    Akifusa, Sumio; Poole, Stephen; Lewthwaite, Jo; Henderson, Brian; Nair, Sean P

    2001-01-01

    It has recently been discovered that Actinobacillus actinomycetemcomitans, an oral bacterium causing periodontitis, produces cytolethal distending toxin (CDT), a cell cycle-modulating toxin that has three protein subunits: CdtA, CdtB, and CdtC. In this study, we have cloned and expressed each toxin gene from A. actinomycetemcomitans in Escherichia coli and purified the recombinant Cdt proteins to homogeneity. Individual Cdt proteins failed to induce cell cycle arrest of the human epithelial c...

  15. Modification of Pectin and Hemicellulose Polysaccharides in Relation to Aril Breakdown of Harvested Longan Fruit

    OpenAIRE

    Duoduo Wang; Haiyan Zhang; Fuwang Wu; Taotao Li; Yuxiang Liang; Xuewu Duan

    2013-01-01

    To investigate the modification of cell wall polysaccharides in relation to aril breakdown in harvested longan fruit, three pectin fractions (WSP, water soluble pectin; CSP, CDTA-soluble pectin; ASP, alkali soluble pectin) and one hemicellulose fraction (4 M KOH-SHC, 4 M KOH-soluble hemicellulose) were extracted, and their contents, monosaccharide compositions and molecular weights were evaluated. As aril breakdown intensified, CSP content increased while ASP and 4 M KOH-SHC contents decreas...

  16. Dynamic Duo—The Salmonella Cytolethal Distending Toxin Combines ADP-Ribosyltransferase and Nuclease Activities in a Novel Form of the Cytolethal Distending Toxin

    OpenAIRE

    Rachel Miller; Martin Wiedmann

    2016-01-01

    The cytolethal distending toxin (CDT) is a well characterized bacterial genotoxin encoded by several Gram-negative bacteria, including Salmonella enterica (S. enterica). The CDT produced by Salmonella (S-CDT) differs from the CDT produced by other bacteria, as it utilizes subunits with homology to the pertussis and subtilase toxins, in place of the traditional CdtA and CdtC subunits. Previously, S-CDT was thought to be a unique virulence factor of S. enterica subspecies enterica serotype Typh...

  17. Multiplex Real-Time PCR Method for Simultaneous Identification and Toxigenic Type Characterization of Clostridium difficile From Stool Samples

    OpenAIRE

    Kilic, Abdullah; Alam, Mohammad J; Tisdel, Naradah L.; Shah, Dhara N.; Yapar, Mehmet; Lasco, Todd M.; Garey, Kevin W.

    2015-01-01

    Background The aim of this study was to develop and validate a multiplex real-time PCR assay for simultaneous identification and toxigenic type characterization of Clostridium difficile. Methods The multiplex real-time PCR assay targeted and simultaneously detected triose phosphate isomerase (tpi) and binary toxin (cdtA) genes, and toxin A (tcdA) and B (tcdB) genes in the first and sec tubes, respectively. The results of multiplex real-time PCR were compared to those of the BD GeneOhm Cdiff a...

  18. Chelation in metal intoxication X: influence of different polyaminocarboxylic acids and thiol chelators in the excretion and tissue distribution of 54Mn in rat

    International Nuclear Information System (INIS)

    The influence of some selected polyaminocarboxylic acids and thiol metal binding agents on the urinary and faecal excretions of 54Mn and on the tissue distribution of 54Mn in 54MnC12 administered rats was studied to find a suitable chelating drug for Mn poisoning. HEDTA, CDTA, DTPA and TTHA were highly successful in enhancing the excretion of 54Mn and reducing the tissue levels of 54Mn in rats. The thiol chelators viz. D L-penicillamine, N-acetyl D L-penicillamine and DMS could neither influence the excretion nor the tissue distribution of 54Mn suggesting poor affinity of the metal towards sulfhydryl groups

  19. First isolation of Clostridium difficile PCR-ribotype 027/toxinotype III in Poland.

    Science.gov (United States)

    Pituch, Hanna; Bakker, Dennis; Kuijper, Ed; Obuch-Woszczatyński, Piotr; Wultańska, Dorota; Nurzyńska, Grazyna; Bielec, Anna; Bar-Andziak, Ewa; Łuczak, Mirosław

    2008-01-01

    Of 175 Clostridium difficile strains isolated from patient hospitalized in one academic hospital in Warsaw between 2005-2006, one isolate belonged to PCR-ribotype 027/toxinotype III. This isolate had tcdA, tcdB, binary toxin genes (cdtA and cdtB), a 18-bp deletion and a 1 bp deletion at 117 position in the tcdC gene. Antimicrobial susceptibility tests revealed high level resistance to erythromycin, moxifloxacin and gatifloxacin. This is a first report of the 027 strain of C. difficile in Poland. PMID:19004250

  20. Haemophilus parasuis Encodes Two Functional Cytolethal Distending Toxins: CdtC Contains an Atypical Cholesterol Recognition/Interaction Region

    OpenAIRE

    Mingguang Zhou; Qiang Zhang; Jianping Zhao; Meilin Jin

    2012-01-01

    Haemophilus parasuis is the causative agent of Glässer's disease of pigs, a disease associated with fibrinous polyserositis, polyarthritis and meningitis. We report here H. parasuis encodes two copies of cytolethal distending toxins (Cdts), which these two Cdts showed the uniform toxin activity in vitro. We demonstrate that three Cdt peptides can form an active tripartite holotoxin that exhibits maximum cellular toxicity, and CdtA and CdtB form a more active toxin than CdtB and CdtC. Moreover...

  1. Chelant extraction of heavy metals from contaminated soils using new selective EDTA derivatives.

    Science.gov (United States)

    Zhang, Tao; Liu, Jun-Min; Huang, Xiong-Fei; Xia, Bing; Su, Cheng-Yong; Luo, Guo-Fan; Xu, Yao-Wei; Wu, Ying-Xin; Mao, Zong-Wan; Qiu, Rong-Liang

    2013-11-15

    Soil washing is one of the few permanent treatment alternatives for removing metal contaminants. Ethylenediaminetetraacetic acid (EDTA) and its salts can substantially increase heavy metal removal from contaminated soils and have been extensively studied for soil washing. However, EDTA has a poor utilization ratio due to its low selectivity resulting from the competition between soil major cations and trace metal ions for chelation. The present study evaluated the potential for soil washing using EDTA and three of its derivatives: CDTA (trans-1,2-cyclohexanediaminetetraacetic acid), BDTA (benzyldiaminetetraacetic acid), and PDTA (phenyldiaminetetraacetic acid), which contain a cylcohexane ring, a benzyl group, and a phenyl group, respectively. Titration results showed that PDTA had the highest stability constants for Cu(2+) and Ni(2+) and the highest overall selectivity for trace metals over major cations. Equilibrium batch experiments were conducted to evaluate the efficacy of the EDTA derivatives at extracting Cu(2+), Zn(2+), Ni(2+), Pb(2+), Ca(2+), and Fe(3+) from a contaminated soil. At pH 7.0, PDTA extracted 1.5 times more Cu(2+) than did EDTA, but only 75% as much Ca(2+). Although CDTA was a strong chelator of heavy metal ions, its overall selectivity was lower and comparable to that of EDTA. BDTA was the least effective extractant because its stability constants with heavy metals were low. PDTA is potentially a practical washing agent for soils contaminated with trace metals. PMID:24076482

  2. Development of a new radiolabel (lead-203) and new chelating agents for labeling monoclonal anntibodies for imaging

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.; Mease, R.C.; Meinken, G.E.; Mausner, L.F.; Steplewski, Z.

    1988-01-01

    High liver uptake and slow body clearance presently limit the usefulness of /sup 111/In labeled antibodies for tumor imaging. We have investigated /sup 203/Pb as an alternate and better antibody label. The DTPA and cyclohexyl EDTA (CDTA) conjugates of an anticolon carcinoma antibody, 17-1A were labeled (bicyclic anhydride method) with /sup 203/Pb and /sup 111/In with 60 and 90% labeling yields, respectively. The biodistribution of /sup 203/Pb-17-1A conjugates was compared with the corresponding /sup 111/In-labeled preparations and with /sup 203/Pb-DTPA, /sup 203/Pb-nitrate and nonrelevant antibody controls in normal and human tumor (SW948) xenografted nude mice at 24, and 96 hr. Lead-203-labeled CDTA and DTPA antibody conjugates gave similar in vivo distributions. Even though the lead bound to these chelate-antibody conjugates was more labile in serum and in vivo, compared to indium, it cleared much faster from the liver and the whole body. A new series of chelating agents based on the incorporation of a trans-1,2- diaminocyclohexane moiety into the carbon backbone of polyaminocarboxylates is being synthesized. These are expected to provide stronger complexing ability for lead and produce greater in vivo stability. These ligands are also expected to be superior to EDTA and DTPA for labeling antibodies with other radiometals, including indium. 32 refs., 3 tabs.

  3. Outer membrane vesicle-mediated release of cytolethal distending toxin (CDT from Campylobacter jejuni

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    Uhlin Bernt

    2009-10-01

    Full Text Available Abstract Background Background: Cytolethal distending toxin (CDT is one of the well-characterized virulence factors of Campylobacter jejuni, but it is unknown how CDT becomes surface-exposed or is released from the bacterium to the surrounding environment. Results Our data suggest that CDT is secreted to the bacterial culture supernatant via outer membrane vesicles (OMVs released from the bacteria. All three subunits (the CdtA, CdtB, and CdtC proteins were detected by immunogold labeling and electron microscopy of OMVs. Subcellular fractionation of the bacteria indicated that, apart from the majority of CDT detected in the cytoplasmic compartment, appreciable amounts (20-50% of the cellular pool of CDT proteins were present in the periplasmic compartment. In the bacterial culture supernatant, we found that a majority of the extracellular CDT was tightly associated with the OMVs. Isolated OMVs could exert the cell distending effects typical of CDT on a human intestinal cell line, indicating that CDT is present there in a biologically active form. Conclusion Our results strongly suggest that the release of outer membrane vesicles is functioning as a route of C. jejuni to deliver all the subunits of CDT toxin (CdtA, CdtB, and CdtC to the surrounding environment, including infected host tissue.

  4. Capillary zone electrophoresis of lanthanoid elements after complexation with aminopolycarboxylic acids

    International Nuclear Information System (INIS)

    Capillary zone electrophoresis was applied to the separation of the lanthanoid elements chelated with aminopolycarboxylic acids. Several aminopolycarboxylic reagents (ethylenediaminetetraacetic acid and chemically similar analogues) were varied in an effort to optimize the separation resolution. By varying the pH and concentration of the electrophoretic buffer, it was also possible to manipulate the migration times, efficiency and detectability. Optimum resolution and analysis time (within 12 min) for lanthanoids(III), and also scandium(III) and yttrium(III), was achieved with cyclohexane-1,2-diaminetetraacetic acid (CDTA) and simple electrolytes such as a borate buffer (20 mmol 1-1, pH 11.0) containing 1 mmol 1-1 CDTA. Determination of the lanthanoid complexes was performed by direct UV detection at 214 nm. The calibration graphs were linear (r > 0.99) over at least two orders of magnitude of concentration. The detection limits were at the mid-ppb level and the relative standard deviation was about 2.8% at the mid-calibration range. The method appeared to be feasible to determining the lanthanoid elements in nuclear fuel waste, and may also be recommended for assessing lanthanoid impurities in nuclear field. (author)

  5. Impact of Liquidity on Islamic Banks' Profitability: Evidence from Bangladesh

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    Limon Moinur Rasul

    2013-04-01

    Full Text Available This study examines the impact of liquidity on Islamic banks’ profitability during an 11 years period of 2001 to 2011. To explore and interpret the results the study has taken samples from five Islamic banks that have been in operation in Bangladesh on or before 2001 to till date. In order to construct the liquidity model it used four liquidity variables namely cash & due from banks to total assets (CDTA, cash & due from banks to total deposits (CDDEP, investment to total assets (INVSTA and investment to total deposits (INVSDEP. According to adjusted R squares profitability variables return on assets (ROA, return on equity (ROE and return on deposits (ROD are respectively 17.1%, 4.5% and 24.6% dependent on independent variables. The statistical results suggest that CDTA is found insignificant with all profitability variables, whereas CDDEP is individually significant with all profitability variables except ROE. On the other hand INVSTA and INVSDEP are recognized significant with all three profitability variables. However, when ROE stands for an insignificant relationship with the overall liquidity model, ROA and ROD are identified significantly correlated with the similar model at 1% significant level. Unsurprisingly the findings do strengthen the specification that the impact of liquidity reflects adequate imposition on profitability that the Islamic banks in Bangladesh must abide by.

  6. Characterization of putative cholesterol recognition/interaction amino acid consensus-like motif of Campylobacter jejuni cytolethal distending toxin C.

    Directory of Open Access Journals (Sweden)

    Chih-Ho Lai

    Full Text Available Cytolethal distending toxin (CDT produced by Campylobacter jejuni comprises a heterotrimeric complex formed by CdtA, CdtB, and CdtC. Among these toxin subunits, CdtA and CdtC function as essential proteins that mediate toxin binding to cytoplasmic membranes followed by delivery of CdtB into the nucleus. The binding of CdtA/CdtC to the cell surface is mediated by cholesterol, a major component in lipid rafts. Although the putative cholesterol recognition/interaction amino acid consensus (CRAC domain of CDT has been reported from several bacterial pathogens, the protein regions contributing to CDT binding to cholesterol in C. jejuni remain unclear. Here, we selected a potential CRAC-like region present in the CdtC from C. jejuni for analysis. Molecular modeling showed that the predicted functional domain had the shape of a hydrophobic groove, facilitating cholesterol localization to this domain. Mutation of a tyrosine residue in the CRAC-like region decreased direct binding of CdtC to cholesterol rather than toxin intermolecular interactions and led to impaired CDT intoxication. These results provide a molecular link between C. jejuni CdtC and membrane-lipid rafts through the CRAC-like region, which contributes to toxin recognition and interaction with cholesterol.

  7. Capillary electrophoretic-ultraviolet method for the separation and estimation of zineb, maneb, and ferbam in food samples.

    Science.gov (United States)

    Aulakh, Jatinder Singh; Fekete, Agnes; Malik, Ashok Kumar; Mahajan, Rakesh Kumar; Schmitt-Kopplin, Philippe

    2007-01-01

    A simple and sensitive capillary electrophoretic method with ultraviolet detection has been developed for the separation and determination of ferbam [iron(III)-dimethyldithiocarbamate], maneb [manganese(II)-ethylenebisdithiocarbamate] and zineb [zinc(II)-ethylenebisdithiocarbamate], in borate buffer, after their acidic decomposition and complexation with CDTA (trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid monohydrate), as CDTA-metal complexes of Fe+3, Mn +2, and Zn+2. The determination is dependent on the pH and the nature of the buffer solutions. In this method, the detection limit (signal-to-noise ratio = 3) is 0.0013, 0.0022, and 0.0023 mM for ferbam, maneb, and zineb, respectively. The relative standard deviation for the analysis of 1 mM of each was found to be 1.5 +/- 0.2%. The method was successfully applied for the analysis of red beans and grain samples spiked with ferbam, maneb, and zineb. The applicability of capillary electrophoresis as a useful tool for the simultaneous determination and analysis of ferbam, maneb, and zineb is demonstrated. PMID:17580637

  8. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    International Nuclear Information System (INIS)

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SFLn/Am obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as a Zr

  9. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    Energy Technology Data Exchange (ETDEWEB)

    Sypula, Michal

    2013-07-01

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF{sub Ln/Am} obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as

  10. Use of activable cations as tracers in groundwater hydrology. The case of DTPA-Indium

    International Nuclear Information System (INIS)

    The possibilities of EDTA, CDTA and DTPA metallic complexes use as activable groundwater, tracers are discussed. Indium, which has good nuclear caracteristics for activation analysis and forms complexes of great stability with polyamino carboxylic acid has been for Laboratory and field studies. For corporative studies, Rhodomine B, a fluorescent tracer have been studied together with Indium complexes. In laboratory retention studies have been carried with In-EDTA, Iodine 131 and Rhodomine B, as tracers and bentonite, zeolite 13X and Dowex-1 and Dowex-50 as sorbents. As field studies, drainage evolution flow and resident time distribution of tracers substances in water, have been carried, under artificial rain conditions realized by aspersion. Results from field studies showed good characteristics of Indium Complexes especially in very absorbent medium (argilaceous limon) where their restitution balance were superior to that of Rhodomine B

  11. Performance Analysis of Various Readout Circuits for Monitoring Quality of Water Using Analog Integrated Circuits

    Directory of Open Access Journals (Sweden)

    Pawan Whig

    2012-10-01

    Full Text Available This paper presents a comparative performance study of various analog integrated circuits (namely CC-II, DVCC, CDBA and CDTA used with ISFET for monitoring the quality of water. The use of these active components makes the implementation simple and attractive. The functionality of the circuits are tested using Tanner simulator version 15 for a 70nm CMOS process model also the transfer functions realization for each is done on MATLAB R2011a version, the Very high speed integrated circuit Hardware description language(VHDL code for all scheme is simulated on Xilinx ISE 10.1 and various simulation results are obtained and its is found that DVCC is most stable and consume maximum power whereas CC-II is the least stable and consumes minimum power amongst all the four deployed analog IC’s. Detailed simulation results are included in the paper to give insight into the research work carried out.

  12. Prevalence of virulence genes and cytolethal distending toxin production in Campylobacter jejuni isolates from diarrheal patients in Bangladesh.

    Science.gov (United States)

    Talukder, Kaisar A; Aslam, Mohammad; Islam, Zhahirul; Azmi, Ishrat J; Dutta, Dilip K; Hossain, Sabir; Nur-E-Kamal, Alam; Nair, Gopinath B; Cravioto, Alejandro; Sack, David A; Endtz, Hubert P

    2008-04-01

    From 300 stool samples, 58 Campylobacter strains were isolated by standard microbiological and biochemical methods. Of these, 40 strains were identified as Campylobacter jejuni and 5 as Campylobacter coli. The presence of flaA (100%), cadF (100%), racR (100%), dnaJ (100%), pldA (100%), ciaB (95%), virB11 (0%), ceuE (82.5%), cdtA (97.5%), cdtB (97.5%), cdtC (97.5%), and wlaN (7.5%) genes was detected in C. jejuni by PCR. All C. jejuni strains but one produced cytolethal distending toxin in a HeLa cell assay. PMID:18287317

  13. INL DPAH STAAR 2015 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterman, Dean Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-15

    Research conducted at the INL has demonstrated the synergistic extraction of americium using solvents comprised of bis(o,o-(trifluoromethyl)phenyl) dithiophosphinic acid (DPAH “1”) and trioctylphosphine oxide (TOPO), butyl bis(2,4,4-trimethylpentyl) phosphinate (BuCy272), or dibutyl butylphosphonate (DBBP). One potential drawback of this separations scheme is that soft metals such as silver, cadmium, or palladium and fission products such as zirconium are well extracted by these solvents. Several potential scrubbing reagents were examined. Of the scrubbing reagents studied, cysteine and methione exhibited some ability to scrub soft metals from the loaded solvent. More conventional scrub reagents such as ammonium fluoride or oxalic acid were not effective. Reagents like Bimet and CDTA were not soluble at the acidities used in these studies. Unfortunately, these results indicate that the identification of effective scrubbing reagents for use in a flowsheet based upon the INL DPAH is going to be very difficult.

  14. Determination of synthetic ferric chelates used as fertilizers by liquid chromatography-electrospray/mass spectrometry in agricultural matrices.

    Science.gov (United States)

    Alvarez-Fernández, Ana; Orera, Irene; Abadía, Javier; Abadía, Anunciación

    2007-01-01

    A high-performance liquid chromatography-electrospray ionization/mass spectrometry (time of flight) method has been developed for the simultaneous determination of synthetic Fe(III)-chelates used as fertilizers. Analytes included the seven major Fe(III)-chelates used in agriculture, Fe(III)-EDTA, Fe(III)-DTPA, Fe(III)-HEDTA, Fe(III)-CDTA, Fe(III)-o,oEDDHA, Fe(III)-o,pEDDHA, and Fe(III)-EDDHMA, and the method was validated using isotope labeled (57)Fe(III)-chelates as internal standards. Calibration curves had R values in the range 0.9962-0.9997. Limits of detection and quantification were in the ranges 3-164 and 14-945 pmol, respectively. Analyte concentrations could be determined between the limits of quantification and 25 muM (racemic and meso Fe(III)-o,oEDDHA and Fe(III)-EDDHMA) or 50 muM (Fe(III)-EDTA, Fe(III)-HEDTA, Fe(III)-DTPA, Fe(III)-CDTA and Fe(III)-o,pEDDHA). The average intraday repeatability values were approximately 0.5 and 5% for retention time and peak area, respectively, whereas the interday repeatability values were approximately 0.7 and 8% for retention time and peak area, respectively. The method was validated using four different agricultural matrices, including nutrient solution, irrigation water, soil solution, and plant xylem exudates, spiked with Fe(III)-chelate standards and their stable isotope-labeled corresponding chelates. Analyte recoveries found were in the ranges 92-101% (nutrient solution), 89-102% (irrigation water), 82-100% (soil solution), and 70-111% (plant xylem exudates). Recoveries depended on the analyte, with Fe(III)-EDTA and Fe(III)-DTPA showing the lowest recoveries (average values of 87 and 88%, respectively, for all agricultural matrices used), whereas for other analytes recoveries were between 91 and 101%. The method was also used to determine the real concentrations of Fe(III)-chelates in commercial fertilizers. Furthermore, the method is also capable of resolving two more synthetic Fe(III)-chelates, Fe

  15. First report of Clostridium difficile NAP1/027 in a Mexican hospital.

    Directory of Open Access Journals (Sweden)

    Adrián Camacho-Ortiz

    Full Text Available Clostridium difficile NAP1/ribotype 027 is associated with severe disease and high mortality rates. Our aim was to determine the prevalence of NAP1/ribotype 027 among C. difficile isolates in a tertiary care hospital, and review the main clinical data.We included 106 stool samples from 106 patients. Samples were tested for A&B toxins and were cultured on CCFA agar. The genes tcdA, tcdB, tcdC, cdtA, and cdtB were amplified using PCR in clinical isolates. The tcdA 3'-end deletion analysis, PCR-ribotyping, and pulsed-field gel electrophoresis (PFGE were also performed. Stool samples that were positive for culture were tested by the GeneXpert C. difficile assay. Clinical data were collected.Thirty-six patients tested positive for A&B toxins; and 22 patients had positive culture for C. difficile, 14 of which tested positive for the A&B toxins and all 22 patients tested positive by the GeneXpert C. difficile assay. Risk factors included an average hospital stay of 16.1 days prior to toxin detection, average antibiotic use for 16.2 days, and a median of 3 antibiotics used. The 30-day crude mortality rate was 8.4%. Six of the 22 patients died, and 3 of those deaths were directly attributed to C. difficile infection. The majority of isolates, 90.9% (20/22, carried genes tcdB, tcdA, cdtA, and cdtB; and these strains carried the corresponding downregulator gene tcdC, with an 18-bp deletion. PFGE was performed on 17 isolates, and one main pattern was observed. Analysis of the ribotyping data showed similar results.The above findings represent the clonal spread of C. difficile in our institution, which mainly includes the NAP1/027 strain. This is the first report of C. difficile ribotype NAP1/027 in Mexico.

  16. ICU-Onset Clostridium difficile infection in a university hospital in China: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Xiaohui Wang

    Full Text Available A prospective study was conducted to investigate the incidence, clinical profiles and outcome of ICU-onset CDI in a 50-bed medical ICU at a university hospital in China. Stools were collected from patients who developed ICU-onset diarrhea and was screened for tcdA (toxin A gene and tcdB (toxin B gene by PCR. CDI cases were compared with the ICU-onset non-CDI diarrhea cases for demographics, comorbidities, potential risk factors, major laboratory findings and outcomes. Stool samples from CDI cases were subjected to C. difficile culture and C. difficile isolates were screened for tcdA, tcdB and the binary toxin genes (cdtA and cdtB using multiplex PCR. Strain typing of toxigenic C. difficile isolates was performed using multilocus sequence typing. There were 1,277 patients in the ICU during the study period and 124 (9.7% developed ICU-onset diarrhea, of which 31 patients had CDI. The incidence of ICU-onset CDI was 25.2 cases per 10,000 ICU days. ICU-onset CDI cases had similar features with ICU-onset non-CDI diarrhea cases including the use of proton pump inhibitors and antibacterial agents. The crude mortality rate of ICU-onset CDI was 22.6%, but the attributable mortality rate of ICU-onset CDI was only 3.2% here. Toxigenic C. difficile isolates were recovered from 28 out of the 31 patients with CDI. cdtA and cdtB were found in two strains. Seventeen STs including 11 new STs were identified. All of the 11 new STs were single-locus variants of known STs and the 17 STs identified here could be clustered into 3 clades. The incidence of ICU-onset CDI here is similar to those in Europe and North America, suggesting that CDI is likely to be a common problem in China. Toxigenic C. difficile here belonged to a variety of STs, which may represent a significant clonal expansion rather than the true clonal diversity.

  17. Rapid molecular characterization of Clostridium difficile and assessment of populations of C. difficile in stool specimens.

    Science.gov (United States)

    Wroblewski, Danielle; Hannett, George E; Bopp, Dianna J; Dumyati, Ghinwa K; Halse, Tanya A; Dumas, Nellie B; Musser, Kimberlee A

    2009-07-01

    Our laboratory has developed testing methods that use real-time PCR and pyrosequencing analysis to enable the rapid identification of potential hypervirulent Clostridium difficile strains. We describe a real-time PCR assay that detects four C. difficile genes encoding toxins A (tcdA) and B (tcdB) and the binary toxin genes (cdtA and cdtB), as well as a pyrosequencing assay that detects common deletions in the tcdC gene in less than 4 h. A subset of historical and recent C. difficile isolates (n = 31) was also analyzed by pulsed-field gel electrophoresis to determine the circulating North American pulsed-field (NAP) types that have been isolated in New York State. Thirteen different NAP types were found among the 31 isolates tested, 13 of which were NAP type 1 strains. To further assess the best approach to utilizing our conventional and molecular methods, we studied the populations of C. difficile in patient stool specimens (n = 23). Our results indicated that 13% of individual stool specimens had heterogeneous populations of C. difficile when we compared the molecular characterization results for multiple bacterial isolates (n = 10). Direct molecular analysis of stool specimens gave results that correlated well with the results obtained with cultured stool specimens; the direct molecular analysis was rapid, informative, and less costly than the testing of multiple patient stool isolates. PMID:19403775

  18. Characterization of Clostridium difficile strains isolated from immunosuppressed inpatients in a hospital in Rio de Janeiro, Brazil.

    Science.gov (United States)

    Balassiano, Ilana T; Miranda, Karla R; Boente, Renata F; Pauer, Heidi; Oliveira, Ivi Cristina M; Santos-Filho, Joaquim; Amorim, Efigênia L T; Caniné, Gerson A; Souza, Cristina F; Gomes, Mariza Z R; Ferreira, Eliane O; Brazier, Jon S; Domingues, Regina M C P

    2009-06-01

    The aim of this work was to identify and characterize Clostridium difficile strains from fecal and hospital environmental samples. C. difficile toxins were detected by ELISA in 28.5% of the analyzed samples. Four strains were isolated from immunosuppressed inpatients presenting antibiotic-associated diarrhea. All strains possessed tcdA and tcdB genes and did not present neither the cdtA and cdtB genes nor any significant deletions in the tcdC gene. PFGE and PCR-ribotyping analysis showed that two strains belonged to the same clonal type (ribotype 014) and the other two were grouped into ribotype 106, in spite of presenting a similar, but not identical genetic fingerprint. This report shows that for the first time ribotype 106 was found outside the United Kingdom. All isolates were equally sensitive to metronidazole. The ribotype 014 isolates were highly resistant to clindamycin, while the ribotype 106 isolates were resistant to all fluoroquinolones tested. This work reveals the spread of C. difficile in the hospital unit studied and the presence of three genetically related types, two of them presenting resistance to fluoroquinolones. PMID:19154793

  19. A multiplex, internally controlled real-time PCR assay for detection of toxigenic Clostridium difficile and identification of hypervirulent strain 027/ST-1.

    Science.gov (United States)

    Hoegh, A M; Nielsen, J B; Lester, A; Friis-Møller, A; Schønning, K

    2012-06-01

    The purpose of this study was to validate a multiplex real-time PCR assay capable of detecting toxigenic Clostridium difficile and simultaneously identifying C. difficile ribotype 027/ST-1 by targeting the toxin genes tcdA, tcdB and cdtA in one reaction and in a separate reaction identifying the Δ117 deletion in tcdC associated with ribotype 027/ST-1. PCR was done prospectively on 704 samples routinely submitted to our department and results were compared to results of toxigenic culture. Sequencing of tcdC, multi locus sequence typing (MLST) and PCR ribotyping were done on cultured isolates to confirm the correct identification of the Δ117 deletion in tcdC and C. difficile ribotype 027/ST-1, respectively. The PCR assay displayed a sensitivity, specificity, PPV and NPV of 99.0%, 97.4%, 87.4% and 99.8%, respectively, compared to toxigenic culture on 665 samples evaluable both by PCR and culture. Sequencing of tcdC, ribotyping and MLST of cultured isolates validated the genotyping assay and confirmed the ability of the assay to correctly identify C. difficile ribotype 027/ST-1 in our current epidemiological setting. We describe the use of a combination of two separate PCR assays for sensitive and specific detection of toxigenic C. difficile and presumptive identification of C. difficile 027/ST-1. PMID:21938539

  20. Dynamic Duo-The Salmonella Cytolethal Distending Toxin Combines ADP-Ribosyltransferase and Nuclease Activities in a Novel Form of the Cytolethal Distending Toxin.

    Science.gov (United States)

    Miller, Rachel; Wiedmann, Martin

    2016-01-01

    The cytolethal distending toxin (CDT) is a well characterized bacterial genotoxin encoded by several Gram-negative bacteria, including Salmonella enterica (S. enterica). The CDT produced by Salmonella (S-CDT) differs from the CDT produced by other bacteria, as it utilizes subunits with homology to the pertussis and subtilase toxins, in place of the traditional CdtA and CdtC subunits. Previously, S-CDT was thought to be a unique virulence factor of S. enterica subspecies enterica serotype Typhi, lending to its classification as the "typhoid toxin." Recently, this important virulence factor has been identified and characterized in multiple nontyphoidal Salmonella (NTS) serotypes as well. The significance of S-CDT in salmonellosis with regards to the: (i) distribution of S-CDT encoding genes among NTS serotypes, (ii) contributions to pathogenicity, (iii) regulation of S-CDT expression, and (iv) the public health implication of S-CDT as it relates to disease severity, are reviewed here. PMID:27120620

  1. Synthesis, structure, properties and biological behaviour of the complex [RuIV (H2L) Cl2].2H2O (H4L= 1,2-cyclohexanediamminetetraacetic acid).

    Science.gov (United States)

    Vilaplana, Rosario A; Castiñeiras, A; González-Vílchez, Francisco

    2004-01-01

    The highly water-soluble ruthenium complex [Ru(H(2)L)Cl(2)](2)H(2)o, in which H(4)L is the sequestering ligand trans-l, 2-cyclohexanediamminetetraacetic acid (cdta) has been synthesized, structurally characterized and its properties studied. The X-ray crystallographic study shows that the chelating coordinated ligand is tetradentate while the ruthenium environment is octahedral and slightly distorted, with two chloride anions coordinated in cis positions. Potentiometric, conductimetric and infrared studies confirm the presence of two free carboxylic groups, while electronic and voltammetric studies show that the central ion is Ru(IV). The testing of the cytotoxic activity of this complex against three different human cancer cell lines indicates that [Ru(H(2)L)Cl(2)].2H(2)O shows a remarkable and selective antiproliferative effect against the human uterine neck carcinoma HeLa and the malign adenocarcinoma ADLD, showing only a discrete turnout cell inhibition activity against colon adenocarcinoma HT-29. The important antiprotiferative behaviour of complex 1 against the human adenocarcinoma ADLD, indicates that [Ru(H(2)L)Cl(2)].2H(2)O might be considered as potential antineoplastic compound. PMID:18365080

  2. Dynamic Duo—The Salmonella Cytolethal Distending Toxin Combines ADP-Ribosyltransferase and Nuclease Activities in a Novel Form of the Cytolethal Distending Toxin

    Science.gov (United States)

    Miller, Rachel; Wiedmann, Martin

    2016-01-01

    The cytolethal distending toxin (CDT) is a well characterized bacterial genotoxin encoded by several Gram-negative bacteria, including Salmonella enterica (S. enterica). The CDT produced by Salmonella (S-CDT) differs from the CDT produced by other bacteria, as it utilizes subunits with homology to the pertussis and subtilase toxins, in place of the traditional CdtA and CdtC subunits. Previously, S-CDT was thought to be a unique virulence factor of S. enterica subspecies enterica serotype Typhi, lending to its classification as the “typhoid toxin.” Recently, this important virulence factor has been identified and characterized in multiple nontyphoidal Salmonella (NTS) serotypes as well. The significance of S-CDT in salmonellosis with regards to the: (i) distribution of S-CDT encoding genes among NTS serotypes, (ii) contributions to pathogenicity, (iii) regulation of S-CDT expression, and (iv) the public health implication of S-CDT as it relates to disease severity, are reviewed here. PMID:27120620

  3. Modification of Pectin and Hemicellulose Polysaccharides in Relation to Aril Breakdown of Harvested Longan Fruit

    Directory of Open Access Journals (Sweden)

    Duoduo Wang

    2013-11-01

    Full Text Available To investigate the modification of cell wall polysaccharides in relation to aril breakdown in harvested longan fruit, three pectin fractions (WSP, water soluble pectin; CSP, CDTA-soluble pectin; ASP, alkali soluble pectin and one hemicellulose fraction (4 M KOH-SHC, 4 M KOH-soluble hemicellulose were extracted, and their contents, monosaccharide compositions and molecular weights were evaluated. As aril breakdown intensified, CSP content increased while ASP and 4 M KOH-SHC contents decreased, suggesting the solubilization and conversion of cell wall components. Furthermore, the molar percentage of arabinose (Ara, as the main component of the side-chains, decreased largely in CSP and ASP while that of rhamnose (Rha, as branch point for the attachment of neutral sugar side chains, increased during aril breakdown. Analysis of (Ara + Gal/Rha ratio showed that the depolymerization of CSP and ASP happened predominantly in side-chains formed of Ara residues. For 4 M KOH-SHC, more backbones were depolymerized during aril breakdown. Moreover, it was found that the molecular weights of CSP, ASP and 4 M KOH-SHC polysaccharides tended to decrease as aril breakdown intensified. These results suggest that both enhanced depolymerization and structural modifications of polysaccharides in the CSP, ASP and 4 M KOH-SHC fractions might be responsible for aril breakdown of harvested longan fruit.

  4. Labile synthetic cadmium complexes are not bioavailable to Pseudokirchneriella subcapitata in resin buffered solutions

    International Nuclear Information System (INIS)

    The Free Ion Activity Model (FIAM) predicts that cadmium (Cd) uptake by organisms is identical for solutions with the same free Cd2+ concentration and inorganic composition. Clear exceptions to the FIAM have been shown for Cd uptake by plant roots, periphyton and human cells where labile Cd complexes increase bioavailability and which has been attributed to their role in enhancing Cd diffusion towards the uptake cells. Here, we assessed the role of labile Cd complexes on Cd uptake by algae, for which diffusion limitations should be less pronounced due to their smaller size. Long-term (3 days) Cd uptake by the green algae Pseudokirchneriella subcapitata was measured in resin buffered solutions with or without synthetic ligands and at three Cd2+ ion activities (pCd 8.2–5.7). The free Cd2+ activity was maintained during the test using a metal-selective resin located in the algal bottles. Total dissolved Cd increased up to 35-fold by adding the synthetic ligands at constant Cd2+ activity. In contrast, Cd uptake by algae increased maximally 2.8 fold with increasing concentration of the synthetic ligands and the availability of the complexes were maximally 5.2% relative to Cd2+ for NTA and CDTA complexes. It is concluded that labile Cd complexes do not greatly enhance Cd bioavailability to the unicellular algae and calculations suggest that Cd transport from solution to these small cells is not rate limiting.

  5. Dynamic Duo—The Salmonella Cytolethal Distending Toxin Combines ADP-Ribosyltransferase and Nuclease Activities in a Novel Form of the Cytolethal Distending Toxin

    Directory of Open Access Journals (Sweden)

    Rachel Miller

    2016-04-01

    Full Text Available The cytolethal distending toxin (CDT is a well characterized bacterial genotoxin encoded by several Gram-negative bacteria, including Salmonella enterica (S. enterica. The CDT produced by Salmonella (S-CDT differs from the CDT produced by other bacteria, as it utilizes subunits with homology to the pertussis and subtilase toxins, in place of the traditional CdtA and CdtC subunits. Previously, S-CDT was thought to be a unique virulence factor of S. enterica subspecies enterica serotype Typhi, lending to its classification as the “typhoid toxin.” Recently, this important virulence factor has been identified and characterized in multiple nontyphoidal Salmonella (NTS serotypes as well. The significance of S-CDT in salmonellosis with regards to the: (i distribution of S-CDT encoding genes among NTS serotypes, (ii contributions to pathogenicity, (iii regulation of S-CDT expression, and (iv the public health implication of S-CDT as it relates to disease severity, are reviewed here.

  6. A multiplex, internally controlled real-time PCR assay for detection of toxigenic Clostridium difficile and identification of hypervirulent strain 027/ST-1

    DEFF Research Database (Denmark)

    Hoegh, A M; Nielsen, J B; Lester, A;

    2012-01-01

    The purpose of this study was to validate a multiplex real-time PCR assay capable of detecting toxigenic Clostridium difficile and simultaneously identifying C. difficile ribotype 027/ST-1 by targeting the toxin genes tcdA, tcdB and cdtA in one reaction and in a separate reaction identifying the Δ...... confirm the correct identification of the Δ117 deletion in tcdC and C. difficile ribotype 027/ST-1, respectively. The PCR assay displayed a sensitivity, specificity, PPV and NPV of 99.0%, 97.4%, 87.4% and 99.8%, respectively, compared to toxigenic culture on 665 samples evaluable both by PCR and culture....... Sequencing of tcdC, ribotyping and MLST of cultured isolates validated the genotyping assay and confirmed the ability of the assay to correctly identify C. difficile ribotype 027/ST-1 in our current epidemiological setting. We describe the use of a combination of two separate PCR assays for sensitive and...

  7. Separation of Ra and Th from rock matrices for alpha-spectrometry

    International Nuclear Information System (INIS)

    Dating rocks using 226Ra/230Th isochrons demands radiochemical purification of radium and thorium. This paper presents an improved method. Rocks are solubilised by nitric/hydrofluoric digestion followed by dissolution of insoluble fluorides by boric/nitric acids, and Th is extracted by passing the 8M nitric solution through an anion column in nitrate form. The eluant contains Ra and Ba which are precipitated as sulphate and redissolved in alkaline EDTA. Complete separation of Ba and Ra from sulphate is on an AG 1 x 8 anion column in EDTA form, which was found better than the chloride form. The Ba+Ra is separated on an AG 50W x 8 cation column, and uses CDTA as an eluant for Ba. Careful pH control is essential. Ra elutes later with EDTA or 4M HCl and is precipitated with 125μg barium as sulphate to yield a source suitable for α-spectrometry, or further treated to electroplate the Ra. The yield tracers used are 228Th and 224Ra. Because the sample contains natural 224Ra a correction must be applied, calculated from the amount of natural 232Th in the Th spectrum. Th may be precipitated with 100 μg of ferric iron and gives a spectrometry-quality source, but further purification and electrodeposition was found to be preferable. Variations on the method for the case of analysis of calcium-rich fish otoliths are described. (author) 37 refs.; 3 figs

  8. Application of pressurized fluid extraction to determine cadmium and zinc in plants

    Energy Technology Data Exchange (ETDEWEB)

    Mauri-Aucejo, A.R. [Department of Analytical Chemistry, Universitat de Valencia, Dr. Moliner, 50, 46100 Burjassot, Valencia (Spain)]. E-mail: adela.mauri@uv.es; Arnandis-Chover, T. [Department of Analytical Chemistry, Universitat de Valencia, Dr. Moliner, 50, 46100 Burjassot, Valencia (Spain); Marin-Saez, R. [Department of Analytical Chemistry, Universitat de Valencia, Dr. Moliner, 50, 46100 Burjassot, Valencia (Spain); Llobat-Estelles, M. [Department of Analytical Chemistry, Universitat de Valencia, Dr. Moliner, 50, 46100 Burjassot, Valencia (Spain)

    2007-01-02

    A procedure for the determination of Cd and Zn in plants is proposed. The metals are extracted by pressurized fluid extraction (PFE). Operational conditions are: pressure 1500 psi, temperature 75 deg. C, static time 5 min, flush volume 35%, purge time 60 s, cycles 1 and 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CDTA) 0.01 M at pH 4.5 as extracting solution. Determination of Zn is carried out by flame atomic absorption spectroscopy and depending on the concentration level, Cd content is determined by flame or electrothermal atomic absorption spectroscopy. Certified samples of Virginia tobacco leaves, tea leaves, spinach leaves, poplar leaves, a commercial spinach sample (Spinacea oleracea) and genetically modified Arabidopsis thaliana were analysed by the proposed procedure and also by microwave acid digestion and extraction with HCl-Triton X-100. Confidence intervals for Cd and Zn content obtained by the proposed procedure overlap with the certified values. The other procedures, however, provide inaccurate results for Cd. Recoveries obtained for a confidence level of 95% are 96 {+-} 6% and 95 {+-} 5% for Zn and Cd, respectively. Reproducibility of Zn by the proposed procedure is 7% (n = 8), similar to the other tests and the detection limit is 2.6 {mu}g. For Cd reproducibility is 8.5% (n = 8), better than with HCl-Triton X-100 and similar to acid digestion, the detection limit is 3.5 ng of Cd.

  9. Clostridium difficile infection diagnosis in a paediatric population: comparison of methodologies.

    Science.gov (United States)

    Hart, J; Putsathit, P; Knight, D R; Sammels, L; Riley, T V; Keil, A

    2014-09-01

    The increasing incidence of Clostridium difficile infection (CDI) in paediatric hospitalised populations, combined with the emergence of hypervirulent strains, community-acquired CDI and the need for prompt treatment and infection control, makes the rapid, accurate diagnosis of CDI crucial. We validated commonly used C. difficile diagnostic tests in a paediatric hospital population. From October 2011 to January 2012, 150 consecutive stools were collected from 75 patients at a tertiary paediatric hospital in Perth, Western Australia. Stools were tested using: C. Diff Quik Chek Complete, Illumigene C. difficile, GeneOhm Cdiff, cycloserine cefoxitin fructose agar (CCFA) culture, and cell culture cytotoxin neutralisation assay (CCNA). The reference standard was growth on CCFA or Cdiff Chromagar and PCR on isolates to detect tcdA, tcdB, cdtA, and cdtB. Isolates were PCR ribotyped. The prevalence of CDI was high (43 % of patients). Quik Chek Complete glutamate dehydrogenase (GDH) demonstrated a low negative predictive value (NPV) (93 %). Both CCNA and Quik Chek Complete toxin A/B had poor sensitivity (33 % and 29 % respectively). Molecular methods both had 89 % sensitivity. Algorithms using GDH + Illumigene or GeneOhm reduced the sensitivity to 85 % and 83 % respectively. Ribotype UK014/20 predominated. GDH NPV and GeneOhm and Illumigene sensitivities were reduced compared with adult studies. Quik Chek Complete and CCNA cannot reliably detect toxigenic CDI. A GDH first algorithm showed reduced sensitivity. In a high prevalence paediatric population, molecular methods alone are recommended over the use of GDH algorithm or culture and CCNA, as they demonstrate the best test performance characteristics. PMID:24781004

  10. Characterization of Clostridium difficile isolates from human fecal samples and retail meat from Pennsylvania.

    Science.gov (United States)

    Varshney, Jyotika B; Very, Katherine J; Williams, Jen L; Hegarty, John P; Stewart, David B; Lumadue, Jeanne; Venkitanarayanan, Kumar; Jayarao, Bhushan M

    2014-10-01

    A study was conducted to determine the prevalence of Clostridium difficile and characterize C. difficile isolates from human stool and retail grocery meat samples. Human stool samples (n=317) were obtained from a clinical laboratory and meat samples (n=303) were collected from 8 retail grocery stores from October 2011 through September 2012 from Centre County of Pennsylvania and were examined for C. difficile. C. difficile was isolated from 16.7% of stool samples (n=317) and 6.9%, 11.5%, 14.5%, and 7.8% of beef (n=72), pork (n=78), turkey (n=76), and chicken (n=77) samples, respectively. Six different toxin gene profiles were detected in all human and meat isolates of C. difficile based on the presence or absence of toxin genes tcdA, tcdB, and cdtA and cdtB. Interestingly, 75.6% of the human C. difficile isolates lacked any deletion in the tcdC gene (139-bp), whereas a 39-bp deletion was observed in 61.3% of the C. difficile strains isolated from meat samples. C. difficile from meat samples were more susceptible to clindamycin, moxifloxacin, vancomycin, and metronidazole than C. difficile isolates from human samples. Twenty-five different ribotypes were identified in human and meat C. difficile isolates. In conclusion, significant genotypic and phenotypic differences were observed between human and meat isolates of C. difficile; however, a few C. difficile isolates from meat-in particular ribotypes 078, PA01, PA05, PA16, and PA22 with unique profiles (toxin gene, tcdC gene size and antimicrobial resistance profiles)-were similar to human C. difficile isolates. PMID:25269079

  11. Detection of cross-infection associated to a Brazilian PCR-ribotype of Clostridium difficile in a university hospital in Rio de Janeiro, Brazil.

    Science.gov (United States)

    Balassiano, Ilana T; dos Santos-Filho, Joaquim; Vital-Brazil, Juliana M; Nouér, Simone A; Souza, Claudia R C; Brazier, Jon S; Ferreira, Eliane de O; Domingues, Regina M C P

    2011-02-01

    Clostridium difficile is an important nosocomial enteric pathogen and is the etiological agent of pseudomembranous colites. Recently, the rates of C. difficile infection (CDI) have increased worldwide, but in Brazil few data about this situation and the incidence of clonal types of C. difficile exist. This study aimed to isolate and characterize C. difficile strains from samples obtained of a university hospital (HUCFF) in Rio de Janeiro city, Brazil. CDI was identified by ELISA in 27.1% of HUCFF-in-patients enrolled in the study, and the bacterium was recovered from eight of these fecal samples. All strains, except one, presented tcdA and tcdB genes and presented neither the cdtA and cdtB genes nor any significant deletions in the tcdC gene. All strains were sensitive to metronidazole, vancomycin and moxifloxacin, and resistant to clindamycin, ciprofloxacin and levofloxacin. PCR-ribotyping and PFGE revealed four different clonal types among the isolates. The Brazilian PCR-ribotype 133 accounted for 50% of strains isolated, and PCR-ribotype 233 strains were obtained from 25% of the in-patients. The prevalence and resurgence of the Brazilian PCR-ribotype 133 among the hospitalized patients of HUCFF was established, and cross-infection of different patients associated to the same PCR-ribotypes was detected. Our results emphasize the importance of the diagnosis and control of CDI in order to prevent the emergence of specific clones that can lead to C. difficile-associated outbreaks in Brazilian hospitals. PMID:20623188

  12. Antimicrobial susceptibilities and molecular epidemiology of clinical isolates of Clostridium difficile in taiwan.

    Science.gov (United States)

    Lin, Yi-Chun; Huang, Yu-Tsung; Tsai, Pei-Jane; Lee, Tai-Fen; Lee, Nan-Yao; Liao, Chun-Hsing; Lin, Shyr-Yi; Ko, Wen-Chien; Hsueh, Po-Ren

    2011-04-01

    The antimicrobial susceptibility and virulence factors of Clostridium difficile clinical isolates in Taiwan have not previously been reported. One hundred and thirteen isolates were collected from two major teaching hospitals in Taiwan from 2001 to 2009. Molecular typing was performed by an automated repetitive extragenic palindromic sequence-based PCR (rep-PCR) method (DiversiLab; Bacterial Barcodes, Inc., Athens, GA) and PCR ribotyping. Detection of tcdA, tcdB, cdtA, and cdtB genes was performed using a multiplex PCR assay, and gyrA and gyrB genes of moxifloxacin-nonsusceptible isolates were sequenced. All isolates were susceptible to vancomycin and metronidazole. Ninety-five (84%) isolates were susceptible to moxifloxacin, and the MIC(90) for nemonoxacin was 4 μg/ml. Tigecycline showed favorable antibacterial activity (MIC(90) of 0.06 μg/ml). Thirteen rep-PCR types were identified as a predominant rep-PCR type (type A; non-North American pulsed-field gel electrophoresis type 1 [NAP1], -NAP7, or -NAP8) accounting for 52.2% (59 isolates). Nine of 18 moxifloxacin-nonsusceptible isolates belonged to the rep-PCR type A. The rep-PCR type A and C isolates were distinct from NAP1 (ribotype 027) and NAP8 (ribotype 078) as determined by PCR ribotyping. Seventy-four (65%) isolates harbored tcdA and tcdB, and 15 (13%) harbored cdtAB encoding binary toxin. Eleven isolates had a gene deletion in tcdC, including a 39-bp deletion (9 isolates) and an 18-bp deletion (2). In conclusion, dissemination of a predominant C. difficile clone in southern and northern Taiwan was noted. However, no NAP1 (ribotype 027) isolate could be discovered in this study. PMID:21263053

  13. New multiplex PCR method for the detection of Clostridium difficile toxin A (tcdA) and toxin B (tcdB) and the binary toxin (cdtA/cdtB) genes applied to a Danish strain collection.

    Science.gov (United States)

    Persson, S; Torpdahl, M; Olsen, K E P

    2008-11-01

    Isolates of Clostridium difficile from 159 hospitalized Danish patients (2005) were analysed by a new 5-plex PCR method targeting the toxin genes tcdA, tcdB, cdtA and cdtB, and 16S rDNA as an internal positive control. Additionally, the toxin-regulating gene tcdC was partially sequenced by a new sequencing-based method that revealed genetic changes that may render the gene product inactive. Finally tcdA was analysed using a previously published method for the detection of internal deletions. The 5-plex PCR revealed four different toxin gene profiles: 36 tcdA+, tcdB+, cdtA+/cdtB+; one tcdA+, tcdB-, cdtA+/cdtB+; 98 tcdA+, tcdB+, cdtA-/cdtB-; and 24 non-toxigenic tcdA-, tcdB-, cdtA-/cdtB-. Deletion studies revealed that 26 strains contained a c. 700-bp deletion in tcdA, and 39 strains contained at least one possible inactivation feature in tcdC. The prevalence of the binary toxin genes was 23%. All strains with the tcdA+, tcdB+, cdtA+/cdtB+ profile were investigated by PCR ribotyping, and this revealed eight different ribotypes, none of which were 027. The 5-plex PCR method offers a one-step, rapid and specific screening method for C. difficile toxin genes. This toxin gene profiling, together with deletion studies in tcdA and tcdC, may allow an evaluation of the pathogenic potential of C. difficile. PMID:19040478

  14. Diversity of moxifloxacin resistance during a nosocomial outbreak of a predominantly ribotype ARU 027 Clostridium difficile diarrhea.

    Science.gov (United States)

    Carman, Robert J; Genheimer, Christopher W; Rafii, Fatemeh; Park, Miseon; Hiltonsmith, Megan F; Lyerly, David M

    2009-12-01

    To characterize the extent and diversity of moxifloxacin resistance among Clostridium difficile isolates recovered during a predominantly Anaerobe Reference Unit (ARU) ribotype 027-associated nosocomial outbreak of antibiotic associated diarrhea we measured the susceptibility of 34 field isolates and 6 laboratory strains of C. difficile to moxifloxacin. We ribotyped the isolates as well as assaying them by PCR for the metabolic gene, gdh, and the virulence genes, tcdA, tcdB, tcdC, cdtA and cdtB. All the laboratory isolates, including the historical ARU 027 isolate Cd196, were susceptible to moxifloxacin (or=16 microg/mL (high resistance). We sequenced the quinolone resistance determining regions of gyrA (position 71-460) and gyrB (position 1059-1448) from two susceptible laboratory strains, all five isolates with moderate resistance and two highly resistant isolates. Two highly resistant isolates (Pitt 40, ribotype ARU 027 and Pitt 33, ribotype ARU 001) had the same C245T (Thr(82)Delta Ile) mutation. No other changes were seen. Amplification with primer pairs specific for the C245T mutant gyrA and for the wild type gene respectively confirmed all 16 highly resistant ARU 027 isolates, as well as the highly resistant isolates from other ribotypes, had the C245T mutation and that the mutation was absent from all other isolates. Among the five isolates with moderate resistance we found combinations of mutations within gyrA (T128A, Val(43)Delta Asp and G349T, Ala(117)Delta Ser) and gyrB (G1276A, Arg(426)Delta Asn). The G1396A (Glu(466)Delta Lys) mutation was not associated with increased resistance. PMID:19818865

  15. Fulminant colitis from Clostridium difficile infection, the epidemic strain ribotype 027, in Japan.

    Science.gov (United States)

    Nakamura, Itaru; Yamaguchi, Tetsuo; Tsukimori, Ayaka; Sato, Akihiro; Fukushima, Shinji; Mizuno, Yasutaka; Matsumoto, Tetsuya

    2014-06-01

    In December 2012, a 32-year-old woman with no previous medical history and no previous antibiotic treatment had a fever and diarrhea 2 days after a cesarean section in which cefazolin was used as a prophylactic antimicrobial agent. She was transferred to our hospital 5 days after the cesarean for severe colitis. A rapid test of stool for Clostridium difficile toxin A and B was positive. Although oral vancomycin (0.5-2.0 g/day) and intravenous immunoglobulin (5 g/day) were administered after her transfer, 7 days after admission emergency exploratory surgery was performed because of poor response to therapy. Bowel perforation was noted and a temporary colostomy was created without colectomy. Vancomycin (2.0 g/day) was administered via the colostomy, in addition to a vancomycin enema (2.0 g/day), oral metronidazole (1500 mg/day), and oral vancomycin (2.0 g/day). Three days after the operation, linezolid (1200 mg/day IV) was added. She was treated with antibiotics against C. difficile for a total of 18 days after the operation. The same strain was not isolated from other patients in the same ward. Microbiological analysis of the isolate revealed housekeeping gene (tpi), toxin A gene (tcdA), toxin B gene (tcdB), and binary toxin gene (cdtA and cdtB). DNA sequencing of tcdC revealed a base 117 deletion and contained an 18-bp tcdC deletion. PCR ribotyping showed ribotype 027 patterns. The MIC of moxifloxacin was >32 μg/ml, indicating resistance to fluoroquinolones. This isolate was considered as the epidemic strain. Our case of fulminant colitis is apparently the first case involving the epidemic strain ribotype 027 in Japan. PMID:24726377

  16. Down-regulation of POLYGALACTURONASE1 alters firmness, tensile strength and water loss in apple (Malus x domestica fruit

    Directory of Open Access Journals (Sweden)

    Atkinson Ross G

    2012-08-01

    Full Text Available Abstract Background While there is now a significant body of research correlating apple (Malus x domestica fruit softening with the cell wall hydrolase ENDO-POLYGALACTURONASE1 (PG1, there is currently little knowledge of its physiological effects in planta. This study examined the effect of down regulation of PG1 expression in ‘Royal Gala’ apples, a cultivar that typically has high levels of PG1, and softens during fruit ripening. Results PG1-suppressed ‘Royal Gala’ apples harvested from multiple seasons were firmer than controls after ripening, and intercellular adhesion was higher. Cell wall analyses indicated changes in yield and composition of pectin, and a higher molecular weight distribution of CDTA-soluble pectin. Structural analyses revealed more ruptured cells and free juice in pulled apart sections, suggesting improved integrity of intercellular connections and consequent cell rupture due to failure of the primary cell walls under stress. PG1-suppressed lines also had reduced expansion of cells in the hypodermis of ripe apples, resulting in more densely packed cells in this layer. This change in morphology appears to be linked with reduced transpirational water loss in the fruit. Conclusions These findings confirm PG1’s role in apple fruit softening and suggests that this is achieved in part by reducing cellular adhesion. This is consistent with previous studies carried out in strawberry but not with those performed in tomato. In apple PG1 also appears to influence other fruit texture characters such as juiciness and water loss.

  17. Campylobacter jejuni cell lysates differently target mitochondria and lysosomes on HeLa cells.

    Science.gov (United States)

    Canonico, B; Campana, R; Luchetti, F; Arcangeletti, M; Betti, M; Cesarini, E; Ciacci, C; Vittoria, E; Galli, L; Papa, S; Baffone, W

    2014-08-01

    Campylobacter jejuni is the most common cause of bacterial gastroenteritis in humans. The synthesis of cytolethal distending toxin appears essential in the infection process. In this work we evaluated the sequence of lethal events in HeLa cells exposed to cell lysates of two distinct strains, C. jejuni ATCC 33291 and C. jejuni ISS3. C. jejuni cell lysates (CCLys) were added to HeLa cell monolayers which were analysed to detect DNA content, death features, bcl-2 and p53 status, mitochondria/lysosomes network and finally, CD54 and CD59 alterations, compared to cell lysates of C. jejuni 11168H cdtA mutant. We found mitochondria and lysosomes differently targeted by these bacterial lysates. Death, consistent with apoptosis for C. jejuni ATCC 33291 lysate, occurred in a slow way (>48 h); concomitantly HeLa cells increase their endolysosomal compartment, as a consequence of toxin internalization besides a simultaneous and partial lysosomal destabilization. C. jejuni CCLys induces death in HeLa cells mainly via a caspase-dependent mechanism although a p53 lysosomal pathway (also caspase-independent) seems to appear in addition. In C. jejuni ISS3-treated cells, the p53-mediated oxidative degradation of mitochondrial components seems to be lost, inducing the deepest lysosomal alterations. Furthermore, CD59 considerably decreases, suggesting both a degradation or internalisation pathway. CCLys-treated HeLa cells increase CD54 expression on their surface, because of the action of lysate as its double feature of toxin and bacterial peptide. In conclusion, we revealed that C. jejuni CCLys-treated HeLa cells displayed different features, depending on the particular strain. PMID:24880782

  18. Quality Characteristics and Content of Polysaccharides in Green Tea Fermented by Monascus pilosus.

    Science.gov (United States)

    Kim, Mee-Jung; Kim, Song-Suk; Lee, Sang-Il

    2012-12-01

    In this study, we designed a method to manufacture elevated fermented green tea by using Monascus pilosus, which is known as a functional microbe, and observe its antioxidant abilities and quality characteristics. The water-soluble substance (WSS) content of the fermented tea by M. pilosus (FTM) was lower than that of the non-fermented tea (NFT), although the alcohol-insoluble substance (AIS) content of the FTM was higher than that of NTM. On the other hand, the fractionated distilled water-soluble polysaccharide (DWSP), CDTA-soluble polysaccharides (CDSP), sodium carbonate-soluble polysaccharide (SCSP) and KOH soluble hemicellulose (HC) obtained from the AIS of the FTM was markedly higher than that of NFT. In the antioxidant parameters, the electron donating ability of all fractions, except HC, extracted from FTM was higher than that of NFT, and iron chelating ability of all fractions, except CDSP, extracted from FTM was higher than that of NFT. Whereas the DWSP and SCSP obtained from the FTM were higher than that of NFT, the activity of the HC fraction from both NFT and the FTM could not be detected. In addition, the xanthin oxidase (XO) inhibitory activities of the DWSP, CDSP and the SCSP obtained from the NFT were significantly higher than that of FTM, the aldehyde oxidase (AO) inhibitory activities of the DWSP and SCSP extracted from the FTM were markedly higher than that of the NFT. Meanwhile, the acceptance of NFT and FTM had no significant difference, while the quality of aroma, taste and mouthfeel of the FTM was higher than that of NFT. These results suggest that the post-fermented tea by Monascus microorgan-isms may be responsible for functional components as well as contribute to the improvement of the tea quality. PMID:24471099

  19. Analytical methodology for the study of decontamination factors in mixer-settlers

    International Nuclear Information System (INIS)

    Due to the complexity of the samples, the choice of the analytical methodology to be applied at a radiochemical laboratory, for the evaluation of different separation steps if of a great importance. It is necessary to know the performance of mixer-settlers in two extreme situations: efficiency limit determined by fluid dynamic factors and separation factor determined by physicochemical variables. The element used to determine the efficiency limit was magnesium, due to its low distribution coefficient in tri-n-butyl phosphate (TBP). Zirconium, being one of the principal fission product, is partially extracted and was used to study the influence of chemical conditions. Atomic absorption spectrometry was selected for the determination of micro quantities of magnesium, and complexometry for macro quantities of this element. It was necessary to separate uranium using extraction chromatography with Kel F-TBP columns. Concentration range was 0.1 - 1 mg/L and 7 - 70 g/L respectively. Zirconium was determined by spectrophotometry with xylenol orange. For organic samples, it was necessary to reextract the analyte with fluoride, to evaporate with sulfuric acid and to complex the excess of fluoride with aluminum. Uranium determinations, required for mass balance, were carried out by spectrophotometry and potentiometry depending upon concentration. Because of the presence of zirconium, two methods were developed for uranium determination using liquid-liquid extraction in the presence of complexing agents. In one case, TBP was used as extractant, dibenzoylmethane as chromogenic reagent and EDTA as complexing agent. For very low quantities of uranium, tri-octyl phosphine oxide (TOPO) was the extractant, 2-(2-thiazolylazo)-5-diethylaminophenol (TAAP) the chromogenic reagent, and (1-2-cyclohexylenedinitrilo) tetraacetic acid (CDTA) the complexing agent. (Author)

  20. Phenotypic Characters and Molecular Epidemiology of Campylobacter Jejuni in East China.

    Science.gov (United States)

    Zeng, Dexin; Zhang, Xiaoping; Xue, Feng; Wang, Yanhong; Jiang, Luyan; Jiang, Yuan

    2016-01-01

    In this study, we investigated the distribution, phenotypic and molecular typing characters of Campylobacter jejuni in domestic fowl, and livestock populations in East China, to provide some reference for researches on its molecular epidemiology. A total of 1250 samples were collected from different animal sources, and C. jejuni strains were then isolated and tested for antibiotic sensitivity. Antibiotics-resistance gene and pathogenic genes were detected by polymerase chain reaction. Phylogenic analysis on the C. jejuni strains was performed by multilocus sequence typing (MLST) method. The results showed that 108 out of the 1250 samples (mean 8.64%) were C. jejuni positive. These 108 C. jejuni strains were highly sensitive to antibiotics such as chloramphenicol, amoxicillin, amikacin, cefotaxime, and azithromycin, whereas they were highly resistant to antibiotics such as cefoperazone, cotrimoxazole, cefamandole, sulfamethoxazole, and cefradine. Pathogenicity related gene identification indicated that the mean carrying rate of adhesion related gene cadF and racR, flagellin gene flaA, toxin regulating gene cdtA, cdtB, cdtC, wlaN and virB11, heat shock proteins and transferring proteins related genes dnaJ and ceuE, CiaB and pldA were 92.45%, 38.69%, 73.58%, 71.70%, 52.83%, 96.23%, 12.26%, 1.89%, 0.94%, 65.09%, 39.62% and 9.43%, respectively. A total of 58.82% of these strains contained more than 6 pathogenicity-related genes. MLST typed 58 ST types from the 108 isolated C. jejuni strains, including 24 new types, and ST-21 was the major type, accounting for 39.3% of the total strains. PMID:26565657

  1. Detecção dos genes codificantes da toxina CDT, e pesquisa de fatores que influenciam na produção de hemolisinas em amostras de Campylobacter jejuni de origem avícola

    Directory of Open Access Journals (Sweden)

    Michele M. Trindade

    2015-08-01

    Full Text Available Resumo: Membros termofílicos do gênero Campylobacter são reconhecidos como importantes enteropatógenos para o ser humano e animais. A grande diversidade ecológica destes micro-organismos em diferentes habitats tais como água, animais e alimentos predispõem ao aparecimento de novos fatores de virulência. Este trabalho teve por objetivo detectar os genes codificantes da Toxina Distensiva Citoletal (CDT por meio da técnica de PCR, pesquisar a atividade de hemolisinas e a influência de soluções quelantes e de íons nesta atividade. Foram utilizadas 45 amostras de Campylobacter jejuni de origem avícola para pesquisa de atividade hemolítica, cultivadas em Caldo Triptona de Soja (TSB. Após o crescimento bacteriano, as amostras foram semeadas em Ágar tríptico de soja (TSA contendo 5% de sangue de ovino. Para verificar a influência de agentes quelantes e solução de íons na atividade hemolítica, as amostras de C. jejuni foram cultivadas em TSB contendo separadamente os quelantes EDTA, ácido acético, soluções de íons CaCl2, MgCl2 e FeCl3, em atmosfera de microaerofilia. Quanto à atividade de hemolisina de C. jejuni em placas de TSA - sangue ovino foi possível observar que houve hemólise em 40% das amostras analisadas apenas com caldo TSB. Somente o ácido acético apresentou ação quelante sobre a atividade de hemolisinas em amostras de C. jejuni semeadas em placas de TSA - sangue ovino. Para detecção dos genes cdtA, cdtB e cdtC através da técnica da Reação em Cadeia da Polimerase (PCR foram utilizadas 119 amostras de C. jejuni de origem avícola. Foi possível observar que 37,8% possuíam o perfil de genes cdtABC. Os resultados demonstraram em amostras avícolas a presença de cepas de C. jejuni com potencial virulento, devido à presença dos genes da toxina CDT e potencial hemolítico, que apresentou ação reduzida in vitro com ácido acético.

  2. Chromium speciation in particulate matter samples (Cr(VI)/Cr(III) stability in solutions of leaching agents)

    International Nuclear Information System (INIS)

    Complete text of publication follows. In recent years extensive research was conducted to estimate the bioavailability and toxicity of metals in environmental samples. Substantial health risk could be associated with high particulate matter concentrations in ambient air and with a consumption of contaminated food-stuffs, both accompanied by an occurrence of toxic elements. One of the main causes of exceedance of ambient air quality limit values is traffic, despite emissions reductions. Among other factors, the mobility of an element is usually related to its chemical properties and the toxicity mainly to its oxidation state. Thus, chromium in the hexavalent form, Cr(VI), has long been recognized as a carcinogen and mutagen at low sub-ppm levels. Therefore, in this work, the presence and stability of Cr(VI)/Cr(III) species have been determined in particular matter of urban dust samples (the modified BCR three step sequential extraction procedure). For testing of stability and presence of Cr species a coupled technique connecting on-line HPLC with element-sensitive detector ICP-OES has been used (chromium was detected on line 205,560 nm). The anion exchange column Hamilton PRP-X100 (250 x 4,6 mm, 5 μm, PEEK, (Hamilton, USA)) was used for separation of Cr species. Optimal conditions for the separation were following: mobile phase 50 mmol x l-1 CH3COOH and 10 mmol xl-1 NaClO4 (pH 7.0; flow rate 1.5 ml x min-1), injected 200 μl of the sample, addition of 30 μg x ml-1 CDTA to the sample for a transfer of Cr(III) to anion complex. This combined technique allowed to determine 10 μg of Cr(III) and 13 μg of Cr(VI) in the sample (absolute LOD). It was found out that all three extraction agents used for a fractionation of elements negatively influenced the stability of Cr(VI) species in the solution immediately after their contact with the sample. The quantitatively smallest influence was found for the acetic acid. Probably this is a reason why only species of Cr

  3. Campylobacter spp.isolation, its toxin genes detection and molecular subtyping in diarrhea patients in Shanghai in 2014%上海市2014年腹泻患者弯曲菌分离、毒力基因检测及分子分型结果

    Institute of Scientific and Technical Information of China (English)

    屠丽红; 陈洪友; 陈敏

    2015-01-01

    positive for flaA and cadF, and 93.0%(40/43) of the isolates positive for cdtA and cdtB.And 88.4%(38/43) of the isolates were posi-tive for cdtC.Only 7.0%(3/43) of the isolates were positive for virB11.Using PFGE, 43 Campylobacter jejuni and Campylobacter coli strains were subtyped into 6 clusters. [ Conclusion] The genes of flaA and cadF are ubiquitous on Campylobacter spp.isolates.The distribution of cdt gene cluster in Campylobacter spp.is high, while that of virB11 is low.The PFGE types of Campylobacter spp.isolated in Shanghai are of diversified and complicated features, which causes mainly sporatic diarrhea.