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Sample records for bacterial elongation factor

  1. Loss of elongation factor P disrupts bacterial outer membrane integrity

    DEFF Research Database (Denmark)

    Zou, S Betty; Hersch, Steven J; Roy, Hervé;

    2012-01-01

    Elongation factor P (EF-P) is posttranslationally modified at a conserved lysyl residue by the coordinated action of two enzymes, PoxA and YjeK. We have previously established the importance of this modification in Salmonella stress resistance. Here we report that, like poxA and yjeK mutants......, Salmonella strains lacking EF-P display increased susceptibility to hypoosmotic conditions, antibiotics, and detergents and enhanced resistance to the compound S-nitrosoglutathione. The susceptibility phenotypes are largely explained by the enhanced membrane permeability of the efp mutant, which exhibits...... increased uptake of the hydrophobic dye 1-N-phenylnaphthylamine (NPN). Analysis of the membrane proteomes of wild-type and efp mutant Salmonella strains reveals few changes, including the prominent overexpression of a single porin, KdgM, in the efp mutant outer membrane. Removal of KdgM in the efp mutant...

  2. Bacterial elongation factors EF-Tu, their mutants, chimeric forms, and domains: isolation and purification

    Czech Academy of Sciences Publication Activity Database

    Jonák, Jiří

    2007-01-01

    Roč. 849, 1-2 (2007), s. 141-153. ISSN 1570-0232 R&D Projects: GA AV ČR IAA5052206; GA AV ČR KJB500520503; GA MŠk 2B06065 Institutional research plan: CEZ:AV0Z50520514 Keywords : bacterial elongation factors EF-Tu, , G-domain * recombinant EF-Tus * preparation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.935, year: 2007

  3. Elongation factor P mediates a novel post-transcriptional regulatory pathway critical for bacterial virulence

    DEFF Research Database (Denmark)

    Zou, S Betty; Roy, Hervé; Ibba, Michael;

    2012-01-01

    Bacterial pathogens detect and integrate multiple environmental signals to coordinate appropriate changes in gene expression including the selective expression of virulence factors, changes to metabolism and the activation of stress response systems. Mutations that abolish the ability of the...... lysine residue in the translation factor elongation factor P (EF-P). Strains in which EF-P is unmodified due to the absence of PoxA or YjeK are attenuated for virulence and display highly pleiotropic phenotypes, including hypersusceptibility to a wide range of unrelated antimicrobial compounds. Work from...... pathogen to respond to external cues are typically attenuating. Here we discuss our recent discovery of a novel post-transcriptional regulatory pathway critical for Salmonella virulence and stress resistance. The enzymes PoxA and YjeK coordinately attach a unique beta-amino acid onto a highly conserved...

  4. Crystal structure of the full-length bacterial selenocysteine-specific elongation factor SelB.

    Science.gov (United States)

    Itoh, Yuzuru; Sekine, Shun-Ichi; Yokoyama, Shigeyuki

    2015-10-15

    Selenocysteine (Sec), the 21(st) amino acid in translation, uses its specific tRNA (tRNA(Sec)) to recognize the UGA codon. The Sec-specific elongation factor SelB brings the selenocysteinyl-tRNA(Sec) (Sec-tRNA(Sec)) to the ribosome, dependent on both an in-frame UGA and a Sec-insertion sequence (SECIS) in the mRNA. The bacterial SelB binds mRNA through its C-terminal region, for which crystal structures have been reported. In this study, we determined the crystal structure of the full-length SelB from the bacterium Aquifex aeolicus, in complex with a GTP analog, at 3.2-Å resolution. SelB consists of three EF-Tu-like domains (D1-3), followed by four winged-helix domains (WHD1-4). The spacer region, connecting the N- and C-terminal halves, fixes the position of WHD1 relative to D3. The binding site for the Sec moiety of Sec-tRNA(Sec) is located on the interface between D1 and D2, where a cysteine molecule from the crystallization solution is coordinated by Arg residues, which may mimic Sec binding. The Sec-binding site is smaller and more exposed than the corresponding site of EF-Tu. Complex models of Sec-tRNA(Sec), SECIS RNA, and the 70S ribosome suggest that the unique secondary structure of tRNA(Sec) allows SelB to specifically recognize tRNA(Sec) and characteristically place it at the ribosomal A-site. PMID:26304550

  5. Predicting the pathway involved in post-translational modification of Elongation factor P in a subset of bacterial species

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    de Crécy-Lagard Valérie

    2010-01-01

    Full Text Available Abstract Background The bacterial elongation factor P (EF-P is strictly conserved in bacteria and essential for protein synthesis. It is homologous to the eukaryotic translation initiation factor 5A (eIF5A. A highly conserved eIF5A lysine is modified into an unusual amino acid derived from spermidine, hypusine. Hypusine is absolutely required for eIF5A's role in translation in Saccharomyces cerevisiae. The homologous lysine of EF-P is also modified to a spermidine derivative in Escherichia coli. However, the biosynthesis pathway of this modification in the bacterial EF-P is yet to be elucidated. Presentation of the Hypothesis Here we propose a potential mechanism for the post-translational modification of EF-P. By using comparative genomic methods based on physical clustering and phylogenetic pattern analysis, we identified two protein families of unknown function, encoded by yjeA and yjeK genes in E. coli, as candidates for this missing pathway. Based on the analysis of the structural and biochemical properties of both protein families, we propose two potential mechanisms for the modification of EF-P. Testing the hypothesis This hypothesis could be tested genetically by constructing a bacterial strain with a tagged efp gene. The tag would allow the purification of EF-P by affinity chromatography and the analysis of the purified protein by mass spectrometry. yjeA or yjeK could then be deleted in the efp tagged strain and the EF-P protein purified from each mutant analyzed by mass spectrometry for the presence or the absence of the modification. This hypothesis can also be tested by purifying the different components (YjeK, YjeA and EF-P and reconstituting the pathway in vitro. Implication of the hypothesis The requirement for a fully modified EF-P for protein synthesis in certain bacteria implies the presence of specific post-translational modification mechanism in these organisms. All of the 725 bacterial genomes analyzed, possess an efp gene

  6. An Entamoeba histolytica ADP-ribosyl transferase from the diphtheria toxin family modifies the bacterial elongation factor Tu.

    Science.gov (United States)

    Avila, Eva E; Rodriguez, Orlando I; Marquez, Jaqueline A; Berghuis, Albert M

    2016-06-01

    ADP-ribosyl transferases are enzymes involved in the post-translational modification of proteins; they participate in multiple physiological processes, pathogenesis and host-pathogen interactions. Several reports have characterized the functions of these enzymes in viruses, prokaryotes and higher eukaryotes, but few studies have reported ADP-ribosyl transferases in lower eukaryotes, such as parasites. The locus EHI_155600 from Entamoeba histolytica encodes a hypothetical protein that possesses a domain from the ADP-ribosylation superfamily; this protein belongs to the diphtheria toxin family according to a homology model using poly-ADP-ribosyl polymerase 12 (PARP12 or ARTD12) as a template. The recombinant protein expressed in Escherichia coli exhibited in vitro ADP-ribosylation activity that was dependent on the time and temperature. Unlabeled βNAD(+), but not ADP-ribose, competed in the enzymatic reaction using biotin-βNAD(+) as the ADP-ribose donor. The recombinant enzyme, denominated EhToxin-like, auto-ADP-ribosylated and modified an acceptor from E. coli that was identified by MS/MS as the elongation factor Tu (EF-Tu). To the best of our knowledge, this is the first report to identify an ADP-ribosyl transferase from the diphtheria toxin family in a protozoan parasite. The known toxins from this family (i.e., the diphtheria toxin, the Pseudomonas aeruginosa toxin Exo-A, and Cholix from Vibrio cholerae) modify eukaryotic elongation factor two (eEF-2), whereas the amoeba EhToxin-like modified EF-Tu, which is another elongation factor involved in protein synthesis in bacteria and mitochondria. PMID:27234208

  7. A novel receptor – ligand pathway for entry of Francisella tularensis in monocyte-like THP-1 cells: interaction between surface nucleolin and bacterial elongation factor Tu

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    Charbit Alain

    2008-09-01

    Full Text Available Abstract Background Francisella tularensis, the causative agent of tularemia, is one of the most infectious human bacterial pathogens. It is phagocytosed by immune cells, such as monocytes and macrophages. The precise mechanisms that initiate bacterial uptake have not yet been elucidated. Participation of C3, CR3, class A scavenger receptors and mannose receptor in bacterial uptake have been already reported. However, contribution of an additional, as-yet-unidentified receptor for F. tularensis internalization has been suggested. Results We show here that cell-surface expressed nucleolin is a receptor for Francisella tularensis Live Vaccine Strain (LVS and promotes LVS binding and infection of human monocyte-like THP-1 cells. The HB-19 pseudopeptide that binds specifically carboxy-terminal RGG domain of nucleolin inhibits LVS binding and infection of monocyte-like THP-1 cells. In a pull-down assay, elongation factor Tu (EF-Tu, a GTP-binding protein involved in protein translation, usually found in cytoplasm, was recovered among LVS bacterial membrane proteins bound on RGG domain of nucleolin. A specific polyclonal murine antibody was raised against recombinant LVS EF-Tu. By fluorescence and electron microscopy experiments, we found that a fraction of EF-Tu could be detected at the bacterial surface. Anti-EF-Tu antibodies reduced LVS binding to monocyte-like THP-1 cells and impaired infection, even in absence of complement and complement receptors. Interaction between EF-Tu and nucleolin was illustrated by two different pull-down assays using recombinant EF-Tu proteins and either RGG domain of nucleolin or cell solubilized nucleolin. Discussion Altogether, our results demonstrate that the interaction between surface nucleolin and its bacterial ligand EF-Tu plays an important role in Francisella tularensis adhesion and entry process and may therefore facilitate invasion of host tissues. Since phagosomal escape and intra-cytosolic multiplication of

  8. (R)-β-lysine-modified elongation factor P functions in translation elongation

    DEFF Research Database (Denmark)

    Bullwinkle, Tammy J; Zou, S Betty; Rajkovic, Andrei;

    2013-01-01

    also recently been described. The roles of modified and unmodified EF-P during different steps in translation, and how this correlates to its physiological role in the cell, have recently been linked to the synthesis of polyproline stretches in proteins. Polysome analysis indicated that EF-P functions......Post-translational modification of bacterial elongation factor P (EF-P) with (R)-β-lysine at a conserved lysine residue activates the protein in vivo and increases puromycin reactivity of the ribosome in vitro. The additional hydroxylation of EF-P at the same lysine residue by the YfcM protein has...... in translation elongation, rather than initiation as proposed previously. This was further supported by the inability of EF-P to enhance the rate of formation of fMet-Lys or fMet-Phe, indicating that the role of EF-P is not to specifically stimulate formation of the first peptide bond. Investigation...

  9. One-step purification of E. coli elongation factor Tu

    DEFF Research Database (Denmark)

    Knudsen, Charlotte Rohde; Clark, Brian F. C.; Degn, B;

    1993-01-01

    The tuf A gene, encoding the E. coli elongation factor Tu, was cloned in the pGEX gene fusion system. Upon expression EF-Tu is fused to glutathione-S-transferase serving as a purification handle with affinity for glutathione immobilised on agarose. This allows purification of EF-Tu in a one...

  10. Divergent protein motifs direct elongation factor P-mediated translational regulation in Salmonella enterica and Escherichia coli

    DEFF Research Database (Denmark)

    Hersch, Steven J; Wang, Mengchi; Zou, S Betty;

    2013-01-01

    Elongation factor P (EF-P) is a universally conserved bacterial translation factor homologous to eukaryotic/archaeal initiation factor 5A. In Salmonella, deletion of the efp gene results in pleiotropic phenotypes, including increased susceptibility to numerous cellular stressors. Only a limited n...

  11. The primary structure of elongation factor EF-1 alpha from the brine shrimp Artemia.

    OpenAIRE

    Hemert, F.J. van; Amons, R; Pluijms, W J; van Ormondt, H; Möller, W.

    1984-01-01

    cDNA as well as amino acid sequencing has revealed the complete primary structure of elongation factor EF-1 alpha from the brine shrimp Artemia. A comparison with the published sequences of bacterial EF-Tu, mitochondrial EF-Tu and chloroplastic EF-Tu shows that distinct areas of these polypeptide chains are conserved in evolution. The evolutionary distance between prokaryotic and eukaryotic types of EF-Tu is larger than among bacterial and organellar EF- Tus . A number of regions present in b...

  12. The life and death of translation elongation factor 2

    DEFF Research Database (Denmark)

    Jørgensen, Rene; Merrill, A.R.; Andersen, Gregers Rom

    2006-01-01

    The eukaryotic elongation factor 2 (eEF2) occupies an essential role in protein synthesis where it catalyses the translocation of the two tRNAs and the mRNA after peptidyl transfer on the 80S ribosome. Recent crystal structures of eEF2 and the cryo-EM reconstruction of its 80S complex now provide...... diphthamide residue, which is ADP-ribosylated by diphtheria toxin from Corynebacterium diphtheriae and exotoxin A from Pseudomonas aeruginosa....

  13. Structure of the GTP Form of Elongation Factor 4 (EF4) Bound to the Ribosome.

    Science.gov (United States)

    Kumar, Veerendra; Ero, Rya; Ahmed, Tofayel; Goh, Kwok Jian; Zhan, Yin; Bhushan, Shashi; Gao, Yong-Gui

    2016-06-17

    Elongation factor 4 (EF4) is a member of the family of ribosome-dependent translational GTPase factors, along with elongation factor G and BPI-inducible protein A. Although EF4 is highly conserved in bacterial, mitochondrial, and chloroplast genomes, its exact biological function remains controversial. Here we present the cryo-EM reconstitution of the GTP form of EF4 bound to the ribosome with P and E site tRNAs at 3.8-Å resolution. Interestingly, our structure reveals an unrotated ribosome rather than a clockwise-rotated ribosome, as observed in the presence of EF4-GDP and P site tRNA. In addition, we also observed a counterclockwise-rotated form of the above complex at 5.7-Å resolution. Taken together, our results shed light on the interactions formed between EF4, the ribosome, and the P site tRNA and illuminate the GTPase activation mechanism at previously unresolved detail. PMID:27137929

  14. Rates of gyrase supercoiling and transcription elongation control supercoil density in a bacterial chromosome.

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    Nikolay Rovinskiy

    Full Text Available Gyrase catalyzes negative supercoiling of DNA in an ATP-dependent reaction that helps condense bacterial chromosomes into a compact interwound "nucleoid." The supercoil density (σ of prokaryotic DNA occurs in two forms. Diffusible supercoil density (σ(D moves freely around the chromosome in 10 kb domains, and constrained supercoil density (σ(C results from binding abundant proteins that bend, loop, or unwind DNA at many sites. Diffusible and constrained supercoils contribute roughly equally to the total in vivo negative supercoil density of WT cells, so σ = σ(C+σ(D. Unexpectedly, Escherichia coli chromosomes have a 15% higher level of σ compared to Salmonella enterica. To decipher critical mechanisms that can change diffusible supercoil density of chromosomes, we analyzed strains of Salmonella using a 9 kb "supercoil sensor" inserted at ten positions around the genome. The sensor contains a complete Lac operon flanked by directly repeated resolvase binding sites, and the sensor can monitor both supercoil density and transcription elongation rates in WT and mutant strains. RNA transcription caused (- supercoiling to increase upstream and decrease downstream of highly expressed genes. Excess upstream supercoiling was relaxed by Topo I, and gyrase replenished downstream supercoil losses to maintain an equilibrium state. Strains with TS gyrase mutations growing at permissive temperature exhibited significant supercoil losses varying from 30% of WT levels to a total loss of σ(D at most chromosome locations. Supercoil losses were influenced by transcription because addition of rifampicin (Rif caused supercoil density to rebound throughout the chromosome. Gyrase mutants that caused dramatic supercoil losses also reduced the transcription elongation rates throughout the genome. The observed link between RNA polymerase elongation speed and gyrase turnover suggests that bacteria with fast growth rates may generate higher supercoil densities

  15. Phosphoglycerylethanolamine posttranslational modification of plant eukaryotic elongation factor 1 alpha

    International Nuclear Information System (INIS)

    Eukaryotic elongation factor 1alpha (eEF-1A) is a multifunctional protein. There are three known posttranslational modifications of eEF-1A that could potentially affect its function. Except for phosphorylation, the other posttranslational modifications have not been demonstrated in plants. Using matrix-assisted laser desorption/ionization-mass spectrometry and peptide mass mapping, we show that carrot (Daucus carota L.) eEF-1A contains a phosphoglycerylethanolamine (PGE) posttranslational modification. eEF-1A was the only protein labeled with [14C]ethanolamine in carrot cells and was the predominant ethanolamine-labeled protein in Arabidopsis seedlings and tobacco (Nicotiana tabacum L.) cell cultures. In vivo-labeling studies using [3H]glycerol, [32P][Pi,[14C]myristic acid, and [14C]linoleic acid indicated that the entire phospholipid phosphatidylethanolamine is covalently attached to the protein. The PGE lipid modification did not affect the partitioning of eEF-1A in Triton X-114 or its actin-binding activity in in vitro assays. Our in vitro data indicate that this newly characterized posttranslational modification alone does not affect the function of eEF-1A. Therefore, the PGE lipid modification may work in combination with other posttranslational modifications to affect the distribution and the function of eEF-1A within the cell

  16. Architecture and RNA binding of the human negative elongation factor

    Science.gov (United States)

    Vos, Seychelle M; Pöllmann, David; Caizzi, Livia; Hofmann, Katharina B; Rombaut, Pascaline; Zimniak, Tomasz; Herzog, Franz; Cramer, Patrick

    2016-01-01

    Transcription regulation in metazoans often involves promoter-proximal pausing of RNA polymerase (Pol) II, which requires the 4-subunit negative elongation factor (NELF). Here we discern the functional architecture of human NELF through X-ray crystallography, protein crosslinking, biochemical assays, and RNA crosslinking in cells. We identify a NELF core subcomplex formed by conserved regions in subunits NELF-A and NELF-C, and resolve its crystal structure. The NELF-AC subcomplex binds single-stranded nucleic acids in vitro, and NELF-C associates with RNA in vivo. A positively charged face of NELF-AC is involved in RNA binding, whereas the opposite face of the NELF-AC subcomplex binds NELF-B. NELF-B is predicted to form a HEAT repeat fold, also binds RNA in vivo, and anchors the subunit NELF-E, which is confirmed to bind RNA in vivo. These results reveal the three-dimensional architecture and three RNA-binding faces of NELF. DOI: http://dx.doi.org/10.7554/eLife.14981.001 PMID:27282391

  17. A bacterial toxin inhibits DNA replication elongation through a direct interaction with the β sliding clamp.

    Science.gov (United States)

    Aakre, Christopher D; Phung, Tuyen N; Huang, David; Laub, Michael T

    2013-12-12

    Toxin-antitoxin (TA) systems are ubiquitous on bacterial chromosomes, yet the mechanisms regulating their activity and the molecular targets of toxins remain incompletely defined. Here, we identify SocAB, an atypical TA system in Caulobacter crescentus. Unlike canonical TA systems, the toxin SocB is unstable and constitutively degraded by the protease ClpXP; this degradation requires the antitoxin, SocA, as a proteolytic adaptor. We find that the toxin, SocB, blocks replication elongation through an interaction with the sliding clamp, driving replication fork collapse. Mutations that suppress SocB toxicity map to either the hydrophobic cleft on the clamp that binds DNA polymerase III or a clamp-binding motif in SocB. Our findings suggest that SocB disrupts replication by outcompeting other clamp-binding proteins. Collectively, our results expand the diversity of mechanisms employed by TA systems to regulate toxin activity and inhibit bacterial growth, and they suggest that inhibiting clamp function may be a generalizable antibacterial strategy. PMID:24239291

  18. Elongation factor G initiates translocation through a power stroke.

    Science.gov (United States)

    Chen, Chunlai; Cui, Xiaonan; Beausang, John F; Zhang, Haibo; Farrell, Ian; Cooperman, Barry S; Goldman, Yale E

    2016-07-01

    During the translocation step of prokaryotic protein synthesis, elongation factor G (EF-G), a guanosine triphosphatase (GTPase), binds to the ribosomal PRE-translocation (PRE) complex and facilitates movement of transfer RNAs (tRNAs) and messenger RNA (mRNA) by one codon. Energy liberated by EF-G's GTPase activity is necessary for EF-G to catalyze rapid and precise translocation. Whether this energy is used mainly to drive movements of the tRNAs and mRNA or to foster EF-G dissociation from the ribosome after translocation has been a long-lasting debate. Free EF-G, not bound to the ribosome, adopts quite different structures in its GTP and GDP forms. Structures of EF-G on the ribosome have been visualized at various intermediate steps along the translocation pathway, using antibiotics and nonhydolyzable GTP analogs to block translocation and to prolong the dwell time of EF-G on the ribosome. However, the structural dynamics of EF-G bound to the ribosome have not yet been described during normal, uninhibited translocation. Here, we report the rotational motions of EF-G domains during normal translocation detected by single-molecule polarized total internal reflection fluorescence (polTIRF) microscopy. Our study shows that EF-G has a small (∼10°) global rotational motion relative to the ribosome after GTP hydrolysis that exerts a force to unlock the ribosome. This is followed by a larger rotation within domain III of EF-G before its dissociation from the ribosome. PMID:27313204

  19. Mapping Escherichia coli elongation factor Tu residues involved in binding of aminoacyl-tRNA

    DEFF Research Database (Denmark)

    Wiborg, Ove; Andersen, C; Knudsen, Charlotte Rohde;

    1996-01-01

    were characterized with respect to thermal and chemical stability, GTPase activity, tRNA affinity, and activity in an in vitro translation assay. Most conspicuously tRNA affinities were reduced for all mutants. The results verify our structural analysis of elongation factor Tu in complex with aminoacyl....... Their functional roles are discussed in relation to the structure of elongation factor Tu in complex with aminoacyl-tRNA. Udgivelsesdato: 1996-Aug-23...

  20. Mutation of the conserved Gly83 and Gly94 in Escherichia coli elongation factor Tu. Indication of structural pivots

    DEFF Research Database (Denmark)

    Kjaersgård, I V; Knudsen, Charlotte Rohde; Wiborg, O

    1995-01-01

    Elongation factor Tu from Escherichia coli cycles between an active conformation where GTP is bound, and an inactive conformation where GDP is bound. Between the two conformations, elongation factor Tu undergoes major structural changes. The aim of this work has been to reveal the role of two ver...... important pivot point in elongation factor-Tu. Udgivelsesdato: 1995-Feb-15...

  1. Elongation factor-P at the crossroads of the host-endosymbiont interface

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    Andrei Rajkovic

    2015-09-01

    Full Text Available Elongation factor P (EF-P is an ancient bacterial translational factor that aids the ribosome in polymerizing oligo-prolines. EF-P structurally resembles tRNA and binds in-between the exit and peptidyl sites of the ribosome to accelerate the intrinsically slow reaction of peptidyl-prolyl bond formation. Recent studies have identified in separate organisms, two evolutionarily convergent EF-P posttranslational modification systems (EPMS, split predominantly between gammaproteobacteria, and betaproteobacteria. In both cases EF-P receives a post-translational modification, critical for its function, on a highly conserved residue that protrudes into the peptidyl-transfer center of the ribosome. EPMSs are comprised of a gene(s that synthesizes the precursor molecule used in modifying EF-P, and a gene(s encoding an enzyme that reacts with the precursor molecule to catalyze covalent attachment to EF-P. However, not all organisms genetically encode a complete EPMS. For instance, some symbiotic bacteria harbor efp and the corresponding gene that enzymatically attaches the modification, but lack the ability to synthesize the substrate used in the modification reaction. Here we highlight the recent discoveries made regarding EPMSs, with a focus on how these incomplete modification pathways shape or have been shaped by the endosymbiont-host relationship.

  2. The initiation factor TFE and the elongation factor Spt4/5 compete for the RNAP clamp during transcription initiation and elongation.

    Science.gov (United States)

    Grohmann, Dina; Nagy, Julia; Chakraborty, Anirban; Klose, Daniel; Fielden, Daniel; Ebright, Richard H; Michaelis, Jens; Werner, Finn

    2011-07-22

    TFIIE and the archaeal homolog TFE enhance DNA strand separation of eukaryotic RNAPII and the archaeal RNAP during transcription initiation by an unknown mechanism. We have developed a fluorescently labeled recombinant M. jannaschii RNAP system to probe the archaeal transcription initiation complex, consisting of promoter DNA, TBP, TFB, TFE, and RNAP. We have localized the position of the TFE winged helix (WH) and Zinc ribbon (ZR) domains on the RNAP using single-molecule FRET. The interaction sites of the TFE WH domain and the transcription elongation factor Spt4/5 overlap, and both factors compete for RNAP binding. Binding of Spt4/5 to RNAP represses promoter-directed transcription in the absence of TFE, which alleviates this effect by displacing Spt4/5 from RNAP. During elongation, Spt4/5 can displace TFE from the RNAP elongation complex and stimulate processivity. Our results identify the RNAP "clamp" region as a regulatory hot spot for both transcription initiation and transcription elongation. PMID:21777815

  3. Molecular cloning and phylogenetic analysis of Clonorchis sinensis elongation factor-1alpha.

    Science.gov (United States)

    Kim, Tae Yun; Cho, Pyo Yun; Na, Jong Won; Hong, Sung-Jong

    2007-11-01

    Elongation factor-1 (EF-1) plays a primary role in protein synthesis, e.g., in the regulation of cell growth, aging, motility, embryogenesis, and signal transduction. The authors identified a clone CsIH23 by immunoscreening a Clonorchis sinensis cDNA library. The cDNA of CsIH23 was found to have a putative open reading frame containing 461 amino acids with a predicted molecular mass of 50.5 kDa. Its polypeptide sequence was highly homologous with EF-1alpha of parasites and vertebrate animals. CsIH23 polypeptide contained three GTP/GDP-binding sites, one ribosome-binding domain, one actin-binding domain, one tRNA-binding domain, and two glyceryl-phosphoryl-ethanolamine attachment sites. Based on these primary and secondary structural similarities, it was concluded that CsIH23 cDNA encodes C. sinensis EF-1alpha (CsEF-1alpha). In a molecular phylogenic tree, CsEF-1alpha clustered with the EF-1alpha of helminthic parasites. Subsequently, CsEF-1alpha recombinant protein was bacterially overexpressed and purified by Ni-NTA affinity column chromatography. Immunoblotting using CsEF-1alpha recombinant protein produced positive signals for all serum samples tested from clonorchiasis, opisthorchiasis viverinii, and paragonimiasis westermani patients and normal healthy controls. These findings suggest that recombinant CsEF-1alpha is of limited usefulness as serodiagnostic antigen for clonorchiasis. PMID:17674047

  4. The Positive Transcription Elongation Factor b Is an Essential Cofactor for the Activation of Transcription by Myocyte Enhancer Factor 2

    OpenAIRE

    Nojima, Masanori; Huang, Yehong; Tyagi, Mudit; Kao, Hung-Ying; Fujinaga, Koh

    2008-01-01

    The positive transcription elongation factor b (P-TEFb), composed of cyclin-dependent kinase 9 and cyclin T1, stimulates the elongation of transcription by hyperphosphorylating the C-terminal region of RNA polymerase II. Aberrant activation of P-TEFb results in manifestations of cardiac hypertrophy in mice, suggesting that P-TEFb is an essential factor for cardiac myocyte function and development. Here, we present evidence that P-TEFb selectively activates transcription mediated by the myocyt...

  5. Isolation of chimaeric forms of elongation factor EF-Tu by affinity chromatography

    Czech Academy of Sciences Publication Activity Database

    Šanderová, Hana; Krásný, Libor; Jonák, Jiří

    2002-01-01

    Roč. 770, 1-2 (2002), s. 129-135. ISSN 1570-0232 R&D Projects: GA ČR GA204/98/0863 Institutional research plan: CEZ:AV0Z5052915 Keywords : elongation factor EF-Tu, chimeric protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.913, year: 2002

  6. A putative transcriptional elongation factor hIws1 is essential for mammalian cell proliferation

    International Nuclear Information System (INIS)

    Iws1 has been implicated in transcriptional elongation by interaction with RNA polymerase II (RNAP II) and elongation factor Spt6 in budding yeast Saccharomyces cerevisiae, and association with transcription factor TFIIS in mammalian cells, but its role in controlling cell growth and proliferation remains unknown. Here we report that the human homolog of Iws1, hIws1, physically interacts with protein arginine methyltransferases PRMT5 which methylates elongation factor Spt5 and regulates its interaction with RNA polymerase II. Gene-specific silencing of hIws1 by RNA interference reveals that hIws1 is essential for cell viability. GFP fusion protein expression approaches demonstrate that the hIws1 protein is located in the nucleus, subsequently, two regions harbored within the hIws1 protein are demonstrated to contain nuclear localization signals (NLSs). In addition, mouse homolog of hiws1 is found to express ubiquitously in various tissues

  7. Reconstitution of Qbeta RNA replicase from a covalently bonded elongation factor Tu-Ts complex

    DEFF Research Database (Denmark)

    Brown, S; Blumenthal, T

    1976-01-01

    of these polypeptides, protein synthesis elongation factors EF-Tu and EF-Ts, can be covalently crosslinked with dimethyl suberimidate to form a complex which lacks the ability to catalyze the known host functions catalyzed by the individual elongation factors. Using a previously developed...... postribosomal supernatant by its ability to replace EF-Tu and EF-Ts in the renaturation of denatured Qbeta replicase. A sample of Qbeta replicase with crosslinked EF-Tu-Ts replacing the individual elongation factors was prepared. Although it lacked EF-Tu and EF-Ts activities, it could initiate transcription of...... GDP. The results demonstrate that EF-Tu and EF-Ts function as complex in Qbeta replicase and do not perform their known protein biosynthetic function in the RNA synthetic reaction....

  8. Interaction of mammalian mitochondrial elongation factor EF-Tu with guanine nucleotides.

    OpenAIRE

    Cai, Y. C.; Bullard, J. M.; Thompson, N L; Spremulli, L L

    2000-01-01

    Elongation factor Tu (EF-Tu) promotes the binding of aminoacyl-tRNA (aa-tRNA) to the acceptor site of the ribosome. During the elongation cycle, EF-Tu interacts with guanine nucleotides, aa-tRNA and its nucleotide exchange factor (EF-Ts). Quantitative determination of the equilibrium dissociation constants that govern the interactions of mammalian mitochondrial EF-Tu (EF-Tu(mt)) with guanine nucleotides was the focus of the work reported here. Equilibrium dialysis with [3H]GDP was used to mea...

  9. DNA barcoding for identification of 'Candidatus Phytoplasmas' using a fragment of the elongation factor Tu gene.

    Directory of Open Access Journals (Sweden)

    Olga Makarova

    Full Text Available BACKGROUND: Phytoplasmas are bacterial phytopathogens responsible for significant losses in agricultural production worldwide. Several molecular markers are available for identification of groups or strains of phytoplasmas. However, they often cannot be used for identification of phytoplasmas from different groups simultaneously or are too long for routine diagnostics. DNA barcoding recently emerged as a convenient tool for species identification. Here, the development of a universal DNA barcode based on the elongation factor Tu (tuf gene for phytoplasma identification is reported. METHODOLOGY/PRINCIPAL FINDINGS: We designed a new set of primers and amplified a 420-444 bp fragment of tuf from all 91 phytoplasmas strains tested (16S rRNA groups -I through -VII, -IX through -XII, -XV, and -XX. Comparison of NJ trees constructed from the tuf barcode and a 1.2 kbp fragment of the 16S ribosomal gene revealed that the tuf tree is highly congruent with the 16S rRNA tree and had higher inter- and intra- group sequence divergence. Mean K2P inter-/intra- group divergences of the tuf barcode did not overlap and had approximately one order of magnitude difference for most groups, suggesting the presence of a DNA barcoding gap. The use of the tuf barcode allowed separation of main ribosomal groups and most of their subgroups. Phytoplasma tuf barcodes were deposited in the NCBI GenBank and Q-bank databases. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that DNA barcoding principles can be applied for identification of phytoplasmas. Our findings suggest that the tuf barcode performs as well or better than a 1.2 kbp fragment of the 16S rRNA gene and thus provides an easy procedure for phytoplasma identification. The obtained sequences were used to create a publicly available reference database that can be used by plant health services and researchers for online phytoplasma identification.

  10. Towards an understanding of structure-function relationships of elongation factor Tu

    DEFF Research Database (Denmark)

    Wiborg, O; Andersen, C; Knudsen, Charlotte Rohde;

    1994-01-01

    In light of the recently determined structure of elongation factor Tu, and taking into account chemical studies mapping functional sites, a number of residues have been selected for site-directed mutagenesis studies. Gly94, Gly126, His66, His118, Lys89 and Asp90 have each been point...

  11. CHARACTERIZATION AND GENE EXPRESSION OF BABESIA BOVIS ELONGATION FACTOR-1ALPHA

    Science.gov (United States)

    Elongation factor 1 alpha (EF-1') is a constitutively expressed, abundant protein that is a key element in eukaryotic protein translation. Because of its high level of transcription, the EF-1''promoter has been utilized to drive exogenous gene expression in transfected cells. In this study, we ident...

  12. Negative elongation factor NELF controls transcription of immediate early genes in a stimulus-specific manner

    International Nuclear Information System (INIS)

    The transcription rate of immediate early genes (IEGs) is controlled directly by transcription elongation factors at the transcription elongation step. Negative elongation factor (NELF) and 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) sensitivity-inducing factor (DSIF) stall RNA polymerase II (pol II) soon after transcription initiation. Upon induction of IEG transcription, DSIF is converted into an accelerator for pol II elongation. To address whether and how NELF as well as DSIF controls overall IEG transcription, its expression was reduced using stable RNA interference in GH4C1 cells. NELF knock-down reduced thyrotropin-releasing hormone (TRH)-induced transcription of the IEGs c-fos, MKP-1, and junB. In contrast, epidermal growth factor (EGF)-induced transcription of these IEGs was unaltered or even slightly increased by NELF knock-down. Thus, stable knock-down of NELF affects IEG transcription stimulation-specifically. Conversely, DSIF knock-down reduced both TRH- and EGF-induced transcription of the three IEGs. Interestingly, TRH-induced activation of the MAP kinase pathway, a pathway essential for transcription of the three IEGs, was down-regulated by NELF knock-down. Thus, stable knock-down of NELF, by modulating intracellular signaling pathways, caused stimulation-specific loss of IEG transcription. These observations indicate that NELF controls overall IEG transcription via multiple mechanisms both directly and indirectly

  13. Divergence of a conserved elongation factor and transcription regulation in budding and fission yeast.

    Science.gov (United States)

    Booth, Gregory T; Wang, Isabel X; Cheung, Vivian G; Lis, John T

    2016-06-01

    Complex regulation of gene expression in mammals has evolved from simpler eukaryotic systems, yet the mechanistic features of this evolution remain elusive. Here, we compared the transcriptional landscapes of the distantly related budding and fission yeast. We adapted the Precision Run-On sequencing (PRO-seq) approach to map the positions of RNA polymerase active sites genome-wide in Schizosaccharomyces pombe and Saccharomyces cerevisiae. Additionally, we mapped preferred sites of transcription initiation in each organism using PRO-cap. Unexpectedly, we identify a pause in early elongation, specific to S. pombe, that requires the conserved elongation factor subunit Spt4 and resembles promoter-proximal pausing in metazoans. PRO-seq profiles in strains lacking Spt4 reveal globally elevated levels of transcribing RNA Polymerase II (Pol II) within genes in both species. Messenger RNA abundance, however, does not reflect the increases in Pol II density, indicating a global reduction in elongation rate. Together, our results provide the first base-pair resolution map of transcription elongation in S. pombe and identify divergent roles for Spt4 in controlling elongation in budding and fission yeast. PMID:27197211

  14. Self-Elongation with Sequential Folding of a Filament of Bacterial Cells

    Science.gov (United States)

    Honda, Ryojiro; Wakita, Jun-ichi; Katori, Makoto

    2015-11-01

    Under hard-agar and nutrient-rich conditions, a cell of Bacillus subtilis grows as a single filament owing to the failure of cell separation after each growth and division cycle. The self-elongating filament of cells shows sequential folding processes, and multifold structures extend over an agar plate. We report that the growth process from the exponential phase to the stationary phase is well described by the time evolution of fractal dimensions of the filament configuration. We propose a method of characterizing filament configurations using a set of lengths of multifold parts of a filament. Systems of differential equations are introduced to describe the folding processes that create multifold structures in the early stage of the growth process. We show that the fitting of experimental data to the solutions of equations is excellent, and the parameters involved in our model systems are determined.

  15. Plant Natural Products Targeting Bacterial Virulence Factors.

    Science.gov (United States)

    Silva, Laura Nunes; Zimmer, Karine Rigon; Macedo, Alexandre José; Trentin, Danielle Silva

    2016-08-24

    Decreased antimicrobial efficiency has become a global public health issue. The paucity of new antibacterial drugs is evident, and the arsenal against infectious diseases needs to be improved urgently. The selection of plants as a source of prototype compounds is appropriate, since plant species naturally produce a wide range of secondary metabolites that act as a chemical line of defense against microorganisms in the environment. Although traditional approaches to combat microbial infections remain effective, targeting microbial virulence rather than survival seems to be an exciting strategy, since the modulation of virulence factors might lead to a milder evolutionary pressure for the development of resistance. Additionally, anti-infective chemotherapies may be successfully achieved by combining antivirulence and conventional antimicrobials, extending the lifespan of these drugs. This review presents an updated discussion of natural compounds isolated from plants with chemically characterized structures and activity against the major bacterial virulence factors: quorum sensing, bacterial biofilms, bacterial motility, bacterial toxins, bacterial pigments, bacterial enzymes, and bacterial surfactants. Moreover, a critical analysis of the most promising virulence factors is presented, highlighting their potential as targets to attenuate bacterial virulence. The ongoing progress in the field of antivirulence therapy may therefore help to translate this promising concept into real intervention strategies in clinical areas. PMID:27437994

  16. PoxA, yjeK, and elongation factor P coordinately modulate virulence and drug resistance in Salmonella enterica

    DEFF Research Database (Denmark)

    Navarre, William Wiley; Zou, S Betty; Roy, Hervé;

    2010-01-01

    We report an interaction between poxA, encoding a paralog of lysyl tRNA-synthetase, and the closely linked yjeK gene, encoding a putative 2,3-beta-lysine aminomutase, that is critical for virulence and stress resistance in Salmonella enterica. Salmonella poxA and yjeK mutants share extensive...... phenotypic pleiotropy, including attenuated virulence in mice, an increased ability to respire under nutrient-limiting conditions, hypersusceptibility to a variety of diverse growth inhibitors, and altered expression of multiple proteins, including several encoded on the SPI-1 pathogenicity island. Pox......A mediates posttranslational modification of bacterial elongation factor P (EF-P), analogous to the modification of the eukaryotic EF-P homolog, eIF5A, with hypusine. The modification of EF-P is a mechanism of regulation whereby PoxA acts as an aminoacyl-tRNA synthetase that attaches an amino acid to a...

  17. Elongation in translation as a dynamic interaction among the ribosome, tRNA, and elongation factors EF-G and EF-Tu.

    Science.gov (United States)

    Agirrezabala, Xabier; Frank, Joachim

    2009-08-01

    The ribosome is a complex macromolecular machine that translates the message encoded in the messenger RNA and synthesizes polypeptides by linking the individual amino acids carried by the cognate transfer RNAs (tRNAs). The protein elongation cycle, during which the tRNAs traverse the ribosome in a coordinated manner along a path of more than 100 A, is facilitated by large-scale rearrangements of the ribosome. These rearrangements go hand in hand with conformational changes of tRNA as well as elongation factors EF-Tu and EF-G - GTPases that catalyze tRNA delivery and translocation, respectively. This review focuses on the structural data related to the dynamics of the ribosomal machinery, which are the basis, in conjunction with existing biochemical, kinetic, and fluorescence resonance energy transfer data, of our knowledge of the decoding and translocation steps of protein elongation. PMID:20025795

  18. Elongation factor-1A1 is a novel substrate of the protein phosphatase 1-TIMAP complex.

    Science.gov (United States)

    Boratkó, Anita; Péter, Margit; Thalwieser, Zsófia; Kovács, Előd; Csortos, Csilla

    2015-12-01

    TIMAP (TGF-β inhibited membrane associated protein) is a protein phosphatase 1 (PP1) regulatory subunit highly abundant in endothelial cells and it is involved in the maintenance of pulmonary endothelial barrier function. It localizes mainly in the plasma membrane, but it is also present in the nuclei and cytoplasm. Direct interaction of TIMAP with the eukaryotic elongation factor 1 A1 (eEF1A1) is shown by pull-down, LC-MS/MS, Far-Western and immunoprecipitations. In connection with the so called moonlighting functions of the elongation factor, eEF1A is thought to establish protein-protein interactions through a transcription-dependent nuclear export motif, TD-NEM, and to aid nuclear export of TD-NEM containing proteins. We found that a TD-NEM-like motif of TIMAP has a critical role in its specific binding to eEF1A1. However, eEF1A1 is not or not exclusively responsible for the nuclear export of TIMAP. On the contrary, TIMAP seems to regulate membrane localization of eEF1A1 as the elongation factor co-localized with TIMAP in the plasma membrane fraction of control endothelial cells, but it has disappeared from the membrane in TIMAP depleted cells. It is demonstrated that membrane localization of eEF1A1 depends on the phosphorylation state of its Thr residue(s); and ROCK phosphorylated eEF1A1 is a novel substrate for TIMAP-PP1 underlining the complex regulatory role of TIMAP in the endothelium. The elongation factor seems to be involved in the regulation of endothelial cell attachment and spreading as silencing of eEF1A1 positively affected these processes which were monitored by transendothelial resistance measurements. PMID:26497934

  19. The ERF11 Transcription Factor Promotes Internode Elongation by Activating Gibberellin Biosynthesis and Signaling1[OPEN

    Science.gov (United States)

    Zhou, Xin; Zhang, Zhong-Lin; Tyler, Ludmila; Yusuke, Jikumaru; Qiu, Kai; Lumba, Shelley; Desveaux, Darrell; McCourt, Peter; Sun, Tai-ping

    2016-01-01

    The phytohormone gibberellin (GA) plays a key role in promoting stem elongation in plants. Previous studies show that GA activates its signaling pathway by inducing rapid degradation of DELLA proteins, GA signaling repressors. Using an activation-tagging screen in a reduced-GA mutant ga1-6 background, we identified AtERF11 to be a novel positive regulator of both GA biosynthesis and GA signaling for internode elongation. Overexpression of AtERF11 partially rescued the dwarf phenotype of ga1-6. AtERF11 is a member of the ERF (ETHYLENE RESPONSE FACTOR) subfamily VIII-B-1a of ERF/AP2 transcription factors in Arabidopsis (Arabidopsis thaliana). Overexpression of AtERF11 resulted in elevated bioactive GA levels by up-regulating expression of GA3ox1 and GA20ox genes. Hypocotyl elongation assays further showed that overexpression of AtERF11 conferred elevated GA response, whereas loss-of-function erf11 and erf11 erf4 mutants displayed reduced GA response. In addition, yeast two-hybrid, coimmunoprecipitation, and transient expression assays showed that AtERF11 enhances GA signaling by antagonizing the function of DELLA proteins via direct protein-protein interaction. Interestingly, AtERF11 overexpression also caused a reduction in the levels of another phytohormone ethylene in the growing stem, consistent with recent finding showing that AtERF11 represses transcription of ethylene biosynthesis ACS genes. The effect of AtERF11 on promoting GA biosynthesis gene expression is likely via its repressive function on ethylene biosynthesis. These results suggest that AtERF11 plays a dual role in promoting internode elongation by inhibiting ethylene biosynthesis and activating GA biosynthesis and signaling pathways. PMID:27255484

  20. Purification and crystallization of the yeast translation elongation factor eEF3

    DEFF Research Database (Denmark)

    Andersen, Christian Folsted; Anand, Monika; Boesen, Thomas;

    2004-01-01

    A Saccharomyces cerevisiae strain expressing full-length histidine-tagged translation elongation factor 3 (eEF3) as the only form of the protein facilitated purification of the factor for both structural and functional studies. Additionally, an identical full-length form has been successfully...... expressed in Escherichia coli and a C-terminally truncated form of histidine-tagged eEF3 has been successfully expressed in E. coli and S. cerevisiae. Both forms have been crystallized and crystals of the truncated protein expressed in yeast diffract synchrotron radiation to a maximum resolution of 2.3 A. A...

  1. A Conserved Proline Triplet in Val-tRNA Synthetase and the Origin of Elongation Factor P

    Directory of Open Access Journals (Sweden)

    Agata L. Starosta

    2014-10-01

    Full Text Available Bacterial ribosomes stall on polyproline stretches and require the elongation factor P (EF-P to relieve the arrest. Yet it remains unclear why evolution has favored the development of EF-P rather than selecting against the occurrence of polyproline stretches in proteins. We have discovered that only a single polyproline stretch is invariant across all domains of life, namely a proline triplet in ValS, the tRNA synthetase, that charges tRNAVal with valine. Here, we show that expression of ValS in vivo and in vitro requires EF-P and demonstrate that the proline triplet located in the active site of ValS is important for efficient charging of tRNAVal with valine and preventing formation of mischarged Thr-tRNAVal as well as efficient growth of E. coli in vivo. We suggest that the critical role of the proline triplet for ValS activity may explain why bacterial cells coevolved the EF-P rescue system.

  2. Rapid fold and structure determination of the archaeal translation elongation factor 1β from Methanobacterium thermoautotrophicum

    International Nuclear Information System (INIS)

    The tertiary fold of the elongation factor, aEF-1β, from Methanobacterium thermoautotrophicum was determined in a high-throughput fashion using a minimal set of NMR experiments. NMR secondary structure prediction, deuterium exchange experiments and the analysis of chemical shift perturbations were combined to identify the protein fold as an alpha-beta sandwich typical of many RNA binding proteins including EF-G. Following resolution of the tertiary fold, a high resolution structure of aEF-1β was determined using heteronuclear and homonuclear NMR experiments and a semi-automated NOESY assignment strategy. Analysis of the aEF-1β structure revealed close similarity to its human analogue, eEF-1β. In agreement with studies on EF-Ts and human EF-1β, a functional mechanism for nucleotide exchange is proposed wherein Phe46 on an exposed loop acts as a lever to eject GDP from the associated elongation factor G-protein, aEF-1α. aEF-1β was also found to bind calcium in the groove between helix α2 and strand β4. This novel feature was not observed previously and may serve a structural function related to protein stability or may play a functional role in archaeal protein translation

  3. Elongation factor Ts of Chlamydia trachomatis: structure of the gene and properties of the protein.

    Science.gov (United States)

    Zhang, Y; Tao, J; Zhou, M; Meng, Q; Zhang, L; Shen, L; Klein, R; Miller, D L

    1997-08-01

    A putative structural gene cluster containing four open reading frames (ORFs) located downstream of the omp1 gene of Chlamydia trachomatis mouse pneumonitis (MoPn) was cloned and sequenced. A GenBank survey indicated that the identified cluster is similar to the rpsB-tsf-pyrH(smbA)-frr region of Escherichia coli. The second ORF was 846 bp encoding a 282-amino-acid polypeptide with a calculated M(r) 30,824. Alignment of this deduced protein sequence and E. coli elongation factor Ts (EF-Ts, product of tsf) demonstrated 34% identity and an additional 14% similarity. The putative chlamydial tsf gene was expressed in E. coli as a nonfusion protein and as a 6x His-tagged fusion protein. By SDS-PAGE analysis, the molecular weights of the nonfusion recombinant protein and a protein of chlamydial elementary bodies (EBs), which was recognized by monoclonal antibodies derived from the nonfusion recombinant protein, are 34 kDa. The purified recombinant 6x His-tagged fusion protein increased the rate of GDP exchange with both Chlamydia and E. coli elongation factor Tu (EF-Tu). These data show that the second gene of the identified cluster is tsf. Unlike EF-Ts from any other species, its activity was comparable to that of E. coli EF-Ts in exchange reaction with E. coli EF-Tu. PMID:9244380

  4. Elongation Factor-Tu (EF-Tu) proteins structural stability and bioinformatics in ancestral gene reconstruction

    Science.gov (United States)

    Dehipawala, Sunil; Nguyen, A.; Tremberger, G.; Cheung, E.; Schneider, P.; Lieberman, D.; Holden, T.; Cheung, T.

    2013-09-01

    A paleo-experimental evolution report on elongation factor EF-Tu structural stability results has provided an opportunity to rewind the tape of life using the ancestral protein sequence reconstruction modeling approach; consistent with the book of life dogma in current biology and being an important component in the astrobiology community. Fractal dimension via the Higuchi fractal method and Shannon entropy of the DNA sequence classification could be used in a diagram that serves as a simple summary. Results from biomedical gene research provide examples on the diagram methodology. Comparisons between biomedical genes such as EEF2 (elongation factor 2 human, mouse, etc), WDR85 in epigenetics, HAR1 in human specificity, DLG1 in cognitive skill, and HLA-C in mosquito bite immunology with EF Tu DNA sequences have accounted for the reported circular dichroism thermo-stability data systematically; the results also infer a relatively less volatility geologic time period from 2 to 3 Gyr from adaptation viewpoint. Comparison to Thermotoga maritima MSB8 and Psychrobacter shows that Thermus thermophilus HB8 EF-Tu calibration sequence could be an outlier, consistent with free energy calculation by NUPACK. Diagram methodology allows computer simulation studies and HAR1 shows about 0.5% probability from chimp to human in terms of diagram location, and SNP simulation results such as amoebic meningoencephalitis NAF1 suggest correlation. Extensions to the studies of the translation and transcription elongation factor sequences in Megavirus Chiliensis, Megavirus Lba and Pandoravirus show that the studied Pandoravirus sequence could be an outlier with the highest fractal dimension and lowest entropy, as compared to chicken as a deviant in the DNMT3A DNA methylation gene sequences from zebrafish to human and to the less than one percent probability in computer simulation using the HAR1 0.5% probability as reference. The diagram methodology would be useful in ancestral gene

  5. Factors influencing bacterial adhesion to contact lenses

    OpenAIRE

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The ...

  6. Exercise rapidly increases eukaryotic elongation factor 2 phosphorylation in skeletal muscle of men

    DEFF Research Database (Denmark)

    Rose, Adam John; Broholm, Christa; Kiillerich, Kristian;

    2005-01-01

    Protein synthesis in skeletal muscle is known to decrease during contractions but the underlying regulatory mechanisms are unknown. Here, the effect of exercise on skeletal muscle eukaryotic elongation factor 2 (eEF2) phosphorylation, a key component in protein translation machinery, was examined...... of eEF2 kinase by Ca2+ signalling via calmodulin. Given that eEF2 phosphorylation inhibits eEF2 activity and mRNA translation, these findings suggest that the inhibition of protein synthesis in contracting skeletal muscle is due to the Ca2+-induced stimulation of eEF2 kinase........ Eight healthy men exercised on a cycle ergometer at a workload eliciting ~67% peak pulmonary oxygen consumption (VO2peak) with skeletal muscle biopsies taken from the vastus lateralis muscle at rest as well as after 1, 10, 30, 60 and 90 min of exercise. In response to exercise, there was a rapid (i...

  7. Mutational analysis of Glu272 in elongation factor 1A of E. coli

    DEFF Research Database (Denmark)

    Mansilla, Francisco; Knudsen, Charlotte Rohde; Clark, Brian F. C.

    1998-01-01

    In our previous work (Mansilla et al. (1997) Protein Eng. 10, 927-934) we showed that Arg7 of Escherichia coli elongation factor Tu (EF1A) plays an essential role in aminoacyl-tRNA (aa-tRNA) binding. Substitution of Arg7 by Ala or Glu lost this activity. We proposed that Arg7 forms a salt bridge...... combination with one of the above mentioned mutations (Arg7Glu/Glu272Arg) in order to test this hypothesis. Our results show that, in confirmation of our thesis based on structural knowledge, the substitution of Glu272 (Asp284) decreases the ability of EF1A:GTP to bind aa-tRNA. Udgivelsesdato: 1998-Jun-16...

  8. Elongation factor 2 kinase promotes cell survival by inhibiting protein synthesis without inducing autophagy.

    Science.gov (United States)

    Moore, Claire E J; Wang, Xuemin; Xie, Jianling; Pickford, Jo; Barron, John; Regufe da Mota, Sergio; Versele, Matthias; Proud, Christopher G

    2016-04-01

    Eukaryotic elongation factor 2 kinase (eEF2K) inhibits the elongation stage of protein synthesis by phosphorylating its only known substrate, eEF2. eEF2K is tightly regulated by nutrient-sensitive signalling pathways. For example, it is inhibited by signalling through mammalian target of rapamycin complex 1 (mTORC1). It is therefore activated under conditions of nutrient deficiency. Here we show that inhibiting eEF2K or knocking down its expression renders cancer cells sensitive to death under nutrient-starved conditions, and that this is rescued by compounds that block protein synthesis. This implies that eEF2K protects nutrient-deprived cells by inhibiting protein synthesis. Cells in which signalling through mTORC1 is highly active are very sensitive to nutrient withdrawal. Inhibiting mTORC1 protects them. Our data reveal that eEF2K makes a substantial contribution to the cytoprotective effect of mTORC1 inhibition. eEF2K is also reported to promote another potentially cytoprotective process, autophagy. We have used several approaches to test whether inhibition or loss of eEF2K affects autophagy under a variety of conditions. We find no evidence that eEF2K is involved in the activation of autophagy in the cell types we have studied. We conclude that eEF2K protects cancer cells against nutrient starvation by inhibiting protein synthesis rather than by activating autophagy. PMID:26795954

  9. The surface-associated elongation factor Tu is concealed for antibody binding on viable pneumococci and meningococci

    Czech Academy of Sciences Publication Activity Database

    Kolberg, J.; Hammerschmidt, S.; Frank, R.; Jonák, Jiří; Šanderová, Hana; Aase, A.

    2008-01-01

    Roč. 53, č. 2 (2008), s. 222-230. ISSN 0928-8244 R&D Projects: GA AV ČR KJB500520503 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z50200510 Keywords : Streptococcus pneumoniae * Neisseria meningitidis * elongation factor EF-Tu Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.972, year: 2008

  10. The transcription elongation factor Bur1-Bur2 interacts with replication protein A and maintains genome stability during replication stress

    DEFF Research Database (Denmark)

    Clausing, Emanuel; Mayer, Andreas; Chanarat, Sittinan; Müller, Barbara; Germann, Susanne M; Cramer, Patrick; Lisby, Michael; Strässer, Katja

    2010-01-01

    Multiple DNA-associated processes such as DNA repair, replication, and recombination are crucial for the maintenance of genome integrity. Here, we show a novel interaction between the transcription elongation factor Bur1-Bur2 and replication protein A (RPA), the eukaryotic single-stranded DNA...... foci. Interestingly, the DNA damage sensitivity of an rfa1 mutant was suppressed by bur1 mutation, further underscoring a functional link between these two protein complexes. The transcription elongation factor Bur1-Bur2 interacts with RPA and maintains genome integrity during DNA replication stress....

  11. Kinetics of the interactions between yeast elongation factors 1A and 1Balpha, guanine nucleotides, and aminoacyl-tRNA

    DEFF Research Database (Denmark)

    Gromadski, Kirill B; Schümmer, Tobias; Strømgaard, Anne;

    2007-01-01

    The interactions of elongation factor 1A (eEF1A) from Saccharomyces cerevisiae with elongation factor 1Balpha (eEF1Balpha), guanine nucleotides, and aminoacyl-tRNA were studied kinetically by fluorescence stopped-flow. eEF1A has similar affinities for GDP and GTP, 0.4 and 1.1 microm, respectively...... no significant binding, indicating that eEF1A has similar tRNA binding properties as its prokaryotic homolog, EF-Tu. Udgivelsesdato: 2007-Dec-7......The interactions of elongation factor 1A (eEF1A) from Saccharomyces cerevisiae with elongation factor 1Balpha (eEF1Balpha), guanine nucleotides, and aminoacyl-tRNA were studied kinetically by fluorescence stopped-flow. eEF1A has similar affinities for GDP and GTP, 0.4 and 1.1 microm, respectively...... guanine nucleotides. At the concentrations of nucleotides and factors prevailing in the cell, the overall exchange rate is expected to be in the range of 6 s(-1), which is compatible with the rate of protein synthesis in the cell. eEF1A.GTP binds Phe-tRNA(Phe) with a K(d) of 3 nm, whereas eEF1A.GDP shows...

  12. DNA Barcoding for Identification of "Candidatus Phytoplasmas" Using a Fragment of the Elongation Factor Tu Gene

    DEFF Research Database (Denmark)

    Makarova, Olga; Contaldo, Nicoletta; Paltrinieri, Samanta;

    2012-01-01

    different groups simultaneously or are too long for routine diagnostics. DNA barcoding recently emerged as a convenient tool for species identification. Here, the development of a universal DNA barcode based on the elongation factor Tu (tuf) gene for phytoplasma identification is reported. Methodology....../Principal Findings We designed a new set of primers and amplified a 420–444 bp fragment of tuf from all 91 phytoplasmas strains tested (16S rRNA groups -I through -VII, -IX through -XII, -XV, and -XX). Comparison of NJ trees constructed from the tuf barcode and a 1.2 kbp fragment of the 16S ribosomal gene revealed...... that the tuf tree is highly congruent with the 16S rRNA tree and had higher inter- and intra- group sequence divergence. Mean K2P inter−/intra- group divergences of the tuf barcode did not overlap and had approximately one order of magnitude difference for most groups, suggesting the presence of a DNA...

  13. Cloning and expression of Bombyx mori silk gland elongation factor 1gamma in Escherichia coli.

    Science.gov (United States)

    Kamiie, Katsuyoshi; Nomura, Yoshitaka; Kobayashi, Satoru; Taira, Hideharu; Kobayashi, Kohmei; Yamashita, Tetsuro; Kidou, Shin-ichiro; Ejiri, Shin-ichiro

    2002-03-01

    Elongation factor 1 (EF-1) from the silk gland of Bombyx mori consists of alpha-, beta-, gamma-, and delta-subunits. EF-1alpha GTP catalyzes the binding of aminoacyl-tRNA to ribosomes concomitant with the hydrolysis of GTP. EF-1betagammadelta catalyzes the exchange of EF-1alpha-bound GDP for exogenous GTP and stimulates the EF-1alpha-dependent binding of aminoacyl-tRNA to ribosomes. EF-1gamma cDNA, which contains an open reading frame (ORF) encoding a polypeptide of 423 amino acid residues, was amplified and cloned by PCR from a silk gland cDNA library. The calculated molecular mass and predicted pI of the product were 48,388 Da and 5.84, respectively. The silk gland EF-1gamma shares 67.3% amino acid identity with Artemia salina EF-lgamma. The N-terminal domain (amino acid residues 1-211) of silk gland EF-lgamma is 29.3% identical to maize glutathione S-transferase. We demonstrated that silk gland EF-lgamma bound to glutathione Sepharose, suggesting that the N-terminal domain of EF-1gamma may have the capacity to bind to glutathione. PMID:12005049

  14. Translation Control of Swarming Proficiency in Bacillus subtilis by 5-Amino-pentanolylated Elongation Factor P.

    Science.gov (United States)

    Rajkovic, Andrei; Hummels, Katherine R; Witzky, Anne; Erickson, Sarah; Gafken, Philip R; Whitelegge, Julian P; Faull, Kym F; Kearns, Daniel B; Ibba, Michael

    2016-05-20

    Elongation factor P (EF-P) accelerates diprolyl synthesis and requires a posttranslational modification to maintain proteostasis. Two phylogenetically distinct EF-P modification pathways have been described and are encoded in the majority of Gram-negative bacteria, but neither is present in Gram-positive bacteria. Prior work suggested that the EF-P-encoding gene (efp) primarily supports Bacillus subtilis swarming differentiation, whereas EF-P in Gram-negative bacteria has a more global housekeeping role, prompting our investigation to determine whether EF-P is modified and how it impacts gene expression in motile cells. We identified a 5-aminopentanol moiety attached to Lys(32) of B. subtilis EF-P that is required for swarming motility. A fluorescent in vivo B. subtilis reporter system identified peptide motifs whose efficient synthesis was most dependent on 5-aminopentanol EF-P. Examination of the B. subtilis genome sequence showed that these EF-P-dependent peptide motifs were represented in flagellar genes. Taken together, these data show that, in B. subtilis, a previously uncharacterized posttranslational modification of EF-P can modulate the synthesis of specific diprolyl motifs present in proteins required for swarming motility. PMID:27002156

  15. Mutational analysis of Escherichia coli elongation factor Tu in search of a role for the N-terminal region

    DEFF Research Database (Denmark)

    Mansilla, Francisco; Knudsen, Charlotte Rohde; Laurberg, M;

    1998-01-01

    We have mutated lysine 2 and arginine 7 in elongation factor Tu from Escherichia coli separately either to alanine or glutamic acid. The aim of the work was to reveal the possible interactions between the conserved N-terminal part of the molecule, which is rich in basic residues and aminoacyl...

  16. Blood Translation Elongation Factor-1δ Is a Novel Marker for Cadmium Exposure

    Directory of Open Access Journals (Sweden)

    Zi-Ning Lei

    2013-03-01

    Full Text Available Translation elongation factor-1d (TEF-1δ has been identified as a novel cadmium-responsive proto-oncogene. However, it is still unclear whether TEF-1δ could be a potential biomarker of cadmium exposure. Rats were treated with CdCl2 at different concentrations (high dose 1.225, mid-dose 0.612 and low dose 0.306 mg/kg body weight, respectively for 14 weeks, and the cadmium levels, weight coefficients, serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, blood urea nitrogen (BUN, serum creatinine (SCR, 24-h urine protein (24hPro, urinary creatinine (Cr and pathological features were determined. The TEF-1δ expression in white blood cells and multiple organs were examined by reverse transcription polymerase chain reaction (PCR and were also confirmed with fluorescence quantitative PCR. A cadmium dose-dependent increase (p < 0.05 of cadmium levels in blood, urine, liver, kidney, heart and lung, and the weight coefficients was observed. The liver and renal function indictors including AST, ALT, SCR, BUN and 24hPro, were elevated in a cadmium dose-dependent manner (p < 0.05. Significant pathological changes in liver, kidney, heart and lung were indicated. The TEF-1δ expression was up-regulated in both blood and organs (p < 0.05. Moreover, the expression level of blood TEF-1δ was positively correlated to TEF-1δ expression level, cadmium level and toxicity in the organs (p < 0.01. This study indicates that blood TEF-1δ is a novel valuable biomarker for cadmium exposure and its organ toxicity.

  17. Elongation Factor 1β' Gene from Spodoptera exigua: Characterization and Function Identification through RNA Interference

    Directory of Open Access Journals (Sweden)

    Li-Na Zhao

    2012-06-01

    Full Text Available Elongation factor (EF is a key regulation factor for translation in many organisms, including plants, bacteria, fungi, animals and insects. To investigate the nature and function of elongation factor 1β' from Spodoptera exigua (SeEF-1β', its cDNA was cloned. This contained an open reading frame of 672 nucleotides encoding a protein of 223 amino acids with a predicted molecular weight of 24.04 kDa and pI of 4.53. Northern blotting revealed that SeEF-1β' mRNA is expressed in brain, epidermis, fat body, midgut, Malpighian tubules, ovary and tracheae. RT-PCR revealed that SeEF-1β' mRNA is expressed at different levels in fat body and whole body during different developmental stages. In RNAi experiments, the survival rate of insects injected with SeEF-1β' dsRNA was 58.7% at 36 h after injection, which was significantly lower than three control groups. Other elongation factors and transcription factors were also influenced when EF-1β' was suppressed. The results demonstrate that SeEF-1β' is a key gene in transcription in S. exigua.

  18. Site-directed mutagenesis of Arg58 and Asp86 of elongation factor Tu from Escherichia coli: effects on the GTPase reaction and aminoacyl-tRNA binding

    DEFF Research Database (Denmark)

    Knudsen, Charlotte Rohde; Clark, Brian F. C.

    1996-01-01

    Elongation factor Tu from Escherichia coli was mutated separately at positions Asp86 and Arg58, in order to shed light both on the GTPase mechanism of elongation factor Tu and on the binding of aminoacyl-tRNA. In addition, the binding of guanine nucleotides was investigated by determination of th...

  19. Purification, crystallization and preliminary X-ray crystallographic analysis of mammalian translation elongation factor eEF1A2

    International Nuclear Information System (INIS)

    Translation elongation factor eEF1A2 was purified to homogeneity from rabbit muscles. Obtained crystals of eEF1A2 diffracted to 2.5 Å resolution and belonged to space group P6122 or P6322. Translation elongation factor eEF1A2 was purified to homogeneity from rabbit muscle by two consecutive ion-exchange column-chromatography steps and this mammalian eEF1A2 was successfully crystallized for the first time. Protein crystals obtained using ammonium sulfate as precipitant diffracted to 2.5 Å resolution and belonged to space group P6122 or P6322 (unit-cell parameters a = b = 135.4, c = 304.6 Å). A complete native data set was collected to 2.7 Å resolution

  20. [Factors influencing the pulse character of RNA elongation in vitro by E. coli RNA polymerase].

    Science.gov (United States)

    Aivazashvili, V A; Bibilashvili, R Sh; Vartikian, R M; Kutateladze, T V

    1981-01-01

    Pause location along primary structure of two RNA fragments each 200 nucleotide residues in the length synthesized from A1 promoters of T7 phage DNA and delta D111 T7 phage DNA was analyzed. No correlation between the location of pauses and GC-rich or self complementary regions of RNA were found. The location of pauses does not change upon the variation of the temperature or ionic strength. Concurrent variation of all four NTP concentrations also did not influence pausing pattern. However the distribution of pauses depends highly on the ratio of the individual substrate concentrations. Substitution of GTP by ITP changes the pausing pattern completely. Inorganic pyrophosphate (PPi) of inhibits RNA elongation preferentially in the regions: NAUN, CGUAG. The study of PPi action on RNA terminated with 3' OCH3-NMP suggest that the sequence-specific inhibition of RNA elongation may be a result of pyrophosphorolysis of terminal nucleotide residues of RNA. It was proposed that the pulse character of RNA elongation stems rather from differences in the kinetic constants of nucleotides attachment and pyrophosphorolysis from the 3'-termini of RNA than by termination signals encoded in the primary structure of DNA. The stable location of pauses in certain short oligonucleotides: AUG, AUU, AAU and some others is in favour of the hypothesis. PMID:6265762

  1. A dynamic RNA loop in an IRES affects multiple steps of elongation factor-mediated translation initiation.

    Science.gov (United States)

    Ruehle, Marisa D; Zhang, Haibo; Sheridan, Ryan M; Mitra, Somdeb; Chen, Yuanwei; Gonzalez, Ruben L; Cooperman, Barry S; Kieft, Jeffrey S

    2015-01-01

    Internal ribosome entry sites (IRESs) are powerful model systems to understand how the translation machinery can be manipulated by structured RNAs and for exploring inherent features of ribosome function. The intergenic region (IGR) IRESs from the Dicistroviridae family of viruses are structured RNAs that bind directly to the ribosome and initiate translation by co-opting the translation elongation cycle. These IRESs require an RNA pseudoknot that mimics a codon-anticodon interaction and contains a conformationally dynamic loop. We explored the role of this loop and found that both the length and sequence are essential for translation in different types of IGR IRESs and from diverse viruses. We found that loop 3 affects two discrete elongation factor-dependent steps in the IRES initiation mechanism. Our results show how the IRES directs multiple steps after 80S ribosome placement and highlights the often underappreciated significance of discrete conformationally dynamic elements within the context of structured RNAs. PMID:26523395

  2. Heat shock-induced accumulation of translation elongation and termination factors precedes assembly of stress granules in S. cerevisiae.

    Directory of Open Access Journals (Sweden)

    Tomas Grousl

    Full Text Available In response to severe environmental stresses eukaryotic cells shut down translation and accumulate components of the translational machinery in stress granules (SGs. Since they contain mainly mRNA, translation initiation factors and 40S ribosomal subunits, they have been referred to as dominant accumulations of stalled translation preinitiation complexes. Here we present evidence that the robust heat shock-induced SGs of S. cerevisiae also contain translation elongation factors eEF3 (Yef3p and eEF1Bγ2 (Tef4p as well as translation termination factors eRF1 (Sup45p and eRF3 (Sup35p. Despite the presence of the yeast prion protein Sup35 in heat shock-induced SGs, we found out that its prion-like domain is not involved in the SGs assembly. Factors eEF3, eEF1Bγ2 and eRF1 were accumulated and co-localized with Dcp2 foci even upon a milder heat shock at 42°C independently of P-bodies scaffolding proteins. We also show that eEF3 accumulations at 42°C determine sites of the genuine SGs assembly at 46°C. We suggest that identification of translation elongation and termination factors in SGs might help to understand the mechanism of the eIF2α factor phosphorylation-independent repression of translation and SGs assembly.

  3. Transcriptional Elongation Factor Elongin A Regulates Retinoic Acid-Induced Gene Expression during Neuronal Differentiation

    Directory of Open Access Journals (Sweden)

    Takashi Yasukawa

    2012-11-01

    Full Text Available Elongin A increases the rate of RNA polymerase II (pol II transcript elongation by suppressing transient pausing by the enzyme. Elongin A also acts as a component of a cullin-RING ligase that can target stalled pol II for ubiquitylation and proteasome-dependent degradation. It is not known whether these activities of Elongin A are functionally interdependent in vivo. Here, we demonstrate that Elongin A-deficient (Elongin A−/− embryos exhibit abnormalities in the formation of both cranial and spinal nerves and that Elongin A−/− embryonic stem cells (ESCs show a markedly decreased capacity to differentiate into neurons. Moreover, we identify Elongin A mutations that selectively inactivate one or the other of the aforementioned activities and show that mutants that retain the elongation stimulatory, but not pol II ubiquitylation, activity of Elongin A rescue neuronal differentiation and support retinoic acid-induced upregulation of a subset of neurogenesis-related genes in Elongin A−/− ESCs.

  4. The positive transcriptional elongation factor (P-TEFb) is required for neural crest specification.

    Science.gov (United States)

    Hatch, Victoria L; Marin-Barba, Marta; Moxon, Simon; Ford, Christopher T; Ward, Nicole J; Tomlinson, Matthew L; Desanlis, Ines; Hendry, Adam E; Hontelez, Saartje; van Kruijsbergen, Ila; Veenstra, Gert Jan C; Münsterberg, Andrea E; Wheeler, Grant N

    2016-08-15

    Regulation of gene expression at the level of transcriptional elongation has been shown to be important in stem cells and tumour cells, but its role in the whole animal is only now being fully explored. Neural crest cells (NCCs) are a multipotent population of cells that migrate during early development from the dorsal neural tube throughout the embryo where they differentiate into a variety of cell types including pigment cells, cranio-facial skeleton and sensory neurons. Specification of NCCs is both spatially and temporally regulated during embryonic development. Here we show that components of the transcriptional elongation regulatory machinery, CDK9 and CYCLINT1 of the P-TEFb complex, are required to regulate neural crest specification. In particular, we show that expression of the proto-oncogene c-Myc and c-Myc responsive genes are affected. Our data suggest that P-TEFb is crucial to drive expression of c-Myc, which acts as a 'gate-keeper' for the correct temporal and spatial development of the neural crest. PMID:27343897

  5. Bacterial Sphingomyelinases and Phospholipases as Virulence Factors.

    Science.gov (United States)

    Flores-Díaz, Marietta; Monturiol-Gross, Laura; Naylor, Claire; Alape-Girón, Alberto; Flieger, Antje

    2016-09-01

    Bacterial sphingomyelinases and phospholipases are a heterogeneous group of esterases which are usually surface associated or secreted by a wide variety of Gram-positive and Gram-negative bacteria. These enzymes hydrolyze sphingomyelin and glycerophospholipids, respectively, generating products identical to the ones produced by eukaryotic enzymes which play crucial roles in distinct physiological processes, including membrane dynamics, cellular signaling, migration, growth, and death. Several bacterial sphingomyelinases and phospholipases are essential for virulence of extracellular, facultative, or obligate intracellular pathogens, as these enzymes contribute to phagosomal escape or phagosomal maturation avoidance, favoring tissue colonization, infection establishment and progression, or immune response evasion. This work presents a classification proposal for bacterial sphingomyelinases and phospholipases that considers not only their enzymatic activities but also their structural aspects. An overview of the main physiopathological activities is provided for each enzyme type, as are examples in which inactivation of a sphingomyelinase- or a phospholipase-encoding gene impairs the virulence of a pathogen. The identification of sphingomyelinases and phospholipases important for bacterial pathogenesis and the development of inhibitors for these enzymes could generate candidate vaccines and therapeutic agents, which will diminish the impacts of the associated human and animal diseases. PMID:27307578

  6. The tRNA synthetase paralog PoxA modifies elongation factor-P with (R)-ß-lysine

    DEFF Research Database (Denmark)

    Roy, Hervé; Zou, S Betty; Bullwinkle, Tammy J;

    2011-01-01

    The lysyl-tRNA synthetase paralog PoxA modifies elongation factor P (EF-P) with a-lysine at low efficiency. Cell-free extracts containing non-a-lysine substrates of PoxA modified EF-P with a change in mass consistent with addition of ß-lysine, a substrate also predicted by genomic analyses. EF......-P was efficiently functionally modified with (R)-ß-lysine but not (S)-ß-lysine or genetically encoded a-amino acids, indicating that PoxA has evolved an activity orthogonal to that of the canonical aminoacyl-tRNA synthetases....

  7. Host-cell positive transcription elongation factor b kinase activity is essential and limiting for HIV type 1 replication

    OpenAIRE

    Flores, Osvaldo; Lee, Gary; Kessler, Joseph; Miller, Michael; Schlief, William; Tomassini, Joanne; Hazuda, Daria

    1999-01-01

    HIV-1 gene expression and viral replication require the viral transactivator protein Tat. The RNA polymerase II transcriptional elongation factor P-TEFb (cyclin-dependent kinase 9/cyclin T) is a cellular protein kinase that has recently been shown to be a key component of the Tat-transactivation process. For this report, we studied the requirement for P-TEFb in HIV-1 infection, and we now show that P-TEFb is both essential and limiting for HIV-1 replication. Attenuation of P-TEFb kinase activ...

  8. Elongation in translation as a dynamic interaction among the ribosome, tRNA, and elongation factors EF-G and EF-Tu

    OpenAIRE

    Agirrezabala, Xabier; Frank, Joachim

    2009-01-01

    The ribosome is a complex macromolecular machine that translates the message encoded in the messenger RNA and synthesizes polypeptides by linking the individual amino acids carried by the cognate transfer RNAs (tRNAs). The protein elongation cycle, during which the tRNAs traverse the ribosome in a coordinated manner along a path of more than 100 Å, is facilitated by large-scale rearrangements of the ribosome. These rearrangements go hand in hand with conformational changes of tRNA as well as ...

  9. Inactivation of the Elongation Factor Tu by Mosquitocidal Toxin-Catalyzed Mono-ADP-Ribosylation

    OpenAIRE

    Schirmer, Jörg; Wieden, Hans-Joachim; Rodnina, Marina V.; Aktories, Klaus

    2002-01-01

    The mosquitocidal toxin (MTX) produced by Bacillus sphaericus strain SSII-1 is an ∼97-kDa single-chain toxin which contains a 27-kDa enzyme domain harboring ADP-ribosyltransferase activity and a 70-kDa putative binding domain. Due to cytotoxicity toward bacterial cells, the 27-kDa enzyme fragment cannot be produced in Escherichia coli expression systems. However, a nontoxic 32-kDa N-terminal truncation of MTX can be expressed in E. coli and subsequently cleaved to an active 27-kDa enzyme frag...

  10. Contribution of Arg288 of Escherichia coli elongation factor Tu to translational functionality

    DEFF Research Database (Denmark)

    Rattenborg, Thomas; Nautrup-Pedersen, Gitte; Clark, Brian F. C.;

    1997-01-01

    network is disrupted upon formation of the ternary complex. Arg288 was replaced by alanine, isoleucine, lysine or glutamic acid, and the resulting mutants have been subjected to an in vitro characterisation with the aim of clarifying the function of Arg288. Unexpectedly, the mutants behaved like the wild......-type factor with regard to the association and dissociation of guanine nucleotides, and the intrinsic GTPase activities are unchanged. Furthermore, the mutants were as efficient as the wild-type factor in carrying out protein synthesis in vitro in the presence of an excess of aminoacyl-tRNA. However, the...

  11. Wolbachia transcription elongation factor "Wol GreA" interacts with α2ββ'σ subunits of RNA polymerase through its dimeric C-terminal domain.

    Directory of Open Access Journals (Sweden)

    Jeetendra Kumar Nag

    2014-06-01

    Full Text Available OBJECTIVES: Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for therapy against lymphatic filariasis. Transcription elongation factor GreA is an essential factor that mediates transcriptional transition from abortive initiation to productive elongation by stimulating the escape of RNA polymerase (RNAP from native prokaryotic promoters. Upon screening of 6257 essential bacterial genes, 57 were suggested as potential future drug targets, and GreA is among these. The current study emphasized the characterization of Wol GreA with its domains. METHODOLOGY/PRINCIPAL FINDINGS: Biophysical characterization of Wol GreA with its N-terminal domain (NTD and C-terminal domain (CTD was performed with fluorimetry, size exclusion chromatography, and chemical cross-linking. Filter trap and far western blotting were used to determine the domain responsible for the interaction with α2ββ'σ subunits of RNAP. Protein-protein docking studies were done to explore residual interaction of RNAP with Wol GreA. The factor and its domains were found to be biochemically active. Size exclusion and chemical cross-linking studies revealed that Wol GreA and CTD exist in a dimeric conformation while NTD subsists in monomeric conformation. Asp120, Val121, Ser122, Lys123, and Ser134 are the residues of CTD through which monomers of Wol GreA interact and shape into a dimeric conformation. Filter trap, far western blotting, and protein-protein docking studies revealed that dimeric CTD of Wol GreA through Lys82, Ser98, Asp104, Ser105, Glu106, Tyr109, Glu116, Asp120, Val121, Ser122, Ser127, Ser129, Lys140, Glu143, Val147, Ser151, Glu153, and Phe163 residues exclusively participates in binding with α2ββ'σ subunits of polymerase. CONCLUSIONS/SIGNIFICANCE: To the best of our knowledge, this research is the first documentation of the residual mode of action in wolbachial mutualist. Therefore, findings may be crucial to understanding the

  12. Mutations in a plastid-localized elongation factor G alter early stages of plastid development in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Hangarter Roger P

    2007-07-01

    Full Text Available Abstract Background Proper development of plastids in embryo and seedling tissues is critical for plant development. During germination, plastids develop to perform many critical functions that are necessary to establish the seedling for further growth. A growing body of work has demonstrated that components of the plastid transcription and translation machinery must be present and functional to establish the organelle upon germination. Results We have identified Arabidopsis thaliana mutants in a gene that encodes a plastid-targeted elongation factor G (SCO1 that is essential for plastid development during embryogenesis since two T-DNA insertion mutations in the coding sequence (sco1-2 and sco1-3 result in an embryo-lethal phenotype. In addition, a point mutation allele (sco1-1 and an allele with a T-DNA insertion in the promoter (sco1-4 of SCO1 display conditional seedling-lethal phenotypes. Seedlings of these alleles exhibit cotyledon and hypocotyl albinism due to improper chloroplast development, and normally die shortly after germination. However, when germinated on media supplemented with sucrose, the mutant plants can produce photosynthetically-active green leaves from the apical meristem. Conclusion The developmental stage-specific phenotype of the conditional-lethal sco1 alleles reveals differences in chloroplast formation during seedling germination compared to chloroplast differentiation in cells derived from the shoot apical meristem. Our identification of embryo-lethal mutant alleles in the Arabidopsis elongation factor G indicates that SCO1 is essential for plant growth, consistent with its predicted role in chloroplast protein translation.

  13. Vps Factors Are Required for Efficient Transcription Elongation in Budding Yeast

    Czech Academy of Sciences Publication Activity Database

    Gaur, N. A.; Hašek, Jiří; Brickner, D. G.; Qiu, H.; Zhang, F.; Wong, Ch.; M.; Malcová, Ivana; Vašicová, Pavla; Brickner, J. H.; Hinnebusch, A. G.

    2013-01-01

    Roč. 193, č. 3 (2013), s. 829-851. ISSN 0016-6731 R&D Projects: GA ČR GAP305/12/0480 Institutional support: RVO:61388971 Keywords : RNA-POLYMERASE-II * SACCHAROMYCES - CEREVISIAE GENOME * ELL-ASSOCIATED PROTEINS Subject RIV: EE - Microbiology, Virology Impact factor: 4.389, year: 2012

  14. Exploratory factor analysis for differentiating sensory and mechanical variables related to muscle-tendon unit elongation

    Directory of Open Access Journals (Sweden)

    Mauro H. Chagas

    2016-01-01

    Full Text Available ABSTRACT Background Stretching exercises are able to promote adaptations in the muscle-tendon unit (MTU, which can be tested through physiological and biomechanical variables. Identifying the key variables in MTU adaptations is crucial to improvements in training. Objective To perform an exploratory factor analysis (EFA involving the variables often used to evaluate the response of the MTU to stretching exercises. Method Maximum joint range of motion (ROMMAX, ROM at first sensation of stretching (FSTROM, peak torque (torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy were investigated in 36 participants during passive knee extension on an isokinetic dynamometer. Stiffness and energy values were normalized by the muscle cross-sectional area and their passive mode assured by monitoring the EMG activity. Results EFA revealed two major factors that explained 89.68% of the total variance: 53.13% was explained by the variables torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy, whereas the remaining 36.55% was explained by the variables ROMMAX and FSTROM. Conclusion This result supports the literature wherein two main hypotheses (mechanical and sensory theories have been suggested to describe the adaptations of the MTU to stretching exercises. Contrary to some studies, in the present investigation torqueMAX was significantly correlated with the variables of the mechanical theory rather than those of the sensory theory. Therefore, a new approach was proposed to explain the behavior of the torqueMAX during stretching exercises.

  15. Mapping the human translation elongation factor eEF1H complex using the yeast two-hybrid system

    DEFF Research Database (Denmark)

    Mansilla, Francisco; Friis, Irene; Jadidi, Mandana;

    2002-01-01

    In eukaryotes, the eukaryotic translation elongation factor eEF1A responsible for transporting amino-acylated tRNA to the ribosome forms a higher-order complex, eEF1H, with its guanine-nucleotide-exchange factor eEF1B. In metazoans, eEF1B consists of three subunits: eEF1B alpha, eEF1B eta and eEF1B...... gamma:eEF1B beta, where the last was observed using a three-hybrid approach. Surprisingly, eEF1A2 showed no or only little affinity for the guanine-nucleotide-exchange factors. Truncated versions of the subunits of eEF1B were used to orientate these subunits within the resulting model. The model unit is...... a pentamer composed of two molecules of eEF1A, each interacting with either eEF1B alpha or eEF1B beta held together by eEF1B gamma. These units can dimerize via eEF1B beta. Our model is compared with other models, and structural as well as functional aspects of the model are discussed....

  16. Depletion of elongation initiation factor 4E binding proteins by CRISPR/Cas9 genome editing enhances antiviral response in porcine cells

    Science.gov (United States)

    Type I interferons (IFN) are key mediators of the innate antiviral response in mammalian cells. Elongation initiation factor 4E binding proteins (4E-BPs) are translational controllers of interferon regulatory factor 7 (IRF7), the master regulator of IFN transcription. The role of 4EBPs in the negat...

  17. Factors that influence the speed of bacterial wood degradation

    NARCIS (Netherlands)

    Klaassen, R.K.W.M.; Overeem, van B.S.

    2012-01-01

    Bacterial wood decay is a serious threat to the many wooden foundation piles in the Netherlands. In order to learn more about the factors that influence the process of decay, approx. 2000 wood samples taken from Amsterdam piles heads were analysed on type and degree of decay and for 59 extracted pil

  18. Translation elongation factor 1A facilitates the assembly of the tombusvirus replicase and stimulates minus-strand synthesis.

    Directory of Open Access Journals (Sweden)

    Zhenghe Li

    Full Text Available Replication of plus-strand RNA viruses depends on host factors that are recruited into viral replicase complexes. Previous studies showed that eukaryotic translation elongation factor (eEF1A is one of the resident host proteins in the highly purified tombusvirus replicase complex. Using a random library of eEF1A mutants, we identified one mutant that decreased and three mutants that increased Tomato bushy stunt virus (TBSV replication in a yeast model host. Additional in vitro assays with whole cell extracts prepared from yeast strains expressing the eEF1A mutants demonstrated several functions for eEF1A in TBSV replication: facilitating the recruitment of the viral RNA template into the replicase complex; the assembly of the viral replicase complex; and enhancement of the minus-strand synthesis by promoting the initiation step. These roles for eEF1A are separate from its canonical role in host and viral protein translation, emphasizing critical functions for this abundant cellular protein during TBSV replication.

  19. Regulation of oxidative enzyme activity and eukaryotic elongation factor 2 in human skeletal muscle: influence of gender and exercise

    DEFF Research Database (Denmark)

    Roepstorff, Carsten; Schjerling, P.; Vistisen, Bodil;

    2005-01-01

    AIM: To investigate gender-related differences in the responses of oxidative enzymes and eukaryotic elongation factor-2 (eEF2) to exercise. METHODS: The influence of exercise (90 min, 60%VO(2peak)) on citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (HAD) activity and mRNA content......, together with eEF2 expression and phosphorylation at rest, were assessed in skeletal muscle of untrained (UT) and endurance trained (ET) females and males. RESULTS: Citrate synthase and HAD mRNA were higher in females than in males (27% and 48%, respectively, P < 0.05) whereas CS and HAD activity did not...... differ between females and males (NS). In females only, CS activity was enhanced (P < 0.05) by 90 min exercise. Resting CS mRNA content did not differ between UT and ET but, nevertheless, CS activity was 56% higher in ET than in UT volunteers (P < 0.001). HAD mRNA and activity were not influenced by...

  20. The nuclear elongation factor-1α gene: a promising marker for phylogenetic studies of Triatominae (Hemiptera: Reduviidae).

    Science.gov (United States)

    Díaz, Sebastián; Triana-Chávez, Omar; Gómez-Palacio, Andrés

    2016-09-01

    Molecular systematics is a remarkable approach for understanding the taxonomic traits and allows the exploration of the inter-population dynamics of several species in the Triatominae subfamily that are involved in Trypanosoma cruzi transmission. Compared to other relevant species that transmit vector-borne diseases, such as some species of the Diptera, there are relatively few nuclear genetic markers available for systematic studies in the Triatominae subfamily. Molecular systematic studies performed on Triatominae are based on mitochondrial gene fragments and, less frequently, on nuclear ribosomal genes or spacers. Due to the fact that these markers can occasionally present problems such as nuclear mitochondrial genes (NUMTs) or intra-genomic variation for high gene copy numbers, it is necessary to use additional nuclear markers to more reliably address the molecular evolution of Triatominae. In this study, we performed phylogenetic analysis using the nuclear elongation factor-1 alpha (EF-1α) gene in individuals from 12 species belonging to the Triatomini and Rhodniini tribes. Genetic diversities and phylogenetic topologies were compared with those obtained for the mitochondrial 16S rRNA and Cytochrome b (cyt b) genes, as well as for the D2 variable region of the ribosomal 28S rRNA gene. These results indicate that the EF-1α marker exhibits an intermediate level of diversity compared to mitochondrial and nuclear ribosomal genes, and that phylogenetic analysis based on EF-1α is highly informative for resolving deep phylogenetic relationships in Triatominae, such as tribe or genera. PMID:27268149

  1. Decoding the biosynthesis and function of diphthamide, an enigmatic modification of translation elongation factor 2 (EF2

    Directory of Open Access Journals (Sweden)

    Raffael Schaffrath

    2014-05-01

    Full Text Available Diphthamide is a highly conserved modification of archaeal and eukaryal translation elongation factor 2 (EF2 and yet why cells need EF2 to contain diphthamide is unclear. In yeast, the first steps of diphthamide synthesis and the genes (DPH1-DPH5 required to form the intermediate diphthine are well-documented. However, the last step, amidadation of diphthine to diphthamide, had largely been ill-defined. Remarkably, through mining genome-wide synthetic gene array (SGA and chemical genomics databases, recent studies by Uthman et al. [PLoS Genetics (2013 9, e1003334] and Su et al. [Proc. Natl. Acad. Sci. USA (2012 109, 19983-19987] have identified two more diphthamide players, DPH6 and DPH7. Consistent with roles in the amidation step, dph6 and dph7 deletion strains fail to complete diphthamide synthesis and accumulate diphthine-modified EF2. In contrast to Dph6, the catalytically relevant amidase, Dph7 appears to be regulatory. As shown by Uthman et al., it promotes dissociation of diphthine synthase (Dph5 from EF2, allowing diphthine amidation by Dph6 to occur and thereby coupling diphthine synthesis to the terminal step in the pathway. Remarkably, the study by Uthman et al. suggests that Dph5 has a novel role as an EF2 inhibitor that affects cell growth when diphthamide synthesis is blocked or incomplete and, importantly, shows that diphthamide promotes the accuracy of EF2 performance during translation.

  2. Endogenous ADP-ribosylation of elongation factor 2 in polyoma virus-transformed baby hamster kidney cells

    Energy Technology Data Exchange (ETDEWEB)

    Fendrick, J.L.; Iglewski, W.J. (Univ. of Rochester, NY (USA))

    1989-01-01

    Polyoma virus-transformed baby hamster kidney (pyBHK) cells were cultured in medium containing ({sup 32}P)orthophosphate and 105 (vol/vol) fetal bovine serum. A {sup 32}P-labeled protein with an apparent molecular mass of 97 kDa was immunoprecipitated from cell lysates with antiserum to ADP-ribosylated elongation factor 2 (EF-2). The {sup 32}P labeling of the protein was enhanced by culturing cells in medium containing 2% serum instead of 10% serum. The {sup 32}P label was completely removed from the protein by treatment with snake venom phosphodiesterase and the digestion product was identified as ({sup 32}P)AMP, indicating the protein was mono-ADP-ribosylated. HPLC analysis of tryptic peptides of the {sup 32}P-labeled 97-kDa protein and purified EF-2, which was ADP-ribosylated in vitro with diphtheria toxin fragment A and ({sup 32}P)NAD, demonstrated an identical labeled peptide in the two proteins. The data strongly suggest that EF-2 was endogenously ADP-ribosylated in pyBHK cells. Maximum incorporation of radioactivity in EF-2 occurred by 12 hr and remained constant over the subsequent 12 hr. It was estimated that 30-35% of the EF-2 was ADP-ribosylated in cells cultured in medium containing 2% serum. When {sup 32}P-labeled cultures were incubated in medium containing unlabeled phosphate, the {sup 32}P label was lost from the EF-2 within 30 min.

  3. Elongation Factor Tu Prevents Misediting of Gly-tRNA(Gly Caused by the Design Behind the Chiral Proofreading Site of D-Aminoacyl-tRNA Deacylase.

    Directory of Open Access Journals (Sweden)

    Satya Brata Routh

    2016-05-01

    Full Text Available D-aminoacyl-tRNA deacylase (DTD removes D-amino acids mischarged on tRNAs and is thus implicated in enforcing homochirality in proteins. Previously, we proposed that selective capture of D-aminoacyl-tRNA by DTD's invariant, cross-subunit Gly-cisPro motif forms the mechanistic basis for its enantioselectivity. We now show, using nuclear magnetic resonance (NMR spectroscopy-based binding studies followed by biochemical assays with both bacterial and eukaryotic systems, that DTD effectively misedits Gly-tRNAGly. High-resolution crystal structure reveals that the architecture of DTD's chiral proofreading site is completely porous to achiral glycine. Hence, L-chiral rejection is the only design principle on which DTD functions, unlike other chiral-specific enzymes such as D-amino acid oxidases, which are specific for D-enantiomers. Competition assays with elongation factor thermo unstable (EF-Tu and DTD demonstrate that EF-Tu precludes Gly-tRNAGly misediting at normal cellular concentrations. However, even slightly higher DTD levels overcome this protection conferred by EF-Tu, thus resulting in significant depletion of Gly-tRNAGly. Our in vitro observations are substantiated by cell-based studies in Escherichia coli that show that overexpression of DTD causes cellular toxicity, which is largely rescued upon glycine supplementation. Furthermore, we provide direct evidence that DTD is an RNA-based catalyst, since it uses only the terminal 2'-OH of tRNA for catalysis without the involvement of protein side chains. The study therefore provides a unique paradigm of enzyme action for substrate selection/specificity by DTD, and thus explains the underlying cause of DTD's activity on Gly-tRNAGly. It also gives a molecular and functional basis for the necessity and the observed tight regulation of DTD levels, thereby preventing cellular toxicity due to misediting.

  4. Elongation Factor Tu Prevents Misediting of Gly-tRNA(Gly) Caused by the Design Behind the Chiral Proofreading Site of D-Aminoacyl-tRNA Deacylase.

    Science.gov (United States)

    Routh, Satya Brata; Pawar, Komal Ishwar; Ahmad, Sadeem; Singh, Swati; Suma, Katta; Kumar, Mantu; Kuncha, Santosh Kumar; Yadav, Kranthikumar; Kruparani, Shobha P; Sankaranarayanan, Rajan

    2016-05-01

    D-aminoacyl-tRNA deacylase (DTD) removes D-amino acids mischarged on tRNAs and is thus implicated in enforcing homochirality in proteins. Previously, we proposed that selective capture of D-aminoacyl-tRNA by DTD's invariant, cross-subunit Gly-cisPro motif forms the mechanistic basis for its enantioselectivity. We now show, using nuclear magnetic resonance (NMR) spectroscopy-based binding studies followed by biochemical assays with both bacterial and eukaryotic systems, that DTD effectively misedits Gly-tRNAGly. High-resolution crystal structure reveals that the architecture of DTD's chiral proofreading site is completely porous to achiral glycine. Hence, L-chiral rejection is the only design principle on which DTD functions, unlike other chiral-specific enzymes such as D-amino acid oxidases, which are specific for D-enantiomers. Competition assays with elongation factor thermo unstable (EF-Tu) and DTD demonstrate that EF-Tu precludes Gly-tRNAGly misediting at normal cellular concentrations. However, even slightly higher DTD levels overcome this protection conferred by EF-Tu, thus resulting in significant depletion of Gly-tRNAGly. Our in vitro observations are substantiated by cell-based studies in Escherichia coli that show that overexpression of DTD causes cellular toxicity, which is largely rescued upon glycine supplementation. Furthermore, we provide direct evidence that DTD is an RNA-based catalyst, since it uses only the terminal 2'-OH of tRNA for catalysis without the involvement of protein side chains. The study therefore provides a unique paradigm of enzyme action for substrate selection/specificity by DTD, and thus explains the underlying cause of DTD's activity on Gly-tRNAGly. It also gives a molecular and functional basis for the necessity and the observed tight regulation of DTD levels, thereby preventing cellular toxicity due to misediting. PMID:27224426

  5. Elongation Factor Tu Prevents Misediting of Gly-tRNA(Gly) Caused by the Design Behind the Chiral Proofreading Site of D-Aminoacyl-tRNA Deacylase

    Science.gov (United States)

    Routh, Satya Brata; Ahmad, Sadeem; Suma, Katta; Kumar, Mantu; Kuncha, Santosh Kumar; Yadav, Kranthikumar; Kruparani, Shobha P; Sankaranarayanan, Rajan

    2016-01-01

    D-aminoacyl-tRNA deacylase (DTD) removes D-amino acids mischarged on tRNAs and is thus implicated in enforcing homochirality in proteins. Previously, we proposed that selective capture of D-aminoacyl-tRNA by DTD’s invariant, cross-subunit Gly-cisPro motif forms the mechanistic basis for its enantioselectivity. We now show, using nuclear magnetic resonance (NMR) spectroscopy-based binding studies followed by biochemical assays with both bacterial and eukaryotic systems, that DTD effectively misedits Gly-tRNAGly. High-resolution crystal structure reveals that the architecture of DTD’s chiral proofreading site is completely porous to achiral glycine. Hence, L-chiral rejection is the only design principle on which DTD functions, unlike other chiral-specific enzymes such as D-amino acid oxidases, which are specific for D-enantiomers. Competition assays with elongation factor thermo unstable (EF-Tu) and DTD demonstrate that EF-Tu precludes Gly-tRNAGly misediting at normal cellular concentrations. However, even slightly higher DTD levels overcome this protection conferred by EF-Tu, thus resulting in significant depletion of Gly-tRNAGly. Our in vitro observations are substantiated by cell-based studies in Escherichia coli that show that overexpression of DTD causes cellular toxicity, which is largely rescued upon glycine supplementation. Furthermore, we provide direct evidence that DTD is an RNA-based catalyst, since it uses only the terminal 2′-OH of tRNA for catalysis without the involvement of protein side chains. The study therefore provides a unique paradigm of enzyme action for substrate selection/specificity by DTD, and thus explains the underlying cause of DTD’s activity on Gly-tRNAGly. It also gives a molecular and functional basis for the necessity and the observed tight regulation of DTD levels, thereby preventing cellular toxicity due to misediting. PMID:27224426

  6. Crosslinking of tRNA containing a long extra arm to elongation factor Tu by trans-diamminedichloroplatinum(II)

    DEFF Research Database (Denmark)

    Rasmussen, Nils-Jørgen; Wikman, Friedrik; Clark, Brian F. C.

    1990-01-01

    A tRNA containing a long extra arm, namely E. coli tRNA1Leu has been crosslinked to elongation factor Tu, with the crosslinking reagent trans-diamminedichloroplatinum(II). The nucleotide involved in the crosslinking was identified to be a guanosine in the variable region at position 47F or 47G....

  7. Identification and cloning of two immunogenic C. perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO) of Clostridium perfringens

    Science.gov (United States)

    Clostridium related poultry diseases such as necrotic enteritis (NE) and gangrenous dermatitis (GD) cause substantial economic losses on a global scale. Two antigenic C. perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO), were identified by reaction with...

  8. Synthesis of Elongated Microcapsules

    Science.gov (United States)

    Li, Wenyan; Buhrow, Jerry; Calle, Luz M.

    2011-01-01

    One of the factors that influence the effectiveness of self-healing in functional materials is the amount of liquid healing agents that can be delivered to the damaged area. The use of hollow tubes or fibers and the more sophisticated micro-vascular networks has been proposed as a way to increase the amount of healing agents that can be released when damage is inflicted. Although these systems might be effective in some specific applications, they are not practical for coatings applications. One possible practical way to increase the healing efficiency is to use microcapsules with high-aspect-ratios, or elongated microcapsules. It is understood that elongated microcapsules will be more efficient because they can release more healing agent than a spherical microcapsule when a crack is initiated in the coating. Although the potential advantage of using elongated microcapsules for self healing applications is clear, it is very difficult to make elongated microcapsules from an emulsion system because spherical microcapsules are normally formed due to the interfacial tension between the dispersed phase and the continuous phase. This paper describes the two methods that have been developed by the authors to synthesize elongated microcapsules. The first method involves the use of an emulsion with intermediate stability and the second involves the application of mechanical shear conditions to the emulsion.

  9. Mitochondrial translation factors of Trypanosoma brucei: elongation factor-Tu has a unique subdomain that is essential for its function

    Czech Academy of Sciences Publication Activity Database

    Cristodero, M.; Mani, J.; Oeljeklaus, S.; Aeberhard, L.; Hashimi, Hassan; Ramrath, D.J.F.; Lukeš, Julius; Warscheid, B.; Schneider, A.

    2013-01-01

    Roč. 90, č. 4 (2013), s. 744-755. ISSN 0950-382X R&D Projects: GA ČR GAP305/12/2261 Institutional support: RVO:60077344 Keywords : mitochondrial translation * Trypanosoma brucei * EF-Tu Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.026, year: 2013

  10. Systematic Analysis Reveals Elongation Factor 2 and α-Enolase as Novel Interaction Partners of AKT2.

    Directory of Open Access Journals (Sweden)

    Katharina Bottermann

    Full Text Available AKT2 is one of the three isoforms of the protein kinase AKT being involved in the modulation of cellular metabolism. Since protein-protein interactions are one possibility to convey specificity in signal transduction, we performed AKT2-protein interaction analysis to elucidate their relevance for AKT2-dependent cellular functions. We identified heat shock protein 90 kDa (HSP90, Cdc37, heat shock protein 70 kDa (HSP70, 78 kDa glucose regulated protein (GRP78, tubulin, GAPDH, α-enolase and elongation factor 2 (EF2 as AKT2-interacting proteins by a combination of tandem affinity purification and mass spectrometry in HEK293T cells. Quantitative MS-analysis using stable isotope labeling by amino acids in cell culture (SILAC revealed that only HSP90 and Cdc37 interact stably with AKT2, whereas the other proteins interact with low affinity with AKT2. The interactions of AKT2 with α-enolase and EF2 were further analyzed in order to uncover the functional relevance of these newly discovered binding partners. Despite the interaction of AKT2 and α-enolase, which was additionally validated by proximity ligation assay (PLA, no significant impact of AKT on α-enolase activity was detected in activity measurements. AKT stimulation via insulin and/or inhibition with the ATP-competitive inhibitor CCT128930 did not alter enzymatic activity of α-enolase. Interestingly, the direct interaction of AKT2 and EF2 was found to be dynamically regulated in embryonic rat cardiomyocytes. Treatment with the PI3-kinase inhibitor LY294002 before stimulation with several hormones stabilized the complex, whereas stimulation alone led to complex dissociation which was analyzed in situ with PLA. Taken together, these findings point to new aspects of AKT2-mediated signal transduction in protein synthesis and glucose metabolism.

  11. A structural domain mediates attachment of ethanolamine phosphoglycerol to eukaryotic elongation factor 1A in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Eva Greganova

    Full Text Available Ethanolamine phosphoglycerol (EPG represents a protein modification that so far has only been found in eukaryotic elongation factor 1A (eEF1A. In mammals and plants, EPG is covalently attached to two conserved glutamate residues located in domains II and III of eEF1A. In contrast, Trypanosoma brucei eEF1A contains a single EPG attached to Glu362 in domain III. The sequence and/or structural requirements for covalent linkage of EPG to eEF1A have not been determined for any organism. Using a combination of biosynthetic labelling of parasites with tritiated ethanolamine and mass spectrometry analyses, we demonstrate that replacement of Glu362 in T. brucei eEF1A by site-directed mutagenesis prevents EPG attachment, whereas single or multiple amino acid substitutions around the attachment site are not critical. In addition, by expressing a series of eEF1A deletion mutants in T. brucei procyclic forms, we demonstrate that a peptide consisting of 80 amino acids of domain III of eEF1A is sufficient for EPG attachment to occur. Furthermore, EPG addition also occurs if domain III of eEF1A is fused to a soluble reporter protein. To our knowledge, this is the first report addressing amino acid sequence, or structure, requirements for EPG modification of eEF1A in any organism. Using T. brucei as a model organism, we show that amino acid substitutions around the modification site are not critical for EPG attachment and that a truncated version of domain III of eEF1A is sufficient to mediate EPG addition.

  12. Interaction of plant chimeric calcium/calmodulin-dependent protein kinase with a homolog of eukaryotic elongation factor-1alpha

    Science.gov (United States)

    Wang, W.; Poovaiah, B. W.

    1999-01-01

    A chimeric Ca2+/calmodulin-dependent protein kinase (CCaMK) was previously cloned and characterized in this laboratory. To investigate the biological functions of CCaMK, the yeast two-hybrid system was used to isolate genes encoding proteins that interact with CCaMK. One of the cDNA clones obtained from the screening (LlEF-1alpha1) has high similarity with the eukaryotic elongation factor-1alpha (EF-1alpha). CCaMK phosphorylated LlEF-1alpha1 in a Ca2+/calmodulin-dependent manner. The phosphorylation site for CCaMK (Thr-257) was identified by site-directed mutagenesis. Interestingly, Thr-257 is located in the putative tRNA-binding region of LlEF-1alpha1. An isoform of Ca2+-dependent protein kinase (CDPK) phosphorylated multiple sites of LlEF-1alpha1 in a Ca2+-dependent but calmodulin-independent manner. Unlike CDPK, CCaMK phosphorylated only one site, and this site is different from CDPK phosphorylation sites. This suggests that the phosphorylation of EF-1alpha by these two kinases may have different functional significance. Although the phosphorylation of LlEF-1alpha1 by CCaMK is Ca2+/calmodulin-dependent, in vitro binding assays revealed that CCaMK binds to LlEF-1alpha1 in a Ca2+-independent manner. This was further substantiated by coimmunoprecipitation of CCaMK and EF-1alpha using the protein extract from lily anthers. Dissociation of CCaMK from EF-1alpha by Ca2+ and phosphorylation of EF-1alpha by CCaMK in a Ca2+/calmodulin-dependent manner suggests that these interactions may play a role in regulating the biological functions of EF-1alpha.

  13. Analysis of a splice array experiment elucidates roles of chromatin elongation factor Spt4-5 in splicing.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Xiao

    2005-09-01

    Full Text Available Splicing is an important process for regulation of gene expression in eukaryotes, and it has important functional links to other steps of gene expression. Two examples of these linkages include Ceg1, a component of the mRNA capping enzyme, and the chromatin elongation factors Spt4-5, both of which have recently been shown to play a role in the normal splicing of several genes in the yeast Saccharomyces cerevisiae. Using a genomic approach to characterize the roles of Spt4-5 in splicing, we used splicing-sensitive DNA microarrays to identify specific sets of genes that are mis-spliced in ceg1, spt4, and spt5 mutants. In the context of a complex, nested, experimental design featuring 22 dye-swap array hybridizations, comprising both biological and technical replicates, we applied five appropriate statistical models for assessing differential expression between wild-type and the mutants. To refine selection of differential expression genes, we then used a robust model-synthesizing approach, Differential Expression via Distance Synthesis, to integrate all five models. The resultant list of differentially expressed genes was then further analyzed with regard to select attributes: we found that highly transcribed genes with long introns were most sensitive to spt mutations. QPCR confirmation of differential expression was established for the limited number of genes evaluated. In this paper, we showcase splicing array technology, as well as powerful, yet general, statistical methodology for assessing differential expression, in the context of a real, complex experimental design. Our results suggest that the Spt4-Spt5 complex may help coordinate splicing with transcription under conditions that present kinetic challenges to spliceosome assembly or function.

  14. The surface-associated elongation factor Tu is concealed for antibody binding on viable pneumococci and meningococci.

    Science.gov (United States)

    Kolberg, Jan; Hammerschmidt, Sven; Frank, Ronald; Jonák, Jirí; Sanderová, Hana; Aase, Audun

    2008-07-01

    Proteome analyses revealed that elongation factor-Tu (EF-Tu) is associated with cytoplasmic membranes of Gram-positive bacteria and outer membranes of Gram-negative bacteria. It is still debatable whether EF-Tu is located on the external side or the internal side of the membranes. Here, we have generated two new monoclonal antibodies (mAbs) and polyclonal rabbit antibodies against pneumococcal EF-Tu. These antibodies were used to investigate the amount of surface-exposed EF-Tu on viable bacteria using a flow cytometric analysis. The control antibodies recognizing the pneumococcal surface protein A and phosphorylcholine showed a significant binding to viable pneumococci. In contrast, anti-EF-Tu antibodies did not recognize pneumococcal EF-Tu. However, heat killing of pneumococci lacking capsular polysaccharides resulted in specific antibody binding to EF-Tu and, moreover, increased the exposure of recognized phosphorylcholine epitopes. Similarly, our EF-Tu-specific antibodies did not recognize EF-Tu of viable Neisseria meningitidis. However, pretreatment of meningococci with ethanol resulted in specific antibody binding to EF-Tu on outer membranes. Importantly, these treatments did not destroy the membrane integrity as analysed with control mAbs directed against cytoplasmic proteins. In conclusion, our flow cytrometric assays emphasize the importance of using viable bacteria and not heat-killed or ethanol-treated bacteria for surface-localization experiments of proteins, because these treatments modulate the cytoplasmic and outer membranes of bacteria and the binding results may not reflect the situation under physiological conditions. PMID:18462389

  15. Crystallization and preliminary X-ray analysis of the mRNA-binding domain of elongation factor SelB in complex with RNA

    International Nuclear Information System (INIS)

    The mRNA-binding domain of M. thermoacetica selenocysteine-specific elongation factor SelB (residues 512–634, SelB-M) was overproduced in E. coli and its cognate mRNA ligand, 23 nucleotides of the SECIS RNA hairpin, was chemically prepared. The purified SelB-M–SECIS RNA complex has been crystallized in space group P21212 and diffracted to 2.3 Å

  16. Factors affecting proliferation and elongation of shoots of Phak Liang (Gnetum gnemon Linn.) through tissue culture technique

    OpenAIRE

    Te-chato, S.; Noochum, P.

    2003-01-01

    The tissue culture of Phak Liang (Gnetum gnemon Linn.) was investigated for micropropagation. The types of explant, culture media, types and concentrations of plant growth regulators, orientation of explant and section of explant were tested for their efficacy in inducing and proliferating shoot buds. The elongation of shoots and root induction was also studied. Young leaves gave the highest number of shoot buds when they were cultured in Murashige and Skoog (MS) medium supplemented with 0.25...

  17. A new purification scheme for elongation factor 1 from rabbit reticulocytes and investigation of the homology of the subunits with those of initiation factor 2.

    Science.gov (United States)

    Moretti, S; Staehelin, T; Trachsel, H; Gordon, J

    1979-07-01

    The aim of this work was to compare the subunits of the elongation factor EF-1 and the initiation factor eIF-2 from rabbit reticulocytes. We devised a simple procedure for the purification of EF-1: stepwise chromatography on heparin-Sepharose, separation of the heavy form by sucrose gradient centrifugation, and a final step of stepwise chromatography on RNA-Sepharose. The heparin-Sepharose column also clearly separated EF-1 and EF-2 within one chromatographic step. The EF-1 was 350-fold puried and the yield was 10%. This preparation showed after electrophoresis on polyacylamide gels in the presence of sodium dodecyl sulfate three bands corresponding to those described by others as the subunits, with Mr of 54000, 49000 and 29200. An additional band of Mr 34000 was present but no others. The 49000-Mr and 34000-Mr bands corresponded exactly in molecular weight to two of three subunits of eIF-2. A more detailed comparison was therefore made of all subunits of EF-1 and eIF-2. This was done by examination of chymotryptic fingerprints on polyacrylamide gel electrophoresis. No evidence for homology between EF-1 and eIF-2 was found. However, the two larger subunits of eIF-2 had a majority of chymotryptic fragments in common, thus indicating some homology between these polypeptides. PMID:467435

  18. Oxidation of a Cysteine Residue in Elongation Factor EF-Tu Reversibly Inhibits Translation in the Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Yutthanasirikul, Rayakorn; Nagano, Takanori; Jimbo, Haruhiko; Hihara, Yukako; Kanamori, Takashi; Ueda, Takuya; Haruyama, Takamitsu; Konno, Hiroki; Yoshida, Keisuke; Hisabori, Toru; Nishiyama, Yoshitaka

    2016-03-11

    Translational elongation is susceptible to inactivation by reactive oxygen species (ROS) in the cyanobacterium Synechocystis sp. PCC 6803, and elongation factor G has been identified as a target of oxidation by ROS. In the present study we examined the sensitivity to oxidation by ROS of another elongation factor, EF-Tu. The structure of EF-Tu changes dramatically depending on the bound nucleotide. Therefore, we investigated the sensitivity to oxidation in vitro of GTP- and GDP-bound EF-Tu as well as that of nucleotide-free EF-Tu. Assays of translational activity with a reconstituted translation system from Escherichia coli revealed that GTP-bound and nucleotide-free EF-Tu were sensitive to oxidation by H2O2, whereas GDP-bound EF-Tu was resistant to H2O2. The inactivation of EF-Tu was the result of oxidation of Cys-82, a single cysteine residue, and subsequent formation of both an intermolecular disulfide bond and sulfenic acid. Replacement of Cys-82 with serine rendered EF-Tu resistant to inactivation by H2O2, confirming that Cys-82 was a target of oxidation. Furthermore, oxidized EF-Tu was reduced and reactivated by thioredoxin. Gel-filtration chromatography revealed that some of the oxidized nucleotide-free EF-Tu formed large complexes of >30 molecules. Atomic force microscopy revealed that such large complexes dissociated into several smaller aggregates upon the addition of dithiothreitol. Immunological analysis of the redox state of EF-Tu in vivo showed that levels of oxidized EF-Tu increased under strong light. Thus, resembling elongation factor G, EF-Tu appears to be sensitive to ROS via oxidation of a cysteine residue, and its inactivation might be reversed in a redox-dependent manner. PMID:26786107

  19. Function of the Bacillus subtilis transcription elongation factor NusG in hairpin-dependent RNA polymerase pausing in the trp leader

    OpenAIRE

    Yakhnin, Alexander V.; Yakhnin, Helen; Babitzke, Paul

    2008-01-01

    NusA and NusG are transcription elongation factors that bind to RNA polymerase (RNAP) after σ subunit release. Escherichia coli NusA (NusAEc) stimulates intrinsic termination and RNAPEc pausing, whereas NusGEc promotes Rho-dependent termination and pause escape. Both Nus factors also participate in the formation of RNAPEc antitermination complexes. We showed that Bacillus subtilis NusA (NusABs) stimulates intrinsic termination and RNAPBs pausing at U107 and U144 in the trpEDCFBA operon leader...

  20. Translationally controlled tumor protein acts as a guanine nucleotide dissociation inhibitor on the translation elongation factor eEF1A

    OpenAIRE

    Cans, Christophe; Passer, Brent J.; Shalak, Vyacheslav; Nancy-Portebois, Vanessa; Crible, Virginie; Amzallag, Nathalie; Allanic, David; Tufino, Rowena; Argentini, Manuela; Moras, Dino; Fiucci, Giusy; Goud, Bruno; Mirande, Marc; Amson, Robert; Telerman, Adam

    2003-01-01

    Recently, we demonstrated that the expression levels of the translationally controlled tumor protein (TCTP) were strongly down-regulated at the mRNA and protein levels during tumor reversion/suppression and by the activation of p53 and Siah-1. To better characterize the function of TCTP, a yeast two-hybrid hunt was performed. Subsequent analysis identified the translation elongation factor, eEF1A, and its guanine nucleotide exchange factor, eEF1Bβ, as TCTP-interacting partners. In vitro and i...

  1. Factors affecting proliferation and elongation of shoots of Phak Liang (Gnetum gnemon Linn. through tissue culture technique

    Directory of Open Access Journals (Sweden)

    Te-chato, S.

    2003-09-01

    Full Text Available The tissue culture of Phak Liang (Gnetum gnemon Linn. was investigated for micropropagation. The types of explant, culture media, types and concentrations of plant growth regulators, orientation of explant and section of explant were tested for their efficacy in inducing and proliferating shoot buds. The elongation of shoots and root induction was also studied. Young leaves gave the highest number of shoot buds when they were cultured in Murashige and Skoog (MS medium supplemented with 0.25 mg/l IBA and 1.53 mg/l BA. The medium supplemented with 0.25 mg/l thidiazuron (TDZ alone provided the best result on multiple shoot bud induction both in percentage of explant forming shoots and number of shoot buds per explant. The percentage of explant forming shoot buds and number of shoot buds obtained from leaves were 90% and 26.50 shoot buds, while those from stems were 96.25% and 23.00 shoot buds, respectively. One hundred percent friable callus was induced from stem explant in the same medium supplemented with 1.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D after 2 months of culture. Culturing whole leaf in the position of dorsal contact with medium gave the best multiple shoot bud formation of 92% and 23.00 shoot buds/explant. Cutting stem into half and culturing in horizontal position gave the best multiple shoot bud formation of 96% and 23.00 shoot buds/explant after culture for 2 months. The best elongation of shoot buds (2.54 shoots derived from cultured leaves was induced in the liquid medium. While stem-derived shoot buds (3.45 shoots was induced in the solid medium of the same medium components. However, root could not be induced from elongated shoots.

  2. Regulation of Transcription Elongation and Termination

    Directory of Open Access Journals (Sweden)

    Robert S. Washburn

    2015-05-01

    Full Text Available This article will review our current understanding of transcription elongation and termination in E. coli. We discuss why transcription elongation complexes pause at certain template sites and how auxiliary host and phage transcription factors affect elongation and termination. The connection between translation and transcription elongation is described. Finally we present an overview indicating where progress has been made and where it has not.

  3. Severe bacterial infections in patients with non-transfusion-dependent thalassemia: prevalence and clinical risk factors

    Directory of Open Access Journals (Sweden)

    Nattiya Teawtrakul

    2015-10-01

    Conclusion: The prevalence of bacterial infection in patients with NTDT was found to be moderate. Time after splenectomy >10 years, deferoxamine therapy, and iron overload may be clinical risk factors for severe bacterial infection in patients with NTDT. Bacterial infection should be recognized in splenectomized patients with NTDT, particularly those who have an iron overload.

  4. Severe bacterial infections in patients with non-transfusion-dependent thalassemia: prevalence and clinical risk factors

    OpenAIRE

    Nattiya Teawtrakul; Arunee Jetsrisuparb; Chittima Sirijerachai; Kanchana Chansung; Chinadol Wanitpongpun

    2015-01-01

    Introduction: Bacterial infection is one of the major causes of death in patients with thalassemia. Clinical predictive factors for severe bacterial infection were evaluated in patients with non-transfusion-dependent thalassemia (NTDT). Methods: A retrospective study was conducted of patients with NTDT aged ≥10 years at Srinagarind Hospital, Khon Kaen University, Thailand. Clinical characteristics and potential clinical risk factors for bacterial infection were collected. Risk factors for ...

  5. Axonal transport of eukaryotic translation elongation factor 1α mRNA couples transcription in the nucleus to long-term facilitation at the synapse

    OpenAIRE

    Giustetto, Maurizio; Hegde, Ashok N.; Si, Kausik; Casadio, Andrea; Inokuchi, Kaoru; Pei, Wanzheng; Kandel, Eric R.; Schwartz, James H.

    2003-01-01

    Long-term synaptic plasticity requires both gene expression in the nucleus and local protein synthesis at synapses. The effector proteins that link molecular events in the cell body with local maintenance of synaptic strength are not known. We now show that treatment with serotonin (5-HT) that produces long-term facilitation induces the Aplysia eukaryotic translation elongation factor 1α (Ap-eEF1A) as a late gene that might serve this coupling function in sensory neurons. Although the transla...

  6. A Conserved Loop in the Catalytic Domain of Eukaryotic Elongation Factor 2 Kinase Plays a Key Role in Its Substrate Specificity

    OpenAIRE

    Moore, Claire E.; Regufe da Mota, Sergio; Mikolajek, Halina; Proud, Christopher G.

    2014-01-01

    Eukaryotic elongation factor 2 kinase (eEF2K) is the best-characterized member of the α-kinase family. Within this group, only eEF2K and myosin heavy chain kinases (MHCKs) have known substrates. Here we have studied the roles of specific residues, selected on the basis of structural data for MHCK A and TRPM7, in the function of eEF2K. Our data provide the first information regarding the basis of the substrate specificity of α-kinases, in particular the roles of residues in the so-called N/D l...

  7. Mutation of the conserved Gly94 and Gly126 in elongation factor Tu from Escherichia coli. Elucidation of their structural and functional roles

    DEFF Research Database (Denmark)

    Knudsen, Charlotte Rohde; Kjaersgård, I V; Wiborg, O;

    1995-01-01

    All guanine-nucleotide-binding proteins cycle between an inactive, GDP-bound and an active, GTP-bound conformation whereby they function as molecular switches. Elongation factor Tu from Escherichia coli is used as a model for defining residues important in the switch mechanism. Gly94 and Gly126...... were separately mutated to alanine residues to study their role in the switch mechanism. The mutant proteins are denoted [G94A]EF-Tu and [G126A]EF-Tu, respectively. Both mutations affect the affinities for guanine nucleotides considerably, resulting in a decrease in the characteristic preference for...

  8. Nucleotide sequence of a Euglena gracilis chloroplast genome region coding for the elongation factor Tu; evidence for a spliced mRNA.

    OpenAIRE

    Montandon, P E; Stutz, E

    1983-01-01

    We characterize a 1.95 kb transcription product of the Euglena gracilis chloroplast DNA fragment Eco-N + Q by S1 nuclease analysis and DNA sequencing and show that it is the product of three splicing events. Exon 1 (0.45 kb), exon 2 (0.74 kb) and 175 nucleotides of exon 3 (0.53 kb) code for the chloroplast elongation factor protein (EF-Tu). The remaining part of exon 3 and exon 4 (0.23 kb) have unidentified open reading frames. The chloroplast EF-Tu protein has 408 aminoacids and is to 70% ho...

  9. Increased expression of stathmin and elongation factor 1α in precancerous nodules with telomere dysfunction in hepatitis B viral cirrhotic patients

    OpenAIRE

    Ahn, Ei Yong; Yoo, Jeong Eun; Rhee, Hyungjin; Kim, Myung Soo; Choi, Junjeong; Ko, Jung Eun; Lee, Jee San; Park, Young Nyun

    2014-01-01

    Background Telomere dysfunction is important in carcinogenesis, and recently, stathmin and elongation factor 1α (EF1α) were reported to be up-regulated in telomere dysfunctional mice. Methods In the present study, the expression levels of stathmin and EF1α in relation to telomere length, telomere dysfunction-induced foci (TIF), γ-H2AX, and p21WAF1/CIP1 expression were assessed in specimens of hepatitis B virus (HBV)-related multistep hepatocarcinogenesis, including 13 liver cirrhosis specimen...

  10. Risk factors for community-acquired bacterial meningitis in adults

    NARCIS (Netherlands)

    K.S. Adriani

    2015-01-01

    Bacterial meningitis is an inflammation of the meninges and occurs when bacteria invade the subarachnoid space. The meninges are the protective membranes that surround the brain and the spinal cord. Bacterial meningitis is a life-threatening disease because the proximity of the infection to the brai

  11. The translation elongation factor eEF-1Bβ1 is involved in cell wall biosynthesis and plant development in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Zakir Hossain

    Full Text Available The eukaryotic translation elongation factor eEF-1Bβ1 (EF1Bβ is a guanine nucleotide exchange factor that plays an important role in translation elongation. In this study, we show that the EF1Bβ protein is localized in the plasma membrane and cytoplasm, and that the transcripts should be expressed in most tissue types in seedlings. Sectioning of the inflorescence stem revealed that EF1Bβ predominantly localizes to the xylem vessels and in the interfascicular cambium. EF1Bβ gene silencing in efβ caused a dwarf phenotype with 38% and 20% reduction in total lignin and crystalline cellulose, respectively. This loss-of-function mutant also had a lower S/G lignin monomer ratio relative to wild type plants, but no changes were detected in a gain-of-function mutant transformed with the EF1Bβ gene. Histochemical analysis showed a reduced vascular apparatus, including smaller xylem vessels in the inflorescence stem of the loss-of-function mutant. Over-expression of EF1Bβ in an eli1 mutant background restored a WT phenotype and abolished ectopic lignin deposition as well as cell expansion defects in the mutant. Taken together, these data strongly suggest a role for EF1Bβ in plant development and cell wall formation in Arabidopsis.

  12. The transcription elongation factor ELL2 is specifically upregulated in HTLV-1-infected T-cells and is dependent on the viral oncoprotein Tax

    International Nuclear Information System (INIS)

    The oncoprotein Tax of human T-cell leukemia virus type 1 (HTLV-1) is a potent transactivator of viral and cellular transcription. Here, we identified ELL2 as the sole transcription elongation factor to be specifically upregulated in HTLV-1-/Tax-transformed T-cells. Tax contributes to regulation of ELL2, since transient transfection of Tax increases ELL2 mRNA, Tax transactivates the ELL2 promoter, and repression of Tax results in decrease of ELL2 in transformed T-lymphocytes. However, we also measured upregulation of ELL2 in HTLV-1-transformed cells exhibiting undetectable amounts of Tax, suggesting that ELL2 can still be maintained independent of continuous Tax expression. We further show that Tax and ELL2 synergistically activate the HTLV-1 promoter, indicating that ELL2 cooperates with Tax in viral transactivation. This is supported by our findings that Tax and ELL2 accumulate in nuclear fractions and that they co-precipitate upon co-expression in transiently-transfected cells. Thus, upregulation of ELL2 could contribute to HTLV-1 gene regulation. - Highlights: • ELL2, a transcription elongation factor, is upregulated in HTLV-1-positive T-cells. • Tax transactivates the ELL2 promoter. • Tax and ELL2 synergistically activate the HTLV-1 promoter. • Tax and ELL2 interact in vivo

  13. The transcription elongation factor ELL2 is specifically upregulated in HTLV-1-infected T-cells and is dependent on the viral oncoprotein Tax

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Melanie C., E-mail: melanie.mann@viro.med.uni-erlangen.de; Strobel, Sarah, E-mail: sarah.strobel@viro.med.uni-erlangen.de; Fleckenstein, Bernhard, E-mail: bernhard.fleckenstein@viro.med.uni-erlangen.de; Kress, Andrea K., E-mail: andrea.kress@viro.med.uni-erlangen.de

    2014-09-15

    The oncoprotein Tax of human T-cell leukemia virus type 1 (HTLV-1) is a potent transactivator of viral and cellular transcription. Here, we identified ELL2 as the sole transcription elongation factor to be specifically upregulated in HTLV-1-/Tax-transformed T-cells. Tax contributes to regulation of ELL2, since transient transfection of Tax increases ELL2 mRNA, Tax transactivates the ELL2 promoter, and repression of Tax results in decrease of ELL2 in transformed T-lymphocytes. However, we also measured upregulation of ELL2 in HTLV-1-transformed cells exhibiting undetectable amounts of Tax, suggesting that ELL2 can still be maintained independent of continuous Tax expression. We further show that Tax and ELL2 synergistically activate the HTLV-1 promoter, indicating that ELL2 cooperates with Tax in viral transactivation. This is supported by our findings that Tax and ELL2 accumulate in nuclear fractions and that they co-precipitate upon co-expression in transiently-transfected cells. Thus, upregulation of ELL2 could contribute to HTLV-1 gene regulation. - Highlights: • ELL2, a transcription elongation factor, is upregulated in HTLV-1-positive T-cells. • Tax transactivates the ELL2 promoter. • Tax and ELL2 synergistically activate the HTLV-1 promoter. • Tax and ELL2 interact in vivo.

  14. Investigation of functional aspects of the N-terminal region of elongation factor Tu from Escherichia coli using a protein engineering approach

    DEFF Research Database (Denmark)

    Laurberg, M; Mansilla, Francisco; Clark, Brian F. C.;

    1998-01-01

    importance for the factor to function properly. In this study, two lysines at positions 4 and 9 were mutated separately to alanine or glutamate. The resulting four point mutants were expressed and purified using the pGEX system. The untagged products were characterized with regard to guanine......The function of the N-terminal region of elongation factor Tu is still unexplained. Until recently, it has not been visible in electron density maps from x-ray crystallography studies, but the presence of several well conserved basic residues suggest that this part of the molecule is of structural......-nucleotide interaction, intrinsic GTPase activity, and binding of aminoacyl-tRNA (aa-tRNA). The results show that Lys9 is especially strongly involved in the association with guanine nucleotides and the binding of aa-tRNA. Also Lys4 plays a role in the association of GDP and GTP and is also of some importance in aa...

  15. The σ enigma: Bacterial σ factors, archaeal TFB and eukaryotic TFIIB are homologs

    OpenAIRE

    Burton, Samuel P; Burton, Zachary F.

    2014-01-01

    Structural comparisons of initiating RNA polymerase complexes and structure-based amino acid sequence alignments of general transcription initiation factors (eukaryotic TFIIB, archaeal TFB and bacterial σ factors) show that these proteins are homologs. TFIIB and TFB each have two-five-helix cyclin-like repeats (CLRs) that include a C-terminal helix-turn-helix (HTH) motif (CLR/HTH domains). Four homologous HTH motifs are present in bacterial σ factors that are relics of CLR/HTH domains. Sequen...

  16. Higher-level phylogeny of the Therevidae (Diptera: insecta) based on 28S ribosomal and elongation factor-1 alpha gene sequences.

    Science.gov (United States)

    Yang, L; Wiegmann, B M; Yeates, D K; Irwin, M E

    2000-06-01

    Therevidae (stilleto flies) are a little-known family of asiloid brachyceran Diptera (Insecta). Separate and combined phylogenetic analyses of 1200 bases of the 28S ribosomal DNA and 1100 bases of elongation factor-1alpha were used to infer phylogenetic relationships within the family. The position of the enigmatic taxon Apsilocephala Kröber is evaluated in light of the molecular evidence. In all analyses, molecular data strongly support the monophyly of Therevidae, excluding Apsilocephala, and the division of Therevidae into two main clades corresponding to a previous classification of the family into the subfamilies Phycinae and Therevinae. Despite strong support for some relationships within these groups, relationships at the base of the two main clades are weakly supported. Short branch lengths for Australasian clades at the base of the Therevinae may represent a rapid radiation of therevids in Australia. PMID:10860652

  17. The Caenorhabditis elegans Protein FIC-1 Is an AMPylase That Covalently Modifies Heat-Shock 70 Family Proteins, Translation Elongation Factors and Histones

    Science.gov (United States)

    Truttmann, Matthias C.; Guo, Xuanzong; Engert, Christoph; Schwartz, Thomas U.; Ploegh, Hidde L.

    2016-01-01

    Protein AMPylation by Fic domain-containing proteins (Fic proteins) is an ancient and conserved post-translational modification of mostly unexplored significance. Here we characterize the Caenorhabditis elegans Fic protein FIC-1 in vitro and in vivo. FIC-1 is an AMPylase that localizes to the nuclear surface and modifies core histones H2 and H3 as well as heat shock protein 70 family members and translation elongation factors. The three-dimensional structure of FIC-1 is similar to that of its human ortholog, HYPE, with 38% sequence identity. We identify a link between FIC-1-mediated AMPylation and susceptibility to the pathogen Pseudomonas aeruginosa, establishing a connection between AMPylation and innate immunity in C. elegans. PMID:27138431

  18. Site of ADP-ribosylation and the RNA-binding site are situated in different domains of the elongation factor EF-2

    International Nuclear Information System (INIS)

    One of the proteins participating in the process of elongation of polypeptide chains - elongation factor 2 (EF-2) - can be ADP-ribosylated at a unique amino acid residue - diphthamide. Since the ADP-ribosylation of EF-2 at dipthamide leads to a loss of affinity of the factor for RNA while the presence of RNA inhibits the ADP-ribosylation reaction, it seemed probable to the authors that diphthamide participated directly in the binding of EF-2 to DNA. The experiments presented in this article showed that this was not the case: diphthamide and the RNA-binding site are situated on different domains of EF-2. Thus, ADP-ribosylation of factor EF-2 in one domain leads to a loss of the ability to bind to RNA in the other. The authors investigated the mutual arrangement of diphthamide and the RNA-binding site on the EF-2 molecule by preparing a factor from rabbit reticulocytes and subjecting it to proteolytic digestion with elastase. The factor was incubated with elastase for 15 min at 370C at an enzyme:substrate ratio of 1:100 in buffer solution containing 20 mM Tris-HCl, pH 7.6, 10 mM KCl, 1 mM MgCl2, and 2 mM dithiothreitol. The reaction was stopped by adding para-methylsulfonyl fluoride to 50 micro-M. The authors obtained a preparation as a result of proteolysis and applied it on a column with RNA-Sepharose and separated into two fractions: RNA-binding and without affinity for RNA. The initial preparation and its fractions were subjected to exhaustive ADP-ribosylation in the presence of diphtheria toxin and [U-14C] nicotinaide adenine dinucleotide ([14C]NAD) (296 mCi/mmole). The samples were analyzed electrophoretically in a polyacrylamide gel gradient in the presence of sodium dodecyl sulfate. For the detection of [14C] ADP-ribosylated components, the gels were dried and exposed with RM-V x-ray film

  19. Translation elongation factor-1A1 (eEF1A1 localizes to the spine by domain III

    Directory of Open Access Journals (Sweden)

    Sun-Jung Cho

    2012-04-01

    Full Text Available In vertebrates, there are two variants of eukaryotic peptideelongation factor 1A (eEF1A; formerly eEF-1α, eEF1A1 andeEF1A2, which have three well-conserved domains (DI, DII,and DIII. In neurons, eEF1A1 is the embryonic type, which isexpressed during embryonic development as well as the firsttwo postnatal weeks. In the present study, EGFP-tagged eEF1A1truncates were expressed in cortical neurons isolated from ratembryo (E18-19. Live cell images of transfected neurons showedthat DIII-containing EGFP-fusion proteins (EGFP-DIII, -DII-III,-DI-III formed clusters that were confined within somatodendriticdomains, while DIII-missing ones (EGFP-DI, -DII, -DI-II andcontrol EGFP were homogeneously dispersed throughout theneuron including axons. In dendrites, EGFP-DIII was targeted tothe heads of spine- and filopodia-like protrusions, where it wascolocalized with SynGAPα, a postsynaptic marker. Our dataindicate that DIII of eEF1A1 mediates formation of clusters andlocalization to spines. [BMB reports 2012; 45(4: 227-232

  20. Genetic Identification and Risk Factor Analysis of Asymptomatic Bacterial Colonization on Cardiovascular Implantable Electronic Devices

    Science.gov (United States)

    Chu, Xian-Ming; An, Yi; Li, Xue-Bin; Guo, Ji-Hong

    2014-01-01

    Asymptomatic bacterial colonization of cardiovascular implantable electronic devices (CIEDs) is widespread and increases the risk of clinical CIED infection. The aim of the study was to evaluate the incidence of bacterial colonization of generator pockets in patients without signs of infection and to analyze the relationship with clinical infection and risk factors. From June 2011 to December 2012, 78 patients underwent CIED replacement or upgrade. Exclusion criteria included a clinical diagnosis of CIED infection, bacteremia, or infective endocarditis. All patients were examined for evidence of bacterial 16S rDNA on the device and in the surrounding tissues. Infection cases were recorded during follow-up. The bacterial-positive rate was 38.5% (30 cases); the coagulase-negative Staphylococcus detection rate was the highest (9 cases, 11.5%). Positive bacterial DNA results were obtained from pocket tissue in 23.1% of patients (18 cases), and bacterial DNA was detected on the device in 29.5% of patients (23 cases). During follow-up (median 24.6 months), two patients (6.7%, 2/30) became symptomatic with the same species of microorganism, S. aureus and S. epidermidis. Multivariable logistic regression analysis found that the history of bacterial infection, use of antibiotics, application of antiplatelet drugs, replacement frequency, and renal insufficiency were independent risk factors for asymptomatic bacterial colonization. PMID:25530969

  1. Genetic Identification and Risk Factor Analysis of Asymptomatic Bacterial Colonization on Cardiovascular Implantable Electronic Devices

    Directory of Open Access Journals (Sweden)

    Xian-Ming Chu

    2014-01-01

    Full Text Available Asymptomatic bacterial colonization of cardiovascular implantable electronic devices (CIEDs is widespread and increases the risk of clinical CIED infection. The aim of the study was to evaluate the incidence of bacterial colonization of generator pockets in patients without signs of infection and to analyze the relationship with clinical infection and risk factors. From June 2011 to December 2012, 78 patients underwent CIED replacement or upgrade. Exclusion criteria included a clinical diagnosis of CIED infection, bacteremia, or infective endocarditis. All patients were examined for evidence of bacterial 16S rDNA on the device and in the surrounding tissues. Infection cases were recorded during follow-up. The bacterial-positive rate was 38.5% (30 cases; the coagulase-negative Staphylococcus detection rate was the highest (9 cases, 11.5%. Positive bacterial DNA results were obtained from pocket tissue in 23.1% of patients (18 cases, and bacterial DNA was detected on the device in 29.5% of patients (23 cases. During follow-up (median 24.6 months, two patients (6.7%, 2/30 became symptomatic with the same species of microorganism, S. aureus and S. epidermidis. Multivariable logistic regression analysis found that the history of bacterial infection, use of antibiotics, application of antiplatelet drugs, replacement frequency, and renal insufficiency were independent risk factors for asymptomatic bacterial colonization.

  2. Translation elongation factor eEF1A2 is a potential oncoprotein that is overexpressed in two-thirds of breast tumours

    International Nuclear Information System (INIS)

    The tissue-specific translation elongation factor eEF1A2 was recently shown to be a potential oncogene that is overexpressed in ovarian cancer. Although there is no direct evidence for an involvement of eEF1A2 in breast cancer, the genomic region to which EEF1A2 maps, 20q13, is frequently amplified in breast tumours. We therefore sought to establish whether eEF1A2 expression might be upregulated in breast cancer. eEF1A2 is highly similar (98%) to the near-ubiquitously expressed eEF1A1 (formerly known as EF1-α) making analysis with commercial antibodies difficult. We have developed specific anti-eEF1A2 antibodies and used them in immunohistochemical analyses of tumour samples. We report the novel finding that although eEF1A2 is barely detectable in normal breast it is moderately to strongly expressed in two-thirds of breast tumours. This overexpression is strongly associated with estrogen receptor positivity. eEF1A2 should be considered as a putative oncogene in breast cancer that may be a useful diagnostic marker and therapeutic target for a high proportion of breast tumours. The oncogenicity of eEF1A2 may be related to its role in protein synthesis or to its potential non-canonical functions in cytoskeletal remodelling or apoptosis

  3. Eukaryotic translation elongation factor 1A (eEF1A domain I from S. cerevisiae is required but not sufficient for inter-species complementation.

    Directory of Open Access Journals (Sweden)

    Sandra Eltschinger

    Full Text Available Ethanolamine phosphoglycerol (EPG is a protein modification attached exclusively to eukaryotic elongation factor 1A (eEF1A. In mammals and plants, EPG is linked to conserved glutamate residues located in eEF1A domains II and III, whereas in the unicellular eukaryote Trypanosoma brucei, only domain III is modified by a single EPG. A biosynthetic precursor of EPG and structural requirements for EPG attachment to T. brucei eEF1A have been reported, but nothing is known about the EPG modifying enzyme(s. By expressing human eEF1A in T. brucei, we now show that EPG attachment to eEF1A is evolutionarily conserved between T. brucei and Homo sapiens. In contrast, S. cerevisiae eEF1A, which has been shown to lack EPG is not modified in T. brucei. Furthermore, we show that eEF1A cannot functionally complement across species when using T. brucei and S. cerevisiae as model organisms. However, functional complementation in yeast can be obtained using eEF1A chimera containing domains II or III from other species. In contrast, yeast domain I is strictly required for functional complementation in S. cerevisiae.

  4. Translation elongation factor eEF1A2 is a potential oncoprotein that is overexpressed in two-thirds of breast tumours

    Directory of Open Access Journals (Sweden)

    Miller William R

    2005-09-01

    Full Text Available Abstract Background The tissue-specific translation elongation factor eEF1A2 was recently shown to be a potential oncogene that is overexpressed in ovarian cancer. Although there is no direct evidence for an involvement of eEF1A2 in breast cancer, the genomic region to which EEF1A2 maps, 20q13, is frequently amplified in breast tumours. We therefore sought to establish whether eEF1A2 expression might be upregulated in breast cancer. Methods eEF1A2 is highly similar (98% to the near-ubiquitously expressed eEF1A1 (formerly known as EF1-α making analysis with commercial antibodies difficult. We have developed specific anti-eEF1A2 antibodies and used them in immunohistochemical analyses of tumour samples. We report the novel finding that although eEF1A2 is barely detectable in normal breast it is moderately to strongly expressed in two-thirds of breast tumours. This overexpression is strongly associated with estrogen receptor positivity. Conclusion eEF1A2 should be considered as a putative oncogene in breast cancer that may be a useful diagnostic marker and therapeutic target for a high proportion of breast tumours. The oncogenicity of eEF1A2 may be related to its role in protein synthesis or to its potential non-canonical functions in cytoskeletal remodelling or apoptosis.

  5. Drosophila egg chamber elongation

    OpenAIRE

    Gates, Julie

    2012-01-01

    As tissues and organs are formed, they acquire a specific shape that plays an integral role in their ability to function properly. A relatively simple system that has been used to examine how tissues and organs are shaped is the formation of an elongated Drosophila egg. While it has been known for some time that Drosophila egg elongation requires interactions between a polarized intracellular basal actin network and a polarized extracellular network of basal lamina proteins, how these interac...

  6. Biotypes and virulence factors of Gardnerella vaginalis isolated from cases of bacterial vaginosis

    OpenAIRE

    J Udayalaxmi; Bhat, G. K.; S Kotigadde

    2011-01-01

    The present study was conducted to correlate the biotypes of Gardnerella vaginalis strains isolated from cases of bacterial vaginosis and their virulence factors. Thirty-two strains of G. vaginalis isolated from cases of bacterial vaginosis were biotyped. Adherence to vaginal epithelial cells, biofilm production, surface hydrophobicity, phospholipase C and protease activity were tested on these isolates. Biotype 1 was the most prevalent (8; 25%), followed by biotype 2 (7; 21.9%) and biotypes ...

  7. Biotypes and virulence factors of Gardnerella vaginalis isolated from cases of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    J Udayalaxmi

    2011-01-01

    Full Text Available The present study was conducted to correlate the biotypes of Gardnerella vaginalis strains isolated from cases of bacterial vaginosis and their virulence factors. Thirty-two strains of G. vaginalis isolated from cases of bacterial vaginosis were biotyped. Adherence to vaginal epithelial cells, biofilm production, surface hydrophobicity, phospholipase C and protease activity were tested on these isolates. Biotype 1 was the most prevalent (8; 25%, followed by biotype 2 (7; 21.9% and biotypes 5 and 8 (5; 15.6%. We did not find any statistical correlation between G. vaginalis biotypes and its virulence factors. Virulence factors expressed by G. vaginalis were not associated with a single biotype.

  8. Biotypes and virulence factors of Gardnerella vaginalis isolated from cases of bacterial vaginosis.

    Science.gov (United States)

    Udayalaxmi, J; Bhat, G K; Kotigadde, S

    2011-01-01

    The present study was conducted to correlate the biotypes of Gardnerella vaginalis strains isolated from cases of bacterial vaginosis and their virulence factors. Thirty-two strains of G. vaginalis isolated from cases of bacterial vaginosis were biotyped. Adherence to vaginal epithelial cells, biofilm production, surface hydrophobicity, phospholipase C and protease activity were tested on these isolates. Biotype 1 was the most prevalent (8; 25%), followed by biotype 2 (7; 21.9%) and biotypes 5 and 8 (5; 15.6%). We did not find any statistical correlation between G. vaginalis biotypes and its virulence factors. Virulence factors expressed by G. vaginalis were not associated with a single biotype. PMID:21654113

  9. The eukaryotic translation elongation factor eEF1A2 induces neoplastic properties and mediates tumorigenic effects of ZNF217 in precursor cells of human ovarian carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yu; Wong, Nicholas; Guan, Yinghui; Salamanca, Clara M.; Cheng, Jung Chien; Lee, Jonathan M.; Gray, Joe W.; Auersperg, Nelly

    2008-04-25

    Ovarian epithelial carcinomas (OEC) frequently exhibit amplifications at the 20q13 locus which is the site of several oncogenes, including the eukaryotic elongation factor EEF1A2 and the transcription factor ZNF217. We reported previously that overexpressed ZNF217 induces neoplastic characteristics in precursor cells of OEC. Unexpectedly, ZNF217, which is a transcriptional repressor, enhanced expression of eEF1A2. In this study, array comparative genomic hybridization, single nucleotide polymorphism and Affymetrix analysis of ZNF217-overexpressing cell lines confirmed consistently increased expression of eEF1A2 but not of other oncogenes, and revealed early changes in EEF1A2 gene copy numbers and increased expression at crisis during immortalization. We defined the influence of eEF1A2 overexpression on immortalized ovarian surface epithelial cells, and investigated interrelationships between effects of ZNF217 and eEF1A2 on cellular phenotypes. Lentivirally induced eEF1A2 overexpression caused delayed crisis, apoptosis resistance and increases in serum-independence, saturation densities, and anchorage independence. siRNA to eEF1A2 reversed apoptosis resistance and reduced anchorage independence in eEF1A2-overexpressing lines. Remarkably, siRNA to eEF1A2 was equally efficient in inhibiting both anchorage independence and resistance to apoptosis conferred by ZNF217 overexpression. Our data define neoplastic properties that are caused by eEF1A2 in nontumorigenic ovarian cancer precursor cells, and suggest that eEF1A2 plays a role in mediating ZNF217-induced neoplastic progression.

  10. Function of the Bacillus subtilis transcription elongation factor NusG in hairpin-dependent RNA polymerase pausing in the trp leader.

    Science.gov (United States)

    Yakhnin, Alexander V; Yakhnin, Helen; Babitzke, Paul

    2008-10-21

    NusA and NusG are transcription elongation factors that bind to RNA polymerase (RNAP) after sigma subunit release. Escherichia coli NusA (NusA(Ec)) stimulates intrinsic termination and RNAP(Ec) pausing, whereas NusG(Ec) promotes Rho-dependent termination and pause escape. Both Nus factors also participate in the formation of RNAP(Ec) antitermination complexes. We showed that Bacillus subtilis NusA (NusA(Bs)) stimulates intrinsic termination and RNAP(Bs) pausing at U107 and U144 in the trpEDCFBA operon leader. Pausing at U107 and U144 participates in the transcription attenuation and translational control mechanisms, respectively, presumably by providing additional time for trp RNA-binding attenuation protein (TRAP) to bind to the nascent trp leader transcript. Here, we show that NusG(Bs) causes modest pause stimulation at U107 and dramatic pause stimulation at U144. NusA(Bs) and NusG(Bs) act synergistically to increase the U107 and U144 pause half-lives. NusG(Bs)-stimulated pausing at U144 requires RNAP(Bs), whereas NusA(Bs) stimulates pausing of RNAP(Bs) and RNAP(Ec) at the U144 and E. coli his pause sites. Although NusG(Ec) does not stimulate pausing at U144, it competes with NusG(Bs)-stimulated pausing, suggesting that both proteins bind to the same surface of RNAP(Bs). Inactivation of nusG results in the loss of RNAP pausing at U144 in vivo and elevated trp operon expression, whereas plasmid-encoded NusG complements the mutant defects. Overexpression of nusG reduces trp operon expression to a larger extent than overexpression of nusA. PMID:18852477

  11. Factors Affecting Bacterial Growth in Drinking Water Distribution System

    Institute of Scientific and Technical Information of China (English)

    WEI LU; XIAO-JIAN ZHANG

    2005-01-01

    Objective To define the influence of some parameters, including assimilable organic carbon (AOC), chloramine residual, etc. on the bacterial growth in drinking water distribution systems. Methods Three typical water treatment plants in a northern city (City T) of China and their corresponding distribution systems were investigated. Some parameters of the water samples, such as heterotrophic plate content (HPC), AOC, CODMn, TOC, and phosphate were measured. Results The AOC in most water samples were more than 100 μg/L, or even more than 200 μg/L in some cases. The HPC in distribution systems increased significantly with the decrease of residual chlorine. When the residual chlorine was less than 0.1 mg/L, the magnitude order of HPC was 104 CFU/mL; when it was 0.5-0.7 mg/L, the HPC was about 500 CFU/mL. Conclusion For controlling the biostability of drinking water, the controlling of AOC and residual chlorine should be considered simultaneously. The influence of phosphors on the AOC tests of water is not significant. Phosphors may not be the limiting nutrient in the water distribution systems.

  12. Sulpiride, but not SCH23390, modifies cocaine-induced conditioned place preference and expression of tyrosine hydroxylase and elongation factor 1α in zebrafish.

    Science.gov (United States)

    Darland, Tristan; Mauch, Justin T; Meier, Ellen M; Hagan, Shannon J; Dowling, John E; Darland, Diane C

    2012-12-01

    Finding genetic polymorphisms and mutations linked to addictive behavior can provide important targets for pharmaceutical and therapeutic interventions. Forward genetic approaches in model organisms such as zebrafish provide a potentially powerful avenue for finding new target genes. In order to validate this use of zebrafish, the molecular nature of its reward system must be characterized. We have previously reported the use of cocaine-induced conditioned place preference (CPP) as a reliable method for screening mutagenized fish for defects in the reward pathway. Here we test if CPP in zebrafish involves the dopaminergic system by co-treating fish with cocaine and dopaminergic antagonists. Sulpiride, a potent D2 receptor (DR2) antagonist, blocked cocaine-induced CPP, while the D1 receptor (DR1) antagonist SCH23390 had no effect. Acute cocaine exposure also induced a rise in the expression of tyrosine hydroxylase (TH), an important enzyme in dopamine synthesis, and a significant decrease in the expression of elongation factor 1α (EF1α), a housekeeping gene that regulates protein synthesis. Cocaine selectively increased the ratio of TH/EF1α in the telencephalon, but not in other brain regions. The cocaine-induced change in TH/EF1α was blocked by co-treatment with sulpiride, but not SCH23390, correlating closely with the action of these drugs on the CPP behavioral response. Immunohistochemical analysis revealed that the drop in EF1α was selective for the dorsal nucleus of the ventral telencephalic area (Vd), a region believed to be the teleost equivalent of the striatum. Examination of TH mRNA and EF1α transcripts suggests that regulation of expression is post-transcriptional, but this requires further examination. These results highlight important similarities and differences between zebrafish and more traditional mammalian model organisms. PMID:22910534

  13. Isoforms of elongation factor eEF1A may be differently regulated at post-transcriptional level in breast cancer progression

    Directory of Open Access Journals (Sweden)

    Vislovukh A. A.

    2013-01-01

    Full Text Available Eukaryotic translation elongation factor 1A exists as two 98 % homologous isoforms: eEF1A1 (A1 and eEF1A2 (A2 which are tissue and development specific. Despite high homology in an open reading frame (ORF region, mRNAs coding for eEF1A1 and eEF1A2 are different in their untranslated regions (UTR, suggesting a possibility of their dissimilar post-transcriptional regulation. Aim. To analyze the existence of cis-acting motifs in the UTRs of EEF1A1/A2 mRNAs, to confirm the possibility of post-transcriptional control of eEF1A1 and eEF1A2 expression. Methods. An ensemble of bioinformatic methods was applied to predict regulatory motifs in the UTRs of EEF1A1/A2 mRNAs. Dual-luciferase reporter assay was employed to detect post-transcriptional regulation of eEF1A1/A2 expression. Results. Numerous regulatory motifs in the UTR of EEF1A1/A2 mRNAs were found bioinformatically. The experimental evidence was obtained for the existence of negative regulation of EEF1A1 and positive regulation of EEF1A2 mRNA in the model of breast cancer development. Conclusions. EEF1A1 and EEF1A2 mRNAs contain distinct motifs in the UTRs and are differently regulated in cancer suggesting the possibility of their control by different cellular signals.

  14. Surface roughness : causal factors : and its relation to bacterial adhesion

    OpenAIRE

    Tellefsen, Georg

    2013-01-01

    Inflammation around teeth and dental implants is considered to be due to microorganisms producing biofilm and thereby initiating the inflammatory reaction. The etiology is not yet fully understood though many risk factors have been identified, e.g. smoking, oral hygiene, stress etc. That surface roughness plays a role both in the development of the biofilm and discoloration of teeth is nowadays beyond doubt. To create a smooth surface is an important part of the oral hygien...

  15. Bacterial Sigma Factors as Targets for Engineered or Synthetic Transcriptional Control

    Science.gov (United States)

    Tripathi, Lakshmi; Zhang, Yan; Lin, Zhanglin

    2014-01-01

    Sigma (σ) factors are the predominant constituents of transcription regulation in bacteria. σ Factors recruit the core RNA polymerase to recognize promoters with specific DNA sequences. Recently, engineering of transcriptional regulators has become a significant tool for strain engineering. The present review summarizes the recent advances in σ factor based engineering or synthetic design. The manipulation of σ factors presents insights into the bacterial stress tolerance and metabolite productivity. We envision more synthetic design based on σ factors that can be used to tune the regulatory network of bacteria. PMID:25232540

  16. Bacterial sigma factors as targets for engineered or synthetic transcriptional control

    Directory of Open Access Journals (Sweden)

    Lakshmi eTripathi

    2014-09-01

    Full Text Available Sigma (σ factors are the predominant constituents of transcription regulation in bacteria. σ factors recruit the core RNA polymerase (RNAP to recognize promoters with specific DNA sequences. Recently engineering of transcriptional regulators has become a significant tool for strain engineering. The present review summarizes the recent advances in σ factor based engineering or synthetic design. The manipulation of σ factors presents insights into the bacterial stress tolerance and metabolite productivity. We envision more synthetic design based on σ factors that can be used to tune the regulatory network of bacteria.

  17. Bacterial sigma factors: a historical, structural, and genomic perspective.

    Science.gov (United States)

    Feklístov, Andrey; Sharon, Brian D; Darst, Seth A; Gross, Carol A

    2014-01-01

    Transcription initiation is the crucial focal point of gene expression in prokaryotes. The key players in this process, sigma factors (σs), associate with the catalytic core RNA polymerase to guide it through the essential steps of initiation: promoter recognition and opening, and synthesis of the first few nucleotides of the transcript. Here we recount the key advances in σ biology, from their discovery 45 years ago to the most recent progress in understanding their structure and function at the atomic level. Recent data provide important structural insights into the mechanisms whereby σs initiate promoter opening. We discuss both the housekeeping σs, which govern transcription of the majority of cellular genes, and the alternative σs, which direct RNA polymerase to specialized operons in response to environmental and physiological cues. The review concludes with a genome-scale view of the extracytoplasmic function σs, the most abundant group of alternative σs. PMID:25002089

  18. Uniaxial Elongational viscosity of bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational...... viscosity, of up to a factor of 7 times the Trouton limit of 3 times the zero-shear viscosity....

  19. Identification and cloning of two immunogenic Clostridium perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO) of C. perfringens

    Science.gov (United States)

    Clostridium-related diseases such as gangrenous dermatitis (GD) and necrotic enteritis (NE) are increasingly emerging as major diseases in recent years with high economic loss around the world. In this report, we characterized two immunogenic Clostridium perfringens (CP) proteins (e.g., elongation f...

  20. The σ enigma: bacterial σ factors, archaeal TFB and eukaryotic TFIIB are homologs.

    Science.gov (United States)

    Burton, Samuel P; Burton, Zachary F

    2014-01-01

    Structural comparisons of initiating RNA polymerase complexes and structure-based amino acid sequence alignments of general transcription initiation factors (eukaryotic TFIIB, archaeal TFB and bacterial σ factors) show that these proteins are homologs. TFIIB and TFB each have two-five-helix cyclin-like repeats (CLRs) that include a C-terminal helix-turn-helix (HTH) motif (CLR/HTH domains). Four homologous HTH motifs are present in bacterial σ factors that are relics of CLR/HTH domains. Sequence similarities clarify models for σ factor and TFB/TFIIB evolution and function and suggest models for promoter evolution. Commitment to alternate modes for transcription initiation appears to be a major driver of the divergence of bacteria and archaea. PMID:25483602

  1. Use of radioisotopes in studying factors responsible for alfalfa resistance to bacterial wiltxng

    International Nuclear Information System (INIS)

    Studies are summarized dealing with possible causes of vascular dysfunction and resistance of alfalfa to bacterial wilting caused by Corynebacterium insidiosum (McCull.) H.L. Jens from the physiological and biochemical points of view. Using 32P, 35S, 54Mn, 45Ca, 65Zn, and 86Rb the uptake, distribution, translocation, and metabolism of these elements in plants with a different resistance against diseases were investigated. The possible use is discussed of 86Rb as a tracer of potassium. The results suggest that the resistance of alfalfa to bacterial wilting is probably determined by several factors. (author)

  2. The Level of Autoantibodies Targeting Eukaryote Translation Elongation Factor 1 α1 and Ubiquitin-Conjugating Enzyme 2L3 in Nondiabetic Young Adults

    Science.gov (United States)

    Kim, Eunhee G.; Kwak, Soo Heon; Hwang, Daehee; Yi, Eugene C.; Park, Kyong Soo

    2016-01-01

    Background The prevalence of novel type 1 diabetes mellitus (T1DM) antibodies targeting eukaryote translation elongation factor 1 alpha 1 autoantibody (EEF1A1-AAb) and ubiquitin-conjugating enzyme 2L3 autoantibody (UBE2L3-AAb) has been shown to be negatively correlated with age in T1DM subjects. Therefore, we aimed to investigate whether age affects the levels of these two antibodies in nondiabetic subjects. Methods EEF1A1-AAb and UBE2L3-AAb levels in nondiabetic control subjects (n=150) and T1DM subjects (n=101) in various ranges of age (18 to 69 years) were measured using an enzyme-linked immunosorbent assay. The cutoff point for the presence of each autoantibody was determined based on control subjects using the formula: [mean absorbance+3×standard deviation]. Results In nondiabetic subjects, there were no significant correlations between age and EEF1A1-AAb and UBE2L3-AAb levels. However, there was wide variation in EEF1A1-AAb and UBE2L3-AAb levels among control subjects <40 years old; the prevalence of both EEF1A1-AAb and UBE2L3-AAb in these subjects was 4.4%. When using cutoff points determined from the control subjects <40 years old, the prevalence of both autoantibodies in T1DM subjects was decreased (EEFA1-AAb, 15.8% to 8.9%; UBE2L3-AAb, 10.9% to 7.9%) when compared to the prevalence using the cutoff derived from the totals for control subjects. Conclusion There was no association between age and EEF1A1-AAb or UBE2L3-AAb levels in nondiabetic subjects. However, the wide variation in EEF1A1-AAb and UBE2L3-AAb levels apparent among the control subjects <40 years old should be taken into consideration when determining the cutoff reference range for the diagnosis of T1DM. PMID:26616590

  3. Molecular pathogenesis of Helicobacter pylori infection: the role of bacterial virulence factors.

    Science.gov (United States)

    Molnar, Bela; Galamb, Orsolya; Sipos, Ferenc; Leiszter, Katalin; Tulassay, Zsolt

    2010-01-01

    Helicobacter pylori is one of the most common pathogens affecting humankind, infecting approximately 50% of the world's population. Of those infected, many will develop asymptomatic gastritis, but 10% develop gastric or duodenal ulcers. The clinical outcome of the infection may involve a combination of bacterial factors, host factors and environmental factors. In the process of development of gastritis, ulceration and cancer, several cellular and molecular steps follow each other. Infection, acid survival, adhesion, cytotoxicity, epithelial cell turnover changes, inflammation, regeneration or pathological alteration towards erosions, ulceration, and cancer can be observed on the cellular level. Bacterial factors like urease, AmiE, AmiF, hydrogenase and arginase are needed for survival in the acidic gastric environment. The bacterial flagellae are essential to move the bacteria towards the epithelial surface. Adhesive factors like BabA, SabA and ureaseA are necessary for adhesion against MHC-II complexes and Le antigens. The bacteria VacA and CagA are cytotoxic factors. The Cag type IV secretion system delivers these proteins inside the epithelial cells. After disruption of epithelial cell junctions, the bacteria can pass through the gastric wall facing direct immune response from neutrophils, lymphocytes, mast cells and dendritic cells. This review describes and summarizes our present molecular biological information and knowledge about the Helicobacter infective component, cell functions and processes. The possible role of host counter responses and interactions with gastric epithelia and immune cells are also detailed. PMID:21088410

  4. Post-Meal Responses of Elongation Factor 2 (eEF2) and Adenosine Monophosphate-Activated Protein Kinase (AMPK) to Leucine and Carbohydrate Supplements for Regulating Protein Synthesis Duration and Energy Homeostasis in Rat Skeletal Muscle

    OpenAIRE

    Layman, Donald K; Anthony, Tracy G.; Garlick, Peter J.; Wilson, Gabriel J; Moulton, Christopher J

    2012-01-01

    Previous research demonstrates that the anabolic response of muscle protein synthesis (MPS) to a meal is regulated at the level of translation initiation with signals derived from leucine (Leu) and insulin to activate mTORC1 signaling. Recent evidence suggests that the duration of the meal response is limited by energy status of the cell and inhibition of translation elongation factor 2 (eEF2). This study evaluates the potential to extend the anabolic meal response with post-meal supplements ...

  5. Large amplitude oscillatory elongation flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Laillé, Philippe; Yu, Kaijia

    2008-01-01

    A filament stretching rheometer (FSR) was used for measuring the elongation flow with a large amplitude oscillative elongation imposed upon the flow. The large amplitude oscillation imposed upon the elongational flow as a function of the time t was defined as epsilon(t) =(epsilon) over dot(0)t...

  6. Serialization of elongated members

    International Nuclear Information System (INIS)

    Elongated members such as nuclear fuel end plugs are provided to a robot by a vibratory feeder. The robot singly inserts the members into a character stamper or marker and then removes them and drops them down a chute to an inspection site. The member is inserted into a character reader and inspected. Unacceptably stamped members are rejected and for each accepted member the stamper is advanced to a next character. Thus, a next member is stamped with the next character, or permutation of characters, the robot already having provided a new member to the stamper

  7. Anaerobes and Bacterial Vaginosis in Pregnancy: Virulence Factors Contributing to Vaginal Colonisation

    OpenAIRE

    Africa, Charlene W.J.; Janske Nel; Megan Stemmet

    2014-01-01

    The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding poss...

  8. Factors shaping bacterial phylogenetic and functional diversity in coastal waters of the NW Mediterranean Sea

    Science.gov (United States)

    Boras, Julia A.; Vaqué, Dolors; Maynou, Francesc; Sà, Elisabet L.; Weinbauer, Markus G.; Sala, Maria Montserrat

    2015-03-01

    To evaluate the main factors shaping bacterioplankton phylogenetic and functional diversity in marine coastal waters, we carried out a two-year study based on a monthly sampling in Blanes Bay (NW Mediterranean). We expected the key factors driving bacterial diversity to be (1) temperature and nutrient concentration, together with chlorophyll a concentration as an indicator of phytoplankton biomass and, hence, a carbon source for bacteria (here called bottom-up factors), and (2) top-down pressure (virus- and protist-mediated mortality of bacteria). Phylogenetic diversity was analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA. Functional diversity was assessed by using monomeric carbon sources in Biolog EcoPlates and by determining the activity of six extracellular enzymes. Our results indicate that the bacterial phylogenetic and functional diversity in this coastal system is shaped mainly by bottom-up factors. A dendrogram analysis of the DGGE banding patterns revealed three main sample clusters. Two clusters differed significantly in temperature, nitrate and chlorophyll a concentration, and the third was characterized by the highest losses of bacterial production due to viral lysis detected over the whole study period. Protistan grazing had no effect on bacterial functional diversity, since there were no correlations between protist-mediated mortality (PMM) and extracellular enzyme activities, and utilization of only two out of the 31 carbon sources (N-acetyl-D-glucosamine and α-cyclodextrin) was correlated with PMM. In contrast, virus-mediated mortality correlated with changes in the percentage of use of four carbon sources, and also with specific leu-aminopeptidase and β-glucosidase activity. This suggests that viral lysate provides a pool of labile carbon sources, presumably including amino acids and glucose, which may inhibit proteolytic and glucosidic activity. Our results indicate that bottom-up factors play a more important role than

  9. Analysis on the risk factors of bacterial meningitis complicated with subdural effusion

    Directory of Open Access Journals (Sweden)

    Zhi JIANG

    2015-08-01

    Full Text Available Objective To investigate the risk factors of bacterial meningitis complicated with subdural effusion.  Methods The clinical data of children with bacterial meningitis in our hospital were collected and analyzed retrospectively. Logistic regression analysis was used to investigate the risk factors for subdural effusion.  Results A total of 128 cases were divided into control group (N = 64 and subdural effusion group (N = 64. There was no significant difference on serum erythrocyte sedimentation rate (ESR, C-reactive protein (CRP, and white blood cell (WBC between 2 groups (P > 0.05, for all. Compared with control group, cerebrospinal fluid (CSF WBC (Z = 3.126, P = 0.003, CSF protein (Z = 4.928, P = 0.000 and serum procalcitonin (PCT; Z = 2.823, P = 0.007 in subdural effusion group were significantly higher, while CSF glucose (t = 2.166, P = 0.033 was significantly lower. After treatment, CSF WBC (Z = 2.467, P = 0.012 in subdural effusion group was still significantly higher than that of control group, and CSF glucose (t = 4.938, P = 0.000 was still significantly lower. Logistic regression analysis showed that WBC in CSF (P = 0.027, CSF protein (P = 0.002 and serum PCT (P = 0.014 were independent risk factors for bacterial meningitis complicated with subdural effusion.  Conclusions CSF examination of children with bacterial meningitis reveals significant increase of CSF WBC, CSF protein and serum PCT, suggesting concurrent subdural effusion is easily occurred. DOI: 10.3969/j.issn.1672-6731.2015.08.012

  10. Bacterial and fungal endophthalmitis in Upper Egypt:related species and risk factors

    Institute of Scientific and Technical Information of China (English)

    AA Gharamah; AM Moharram; MA Ismail; AK AL-Hussaini

    2012-01-01

    Objective: To study risk factors, contributing factors of bacterial and fungal endophthalmitis in Upper Egypt, test the isolated species sensitive to some therapeutic agents, and to investigate the air-borne bacteria and fungi in opthalmology operating rooms. Methods: Thirty one cases of endophthalmitis were clinically diagnosed and microbiologically studied. Indoor air-borne bacteria and fungi inside four air-conditioned operating rooms in the Ophthalmology Department at Assiut University Hospitals were also investigated. The isolated microbes from endophthalmitis cases were tested for their ability to produce some extracellular enzymes including protease, lipase, urease, phosphatase and catalase. Also the ability of 5 fungal isolates from endophthalmitis origin to produce mycotoxins and their sensitivity to some therapeutic agents were studied. Results: Results showed that bacteria and fungi were responsihle for infection in 10 and 6 cases of endophthalmitis, respectively and only 2 cases produced a mixture of bacteria and fungi. Trauma was the most prevalent risk factor of endophthalmitis where 58.1% of the 31 cases were due to trauma. In ophthalmology operating rooms, different bacterial and fungal species were isolated. 8 bacterial and 5 fungal isolates showed their ability to produce enzymes while only 3 fungal isolates were able to produce mycotoxins. Terbinafine showed the highest effect against most isolates in vitro. Conclusions: The ability of bacterial and fungal isolates to produce extracellular enzymes and mycotoxins may be aid in the invasion and destruction of eye tissues. Microbial contamination of operating rooms with air-borne bacteria and fungi in the present work may be a source of postoperative endophthalmitis.

  11. Elongated toroid fusion device

    International Nuclear Information System (INIS)

    A device for achieving ignition of a plasma with ohmic heating is described comprising: means for defining a toroidal plasma chamber,a and confining gas therein, and means including electrically conductive coils for generating plasma within the chamber and for confining and shaping such plasma substantially into and filling a predetermined single region of the chamber without an axisymmetric internal separatix and ohmically heating the confined plasma to ignition. The predetermined region is toroidal with a major axis defining an axial direction parallel thereto and a transaxial direction perpendicular to the axis and having an axial cross section with an elongation, k, greater than 4, where k is the ratio of the maximum axial dimension of the cross section to the maximum transaxial dimension of the cross section

  12. Correlation models between environmental factors and bacterial resistance to antimony and copper.

    Directory of Open Access Journals (Sweden)

    Zunji Shi

    Full Text Available Antimony (Sb and copper (Cu are toxic heavy metals that are associated with a wide variety of minerals. Sb(III-oxidizing bacteria that convert the toxic Sb(III to the less toxic Sb(V are potentially useful for environmental Sb bioremediation. A total of 125 culturable Sb(III/Cu(II-resistant bacteria from 11 different types of mining soils were isolated. Four strains identified as Arthrobacter, Acinetobacter and Janibacter exhibited notably high minimum inhibitory concentrations (MICs for Sb(III (>10 mM,making them the most highly Sb(III-resistant bacteria to date. Thirty-six strains were able to oxidize Sb(III, including Pseudomonas-, Comamonas-, Acinetobacter-, Sphingopyxis-, Paracoccus- Aminobacter-, Arthrobacter-, Bacillus-, Janibacter- and Variovorax-like isolates. Canonical correspondence analysis (CCA revealed that the soil concentrations of Sb and Cu were the most obvious environmental factors affecting the culturable bacterial population structures. Stepwise linear regression was used to create two predictive models for the correlation between soil characteristics and the bacterial Sb(III or Cu(II resistance. The concentrations of Sb and Cu in the soil was the significant factors affecting the bacterial Sb(III resistance, whereas the concentrations of S and P in the soil greatly affected the bacterial Cu(II resistance. The two stepwise linear regression models that we derived are as follows: MIC(Sb(III=606.605+0.14533 x C(Sb+0.4128 x C(Cu and MIC((Cu(II=58.3844+0.02119 x C(S+0.00199 x CP [where the MIC(Sb(III and MIC(Cu(II represent the average bacterial MIC for the metal of each soil (μM, and the C(Sb, C(Cu, C(S and C(P represent concentrations for Sb, Cu, S and P (mg/kg in soil, respectively, p<0.01]. The stepwise linear regression models we developed suggest that metals as well as other soil physicochemical parameters can contribute to bacterial resistance to metals.

  13. [The bacterial microflora of diabetic foot infection and factors determining its spectrum in Ouagadougou (Burkina Faso)].

    Science.gov (United States)

    Guira, O; Tiéno, H; Traoré, S; Diallo, I; Ouangré, E; Sagna, Y; Zabsonré, J; Yanogo, D; Traoré, S S; Drabo, Y J

    2015-12-01

    The aim of the study was to describe the bacterial microflora of diabetic foot infection and to identify the factors which determine the bacterial spectrum in order to increase empiric antibiotic prescription in Ouagadougou. The study was a cross-sectional one, carried from July 1st, 2011 to June 30, 2012 in the departments of internal medicine and general and digestive surgery in Yalgado Ouédraogo teaching hospital. Samples for bacteriological tests consisted of aspiration of pus through the healthy skin, curettage and swab of the base of the ulceration or tissue biopsy from foot lesions. The bacteria's sensitivity to antibiotics has been tested by the qualitative method (Kirby-Bauer). The frequency of diabetic foot infection was 14.45% and the monthly incidence 5.33. The mean age of patients was 56 years and the sex ratio 1.37. Foot ulcerations were chronic in 33 (51.56%), necrotic in 51 (79.69%) and associated with osteitis in 40 (62.5%) patients. Infection was grade 3 in 70.3% cases. Thirty-nine patients had received antibiotics before hospital admission. Among the 71 samples, 62 (87.32%) cultures were positive: 53 (85.48%) monomicrobial and 9 (14.52%) bimicrobial. Aerobic Gram-positive cocci (76%) were the most frequent from ulcerations: Staphylococcus aureus (32.39%), Streptococcus sp (18.30%). Negative coagulase staphylococci have been found in 23.94% cases. Aerobic gram-negative bacilli have been isolated from 24% ulcerations. No factor was associated with the type of bacteria. Gram-positive pathogen cocci showed a high sensitivity to amoxicillin-clavulanic acid and oxacillin. No methicillin-resistant Staphylococcus aureus (MRSA) or extended-spectrum beta lactamase Enterobacteriaceae (ESBL) have been isolated. A better design is necessary to a clarification of bacterial flora in diabetic foot infections. Prevention of bacterial resistance is also needed. PMID:26187771

  14. Promoter recognition by bacterial alternative sigma factors: the price of high selectivity?

    Science.gov (United States)

    Feklistov, Andrey; Darst, Seth A

    2009-10-15

    A key step in bacterial transcription initiation is melting of the double-stranded promoter DNA by the RNA polymerase holoenzyme. Primary sigma factors mediate the melting of thousands of promoters through a conserved set of aromatic amino acids. Alternative sigmas, which direct transcription of restricted regulons, lack the full set of melting residues. In this issue of Genes & Development, Koo and colleagues (pp. 2426-2436) show that introducing the primary sigma melting residues into alternative sigmas relaxes their promoter specificity, pointing to a trade-off of reduced promoter melting capacity for increased promoter stringency. PMID:19833764

  15. Role of bacterial γ-glutamyltranspeptidase as a novel virulence factor in bone-resorbing pathogenesis.

    Science.gov (United States)

    Kim, Jinmoon; Jang, Sungil; Kim, Aeryun; Su, Hanfu; Gunawardhana, Niluka; Jeon, Yeong-Eui; Bak, Eun Jung; Kim, Ji-Hye; Cha, Jeong-Heon

    2016-05-01

    Mammalian γ-glutamyltranspeptidase (GGT) has been identified as a bone-resorbing factor. Since GGT of Bacillus subtilis exhibits similarity in their primary structure and enzymatic characteristics with mammalian GGTs, the bone-resorbing activity of bacterial GGT was examined in this study. Osteoclastogenesis was performed in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. A conditioned medium from GGT-overproducing B. subtilis culture showed significantly higher activity of osteoclast formation than a conditioned medium from wild-type B. subtilis culture. Recombinant GGT (rGGT) of wild-type B. subtilis and an enzymatic activity-defected rGGT of B. subtilis 2288 mutant were expressed in Escherichia coli and purified using His tag. Both purified rGGTs induced similar levels of osteoclastogenesis, suggesting that B. subtilis GGT possesses virulent bone-resorbing activity and its activity is probably independent of its enzymatic activity. Furthermore, a recombinant protein of B. subtilis GGT heavy subunit (Bs rGGT/H) showed strong activity of osteoclastogenesis while the light subunit failed to show strong activity, suggesting that the bone-resorbing activity is mainly located at the heavy subunit. More importantly, the GGT enzymatic activity may not be required for this virulence activity since the light subunit contains the catalytic pocket. In addition, B. subtilis rGGT stimulated mRNA expressions of receptor activator of nuclear factor kappa-B ligand (RANKL) and cyclooxygenase-2 (COX-2), while an osteoprotegerin inhibited the osteoclast formation induced by Bs rGGT/H. This is the first demonstration that bacterial GGT itself is sufficient to act as a bone-resorbing virulence factor via RANKL-dependent pathway. Therefore, it can be hypothesized that GGT of periodontopathic bacteria may play an important role as a virulence factor in bone destruction. PMID:27095459

  16. Key factors for causing poplar Ice Nucleation Active bacterial canker and its control techniques

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The isolation, culture and the active determination of poplar ice nucleation active (INA) bacteria and the inoculation tests in laboratory and field were conducted, and the varieties, distribution and number of poplar INA bacteria and its pathogenicity and freezing injury property were determined. The study results showed that the INA bacteria widely spread on poplar in Northeast China and caused the frozen injury for poplar under the frost condition in Spring or Autumn, which was the key factor to induce INA bacterial canker. Through evaluation and investigation of different poplar varieties and inoculation tests, fine disease-resistant varieties and strains of poplar suitable for Northeast China were selected. Further tests for strong seedling showed that burying cuttings in sand and covering with plastic film could effectively avoid the frostbite, frozen and drought damage, reduce INA bacteria infection, and promote poplar growth. INA bacterial canker was detected early by highly specialized antiserums of INA bacteria and the agglutinated test of ring-shaped boundary surface. The inducers such as streptomycin, phenylmercuric acetae, salicylic acid and heat-killed bacteria to immerse cuttings, have obvious induced disease-resistant effect. Before poplar sprouted in early spring, through spraying the solution of frostbite agent, the control effect also was obvious.

  17. Temporal scaling of bacterial taxa is influenced by both stochastic and deterministic ecological factors.

    Science.gov (United States)

    van der Gast, Christopher J; Ager, Duane; Lilley, Andrew K

    2008-06-01

    Microorganisms operate at a range of spatial and temporal scales acting as key drivers of ecosystem properties. Therefore, many key questions in microbial ecology require the consideration of both spatial and temporal scales. Spatial scaling, in particular the species-area relationship (SAR), has a long history in ecology and has recently been addressed in microbial ecology. However, the temporal analogue of the SAR, the species-time relationship, has received far less attention even in the science of general ecology. Here we focus upon the role of temporal scaling in microbial ecological patterns by coupling molecular characterization of bacterial communities in discrete island (bioreactor) systems with a macroecological approach. Our findings showed that the temporal scaling exponent (slope), and therefore taxa turnover of the bacterial taxa-time relationship decreased as selective pressure (industrial wastewater concentration) increased. Also, as the concentration of industrial wastewater increased across the bioreactors, we observed a gradual switch from stochastic community assembly to more deterministic (niche)-based considerations. The identification of broad-scale statistical patterns is particularly relevant to microbial ecology, as it is frequently difficult to identify individual species or their functions. In this study, we identify wide-reaching statistical patterns of diversity and show that they are shaped by the prevalent underlying ecological factors. PMID:18205822

  18. A Common Structural Motif in the Binding of Virulence Factors to Bacterial Secretion Chaperones

    International Nuclear Information System (INIS)

    Salmonella invasion protein A (SipA) is translocated into host cells by a type III secretion system (T3SS) and comprises two regions: one domain binds its cognate type III secretion chaperone, InvB, in the bacterium to facilitate translocation, while a second domain functions in the host cell, contributing to bacterial uptake by polymerizing actin. We present here the crystal structures of the SipA chaperone binding domain (CBD) alone and in complex with InvB. The SipA CBD is found to consist of a nonglobular polypeptide as well as a large globular domain, both of which are necessary for binding to InvB. We also identify a structural motif that may direct virulence factors to their cognate chaperones in a diverse range of pathogenic bacteria. Disruption of this structural motif leads to a destabilization of several chaperone-substrate complexes from different species, as well as an impairment of secretion in Salmonella

  19. New insights in the bacterial spore resistance to extreme terrestrial and extraterrestrial factors

    Science.gov (United States)

    Moeller, Ralf; Horneck, Gerda; Reitz, Guenther

    Based on their unique resistance to various space parameters, Bacillus endospores are one of the model systems used for astrobiological studies. The extremely high resistance of bacterial endospores to environmental stress factors has intrigued researchers since long time and many characteristic spore features, especially those involved in the protection of spore DNA, have already been uncovered. The disclosure of the complete genomic sequence of Bacillus subtilis 168, one of the often used astrobiological model system, and the rapid development of tran-scriptional microarray techniques have opened new opportunities of gaining further insights in the enigma of spore resistance. Spores of B. subtilis were exposed to various extreme ter-restrial and extraterrestrial stressors to reach a better understanding of the DNA protection and repair strategies, which them to cope with the induced DNA damage. Following physical stress factors of environmental importance -either on Earth or in space -were selected for this thesis: (i) mono-and polychromatic UV radiation, (ii) ionizing radiation, (iii) exposure to ultrahigh vacuum; and (iv) high shock pressures simulating meteorite impacts. To reach a most comprehensive understanding of spore resistance to those harsh terrestrial or simulated extraterrestrial conditions, a standardized experimental protocol of the preparation and ana-lyzing methods was established including the determination of the following spore responses: (i) survival, (ii) induced mutations, (iii) DNA damage, (iv) role of different repair pathways by use of a set of repair deficient mutants, and (v) transcriptional responses during spore germi-nation by use of genome-wide transcriptome analyses and confirmation by RT-PCR. From this comprehensive set of data on spore resistance to a variety of environmental stress parameters a model of a "built-in" transcriptional program of bacterial spores in response to DNA damaging treatments to ensure DNA restoration

  20. DMPD: Lipopolysaccharide sensing an important factor in the innate immune response toGram-negative bacterial infections: benefits and hazards of LPShypersensitivity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available se toGram-negative bacterial infections: benefits and hazards of LPShypersensitivity. Freudenberg MA, Tchapt...portant factor in the innate immune response toGram-negative bacterial infections: benefits and hazards of L...une response toGram-negative bacterial infections: benefits and hazards of LPShyp

  1. Arabidopsis Clade I TGA Factors Regulate Apoplastic Defences against the Bacterial Pathogen Pseudomonas syringae through Endoplasmic Reticulum-Based Processes

    OpenAIRE

    Wang, Lipu; Fobert, Pierre R.

    2013-01-01

    During the plant immune response, large-scale transcriptional reprogramming is modulated by numerous transcription (co) factors. The Arabidopsis basic leucine zipper transcription factors TGA1 and TGA4, which comprise the clade I TGA factors, have been shown to positively contribute to disease resistance against virulent strains of the bacterial pathogen Pseudomonas syringae . Despite physically interacting with the key immune regulator, NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), f...

  2. Comparative Study of the Life Cycle Dependent Post-Translation Modifications of Protein Synthesis Elongation Factor Tu Present in the Membrane Proteome of Streptomycetes and Mycobacteria

    Czech Academy of Sciences Publication Activity Database

    Holub, Martin; Bezoušková, Silvia; Petráčková, Denisa; Kalachová, Ladislava; Kofroňová, Olga; Benada, Oldřich; Weiser, Jaroslav

    2010-01-01

    Roč. 55, č. 3 (2010), s. 203-210. ISSN 0015-5632 R&D Projects: GA AV ČR IAA600200702; GA AV ČR IAA500200913 Institutional research plan: CEZ:AV0Z50200510 Keywords : ESCHERICHIA-COLI * COELICOLOR A3(2) * OUTER-MEMBRANE Subject RIV: EE - Microbiology, Virology Impact factor: 0.977, year: 2010

  3. Post-Meal Responses of Elongation Factor 2 (eEF2 and Adenosine Monophosphate-Activated Protein Kinase (AMPK to Leucine and Carbohydrate Supplements for Regulating Protein Synthesis Duration and Energy Homeostasis in Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Donald K. Layman

    2012-11-01

    Full Text Available Previous research demonstrates that the anabolic response of muscle protein synthesis (MPS to a meal is regulated at the level of translation initiation with signals derived from leucine (Leu and insulin to activate mTORC1 signaling. Recent evidence suggests that the duration of the meal response is limited by energy status of the cell and inhibition of translation elongation factor 2 (eEF2. This study evaluates the potential to extend the anabolic meal response with post-meal supplements of Leu or carbohydrates. Adult (~256 g male Sprague-Dawley rats were food deprived for 12 h, then either euthanized before a standard meal (time 0 or at 90 or 180 min post-meal. At 135 min post-meal, rats received one of five oral supplements: 270 mg leucine (Leu270, 80:40:40 mg leucine, isoleucine, and valine (Leu80, 2.63 g carbohydrates (CHO2.6, 1 g carbohydrates (CHO1.0, or water (Sham control. Following the standard meal, MPS increased at 90 min then declined to pre-meal baseline at 180 min. Rats administered Leu270, Leu80, CHO2.6, or CHO1.0 maintained elevated rates of MPS at 180 min, while Sham controls declined from peak values. Leu80 and CHO1.0 treatments maintained MPS, but with values intermediate between Sham controls and Leu270 and CHO2.6 supplements. Consistent with MPS findings, the supplements maintained elongation activity and cellular energy status by preventing increases in AMP/ATP and phosphorylation of adenosine monophosphate-activated protein kinase (AMPK, acetyl-CoA carboxylase ACC and eEF2. The impact of the supplements on MPS and cellular energy status was in proportion to the energy content within the individual treatments (i.e., Leu270 > Leu80; CHO2.6 > CHO1.0, but the Leu supplements produced a disproportionate anabolic stimulation of MPS, eEF2 and energy status with significantly lower energy content. In summary, the incongruity between MPS and translation initiation at 180 min reflects a block in translation elongation due to

  4. Coevolution between Stop Codon Usage and Release Factors in Bacterial Species.

    Science.gov (United States)

    Wei, Yulong; Wang, Juan; Xia, Xuhua

    2016-09-01

    Three stop codons in bacteria represent different translation termination signals, and their usage is expected to depend on their differences in translation termination efficiency, mutation bias, and relative abundance of release factors (RF1 decoding UAA and UAG, and RF2 decoding UAA and UGA). In 14 bacterial species (covering Proteobacteria, Firmicutes, Cyanobacteria, Actinobacteria and Spirochetes) with cellular RF1 and RF2 quantified, UAA is consistently over-represented in highly expressed genes (HEGs) relative to lowly expressed genes (LEGs), whereas UGA usage is the opposite even in species where RF2 is far more abundant than RF1. UGA usage relative to UAG increases significantly with PRF2 [=RF2/(RF1 + RF2)] as expected from adaptation between stop codons and their decoders. PRF2 is > 0.5 over a wide range of AT content (measured by PAT3 as the proportion of AT at third codon sites), but decreases rapidly toward zero at the high range of PAT3 This explains why bacterial lineages with high PAT3 often have UGA reassigned because of low RF2. There is no indication that UAG is a minor stop codon in bacteria as claimed in a recent publication. The claim is invalid because of the failure to apply the two key criteria in identifying a minor codon: (1) it is least preferred by HEGs (or most preferred by LEGs) and (2) it corresponds to the least abundant decoder. Our results suggest a more plausible explanation for why UAA usage increases, and UGA usage decreases, with PAT3, but UAG usage remains low over the entire PAT3 range. PMID:27297468

  5. Cold Plasma Inactivation of Bacterial Biofilms and Reduction of Quorum Sensing Regulated Virulence Factors.

    Directory of Open Access Journals (Sweden)

    Dana Ziuzina

    Full Text Available The main objectives of this work were to investigate the effect of atmospheric cold plasma (ACP against a range of microbial biofilms commonly implicated in foodborne and healthcare associated human infections and against P. aeruginosa quorum sensing (QS-regulated virulence factors, such as pyocyanin, elastase (Las B and biofilm formation capacity post-ACP treatment. The effect of processing factors, namely treatment time and mode of plasma exposure on antimicrobial activity of ACP were also examined. Antibiofilm activity was assessed for E. coli, L. monocytogenes and S. aureus in terms of reduction of culturability and retention of metabolic activity using colony count and XTT assays, respectively. All samples were treated 'inpack' using sealed polypropylene containers with a high voltage dielectric barrier discharge ACP generated at 80 kV for 0, 60, 120 and 300 s and a post treatment storage time of 24 h. According to colony counts, ACP treatment for 60 s reduced populations of E. coli to undetectable levels, whereas 300 s was necessary to significantly reduce populations of L. monocytogenes and S. aureus biofilms. The results obtained from XTT assay indicated possible induction of viable but non culturable state of bacteria. With respect to P. aeruginosa QS-related virulence factors, the production of pyocyanin was significantly inhibited after short treatment times, but reduction of elastase was notable only after 300 s and no reduction in actual biofilm formation was achieved post-ACP treatment. Importantly, reduction of virulence factors was associated with reduction of the cytotoxic effects of the bacterial supernatant on CHO-K1 cells, regardless of mode and duration of treatment. The results of this study point to ACP technology as an effective strategy for inactivation of established biofilms and may play an important role in attenuation of virulence of pathogenic bacteria. Further investigation is warranted to propose direct evidence

  6. Cold Plasma Inactivation of Bacterial Biofilms and Reduction of Quorum Sensing Regulated Virulence Factors

    Science.gov (United States)

    Ziuzina, Dana; Boehm, Daniela; Patil, Sonal; Cullen, P. J.; Bourke, Paula

    2015-01-01

    The main objectives of this work were to investigate the effect of atmospheric cold plasma (ACP) against a range of microbial biofilms commonly implicated in foodborne and healthcare associated human infections and against P. aeruginosa quorum sensing (QS)-regulated virulence factors, such as pyocyanin, elastase (Las B) and biofilm formation capacity post-ACP treatment. The effect of processing factors, namely treatment time and mode of plasma exposure on antimicrobial activity of ACP were also examined. Antibiofilm activity was assessed for E. coli, L. monocytogenes and S. aureus in terms of reduction of culturability and retention of metabolic activity using colony count and XTT assays, respectively. All samples were treated ‘inpack’ using sealed polypropylene containers with a high voltage dielectric barrier discharge ACP generated at 80 kV for 0, 60, 120 and 300 s and a post treatment storage time of 24 h. According to colony counts, ACP treatment for 60 s reduced populations of E. coli to undetectable levels, whereas 300 s was necessary to significantly reduce populations of L. monocytogenes and S. aureus biofilms. The results obtained from XTT assay indicated possible induction of viable but non culturable state of bacteria. With respect to P. aeruginosa QS-related virulence factors, the production of pyocyanin was significantly inhibited after short treatment times, but reduction of elastase was notable only after 300 s and no reduction in actual biofilm formation was achieved post-ACP treatment. Importantly, reduction of virulence factors was associated with reduction of the cytotoxic effects of the bacterial supernatant on CHO-K1 cells, regardless of mode and duration of treatment. The results of this study point to ACP technology as an effective strategy for inactivation of established biofilms and may play an important role in attenuation of virulence of pathogenic bacteria. Further investigation is warranted to propose direct evidence for the

  7. Factors Associated with Bacterial Vaginosis among Women Who Have Sex with Women: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Dana S Forcey

    Full Text Available Women who have sex with women (WSW have a higher burden of bacterial vaginosis (BV than heterosexual women; studies of risk factors specific to this population are limited. We summarised current knowledge regarding risk factors for BV among WSW by systematic review.This systematic review was conducted according to the PRISMA statement. PUBMED, EMBASE, Web of Science and The Cochrane Library were searched to 31st December, 2014.1 WSW included in the study population; 2 accepted BV diagnostic method; 3 investigated or could extrapolate factors(s associated with BV acquisition, persistence or transmission in WSW specifically by comparing BV positive to BV negative women. Search was limited to English-language publications.A limited number of studies have investigated BV in WSW. Of 71 unique references, 18 full-text articles were assessed and 14 studies fulfilled inclusion criteria. BV was positively associated with higher numbers of female partners, both lifetime and in the three months prior to diagnosis, and confirmed BV in a female partner, but inconsistently associated with partners' BV history or symptoms. BV was not associated with ethnicity, vaginal douching or hormonal contraception. The impact of specific sexual activities, male sexual contact, smoking and the menstrual cycle varied considerably between study populations.BV in WSW is associated with increased numbers of recent and past female partners and confirmed BV in a female partner. There are limited studies of BV in WSW populations, and research is needed to further elucidate risk factors for BV among WSW. However these data provide epidemiological evidence that BV risk in women is directly related to exposure to other female partners and a partner with BV, providing support for the concept that BV is likely to be transmitted between women.CRD42014009536 (PROSPERO.

  8. mADP-RTs: Versatile virulence factors from bacterial pathogens of plants and mammals

    Directory of Open Access Journals (Sweden)

    Lennart eWirthmueller

    2012-06-01

    Full Text Available Mono ADP-ribosyltransferases (mADP-RTs are a family of enzymes that cleave NAD+ and covalently attach the ADP-ribosyl moiety to target proteins. mADP-RTs are well established as important virulence factors of bacteria that infect mammals. Cholera toxin, pertussis toxin and diphteria toxin are three of the best-known examples of mADP-RTs. They modify host target proteins in order to promote infection and/or killing of the host cell. Despite low sequence similarity at the primary amino acid level, mADP-RTs share a conserved core catalytic fold and structural biology has made important contributions to elucidating how mADP-RTs modify mammalian host targets. Recently, mADP-RTs were shown to be present in plant pathogenic bacteria, suggesting that mADP-RTs are also important virulence factors of plant pathogens. Crystal structures of plant pathogenic bacterial mADP-RTs are also now available. Here we review the structure/function of mADP-RTs from pathogens of mammals and plants, highlighting both commonalities and differences.

  9. Anaerobes and bacterial vaginosis in pregnancy: virulence factors contributing to vaginal colonisation.

    Science.gov (United States)

    Africa, Charlene W J; Nel, Janske; Stemmet, Megan

    2014-07-01

    The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM), LISTA (EBSCO), and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes. PMID:25014248

  10. Anaerobes and Bacterial Vaginosis in Pregnancy: Virulence Factors Contributing to Vaginal Colonisation

    Directory of Open Access Journals (Sweden)

    Charlene W. J. Africa

    2014-07-01

    Full Text Available The aetiology and pathogenesis of bacterial vaginosis (BV is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM, LISTA (EBSCO, and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes.

  11. A bacteriophage transcription regulator inhibits bacterial transcription initiation by σ-factor displacement

    OpenAIRE

    Liu, Bing; Shadrin, Andrey; Sheppard, Carol; Mekler, Vladimir; Xu, Yingqi; Severinov, Konstantin; Matthews, Steve; Wigneshweraraj, Sivaramesh

    2014-01-01

    Bacteriophages (phages) appropriate essential processes of bacterial hosts to benefit their own development. The multisubunit bacterial RNA polymerase (RNAp) enzyme, which catalyses DNA transcription, is targeted by phage-encoded transcription regulators that selectively modulate its activity. Here, we describe the structural and mechanistic basis for the inhibition of bacterial RNAp by the transcription regulator P7 encoded by Xanthomonas oryzae phage Xp10. We reveal that P7 uses a two-step ...

  12. Identification of host cytosolic sensors and bacterial factors regulating the type I interferon response to Legionella pneumophila.

    Directory of Open Access Journals (Sweden)

    Kathryn M Monroe

    2009-11-01

    Full Text Available Legionella pneumophila is a gram-negative bacterial pathogen that replicates in host macrophages and causes a severe pneumonia called Legionnaires' Disease. The innate immune response to L. pneumophila remains poorly understood. Here we focused on identifying host and bacterial factors involved in the production of type I interferons (IFN in response to L. pneumophila. It was previously suggested that the delivery of L. pneumophila DNA to the host cell cytosol is the primary signal that induces the type I IFN response. However, our data are not easily reconciled with this model. We provide genetic evidence that two RNA-sensing proteins, RIG-I and MDA5, participate in the IFN response to L. pneumophila. Importantly, these sensors do not seem to be required for the IFN response to L. pneumophila DNA, whereas we found that RIG-I was required for the response to L. pneumophila RNA. Thus, we hypothesize that bacterial RNA, or perhaps an induced host RNA, is the primary stimulus inducing the IFN response to L. pneumophila. Our study also identified a secreted effector protein, SdhA, as a key suppressor of the IFN response to L. pneumophila. Although viral suppressors of cytosolic RNA-sensing pathways have been previously identified, analogous bacterial factors have not been described. Thus, our results provide new insights into the molecular mechanisms by which an intracellular bacterial pathogen activates and also represses innate immune responses.

  13. Bacterial profiles of saliva in relation to diet, lifestyle factors, and socioeconomic status

    Directory of Open Access Journals (Sweden)

    Daniel Belstrøm

    2014-04-01

    Full Text Available Background and objective: The bacterial profile of saliva is composed of bacteria from different oral surfaces. The objective of this study was to determine whether different diet intake, lifestyle, or socioeconomic status is associated with characteristic bacterial saliva profiles. Design: Stimulated saliva samples from 292 participants with low levels of dental caries and periodontitis, enrolled in the Danish Health Examination Survey (DANHES, were analyzed for the presence of approximately 300 bacterial species by means of the Human Oral Microbe Identification Microarray (HOMIM. Using presence and levels (mean HOMIM-value of bacterial probes as endpoints, the influence of diet intake, lifestyle, and socioeconomic status on the bacterial saliva profile was analyzed by Mann–Whitney tests with Benjamini–Hochberg's correction for multiple comparisons and principal component analysis. Results: Targets for 131 different probes were identified in 292 samples, with Streptococcus and Veillonella being the most predominant genera identified. Two bacterial taxa (Streptococcus sobrinus and Eubacterium [11][G-3] brachy were more associated with smokers than non-smokers (adjusted p-value<0.01. Stratification of the group based on extreme ends of the parameters age, gender, alcohol consumption, body mass index (BMI, and diet intake had no statistical influence on the composition of the bacterial profile of saliva. Conversely, differences in socioeconomic status were reflected by the bacterial profiles of saliva. Conclusions: The bacterial profile of saliva seems independent of diet intake, but influenced by smoking and maybe socioeconomic status.

  14. Spatial Distribution of Bacterial Communities Driven by Multiple Environmental Factors in a Beach Wetland of the Largest Freshwater Lake in China

    Directory of Open Access Journals (Sweden)

    Xia eDing

    2015-02-01

    Full Text Available The spatial distributions of bacterial communities may be driven by multiple environmental factors. Thus, understanding the relationships between bacterial distribution and environmental factors is critical for understanding wetland stability and the functioning of freshwater lakes. However, little research on the bacterial communities in deep sediment layers exists. In this study, thirty clone libraries of 16S rRNA were constructed from a beach wetland of the Poyang Lake along both horizontal (distance to the water-land junction and vertical (sediment depth gradients to assess the effects of sediment properties on bacterial community structure and diversity. Our results showed that bacterial diversity increased along the horizontal gradient and decreased along the vertical gradient. The heterogeneous sediment properties along gradients substantially affected the dominant bacterial groups at the phylum and species levels. For example, the NH4+ concentration decreased with increasing depth, which was positively correlated with the relative abundance of Alphaproteobacteria. The changes in bacterial diversity and dominant bacterial groups showed that the top layer had a different bacterial community structure than the deeper layers. Principal component analysis revealed that both gradients, not each gradient independently, contributed to the shift in the bacterial community structure. A multiple linear regression model explained the changes in bacterial diversity and richness along the depth and distance gradients. Overall, our results suggest that spatial gradients associated with sediment properties shaped the bacterial communities in the Poyang Lake beach wetland.

  15. Interleukin-10 Regulates the Tissue Factor Activity of Monocytes in an In Vitro Model of Bacterial Endocarditis

    OpenAIRE

    Veltrop, Marcel H. A. M.; Langermans, Jan A. M.; Thompson, Jan; Bancsi, Maurice J. L. M. F.

    2001-01-01

    Monocytes are important effector cells in the pathogenesis of bacterial endocarditis since they provide the tissue factor that activates the coagulation system and maintains established vegetations. Monocytes secrete cytokines that can modulate monocyte tissue factor activity (TFA), thereby affecting the formation and maintenance of vegetations. In this study, we show that monocytes cultured for 4 h on a Streptococcus sanguis-infected fibrin matrix mimicking the in vivo vegetational surface e...

  16. Factors related to occurrence and distribution of selected bacterial and protozoan pathogens in Pennsylvania streams

    Science.gov (United States)

    Duris, Joseph W.; Reif, Andrew G.; Donna A. Crouse; Isaacs, Natasha M.

    2013-01-01

    The occurrence and distribution of fecal indicator bacteria (FIB) and bacterial and protozoan pathogens are controlled by diverse factors. To investigate these factors in Pennsylvania streams, 217 samples were collected quarterly from a 27-station water-quality monitoring network from July 2007 through August 2009. Samples were analyzed for concentrations of Escherichia coli (EC) and enterococci (ENT) indicator bacteria, concentrations of Cryptosporidium oocysts and Giardia cysts, and the presence of four genes related to pathogenic types of EC (eaeA, stx2, stx1, rfbO157) plus three microbial source tracking (MST) gene markers that are also associated with pathogenic ENT and EC (esp, LTIIa, STII). Water samples were concurrently analyzed for basic water chemistry, physical measures of water quality, nutrients, metals, and a suite of 79 organic compounds that included hormones, pharmaceuticals, and antibiotics. For each sample location, stream discharge was measured by using standardized methods at the time of sample collection, and ancillary sample site information, such as land use and geological characteristics, was compiled. Samples exceeding recreational water quality criteria were more likely to contain all measured pathogen genes but notCryptosporidium or Giardia (oo)cysts. FIB and Giardia density and frequency of eaeA gene occurrence were significantly related to season. When discharge at a sampling location was high (>75th percentile of daily mean discharge), there were greater densities of FIB and Giardia, and the stx2, rfbO157, STII, and esp genes were found more frequently than at other discharge conditions. Giardia occurrence was likely related to nonpoint sources, which are highly influential during seasonal overland transport resulting from snowmelt and elevated precipitation in late winter and spring in Pennsylvania. When MST markers of human, swine, or bovine origin were present, samples more frequently carried the eaeA, stx2

  17. Murine elongation factor 1 alpha (EF-1 alpha) is posttranslationally modified by novel amide-linked ethanolamine-phosphoglycerol moieties. Addition of ethanolamine-phosphoglycerol to specific glutamic acid residues on EF-1 alpha

    International Nuclear Information System (INIS)

    Elongation Factor 1 alpha (EF-1 alpha), an important eukaryotic translation factor, transports charged aminoacyl-tRNA from the cytosol to the ribosomes during poly-peptide synthesis. Metabolic radiolabeling with [3H] ethanolamine shows that, in all cells examined, EF-1 alpha is the major radiolabeled protein. Radiolabeled EF-1 alpha has an apparent Mr = 53,000 and a basic isoelectric point. It is cytosolic and does not contain N-linked oligosaccharides. Trypsin digestion of murine EF-1 alpha generated two major [3H]ethanolamine-labeled peptides. Three peptides were sequenced and were identical to two distinct regions of the human EF-1 alpha protein. Blank sequencing cycles coinciding with glutamic acid in the human cDNA-derived sequence were also found to release [3H]ethanolamine, and compositional analysis of these peptides confirmed the presence of glutamic acid. Dansylation analysis demonstrates that the amine group of the ethanolamine is blocked. These results indicate that EF-1 alpha is posttranslationally modified by the covalent attachment of ethanolamine via an amide bond to at least two specific glutamic acid residues (Glu-301 and Glu-374). The hydroxyl group of the attached ethanolamine was shown by mass spectrometry and compositional analysis, to be further modified by the addition of a phosphoglycerol unit. This novel posttranslational modification may represent an important alteration of EF-1 alpha, comparable to the regulatory effects of posttranslational methylation of EF-1 alpha lysine residues

  18. Negative elongation factor is required for the maintenance of proviral latency but does not induce promoter-proximal pausing of RNA polymerase II on the HIV long terminal repeat.

    Science.gov (United States)

    Jadlowsky, Julie K; Wong, Julian Y; Graham, Amy C; Dobrowolski, Curtis; Devor, Renee L; Adams, Mark D; Fujinaga, Koh; Karn, Jonathan

    2014-06-01

    The role of the negative elongation factor (NELF) in maintaining HIV latency was investigated following small hairpin RNA (shRNA) knockdown of the NELF-E subunit, a condition that induced high levels of proviral transcription in latently infected Jurkat T cells. Chromatin immunoprecipitation (ChIP) assays showed that latent proviruses accumulate RNA polymerase II (RNAP II) on the 5' long terminal repeat (LTR) but not on the 3' LTR. NELF colocalizes with RNAP II, and its level increases following proviral induction. RNAP II pause sites on the HIV provirus were mapped to high resolution by ChIP with high-throughput sequencing (ChIP-Seq). Like cellular promoters, RNAP II accumulates at around position +30, but HIV also shows additional pausing at +90, which is immediately downstream of a transactivation response (TAR) element and other distal sites on the HIV LTR. Following NELF-E knockdown or tumor necrosis factor alpha (TNF-α) stimulation, promoter-proximal RNAP II levels increase up to 3-fold, and there is a dramatic increase in RNAP II levels within the HIV genome. These data support a kinetic model for proviral transcription based on continuous replacement of paused RNAP II during both latency and productive transcription. In contrast to most cellular genes, HIV is highly activated by the combined effects of NELF-E depletion and activation of initiation by TNF-α, suggesting that opportunities exist to selectively activate latent HIV proviruses. PMID:24636995

  19. Using artificial neural networks to predict the distribution of bacterial crop diseases from biotic and abiotic factors

    Directory of Open Access Journals (Sweden)

    Michael J. Watts

    2012-03-01

    Full Text Available Constructing accurate computational global distribution models is an important first step towards the understanding of bacterial crop diseases and can lead to insights into the biology of disease-causing bacteria species. We constructed artificial neural network models of the geographic distribution of six bacterial diseases of crop plants. These ANN modelled the distribution of these species from regional climatic factors and from regional assemblages of host crop plants. Multiple ANN were combined into ensembles using statistical methods. Tandem ANN, where an ANN combined the outputs of individual ANN, were also investigated. We found that for all but one species, superior accuracies were attained by methods that combined biotic and abiotic factors. These combinations were produced by both ensemble and cascaded ANN. This shows that firstly, ANN are able to model the geographic distribution of bacterial crop diseases, and secondly, that combining abiotic and biotic factors is necessary to achieve high modelling accuracies. The work reported in this paper therefore provides a basis for constructing models of the distribution of bacterial crop diseases.

  20. Bacterial profiles of saliva in relation to diet, lifestyle factors, and socioeconomic status

    DEFF Research Database (Denmark)

    Belstrøm, Daniel; Holmstrup, Palle; Nielsen, Claus H;

    2014-01-01

    BACKGROUND AND OBJECTIVE: The bacterial profile of saliva is composed of bacteria from different oral surfaces. The objective of this study was to determine whether different diet intake, lifestyle, or socioeconomic status is associated with characteristic bacterial saliva profiles. DESIGN......: Stimulated saliva samples from 292 participants with low levels of dental caries and periodontitis, enrolled in the Danish Health Examination Survey (DANHES), were analyzed for the presence of approximately 300 bacterial species by means of the Human Oral Microbe Identification Microarray (HOMIM). Using...... presence and levels (mean HOMIM-value) of bacterial probes as endpoints, the influence of diet intake, lifestyle, and socioeconomic status on the bacterial saliva profile was analyzed by Mann-Whitney tests with Benjamini-Hochberg's correction for multiple comparisons and principal component analysis...

  1. Canine uterine bacterial infection induces upregulation of proteolysis-related genes and downregulation of homeobox and zinc finger factors.

    Directory of Open Access Journals (Sweden)

    Ragnvi Hagman

    Full Text Available BACKGROUND: Bacterial infection with the severe complication of sepsis is a frequent and serious condition, being a major cause of death worldwide. To cope with the plethora of occurring bacterial infections there is therefore an urgent need to identify molecular mechanisms operating during the host response, in order both to identify potential targets for therapeutic intervention and to identify biomarkers for disease. Here we addressed this issue by studying global gene expression in uteri from female dogs suffering from spontaneously occurring uterine bacterial infection. PRINCIPAL FINDINGS: The analysis showed that almost 800 genes were significantly (p2-fold in the uteri of diseased animals. Among these were numerous chemokine and cytokine genes, as well as genes associated with inflammatory cell extravasation, anti-bacterial action, the complement system and innate immune responses, as well as proteoglycan-associated genes. There was also a striking representation of genes associated with proteolysis. Robust upregulation of immunoglobulin components and genes involved in antigen presentation was also evident, indicating elaboration of a strong adaptive immune response. The bacterial infection was also associated with a significant downregulation of almost 700 genes, of which various homeobox and zinc finger transcription factors were highly represented. CONCLUSIONS/SIGNIFICANCE: Together, these finding outline the molecular patterns involved in bacterial infection of the uterus. The study identified altered expression of numerous genes not previously implicated in bacterial disease, and several of these may be evaluated for potential as biomarkers of disease or as therapeutic targets. Importantly, since humans and dogs show genetic similarity and develop diseases that share many characteristics, the molecular events identified here are likely to reflect the corresponding situation in humans afflicted by similar disease.

  2. Heterotrophic bacterial production: Relationships to biological and abiological factors in estuarine environments

    International Nuclear Information System (INIS)

    Ecotoxicological effects of creosote contamination on benthic bacterial communities in the Elizabeth River, Virginia were investigated using both structural an functional microbial parameters. Results indicated that cell specific and total heterotrophic bacterial production parameters were depressed in a dose-dependent manner with increasing sediment PAH concentrations. Toxicity effects upon production were modified by temporal trends associated with temperature as well as spatial sediment characteristics. Of the parameters employed, the tritiated thymidine production assay was found to be the most sensitive for detection of ecotoxicological effects. Bacterial abundance and production were examined during a destratification event in the lower James River, Virginia. Bacterial abundance, although significantly different between stations, did not change over the study. Bacterial production (3H-Tdr incorporation) in surface waters was significantly less during the mixed period 187 μg C·1-1· d-1 compared to the most stratified state (324μg C·1-1· d-1). Correlations between bacteria and chlorophyll were diminished during the mixed period. Total and flagellate specific grazing rates upon bacteria were reduced during the onset of destratification. Relationships between bacterial and nutrient parameters also indicated a strong influence of destratification. These results indicate that destratification changes trophic interactions within the microbial loop, which are not necessarily reflected in temporal patterns of bacterial abundance. Bacterioplankton production, and ammonium assimilation and remineralization were examined between April and August 1988 in the lower York River, Va

  3. Proteus sp. – an opportunistic bacterial pathogen – classification, swarming growth, clinical significance and virulence factors

    OpenAIRE

    Różalski Antoni; Torzewska Agnieszka; Moryl Magdalena; Kwil Iwona; Maszewska Agnieszka; Ostrowska Kinga; Drzewiecka Dominika; Zabłotni Agnieszka; Palusiak Agata; Siwińska Małgorzata; Staçzek Paweł

    2013-01-01

    The genus Proteus belongs to the Enterobacteriaceae family, where it is placed in the tribe Proteeae, together with the genera Morganella and Providencia. Currently, the genus Proteus consists of five species: P. mirabilis, P. vulgaris, P. penneri, P. hauseri and P. myxofaciens, as well as three unnamed Proteus genomospecies. The most defining characteristic of Proteus bacteria is a swarming phenomenon, a multicellular differentiation process of short rods to elongated swarmer cells. It allow...

  4. Environmental factors shaping cultured free-living amoebae and their associated bacterial community within drinking water network.

    Science.gov (United States)

    Delafont, Vincent; Bouchon, Didier; Héchard, Yann; Moulin, Laurent

    2016-09-01

    Free-living amoebae (FLA) constitute an important part of eukaryotic populations colonising drinking water networks. However, little is known about the factors influencing their ecology in such environments. Because of their status as reservoir of potentially pathogenic bacteria, understanding environmental factors impacting FLA populations and their associated bacterial community is crucial. Through sampling of a large drinking water network, the diversity of cultivable FLA and their bacterial community were investigated by an amplicon sequencing approach, and their correlation with physicochemical parameters was studied. While FLA ubiquitously colonised the water network all year long, significant changes in population composition were observed. These changes were partially explained by several environmental parameters, namely water origin, temperature, pH and chlorine concentration. The characterisation of FLA associated bacterial community reflected a diverse but rather stable consortium composed of nearly 1400 OTUs. The definition of a core community highlighted the predominance of only few genera, majorly dominated by Pseudomonas and Stenotrophomonas. Co-occurrence analysis also showed significant patterns of FLA-bacteria association, and allowed uncovering potentially new FLA - bacteria interactions. From our knowledge, this study is the first that combines a large sampling scheme with high-throughput identification of FLA together with associated bacteria, along with their influencing environmental parameters. Our results demonstrate the importance of physicochemical parameters in the ecology of FLA and their bacterial community in water networks. PMID:27219048

  5. Risk factors for bacterial vaginosis in pregnancy: a population-based study on Danish women

    DEFF Research Database (Denmark)

    Thorsen, Poul; Vogel, Ida; Molsted, Kirsten;

    2006-01-01

    .5, homogenous discharge, clue cells, and positive amine test). Data were collected from three questionnaires completed during the second and third trimesters and correlated with the diagnosis of bacterial vaginosis. Crude and adjusted relative risks (reproductive, medical, behavioral, sexual, and...

  6. A Laboratory Assessment of Factors That Affect Bacterial Adhesion to Contact Lenses

    Directory of Open Access Journals (Sweden)

    Debarun Dutta

    2013-11-01

    Full Text Available Adhesion of pathogenic microbes, particularly bacteria, to contact lenses is implicated in contact lens related microbial adverse events. Various in vitro conditions such as type of bacteria, the size of initial inoculum, contact lens material, nutritional content of media, and incubation period can influence bacterial adhesion to contact lenses and the current study investigated the effect of these conditions on bacterial adhesion to contact lenses. There was no significant difference in numbers of bacteria that adhered to hydrogel etafilcon A or silicone hydrogel senofilcon A contact lenses. Pseudomonas aeruginosa adhered in higher numbers compared to Staphylococcus aureus. Within a genera/species, adhesion of different bacterial strains did not differ appreciably. The size of initial inoculum, nutritional content of media, and incubation period played significant roles in bacterial adhesion to lenses. A set of in vitro assay conditions to help standardize adhesion between studies have been recommended.

  7. A Laboratory Assessment of Factors That Affect Bacterial Adhesion to Contact Lenses

    OpenAIRE

    Debarun Dutta; Mark DP Willcox

    2013-01-01

    Adhesion of pathogenic microbes, particularly bacteria, to contact lenses is implicated in contact lens related microbial adverse events. Various in vitro conditions such as type of bacteria, the size of initial inoculum, contact lens material, nutritional content of media, and incubation period can influence bacterial adhesion to contact lenses and the current study investigated the effect of these conditions on bacterial adhesion to contact lenses. There was no significant difference in num...

  8. Bacterial profiles of saliva in relation to diet, lifestyle factors, and socioeconomic status

    OpenAIRE

    Belstrøm, Daniel; Holmstrup, Palle; Nielsen, Claus H.; Kirkby, Nikolai; Twetman, Svante; Heitmann, Berit L.; Klepac-Ceraj, Vanja; Paster, Bruce J; Fiehn, Nils-Erik

    2014-01-01

    Background and objective: The bacterial profile of saliva is composed of bacteria from different oral surfaces. The objective of this study was to determine whether different diet intake, lifestyle, or socioeconomic status is associated with characteristic bacterial saliva profiles.Design: Stimulated saliva samples from 292 participants with low levels of dental caries and periodontitis, enrolled in the Danish Health Examination Survey (DANHES), were analyzed for the presence of approximately...

  9. Effect of Environmental Factors and Influence of Rumen and Hindgut Biogeography on Bacterial Communities in Steers▿

    OpenAIRE

    Romero-Pérez, Gustavo A.; Ominski, Kim H.; McAllister, Tim A.; Denis O Krause

    2010-01-01

    Feces from cattle production are considered important sources of bacterial contamination of food and the environment. Little is known about the combined effects of arctic temperatures and fodder tannins on rumen and hindgut bacterial populations. Individual rumen liquor and rectal fecal samples from donor steers fed either alfalfa silage or sainfoin (Onobrychis viciifolia Scop.) silage and water ad libitum were collected weekly on the first three sampling days and fortnightly afterwards. The ...

  10. Prevalence of bacterial vaginosis and its risk factors in HIV/AIDSpatients with abnormal vaginal discharge

    Institute of Scientific and Technical Information of China (English)

    Samuel Nwadioha; Daniel Egah; Edmond Banwat; Julie Egesie; Ifeanyi Onwuezobe

    2011-01-01

    Objective:To determine the prevalence of bacterial vaginosis in theHIV/AIDS patients of primary health care clinics in Jos Plateau state, Nigeria.Methods: Female genital swabs were collected from primary health care centers, Jos and analyzed by microscopy, culture,etc. in Jos University Teaching Hospital from December2006 to December2007. Data on epidemiologic indices were collected, using structured interviewer-administered questionnaires.Results:The incidence of bacterial vaginosis in the study was 28%(n=196/700). Among theHIV/AIDS group, the bacterial vaginosis incidence was36% (n=126/350), while in the control (non-HIV patients) group, the rate was20% (70/350) with a statistically significant difference at 95 percent confidence level(P<0.05) .HIV/AIDSand non-HIV (control) patients contributed64% (n=126/196) and36%(n=70/196), respectively. The risks to bacterial vaginosis included vaginal douching with disinfectant/detergent constituted(60%), poor use of condom40%, a median age of26years, and a median number of3 sex partners per week.Conclusions: There was a significant statistical difference in prevalence of bacterial vaginosis between theHIV/AIDS group and non-HIV(control) group of patients in the study. Risk behaviors that promote the incidence of bacterial vaginosis should be especially paid attention.

  11. Amyloid-like fibril elongation follows michaelis-menten kinetics.

    Directory of Open Access Journals (Sweden)

    Katazyna Milto

    Full Text Available A number of proteins can aggregate into amyloid-like fibrils. It was noted that fibril elongation has similarities to an enzymatic reaction, where monomers or oligomers would play a role of substrate and nuclei/fibrils would play a role of enzyme. The question is how similar these processes really are. We obtained experimental data on insulin amyloid-like fibril elongation at the conditions where other processes which may impact kinetics of fibril formation are minor and fitted it using Michaelis-Menten equation. The correlation of the fit is very good and repeatable. It speaks in favour of enzyme-like model of fibril elongation. In addition, obtained [Formula: see text] and [Formula: see text] values at different conditions may help in better understanding influence of environmental factors on the process of fibril elongation.

  12. Elongation Transducer For Tensile Tests

    Science.gov (United States)

    Roberts, Paul W.; Stokes, Thomas R.

    1994-01-01

    Extensometer transducer measures elongation of tensile-test specimen with negligible distortion of test results. Used in stress-versus-strain tests of small specimens of composite materials. Clamping stress distributed more evenly. Specimen clamped gently between jaw and facing surface of housing. Friction force of load points on conical tips onto specimen depends on compression of spring, adjusted by turning cover on housing. Limp, light nylon-insulated electrical leads impose minimal extraneous loads on measuring elements.

  13. The role of small intestinal bacterial overgrowth, intestinal permeability, endotoxaemia, and tumour necrosis factor α in the pathogenesis of non-alcoholic steatohepatitis

    OpenAIRE

    Wigg, A.; Roberts-Thomson, I; Dymock, R; McCarthy, P.; Grose, R; CUMMINS, A

    2001-01-01

    BACKGROUND—Small intestinal bacterial overgrowth may contribute to the development of non-alcoholic steatohepatitis, perhaps by increasing intestinal permeability and promoting the absorption of endotoxin or other enteric bacterial products.
AIMS—To investigate the prevalence of small intestinal bacterial overgrowth, increased intestinal permeability, elevated endotoxin, and tumour necrosis factor α (TNF-α) levels in patients with non-alcoholic steatohepatitis and in control subjects.
PATIENT...

  14. Heterotrophic bacterial production: Relationships to biological and abiological factors in estuarine environments

    Energy Technology Data Exchange (ETDEWEB)

    Koepfler, E.T.

    1989-01-01

    Ecotoxicological effects of creosote contamination on benthic bacterial communities in the Elizabeth River, Virginia were investigated using both structural an functional microbial parameters. Results indicated that cell specific and total heterotrophic bacterial production parameters were depressed in a dose-dependent manner with increasing sediment PAH concentrations. Toxicity effects upon production were modified by temporal trends associated with temperature as well as spatial sediment characteristics. Of the parameters employed, the tritiated thymidine production assay was found to be the most sensitive for detection of ecotoxicological effects. Bacterial abundance and production were examined during a destratification event in the lower James River, Virginia. Bacterial abundance, although significantly different between stations, did not change over the study. Bacterial production ({sup 3}H-Tdr incorporation) in surface waters was significantly less during the mixed period 187 {mu}g C{center dot}1-1{center dot} d{sup {minus}1} compared to the most stratified state (324{mu}g C{center dot}1-1{center dot} d{sup {minus}1}). Correlations between bacteria and chlorophyll were diminished during the mixed period. Total and flagellate specific grazing rates upon bacteria were reduced during the onset of destratification. Relationships between bacterial and nutrient parameters also indicated a strong influence of destratification. These results indicate that destratification changes trophic interactions within the microbial loop, which are not necessarily reflected in temporal patterns of bacterial abundance. Bacterioplankton production, and ammonium assimilation and remineralization were examined between April and August 1988 in the lower York River, Va.

  15. Role of granulocyte colony-stimulating factor in paclitaxel-induced intestinal barrier breakdown and bacterial translocation in rats

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chi; XU Yang-guang; DUAN Xue-ning; LIU Yin-hua; ZHAO Jian-xin; XU Ling; YE Jing-ming

    2011-01-01

    Background Chemotherapy causes breakdown of the intestinal barrier, which may lead to bacterial translocation. Paclitaxel, an anti-tubulin agent, has many side effects; however, its effect on the intestinal barrier is unknown. Previous studies show that granulocyte colony-stimulating factor (G-CSF) plays an important role in modulating intestinal barrier function, but these studies are not conclusive. Here, we investigated the effects of paclitaxel on the intestinal barrier, and whether G-CSF could prevent paclitaxel-induced bacterial translocation.Methods Twenty-four male Sprague-Dawley rats were divided into three groups: control group, paclitaxel group and paclitaxel + G-CSF group. Intestinal permeability was measured by the urinary excretion rates of lactulose and mannitol administered by gavage. The mesenteric lymph nodes, spleen and liver were aseptically harvested for bacterial culture. Endotoxin levels and white blood cell (WBC) counts were measured and bacterial quantification performed using relative real-time PCR. Jejunum samples were also obtained for histological observation. Intestinal apoptosis was evaluated using a fragmented DNA assay and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick end-labeling staining. One-way analysis of variance and Fisher's exact test were used to compare differences between groups.Results Paclitaxel induced apoptosis in 12.5% of jejunum villus cells, which was reduced to 3.8% by G-CSF treatment. Apoptosis in the control group was 0.6%. Paclitaxel treatment also resulted in villus atrophy, increased intestinal permeability and a reduction in the WBC count. G-CSF treatment resulted in increased villus height and returned WBC counts to normal levels. No bacterial translocation was detected in the control group, whereas 6/8,8/8, and 8/8 rats in the paclitaxel group were culture-positive in the liver, spleen and mesenteric lymph nodes, respectively. Bacterial translocation was

  16. Spatial isolation and environmental factors drive distinct bacterial and archaeal communities in different types of petroleum reservoirs in China

    Science.gov (United States)

    Gao, Peike; Tian, Huimei; Wang, Yansen; Li, Yanshu; Li, Yan; Xie, Jinxia; Zeng, Bing; Zhou, Jiefang; Li, Guoqiang; Ma, Ting

    2016-02-01

    To investigate the spatial distribution of microbial communities and their drivers in petroleum reservoir environments, we performed pyrosequencing of microbial partial 16S rRNA, derived from 20 geographically separated water-flooding reservoirs, and two reservoirs that had not been flooded, in China. The results indicated that distinct underground microbial communities inhabited the different reservoirs. Compared with the bacteria, archaeal alpha-diversity was not strongly correlated with the environmental variables. The variation of the bacterial and archaeal community compositions was affected synthetically, by the mining patterns, spatial isolation, reservoir temperature, salinity and pH of the formation brine. The environmental factors explained 64.22% and 78.26% of the total variance for the bacterial and archaeal communities, respectively. Despite the diverse community compositions, shared populations (48 bacterial and 18 archaeal genera) were found and were dominant in most of the oilfields. Potential indigenous microorganisms, including Carboxydibrachium, Thermosinus, and Neptunomonas, were only detected in a reservoir that had not been flooded with water. This study indicates that: 1) the environmental variation drives distinct microbial communities in different reservoirs; 2) compared with the archaea, the bacterial communities were highly heterogeneous within and among the reservoirs; and 3) despite the community variation, some microorganisms are dominant in multiple petroleum reservoirs.

  17. Crystallization and preliminary X-ray crystallographic study of GenX, a lysyl-tRNA synthetase paralogue from Escherichia coli, in complex with translation elongation factor P

    International Nuclear Information System (INIS)

    GenX, a lysyl-tRNA synthetase paralogue from Escherichia coli, has been overexpressed in E. coli, purified by three chromatographic steps and cocrystallized with a lysyl adenylate analogue (LysAMS) by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. GenX, a lysyl-tRNA synthetase paralogue from Escherichia coli, was overexpressed in E. coli, purified by three chromatographic steps and cocrystallized with a lysyl adenylate analogue (LysAMS) by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The GenX–LysAMS crystals belonged to the triclinic space group P1, with unit-cell parameters a = 54.80, b = 69.15, c = 94.08 Å, α = 95.47, β = 106.51, γ = 90.46°, and diffracted to 1.9 Å resolution. Furthermore, GenX was cocrystallized with translation elongation factor P (EF-P), which is believed to be a putative substrate of GenX, and LysAMS using PEG 4000 and ammonium sulfate as precipitants. The GenX–EF-P–LysAMS crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 105.93, b = 102.96, c = 119.94 Å, β = 99.4°, and diffracted to 2.5 Å resolution. Structure determination of the E. coli GenX–LysAMS and GenX–EF-P–LysAMS complexes by molecular replacement was successful and structure refinements are now in progress

  18. Elongational dynamics of multiarm polystyrene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Skov, Anne Ladegaard; Nielsen, Jens Kromann;

    2009-01-01

    The startup of uni-axial elongational flow followed by stress relaxation and reversed bi-axial flow has been measured for a branched polystyrene melt with narrow molar mass distribution using the filament stretching rheometer. The branched polystyrene melt was a multiarm A(q)-C-C-A(q) pom......-pom polystyrene with an estimated average number of arms of q=2.5. The molar mass of each arm is about 28 kg/mole with an overall molar mass of M-w=280 kg/mole. An integral molecular stress function constitutive formulation within the "interchain pressure" concept agrees reasonably well with the experiments....

  19. Propionibacterium acnes CAMP factor and host acid sphingomyelinase contribute to bacterial virulence: potential targets for inflammatory acne treatment.

    Directory of Open Access Journals (Sweden)

    Teruaki Nakatsuji

    Full Text Available BACKGROUND: In the progression of acne vulgaris, the disruption of follicular epithelia by an over-growth of Propionibacterium acnes (P. acnes permits the bacteria to spread and become in contact with various skin and immune cells. METHODOLOGY/PRINCIPAL FINDINGS: We have demonstrated in the present study that the Christie, Atkins, Munch-Peterson (CAMP factor of P. acnes is a secretory protein with co-hemolytic activity with sphingomyelinase that can confer cytotoxicity to HaCaT keratinocytes and RAW264.7 macrophages. The CAMP factor from bacteria and acid sphingomyelinase (ASMase from the host cells were simultaneously present in the culture supernatant only when the cells were co-cultured with P. acnes. Either anti-CAMP factor serum or desipramine, a selective ASMase inhibitor, significantly abrogated the P. acnes-induced cell death of HaCaT and RAW264.7 cells. Intradermal injection of ICR mouse ears with live P. acnes induced considerable ear inflammation, macrophage infiltration, and an increase in cellular soluble ASMase. Suppression of ASMase by systemic treatment with desipramine significantly reduced inflammatory reaction induced by intradermal injection with P. acnes, suggesting the contribution of host ASMase in P. acnes-induced inflammatory reaction in vivo. Vaccination of mice with CAMP factor elicited a protective immunity against P. acnes-induced ear inflammation, indicating the involvement of CAMP factor in P. acnes-induced inflammation. Most notably, suppression of both bacterial CAMP factor and host ASMase using vaccination and specific antibody injection, respectively, cooperatively alleviated P. acnes-induced inflammation. CONCLUSIONS/SIGNIFICANCE: These findings envision a novel infectious mechanism by which P. acnes CAMP factor may hijack host ASMase to amplify bacterial virulence to degrade and invade host cells. This work has identified both CAMP factor and ASMase as potential molecular targets for the development of drugs

  20. Predisposing factors for positive D-Xylose breath test for evaluation of small intestinal bacterial overgrowth: A retrospective study of 932 patients

    OpenAIRE

    Schatz, Richard A; Zhang, Qing; Lodhia, Nilesh; Shuster, Jonathan; Phillip P Toskes; Moshiree, Baharak

    2015-01-01

    AIM: To investigate, in the largest cohort to date, patient characteristics and associated risk factors for developing small intestinal bacterial overgrowth (SIBO) using the D-Xylose breath test (XBT).

  1. Overexpression of the Eggplant (Solanum melongena) NAC Family Transcription Factor SmNAC Suppresses Resistance to Bacterial Wilt.

    Science.gov (United States)

    Na, Chen; Shuanghua, Wu; Jinglong, Fu; Bihao, Cao; Jianjun, Lei; Changming, Chen; Jin, Jiang

    2016-01-01

    Bacterial wilt (BW) is a serious disease that affects eggplant (Solanum melongena) production. Although resistance to this disease has been reported, the underlying mechanism is unknown. In this study, we identified a NAC family transcription factor (SmNAC) from eggplant and characterized its expression, its localization at the tissue and subcellular levels, and its role in BW resistance. To this end, transgenic eggplant lines were generated in which the expression of SmNAC was constitutively up regulated or suppressed using RNAi. The results indicated that overexpression of SmNAC decreases resistance to BW. Moreover, SmNAC overexpression resulted in the reduced accumulation of the plant immune signaling molecule salicylic acid (SA) and reduced expression of ICS1 (a gene that encode isochorismate synthase 1, which is involved in SA biosynthesis). We propose that reduced SA content results in increased bacterial wilt susceptibility in the transgenic lines. Our results provide important new insights into the regulatory mechanisms of bacterial wilt resistance in eggplant. PMID:27528282

  2. Laboratory testing protocol to identify critical factors in bacterial compliance monitoring.

    Science.gov (United States)

    Abbaszadegan, M; Ghatpande, P; Brereton, J; Alum, A; Narasimhan, R

    2003-01-01

    This research focused on providing guidelines for water utilities on the collection and handling of routine bacteriological samples and in developing scientifically-based approaches in selecting the most representative sampling locations. A laboratory-scale pilot distribution system was designed comprising two parallel loops, one using unlined cast-iron pipe and one using PVC pipe. Each loop contained six sampling ports, including (1) a distribution main dead end faucet, (2) one long (5.5 m; 18 feet) and (3) one short (0.3 m; 1 foot) household copper service line with threaded hose-bibb taps, (4) one hose-bibb with welded faucet, (5) one dedicated sampling port (modeled after a manufacturer's specifications) and (6) one laboratory-style (PVC) stop-cock sampling port. Residual chlorine concentrations were maintained at 0, 0.5, 1.5 and 2.0 mg/L stages during the course of the experiment. Bacterial samples were collected from the different sampling ports and assayed by membrane filtration and/or spread plate. Nutrient and R2A agars were used for heterotrophic plate counts (HPC), m-Endo agar for total coliform (TC) counts and Chromocult agar for injured bacterial analyses. Several methods of sample collection were tested using various combinations of flushing and tap disinfection, including "first flush" (no flushing, without tap disinfection), flushing only, tap disinfection only (using alcohol or hypochlorite solution) and flushing coupled with tap disinfection. The results indicated that the bacterial counts in samples drawn from dead ends were not significantly different from counts in samples from the other sample port configurations. First flush samples consistently produced the highest bacterial count results. Bacterial counts in samples from the long household copper service line were typically three orders of magnitude higher than in samples from the other sample ports. Thus, there is evidence that long copper household service connections may be unsuitable

  3. Bacterial enteropathogens and factors associated with seasonal episodes of gastroenteritis in Nsukka, Nigeria.

    Science.gov (United States)

    Nzeako, Basil; Okafor, Nduka

    2002-01-01

    Each year, between April and October, many children of school age and some young adults in Nsukka, Nigeria suffer from gastroenteritis. The period covers the rainy season in this part of Africa, when manured farmland occasionally is flooded. In view of the number of people suffering diarrhoea and occasionally low-grade fever, it became necessary to investigate the nature of the bacterial agents responsible. Between April and October (1996-1998), 500 loose or watery stools were collected from patients, the ages of which ranged from one month to 31 years. Stools that contained parasites were excluded from the study. Samples were cultured on 5% blood agar and 1% egg-yolk agar (both containing 10 microg/mL ampicillin), MacConkey agar, Shigella Salmonella agar and in alkaline peptone water. Bacterial growths were identified using standard bacteriological procedures. Drinking water and some fruit and vegetables prevalent during this period of the year also were cultured. Of the 500 stool samples tested, 138 (27.6%) grew a range of organisms including Aeromonas hydrophila (65 [13%]), Salmonella spp. (55 [11%]), Shigella spp. (9 [1.8%]) and enteropathogenic Escherichia coli (9 [1.8%]). Drinking water and some vegetables grew Pseudomonas aeruginosa and Enterococcus faecalis, respectively. The highest isolation rate occurred during June and July, corresponding to the period of greatest flooding of arable land. Although no enteropathogens were isolated from the fruit and vegetables examined, they contained E. faecalis--an organism found in faeces. Our findings failed to explain why 72% of the samples grew no bacterial enteropathogens. PMID:12113407

  4. Visualization of elongation measurements using an SER universal testing platform

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Radek; Filip, Petr; Zelenková, Jana

    2015-01-01

    Roč. 25, č. 1 (2015), s. 1-8. ISSN 1430-6395 R&D Projects: GA ČR(CZ) GAP105/11/2342 Institutional support: RVO:67985874 Keywords : elongational viscosity * Universal Testing Platform (SER) * polymer melts * LDPE Subject RIV: BK - Fluid Dynamics Impact factor: 1.078, year: 2014

  5. Auxin, H/sup +/-excretion and cell elongation

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, R.E.; Rayle, D.L.

    1978-01-01

    By the use of Avena coleoptiles, the biochemical reactions of auxin-induced plant cell elongation are studied. A biological model of H/sup +/ as a cell wall loosening factor is presented for auxin-induced plant growth in the acid-growth theory. (DS)

  6. Nasopharyngeal vs. adenoid cultures in children undergoing adenoidectomy: prevalence of bacterial pathogens, their interactions and risk factors.

    Science.gov (United States)

    Korona-Glowniak, I; Niedzielski, A; Kosikowska, U; Grzegorczyk, A; Malm, A

    2015-03-01

    Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus colonization of the adenoids and nasopharynx in 103 preschool children who underwent adenoidectomy for recurrent upper respiratory tract infections was examined. Bacterial interactions and risk factors for bacterial colonization of the nasopharynx and adenoids, separately, were analysed statistically. The prevalence of simultaneous isolation from both anatomical sites was 45·6% for S. pneumoniae, 29·1% for H. influenzae, 15·5% for M. catarrhalis and 18·4% for S. aureus. Three pathogens were significantly more frequent together from adenoid samples; nasopharyngeal swabs more often yielded a single organism, but without statistical significance. M. catarrhalis and S. aureus significantly more frequently co-existed with S. pneumoniae and H. influenzae than with each other and a positive association of S. pneumoniae and H. influenzae in adenoid samples was evident. Several differences between risk factors for nasopharyngeal and adenoid colonization by the individual pathogens were observed. We conclude that the adenoids and nasopharynx appear to differ substantially in colonization by pathogenic microbes but occurrence of H. influenzae and S. pneumoniae in the nasopharynx could be predictive of upper respiratory tract infections. PMID:25703401

  7. Comparative usefulness of inflammatory markers to indicate bacterial infection-analyzed according to blood culture results and related clinical factors.

    Science.gov (United States)

    Nishikawa, Hirokazu; Shirano, Michinori; Kasamatsu, Yu; Morimura, Ayumi; Iida, Ko; Kishi, Tomomi; Goto, Tetsushi; Okamoto, Saki; Ehara, Eiji

    2016-01-01

    To assess relationships of inflammatory markers and 2 related clinical factors with blood culture results, we retrospectively investigated inpatients' blood culture and blood chemistry findings that were recorded from January to December 2014 using electronic medical records and analyzed the data of 852 subjects (426 culture-positive and 426 culture-negative). Results suggested that the risk of positive blood culture statistically increased as inflammatory marker levels and the number of related factors increased. Concerning the effectiveness of inflammatory markers, when the outcome definition was also changed for C-reactive protein (CRP), the odds ratio had a similar value, whereas when the outcome definition of blood culture positivity was used for procalcitonin (PCT), the greatest effectiveness of that was detected. Therefore, the current results suggest that PCT is more useful than CRP as an auxiliary indication of bacterial infection. PMID:26525643

  8. Characterizing the interplay betwen mulitple levels of organization within bacterial sigma factor regulatory networks

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Qiu [University of California, San Diego; Nagarajan, Harish [University of California, San Diego; Embree, Mallory [University of California, San Diego; Shieu, Wendy [University of California, San Diego; Abate, Elisa [University of California, San Diego; Juarez, Katy [Universidad Nacional Autonoma de Mexico (UNAM); Cho, Byung-Kwan [University of California, San Diego; Elkins, James G [ORNL; Nevin, Kelly P. [University of Massachusetts, Amherst; Barrett, Christian [University of California, San Diego; Lovley, Derek [University of Massachusetts, Amherst; Palsson, Bernhard O. [University of California, San Diego; Zengler, Karsten [University of California, San Diego

    2013-01-01

    Bacteria contain multiple sigma factors, each targeting diverse, but often overlapping sets of promoters, thereby forming a complex network. The layout and deployment of such a sigma factor network directly impacts global transcriptional regulation and ultimately dictates the phenotype. Here we integrate multi-omic data sets to determine the topology, the operational, and functional states of the sigma factor network in Geobacter sulfurreducens, revealing a unique network topology of interacting sigma factors. Analysis of the operational state of the sigma factor network shows a highly modular structure with sN being the major regulator of energy metabolism. Surprisingly, the functional state of the network during the two most divergent growth conditions is nearly static, with sigma factor binding profiles almost invariant to environmental stimuli. This first comprehensive elucidation of the interplay between different levels of the sigma factor network organization is fundamental to characterize transcriptional regulatory mechanisms in bacteria.

  9. Experimental and Theoretical Investigations of Phonation Threshold Pressure as a Function of Vocal Fold Elongation

    Science.gov (United States)

    Tao, Chao; Regner, Michael F.; Zhang, Yu; Jiang, Jack J.

    2014-01-01

    Summary The relationship between the vocal fold elongation and the phonation threshold pressure (PTP) was experimentally and theoretically investigated. The PTP values of seventeen excised canine larynges with 0% to 15% bilateral vocal fold elongations in 5% elongation steps were measured using an excised larynx phonation system. It was found that twelve larynges exhibited a monotonic relationship between PTP and elongation; in these larynges, the 0% elongation condition had the lowest PTP. Five larynges exhibited a PTP minimum at 5% elongation. To provide a theoretical explanation of these phenomena, a two-mass model was modified to simulate vibration of the elongated vocal folds. Two pairs of longitudinal springs were used to represent the longitudinal elastin in the vocal folds. This model showed that when the vocal folds were elongated, the increased longitudinal tension would increase the PTP value and the increased vocal fold length would decrease the PTP value. The antagonistic effects contributed by these two factors were found to be able to cause either a monotonic or a non-monotonic relationship between PTP and elongation, which were consistent with experimental observations. Because PTP describes the ease of phonation, this study suggests that there may exist a nonzero optimal vocal fold elongation for the greatest ease for phonation in some larynges. PMID:25530744

  10. Risk Factors and Scoring System for Predicting Bacterial Resistance to Cefepime as Used Empirically in Haematology Wards

    Directory of Open Access Journals (Sweden)

    Hicham El Maaroufi

    2015-01-01

    Full Text Available Objectives. Bacterial resistance is of growing concern in haematology wards. As the inappropriate administration of empirical antibacterial may alter survival, we studied risk factors for resistance to our usual empirical first-line antibacterial therapy, cefepime. Methods. We retrospectively studied 103 first episodes of bacteraemia recorded in our haematology department over 2.5 years. Risk factors for cefepime-resistance were identified by multivariate logistic regression with backward selection (P<0.05. A scoring system for predicting cefepime-resistance was built on independent factor, with an internal validation by the bootstrap resampling technique. Results. 38 (37% episodes were due to Gram-negative bacteria. Fifty (49% were due to bacteria resistant to cefepime. Cefepime resistance was significantly associated with a decreased survival at day 30 (P<0.05. Three risk factors were independently associated with cefepime-resistance: acute lymphoblastic leukaemia; ≥18 days since hospital admission; and receipt of any β-lactam in the last month. Patients with ≥2 of these risk factors had a probability of 86% (CI 95%, 25 to 100% to carry a cefepime-resistant strain. Conclusion. Using our scoring system should reduce the indication of very broad antibacterial regimens in the empirical, first-line treatment of febrile hematology patients in more than 80% of the cases.

  11. Possible interaction between the bacterial transcription factor ArtA and the eukaryotic RNA polymerase III promoter.

    Science.gov (United States)

    Matsutani, Sachiko

    2016-06-01

    Eukaryotic RNA polymerase III (RNAP III) transcribes tRNA genes and short interspersed elements that have internal promoters consisting of A- and B-blocks. The B-block binding subunit of the transcription initiation factor TFIIIC binds to the B-block. The mobile bacterial insertion sequence (IS) 1 contains a RNAP III promoter-like sequence, which stimulates bacterial transcription along with the bacterial ArtA protein. Here, the DNA-binding ability of ArtA was examined in vitro using a simple, newly developed method. Various DNA fragments, including RNAP III promoter fragments, were separately incubated with purified ArtA, and then loaded onto a polyacrylamide gel. Since DNAs bound by ArtA remain in the gel wells during electrophoresis, SDS was added into the wells at the electrophoresis halfway point. It was hypothesized that SDS would dissociate the DNA-ArtA complexes in the wells, and then the DNAs would begin to migrate. In fact, new bands appeared in all of the lanes at similar intensities, indicating that ArtA binds nonspecifically to DNA. Therefore, labeled wild-type RNAP III promoter fragments were incubated with either the unlabeled wild-type or mutant fragments and ArtA, and electrophoresed. The B-block(-like) sequences of IS1, a human Alu element, and an anuran tRNA gene were important for binding to ArtA. Additionally, in silico analyses revealed the presence of the RNAP III promoter-like structures in the IS1 isoforms and the IS3 family elements. These results suggest the presence of parts of the RNAP III transcription machinery in bacteria, and might imply that its prototype existed in the common ancestor. PMID:27178279

  12. Mechanism of fusidic acid inhibition of RRF- and EF-G-dependent splitting of the bacterial post-termination ribosome

    OpenAIRE

    Borg, Anneli; Pavlov, Michael; Ehrenberg, Måns

    2016-01-01

    The antibiotic drug fusidic acid (FA) is commonly used in the clinic against gram-positive bacterial infections. FA targets ribosome-bound elongation factor G (EF-G), a translational GTPase that accelerates both messenger RNA (mRNA) translocation and ribosome recycling. How FA inhibits translocation was recently clarified, but FA inhibition of ribosome recycling by EF-G and ribosome recycling factor (RRF) has remained obscure. Here we use fast kinetics techniques to estimate mean times of rib...

  13. EVALUATION OF BIOTIC AND TREATMENT FACTORS RELATING TO BACTERIAL CONTROL OF ZEBRA MUSSELS

    International Nuclear Information System (INIS)

    Testing over the last quarter has indicated the following regarding control of zebra mussels with bacterium Pseudomonas fluorescens strain CL0145A: (1) the concentration of bacteria suspended in water is directly correlated with mussel kill; (2) the ratio of bacterial mass per mussel, if too low, could limit mussel kill; a treatment must be done at a high enough ratio so that mussels do not deplete all the suspended bacteria before the end of the desired exposure period; (3) bacteria appear to lose almost all their toxicity after suspension for 24 hr in highly oxygenated water; (4) in a recirculating pipe system, the same percentage mussel kill will be achieved irrespective of whether all the bacteria are applied at once or divided up and applied intermittently in smaller quantities over a 10-hr period. Since this is the fourth quarterly report, a summation of all test results over the last twelve months is provided as a table in this report. The table includes the above-mentioned fourth-quarter results

  14. Bacterial gastroenteritis

    Science.gov (United States)

    Infectious diarrhea - bacterial gastroenteritis; Acute gastroenteritis; Gastroenteritis - bacterial ... Bacterial gastroenteritis can affect 1 person or a group of people who all ate the same food. It is ...

  15. Environmental factors affecting methane distribution and bacterial methane oxidation in the German Bight (North Sea)

    Czech Academy of Sciences Publication Activity Database

    Osudar, R.; Matoušů, Anna; Alawi, M.; Wagner, D.; Bussmann, I.

    2015-01-01

    Roč. 160, July (2015), s. 10-21. ISSN 0272-7714 R&D Projects: GA ČR(CZ) GA13-00243S Institutional support: RVO:60077344 Keywords : methanotrophy * estuary * Elbe River Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.057, year: 2014

  16. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    parameters, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion is...... the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental...

  17. Abundance and Diversity of Bacterial, Archaeal, and Fungal Communities Along an Altitudinal Gradient in Alpine Forest Soils: What Are the Driving Factors?

    Science.gov (United States)

    Siles, José A; Margesin, Rosa

    2016-07-01

    Shifts in soil microbial communities over altitudinal gradients and the driving factors are poorly studied. Their elucidation is indispensable to gain a comprehensive understanding of the response of ecosystems to global climate change. Here, we investigated soil archaeal, bacterial, and fungal communities at four Alpine forest sites representing a climosequence, over an altitudinal gradient from 545 to 2000 m above sea level (asl), regarding abundance and diversity by using qPCR and Illumina sequencing, respectively. Archaeal community was dominated by Thaumarchaeota, and no significant shifts were detected in abundance or community composition with altitude. The relative bacterial abundance increased at higher altitudes, which was related to increasing levels of soil organic matter and nutrients with altitude. Shifts in bacterial richness and diversity as well as community structure (comprised basically of Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes) significantly correlated with several environmental and soil chemical factors, especially soil pH. The site at the lowest altitude harbored the highest bacterial richness and diversity, although richness/diversity community properties did not show a monotonic decrease along the gradient. The relative size of fungal community also increased with altitude and its composition comprised Ascomycota, Basidiomycota, and Zygomycota. Changes in fungal richness/diversity and community structure were mainly governed by pH and C/N, respectively. The variation of the predominant bacterial and fungal classes over the altitudinal gradient was the result of the environmental and soil chemical factors prevailing at each site. PMID:26961712

  18. Role of bacterial and genetic factors in gastric cancer in Costa Rica

    Institute of Scientific and Technical Information of China (English)

    Sergio A Con; Hiroaki Takeuchi; Gil R Con-Chin; Vicky G Con-Chin; Nobufumi Yasuda; Reinaldo Con-Wong

    2009-01-01

    AIM: To evaluate several risk factors for gastric cancer (GC) in Costa Rican regions with contrasting GC incidence rate (GCIR). METHODS: According to GCIR, 191 Helicobacter pylori ( H pylori)-positive patients were classified into groups A (high GCIR, n = 101) and B (low GCIR, n = 90). Human DNA obtained from biopsy specimens was used in the determination of polymorphisms of the genes coding for interleukin (IL)-1o play a major role in GCIR variability in Costa Rica.

  19. Food safety in raw milk production: risk factors associated to bacterial DNA contamination.

    Science.gov (United States)

    Cerva, Cristine; Bremm, Carolina; Reis, Emily Marques dos; Bezerra, André Vinícius Andrade; Loiko, Márcia Regina; Cruz, Cláudio Estêvão Farias da; Cenci, Alexander; Mayer, Fabiana Quoos

    2014-06-01

    While human illness from milkborne pathogens may be linked to contamination of the product after pasteurization or improper pasteurization, such diseases are usually associated with consumption of raw milk or its by-products. Molecular biology tools were applied to investigate contamination by Listeria monocytogenes, Salmonella spp., some pathogenic strains of Escherichia coli, and Campylobacter jejuni in 548 raw milk samples from 125 dairy farms established in two regions from southern Brazil. Moreover, 15 variables were evaluated for their association with raw milk contamination levels, and the risk factors were determined by multiple regression analysis. Salmonella spp. were more frequently detected, followed by pathogenic E. coli. There was difference in contamination index between the regions, in which risk factors such as temporary cattle confinement, low milk production, low milking machine cleaning frequency, and milk storage area without tile walls were identified. The risk factors were specific to each region studied. Nevertheless, the data can be used to improve milk quality of dairy farms/herds with similar management practices. PMID:24715203

  20. Enhancement of Methacholine-Evoked Tracheal Contraction Induced by Bacterial Lipopolysaccharides Depends on Epithelium and Tumor Necrosis Factor

    Directory of Open Access Journals (Sweden)

    T. Secher

    2012-01-01

    Full Text Available Inhaled bacterial lipopolysaccharides (LPSs induce an acute tumour necrosis factor-alpha (TNF-α- dependent inflammatory response in the murine airways mediated by Toll-like receptor 4 (TLR4 via the myeloid differentiation MyD88 adaptor protein pathway. However, the contractile response of the bronchial smooth muscle and the role of endogenous TNFα in this process have been elusive. We determined the in vivo respiratory pattern of C57BL/6 mice after intranasal LPS administration with or without the presence of increasing doses of methacholine (MCh. We found that LPS administration altered the basal and MCh-evoked respiratory pattern that peaked at 90 min and decreased thereafter in the next 48 h, reaching basal levels 7 days later. We investigated in controlled ex vivo condition the isometric contraction of isolated tracheal rings in response to MCh cholinergic stimulation. We observed that preincubation of the tracheal rings with LPS for 90 min enhanced the subsequent MCh-induced contractile response (hyperreactivity, which was prevented by prior neutralization of TNFα with a specific antibody. Furthermore, hyperreactivity induced by LPS depended on an intact epithelium, whereas hyperreactivity induced by TNFα was well maintained in the absence of epithelium. Finally, the enhanced contractile response to MCh induced by LPS when compared with control mice was not observed in tracheal rings from TLR4- or TNF- or TNF-receptor-deficient mice. We conclude that bacterial endotoxin-mediated hyperreactivity of isolated tracheal rings to MCh depends upon TLR4 integrity that signals the activation of epithelium, which release endogenous TNFα.

  1. Effects of elongation delay in transcription dynamics.

    Science.gov (United States)

    Zhang, Xuan; Jin, Huiqin; Yang, Zhuoqin; Lei, Jinzhi

    2014-12-01

    In the transcription process, elongation delay is induced by the movement of RNA polymerases (RNAP) along the DNA sequence, and can result in changes in the transcription dynamics. This paper studies the transcription dynamics that involved the elongation delay and effects of cell division and DNA replication. The stochastic process of gene expression is modeled with delay chemical master equation with periodic coefficients, and is studied numerically through the stochastic simulation algorithm with delay. We show that the average transcription level approaches to a periodic dynamics over cell cycles at homeostasis, and the elongation delay can reduce the transcription level and increase the transcription noise. Moreover, the transcription elongation can induce bimodal distribution of mRNA levels that can be measured by the techniques of flow cytometry. PMID:25365608

  2. Extensometer automatically measures elongation in elastomers

    Science.gov (United States)

    Hooper, C. D.

    1966-01-01

    Extensometer, with a calibrated shaft, measures the elongation of elastomers and automatically records this distance on a chart. It is adaptable to almost any tensile testing machine and is fabricated at a relatively low cost.

  3. Functional equivalence of HMGA- and histone H1-like domains in a bacterial transcriptional factor

    OpenAIRE

    García-Heras, Francisco; Padmanabhan, S.; Murillo, Francisco J.; Elías-Arnanz, Montserrat

    2009-01-01

    Histone H1 and high-mobility group A (HMGA) proteins compete dynamically to modulate chromatin structure and regulate DNA transactions in eukaryotes. In prokaryotes, HMGA-like domains are known only in Myxococcus xanthus CarD and its Stigmatella aurantiaca ortholog. These have an N-terminal module absent in HMGA that interacts with CarG (a zinc-associated factor that does not bind DNA) to form a stable complex essential in regulating multicellular development, light-induced carotenogenesis, a...

  4. mADP-RTs: Versatile virulence factors from bacterial pathogens of plants and mammals

    OpenAIRE

    Lennart eWirthmueller; Banfield, Mark J.

    2012-01-01

    Mono ADP-ribosyltransferases (mADP-RTs) are a family of enzymes that cleave NAD+ and covalently attach the ADP-ribosyl moiety to target proteins. mADP-RTs are well established as important virulence factors of bacteria that infect mammals. Cholera toxin, pertussis toxin and diphteria toxin are three of the best-known examples of mADP-RTs. They modify host target proteins in order to promote infection and/or killing of the host cell. Despite low sequence similarity at the primary amino acid le...

  5. Small Intestinal Bacterial Overgrowth in Patients with Irritable Bowel Syndrome: Clinical Characteristics, Psychological Factors, and Peripheral Cytokines

    Science.gov (United States)

    Chu, Hua; Fox, Mark; Zheng, Xia; Deng, Yanyong; Long, Yanqin; Huang, Zhihui; Du, Lijun; Xu, Fei; Dai, Ning

    2016-01-01

    Small intestinal bacterial overgrowth (SIBO) has been implicated in the pathogenesis of irritable bowel syndrome (IBS). Psychosocial factors and low-grade colonic mucosal immune activation have been suggested to play important roles in the pathophysiology of IBS. In total, 94 patients with IBS and 13 healthy volunteers underwent a 10 g lactulose hydrogen breath test (HBT) with concurrent 99mTc scintigraphy. All participants also completed a face-to-face questionnaire survey, including the Hospital Anxiety and Depression Scale, Life Event Stress (LES), and general information. Serum tumour necrosis factor-α, interleukin- (IL-) 6, IL-8, and IL-10 levels were measured. The 89 enrolled patients with IBS and 13 healthy controls had no differences in baseline characteristics. The prevalence of SIBO in patients with IBS was higher than that in healthy controls (39% versus 8%, resp.; p = 0.026). Patients with IBS had higher anxiety, depression, and LES scores, but anxiety, depression, and LES scores were similar between the SIBO-positive and SIBO-negative groups. Psychological disorders were not associated with SIBO in patients with IBS. The serum IL-10 level was significantly lower in SIBO-positive than SIBO-negative patients with IBS. PMID:27379166

  6. Telomere elongation chooses TERRA ALTernatives

    OpenAIRE

    Arora, Rajika; Azzalin, Claus M.

    2015-01-01

    Alternative Lengthening of Telomeres (ALT) mechanisms allow telomerase-negative immortal cells to buffer replicative telomere shortening. ALT is naturally active in a number of human cancers and might be selected upon telomerase inactivation. ALT is thought to operate through homologous recombination (HR) occurring between telomeric repeats from independent chromosome ends. Indeed, suppression of a number of HR factors impairs ALT cell proliferation. Yet, how HR is initiated at ALT telomeres ...

  7. Evaporation of elongated droplets on chemically stripe-patterned surfaces

    NARCIS (Netherlands)

    Jansen, H.P.; Zandvliet, H.J.W.; Kooij, E.S.

    2015-01-01

    We investigate the evaporation of elongated droplets on chemically striped patterned surfaces. Variation of elongation is achieved by depositing droplets on surfaces with varying ratios of hydrophobic and hydrophilic stripe widths. Elongated droplets evaporate faster than more spherical droplets. Bo

  8. Inhibition of host cell translation elongation by Legionella pneumophila blocks the host cell unfolded protein response

    Science.gov (United States)

    Hempstead, Andrew D.; Isberg, Ralph R.

    2015-01-01

    Cells of the innate immune system recognize bacterial pathogens by detecting common microbial patterns as well as pathogen-specific activities. One system that responds to these stimuli is the IRE1 branch of the unfolded protein response (UPR), a sensor of endoplasmic reticulum (ER) stress. Activation of IRE1, in the context of Toll-like receptor (TLR) signaling, induces strong proinflammatory cytokine induction. We show here that Legionella pneumophila, an intravacuolar pathogen that replicates in an ER-associated compartment, blocks activation of the IRE1 pathway despite presenting pathogen products that stimulate this response. L. pneumophila TLR ligands induced the splicing of mRNA encoding XBP1s, the main target of IRE1 activity. L. pneumophila was able to inhibit both chemical and bacterial induction of XBP1 splicing via bacterial translocated proteins that interfere with host protein translation. A strain lacking five translocated translation elongation inhibitors was unable to block XBP1 splicing, but this could be rescued by expression of a single such inhibitor, consistent with limitation of the response by translation elongation inhibitors. Chemical inhibition of translation elongation blocked pattern recognition receptor-mediated XBP1 splicing, mimicking the effects of the bacterial translation inhibitors. In contrast, host cell-promoted inhibition of translation initiation in response to the pathogen was ineffective in blocking XBP1 splicing, demonstrating the need for the elongation inhibitors for protection from the UPR. The inhibition of host translation elongation may be a common strategy used by pathogens to limit the innate immune response by interfering with signaling via the UPR. PMID:26598709

  9. A Salmonella small non-coding RNA facilitates bacterial invasion and intracellular replication by modulating the expression of virulence factors.

    Directory of Open Access Journals (Sweden)

    Hao Gong

    2011-09-01

    Full Text Available Small non-coding RNAs (sRNAs that act as regulators of gene expression have been identified in all kingdoms of life, including microRNA (miRNA and small interfering RNA (siRNA in eukaryotic cells. Numerous sRNAs identified in Salmonella are encoded by genes located at Salmonella pathogenicity islands (SPIs that are commonly found in pathogenic strains. Whether these sRNAs are important for Salmonella pathogenesis and virulence in animals has not been reported. In this study, we provide the first direct evidence that a pathogenicity island-encoded sRNA, IsrM, is important for Salmonella invasion of epithelial cells, intracellular replication inside macrophages, and virulence and colonization in mice. IsrM RNA is expressed in vitro under conditions resembling those during infection in the gastrointestinal tract. Furthermore, IsrM is found to be differentially expressed in vivo, with higher expression in the ileum than in the spleen. IsrM targets the mRNAs coding for SopA, a SPI-1 effector, and HilE, a global regulator of the expression of SPI-1 proteins, which are major virulence factors essential for bacterial invasion. Mutations in IsrM result in disregulation of expression of HilE and SopA, as well as other SPI-1 genes whose expression is regulated by HilE. Salmonella with deletion of isrM is defective in bacteria invasion of epithelial cells and intracellular replication/survival in macrophages. Moreover, Salmonella with mutations in isrM is attenuated in killing animals and defective in growth in the ileum and spleen in mice. Our study has shown that IsrM sRNA functions as a pathogenicity island-encoded sRNA directly involved in Salmonella pathogenesis in animals. Our results also suggest that sRNAs may represent a distinct class of virulence factors that are important for bacterial infection in vivo.

  10. Aetiology and factors associated with bacterial diarrhoeal diseases amongst urban refugee children in Eastleigh, Kenya: A case control study

    Directory of Open Access Journals (Sweden)

    Waqo G. Boru

    2013-03-01

    Full Text Available Introduction: Kenya is home to over 400 000 refugees from neighbouring countries. There is scanty information about diarrhoea amongst urban refugees in Kenya.Objectives: We investigated the enteric bacteria causing diarrhoea amongst urban refugee children and described the associated factors.Method: During the period of August–December 2010, urban refugee children between the ages of two and five who attended Eastleigh County Council Health Centre were enrolled into the study. Diarrhoeal cases were compared with age-matched children with no diarrhoea (controls. Stool specimens were collected and enteric bacteria isolated. A questionnaire was administered to identify risk factors.Results: A total of 41 cases and 41 controls were enrolled in the study. The age and country of origin were similar for cases and controls. The bacterial isolation rates amongst the cases were: non-pathogenic Escherichia coli 71%, Shigella dysenteriae 2.4%, Shigella flexneri 2.4%, Salmonella paratyphi 5%. For the controls, non-pathogenic E. coli 90% and enterotoxigenic E. coli (ETEC2.4% were amongst the organisms isolated. All isolates were resistant to amoxicillin; resistance to other antibiotics varied by isolate type. Factors associated independently with diarrhoea included children not washing their hands with soap (aOR 5.9, p < 0.05, neighbour(s having diarrhoea (aOR 39.8, p < 0.05, children not exclusively breastfed for their first 6 months (aOR 7.6, p < 0.05 and children eating food cooked the previous day (aOR 23.8, p = 0.002.Conclusions: Shigella species, Salmonella species and ETEC were found to be responsible for diarrhoea amongst the urban refugee children. Measures to control and guide the use of antibiotics are critical for the prevention of antibiotic resistance. Efforts to improve personal and domestic hygiene, including educational campaigns to promote appropriate handwashing, should be encouraged.

  11. Women's Views and Experiences of the Triggers for Onset of Bacterial Vaginosis and Exacerbating Factors Associated with Recurrence.

    Directory of Open Access Journals (Sweden)

    Jade Bilardi

    Full Text Available Bacterial vaginosis (BV is the most common vaginal infection affecting women of childbearing age. While the aetiology and transmissibility of BV remain unclear, there is strong evidence to suggest an association between BV and sexual activity. This study explored women's views and experiences of the triggers for BV onset and factors associated with recurrence.A descriptive, social constructionist approach was chosen as the framework for the study. Thirty five women of varying sexual orientation who had experienced recurrent BV in the past five years took part in semi-structured interviews.The majority of women predominantly reported sexual contact triggered the onset of BV and sexual and non-sexual factors precipitated recurrence. Recurrence was most commonly referred to in terms of a 'flare-up' of symptoms. The majority of women did not think BV was a sexually transmitted infection however many reported being informed this by their clinician. Single women who attributed BV onset to sex with casual partners were most likely to display self-blame tendencies and to consider changing their future sexual behaviour. Women who have sex with women (WSW were more inclined to believe their partner was responsible for the transmission of or reinfection with BV and seek partner treatment or change their sexual practices.Findings from this study strongly suggest women believe that BV onset is associated with sexual activity, concurring with epidemiological data which increasingly suggest BV may be sexually transmitted. Exacerbating factors associated with recurrence were largely heterogeneous and may reflect the fact it is difficult to determine whether recurrence is due to persistent BV or a new infection in women. There was however evidence to suggest possible transmission and reinfection among WSW, reinforcing the need for new approaches to treatment and management strategies including male and female partner treatment trials.

  12. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz;

    2003-01-01

    Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...... above the linear viscoelastic prediction at intermediate strains, indicating strain hardening. The steady elongational viscosities are monotone decreasing functions of elongation rate. At elongation rates larger than the inverse reptation time, the steady elongational viscosity scales linearly with...

  13. THE ROLE OF BACTERIAL FACTOR AND IMMUNOLOGICAL СHANGES IN NONINFECTIOUS DISEASES OF MICROBIAL ORIGIN

    Directory of Open Access Journals (Sweden)

    Korniychuk O.P.

    2015-05-01

    Full Text Available Introduction. Today during the study of the development mechanisms of any somatic disease possible participation of the microorganism as trigger factor or its influence on the course of the disease or development of complications is considered. Microflora participation in the etiopathogenesis of noninfectious diseases allows to divide the latest into the following groups: Naturally, the first aspects of the study of the role of microorganisms in the development of noninfectious diseases are pathological processes developing in the organs and systems of the body, which are natural biotope, particularly gastrointestinal tract. The imbalance in the functioning of the macroorganism (stress, poor diet causes changes in the composition of endogenous microcenosis and therefore dysbiosis. Thus changes in the hormonal homeostasis, immunoreactivity, in the hypothalamic-adrenal system, speed of peristalsis of the intestines are observed, the overgrowth syndrome in the small intestine developes. A classic disease of a group of diseases that are accompanied by the development of erosive conditions are Helicobacter pylori - associated ulcerous disease of 12 duodenal ulcer. Diseases of the colon digestive canal can be divided into 2 groups - ulcerative colitis and tumors. Escherichia are the main representatives of facultative anaerobic microflora of the colon and are involved in the pathogenesis of both ulcerative colitis and cancer. Material and methods. A study in order to compare the inducing impact of Escherichia lipopolysaccharide isolated from patients with nonspecific ulcerative colitis (NUC, N =38, Crohn's disease (CD, N =30 and colon cancer (CC, N =38, on the humoral and cellular (cytokine links of immunity in ulcerative colitis and colon cancer. From the patients in both study groups and individuals from the control group E. coli were isolated from fecal for obtainining LPS. Synthesis induction of TNFα, IL.-8 and IL.-10 was conducted by

  14. OK-432 reduces mortality and bacterial translocation in irradiated and granulocyte-colony stimulating factor (G-CSF)-treated mice

    Energy Technology Data Exchange (ETDEWEB)

    Nose, Masako; Uzawa, Akiko; Ogyu, Toshiaki [National Inst. of Radiological Sciences, Chiba (Japan); Suzuki, Gen

    2001-06-01

    Acute radiation induces bacterial translocation from the gut, followed by systemic infection and sepsis. In order to reduce the mortality after acute whole body irradiation, it is essential to control bacterial translocation. In this study, we established a bacterial translocation assay as a sensitive method to detect minor mucosal injury by radiation. By utilizing this assay, we evaluated the adverse effects, if any, of hematopoietic reagents on the mucosal integrity in the respiratory and gastro-intestinal tracts. Bacterial translocation to the liver and spleen occurred after whole-body irradiation if the dose exceeded 6 Gy. The administration of G-CSF unexpectedly increased the bacterial translocation in 8 Gy-irradiated mice. The pharmaceutical preparation of low-virulent Streptococcus pyogenes, OK-432, significantly reduced the endotoxin levels in peripheral blood without any reduction of bacterial translocation. A combined treatment with G-CSF and OK-432 decreased bacterial translocation and prevented death. This result indicates that the early administration of G-CSF has an adverse effect on bacterial translocation, and that a combined treatment of G-CSF and OK-432 attenuates the adverse effect of G-CSF and improves the survival rate after acute irradiation. (author)

  15. OK-432 reduces mortality and bacterial translocation in irradiated and granulocyte-colony stimulating factor (G-CSF)-treated mice

    International Nuclear Information System (INIS)

    Acute radiation induces bacterial translocation from the gut, followed by systemic infection and sepsis. In order to reduce the mortality after acute whole body irradiation, it is essential to control bacterial translocation. In this study, we established a bacterial translocation assay as a sensitive method to detect minor mucosal injury by radiation. By utilizing this assay, we evaluated the adverse effects, if any, of hematopoietic reagents on the mucosal integrity in the respiratory and gastro-intestinal tracts. Bacterial translocation to the liver and spleen occurred after whole-body irradiation if the dose exceeded 6 Gy. The administration of G-CSF unexpectedly increased the bacterial translocation in 8 Gy-irradiated mice. The pharmaceutical preparation of low-virulent Streptococcus pyogenes, OK-432, significantly reduced the endotoxin levels in peripheral blood without any reduction of bacterial translocation. A combined treatment with G-CSF and OK-432 decreased bacterial translocation and prevented death. This result indicates that the early administration of G-CSF has an adverse effect on bacterial translocation, and that a combined treatment of G-CSF and OK-432 attenuates the adverse effect of G-CSF and improves the survival rate after acute irradiation. (author)

  16. Cinnamide Derivatives of d-Mannose as Inhibitors of the Bacterial Virulence Factor LecB from Pseudomonas aeruginosa.

    Science.gov (United States)

    Sommer, Roman; Hauck, Dirk; Varrot, Annabelle; Wagner, Stefanie; Audfray, Aymeric; Prestel, Andreas; Möller, Heiko M; Imberty, Anne; Titz, Alexander

    2015-12-01

    Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen with high antibiotic resistance. Its lectin LecB was identified as a virulence factor and is relevant in bacterial adhesion and biofilm formation. Inhibition of LecB with carbohydrate-based ligands results in a decrease in toxicity and biofilm formation. We recently discovered two classes of potent drug-like glycomimetic inhibitors, that is, sulfonamides and cinnamides of d-mannose. Here, we describe the chemical synthesis and biochemical evaluation of more than 20 derivatives with increased potency compared to the unsubstituted cinnamide. The structure-activity relationship (SAR) obtained and the extended biophysical characterization allowed the experimental determination of the binding mode of these cinnamides with LecB. The established surface binding mode now allows future rational structure-based drug design. Importantly, all glycomimetics tested showed extended receptor residence times with half-lives in the 5-20 min range, a prerequisite for therapeutic application. Thus, the glycomimetics described here provide an excellent basis for future development of anti-infectives against this multidrug-resistant pathogen. PMID:27308201

  17. The role of host and microbial factors in the pathogenesis of pneumococcal bacteraemia arising from a single bacterial cell bottleneck.

    Directory of Open Access Journals (Sweden)

    Alice Gerlini

    2014-03-01

    Full Text Available The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic variants was investigated. Sequential analyses of blood samples indicated that most episodes of bacteraemia were monoclonal events providing compelling evidence for a single bacterial cell bottleneck at the origin of invasive disease. With respect to host determinants, results identified novel properties of splenic macrophages and a role for neutrophils in early clearance of pneumococci. Concerning microbial factors, whole genome sequencing provided genetic evidence for the clonal origin of the bacteraemia and identified SNPs in distinct sub-units of F0/F1 ATPase in the majority of the ex vivo isolates. When compared to parental organisms of the inoculum, ex-vivo pneumococci with mutant alleles of the F0/F1 ATPase had acquired the capacity to grow at low pH at the cost of the capacity to grow at high pH. Although founded by a single cell, the genotypes of pneumococci in septicaemic mice indicate strong selective pressure for fitness, emphasising the within-host complexity of the pathogenesis of invasive disease.

  18. Bacterial antigen induced release of soluble vascular endothelial growth factor (VEGF) and VEGFR1 before and after surgery

    DEFF Research Database (Denmark)

    Svendsen, Mads N; Lykke, J; Werther, Kim;

    2005-01-01

    -induced release of sVEGF and sVEGFR1 from whole blood in vitro. MATERIAL AND METHODS: Sixty-one patients with abdominal diseases undergoing five different surgical procedures were included in the study. Blood samples were drawn from patients before and after the operation. White blood cells and platelets were......OBJECTIVE: The influence of surgery on release of soluble vascular endothelial growth factor (sVEGF) and the soluble inhibitory receptor (sVEGFR1) is unknown. The effect of major and minor surgery on variations in sVEGF and sVEGFR1 concentrations in vivo was studied, and on bacterial antigen...... counted, and plasma sVEGF and sVEGFR1 were determined. Whole blood from each blood sample was stimulated in vitro with bacteria-derived antigens (lipopolysaccharides or protein A) and sVEGF and sVEGFR1 levels were subsequently determined in the supernatants. RESULTS: Neither sVEGF nor sVEGFR1...

  19. Role of environmental factors for the vertical distribution (0–1000 m of marine bacterial communities in the NW Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    J. F. Ghiglione

    2008-12-01

    Full Text Available Bacterioplankton plays a central role in energy and matter fluxes in the sea, yet the factors that constrain its variation in marine systems are still poorly understood. Here we use the explanatory power of direct multivariate gradient analysis to evaluate the driving forces exerted by environmental parameters on bacterial community distribution in the water column. We gathered and analysed data from a one month sampling period from the surface to 1000 m depth at the JGOFS-DYFAMED station (NW Mediterranean Sea. This station is characterized by very poor horizontal advection currents which makes it an ideal model to test hypotheses on the causes of vertical stratification of bacterial communities. Capillary electrophoresis single strand conformation polymorphism (CE-SSCP fingerprinting profiles analyzed using multivariate statistical methods demonstrated a vertical zonation of bacterial assemblages in three layers, above, in or just below the chlorophyll maximum and deeper, that remained stable during the entire sampling period. Through the use of direct gradient multivariate ordination analyses we demonstrate that a complex array of biogeochemical parameters is the driving force behind bacterial community structure shifts in the water column. Physico-chemical parameters such as phosphate, nitrate, salinity and to a lesser extent temperature, oxygen, dissolved organic carbon and photosynthetically active radiation acted in synergy to explain bacterial assemblages changes with depth. Analysis of lipid biomarkers of organic matter sources and fates suggested that bacterial community structure in the surface layers was in part explained by lipids of chloroplast origin. Further detailed analysis of pigment-based phytoplankton diversity gave evidence of a compartmentalized influence of several phytoplankton groups on bacterial community structure in the first 150 m depth.

  20. Etiology and Risk Factors of Acute Gastroenteritis in a Taipei Emergency Department: Clinical Features for Bacterial Gastroenteritis

    Directory of Open Access Journals (Sweden)

    Chao-Chih Lai

    2016-04-01

    Full Text Available Background: The causative pathogen is rarely identified in the emergency department (ED, since the results of cultures are usually unavailable. As a result, antimicrobial treatment may be overused. The aim of our study was to investigate the pathogens, risk factors of acute gastroenteritis, and predictors of acute bacterial gastroenteritis in the ED. Methods: We conducted a matched case-control study of 627 stool samples and 612 matched pairs. Results: Viruses (41.3% were the leading cause of gastroenteritis, with noroviruses (32.2% being the most prevalent, followed by bacteria (26.8% and Giardia lamblia (12.4%. Taking antacids (adjusted odds ratio [aOR] 4.10; 95% confidence interval [CI], 2.57–6.53, household members/classmates with gastroenteritis (aOR 4.69; 95% CI, 2.76–7.96, attending a banquet (aOR 2.29; 95% CI, 1.64–3.20, dining out (aOR 1.70; 95% CI, 1.13–2.54, and eating raw oysters (aOR 3.10; 95% CI, 1.61–5.94 were highly associated with gastroenteritis. Elders (aOR 1.04; 05% CI, 1.02–1.05, those with CRP >10 mg/L (aOR 2.04; 95% CI, 1.15–3.62, or those who were positive for fecal leukocytes (aOR 2.04; 95% CI, 1.15–3.62 or fecal occult blood (aOR 1.97; 95% CI, 1.03–3.77 were more likely to be hospitalized in ED. In addition, presence of fecal leukocytes (time ratio [TR] 1.22; 95% CI, 1.06–1.41, abdominal pain (TR 1.20; 95% CI, 1.07–1.41, and frequency of vomiting (TR 0.79; 95% CI, 0.64–0.98 were significantly associated with the duration of acute gastroenteritis. Presence of fecal leukocytes (aOR 2.08; 95% CI, 1.42–3.05, winter season (aOR 0.45; 95% CI, 0.28–0.74, frequency of diarrhea (aOR 1.69; 95% CI, 1.01–2.83, and eating shrimp or crab (aOR 1.53; 95% CI, 1.05–2.23 were highly associated with bacterial gastroenteritis. The area under the receiver operating characteristic curve of the final model was 0.68 (95% CI, 0.55–0.63. Conclusions: Acute bacterial gastroenteritis was highly associated with

  1. Planar elongation of soft polymeric networks

    DEFF Research Database (Denmark)

    Jensen, Mette Krog; Hassager, Ole; Rasmussen, Henrik K.; Skov, Anne Ladegaard; Bach, Anders; Koldbech, Henning Vitus

    2010-01-01

    A new test fixture for the filament stretch rheometer (FSR) has been developed to measure planar elongation of soft polymeric networks with application towards pressure-sensitive adhesives (PSAs). The concept of this new geometry is to elongate a tube-like sample by keeping the perimeter constant....... To validate this new technique, soft polymeric networks of poly(propylene oxide) (PPO) were investigated during deformation. Particle tracking and video recording were used to detect to what extent the imposed strain rate and the sample perimeter remained constant. It was observed that, by using an...

  2. Activity Of Bacterial Proteolytic Enzymes on Antinutritional Factors in Soybeans and the Effect on Growth and Organ Weights of Piglets

    Institute of Scientific and Technical Information of China (English)

    HuoGui-cheng; YangLi-jie; 等

    1999-01-01

    A significant reduction of trypsin inhibitory activity by selected bacterial proteolytic enzymes was demonstrated in vitro.Two trials were conducted to examine the capacity of the tested enzymes to inactivate soybean ANFs in vivo.In trial I,twenty-four piglets weaned at four weeks of age were assigned in replicate groups of 4 piglets per pen to one of three dietary treatments:(1)control;(2)Enzyme 1-supplemented(E1);(3)Enzyme 2-supplemented (E2).In trial II,twenty piglets weaned at five weeks of age were alloted to five treatment diets:(1)contro,1:(2) 0.1% P4-supplemented;(3)0.5% P4-supplemented;(4)0.1% P7-supplemented;(5)0.5% P7-supplemented.The optimum pH for hydrolysis was 8 for E.9-11 for E2,8.5 for P4 and nuctral for P7.After 17 days of the trial,daily gain of piglets on enzymes E1 and E2 was 36% and 18% more than that in the control group,although the difference was not significant.the animals on the treated groups had a tendency to have lighter heart(7.8 and 5.9%),spleen(11.1 and 7.4%) and pancreas(16.7 and 12.5% for E1 and E2 respectively)in relation to empty body weight than those in the control.the small intestine of pigs on the treated groups was significantly lighter(18.9 for E1 and 7.7% for E2) than that in the control(P<0.05).The stomach(26.4 and 24%,p=0.198) and cecum (21.9 and 9.4%,p=0.114) also showed the same pattern.The growth depression was attributed to reduced feed intake caused by antinutritional factors in soybeans.It is concluded that supplements of proteolytic enzymes E1 or E2 had a positive effect on growth and efficiency and caused much less reaction in the gut as manifested by the weight of the tract and of its accessory organs.Dietary saupplements of P4 or P7 had no significant effect on growth,but reduced reaction of soybean antinutritional factors in the gut,especialy P4 in dose of 0.5%.The growth depression was attributed to low feed intake caused by antinutritional factors in soybeans.

  3. Activity Of Bacterial Proteolytic Enzymes on Antinutritional Factors in Soybeans and the Effect on Growth and Organ Weights of Piglets

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A significant reduction of trypsin inhibitory activity by selected bacterial proteolytic enzymes was demon- strated in vitro. Two trials were conducted to examine the capacity of the tested enzymes to inactivate soybean ANFs in vivo. In trial I,twenty-four piglets weaned at four weeks of age were assigned in replicate groups of 4 piglets per pen to one of three dietary treatments: (1)control; (2)Enzyme 1-supplemented(E1); (3)Enzyme 2-supplemented (E2). In trial II,twenty piglets weaned at five weeks of age were alloted to five treatment di- ets:(1)contro,l: (2)0. 1% P4-supplemented; (3)0. 5% P4-supplemented; (4)0. 1% P7-supplemented; (5)0. 5% P7-supplemented. The optimum pH for hydrolysis was 8 for E,9-11 for E2,8.5 for P4 and nuctral for P7. After 17 days of the trial,daily gain of piglets on enzymes E1 and E2 was 36% and 18% more than that in the control group,although the difference was not significant. The animals on the treated groups had a tendency to have lighter heart(7.8 and 5.9%),spleen(11. 1 and 7.4%) and pancreas(16.7 and 12.5% for E1 and E2 respectively)in relation to empty body weight than those in the control. The small intestine of pigs on the treated groups was significantly lighter(18.9 for E1 and 7.7% for E2) than that in the control( P < 0.05 ). The stomach (26.4 and 24%,p=0. 198) and cecum(21.9and 9.4%,p=0. 114) also showed the same pat- tern. The growth depression was attributed to reduced feed intake caused by antinutritional factors in soy beans. It is concluded that supplements of proteolytic enzymes E1 or E2 had a positive effect on growth and ef- ficiency and caused much less reaction in the gut as manifested by the weight of the tract and of its accessory organs. Dietary saupplements of P4 or P7 had no significant effect on growth,but reduced reaction of soybean antinutritional factors in the gut,especialy P4 in dose of 0.5%. The growth depression was attributed to low feed intake caused by antinutritional

  4. Microinjection of Francisella tularensis and Listeria monocytogenes reveals the importance of bacterial and host factors for successful replication.

    Science.gov (United States)

    Meyer, Lena; Bröms, Jeanette E; Liu, Xijia; Rottenberg, Martin E; Sjöstedt, Anders

    2015-08-01

    Certain intracellular bacteria use the host cell cytosol as the replicative niche. Although it has been hypothesized that the successful exploitation of this compartment requires a unique metabolic adaptation, supportive evidence is lacking. For Francisella tularensis, many genes of the Francisella pathogenicity island (FPI) are essential for intracellular growth, and therefore, FPI mutants are useful tools for understanding the prerequisites of intracytosolic replication. We compared the growth of bacteria taken up by phagocytic or nonphagocytic cells with that of bacteria microinjected directly into the host cytosol, using the live vaccine strain (LVS) of F. tularensis; five selected FPI mutants thereof, i.e., ΔiglA, ΔiglÇ ΔiglG, ΔiglI, and ΔpdpE strains; and Listeria monocytogenes. After uptake in bone marrow-derived macrophages (BMDM), ASC(-/-) BMDM, MyD88(-/-) BMDM, J774 cells, or HeLa cells, LVS, ΔpdpE and ΔiglG mutants, and L. monocytogenes replicated efficiently in all five cell types, whereas the ΔiglA and ΔiglC mutants showed no replication. After microinjection, all 7 strains showed effective replication in J774 macrophages, ASC(-/-) BMDM, and HeLa cells. In contrast to the rapid replication in other cell types, L. monocytogenes showed no replication in MyD88(-/-) BMDM and LVS showed no replication in either BMDM or MyD88(-/-) BMDM after microinjection. Our data suggest that the mechanisms of bacterial uptake as well as the permissiveness of the cytosolic compartment per se are important factors for the intracytosolic replication. Notably, none of the investigated FPI proteins was found to be essential for intracytosolic replication after microinjection. PMID:26034213

  5. Prevalence, risk factors, and major bacterial causes of camel mastitis in Borana Zone, Oromia Regional State, Ethiopia.

    Science.gov (United States)

    Regassa, Alemayehu; Golicha, Gelma; Tesfaye, Dawit; Abunna, Fufa; Megersa, Bekele

    2013-10-01

    A cross-sectional study was carried out from November 2010 up to April 2011 to estimate mastitis prevalence and associated risk factors and to assess its bacterial causes in traditionally managed camels in Borana Zone, Southern Ethiopia. Thus, 348 lactating camels were examined clinically, and subclinical cases were checked with California mastitis test (CMT). The overall prevalence of mastitis was 44.8 % (156/348), comprising clinical (19, 5.4 %) and subclinical (137, 39.4 %) cases. The quarter level prevalence of mastitis was 24.0 % (334/1,392). Of the total 1,392 examined teats, 30 were blind, and hence, from the 1,362 non-blind CMT-examined teats, 22.3 % (304/1,362) were CMT positive. Of the 304 CMT-positive samples, 264 were culture positive (197 Gram-positive, 41 Gram-negative, and 26 mixed isolates), and 40 were culture negative. The prevalence of Staphylococcus aureus was found to be the highest at both the animal (12.8 %, 39/304) and quarter level (2.9 %, 39/1,362). Regression analysis revealed higher likelihood of mastitis occurrence among camels from Dharito (OR = 3.4, 95 % confidence interval (CI) = 1.8, 6.4), Gagna (OR = 3.4, 95 % CI = 1.8, 6.5), and Haro Bake (OR = 2.6, 95 % CI = 1.3, 5.1) than camels from Surupha. Likewise, there was higher chance of mastitis occurrence among camels at the early lactation stage (OR = 2.3, 95 % CI = 1.1, 4.6) and camels with udder/teat lesions (OR = 13.7, 95 % CI = 1.7, 109.4) than among camels at late lactation stage and camels with healthy udder/teats, respectively. In conclusion, this study reveals the current status of camel mastitis in Southern Ethiopia. PMID:23563738

  6. Transcriptional activation domains stimulate initiation and elongation at different times and via different residues.

    OpenAIRE

    Brown, S. A.; Weirich, C S; Newton, E M; Kingston, R E

    1998-01-01

    Transcriptional activators can stimulate multiple steps in the transcription process. We have used GAL4 fusion proteins to characterize the ability of different transcriptional activation domains to stimulate transcriptional elongation on the hsp70 gene in vitro. Stimulation of elongation apparently occurs via a mechanistic pathway different from that of stimulation of initiation: the herpes simplex virus VP16, heat shock factor 1 (HSF1) and amphipathic helix (AH) activation domains all stimu...

  7. The Effects of High Steady State Auxin Levels on Root Cell Elongation in Brachypodium.

    Science.gov (United States)

    Pacheco-Villalobos, David; Díaz-Moreno, Sara M; van der Schuren, Alja; Tamaki, Takayuki; Kang, Yeon Hee; Gujas, Bojan; Novak, Ondrej; Jaspert, Nina; Li, Zhenni; Wolf, Sebastian; Oecking, Claudia; Ljung, Karin; Bulone, Vincent; Hardtke, Christian S

    2016-05-01

    The long-standing Acid Growth Theory of plant cell elongation posits that auxin promotes cell elongation by stimulating cell wall acidification and thus expansin action. To date, the paucity of pertinent genetic materials has precluded thorough analysis of the importance of this concept in roots. The recent isolation of mutants of the model grass species Brachypodium distachyon with dramatically enhanced root cell elongation due to increased cellular auxin levels has allowed us to address this question. We found that the primary transcriptomic effect associated with elevated steady state auxin concentration in elongating root cells is upregulation of cell wall remodeling factors, notably expansins, while plant hormone signaling pathways maintain remarkable homeostasis. These changes are specifically accompanied by reduced cell wall arabinogalactan complexity but not by increased proton excretion. On the contrary, we observed a tendency for decreased rather than increased proton extrusion from root elongation zones with higher cellular auxin levels. Moreover, similar to Brachypodium, root cell elongation is, in general, robustly buffered against external pH fluctuation in Arabidopsis thaliana However, forced acidification through artificial proton pump activation inhibits root cell elongation. Thus, the interplay between auxin, proton pump activation, and expansin action may be more flexible in roots than in shoots. PMID:27169463

  8. The Effects of High Steady State Auxin Levels on Root Cell Elongation in Brachypodium[OPEN

    Science.gov (United States)

    Pacheco-Villalobos, David; Tamaki, Takayuki; Gujas, Bojan; Jaspert, Nina; Oecking, Claudia; Bulone, Vincent; Hardtke, Christian S.

    2016-01-01

    The long-standing Acid Growth Theory of plant cell elongation posits that auxin promotes cell elongation by stimulating cell wall acidification and thus expansin action. To date, the paucity of pertinent genetic materials has precluded thorough analysis of the importance of this concept in roots. The recent isolation of mutants of the model grass species Brachypodium distachyon with dramatically enhanced root cell elongation due to increased cellular auxin levels has allowed us to address this question. We found that the primary transcriptomic effect associated with elevated steady state auxin concentration in elongating root cells is upregulation of cell wall remodeling factors, notably expansins, while plant hormone signaling pathways maintain remarkable homeostasis. These changes are specifically accompanied by reduced cell wall arabinogalactan complexity but not by increased proton excretion. On the contrary, we observed a tendency for decreased rather than increased proton extrusion from root elongation zones with higher cellular auxin levels. Moreover, similar to Brachypodium, root cell elongation is, in general, robustly buffered against external pH fluctuation in Arabidopsis thaliana. However, forced acidification through artificial proton pump activation inhibits root cell elongation. Thus, the interplay between auxin, proton pump activation, and expansin action may be more flexible in roots than in shoots. PMID:27169463

  9. Hypoxia-inducible Factor-dependent Regulation of Platelet-activating Factor Receptor as a Route for Gram-Positive Bacterial Translocation across Epithelia

    OpenAIRE

    Keely, Simon; Glover, Louise E.; Weissmueller, Thomas; MacManus, Christopher F.; Fillon, Sophie; Fennimore, Blair; Colgan, Sean P.

    2010-01-01

    Mucosal surfaces, such as the lung and intestine, are lined by a monolayer of epithelia that provides tissue barrier and transport function. It is recently appreciated that a common feature of inflammatory processes within the mucosa is hypoxia (so-called inflammatory hypoxia). Given the strong association between bacterial translocation and mucosal inflammatory disease, we hypothesized that intestinal epithelial hypoxia influences bacterial translocation. Initial studies revealed that exposu...

  10. Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing.

    LENUS (Irish Health Repository)

    Power, C

    2012-02-03

    INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR\\/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis. MATERIALS AND METHODS: We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP. RESULTS: Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble\\/serum CD14, a highly specific bacterial wall product receptor, in

  11. pix-1 controls early elongation in parallel with mel-11 and let-502 in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Emmanuel Martin

    Full Text Available Cell shape changes are crucial for metazoan development. During Caenorhabditis elegans embryogenesis, epidermal cell shape changes transform ovoid embryos into vermiform larvae. This process is divided into two phases: early and late elongation. Early elongation involves the contraction of filamentous actin bundles by phosphorylated non-muscle myosin in a subset of epidermal (hypodermal cells. The genes controlling early elongation are associated with two parallel pathways. The first one involves the rho-1/RHOA-specific effector let-502/Rho-kinase and mel-11/myosin phosphatase regulatory subunit. The second pathway involves the CDC42/RAC-specific effector pak-1. Late elongation is driven by mechanotransduction in ventral and dorsal hypodermal cells in response to body-wall muscle contractions, and involves the CDC42/RAC-specific Guanine-nucleotide Exchange Factor (GEF pix-1, the GTPase ced-10/RAC and pak-1. In this study, pix-1 is shown to control early elongation in parallel with let-502/mel-11, as previously shown for pak-1. We show that pix-1, pak-1 and let-502 control the rate of elongation, and the antero-posterior morphology of the embryos. In particular, pix-1 and pak-1 are shown to control head, but not tail width, while let-502 controls both head and tail width. This suggests that let-502 function is required throughout the antero-posterior axis of the embryo during early elongation, while pix-1/pak-1 function may be mostly required in the anterior part of the embryo. Supporting this hypothesis we show that low pix-1 expression level in the dorsal-posterior hypodermal cells is required to ensure high elongation rate during early elongation.

  12. Vascular Endothelial Growth Factor And Soluble Adhesion Molecules As A Diagnostic Markers For Spontaneous Bacterial Peritonitis In Cirrhotic Liver Disease

    Directory of Open Access Journals (Sweden)

    Hamdia Ezzat Ahmed, (2Ahmed Dorrah,

    2006-03-01

    Full Text Available Spontaneous bacterial peritonitis (SBP is a frequent and severe complication in cirrhotic patients with ascites that usually results in renal failure and death despite the efficacy of the current antibiotic therapy. The aim of this study was determine serum and ascitic fluid of soluble-L selectin (s-L Selectin, intracellular adhesion molecule-1 (ICAM-1, Vascular cell adhesion molecule-1 (VCAM-1 and vascular endothelial growth factor (VEGF in cirrhotic patients, and to search for a relationship between them and SBP. This study was performed on 30 cirrhotic patients with SBP. Their ages ranged (from 38-55 years with mean of (32 + 5.5, 30 cirrhotic patients with non-infected ascites; their ages ranged (from 30-52 years with mean of (35 + 6.5. This group considered as cirrhotic control group and 20 healthy control subjects their ages ranged (from 28-55 years with mean of (30 + 7.5. Serum and ascitic fluid of adhesion molecules as well as VEGF levels were significantly higher in cirrhotic patients with SBP as well as cirrhotic patients with non-infected ascites as compared to healthy control group. There were significant increase in serum and ascitic fluid level of leukocyte, PMN and ICAM-1 in SBP as compared to cirrhotic with non-infected ascites. There was non-significant decrease in serum and AF level of VEGF in cirrhotic control group as compared to SBP group. The ascitic fluid PMN and s-L Selectin were higher in culture positive SBP patients particularly in those with gram positive isolates, where these are non-significant increase in serum and ascitic fluid level of VEGF in culture positive SBP than culture negative cases. Positive correlation was found between serum and ascitic fluid level of ICAM-1 in SBP and non-infected cirrhotic group. Also, positive correlation was found between VEGF levels in serum ascetic fluid levels in both cirrhotic groups (SBP and non-infected cirrhotic group. These data suggest that: Significant elevated level of

  13. Vertically stabilized elongated cross-section tokamak

    Science.gov (United States)

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  14. Low Temperature Viscosity in Elongated Ferrofluids

    OpenAIRE

    Alarcon, T.; Perez-Madrid, A.; Rubi, J. M.

    1997-01-01

    We have studied the relaxation and transport properties of a ferrofluid in an elongational flow. These properties are influenced by the bistable nature of the potential energy. Bistability comes from the irrotational character of the flow together with the symmetry of the dipoles. Additionally, the presence of a constant magnetic field destroys the symmetry of the potential energy magnetizing the system. We have shown that at a moderate temperature, compared to the height of the energy barrie...

  15. Rhizome elongation and seagrass clonal growth

    OpenAIRE

    Marbà, N.; C. M. Duarte

    1998-01-01

    A compilation of published and original data on rhizome morphometry, horizontal and vertical elongation rates and branching patterns for 27 seagrass species developing in 192 seagrass stands allowed an examination of the variability of seagrass rhizome and clonal growth programmes across and within species. Seagrass horizontal rhizomes extend at rates ranging between 1.2 and 574 cm yr(-1), develop a branch, with an angle from 19 to 72 degrees, for every 6 to 1800 horizontal internodes, and ad...

  16. Faraday waves in elongated superfluid fermionic clouds

    OpenAIRE

    Capuzzi, P.; Vignolo, P.

    2008-01-01

    We use hydrodynamic equations to study the formation of Faraday waves in a superfluid Fermi gas at zero temperature confined in a strongly elongated cigar-shaped trap. First, we treat the role of the radial density profile in the limit of an infinite cylindrical geometry and analytically evaluate the wavelength of the Faraday pattern. The effect of the axial confinement is fully taken into account in the numerical solution of hydrodynamic equations and shows that the infinite cylinder geometr...

  17. Magnetization Reversal in Elongated Fe Nanoparticles

    OpenAIRE

    Li, Yongqing; Xiong, Peng; von Molnar, Stephan; Ohno, Yuzo; Ohno, Hideo

    2005-01-01

    Magnetization reversal of individual, isolated high-aspect-ratio Fe nanoparticles with diameters comparable to the magnetic exchange length is studied by high-sensitivity submicron Hall magnetometry. For a Fe nanoparticle with diameter of 5 nm, the magnetization reversal is found to be an incoherent process with localized nucleation assisted by thermal activation, even though the particle has a single-domain static state. For a larger elongated Fe nanoparticle with a diameter greater than 10 ...

  18. Photoautotrophic symbiont and geography are major factors affecting highly structured and diverse bacterial communities in the lichen microbiome

    Energy Technology Data Exchange (ETDEWEB)

    Hodkinson, Brendan P [ORNL; Gottel, Neil R [ORNL; Schadt, Christopher Warren [ORNL; Lutzoni, Francois [Duke University

    2011-01-01

    Although common knowledge dictates that the lichen thallus is formed solely by a fungus (mycobiont) that develops a symbiotic relationship with an alga and/or cyanobacterium (photobiont), the non-photoautotrophic bacteria found in lichen microbiomes are increasingly regarded as integral components of lichen thalli. For this study, comparative analyses were conducted on lichen-associated bacterial communities to test for effects of photobiont-types (i.e. green algal vs. cyanobacterial), mycobiont-types and large-scale spatial distances (from tropical to arctic latitudes). Amplicons of the 16S (SSU) rRNA gene were examined using both Sanger sequencing of cloned fragments and barcoded pyrosequencing. Rhizobiales is typically the most abundant and taxonomically diverse order in lichen microbiomes; however, overall bacterial diversity in lichens is shown to be much higher than previously reported. Members of Acidobacteriaceae, Acetobacteraceae, Brucellaceae and sequence group LAR1 are the most commonly found groups across the phylogenetically and geographically broad array of lichens examined here. Major bacterial community trends are significantly correlated with differences in large-scale geography, photobiont-type and mycobiont-type. The lichen as a microcosm represents a structured, unique microbial habitat with greater ecological complexity and bacterial diversity than previously appreciated and can serve as a model system for studying larger ecological and evolutionary principles.

  19. Preparation and preliminary X-ray diffraction analysis of crystals of bacterial flagellar sigma factor σ28 in complex with the σ28-binding region of its antisigma factor, FlgM

    International Nuclear Information System (INIS)

    A complex of E. coli flagellar and chemotaxis-specific sigma factor σ28 bound to the σ28-binding region of its antisigma factor FlgM was crystallized. Diffraction data were collected to a resolution of 2.7 Å. The sigma 28 kDa (σ28) factor is a transcription factor specific for the expression of bacterial flagellar and chemotaxis genes. Its antisigma factor, FlgM, binds σ28 factor and inhibits its activity as a transcription factor. In this study, crystals of the complex between Escherichia coli σ28 and the C-terminal σ28-binding region of FlgM were obtained. The crystals belong to space group P3121 or P3221, with unit-cell parameters a = b = 106.7 (2), c = 51.74 (3) Å, containing one complex in the crystallographic asymmetric unit. An X-ray intensity data set was collected to a resolution of 2.7 Å

  20. Improving protein delivery of fibroblast growth factor-2 from bacterial inclusion bodies used as cell culture substrates

    OpenAIRE

    Seras Franzoso, Joaquin; Peebo, Karl; Garcia Fruitós, Elena; Vázquez Gómez, Esther; Rinas, Ursula; Villaverde Corrales, Antonio

    2014-01-01

    Altres ajuts: We are indebted CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN, Spain) for funding our research on inclusion bodies. Bacterial inclusion bodies (IBs) have recently been used to generate biocompatible cell culture interfaces, with diverse effects on cultured cells such as cell adhesion enhancement, stimulation of cell growth or induction of mesenchymal stem cell differentiation. Additionally, novel applications of IBs as sustained protein delivery systems with...

  1. Spontaneous elaboration of transforming growth factor beta suppresses host defense against bacterial infection in autoimmune MRL/lpr mice

    OpenAIRE

    1994-01-01

    Infection with gram-negative and gram-positive bacteria remains a leading cause of death in patients with systemic lupus erythematosis (SLE), even in the absence of immunosuppressive therapy. To elucidate the mechanisms that underly the increased risk of infection observed in patients with systemic autoimmunity, we have investigated host defense against bacterial infection in a murine model of autoimmunity, the MRL/Mp-lpr/lpr (MRL/lpr) mouse. Our previous study implicated transforming growth ...

  2. Structure–function studies of the RNA polymerase II elongation complex

    International Nuclear Information System (INIS)

    X-ray crystallographic and complementary functional studies have contributed significantly to the current understanding of gene transcription. Here, recent structure–function studies on various aspects of the elongation phase of transcription are summarized. RNA polymerase II (Pol II) is the eukaryotic enzyme that is responsible for transcribing all protein-coding genes into messenger RNA (mRNA). The mRNA-transcription cycle can be divided into three stages: initiation, elongation and termination. During elongation, Pol II moves along a DNA template and synthesizes a complementary RNA chain in a processive manner. X-ray structural analysis has proved to be a potent tool for elucidating the mechanism of Pol II elongation. Crystallographic snapshots of different functional states of the Pol II elongation complex (EC) have elucidated mechanistic details of nucleotide addition and Pol II translocation. Further structural studies in combination with in vitro transcription experiments led to a mechanistic understanding of various additional features of the EC, including its inhibition by the fungal toxin α-amanitin, the tunability of the active site by the elongation factor TFIIS, the recognition of DNA lesions and the use of RNA as a template

  3. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole;

    2006-01-01

    The start-up and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 and 103 kg/mole, and for three bidisperse polystyrene melts. The monodisperse melts show a maximum in the steady elongational viscosity vs. the elongational...

  4. Faraday waves in elongated superfluid fermionic clouds

    Science.gov (United States)

    Capuzzi, P.; Vignolo, P.

    2008-10-01

    We use hydrodynamic equations to study the formation of Faraday waves in a superfluid Fermi gas at zero temperature confined in a strongly elongated cigar-shaped trap. First, we treat the role of the radial density profile in the limit of an infinite cylindrical geometry and analytically evaluate the wavelength of the Faraday pattern. The effect of the axial confinement is fully taken into account in the numerical solution of hydrodynamic equations, and shows that the infinite cylinder geometry provides a very good description of the phenomena.

  5. Natural elongation and triangularity of tokamak equilibria

    International Nuclear Information System (INIS)

    Quasianalytic formulas are calculated for the elongation κ and triangularity δ of the plasma surface of a free-boundary tokamak equilibrium. The final results give κ and δ as functions of five quantities: the inverse aspect ratio ε, the poloidal beta βp, the internal inductance li, and the quadrupole and hexapole moments of the externally applied field. The agreement with numerically computed equilibria is found to be quite good when A≥3, κ≤1.5, and δ≤0.2 and when the plasma is limited by the vacuum vessel wall and not diverted by the presence of a separatrix on the plasma surface

  6. A Burkholderia pseudomallei type III secreted protein, BopE, facilitates bacterial invasion of epithelial cells and exhibits guanine nucleotide exchange factor activity

    OpenAIRE

    M.P. Stevens; Friebel, A; Taylor, L A; Wood, M W; Brown, P. J.; Hardt, W D; Galyov, E E

    2003-01-01

    We report the characterization of BopE, a type III secreted protein that is encoded adjacent to the Burkholderia pseudomallei bsa locus and is homologous to Salmonella enterica SopE/SopE2. Inactivation of bopE impaired bacterial entry into HeLa cells, indicating that BopE facilitates invasion. Consistent with this notion, BopE expressed in eukaryotic cells induced rearrangements in the subcortical actin cytoskeleton, and purified BopE exhibited guanine nucleotide exchange factor activity for ...

  7. Elongational viscosity of multiarm (Pom-Pom) polystyrene

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Almdal, Kristoffer;

    2006-01-01

    -Pom was estimated to have 2.5 arms on average, while the estimate is 3.3 for the asymmetric star. The molar mass of each arm is about 27 kg/mol. The melts were characterized in the linear viscoelastic regime and in non-linear elongational rheometry. The transient elongational viscosity for the Pom...... corresponds well with an estimate of the maximum stretchability of the backbone. Time-strain separability was not observed for the 'Asymmetric star' molecule at the elongation rates investigated. The transient elongational viscosity for the 'Pom-Pom' molecule went through a reproducible maximum in the...... viscosity at the highest elongational rate....

  8. Impaired rate of microsomal fatty acid elongation in undernourished neonatal rat brain

    International Nuclear Information System (INIS)

    Hypomyelination caused by undernourishment in characterized by low concentrations of myelin lipids and marked reduction in lignocerate (C/sub 24:0/) and nervonate (C/sub 24:1/) moiety of cerebroside and sulfatide. Since microsomal elongation is the major source of long chain (22 to 24 carbons) fatty acids in the brain, the effect of neonatal undernourishment on acyl elongation was investigated. Undernourishment of suckling rats were induced after birth by restricting maternal dietary intake to 40% of that consumed by dams fed ad libitum. Neonates suckled by the normally fed dams served as controls. Microsomal elongation was measured as nmol from [2-14C] malonyl CoA incorporated/h per mg of protein. At 19 days of age, rates of behenoyl CoA (C/sub 22:0/) and erucoyl CoA (C/sub 22:1/) elongation in whole brain of undernourished neonates were 30-40% lower than that of the control, whereas the elongation rates of acyl CoA 16, 18 and 20 carbons in length either saturated or monounsaturated were similar in both groups. Undernourishment had no effect on cytoplasmic de novo fatty acid synthesis from acetyl CoA. If there are multiple elongation factors, the results indicate that the depressed activity of elongating enzyme(s) for C/sub 22:0/ and C/sub 22:1/ is an important contributing factor in lowering S/sub 24:0/ and C/sub 24:1/ content in cerebroside and sulfatide. This impairment may be a specific lesion leading to hypomyelination in undernourished rats

  9. Investigation of nonlinearity as an error source in strain gauge measurements of high elongations, and comparison with other measuring methods

    International Nuclear Information System (INIS)

    High elongation measurement using strain gauges presents problems with regard to accuracy of results, emanating on the one hand from the measuring technique applied (bridge linearity at constant current or constant voltage), or from the strain gauge itself (k factor). Error correction has to take into account all parameters influencing the electric signal, as certain effects are opposite in their signs. The maximum deviations of the elongations measured by the various measuring devices in comparison with true elongation vary with the measuring technique applied, and within the elongation range investigated (0-0.1 m/m) may reach a maximum between 1 p.c. and 11 p.c.. Measurements with equipment using constant current or constant voltage supply have shown to be also appropriate in the high elongation range, if their specific errors within ≤ p.c. are duly corrected. (orig.)

  10. 茶园土壤细菌丰度及其影响因子研究%Bacterial Abundance of Tea Garden Soils and Its Influencing Factors

    Institute of Scientific and Technical Information of China (English)

    韩文炎; 王皖蒙; 郭赟; 杨明臻; 贾仲君

    2013-01-01

    Bacterial abundances in tea garden and their adjacent forest and vegetable soils were investigated by real-time quantitative PCR (qPCR) as well as the factors that may affect the population size of bacterial communities. Soil DNA was extracted by using Griffiths’ method and bacterial abundance was determined by quantifying the copy number of 16S rRNA genes. The results showed that the bacterial abundance of tea garden soils ranged from 0.01×108 to 20.32×108 16 S rRNA gene copies/g (gram dry weight soil) with an average of 3.70×108 16 S rRNA gene copies/g, being similar with that in the forest soil, but far below that in the vegetable soil. The bacterial abundance in the tea garden soils was significantly and positively correlated with the soil pH and microbial biomass C (P<0.001) respectively, but significantly and negatively correlated with N application rate and age of tea plantation (P<0.01) respectively. There was no significant correlation between bacterial abundance and total organic C and total N in soil. Multiple regression analysis further indicated that bacterial abundance was affected most significantly by soil pH, followed by age of tea stand and annual N application rate. The results of this study suggested that soil amelioration such as raising soil pH and reducing the high rates of nitrogen application could be of great help for maintaining bacterial abundance and microbial diversity in tea garden soils.%  采用 Griffiths 法直接提取土壤微生物基因组 DNA,并通过实时荧光定量 PCR 技术分析土壤微生物16 S rRNA 基因数量,对茶园及其附近森林和菜园土壤的细菌丰度及其影响因素进行了研究。结果表明,茶园土壤细菌丰度在0.01×108~20.32×10816 S rRNA 基因拷贝数/g 之间,平均为3.70×10816 S rRNA 基因拷贝数/g,与酸性森林土壤大致相当,但明显低于中性菜园土壤。土壤细菌丰度与 pH 和微生物量 C 呈极显著正相关(P<0.001

  11. Trade studies of plasma elongation for next-step tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Galambos, J.D.; Strickler, D.J.; Peng, Y.K.M.; Reid, R.L.

    1988-09-01

    The effect of elongation on minimum-cost devices is investigated for elongations ranging from 2 to 3. The analysis, carried out with the TETRA tokamak systems code, includes the effects of elongation on both physics (plasma beta limit) and engineering (poloidal field coil currents) issues. When ignition is required, the minimum cost occurs for elongations from 2.3 to 2.9, depending on the plasma energy confinement scaling used. Scalings that include favorable plasma current dependence and/or degradation with fusion power tend to have minimum cost at higher elongation (2.5-2.9); scalings that depend primarily on size result in lower elongation (/approximately/2.3) for minimum cost. For design concepts that include steady-state current-driven operation, minimum cost occurs at an elongation of 2.3. 12 refs., 13 figs.

  12. 灰葡萄孢霉高效拮抗木霉菌株的筛选及其翻译延伸因子序列分析%The Screen of the Antagonism of Trichoderma spp.Against Botrytis cinerea and Sequence Analysis of Translation Elongation Factor

    Institute of Scientific and Technical Information of China (English)

    王勇; 王万立; 霍建飞; 刘春艳; 郝永娟

    2012-01-01

    为进一步开发利用木霉菌资源,对从菜田土壤中初步分离纯化获得的12株木霉菌株,采用对峙培养和生长速度测定法进行灰葡萄孢霉(Botrytis cinerea)高效拮抗木霉菌株的筛选,并通过翻译延伸因子序列同源性比较对其进行分子鉴定.结果表明:菌株Tr9701和Tr1108的生长速度快,对病原菌的抑制率高,且协同应用有一定的增效作用.经对Tr9701和Tr1108翻译延伸因子同源序列分析,并结合其形态特征结果表明,Tr9701为绿色木霉(Trichoderma viride)和Tr1108为深绿木霉(Trichoderma atroviride).绿色木霉和深绿木霉为菜田生境习居菌,2种菌株协同利用对蔬菜灰霉病有较好的协同增效作用,应进一步设计利用多靶位木霉菌来提高防病效果.%The aim was to utilize the biological agents of Trichoderma spp.. There were 12 strains of Trichoderma species separated from vegetable fields, New antagonistic Trichoderma spp. Were screened through the confront culture and growth rate determination, and the sequence homology of translation elongation factor was analyzed. The results showed that, strain Tr 9701 and Tr 1108 had high growth rates and strong inhibitions. With the identification of translation elongation factor of these strains, strain Tr9701 was classified as Trichoderma viride, and Tr1108 was classified as Trichoderma atroviride respectively. Trichoderma viride and Trichoderma atroviride were all inhabitants in vegetable field. The two strains which were used to control vegetable gray mold cooperatively were effective, so it should be studied to utilize Trichoderma spp. With more targets in order to increase control efficiency.

  13. The Survival and Recovery of Irradiated Bacterial Spores as Affected by Population Density and Some External Factors

    International Nuclear Information System (INIS)

    The radiation resistance of Bacillus cereus spores as affected by the pH-value and cell density of the irradiated spore suspensions was investigated. The portions of the survival curves of suspensions of 108, 4 x 103 and 5 x 101 per millilitre viable cell counts, respectively, were compared for a three-orders-of-magnitude decrease in viable cell count. It was established that the initial cell density did not affect radiation resistance of spores. Radiation resistance as affected by pH-value in the range of 3 to 8 was investigated. In the range of pH 5 to 8, the radiation resistance of B. cereus spores was not affected. By lowering the pH-value to below 5, the radiation resistance decreased below that observed in the neutral region. The colony-forming capacity of B. cereus, B. coagulans and B. pumilus as a function of the pH-value in the nutrient medium, and the pH-sensitivity of bacterial spores as affected by radiation, were also investigated. It was established that irradiation increased the pH-sensitivity of surviving bacterial spores in all three strains. The initial phase of spore germination (the phase accompanied by decrease of refractivity of the spores) and the division stage of vegetative cells proved to be the most sensitive to the value of the hydrogen ion concentration. (author)

  14. Stability of the rhizosphere and endophytic bacterial communities associated with Arabidopsis thaliana (L.) Heynh under impact of cosmic factors

    Science.gov (United States)

    Kordium, V. A.; Adamchuk-Chala, N. I.; Moshinec, H. V.

    The orbital experiment will involve a growing of Arabidopsis plant seed to seed in the presence of a plant probiotic bacteria consortium introduced into the system The purpose of experiment is to characterize microbial community associated with Arabidopsis thaliana and determine how consortium of introduced bacteria along with the endemic plant-associated bacteria influences the plant development reproductive system and seed formation in spaceflight conditions The first study will be an examination of the survival of model bacteria in on the inoculated plant The second complex study is to examine the plant traits in particular the ultrastructure of root statocytes in order to determine whether the plant development proceeds normally under microgravity conditions on background of introduced bacteria and to assess the structural changes occurring in the cotyledons generative organs and seeds The third set of observations will concern studies of the structure of microbial community associated with Arabidopsis plants with traditional and molecular tools The fourth part of the work will be an examination of mobile genetic elements that can play a role in adaptation of bacteria to the spaceflight conditions however they may affect the stability of bacterial endo- and rhizosphere communities The final part of the proposal initiates the study of possible risk of the bacterial consortium use for a plant inoculation in spaceflight conditions An evaluation of this risk will be performed via examination of expression of the Klebsiella

  15. Vimentin in Bacterial Infections.

    Science.gov (United States)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection. PMID:27096872

  16. Vimentin in Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Tim N. Mak

    2016-04-01

    Full Text Available Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs. IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection.

  17. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  18. A new pharmacological agent (AKB-4924) stabilizes hypoxia inducible factor-1 (HIF-1) and increases skin innate defenses against bacterial infection.

    Science.gov (United States)

    Okumura, Cheryl Y M; Hollands, Andrew; Tran, Dan N; Olson, Joshua; Dahesh, Samira; von Köckritz-Blickwede, Maren; Thienphrapa, Wdee; Corle, Courtney; Jeung, Seung Nam; Kotsakis, Anna; Shalwitz, Robert A; Johnson, Randall S; Nizet, Victor

    2012-09-01

    Hypoxia inducible factor-1 (HIF-1) is a transcription factor that is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. HIF-1 is also activated in response to bacterial pathogens and supports the innate immune response of both phagocytes and keratinocytes. In this work, we show that a new pharmacological compound AKB-4924 increases HIF-1 levels and enhances the antibacterial activity of phagocytes and keratinocytes against both methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus in vitro. AKB-4924 is also effective in stimulating the killing capacity of keratinocytes against the important opportunistic skin pathogens Pseudomonas aeruginosa and Acinetobacter baumanii. The effect of AKB-4924 is mediated through the activity of host cells, as the compound exerts no direct antimicrobial activity. Administered locally as a single agent, AKB-4924 limits S. aureus proliferation and lesion formation in a mouse skin abscess model. This approach to pharmacologically boost the innate immune response via HIF-1 stabilization may serve as a useful adjunctive treatment for antibiotic-resistant bacterial infections. PMID:22371073

  19. Biomechanics of bacterial walls: studies of bacterial thread made from Bacillus subtilis.

    OpenAIRE

    Thwaites, J J; Mendelson, N H

    1985-01-01

    Bacterial threads of up to 1 m in length have been produced from filaments of separation-suppressed mutants of Bacillus subtilis. Individual threads may contain 20,000 cellular filaments in parallel alignment. The tensile properties of bacterial threads have been examined by using conventional textile engineering techniques. The kinetics of elongation at constant load are indicative of a viscoelastic material. Both Young's modulus and breaking stress are highly dependent upon relative humidit...

  20. Characterization of Elongation Factor Tu of Mycoplasma ovipneumoniae

    Directory of Open Access Journals (Sweden)

    Xuan Zhang, Yue-feng Chu, Ping Zhao, Peng-cheng Gao, Ying He, Nu Wang and Zhong-xin Lu*

    2013-11-01

    Full Text Available Mycoplasma ovipneumoniae is considered as an important pathogen of small ruminants, but its antigenic proteins are not well known so far. In this study, we cloned the EF-Tu gene of M. ovipneumoniae and analyzed the molecular features of the gene and its coding protein for the first time. The gene was then expressed in E.coli and the antigenicity of the coding protein was evaluated as well. The EF-Tu gene of M. ovipneumoniae is 1209 bp in length, encodes 402 amino acids, and shares the highest DNA sequence identity of 87.5% and deduced amino acid sequence identity of 97.8% with those of M. hyopneumoniae, respectively. The recombinant EF-Tu protein can react with the polyclonal antiserum of M. ovipneumoniae and can induce humoral immune responses in mice, which indicated that the EF-Tu may be used as a candidate protein in developing the technologies to control the disease.

  1. Low temperature viscosity in elongated ferrofluids

    Science.gov (United States)

    Alarcón, T.; Pérez-Madrid, A.; Rubí, J. M.

    1997-12-01

    We have studied the relaxation and transport properties of a ferrofluid in an elongational flow. These properties are influenced by the bistable nature of the potential energy. Bistability comes from the irrotational character of the flow together with the symmetry of the dipoles. Additionally, the presence of a constant magnetic field destroys the symmetry of the potential energy magnetizing the system. We have shown that at a moderate temperature, compared to the height of the energy barrier, the viscosity decreases with respect to the value it would have if the potential were stable. This phenomenon is known as the "negative viscosity" effect. Thermal motion induces jumps of the magnetic moment between the two stable states of the system leading to the aforementioned lowered dissipation effect.

  2. Contactless Measurement Of Rectilinearity Of An Elongated Object Based On The Example A Crane Rail

    Directory of Open Access Journals (Sweden)

    Ćmielewski Kazimierz

    2015-07-01

    Full Text Available The common aim of engineering surveys is to determine deviations from rectilinearity for elongated objects. We have developed a number of methods for measuring points that represent an elongated object. These are the constant straight (optical, laser, mechanical-string method, the trigonometric method, geometric levelling method, photogrammetric methods and terrestrial laser scanning. When taking these measurements, it is crucial to have a direct access to the survey points of the measured object. Factors impeding the measurements include: adverse lighting conditions, vibration, dust, refractory effects, lack of direct access to the survey points, etc.

  3. A conserved PUF/Ago/eEF1A complex attenuates translation elongation

    OpenAIRE

    Friend, Kyle; Campbell, Zachary T.; Cooke, Amy; Kroll-Conner, Peggy; Wickens, Marvin P.; Kimble, Judith

    2012-01-01

    SUMMARY PUF (Pumilio/FBF) RNA-binding proteins and Argonaute (Ago) miRNA-binding proteins regulate mRNAs post-transcriptionally, each acting through similar yet distinct mechanisms. Here, we report that PUF and Ago proteins can also function together in a complex with a core translation elongation factor, eEF1A, to repress translation elongation. Both nematode and mammalian PUF/Ago/eEF1A complexes were identified, using co-immunoprecipitation and recombinant protein assays. Nematode CSR-1 (Ag...

  4. Dependence of plasma properties on elongation ratio in non-circular tokamak TNT-A

    International Nuclear Information System (INIS)

    The relation between the plasma properties and elongation ratio is studies in a non-circular tokamak in the case of the safety factor qsub(a) -- 2. With the increase of elongation ratio kappa(1.3 → 1.5), the plasma current increases from 19.5 to 25 kA, the loop voltage decreases from 4 to 3 V, the mean current density and the electron temperature increase slightly (--10%), while the relative amplitude and the poloidal dependence of Mirnov oscillations (m = 2 mode) change little. (author)

  5. Aspirin inhibits Chlamydia pneumoniae : Induced nuclear factor-kappa B activation, cytokine expression, and bacterial development in human endothelial cells

    NARCIS (Netherlands)

    Tiran, A; Gruber, HJ; Graier, WF; Wagner, AH; van Leeuwen, EBM; Tiran, B

    2002-01-01

    Objective-Chlamydia pneumoniae has been associated with atherosclerosis. Infection of vascular endothelial cells with C pneumoniae increases the expression of proatherogenic cytokines mediated by nuclear factor (NF)-kappaB, a transcription factor. The present study was designed to test the effect of

  6. Tokamak elongation: how much is too much? I Theory

    CERN Document Server

    Freidberg, Jeff P; Lee, Jungpyo

    2015-01-01

    In this and the accompanying paper the problem of the maximally achievable elongation in a tokamak is investigated. The work represents an extension of many earlier studies, which were often focused on determining the elongation limits due to (1) natural elongation in a simple applied pure vertical field or (2) axisymmetric stability in the presence of a perfectly conducting wall. The extension investigated here includes the effect of the vertical stability feedback system which actually sets the maximum practical elongation limit in a real experiment. A basic resistive wall stability parameter (gammatau) is introduced to model the feedback system which although simple in appearance actually captures the essence of the feedback system. Elongation limits in the presence of feedback are then determined by calculating the maximum elongation against n=0 resistive wall modes for fixed gammatau. The results are obtained by means of a general formulation culminating in a variational principle which is particularly a...

  7. The Caenorhabditis elegans Elongator complex regulates neuronal alpha-tubulin acetylation.

    Directory of Open Access Journals (Sweden)

    Jachen A Solinger

    2010-01-01

    Full Text Available Although acetylated alpha-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate alpha-tubulin acetylation are, to date, largely unknown. Therefore, a genetic screen was employed in the nematode Caenorhabditis elegans that identified the Elongator complex as a possible regulator of alpha-tubulin acetylation. Detailed characterization of mutant animals revealed that the acetyltransferase activity of the Elongator is indeed required for correct acetylation of microtubules and for neuronal development. Moreover, the velocity of vesicles on microtubules was affected by mutations in Elongator. Elongator mutants also displayed defects in neurotransmitter levels. Furthermore, acetylation of alpha-tubulin was shown to act as a novel signal for the fine-tuning of microtubules dynamics by modulating alpha-tubulin turnover, which in turn affected neuronal shape. Given that mutations in the acetyltransferase subunit of the Elongator (Elp3 and in a scaffold subunit (Elp1 have previously been linked to human neurodegenerative diseases, namely Amyotrophic Lateral Sclerosis and Familial Dysautonomia respectively highlights the importance of this work and offers new insights to understand their etiology.

  8. Using dynamic input allocation for elongation control at FTU

    International Nuclear Information System (INIS)

    In this paper we exploit the dynamic allocation scheme for input redundant control systems proposed in to achieve elongation control on FTU (Frascati Tokamak Upgrade). The scheme first serves as a means for regulating the current in the F coils. Then, due to the quasi-static relationship between the plasma elongation and the F coils current, elongation control is achieved by suitably generalizing the allocation scheme. Both simulation and experimental results are reported.

  9. Analysis of Percent Elongation for Ductile Metal in Uniaxial Tension

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-bin; YANG Mei; JIANG Jian

    2005-01-01

    Percent elongation of ductile metal in uniaxial tension due to non-homogeneity was analyzed based on gradient-dependent plasticity. Three assumptions are used to get the analytical solution of percent elongation: one is static equilibrium condition in axial direction; another is that plastic volumetric strain is zero in necking zone;the other is that the diameter in unloading zone remains constant after strain localization is initiated. The strain gradient term was introduced into the yield function of classical plastic mechanics to obtain the analytical solution of distributed plastic strain. Integrating the plastic strain and considering the influence of necking on plastic elongation, a one-dimensional analytical solution of percent elongation was proposed. The analytical solution shows that the percent elongation is inversely proportional to the gauge length, and the solution is formally similar to earlier empirical formula proposed by Barba. Comparisons of existing experimental results and present analytical solutions for relation between load and total elongation and for relation between percent elongation and gauge lengthwere carried out and the new mechanical model for percent elongation was verified. Moreover, higher ductility,toughness and heterogeneity can cause much larger percentage elongation, which coincides with usual viewpoints.

  10. Calcineurin Links Mitochondrial Elongation with Energy Metabolism.

    Science.gov (United States)

    Pfluger, Paul T; Kabra, Dhiraj G; Aichler, Michaela; Schriever, Sonja C; Pfuhlmann, Katrin; García, Verónica Casquero; Lehti, Maarit; Weber, Jon; Kutschke, Maria; Rozman, Jan; Elrod, John W; Hevener, Andrea L; Feuchtinger, Annette; Hrabě de Angelis, Martin; Walch, Axel; Rollmann, Stephanie M; Aronow, Bruce J; Müller, Timo D; Perez-Tilve, Diego; Jastroch, Martin; De Luca, Maria; Molkentin, Jeffery D; Tschöp, Matthias H

    2015-11-01

    Canonical protein phosphatase 3/calcineurin signaling is central to numerous physiological processes. Here we provide evidence that calcineurin plays a pivotal role in controlling systemic energy and body weight homeostasis. Knockdown of calcineurin in Drosophila melanogaster led to a decrease in body weight and energy stores, and increased energy expenditure. In mice, global deficiency of catalytic subunit Ppp3cb, and tissue-specific ablation of regulatory subunit Ppp3r1 from skeletal muscle, but not adipose tissue or liver, led to protection from high-fat-diet-induced obesity and comorbid sequelæ. Ser637 hyperphosphorylation of dynamin-related protein 1 (Drp1) in skeletal muscle of calcineurin-deficient mice was associated with mitochondrial elongation into power-cable-shaped filaments and increased mitochondrial respiration, but also with attenuated exercise performance. Our data suggest that calcineurin acts as highly conserved pivot for the adaptive metabolic responses to environmental changes such as high-fat, high-sugar diets or exercise. PMID:26411342

  11. Mass composition analysis using elongation rate

    Energy Technology Data Exchange (ETDEWEB)

    Ochilo, Livingstone; Risse, Markus; Yushkov, Alexey [University of Siegen, Siegen (Germany)

    2015-07-01

    The all-particle cosmic ray energy spectrum has been observed to flatten at around 5.2 x 10{sup 18} eV where the spectral index changes from γ = 3.2 to γ = 2.6, a feature called the ''ankle'' of the spectrum. Cosmic rays with energy around the ankle and beyond, known as ultra-high energy cosmic rays (UHECR), have a very low flux and reconstruction of their properties from extensive air shower measurements is subject to uncertainties for instance from hadronic interaction models. Since the year 2004, the Pierre Auger Observatory has recorded a considerable number of UHECR events beyond the ankle. With the greatly improved statistics, the mass composition of the extreme end of the cosmic ray energy spectrum is now being investigated with improved accuracy. The measured composition of UHECR is an important parameter in validating the models used to explain their sources and acceleration mechanisms. In this study, we perform a mass composition analysis using elongation rate (the rate of change of the depth of shower maximum with energy), measured by the fluorescence detector of the Pierre Auger Observatory. The advantage of this approach is a weak dependence of the results on the choice of the hadronic interaction models.

  12. Genome-Wide and Experimental Resolution of Relative Translation Elongation Speed at Individual Gene Level in Human Cells.

    Directory of Open Access Journals (Sweden)

    Xinlei Lian

    2016-02-01

    Full Text Available In the process of translation, ribosomes first assemble on mRNAs (translation initiation and then translate along the mRNA (elongation to synthesize proteins. Elongation pausing is deemed highly relevant to co-translational folding of nascent peptides and the functionality of protein products, which positioned the evaluation of elongation speed as one of the central questions in the field of translational control. By integrating three types of RNA-seq methods, we experimentally and computationally resolved elongation speed, with our proposed elongation velocity index (EVI, a relative measure at individual gene level and under physiological condition in human cells. We successfully distinguished slow-translating genes from the background translatome. We demonstrated that low-EVI genes encoded more stable proteins. We further identified cell-specific slow-translating codons, which might serve as a causal factor of elongation deceleration. As an example for the biological relevance, we showed that the relatively slow-translating genes tended to be associated with the maintenance of malignant phenotypes per pathway analyses. In conclusion, EVI opens a new view to understand why human cells tend to avoid simultaneously speeding up translation initiation and decelerating elongation, and the possible cancer relevance of translating low-EVI genes to gain better protein quality.

  13. Identification of genes involved in the ACC-mediated control of root cell elongation in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Markakis Marios

    2012-11-01

    signaling cascade, these are converged to a ’common pathway’. Furthermore, several potential keyplayers, such as transcription factors and auxin-responsive genes, were identified by the microarray analysis. They await further analysis to reveal their exact role in the control of cell elongation.

  14. Blastocyst Elongation, Trophoblastic Differentiation and Embryonic Pattern Formation

    Science.gov (United States)

    The molecular basis behind elongation and concomitant gastrulation in ungulates that occurs during pre-implantation is still poorly understood. In-depth transcriptome analysis of the elongating porcine conceptus at specific stages has demonstrated that protein synthesis, protein trafficking, cell g...

  15. The Effects of Microgravity on Seated Height (Spinal Elongation)

    Science.gov (United States)

    Young, K. S.; Rajulu, S.

    2011-01-01

    ABSTRACT Many physiological factors, such as spinal elongation, fluid shifts, bone atrophy, and muscle loss, occur during an exposure to a microgravity environment. Spinal elongation is just one of the factors that can also affect the safety and performance of a crewmember while in space. Spinal elongation occurs due to the lack of gravity/compression on the spinal column. This allows for the straightening of the natural spinal curve. There is a possible fluid shift in the inter-vertebral disks that may also result in changes in height. This study aims at collecting the overall change in seated height for crewmembers exposed to a microgravity environment. During previous Programs, Apollo-Soyuz Test Project (ASTP) and Skylab, spinal elongation data was collected from a small number of subjects in a standing posture but were limited in scope. Data from these studies indicated a quick increase in stature during the first few days of weightlessness, after which stature growth reached a plateau resulting in up to a 3% increase of the original measurement [1-5]. However, this data was collected only for crewmembers in standing posture and not in a seated posture. Seated height may have a different effect than standing height due to a change in posture as well as due to a compounded effect of wearing restraints and a potential compression of the gluteal area. Seated height was deemed as a critical measurement in the design of the Constellation Program s (CxP) Crew Exploration Vehicle (CEV), called Orion which is now the point-of-departure vehicle for the Multi-Purpose Crew Vehicle (MPCV) Program; therefore a better understanding of the effects of microgravity on seated height is necessary. Potential changes in seated height that may not have impacted crew accommodation in previous Programs will have significant effects on crew accommodation due to the layout of seats in the Orion.. The current and existing configuration is such that the four crewmembers are stacked two by

  16. High-n ballooning modes in highly elongated tokamaks

    International Nuclear Information System (INIS)

    An analytic study of stability against high-n ballooning modes is highly elongated axisymmetric plasmas is presented and compared with computational results. - From the equation for the marginal pressure gradient, it is found that local shear has an important effect on the stability of elongated plasmas, and that stability deteriorates through high elongation since the stabilizing effects of field line bending and local shear are reduced. The net contribution of the local shear to stability decreases with elongation for strong ballooning modes (eigenfunctions strongly localized near the outer edge of the toroidal flux surfaces) but increases for interchange modes (eigenfunctions more uniform along the flux surfaces). - The computational study of high-n ballooning modes in a highly elongated plasma reveals that lowering the aspect ratio and broadening the pressure profile enhance the marginal beta for βsub(p) less than unity but severely reduce the marginal beta for βsub(p) larger than unity. (author)

  17. The transcription factor IRF3 triggers “defensive suicide” necrosis in response to viral and bacterial pathogens

    OpenAIRE

    Nelson C. Di Paolo; Konstantin Doronin; Lisa K. Baldwin; Thalia Papayannopoulou; Dmitry M. Shayakhmetov

    2013-01-01

    Although molecular components that execute non-inflammatory apoptotic cell death are well defined, molecular pathways that trigger necrotic cell death remain poorly characterized. Here we show that in response to infection with adenovirus or Listeria monocytogenes, macrophages in vivo undergo rapid pro-inflammatory necrotic death that is controlled by interferon-regulatory factor 3 (IRF3). The transcriptional activity of IRF3 is, surprisingly, not required for the induction of necrosis, and i...

  18. Ecological factors characterizing the prevalence of bacterial tick-borne pathogens in Ixodes ricinus ticks in pastures and woodlands

    OpenAIRE

    Halos, Lenaïg; Bord, Severine; Cotté, Violaine; Gasqui, Patrick; Abrial, David; Barnouin, Jacques; Boulouis, Henri-Jean; Taussat, Muriel; Vourc'H, Gwenaël

    2010-01-01

    Ecological changes are recognized as an important driver behind the emergence of infectious diseases. The prevalence of infection in ticks depends upon ecological factors that are rarely taken into account simultaneously. Our objective was to investigate the influences of forest fragmentation, vegetation, adult tick hosts, and habitat on the infection prevalence of three tick-borne bacteria, Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Rickettsia sp. of the spotted fever gr...

  19. DNA transfer occurs during a cell surface contact stage of F sex factor-mediated bacterial conjugation.

    OpenAIRE

    Panicker, M M; Minkley, E G

    1985-01-01

    Donor bacteria containing JCFL39, a temperature-sensitive traD mutant of the F sex factor, were used at the nonpermissive temperature to accumulate stable mating pairs with recipient cells. At this stage in conjugation, extracellular F pili were removed by treatment with 0.01% sodium dodecyl sulfate. Upon then shifting to the permissive temperature for JCFL39, transfer of the F plasmid was observed. The mating pairs that were accumulated with JCFL39 at the nonpermissive temperature were readi...

  20. Factors predisposing to acute and recurrent bacterial non-necrotizing cellulitis in hospitalized patients: a prospective case-control study.

    Science.gov (United States)

    Karppelin, M; Siljander, T; Vuopio-Varkila, J; Kere, J; Huhtala, H; Vuento, R; Jussila, T; Syrjänen, J

    2010-06-01

    Acute non-necrotizing cellulitis is a skin infection with a tendency to recur. Both general and local risk factors for erysipelas or cellulitis have been recognized in previous studies using hospitalized controls. The aim of this study was to identify risk factors for cellulitis using controls recruited from the general population. We also compared patients with a history of previous cellulitis with those suffering a single episode, with regard to the risk factors: length of stay in hospital, duration of fever, and inflammatory response as measured by C-reactive protein (CRP) level and leukocyte count. Ninety hospitalized cellulitis patients and 90 population controls matched for age and sex were interviewed and clinically examined during the period April 2004 to March 2005. In multivariate analysis, chronic oedema of the extremity, disruption of the cutaneous barrier and obesity were independently associated with acute cellulitis. Forty-four (49%) patients had a positive history (PH) of at least one cellulitis episode before entering the study. Obesity and previous ipsilateral surgical procedure were statistically significantly more common in PH patients, whereas a recent (<1 month) traumatic wound was more common in patients with a negative history (NH) of cellulitis. PH patients had longer duration of fever and hospital stay, and their CRP and leukocyte values more often peaked at a high level than those of NH patients. Oedema, broken skin and obesity are risk factors for acute cellulitis. The inflammatory response as indicated by CRP level and leukocyte count is statistically significantly more severe in PH than NH patients. PMID:19694769

  1. Genomes and virulence factors of novel bacterial pathogens causing bleaching disease in the marine red alga Delisea pulchra.

    Directory of Open Access Journals (Sweden)

    Neil Fernandes

    Full Text Available Nautella sp. R11, a member of the marine Roseobacter clade, causes a bleaching disease in the temperate-marine red macroalga, Delisea pulchra. To begin to elucidate the molecular mechanisms underpinning the ability of Nautella sp. R11 to colonize, invade and induce bleaching of D. pulchra, we sequenced and analyzed its genome. The genome encodes several factors such as adhesion mechanisms, systems for the transport of algal metabolites, enzymes that confer resistance to oxidative stress, cytolysins, and global regulatory mechanisms that may allow for the switch of Nautella sp. R11 to a pathogenic lifestyle. Many virulence effectors common in phytopathogenic bacteria are also found in the R11 genome, such as the plant hormone indole acetic acid, cellulose fibrils, succinoglycan and nodulation protein L. Comparative genomics with non-pathogenic Roseobacter strains and a newly identified pathogen, Phaeobacter sp. LSS9, revealed a patchy distribution of putative virulence factors in all genomes, but also led to the identification of a quorum sensing (QS dependent transcriptional regulator that was unique to pathogenic Roseobacter strains. This observation supports the model that a combination of virulence factors and QS-dependent regulatory mechanisms enables indigenous members of the host alga's epiphytic microbial community to switch to a pathogenic lifestyle, especially under environmental conditions when innate host defence mechanisms are compromised.

  2. Bacterial Vaginosis

    Science.gov (United States)

    ... 586. Related Content STDs during Pregnancy Fact Sheet Pregnancy and HIV, Viral Hepatitis, and STD Prevention Pelvic Inflammatory Disease ( ... Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ... STDs See Also Pregnancy Reproductive ...

  3. Bacterial Meningitis

    Science.gov (United States)

    ... Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Recommend on Facebook Tweet Share Compartir On this ... serious disease. Laboratory Methods for the Diagnosis of Meningitis This manual summarizes laboratory methods used to isolate, ...

  4. Prostatitis - bacterial

    Science.gov (United States)

    Any bacteria that can cause a urinary tract infection can cause acute bacterial prostatitis. Infections spread through sexual contact can cause prostatitis. These include chlamydia and gonorrhea . Sexually transmitted ...

  5. Bacterial Conjunctivitis

    OpenAIRE

    Köhle, Ülkü; Kükner, Şahap

    2003-01-01

    Conjunctivitis is an infection of the conjunctiva, generally characterized by irritation, itching, foreign body sensation, tearing and discharge. Bacterial conjunctivitis may be distinguished from other types of conjunctivitis by the presence of yellow–white mucopurulent discharge. It is the most common form of ocular infection all around the world. Staphylococcus species are the most common bacterial pathogenes, followed by Streptococcus pneumoniae and Haemophilus i...

  6. Identification of two proteins that interact with the Erp virulence factor from Mycobacterium tuberculosis by using the bacterial two-hybrid system

    Directory of Open Access Journals (Sweden)

    Cataldi Angel A

    2009-01-01

    Full Text Available Abstract Background The exported repetitive protein (erp gene encodes a secreted 36-kDa protein with a central domain containing several proline-glycine-leucine-threonine-serine (PGLTS repeats. It has been demonstrated that erp is a virulence-associated factor since the disruption of this gene impairs the growth of Mycobacterium bovis and Mycobacterium tuberculosis in mice. Results In order to elucidate the function of Erp we searched for Erp-binding proteins from M. tuberculosis by using a bacterial two-hybrid system. Our results indicate that Erp interacts specifically with two putative membrane proteins, Rv1417 and Rv2617c. Further analysis revealed that the latter two interact with each other, indicating that Rv1417, Rv2617c and Erp are connected through multiple interactions. While Rv1417 is disseminated in several Actinomycetales genera, orthologues of Rv2617c are exclusively present in members of the M. tuberculosis complex (MTC. The central and amino-terminal regions of Erp were determined to be involved in the interaction with Rv1417 and Rv2627c. Erp forms from Mycobacterium smegmatis and Mycobacterium leprae were not able to interact with Rv2617c in two-hybrid assays. Immunolocalization experiments showed that Rv1417 and Rv2617c are found on the cell membrane and Erp on the bacterial cell wall. Finally, comparative genomics and expression studies revealed a possible role of Rv1417 in riboflavin metabolism. Conclusion We identified interactive partners of Erp, an M. tuberculosis protein involved in virulence, which will be the focus of future investigation to decipher the function of the Erp family protein.

  7. Crystallization and preliminary X-ray crystallographic analysis of Thermus thermophilus transcription elongation complex bound to Gfh1

    International Nuclear Information System (INIS)

    To elucidate which RNA polymerase structural state a particular T. thermophilus Gre-family protein (Gfh1) associates with, the T. thermophilus RNAP elongation complex was cocrystallized with Gfh1. RNA polymerase (RNAP) elongates RNA by iterative nucleotide-addition cycles (NAC). A specific structural state (or states) of RNAP may be the target of transcription elongation factors. Gfh1, a Thermus thermophilus Gre-family protein, inhibits NAC. To elucidate which RNAP structural state Gfh1 associates with, the T. thermophilus RNAP elongation complex (EC) was cocrystallized with Gfh1. Of the 70 DNA/RNA scaffolds tested, two (for EC1 and EC2) were successfully crystallized. In the presence of Gfh1, EC1 and EC2 yielded crystals belonging to space group P21 with similar unit-cell parameters (crystals 1 and 2, respectively). X-ray diffraction data sets were obtained at 3.6 and 3.8 Å resolution, respectively

  8. In Vitro Whole Genome DNA Binding Analysis of the Bacterial Replication Initiator and Transcription Factor DnaA

    OpenAIRE

    Smith, Janet L.; Grossman, Alan D.

    2015-01-01

    DnaA, the replication initiation protein in bacteria, is an AAA+ ATPase that binds and hydrolyzes ATP and exists in a heterogeneous population of ATP-DnaA and ADP-DnaA. DnaA binds cooperatively to the origin of replication and several other chromosomal regions, and functions as a transcription factor at some of these regions. We determined the binding properties of Bacillus subtilis DnaA to genomic DNA in vitro at single nucleotide resolution using in vitro DNA affinity purification and deep ...

  9. In Vitro Whole Genome DNA Binding Analysis of the Bacterial Replication Initiator and Transcription Factor DnaA.

    Directory of Open Access Journals (Sweden)

    Janet L Smith

    2015-05-01

    Full Text Available DnaA, the replication initiation protein in bacteria, is an AAA+ ATPase that binds and hydrolyzes ATP and exists in a heterogeneous population of ATP-DnaA and ADP-DnaA. DnaA binds cooperatively to the origin of replication and several other chromosomal regions, and functions as a transcription factor at some of these regions. We determined the binding properties of Bacillus subtilis DnaA to genomic DNA in vitro at single nucleotide resolution using in vitro DNA affinity purification and deep sequencing (IDAP-Seq. We used these data to identify 269 binding regions, refine the consensus sequence of the DnaA binding site, and compare the relative affinity of binding regions for ATP-DnaA and ADP-DnaA. Most sites had a slightly higher affinity for ATP-DnaA than ADP-DnaA, but a few had a strong preference for binding ATP-DnaA. Of the 269 sites, only the eight strongest binding ones have been observed to bind DnaA in vivo, suggesting that other cellular factors or the amount of available DnaA in vivo restricts DnaA binding to these additional sites. Conversely, we found several chromosomal regions that were bound by DnaA in vivo but not in vitro, and that the nucleoid-associated protein Rok was required for binding in vivo. Our in vitro characterization of the inherent ability of DnaA to bind the genome at single nucleotide resolution provides a backdrop for interpreting data on in vivo binding and regulation of DnaA, and is an approach that should be adaptable to many other DNA binding proteins.

  10. Analysis of perspective elongation for sodium laser guide star

    Science.gov (United States)

    Wang, Feng; Zhang, Wei; Chen, Tianjiang; Zhou, Wenchao; Yan, Hong

    2015-10-01

    Laser Guide Star Adaptive Optical systems become an established technique at telescope facilities with large apertures. At these aperture diameters, such as 8m class telescope facilities, the finite distance and vertical extend of an artificial excited guide star result in perspective elongation, which produces errors in wave-front reconstruction and could influence the performance of adaptive optical systems seriously. In this paper, we shall briefly introduce and explain the effect of the perspective elongation, and show some results of theoretical simulation and experiment. First of all, we analyzed how the perspective elongation of sodium LGS changes, and gave the results of simulation which indicated the relation between the perspective elongation and some related parameters. The aberration caused by the elongation was analyzed, and the possibility of aberration correction was discussed. Based on the results of the theoretical simulation, we designed an experiment to observe the perspective elongation. A transmitting and receiving system has been set up. The system consisted of a 300mJ sodium LGS laser, a telescope with an aperture diameter of 450mm, a beam expander with an aperture diameter of 200mm, a LGS detecting device, etc. Based on the pulsed laser and the mobile LGS projector, we operated the experiment at different distance between the telescope and the laser projector. A series of elongated images, corresponding the distance from 5m to 30m, was obtained. The analytic results of the image data agreed with the theoretical simulation. Based on the experimental data, we deduced the aberration of wave-front at 30m separation. According to theoretical simulation of the perspective elongation, the effects including the aberration of wave-front could be achieved, which had been partially verified in the experiment. We suggest that one could improve the reconstruction accuracy in a sodium or Rayleigh LGS adaptive optical system by eliminating the influence of

  11. Bacterial carbonatogenesis

    International Nuclear Information System (INIS)

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The 'passive' carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The 'active' carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author)

  12. PREVALENCE AND RISK FACTORS OF BACTERIAL VAGINOSIS AMONG WOMEN OF REPRODUCTIVE AGE ATTENDING RURAL TERTIARY CARE INSTITUTE OF WESTERN UTTAR PRADESH

    Directory of Open Access Journals (Sweden)

    Amit

    2016-05-01

    Full Text Available BACKGROUND Bacterial vaginosis (BV is the most common cause of abnormal vaginal discharge among women of child bearing age and is associated with adverse obstetric and gynaecologic outcomes. OBJECTIVES The aim of the study was to determine the prevalence of BV by use of Nugent’s criteria and to identify modifiable and nonmodifiable, the risk factors associated with BV in women of reproductive age. METHODOLOGY A descriptive cross sectional study was conducted from January 2013 to December 2013, among women of child bearing age with complaints of vaginal discharge, attending Gynaecology and Obstetric OPD at UPRIMS & R, Saifai, Etawah. Bacterial morphotypes indicative of BV were identified by Nugent’s criteria. A pre-coded questionnaire was used to collect demographic and behavioural characteristics (including contraceptive usage, douching practice in the study participants. DATA ANALYSIS Bivariate and multivariate analyses by logistic regression method performed. Crude Odds ratio and Adjusted Odds Ratio for the association between BV and demographic or behavioural characteristics was calculated using Poisson regression. Sensitivity, specificity, PPV and NPV were calculated keeping Nugent score of 7 for BV as ‘Gold standard.’ RESULTS A prevalence of 31.5.0%, (95% CI 25.6-38.2 was obtained from the study population. Sensitivity, specificity, PPV and NPV of Amsler’s criteria for clinical diagnosis of BV was 67.7%, 89.39%, 74.58% and 85.02% respectively. Low socioeconomic status including occupation, illiteracy, Intrauterine Contraceptive Device (IUCD usage, douching practice and condom usage were significantly associated with BV. CONCLUSIONS The prevalence of BV was 31.5% in this population. Concordance between Amsel’s criteria and Nugent’s was low (67.67%. Among individual Amsel’s parameters, vaginal pH >4.5 had highest sensitivity (84.61% and demonstration of ‘Clue Cell’ was most specific (92.2%. Risk factors for BV ought to

  13. Cycle inhibiting factors (CIFs are a growing family of functional cyclomodulins present in invertebrate and mammal bacterial pathogens.

    Directory of Open Access Journals (Sweden)

    Grégory Jubelin

    Full Text Available The cycle inhibiting factor (Cif produced by enteropathogenic and enterohemorrhagic Escherichia coli was the first cyclomodulin to be identified that is injected into host cells via the type III secretion machinery. Cif provokes cytopathic effects characterized by G(1 and G(2 cell cycle arrests, accumulation of the cyclin-dependent kinase inhibitors (CKIs p21(waf1/cip1 and p27(kip1 and formation of actin stress fibres. The X-ray crystal structure of Cif revealed it to be a divergent member of a superfamily of enzymes including cysteine proteases and acetyltransferases that share a conserved catalytic triad. Here we report the discovery and characterization of four Cif homologs encoded by different pathogenic or symbiotic bacteria isolated from vertebrates or invertebrates. Cif homologs from the enterobacteria Yersinia pseudotuberculosis, Photorhabdus luminescens, Photorhabdus asymbiotica and the beta-proteobacterium Burkholderia pseudomallei all induce cytopathic effects identical to those observed with Cif from pathogenic E. coli. Although these Cif homologs are remarkably divergent in primary sequence, the catalytic triad is strictly conserved and was shown to be crucial for cell cycle arrest, cytoskeleton reorganization and CKIs accumulation. These results reveal that Cif proteins form a growing family of cyclomodulins in bacteria that interact with very distinct hosts including insects, nematodes and humans.

  14. Purification and Characterization of a Rabbit Serum Factor That Kills Listeria Species and Other Foodborne Bacterial Pathogens.

    Science.gov (United States)

    Kothary, Mahendra H; Franco, Augusto A; Tall, Ben D; Gopinath, Gopal R; Datta, Atin R

    2016-08-01

    In an in-vitro assay, rabbit serum, but not human serum, killed Listeria monocytogenes, a foodborne pathogen. The aim of our study was to purify and partially characterize this killing factor. Listericidin was purified from rabbit serum by a single-step ion-exchange chromatography with DEAE-Sephadex A-50 and its antimicrobial activity was assessed by a microdilution method. Listericidin is a protein with a molecular weight of 9 kDa and an isoelectric point of 8.1. It kills L. monocytogenes at 4°C, 25°C, and 37°C, and its activity is resistant to heat (boiling) and acidic conditions (pH <2). Listericidin's activity is inhibited by sodium chloride and various growth media, is sensitive to proteolytic enzymes and is enhanced by calcium chloride, and is neutralized by monoclonal antibodies to human complement C3a. However, the listericidin reacts weakly with these antibodies in an ELISA. The first 33 N-terminal residues of listericidin (SVQLTEKRMDKVGQYTNKELRKXXEDGMRDNPM) have homology to various complement C3a components. Listericidin also kills other Listeria spp., Vibrio spp., Salmonella spp., Escherichia spp., Cronobacter spp., and Bacillus spp. The listericidin peptide purified in a single-step chromatography is pH and heat stable, and has a broad antimicrobial spectrum against major foodborne pathogens in addition to L. monocytogenes. PMID:27455064

  15. High-yield bacterial expression and structural characterization of recombinant human insulin-like growth factor binding protein-2

    Science.gov (United States)

    Swain, Monalisa; Slomiany, Mark G.; Rosenzweig, Steven A.; Atreya, Hanudatta S.

    2010-01-01

    The diverse biological activities of the insulin-like growth factors (IGF-1 and IGF-2) are mediated by the IGF-1 receptor (IGF-IR). These actions are modulated by a family of six IGF-binding proteins (IGFBP-1–6; 22–31 kDa) that via high affinity binding to the IGFs (KD ~ 300–700 pM) both protect the IGFs in the circulation and attenuate IGF action by blocking their receptor access. In recent years, IGFBPs have been implicated in a variety of cancers. However, the structural basis of their interaction with IGFs and/or other proteins is not completely understood. A critical challenge in the structural characterization of full-length IGFBPs has been the difficulty in expressing these proteins at levels suitable for NMR/X-ray crystallography analysis. Here we describe the high-yield expression of full-length recombinant human IGFBP-2 (rhIGFBP-2) in E. coli. Using a single step purification protocol, rhIGFBP-2 was obtained with >95% purity and structurally characterized using NMR spectroscopy. The protein was found to exist as a monomer at the high concentrations required for structural studies and to exist in a single conformation exhibiting a unique intra-molecular disulfide-bonding pattern. The protein retained full biologic activity. This study represents the first high-yield expression of wild-type recombinant human IGFBP-2 in E. coli and first structural characterization of a full-length IGFBP. PMID:20541521

  16. Incidence and Risk Factors for Severe Bacterial Infections in People Living with HIV. ANRS CO3 Aquitaine Cohort, 2000–2012

    Science.gov (United States)

    Collin, Amandine; Le Marec, Fabien; Vandenhende, Marie-Anne; Lazaro, Estibaliz; Duffau, Pierre; Cazanave, Charles; Gérard, Yann; Dabis, François; Bruyand, Mathias; Bonnet, Fabrice

    2016-01-01

    Severe non-AIDS bacterial infections (SBI) are the leading cause of hospital admissions among people living with HIV (PLHIV) in industrialized countries. We aimed to estimate the incidence of SBI and their risk factors in a large prospective cohort of PLHIV patients over a 13-year period in France. Patients followed up in the ANRS CO3 Aquitaine cohort between 2000 and 2012 were eligible; SBI was defined as a clinical diagnosis associated with hospitalization of ≥48 hours or death. Survival analysis was conducted to identify risk factors for SBI.Total follow-up duration was 39,256 person-years [PY] (31,370 PY on antiretroviral treatment [ART]). The incidence of SBI decreased from 26.7/1000 PY [95% CI: 22.9–30.5] over the period 2000–2002 to 11.9/1000 PY [10.1–13.8] in 2009–2012 (p 50 copies/mL (Hazard Ratio [HR] = 5.1, 95% Confidence Interval: 4.2–6.2), CD4 count <500 cells/mm3 and CD4/CD8 ratio <0.8 (with a dose-response relationship for both markers), history of cancer (HR = 1.4 [1.0–1.9]), AIDS stage (HR = 1.7 [1.3–2.1]) and HCV coinfection (HR = 1.4, [1.1–1.6]). HIV-positive patients with diabetes were more prone to SBI (HR = 1.6 [0.9–2.6]). Incidence of SBI decreased over a 13-year period due to the improvement in the virological and immune status of PLHIV on ART. Risk factors for SBI include low CD4 count and detectable HIV RNA, but also CD4/CD8 ratio, HCV coinfection, history of cancer and diabetes, comorbid conditions that have been frequent among PLHIV in recent years. PMID:27050752

  17. Sample Dilution and Bacterial Community Composition Influence Empirical Leucine-to-Carbon Conversion Factors in Surface Waters of the World's Oceans

    KAUST Repository

    Teira, Eva

    2015-09-25

    The transformation of leucine incorporation rates to prokaryotic carbon production rates requires the use of either theoretical or empirically determined conversion factors. Empirical leucine-to-carbon conversion factors (eCFs) vary widely across environments, and little is known about their potential controlling factors. We conducted 10 surface seawater manipulation experiments across the world\\'s oceans, where the growth of the natural prokaryotic assemblages was promoted by filtration (i.e., removal of grazers [F treatment]) or filtration combined with dilution (i.e., also relieving resource competition [FD treatment]). The impact of sunlight exposure was also evaluated in the FD treatments, and we did not find a significant effect on the eCFs. The eCFs varied from 0.09 to 1.47 kg C mol Leu−1 and were significantly lower in the FD than in the F samples. Also, changes in bacterial community composition during the incubations, as assessed by automated ribosomal intergenic spacer analysis (ARISA), were more pronounced in the FD than in the F treatments, compared to unmanipulated controls. Thus, we discourage the common procedure of diluting samples (in addition to filtration) for eCF determination. The eCFs in the filtered treatment were negatively correlated with the initial chlorophyll a concentration, picocyanobacterial abundance (mostly Prochlorococcus), and the percentage of heterotrophic prokaryotes with high nucleic acid content (%HNA). The latter two variables explained 80% of the eCF variability in the F treatment, supporting the view that both Prochlorococcus and HNA prokaryotes incorporate leucine in substantial amounts, although this results in relatively low carbon production rates in the oligotrophic ocean.

  18. Mechanical modelling quantifies the functional importance of outer tissue layers during root elongation and bending

    Science.gov (United States)

    Dyson, Rosemary J; Vizcay-Barrena, Gema; Band, Leah R; Fernandes, Anwesha N; French, Andrew P; Fozard, John A; Hodgman, T Charlie; Kenobi, Kim; Pridmore, Tony P; Stout, Michael; Wells, Darren M; Wilson, Michael H; Bennett, Malcolm J; Jensen, Oliver E

    2014-01-01

    Root elongation and bending require the coordinated expansion of multiple cells of different types. These processes are regulated by the action of hormones that can target distinct cell layers. We use a mathematical model to characterise the influence of the biomechanical properties of individual cell walls on the properties of the whole tissue. Taking a simple constitutive model at the cell scale which characterises cell walls via yield and extensibility parameters, we derive the analogous tissue-level model to describe elongation and bending. To accurately parameterise the model, we take detailed measurements of cell turgor, cell geometries and wall thicknesses. The model demonstrates how cell properties and shapes contribute to tissue-level extensibility and yield. Exploiting the highly organised structure of the elongation zone (EZ) of the Arabidopsis root, we quantify the contributions of different cell layers, using the measured parameters. We show how distributions of material and geometric properties across the root cross-section contribute to the generation of curvature, and relate the angle of a gravitropic bend to the magnitude and duration of asymmetric wall softening. We quantify the geometric factors which lead to the predominant contribution of the outer cell files in driving root elongation and bending. PMID:24641449

  19. APOBEC3G inhibits elongation of HIV-1 reverse transcripts.

    Directory of Open Access Journals (Sweden)

    Kate N Bishop

    2008-12-01

    Full Text Available APOBEC3G (A3G is a host cytidine deaminase that, in the absence of Vif, restricts HIV-1 replication and reduces the amount of viral DNA that accumulates in cells. Initial studies determined that A3G induces extensive mutation of nascent HIV-1 cDNA during reverse transcription. It has been proposed that this triggers the degradation of the viral DNA, but there is now mounting evidence that this mechanism may not be correct. Here, we use a natural endogenous reverse transcriptase assay to show that, in cell-free virus particles, A3G is able to inhibit HIV-1 cDNA accumulation not only in the absence of hypermutation but also without the apparent need for any target cell factors. We find that although reverse transcription initiates in the presence of A3G, elongation of the cDNA product is impeded. These data support the model that A3G reduces HIV-1 cDNA levels by inhibiting synthesis rather than by inducing degradation.

  20. Arabidopsis thaliana root elongation growth is sensitive to lunisolar tidal acceleration and may also be weakly correlated with geomagnetic variations

    Science.gov (United States)

    Barlow, Peter W.; Fisahn, Joachim; Yazdanbakhsh, Nima; Moraes, Thiago A.; Khabarova, Olga V.; Gallep, Cristiano M.

    2013-01-01

    Background Correlative evidence suggests a relationship between the lunisolar tidal acceleration and the elongation rate of arabidopsis roots grown under free-running conditions of constant low light. Methods Seedlings of Arabidopsis thaliana were grown in a controlled-climate chamber maintained at a constant temperature and subjected to continuous low-level illumination from fluorescent tubes, conditions that approximate to a ‘free-running’ state in which most of the abiotic factors that entrain root growth rates are excluded. Elongation of evenly spaced, vertical primary roots was recorded continuously over periods of up to 14 d using high temporal- and spatial-resolution video imaging and were analysed in conjunction with geophysical variables. Key Results and Conclusions The results confirm the lunisolar tidal/root elongation relationship. Also presented are relationships between the hourly elongation rates and the contemporaneous variations in geomagnetic activity, as evaluated from the disturbance storm time and ap indices. On the basis of time series of root elongation rates that extend over ≥4 d and recorded at different seasons of the year, a provisional conclusion is that root elongation responds to variation in the lunisolar force and also appears to adjust in accordance with variations in the geomagnetic field. Thus, both lunisolar tidal acceleration and the geomagnetic field should be considered as modulators of root growth rate, alongside other, stronger and more well-known abiotic environmental regulators, and perhaps unexplored factors such as air ions. Major changes in atmospheric pressure are not considered to be a factor contributing to oscillations of root elongation rate. PMID:23532042

  1. ELONGATED STYLOID PROCESS: A REPORT OF TWO CADAVERIC CASES

    Directory of Open Access Journals (Sweden)

    Komala Nanjundaiah

    2014-06-01

    Full Text Available Introduction: Styloid process is a part of temporal bone. It measures 2 to 3 cms in length and lies antero-medial to the mastoid process. An elongated styloid process can compress the vital vessels and nerves close to it. This can lead to pain, foreign body sensation in the pharyngeal region and can also cause dysphagia. Observation: During routine dissection, we encountered elongated styloid process in two cadavers. In one it was unilateral and in another it was bilateral. The measurements of the elongated styloid process were taken using digital Vernier slide calipers. Conclusion: The awareness of the embryological cause and the clinical implications of an elongated styloid process are important for accurate diagnosis and treatment

  2. Elongation of confined ferrofluid droplets under applied fields

    OpenAIRE

    Banerjee, S.; Fasnacht, M.; Garoff, S.; Widom, M.

    1999-01-01

    Ferrofluids are strongly paramagnetic liquids. We study the behavior of ferrofluid droplets confined between two parallel plates with a weak applied field parallel to the plates. The droplets elongate under the applied field to reduce their demagnetizing energy and reach an equilibrium shape where the magnetic forces balance against the surface tension. This elongation varies logarithmically with aspect ratio of droplet thickness to its original radius, in contrast to the behavior of unconfin...

  3. Evolution of Body Elongation in Gymnophthalmid Lizards: Relationships with Climate

    OpenAIRE

    Grizante, Mariana B.; Brandt, Renata; Kohlsdorf, Tiana

    2012-01-01

    The evolution of elongated body shapes in vertebrates has intrigued biologists for decades and is particularly recurrent among squamates. Several aspects might explain how the environment influences the evolution of body elongation, but climate needs to be incorporated in this scenario to evaluate how it contributes to morphological evolution. Climatic parameters include temperature and precipitation, two variables that likely influence environmental characteristics, including soil texture an...

  4. Observation of improved ohmic confinement in highly elongated TCV discharges

    International Nuclear Information System (INIS)

    The primary goals of the TCV tokamak are to produce plasmas with high elongation and to investigate confinement behaviour for a variety of plasma shapes. A spontaneous transition to an improved ohmic confinement regime has recently been observed in moderately and highly elongated discharges limited by the central column. The observed features are similar to those observed in ASDEX (IOC regime). (author) 5 tab., 5 refs

  5. New Insights on Plant Cell Elongation: A Role for Acetylcholine

    OpenAIRE

    Gian-Pietro Di Sansebastiano; Silvia Fornaciari; Fabrizio Barozzi; Gabriella Piro; Laura Arru

    2014-01-01

    We investigated the effect of auxin and acetylcholine on the expression of the tomato expansin gene LeEXPA2, a specific expansin gene expressed in elongating tomato hypocotyl segments. Since auxin interferes with clathrin-mediated endocytosis, in order to regulate cellular and developmental responses we produced protoplasts from tomato elongating hypocotyls and followed the endocytotic marker, FM4-64, internalization in response to treatments. Tomato protoplasts were observed during auxin and...

  6. REPRODUCTIVE BIOLOGY OF ELONGATE SURGEON FISH Acanthurus mata

    OpenAIRE

    Tresnati, Joeharnani

    2010-01-01

    Elongate surgeonfish, Acanthurus mata is a commercial fish targetting by local fishermen in Makassar Strait , South SulawesiThe study aims to analyze reproductive biology of elongate surgeonfish including ., sex ratio, gonad maturity stage (GS), size at first maturity sexual, and gonad maturity index (GI). The specimens were collected from the fishermen. Total length and body-wet weight were measured for each specimen. Sex ratio was determined for each sampling period and the whole samples...

  7. THE INFLUENCE OF HUMIDITY ON THE TENSILE STRENGTH AND BREAKING ELONGATION OF YARNS FOR KNITTING SOCKS

    OpenAIRE

    Dorin Vlad; Alina Mihaela Coldea

    2013-01-01

    Tensile property of textile yarn is a prime important parameter in establish the suitability for any particular application. Breaking strength, elongation, elastic modulus, abrasion resistence etc. are some important factors which will represent the performance of the yarn. It is therefore of utmost importance to determine this characteristic accurately. Raw material characteristics influence properties of the knitted products. The yarns are subjected to mechanical stress during knitting and ...

  8. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  9. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  10. Cloning and characterization of hIF2, a human homologue of bacterial translation initiation factor 2, and its interaction with HIV-1 matrix.

    Science.gov (United States)

    Wilson, S A; Sieiro-Vazquez, C; Edwards, N J; Iourin, O; Byles, E D; Kotsopoulou, E; Adamson, C S; Kingsman, S M; Kingsman, A J; Martin-Rendon, E

    1999-08-15

    The cDNA for a human homologue (hIF2) of bacterial (bIF2) and yeast (yIF2) translation initiation factor two (IF2) has been identified during a screen for proteins which interact with HIV-1 matrix. The hIF2 cDNA encodes a 1220-amino-acid protein with a predicted relative molecular mass of 139 kDa, though endogeneous hIF2 migrates anomalously on SDS/PAGE at 180 kDa. hIF2 has an extended N-terminus compared with its homologues, although its central GTP-binding domain and C-terminus are highly conserved, with 58% sequence identity with yIF2. We have confirmed that hIF2 is required for general translation in human cells by generation of a point mutation in the P-loop of the GTP-binding domain. This mutant protein behaves in a transdominant manner in transient transfections and leads to a significant decrease in the translation of a reporter gene. hIF2 interacts directly with HIV-1 matrix and Gag in vitro, and the protein complex can be immunoprecipitated from human cells. This interaction appears to block hIF2 function, since purified matrix protein inhibits translation in a reticulocyte lysate. hIF2 does not correspond to any of the previously characterized translation initiation factors identified in mammals, but its essential role in translation appears to have been conserved from bacteria to humans. PMID:10432305

  11. Identification and characterization of transforming growth factor β-activated kinase 1 from Litopenaeus vannamei involved in anti-bacterial host defense.

    Science.gov (United States)

    Wang, Sheng; Li, Haoyang; L, Kai; Qian, Zhe; Weng, Shaoping; He, Jianguo; Li, Chaozheng

    2016-05-01

    LvTAK1, a member of transforming growth factor β-activated kinase 1 (TAK1) families, has been identified from Litopenaeus vannamei in this study. The full length of LvTAK1 is 2670 bp, including a 2277 bp open reading frame (ORF) that encoded a putative protein of 758 amino acids with a calculated molecular weight of ∼83.4 kDa LvTAK1 expression was most abundant in muscles and was up-regulated in gills after LPS, Vibrio parahaemolyticus, Staphhylococcu saureus, Poly (I:C) and WSSV challenge. Both in vivo and in vitro experiments indicated that LvTAK1 could activate the expression of several antimicrobial peptide genes (AMPs). In addition, the dsRNA-mediated knockdown of LvTAK1 enhanced the susceptibility of shrimps to Vibrio parahaemolyticus, a kind of Gram-negative bacteria. These results suggested LvTAK1 played important roles in anti-bacterial infection. CoIP and subcellular localization assay demonstrated that LvTAK1 could interact with its binding protein LvTAB2, a key component of IMD pathway. Moreover, over-expression of LvTAK1 in Drosophila S2 cell could strongly induce the promoter activity of Diptericin (Dpt), a typical AMP which is used to read out of the activation of IMD pathway. These findings suggested that LvTAK1 could function as a component of IMD pathway. Interestingly, with the over-expression of LvTAK1 in S2 cell, the promoter activity of Metchnikowin (Mtk), a main target gene of Toll/Dif pathway, was up-regulated over 30 times, suggesting that LvTAK1 may also take part in signal transduction of the Toll pathway. In conclusion, we provided some evidences that the involvement of LvTAK1 in the regulation of both Toll and IMD pathways, as well as innate immune against bacterial infection in shrimp. PMID:27033469

  12. Risk factors for bulk milk somatic cell counts and total bacterial counts in smallholder dairy farms in the 10th region of Chile.

    Science.gov (United States)

    van Schaik, G; Green, L E; Guzmán, D; Esparza, H; Tadich, N

    2005-01-01

    We investigated the principal management factors that influenced bulk milk somatic cell count (BMSCC) and total bacterial count (TBC) of smallholder dairy farms in the 10th region of Chile. One hundred and fifty smallholder milk producers were selected randomly from 42 milk collection centres (MCCs). In April and May of 2002, all farms were visited and a detailed interview questionnaire on dairy-cow management related to milk quality was conducted. In addition, the BMSCC and TBC results from the previous 2 months' fortnightly tests were obtained from the MCCs. The mean BMSCC and TBC were used as the dependent variables in the analyses and were normalised by a natural-logarithm transformation (LN). All independent management variables were categorised into binary outcomes and present (=1) was compared with absent (=0). Biserial correlations were calculated between the LNBMSCC or LNTBC and the management factors of the smallholder farms. Management factors with correlations with P0.05) factors. A random MCC effect was included in the models to investigate the importance of clustering of herds within MCC. In the null model for mean LNTBC, the random effect of MCCs was highly significant. It was explained by: milk collected once a day or less compared with collection twice a day, not cleaning the bucket after milking mastitic cows versus cleaning the bucket and cooling milk in a vat of water versus not cooling milk or using ice or a bulk tank to cool milk. Other factors that increased the LNTBC were a waiting yard with a soil or gravel floor versus concrete, use of plastic buckets for milking instead of metal, not feeding California mastitis test (CMT)-positive milk to calves and cows of dual-purpose breed. The final model explained 35% of the variance. The model predicted that a herd that complied with all the management practices had a mean predicted TBC of 105 colony forming units (cfu)/ml, whereas a herd that did not comply with any of these management factors had

  13. Parasitism enhances susceptibility to bacterial infection in tilapia

    Science.gov (United States)

    Gyrodactylus is a small elongate monogenetic parasite that mainly lives on the skin and gills of freshwater fish. Gyrodactylus causes mechanical injuries on fish epithelium that can lead to fish mortality under crowded conditions. Streptococcus iniae is a severe bacterial pathogen and the economic l...

  14. Transcription impairment and cell migration defects in elongator-depleted cells: Implication for familial dysautonomia

    OpenAIRE

    Close, Pierre; Hawkes, Nicola; Cornez, Isabelle; Creppe, Catherine; Lambert, Charles A.; Rogister, Bernard; Siebenlist, Ulrich; Merville, Marie-Paule; Slaugenhaupt, Susan A.; Bours, Vincent; Svejstrup, Jesper Q.; Chariot, Alain

    2006-01-01

    Mutations in IKBKAP, encoding a subunit of Elongator, cause familial dysautonomia (FD), a severe neuro-developmental disease with complex clinical characteristics. Elongator was previously linked not only with transcriptional elongation and histone acetylation but also with other cellular processes. Here, we used RNA interference (RNAi) and fibroblasts from FD patients to identify Elongator target genes and study the role of Elongator in transcription. Strikingly, whereas Elongator is recruit...

  15. Evolution of body elongation in gymnophthalmid lizards: relationships with climate.

    Directory of Open Access Journals (Sweden)

    Mariana B Grizante

    Full Text Available The evolution of elongated body shapes in vertebrates has intrigued biologists for decades and is particularly recurrent among squamates. Several aspects might explain how the environment influences the evolution of body elongation, but climate needs to be incorporated in this scenario to evaluate how it contributes to morphological evolution. Climatic parameters include temperature and precipitation, two variables that likely influence environmental characteristics, including soil texture and substrate coverage, which may define the selective pressures acting during the evolution of morphology. Due to development of geographic information system (GIS techniques, these variables can now be included in evolutionary biology studies and were used in the present study to test for associations between variation in body shape and climate in the tropical lizard family Gymnophthalmidae. We first investigated how the morphological traits that define body shape are correlated in these lizards and then tested for associations between a descriptor of body elongation and climate. Our analyses revealed that the evolution of body elongation in Gymnophthalmidae involved concomitant changes in different morphological traits: trunk elongation was coupled with limb shortening and a reduction in body diameter, and the gradual variation along this axis was illustrated by less-elongated morphologies exhibiting shorter trunks and longer limbs. The variation identified in Gymnophthalmidae body shape was associated with climate, with the species from more arid environments usually being more elongated. Aridity is associated with high temperatures and low precipitation, which affect additional environmental features, including the habitat structure. This feature may influence the evolution of body shape because contrasting environments likely impose distinct demands for organismal performance in several activities, such as locomotion and thermoregulation. The present

  16. Tryptophan inhibits Proteus vulgaris TnaC leader peptide elongation, activating tna operon expression.

    Science.gov (United States)

    Cruz-Vera, Luis R; Yang, Rui; Yanofsky, Charles

    2009-11-01

    Expression of the tna operon of Escherichia coli and of Proteus vulgaris is induced by L-tryptophan. In E. coli, tryptophan action is dependent on the presence of several critical residues (underlined) in the newly synthesized TnaC leader peptide, WFNIDXXL/IXXXXP. These residues are conserved in TnaC of P. vulgaris and of other bacterial species. TnaC of P. vulgaris has one additional feature, distinguishing it from TnaC of E. coli; it contains two C-terminal lysine residues following the conserved proline residue. In the present study, we investigated L-tryptophan induction of the P. vulgaris tna operon, transferred on a plasmid into E. coli. Induction was shown to be L-tryptophan dependent; however, the range of induction was less than that observed for the E. coli tna operon. We compared the genetic organization of both operons and predicted similar folding patterns for their respective leader mRNA segments. However, additional analyses revealed that L-tryptophan action in the P. vulgaris tna operon involves inhibition of TnaC elongation, following addition of proline, rather than inhibition of leader peptide termination. Our findings also establish that the conserved residues in TnaC of P. vulgaris are essential for L-tryptophan induction, and for inhibition of peptide elongation. TnaC synthesis is thus an excellent model system for studies of regulation of both peptide termination and peptide elongation, and for studies of ribosome recognition of the features of a nascent peptide. PMID:19767424

  17. Elongator Plays a Positive Role in Exogenous NAD-Induced Defense Responses in Arabidopsis.

    Science.gov (United States)

    An, Chuanfu; Ding, Yezhang; Zhang, Xudong; Wang, Chenggang; Mou, Zhonglin

    2016-05-01

    Extracellular NAD is emerging as an important signal molecule in animal cells, but its role in plants has not been well-established. Although it has been shown that exogenous NAD(+) activates defense responses in Arabidopsis, components in the exogenous NAD(+)-activated defense pathway remain to be fully discovered. In a genetic screen for mutants insensitive to exogenous NAD(+) (ien), we isolated a mutant named ien2. Map-based cloning revealed that IEN2 encodes ELONGATA3 (ELO3)/AtELP3, a subunit of the Arabidopsis Elongator complex, which functions in multiple biological processes, including histone modification, DNA (de)methylation, and transfer RNA modification. Mutations in the ELO3/AtELP3 gene compromise exogenous NAD(+)-induced expression of pathogenesis-related (PR) genes and resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326, and transgenic expression of the coding region of ELO3/AtELP3 in elo3/Atelp3 restores NAD(+) responsiveness to the mutant plants, demonstrating that ELO3/AtELP3 is required for exogenous NAD(+)-induced defense responses. Furthermore, mutations in genes encoding the other five Arabidopsis Elongator subunits (ELO2/AtELP1, AtELP2, ELO1/AtELP4, AtELP5, and AtELP6) also compromise exogenous NAD(+)-induced PR gene expression and resistance to P. syringae pv. maculicola ES4326. These results indicate that the Elongator complex functions as a whole in exogenous NAD(+)-activated defense signaling in Arabidopsis. PMID:26926998

  18. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  19. Cooperative folding of intrinsically disordered domains drives assembly of a strong elongated protein

    Science.gov (United States)

    Gruszka, Dominika T.; Whelan, Fiona; Farrance, Oliver E.; Fung, Herman K. H.; Paci, Emanuele; Jeffries, Cy M.; Svergun, Dmitri I.; Baldock, Clair; Baumann, Christoph G.; Brockwell, David J.; Potts, Jennifer R.; Clarke, Jane

    2015-06-01

    Bacteria exploit surface proteins to adhere to other bacteria, surfaces and host cells. Such proteins need to project away from the bacterial surface and resist significant mechanical forces. SasG is a protein that forms extended fibrils on the surface of Staphylococcus aureus and promotes host adherence and biofilm formation. Here we show that although monomeric and lacking covalent cross-links, SasG maintains a highly extended conformation in solution. This extension is mediated through obligate folding cooperativity of the intrinsically disordered E domains that couple non-adjacent G5 domains thermodynamically, forming interfaces that are more stable than the domains themselves. Thus, counterintuitively, the elongation of the protein appears to be dependent on the inherent instability of its domains. The remarkable mechanical strength of SasG arises from tandemly arrayed `clamp' motifs within the folded domains. Our findings reveal an elegant minimal solution for the assembly of monomeric mechano-resistant tethers of variable length.

  20. Deepwater rice: A model plant to study stem elongation

    Energy Technology Data Exchange (ETDEWEB)

    Kende, H.; Knaap, E. van der; Cho, H.T. [Michigan State Univ., East Lansing, MI (United States). Plant Research Lab.

    1998-12-01

    Semiaquatic plants grow mostly in flood plains and along river beds and are adapted to survive partial submergence during periods of flooding. Among their adaptive features are the development of internal air channels (aerenchyma) that facilitate aeration of submerged organs and the capacity for rapid elongation when the plants become partially covered by floodwaters. In addition to its importance as a crop plant, deepwater rice is also excellent for studying basic aspects of plant growth. The growth response is induced by an environmental signal and is mediated by at least three interacting hormones, namely ethylene, ABA, and GA. Internodal elongation is based on increased cell-division activity and enhanced cell elongation in well-delineated zones of the internode. This allows one to study both processes of growth in an integrated manner. Also, the unusually high growth rates magnify growth-related cellular, physiological, biochemical, and molecular processes, thereby facilitating their analysis. In addition to yielding fundamental insights into the growth process, studies of internodal elongation in deepwater rice may ultimately help to identify genes that could confer at least limited elongation capacity onto modern, high-yielding cultivars.

  1. Correlation Between NDE Measurements and Elongation of Aluminum

    International Nuclear Information System (INIS)

    Complex aluminum forgings can have engineering properties which vary with position due to changes in the underlying local metal microstructure. Consequently, the material properties may be in compliance with production requirements in some regions of the forging, but out of compliance in others. One conical Al-7050 forging of interest was found to have elongation properties which failed required tests in certain regions. NDE measurements sensitive to microstructural changes were carried out to search for correlations with elongation properties. The results of a set of initial feasibility experiments will be reported. Both ultrasonic and eddy current NDE methods were used, with the goal being to determine which properties were sensitive to the elongation. Ultrasonic testing included the measurement of longitudinal and shear-wave velocity, longitudinal wave attenuation, and longitudinal and shear-wave backscattered grain noise. All tests were performed with the sonic beam entering through the coupon face that would be adjacent to the outer surface of the forging. Only modest differences in wave speed and attenuation values were seen among the suite of coupons, but significant differences were seen in backscattered noise levels. These appeared to indicate changes in grain structure but only exhibited partial correlation with elongation. The eddy current measurements were designed to be sensitive to the electrical resistivity. Included were a number of measurement configurations and frequencies. The signals exhibited a significant correlation with elongation

  2. A transcript cleavage factor of Mycobacterium tuberculosis important for its survival.

    Directory of Open Access Journals (Sweden)

    Arnab China

    Full Text Available After initiation of transcription, a number of proteins participate during elongation and termination modifying the properties of the RNA polymerase (RNAP. Gre factors are one such group conserved across bacteria. They regulate transcription by projecting their N-terminal coiled-coil domain into the active center of RNAP through the secondary channel and stimulating hydrolysis of the newly synthesized RNA in backtracked elongation complexes. Rv1080c is a putative gre factor (MtbGre in the genome of Mycobacterium tuberculosis. The protein enhanced the efficiency of promoter clearance by lowering abortive transcription and also rescued arrested and paused elongation complexes on the GC rich mycobacterial template. Although MtbGre is similar in domain organization and shares key residues for catalysis and RNAP interaction with the Gre factors of Escherichia coli, it could not complement an E. coli gre deficient strain. Moreover, MtbGre failed to rescue E. coli RNAP stalled elongation complexes, indicating the importance of specific protein-protein interactions for transcript cleavage. Decrease in the level of MtbGre reduced the bacterial survival by several fold indicating its essential role in mycobacteria. Another Gre homolog, Rv3788 was not functional in transcript cleavage activity indicating that a single Gre is sufficient for efficient transcription of the M. tuberculosis genome.

  3. Comparison of result judgment algorithm of test for interfering factors in the bacterial endotoxins test among Chinese, Japanese,European, American, and Indian pharmacopeias

    Institute of Scientific and Technical Information of China (English)

    Pei Yusheng; Cai Tong; Gao Hua; Tan Dejiang; Zhang Yuchen; Zhang Guolai

    2014-01-01

    Background The bacterial endotoxins test (BET) is a method used to detect or quantify endotoxins (lipo-polysaccharide,LPS) and is widely used in the quality control of parenteral medicines/vaccines and clinical dialysis fluid.It is also used in the diagnosis of endotoxemia and in detection of environment air quality control.Although BET has been adopted by most pharmacopoeias,result judgment algorithms (RJAs) of the test for interfering factors in the BET still differ between certain pharmacopoeias.We have evaluated RJAs of the test for interfering factors for the revision of BET described in the Chinese Pharmacopoeia 2010 (CHP2010).Methods Original data from 1 748 samples were judged by RJAs of the Chinese Pharmacopoeia 2010,the Japanese Pharmacopoeia 2011 (JP2011),the European Pharmacopoeia 7.0 (EP7.0),the United States Pharmacopoeia 36 (USP36),and the Indian Pharmacopoeia 2010 (IP2010),respectively.A SAS software package was used in the statistical analysis.Results The results using CHP2010 and USP36,JP2011,EP7.0,and IP2010 had no significant difference (P=-0.7740).The results using CHP2010 of 1 748 samples showed that 132 samples (7.6%) required an additional step; nevertheless there was no such requirement when using the other pharmacopeias.The kappa value of two RJAs (CHP2010 and EP7.0) was 0.6900 (0.6297-0.7504) indicating that the CHP2010 and other pharmacopoeias have good consistency.Conclusions The results using CHP2010 and USP36,JP2011,EP7.0,and IP2010 have different characteristics.CHP2010 method shows a good performance in Specificity,mistake diagnostic rate,agreement rate,predictive value for suspicious rate,and predictive value for passed rate.The CHP2010 method only had disadvantages in sensitivity compared with other pharmacopeias.We suggest that the Chinese pharmacopoeia interference test be revised in accordance with the USP36,JP2011,EP7.0,and IP2010 judgment model.

  4. Three Cases of Elongated Mandibular Coronoid Process with Different Presentations

    International Nuclear Information System (INIS)

    Abnormal elongation of the mandibular coronoid process is rare and its etiology is not yet elucidated. The aim of this report is to demonstrate and discuss the relationship between elongated mandibular coronoid process and limitation of mouth opening with cone beam computed tomography. Although the clinical characteristic of elongation of the coronoid process is mandibular limitation, in this report, one case had problem with mouth opening. Axial scans revealed that the distance between the coronoid process and the inner face of the frontal part of the zygomatic bone may cause limitation in mouth opening. In conclusion, instead of the length, the distance between the coronoid process and the inner face of the frontal part of the zygomatic bone may be the actual reason for limitation of mouth opening. This may prevent misdiagnosis

  5. Tokamak elongation: how much is too much? II Numerical results

    CERN Document Server

    Lee, Jungpyo; Freidberg, Jeffrey P

    2015-01-01

    The analytic theory presented in Paper I is converted into a form convenient for numerical analysis. A fast and accurate code has been written using this numerical formulation. The results are presented by first defining a reference set of physical parameters based on experimental data from high performance discharges. Numerically obtained scaling relations of maximum achievable elongation versus inverse aspect ratio are obtained for various values of poloidal beta, wall radius and feedback capability parameter in ranges near the reference values. It is also shown that each value of maximum elongation occurs at a corresponding value of optimized triangularity, whose scaling is also determined as a function of inverse aspect ratio. The results show that the theoretical predictions of maximum elongation are slightly higher than experimental observations for high performance discharges as measured by high average pressure. The theoretical optimized triangularity values are noticeably lower. We suggest that the e...

  6. Wnt5a is essential for intestinal elongation in mice

    Science.gov (United States)

    Cervantes, Sara; Yamaguchi, Terry P.; Hebrok, Matthias

    2009-01-01

    Summary Morphogenesis of the mammalian small intestine entails extensive elongation and folding of the primitive gut into a tightly coiled digestive tube. Surprisingly, little is known about the cellular and molecular mechanisms that mediate the morphological aspects of small intestine formation. Here, we demonstrate that Wnt5a, a member of the Wnt family of secreted proteins, is essential for the development and elongation of the small intestine from the midgut region. We found that the small intestine in mice lacking Wnt5a was dramatically shortened and duplicated, forming a bifurcated lumen instead of a single tube. In addition, cell proliferation was reduced and re-intercalation of post-mitotic cells into the elongating gut tube epithelium was disrupted. Thus, our study demonstrates that Wnt5a functions as a critical regulator of midgut formation and morphogenesis in mammals. PMID:19100728

  7. Bacterial Culture of Neonatal Sepsis

    OpenAIRE

    AH Movahedian; R Moniri; Z Mosayebi

    2006-01-01

    Neonatal bacterial sepsis is one of the major cause of morbidity and mortality in neonates. This retrospective study was performed to determine the incidence of bacterial sepsis with focus on Gram negative organisms in neonates admitted at Beheshti Hospital in Kashan, during a 3-yr period, from September 2002 to September 2005. Blood culture was performed on all neonates with risk factors or signs of suggestive sepsis. Blood samples were cultured using brain heart infusion (BHI) broth accordi...

  8. Bacterial contamination of radiopharmaceutical preparations

    International Nuclear Information System (INIS)

    Examinations of the microflora of the air, personnel hands' skin, and surface of the equipment were performed in the Centre for Nuclear research, Libya. It is stated that bacterial contamination was maximal in winter and minimal in summer. The authors believe that human factor is the crucial in bacterial contamination. The microflora detected at the surfaces of equipment contains increased levels of radioresistent forms of bacteria. 8 refs.; 3 tabs

  9. Regulation of bacterial virulence by Csr (Rsm) systems.

    Science.gov (United States)

    Vakulskas, Christopher A; Potts, Anastasia H; Babitzke, Paul; Ahmer, Brian M M; Romeo, Tony

    2015-06-01

    Most bacterial pathogens have the remarkable ability to flourish in the external environment and in specialized host niches. This ability requires their metabolism, physiology, and virulence factors to be responsive to changes in their surroundings. It is no surprise that the underlying genetic circuitry that supports this adaptability is multilayered and exceedingly complex. Studies over the past 2 decades have established that the CsrA/RsmA proteins, global regulators of posttranscriptional gene expression, play important roles in the expression of virulence factors of numerous proteobacterial pathogens. To accomplish these tasks, CsrA binds to the 5' untranslated and/or early coding regions of mRNAs and alters translation, mRNA turnover, and/or transcript elongation. CsrA activity is regulated by noncoding small RNAs (sRNAs) that contain multiple CsrA binding sites, which permit them to sequester multiple CsrA homodimers away from mRNA targets. Environmental cues sensed by two-component signal transduction systems and other regulatory factors govern the expression of the CsrA-binding sRNAs and, ultimately, the effects of CsrA on secretion systems, surface molecules and biofilm formation, quorum sensing, motility, pigmentation, siderophore production, and phagocytic avoidance. This review presents the workings of the Csr system, the paradigm shift that it generated for understanding posttranscriptional regulation, and its roles in virulence networks of animal and plant pathogens. PMID:25833324

  10. Viscosity overshoot in the start-up of uniaxial elongation of low density polyethylene melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Nielsen, Jens Kromann; Bach, Anders;

    2005-01-01

    The transient uniaxial elongational viscosity of BASF Lupolen 1840D and 3020D melts has been measured on a filament stretch rheometer up to Hencky strains of 6-7. The elongational viscosity of both melts was measured at 130 degrees C within a broad range of elongational rates. At high elongation...

  11. Fatty Acid Elongation in Non-Alcoholic Steatohepatitis and Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Sonja M. Kessler

    2014-04-01

    Full Text Available Non-alcoholic steatohepatitis (NASH represents a risk factor for the development of hepatocellular carcinoma (HCC and is characterized by quantitative and qualitative changes in hepatic lipids. Since elongation of fatty acids from C16 to C18 has recently been reported to promote both hepatic lipid accumulation and inflammation we aimed to investigate whether a frequently used mouse NASH model reflects this clinically relevant feature and whether C16 to C18 elongation can be observed in HCC development. Feeding mice a methionine and choline deficient diet to model NASH not only increased total hepatic fatty acids and cholesterol, but also distinctly elevated the C18/C16 ratio, which was not changed in a model of simple steatosis (ob/ob mice. Depletion of Kupffer cells abrogated both quantitative and qualitative methionine-and-choline deficient (MCD-induced alterations in hepatic lipids. Interestingly, mimicking inflammatory events in early hepatocarcinogenesis by diethylnitrosamine-induced carcinogenesis (48 h increased hepatic lipids and the C18/C16 ratio. Analyses of human liver samples from patients with NASH or NASH-related HCC showed an elevated expression of the elongase ELOVL6, which is responsible for the elongation of C16 fatty acids. Taken together, our findings suggest a detrimental role of an altered fatty acid pattern in the progression of NASH-related liver disease.

  12. Analysis on the prevalence and risk factors of bacterial vaginosis%育龄妇女细菌性阴道病的发病情况及高危因素分析

    Institute of Scientific and Technical Information of China (English)

    李素萍; 袁超燕; 陈兰; 武玉莲

    2014-01-01

    Objective To investigate the women of childbearing age in the region of bacterial vaginosis (BV)inci-dence and related risk factors.Methods 1967 local cases of examination results in women of childbearing age during January of 2011 year to January of 2013 year were analyzed,and the questionnaire research object,to explore the risk factors of BV infection.Results 1967 cases the women of childbearing age BV positive rate was 12.35% (243/1967);243 patients with bacterial vaginal disease secretions check gradeⅠ-Ⅱ 24 cases,accounting for 9.9%,more than grade 219 cases,accounting for 90.1%,amine test was positive in 201 cases,accounting for 82.7%;induced abortion history, oral sex for bacterial vaginosis the risk factors,the use of condoms for bacterial vaginosis protective factors.Conclusion Study on bacterial vaginal disease epidemiology and risk factors for prevention and treatment of the conclusions are helpful to the clinical better,protect women's reproductive health.%目的:了解本地区育龄妇女细菌性阴道病(BV)的发病情况及相关高危因素。方法对2011年1月-2013年1月本地区1967例育龄妇女体检结果进行统计分析,并对研究对象行问卷调查,探讨 BV感染的高危因素。结果1967例体检育龄妇女BV检出率12.35%(243/1967);243例细菌性阴道病患者阴道分泌物清洁度检查Ⅰ-Ⅱ级24例,占9.9%,Ⅲ级以上为219例,占90.1%,胺实验阳性201例,占82.7%;人流史、口交为细菌性阴道病高危因素,使用避孕套为细菌性阴道病保护性因素。结论对细菌性阴道病流行病学特征及高危因素的研究有助于临床更好的预防及治疗,维护女性的生殖健康。

  13. High toughness alumina ceramics with elongated grains developed from seeds

    Institute of Scientific and Technical Information of China (English)

    XIE; Zhipeng; (谢志鹏); GAO; Lichun; (高立春); LI; Wenchao; (李文超); XU; Lihua; (徐利华); WANG; Xidong; (王习东)

    2003-01-01

    In the present paper, the influence of α-Al2O3 seeds and sintering methods on elongated grain growth and fracture toughness is investigated. The preparation of alumina ceramics started with commercial aluminum hydroxide. Abrasives were introduced to the starting materials by wet-grinding of high-purity alumina milling balls. Abrasives, playing the role of seeds, lowered the transformation temperature of aluminum hydroxide to alumina. Microstructures with elongated grains were developed by hot-pressing for the above calcined powders containing α-Al2O3 seeds, and alumina grain shapes changed with the amount of seeds introduced. However, only equiaxed grains were observed for the samples pressureless sintered. Fracture toughness of the alumina ceramics was dramatically improved by elongated grains. For the sample hot-pressed at 1600℃ for 2 h under 40 MPa pressure, fracture toughness reached 7.1 MPa·m1/2, which is much higher than that of normal alumina ceramics without elongated grains. In addition, high flexural strength of 630 MPa for the hot-pressed samples was also obtained.

  14. Twin loops for vertical control of highly elongated plasma

    International Nuclear Information System (INIS)

    The plasma shape in the proposed ITER tokamak will be highly elongated, necessitating stabilization of the vertical instability. A method of passive stabilization using twin loops has been examined as part of the ITER Conceptual Design Activities. Results are given in this report. Comparison with the saddle loop concept details the advantages of the twin loops. 5 refs, 8 figs, 2 tabs

  15. Biochemical Pathways That Are Important for Cotton Fiber Cell Elongation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The regulatory mechanism that controls the sustained cotton fiber cell elongation is gradually being elucidated by coupling genome-wide transcriptome profiling with systematic biochemical and physiological studies.Very long chain fatty acids(VLCFA),H2O2,and several types of plant hormones

  16. Longitudinal domain wall formation in elongated assemblies of ferromagnetic nanoparticles

    DEFF Research Database (Denmark)

    Varón, Miriam; Beleggia, Marco; Jordanovic, Jelena;

    2015-01-01

    Through evaporation of dense colloids of ferromagnetic ~13 nm ε-Co particles onto carbon substrates, anisotropic magnetic dipolar interactions can support formation of elongated particle structures with aggregate thicknesses of 100-400 nm and lengths of up to some hundred microns. Lorenz microsco...

  17. On the measurement of elongational viscosity of polyethylene materials

    Czech Academy of Sciences Publication Activity Database

    Švrčinová, Petra; Kharlamov, Alexander; Filip, Petr

    2009-01-01

    Roč. 54, č. 1 (2009), s. 49-57. ISSN 0001-7043 R&D Projects: GA ČR GA103/08/1307 Institutional research plan: CEZ:AV0Z20600510 Keywords : Elongational viscosity * SER Universal * Testing Platform * LDPE Escorene Subject RIV: BK - Fluid Dynamics

  18. Bilateral elongated styloid process: Its anatomical, embryological and clinical implications

    Directory of Open Access Journals (Sweden)

    Bagoji Ishwar B, Hadimani Gavishiddappa A, Patil Balasaheb G, Bannur Balappa M,Ambadasu B

    2013-04-01

    Full Text Available The styloid process is a slender, elongated, cylindrical bony projection from temporal bone. It normally varies in length from 2 cm to 3 cm. During a routine demonstration of skull for MBBS students we found the bilateral elongated styloid process in dry human skull. The length of elongation measured on the right and left side was 6.0 & 5.9 cms respectively. Such abnormal elongation of the styloid process may cause compression on a number of vital vessels and nerves related to it, producing inflammatory changes that include continuous chronic pain in the pharyngeal region. Mechanical stresses stretching the second brachial arch during fetal development probably induce variable involvement of Reichert’s cartilage in morphogenesis of the styloid process. It is important that clinicians especially dentists and otolaryngologists are aware of the natural variations of the styloid process and do not consider the styloid process with a length of 30 mm as an abnormality or as an anomaly.

  19. Adenylate cyclase regulates elongation of mammalian primary cilia

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Young; Ruan, Yibing; Cheng, Min; Moser, Joanna J. [Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1 (Canada); Rattner, Jerome B. [Department of Cell Biology and Anatomy, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1 (Canada); Hoorn, Frans A. van der, E-mail: fvdhoorn@ucalgary.ca [Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1 (Canada)

    2009-10-01

    The primary cilium is a non-motile microtubule-based structure that shares many similarities with the structures of flagella and motile cilia. It is well known that the length of flagella is under stringent control, but it is not known whether this is true for primary cilia. In this study, we found that the length of primary cilia in fibroblast-like synoviocytes, either in log phase culture or in quiescent state, was confined within a range. However, when lithium was added to the culture to a final concentration of 100 mM, primary cilia of synoviocytes grew beyond this range, elongating to a length that was on average approximately 3 times the length of untreated cilia. Lithium is a drug approved for treating bipolar disorder. We dissected the molecular targets of this drug, and observed that inhibition of adenylate cyclase III (ACIII) by specific inhibitors mimicked the effects of lithium on primary cilium elongation. Inhibition of GSK-3{beta} by four different inhibitors did not induce primary cilia elongation. ACIII was found in primary cilia of a variety of cell types, and lithium treatment of these cell types led to their cilium elongation. Further, we demonstrate that different cell types displayed distinct sensitivities to the lithium treatment. However, in all cases examined primary cilia elongated as a result of lithium treatment. In particular, two neuronal cell types, rat PC-12 adrenal medulla cells and human astrocytes, developed long primary cilia when lithium was used at or close to the therapeutic relevant concentration (1-2 mM). These results suggest that the length of primary cilia is controlled, at least in part, by the ACIII-cAMP signaling pathway.

  20. Adenylate cyclase regulates elongation of mammalian primary cilia

    International Nuclear Information System (INIS)

    The primary cilium is a non-motile microtubule-based structure that shares many similarities with the structures of flagella and motile cilia. It is well known that the length of flagella is under stringent control, but it is not known whether this is true for primary cilia. In this study, we found that the length of primary cilia in fibroblast-like synoviocytes, either in log phase culture or in quiescent state, was confined within a range. However, when lithium was added to the culture to a final concentration of 100 mM, primary cilia of synoviocytes grew beyond this range, elongating to a length that was on average approximately 3 times the length of untreated cilia. Lithium is a drug approved for treating bipolar disorder. We dissected the molecular targets of this drug, and observed that inhibition of adenylate cyclase III (ACIII) by specific inhibitors mimicked the effects of lithium on primary cilium elongation. Inhibition of GSK-3β by four different inhibitors did not induce primary cilia elongation. ACIII was found in primary cilia of a variety of cell types, and lithium treatment of these cell types led to their cilium elongation. Further, we demonstrate that different cell types displayed distinct sensitivities to the lithium treatment. However, in all cases examined primary cilia elongated as a result of lithium treatment. In particular, two neuronal cell types, rat PC-12 adrenal medulla cells and human astrocytes, developed long primary cilia when lithium was used at or close to the therapeutic relevant concentration (1-2 mM). These results suggest that the length of primary cilia is controlled, at least in part, by the ACIII-cAMP signaling pathway.

  1. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  2. Bacterial flora of sturgeon fingerling

    International Nuclear Information System (INIS)

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  3. Binary asteroid population. 3. Secondary rotations and elongations

    Science.gov (United States)

    Pravec, P.; Scheirich, P.; Kušnirák, P.; Hornoch, K.; Galád, A.; Naidu, S. P.; Pray, D. P.; Világi, J.; Gajdoš, Š.; Kornoš, L.; Krugly, Yu. N.; Cooney, W. R.; Gross, J.; Terrell, D.; Gaftonyuk, N.; Pollock, J.; Husárik, M.; Chiorny, V.; Stephens, R. D.; Durkee, R.; Reddy, V.; Dyvig, R.; Vraštil, J.; Žižka, J.; Mottola, S.; Hellmich, S.; Oey, J.; Benishek, V.; Kryszczyńska, A.; Higgins, D.; Ries, J.; Marchis, F.; Baek, M.; Macomber, B.; Inasaridze, R.; Kvaratskhelia, O.; Ayvazian, V.; Rumyantsev, V.; Masi, G.; Colas, F.; Lecacheux, J.; Montaigut, R.; Leroy, A.; Brown, P.; Krzeminski, Z.; Molotov, I.; Reichart, D.; Haislip, J.; LaCluyze, A.

    2016-03-01

    We collected data on rotations and elongations of 46 secondaries of binary and triple systems among near-Earth, Mars-crossing and small main belt asteroids. 24 were found or are strongly suspected to be synchronous (in 1:1 spin-orbit resonance), and the other 22, generally on more distant and/or eccentric orbits, were found or are suggested to have asynchronous rotations. For 18 of the synchronous secondaries, we constrained their librational angles, finding that their long axes pointed to within 20° of the primary on most epochs. The observed anti-correlation of secondary synchroneity with orbital eccentricity and the limited librational angles agree with the theories by Ćuk and Nesvorný (Ćuk, M., Nesvorný, D. [2010]. Icarus 207, 732-743) and Naidu and Margot (Naidu, S.P., Margot, J.-L. [2015]. Astron. J. 149, 80). A reason for the asynchronous secondaries being on wider orbits than synchronous ones may be longer tidal circularization time scales at larger semi-major axes. The asynchronous secondaries show relatively fast spins; their rotation periods are typically synchronous secondaries with greater elongations appears consistent, considering uncertainties of the axis ratio estimates, with the theory by Ćuk and Nesvorný that predicts large regions of chaotic rotation in the phase space for a2 /b2 ≳√{ 2 } . Alternatively, secondaries may not form or stay very elongated in gravitational (tidal) field of the primary. It could be due to the secondary fission mechanism suggested by Jacobson and Scheeres (Jacobson, S.A., Scheeres, D.J. [2011]. Icarus 214, 161-178), as its efficiency is correlated with the secondary elongation. Sharma (Sharma, I. [2014]. Icarus 229, 278-294) found that rubble-pile satellites with a2 /b2 ≲ 1.5 are more stable to finite structural perturbations than more elongated ones. It appears that more elongated secondaries, if they originally formed in spin fission of parent asteroid, are less likely to survive intact and they more

  4. Vertical stratification of bacterial communities driven by multiple environmental factors in the waters (0-5000 m) off the Galician coast (NW Iberian margin)

    Science.gov (United States)

    Dobal-Amador, Vladimir; Nieto-Cid, Mar; Guerrero-Feijoo, Elisa; Hernando-Morales, Victor; Teira, Eva; Varela-Rozados, Marta M.

    2016-08-01

    The processes mediated by microbial planktonic communities occur along the entire water column, yet the microbial activity and composition have been studied mainly in surface waters. This research examined the vertical variation in bacterial abundance, activity and community composition and structure from surface down to 5000 m depth following a longitudinal transect off the Galician coast (NW Iberian margin, from 43°N, 9°W to 43°N, 15°W). Community activity and composition changed with depth. The leucine incorporation rates decreased from the euphotic layer to the bathypelagic waters by three orders of magnitude, whereas prokaryotic abundance decreased only by one order of magnitude. The relative abundance of SAR11 and Alteromonas, determined by catalyzed reported deposition fluorescence in situ hybridization (CARD-FISH), decreased with depth. Meanwhile, the contribution of SAR 202 and SAR324 was significantly higher in the deeper layers (i.e. NEADW, North East Atlantic Deep Water and LDW, Lower Deep Water) than in the euphotic zone. Bacterial community structure, assessed by Automated Ribosomal Intergenic Spacer Analysis (ARISA), was depth-specific. A distance based linear model (DistLM) revealed that the variability found in bacterial community structure was mainly explained by temperature nitrate, phosphate, dissolved organic matter (DOM) fluorescence, prokaryotic abundance, leucine incorporation and to a lesser extent salinity, oxygen, CDOM absorbance and dissolved organic carbon concentration. Our results displayed a bacterial community structure shaped not only by depth-related physicochemical features but also by DOM quality, indicating that different prokaryotic taxa have the potential to metabolize particular DOM sources.

  5. Toll-like receptor 5 (TLR5), IL-1β secretion, and asparagine endopeptidase are critical factors for alveolar macrophage phagocytosis and bacterial killing.

    OpenAIRE

    Descamps, Delphyne; Mathieu, Le Gars; Balloy, Viviane; Diane, Barbier; Sophia, Maschalidi; Mira, Tohme; Chignard, Michel; Ramphal, Reuben; Bénédicte, Manoury; Sallenave, Jean-Michel

    2012-01-01

    A deficit in early clearance of Pseudomonas aeruginosa (P. aeruginosa) is crucial in nosocomial pneumonia and in chronic lung infections. Few studies have addressed the role of Toll-like receptors (TLRs), which are early pathogen associated molecular pattern receptors, in pathogen uptake and clearance by alveolar macrophages (AMs). Here, we report that TLR5 engagement is crucial for bacterial clearance by AMs in vitro and in vivo because unflagellated P. aeruginosa or different mutants defect...

  6. Attenuation of the bacterial load in blood by pretreatment with granulocyte-colony-stimulating factor protects rats from fatal outcome and brain damage during Streptococcus pneumoniae meningitis

    DEFF Research Database (Denmark)

    Brandt, Christian T; Lundgren, Jens D; Lund, Søren Peter;

    2004-01-01

    to the infection compared to that for untreated rats (P = 0.039 by the log rank test). The improved outcome was associated with reduced signs of cerebral cortical damage (P = 0.008). Furthermore, the beneficial effects of G-CSF were associated with reduced bacterial loads in the cerebrospinal fluid...... meningitis result in reduced risks of death and brain damage. This beneficial effect is most likely achieved through improved control of the systemic disease....

  7. Role of quorum sensing in bacterial infections

    OpenAIRE

    Castillo-Juárez, Israel; Maeda, Toshinari; Mandujano-Tinoco, Edna Ayerim; Tomás, María; Pérez-Eretza, Berenice; García-Contreras, Silvia Julieta; Wood, Thomas K.; García-Contreras, Rodolfo

    2015-01-01

    Quorum sensing (QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. I...

  8. Correlations Between Bacterial Ecology and Mobile DNA

    OpenAIRE

    Newton, Irene L. G.; Bordenstein, Seth R.

    2010-01-01

    Several factors can affect the density of mobile DNA in bacterial genomes including rates of exposure to novel gene pools, recombination, and reductive evolution. These traits are difficult to measure across a broad range of bacterial species, but the ecological niches occupied by an organism provide some indication of the relative magnitude of these forces. Here, by analyzing 384 bacterial genomes assigned to three ecological categories (obligate intracellular, facultative intracellular, and...

  9. Accumulation of motile elongated micro-organisms in turbulence

    Science.gov (United States)

    Zhan, Caijuan; Sardina, Gaetano; Lushi, Enkeleida; Brandt, Luca

    2014-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react slower to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of microorganisms that can vary their shape and their preferential orientation.

  10. Biochemical Pathways That Are Important for Cotton Fiber Cell Elongation

    Institute of Scientific and Technical Information of China (English)

    ZHU YU-xian

    2008-01-01

    @@ The regulatory mechanism that controls the sustained cotton fiber cell elongation is gradually being elucidated by coupling genome-wide transcriptome profiling with systematic biochemical and physiological studies.Very long chain fatty acids (VLCFA),H2O2,and several types of plant hormones including ethylene,gibberellin,and brassinolide have been reported to be involved in this process.Here we first identified by proteomic analysis a cotton cytosolic APX1 (GhAPX1) that was specifically accumulated during cotton fiber elongation.GhAPX1 expression was up-regulated in response to cellular H2O2 and ethylene,and it was involved in modulating the stead-state level of H2O2.

  11. Methanofullerene elongated nanostructure formation for enhanced organic solar cells

    International Nuclear Information System (INIS)

    Using transmission electron microscopy (TEM) and Z-contrast imaging we have demonstrated elongated nanostructure formation of fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) within an organic host through annealing. The annealing provides an enhanced mobility of the PCBM molecules and, with good initial dispersion, allows for the formation of exaggerated grain growth within the polymer host. We have assembled these nanostructures within the regioregular conjugated polymer poly(3-hexylthiophene) (P3HT). This PCBM elongated nanostructure formation maybe responsible for the very high efficiencies observed, at very low loadings of PCBM (1:0.6, polymer to PCBM), in annealed photovoltaics. Moreover, our high resolution TEM and electron energy loss spectroscopy studies clearly show that the PCBM crystals remain crystalline and are unaffected by the 200-keV electron beam

  12. Methanofullerene elongated nanostructure formation for enhanced organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Reyes, M. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)], E-mail: reyesm@cactus.iico.uaslp.mx; Lopez-Sandoval, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Arenas-Alatorre, J. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000, Mexico, D.F. (Mexico); Garibay-Alonso, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Carroll, D.L. [Center for Nanotechnology and Molecular Materials, Department of Physics. Wake Forest University, Winston-Salem NC 27109 (United States); Lastras-Martinez, A. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)

    2007-11-01

    Using transmission electron microscopy (TEM) and Z-contrast imaging we have demonstrated elongated nanostructure formation of fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) within an organic host through annealing. The annealing provides an enhanced mobility of the PCBM molecules and, with good initial dispersion, allows for the formation of exaggerated grain growth within the polymer host. We have assembled these nanostructures within the regioregular conjugated polymer poly(3-hexylthiophene) (P3HT). This PCBM elongated nanostructure formation maybe responsible for the very high efficiencies observed, at very low loadings of PCBM (1:0.6, polymer to PCBM), in annealed photovoltaics. Moreover, our high resolution TEM and electron energy loss spectroscopy studies clearly show that the PCBM crystals remain crystalline and are unaffected by the 200-keV electron beam.

  13. Accumulation of motile elongated micro-organisms in turbulence

    CERN Document Server

    Zhan, Caijuan; Lushi, Enkeleida; Brandt, Luca

    2013-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react slower to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of microor...

  14. Efficient fidelity control by stepwise nucleotide selection in polymerase elongation

    CERN Document Server

    Yu, Jin

    2014-01-01

    Polymerases select nucleotides before incorporating them for chemical synthesis during gene replication or transcription. How the selection proceeds stepwise efficiently to achieve sufficiently high fidelity and speed is essential for polymerase function. We examined step-by-step selections that have conformational transition rates tuned one at time in the polymerase elongation cycle, with a controlled differentiation free energy at each checkpoint. The elongation is sustained at non-equilibrium steady state with constant free energy input and heat dissipation. It is found that error reduction capability does not improve for selection checkpoints down the reaction path. Hence, it is essential to select early to achieve an efficient fidelity control. In particular, for two consecutive selections that reject the wrong substrate back and inhibit it forward from a same kinetic state, the same error rates are obtained at the same free energy differentiation. The initial screening is indispensible for maintaining t...

  15. Influence of lead on auxin-induced cell elongation

    Directory of Open Access Journals (Sweden)

    Marek Burzyński

    2014-02-01

    Full Text Available The influence of lead chloride on plant tissue growth is described. Lead reduced elongation of etiolated wheat coleoptile segments, green pea epicotyl fragments and etiolated and green sunflower hypocotyls. Green tissues were more susceptible to lead than etiolated ones. PbCl2 in a 10-4 M concentration significantly reduced plastic and elastic extensibility of the wheat coleoptile cell walls and diminished the hydration of sunflower hypocotyl segments. Auxin (indolyl-3-acetic acid - IAA applied in concentration optimal for growth of the particular tissues partly attenuated the inhibitory action of lead on elongation, plastic and elastic extensibility and water absorption. Auxin applied in supraoptimal concentrations did not abolish the inhibitory action of lead on tissue growth.

  16. New Insights on Plant Cell Elongation: A Role for Acetylcholine

    Directory of Open Access Journals (Sweden)

    Gian-Pietro Di Sansebastiano

    2014-03-01

    Full Text Available We investigated the effect of auxin and acetylcholine on the expression of the tomato expansin gene LeEXPA2, a specific expansin gene expressed in elongating tomato hypocotyl segments. Since auxin interferes with clathrin-mediated endocytosis, in order to regulate cellular and developmental responses we produced protoplasts from tomato elongating hypocotyls and followed the endocytotic marker, FM4-64, internalization in response to treatments. Tomato protoplasts were observed during auxin and acetylcholine treatments after transient expression of chimerical markers of volume-control related compartments such as vacuoles. Here we describe the contribution of auxin and acetylcholine to LeEXPA2 expression regulation and we support the hypothesis that a possible subcellular target of acetylcholine signal is the vesicular transport, shedding some light on the characterization of this small molecule as local mediator in the plant physiological response.

  17. New insights on plant cell elongation: a role for acetylcholine.

    Science.gov (United States)

    Di Sansebastiano, Gian-Pietro; Fornaciari, Silvia; Barozzi, Fabrizio; Piro, Gabriella; Arru, Laura

    2014-01-01

    We investigated the effect of auxin and acetylcholine on the expression of the tomato expansin gene LeEXPA2, a specific expansin gene expressed in elongating tomato hypocotyl segments. Since auxin interferes with clathrin-mediated endocytosis, in order to regulate cellular and developmental responses we produced protoplasts from tomato elongating hypocotyls and followed the endocytotic marker, FM4-64, internalization in response to treatments. Tomato protoplasts were observed during auxin and acetylcholine treatments after transient expression of chimerical markers of volume-control related compartments such as vacuoles. Here we describe the contribution of auxin and acetylcholine to LeEXPA2 expression regulation and we support the hypothesis that a possible subcellular target of acetylcholine signal is the vesicular transport, shedding some light on the characterization of this small molecule as local mediator in the plant physiological response. PMID:24642879

  18. Quantifying elongation rhythm during full-length protein synthesis.

    Science.gov (United States)

    Rosenblum, Gabriel; Chen, Chunlai; Kaur, Jaskiran; Cui, Xiaonan; Zhang, Haibo; Asahara, Haruichi; Chong, Shaorong; Smilansky, Zeev; Goldman, Yale E; Cooperman, Barry S

    2013-07-31

    Pauses regulate the rhythm of ribosomal protein synthesis. Mutations disrupting even minor pauses can give rise to improperly formed proteins and human disease. Such minor pauses are difficult to characterize by ensemble methods, but can be readily examined by single-molecule (sm) approaches. Here we use smFRET to carry out real-time monitoring of the expression of a full-length protein, the green fluorescent protein variant Emerald GFP. We demonstrate significant correlations between measured elongation rates and codon and isoacceptor tRNA usage, and provide a quantitative estimate of the effect on elongation rate of replacing a codon recognizing an abundant tRNA with a synonymous codon cognate to a rarer tRNA. Our results suggest that tRNA selection plays an important general role in modulating the rates and rhythms of protein synthesis, potentially influencing simultaneous co-translational processes such as folding and chemical modification. PMID:23822614

  19. Elongation and current scalings of local and global energy transport

    International Nuclear Information System (INIS)

    The scaling of local and global energy confinement with elongation κ and current in L- and H-mode plasmas is explored. It is shown that the elongation enters global confinement only through the geometrical quantities of plasma volume and surface area, while local transport does not contribute. The global scaling τE∝κ0.8 is caused by W∝nT0V with the volume V∝κ and the surface area leading to T0∝κ-0.2. Empirical scalings of the effective heat diffusivity χ with κ, the current inside a flux surface I(x), Bp and q are presented. Applying I(x) makes χ independent of κ, while a formulation with q yields strong implicit and explicit κ dependences. (author). Letter-to-the-editor

  20. [Small intestine bacterial overgrowth].

    Science.gov (United States)

    Leung Ki, E L; Roduit, J; Delarive, J; Guyot, J; Michetti, P; Dorta, G

    2010-01-27

    Small intestine bacterial overgrowth (SIBO) is a condition characterised by nutrient malabsorption and excessive bacteria in the small intestine. It typically presents with diarrhea, flatulence and a syndrome of malabsorption (steatorrhea, macrocytic anemia). However, it may be asymptomatic in the eldery. A high index of suspicion is necessary in order to differentiate SIBO from other similar presenting disorders such as coeliac disease, lactose intolerance or the irritable bowel syndrome. A search for predisposing factor is thus necessary. These factors may be anatomical (stenosis, blind loop), or functional (intestinal hypomotility, achlorydria). The hydrogen breath test is the most frequently used diagnostic test although it lacks standardisation. The treatment of SIBO consists of eliminating predisposing factors and broad-spectrum antibiotic therapy. PMID:20214190

  1. Accumulation of motile elongated micro-organisms in turbulence

    OpenAIRE

    Zhan, Caijuan; Sardina, Gaetano; Lushi, Enkeleida; Brandt, Luca

    2013-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignmen...

  2. Magnetic properties of ferrofluid emulsions: The effect of droplet elongation

    OpenAIRE

    Ivanov, A. O.; Kuznetsova, O. B.; Subbotin, I. M.

    2013-01-01

    The paper is concerned with a theoretical explanation of the experimentally observed effect of non-monotonic field dependence of the effective magnetic permeability of ferrofluid emulsion. In a weak magnetic field, the growth of the induced droplet magnetic moment is faster than the linear one due to the droplet elongation accompanied by the reduction of the demagnetizing field. Thus, the emulsion magnetic permeability increases in weak magnetic fields. Further strengthening of the external m...

  3. Simulations of nucleation and elongation of amyloid fibrils

    OpenAIRE

    Zhang, Jianing; Muthukumar, M.

    2009-01-01

    We present a coarse-grained model for the growth kinetics of amyloid fibrils from solutions of peptides and address the fundamental mechanism of nucleation and elongation by using a lattice Monte Carlo procedure. We reproduce the three main characteristics of nucleation of amyloid fibrils: (1) existence of lag time, (2) occurrence of a critical concentration, and (3) seeding. We find the nucleation of amyloid fibrils to require a quasi-two-dimensional configuration, where a second layer of β ...

  4. Neuroprotective copper bis(thiosemicarbazonato complexes promote neurite elongation.

    Directory of Open Access Journals (Sweden)

    Laura Bica

    Full Text Available Abnormal biometal homeostasis is a central feature of many neurodegenerative disorders including Alzheimer's disease (AD, Parkinson's disease (PD, and motor neuron disease. Recent studies have shown that metal complexing compounds behaving as ionophores such as clioquinol and PBT2 have robust therapeutic activity in animal models of neurodegenerative disease; however, the mechanism of neuroprotective action remains unclear. These neuroprotective or neurogenerative processes may be related to the delivery or redistribution of biometals, such as copper and zinc, by metal ionophores. To investigate this further, we examined the effect of the bis(thiosemicarbazonato-copper complex, Cu(II(gtsm on neuritogenesis and neurite elongation (neurogenerative outcomes in PC12 neuronal-related cultures. We found that Cu(II(gtsm induced robust neurite elongation in PC12 cells when delivered at concentrations of 25 or 50 nM overnight. Analogous effects were observed with an alternative copper bis(thiosemicarbazonato complex, Cu(II(atsm, but at a higher concentration. Induction of neurite elongation by Cu(II(gtsm was restricted to neurites within the length range of 75-99 µm with a 2.3-fold increase in numbers of neurites in this length range with 50 nM Cu(II(gtsm treatment. The mechanism of neurogenerative action was investigated and revealed that Cu(II(gtsm inhibited cellular phosphatase activity. Treatment of cultures with 5 nM FK506 (calcineurin phosphatase inhibitor resulted in analogous elongation of neurites compared to 50 nM Cu(II(gtsm, suggesting a potential link between Cu(II(gtsm-mediated phosphatase inhibition and neurogenerative outcomes.

  5. A Note on Elongations of Summable QTAG-Modules

    Science.gov (United States)

    Mehdi, Alveera; Naji, Sabah A. R. K.

    2013-01-01

    A right module M over an associative ring with unity is a QTAG-module if every finitely generated submodule of any homomorphic image of M is a direct sum of uniserial modules. In this paper we find a suitable condition under which a special ω-elongation of a summable QTAG-module by a (ω+k)-projective QTAG-module is also a summable QTAG-module. PMID:24459429

  6. Connectedness percolation of elongated hard particles in an external field

    OpenAIRE

    Otten, R. H. J.; van der Schoot, P. P. A. M.

    2012-01-01

    A theory is presented of how orienting fields and steric interactions conspire against the formation of a percolating network of, in some sense, connected elongated colloidal particles in fluid dispersions. We find that the network that forms above a critical loading breaks up again at higher loadings due to interaction-induced enhancement of the particle alignment. Upon approach of the percolation threshold, the cluster dimensions diverge with the same critical exponent parallel and perpendi...

  7. Elongation of discotic liquid crystal strands and lubricant effects

    OpenAIRE

    Bhattacharyya, Surjya Sarathi; Galerne, Yves

    2013-01-01

    International audience After a short review on the physics of pulled threads and their mechanical properties, the paper reports and discusses on the strand elongation of disordered columnar phases, hexagonal or lamello-columnar, of small molecules or polymers. The mechanical properties appear to be relevant to the length of the columns of molecules compared to the thread length, instead of the usual correlation length. When short, the column entanglement being taken into account, the stran...

  8. IAA-glucopyranoside stimulation of corn coleoptiles elongation

    OpenAIRE

    Adriana Szmidt-Jaworska; Jacek Kęsy; Jan Kopcewicz

    2014-01-01

    It has been previously suggested that 1-O-IAGIuc growth stimulation occurs as the effect of its hydrolysis into a free IAA. In present experiments castanospermine, a known β-glucosidase inhibitor, was included. 1-O-IAGluc in the presence of castanospermine stimulated growth of corn coleoptiles segments even stronger then free IAA. So, it seems that 1-O-IAGluc itself, is responsible for the observed stimulation of corn coleoptile segments elongation.

  9. Transcription within Condensed Chromatin: Steric Hindrance Facilitates Elongation

    OpenAIRE

    Bécavin, Christophe; Barbi, Maria; Victor, Jean-Marc; Lesne, Annick

    2010-01-01

    During eukaryotic transcription, RNA-polymerase activity generates torsional stress in DNA, having a negative impact on the elongation process. Using our previous studies of chromatin fiber structure and conformational transitions, we suggest that this torsional stress can be alleviated, thanks to a tradeoff between the fiber twist and nucleosome conformational transitions into an activated state named “reversome”. Our model enlightens the origin of polymerase pauses, and leads to the counter...

  10. Saturation conditions in elongated single-cavity boiling water targets

    OpenAIRE

    Steyn, G. F.; Vermeulen, C.

    2015-01-01

    Introduction It is shown that a very simple model reproduces the pressure versus beam current characteristics of elongated single-cavity boiling water targets for 18F production surprisingly well. By fitting the model calculations to measured data, values for a single free parameter, namely an overall heat-transfer coefficient, have been extracted for several IBA Nirta H218O targets. IBA recently released details on their new Nirta targets that have a conical shape, which constitutes an im...

  11. Experimental study of flow instability in elongated natural circulation system

    International Nuclear Information System (INIS)

    The visual experimental study with water as the working substance was performed to investigate the operation behavior of a natural circulation system with elongated loops and long horizontal sections at atmospheric pressure, and the transient operation behavior and instability mechanism of typical experimental phenomenon (P= 1.46 kW) were given. The results show that the single natural circulation in elongated system with the great resistance coefficient is difficult to appear, but the heat can be removed by two-phase intermittent boiling. The driven force caused by the sub-cooled boiling can not drive the fluid to produce the effective natural circulation because of the great loop resistance, and the circular flow occurs only when the fluid in heat section produces the saturation boiling. The big loop resistance and flashing because of pressure drop in boiling process make the elongated natural circulation difficult to maintain a stable flow driven head and they are the fundamental reasons of intermittent boiling and strong flow instability. (authors)

  12. Mechanism of fusidic acid inhibition of RRF- and EF-G-dependent splitting of the bacterial post-termination ribosome.

    Science.gov (United States)

    Borg, Anneli; Pavlov, Michael; Ehrenberg, Måns

    2016-04-20

    The antibiotic drug fusidic acid (FA) is commonly used in the clinic against gram-positive bacterial infections. FA targets ribosome-bound elongation factor G (EF-G), a translational GTPase that accelerates both messenger RNA (mRNA) translocation and ribosome recycling. How FA inhibits translocation was recently clarified, but FA inhibition of ribosome recycling by EF-G and ribosome recycling factor (RRF) has remained obscure. Here we use fast kinetics techniques to estimate mean times of ribosome splitting and the stoichiometry of GTP hydrolysis by EF-G at varying concentrations of FA, EF-G and RRF. These mean times together with previous data on uninhibited ribosome recycling were used to clarify the mechanism of FA inhibition of ribosome splitting. The biochemical data on FA inhibition of translocation and recycling were used to model the growth inhibitory effect of FA on bacterial populations. We conclude that FA inhibition of translocation provides the dominant cause of bacterial growth reduction, but that FA inhibition of ribosome recycling may contribute significantly to FA-induced expression of short regulatory open reading frames, like those involved in FA resistance. PMID:27001509

  13. T-bet Activates Th1 Genes through Mediator and the Super Elongation Complex.

    Science.gov (United States)

    Hertweck, Arnulf; Evans, Catherine M; Eskandarpour, Malihe; Lau, Jonathan C H; Oleinika, Kristine; Jackson, Ian; Kelly, Audrey; Ambrose, John; Adamson, Peter; Cousins, David J; Lavender, Paul; Calder, Virginia L; Lord, Graham M; Jenner, Richard G

    2016-06-21

    The transcription factor T-bet directs Th1 cell differentiation, but the molecular mechanisms that underlie this lineage-specific gene regulation are not completely understood. Here, we show that T-bet acts through enhancers to allow the recruitment of Mediator and P-TEFb in the form of the super elongation complex (SEC). Th1 genes are occupied by H3K4me3 and RNA polymerase II in Th2 cells, while T-bet-mediated recruitment of P-TEFb in Th1 cells activates transcriptional elongation. P-TEFb is recruited to both genes and enhancers, where it activates enhancer RNA transcription. P-TEFb inhibition and Mediator and SEC knockdown selectively block activation of T-bet target genes, and P-TEFb inhibition abrogates Th1-associated experimental autoimmune uveitis. T-bet activity is independent of changes in NF-κB RelA and Brd4 binding, with T-bet- and NF-κB-mediated pathways instead converging to allow P-TEFb recruitment. These data provide insight into the mechanism through which lineage-specifying factors promote differentiation of alternative T cell fates. PMID:27292648

  14. T-bet Activates Th1 Genes through Mediator and the Super Elongation Complex

    Directory of Open Access Journals (Sweden)

    Arnulf Hertweck

    2016-06-01

    Full Text Available The transcription factor T-bet directs Th1 cell differentiation, but the molecular mechanisms that underlie this lineage-specific gene regulation are not completely understood. Here, we show that T-bet acts through enhancers to allow the recruitment of Mediator and P-TEFb in the form of the super elongation complex (SEC. Th1 genes are occupied by H3K4me3 and RNA polymerase II in Th2 cells, while T-bet-mediated recruitment of P-TEFb in Th1 cells activates transcriptional elongation. P-TEFb is recruited to both genes and enhancers, where it activates enhancer RNA transcription. P-TEFb inhibition and Mediator and SEC knockdown selectively block activation of T-bet target genes, and P-TEFb inhibition abrogates Th1-associated experimental autoimmune uveitis. T-bet activity is independent of changes in NF-κB RelA and Brd4 binding, with T-bet- and NF-κB-mediated pathways instead converging to allow P-TEFb recruitment. These data provide insight into the mechanism through which lineage-specifying factors promote differentiation of alternative T cell fates.

  15. CCAAT/enhancer-binding protein δ facilitates bacterial dissemination during pneumococcal pneumonia in a platelet-activating factor receptor-dependent manner

    OpenAIRE

    Duitman, JanWillem; Schouten, Marcel; Groot, Angelique P.; Borensztajn, Keren S.; Daalhuisen, Joost B.; Florquin, Sandrine; van der Poll, Tom; Spek, C Arnold

    2012-01-01

    CCAAT/enhancer-binding protein δ (C/EBPδ) recently emerged as an essential player in the inflammatory response to bacterial infections. C/EBPδ levels increase rapidly after a proinflammatory stimulus, and increasing C/EBPδ levels seem to be indispensable for amplification of the inflammatory response. Here we aimed to elucidate the role of C/EBPδ in host defense in community-acquired pneumococcal pneumonia. We show that C/EBPδ−/− mice are relatively resistant to pneumococcal pneumonia, as ind...

  16. Incidence of bacterial colpitis in gynecology outpatient department and analysis of related risk factors%妇科门诊细菌性阴道病发病率及相关危险因素分析

    Institute of Scientific and Technical Information of China (English)

    周亚芬; 张静

    2013-01-01

    目的 探讨妇科门诊细菌性阴道病发病情况及导致细菌性阴道炎发生的危险因素,降低其发病率.方法 对2012年6月在医院妇科门诊就诊诊断为阴道炎的150例患者进行病原菌检测及问卷调查,分析细菌性阴道病发病率及相关危险因素.结果 调查问卷回收率100.00%,合格率95.33%%%;诊断为细菌性阴道病者76例,发病率50.67%,外阴阴道假丝酵母菌病51例,发病率34.00%,滴虫性阴道炎23例,发病率15.33%;患者年龄、文化程度、月收入、流产次数、自行阴道冲洗、月经期用消毒卫生巾、非经期使用护垫、每周性生活次数、避孕方式、阴道炎史均是引起细菌性阴道病的单危险因素,差异有统计学意义(P<0.05);非条件logistic回归分析结果显示,自行阴道冲洗、非月经期使用护垫、阴道炎史是导致细菌性阴道病发生的独立危险因素,月经期使用消毒卫生巾、避孕套避孕是降低细菌性阴道病发生的保护因素.结论 妇科门诊细菌性阴道病发病率占阴道炎约50.00%,自行阴道冲洗、非月经期使用护垫及阴道炎史均能增加患有细菌性阴道病的危险性,月经期使用消毒卫生巾及避孕套避孕能减少细菌性阴道病患病概率.%OBJECTIVE To explore the incidence of bacterial colpitis in the gynecology clinic and analyze the related risk factors of the bacterial colpitis so as to reduce the incidence of this disease. METHODS A total of 150 patients who were diagnosed as the vaginitis and were treated in the gynecology outpatient department from Jan 2012 to Jun 2012 were enrolled in the study, the patients were tested for pathogens and were investigated with questionnaires, and the incidence of bacterial colpitis and the related risk factors were analyzed. RESULTS The recovery rate of the questionnaires was 100. 00% , and the qualified rate was 95. 33%. Totally 76 cases were diagnosed as the bacterial colpitis with

  17. Relative Mesothelioma Potencies for Unregulated Respirable Elongated Mineral and Synthetic Particles

    Science.gov (United States)

    For decades uncertainties and contradictions have surrounded the issue of whether exposures to respirable elongated mineral and synthetic particles (REMPs and RESPs) present health risks such as those recognized for exposures to elongated asbestiform mineral particles from the fi...

  18. Effect of Elongation on Critical Gradient for Toroidal Electron Temperature Gradient Modes

    Institute of Scientific and Technical Information of China (English)

    PENG Li-Li; GAO Zhe

    2008-01-01

    The electron temperature gradient mode is investigated in elongated toroidal plasmas with a gyrokinetic integral eigenmode equation code. Dependence of the critical electron temperature gradient on the elongation is calculated.It is found that when the elongation increases, the growth rate spectrum is greatly shifted towards shorter poloidal wavelength, and then the poloidal wavenumber at which the mode is destabilizing critically in elongated plasmas will be larger than that in circular plasmas.

  19. Gibberellin biosynthesis and signal transduction is essential for internode elongation in deepwater rice

    OpenAIRE

    Ayano, Madoka; Kani, Takahiro; Kojima, Mikiko; Sakakibara, Hitoshi; Kitaoka, Takuya; Kuroha, Takeshi; Angeles-Shim, Rosalyn B.; Kitano, Hidemi; Nagai, Keisuke; Ashikari, Motoyuki

    2014-01-01

    Under flooded conditions, the leaves and internodes of deepwater rice can elongate above the water surface to capture oxygen and prevent drowning. Our previous studies showed that three major quantitative trait loci (QTL) regulate deepwater-dependent internode elongation in deepwater rice. In this study, we investigated the age-dependent internode elongation in deepwater rice. We also investigated the relationship between deepwater-dependent internode elongation and the phytohormone gibberell...

  20. Gibberellin-Regulation and Genetic Variations in Leaf Elongation for Tall Fescue in Association with Differential Gene Expression Controlling Cell Expansion.

    Science.gov (United States)

    Xu, Qian; Krishnan, Sanalkumar; Merewitz, Emily; Xu, Jichen; Huang, Bingru

    2016-01-01

    Leaf elongation rate (LER) is an important factor controlling plant growth and productivity. The objective of this study was to determine whether genetic variation in LER for a fast-growing ('K-31'), and a dwarf cultivar ('Bonsai') of tall fescue (Festuca arundinacea) and gibberellic acid (GA) regulation of LER were associated with differential expression of cell-expansion genes. Plants were treated with GA3, trinexapac-ethyl (TE) (GA inhibitor), or water (untreated control) in a hydroponic system. LER of 'K-31' was 63% greater than that of 'Bonsai', which corresponded with 32% higher endogenous GA4 content in leaf and greater cell elongation and production rates under the untreated control condition. Exogenous application of GA3 significantly enhanced LER while TE treatment inhibited leaf elongation due to GA3-stimulation or TE-inhibition of cell elongation and production rate in leaves for both cultivars. Real-time quantitative polymerase chain reaction analysis revealed that three α-expansins, one β-expansin, and three xyloglucan endotransglycosylase (XET) genes were associated with GA-stimulation of leaf elongation, of which, the differential expression of EXPA4 and EXPA7 was related to the genotypic variation in LER of two cultivars. Those differentially-expressed expansin and XET genes could play major roles in genetic variation and GA-regulated leaf elongation in tall fescue. PMID:27457585

  1. Induction of a Soluble Anti-HIV-1 factor (s with IFN-γ, IL-10, and β-Chemokine Modulating Activity by an Influenza-Bacterial Polyantigenic Mixture

    Directory of Open Access Journals (Sweden)

    José W. Rodríguez

    2007-01-01

    Full Text Available Partial immune restoration may be obtained with highly active antiretroviral therapy (HAART, but specific anti-HIV-1 immune responses do not appear to improve substantially. We have demonstrated that a soluble factor(s induced by a mixture of inactivated influenza and bacterial vaccines called polyantigenic immunomodulator (PAI, possesses strong immunoregulatory and anti-HIV-1 activities. In the present study, we show that culture fluids from both PAI-stimulated peripheral blood mononuclear cells (PBMC and CD8+ T-cells of HIV-1 infected patients were able to suppress HIV-1 replication in an MHC-unrestricted fashion. The PAI-induced antiviral activity was eliminated when culture fluids were pre-heated at 100oC for 10 min. and it is associated with induction of IFN-Γ, MIP-1α, MIP-1β, and RANTES production, but inhibition of IL-10. Furthermore, this induction is dependent on the immunological status (CD4:CD8 ratio of the HIV-1 infected patient. Taken together, our results suggest that the MHC-unrestricted HIV-1 suppression that is induced by culture fluids from PAI-stimulated PBMC may result from the stimulation of immune cell subpopulations to produce a heat-labile antiviral soluble factor(s, which in turn modulate cytokine and β-chemokine production. The identification of this PAI-induced soluble factor(s may have major therapeutic potential.

  2. Single-Plane Magnetically Focused Elongated Small Field Proton Beams.

    Science.gov (United States)

    McAuley, Grant A; Slater, James M; Wroe, Andrew J

    2015-08-01

    We previously performed Monte Carlo simulations of magnetically focused proton beams shaped by a single quadrapole magnet and thereby created narrow elongated beams with superior dose delivery characteristics (compared to collimated beams) suitable for targets of similar geometry. The present study seeks to experimentally validate these simulations using a focusing magnet consisting of 24 segments of samarium cobalt permanent magnetic material adhered into a hollow cylinder. Proton beams with properties relevant to clinical radiosurgery applications were delivered through the magnet to a water tank containing a diode detector or radiochromic film. Dose profiles were analyzed and compared with analogous Monte Carlo simulations. The focused beams produced elongated beam spots with high elliptical symmetry, indicative of magnet quality. Experimental data showed good agreement with simulations, affirming the utility of Monte Carlo simulations as a tool to model the inherent complexity of a magnetic focusing system. Compared to target-matched unfocused simulations, focused beams showed larger peak to entrance ratios (26% to 38%) and focused simulations showed a two-fold increase in beam delivery efficiency. These advantages can be attributed to the magnetic acceleration of protons in the transverse plane that tends to counteract the particle outscatter that leads to degradation of peak to entrance performance in small field proton beams. Our results have important clinical implications and suggest rare earth focusing magnet assemblies are feasible and could reduce skin dose and beam number while delivering enhanced dose to narrow elongated targets (eg, in and around the spinal cord) in less time compared to collimated beams. PMID:25414143

  3. Elongation distribution between tension leveler and temper mill for pickling line 2030 in Baosteel

    Institute of Scientific and Technical Information of China (English)

    LIU Xiancui; SU Lanhai; LI Zhongfu; FU Zhilin; ZHANG Qingdong; HE Chun

    2007-01-01

    Research into plate elongation distribution between the tension leveler and temper mill for pickling line 2030 at Baosteel is conducted.The study,which involved performance testing of mechanics,is designed at different elongation distributions and analyzed from many aspects.Finally,the optimal elongation of the tension leveler and temper mill is given.

  4. Time Dependent and Steady Uni-axial Elongational Viscosity

    DEFF Research Database (Denmark)

    Nielsen, Jens K.; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    Here we present measurements of transient and steady uni-axial elongational viscosity, using the Filament Stretching Rheometer1 or FSR1 (see Fig. 1) of the following melts: Four narrow MMD polystyrene (PS) samples with weight-average molar mass Mw in the range of 50k to 390k. Three different bi......-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements....

  5. Connectedness percolation of elongated hard particles in an external field.

    Science.gov (United States)

    Otten, Ronald H J; van der Schoot, Paul

    2012-02-24

    A theory is presented of how orienting fields and steric interactions conspire against the formation of a percolating network of, in some sense, connected elongated colloidal particles in fluid dispersions. We find that the network that forms above a critical loading breaks up again at higher loadings due to interaction-induced enhancement of the particle alignment. Upon approach of the percolation threshold, the cluster dimensions diverge with the same critical exponent parallel and perpendicular to the field direction, implying that connectedness percolation is not in the universality class of directed percolation. PMID:22463580

  6. The acoustical significance of age-dependent ear elongation

    DEFF Research Database (Denmark)

    Christensen, Flemming

    2015-01-01

    Elderly people, especially some old men, appear to have very large ears. This paper presents an investigation on the acoustic significance of the age dependent ear elongation. HRTFs and ear lengths were measured for two groups of young and old people. The older groups had larger ears on average......, corresponding to what is reported in the literature. For female ears, virtually no acoustical effect was found. For male ears directional dependent effects in the range up to 5 dB on average was found for certain directions and frequencies. Implications on age dependent hearing loss (presbycusis) and...

  7. Collisions of Dark Solitons in Elongated Bose-Einstein Condensates

    International Nuclear Information System (INIS)

    We present experimental data showing the head-on collision of dark solitons generated in an elongated Bose-Einstein condensate. No discernable interaction can be recorded, in full agreement with the fundamental theoretical concepts of solitons as mutually transparent quasiparticles. Our soliton generation technique allows for the creation of solitons with different depths; hence, they can be distinguished and their trajectories be followed. Simulations of the 1D-Gross-Pitaevskii equation have been performed to compare the experiment with a mean-field description

  8. Cross-linking inhomogeneity in nano-composite hydrogels can be observed as sharp peaks by SAXS experiments under elongation

    OpenAIRE

    Nishi, Kengo; Shibayama, Mitsuhiro

    2016-01-01

    We introduced silica nanoparticles into poly ($N$,$N$-dimethylacrylamide) gel, (PDAM-NC gel), and poly (acrylamide) gel (PAM-NC gel), and carried out SAXS measurements under uniaxial elongation. It is well known that PDAM chains are strongly adsorbed onto silica nanoparticles while PAM chains are not. Interestingly, we found from SAXS measurements that scattering profiles depend on the polymer-nanoparticle interaction. A four-spot pattern was observed in the 2D structure factors of PDAM-NC ge...

  9. Measurement of Behavioral Evolution in Bacterial Populations

    Science.gov (United States)

    Austin, Robert

    2013-03-01

    A curious aspect of bacterial behavior under stress is the induction of filamentation: the anomalous growth of certain bacteria in which cells continue to elongate but do not divide into progeny. We show that E.coli under the influence of the genotoxic antibiotic ciprofloxacin have robust filamentous growth, which provides individual bacteria a mesoscopic niche for evolution until resistant progeny can bud off and propagate. Hence, filamentation is a form of genomic amplification where even a single, isolated bacteria can have access to multiple genomes. We propose a model that predicts that the first arrival time of the normal sized progeny should follow a Gompertz distribution with the mean first arrival time proportional to the elongation rate of filament. These predictions agree with our experimental measurements. Finally, we suggest bacterial filament growth and budding has many similarities to tumor growth and metastasis and can serve as a simpler model to study those complicated processes. Sponsored by the NCI/NIH Physical Sciences Oncology Centers

  10. Factoring

    OpenAIRE

    Lenstra, Arjen K.

    1994-01-01

    Factoring, finding a non-trivial factorization of a composite positive integer, is believed to be a hard problem. How hard we think it is, however, changes almost on a daily basis. Predicting how hard factoring will be in the future, an important issue for cryptographic applications of composite numbers, is therefore a challenging task. The author presents a brief survey of general purpose integer factoring algorithms and their implementations

  11. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    The startup and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 kg/mole (PS52K) and 103 kg/mole (PS103K), and for three bidisperse polystyrene melts. The bidisperse melts consist of PS103K or PS52K and a monodisperse...... (closed loop proportional regulator) using the laser in such a way that the stretch rate at the neck is kept constant. The rheometer has been described in more detail in (A. Bach, H.K. Rasmussen and O. Hassager, Journal of Rheology, 47 (2003) 429). PS390K show a decrease in the steady viscosity as a power......-law function of the elongational rate (A. Bach, K. Almdal, H.K. Rasmussen and O. Hassager, Macromolecules 36 (2003) 5174). PS52K and PS103K show that the steady viscosity has a maximum that is respectively 100% and 50% above 3 times the zero-shear-rate viscosity. The bidisperse melts show a significant...

  12. Granular packings of elongated faceted particles deposited under gravity

    International Nuclear Information System (INIS)

    We report experimental and theoretical results of the effect that particle shape has on the packing properties of granular materials. We have systematically measured the particle angular distribution, the cluster size distribution and the stress profiles of ensembles of faceted elongated particles deposited in a bidimensional box. Stress transmission through this granular system has been numerically simulated using a two-dimensional model of irregular particles. For grains of maximum symmetry (squares), the stress propagation localizes and forms chain-like forces analogous to those observed for granular materials composed of spheres. For thick layers of grains, a pressure saturation is observed for deposit depths beyond a characteristic length. This scenario correlates with packing morphology and can be understood in terms of stochastic models of aggregation and random multiplicative processes. As grains elongate and lose their symmetry, stress propagation is strongly affected. Lateral force transmission becomes less favored than vertical transfer, and hence, an increase in the pressure develops with depth, hindering force saturation

  13. Local auxin metabolism regulates environment-induced hypocotyl elongation.

    Science.gov (United States)

    Zheng, Zuyu; Guo, Yongxia; Novák, Ondřej; Chen, William; Ljung, Karin; Noel, Joseph P; Chory, Joanne

    2016-01-01

    A hallmark of plants is their adaptability of size and form in response to widely fluctuating environments. The metabolism and redistribution of the phytohormone auxin play pivotal roles in establishing active auxin gradients and resulting cellular differentiation. In Arabidopsis thaliana, cotyledons and leaves synthesize indole-3-acetic acid (IAA) from tryptophan through indole-3-pyruvic acid (3-IPA) in response to vegetational shade. This newly synthesized auxin moves to the hypocotyl where it induces elongation of hypocotyl cells. Here we show that loss of function of VAS2 (IAA-amido synthetase Gretchen Hagen 3 (GH3).17) leads to increases in free IAA at the expense of IAA-Glu (IAA-glutamate) in the hypocotyl epidermis. This active IAA elicits shade- and high temperature-induced hypocotyl elongation largely independently of 3-IPA-mediated IAA biosynthesis in cotyledons. Our results reveal an unexpected capacity of local auxin metabolism to modulate the homeostasis and spatial distribution of free auxin in specialized organs such as hypocotyls in response to shade and high temperature. PMID:27249562

  14. Fluoride exposure regulates the elongation phase of protein synthesis in cultured Bergmann glia cells.

    Science.gov (United States)

    Flores-Méndez, Marco; Ramírez, Diana; Alamillo, Nely; Hernández-Kelly, Luisa C; Del Razo, Luz María; Ortega, Arturo

    2014-08-17

    Fluoride is an environmental pollutant present in dental products, food, pesticides and water. The latter, is the greatest source of exposure to this contaminant. Structural and functional damages to the central nervous system are present in exposed population. An established consequence of the neuronal is the release of a substantial amount of glutamate to the extracellular space, leading to an excitotoxic insult. Glutamate exerts its actions through the activation of specific plasma membrane receptors and transporters present in neurons and in glia cells and it is the over-activation of glutamate receptors and transporters, the biochemical hallmark of neuronal and oligodendrocyte cell death. In this context, taking into consideration that fluoride leads to degeneration of cerebellar cells, we took the advantage of the well-established model of cerebellar Bergmann glia cultures to gain insight into the molecular mechanisms inherent to fluoride neurotoxicity that might be triggered in glia cells. We could establish that fluoride decreases [(35)S]-methionine incorporation into newly synthesized polypeptides, in a time-dependent manner, and that this halt in protein synthesis is the result of a decrease in the elongation phase of translation, mediated by an augmentation of eukaryotic elongation factor 2 phosphorylation. These results favor the notion of glial cells as targets of fluoride toxicity and strengthen the idea of a critical involvement of glia cells in the function and dysfunction of the brain. PMID:24954634

  15. Stress significantly increases mortality following a secondary bacterial respiratory infection

    OpenAIRE

    Hodgson Paul D; Aich Palok; Stookey Joseph; Popowych Yurij; Potter Andrew; Babiuk Lorne; Griebel Philip J

    2012-01-01

    Abstract A variety of mechanisms contribute to the viral-bacterial synergy which results in fatal secondary bacterial respiratory infections. Epidemiological investigations have implicated physical and psychological stressors as factors contributing to the incidence and severity of respiratory infections and psychological stress alters host responses to experimental viral respiratory infections. The effect of stress on secondary bacterial respiratory infections has not, however, been investig...

  16. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M;

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...... susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p <0.001). Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate...... was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p <0.001). Cases involving staphylococci, Pseudomonas spp. and Enterobacteriaceae were under-reported. Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin...

  17. A Mutation in fat2 Uncouples Tissue Elongation from Global Tissue Rotation

    Directory of Open Access Journals (Sweden)

    Franziska Aurich

    2016-03-01

    Full Text Available Global tissue rotation was proposed as a morphogenetic mechanism controlling tissue elongation. In Drosophila ovaries, global tissue rotation of egg chambers coincides with egg chamber elongation. Egg chamber rotation was put forward to result in circumferential alignment of extracellular fibers. These fibers serve as molecular corsets to restrain growth of egg chambers perpendicular to the anteroposterior axis, thereby leading to the preferential egg chamber elongation along this axis. The atypical cadherin Fat2 is required for egg chamber elongation, rotation, and the circumferential alignment of extracellular fibers. Here, we have generated a truncated form of Fat2 that lacks the entire intracellular region. fat2 mutant egg chambers expressing this truncated protein fail to rotate yet display normal extracellular fiber alignment and properly elongate. Our data suggest that global tissue rotation, even though coinciding with tissue elongation, is not a necessary prerequisite for elongation.

  18. Bacterial Nail Infection (Paronychia)

    Science.gov (United States)

    ... of nail infection is often caused by a bacterial infection but may also be caused by herpes, a ... to a type of yeast called Candida , or bacterial infection, and this may lead to abnormal nail growth. ...

  19. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will...

  20. Toll-like receptor 5 (TLR5), IL-1β secretion, and asparagine endopeptidase are critical factors for alveolar macrophage phagocytosis and bacterial killing.

    Science.gov (United States)

    Descamps, Delphyne; Le Gars, Mathieu; Balloy, Viviane; Barbier, Diane; Maschalidi, Sophia; Tohme, Mira; Chignard, Michel; Ramphal, Reuben; Manoury, Bénédicte; Sallenave, Jean-Michel

    2012-01-31

    A deficit in early clearance of Pseudomonas aeruginosa (P. aeruginosa) is crucial in nosocomial pneumonia and in chronic lung infections. Few studies have addressed the role of Toll-like receptors (TLRs), which are early pathogen associated molecular pattern receptors, in pathogen uptake and clearance by alveolar macrophages (AMs). Here, we report that TLR5 engagement is crucial for bacterial clearance by AMs in vitro and in vivo because unflagellated P. aeruginosa or different mutants defective in TLR5 activation were resistant to AM phagocytosis and killing. In addition, the clearance of PAK (a wild-type P. aeruginosa strain) by primary AMs was causally associated with increased IL-1β release, which was dramatically reduced with PAK mutants or in WT PAK-infected primary TLR5(-/-) AMs, demonstrating the dependence of IL-1β production on TLR5. We showed that this IL-1β production was important in endosomal pH acidification and in inducing the killing of bacteria by AMs through asparagine endopeptidase (AEP), a key endosomal cysteine protease. In agreement, AMs from IL-1R1(-/-) and AEP(-/-) mice were unable to kill P. aeruginosa. Altogether, these findings demonstrate that TLR5 engagement plays a major role in P. aeruginosa internalization and in triggering IL-1β formation. PMID:22307620

  1. Expression of bacterial virulence factors and cytokines during in vitro macrophage infection by enteroinvasive Escherichia coli and Shigella flexneri: a comparative study

    Directory of Open Access Journals (Sweden)

    Silvia Y Bando

    2010-09-01

    Full Text Available Enteroinvasive Escherichia coli (EIEC and Shigellaspp cause bacillary dysentery in humans by invading and multiplying within epithelial cells of the colonic mucosa. Although EIEC and Shigellashare many genetic and biochemical similarities, the illness caused by Shigellais more severe. Thus, genomic and structure-function molecular studies on the biological interactions of these invasive enterobacteria with eukaryotic cells have focused on Shigella rather than EIEC. Here we comparatively studied the interactions of EIEC and of Shigella flexneriwith cultured J774 macrophage-like cells. We evaluated several phenotypes: (i bacterial escape from macrophages after phagocytosis, (ii macrophage death induced by EIEC and S. flexneri, (iii macrophage cytokine expression in response to infection and (iv expression of plasmidial (pINV virulence genes. The results showed thatS. flexneri caused macrophage killing earlier and more intensely than EIEC. Both pathogens induced significant macrophage production of TNF, IL-1 and IL-10 after 7 h of infection. Transcription levels of the gene invasion plasmid antigen-C were lower in EIEC than in S. flexneri throughout the course of the infection; this could explain the diminished virulence of EIEC compared to S. flexneri.

  2. Expression of bacterial virulence factors and cytokines during in vitro macrophage infection by enteroinvasive Escherichia coli and Shigella flexneri: a comparative study.

    Science.gov (United States)

    Bando, Silvia Y; Moreno, Ana C R; Albuquerque, José A T; Amhaz, Juliana M K; Moreira-Filho, Carlos A; Martinez, Marina B

    2010-09-01

    Enteroinvasive Escherichia coli (EIEC) and Shigella spp cause bacillary dysentery in humans by invading and multiplying within epithelial cells of the colonic mucosa. Although EIEC and Shigella share many genetic and biochemical similarities, the illness caused by Shigella is more severe. Thus, genomic and structure-function molecular studies on the biological interactions of these invasive enterobacteria with eukaryotic cells have focused on Shigella rather than EIEC. Here we comparatively studied the interactions of EIEC and of Shigella flexneri with cultured J774 macrophage-like cells. We evaluated several phenotypes: (i) bacterial escape from macrophages after phagocytosis, (ii) macrophage death induced by EIEC and S. flexneri, (iii) macrophage cytokine expression in response to infection and (iv) expression of plasmidial (pINV) virulence genes. The results showed that S. flexneri caused macrophage killing earlier and more intensely than EIEC. Both pathogens induced significant macrophage production of TNF, IL-1 and IL-10 after 7 h of infection. Transcription levels of the gene invasion plasmid antigen-C were lower in EIEC than in S. flexneri throughout the course of the infection; this could explain the diminished virulence of EIEC compared to S. flexneri. PMID:20944993

  3. Dynamics of macroscopic tunneling in elongated Bose-Einstein condensates

    International Nuclear Information System (INIS)

    We investigate macroscopic tunneling from an elongated quasi-one-dimensional trap, forming a 'cigar-shaped' Bose-Einstein condensate (BEC). Using a recently developed formalism we get the leading analytical approximation for the right-hand side of the potential wall, i.e., outside the trap, and a formalism based on Wigner functions, for the left side of the potential wall, i.e., inside the BEC. We then present accomplished results of numerical calculations, which show a 'blip' in the particle density traveling with an asymptotic shock velocity, as resulted from previous works on a dotlike trap but with significant differences from the latter. Inside the BEC a pattern of a traveling dispersive shock wave is revealed. In the attractive case, we find trains of bright solitons frozen near the boundary.

  4. Observation of Universal Solidification in the Elongated Water Nanomeniscus.

    Science.gov (United States)

    Kim, Jongwoo; Won, Donghyun; Sung, Baekman; Jhe, Wonho

    2014-02-20

    The ubiquitous capillary water bridge in nature plays an important role in interfacial phenomena under ambient conditions such as adhesion and friction. We present experimental measurements of the mechanical properties of the nanometric water column by using noncontact atomic force microscopy. We observe the universal behaviors that the relaxation time (RT) associated with the meniscus increases with its elongation and ruptures at the same value of RT, independent of the meniscus volume. In particular, the enhancement of RT between formation and rupture of the meniscus is indicative of the increased solid-like response, similar to that observed in nanoconfined water layers. Our results that the longer water column is more solid-like and less stable suggest (i) water at the vapor/liquid interface is more solid-like than that inside the meniscus and (ii) the associated smaller mobility of the interfacial water molecules is responsible for the structural stability of the water meniscus. PMID:26270845

  5. Reconstruction of recurrent diaphragmatic eventration with an elongated polytetrafluoroethylene sheet.

    Science.gov (United States)

    Ikeda, Masaki; Sonobe, Makoto; Bando, Toru; Date, Hiroshi

    2013-08-01

    We report the case of a 31-year old woman with recurrence of left diaphragmatic eventration 3 years after a previous surgery for this condition. At the initial occurrence, she had experienced dyspnoea on exercise and subsequently underwent laparoscopic plication of the diaphragm with an endo-stapler at a local hospital. Immediately after the operation, the diaphragm was torn and the intestine entered the thorax. Therefore, plication involving sewing was performed. Then, 3 years later, the patient again experienced dyspnoea and was diagnosed as having recurrence of left diaphragmatic eventration. Observation under thoracoscopy revealed that the centre of the left diaphragm was thin but not torn. We reconstructed the left diaphragm with an elongated polytetrafluoroethylene sheet on the naïve diaphragm. The patient was discharged from our hospital 5 days after surgery. Her respiratory function improved and she has not experienced recurrence. PMID:23644727

  6. Elongation method for electronic structure calculations of random DNA sequences.

    Science.gov (United States)

    Orimoto, Yuuichi; Liu, Kai; Aoki, Yuriko

    2015-10-30

    We applied ab initio order-N elongation (ELG) method to calculate electronic structures of various deoxyribonucleic acid (DNA) models. We aim to test potential application of the method for building a database of DNA electronic structures. The ELG method mimics polymerization reactions on a computer and meets the requirements for linear scaling computational efficiency and high accuracy, even for huge systems. As a benchmark test, we applied the method for calculations of various types of random sequenced A- and B-type DNA models with and without counterions. In each case, the ELG method maintained high accuracy with small errors in energy on the order of 10(-8) hartree/atom compared with conventional calculations. We demonstrate that the ELG method can provide valuable information such as stabilization energies and local densities of states for each DNA sequence. In addition, we discuss the "restarting" feature of the ELG method for constructing a database that exhaustively covers DNA species. PMID:26337429

  7. Elongational rheology and cohesive fracture of photo-oxidated LDPE

    International Nuclear Information System (INIS)

    It was found recently that low-density polyethylene (LDPE) samples with different degrees of photo-oxidation represent an interesting system to study the transition from ductile to cohesive fracture and the aspects of the cohesive rupture in elongational flow. Sheets of LDPE were subjected to photo-oxidation in the presence of air using a xenon lamp to irradiate the samples for times between 1 day and 6 weeks. Characterisation methods included Fourier transform infrared spectroscopy, solvent extraction method, and rheology in shear and uniaxial extensional flows. Linear viscoelasticity was increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by the carbonyl index, acid and aldehydes groups, and gel fraction. The molecular stress function model was used to quantify the experimental data, and the nonlinear model parameter β was found to be correlated with the gel content. The uniaxial data showed that the transition from ductile to cohesive fracture was shifted to lower elongational rates, the higher the gel content was. From 2 weeks photo-oxidation onwards, cohesive rupture occurred at every strain rate investigated. The true strain and true stress at cohesive fracture as well as the energy density applied to the sample up to fracture were analyzed. At low gel content, rupture was mainly determined by the melt fraction while at high gel content, rupture occurred predominantly in the gel structure. The strain at break was found to be independent of strain rate, contrary to the stress at break and the energy density. Thus, the true strain and not the stress at break or the energy density was found to be the relevant physical quantity to describe cohesive fracture behavior of photo-oxidated LDPE. The equilibrium modulus of the gel structures was correlated with the true strain at rupture. The stiffer the gel structure, the lower was the deformation tolerated before the sample breaks

  8. Gibberellin-Stimulation of Rhizome Elongation and Differential GA-Responsive Proteomic Changes in Two Grass Species

    Science.gov (United States)

    Ma, Xiqing; Huang, Bingru

    2016-01-01

    Rapid and extensive rhizome development is a desirable trait for perennial grass growth and adaptation to environmental stresses. The objective of this study was to determine proteomic changes and associated metabolic pathways of gibberellin (GA) -regulation of rhizome elongation in two perennial grass species differing in rhizome development. Plants of a short-rhizome bunch-type tall fescue (TF; Festuca arundinacea; ‘BR’) and an extensive rhizomatous Kentucky bluegrass (KB; Poa pratensis; ‘Baron’) were treated with 10 μM GA3 in hydroponic culture in growth chambers. The average rhizome length in KB was significantly longer than that in TF regardless of GA3 treatment, and increased significantly with GA3 treatment, to a greater extent than that in TF. Comparative proteomic analysis using two-dimensional electrophoresis and mass spectrometry was performed to further investigate proteins and associated metabolic pathways imparting increased rhizome elongation by GA. A total of 37 and 38 differentially expressed proteins in response to GA3 treatment were identified in TF and KB plants, respectively, which were mainly involved in photosynthesis, energy and amino acid metabolism, protein synthesis, defense and cell development processes. Accelerated rhizome elongation in KB by GA could be mainly associated with the increased abundance of proteins involved in energy metabolism (glyceraldehyde-3-phosphate dehydrogenase, fructose-bisphosphate aldolase, and ATP synthase), amino acid metabolism (S-adenosylmethionine and adenosylhomocysteinase), protein synthesis (HSP90, elongation factor Tu and eukaryotic translation initiation factor 5A), cell-wall development (cell dividion cycle protein, alpha tubulin-2A and actin), and signal transduction (calreticulin). These proteins could be used as candidate proteins for further analysis of molecular mechanisms controlling rhizome growth. PMID:27446135

  9. Numerical simulation of anisotropic shrinkage in a 2D compact of elongated particles.

    Energy Technology Data Exchange (ETDEWEB)

    Braginsky, Michael V.; Olevsky, Eugene A. (San Diego State University, San Diego, CA); Johnson, D. Lynn (Norwest University, Evanston, IL); Tikare, Veena

    2003-08-01

    Microstructural evolution during simple solid-state sintering of two-dimensional compacts of elongated particles packed in different arrangements was simulated using a kinetic, Monte Carlo model. The model used simulates curvature-driven grain growth, pore migration by surface diffusion, vacancy formation, diffusion along grain boundaries, and annihilation. Only the shape of the particles was anisotropic; all other extensive thermodynamic and kinetic properties such as surface energies and diffusivities were isotropic. We verified our model by simulating sintering in the analytically tractable cases of simple-packed and close-packed, elongated particles and comparing the shrinkage rate anisotropies with those predicted analytically. Once our model was verified, we used it to simulate sintering in a powder compact of aligned, elongated particles of arbitrary size and shape to gain an understanding of differential shrinkage. Anisotropic shrinkage occurred in all compacts with aligned, elongated particles. However, the direction of higher shrinkage was in some cases along the direction of elongation and in other cases in the perpendicular direction, depending on the details of the powder compact. In compacts of simple-packed, mono-sized, elongated particles, shrinkage was higher in the direction of elongation. In compacts of close-packed, mono-sized, elongated particles and of elongated particles with a size and shape distribution, the shrinkage was lower in the direction of elongation. The results of these simulations are analyzed, and the implication of these results is discussed.

  10. Defective Dendrite Elongation but Normal Fertility in Mice Lacking the Rho-Like GTPase Activator Dbl

    Science.gov (United States)

    Hirsch, Emilio; Pozzato, Michela; Vercelli, Alessandro; Barberis, Laura; Azzolino, Ornella; Russo, Chiara; Vanni, Cristina; Silengo, Lorenzo; Eva, Alessandra; Altruda, Fiorella

    2002-01-01

    Dbl is the prototype of a large family of GDP-GTP exchange factors for small GTPases of the Rho family. In vitro, Dbl is known to activate Rho and Cdc42 and to induce a transformed phenotype. Dbl is specifically expressed in brain and gonads, but its in vivo functions are largely unknown. To assess its role in neurogenesis and gametogenesis, targeted deletion of the murine Dbl gene was accomplished in embryonic stem cells. Dbl-null mice are viable and did not show either decreased reproductive performances or obvious neurological defects. Histological analysis of mutant testis showed normal morphology and unaltered proliferation and survival of spermatogonia. Dbl-null brains indicated a correct disposition of the major neural structures. Analysis of cortical stratification indicated that Dbl is not crucial for neuronal migration. However, in distinct populations of Dbl-null cortical pyramidal neurons, the length of dendrites was significantly reduced, suggesting a role for Dbl in dendrite elongation. PMID:11940671

  11. Phytotoxicity of veterinary antibiotics to seed germination and root elongation of crops.

    Science.gov (United States)

    Pan, Min; Chu, L M

    2016-04-01

    Large quantities of veterinary antibiotics (VAs) are being used worldwide in agricultural fields through wastewater irrigation and manure application. They cause damages to the ecosystem when discharged into the environment, but there is a lack of information on their toxicity to plants and animals. This study evaluated the phytotoxic effects of five major VAs, namely tetracycline (TC), sulfamethazine (SMZ), norfloxacin (NOR), erythromycin (ERY) and chloramphenicol (CAP), on seed germination and root elongation in lettuce, tomato, carrot and cucumber, and investigated the relationship between their physicochemical properties and phytotoxicities. Results show that these compounds significantly inhibited root elongation (p<0.05), the most sensitive endpoint for the phytotoxicity test. TC was associated with the highest level of toxicity, followed by NOR, ERY, SMZ and CAP. Regarding crop species, lettuce was found to be sensitive to most of the VAs. The median effect concentration (EC50) of TC, SMZ, NOR, ERY and CAP to lettuce was 14.4, 157, 49.4, 68.8 and 204 mg/L, respectively. A quantitative structure-activity relationship (QSAR) model has been established based on the measured data. It is evident that hydrophobicity was the most important factor governing the phytotoxicity of these compounds to seeds, which could be explained by the polar narcosis mechanism. Lettuce is considered a good biomarker for VAs in the environment. According to the derived equation, phytotoxicities of selected VA compounds on different crops can be calculated, which could be applicable to other VAs. Environmental risks of VAs were summarized based on the phytotoxicity results and other persistent factors. PMID:26773832

  12. Amplification of pico-scale DNA mediated by bacterial carrier DNA for small-cell-number transcription factor ChIP-seq

    DEFF Research Database (Denmark)

    Jakobsen, Janus S; Bagger, Frederik O; Hasemann, Marie S;

    2015-01-01

    BACKGROUND: Chromatin-Immunoprecipitation coupled with deep sequencing (ChIP-seq) is used to map transcription factor occupancy and generate epigenetic profiles genome-wide. The requirement of nano-scale ChIP DNA for generation of sequencing libraries has impeded ChIP-seq on in vivo tissues of low...... transcription factor (CEBPA) and histone mark (H3K4me3) ChIP. We further demonstrate that genomic profiles are highly resilient to changes in carrier DNA to ChIP DNA ratios. CONCLUSIONS: This represents a significant advance compared to existing technologies, which involve either complex steps of pre...

  13. Elevated soluble urokinase receptor values in CSF, age and bacterial meningitis infection are independent and additive risk factors of fatal outcome

    DEFF Research Database (Denmark)

    Tzanakaki, G; Paparoupa, M; Kyprianou, M;

    2012-01-01

    The aim of the present study was to evaluate the potential role of cerebrospinal fluid soluble urokinase receptor (suPAR) level, infection and age as risk factors for fatal outcome in patients suspected of having meningitis and/or bacteraemia on admission to hospital. A total of 545 cerebrospinal...

  14. A Novel WRKY transcription factor is required for induction of PR-1a gene expression by salicylic acid and bacterial elicitors

    NARCIS (Netherlands)

    van Verk, Marcel C; Pappaioannou, Dimitri; Neeleman, Lyda; Bol, John F; Linthorst, Huub J M

    2008-01-01

    PR-1a is a salicylic acid-inducible defense gene of tobacco (Nicotiana tabacum). One-hybrid screens identified a novel tobacco WRKY transcription factor (NtWRKY12) with specific binding sites in the PR-1a promoter at positions -564 (box WK(1)) and -859 (box WK(2)). NtWRKY12 belongs to the class of t

  15. Organization of the bacterial chromosome.

    OpenAIRE

    Krawiec, S.; Riley, M

    1990-01-01

    Recent progress in studies on the bacterial chromosome is summarized. Although the greatest amount of information comes from studies on Escherichia coli, reports on studies of many other bacteria are also included. A compilation of the sizes of chromosomal DNAs as determined by pulsed-field electrophoresis is given, as well as a discussion of factors that affect gene dosage, including redundancy of chromosomes on the one hand and inactivation of chromosomes on the other hand. The distinction ...

  16. Coculture of elongated neuron axon with poly (D, L-lactide-co-glycolide) biomembrane in vitro

    Institute of Scientific and Technical Information of China (English)

    程飚; 陈峥嵘

    2004-01-01

    Objective: To elongate human nerve axon in culture and search for suitable support matrices for peripheral nervous system transplantation.Methods: Human embryo cortical neuronal cells,seeded on poly ( D, L-lactide-co-glycolide ) ( PLGA )membrane scaffolds, were elongated with a self-made neuro-axon extending device. The growth and morphological changes of neuron axons were observed to measure axolemmal permeability after elongation.Neurofilament protein was stained by immunohistochemical technique.Results: Human embryo neuron axon could be elongated and cultured on the PLGA membrane and retain their normal form and function.Conclusions: Three dimensional scaffolds with elongated neuron axon have the basic characteristics of artificial nerves, indicating a fundemental theory of nerve repair with elongated neuron axon.

  17. Structure of the Legionella Virulence Factor, SidC Reveals a Unique PI(4P-Specific Binding Domain Essential for Its Targeting to the Bacterial Phagosome.

    Directory of Open Access Journals (Sweden)

    Xi Luo

    2015-06-01

    Full Text Available The opportunistic intracellular pathogen Legionella pneumophila is the causative agent of Legionnaires' disease. L. pneumophila delivers nearly 300 effector proteins into host cells for the establishment of a replication-permissive compartment known as the Legionella-containing vacuole (LCV. SidC and its paralog SdcA are two effectors that have been shown to anchor on the LCV via binding to phosphatidylinositol-4-phosphate [PI(4P] to facilitate the recruitment of ER proteins to the LCV. We recently reported that the N-terminal SNL (SidC N-terminal E3 Ligase domain of SidC is a ubiquitin E3 ligase, and its activity is required for the recruitment of ER proteins to the LCV. Here we report the crystal structure of SidC (1-871. The structure reveals that SidC contains four domains that are packed into an arch-like shape. The P4C domain (PI(4P binding of SidC comprises a four α-helix bundle and covers the ubiquitin ligase catalytic site of the SNL domain. Strikingly, a pocket with characteristic positive electrostatic potentials is formed at one end of this bundle. Liposome binding assays of the P4C domain further identified the determinants of phosphoinositide recognition and membrane interaction. Interestingly, we also found that binding with PI(4P stimulates the E3 ligase activity, presumably due to a conformational switch induced by PI(4P from a closed form to an open active form. Mutations of key residues involved in PI(4P binding significantly reduced the association of SidC with the LCV and abolished its activity in the recruitment of ER proteins and ubiquitin signals, highlighting that PI(4P-mediated targeting of SidC is critical to its function in the remodeling of the bacterial phagosome membrane. Finally, a GFP-fusion with the P4C domain was demonstrated to be specifically localized to PI(4P-enriched compartments in mammalian cells. This domain shows the potential to be developed into a sensitive and accurate PI(4P probe in living cells.

  18. Structure of the Legionella Virulence Factor, SidC Reveals a Unique PI(4)P-Specific Binding Domain Essential for Its Targeting to the Bacterial Phagosome

    Science.gov (United States)

    Luo, Xi; Wasilko, David J.; Liu, Yao; Sun, Jiayi; Wu, Xiaochun; Luo, Zhao-Qing; Mao, Yuxin

    2015-01-01

    The opportunistic intracellular pathogen Legionella pneumophila is the causative agent of Legionnaires’ disease. L. pneumophila delivers nearly 300 effector proteins into host cells for the establishment of a replication-permissive compartment known as the Legionella-containing vacuole (LCV). SidC and its paralog SdcA are two effectors that have been shown to anchor on the LCV via binding to phosphatidylinositol-4-phosphate [PI(4)P] to facilitate the recruitment of ER proteins to the LCV. We recently reported that the N-terminal SNL (SidC N-terminal E3 Ligase) domain of SidC is a ubiquitin E3 ligase, and its activity is required for the recruitment of ER proteins to the LCV. Here we report the crystal structure of SidC (1-871). The structure reveals that SidC contains four domains that are packed into an arch-like shape. The P4C domain (PI(4)P binding of SidC) comprises a four α-helix bundle and covers the ubiquitin ligase catalytic site of the SNL domain. Strikingly, a pocket with characteristic positive electrostatic potentials is formed at one end of this bundle. Liposome binding assays of the P4C domain further identified the determinants of phosphoinositide recognition and membrane interaction. Interestingly, we also found that binding with PI(4)P stimulates the E3 ligase activity, presumably due to a conformational switch induced by PI(4)P from a closed form to an open active form. Mutations of key residues involved in PI(4)P binding significantly reduced the association of SidC with the LCV and abolished its activity in the recruitment of ER proteins and ubiquitin signals, highlighting that PI(4)P-mediated targeting of SidC is critical to its function in the remodeling of the bacterial phagosome membrane. Finally, a GFP-fusion with the P4C domain was demonstrated to be specifically localized to PI(4)P-enriched compartments in mammalian cells. This domain shows the potential to be developed into a sensitive and accurate PI(4)P probe in living cells. PMID

  19. Multiple Pilus Motors Cooperate for Persistent Bacterial Movement in Two Dimensions

    Science.gov (United States)

    Holz, Claudia; Opitz, Dirk; Greune, Lilo; Kurre, Rainer; Koomey, Michael; Schmidt, M. Alexander; Maier, Berenike

    2010-04-01

    In various bacterial species surface motility is mediated by cycles of type IV pilus motor elongation, adhesion, and retraction, but it is unclear whether bacterial movement follows a random walk. Here we show that the correlation time of persistent movement in Neisseria gonorrhoeae increases with the number of pili. The unbinding force of individual pili from the surface F=10pN was considerably lower than the stalling force F>100pN, suggesting that density, force, and adhesive properties of the pilus motor enable a tug-of-war mechanism for bacterial movement.

  20. On the Equilibria of the Extended Nematic Polymers under Elongational Flow

    Directory of Open Access Journals (Sweden)

    Hong Zhou

    2007-01-01

    Full Text Available We classify the equilibrium solutions of the Smoluchowski equation for dipolar (extended rigid nematic polymers under imposed elongational flow. The Smoluchowski equation couples the Maier-Saupe short-range interaction, dipole-dipole interaction, and an external elongational flow. We show that all stable equilibria of rigid, dipolar rod dispersions under imposed uniaxial elongational flow field are axisymmetric. This finding of axisymmetry significantly simplifies any procedure of obtaining experimentally observable equilibria.

  1. Effect of benzyladenine (BA on auxin-induced stem elongation and thickening in tulip (Tulipa gesneriana L.

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2016-03-01

    Full Text Available It is well known that stem elongation in tulip is induced by the auxin produced in the leaves and gynoecium. Excision of the flower bud and all the leaves in an early stage of tulip growth resulted in almost total inhibition of stem growth, but the inhibition was completely recovered by the exogenous application of auxin to the place from which the flower bud had been removed. Hormonal control of stem thickening in tulip is much less known. Additional application of benzyladenine (BA to the tulip stem by soaking a cotton wick wrapped around all the internodes only slightly inhibited stem growth induced by IAA at a concentration of 0.1 and 2.0%, but substantially stimulated the thickening of all the internodes. The treatment of the tulip stem with benzyladenine enabled direct contact of the cytokinin with the epidermis, which is an important factor in stem elongation. The experiment conducted in field conditions also showed that BA only slightly inhibited the elongation of the fourth internode induced by IAA, but stimulated the thickening of that internode. IAA applied at a concentration of 2.0% stimulated ethylene production to a much higher extent than IAA at a concentration of 0.1%, and BA affected the auxin-induced ethylene production only to a small extent. Metabolic significance of these findings is discussed.

  2. The IKAROS Interaction with a Complex Including Chromatin Remodeling and Transcription Elongation Activities Is Required for Hematopoiesis

    Science.gov (United States)

    Bottardi, Stefania; Mavoungou, Lionel; Pak, Helen; Daou, Salima; Bourgoin, Vincent; Lakehal, Yahia A.; Affar, El Bachir; Milot, Eric

    2014-01-01

    IKAROS is a critical regulator of hematopoietic cell fate and its dynamic expression pattern is required for proper hematopoiesis. In collaboration with the Nucleosome Remodeling and Deacetylase (NuRD) complex, it promotes gene repression and activation. It remains to be clarified how IKAROS can support transcription activation while being associated with the HDAC-containing complex NuRD. IKAROS also binds to the Positive-Transcription Elongation Factor b (P-TEFb) at gene promoters. Here, we demonstrate that NuRD and P-TEFb are assembled in a complex that can be recruited to specific genes by IKAROS. The expression level of IKAROS influences the recruitment of the NuRD-P-TEFb complex to gene regulatory regions and facilitates transcription elongation by transferring the Protein Phosphatase 1α (PP1α), an IKAROS-binding protein and P-TEFb activator, to CDK9. We show that an IKAROS mutant that is unable to bind PP1α cannot sustain gene expression and impedes normal differentiation of IkNULL hematopoietic progenitors. Finally, the knock-down of the NuRD subunit Mi2 reveals that the occupancy of the NuRD complex at transcribed regions of genes favors the relief of POL II promoter-proximal pausing and thereby, promotes transcription elongation. PMID:25474253

  3. Attenuation of the bacterial load in blood by pretreatment with granulocyte-colony-stimulating factor protects rats from fatal outcome and brain damage during Streptococcus pneumoniae meningitis

    DEFF Research Database (Denmark)

    Brandt, Christian T; Lundgren, Jens D; Lund, Søren Peter;

    2004-01-01

    postinfection did not alter the clinical or histological outcome relative to that for non-G-CSF-treated rats. The magnitude of bacteremia and pretreatment with G-CSF were found to be prognostic factors for both outcome and brain damage. In summary, elevated neutrophil levels prior to the development of...... meningitis result in reduced risks of death and brain damage. This beneficial effect is most likely achieved through improved control of the systemic disease....

  4. A transplant experiment to identify the factors controlling bacterial abundance, activity, production and community composition in a eutrophic canyon-shaped reservoir

    Czech Academy of Sciences Publication Activity Database

    Gasol, J. M. .; Comerma, M.; García, J. C.; Armengol, J.; Casamayor, E. O.; Kojecká, Petra; Šimek, Karel

    2002-01-01

    Roč. 47, č. 1 (2002), s. 62-77. ISSN 0024-3590 R&D Projects: GA ČR GA206/99/0028 Grant ostatní: CICYT(ES) HID99-599-CO2-01; EC(XE) MIDAS MAS3-CT97-0154 Keywords : natural planktonic bacteria * bacterioplankton diversity * assemblages Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.169, year: 2002

  5. Anisotropic rigidity sensing on grating topography directs human mesenchymal stem cell elongation.

    Science.gov (United States)

    Wong, Sum Thai; Teo, Soo-Kng; Park, Sungsu; Chiam, Keng-Hwee; Yim, Evelyn K F

    2014-01-01

    Through mechanotransduction, cells can sense physical cues from the extracellular environment and convert them into internal signals that affect various cellular functions. For example, human mesenchymal stem cells (hMSCs) cultured on topographical gratings have been shown to elongate and differentiate to different extents depending on grating width. Using a combination of experiments and mathematical modeling, the physical parameters of substrate topography that direct cell elongation were determined. On a variety of topographical gratings with different grating widths, heights and rigidity, elongation of hMSCs was measured and a monotonic increase was observed for grating aspect ratio (crosssectional height to line-width ratio) between 0.035 and 2. The elongation was also dependent on the grating substrate rigidity over a range of 0.18-1.43 MPa. A mathematical model was developed to explain our observations by relating cell elongation to the anisotropic deformation of the gratings and how this anisotropy depends on the aspect ratio and rigidity of the gratings. Our model was in good agreement with the experimental data for the range of grating aspect ratio and substrate rigidity studied. In addition, we also showed that the percentage of aligned cells, which had a strong linear correlation with elongation for slightly elongated cells, saturated toward 100 % at higher level of cell elongation. Our results may be useful in designing gratings to elicit specific cellular responses that may depend on the extent of cell elongation. PMID:23529613

  6. Fatores associados à bacteriúria após sondagem vesical na cirurgia ginecológica Factors associated with bacteriuria after indwelling urethral catheterization in gynecologic surgery

    Directory of Open Access Journals (Sweden)

    Sonia Cristina Araújo Hinrichsen

    2009-01-01

    Full Text Available OBJETIVOS: Determinar a frequência e os principais fatores associados à bacteriúria após a sondagem vesical em mulheres submetidas à cirurgia ginecológica eletiva. MÉTODOS: Realizou-se um estudo do tipo coorte em mulheres submetidas à cirurgia ginecológica após sondagem vesical no Instituto de Medicina Integral Prof. Fernando Figueira, no período de janeiro a maio de 2007. As uroculturas foram coletadas até 24 horas após a retirada da sonda e 7/10 dias após a sondagem vesical. A análise estatística bivariada e multivariada foi realizada calculando-se a razão de risco e os seus intervalos de confiança a 95%. RESULTADOS: Foram incluídas no estudo 249 mulheres. A frequência de uroculturas positivas até 24 horas depois da retirada da sonda foi de 23,6%, diminuindo para 11,1% 7/10 dias após a sondagem. Destas, apenas 2,4% eram sintomáticas. Verificou-se menor risco de bacteriúria com 7/10 dias após a sondagem vesical quando a paciente referiu vulvovaginite tratada nos últimos três meses, não permanecendo estatisticamente significativa após a análise multivariada. Não houve associação significativa com idade, escolaridade, número de gestações, paridade, fase da vida reprodutiva, tipo e duração da cirurgia, tipo da anestesia, uso de antibiótico profilático, profissional que colocou a sonda e o tempo de permanência da sonda vesical. CONCLUSÃO: A frequência de bacteriúria foi de 23,6% e 11,1% com 24 horas e 7/10 dias, respectivamente. Não se encontrou associação significativa das variáveis pesquisadas com a bacteriúria evidenciada na urocultura com 7/10 dias.OBJECTIVES: To determine the frequency and risk factors associated to bacteriuria after urinary catheterization in women submitted to elective gynecological surgery. METHODS: A cohort study was carried out among women submitted to gynecological surgery after urinary catheterization. This study took place at the "Instituto de Medicina Integral Professor

  7. Bacterial strategies to overcome insect defences.

    OpenAIRE

    Vallet-Gely, Isabelle; Lemaitre, Bruno; Boccard, Frédéric

    2008-01-01

    Recent genetic and molecular analyses have revealed how several strategies enable bacteria to persist and overcome insect immune defences. Genetic and genomic tools that can be used with Drosophila melanogaster have enabled the characterization of the pathways that are used by insects to detect bacterial invaders and combat infection. Conservation of bacterial virulence factors and insect immune repertoires indicates that there are common strategies of host invasion and pathogen eradication. ...

  8. Effect of the dilution factor on 18FDG and Na18F samples for bacterial endotoxin test using PTS (portable test system)

    International Nuclear Information System (INIS)

    18FDG and Na18F are radiopharmaceuticals produced as sterile solutions suitable for intravenous administration, which must contain no more than 175 EV/V. The most commonly used approach to detect endotoxins is the gelclot technique that requires 60 minutes for results. For radiopharmaceuticals containing short-life radionuclides, such as 18F, there is an increasing interest for faster quality control methods. FDA licensed the Endosafe, PTS, a kinetic chromogenic endotoxin detection system that takes about 15 minutes for results. As other techniques, PTS test is susceptible to interferences which can be solved by product dilution. The aim of this study was to establish the best dilution of 18FDG and Na18F for PTS analysis. Two different dilution factors for 18FDG and 1:10 for Na18F were essayed: 1:10 and 1:100. 18FDG and Na18 solutions were prepared by the addition of LAL reagent water. Considering the assay acceptance criteria, the best dilution factor was 1:100 for 18FDG and 1:10 for Na18F. The recovery of the product positive control was 98-12% for 18FDG 1:100 and 104-120% for Na18F 1:10, which were, in both cases, within the specification (50-200%) and very close to 100%. Results obtained with these dilution studies were important to establish the most appropriate and non-interfering dilution factor for 18FDG and Na18F routine endotoxin test. (author)

  9. Effect of the dilution factor on {sup 18}FDG and Na{sup 18}F samples for bacterial endotoxin test using PTS (portable test system)

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Marina B.; Costa, Flavia M.; Ferreira, Soraya Z., E-mail: mbs@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

    2011-07-01

    {sup 18}FDG and Na{sup 18}F are radiopharmaceuticals produced as sterile solutions suitable for intravenous administration, which must contain no more than 175 EV/V. The most commonly used approach to detect endotoxins is the gelclot technique that requires 60 minutes for results. For radiopharmaceuticals containing short-life radionuclides, such as {sup 18}F, there is an increasing interest for faster quality control methods. FDA licensed the Endosafe, PTS, a kinetic chromogenic endotoxin detection system that takes about 15 minutes for results. As other techniques, PTS test is susceptible to interferences which can be solved by product dilution. The aim of this study was to establish the best dilution of {sup 18}FDG and Na{sup 18}F for PTS analysis. Two different dilution factors for {sup 18}FDG and 1:10 for Na{sup 18}F were essayed: 1:10 and 1:100. {sup 18}FDG and Na{sup 18} solutions were prepared by the addition of LAL reagent water. Considering the assay acceptance criteria, the best dilution factor was 1:100 for {sup 18}FDG and 1:10 for Na{sup 18}F. The recovery of the product positive control was 98-12% for {sup 18}FDG 1:100 and 104-120% for Na{sup 18}F 1:10, which were, in both cases, within the specification (50-200%) and very close to 100%. Results obtained with these dilution studies were important to establish the most appropriate and non-interfering dilution factor for {sup 18}FDG and Na{sup 18}F routine endotoxin test. (author)

  10. A case of arterial switch operation with coronary elongation technique.

    Science.gov (United States)

    Matsuba, Tomoyuki; Shigehisa, Yoshiya; Imagama, Itsumi; Imoto, Yutaka

    2016-12-01

    A 28-day-old infant with D-transposition of the great arteries underwent arterial switch operation. The coronary pattern was Yacoub type A, in which coronary transfer is usually thought to be easy. However, a dominant conus branch diverged from the proximal portion of the left coronary artery (LCA). Moreover, the LCA ostium itself was near the remote commissure in sinus 1, very far from the target re-implantation point. All of these conditions made LCA transfer very difficult. We used a coronary elongation technique to solve this problem. An inverted U-shaped flap was made in the wall of the neoaorta, and the LCA cuff was anastomosed to this flap (the inferior half from the neoaortic flap and the superior half from the LCA cuff). To prevent compression of the LCA, the neopulmonary trunk was shifted rightward. Postoperative echocardiography showed good left ventricular wall motion, and the LCA was easily visualized on chest computed tomography, with no compression from the neopulmonary artery. PMID:26943683

  11. Cooling dynamics of a granular gas of elongated particles

    International Nuclear Information System (INIS)

    The cooling dynamics of a 2D granular gas of elongated particles is analyzed. We perform simulations on the temporal evolution of soft particles, using a molecular dynamics algorithm. For weakly dissipative particles, we found a homogeneous cooling process where the overall translational kinetic energy decreases analogously to viscoelastic circular particles. In contrast, for strongly dissipative particles we observed an inhomogeneous cooling process where the diminishing of translational kinetic energy notably slows down. The rotational kinetic energy, however, always decays in agreement with Haff's prediction for the homogeneous cooling state of inelastic particles. We mainly found that the cooling kinetics of the system is controlled by the mechanisms that determine the local energy dissipation (collisions). However, we detected a strong influence of particle shape and inelasticity on the structure of the clusters which develop in the inhomogeneous cooling regimes. Our numerical outcomes suggest that strong dissipation and particle anisotropy induce the formation of ordered cluster structures that retards the relaxation to the final asymptotic regime

  12. Experiment design of the terrestrial laser scanning of elongated objects

    Directory of Open Access Journals (Sweden)

    Marko PEJIĆ

    2014-03-01

    Full Text Available In high-demanding engineering applications, the latest performance improvements of the terrestrial lasers scanning (TLS system and price decreasing trend shows the significant potential of this technology. Beside the fact that some scanners have the scanning frequency of over 1.000.000 Hz, in the engineering applications the accuracy of this survey method plays the key role. Achievement of the satisfactory accuracy of the object modelling using TLS has to be done by experiment designing. This implies the optimization process of the relevant measurements parameters and of the methodology of measurement processing through analysis of the different sources of measurement errors, instrumental precision and performance of the specific TLS, spatial configuration of the object and analysis of the models of registration and georeferencing errors. The proposed methodology of the TLS experiment design is related to the scanning of elongated objects (tunnels, corridors, pipelines, underground passages etc, which generally represent unfavourable cases in providing geodetic measurements of sufficient accuracy and reliability.

  13. Chain elongation analog of resveratrol as potent cancer chemoprevention agent.

    Science.gov (United States)

    Kang, Yan-Fei; Qiao, Hai-Xia; Xin, Long-Zuo; Ge, Li-Ping

    2016-09-01

    Resveratrol is identified as a natural cancer chemoprevention agent. There has been a lot of interest in designing and developing resveratrol analogs with cancer chemoprevention activity superior to that of parent molecule and exploring their action mechanism in the past several decades. In this study, we have synthesized resveratrol analogs of compounds A-C via conjugated chain elongation based on isoprene unit retention strategy. Remarkably, cytotoxic activity analysis results indicated that compound B possesses the best proliferation inhibition activity for NCI-H460 cells in all the test compounds. Intriguingly, compound B displayed a higher cytotoxicity against human non-small cell lung cancer cells (NCI-H460) compared to normal human embryonic lung fibroblasts (MRC-5). Afterward, flow cytometry analysis showed that compound B would induce cell apoptosis. We further researched the action mechanism. When NCI-H460 cells were incubated by compound B for 6 or 9 h, respectively, the intracellular reactive oxygen species (ROS) level was enhanced obviously. With elevation of intracellular ROS level, flow cytometry measurement verified mitochondrial transmembrane potential collapse, which was accompanied by the up-regulation of Bax and down-regulation of Bcl-2. More interestingly, compound B increased the expression of caspase-9 and caspase-3, which induced cell apoptosis. Moreover, compound B arrested cell cycle in G0/G1 phase. These are all to provide useful information for designing resveratrol-based chemoprevention agent and understanding the action mechanism. PMID:27160168

  14. 2008 OG$_{19}$: A highly elongated Trans-Neptunian Object

    CERN Document Server

    Fernández-Valenzuela, Estela; Duffard, René; Santos-Sanz, Pablo; Morales, Nicolás

    2015-01-01

    From two observing runs during the 2014 summer at Calar Alto Observatory in Almer\\'ia (Spain) and at Sierra Nevada Observatory in Granada (Spain), we were able to derive CCD photometry of the Trans-Neptunian Object 2008 OG$_{19}$. We analyzed the time series and obtained a double-peaked light curve with a peak to valley amplitude of (0.437 $\\pm$ 0.011) mag and a rotational period of (8.727$\\pm$ 0.003) h. This implies that this object is very elongated, closely resembling Varuna's case. The photometry also allowed us to obtain an absolute magnitude in R-band of (4.39 $\\pm$ 0.07) mag. From this result we estimated an equivalent diameter of 2008 OG$_{19}$ which is 619$^{+56}_{-113}$ km using an average albedo for Scattered Disk Objects. Finally we interpreted the results under the assumption of hydrostatic equilibrium and found a lower limit for the density of 544$^{+42}_{-4}$ kg$\\,$m$^{-3}$. However, a more likely density is (609 $\\pm$ 4) kg$\\,$m$^{-3}$ using an aspect angle of 60$^\\circ$, which corresponds to ...

  15. Cytotoxic factor secreted by Escherichia coli associated with sepsis facilitates transcytosis through human umbilical vein endothelial cell monolayers.

    Science.gov (United States)

    Tibo, Luiz Henrique Soares; Bertol, Jéssica Wildgrube; Bernedo-Navarro, Robert Alvin; Yano, Tomomasa

    2016-01-01

    Culture supernatant of sepsis-associated Escherichia coli (SEPEC) isolated from patients with sepsis caused loss of intercellular junctions and elongation of human umbilical vein endothelial cells (HUVEC). The cytotoxic factor was purified from culture supernatant of SEPEC 15 (serogroup O153) by liquid chromatography process. PAGE (polyacrylamide gel electrophoresis) showed that the purified SEPEC cytotoxic factor had a molecular mass of ∼150kDa and consisted of at least two subunits. At the concentration of 1 CD50 (40μg/mL) did facilitate transcytosis through the HUVEC cells monolayer of SEPEC 15 as much as E. coli K12 within 30min without affecting cell viability. These results suggest that this cytotoxic factor, named as SPF (SEPEC's permeabilizing factor), may be an important SEPEC virulence factor that facilitates bacterial access to the bloodstream. PMID:26963151

  16. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    -vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial......Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...

  17. Drosophila Kismet regulates histone H3 lysine 27 methylation and early elongation by RNA polymerase II.

    Directory of Open Access Journals (Sweden)

    Shrividhya Srinivasan

    2008-10-01

    Full Text Available Polycomb and trithorax group proteins regulate cellular pluripotency and differentiation by maintaining hereditable states of transcription. Many Polycomb and trithorax group proteins have been implicated in the covalent modification or remodeling of chromatin, but how they interact with each other and the general transcription machinery to regulate transcription is not well understood. The trithorax group protein Kismet-L (KIS-L is a member of the CHD subfamily of chromatin-remodeling factors that plays a global role in transcription by RNA polymerase II (Pol II. Mutations in CHD7, the human counterpart of kis, are associated with CHARGE syndrome, a developmental disorder affecting multiple tissues and organs. To clarify how KIS-L activates gene expression and counteracts Polycomb group silencing, we characterized defects resulting from the loss of KIS-L function in Drosophila. These studies revealed that KIS-L acts downstream of P-TEFb recruitment to stimulate elongation by Pol II. The presence of two chromodomains in KIS-L suggested that its recruitment or function might be regulated by the methylation of histone H3 lysine 4 by the trithorax group proteins ASH1 and TRX. Although we observed significant overlap between the distributions of KIS-L, ASH1, and TRX on polytene chromosomes, KIS-L did not bind methylated histone tails in vitro, and loss of TRX or ASH1 function did not alter the association of KIS-L with chromatin. By contrast, loss of kis function led to a dramatic reduction in the levels of TRX and ASH1 associated with chromatin and was accompanied by increased histone H3 lysine 27 methylation-a modification required for Polycomb group repression. A similar increase in H3 lysine 27 methylation was observed in ash1 and trx mutant larvae. Our findings suggest that KIS-L promotes early elongation and counteracts Polycomb group repression by recruiting the ASH1 and TRX histone methyltransferases to chromatin.

  18. Elongation, proliferation & migration differentiate endothelial cell phenotypes and determine capillary sprouting

    Directory of Open Access Journals (Sweden)

    Popel Aleksander S

    2009-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of capillaries from preexisting blood vessels, has been extensively studied experimentally over the past thirty years. Molecular insights from these studies have lead to therapies for cancer, macular degeneration and ischemia. In parallel, mathematical models of angiogenesis have helped characterize a broader view of capillary network formation and have suggested new directions for experimental pursuit. We developed a computational model that bridges the gap between these two perspectives, and addresses a remaining question in angiogenic sprouting: how do the processes of endothelial cell elongation, migration and proliferation contribute to vessel formation? Results We present a multiscale systems model that closely simulates the mechanisms underlying sprouting at the onset of angiogenesis. Designed by agent-based programming, the model uses logical rules to guide the behavior of individual endothelial cells and segments of cells. The activation, proliferation, and movement of these cells lead to capillary growth in three dimensions. By this means, a novel capillary network emerges out of combinatorially complex interactions of single cells. Rules and parameter ranges are based on literature data on endothelial cell behavior in vitro. The model is designed generally, and will subsequently be applied to represent species-specific, tissue-specific in vitro and in vivo conditions. Initial results predict tip cell activation, stalk cell development and sprout formation as a function of local vascular endothelial growth factor concentrations and the Delta-like 4 Notch ligand, as it might occur in a three-dimensional in vitro setting. Results demonstrate the differential effects of ligand concentrations, cell movement and proliferation on sprouting and directional persistence. Conclusion This systems biology model offers a paradigm closely related to biological phenomena and highlights previously

  19. Mapping Sites of O-Glycosylation and Fringe Elongation on Drosophila Notch.

    Science.gov (United States)

    Harvey, Beth M; Rana, Nadia A; Moss, Hillary; Leonardi, Jessica; Jafar-Nejad, Hamed; Haltiwanger, Robert S

    2016-07-29

    Glycosylation of the Notch receptor is essential for its activity and serves as an important modulator of signaling. Three major forms of O-glycosylation are predicted to occur at consensus sites within the epidermal growth factor-like repeats in the extracellular domain of the receptor: O-fucosylation, O-glucosylation, and O-GlcNAcylation. We have performed comprehensive mass spectral analyses of these three types of O-glycosylation on Drosophila Notch produced in S2 cells and identified peptides containing all 22 predicted O-fucose sites, all 18 predicted O-glucose sites, and all 18 putative O-GlcNAc sites. Using semiquantitative mass spectral methods, we have evaluated the occupancy and relative amounts of glycans at each site. The majority of the O-fucose sites were modified to high stoichiometries. Upon expression of the β3-N-acetylglucosaminyltransferase Fringe with Notch, we observed varying degrees of elongation beyond O-fucose monosaccharide, indicating that Fringe preferentially modifies certain sites more than others. Rumi modified O-glucose sites to high stoichiometries, although elongation of the O-glucose was site-specific. Although the current putative consensus sequence for O-GlcNAcylation predicts 18 O-GlcNAc sites on Notch, we only observed apparent O-GlcNAc modification at five sites. In addition, we performed mass spectral analysis on endogenous Notch purified from Drosophila embryos and found that the glycosylation states were similar to those found on Notch from S2 cells. These data provide foundational information for future studies investigating the mechanisms of how O-glycosylation regulates Notch activity. PMID:27268051

  20. A Function for the hnRNP A1/A2 Proteins in Transcription Elongation.

    Directory of Open Access Journals (Sweden)

    Bruno Lemieux

    Full Text Available The hnRNP A1 and A2 proteins regulate processes such as alternative pre-mRNA splicing and mRNA stability. Here, we report that a reduction in the levels of hnRNP A1 and A2 by RNA interference or their cytoplasmic retention by osmotic stress drastically increases the transcription of a reporter gene. Based on previous work, we propose that this effect may be linked to a decrease in the activity of the transcription elongation factor P-TEFb. Consistent with this hypothesis, the transcription of the reporter gene was stimulated when the catalytic component of P-TEFb, CDK9, was inhibited with DRB. While low levels of A1/A2 stimulated the association of RNA polymerase II with the reporter gene, they also increased the association of CDK9 with the repressor 7SK RNA, and compromised the recovery of promoter-distal transcription on the Kitlg gene after the release of pausing. Transcriptome analysis revealed that more than 50% of the genes whose expression was affected by the siRNA-mediated depletion of A1/A2 were also affected by DRB. RNA polymerase II-chromatin immunoprecipitation assays on DRB-treated and A1/A2-depleted cells identified a common set of repressed genes displaying increased occupancy of polymerases at promoter-proximal locations, consistent with pausing. Overall, our results suggest that lowering the levels of hnRNP A1/A2 elicits defective transcription elongation on a fraction of P-TEFb-dependent genes, hence favoring the transcription of P-TEFb-independent genes.

  1. Demonstrating Bacterial Flagella.

    Science.gov (United States)

    Porter, John R.; And Others

    1992-01-01

    Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

  2. Amebic liver abscess with bacterial superinfection in a patient with no epidemiologic risk factors Absceso hepático amebiano sobreinfectado sin antecedentes epidemiológicos

    Directory of Open Access Journals (Sweden)

    P. Sánchez-Pobre

    2004-11-01

    Full Text Available The amebic liver abscess is uncommon in developed countries like Spain, but the incidence is increasing probably due to the migratory movements of the population. We report a case of an amebic abscess, initially unsuspected due to the absence of epidemiologic risk factors and the negative serology for amebiasis, in the early stages of the disease.El absceso hepático amebiano es infrecuente en países desarrollados, como lo es el caso de España, pero su incidencia está aumentando, posiblemente en relación con los movimientos migratorios de la población. Presentamos un caso de absceso hepático amebiano, no sospechado inicialmente, debido a la ausencia de antecedentes epidemiológicos y a la negatividad de las pruebas serológicas en las fases iniciales de enfermedad.

  3. Dynamic properties of bacterial pili measured by optical tweezers

    CERN Document Server

    Fallman, Erik; Schedin, Staffan; Jass, Jana; Uhlin, Bernt Eric; Axner, Ove

    2014-01-01

    The ability of uropathogenic Escherichia coli (UPEC) to cause urinary tract infections is dependent on their ability to colonize the uroepithelium. Infecting bacteria ascend the urethra to the bladder and then kidneys by attaching to the uroepithelial cells via the differential expression of adhesins. P pili are associated with pyelonephritis, the more severe infection of the kidneys. In order to find means to treat pyelonephritis, it is therefore of interest to investigate the properties P pili. The mechanical behavior of individual P pili of uropathogenic Escherichia coli has recently been investigated using optical tweezers. P pili, whose main part constitutes the PapA rod, composed of ~1000 PapA subunits in a helical arrangement, are distributed over the bacterial surface and mediate adhesion to host cells. We have earlier studied P pili regarding its stretching/elongation properties where we have found and characterized three different elongation regions, of which one constitute an unfolding of the quate...

  4. The influence of elongation exercises on the anterior-posterior spine curvatures

    Directory of Open Access Journals (Sweden)

    Drzał-Grabiec Justyna

    2014-01-01

    Full Text Available Introduction: Elongation exercises are designed to reduce existing pathological or increased physiological curvatures of the spine. The aim of the study was to evaluate the changes occurring in the parameters describing the anterior-posterior spinal curvatures during the performance of symmetric elongation exercises.

  5. Experimental results on elongation control using dynamic input allocation at FTU

    International Nuclear Information System (INIS)

    We report on the experimental results related to a recently proposed control scheme for the regulation of plasma elongation using the poloidal field coils available at FTU, already used for the horizontal position control. The proposed technique allows to realize elongation regulation as a secondary task using the same poloidal coils.

  6. Increase in Bacterial Colony Formation from a Permafrost Ice Wedge Dosed with a Tomitella biformata Recombinant Resuscitation-Promoting Factor Protein.

    Science.gov (United States)

    Puspita, Indun Dewi; Kitagawa, Wataru; Kamagata, Yoichi; Tanaka, Michiko; Nakatsu, Cindy H

    2015-01-01

    Resuscitation-promoting factor (Rpf) is a protein that has been found in a number of different Actinobacteria species and has been shown to promote the growth of active cells and resuscitate dormant (non-dividing) cells. We previously reported the biological activity of an Rpf protein in Tomitella biformata AHU 1821(T), an Actinobacteria isolated from a permafrost ice wedge. This protein is excreted outside the cell; however, few studies have investigated its contribution in environmental samples to the growth or resuscitation of bacteria other than the original host. Therefore, the aim of the present study was to determine whether Rpf from T. biformata impacted the cultivation of other bacteria from the permafrost ice wedge from which it was originally isolated. All experiments used recombinant Rpf proteins produced using a Rhodococcus erythropolis expression system. Dilutions of melted surface sterilized ice wedge samples mixed with different doses of the purified recombinant Rpf (rRpf) protein indicated that the highest concentration tested, 1250 pM, had a significantly (p Brevibacterium antiquum strain VKM Ac-2118 (AY243344), with 98-99% sequence identity. This species is also a member of the phylum Actinobacteria and was originally isolated from Siberian permafrost sediments. The results of the present study demonstrated that rRpf not only promoted the growth of T. biformata from which it was isolated, but also enhanced colony formation by another Actinobacteria in an environmental sample. PMID:25843055

  7. Germination and root elongation bioassays in six different plant species for testing Ni contamination in soil.

    Science.gov (United States)

    Visioli, Giovanna; Conti, Federica D; Gardi, Ciro; Menta, Cristina

    2014-04-01

    In vitro short-term chronic phytotoxicity germination and root elongation test were applied to test the effects of nickel (Ni) in seed germination and root elongation in six plants species: Cucumis sativus (Cucurbitaceae), Lepidium sativum and Brassica nigra (Brassicaceae), Trifolium alexandrinum and Medicago sativa (Fabaceae), Phacelia tanacetifolia (Boraginaceae). A naturally Ni rich soil was used to compare the results obtained. Unlike root elongation, germination was not affected by Ni in any of the six species tested. EC50 values, calculated on the root elongation, showed that Ni toxicity decreases in the following order: P. tanacetifolia > B. nigra > C. sativus > L. sativum > M. sativa > T. alexandrinum. The test conducted using soil elutriate revealed a significantly lower effect in both seed germination and root elongation when compared to the results obtained using untreated soil. Conversely, the test performed on soil confirmed the high sensitivity of C. sativus, P. tanacetifolia and L. sativum to Ni. PMID:24288040

  8. Shuffling bacterial metabolomes

    OpenAIRE

    Thomason, Brendan; Read, Timothy D.

    2006-01-01

    Horizontal gene transfer (HGT) has a far more significant role than gene duplication in bacterial evolution. This has recently been illustrated by work demonstrating the importance of HGT in the emergence of bacterial metabolic networks, with horizontally acquired genes being placed in peripheral pathways at the outer branches of the networks.

  9. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  10. Molecular dynamics study on effect of elongational flow on morphology of immiscible mixtures

    Science.gov (United States)

    Tran, Chau; Kalra, Vibha

    2014-04-01

    We studied the effect of elongational flow on structure and kinetics of phase separation in immiscible blends using molecular dynamics simulations. Two different blend systems have been investigated—binary blend of polymers and binary mixture of molecular fluids. The interaction potential parameters in both material systems were chosen to ensure complete phase-separation in equilibrium. We found that elongational flow, beyond a certain rate, significantly alters the steady state morphology in such immiscible mixtures. For the case of polymer blends, perpendicular lamellar morphology was formed under elongation rates (dot \\varepsilon) from 0.05 to 0.5 MD units possibly due to the interplay of two opposing phenomena—domain deformation/rupture under elongation and aggregation of like-domains due to favorable energetic interactions. The elongation timescale at the critical rate of transition from phase-separated to the lamellar structure (dot \\varepsilon = 0.05) was found to be comparable to the estimated polymer relaxation time, suggesting a cross-over to the elongation/rupture-dominant regime. Under strong elongational flow rate, dot \\varepsilon > 0.5, the formation of disordered morphology was seen in polymer blend systems. The kinetics of phase separation was monitored by calculating domain size as a function of time for various elongational flow rates. The domain growth along the vorticity-axis was shown to follow a power law, Rz(t) ˜ t α. A growth exponent, α of 1/3 for the polymer blend and 0.5-0.6 for the fluid molecular mixture was found under elongation rates from 0.005 to 0.1. The higher growth exponent in the fluid mixture is a result of its faster diffusion time scale compared to that of polymer chains. The steady state end-to-end distance of polymer chains and viscosity of the polymer blend were examined and found to depend on the steady state morphology and elongation rate.

  11. Analysis of bacterial vaginosis and vulvovaginal candidiasis infection in women and its related factors%细菌性阴道病及假丝酵母菌病的感染情况及相关因素分析

    Institute of Scientific and Technical Information of China (English)

    李素萍; 袁超燕; 陈兰; 武玉莲

    2014-01-01

    Objective To investigate bacterial vaginosis (BV)and vulvovaginal candidiasis (VVC)in women and to analyze its related factors.Methods The conditions of Physical examina-tion of 1967 female patients in the region from 2011 to 2013 were analyzed,and questionnaire was used to explore the relevant factors that affect the occurrence of BV and VVC.Results There were 282 patients with vulvovaginal yeast disease with the detection rate of 14.34%(282 /1967);231 patients were detected with bacterial vaginosis with 11.74% of detection rate (231 /1967);The higher detection rate of vulvovaginal candidiasis occurred among 25 to 35 year old and there was no significant difference in the occurrence of BV (P >0.05);Logistic analysis revealed that abortion was the risk factors that affect the treatment of VVC and BV;The man cooperated with the treatment and used condoms as protective factor as the safe factor.Conclusion VVC and BV are associated with vaginal microflora imbalance,so the patients should pay attention to healthy hy-giene habits as well as focus on treatment of the partners to block cross-infection and ensure good treatment effect.%目的:了解本地区女性细菌性阴道病(BV)及外阴阴道假丝酵母菌病(VVC)的发病情况及影响疾病的相关因素。方法回顾性分析2011-2013年本院1967例女性体检情况,并进行统计分析,采用问卷调查方式分析影响 BV、VVC 发病的相关因素。结果1967例体检检出282例女性 VVC,检出率14.34%(282/1967);检出231例 BV,检出率11.74%(231/1967);VVC 以25~35岁性活跃期年龄段检出率较高,BV 发病率各年龄层差异无统计学意义(P >0.05);VVC 及 BV 治疗效果及疗效影响因素经 Logistic 分析,流产为影响治疗效果的危险因素;男方配合治疗及使用避孕套为康复效果的保护性因素。结论 VVC 与 BV 均与阴道微生态失衡相关,治疗中应注意指导患者养成健康的卫

  12. Proteomics in the Study of Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Rachida Bouhenni

    2015-12-01

    Full Text Available Bacterial keratitis is a serious ocular infection that can cause severe visual loss if treatment is not initiated at an early stage. It is most commonly caused by Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae, or Serratia species. Depending on the invading organism, bacterial keratitis can progress rapidly, leading to corneal destruction and potential blindness. Common risk factors for bacterial keratitis include contact lens wear, ocular trauma, ocular surface disease, ocular surgery, lid deformity, chronic use of topical steroids, contaminated ocular medications or solutions, and systemic immunosuppression. The pathogenesis of bacterial keratitis, which depends on the bacterium-host interaction and the virulence of the invading bacterium, is complicated and not completely understood. This review highlights some of the proteomic technologies that have been used to identify virulence factors and the host response to infections of bacterial keratitis in order to understand the disease process and develop improved methods of diagnosis and treatment. Although work in this field is not abundant, proteomic technologies have provided valuable information toward our current knowledge of bacterial keratitis. More studies using global proteomic approaches are warranted because it is an important tool to identify novel targets for intervention and prevention of corneal damage caused by these virulent microorganisms.

  13. Detailed kinetic performance analysis of micromachined radially elongated pillar array columns for liquid chromatography.

    Science.gov (United States)

    Callewaert, Manly; Desmet, Gert; Ottevaere, Heidi; De Malsche, Wim

    2016-02-12

    The individual factors that determine the kinetic performance (B- and C-term band broadening and bed permeability Kv) of radially elongated pillar (REP) columns are studied. To this end, columns with REPs having 4 different aspect ratios (AR=9, 12, 15, 20) were characterized experimentally and by means of numerical simulations. A tortuosity and retention based plate height equation was established, enabling a good global fit for all studied conditions. The B-term plate height contribution appears to decrease with a factor equaling the square of the flow path tortuosity τ. Going from AR=12 to AR=20 (τ=5.7 and τ=9.0 respectively), this resulted in a shift in plate height expressed in axial coordinates from Hmin=0.42 μm to Hmin=0.25 for non-retained conditions and from H=0.77 μm to H=0.57 μm for a component with k=1.0. The obtained parameters were combined to predict optimal time-efficiency combinations for all possible channel lengths. This revealed an efficiency limit of N=10(7) plates for a non-retained component and N=7-8 × 10(6) for k=1 for a channel with an AR=20, corresponding to a channel length of 2.5m and a void time of 2.4h. PMID:26795281

  14. Estimation of the lag time in a subsequent monomer addition model for fibril elongation.

    Science.gov (United States)

    Shoffner, Suzanne K; Schnell, Santiago

    2016-08-01

    Fibrillogenesis, the production or development of protein fibers, has been linked to protein folding diseases. The progress curve of fibrils or aggregates typically takes on a sigmoidal shape with a lag phase, a rapid growth phase, and a final plateau regime. The study of the lag phase and the estimation of its critical timescale provide insight into the factors regulating the fibrillation process. However, methods to estimate a quantitative expression for the lag time rely on empirical expressions, which cannot connect the lag time to kinetic parameters associated with the reaction mechanisms of protein fibrillation. Here we introduce an approach for the estimation of the lag time using the governing rate equations of the elementary reactions of a subsequent monomer addition model for protein fibrillation as a case study. We show that the lag time is given by the sum of the critical timescales for each fibril intermediate in the subsequent monomer addition mechanism and therefore reveals causal connectivity between intermediate species. Furthermore, we find that single-molecule assays of protein fibrillation can exhibit a lag phase without a nucleation process, while dyes and extrinsic fluorescent probe bulk assays of protein fibrillation do not exhibit an observable lag phase during template-dependent elongation. Our approach could be valuable for investigating the effects of intrinsic and extrinsic factors to the protein fibrillation reaction mechanism and provides physicochemical insights into parameters regulating the lag phase. PMID:27250246

  15. CLASH: THE ENHANCED LENSING EFFICIENCY OF THE HIGHLY ELONGATED MERGING CLUSTER MACS J0416.1-2403

    Energy Technology Data Exchange (ETDEWEB)

    Zitrin, A.; Bartelmann, M.; Carrasco, M. [Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie, Universitaet Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); Meneghetti, M. [INAF, Osservatorio Astronomico di Bologna, and INFN, Sezione di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Umetsu, K. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Broadhurst, T. [Department of Theoretical Physics, University of Basque Country UPV/EHU, P.O. Box 644, E-48080 Bilbao (Spain); Bouwens, R. [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Bradley, L.; Coe, D.; Koekemoer, A. M.; Postman, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Ford, H.; Medezinski, E. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Kelson, D. [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States); Moustakas, J. [Department of Physics and Astronomy, Siena College, Loudonville, NY 12211 (United States); Moustakas, L. A. [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, Pasadena, CA 91109 (United States); Nonino, M. [INAF-Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, I-40131 Trieste (Italy); Rosati, P. [ESO-European Southern Observatory, D-85748 Garching bei Muenchen (Germany); Seidel, G. [Max-Planck-Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Seitz, S., E-mail: adizitrin@gmail.com [University Observatory Munich, Scheinerstrasse 1, D-81679 Muenchen (Germany); and others

    2013-01-10

    We perform a strong lensing analysis of the merging galaxy cluster MACS J0416.1-2403 (M0416; z = 0.42) in recent CLASH/HST observations. We identify 70 new multiple images and candidates of 23 background sources in the range 0.7 {approx}< z{sub phot} {approx}< 6.14 including two probable high-redshift dropouts, revealing a highly elongated lens with axis ratio {approx_equal}5:1, and a major axis of {approx}100'' (z{sub s} {approx} 2). Compared to other well-studied clusters, M0416 shows an enhanced lensing efficiency. Although the critical area is not particularly large ({approx_equal} 0.6 {open_square}'; z{sub s} {approx} 2), the number of multiple images, per critical area, is anomalously high. We calculate that the observed elongation boosts the number of multiple images, per critical area, by a factor of {approx}2.5 Multiplication-Sign , due to the increased ratio of the caustic area relative to the critical area. Additionally, we find that the observed separation between the two main mass components enlarges the critical area by a factor of {approx}2. These geometrical effects can account for the high number (density) of multiple images observed. We find in numerical simulations that only {approx}4% of the clusters (with M{sub vir} {>=} 6 Multiplication-Sign 10{sup 14} h {sup -1} M{sub Sun }) exhibit critical curves as elongated as in M0416.

  16. Phosphorylation of the Peptidoglycan Synthase PonA1 Governs the Rate of Polar Elongation in Mycobacteria.

    Directory of Open Access Journals (Sweden)

    Karen J Kieser

    2015-06-01

    Full Text Available Cell growth and division are required for the progression of bacterial infections. Most rod-shaped bacteria grow by inserting new cell wall along their mid-section. However, mycobacteria, including the human pathogen Mycobacterium tuberculosis, produce new cell wall material at their poles. How mycobacteria control this different mode of growth is incompletely understood. Here we find that PonA1, a penicillin binding protein (PBP capable of transglycosylation and transpeptidation of cell wall peptidoglycan (PG, is a major governor of polar growth in mycobacteria. PonA1 is required for growth of Mycobacterium smegmatis and is critical for M. tuberculosis during infection. In both cases, PonA1's catalytic activities are both required for normal cell length, though loss of transglycosylase activity has a more pronounced effect than transpeptidation. Mutations that alter the amount or the activity of PonA1 result in abnormal formation of cell poles and changes in cell length. Moreover, altered PonA1 activity results in dramatic differences in antibiotic susceptibility, suggesting that a balance between the two enzymatic activities of PonA1 is critical for survival. We also find that phosphorylation of a cytoplasmic region of PonA1 is required for normal activity. Mutations in a critical phosphorylated residue affect transglycosylase activity and result in abnormal rates of cell elongation. Together, our data indicate that PonA1 is a central determinant of polar growth in mycobacteria, and its governance of cell elongation is required for robust cell fitness during both host-induced and antibiotic stress.

  17. Control of tick infestations in cattle vaccinated with bacterial membranes containing surface-exposed tick protective antigens.

    Science.gov (United States)

    Almazán, Consuelo; Moreno-Cantú, Orlando; Moreno-Cid, Juan A; Galindo, Ruth C; Canales, Mario; Villar, Margarita; de la Fuente, José

    2012-01-01

    Vaccines containing the Rhipicephalus (Boophilus) microplus BM86 and BM95 antigens protect cattle against tick infestations. Tick subolesin (SUB), elongation factor 1a (EF1a) and ubiquitin (UBQ) are new candidate protective antigens for the control of cattle tick infestations. Previous studies showed that R. microplus BM95 immunogenic peptides fused to the Anaplasma marginale major surface protein (MSP) 1a N-terminal region (BM95-MSP1a) for presentation on the Escherichia coli membrane were protective against R. microplus infestations in rabbits. In this study, we extended these results by expressing SUB-MSP1a, EF1a-MSP1a and UBQ-MSP1a fusion proteins on the E. coli membrane using this system and demonstrating that bacterial membranes containing the chimeric proteins BM95-MSP1a and SUB-MSP1a were protective (>60% vaccine efficacy) against experimental R. microplus and Rhipicephalus annulatus infestations in cattle. This system provides a novel, simple and cost-effective approach for the production of tick protective antigens by surface display of antigenic protein chimera on the E. coli membrane and demonstrates the possibility of using recombinant bacterial membrane fractions in vaccine preparations to protect cattle against tick infestations. PMID:22085549

  18. Particle Counter Determination of Bacterial Biomass in Seawater

    OpenAIRE

    Kogure, Kazuhiro; Koike, Isao

    1987-01-01

    The applicability of the Elzone particle counter to the determination of marine bacterial biomass was investigated. The biomass of bacterial pure cultures and a mixed natural population were followed by using the particle counter, a CHN analyzer, and an ATP analyzer. The particle counter showed the precise size distribution of number and volume of submicron-size particles in seawater. For the pure cultured bacterial strains, the conversion factor from volume to carbon is 0.209 mg of C per mm3...

  19. Study of prevalence of bacterial vaginosis in preterm and term labour

    Directory of Open Access Journals (Sweden)

    Deepa Masand

    2016-02-01

    Conclusions: Bacterial vaginosis is major risk factor for preterm labour. Therefore, testing for bacterial vaginosis and prompt treatment may reduce risk of preterm labour. [Int J Reprod Contracept Obstet Gynecol 2016; 5(2.000: 477-481

  20. A novel tomato mutant, Solanum lycopersicum elongated fruit1 (Slelf1), exhibits an elongated fruit shape caused by increased cell layers in the proximal region of the ovary.

    Science.gov (United States)

    Chusreeaeom, Katarut; Ariizumi, Tohru; Asamizu, Erika; Okabe, Yoshihiro; Shirasawa, Kenta; Ezura, Hiroshi

    2014-06-01

    Genes controlling fruit morphology offer important insights into patterns and mechanisms determining organ shape and size. In cultivated tomato (Solanum lycopersicum L.), a variety of fruit shapes are displayed, including round-, bell pepper-, pear-, and elongate-shaped forms. In this study, we characterized a tomato mutant possessing elongated fruit morphology by histologically analyzing its fruit structure and genetically analyzing and mapping the genetic locus. The mutant line, Solanum lycopersicum elongated fruit 1 (Slelf1), was selected in a previous study from an ethylmethane sulfonate-mutagenized population generated in the background of Micro-Tom, a dwarf and rapid-growth variety. Histological analysis of the Slelf1 mutant revealed dramatically increased elongation of ovary and fruit. Until 6 days before flowering, ovaries were round and they began to elongate afterward. We also determined pericarp thickness and the number of cell layers in three designated fruit regions. We found that mesocarp thickness, as well as the number of cell layers, was increased in the proximal region of immature green fruits, making this the key sector of fruit elongation. Using 262 F2 individuals derived from a cross between Slelf1 and the cultivar Ailsa Craig, we constructed a genetic map, simple sequence repeat (SSR), cleaved amplified polymorphism sequence (CAPS), and derived CAPS (dCAPS) markers and mapped to the 12 tomato chromosomes. Genetic mapping placed the candidate gene locus within a 0.2 Mbp interval on the long arm of chromosome 8 and was likely different from previously known loci affecting fruit shape. PMID:24519535

  1. Analysis of risk factors for spontaneous bacterial peritonitis in hepatic cirrhosis%慢性肝炎肝硬化腹水并发自发性细菌性腹膜炎相关危险因素分析

    Institute of Scientific and Technical Information of China (English)

    邓媛; 廖毅

    2011-01-01

    Objective To study the risk factors of spontaneous bacterial peritonitis(SBP) in cirrhotic patients with ascites. Methods The clinical data of 186 cirrhotic patients with ascities from February 2005 to March 2010 were retrospectively analyzed were divided into two groups,the one with SBP and the other without SBP. The following factors such as sex, Child-Pugh grade were analyzed with binary logistic regression. Results Among those factors ,3 factors were proved to be risk factors for SBP in cirrhotic patients with ascites by analysis of single and multiple variables. Those were Child-Pugh grade score, serum bilirubin level and ascitic fluid albumin. Conclusion SBP in cirrhotic patients with ascites was affected by many factors. The Child-Pugh grade score, serum bilirubin level and ascitic fluid albumin were independently associated with risk factors of SBP, so it was important to pay attention to those factors in preventing the onset of SBP.%目的 探讨慢性肝炎肝硬化患者腹水并发自发性腹膜炎的相关危险因素,为临床病情判断和预防提供依据。方法 回顾性分析慢性肝炎肝硬化患者186例,根据患者是否并发SBP分为SBP组(观察组)和非SBP组(对照组)。对并发SBP的危险因素进行单因素和多因素Logistic回归分析。结果 单因素分析显示观察组在Child-Pugh分级、AST、T-Bil、腹水白蛋白方面较对照组增高;对照组在男性比例较观察组高,差异有统计学意义(P<0.05),观察组在上消化道出血、肝性脑病和肝肾综合征的发生率(24.2%、12.6%、13.7%)较对照组高(9.9%、7.7%、8.8%),但差异无统计学意义(P>0.05),其他各项指标比较差异无统计学意义。Logistic回归分析显示Child-Pugh分级、T-Bil、腹水白蛋白3个因素是其独立的危险因素(P<0.05)。结论 慢性肝炎肝硬化患者腹水并发自发性腹膜炎的危险因素是多方面的,其中Child-Pugh分级、总胆红素、腹

  2. The Yeast Elongator Histone Acetylase Requires Sit4-dependent Dephosphorylation for Toxin-Target Capacity

    OpenAIRE

    Jablonowski, Daniel; Fichtner, Lars; Stark, Michael J. R.; Schaffrath, Raffael

    2004-01-01

    Kluyveromyces lactis zymocin, a heterotrimeric toxin complex, imposes a G1 cell cycle block on Saccharomyces cerevisiae that requires the toxin-target (TOT) function of holo-Elongator, a six-subunit histone acetylase. Here, we demonstrate that Elongator is a phospho-complex. Phosphorylation of its largest subunit Tot1 (Elp1) is supported by Kti11, an Elongator-interactor essential for zymocin action. Tot1 dephosphorylation depends on the Sit4 phosphatase and its associators Sap185 and Sap190....

  3. Age, sun and substrate: triggers of bacterial communities in lichens.

    Science.gov (United States)

    Cardinale, Massimiliano; Steinová, Jana; Rabensteiner, Johannes; Berg, Gabriele; Grube, Martin

    2012-02-01

    Bacterial communities colonize the surfaces of lichens in a biofilm-like manner. The overall structure of the bacterial communities harboured by the lichens shows similarities, in particular the dominance of not yet cultured Alphaproteobacteria. Parameters causing variation in abundance, composition and spatial organization of the lichen-associated bacterial communities are so far poorly understood. As a first step, we used a microscopic approach to test the significance of both lichen-intrinsic and extrinsic environmental factors on the bacterial communities associated with 11 lichen samples, belonging to six species. Some of these species have thalli with a distinct age gradient. A statistically significant effect can be attributed to the age of the thallus parts, which is an intrinsic factor: growing parts of the lichens host bacterial communities that significantly differ from those of the ageing portions of the thalli. The substrate type (rock, tree, understory) and (at a lower extent) the exposition to the sun also affected the bacterial communities. Interestingly, the abundance of bacterial cells in the lichens was also influenced by the same structure-triggering factors. No effect on the composition with main bacterial groups was attributed to different lichen species, differentiated thallus parts or thallus growth type. Our results are important for the experimental designs in lichen-bacterial ecology. PMID:23757225

  4. G-domains of elongation factors Tu: model proteins for the elucidation of thermostability elements

    Czech Academy of Sciences Publication Activity Database

    Šanderová, Hana; Jonák, Jiří

    Brest: XX, 2006, s. 67-67. [International Congress on Extremophiles /16./. Brest (FR), 17.09.2006-21.09.2006] R&D Projects: GA AV ČR(CZ) KJB500520503 Institutional research plan: CEZ:AV0Z50520514 Keywords : EF-Tu * G-domain * thermostability Subject RIV: EB - Genetics ; Molecular Biology

  5. Thermostability of multidomain proteins: chimeric mesophilic/thermophilic elongation factors EF-Tu

    Czech Academy of Sciences Publication Activity Database

    Šanderová, Hana; Maloň, Petr; Hůlková, Marta; Jonák, Jiří

    Varšava : FEBS, 2004, s. 7. [FEBS Forum for Young Scientists. Varšava (PL), 24.06.2004-26.06.2004] R&D Projects: GA ČR GA303/02/0689 Institutional research plan: CEZ:AV0Z5052915 Keywords : thermostability * EF-Tu * chimeric protein Subject RIV: EB - Genetics ; Molecular Biology

  6. Thermostability of multidomain proteins: chimeric mesophilic/thermophilic elongation factors EF-Tu

    Czech Academy of Sciences Publication Activity Database

    Šanderová, Hana; Maloň, Petr; Hůlková, Marta; Jonák, Jiří

    Oxford : Blackwell Publishing, 2004, s. 219. [Meeting of the Federation of the European Biochemical Societies /29./. Varšava (PL), 26.06.2004-01.07.2004] R&D Projects: GA ČR GA303/02/0689 Institutional research plan: CEZ:AV0Z5052915 Keywords : thermostability * EF-Tu * chimeric protein Subject RIV: EB - Genetics ; Molecular Biology

  7. Inhibition of elongation factor-2 kinase augments the antitumor activity of Temozolomide against glioma.

    Directory of Open Access Journals (Sweden)

    Xiao-Yuan Liu

    Full Text Available BACKGROUND: Glioblastoma multiforme (GBM, the most common form of brain cancer with an average survival of less than 12 months, is a highly aggressive and fatal disease characterized by survival of glioma cells following initial treatment, invasion through the brain parenchyma and destruction of normal brain tissues, and ultimately resistance to current treatments. Temozolomide (TMZ is commonly used chemotherapy for treatment of primary and recurrent high-grade gliomas. Nevertheless, the therapeutic outcome of TMZ is often unsatisfactory. In this study, we sought to determine whether eEF-2 kinase affected the sensitivity of glioma cells to treatment with TMZ. METHODOLOGY/PRINCIPAL FINDINGS: Using RNA interference approach, a small molecule inhibitor of eEF-2 kinase, and in vitro and in vivo glioma models, we observed that inhibition of eEF-2 kinase could enhance sensitivity of glioma cells to TMZ, and that this sensitizing effect was associated with blockade of autophagy and augmentation of apoptosis caused by TMZ. CONCLUSIONS/SIGNIFICANCE: These findings demonstrated that targeting eEF-2 kinase can enhance the anti-glioma activity of TMZ, and inhibitors of this kinase may be exploited as chemo-sensitizers for TMZ in treatment of malignant glioma.

  8. Purification and characterization of Streptomyces auroefaciens translation elongation factor Tu overproduced in Escherichia coli

    Czech Academy of Sciences Publication Activity Database

    Weiser, Jaroslav; Nguyen, Liem Duy; Kalachová, Ladislava; Benada, Oldřich

    SissiHeraklion: Hellenic Society of Biological Sciences, 1999. s. 31. [International Symposium on the Biology of Actinomycetes /11./. 24.10.1999-28.10.1999, Sissi-Heraklion] Institutional research plan: CEZ:A53/98:Z5-020-9ii Subject RIV: EB - Genetics ; Molecular Biology

  9. Roles of Protein Synthesis Elongation Factor EF-Tu in Heat Tolerance in Plants

    Directory of Open Access Journals (Sweden)

    Jianming Fu

    2012-01-01

    Full Text Available EF-Tu proteins of plastids, mitochondria, and the cytosolic counterpart EF-1α in plants, as well as EF-Tu proteins of bacteria, are highly conserved and multifunctional. The functions of EF-Tu include transporting the aminoacyl-tRNA complex to the A site of the ribosome during protein biosynthesis; chaperone activity in protecting other proteins from aggregation caused by environmental stresses, facilitating renaturation of proteins when conditions return to normal; displaying a protein disulfide isomerase activity; participating in the degradation of N-terminally blocked proteins by the proteasome; eliciting innate immunity and triggering resistance to pathogenic bacteria in plants; participating in transcription when an E. coli host is infected with phages. EF-Tu genes are upregulated by abiotic stresses in plants, and EF-Tu plays important role in stress responses. Expression of a plant EF-Tu gene confers heat tolerance in E. coli, maize knock-out EF-Tu null mutants are heat susceptible, and over-expression of an EF-Tu gene improves heat tolerance in crop plants. This review paper summarizes the current knowledge of EF-Tu proteins in stress responses in plants and progress on application of EF-Tu for developing crop varieties tolerant to abiotic stresses, such as high temperatures.

  10. Mass spectrometric characterization of the rubber elongation factor - major allergen in natural latex gloves

    International Nuclear Information System (INIS)

    The aim of the present work is the mass spectrometric characterization of the possible latex allergens present in natural latex gloves. The introduction covers a brief description of the molecular basis and types of allergens, and some of the promising therapeutic possibilities. It shows the composition of the natural latex milk and gives a summary of the conversion of the raw material into its products. The most important natural latex allergens are described and the knowledge about the medical aspects of this illness are summarized. The different chemical and biological methods applied during this study are also introduced in this chapter from the simple methods for protein extraction to the sophisticated ones for primary structure characterization. Chapter 4.1. describes the mass spectrometric analysis of the natural latex milk. Different samples - representing subsequent steps of processing of the raw material before the production of the gloves - were investigated. The effects of the sample preparation methods on the MALDI MS measurements were studied and compared. Several compounds could be detected in the freshly tapped natural latex sap and the change of the composition of the milk following the steps of preparation could be observed. Natural latex gloves were investigated in chapter 4.2. without extraction, directly by means of MALDI mass spectrometry. The protein pattern of the gloves during production - before and after the washing steps - was investigated. We found not only a difference between these two stages of the process, but also a variation of the protein pattern on the inner and outer sides of the gloves. Several types of finished products were studied and it could be concluded, that the detection of a part of the proteins revealed in the natural latex milk is still possible in this goods with MALDI mass spectrometry, without extraction and purification. It turned out, that the characteristics of the surface and the pore structure of the gloves have a remarkable effect on the detection of these compounds and possibly also on the allergen characteristics of the products. Different methods for the extraction of the proteins from the natural latex products were tested in chapter 4.3. The results of the electrophoretic and chromatographic investigations of the extracts showed, that the use of the strong anionic detergent, sodium dodecyl sulfat (SDS), is essential for the extraction of the hydrophobic, particle associated proteins. The temperature and duration of the process were optimized with respect to the amount of the extracted proteins. Chapter 4.4. deals with the chromatographic, electrophoretic and mass spectrometric investigation of the extract. Several bands could be revealed after the electrophoretic separation of the mixture. The chromatographic character of the extracted proteins was studied by means of reversed phase high performance liquid chromatography (HPLC). The separated fractions were further investigated by sodium dodecyl sulfat polyacrylamide electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. These studies showed, that the extracted proteins had hydrophobic characteristics, could be eluted only with high organic modifier content of the applied mobile phase and could not be completely separated from each other by means of reversed phase HPLC. Chapter 4.5. covers the investigation of the protein extracted from the natural latex milk. (author)

  11. Mutant mitochondrial elongation factor G1 and combined oxidative phosphorylation deficiency

    OpenAIRE

    Newbold, RF; Coenen, MJH; Antonicka, H; Ugalde, C; F. Sasarman; Rossi, R.; Heister, A.; Trijbels, FJMF; van den Heuvel, LP; Shoubridge, EA; Smeitink, JAM

    2004-01-01

    Although most components of the mitochondrial translation apparatus are encoded by nuclear genes, all known molecular defects associated with impaired mitochondrial translation are due to mutations in mitochondrial DNA. We investigated two siblings with a severe defect in mitochondrial translation, reduced levels of oxidative phosphorylation complexes containing mitochondrial DNA (mtDNA)–encoded subunits, and progressive hepatoencephalopathy. We mapped the defective gene to a region on chromo...

  12. Recent Advances in the Role of the Elongator Complex in Plant Physiology and tRNA Modiifcation:A Review

    Institute of Scientific and Technical Information of China (English)

    YAN Xu; JIN Xiao-huan; WANG You-mei; ZHENG Bo; CHEN Peng

    2014-01-01

    The Elongator complex is a multifunction protein complex which has been shown to be involved in transcriptional elongation, DNA replication and repair, tubulin and histone acetylation, gene silencing and tranfer RNA uridine modiifcation. The composition of the Elongator complex is found to be highly conserved in eukaryotes, protein homologs of various subunits have been identiifed in fungi, plant, animal, and human. Remarkably, mutation in genes encoding the Elongator complex structural components all results in defects of transfer RNA wobble uridine modiifcation, and this function of the Elongator complex is also conserved in eukaryotes. The Elongator complex mutants in higher plants have pleiotropic phenotypes including defects in vegetative growth, abiscisic acid hypersensitivity, elevated tolerance to drought and oxidative stress. What is the relationship between the Elongator complex’s function in nucleoside modiifcation and its activity in other cellular pathways? This review summarizes the recent advances in study of function of the Elongator complex, in the aspects of cell physiology and molecular biology.

  13. Bacterial Wound Culture

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  14. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  15. Calibrating bacterial evolution

    OpenAIRE

    Ochman, Howard; Elwyn, Susannah; Moran, Nancy A

    1999-01-01

    Attempts to calibrate bacterial evolution have relied on the assumption that rates of molecular sequence divergence in bacteria are similar to those of higher eukaryotes, or to those of the few bacterial taxa for which ancestors can be reliably dated from ecological or geological evidence. Despite similarities in the substitution rates estimated for some lineages, comparisons of the relative rates of evolution at different classes of nucleotide sites indicate no basis for their universal appl...

  16. Role of quorum sensing in bacterial infections.

    Science.gov (United States)

    Castillo-Juárez, Israel; Maeda, Toshinari; Mandujano-Tinoco, Edna Ayerim; Tomás, María; Pérez-Eretza, Berenice; García-Contreras, Silvia Julieta; Wood, Thomas K; García-Contreras, Rodolfo

    2015-07-16

    Quorum sensing (QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed. PMID:26244150

  17. Role of the tumor necrosis factor receptor-associated factor-type zinc finger domain containing protein 1 (TRAFD1) from the hard tick Haemaphysalis longicornis in immunity against bacterial infection.

    Science.gov (United States)

    Takechi, Rie; Galay, Remil Linggatong; Matsuo, Tomohide; Maeda, Hiroki; Kusakisako, Kodai; Talactac, Melbourne Rio; Mochizuki, Masami; Fujisaki, Kozo; Tanaka, Tetsuya

    2016-02-01

    A tumor necrosis factor receptor-associated factor-type zinc finger domain containing protein 1 (TRAFD1) is a negative feedback regulator that controls excessive immune responses in vertebrates. The sequence of tick hemolymph TRAFD1 from the hard tick Haemaphysalis longicornis (HlTRAFD1) was analyzed after identification and cloning from the expressed sequence tag database. RT-PCR and Western blot analyses showed that HlTRAFD1 transcript and protein levels after blood feeding were present in all developmental stages, and the transcript level was consistently high in all organs examined from adult female ticks upon engorgement. Knockdown of HlTRAFD1 gene by RNA interference did not affect blood feeding or oviposition. However, HlTRAFD1 silencing affected the expression of the longicin gene, a defensin-like molecule, but not the lysozyme gene. Moreover, the survival rate of HlTRAFD1-silenced ticks was lower, and the number of E. coli was higher in the hemolymph and plasmatocytes after E. coli injection compared to the control group. These results suggested that HlTRAFD1 strongly affected both the humoral and cellular immunity of ticks. PMID:26283173

  18. Uni-axial Elongational Viscosity of Linear and Branched polymer melts

    DEFF Research Database (Denmark)

    Hassager, Ole; Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz

    2005-01-01

    About 40 years ago interest in the measurement of elongational viscosity of polymer melts started to grow. Here we present measurements of transient (and steady) uni-axial elongational viscosity, using the FSR, of the following melts: Four narrow MMD polystyrene (PS) samples with weight......-average molar mass Mw in the range of 50k to 390k. Three different bi-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements.The measurements on the bi-disperse PS...... melts have demonstrated that both the transient and steady elongational viscosity is quite sensitive to polydispersity. Bi-disperse PS resembles the behaviour of mono-disperse melts only at elongational rates larger then the inverse of maximal time constant of the smallest molecule. As observed in Boger...

  19. Ionizing radiation and DNA-chain elongation in ataxia telangiectasia lymphoblastoid cells

    International Nuclear Information System (INIS)

    DNA-chain elongation rates, determined by sedimentation analysis, were found to be similar in control and ataxia-telangiectasia lymphoblastoid cells. A γ-radiation dose of 6 Gray, which had previously been shown to have a marked inhibitory effect on initiation of DNA-replication, had no appreciable effect on elongation rates in either cell type. Elongation rates were also determined at 20 Gray of γ-rays by pulsing cells with [3H]thymidine prior to irradiation to avoid anomalous sedimentation behaviour. At this radiation dose elongation was almost completely inhibited in control cells while little or no inhibition was observed in ataxia-telangiectasia cells. Deoxyribonucleoside triphosphate pool equilibration times were not altered at either dose. (Auth.)

  20. Bacterial colonization and gut development in preterm neonates

    DEFF Research Database (Denmark)

    Cilieborg, Malene S.; Boye, Mette; Sangild, Per Torp

    2012-01-01

    Necrotizing enterocolitis (NEC) develops in 5–10% of preterm infants in association with enteral feeding and bacterial colonization. It remains unclear how diet and bacteria interact to protect or provoke the immature gastrointestinal tract. Understanding the factors that control bacterial...