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Sample records for bacterial elongation factor

  1. The interaction between bacterial transcription factors and RNA polymerase during the transition from initiation to elongation.

    Science.gov (United States)

    Yang, Xiao; Lewis, Peter J

    2010-01-01

    There are three stages of transcription: initiation, elongation and termination, and traditionally there has been a clear distinction between the stages. The specificity factor sigma is completely released from bacterial RNA polymerase after initiation, and then recycled for another round of transcription. Elongation factors then associate with the polymerase followed by termination factors (where necessary). These factors dissociate prior to initiation of a new round of transcription. However, there is growing evidence suggesting that sigma factors can be retained in the elongation complex. The structure of bacterial RNAP in complex with an essential elongation factor NusA has recently been published, which suggested rather than competing for the major σ binding site, NusA binds to a discrete region on RNAP. A model was proposed to help explain the way in which both factors could be associated with RNAP during the transition from transcription initiation to elongation.

  2. 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...... background ameliorates the detergent, antibiotic, and osmosensitivity phenotypes and restores wild-type permeability to NPN. Our data support a role for EF-P in the translational regulation of a limited number of proteins that, when perturbed, renders the cell susceptible to stress by the adventitious...

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

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    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

  4. 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...

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

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    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

  6. 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

  7. (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

    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...... 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...... 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 of hydroxyl-(β)-lysyl-EF-P...

  8. Eukaryotic elongation factor 2 kinase regulates the cold stress response by slowing translation elongation.

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    Knight, John R P; Bastide, Amandine; Roobol, Anne; Roobol, Jo; Jackson, Thomas J; Utami, Wahyu; Barrett, David A; Smales, C Mark; Willis, Anne E

    2015-01-15

    Cells respond to external stress conditions by controlling gene expression, a process which occurs rapidly via post-transcriptional regulation at the level of protein synthesis. Global control of translation is mediated by modification of translation factors to allow reprogramming of the translatome and synthesis of specific proteins that are required for stress protection or initiation of apoptosis. In the present study, we have investigated how global protein synthesis rates are regulated upon mild cooling. We demonstrate that although there are changes to the factors that control initiation, including phosphorylation of eukaryotic translation initiation factor 2 (eIF2) on the α-subunit, the reduction in the global translation rate is mediated by regulation of elongation via phosphorylation of eukaryotic elongation factor 2 (eEF2) by its specific kinase, eEF2K (eukaryotic elongation factor 2 kinase). The AMP/ATP ratio increases following cooling, consistent with a reduction in metabolic rates, giving rise to activation of AMPK (5'-AMP-activated protein kinase), which is upstream of eEF2K. However, our data show that the major trigger for activation of eEF2K upon mild cooling is the release of Ca2+ ions from the endoplasmic reticulum (ER) and, importantly, that it is possible to restore protein synthesis rates in cooled cells by inhibition of this pathway at multiple points. As cooling has both therapeutic and industrial applications, our data provide important new insights into how the cellular responses to this stress are regulated, opening up new possibilities to modulate these responses for medical or industrial use at physiological or cooler temperatures.

  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 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....

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

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    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

  13. Maintenance of Transcription-Translation Coupling by Elongation Factor P

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    Elgamal, Sara

    2016-01-01

    ABSTRACT Under conditions of tight coupling between translation and transcription, the ribosome enables synthesis of full-length mRNAs by preventing both formation of intrinsic terminator hairpins and loading of the transcription termination factor Rho. While previous studies have focused on transcription factors, we investigated the role of Escherichia coli elongation factor P (EF-P), an elongation factor required for efficient translation of mRNAs containing consecutive proline codons, in maintaining coupled translation and transcription. In the absence of EF-P, the presence of Rho utilization (rut) sites led to an ~30-fold decrease in translation of polyproline-encoding mRNAs. Coexpression of the Rho inhibitor Psu fully restored translation. EF-P was also shown to inhibit premature termination during synthesis and translation of mRNAs encoding intrinsic terminators. The effects of EF-P loss on expression of polyproline mRNAs were augmented by a substitution in RNA polymerase that accelerates transcription. Analyses of previously reported ribosome profiling and global proteomic data identified several candidate gene clusters where EF-P could act to prevent premature transcription termination. In vivo probing allowed detection of some predicted premature termination products in the absence of EF-P. Our findings support a model in which EF-P maintains coupling of translation and transcription by decreasing ribosome stalling at polyproline motifs. Other regulators that facilitate ribosome translocation through roadblocks to prevent premature transcription termination upon uncoupling remain to be identified. PMID:27624127

  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. Architecture and RNA binding of the human negative elongation factor

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    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

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

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    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

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

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    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

  18. 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

    The recently solved structure of the ternary complex formed between GTP-bound elongation factor Tu and aminoacylated tRNA reveals that the elements of aminoacyl-tRNA that interact with elongation factor Tu can be divided into three groups: the T stem; the 3'-end CCA-Phe; and the 5' end. The conse...

  19. NF-κB-repressing factor phosphorylation regulates transcription elongation via its interactions with 5'→3' exoribonuclease 2 and negative elongation factor.

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    Rother, Sascha; Bartels, Myriam; Schweda, Aike Torben; Resch, Klaus; Pallua, Norbert; Nourbakhsh, Mahtab

    2016-01-01

    NF-κB-repressing factor (NKRF) inhibits transcription elongation by binding to specific sequences in target promoters. Stimuli such as IL-1 have been shown to overcome this inhibitory action and enable the resumption of transcription elongation machinery by an unknown mechanism. Using mass spectrometry and in vitro phosphorylation analyses, we demonstrate that NKRF is phosphorylated within 3 different domains in unstimulated HeLa cells. Phosphoamino acid mapping and mutation analysis of NKRF further suggest that only Ser phosphorylation within aa 421-429 is regulated by IL-1 stimulation. In copurification studies, aa 421-429 is required for interactions between NKRF, 5'→3' exoribonuclease 2 (XRN2) and the negative elongation factor (NELF)-E in HeLa cells. Chromatin immunoprecipitation experiments further show that IL-1 stimulation leads to decrease in NKRF aa 421-429 phosphorylation and dissociation of NELF-E and XRN2 by concomitant resumption of transcription elongation of a synthetic reporter or the endogenous NKRF target gene, IL-8. Together, NKRF phosphorylation modulates promoter-proximal transcription elongation of NF-κB/NKRF-regulated genes via direct interactions with elongation complex in response to specific stimuli.

  20. Modes of action of ADP-ribosylated elongation factor 2 in inhibiting the polypeptide elongation cycle: a modeling study.

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    Kevin C Chen

    Full Text Available Despite the fact that ADP-ribosylation of eukaryotic elongation factor 2 (EF2 leads to inhibition of protein synthesis, the mechanism by which ADP-ribosylated EF2 (ADPR•EF2 causes this inhibition remains controversial. Here, we applied modeling approaches to investigate the consequences of various modes of ADPR•EF2 inhibitory actions on the two coupled processes, the polypeptide chain elongation and ADP-ribosylation of EF2. Modeling of experimental data indicates that ADPR•EF2 fully blocks the late-phase translocation of tRNAs; but the impairment in the translocation upstream process, mainly the GTP-dependent factor binding with the pretranslocation ribosome and/or the guanine nucleotide exchange in EF2, is responsible for the overall inhibition kinetics. The reduced ADPR•EF2-ribosome association spares the ribosome to bind and shield native EF2 against toxin attack, thereby deferring the inhibition of protein synthesis inhibition and inactivation of EF2. Minimum association with the ribosome also keeps ADPR•EF2 in an accessible state for toxins to catalyze the reverse reaction when nicotinamide becomes available. Our work underscores the importance of unveiling the interactions between ADPR•EF2 and the ribosome, and argues against that toxins inhibit protein synthesis through converting native EF2 to a competitive inhibitor to actively disable the ribosome.

  1. 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...

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

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    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. Bacterial Cellulose-Binding Domain Modulates in Vitro Elongation of Different Plant Cells1

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    Shpigel, Etai; Roiz, Levava; Goren, Raphael; Shoseyov, Oded

    1998-01-01

    Recombinant cellulose-binding domain (CBD) derived from the cellulolytic bacterium Clostridium cellulovorans was found to modulate the elongation of different plant cells in vitro. In peach (Prunus persica L.) pollen tubes, maximum elongation was observed at 50 μg mL−1 CBD. Pollen tube staining with calcofluor showed a loss of crystallinity in the tip zone of CBD-treated pollen tubes. At low concentrations CBD enhanced elongation of Arabidopsis roots. At high concentrations CBD dramatically inhibited root elongation in a dose-responsive manner. Maximum effect on root hair elongation was at 100 μg mL−1, whereas root elongation was inhibited at that concentration. CBD was found to compete with xyloglucan for binding to cellulose when CBD was added first to the cellulose, before the addition of xyloglucan. When Acetobacter xylinum L. was used as a model system, CBD was found to increase the rate of cellulose synthase in a dose-responsive manner, up to 5-fold compared with the control. Electron microscopy examination of the cellulose ribbons produced by A. xylinum showed that CBD treatment resulted in a splayed ribbon composed of separate fibrillar subunits, compared with a thin, uniform ribbon in the control. PMID:9701575

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

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    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

  5. 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

  6. 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...

  7. Nannocystin A: an Elongation Factor 1 Inhibitor from Myxobacteria with Differential Anti-Cancer Properties.

    Science.gov (United States)

    Krastel, Philipp; Roggo, Silvio; Schirle, Markus; Ross, Nathan T; Perruccio, Francesca; Aspesi, Peter; Aust, Thomas; Buntin, Kathrin; Estoppey, David; Liechty, Brigitta; Mapa, Felipa; Memmert, Klaus; Miller, Howard; Pan, Xuewen; Riedl, Ralph; Thibaut, Christian; Thomas, Jason; Wagner, Trixie; Weber, Eric; Xie, Xiaobing; Schmitt, Esther K; Hoepfner, Dominic

    2015-08-24

    Cultivation of myxobacteria of the Nannocystis genus led to the isolation and structure elucidation of a class of novel cyclic lactone inhibitors of elongation factor 1. Whole genome sequence analysis and annotation enabled identification of the putative biosynthetic cluster and synthesis process. In biological assays the compounds displayed anti-fungal and cytotoxic activity. Combined genetic and proteomic approaches identified the eukaryotic translation elongation factor 1α (EF-1α) as the primary target for this compound class. Nannocystin A (1) displayed differential activity across various cancer cell lines and EEF1A1 expression levels appear to be the main differentiating factor. Biochemical and genetic evidence support an overlapping binding site of 1 with the anti-cancer compound didemnin B on EF-1α. This myxobacterial chemotype thus offers an interesting starting point for further investigations of the potential of therapeutics targeting elongation factor 1. PMID:26179970

  8. SHORT HYPOCOTYL1 Encodes a SMARCA3-Like Chromatin Remodeling Factor Regulating Elongation1[OPEN

    Science.gov (United States)

    Bo, Kailiang; Behera, Tusar K.; Pandey, Sudhakar; Wen, Changlong; Wang, Yuhui; Simon, Philipp W.; Li, Yuhong

    2016-01-01

    In Arabidopsis (Arabidopsis thaliana), the UVR8-mediated signaling pathway is employed to attain UVB protection and acclimation to deal with low-dosage UVB (LDUVB)-induced stresses. Here, we identified SHORT HYPOCOTYL1 (SH1) in cucumber (Cucumis sativus), which regulates LDUVB-dependent hypocotyl elongation by modulating the UVR8 signaling pathway. We showed that hypocotyl elongation in cucumbers carrying the recessive sh1 allele was LDUVB insensitive and that Sh1 encoded a human SMARCA3-like chromatin remodeling factor. The allele frequency and distribution pattern at this locus among natural populations supported the wild cucumber origin of sh1 for local adaptation, which was under selection during domestication. The cultivated cucumber carries predominantly the Sh1 allele; the sh1 allele is nearly fixed in the semiwild Xishuangbanna cucumber, and the wild cucumber population is largely at Hardy-Weinberg equilibrium for the two alleles. The SH1 protein sequence was highly conserved among eukaryotic organisms, but its regulation of hypocotyl elongation in cucumber seems to be a novel function. While Sh1 expression was inhibited by LDUVB, its transcript abundance was highly correlated with hypocotyl elongation rate and the expression level of cell-elongation-related genes. Expression profiling of key regulators in the UVR8 signaling pathway revealed significant differential expression of CsHY5 between two near isogenic lines of Sh1. Sh1 and CsHY5 acted antagonistically at transcriptional level. A working model was proposed in which Sh1 regulates LDUVB-dependent hypocotyl elongation in cucumber through changing the chromatin states and thus the accessibility of CsHY5 in the UVR8 signaling pathway to promoters of LDUVB-responsive genes for hypocotyl elongation. PMID:27559036

  9. 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...

  10. Immunocytochemical localization of the elongation factor Tu in E. coli cells

    NARCIS (Netherlands)

    Slot, J.W.; Schilstra, M.J.; Meide, P.H. van der; Posthuma, G.; Cremers, A.F.M.; Bosch, L.

    1984-01-01

    The localization of the elongation factor Tu (EF-Tu) in ultrathin cryosections of E. coli cells was determined with the electron microscope using a highly specific immunological labellin technique. EF-Tu is distributed almost homogeneously throughout the cytoplasm. Although it has often been suggest

  11. 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...

  12. tef1, a Phytophthora infestans gene encoding translation elongation factor 1-alpha

    NARCIS (Netherlands)

    Klooster, van 't J.W.; Berg-Velthuis, van den G.; West, van P.; Govers, F.

    2000-01-01

    From a set of Phytophthora infestans cDNA clones randomly selected from a potato-P. infestans interaction cDNA library, three out of 22 appeared to correspond to a gene encoding translation elongation factor 1α. The gene, called tef1, is a single copy gene in P. infestans. During the life cycle of P

  13. 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

    Two residues of Escherichia coli elongation factor Tu involved in binding of aminoacyl-tRNA were identified and subjected to mutational analysis. Lys-89 and Asn-90 were each replaced by either Ala or Glu. The four single mutants were denoted K89A, K89E, N90A, and N90E, respectively. The mutants w...

  14. 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.

  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. 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

  17. 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

  18. 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...

  19. 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.

  20. The role of Glu259 in Escherichia coli elongation factor Tu in ternary complex formation

    DEFF Research Database (Denmark)

    Nautrup Pedersen, Gitte; Rattenborg, Thomas; Knudsen, Charlotte Rohde;

    1998-01-01

    -Tu could be involved in the binding of the 3' CCA-Phe end of the aminoacylated tRNA. Therefore, the corresponding residue, Glu259, of Escherichia coli EF-Tu was mutated into alanine, aspartic acid, glutamine and tyrosine, in order to substantiate the crystallographic structural evidence and to obtain...... of interaction with tRNA, while mutation to tyrosine abolished completely the interaction with tRNA. Finally, mutation to glutamine resulted in an elongation factor Tu variant behaving like the wild type. In conclusion, the environment around the site binding the CCA-Phe end of the tRNA is very restricted...

  1. 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

  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. 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...

  4. Phylogeny of the Glomerales and Diversisporales (fungi: Glomeromycota) from actin and elongation factor 1-alpha sequences.

    Science.gov (United States)

    Helgason, Thorunn; Watson, Irene J; Young, J Peter W

    2003-12-01

    The arbuscular mycorrhizal (AM) fungi have been elevated to the phylum Glomeromycota based on a ribosomal gene phylogeny. In order to test this phylogeny, we amplified and sequenced small subunit ribosomal RNA (SSUrRNA), actin and elongation factor 1 (EF1)-alpha gene fragments from single spores of Acaulospora laevis, Glomus caledonium, Gigaspora margarita, and Scutellospora dipurpurescens. Sequence variation within and among spores of an isolate was low except for SSUrRNA in S. dipurpurescens, and the actin amino acid sequence was more conserved than that of EF1-alpha. The AM fungal sequences were more similar to one another than to any other fungal group. Joint phylogenetic analysis of the actin and EF1-alpha sequences suggested that the sister group to the AM fungi was a Zygomycete order, the Mortierellales.

  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. 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;

    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-binding...... 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....

  7. Immune Reactions Against Elongation Factor 2 Kinase: Specific Pathogenesis of Gastric Ulcer from Helicobacter pylori Infection

    Directory of Open Access Journals (Sweden)

    Kiyoshi Ayada

    2009-01-01

    Full Text Available Helicobacter pylori (H. pylori infection is a definite causative factor for gastric ulcers (GUs. In the present study we detected a specific antigen of gastric epithelial cells (HGC-27 using cell ELISA, which was recognized by the sera of GU patients (n=20 but not in patients with chronic gastritis (CG; n=20 or in healthy volunteers (HC; n=10. This antigen was over-expressed by a stressful (heat-stressed environment, and was identified as elongation factor 2 kinase (EF-2K by western blotting. The GU patients' lymphocytes stimulated by H. pylori specifically disrupted heat-stressed HGC-27 cells in a cytotoxic assay. In flow cytometry, the effector cells (lymphocytes from GU patients were significantly differentiated to T helper type 1 lymphocyte (Th1 and cytotoxic T lymphocyte (CTL as opposed to those from CG patients. The target cells (HGC-27 expressed EF-2K and MHC-class I together with costimulatory molecules from heat stress. This antigen specific immune mechanism could have a prominent role in the pathogenesis of GU.

  8. Evolution of elongation factor-like (EFL) protein in Rhizaria is revised by radiolarian EFL gene sequences.

    Science.gov (United States)

    Ishitani, Yoshiyuki; Kamikawa, Ryoma; Yabuki, Akinori; Tsuchiya, Masashi; Inagaki, Yuji; Takishita, Kiyotaka

    2012-01-01

    Elongation factor 1α (EF-1α) and elongation factor-like (EFL) proteins are considered to carry out equivalent functions in translation in eukaryotic cells. Elongation factor 1α and EFL genes are patchily distributed in the global eukaryotic tree, suggesting that the evolution of these elongation factors cannot be reconciled without multiple lateral gene transfer and/or ancestral co-occurrence followed by differential loss of either of the two factors. Our current understanding of the EF-1α/EFL evolution in the eukaryotic group Rhizaria, composed of Foraminifera, Radiolaria, Filosa, and Endomyxa, remains insufficient, as no information on EF-1α/EFL gene is available for any members of Radiolaria. In this study, EFL genes were experimentally isolated from four polycystine radiolarians (i.e. Dictyocoryne, Eucyrtidium, Collozoum, and Sphaerozoum), as well as retrieved from publicly accessible expressed sequence tag data of two acantharean radiolarians (i.e. Astrolonche and Phyllostaurus) and the endomyxan Gromia. The EFL homologs from radiolarians, foraminiferans, and Gromia formed a robust clade in both maximum-likelihood and Bayesian phylogenetic analyses, suggesting that EFL genes were vertically inherited from their common ancestor. We propose an updated model for EF-1α/EFL evolution in Rhizaria by incorporating new EFL data obtained in this study. PMID:22672006

  9. Human oxygen sensing may have origins in prokaryotic elongation factor Tu prolyl-hydroxylation.

    Science.gov (United States)

    Scotti, John S; Leung, Ivanhoe K H; Ge, Wei; Bentley, Michael A; Paps, Jordi; Kramer, Holger B; Lee, Joongoo; Aik, WeiShen; Choi, Hwanho; Paulsen, Steinar M; Bowman, Lesley A H; Loik, Nikita D; Horita, Shoichiro; Ho, Chia-hua; Kershaw, Nadia J; Tang, Christoph M; Claridge, Timothy D W; Preston, Gail M; McDonough, Michael A; Schofield, Christopher J

    2014-09-16

    The roles of 2-oxoglutarate (2OG)-dependent prolyl-hydroxylases in eukaryotes include collagen stabilization, hypoxia sensing, and translational regulation. The hypoxia-inducible factor (HIF) sensing system is conserved in animals, but not in other organisms. However, bioinformatics imply that 2OG-dependent prolyl-hydroxylases (PHDs) homologous to those acting as sensing components for the HIF system in animals occur in prokaryotes. We report cellular, biochemical, and crystallographic analyses revealing that Pseudomonas prolyl-hydroxylase domain containing protein (PPHD) contain a 2OG oxygenase related in structure and function to the animal PHDs. A Pseudomonas aeruginosa PPHD knockout mutant displays impaired growth in the presence of iron chelators and increased production of the virulence factor pyocyanin. We identify elongation factor Tu (EF-Tu) as a PPHD substrate, which undergoes prolyl-4-hydroxylation on its switch I loop. A crystal structure of PPHD reveals striking similarity to human PHD2 and a Chlamydomonas reinhardtii prolyl-4-hydroxylase. A crystal structure of PPHD complexed with intact EF-Tu reveals that major conformational changes occur in both PPHD and EF-Tu, including a >20-Å movement of the EF-Tu switch I loop. Comparison of the PPHD structures with those of HIF and collagen PHDs reveals conservation in substrate recognition despite diverse biological roles and origins. The observed changes will be useful in designing new types of 2OG oxygenase inhibitors based on various conformational states, rather than active site iron chelators, which make up most reported 2OG oxygenase inhibitors. Structurally informed phylogenetic analyses suggest that the role of prolyl-hydroxylation in human hypoxia sensing has ancient origins.

  10. 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

  11. Structural Basis for the Recognition of Eukaryotic Elongation Factor 2 Kinase by Calmodulin.

    Science.gov (United States)

    Lee, Kwangwoon; Alphonse, Sébastien; Piserchio, Andrea; Tavares, Clint D J; Giles, David H; Wellmann, Rebecca M; Dalby, Kevin N; Ghose, Ranajeet

    2016-09-01

    Binding of Ca(2+)-loaded calmodulin (CaM) activates eukaryotic elongation factor 2 kinase (eEF-2K) that phosphorylates eEF-2, its only known cellular target, leading to a decrease in global protein synthesis. Here, using an eEF-2K-derived peptide (eEF-2KCBD) that encodes the region necessary for its CaM-mediated activation, we provide a structural basis for their interaction. The striking feature of this association is the absence of Ca(2+) from the CaM C-lobe sites, even under high Ca(2+) conditions. eEF-2KCBD engages CaM largely through the C lobe of the latter in an anti-parallel 1-5-8 hydrophobic mode reinforced by a pair of unique electrostatic contacts. Sparse interactions of eEF-2KCBD with the CaM N lobe results in persisting inter-lobe mobility. A conserved eEF-2K residue (W85) anchors it to CaM by inserting into a deep hydrophobic cavity within the CaM C lobe. Mutation of this residue (W85S) substantially weakens interactions between full-length eEF-2K and CaM in vitro and reduces eEF-2 phosphorylation in cells. PMID:27499441

  12. 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

  13. Expression of elongation factor-2 kinase contributes to anoikis resistance and invasion of human glioma cells

    Institute of Scientific and Technical Information of China (English)

    Li ZHANG; Yi ZHANG; Xiao-yuan LIU; Zheng-hong QIN; Jin-ming YANG

    2011-01-01

    Aim: To determine whether elongation factor-2 kinase (eEF-2 kinase) contributes to the malignant phenotype of glioblastoma multiforme by promoting the migration and invasion of glioma cells. The mechanism involved was also explored.Methods: Human glioma cell lines T98G and LN-229 were used. The expression of eEF-2 kinase was silenced using siRNA, and the invasive potential of tumor cells was assessed using a wound-healing assay and a Matrigel invasion assay. Apoptosis was determined using propidium iodide (PI) staining and Western blot analysis of cleaved caspase-3.Results: Silencing the expression of eEF-2 kinase by siRNA significantly suppressed both the migration and invasion of human glioma cells. Silencing eEF-2 kinase expression also sensitized glioma cells to anoikis, thereby decreasing tumor cell viability in the absence of attachment. Treatment of tumor cells with the caspase inhibitor z-VAD-fmk down-regulated Bim accumulation and abolished glioma cell sensitivity to anoikis.Conclusion: The results suggest that the expression of eEF-2 kinase contributes to migration and invasion of human glioma cells by protecting them from anoikis. eEF-2 kinase expression may serve as a prognostic marker and a novel target for cancer therapy.

  14. GTPase domains of ras p21 oncogene protein and elongation factor Tu: analysis of three-dimensional structures, sequence families, and functional sites.

    Science.gov (United States)

    Valencia, A; Kjeldgaard, M; Pai, E F; Sander, C

    1991-06-15

    GTPase domains are functional and structural units employed as molecular switches in a variety of important cellular functions, such as growth control, protein biosynthesis, and membrane traffic. Amino acid sequences of more than 100 members of different subfamilies are known, but crystal structures of only mammalian ras p21 and bacterial elongation factor Tu have been determined. After optimal superposition of these remarkably similar structures, careful multiple sequence alignment, and calculation of residue-residue interactions, we analyzed the two subfamilies in terms of structural conservation, sequence conservation, and residue contact strength. There are three main results. (i) A structure-based alignment of p21 and elongation factor Tu. (ii) The definition of a common conserved structural core that may be useful as the basis of model building by homology of the three-dimensional structure of any GTPase domain. (iii) Identification of sequence regions, other than the effector loop and the nucleotide binding site, that may be involved in the functional cycle: they are loop L4, known to change conformation after GTP hydrolysis; helix alpha 2, especially Arg-73 and Met-67 in ras p21; loops L8 and L10, including ras p21 Arg-123, Lys-147, and Leu-120; and residues located spatially near the N and C termini. These regions are candidate sites for interaction either with the GTP/GDP exchange factor, with a GTPase-affected function, or with a molecule delivered to a destination site with the aid of the GTPase domain.

  15. 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.

  16. Isolation and characterization of three cassava elongation factor 1 alpha (MeEF1A promoters.

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    Sony Suhandono

    Full Text Available In plant genetic engineering, the identification of gene promoters leading to particular expression patterns is crucial for the development of new genetically modified plant generations. This research was conducted in order to isolate and characterize several new promoters from cassava (Manihot esculenta Crantz elongation factor 1 alpha (EF1A gene family.Three promoters MeEF1A3, MeEF1A5 and MeEF1A6 were successfully isolated [corrected]. Sequence analyses showed that all of the promoters contain three conserved putative cis-acting elements which are located upstream of the transcription start site. These elements are included a TEF1, a TELO and TATA boxes. In addition, all of the promoters also have the 5'UTR intron but with a different lengths. These promoters were constructed translationally with gusA reporter gene (promoter::gusA fusion in pBI-121 binary vector to build a new binary vector using Overlap Extension PCR Cloning (OEPC technique. Transient expression assay that was done by using agroinfiltration method was used to show functionality of these promoters. Qualitative and quantitative analysis from GUS assay showed that these promoters were functional and conferred a specific activity in tobacco seedlings (Nicotiana tabacum, tomato fruits (Solanum lycopersicum and banana fruits (Musa acuminata. We hypothesized that MeEF1A6 could be categorized as a constitutive promoter because it was able to drive the gene expression in all transformed tissue described in here and also comparable to CaMV35S. On the other hand, MeEF1A3 drove specific expression in the aerial parts of seedlings such as hypocotyl and cotyledon thus MeEF1A5 drove specific expression in fruit tissue. The results obtained from transient analysis showed that these promoters had a distinct activity although they came from same gene family. The DNA sequences identified here are new promoters potentially use for genetic engineering in cassava or other plants.

  17. Mammalian translation elongation factor eEF1A2: X-ray structure and new features of GDP/GTP exchange mechanism in higher eukaryotes.

    Science.gov (United States)

    Crepin, Thibaut; Shalak, Vyacheslav F; Yaremchuk, Anna D; Vlasenko, Dmytro O; McCarthy, Andrew; Negrutskii, Boris S; Tukalo, Michail A; El'skaya, Anna V

    2014-11-10

    Eukaryotic elongation factor eEF1A transits between the GTP- and GDP-bound conformations during the ribosomal polypeptide chain elongation. eEF1A*GTP establishes a complex with the aminoacyl-tRNA in the A site of the 80S ribosome. Correct codon-anticodon recognition triggers GTP hydrolysis, with subsequent dissociation of eEF1A*GDP from the ribosome. The structures of both the 'GTP'- and 'GDP'-bound conformations of eEF1A are unknown. Thus, the eEF1A-related ribosomal mechanisms were anticipated only by analogy with the bacterial homolog EF-Tu. Here, we report the first crystal structure of the mammalian eEF1A2*GDP complex which indicates major differences in the organization of the nucleotide-binding domain and intramolecular movements of eEF1A compared to EF-Tu. Our results explain the nucleotide exchange mechanism in the mammalian eEF1A and suggest that the first step of eEF1A*GDP dissociation from the 80S ribosome is the rotation of the nucleotide-binding domain observed after GTP hydrolysis.

  18. The chvH locus of Agrobacterium encodes a homologue of an elongation factor involved in protein synthesis.

    Science.gov (United States)

    Peng, W T; Banta, L M; Charles, T C; Nester, E W

    2001-01-01

    The virulence of Agrobacterium tumefaciens depends on both chromosome- and Ti plasmid-encoded gene products. In this study, we characterize a chromosomal locus, chvH, previously identified by TnphoA mutagenesis and shown to be required for tumor formation. Through DNA sequencing and comparison of the sequence with identified sequences in the database, we show that this locus encodes a protein similar in sequence to elongation factor P, a protein thought to be involved in peptide bond synthesis in Escherichia coli. The analysis of vir-lacZ and vir-phoA translational fusions as well as Western immunoblotting revealed that the expression of Vir proteins such as VirE2 was significantly reduced in the chvH mutant compared with the wild-type strain. The E. coli efp gene complemented detergent sensitivity, virulence, and expression of VirE2 in the chvH mutant, suggesting that chvH and efp are functionally homologous. As expected, ChvH exerts its activity at the posttranscriptional level. Southern analysis suggests that the gene encoding this elongation factor is present as a single copy in A. tumefaciens. We constructed a chvH deletion mutant in which a 445-bp fragment within its coding sequence was deleted and replaced with an omega fragment. On complex medium, this mutant grew more slowly than the wild-type strain, indicating that elongation factor P is important but not essential for the growth of Agrobacterium. PMID:11114898

  19. 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

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

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    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.

  1. 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......, thus binding the N-terminus tightly to domain 2. We propose that this interaction is needed for aminoacyl-tRNA binding, and also for completing the structural rearrangement, which takes place when the factor switches from its GDP to its GTP form. Udgivelsesdato: 1997-Aug...

  2. 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

  3. Eukaryotic elongation factor 2 kinase as a drug target in cancer, and in cardiovascular and neurodegenerative diseases.

    Science.gov (United States)

    Liu, Rui; Proud, Christopher G

    2016-03-01

    Eukaryotic elongation factor 2 kinase (eEF2K) is an unusual protein kinase that regulates the elongation stage of protein synthesis by phosphorylating and inhibiting its only known substrate, eEF2. Elongation is a highly energy-consuming process, and eEF2K activity is tightly regulated by several signaling pathways. Regulating translation elongation can modulate the cellular energy demand and may also control the expression of specific proteins. Growing evidence links eEF2K to a range of human diseases, including cardiovascular conditions (atherosclerosis, via macrophage survival) and pulmonary arterial hypertension, as well as solid tumors, where eEF2K appears to play contrasting roles depending on tumor type and stage. eEF2K is also involved in neurological disorders and may be a valuable target in treating depression and certain neurodegenerative diseases. Because eEF2K is not required for mammalian development or cell viability, inhibiting its function may not elicit serious side effects, while the fact that it is an atypical kinase and quite distinct from the vast majority of other mammalian kinases suggests the possibility to develop it into compounds that inhibit eEF2K without affecting other important protein kinases. Further research is needed to explore these possibilities and there is an urgent need to identify and characterize potent and specific small-molecule inhibitors of eEF2K. In this article we review the recent evidence concerning the role of eEF2K in human diseases as well as the progress in developing small-molecule inhibitors of this enzyme. PMID:26806303

  4. An ancient family of SelB elongation factor-like proteins with a broad but disjunct distribution across archaea

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    Hauryliuk Vasili

    2011-01-01

    Full Text Available Abstract Background SelB is the dedicated elongation factor for delivery of selenocysteinyl-tRNA to the ribosome. In archaea, only a subset of methanogens utilizes selenocysteine and encodes archaeal SelB (aSelB. A SelB-like (aSelBL homolog has previously been identified in an archaeon that does not encode selenosysteine, and has been proposed to be a pyrrolysyl-tRNA-specific elongation factor (EF-Pyl. However, elongation factor EF-Tu is capable of binding archaeal Pyl-tRNA in bacteria, suggesting the archaeal ortholog EF1A may also be capable of delivering Pyl-tRNA to the ribosome without the need of a specialized factor. Results We have phylogenetically characterized the aSelB and aSelBL families in archaea. We find the distribution of aSelBL to be wider than both selenocysteine and pyrrolysine usage. The aSelBLs also lack the carboxy terminal domain usually involved in recognition of the selenocysteine insertion sequence in the target mRNA. While most aSelBL-encoding archaea are methanogenic Euryarchaea, we also find aSelBL representatives in Sulfolobales and Thermoproteales of Crenarchaea, and in the recently identified phylum Thaumarchaea, suggesting that aSelBL evolution has involved horizontal gene transfer and/or parallel loss. Severe disruption of the GTPase domain suggests that some family members may employ a hitherto unknown mechanism of nucleotide hydrolysis, or have lost their GTPase ability altogether. However, patterns of sequence conservation indicate that aSelBL is still capable of binding the ribosome and aminoacyl-tRNA. Conclusions Although it is closely related to SelB, aSelBL appears unlikely to either bind selenocysteinyl-tRNA or function as a classical GTP hydrolyzing elongation factor. We propose that following duplication of aSelB, the resultant aSelBL was recruited for binding another aminoacyl-tRNA. In bacteria, aminoacylation with selenocysteine is essential for efficient thermodynamic coupling of SelB binding to t

  5. 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...

  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. 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

  8. Relationships Between RNA Polymerase II Activity and Spt Elongation Factors to Spt- Phenotype and Growth in Saccharomyces cerevisiae

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    Ping Cui

    2016-08-01

    Full Text Available The interplay between adjacent transcription units can result in transcription-dependent alterations in chromatin structure or recruitment of factors that determine transcription outcomes, including the generation of intragenic or other cryptic transcripts derived from cryptic promoters. Mutations in a number of genes in Saccharomyces cerevisiae confer both cryptic intragenic transcription and the Suppressor of Ty (Spt- phenotype for the lys2-128∂ allele of the LYS2 gene. Mutants that suppress lys2-128∂ allow transcription from a normally inactive Ty1 ∂ promoter, conferring a LYS+ phenotype. The arrangement of transcription units at lys2-128∂ is reminiscent of genes containing cryptic promoters within their open reading frames. We set out to examine the relationship between RNA Polymerase II (Pol II activity, functions of Spt elongation factors, and cryptic transcription because of the previous observation that increased-activity Pol II alleles confer an Spt- phenotype. We identify both cooperating and antagonistic genetic interactions between Pol II alleles and alleles of elongation factors SPT4, SPT5, and SPT6. We find that cryptic transcription at FLO8 and STE11 is distinct from that at lys2-128∂, though all show sensitivity to reduction in Pol II activity, especially the expression of lys2-128∂ found in Spt- mutants. We determine that the lys2-128∂ Spt- phenotypes for spt6-1004 and increased activity rpo21/rpb1 alleles each require transcription from the LYS2 promoter. Furthermore, we identify the Ty1 transcription start site (TSS within the ∂ element as the position of Spt- transcription in tested Spt- mutants.

  9. 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 activity did...... not differ between females and males (NS). In females only, CS activity was enhanced (P activity was 56% higher in ET than in UT volunteers (P activity were not influenced...

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

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    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.

  11. Thiopental inhibits global protein synthesis by repression of eukaryotic elongation factor 2 and protects from hypoxic neuronal cell death.

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    Christian I Schwer

    Full Text Available Ischemic and traumatic brain injury is associated with increased risk for death and disability. The inhibition of penumbral tissue damage has been recognized as a target for therapeutic intervention, because cellular injury evolves progressively upon ATP-depletion and loss of ion homeostasis. In patients, thiopental is used to treat refractory intracranial hypertension by reducing intracranial pressure and cerebral metabolic demands; however, therapeutic benefits of thiopental-treatment are controversially discussed. In the present study we identified fundamental neuroprotective molecular mechanisms mediated by thiopental. Here we show that thiopental inhibits global protein synthesis, which preserves the intracellular energy metabolite content in oxygen-deprived human neuronal SK-N-SH cells or primary mouse cortical neurons and thus ameliorates hypoxic cell damage. Sensitivity to hypoxic damage was restored by pharmacologic repression of eukaryotic elongation factor 2 kinase. Translational inhibition was mediated by calcium influx, activation of the AMP-activated protein kinase, and inhibitory phosphorylation of eukaryotic elongation factor 2. Our results explain the reduction of cerebral metabolic demands during thiopental treatment. Cycloheximide also protected neurons from hypoxic cell death, indicating that translational inhibitors may generally reduce secondary brain injury. In conclusion our study demonstrates that therapeutic inhibition of global protein synthesis protects neurons from hypoxic damage by preserving energy balance in oxygen-deprived cells. Molecular evidence for thiopental-mediated neuroprotection favours a positive clinical evaluation of barbiturate treatment. The chemical structure of thiopental could represent a pharmacologically relevant scaffold for the development of new organ-protective compounds to ameliorate tissue damage when oxygen availability is limited.

  12. Transcription Factors Mediate the Enzymatic Disassembly of Promoter-Bound 7SK snRNP to Locally Recruit P-TEFb for Transcription Elongation

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    Ryan P. McNamara

    2013-12-01

    Full Text Available The transition from transcription initiation into elongation is controlled by transcription factors, which recruit positive transcription elongation factor b (P-TEFb to promoters to phosphorylate RNA polymerase II. A fraction of P-TEFb is recruited as part of the inhibitory 7SK small nuclear ribonucleoprotein particle (snRNP, which inactivates the kinase and prevents elongation. However, it is unclear how P-TEFb is captured from the promoter-bound 7SK snRNP to activate elongation. Here, we describe a mechanism by which transcription factors mediate the enzymatic release of P-TEFb from the 7SK snRNP at promoters to trigger activation in a gene-specific manner. We demonstrate that Tat recruits PPM1G/PP2Cγ to locally disassemble P-TEFb from the 7SK snRNP at the HIV promoter via dephosphorylation of the kinase T loop. Similar to Tat, nuclear factor (NF-κB recruits PPM1G in a stimulus-dependent manner to activate elongation at inflammatory-responsive genes. Recruitment of PPM1G to promoter-assembled 7SK snRNP provides a paradigm for rapid gene activation through transcriptional pause release.

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

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    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.

  14. 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...

  15. Eukaryotic translation elongation factor 1-alpha 1 inhibits p53 and p73 dependent apoptosis and chemotherapy sensitivity.

    Directory of Open Access Journals (Sweden)

    Alvaro Blanch

    Full Text Available The p53 family of transcription factors is a key regulator of cell proliferation and death. In this report we identify the eukaryotic translation elongation factor 1-alpha 1 (eEF1A1 to be a novel p53 and p73 interacting protein. Previous studies have demonstrated that eEF1A1 has translation-independent roles in cancer. We report that overexpression of eEF1A1 specifically inhibits p53-, p73- and chemotherapy-induced apoptosis resulting in chemoresistance. Short-interfering RNA-mediated silencing of eEF1A1 increases chemosensitivity in cell lines bearing wild type p53, but not in p53 null cells. Furthermore, silencing of eEF1A1 partially rescues the chemoresistance observed in response to p53 or p73 knockdown, suggesting that eEF1A1 is a negative regulator of the pro-apoptotic function of p53 and p73. Thus, in the context of p53-family signaling, eEF1A1 has anti-apoptotic properties. These findings identify a novel mechanism of regulation of the p53 family of proteins by eEF1A1 providing additional insight into potential targets to sensitize tumors to chemotherapy.

  16. 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

  17. Factors limiting heterotrophic bacterial production in the southern Pacific Ocean

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    F. Van Wambeke

    2007-10-01

    Full Text Available The role of potential factors limiting bacterial growth was investigated along vertical and longitudinal gradients across the South Eastern Pacific Gyre. The effects of glucose, nitrate, ammonium and phosphate additions on heterotrophic bacterial production (using leucine technique were studied in parallel in unfiltered seawater samples incubated under natural daily irradiance. Longitudinally, the enrichments realized on the subsurface showed three types of responses. From the Marquesas plateau (8° W to approx 125° W, bacteria were not bottom-up controlled, as confirmed by the huge potential of growth in non-enriched seawater (43±24 times in 24 h. Within the Gyre (125° W–95° W, nitrogen alone stimulated leucine incorporation rates by a factor of 5.6±3.6, but rapidly labile carbon (glucose became a second limiting factor (enhancement factor 49±32 when the two elements were added. Finally from the border of the gyre to the Chilean upwelling (95° W–73° W, labile carbon was the only factor stimulating heterotrophic bacterial production. Interaction between phytoplankton and heterotrophic bacterial communities and the direct versus indirect effect of iron and macronutrients on bacterial production were also investigated in four selected sites: two sites on the vicinity of the Marquesas plateau, the centre of the gyre and the Eastern border of the gyre. Both phytoplankton and heterotrophic bacteria were limited by availability of nitrogen within the gyre, but not by iron. While iron limited phytoplankton at Marquesas plateau and at the eastern border of the gyre, heterotrophic bacteria were only limited by availability of labile DOC in those environments.

  18. RNA interference against transcription elongation factor SII does not support its role in transcription-coupled nucleotide excision repair.

    Science.gov (United States)

    Mackinnon-Roy, Christine; Stubbert, Lawton J; McKay, Bruce C

    2011-01-10

    RNA polymerase II is unable to bypass bulky DNA lesions induced by agents like ultraviolet light (UV light) and cisplatin that are located in the template strand of active genes. Arrested polymerases form a stable ternary complex at the site of DNA damage that is thought to pose an impediment to the repair of these lesions. Transcription-coupled nucleotide excision repair (TC-NER) preferentially repairs these DNA lesions through an incompletely defined mechanism. Based on elegant in vitro experiments, it was hypothesized that the transcription elongation factor IIS (TFIIS) may be required to couple transcription to repair by catalyzing the reverse translocation of the arrested polymerase, allowing access of repair proteins to the site of DNA damage. However the role of TFIIS in this repair process has not been tested in vivo. Here, silencing TFIIS using an RNA interference strategy did not affect the ability of cells to recover nascent RNA synthesis following UV exposure or the ability of cells to repair a UV-damaged reporter gene while a similar strategy to decrease the expression Cockayne syndrome group B protein (CSB) resulted in the expected repair defect. Furthermore, RNA interference against TFIIS did not increase the sensitivity of cells to UV light or cisplatin while decreased expression of CSB did. Taken together, these results indicate that TFIIS is not limiting for the repair of transcription-blocking DNA lesions and thus the present work does not support a role for TFIIS in TC-NER.

  19. 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.

  20. 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.

  1. 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

  2. Climate factors influencing bacterial count in background air samples.

    Science.gov (United States)

    Harrison, Roy M; Jones, Alan M; Biggins, Peter D E; Pomeroy, Nigel; Cox, Christopher S; Kidd, Stephen P; Hobman, Jon L; Brown, Nigel L; Beswick, Alan

    2005-01-01

    Total (as opposed to culturable) bacterial number counts are reported for four sites in the United Kingdom measured during campaigns over four separate seasons. These are interpreted in relation to simple climatic factors, i.e. temperature, wind speed and wind direction. Temperature has a marked effect at all four sites with data for a rural coastal site conforming best to a simple exponential model. Data for the other rural and urban locations show a baseline similar to that determined at the coastal rural location, but with some very significant positive excursions. The temperature dependence of bacterial number is found to conform to that typical of bacterial growth rates. At the coastal rural location, bacterial numbers normalised for temperature show no dependence on wind speed whilst at the inland sites there is a decrease with increasing wind speed of the form expected for a large area source. Only one site appeared to show a systematic relationship of bacterial concentrations to wind direction that being a site in the suburbs of Birmingham with highest number concentrations observed on a wind sector approaching from the city centre. PCR techniques have been used to identify predominant types of bacteria and results are presented which show that Bacillus was the dominant genus observed at the three inland sites during the winter and summer seasons. Pseudomonas appeared with comparable frequency at certain sites and seasons. There was in general a greater diversity of bacteria at the coastal site than at the inland sites.

  3. 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....

  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; 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

  5. 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.

  6. 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

  7. Risk factors for bacterial vaginosis among Indonesian women

    Directory of Open Access Journals (Sweden)

    Dwiana Ocviyanti

    2010-05-01

    Full Text Available Aim To identify risk factors for bacterial vaginosis (BV among Indonesian women.Methods This is a cross sectional study involving 492 women with age ranged 15-50 years. Vaginal discharge was collected. Whiff test and Nugent scoring were utilized to identify BV. Settings are Puskesmas Karawang, Pedes, Cikampek,Tempuran, Batalyon 201 Clinic Cijantung, Faculty of Medicine University of Indonesia and Cipto Mangunkusumo Hospital.Results Age of the subjects were 15-25 years old (26.8%, 26 – 40 years old (59.1%, and > 40 years old (14%. The mean age was 30.9 years. Marital status of the subjects were not-married (16.9%, married (76.4%, married more than once (6.7%. Prevalence of bacterial vaginosis in this study was 30.7% according to Nugent’s score. Age > 40 years old (OR=3.15 IK 95% = 1.15-1.48 and uncircumcised couple (OR=6.25, IK 95% = 2.54 - 15.38 were independently and significantly associated with incidence of BV (p<0.05.Conclusions Prevalence of BV in this study was 30.7%. Determinant risk factors of BV were age and uncircumcised sexual partner. (Med J Indones 2010; 19:130-5Keywords: bacterial vaginosis, risk factors, vaginal flora

  8. 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.

  9. 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.

  10. 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.

  11. 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...... for GDP over GTP. Furthermore the [G94A]EF-Tu mutant possesses an increased GTPase activity. The aminoacyl-tRNA affinity is much reduced for [G94A]EF-Tu, as reflected in an increase of the dissociation rate constant for the ternary complex by a factor of 40. Surprisingly, however, both mutants...... in their GDP forms have a low, but significant affinity for aminoacyl-tRNA, which is not seen for the wild-type elongation factor Tu. The mutants only exhibit minor changes compared to the wild type with respect to in vitro translation of a poly(U) messenger. Udgivelsesdato: 1995-Feb-15...

  12. Liposomes as novel anti-infectives targeting bacterial virulence factors?

    Science.gov (United States)

    Azeredo da Silveira, Samareh; Perez, Antonio

    2015-05-01

    A recent report commissioned by Prime Minister David Cameron and chaired by former Goldman Sachs chief economist Jim O'Neill warns that the emergence, persistence and spread of antimicrobial resistance could lead to 10 million deaths per year and cause an economic burden as much as US$100 trillion by 2050. In the midst of this global crisis, unprecedented paths are being explored to combat bacterial infection. Virulence factors, and more particularly pore-forming toxins, play a key role in increasing morbidity and mortality caused by drug-resistant bacterial infections. Novel anti-infective liposomes specifically targeting and neutralizing these cytotoxic toxins are potential game-changers in the fight against deadly infections. PMID:25850805

  13. The tuf3 gene of Streptomyces coelicolor A3(2) encodes an inessential elongation factor Tu that is apparently subject to positive stringent control

    NARCIS (Netherlands)

    Wezel, Gilles P. van; Takano, Eriko; Vijgenboom, Erik; Bosch, Leendert; Bibb, Mervyn J.

    1995-01-01

    In Streptomyces coelicolor A3(2), two genes, tuf1 and tuf3, encode the apparent polypeptide chain elongation factors EF-Tu1 and EF-Tu3, respectively. While tuf1 appears to code for the major EF-Tu, the function of tuf3 is unknown. To assess the role of EF-Tu3, tuf3 was subjected to mutational and tr

  14. 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.

  15. 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...

  16. 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...

  17. 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.

  18. Local and regional factors influencing bacterial community assembly.

    Science.gov (United States)

    Lindström, Eva S; Langenheder, Silke

    2012-02-01

    The classical view states that microbial biogeography is not affected by dispersal barriers or historical events, but only influenced by the local contemporary habitat conditions (species sorting). This has been challenged during recent years by studies suggesting that also regional factors such as mass effect, dispersal limitation and neutral assembly are important for the composition of local bacterial communities. Here we summarize results from biogeography studies in different environments, i.e. in marine, freshwater and soil as well in human hosts. Species sorting appears to be the most important mechanism. However, this result might be biased since this is the mechanism that is easiest to measure, detect and interpret. Hence, the importance of regional factors may have been underestimated. Moreover, our survey indicates that different assembly mechanisms might be important for different parts of the total community, differing, for example, between generalists and specialists, and between taxa of different dispersal ability and motility. We conclude that there is a clear need for experimental studies, first, to clearly separate regional and local factors in order to study their relative importance, and second, to test whether there are differences in assembly mechanisms depending on different taxonomic or functional groups.

  19. 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.

  20. 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...

  1. 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...

  2. 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.

  3. Characterization of novel peptide-specific antibodies against the translation elongation factor eEF1A2 and their application for cancer research

    Directory of Open Access Journals (Sweden)

    Shalak V. F.

    2014-11-01

    Full Text Available Aim. We intend to characterize the new peptide-specific antibodies against the isoform 2 of translation elongation factor 1A (eEF1A2 and determine its presence in the postoperative samples of human breast, lung and stomach tumor tissues. Methods. The analysis of antibody specificity was performed by enzyme-linked immunosorbent assay, immunoblotting and immunohistochemistry. Immunoblotting and immunohistochemistry were used for the determination of the eEF1A2 in the human tumor samples, as well as in the samples of normal tissues surrounding tumors. Results. The antibodies obtained against the eEF1A2 specifically recognized this protein in the cell extracts and histological sections and did not cross-react with the elongation factor 1A isoform 1. eEF1A2 was revealed in the postoperative samples of breast, lung and stomach tumors as well as in the putative normal tissues surrounding tumors. Conclusions. The antibodies obtained against eEF1A2 are highly specific for the antigen and can be used for the immunological studies of tumors.

  4. 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.

  5. The magic spot ppGpp influences in vitro the molecular and functional properties of the elongation factor 1α from the archaeon Sulfolobus solfataricus.

    Science.gov (United States)

    Martucci, Nicola M; Lamberti, Anna; Vitagliano, Luigi; Cantiello, Piergiuseppe; Ruggiero, Immacolata; Arcari, Paolo; Masullo, Mariorosario

    2012-09-01

    Guanosine tetra-phosphate (ppGpp), also known as "magic spot I", is a key molecule in the stringent control of most eubacteria and some eukarya. Here, we show that ppGpp affects the functional and molecular properties of the archaeal elongation factor 1α from Sulfolobus solfataricus (SsEF-1α). Indeed, ppGpp inhibited archaeal protein synthesis in vitro, even though the concentration required to get inhibition was higher than that required for the eubacterial and eukaryal systems. Regarding the partial reactions catalysed by SsEF-1α the effect produced by ppGpp on the affinity for aa-tRNA was lower than that measured in the presence of GTP but higher than that for GDP. Magic spot I was also able to bind SsEF-1α with an intermediate affinity in comparison to that displayed by GDP and GTP. Furthermore, ppGpp inhibited the intrinsic GTPase of SsEF-1α with a competitive behaviour. Finally, the binding of ppGpp to SsEF-1α rendered the elongation factor more resistant to heat treatment and the analysis of the molecular model of the complex between SsEF-1α and ppGpp suggests that this stabilisation arises from the charge optimisation on the surface of the protein.

  6. 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

  7. 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...

  8. 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

  9. 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

  10. Accelerated evolution of functional plastid rRNA and elongation factor genes due to reduced protein synthetic load after the loss of photosynthesis in the chlorophyte alga Polytoma.

    Science.gov (United States)

    Vernon, D; Gutell, R R; Cannone, J J; Rumpf, R W; Birky, C W

    2001-09-01

    Polytoma obtusum and Polytoma uvella are members of a clade of nonphotosynthetic chlorophyte algae closely related to Chlamydomonas humicola and other photosynthetic members of the Chlamydomonadaceae. Descended from a nonphotosynthetic mutant, these obligate heterotrophs retain a plastid (leucoplast) with a functional protein synthetic system, and a plastid genome (lpDNA) with functional genes encoding proteins required for transcription and translation. Comparative studies of the evolution of genes in chloroplasts and leucoplasts can identify modes of selection acting on the plastid genome. Two plastid genes--rrn16, encoding the plastid small-subunit rRNA, and tufA, encoding elongation factor Tu--retain their functions in protein synthesis after the loss of photosynthesis in two nonphotosynthetic Polytoma clades but show a substantially accelerated rate of base substitution in the P. uvella clade. The accelerated evolution of tufA is due, at least partly, to relaxed codon bias favoring codons that can be read without wobble, mainly in three amino acids. Selection for these codons may be relaxed because leucoplasts are required to synthesize fewer protein molecules per unit time than are chloroplasts (reduced protein synthetic load) and thus require a lower rate of synthesis of elongation factor Tu. Relaxed selection due to a lower protein synthetic load is also a plausible explanation for the accelerated rate of evolution of rrn16, but the available data are insufficient to test the hypothesis for this gene. The tufA and rrn16 genes in Polytoma oviforme, the sole member of a second nonphotosynthetic clade, are also functional but show no sign of relaxed selection.

  11. 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...

  12. 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

    of 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...... no significant binding, indicating that eEF1A has similar tRNA binding properties as its prokaryotic homolog, EF-Tu. Udgivelsesdato: 2007-Dec-7...

  13. 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

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

    Science.gov (United States)

    Ramírez-Carvajal, Lisbeth; Singh, Neetu; de los Santos, Teresa; Rodríguez, Luis L; Long, Charles R

    2016-01-01

    Type I interferons (IFNs) 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 (IRF-7), the "master regulator" of IFN transcription. Previous studies have suggested that mouse cells depleted of 4E-BPs are more sensitive to IFNβ treatment and had lower viral loads as compared to wild type (WT) cells. However, such approach has not been tested as an antiviral strategy in livestock species. In this study, we tested the antiviral activity of porcine cells depleted of 4E-BP1 by a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) genome engineering system. We found that 4E-BP1 knockout (KO) porcine cells had increased expression of IFNα and β, IFN stimulated genes, and significant reduction in vesicular stomatitis virus titer as compare to WT cells. No phenotypical changes associated with CRISPR/Cas9 manipulation were observed in 4E-BP1 KO cells. This work highlights the use of the CRISPR/Cas9 system to enhance the antiviral response in porcine cells.

  15. 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

  16. 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.

  17. 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...

  18. Bacterial ice nucleation: a factor in frost injury to plants.

    Science.gov (United States)

    Lindow, S E; Arny, D C; Upper, C D

    1982-10-01

    Heterogeneous ice nuclei are necessary, and the common epiphytic ice nucleation active (INA) bacteria Pseudomonas syringae van Hall and Erwinia herbicola (Löhnis) Dye are sufficient to incite frost injury to sensitive plants at -5 degrees C. The ice nucleation activity of the bacteria occurs at the same temperatures at which frost injury to sensitive plants occurs in nature. Bacterial ice nucleation on leaves can be detected at about -2 degrees C, whereas the leaves themselves, i.e. without INA bacteria, contain nuclei active only at much lower temperatures. The temperature at which injury to plants occurs is predictable on the basis of the ice nucleation activity of leaf discs, which in turn depends on the number and ice nucleation activity of their resident bacteria. Bacterial isolates which are able to incite injury to corn at -5 degrees C are always active as ice nuclei at -5 degrees C. INA bacteria incited frost injury to all of the species of sensitive plants tested. PMID:16662618

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

    Science.gov (United States)

    Mann, Melanie C; Strobel, Sarah; Fleckenstein, Bernhard; Kress, Andrea K

    2014-09-01

    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.

  20. 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.

  1. 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.

  2. Phylogenetic analysis of evolutionary relationships of the planctomycete division of the domain bacteria based on amino acid sequences of elongation factor Tu.

    Science.gov (United States)

    Jenkins, C; Fuerst, J A

    2001-05-01

    Sequences from the tuf gene coding for the elongation factor EF-Tu were amplified and sequenced from the genomic DNA of Pirellula marina and Isosphaera pallida, two species of bacteria within the order Planctomycetales. A near-complete (1140-bp) sequence was obtained from Pi. marina and a partial (759-bp) sequence was obtained for I. pallida. Alignment of the deduced Pi. marina EF-Tu amino acid sequence against reference sequences demonstrated the presence of a unique 11-amino acid sequence motif not present in any other division of the domain Bacteria. Pi. marina shared the highest percentage amino acid sequence identity with I. pallida but showed only a low percentage identity with other members of the domain Bacteria. This is consistent with the concept of the planctomycetes as a unique division of the Bacteria. Neither primary sequence comparison of EF-Tu nor phylogenetic analysis supports any close relationship between planctomycetes and the chlamydiae, which has previously been postulated on the basis of 16S rRNA. Phylogenetic analysis of aligned EF-Tu amino acid sequences performed using distance, maximum-parsimony, and maximum-likelihood approaches yielded contradictory results with respect to the position of planctomycetes relative to other bacteria. It is hypothesized that long-branch attraction effects due to unequal evolutionary rates and mutational saturation effects may account for some of the contradictions. PMID:11443344

  3. Differential expression pattern of rubber elongation factor (REF) mRNA transcripts from high and low yielding clones of rubber tree (Hevea brasiliensis Muell. Arg.).

    Science.gov (United States)

    Priya, P; Venkatachalam, P; Thulaseedharan, A

    2007-10-01

    In Hevea tree, rubber elongation factor (REF) is a key gene involved in rubber biosynthesis. Since the immaturity period for Hevea is 6 years, identification of molecular marker for latex yield potential will be beneficial for early selection of high yielding clones. The main objective of this research is to study the expression pattern of the REF gene in contrasting latex yield rubber clones (high and low yielding) by Northern blot as well as RT-PCR analysis. Accumulation of REF mRNA transcripts was significantly higher in latex cells compared to other cells of seedlings and mature Hevea trees. Northern results revealed that the level of REF gene expression in latex cells of high yielding rubber clones was significantly higher than in low yielders. According to RT-PCR results, the abundance of REF mRNA transcripts in latex cells was fivefold higher in the RRII105 clone, one of the most high yielding rubber clones. It is evident from the results that both tapping and ethephon treatment had a direct effect on induction of REF gene expression. Results demonstrate a positive correlation between REF gene expression pattern and latex yield.

  4. Progress in effecting factors on telomere elongated process%端粒延长过程影响因素研究新进展

    Institute of Scientific and Technical Information of China (English)

    赵丹丹; 徐慧; 彭剑雄

    2015-01-01

    As the protection of the chromosome structure, telomere plays an important role in maintaining the stability and structural in-tegrity of chromosomes.The telomerase is one of the important enzymes maintaining telomere length, and telomere elongated process is a complicated process involving a variety of factors, mainly related to telomere structure and telomerase regulation.The telomerase related regulation is the most important part of the control system, including the influence of TR structure, regulation on TERT promoter etc.%端粒作为染色体的保护结构,在维持染色体稳定和结构完整上起着重要作用。而端粒酶具有过延长端粒的功能,是维持端粒长度的重要酶复合体。端粒酶延长端粒的过程是一个涉及多种因子多个环节的复杂过程。主要涉及端粒自身结构相关调节以及端粒酶相关的调节。端粒酶相关调节是调节系统中最重要的组成部分。包括TR自身结构的影响,调节因子对TERT启动子的调节等。

  5. 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.

  6. 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

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

    OpenAIRE

    Udayalaxmi, J.; 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 ...

  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.

  9. 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.

  10. 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.

  11. Elongation Factor Tu and Heat Shock Protein 70 Are Membrane-Associated Proteins from Mycoplasma ovipneumoniae Capable of Inducing Strong Immune Response in Mice.

    Science.gov (United States)

    Jiang, Fei; He, Jinyan; Navarro-Alvarez, Nalu; Xu, Jian; Li, Xia; Li, Peng; Wu, Wenxue

    2016-01-01

    Chronic non-progressive pneumonia, a disease that has become a worldwide epidemic has caused considerable loss to sheep industry. Mycoplasma ovipneumoniae (M. ovipneumoniae) is the causative agent of interstitial pneumonia in sheep, goat and bighorn. We here have identified by immunogold and immunoblotting that elongation factor Tu (EF-Tu) and heat shock protein 70 (HSP 70) are membrane-associated proteins on M. ovipneumonaiea. We have evaluated the humoral and cellular immune responses in vivo by immunizing BALB/c mice with both purified recombinant proteins rEF-Tu and rHSP70. The sera of both rEF-Tu and rHSP70 treated BALB/c mice demonstrated increased levels of IgG, IFN-γ, TNF-α, IL-12(p70), IL-4, IL-5 and IL-6. In addition, ELISPOT assay showed significant increase in IFN-γ+ secreting lymphocytes in the rHSP70 group when compared to other groups. Collectively our study reveals that rHSP70 induces a significantly better cellular immune response in mice, and may act as a Th1 cytokine-like adjuvant in immune response induction. Finally, growth inhibition test (GIT) of M. ovipneumoniae strain Y98 showed that sera from rHSP70 or rEF-Tu-immunized mice inhibited in vitro growth of M. ovipneumoniae. Our data strongly suggest that EF-Tu and HSP70 of M. ovipneumoniae are membrane-associated proteins capable of inducing antibody production, and cytokine secretion. Therefore, these two proteins may be potential candidates for vaccine development against M. ovipneumoniae infection in sheep.

  12. 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.

  13. 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

  14. 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

    at conception (1.59 [1.29-1.93]), previous genital infection with Chlamydia trachomatis or Neisseria gonorrhoeae (1.39 [1.07-1.79]), and consuming 2 or more drinks per week (1.33 [1.02-1.74]) after control for confounding factors. Conclusion. In pregnancy, women who have daily coitus, are single, smokers......, with a previous sexually transmitted disease, or with high alcohol consumption in pregnancy are at increased risk for bacterial vaginosis. Information on these risk factors may be important when planning preventive and treatment strategies of bacterial vaginosis in pregnancy....

  15. 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...

  16. 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

  17. 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.

  18. 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

  19. 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 ...

  20. Prokaryotic Expression of Rubber Elongation Factor Gene and Preparation of Its Polyclonal Antibody%橡胶延长因子基因的原核表达及其多克隆抗体的制备

    Institute of Scientific and Technical Information of China (English)

    陈章权; 吴坤鑫; 梁晓东; 黄震; 陆田田

    2008-01-01

    [Objective] The aim of this study was to prepare the recombination protein of rubber elongation factor and its polyclonal antibodies. [Method] The encoding gene of rubber elongation factor (REF) was amplified by RT-PCR, and cloned into the prokaryotic expression vector pDEST17 to transform into Escherichia coil BI2I-AI. The recombinant protein induced by L-Arabinose was purified by the affinity chromatography. As the immunogen, the recombination protein was used to immunize mice for preparing polyclonal antibodies, while ELISA and Western blot hybridization were used to detect the titers and specificity. [Result] The purified recombination protein of REF with high expression was used to immunize house mice for preparing polyclonal antibodies with high titer and specificity. The western blot hybridization showed that the antibody could recognize the natural REF from latex. [Conclusion] The recombination protein of REF was successfully obtained and the mouse anti REF antibody with high titer and specificity was prepared, which lays a basis for further studies on biological functions of rubber elongation factor and other membrane proteins in rubber particles.

  1. 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

  2. Seeds' physicochemical traits and mucilage protection against aluminum effect during germination and root elongation as important factors in a biofuel seed crop (Ricinus communis).

    Science.gov (United States)

    Silva, Giovanni Eustáquio Alves; Ramos, Flávia Toledo; de Faria, Ana Paula; França, Marcel Giovanni Costa

    2014-10-01

    We determined the length, volume, dry biomass, and density in seeds of five castor bean cultivars and verified notable physicochemical trait differences. Seeds were then subjected to different toxic aluminum (Al) concentrations to evaluate germination, relative root elongation, and the role of root apices' rhizosphere mucilage layer. Seeds' physicochemical traits were associated with Al toxicity responses, and the absence of Al in cotyledons near to the embryo was revealed by Al-hematoxylin staining, indicating that Al did not induce significant germination reduction rates between cultivars. However, in the more sensitive cultivar, Al was found around the embryo, contributing to subsequent growth inhibition. After this, to investigate the role of mucilage in Al tolerance, an assay was conducted using NH4Cl to remove root mucilage before or after exposure to different Al concentrations. Sequentially, the roots were stained with hematoxylin and a quantitative analysis of staining intensity was obtained. These results revealed the significant contribution of the mucilage layer to Al toxicity responses in castor bean seedlings. Root growth elongation under Al toxicity confirmed the role of the mucilage layer, which jointly indicated the differential Al tolerance between cultivars and an efficient Al-exclusion mechanism in the tolerant cultivar.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. [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.

  8. Large amplitude oscillatory elongation flow

    DEFF Research Database (Denmark)

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

    2008-01-01

    + Lambda[1 - cos( 2 pi Omega(epsilon) over dot(0)t)] where epsilon is the Hencky strain, (epsilon) over dot(0) is a constant elongational rate for the base elongational flow, Lambda the strain amplitude ( Lambda >= 0), and Omega the strain frequency. A narrow molecular mass distribution linear polystyrene...

  9. 气象因子对广西新植蔗和宿根蔗茎伸长的影响%Effects of Meteorological Factors on Stalk Elongation in New-planting and Ra-tooning Sugarcane

    Institute of Scientific and Technical Information of China (English)

    陈燕丽; 冯利平; 丁美花; 莫伟华; 匡昭敏

    2016-01-01

    Sugarcane stalk elongation is the most important factor for the development evaluation and yield estimation, on which meteorological factors have significant effects. Differences between new planting sugarcane and ratooning sugarcane in develop-ment and response to meteorological factors need to be analyzed for promoting agricultural production. In this paper, taking new-planting sugarcane and ratooning sugarcane of Guangxi as the research materials, observed sugarcane agronomic data and meteorological information at four agro-meteorological experimental stations from 2000 to 2011 were used to analyze the rela-tionship between stalk elongation and meteorological factors that were precipitation, relative humidity, maximum temperature, minimum temperature, mean temperature, air pressure, and sunshine hours at different stages. The results show that there was an obvious difference between new-planting sugarcane and ratooning sugarcane in stalk height. During the sugarcane stem elonga-tion, compared with ratooning sugarcane, new-planting sugarcane had a higher stalk height with a lower background in most of years, besides, its total stem elongation amount was much more but elongation duration was short. There was a significant correla-tion between stalk elongation and most meteorological factors in both new-planting sugarcane and ratooning sugarcane. The effect of most meteorological variables was larger in new-planting sugarcane than in ratooning sugarcane. The correlation between new-planting sugarcane and meteorological factors are obviously higher than that of ratoon sugarcane. Minimum temperature, relative humidity and maximum temperature played a direct positive role on stalk elongation in both new-planting sugarcane and ratooning sugarcane, and average temperature and air pressure played a direct negative role, meanwhile, accumulated temperature and rainfall play a significant indirect effect through other meteorological factors. There was a significant lag in

  10. FtsZ-Dependent Elongation of a Coccoid Bacterium

    NARCIS (Netherlands)

    Pereira, Ana R; Hsin, Jen; Król, Ewa; Tavares, Andreia C; Flores, Pierre; Hoiczyk, Egbert; Ng, Natalie; Dajkovic, Alex; Brun, Yves V; VanNieuwenhze, Michael S; Roemer, Terry; Carballido-Lopez, Rut; Scheffers, Dirk-Jan; Huang, Kerwyn Casey; Pinho, Mariana G

    2016-01-01

    UNLABELLED: A mechanistic understanding of the determination and maintenance of the simplest bacterial cell shape, a sphere, remains elusive compared with that of more complex shapes. Cocci seem to lack a dedicated elongation machinery, and a spherical shape has been considered an evolutionary dead-

  11. Epidemiology and Risk Factors Associated with Developing Bacterial Meningitis among Children in Gaza Strip.

    Directory of Open Access Journals (Sweden)

    Abdel Moat Al Jarousha

    2014-09-01

    Full Text Available Bacterial meningitis is still the leading cause of high morbidity and mortality among the children. The present study was conducted to determine the epidemiology, clinical characteristics of bacterial meningitis and to evaluate the risk factors associated with developing the infection.This cross sectional study was conducted in three hospitals of Gaza strip -Palestine during the period 2009. All the children with clinical diagnosis of meningitis /meningoencephalitis admitted to these hospitals were included in the study. They were subjected to clinical examination as well as CSF bacteriological and serological investigations.During the period (2009, 1853 patients were admitted to the hospitals with suspect of meningitis by pediatricians, 73 (3.9% proved by culture to be acute bacterial meningitis, of these patients 62% were males and 38% were females. The common isolated pathogens were Neisseria meningitides (47.9%, Streptococcus pneumonia (15.1%, Haemophilus influenza (13.7%, E. coli (11.0%, Enterobacter spp. (6.8%, Citrobacter spp. (2.7%, Providencia spp. (1.4%, and Pseudomonas aeruginosa (1.4%. The common recorded symptoms were fever (78%, neck stiffness (47%, vomiting (37%, poor feeding (19%, and irritability (16%. Statistical analysis showed that there was statistical significance associated developing of infection with malnutrition (low hemoglobin level, high house crowdness and irritability (P-value <0.05. The ANOVA statistical analysis showed that S. pneumonia has an impact on developing low hemoglobin level and leukocytosis.N. meningitides is still dominant and needs vaccination. The risk factors should be taken into consideration in any future plan.

  12. Nε-lysine acetylation of a bacterial transcription factor inhibits Its DNA-binding activity.

    Directory of Open Access Journals (Sweden)

    Sandy Thao

    Full Text Available Evidence suggesting that eukaryotes and archaea use reversible N(ε-lysine (N(ε-Lys acetylation to modulate gene expression has been reported, but evidence for bacterial use of N(ε-Lys acetylation for this purpose is lacking. Here, we report data in support of the notion that bacteria can control gene expression by modulating the acetylation state of transcription factors (TFs. We screened the E. coli proteome for substrates of the bacterial Gcn5-like protein acetyltransferase (Pat. Pat acetylated four TFs, including the RcsB global regulatory protein, which controls cell division, and capsule and flagellum biosynthesis in many bacteria. Pat acetylated residue Lys180 of RcsB, and the NAD(+-dependent Sir2 (sirtuin-like protein deacetylase (CobB deacetylated acetylated RcsB (RcsB(Ac, demonstrating that N(ε-Lys acetylation of RcsB is reversible. Analysis of RcsB(Ac and variant RcsB proteins carrying substitutions at Lys180 provided biochemical and physiological evidence implicating Lys180 as a critical residue for RcsB DNA-binding activity. These findings further the likelihood that reversible N(ε-Lys acetylation of transcription factors is a mode of regulation of gene expression used by all cells.

  13. A NusG paralogue from Mycobacterium tuberculosis, Rv0639, has evolved to interact with ribosomal protein S10 (Rv0700) but not to function as a transcription elongation-termination factor.

    Science.gov (United States)

    Kalyani, B Sudha; Kunamneni, Radhika; Wal, Megha; Ranjan, Amitabh; Sen, Ranjan

    2015-01-01

    NusG, a well-conserved protein in all the three forms of life, is involved in transcription elongation and termination, as well as in the process of transcription-translation coupling. The existence of species-specific functional, as well as conformational, divergences in NusG makes it an attractive transcription factor to study, especially if it originates from a pathogen. Here, we report functional and conformational characterizations of the Mycobacterium tuberculosis (Mtb) protein Rv0639 that has been annotated as a homologue of Escherichia coli NusG. Rv0639 failed to complement the in vivo functions of E. coli NusG (Ec NusG) and did not exhibit any signature of a transcription elongation-termination factor. However, it retained the ability to bind to its cognate ribosomal protein S10 (Rv0700). Compared with Ec NusG, Rv0639 possesses unique conformational features characterized by altered secondary structures in the C-terminal domain (CTD), an unusually long and disordered linker region between the N-terminal domain (NTD) and CTD, and a folding of its NTD over its CTD. This unusual folded conformation could have imparted specialized functions to this protein, required to adapt the physiology of Mtb. We speculate that in the absence of a bona fide RfaH, a NusG paralogue that is involved in pathogenicity in E. coli, Rv0639 functions as an RfaH-like factor and is involved in pathogenicity using unidentified ops-like sequences in the Mtb genome. And hence, we reannotate Rv0639 as a paralogue of NusG, instead of a homologue.

  14. 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.

  15. Bacterial global regulators DksA/ppGpp increase fidelity of transcription.

    Science.gov (United States)

    Roghanian, Mohammad; Zenkin, Nikolay; Yuzenkova, Yulia

    2015-02-18

    Collisions between paused transcription elongation complexes and replication forks inevitably happen, which may lead to collapse of replication fork and could be detrimental to cells. Bacterial transcription factor DksA and its cofactor alarmone ppGpp were proposed to contribute to prevention of such collisions, although the mechanism of this activity remains elusive. Here we show that DksA/ppGpp do not destabilise transcription elongation complexes or inhibit their backtracking, as was proposed earlier. Instead, we show, both in vitro and in vivo, that DksA/ppGpp increase fidelity of transcription elongation by slowing down misincorporation events. As misincorporation events cause temporary pauses, contribution to fidelity suggests the mechanism by which DksA/ppGpp contribute to prevention of collisions of transcription elongation complexes with replication forks. DksA is only the second known accessory factor, after transcription factor Gre, that increases fidelity of RNA synthesis in bacteria.

  16. 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

  17. 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.

    Science.gov (United States)

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

    2012-11-13

    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 reduced

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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 inhibition

  4. 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

  5. Bacterial Etiology and Risk Factors Associated with Cellulitis and Purulent Skin Abscesses in Military Trainees

    Science.gov (United States)

    Johnson, Ryan C.; Ellis, Michael W.; Schlett, Carey D.; Millar, Eugene V.; LaBreck, Patrick T.; Mor, Deepika; Elassal, Emad M.; Lanier, Jeffrey B.; Redden, Cassie L.; Cui, Tianyuan; Teneza-Mora, Nimfa; Bishop, Danett K.; Hall, Eric R.; Bishop-Lilly, Kimberly A.

    2016-01-01

    Military trainees are at high risk for skin and soft-tissue infections (SSTIs). Although Staphylococcus aureus is associated with purulent SSTI, it is unclear to what degree this pathogen causes nonpurulent cellulitis. To inform effective prevention strategies and to provide novel insights into SSTI pathogenesis, we aimed to determine the etiology of SSTI in this population. We conducted a prospective observational study in US Army Infantry trainees with SSTI (cutaneous abscesses and cellulitis) from July 2012 through December 2014. We used standard microbiology, serology, and high-throughput sequencing to determine the etiology of SSTI. Furthermore, we compared purported risk factors as well as anatomic site colonization for S. aureus. Among 201 SSTI cases evaluated for SSTI risk factors, cellulitis was associated with lower extremity blisters (P = 0.01) and abscess was associated with methicillin-resistant S. aureus (MRSA) colonization (Pmicrobiome analysis, only 1 leading edge aspirate was culturable (Coagulase-negative Staphylococcus). Microbiome evaluation of aspirate specimens demonstrated that Rhodanobacter terrae was the most abundant species (66.8% average abundance), while abscesses were dominated by S. aureus (92.9% average abundance). Although abscesses and cellulitis share the spectrum of clinical SSTI, the bacterial etiologies as determined by current technology appear distinct. Furthermore, the presence of atypical bacteria within cellulitis aspirates may indicate novel mechanisms of cellulitis pathogenesis. Clinical Trials Registration: NCT01105767. PMID:27780238

  6. 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.

  7. Control of Transcriptional Elongation by RNA Polymerase II: A Retrospective.

    Science.gov (United States)

    Brannan, Kris; Bentley, David L

    2012-01-01

    The origins of our current understanding of control of transcription elongation lie in pioneering experiments that mapped RNA polymerase II on viral and cellular genes. These studies first uncovered the surprising excess of polymerase molecules that we now know to be situated at the at the 5' ends of most genes in multicellular organisms. The pileup of pol II near transcription start sites reflects a ubiquitous bottle-neck that limits elongation right at the start of the transcription elongation. Subsequent seminal work identified conserved protein factors that positively and negatively control the flux of polymerase through this bottle-neck, and make a major contribution to control of gene expression. PMID:22567377

  8. 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.

  9. Bacterial blight (Pseudomonas pisi Sackett) of peas in South Africa, with special reference to frost as a predisposing factor

    NARCIS (Netherlands)

    Boelema, B.H.

    1972-01-01

    In the beginning of the nineteen fifties bacterial blight caused much damage to pea crops in South Africa, particularly to those grown for seed production. A study has been made of the causal organism and the conditioning factors of the disease, special attention being paid to frost as a predisposin

  10. 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.

  11. 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

  12. 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...

  13. 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.

  14. 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

  15. 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

    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...... concentrations in plasma changed during surgery. In vitro stimulation of blood samples with bacteria-derived antigens resulted in a significant increase in sVEGF (p ... significantly with neutrophil cell counts (0.53 surgery. In vitro bacterial stimulation led to increased release of sVEGF, which...

  16. Grain Size Dependence of Uniform Elongation in Single-Phase FCC/BCC Metals

    Science.gov (United States)

    Liu, Haiting; Shen, Yao; Ma, Jiawei; Zheng, Pengfei; Zhang, Lei

    2016-09-01

    We studied the dependence of uniform elongation on grain size in the range of submicron to millimeter for single-phase FCC/BCC metals by reviewing recent experimental results and applying crystal plasticity finite element method simulation. In the order of increasing grain size, uniform elongation can be divided into three stages, namely low elongation stage, nearly constant elongation stage, and decreased elongation with large scatters stage. Low elongation stage features a dramatic increase near the critical grain size at the end of the stage, which is primarily attributed to the emergence of dislocation cell size transition from ultrafine to mid-size grain. Other factors can be neglected due to their negligible influence on overall variation trend. In nearly constant elongation stage, uniform elongation remains unchanged at a high level in general. As grain size keeps growing, uniform elongation starts decreasing and becomes scattered upon a certain grain size, indicating the initiation of decreased elongation with large scatters stage. It is shown that the increase is not linear or smooth but rather sharp at the end of low elongation stage, leading to a wider range in nearly constant elongation stage. The grain size dependence of uniform elongation can serve as a guiding principle for designing small uniaxial tensile specimens for mechanical testing, where size effect matters in most cases.

  17. 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.

  18. 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...

  19. 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.

  20. What doesn’t kill them makes them stronger: an association between elongation factor 1-α overdominance in the sea star Pisaster ochraceus and “sea star wasting disease”

    Science.gov (United States)

    Schiebelhut, Lauren M.

    2016-01-01

    In recent years, a massive mortality event has killed millions of sea stars, of many different species, along the Pacific coast of North America. This disease event, known as ‘sea star wasting disease’ (SSWD), is linked to viral infection. In one affected sea star (Pisaster ochraceus), previous work had identified that the elongation factor 1-α locus (EF1A) harbored an intronic insertion allele that is lethal when homozygous yet appears to be maintained at moderate frequency in populations through increased fitness for heterozygotes. The environmental conditions supporting this increased fitness are unknown, but overdominance is often associated with disease. Here, we evaluate populations of P. ochraceus to identify the relationship between SSWD and EF1A genotype. Our data suggest that there may be significantly decreased occurrence of SSWD in individuals that are heterozygous at this locus. These results suggest further studies are warranted to understand the functional relationship between diversity at EF1A and survival in P. ochraceus. PMID:27069810

  1. Direct Characterization of Transcription Elongation by RNA Polymerase I.

    Science.gov (United States)

    Ucuncuoglu, Suleyman; Engel, Krysta L; Purohit, Prashant K; Dunlap, David D; Schneider, David A; Finzi, Laura

    2016-01-01

    RNA polymerase I (Pol I) transcribes ribosomal DNA and is responsible for more than 60% of transcription in a growing cell. Despite this fundamental role that directly impacts cell growth and proliferation, the kinetics of transcription by Pol I are poorly understood. This study provides direct characterization of S. Cerevisiae Pol I transcription elongation using tethered particle microscopy (TPM). Pol I was shown to elongate at an average rate of approximately 20 nt/s. However, the maximum speed observed was, in average, about 60 nt/s, comparable to the rate calculated based on the in vivo number of active genes, the cell division rate and the number of engaged polymerases observed in EM images. Addition of RNA endonucleases to the TPM elongation assays enhanced processivity. Together, these data suggest that additional transcription factors contribute to efficient and processive transcription elongation by RNA polymerase I in vivo. PMID:27455049

  2. 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.

  3. Relationship among specific bacterial counts and total bacterial and somatic cell counts and factors influencing their variation in ovine bulk tank milk.

    Science.gov (United States)

    de Garnica, M L; Linage, B; Carriedo, J A; De La Fuente, L F; García-Jimeno, M C; Santos, J A; Gonzalo, C

    2013-02-01

    To analyze the relationship among the counts of different organisms and total bacterial count (BTTBC) and somatic cell count (BTSCC) as determined in dairy laboratories in ovine bulk tank milk, 751 bulk tank milk samples from 205 dairy sheep flocks belonging to Consortium for Ovine Promotion (CPO) were collected between January and December 2011. Four samplings were carried out in each flock, once per season, throughout 1 yr. Variables analyzed were bulk tank counts of thermoduric, psychrotrophic, coliform, and gram-positive catalase-negative cocci (GPCNC) bacterial groups. Thermoduric, psychrotrophic, and coliform species were significantly related to BTTBC, whereas GPCNC were correlated with both BTTBC and BTSCC variables. Highest counts were for psychrotroph and coliform groups, and a moderate to high correlation (r=0.51) was found between both variables, indicating that poor cleaning practices in the flocks tend to select for less-resistant organisms, such as gram-negative rods. In addition, BTTBC correlated with BTSCC (r=0.42). Some variation factors for specific bacterial counts, such as breed, season, milking type, dry therapy, and milk yield, were also analyzed. Flock information was collected from flock books, annual audits, and the CPO traceability system. Psychrotrophs and coliforms had elevated counts in winter, whereas GPCNC were higher in summer and in hand-milked flocks. Dry therapy contributed to the reduction in psychrotrophic bacteria; therefore, some strains of mammary pathogens could also be psychrotrophic bacteria. Results of this study would be helpful for troubleshooting milk quality problems and developing premium payment systems in dairy sheep.

  4. Factors influencing neurological outcome of children with bacterial meningitis at the emergency department.

    Science.gov (United States)

    Bargui, Fatiha; D'Agostino, Irene; Mariani-Kurkdjian, Patricia; Alberti, Corinne; Doit, Catherine; Bellier, Nathalie; Morin, Laurence; Galli Gibertini, Giuliano; Smail, Assia; Zanin, Anna; Lorrot, Mathie; Dauger, Stéphane; Neve, Mathieu; Faye, Albert; Armoogum, Priscilla; Bourrillon, Antoine; Bingen, Edouard; Mercier, Jean-Christophe; Bonacorsi, Stéphane; Nigrovic, Lise E; Titomanlio, Luigi

    2012-09-01

    We performed a cohort study of children who survived bacterial meningitis after the neonatal period at a single pediatric center in France over a 10-year period (1995-2004) to identify predictors of death and long-term neurological deficits in children with bacterial meningitis. We performed multivariate regression to determine independent predictors of death and neurologic deficits. We identified 101 children with bacterial meningitis of which 19 died during initial hospitalization. Need for mechanical ventilation [hazard ratio (HR) 11.5, 95 % confidence interval (CI) 2.4-55.5)] and thrombocytopenia defined as a platelet count highest risk.

  5. Hack's Law: Sinuosity, convexity, elongation

    Science.gov (United States)

    Willemin, James H.

    2000-11-01

    Hack's law, an empirical, power law relationship between drainage basin area and the length of the main stream channel, has long been taken to imply that drainage basins become more elongate (relatively longer and narrower) with increasing basin size. A study of the geometry of 38 basins from three distinct geomorphic settings shows that this geometric interpretation of Hack's law is only occasionally true: Even though Hack's power law relationship holds between basin area and main channel length, these basins do not necessarily become more elongate with increasing size. Rather, Hack's law is an expression of a balance between changes in basin shape and changes in channel planform geometry. For the basins in this study, changes in channel sinuosity play the most important role in this balance; changes in basin shape are far less regular. Local conditions appear to determine the partitioning of importance between changes in basin shape and channel sinuosity.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

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

    OpenAIRE

    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...

  12. Fatores de risco para meningite bacteriana no recém-nascido Risk factors for bacterial meningitis in the newborn

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Jornada Krebs

    2004-09-01

    Full Text Available O objetivo do estudo é descrever os fatores de risco para meningite bacteriana em recém-nascidos e analisar a prevalência destes fatores, considerando-se a presença ou não de baixo peso ao nascimento. Foram analisados 50 recém-nascidos com meningite bacteriana, excluindo-se aqueles com meningomielocele ou infecção congênita. Na análise estatística utilizou-se o teste exato de Fisher, considerando-se significantes os valores de p The aim of this study is to describe the risk factors for bacterial meningitis in newborns, and to analyze the prevalence of these factors, considering or not the low birth weight presence. Fifty newborns with bacterial meningitis were analyzed, excluding the ones with meningomyelocele or congenital infection. In the statistical analysis, the Fisher's exact test was used, considering significant the p < 0.05 values. This study has shown that prematurity, low birth weight and presence of previous infectious diseases in the newborn or in the mother were important risk factors for meningitis. Among low birth weight newborns, invasive procedures, especially tracheal intubation, use of central venous catheter and previous use of antibiotics, were significantly associated to the meningitis occurrence. These results indicate that the improvement in the prenatal care and in the hospital infection control are measures of high importance in the decrease of the incidence of neonatal bacterial meningitis.

  13. 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

  14. 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.

  15. 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

  16. 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....

  17. Factors affecting bacterial counts during preparation of the hands for aseptic surgery.

    Science.gov (United States)

    Corder, K; Knowles, T G; Holt, P E

    2007-06-30

    This study was designed to compare the efficacy of four hand preparation techniques in removing bacteria from the hands preoperatively. The effect of bacteriological swabbing itself on bacterial counts was also investigated. The numbers of bacteria obtained from the dominant and non-dominant hands were also determined. The techniques all used 4 per cent chlorhexidine gluconate, and consisted of rubbing for five minutes with one application of antiseptic; rubbing for five minutes with five applications of antiseptic; rubbing for one minute with one application of antiseptic; and scrubbing with a brush for five minutes with one application of antiseptic. The results showed that the four techniques were equally effective at removing bacteria. There was no significant difference in the bacterial counts obtained from the dominant and non-dominant hands. The wearing of gloves for up to 30 minutes after scrubbing had no effect on the bacterial counts. Swabbing itself significantly reduced the number of bacteria cultured from the hands.

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

    Directory of Open Access Journals (Sweden)

    AA Gharamah

    2012-08-01

    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.

  19. 细菌性阴道炎危险因素分析%Risk Factors for Bacterial Vaginitis

    Institute of Scientific and Technical Information of China (English)

    吴宏宇; 王敬华; 祁建青; 卢艳阳

    2011-01-01

    目的:分析细菌性阴道炎患病的相关因素,探讨其预防措施.方法:选择本院门诊检测细菌性阴道炎阳性患者180 例作为病例组,180 例细菌性阴道炎阴性者作为对照组,对其细菌性阴道炎相关因素进行分析,本研究相关危险因素包括:其他性传播疾病(衣原体感染史、淋病史、霉菌性阴道炎史及滴虫性阴道炎史)、避孕方式(避孕套、宫内节育器及安全期避孕)、相关行为因素(阴道清洁次数、方式,内裤消毒、洗澡地点及方式、性卫生习惯,流产次数).结果:单因素分析结果:淋病史、霉菌性阴道炎史、滴虫性阴道炎史、多次流产、及经常清洗阴道可增加细菌性阴道炎患病风险,选择避孕套避孕及良好的卫生习惯是细菌性阴道炎的保护因素;多因素Logistic 回归结果:滴虫性阴道炎史(OR=9.21) 、人流次数(OR=5.34) 、清洗阴道(OR=2.16) 可升高细菌性阴道炎患病风险,使用避孕套(OR=0.49) 、良好性卫生习惯(OR=0.53) 则具有保护作用.结论:避孕套避孕和良好的性卫生习惯可降低细菌性阴道炎的发病风险.%Objective: Analysis the risk factors of bacterial vaginitis and explore its preventive measures. Methods: Detection bacterial vzginosis-positive patients 180 cases as patient case group, 180 patients with bacterial vaginitis-negative as control group and bacterial vaginitis-related faceors were analyzed. In this study, risk factors include other sexually transmitted diseases, contraception and the behavioral factors. Results: Univariste analysia result: the history of ginirrhea, fungal vaginitis, trichomonas vaginitis, miscarriages times and vagina cleaning may increase the disease risk of bacterial vaginitis and the use of condom and the good sexual health habits may be a protective factor for bacterial vaginitis. Logistic regression results: Trichomonas vaginitis history(OR=9.12), flow times(OR=5.34)and cleaning the vagina(OR=2.16) may

  20. 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

  1. Th1 stimulatory proteins of Leishmania donovani: comparative cellular and protective responses of rTriose phosphate isomerase, rProtein disulfide isomerase and rElongation factor-2 in combination with rHSP70 against visceral leishmaniasis.

    Science.gov (United States)

    Jaiswal, Anil Kumar; Khare, Prashant; Joshi, Sumit; Kushawaha, Pramod Kumar; Sundar, Shyam; Dube, Anuradha

    2014-01-01

    In visceral leishmaniasis, the recovery from the disease is always associated with the generation of Th1-type of cellular responses. Based on this, we have previously identified several Th1-stimulatory proteins of Leishmania donovani -triose phosphate isomerase (TPI), protein disulfide isomerase (PDI) and elongation factor-2 (EL-2) etc. including heat shock protein 70 (HSP70) which induced Th1-type of cellular responses in both cured Leishmania patients/hamsters. Since, HSPs, being the logical targets for vaccines aimed at augmenting cellular immunity and can be early targets in the immune response against intracellular pathogens; they could be exploited as vaccine/adjuvant to induce long-term immunity more effectively. Therefore, in this study, we checked whether HSP70 can further enhance the immunogenicity and protective responses of the above said Th1-stimulatory proteins. Since, in most of the studies, immunogenicity of HSP70 of L. donovani was assessed in native condition, herein we generated recombinant HSP70 and tested its potential to stimulate immune responses in lymphocytes of cured Leishmania infected hamsters as well as in the peripheral blood mononuclear cells (PBMCs) of cured patients of VL either individually or in combination with above mentioned recombinant proteins. rLdHSP70 alone elicited strong cellular responses along with remarkable up-regulation of IFN-γ and IL-12 cytokines and extremely lower level of IL-4 and IL-10. Among the various combinations, rLdHSP70 + rLdPDI emerged as superior one augmenting improved cellular responses followed by rLdHSP70 + rLdEL-2. These combinations were further evaluated for its protective potential wherein rLdHSP70 + rLdPDI again conferred utmost protection (∼80%) followed by rLdHSP70 + rLdEL-2 (∼75%) and generated a strong cellular immune response with significant increase in the levels of iNOS transcript as well as IFN-γ and IL-12 cytokines which was further supported by the high level of IgG2 antibody

  2. Ubiquitylation and degradation of elongating RNA polymerase II

    DEFF Research Database (Denmark)

    Wilson, Marcus D; Harreman, Michelle; Svejstrup, Jesper Q

    2013-01-01

    During its journey across a gene, RNA polymerase II has to contend with a number of obstacles to its progression, including nucleosomes, DNA-binding proteins, DNA damage, and sequences that are intrinsically difficult to transcribe. Not surprisingly, a large number of elongation factors have...

  3. 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)

  4. 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

  5. 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

  6. Bilateral elongated mandibular coronoid process in an Anatolian skull

    Science.gov (United States)

    Çorumlu, Ufuk; Demir, Mehmet Tevfik; Pirzirenli, Mennan Ece

    2016-01-01

    Elongation or hyperplasia of coronoid process of mandible is rare condition characterized by abnormal bone development which cause malocclusion and the limited mouth opening. In this study, in an Anatolian skull, a case of bilateral elongation of mandibular coronoid process was presented. Levandoski panographic analysis was performed on the panoramic radiographie to determine the hyperplasia of the coronoid process. The right condylar process was exactly hyperplastic. The measurements of Kr-Go/Cd-Go were 95.10 mm/79.03 mm on right side and 97.53 mm/87.80 mm on left side. The ratio of Kr-Go/Cd-Go on the right side was 1.20. Elongated coronoid process is one of the factors cause mandibular hypomobility, it as reported here might lead to limited mouth opening. The knowledge of this variation or abnormality can be useful for the radiologist and surgeons and prevent misdiagnosis. PMID:27722017

  7. 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

  8. Arabidopsis clade I TGA factors regulate apoplastic defences against the bacterial pathogen Pseudomonas syringae through endoplasmic reticulum-based processes.

    Directory of Open Access Journals (Sweden)

    Lipu Wang

    Full Text Available 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, following elicitation with salicylic acid (SA, clade I function was shown to be largely independent of NPR1. Unlike mutants in NPR1, tga1-1 tga4-1 plants do not display reductions in steady-state levels of SA-pathway marker genes following treatment with this phenolic signaling metabolite or after challenge with virulent or avirulent P. syringae. By exploiting bacterial strains that have limited capacity to suppress Arabidopsis defence responses, the present study demonstrates that tga1-1 tga4-1 plants are compromised in basal resistance and defective in several apoplastic defence responses, including the oxidative burst of reactive oxygen species, callose deposition, as well as total and apoplastic PATHOGENESIS-RELATED 1 (PR-1 protein accumulation. Furthermore, analysis of npr1-1 and the tga1-1 tga4-1 npr1-1 triple mutant indicates that clade I TGA factors act substantially independent of NPR1 in mediating disease resistance against these strains of P. syringae. Increased sensitivity to the N-glycosylation inhibitor tunicamycin and elevated levels of endoplasmic reticulum (ER stress marker genes encoding ER-resident chaperones in mutant seedlings suggest that loss of apoplastic defence responses is associated with aberrant protein secretion and implicate clade I TGA factors as positive regulators of one or more ER-related secretion pathways.

  9. 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

  10. Short communication: bulk tank total bacterial count in dairy sheep: factors of variation and relationship with somatic cell count.

    Science.gov (United States)

    Gonzalo, C; Carriedo, J A; Beneitez, E; Juárez, M T; De La Fuente, L F; San Primitivo, F

    2006-02-01

    A total of 9,353 records for bulk tank total bacterial count (TBC) were obtained over 1 yr from 315 dairy ewe flocks belonging to the Sheep Improvement Consortium (CPO) in Castilla-León (Spain). Analysis of variance showed significant effects of flock, breed, month within flock, dry therapy, milking type and installation, and logSCC on logTBC. Flock and month within flock were important variation factors as they accounted for 22.0 and 22.1% of the variance, respectively. Considerable repeatability values were obtained for both random factors. Hand milking and bucket-milking machines elicited highest logTBC (5.31), whereas parlor systems with looped milkline (5.01) elicited the lowest logTBC. The implementation of dry therapy practice (5.12) showed significantly lower logTBC than when not used (5.25). Variability in logTBC among breeds ranged from 5.24 (Awassi) to 5.07 (Churra). However, clinical outbreaks of contagious agalactia did not increase TBC significantly. A statistically significant relationship was found between logTBC and logSCC, the correlation coefficient between the variables being r = 0.23. Programs for improving milk hygiene should be implemented for both total bacterial count and somatic cell count variables at the same time.

  11. 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.

  12. 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.

  13. 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...

  14. 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.

  15. 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...

  16. 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.

  17. Risk factors and clinical outcomes of bacterial and fungal scleritis at a tertiary eye care hospital

    Directory of Open Access Journals (Sweden)

    Jagadesh C Reddy

    2015-01-01

    Conclusions: Surgery is a major risk factor for infectious scleritis in our series. Fungus was the most common organism isolated. Thorough debridement and intensive use of medications have improved the outcome.

  18. The Bacterial Transcription Termination Factor Rho Coordinates Mg(2+) Homeostasis with Translational Signals.

    Science.gov (United States)

    Kriner, Michelle A; Groisman, Eduardo A

    2015-12-01

    The bacterial protein Rho triggers transcription termination at the ends of many operons and when transcription and translation become uncoupled. In addition to these genome wide activities, Rho implements regulation of specific genes by dictating whether RNA polymerase terminates transcription within the 5' leader region or continues into the downstream coding region. Here, we report that the Mg(2+) channel gene corA in Salmonella enterica serovar Typhimurium, which was previously thought to be constitutively expressed, is regulated by a Rho-dependent terminator located within its 5' leader region. We demonstrate that the unusually long and highly conserved corA leader mRNA can adopt two mutually exclusive conformations that determine whether or not Rho interacts with a Rho utilization site on the nascent RNA and thereby prevents transcription of the corA coding region. The RNA conformation that promotes Rho-dependent termination is favored by efficient translation of corL, a short open reading frame located within the corA leader. Thus, corA transcription is inversely coupled to corL translation. This mechanism resembles those governing expression of Salmonella's other two Mg(2+) transport genes, suggesting that Rho links Mg(2+) uptake to translational signals. PMID:26523680

  19. 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

  20. A systematic approach for the assessment of bacterial growth-controlling factors linked to biological stability of drinking water in distribution systems

    KAUST Repository

    Prest, E. I.

    2016-01-06

    A systematic approach is presented for the assessment of (i) bacterial growth-controlling factors in drinking water and (ii) the impact of distribution conditions on the extent of bacterial growth in full-scale distribution systems. The approach combines (i) quantification of changes in autochthonous bacterial cell concentrations in full-scale distribution systems with (ii) laboratoryscale batch bacterial growth potential tests of drinking water samples under defined conditions. The growth potential tests were done by direct incubation of water samples, without modification of the original bacterial flora, and with flow cytometric quantification of bacterial growth. This method was shown to be reproducible (ca. 4% relative standard deviation) and sensitive (detection of bacterial growth down to 5 μg L-1 of added assimilable organic carbon). The principle of step-wise assessment of bacterial growth-controlling factors was demonstrated on bottled water, shown to be primarily carbon limited at 133 (±18) × 103 cells mL-1 and secondarily limited by inorganic nutrients at 5,500 (±1,700) × 103 cells mL-1. Analysis of the effluent of a Dutch full-scale drinking water treatment plant showed (1) bacterial growth inhibition as a result of end-point chlorination, (2) organic carbon limitation at 192 (±72) × 103 cells mL-1 and (3) inorganic nutrient limitation at 375 (±31) × 103 cells mL-1. Significantly lower net bacterial growth was measured in the corresponding full-scale distribution system (176 (±25) × 103 cells mL-1) than in the laboratory-scale growth potential test of the same water (294 (±35) × 103 cells mL-1), highlighting the influence of distribution on bacterial growth. The systematic approach described herein provides quantitative information on the effect of drinking water properties and distribution system conditions on biological stability, which can assist water utilities in decision-making on treatment or distribution system improvements to

  1. Effect of amphetamine on eukaryotic translation elongation factor 2 in the frontal cortex of mice%苯丙胺对小鼠额叶皮质真核翻译延伸因子2的影响

    Institute of Scientific and Technical Information of China (English)

    刘钦; 曾文钦; 程亚涛; 姚前尹

    2015-01-01

    Objective To explore the effect of amphetamine on eukaryotic translation elongation factor 2 (eEF2) in the frontal cortex of mice.Methods Male C57BL/6 mice were randomly divided into normal control group (n=10),saline group (n=10) and amphetamine treatment group (n=40);the amphetamine treatment group was divided into 1,7,14 and 28 d subgroups (n=10).Mice in the amphetamine treatment group were treated with amphetamine 2 mg/(kg· d) via intraperitoneal injection;those in the saline group received a same dose of saline,while those in the normal control group received no treatment.Autonomous behavior activities were tested during establishing amphetamine models.Immunohistochemistry and Westem blotting were used to identify the eEF2 expressions.Results Behaviour test showed that total moving distance,average speed,maximum speed,moving fast time/total time in the 7,14 and 28 d amphetamine treatment subgroups were significantly increased as compared with those in the normal control group and saline group (P<0.05).Immumohistochemical staining indicated that the grey values of eEF2-positive inummoreactive products in the amphetamine treatment group were significantly lower than those in the normal control group and saline group (P<0.05);those of eEF2-positive inummoreactive products in 14 and 28 d amphetamine treatment subgroups were significantly lower than those in 1 and 7 d amphetamine treatment subgroups (P<0.05).Western blotting showed that eEF2 protein expression in the frontal cortex was significantly elevated in the amphetamine treatment group as compared with that in the other two groups (P<0.05);the eEF2 expression in the amphetamine treatment group increased with time prolonging within 28 days after establishment of models.Conclusion Amphetamine can induce increased eEF2 expression in the frontal cortex of mice.%目的 观察苯丙胺干预后小鼠额叶皮质内真核翻译延伸因子2(eEF2)的表达情况.方法 雄性C57BL/6小鼠按随机数

  2. Role of Staphylococcus aureus Virulence Factors in Inducing Inflammation and Vascular Permeability in a Mouse Model of Bacterial Endophthalmitis.

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    Full Text Available Staphylococcus (S. aureus is a common causative agent of bacterial endophthalmitis, a vision threatening complication of eye surgeries. The relative contribution of S. aureus virulence factors in the pathogenesis of endophthalmitis remains unclear. Here, we comprehensively analyzed the development of intraocular inflammation, vascular permeability, and the loss of retinal function in C57BL/6 mouse eyes, challenged with live S. aureus, heat-killed S. aureus (HKSA, peptidoglycan (PGN, lipoteichoic acid (LTA, staphylococcal protein A (SPA, α-toxin, and Toxic-shock syndrome toxin 1 (TSST1. Our data showed a dose-dependent (range 0.01 μg/eye to 1.0 μg/eye increase in the levels of inflammatory mediators by all virulence factors. The cell wall components, particularly PGN and LTA, seem to induce higher levels of TNF-α, IL-6, KC, and MIP2, whereas the toxins induced IL-1β. Similarly, among the virulence factors, PGN induced higher PMN infiltration. The vascular permeability assay revealed significant leakage in eyes challenged with live SA (12-fold and HKSA (7.3-fold, in comparison to other virulence factors (~2-fold and controls. These changes coincided with retinal tissue damage, as evidenced by histological analysis. The electroretinogram (ERG analysis revealed a significant decline in retinal function in eyes inoculated with live SA, followed by HKSA, SPA, and α-toxin. Together, these findings demonstrate the differential innate responses of the retina to S. aureus virulence factors, which contribute to intraocular inflammation and retinal function loss in endophthalmitis.

  3. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    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 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 significantly...

  4. Mutual interdependence of splicing and transcription elongation.

    Science.gov (United States)

    Brzyżek, Grzegorz; Świeżewski, Szymon

    2015-01-01

    Transcription and splicing are intrinsically linked, as splicing needs a pre-mRNA substrate to commence. The more nuanced view is that the rate of transcription contributes to splicing regulation. On the other hand there is accumulating evidence that splicing has an active role in controlling transcription elongation by DNA-dependent RNA polymerase II (RNAP II). We briefly review those mechanisms and propose a unifying model where splicing controls transcription elongation to provide an optimal timing for successive rounds of splicing.

  5. 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.

  6. 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

  7. 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

  8. 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...

  9. 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 ...

  10. 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

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

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    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.

  12. 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

  13. Prevalence and Risk Factors for Bacterial Vaginosis and Other Vulvovaginitis in a Population of Sexually Active Adolescents from Salvador, Bahia, Brazil

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    Rita Elizabeth Moreira Mascarenhas

    2012-01-01

    Full Text Available Bacterial vaginosis, trichomoniasis, and genital candidiasis are considered the main etiologies of vulvovaginitis. Few studies estimate the prevalence of vulvovaginitis among adolescents, especially in Brazil. This study aimed to determine the prevalence and main risk factors associated with bacterial vaginosis and genital infection by C. albicans and Trichomonas vaginalis among a group of adolescents from Salvador, Bahia, Brazil. One hundred sexually active adolescents followed at an adolescent gynecology clinic were included. Endocervical and vaginal samples were obtained during gynecological examination. Nugent criteria were applied for the diagnosis of bacterial vaginosis. For Candida albicans and Trichomonas vaginalis detection, culture in Sabouraud agar plates and Papanicolaou cytology were used, respectively. The mean age of participants was 16.6±1.6 years. The prevalence of bacterial vaginosis was 20% (95% CI 12–28 and of genital infection by Candida was 22% (95% CI 14–30. Vaginal cytology detected Trichomonas vaginalis in one patient. Alcohol, tobacco, and illegal drug use (P=0.02 and multiple lifetime partners were statistically related to bacterial vaginosis (P=0.01. The prevalence of bacterial vaginosis and genital candidiasis was similar to other studies carried out among adolescents worldwide.

  14. Effects of granulocyte-colony stimulating factor on peritoneal defense mechanisms and bacterial translocation after administration of systemic chemotherapy in rats

    Institute of Scientific and Technical Information of China (English)

    Celal Cerci; Cagri Ergin; Erol Eroglu; Canan Agalar; Fatih Agalar; Sureyya Cerci; Mahmut Bulbul

    2007-01-01

    AIM: To investigate the effects of granulocyte-colony stimulating factor (G-CSF) on peritoneal defense mechanisms and bacterial translocation after systemic 5-Fluorouracil (5-FU) administration.METHODS: Thirty Wistar albino rats were divided into three groups; the control, 5-FU and 5-FU + G-CSF groups. We measured bactericidal activity of the peritoneal fluid, phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid, total peritoneal cell counts and cell types of peritoneal washing fluid.Bacterial translocation was quantified by mesenteric lymph node, liver and spleen tissue cultures.RESULTS: Systemic 5-FU reduced total peritoneal cell counts, neutrophils and macrophage numbers. It also altered bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. 5-FU also caused significant increase in frequencies of bacterial translocation at the liver and mesenteric lymph nodes. G-CSF decreased bacterial translocation, it significantly enhanced bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. It also increased total peritoneal cell counts, neutrophils and macrophage numbers.CONCLUSION: Systemic 5-FU administration caused bacterial translocation, decreased the bactericidal activity of peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. G-CSF increased both bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid, and prevented the bacterial translocation. We conclude that intraperitoneal GCSF administration protects the effects of systemic 5-FU on peritoneal defense mechanisms.

  15. 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

  16. Telomere elongation chooses TERRA ALTernatives.

    Science.gov (United States)

    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 remains elusive. Mounting evidence suggests that the long noncoding telomeric RNA TERRA renders ALT telomeres recombinogenic by forming RNA:DNA hybrids with the telomeric C-rich strand. TERRA and telomeric hybrids act in concert with a number of other factors, including the RNA endoribonuclease RNaseH1 and the single stranded DNA binding protein RPA. The functional interaction network built upon these different players seems indispensable for ALT telomere maintenance, and digging into the molecular details of this previously unappreciated network might open the way to novel avenues for cancer treatments.

  17. Bacterial vaginosis: a synthesis of the literature on etiology, prevalence, risk factors, and relationship with chlamydia and gonorrhea infections.

    Science.gov (United States)

    Bautista, Christian T; Wurapa, Eyako; Sateren, Warren B; Morris, Sara; Hollingsworth, Bruce; Sanchez, Jose L

    2016-01-01

    Bacterial vaginosis (BV) is a common vaginal disorder in women of reproductive age. Since the initial work of Leopoldo in 1953 and Gardner and Dukes in 1955, researchers have not been able to identify the causative etiologic agent of BV. There is increasing evidence, however, that BV occurs when Lactobacillus spp., the predominant species in healthy vaginal flora, are replaced by anaerobic bacteria, such as Gardenella vaginalis, Mobiluncus curtisii, M. mulieris, other anaerobic bacteria and/or Mycoplasma hominis. Worldwide, it estimated that 20-30 % of women of reproductive age attending sexually transmitted infection (STI) clinics suffer from BV, and that its prevalence can be as high as 50-60 % in high-risk populations (e.g., those who practice commercial sex work (CSW). Epidemiological data show that women are more likely to report BV if they: 1) have had a higher number of lifetime sexual partners; 2) are unmarried; 3) have engaged in their first intercourse at a younger age; 4) have engaged in CSW, and 5) practice regular douching. In the past decade, several studies have provided evidence on the contribution of sexual activity to BV. However, it is difficult to state that BV is a STI without being able to identify the etiologic agent. BV has also emerged as a public health problem due to its association with other STIs, including: human immunodeficiency virus (HIV), herpes simplex virus type 2 (HSV-2), Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). The most recent evidence on the association between BV and CT/NG infection comes from two secondary analyses of cohort data conducted among women attending STI clinics. Based on these studies, women with BV had a 1.8 and 1.9-fold increased risk for NG and CT infection, respectively. Taken together, BV is likely a risk factor or at least an important contributor to subsequent NG or CT infection in high-risk women. Additional research is required to determine whether this association is also present in

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

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    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.

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

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    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.

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

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    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.

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

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    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

  2. A Conserved Nuclear Cyclophilin Is Required for Both RNA Polymerase II Elongation and Co-transcriptional Splicing in Caenorhabditis elegans.

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    Jeong H Ahn

    2016-08-01

    Full Text Available The elongation phase of transcription by RNA Polymerase II (Pol II involves numerous events that are tightly coordinated, including RNA processing, histone modification, and chromatin remodeling. RNA splicing factors are associated with elongating Pol II, and the interdependent coupling of splicing and elongation has been documented in several systems. Here we identify a conserved, multi-domain cyclophilin family member, SIG-7, as an essential factor for both normal transcription elongation and co-transcriptional splicing. In embryos depleted for SIG-7, RNA levels for over a thousand zygotically expressed genes are substantially reduced, Pol II becomes significantly reduced at the 3' end of genes, marks of transcription elongation are reduced, and unspliced mRNAs accumulate. Our findings suggest that SIG-7 plays a central role in both Pol II elongation and co-transcriptional splicing and may provide an important link for their coordination and regulation.

  3. A Conserved Nuclear Cyclophilin Is Required for Both RNA Polymerase II Elongation and Co-transcriptional Splicing in Caenorhabditis elegans

    Science.gov (United States)

    Ahn, Jeong H.; Rechsteiner, Andreas; Strome, Susan; Kelly, William G.

    2016-01-01

    The elongation phase of transcription by RNA Polymerase II (Pol II) involves numerous events that are tightly coordinated, including RNA processing, histone modification, and chromatin remodeling. RNA splicing factors are associated with elongating Pol II, and the interdependent coupling of splicing and elongation has been documented in several systems. Here we identify a conserved, multi-domain cyclophilin family member, SIG-7, as an essential factor for both normal transcription elongation and co-transcriptional splicing. In embryos depleted for SIG-7, RNA levels for over a thousand zygotically expressed genes are substantially reduced, Pol II becomes significantly reduced at the 3’ end of genes, marks of transcription elongation are reduced, and unspliced mRNAs accumulate. Our findings suggest that SIG-7 plays a central role in both Pol II elongation and co-transcriptional splicing and may provide an important link for their coordination and regulation. PMID:27541139

  4. 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)

  5. Targeting c-kit receptor in neuroblastomas and colorectal cancers using stem cell factor (SCF)-based recombinant bacterial toxins.

    Science.gov (United States)

    Choudhary, Swati; Pardo, Alessa; Rosinke, Reinhard; Batra, Janendra K; Barth, Stefan; Verma, Rama S

    2016-01-01

    Autocrine activation of c-kit (KIT receptor tyrosine kinase) has been postulated to be a potent oncogenic driver in small cell lung cancer, neuroblastoma (NB), and poorly differentiated colorectal carcinoma (CRC). Although targeted therapy involving tyrosine kinase inhibitors (TKIs) such as imatinib mesylate is highly effective for gastrointestinal stromal tumor carrying V560G c-kit mutation, it does not show much potential for targeting wild-type KIT (WT-KIT). Our study demonstrates the role of stem cell factor (SCF)-based toxin conjugates for targeting WT-KIT-overexpressing malignancies such as NBs and CRCs. We constructed SCF-based recombinant bacterial toxins by genetically fusing mutated form of natural ligand SCF to receptor binding deficient forms of Diphtheria toxin (DT) or Pseudomonas exotoxin A (ETA') and evaluated their efficacy in vitro. Efficient targeting was achieved in all receptor-positive neuroblastoma (IMR-32 and SHSY5Y) and colon cancer cell lines (COLO 320DM, HCT 116, and DLD-1) but not in receptor-negative breast carcinoma cell line (MCF-7) thereby proving specificity. While dose- and time-dependent cytotoxicity was observed in both neuroblastoma cell lines, COLO 320DM and HCT 116 cells, only an anti-proliferative effect was observed in DLD-1 cells. We prove that these novel targeting agents have promising potential as KIT receptor tyrosine kinase targeting system.

  6. Mycobacterium leprae-induced Insulin-like Growth Factor I attenuates antimicrobial mechanisms, promoting bacterial survival in macrophages

    Science.gov (United States)

    Batista-Silva, L. R.; Rodrigues, Luciana Silva; Vivarini, Aislan de Carvalho; Costa, Fabrício da Mota Ramalho; Mattos, Katherine Antunes de; Costa, Maria Renata Sales Nogueira; Rosa, Patricia Sammarco; Toledo-Pinto, T. G.; Dias, André Alves; Moura, Danielle Fonseca; Sarno, Euzenir Nunes; Lopes, Ulisses Gazos; Pessolani, Maria Cristina Vidal

    2016-01-01

    Mycobacterium leprae (ML), the etiologic agent of leprosy, can subvert macrophage antimicrobial activity by mechanisms that remain only partially understood. In the present study, the participation of hormone insulin-like growth factor I (IGF-I) in this phenomenum was investigated. Macrophages from the dermal lesions of the disseminated multibacillary lepromatous form (LL) of leprosy expressed higher levels of IGF-I than those from the self-limited paucibacillary tuberculoid form (BT). Higher levels of IGF-I secretion by ML-infected macrophages were confirmed in ex vivo and in vitro studies. Of note, the dampening of IGF-I signaling reverted the capacity of ML-infected human and murine macrophages to produce antimicrobial molecules and promoted bacterial killing. Moreover, IGF-I was shown to inhibit the JAK/STAT1-dependent signaling pathways triggered by both mycobacteria and IFN-γ most probably through its capacity to induce the suppressor of cytokine signaling-3 (SOCS3). Finally, these in vitro findings were corroborated by in vivo observations in which higher SOCS3 expression and lower phosphorylation of STAT1 levels were found in LL versus BT dermal lesions. Altogether, our data strongly suggest that IGF-I contributes to the maintenance of a functional program in infected macrophages that suits ML persistence in the host, reinforcing a key role for IGF-I in leprosy pathogenesis. PMID:27282338

  7. Pseudomonas fluorescens filamentous hemagglutinin, an iron-regulated protein, is an important virulence factor that modulates bacterial pathogenicity

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    Yuan-yuan Sun

    2016-08-01

    Full Text Available Pseudomonas fluorescens is a common bacterial pathogen to a wide range of aquaculture animals including various species of fish. In this study, we employed proteomic analysis and identified filamentous hemagglutinin (FHA as an iron-responsive protein secreted by TSS, a pathogenic P. fluorescens isolate. In vitro study showed that compared to the wild type, the fha mutant TSSfha (i exhibited a largely similar vegetative growth profile but significantly retarded in the ability of biofilm growth and producing extracellular matrix, (ii displayed no apparent flagella and motility, (iii was defective in the attachment to host cells and unable to form self-aggregation, (iv displayed markedly reduced capacity of hemagglutination and surviving in host serum. In vivo infection analysis revealed that TSSfha was significantly attenuated in the ability of dissemination in fish tissues and inducing host mortality, and that antibody blocking of the natural FHA produced by the wild type TSS impaired the infectivity of the pathogen. Furthermore, when introduced into turbot as a subunit vaccine, recombinant FHA elicited a significant protection against lethal TSS challenge. Taken together, these results indicate for the first time that P. fluorescens FHA is a key virulence factor essential to multiple biological processes associated with pathogenicity.

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

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    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.

  9. 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

  10. Pseudomonas fluorescens Filamentous Hemagglutinin, an Iron-Regulated Protein, Is an Important Virulence Factor that Modulates Bacterial Pathogenicity.

    Science.gov (United States)

    Sun, Yuan-Yuan; Chi, Heng; Sun, Li

    2016-01-01

    Pseudomonas fluorescens is a common bacterial pathogen to a wide range of aquaculture animals including various species of fish. In this study, we employed proteomic analysis and identified filamentous hemagglutinin (FHA) as an iron-responsive protein secreted by TSS, a pathogenic P. fluorescens isolate. In vitro study showed that compared to the wild type, the fha mutant TSSfha (i) exhibited a largely similar vegetative growth profile but significantly retarded in the ability of biofilm growth and producing extracellular matrix, (ii) displayed no apparent flagella and motility, (iii) was defective in the attachment to host cells and unable to form self-aggregation, (iv) displayed markedly reduced capacity of hemagglutination and surviving in host serum. In vivo infection analysis revealed that TSSfha was significantly attenuated in the ability of dissemination in fish tissues and inducing host mortality, and that antibody blocking of the natural FHA produced by the wild type TSS impaired the infectivity of the pathogen. Furthermore, when introduced into turbot as a subunit vaccine, recombinant FHA elicited a significant protection against lethal TSS challenge. Taken together, these results indicate for the first time that P. fluorescens FHA is a key virulence factor essential to multiple biological processes associated with pathogenicity. PMID:27602029

  11. 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.

  12. 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

  13. 中华绒螯蟹延伸因子EF-1δ基因全长cDNA克隆及表达%The full length cDNA cloning and expression of elongation factor 1δ from the Chinese mitten crab(Eriocheir sinensis)

    Institute of Scientific and Technical Information of China (English)

    郭子好; 杨志刚; 刘志伟; 王瑶; 杨筱珍; 成永旭

    2012-01-01

    Elongation factor (EF) is a protein factor which plays roles in the peptide chain elongation in the process of protein synthesis, including elongation factor 1( EF-1) and elongation factor 2(EF-2). Elongation factor 1 consists of four subunits a, p, y and 8, and plays a key role in protein translation process. In this study, we cloned EF-1δ gene from Eriocheir sinensis using reverse transcriptase polymerase chain reaction (RT-PCR) and rapid-amplification of cDNA ends (RACE), and primers were designed according to the conserved sequence of elongation factor-1δ from Xenopus laevis. The full-length cDNA sequence of EF-1δ is 933 bp which codes 263 amino acid residues. And comparison results showed that the nucleotide homology of EF-1δ was 70% similar to Xenopus laevis and amino acid homology of EF-1δ was 54% similar to Danaus plexippus, using BLASTN and BLASTX software. The phylogenetic analysis based on amino acid sequence shows that EF-1δ has highest similarity with EF-1δ of Lepeophtheirus salmonis. The expression of the gene in different tissues and stages of E. sinensis was analyzed by real-time fluorescent quantitative PCR. The result showed the EF-1δ mRNA was mainly detected in muscle and small amount in testis, hepatopancreas and trace in heart, ovary, stomach, intestine, gill. EF-1δ mRNA was detected with high level in muscles compared to hepatopancreas and gill in different developmental states of the crab, and displays significant difference at P<0.05. It also has significant difference at P<0.05 between muscles in different developmental states, and it was detected the highest expression in precocious crab, followed by mature crab and by a lower expression of crablet; And there is no significant expression difference between hepatopancreas and gill tissues in different developmental states.%根据非洲爪蟾延伸因子-1δ(elongation factor-1δ,EF-1δ)基因的保守序列设计引物,采用逆转录聚合酶链反应(RT-PCR)以及cDNA末端

  14. Segmentation of elongated structures in medical images

    NARCIS (Netherlands)

    Staal, Jozef Johannes

    2004-01-01

    The research described in this thesis concerns the automatic detection, recognition and segmentation of elongated structures in medical images. For this purpose techniques have been developed to detect subdimensional pointsets (e.g. ridges, edges) in images of arbitrary dimension. These pointsets ar

  15. Interplay between DNA supercoiling and transcription elongation.

    Science.gov (United States)

    Ma, Jie; Wang, Michelle

    2014-01-01

    Transcription-coupled DNA supercoiling has been shown to be an important regulator of transcription that is broadly present in the cell. Here we review experimental work which shows that RNA polymerase is a powerful torsional motor that can alter DNA topology and structure, and DNA supercoiling in turn directly affects transcription elongation.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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

  1. Factors influencing variation of bulk milk antibiotic residue occurrence, somatic cell count, and total bacterial count in dairy sheep flocks.

    Science.gov (United States)

    Gonzalo, C; Carriedo, J A; García-Jimeno, M C; Pérez-Bilbao, M; de la Fuente, L F

    2010-04-01

    To study the variations of bulk tank milk variables in dairy ewe flocks and to identify the main target practices and flock groups to improve milk quality and safety, a total of 71,228 records of antibiotic residue (AR) and milk yield and 68,781 records of somatic cell count (SCC) and total bacterial count (TBC) were obtained over 5 yr from the same 209 dairy ewe flocks of the Assaf breed belonging to the Consortium for Ovine Promotion of Castilla-León (Spain). Based on a logistic regression model, year, month, semester, SCC, TBC, dry therapy, and milk yield significantly contributed to AR variation. High SCC was associated with increased AR violations. When antibiotic dry therapy was implemented, AR occurrence was higher than when this practice was not used. A polynomial monthly distribution throughout the year was observed for AR occurrence; the highest values were in autumn, coinciding with low milk yields per flock. Yearly occurrences drastically diminished from 2004 (1.36%) to 2008 (0.30%), probably as a result of effective educational programs. The mixed-model ANOVA of factors influencing variation in SCC and TBC indicated that year, month, AR, dry therapy group, milking type, and year interactions were significant variation factors for SCC and TBC; mathematical model accounted for 74.1 and 35.4% of total variance for each variable, respectively. Differences in management and hygiene practice caused significant SCC and TBC variations among flocks and within flocks throughout the 5-yr study. Over time, continuously dry treated flocks showed lower logSCC (5.80) and logTBC (4.92) than untreated (6.10 and 5.18, respectively) or discontinuously dry treated (6.01 and 5.05, respectively) flocks. Continuously dry treated flocks had lower AR occurrences than did discontinuously dry treated flocks. As a whole, AR occurrence and SCC and TBC bulk tank milk variables can be used for monitoring mammary health and milk hygiene and safety in dairy sheep throughout time.

  2. 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.

  3. 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

  4. Membrane tubulation by elongated and patchy nanoparticles

    CERN Document Server

    Raatz, Michael

    2016-01-01

    Advances in nanotechnology lead to an increasing interest in how nanoparticles interact with biomembranes. Nanoparticles are wrapped spontaneously by biomembranes if the adhesive interactions between the particles and membranes compensate for the cost of membrane bending. In the last years, the cooperative wrapping of spherical nanoparticles in membrane tubules has been observed in experiments and simulations. For spherical nanoparticles, the stability of the particle-filled membrane tubules strongly depends on the range of the adhesive particle-membrane interactions. In this article, we show via modeling and energy minimization that elongated and patchy particles are wrapped cooperatively in membrane tubules that are highly stable for all ranges of the particle-membrane interactions, compared to individual wrapping of the particles. The cooperative wrapping of linear chains of elongated or patchy particles in membrane tubules may thus provide an efficient route to induce membrane tubulation, or to store such...

  5. 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...

  6. 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...

  7. 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 ...

  8. Identification and characterization of a novel bacterial virulence factor that shares homology with mammalian Toll/interleukin-1 receptor family proteins.

    Science.gov (United States)

    Newman, Ruchi M; Salunkhe, Prabhakar; Godzik, Adam; Reed, John C

    2006-01-01

    Many important bacterial virulence factors act as mimics of mammalian proteins to subvert normal host cell processes. To identify bacterial protein mimics of components of the innate immune signaling pathway, we searched the bacterial genome database for proteins with homology to the Toll/interleukin-1 receptor (TIR) domain of the mammalian Toll-like receptors (TLRs) and their adaptor proteins. A previously uncharacterized gene, which we have named tlpA (for TIR-like protein A), was identified in the Salmonella enterica serovar Enteritidis genome that is predicted to encode a protein resembling mammalian TIR domains, We show that overexpression of TlpA in mammalian cells suppresses the ability of mammalian TIR-containing proteins TLR4, IL-1 receptor, and MyD88 to induce the transactivation and DNA-binding activities of NF-kappaB, a downstream target of the TIR signaling pathway. In addition, TlpA mimics the previously characterized Salmonella virulence factor SipB in its ability to induce activation of caspase-1 in a mammalian cell transfection model. Disruption of the chromosomal tlpA gene rendered a virulent serovar Enteritidis strain defective in intracellular survival and IL-1beta secretion in a cell culture infection model using human THP1 macrophages. Bacteria with disrupted tlpA also displayed reduced lethality in mice, further confirming an important role for this factor in pathogenesis. Taken together, our findings demonstrate that the bacterial TIR-like protein TlpA is a novel prokaryotic modulator of NF-kappaB activity and IL-1beta secretion that contributes to serovar Enteritidis virulence.

  9. 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

  10. 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.

  11. 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...

  12. 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...

  13. 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.)

  14. Events during eucaryotic rRNA transcription initiation and elongation: Conversion from the closed to the open promoter complex requires nucleotide substrates

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, E.; Paule, M.R.

    1988-05-01

    Chemical footprinting and topological analysis were carried out on the Acanthamoeba castellanii rRNA transcription initiation factor (TIF) and RNA polymerase I complexes with DNA during transcription initiation and elongation. The results show that the binding of TIF and polymerase to the promoter does not alter the supercoiling of the DNA template and the template does not become sensitive to modification by diethylpyro-carbonate, which can identify melted DNA regions. Thus, in contrast to bacterial RNA polymerase, the eucaryotic RNA polymerase I-promoter complex is in a closed configuration preceding addition of nucleotides in vitro. Initiation and 3'-O-methyl CTP-limited translocation by RNA polymerase I results in separation of the polymerase-TIF footprints, leaving the TIF footprint unaltered. In contrast, initiation and translocation result in a significant change in the conformation of the polymerase-DNA complex, culminating in an unwound DNA region of at least 10 base pairs.

  15. 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.

  16. [Empirical therapeutic approach to infection by resistant gram positive (acute bacterial skin and skin structure infections and health care pneumonia). Value of risk factors].

    Science.gov (United States)

    González-DelCastillo, J; Núñez-Orantos, M J; Candel, F J; Martín-Sánchez, F J

    2016-09-01

    Antibiotic treatment inadequacy is common in these sites of infection and may have implications for the patient's prognosis. In acute bacterial skin and skin structure infections, the document states that for the establishment of an adequate treatment it must be assessed the severity, the patient comorbidity and the risk factors for multidrug-resistant microorganism. The concept of health care-associated pneumonia is discussed and leads to errors in the etiologic diagnosis and therefore in the selection of antibiotic treatment. This paper discusses how to perform this approach to the possible etiology to guide empirical treatment. PMID:27608306

  17. 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.

  18. Mechanism of Excretion of a Bacterial Proteinase: Factors Controlling Accumulation of the Extracellular Proteinase of a Sarcina Strain (Coccus P)

    Energy Technology Data Exchange (ETDEWEB)

    BISSELL, MINA J.; TOSI, ROBERTO; GORINI, LUIGI

    1970-06-29

    It has been known that the extracellular proteinase of Coccus P is found only in cultures grown in the presence of Ca{sup 2+}. It is now shown that this cation is required neither for synthesis, excretion, or activation of a zymogen nor as a prosthetic factor necessary for enzymatic activity. The only function of Ca{sup 2+} is to stabilize the active structure of the enzyme molecule, presumably by substituting for absence of S-S bridges. In the absence of Ca{sup 2+} , the excreted proteinase undergoes rapid autodigestion and, instead of the active protein, its hydrolytic products are accumulated in the culture fluid. In minimal medium and under conditions of enzyme stability [presence of Ca{sup 2+} and Ficoll (Pharmacia)], Coccus P accumulates the proteinase at a gradually reduced speed although the rate of cultural growth remains constant. It is shown that this decline in rate of accumulation is caused by the excreted proteinase itself, possibly acting on its own precursor emerging from the cell in a form susceptible to proteolytic attack and not amenable to Ca{sup 2+} protection. A proteinase precursor is actually demonstrable in a calciumless culture at the onset of the enzyme accumulation which follows Ca{sup 2+} addition. It is suggested that excreted proteins require an unfolded (or incompletely folded) structure to cross the cell envelope. The proteinase excreted by a Sarcina strain (Coccus P) is found only in cultures containing Ca{sup 2+} ions (1), a feature common to proteinases of other bacteria (4, 12, 18) and to other excreted enzymes (14). Among the nontoxic divalent cations, Ca{sup 2+} is rather specific in this effect. Other ions such as Mn{sup 2+} or Mg{sup 2+}, the latter being present in all media as an indispensible growth factor, are ineffective. Addition of Ca{sup 2+} to the proteolytically inactive supernatant fluid of a calcium- free culture does not result in the appearance of the missing enzyme activity. The early assumption that Ca{sup 2

  19. 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

  20. 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.

  1. 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

  2. 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)

  3. 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.

  4. 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

  5. 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.

  6. 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...

  7. A constitutive analysis of transient and steady-state elongational viscosities of bidisperse polystyrene blends

    DEFF Research Database (Denmark)

    Wagner, Manfred H.; Rolon-Garrido, Victor H.; Nielsen, Jens Kromann;

    2008-01-01

    The transient and steady-state elongational viscosity data of three bidisperse polystyrene blends were investigated recently by Nielsen et al. [J. Rheol. 50, 453-476 (2006)]. The blends contain a monodisperse high molar mass component (M-L= 390 kg/ mol) in a matrix of a monodisperse small molar......, and allowing (albeit by use of empirical linear-viscoelastic shift factors to correct the linear-viscoelastic predictions) for a quantitative description of the transient and steady-state elongational viscosities of the bidisperse polystyrene blends....

  8. 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...

  9. 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.

  10. Role of lipids on elongation of the preimplantation conceptus in ruminants.

    Science.gov (United States)

    Ribeiro, Eduardo S; Santos, José E P; Thatcher, William W

    2016-10-01

    Elongation of the preimplantation conceptus is a prerequisite for successful pregnancy in ruminants and depends on histotroph secretion by the endometrium. Lipids are an essential component of the histotroph, and recent studies indicate that lipids have important roles in the elongation phase of conceptus development. The onset of elongation is marked by dynamic changes in the transcriptome of trophectoderm cells, which are associated with lipid metabolism. During elongation, the trophectoderm increases transcript expression of genes related to uptake, metabolism and de novo biosynthesis of fatty acids and prostaglandins. Expression of the gene PPARG increases substantially, and activation of the transcription factor PPARG by binding of lipid ligands appears to be crucial for the coordination of cell biology during elongation. Lipids accumulated in the epithelial cells of the endometrium during diestrus are likely the most important source of fatty acids for utilization by the conceptus and become available in the uterine lumen through exporting of exosomes, microvesicles, carrier proteins and lipoproteins. Targeting of uterine lipid metabolism and PPARG activity during preimplantation conceptus development through nutraceutical diets may be a good strategy to improve pregnancy survival and reproductive efficiency in ruminants.

  11. 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.

  12. 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...

  13. 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.

  14. 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

  15. 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.

  16. A Replisome's journey through the bacterial chromosome.

    Science.gov (United States)

    Beattie, Thomas R; Reyes-Lamothe, Rodrigo

    2015-01-01

    Genome duplication requires the coordinated activity of a multi-component machine, the replisome. In contrast to the background of metabolic diversity across the bacterial domain, the composition and architecture of the bacterial replisome seem to have suffered few changes during evolution. This immutability underlines the replisome's efficiency in copying the genome. It also highlights the success of various strategies inherent to the replisome for responding to stress and avoiding problems during critical stages of DNA synthesis. Here we summarize current understanding of bacterial replisome architecture and highlight the known variations in different bacterial taxa. We then look at the mechanisms in place to ensure that the bacterial replisome is assembled appropriately on DNA, kept together during elongation, and disassembled upon termination. We put forward the idea that the architecture of the replisome may be more flexible that previously thought and speculate on elements of the replisome that maintain its stability to ensure a safe journey from origin to terminus. PMID:26097470

  17. 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.

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

    Science.gov (United States)

    Gu, Wei; Cui, Yizhi; Zhong, Jiayong; Jin, Jingjie; He, Qing-Yu; Wang, Tong; Zhang, Gong

    2016-01-01

    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. PMID:26926465

  19. 细菌性阴道病影响因素研究%Study of Influencing Factors of Bacterial Vaginosis

    Institute of Scientific and Technical Information of China (English)

    孙继玮; 韦旭; 周建华

    2009-01-01

    细菌性阴道病(bacterial vaginosis,BV)是由于多种致病菌大量繁殖导致阴道内微生态环境菌群与分泌物生化性质紊乱所引起的一种以阴道黏膜非炎症性表现为特征的一组疾病。对BV的真正认识是从19世纪90年代中期开始,由于对其病因的认识有限,BV曾有不同的名称,如非特异性阴道炎(non—specific vaginitis)、嗜血杆菌性阴道炎(haemophilus vaginitis)、棒状杆菌性阴道炎(corynebacterium vaginitis)、加德纳菌性阴道炎(gardnerella vaginitis GV)、厌氧菌性阴道炎(anaerobie vaginitis)等。

  20. Crystal structure of the primary piRNA biogenesis factor Zucchini reveals similarity to the bacterial PLD endonuclease Nuc.

    Science.gov (United States)

    Voigt, Franka; Reuter, Michael; Kasaruho, Anisa; Schulz, Eike C; Pillai, Ramesh S; Barabas, Orsolya

    2012-12-01

    Piwi-interacting RNAs (piRNAs) are a gonad-specific class of small RNAs that associate with the Piwi clade of Argonaute proteins and play a key role in transposon silencing in animals. Since biogenesis of piRNAs is independent of the double-stranded RNA-processing enzyme Dicer, an alternative nuclease that can process single-stranded RNA transcripts has been long sought. A Phospholipase D-like protein, Zucchini, that is essential for piRNA processing has been proposed to be a nuclease acting in piRNA biogenesis. Here we describe the crystal structure of Zucchini from Drosophila melanogaster and show that it is very similar to the bacterial endonuclease, Nuc. The structure also reveals that homodimerization induces major conformational changes assembling the active site. The active site is situated on the dimer interface at the bottom of a narrow groove that can likely accommodate single-stranded nucleic acid substrates. Furthermore, biophysical analysis identifies protein segments essential for dimerization and provides insights into regulation of Zucchini's activity. PMID:23086923

  1. Crystal structure of the primary piRNA biogenesis factor Zucchini reveals similarity to the bacterial PLD endonuclease Nuc.

    Science.gov (United States)

    Voigt, Franka; Reuter, Michael; Kasaruho, Anisa; Schulz, Eike C; Pillai, Ramesh S; Barabas, Orsolya

    2012-12-01

    Piwi-interacting RNAs (piRNAs) are a gonad-specific class of small RNAs that associate with the Piwi clade of Argonaute proteins and play a key role in transposon silencing in animals. Since biogenesis of piRNAs is independent of the double-stranded RNA-processing enzyme Dicer, an alternative nuclease that can process single-stranded RNA transcripts has been long sought. A Phospholipase D-like protein, Zucchini, that is essential for piRNA processing has been proposed to be a nuclease acting in piRNA biogenesis. Here we describe the crystal structure of Zucchini from Drosophila melanogaster and show that it is very similar to the bacterial endonuclease, Nuc. The structure also reveals that homodimerization induces major conformational changes assembling the active site. The active site is situated on the dimer interface at the bottom of a narrow groove that can likely accommodate single-stranded nucleic acid substrates. Furthermore, biophysical analysis identifies protein segments essential for dimerization and provides insights into regulation of Zucchini's activity.

  2. A bacterial tyrosine phosphatase inhibits plant pattern recognition receptor activation.

    Science.gov (United States)

    Macho, Alberto P; Schwessinger, Benjamin; Ntoukakis, Vardis; Brutus, Alexandre; Segonzac, Cécile; Roy, Sonali; Kadota, Yasuhiro; Oh, Man-Ho; Sklenar, Jan; Derbyshire, Paul; Lozano-Durán, Rosa; Malinovsky, Frederikke Gro; Monaghan, Jacqueline; Menke, Frank L; Huber, Steven C; He, Sheng Yang; Zipfel, Cyril

    2014-03-28

    Innate immunity relies on the perception of pathogen-associated molecular patterns (PAMPs) by pattern-recognition receptors (PRRs) located on the host cell's surface. Many plant PRRs are kinases. Here, we report that the Arabidopsis receptor kinase EF-TU RECEPTOR (EFR), which perceives the elf18 peptide derived from bacterial elongation factor Tu, is activated upon ligand binding by phosphorylation on its tyrosine residues. Phosphorylation of a single tyrosine residue, Y836, is required for activation of EFR and downstream immunity to the phytopathogenic bacterium Pseudomonas syringae. A tyrosine phosphatase, HopAO1, secreted by P. syringae, reduces EFR phosphorylation and prevents subsequent immune responses. Thus, host and pathogen compete to take control of PRR tyrosine phosphorylation used to initiate antibacterial immunity.

  3. Positive grid corrosion elongation analysis using CAE with corrosion deformation transformed into thermal phenomenon

    Science.gov (United States)

    Mukaitani, Ichiroh; Hayashi, Koji; Shimoura, Ichiro; Takemasa, Arihiko; Takahashi, Isamu; Tsubakino, Harushige

    Valve-regulated lead-acid (VRLA) batteries have been commercially available for more than 20 years and have been enthusiastically embraced by users of uninterruptible power supplies (UPS) because of the anticipated reduction in installation and operating costs, smaller footprint and fewer environmental concerns. In Japan, communication networks are demanding reduced costs and longer life from their batteries. Among the factors limiting the life of VRLA batteries, the corrosion of positive grid material has been proven to cause elongation of the plates, loss of electrical contact and shorter lifetime. The content of Sn is also a key factor and addition of Sn in the grid alloy results in better performance in creep resistance, tensile strength and corrosion resistance [R. David Prenagaman, The Battery Man, vol. 39, September 1997, p. 16. I. Mukaitani, T. Sakamoto, T. Kikuoka, Y. Yamaguchi, H. Tsubakino, Proceedings of the 40th Battery Symposium in Japan, 1999, p. 99]. A key point is what the ratio of Sn to Ca should be, since too much Sn may lead to even worse elongation of the plates [I. Mukaitani, T. Sakamoto, T. Kikuoka, Y. Yamaguchi, H. Tsubakino, Proceedings of the 40th Battery Symposium in Japan, 1999, p. 99]. We have determined that microstructure control with a composition of lead-calcium-tin (Pb-Ca-Sn) alloy is optimal for better performance of the plates [I. Mukaitani, T. Sakamoto, T. Kikuoka, Y. Yamaguchi, H. Tsubakino, Proceedings of the 40th Battery Symposium in Japan, 1999, p. 99]. We developed a "simulation of current collector corrosion elongation" which is a technique of estimating corrosion elongation from the current collector design [I. Mukaitani, K. Hayashi, I. Shimoura, H. Takabayashi, M. Terada, A. Takemasa, I. Takahashi, K. Okamoto, Proceedings of the 44th Battery Symposium in Japan, 2003, p. 652]. Corrosion elongation occurs as the corrosion material layer grows out of the current collector metal. We resolved this problem using generally CAD

  4. 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

    A model of pneumococcal meningitis in young adult rats receiving antibiotics once the infection was established was developed. The intent was to mimic clinical and histopathological features of pneumococcal meningitis in humans. The primary aim of the present study was to evaluate whether medical...... boosting of the peripheral neutrophil count affected the outcome of the meningitis. The risk of terminal illness over the first 7 days after infection was significantly reduced for rats who had elevated peripheral white blood cell counts after receiving granulocyte-colony-stimulating factor (G-CSF) prior...... 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 (median, 1.1 x...

  5. 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...

  6. 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

  7. The Bartonella quintana Extracytoplasmic Function Sigma Factor RpoE Has a Role in Bacterial Adaptation to the Arthropod Vector Environment

    Science.gov (United States)

    Abromaitis, Stephanie

    2013-01-01

    Bartonella quintana is a vector-borne bacterial pathogen that causes fatal disease in humans. During the infectious cycle, B. quintana transitions from the hemin-restricted human bloodstream to the hemin-rich body louse vector. Because extracytoplasmic function (ECF) sigma factors often regulate adaptation to environmental changes, we hypothesized that a previously unstudied B. quintana ECF sigma factor, RpoE, is involved in the transition from the human host to the body louse vector. The genomic context of B. quintana rpoE identified it as a member of the ECF15 family of sigma factors found only in alphaproteobacteria. ECF15 sigma factors are believed to be the master regulators of the general stress response in alphaproteobacteria. In this study, we examined the B. quintana RpoE response to two stressors that are encountered in the body louse vector environment, a decreased temperature and an increased hemin concentration. We determined that the expression of rpoE is significantly upregulated at the body louse (28°C) versus the human host (37°C) temperature. rpoE expression also was upregulated when B. quintana was exposed to high hemin concentrations. In vitro and in vivo analyses demonstrated that RpoE function is regulated by a mechanism involving the anti-sigma factor NepR and the response regulator PhyR. The ΔrpoE ΔnepR mutant strain of B. quintana established that RpoE-mediated transcription is important in mediating the tolerance of B. quintana to high hemin concentrations. We present the first analysis of an ECF15 sigma factor in a vector-borne human pathogen and conclude that RpoE has a role in the adaptation of B. quintana to the hemin-rich arthropod vector environment. PMID:23564167

  8. Lower Circulating Levels of Chemokine CXCL10 In Helicobacter Pylori-Infected Patients with Peptic Ulcer: Influence of the Bacterial Virulence Factor CagA

    Directory of Open Access Journals (Sweden)

    Abdollah Jafarzadeh

    2013-03-01

    Full Text Available Background and objectives: Alterations in CXCL10 (a Th1 chemokine expression have been associated with various diseases. The aim of this study was to evaluate the serum CXCL10 levels in H. pylori-infected patients with peptic ulcer (PU and to determine its association with bacterial virulence factor cytotoxin-associated gene A (CagA. Materials and Methods: Serum samples from 90 H. pylori infected patients (70 were anti-CagA+, 20 were anti-CagA-, 65 asymptomatic (AS carriers (40 were anti-CagA+, 25 were anti-CagA- and 30 healthy H. pylori-negative subjects (as a control were tested for the concentrations of CXCL10 by using ELISA method. Results: The mean serum levels of CXCL10 in PU patients (96.64 ± 20.85 Pg/mL was significantly lower than those observed in AS subjects (162.16 ± 53.31 Pg/mL, P < 0.01 and control group (193.93 ± 42.14 Pg/mL, P < 0.02. In the PU group, the levels of CXCL10 in anti-CagA+ subjects was significantly higher in comparison to anti-CagA- patients (P<0.04. Conclusion: These results showed that the mean concentrations of CXCL10 in H. pylori-infected-PU patients was lower than AS carriers and control group. In the PU group, the serum levels of CXCL10 were affected by bacterial factor CagA.

  9. Membrane fluidity as a factor in production and stability of bacterial ice nuclei active at high subfreezing temperatures.

    Science.gov (United States)

    Lindow, S E

    1995-06-01

    Detailed measurements were made of the rate of appearance of bacterial ice nuclei upon cooling of suspensions of Pseudomonas syringae cells and the disappearance of ice nuclei upon warming of the cells before assay for ice nucleation activity. While no substantial change in numbers of ice nuclei active at either -5 or at -9 degrees C was observed in cells that were grown at temperatures lower than 24 degrees C and cooled to 21 degrees C before assay, large increases in -5 but not -9 degrees C ice nuclei were observed in cells grown at temperatures greater than 24 degrees C. Ice nucleation activity of cells subjected to a decrease in temperature before assay increased immediately upon temperature shift, but 8 to 12 min was required before maximum rates of increase in numbers of ice nuclei were observed. The rate of appearance of ice nuclei in cell suspensions incubated at relatively cold temperatures prior to assay was substantially less than those incubated at temperatures approaching 24 degrees C. Cells rapidly lost ice nucleation activity when warmed to above 27 degrees C before assay; the rate of loss of ice nuclei in cells grown at a given temperature increased rapidly as the temperature to which they were warmed before assay increased. Ice nuclei disappeared most rapidly when cells grown at low temperatures were warmed before assay, suggesting that ice nucleus stability was lower in highly fluid membranes. The logarithm of the half-life of ice nuclei in cells was directly related to the concentration of the membrane fluidizing agent, 2-phenethyl alcohol, in which they were suspended. PMID:7781327

  10. 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)

  11. The nucleotide-binding site of bacterial translation initiation factor 2 (IF2) as a metabolic sensor

    NARCIS (Netherlands)

    Milon, P.; Tischenko, E.V.; Tomsic, J.; Caserta, E.; Folkers, G.E.; La Teana, A.; Rodnina, M.V.; Pon, C.L.; Boelens, R.; Gualerzi, C.O.

    2006-01-01

    Translational initiation factor 2 (IF2) is a guanine nucleotide-binding protein that can bind guanosine 3′,5′-(bis) diphosphate (ppGpp), an alarmone involved in stringent response in bacteria. In cells growing under optimal conditions, the GTP concentration is very high, and that of ppGpp very low.

  12. 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.

  13. 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 ...

  14. 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, ...

  15. 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 ...

  16. 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.

  17. Anti-lipopolysaccharide factor in Litopenaeus vannamei (LvALF): a broad spectrum antimicrobial peptide essential for shrimp immunity against bacterial and fungal infection.

    Science.gov (United States)

    de la Vega, Enrique; O'Leary, Nuala A; Shockey, Jessica E; Robalino, Javier; Payne, Caroline; Browdy, Craig L; Warr, Gregory W; Gross, Paul S

    2008-04-01

    Antimicrobial peptides are an essential component of the innate immune system of most organisms. Expressed sequence tag analysis from various shrimp (Litopenaeus vannamei) tissues revealed transcripts corresponding to two distinct sequences (LvALF1 and LvALF2) with strong sequence similarity to anti-lipopolysaccharide factor (ALF), an antimicrobial peptide originally isolated from the horseshoe crab Limulus polyphemus. Full-length clones contained a 528bp transcript with a predicted open reading frame coding for 120 amino acids in LvALF1, and a 623bp transcript with a predicted open reading frame coding for 93 amino acids in LvALF2. A reverse genetic approach was implemented to study the in vivo role of LvALF1 in protecting shrimp from bacterial, fungal and viral infections. Injection of double-stranded RNA (dsRNA) corresponding to the LvALF1 message resulted in a significant reduction of LvALF1 mRNA transcript abundance as determined by qPCR. Following knockdown, shrimp were challenged with low pathogenic doses of Vibrio penaeicida, Fusarium oxysporum or white spot syndrome virus (WSSV) and the resulting mortality curves were compared with controls. A significant increase of mortality in the LvALF1 knockdown shrimp was observed in the V. penaeicida and F. oxysporum infections when compared to controls, showing that this gene has a role in protecting shrimp from both bacterial and fungal infections. In contrast, LvALF1 dsRNA activated the sequence-independent innate anti-viral immune response giving increased protection from WSSV infection.

  18. 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

  19. Research progress in the detecting methods of bacterial risk factors in food%食品中细菌危害因子检测进展

    Institute of Scientific and Technical Information of China (English)

    胡晓清; 潘露; 王小元

    2011-01-01

    The pollution of pathogenic bacteria is a serious threat to food safety.There are many types of risk factors,including not only a variety of bacterial toxins, but also some cell components such as flagella that participate in the process of host infection.Recently,many novel detection methods for the risk factors produced by the pathogenic bacteria in food have been developed,along with the developments and integrations of polymerase chain reaction technology,enzyme-linked immunosorbent assay and nanogold labeling technique.In the present paper,the methods for analyzing the risk factors of Escherichia coli, Clostridium botulinum, Bacillus cereus, Staphylococcus sp. And etc. Were summarized and compared. Furthermore, on the basis of analysis methods reported,some new prospects on the rapid detection of trace amount of risk factors were discussed.%致病细菌污染是影响食品安全的重要因素.细菌危害因子种类繁多,既包括各种细菌毒素,也包括参与宿主侵染过程的细胞组分,如鞭毛等.随着聚合酶链式反应、酶联免疫吸附分析法和纳米金标记技术的交叉融合,近年来涌现了一批新的检测食品中细菌危害因子的方法.本文对大肠杆菌、肉毒梭菌、蜡状芽孢杆菌、葡萄球菌等的危害因子的分析方法进行了综述和比较,并在此基础上讨论了其快速超微量检测的研究方向.

  20. 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.

  1. 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.

  2. 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

  3. Induction of predominant tenogenic phenotype in human dermal fibroblasts via synergistic effect of TGF-β and elongated cell shape.

    Science.gov (United States)

    Wang, Wenbo; Li, Jie; Wang, Keyun; Zhang, Zhiyong; Zhang, Wenjie; Zhou, Guangdong; Cao, Yilin; Ye, Mingliang; Zou, Hanfa; Liu, Wei

    2016-03-01

    Micropattern topography is widely investigated for its role in mediating stem cell differentiation, but remains unexplored for phenotype switch between mature cell types. This study investigated the potential of inducing tenogenic phenotype in human dermal fibroblasts (hDFs) by artificial elongation of cultured cells. Our results showed that a parallel microgrooved topography could convert spread hDFs into an elongated shape and induce a predominant tenogenic phenotype as the expression of biomarkers was significantly enhanced, such as scleraxis, tenomodulin, collagens I, III, VI, and decorin. It also enhanced the expression of transforming growth factor (TGF)-β1, but not α-smooth muscle actin. Elongated hDFs failed to induce other phenotypes, such as adiopogenic, chondrogenic, neurogenic, and myogenic lineages. By contrast, no tenogenic phenotype could be induced in elongated human chondrocytes, although chondrogenic phenotype was inhibited. Exogenous TGF-β1 could enhance the tenogenic phenotype in elongated hDFs at low dose (2 ng/ml), but promoted myofibroblast transdifferentiation of hDFs at high dose (10 ng/ml), regardless of cell shape. Elongated shape also resulted in decreased RhoA activity and increased Rho-associated protein kinase (ROCK) activity. Antagonizing TGF-β or inhibiting ROCK activity with Y27632 or depolymerizing actin with cytochalasin D could all significantly inhibit tenogenic phenotype induction, particularly in elongated hDFs. In conclusion, elongation of cultured dermal fibroblasts can induce a predominant tenogenic phenotype likely via synergistic effect of TGF-β and cytoskeletal signaling. PMID:26632599

  4. 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.

  5. 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

  6. 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

  7. Screening for Rice Germplasms with Specially-Elongated Mesocotyl

    Institute of Scientific and Technical Information of China (English)

    WU Ming-guo; ZHANG Guang-heng; LIN Jian-rong; CHENG Shi-hua

    2005-01-01

    The lengths of mesocotyl in the seedlings of 84 lowland rice varieties and 12 upland rice varieties were measured following the treatments of daylight and darkness during germination. The elongation of mesocotyl in the varieties tested was inhibited under daylight condition, and the mesocotyl of all the varieties elongated variably under darkness condition. The elongated lengths of the mesocotyl in upland rice, ranging from 0.36 cm to 1.61 cm with an average of 0.81 cm, was obviously longer than those in lowland rice, ranging from 0.12 cm to 1.56 cm with an average of 0.42 cm. Among 14 rice varieties with over 1 cm of mesocotyl length, five belonged to upland rice, and nine to lowland rice. The possible utilization of the elongated-mesocotyl rice germplasm in varietal improvement, direct-seeded planting and seed purity testing were discussed.

  8. 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)

  9. 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

  10. 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.

  11. 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

  12. 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 ...

  13. 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...

  14. 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

  15. 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...

  16. Comparative pharmacokinetics of single-dose administration of mammalian and bacterially-derived recombinant human granulocyte-macrophage colony-stimulating factor.

    Science.gov (United States)

    Hovgaard, D; Mortensen, B T; Schifter, S; Nissen, N I

    1993-01-01

    Pharmacokinetics of recombinant human non-glycosylated bacterially-synthesized (E. coli) granulocyte-macrophage colony-stimulating factor (GM-CSF) were studied following single intravenous (i.v.) and subcutaneous (s.c.) bolus injection, and compared to equivalent doses of glycosylated mammalian-derived CHO-GM-CSF. Each route of administration gave a different GM-CSF concentration-time profile. The highest peak serum concentrations (Cmax) were observed following i.v. bolus injection. After i.v. administration, a two-phase decline in concentration was noted for both types of GM-CSF with a significantly shorter t1/2 alpha of 7.8 minutes for the E. coli GM-CSF versus 20.0 min for the CHO-GM-CSF, while no significant difference was observed for the terminal phase. Following s.c. administration of equivalent doses, a higher peak serum concentration was observed in the E. coli-treated patients and, again, a faster elimination where pretreatment serum levels were reached after 16-20 h, versus more than 48 h after administration of CHO-GM-CSF. Although the non-glycosylated E. coli GM-CSF thus seems to undergo a faster elimination that the glycosylated CHO-GM-CSF no significant difference could be demonstrated in the in vivo effect of corresponding doses of the two compounds with respect to stimulation of granulopoiesis--with reservation for small patient numbers and a large individual variations in response.

  17. Functional role of pyruvate kinase from Lactobacillus bulgaricus in acid tolerance and identification of its transcription factor by bacterial one-hybrid.

    Science.gov (United States)

    Zhai, Zhengyuan; An, Haoran; Wang, Guohong; Luo, Yunbo; Hao, Yanling

    2015-11-19

    Lactobacillus delbrueckii subsp. bulgaricus develops acid tolerance response when subjected to acid stress conditions, such as the induction of enzymes associated with carbohydrate metabolism. In this study, pyk gene encoding pyruvate kinase was over-expressed in heterologous host Lactococcus lactis NZ9000, and SDS-PAGE analysis revealed the successful expression of this gene in NZ9000. The survival rate of Pyk-overproducing strain was 45-fold higher than the control under acid stress condition (pH 4.0). In order to determine the transcription factor (TF) which regulates the expression of pyk by bacterial one-hybrid, we constructed a TF library including 65 TFs of L. bulgaricus. Western blotting indicated that TFs in this library could be successfully expressed in host strains. Subsequently, the promoter of pfk-pyk operon in L. bulgaricus was identified by 5'-RACE PCR. The bait plasmid pH3U3-p01 carrying the deletion fragment of pfk-pyk promoter captured catabolite control protein A (CcpA) which could regulate the expression of pyk by binding to a putative catabolite-responsive element (5'-TGTAAGCCCTAACA-3') upstream the -35 region. Real-time qPCR analysis revealed the transcription of pyk was positively regulated by CcpA. This is the first report about identifying the TF of pyk in L. bulgaricus, which will provide new insight into the regulatory network.

  18. 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

    boosting of the peripheral neutrophil count affected the outcome of the meningitis. The risk of terminal illness over the first 7 days after infection was significantly reduced for rats who had elevated peripheral white blood cell counts after receiving granulocyte-colony-stimulating factor (G-CSF) prior...... 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 (median, 1.1 x...... 10(5) versus 2.9 x 10(5) CFU/ml; P = 0.023) and in blood (median, 2.9 x 10(2) versus 6.3 x 10(2) CFU/ml; P = 0.024), as well as attenuated pleocytosis (median, 800 x 10(6) versus 1,231 x 10(6) cells/liter; P = 0.025), 24 h after the infection. Conversely, initiation of G-CSF therapy 28 h...

  19. 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...

  20. 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

  1. 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

  2. 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

  3. Activation of GCN2 kinase by ribosome stalling links translation elongation with translation initiation.

    Science.gov (United States)

    Ishimura, Ryuta; Nagy, Gabor; Dotu, Ivan; Chuang, Jeffrey H; Ackerman, Susan L

    2016-01-01

    Ribosome stalling during translation has recently been shown to cause neurodegeneration, yet the signaling pathways triggered by stalled elongation complexes are unknown. To investigate these pathways we analyzed the brain of C57BL/6J-Gtpbp2(nmf205)(-/-) mice in which neuronal elongation complexes are stalled at AGA codons due to deficiencies in a tRNA(Arg)UCU tRNA and GTPBP2, a mammalian ribosome rescue factor. Increased levels of phosphorylation of eIF2α (Ser51) were detected prior to neurodegeneration in these mice and transcriptome analysis demonstrated activation of ATF4, a key transcription factor in the integrated stress response (ISR) pathway. Genetic experiments showed that this pathway was activated by the eIF2α kinase, GCN2, in an apparent deacylated tRNA-independent fashion. Further we found that the ISR attenuates neurodegeneration in C57BL/6J-Gtpbp2(nmf205)(-/-) mice, underscoring the importance of cellular and stress context on the outcome of activation of this pathway. These results demonstrate the critical interplay between translation elongation and initiation in regulating neuron survival during cellular stress. PMID:27085088

  4. Control of cell proliferation and elongation by miR396.

    Science.gov (United States)

    Ercoli, María Florencia; Rojas, Arantxa M L; Debernardi, Juan Manuel; Palatnik, Javier F; Rodriguez, Ramiro E

    2016-06-01

    The combinatory effects of cell proliferation and cell elongation determines the rate at which organs growth. In the root meristematic zone cells both divide and expand, while post-mitotic cells in the elongation zone only expands until they reach their final size. The transcription factors of the GROWTH-REGULATING FACTOR (GRF) class promote cell proliferation in various plant organs. Their expression is restricted to cells with a high proliferative capacity, yet strong downregulation of the GRF activity compromise the plant survival. Part of expression pattern of the GRFs is ensured by the post-transcriptional repression mediated by the conserved microRNA miR396. Here we show the quantitative effects in root growth caused by GRF depletion in a series of transgenic lines with different miR396 levels. We show that high miRNA levels affect cell elongation and proliferation in roots. Detailed analysis suggests that cell proliferation is restricted due to a reduction in cell cycle speed that might result from defects in the accumulation of mitotic cyclins. The results provide insights into the participation of the miRNA-GRF regulatory network in root development. PMID:27172373

  5. TEFM is a potent stimulator of mitochondrial transcription elongation in vitro.

    Science.gov (United States)

    Posse, Viktor; Shahzad, Saba; Falkenberg, Maria; Hällberg, B Martin; Gustafsson, Claes M

    2015-03-11

    A single-subunit RNA polymerase, POLRMT, transcribes the mitochondrial genome in human cells. Recently, a factor termed as the mitochondrial transcription elongation factor, TEFM, was shown to stimulate transcription elongation in vivo, but its effect in vitro was relatively modest. In the current work, we have isolated active TEFM in recombinant form and used a reconstituted in vitro transcription system to characterize its activities. We show that TEFM strongly promotes POLRMT processivity as it dramatically stimulates the formation of longer transcripts. TEFM also abolishes premature transcription termination at conserved sequence block II, an event that has been linked to primer formation during initiation of mtDNA synthesis. We show that POLRMT pauses at a wide range of sites in a given DNA sequence. In the absence of TEFM, this leads to termination; however, the presence of TEFM abolishes this effect and aids POLRMT in continuation of transcription. Further, we show that TEFM substantially increases the POLRMT affinity to an elongation-like DNA:RNA template. In combination with previously published in vivo observations, our data establish TEFM as an essential component of the mitochondrial transcription machinery.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  12. Prevention and Treatment of Postoperative Complications of the Penile Elongation

    Institute of Scientific and Technical Information of China (English)

    余墨声; 陕声国; 赵月强; 吴晓蔚; 周立纯; 龙道畴

    2003-01-01

    Summary: To explore the cauls of the postoperative complications of the penile elongation and themeasures to prevent them in order to raise the success rate of the penile elongation. 1 000 patientswho had received the penile elongation were reviewed and analyzed for the causes of postoperativecomplications, and the measures of prevention and treatment were discussed. Our results showedthat, of the 1 000 cases, 64 had the postoperative complications, including 20 cases of edema of pre-puce, 15 cases of flap necrosis, 12 hematoma, 9 infections, and 8 cases of fat and clumsy penis. It isconcluded that correct operative manipulation, strict aseptic measures and necessary postoperativecare and management could avoid or reduce the postoperative complications. When complications hap-pened, a satisfactory result can be achieved with timely and correct treatment in the majority of thepatients.

  13. 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...

  14. Elongate summit calderas as Neogene paleostress indicators in Antarctica

    Science.gov (United States)

    Paulsen, T.S.; Wilson, T.J.

    2007-01-01

    The orientations and ages of elongate summit calderas on major polygenetic volcanoes were compiled to document Miocene to Pleistocene Sh (minimum horizontal stress) directions on the western and northern flanks of the West Antarctic rift system. Miocene to Pleistocene summit calderas along the western Ross Sea show relatively consistent ENE long axis trends, which are at a high angle to the Transantarctic Mountain Front and parallel to the N77ºE Sh direction at Cape Roberts. The elongation directions of many Miocene to Pleistocene summit calderas in Marie Byrd Land parallel the alignment of polygenetic volcanoes in which they occur, except several Pleistocene calderas with consistent NNE to NE trends. The overall pattern of elongate calderas in Marie Byrd Land is probably due to a combination of structurally controlled orientations and regional stress fields in which Sh is oriented NNE to NE at a moderate to high angle to the trace of the West Antarctic rift system.

  15. [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

  16. Non-targeted metabolomic evaluation of the uterine milieu during the transitional period of embryo elongation in the pig

    Science.gov (United States)

    Alterations in the signaling of critical molecular factors within the uterine milieu lead to deficiencies in embryo elongation. The objective of this study was to identify metabolites within the uterine environment that are present as porcine embryos transition between spherical, ovoid, and tubular ...

  17. Function of an anti-lipopolysaccharide factor (ALF) isoform isolated from the hemocytes of the giant freshwater prawn Macrobrachium rosenbergii in protecting against bacterial infection.

    Science.gov (United States)

    Liu, Chia-Chen; Chung, Chien-Pang; Lin, Chang-Yi; Sung, Hung-Hung

    2014-02-01

    In this study, a 780-bp full-length cDNA encoding Macrobrachium rosenbergii anti-lipopolysaccharide factor (MrALF) from hemocytes was cloned and identified. The ALF isoform exhibited immune activities, and its concentration in hemolymph was determined. An in vivo expression study showed that the ALF mRNA level of hemocytes could be induced by lipopolysaccharides (LPSs) in an exposure time-dependent manner. Purified recombinant MrALF (rMrALF) expressed in the yeast Pichia pastoris SMD1168 eukaryotic protein expression system demonstrated antibacterial activity against the Gram-negative prawn pathogen Aeromonas hydrophila (minimum inhibitory concentration (MIC)=0.806μM, minimum bactericidal concentration (MBC)=1.606μM) but not the Gram-positive pathogen Lactococcus garvieae exposed to 25.696μM of rALF. However, rMrALF can bind to Gram-negative and -positive bacteria. An in vivo expression study demonstrated that the ALF concentrations in prawn hemocytes and plasma were 0.176μM and 0.168μM, respectively; following LPS treatment for 6h, the corresponding concentrations were 0.133μM in hemocytes and 0.272μM in plasma. Furthermore, the percentage of hemocytes phagocytosing bacteria cells was higher in hemoyctes previously treated with MrALF than those treated with sterile medium. These results suggest that in the innate immune response of M. rosenbergii, the MrALF from hemocytes may play an opsonin during a bacterial invasion.

  18. Involvement of calmodulin in regulation of primary root elongation by N-3-oxo-hexanoyl homoserine lactone in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Qian eZhao

    2015-01-01

    Full Text Available Many bacteria use signal molecules of low molecular weight to monitor their local population density and to coordinate their collective behavior in a process called quorum sensing (QS. N-acyl-homoserine lactones (AHLs are the primary QS signals among Gram-negative bacteria. AHL-mediated QS plays an essential role in diverse bacterial physiological processes. Recent evidence shows that plants are able to sense bacterial AHLs and respond to them appropriately. However, little is known about the mechanism by which plants perceive and transduce the bacterial AHLs within cells. In this study, we found that the stimulatory effect of N-3-oxo-hexanoyl homoserine lactone (3OC6-HSL on primary root elongation of Arabidopsis was abolished by the calmodulin (CaM antagonists N-(6-aminohexyl-5-chloro-1-naphthalene sulfonamide (W-7 and trifluoperazine (TFP. Western-blot and ELISA analysis revealed that the concentration of CaM protein in Arabidopsis roots increased after treatment with 1 μM 3OC6-HSL. Results from quantitative RT-PCR demonstrated that the transcription of all nine CaM genes in Arabidopsis genome was up-regulated in the plants treated with 3OC6-HSL. The loss-of-function mutants of each AtCaM gene (AtCaM1-9 were insensitive to 3OC6-HSL-stimulation of primary root elongation. On the other hand, the genetic evidence showed that CaM may not participates the inhibition of primary root length caused by application of long-chained AHLs such as C10-HSL and C12-HSL. Nevertheless, our results suggest that CaM is involved in the bacterial 3OC6-HSL signaling in plant cells. These data offer new insight into the mechanism of plant response to bacterial QS signals.

  19. Rotation in Free Fall of Rectangular Wings of Elongated Shape

    Science.gov (United States)

    Dupleich, Paul

    1949-01-01

    The present report of Mr. Dupleich is the summary of a very extensive experimental study of the well-known mechanical phenomenon: the rotation in free fall (* air, for instance) of more or less elongated rectangles cut out of paper or pasteboard. This phenomenon, the conditions for existence of which depend chiefly on the elongated of the small plate and its weight per unit area, is essentially an aerodynamic phenomenon and as such, raises questions of a certain interest to our department.We believe that the modern concepts of the mechanics of fluids do not have the range attributed to them.

  20. Extensively drug-resistant bacteria are an independent predictive factor of mortality in 130 patients with spontaneous bacterial peritonitis or spontaneous bacteremia

    Science.gov (United States)

    Alexopoulou, Alexandra; Vasilieva, Larisa; Agiasotelli, Danai; Siranidi, Kyriaki; Pouriki, Sophia; Tsiriga, Athanasia; Toutouza, Marina; Dourakis, Spyridon P

    2016-01-01

    AIM: To evaluate the epidemiology and outcomes of culture-positive spontaneous bacterial peritonitis (SBP) and spontaneous bacteremia (SB) in decompensated cirrhosis. METHODS: We prospectively collected clinical, laboratory characteristics, type of administered antibiotic, susceptibility and resistance of bacteria to antibiotics in one hundred thirty cases (68.5% males) with positive ascitic fluid and/or blood cultures during the period from January 1, 2012 to May 30, 2014. All patients with SBP had polymorphonuclear cell count in ascitic fluid > 250/mm3. In patients with SB a thorough study did not reveal any other cause of bacteremia. The patients were followed-up for a 30-d period following diagnosis of the infection. The final outcome of the patients was recorded in the end of follow-up and comparison among 3 groups of patients according to the pattern of drug resistance was performed. RESULTS: Gram-positive-cocci (GPC) were found in half of the cases. The most prevalent organisms in a descending order were Escherichia coli (33), Enterococcus spp (30), Streptococcus spp (25), Klebsiella pneumonia (16), S. aureus (8), Pseudomanas aeruginosa (5), other Gram-negative-bacteria (GNB) (11) and anaerobes (2). Overall, 20.8% of isolates were multidrug-resistant (MDR) and 10% extensively drug-resistant (XDR). Health-care-associated (HCA) and/or nosocomial infections were present in 100% of MDR/XDR and in 65.5% of non-DR cases. Meropenem was the empirically prescribed antibiotic in HCA/nosocomial infections showing a drug-resistance rate of 30.7% while third generation cephalosporins of 43.8%. Meropenem was ineffective on both XDR bacteria and Enterococcus faecium (E. faecium). All but one XDR were susceptible to colistin while all GPC (including E. faecium) and the 86% of GNB to tigecycline. Overall 30-d mortality was 37.7% (69.2% for XDR and 34.2% for the rest of the patients) (log rank, P = 0.015). In multivariate analysis, factors adversely affecting outcome included

  1. 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.

  2. 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...

  3. RESEARCH ON THE RELATFD FACTORS INFLUENCING THE POSITIVE RATE OF SURGICAL INCISION BACTERIAL CULTURE%影响手术切口细菌培养阳性率相关因素研究

    Institute of Scientific and Technical Information of China (English)

    彭燕萍

    2012-01-01

    Objective To study the relative factors which influence the positive rate of bacterial culture from surgical incision, and to improve the accuracy of detection. Methods Retrospectively investigation was used to analysis 1 000 cases of surgical incisions bacterial culture results in our hospital, and find out the related factors which influence the positive rate. Results Several factors were found affecting the bacterial species and positive rate of surgical incision bacterial culture, including the disinfection of patient's skin and doctor's arm, the type of surgical incision, the time of operation, and so on. Conclusion When collecting and culturing the bacteria from surgical incision, we should pay attention to the disinfection of patient's skin and doctor's arm and other influencing factors, and take actions to obtain the accurate culture results.%目的 研究影响手术切口细菌培养阳性率的相关因素,提高检测的准确性.方法 通过回顾性调查方法,对某医院1000例手术患者切口细菌培养结果进行分析,找出相关因素.结果 切口细菌培养的细菌种类及阳性率与病人的皮肤和医生手臂的消毒、手术切口类型、手术时间、手术接台情况等相关因素呈正相关.结论 患者手术切口细菌学标本采集和培养应考虑到手术皮肤和术者手消毒及其他因素,采取控制措施,获得准确的培养结果.

  4. VAMP-2 promotes neurite elongation and SNAP-25A increases neurite sprouting in PC12 cells.

    Science.gov (United States)

    Shirasu, M; Kimura, K; Kataoka, M; Takahashi, M; Okajima, S; Kawaguchi, S; Hirasawa, Y; Ide, C; Mizoguchi, A

    2000-08-01

    Recent studies suggest that the soluble N-ethylmaleimide-sensitive factor attached protein (SNAP) receptor (SNARE)-mediated membrane fusion system is involved in vesicle fusion in the plasma membrane that allows expansion for neurite elongation. There have been several reports analyzing the effects of neurite outgrowth by inhibition of SNAREs. In this study, we took the opposite approach by overexpressing green fluorescent protein (GFP)-fusion SNAREs, including VAMP-2, SNAP-25A, and syntaxin1A, in PC12 cells to investigate the role of SNAREs in the neurite outgrowth of PC12 cells. Neurite outgrowth analysis demonstrated that: (1) GFP-VAMP-2 increased the length of individual neurites, without changing the number of neurites per cell; (2) GFP-SNAP-25A increased the number of neurites per cell, with no change in the length of the individual neurites. In both cases, the total length of neurites per cell was increased; (3) GFP-syntaxin1A resulted in no significant change, either in neurite length, or in the number of neurites per cell. These findings suggest that when overexpressed in PC12 cells, VAMP-2 can promote neurite elongation, while SNAP-25A can stimulate neurite sprouting. On the other hand, overexpression of syntaxin1A neither promotes nor inhibits neurite outgrowth. Thus VAMP-2 and SNAP-25A play different roles in neurite elongation and sprouting.

  5. 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.

  6. 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

  7. Benthic macrofauna of elongated, shallow-water pockmarks in the Inner Oslofjord, Norway : limnologi marin biologi bløtbunn bunndyr artsdiversitet

    OpenAIRE

    2008-01-01

    A large number of round and elongated pockmarks were recently discovered in the Oslofjord, Norway. Pockmarks are formed by expulsion of fluid, most commonly methane or ground water. The elongated shape is a believed to be a result of either strong bottom currents, linear sub-surface weakness zones, the merging of circular pockmarks, or a combination of these factors. The seeping of methane may generate high microbial production, providing a stable nutrient supply to the benthic fauna. Some sp...

  8. 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.

  9. Thoracoscopic elongation of the esophagus in long gap esophageal atresia.

    NARCIS (Netherlands)

    van der Zee, D.C.; Vieira Travassos, D.; Kramer, W.L.M.; Tytgat, S.H.A.J.

    2007-01-01

    Long gap esophageal atresia in which a primary anastomosis cannot be achieved remains a challenge. Elongation of the esophagus by traction on the 2 ends has been previously described. With the advent of thoracoscopic repair of esophageal atresia, there have thus far been no reports of thoracoscopic

  10. 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.

  11. Quadratic elongation: A quantitative measure of distortion in coordination polyhedra

    Science.gov (United States)

    Robinson, Kelly F.; Gibbs, G.V.; Ribbe, P.H.

    1971-01-01

    Quadratic elongation and the variance of bond angles are linearly correlated for distorted octahedral and tetrahedral coordination complexes, both of which show variations in bond length and bond angle. The quadratic elonga tion is dimensionless, giving a quantitative measure of polyhedral distortion which is independent of the effective size of the polyhedron.

  12. 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...

  13. Relationship between elongation and porosity for high porosity metal materials

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A simplified model was proposed targeting at the isotropic high porosity metal materials with well-distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition.

  14. 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

  15. 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...

  16. 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 VH, the secondary rotations are single-periodic with no signs of chaotic rotation and their periods are constant on timescales from weeks to years. The secondary equatorial elongations show an upper limit of a2 /b2 ∼ 1.5 . The lack of 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

  17. 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.

  18. Stimulation of root elongation and curvature by calcium

    Science.gov (United States)

    Takahashi, H.; Scott, T. K.; Suge, H.

    1992-01-01

    Ca2+ has been proposed to mediate inhibition of root elongation. However, exogenous Ca2+ at 10 or 20 millimolar, applied directly to the root cap, significantly stimulated root elongation in pea (Pisum sativum L.) and corn (Zea mays L.) seedlings. Furthermore, Ca2+ at 1 to 20 millimolar, applied unilaterally to the caps of Alaska pea roots, caused root curvature away from the Ca2+ source, which was caused by an acceleration of elongation growth on the convex side (Ca2+ side) of the roots. Roots of an agravitropic pea mutant, ageotropum, responded to a greater extent. Roots of Merit and Silver Queen corn also responded to Ca2+ in similar ways but required a higher Ca2+ concentration than that of pea roots. Roots of all other cultivars tested (additional four cultivars of pea and one of corn) curved away from the unilateral Ca2+ source as well. The Ca(2+)-stimulated curvature was substantially enhanced by light. A Ca2+ ionophore, A23187, at 20 micromolar or abscisic acid at 0.1 to 100 micromolar partially substituted for the light effect and enhanced the Ca(2+)-stimulated curvature in the dark. Unilateral application of Ca2+ to the elongation zone of intact roots or to the cut end of detipped roots caused either no curvature or very slight curvature toward the Ca2+. Thus, Ca2+ action on root elongation differs depending on its site of application. The stimulatory action of Ca2+ may involve an elevation of cytoplasmic Ca2+ in root cap cells and may partipate in root tropisms.

  19. 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.

  20. 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。

  1. Bacterial Hydrodynamics

    Science.gov (United States)

    Lauga, Eric

    2016-01-01

    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 micrometer 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, I review the biomechanics of bacterial motility and look ahead to future challenges.

  2. 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.

  3. 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

  4. 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.

  5. 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...

  6. TERRA promotes telomerase-mediated telomere elongation in Schizosaccharomyces pombe.

    Science.gov (United States)

    Moravec, Martin; Wischnewski, Harry; Bah, Amadou; Hu, Yan; Liu, Na; Lafranchi, Lorenzo; King, Megan C; Azzalin, Claus M

    2016-07-01

    Telomerase-mediated telomere elongation provides cell populations with the ability to proliferate indefinitely. Telomerase is capable of recognizing and extending the shortest telomeres in cells; nevertheless, how this mechanism is executed remains unclear. Here, we show that, in the fission yeast Schizosaccharomyces pombe, shortened telomeres are highly transcribed into the evolutionarily conserved long noncoding RNA TERRA A fraction of TERRA produced upon telomere shortening is polyadenylated and largely devoid of telomeric repeats, and furthermore, telomerase physically interacts with this polyadenylated TERRA in vivo We also show that experimentally enhanced transcription of a manipulated telomere promotes its association with telomerase and concomitant elongation. Our data represent the first direct evidence that TERRA stimulates telomerase recruitment and activity at chromosome ends in an organism with human-like telomeres.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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...

  12. 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 ...

  13. Thoracoscopic elongation of the esophagus in long gap esophageal atresia.

    OpenAIRE

    Zee, D.C.; Vieira Travassos, D.; Kramer, W.L.M.; Tytgat, S. H. A. J.

    2007-01-01

    Long gap esophageal atresia in which a primary anastomosis cannot be achieved remains a challenge. Elongation of the esophagus by traction on the 2 ends has been previously described. With the advent of thoracoscopic repair of esophageal atresia, there have thus far been no reports of thoracoscopic repair of long gap esophageal atresia. This paper describes the first successful repair of long gap esophageal atresia by thoracoscopic traction of the 2 esophageal ends and delayed thoracoscopic a...

  14. 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...

  15. 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.

  16. Brownian Dynamics Simulation of Microstructures and Elongational Viscosities of Micellar Surfactant Solution

    Institute of Scientific and Technical Information of China (English)

    WEI Jin-Jia; KAWAGUCHI Yasuo; YU Bo; LI Feng-Chen

    2008-01-01

    @@ Brownian dynamics simulation is conducted for a dilute surfactant solution under a steady uniaxial elongational flow.A new inter-cluster potential is used for the interaction among surfactant micelles to determine the micellar network structures in the surfactant solution.The micellar network is successfully simulated.It is formed at low elongation rates and destroyed by high elongation rates.The computed elongational viscosities show elongation-thinning characteristics.The relationship between the elongational viscosities and the microstructure of the surfactant solution is revealed.

  17. Cloning and Expression Analysis of Vvlcc3, a Novel and Functional Laccase Gene Possibly Involved in Stipe Elongation

    Directory of Open Access Journals (Sweden)

    Yuanping Lu

    2015-12-01

    Full Text Available Volvariella volvacea, usually harvested in its egg stage, is one of the most popular mushrooms in Asia. The rapid transition from the egg stage to elongation stage, during which the stipe stretches to almost full length leads to the opening of the cap and rupture of the universal veil, and is considered to be one of the main factors that negatively impacts the yield and value of V. volvacea. Stipe elongation is a common phenomenon in mushrooms; however, the mechanisms, genes and regulation involved in stipe elongation are still poorly understood. In order to study the genes related to the stipe elongation, we analyzed the transcription of laccase genes in stipe tissue of V. volvacea, as some laccases have been suggested to be involved in stipe elongation in Flammulina velutipes. Based on transcription patterns, the expression of Vvlcc3 was found to be the highest among the 11 laccase genes. Moreover, phylogenetic analysis showed that VvLCC3 has a high degree of identity with other basidiomycete laccases. Therefore, we selected and cloned a laccase gene, named Vvlcc3, a cDNA from V. volvacea, and expressed the cDNA in Pichia pastoris. The presence of the laccase signature L1-L4 on the deduced protein sequence indicates that the gene encodes a laccase. Phylogenetic analysis showed that VvLCC3 clusters with Coprinopsis cinerea laccases. The ability to catalyze ABTS (2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid oxidation proved that the product of the Vvlcc3 gene was a functional laccase. We also found that the expression of the Vvlcc3 gene in V. volvacea increased during button stage to the elongation stage; it reached its peak in the elongation stage, and then decreased in the maturation stage, which was similar to the trend in the expression of Fv-lac3 and Fv-lac5 in F. velutipes stipe tissue. The similar trend in expression level of these laccase genes of F. velutipes suggested that this gene could be involved in stipe elongation in V

  18. 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)

  19. Telomerase efficiently elongates highly transcribing telomeres in human cancer cells.

    Directory of Open Access Journals (Sweden)

    Benjamin O Farnung

    Full Text Available RNA polymerase II transcribes the physical ends of linear eukaryotic chromosomes into a variety of long non-coding RNA molecules including telomeric repeat-containing RNA (TERRA. Since TERRA discovery, advances have been made in the characterization of TERRA biogenesis and regulation; on the contrary its associated functions remain elusive. Most of the biological roles so far proposed for TERRA are indeed based on in vitro experiments carried out using short TERRA-like RNA oligonucleotides. In particular, it has been suggested that TERRA inhibits telomerase activity. We have exploited two alternative cellular systems to test whether TERRA and/or telomere transcription influence telomerase-mediated telomere elongation in human cancer cells. In cells lacking the two DNA methyltransferases DNMT1 and DNMT3b, TERRA transcription and steady-state levels are greatly increased while telomerase is able to elongate telomeres normally. Similarly, telomerase can efficiently elongate transgenic inducible telomeres whose transcription has been experimentally augmented. Our data challenge the current hypothesis that TERRA functions as a general inhibitor of telomerase and suggest that telomere length homeostasis is maintained independently of TERRA and telomere transcription.

  20. 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.

  1. 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.

  2. 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...

  3. [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

  4. Gdown1 Associates Efficiently with RNA Polymerase II after Promoter Clearance and Displaces TFIIF during Transcript Elongation

    Science.gov (United States)

    DeLaney, Elizabeth

    2016-01-01

    Pausing during the earliest stage of transcript elongation by RNA polymerase II (Pol II) is a nearly universal control point in metazoan gene expression. The substoichiometric Pol II subunit Gdown1 facilitates promoter proximal pausing in vitro in extract-based transcription reactions, out-competes the initiation/elongation factor TFIIF for binding to free Pol II and co-localizes with paused Pol II in vivo. However, we have shown that Gdown1 cannot functionally associate with the Pol II preinitiation complex (PIC), which contains TFIIF. In the present study, we determined at what point after initiation Gdown1 can associate with Pol II and how rapidly this competition with TFIIF occurs. We show that, as with the PIC, Gdown1 cannot functionally load into open complexes or complexes engaged in abortive synthesis of very short RNAs. Gdown1 can load into early elongation complexes (EECs) with 5–9 nt RNAs, but efficient association with EECs does not take place until the point at which the upstream segment of the long initial transcription bubble reanneals. Tests of EECs assembled on a series of promoter variants confirm that this bubble collapse transition, and not transcript length, modulates Gdown1 functional affinity. Gdown1 displaces TFIIF effectively from all complexes downstream of the collapse transition, but this displacement is surprisingly slow: complete loss of TFIIF stimulation of elongation requires 5 min of incubation with Gdown1. The relatively slow functional loading of Gdown1 in the presence of TFIIF suggests that Gdown1 works in promoter-proximal pausing by locking in the paused state after elongation is already antagonized by other factors, including DSIF, NELF and possibly the first downstream nucleosome. PMID:27716820

  5. 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

  6. 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.

  7. 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 (pcrop 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.

  8. 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

  9. 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...

  10. 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...

  11. 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.

  12. 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

  13. 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.

  14. 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...

  15. 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...

  16. 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

  17. 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

  18. Rayleigh scattering and laser spot elongation problems at ALFA

    CERN Document Server

    Viard, E; Hubin, N; Ageorges, N; Davies, R

    1999-01-01

    This paper describes the qualitative effects of LGS spot elongation and Rayleigh scattering on ALFA wavefront sensor images. An analytical model of Rayleigh scattering and a numerical model of laser plume generation at the altitude of the Na-layer were developed. These models, integrated into a general AO simulation, provide the sensor sub-aperture images. It is shown that the centroid measurement accuracy is affected by these phenomena. The simulation was made both for the ALFA system and for the VLT Nasmyth Adaptive Optics System (NAOS).

  19. 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

  20. 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...

  1. 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....

  2. 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

  3. 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

  4. Strain and elongation of the human semitendinosus muscle - tendon unit.

    Science.gov (United States)

    Kellis, Eleftherios; Patsika, Glykeria; Karagiannidis, Evaggelos

    2013-12-01

    The semitendinosus (ST) consists of a long distal tendon and it is divided in two parts by a tendinous inscription (TI). The purpose of this study was to quantify strain and elongation of the TI and the distal tendon of ST. Fourteen subjects performed ramp isometric contractions of the knee flexors at 0°, 45° and 90° of knee flexion. Two ultrasound probes were used to visualize the displacement of the distal tendon and selected points across the TI and aponeuroses. Three-way analysis of variance designs indicated that: (a) strain and elongation of the ST distal muscle-tendon junction were higher than that of the aponeurosis - TI junction points (p segments significantly increased from 90° to 0° of knee flexion while the inverse was observed for the TI arm length (p segments at 45° and 90° of knee flexion while the opposite was observed at 0° of knee flexion. The arrangement of TI along ST length results in differential local strains, indicating that the mechanical properties of the ST muscle are affected by tendon, aponeuroses and tendinous inscription interactions.

  5. 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

  6. 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.

  7. 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

  8. 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...... polystyrene melt with a molecular weight of 390 kg/mole (PS390K). The measurements have all been preformed on a Filament Streching Rheometer (FSR) equipped with an oven: A cylindrical test sample is placed between two parallel, circular plates and stretched. A load cell measures the transmitted force......, and a laser monitors the central diameter of the stretched filament. Our rheometer is located in a thermostated environment. Notice, a camera to ensure a centered sample during measurement monitors the location of the central necking in the filament. The distance between the end plates is adjusted online...

  9. Centrosome splitting during nuclear elongation in the Drosophila embryo.

    Science.gov (United States)

    Callaini, G; Anselmi, F

    1988-10-01

    In the early Drosophila embryo, nuclear elongation occurs during cellularization of the syncytial blastoderm. This process is closely related to the presence of microtubular bundles forming a basket-like structure surrounding the nuclei. In immunofluorescence observations with antibodies against alpha-tubulin, the microtubules appear to radiate from two bright foci widely separated from each other. We used electron microscopy to show that these foci are true centrosomes constituted by daughter and parent centrioles orthogonally disposed and surrounded by pericentriolar electrondense material. The centrosomes may be observed in the apical region of the blastoderm cells from the beginning of cellularization until the reestablishment of the first postblastodermic mitosis, when they organize the spindle poles. Until this time the dimensions of the procentrioles remain unchanged. The significance of these results is discussed in relation to the known behavior of centrioles in the cell cycle.

  10. 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

  11. Elongational rheology and cohesive fracture of photo-oxidated LDPE

    Energy Technology Data Exchange (ETDEWEB)

    Rolón-Garrido, Víctor H., E-mail: victor.h.rolongarrido@tu-berlin.de; Wagner, Manfred H. [Chair of Polymer Engineering/Polymer Physics, Berlin Institute of Technology (TU Berlin), Fasanenstrasse 90, D-10623 Berlin (Germany)

    2014-01-15

    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.

  12. 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

  13. STUDIES ON THE BACTERIOPHAGE OF D'HERELLE : III. SOME OF THE FACTORS DETERMINING THE NUMBER AND SIZE OF PLAQUES OF BACTERIAL LYSIS ON AGAR.

    Science.gov (United States)

    Bronfenbrenner, J J; Korb, C

    1925-09-30

    The experiments reported above confirm the fact that lytic principle is distributed in active solution in a state of indivisible units. This permits its quantitative evaluation by serial dilution, as well as by plating on agar. The latter method, however, often gives readings considerably lower than those obtained by the broth dilution method of titration. By varying the concentration of agar it has been possible to show that the discrepancy is due to adsorption of the lytic agent on agar. When the concentration of the latter is increased from 0.3 per cent to 2.5 per cent the number of plaques of lysis is reduced more than 100 times. At the same time the average size of the plaques also decreases approximately to one-tenth of the original. The size, as well as the number of plaques, has been found to depend also on the condition of the culture employed in titration. Thus, when the culture exposed to the action of lytic agent is composed of young susceptible bacteria, the greater the concentration of bacteria, the smaller the plaques. When the culture is composed partly of young and partly of old susceptible bacteria, both the size and the number of the plaques are diminished with the increase in the relative concentration of old bacteria. On the other hand, presence in the culture of resistant bacteria does not affect either the size or the number of the plaques so long as the relative concentration of susceptible bacteria in the culture is sufficient to allow formation of them. The plaques appearing in the presence of a high concentration of resistant variants in the culture are relatively indistinct owing to overgrowth. Under carefully controlled conditions the size of plaques is found to be determined by the character of the lytic filtrate. Thus in the case of lytic agents which act upon more than one bacterial species the size of the plaques remains constant, irrespective of the bacterial substratum used for the production of the active filtrate.

  14. Bacterial metabarcoding by 16S rRNA gene ion torrent amplicon sequencing.

    Science.gov (United States)

    Fantini, Elio; Gianese, Giulio; Giuliano, Giovanni; Fiore, Alessia

    2015-01-01

    Ion Torrent is a next generation sequencing technology based on the detection of hydrogen ions produced during DNA chain elongation; this technology allows analyzing and characterizing genomes, genes, and species. Here, we describe an Ion Torrent procedure applied to the metagenomic analysis of 16S rRNA gene amplicons to study the bacterial diversity in food and environmental samples. PMID:25343859

  15. Bacterial metabarcoding by 16S rRNA gene ion torrent amplicon sequencing.

    Science.gov (United States)

    Fantini, Elio; Gianese, Giulio; Giuliano, Giovanni; Fiore, Alessia

    2015-01-01

    Ion Torrent is a next generation sequencing technology based on the detection of hydrogen ions produced during DNA chain elongation; this technology allows analyzing and characterizing genomes, genes, and species. Here, we describe an Ion Torrent procedure applied to the metagenomic analysis of 16S rRNA gene amplicons to study the bacterial diversity in food and environmental samples.

  16. 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.

  17. Three-dimensional structure of photosystem II from Thermosynechococcus elongates in complex with terbutryn

    Energy Technology Data Exchange (ETDEWEB)

    Gabdulkhakov, A. G., E-mail: azat@vega.protes.ru; Dontsova, M. V. [Russian Academy of Sciences, Institute of Protein Research (Russian Federation); Saenger, W. [Free University of Berlin, Institute for Chemistry and Biochemistry/Crystallography (Germany)

    2011-11-15

    Photosystem II is a key component of the photosynthetic pathway producing oxygen at the thylakoid membrane of cyanobacteria, green algae, and plants. The three-dimensional structure of photosystem II from the cyanobacterium Thermosynechococcus elongates in a complex with herbicide terbutryn (a photosynthesis inhibitor) was determined for the first time by X-ray diffraction and refined at 3.2 Angstrom-Sign resolution (R{sub factor} = 26.9%, R{sub free} = 29.9%, rmsd for bond lengths is 0.013 Angstrom-Sign , and rmsd for bond angles is 2.2 Degree-Sign ). The terbutryn molecule was located in the binding pocket of the mobile plastoquinone. The atomic coordinates of the refined structure of photosystem II in a complex with terbutryn were deposited in the Protein Data Bank.

  18. Mitotic Transcriptional Activation: Clearance of Actively Engaged Pol II via Transcriptional Elongation Control in Mitosis.

    Science.gov (United States)

    Liang, Kaiwei; Woodfin, Ashley R; Slaughter, Brian D; Unruh, Jay R; Box, Andrew C; Rickels, Ryan A; Gao, Xin; Haug, Jeffrey S; Jaspersen, Sue L; Shilatifard, Ali

    2015-11-01

    Although it is established that some general transcription factors are inactivated at mitosis, many details of mitotic transcription inhibition (MTI) and its underlying mechanisms are largely unknown. We have identified mitotic transcriptional activation (MTA) as a key regulatory step to control transcription in mitosis for genes with transcriptionally engaged RNA polymerase II (Pol II) to activate and transcribe until the end of the gene to clear Pol II from mitotic chromatin, followed by global impairment of transcription reinitiation through MTI. Global nascent RNA sequencing and RNA fluorescence in situ hybridization demonstrate the existence of transcriptionally engaged Pol II in early mitosis. Both genetic and chemical inhibition of P-TEFb in mitosis lead to delays in the progression of cell division. Together, our study reveals a mechanism for MTA and MTI whereby transcriptionally engaged Pol II can progress into productive elongation and finish transcription to allow proper cellular division.

  19. 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

  20. 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 ...

  1. 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

  2. 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

  3. Risk factors for bacterial meningitis after major craniotomy in adults%成人开颅术后并发细菌性脑膜炎的危险因素分析

    Institute of Scientific and Technical Information of China (English)

    张冰琰; 陈晨; 虞胜镭; 邵凌云; 张文宏; 陈澍

    2014-01-01

    Objective To investigate the incidence,bacterial pathogen and risk factors of bacterial meningitis after major craniotomy.Methods Clinical data of patients who underwent at least one craniotomy in Huashan Hospital Affiliated to Fudan University in 2008 were collected.All subjects were ≥ 18 years old,and survived at least 7 days after surgery.Patients with only cerebrospinal fluid drainage,burr holes,cranioplasty,vascular interventional surgery,transsphenoidal or spinal surgery were excluded.Risk factors for bacterial meningitis after major craniotomy were analyzed by Logistic regression.Results A total of 691 patients were enrolled,in 60 of whom (8.68%) bacterial meningitis was identified.Among 44 samples,5 were positive in culture with 2 of Acinetobacter baumannii,1 of Enterococcus faecalis,1 of Streptococcus intermedius and 1 of Klebsiella pneumonia.Diabetes (OR =5.79,95% CI:1.40-23.93,P =0.02),Glasgow Coma Scale score < 12 (OR =6.56,95% CI:1.17-36.80,P =0.03),external ventricular drainage (OR =4.31,95% CI:1.57-11.82,P =0.01),and continuous lumbar cistern drainage (OR =22.82,95% CI:10.31-50.52,P =0.00) were independent risk factors for bacterial meningitis after major craniotomy.Patients with external ventricular drainage > 7 d were 11.82 times more likely to develop bacterial meningitis,and those with continuous lumbar cistern drainage > 10 d were 25.50 times more likely to develop bacterial meningitis.Conclusions Bacterial meningitis remains a common complication after major craniotomy,and most are induced by Gram-negative bacilli.Diabetes,Glasgow Coma Scale score,external ventricular drainage and continuous lumbar cistern drainage may increase its incidence.%目的 探讨开颅术后细菌性脑膜炎的发生率、常见病原菌及危险因素.方法 连续收集复旦大学附属华山医院2008年至少接受过一次颅脑手术病例的资料.纳入年龄≥18岁,且术后至少存活7d的病例,排除仅行脑脊髓液引流术、颅

  4. 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.

  5. Use of the delta neutrophil index as a prognostic factor of mortality in patients with spontaneous bacterial peritonitis: implications of a simple and useful marker.

    Directory of Open Access Journals (Sweden)

    Tae Seop Lim

    Full Text Available BACKGROUND: Spontaneous bacterial peritonitis (SBP is a common and life-threatening infection in patients with advanced cirrhosis. The prognostic value of a novel marker, the delta neutrophil index (DNI, was investigated relative to mortality in patients with SBP. MATERIALS & METHODS: Seventy-five patients with SBP were studied from April 2010 to May 2012. DNI at initial diagnosis of SBP was determined and compared with 30-day mortality rates. RESULTS: Of the patients, 87.7% were men, and the median age of all patients was 59.0 yrs. The area under the receiver-operating characteristic (ROC curve of DNI for 30-day mortality was 0.701 (95% confidence interval [CI], 0.553-0.849; p = 0.009, which was higher than that of C-reactive protein (0.640, 95% CI, 0.494-0.786; p = 0.076 or the model for end-stage liver disease score (0.592, 95% CI, 0.436-0.748; p = 0.235. From the ROC curve, with the sum of sensitivity and specificity, the cutoff value of DNI was determined to be 5.7%. In the high-DNI group (DNI ≥5.7%, septic shock and 30-day mortality were more prevalent compared with the low-DNI group (84.2% vs. 48.2%, p = 0.007; 57.9% vs. 14.3%, p<0.001, respectively. Patients with an elevated DNI had a higher risk of 30-day mortality compared with those with a low DNI (4.225, 95% CI, 1.631-10.949; p = 0.003. CONCLUSION: A higher DNI at the time of SBP diagnosis is an independent predictor of 30-day mortality in patients with SBP.

  6. Polyketide chain length control by chain length factor.

    Science.gov (United States)

    Tang, Yi; Tsai, Shiou-Chuan; Khosla, Chaitan

    2003-10-22

    Bacterial aromatic polyketides are pharmacologically important natural products. A critical parameter that dictates product structure is the carbon chain length of the polyketide backbone. Systematic manipulation of polyketide chain length represents a major unmet challenge in natural product biosynthesis. Polyketide chain elongation is catalyzed by a heterodimeric ketosynthase. In contrast to homodimeric ketosynthases found in fatty acid synthases, the active site cysteine is absent from the one subunit of this heterodimer. The precise role of this catalytically silent subunit has been debated over the past decade. We demonstrate here that this subunit is the primary determinant of polyketide chain length, thereby validating its designation as chain length factor. Using structure-based mutagenesis, we identified key residues in the chain length factor that could be manipulated to convert an octaketide synthase into a decaketide synthase and vice versa. These results should lead to novel strategies for the engineered biosynthesis of hitherto unidentified polyketide scaffolds.

  7. 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.

  8. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... 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 become...

  9. 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.

  10. Clinical Features and Risk Factors of Hydrocephalus in Children with Bacterial Meningitis%细菌性脑膜炎并脑积水的临床特点及危险因素

    Institute of Scientific and Technical Information of China (English)

    刘敏; 庞玉生; 石靖

    2012-01-01

    Objective To explore the clinical characteristics and correlated risk factors of hydrocephalus secondary to bacterial meningitis in children,in order to reduce its incidence and improve the outcome of hacterial meningitis. Methods The study was retrospectively performed on 111 patients at the First Affiliated Hospital of Guangxi Medical University, from Jan. 2004 to Jun. 2010,with the diagnosis of bacterial meningitis. All cases were divided into bacterial meningitis with hydrocephalus group and without hydrocephalus group according to neu-roimaging findings. The clinical and laboratory data of patients with and without hydroce phalus were analyzed and compared by SPSS 17.0 software. Results Hydrocephalus patients accounted for 14.4% (16/111 cases) of bacterial meningitis cases. A total of 75% (12/16 cases) hydrocephalus manifested itself within 4 weeks following the disease's onset. Fourteen cases (14/16 cases,87. 5%) were obstructive hydrocephalus. One to three times repeated CT/MRI were performed when hydrocephalus was diagnosed. Two cases with hydrocephalus required ventriculoperitoneal shunt al 2 months after bacterial meningitis was onset. Two patients with hydrocephalus were died. There were significant differences between the both groups at admission included young age,prolonged fever > 10 d,the presence of seizures,impaired consciousness, empirical treatment failure, cerebral infarction,low haemoglobin level,high cerebrospinal fluid(CSF) protein level and low CSF glucose level. The Logistic regression analysis showed that impaired consciousness,empirical treatment failure and low haemoglobin level were independent risk factors of hydrocephalus secondary to bacterial meningitis. Conclusions Hydrocephalus was one of the severe sequelaes of bacterial meningitis. Certain clinical parameters and laboratory findings in blood and CSF at the lime of admission can be used as predictors for hydrocephalus in bacterial meningitis.%目的 探讨细菌性脑膜炎并

  11. 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

  12. Micro- and Nanoscale Capacitors that Incorporate an Array of Conductive Elements Having Elongated Bodies

    Science.gov (United States)

    Manohara, Harish (Inventor); Del Castillo, Linda Y. (Inventor); Mojarradi, Mohammed M. (Inventor)

    2016-01-01

    Systems and methods in accordance with embodiments of the invention implement micro- and nanoscale capacitors that incorporate a conductive element that conforms to the shape of an array elongated bodies. In one embodiment, a capacitor that incorporates a conductive element that conforms to the shape of an array of elongated bodies includes: a first conductive element that conforms to the shape of an array of elongated bodies; a second conductive element that conforms to the shape of an array of elongated bodies; and a dielectric material disposed in between the first conductive element and the second conductive element, and thereby physically separates them.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Allen's rule revisited: temperature influences bone elongation during a critical period of postnatal development.

    Science.gov (United States)

    Serrat, Maria A

    2013-10-01

    Limbs of animals raised at warm ambient temperature are significantly and permanently longer than those of siblings housed in the cold. These highly reproducible lab results closely parallel the ecogeographical tenet described by Allen's extremity size rule, which states that appendage length correlates with temperature and latitude. It is unclear what mechanisms underlie these differences and in what pattern they emerge, since the morphology is traditionally thought to reflect naturally selected genomic adaptations for thermoregulation. This study tests the a posteriori hypothesis that adult extremity length is subject to substantial modification by temperature during a brief but critical period of early postnatal development. Weanling mice (N = 28) were divided into three groups and housed at 7°C, 21°C, or 27°C for eight weeks. Tail lengths and body mass were measured weekly. Mass did not differ at any age. Analysis of tail elongation curves revealed two distinct phases: an initial period of rapid temperature-sensitive growth in which elongation rate was directly impacted by temperature; and a second phase of continued growth in which rates were identical among groups. Comparable growth reactions occur in response to other environmental variables such as exercise, suggesting that the skeleton is most responsive to external stimuli during a window of heightened sensitivity when growth occurs most rapidly. Knowledge of the timing and degree to which growth plasticity permits mammals to immediately adjust to novel temperature conditions will be important for analyzing skeletal variation in fluctuating climates, particularly for assessing factors that may accelerate skeletal evolution at temperature extremes.

  19. 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.

  20. 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

  1. 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 ...

  2. Elongated Silicon-Carbon Bonds at Graphene Edges.

    Science.gov (United States)

    Chen, Qu; Robertson, Alex W; He, Kuang; Gong, Chuncheng; Yoon, Euijoon; Kirkland, Angus I; Lee, Gun-Do; Warner, Jamie H

    2016-01-26

    We study the bond lengths of silicon (Si) atoms attached to both armchair and zigzag edges using aberration corrected transmission electron microscopy with monochromation of the electron beam. An in situ heating holder is used to perform imaging of samples at 800 °C in order to reduce chemical etching effects that cause rapid structure changes of graphene edges at room temperature under the electron beam. We provide detailed bond length measurements for Si atoms both attached to edges and also as near edge substitutional dopants. Edge reconstruction is also involved with the addition of Si dopants. Si atoms bonded to the edge of graphene are compared to substitutional dopants in the bulk lattice and reveal reduced out-of-plane distortion and bond elongation. An extended linear array of Si atoms at the edge is found to be energy-favorable due to inter-Si interactions. These results provide detailed structural information about the Si-C bonds in graphene, which may have importance in future catalytic and electronic applications.

  3. 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 lo......-selection for nucleosome-containing chromatin or pre-amplification of precipitated DNA, making them prone to introduce experimental biases....

  4. Microfluidic Approaches to Bacterial Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Hee-Deung Park

    2012-08-01

    Full Text Available Bacterial biofilms—aggregations of bacterial cells and extracellular polymeric substrates (EPS—are an important subject of research in the fields of biology and medical science. Under aquatic conditions, bacterial cells form biofilms as a mechanism for improving survival and dispersion. In this review, we discuss bacterial biofilm development as a structurally and dynamically complex biological system and propose microfluidic approaches for the study of bacterial biofilms. Biofilms develop through a series of steps as bacteria interact with their environment. Gene expression and environmental conditions, including surface properties, hydrodynamic conditions, quorum sensing signals, and the characteristics of the medium, can have positive or negative influences on bacterial biofilm formation. The influences of each factor and the combined effects of multiple factors may be addressed using microfluidic approaches, which provide a promising means for controlling the hydrodynamic conditions, establishing stable chemical gradients, performing measurement in a high-throughput manner, providing real-time monitoring, and providing in vivo-like in vitro culture devices. An increased understanding of biofilms derived from microfluidic approaches may be relevant to improving our understanding of the contributions of determinants to bacterial biofilm development.

  5. Mammary epithelial tubes elongate through MAPK-dependent coordination of cell migration.

    Science.gov (United States)

    Huebner, Robert J; Neumann, Neil M; Ewald, Andrew J

    2016-03-15

    Mammary branching morphogenesis is regulated by receptor tyrosine kinases (RTKs). We sought to determine how these RTK signals alter proliferation and migration to accomplish tube elongation in mouse. Both behaviors occur but it has been difficult to determine their relative contribution to elongation in vivo, as mammary adipocytes scatter light and limit the depth of optical imaging. Accordingly, we utilized 3D culture to study elongation in an experimentally accessible setting. We first used antibodies to localize RTK signals and discovered that phosphorylated ERK1/2 (pERK) was spatially enriched in cells near the front of elongating ducts, whereas phosphorylated AKT was ubiquitous. We next observed a gradient of cell migration speeds from rear to front of elongating ducts, with the front characterized by both high pERK and the fastest cells. Furthermore, cells within elongating ducts oriented both their protrusions and their migration in the direction of tube elongation. By contrast, cells within the organoid body were isotropically protrusive. We next tested the requirement for proliferation and migration. Early inhibition of proliferation blocked the creation of migratory cells, whereas late inhibition of proliferation did not block continued duct elongation. By contrast, pharmacological inhibition of either MEK or Rac1 signaling acutely blocked both cell migration and duct elongation. Finally, conditional induction of MEK activity was sufficient to induce collective cell migration and ductal elongation. Our data suggest a model for ductal elongation in which RTK-dependent proliferation creates motile cells with high pERK, the collective migration of which acutely requires both MEK and Rac1 signaling.

  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. 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)

  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. Rho-modifying bacterial protein toxins.

    Science.gov (United States)

    Aktories, Klaus

    2015-12-01

    Rho proteins are targets of numerous bacterial protein toxins, which manipulate the GTP-binding proteins by covalent modifications, including ADP ribosylation, glycosylation, adenylylation, proteolytic cleavage and deamidation. Bacterial toxins are important virulence factors but are also potent and efficient pharmacological tools to study the physiological functions of their eukaryotic targets. Recent studies indicate that amazing variations exist in the molecular mechanisms by which toxins attack Rho proteins, which are discussed here.

  10. Elongational viscosity of narrow molar mass distribution star and pom-pom polystyrene

    DEFF Research Database (Denmark)

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

    2006-01-01

    We have measured the transient and steady uniaxial elongational viscosity, using the filament stretching rheometer (FSR), of two narrow molar mass distribution (MMD) long-chain branched polystyrene melts: AnBAm (a ‘pom-pom’ molecule) and AnB (a ‘asymmetric star’ molecule). The elongational...

  11. Methanol as an alternative electron donor in chain elongation for butyrate and caproate formation

    NARCIS (Netherlands)

    Chen, W.S.; Ye, Y.; Steinbusch, K.J.J.; Strik, D.P.B.T.B.; Buisman, C.J.N.

    2016-01-01

    Chain elongation is an emerging mixed culture biotechnology converting acetate into valuable biochemicals by using ethanol as an external electron donor. In this study we proposed to test another potential electron donor, methanol, in chain elongation. Methanol can be produced through the thermoc

  12. Rwandan female genital modification: elongation of the Labia minora and the use of local botanical species

    NARCIS (Netherlands)

    Koster, M.; Price, L.L.

    2008-01-01

    The elongation of the labia minora is classified as a Type IV female genital mutilation by the World Health Organization. However, the term mutilation carries with it powerful negative connotations. In Rwanda, the elongation of the labia minora and the use of botanicals to do so is meant to increase

  13. Shaping and vertical stability elongated plasmas on the TVD

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, A.V.; Bortnikov, A.V.; Brevnov, N.N.; Gerasimov, S.N.; Polianchik, K.D. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow (Russian Federation). Inst. Atomnoj Ehnergii)

    1991-01-01

    The plasma column was formed with the poloidal field produced by the currents through six functionally-separated coils. The experimental results discussed below are related with two discharge types. One of them is a quasi-stationary discharge with the plateau current I[sub p]=20 kA. In this case a quadrupole field was produced by the current through one coil only. A two relay control system provides the plasma confinement along the vertical and along the horizontal at a quasi-stationary discharge stage within [+-]2 mm respective to the reference position. The current produces a quadrupole field (-c/I[sub p][partial derivative]B[sub z]/[partial derivative]r) rising in time and extending the plasma column. With an increase in the quadrupole field the plasma ellipticity (k) monotonously rises. The plasma column with the elongation k[approx]1.4-1.5 is formed in the discharges with a quasi-stationary current before disruption along the vertical. Another type of discharge is that with a rapid current rise from a quasi-stationary value I[sub p]=20 kA. It was achieved by additional switching a shape control coil. This coil, along with the production of an additional quadrupole field extending the plasma, generates a rather high loop voltage. The maximal ellipticity of the edge magnetic surface in the discharges with the secondary current rise is k[approx]1.6. The specific feature of the discharge is a continuous rise in the plasma ellipticity even at the discharge current decay stage. (author) 1 ref., 6 figs.

  14. 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...... fluid samples from patients with clinically suspected meningitis were sent to the Hellenic National Meningitis Reference Laboratory. Ten of 545 (1.83%) patients died. Analysis by receiver operating characteristics (ROC) curve revealed that both suPAR and age were significant for prediction of fatal...... outcome. Patients with levels of suPAR above the cut-off values and age ≥51 years, or patients in which either Neisseria meningitis or Streptococcus pneumoniae were detected were categorized as high risk patients. The combination of the above three predictors (suPAR, age and infectious agent...

  15. 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.

  16. Actin and myosin inhibitors block elongation of kinetochore fibre stubs in metaphase crane-fly spermatocytes.

    Science.gov (United States)

    Forer, A; Spurck, T; Pickett-Heaps, J D

    2007-01-01

    We used an ultraviolet microbeam to cut individual kinetochore spindle fibres in metaphase crane-fly spermatocytes. We then followed the growth of the "kinetochore stubs", the remnants of kinetochore fibres that remain attached to kinetochores. Kinetochore stubs elongate with constant velocity by adding tubulin subunits at the kinetochore, and thus elongation is related to tubulin flux in the kinetochore microtubules. Stub elongation was blocked by cytochalasin D and latrunculin A, actin inhibitors, and by butanedione monoxime, a myosin inhibitor. We conclude that actin and myosin are involved in generating elongation and thus in producing tubulin flux in kinetochore microtubules. We suggest that actin and myosin act in concert with a spindle matrix to propel kinetochore fibres poleward, thereby causing stub elongation and generating anaphase chromosome movement in nonirradiated cells. PMID:18094930

  17. 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...

  18. 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.

  19. Influence Factors of Bacterial Colonization in PICC Cancer Patients at Home%居家PICC肿瘤患者穿刺点细菌定植影响因素分析

    Institute of Scientific and Technical Information of China (English)

    刘心菊; 侯惠如; 杨晶; 孟凡慧; 王晓媛

    2016-01-01

    目的:探讨引起居家PICC肿瘤患者穿刺点细菌定植的相关因素,并进行对策分析。方法选择2015年10—12月于本院PICC维护中心进行PICC维护的肿瘤患者472例穿刺点采样,并进行细菌学培养及观察分析,同时对患者维护情况进行记录。结果 Logistic回归分析显示,性别、维护间期、敷料卷边范围、周围皮肤是否清洁、自理能力、穿刺点增生及导管体外长度为PICC穿刺点定植的影响因素,其中体外长度在4 cm以内能减少细菌定植。微生物检验显示,革兰氏阳性菌为主要定植菌,其中凝固酶阴性葡萄球菌居首位。结论肿瘤患者居家期间PICC穿刺点细菌定植情况需得到重视,应对穿刺点细菌定植高风险者进行针对性预防护理。置管时用心电图进行定位,维护过程中将体外长度控制在4 cm之内,加强对男性患者及家属的健康宣教,维持穿刺点周围皮肤清洁,若穿刺点增生应进行碘酊湿敷,建立有效联络方式,建立完善的社区维护机制、推广洗必泰消毒剂的应用,从而减少PICC穿刺点细菌定植,降低感染率,降低导管相关性感染的发生。%Objective To investigate the correlation factors of bacterial colonization of PICC cancer patients at home and to analyze its influence factors. Methods Puncture point samples of 472 patients admitted to maintenance center from November to December in 2015 were bacteriologically cultured and observed. Results Logistic regression analysis showed that gender, membrane exchange interval, crimping degree, the cleanliness of the surrounding skin, self-care ability, proliferation and exposed length were factors affecting the colonization of PICC puncture points and when exposed length was less than 4cm can reduce the bacterial colonization. Microbe testing showed gram positive bacteria were the main pathogenic bacteria and coagulase negative staphylococci in the first place

  20. Inhibited cell spreading on polystyrene nanopillars fabricated by nanoimprinting and in situ elongation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Walter; Crouch, Adam S; Aryal, Mukti [Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080 (United States); Miller, Danielle; Luebke, Kevin J, E-mail: walter.hu@utdallas.edu, E-mail: Kevin.Luebke@UTSouthwestern.edu [Department of Internal Medicine, Division of Translational Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9185 (United States)

    2010-09-24

    Polymer nanopillars (40-80 nm in diameter and 100 nm in pitch) were fabricated at high density over large areas directly on bulk tissue culture polystyrene plates using nanoimprint lithography. Nanoporous Si molds for imprinting were generated by transfer from an anodic alumina membrane. Ultrahigh aspect ratio polymer nanopillars were formed in a novel procedure using controlled elongation of the imprinted pillars during mold release. The resulting nanopillar arrays show significant changes in surface wettability upon brief O{sub 2} plasma treatment. Human dermal fibroblasts were cultured on the nanopillar surfaces in order to study cell-substrate interaction at the nanoscale. The nanopillar topography shows strong effects on the cell morphology, with pillars of widely varying aspect ratios and surface energies resisting cell spreading. This effect on cell behavior can be rationalized in terms of the cells' requirement to form micron-scale focal adhesions. The study indicates that at the nanoscale, physical factors can supersede the effects of chemical factors on the cell-substratum interaction.

  1. 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

  2. Linked circadian outputs control elongation growth and flowering in response to photoperiod and temperature.

    Science.gov (United States)

    Seaton, Daniel D; Smith, Robert W; Song, Young Hun; MacGregor, Dana R; Stewart, Kelly; Steel, Gavin; Foreman, Julia; Penfield, Steven; Imaizumi, Takato; Millar, Andrew J; Halliday, Karen J

    2015-01-01

    Clock-regulated pathways coordinate the response of many developmental processes to changes in photoperiod and temperature. We model two of the best-understood clock output pathways in Arabidopsis, which control key regulators of flowering and elongation growth. In flowering, the model predicted regulatory links from the clock to cycling DOF factor 1 (CDF1) and flavin-binding, KELCH repeat, F-box 1 (FKF1) transcription. Physical interaction data support these links, which create threefold feed-forward motifs from two clock components to the floral regulator FT. In hypocotyl growth, the model described clock-regulated transcription of phytochrome-interacting factor 4 and 5 (PIF4, PIF5), interacting with post-translational regulation of PIF proteins by phytochrome B (phyB) and other light-activated pathways. The model predicted bimodal and end-of-day PIF activity profiles that are observed across hundreds of PIF-regulated target genes. In the response to temperature, warmth-enhanced PIF4 activity explained the observed hypocotyl growth dynamics but additional, temperature-dependent regulators were implicated in the flowering response. Integrating these two pathways with the clock model highlights the molecular mechanisms that coordinate plant development across changing conditions. PMID:25600997

  3. Bacterial classification and susceptible factors of lung fungal infection%肺部真菌感染的菌种分类及易患因素

    Institute of Scientific and Technical Information of China (English)

    党殿杰; 路振宇; 刁淑梅

    2014-01-01

    Objective To explore the common strains, susceptible factors and clinical characteristics of pulmonary fun-gal infection, and strengthen clinical cognition. Methods Clinical data of 77 patients with pulmonary fungal infection from November 2012 to November 2013 in the Infectious Diseases Hospital of Handan City were retrospectively ana-lyzed, and the condition of medical history, Strains classification of fungi, risk factors, diagnosis and treatment, progno-sis were summarized and analyzed. Results The susceptible factors of lung fungal infection included chronic lung dis-eases and drug abuse and so on, including 32 cases of chronic obstructive pulmonary diseases (41.56%), 17 cases of tu-berculosis (22.08%), 11 cases of type 2 diabetes (14.29%), 7 cases of hypoalbuminemia (9.09%), 2 cases of thoracoto-my (2.60%), 3 cases of lung cancer and pulmonary fungi posthepatitic cirrhosis complicated with pulmonary fungal in-fection (3.90%), 3 cases of pulmonary fungi posthepatitic cirrhosis complicated with pulmonary fungal infection (3.90%), 2 cases of blood disease complicated with pulmonary fungal infection (2.60%), 49 cases of long time using of broad-spec-trum antibiotics (63.64%), 15 cases use the glucocorticoid (19.48%). The main fungal species was blastocystis, 47 cases of candida albicans (61.04%), 23 cases of candida glabrata (29.87%), 3 cases of tropical candida (3.90%), 4 cases of aspergillus (5.19%). They were mainly given the antifungal therapy after diagnosis, such as Fluconazole, Voriconazole, 5-Fluorine Cytosine, Amphotericin B, 55 cases (71.43%) were cured, 20 cases (25.97%) were improved, had a good over-all treatment effect. Conclusion Early and correctly diagnosis and treatment according to the strains of pulmonary fun-gal infection is the key to healing, so comprehensive treatment actively, improve the patients' immunity, eliminate risk factors associated with pulmonary fungal infection disease, timely application of antifungal drugs to intervene, can

  4. 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

  5. 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

  6. 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.

  7. Molecular mechanism of Ena/VASP-mediated actin-filament elongation.

    Science.gov (United States)

    Breitsprecher, Dennis; Kiesewetter, Antje K; Linkner, Joern; Vinzenz, Marlene; Stradal, Theresia E B; Small, John Victor; Curth, Ute; Dickinson, Richard B; Faix, Jan

    2011-02-01

    Ena/VASP proteins are implicated in a variety of fundamental cellular processes including axon guidance and cell migration. In vitro, they enhance elongation of actin filaments, but at rates differing in nearly an order of magnitude according to species, raising questions about the molecular determinants of rate control. Chimeras from fast and slow elongating VASP proteins were generated and their ability to promote actin polymerization and to bind G-actin was assessed. By in vitro TIRF microscopy as well as thermodynamic and kinetic analyses, we show that the velocity of VASP-mediated filament elongation depends on G-actin recruitment by the WASP homology 2 motif. Comparison of the experimentally observed elongation rates with a quantitative mathematical model moreover revealed that Ena/VASP-mediated filament elongation displays a saturation dependence on the actin monomer concentration, implying that Ena/VASP proteins, independent of species, are fully saturated with actin in vivo and generally act as potent filament elongators. Moreover, our data showed that spontaneous addition of monomers does not occur during processive VASP-mediated filament elongation on surfaces, suggesting that most filament formation in cells is actively controlled.

  8. Product Diversity Linked to Substrate Usage in Chain Elongation by Mixed-Culture Fermentation.

    Science.gov (United States)

    Coma, Marta; Vilchez-Vargas, Ramiro; Roume, Hugo; Jauregui, Ruy; Pieper, Dietmar H; Rabaey, Korneel

    2016-06-21

    Acetate and ethanol can be converted to caproic acid by microorganisms through reverse β-oxidation. There is limited insight into the versatility of chain elongation in view of different starting substrates, including even- and odd-carbon carboxylates and alcohols other than ethanol. Thermodynamic analyses show that most elongation pathways are energetically feasible. Through incubations of microbial communities with different substrate-pair combinations, we established that ethanol and propanol were both highly suitable for chain elongation. As an electron acceptor, acetate, propionate, and butyrate readily elongated with ethanol, whereas an adaptation period was necessary for formate. Isobutyrate and longer-chained fatty acids above butyrate were not elongated. The microbial communities converged, and consistent enrichment of Clostridium spp. was observed, independent of the supplied alcohol or carboxylate, with a strain related to Clostridium kluyveri dominating the enrichments. Community analysis also showed phylotypes related to Bacteroidaceae and Microbacteriaceae families in all tests that are capable of converting the base substrates to useful intermediates. These organisms were mainly enriched with methanol or formate. Our overall conclusion is thus that multiple substrates can be used for chain elongation and that this process is carried out by highly similar organisms for direct chain elongation irrespective of the substrate. PMID:27162101

  9. 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.

  10. 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

  11. A study on elongation/contraction behavior and mechanical properties of oxy-polyacrylonitrile(PAN) fiber in basic/acidic solution for artificial muscle applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.K.; Kim, S.W.; Lee, K.S.; Cho, I.H.; Lee, J.H.; Lee, J.W. [Sungkyunkwan University, Suwon (Korea); Kim, K.J. [University of Nevada, Reno (United States); Nam, J.D. [Sungkyunkwan University, Suwon (Korea)

    2002-07-01

    Oxy-PAN fiber prepared from the preoxidation and saponification of raw PAN fiber is known to elongate and contract when immersed in basic and acidic solutions, respectively. In this study, about 30% elongation in NaOH solution and 30{approx}50% contraction in HCl solution have been observed. In mechanical test, the mechanical properties of oxy-PAN fiber in the contracted state was stronger than that in the elongated state. These behaviors and mechanical properties are compared to those of living muscle and linear actuator. The change of length in NaOH and HCl solutions is due to switching between a hydrophilic and a hydrophobic structure. Other reasons are exchange of ion and water in/out of oxy-PAN fiber, and osmotic pressure difference associated with relevant ions. Much studies are needed to clarify the effective factors on but the oxy-PAN fiber's elongation/contraction behavior and mechanical properties, but the oxy-PAN fiber prepared in our laboratory has a sufficient potential for application as artificial muscle and linear actuator. (author). 20 refs., 1 tab., 9 figs.

  12. 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

  13. 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.

  14. A Replisome’s journey through the bacterial chromosome

    Directory of Open Access Journals (Sweden)

    Thomas Robert Beattie

    2015-06-01

    Full Text Available Genome duplication requires the coordinated activity of a multi-component machine, the replisome. In contrast to the background of metabolic diversity across the bacterial domain, the composition and architecture of the bacterial replisome seems to have suffered few changes during evolution. This immutability underlines the replisome’s efficiency in copying the genome. It also highlights the success of various strategies inherent to the replisome for responding to stress and avoiding problems during critical stages of DNA synthesis. Here we summarise current understanding of bacterial replisome architecture and highlight the known variations in different bacterial taxa. We then look at the mechanisms in place to ensure that the bacterial replisome is assembled appropriately on DNA, kept together during elongation, and disassembled upon termination. We put forward the idea that the architecture of the replisome may be more flexible that previously thought and speculate on elements of the replisome that maintain its stability to ensure a safe journey from origin to terminus.

  15. 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.

  16. 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.

  17. 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

    /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...... 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...... 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...

  18. Rubber elongation factor (REF), a major allergen component in Hevea brasiliensis latex has amyloid properties.

    Science.gov (United States)

    Berthelot, Karine; Lecomte, Sophie; Estevez, Yannick; Coulary-Salin, Bénédicte; Bentaleb, Ahmed; Cullin, Christophe; Deffieux, Alain; Peruch, Frédéric

    2012-01-01

    REF (Hevb1) and SRPP (Hevb3) are two major components of Hevea brasiliensis latex, well known for their allergenic properties. They are obviously taking part in the biosynthesis of natural rubber, but their exact function is still unclear. They could be involved in defense/stress mechanisms after tapping or directly acting on the isoprenoid biosynthetic pathway. The structure of these two proteins is still not described. In this work, it was discovered that REF has amyloid properties, contrary to SRPP. We investigated their structure by CD, TEM, ATR-FTIR and WAXS and neatly showed the presence of β-sheet organized aggregates for REF, whereas SRPP mainly fold as a helical protein. Both proteins are highly hydrophobic but differ in their interaction with lipid monolayers used to mimic the monomembrane surrounding the rubber particles. Ellipsometry experiments showed that REF seems to penetrate deeply into the monolayer and SRPP only binds to the lipid surface. These results could therefore clarify the role of these two paralogous proteins in latex production, either in the coagulation of natural rubber or in stress-related responses. To our knowledge, this is the first report of an amyloid formed from a plant protein. This suggests also the presence of functional amyloid in the plant kingdom.

  19. Rubber elongation factor (REF, a major allergen component in Hevea brasiliensis latex has amyloid properties.

    Directory of Open Access Journals (Sweden)

    Karine Berthelot

    Full Text Available REF (Hevb1 and SRPP (Hevb3 are two major components of Hevea brasiliensis latex, well known for their allergenic properties. They are obviously taking part in the biosynthesis of natural rubber, but their exact function is still unclear. They could be involved in defense/stress mechanisms after tapping or directly acting on the isoprenoid biosynthetic pathway. The structure of these two proteins is still not described. In this work, it was discovered that REF has amyloid properties, contrary to SRPP. We investigated their structure by CD, TEM, ATR-FTIR and WAXS and neatly showed the presence of β-sheet organized aggregates for REF, whereas SRPP mainly fold as a helical protein. Both proteins are highly hydrophobic but differ in their interaction with lipid monolayers used to mimic the monomembrane surrounding the rubber particles. Ellipsometry experiments showed that REF seems to penetrate deeply into the monolayer and SRPP only binds to the lipid surface. These results could therefore clarify the role of these two paralogous proteins in latex production, either in the coagulation of natural rubber or in stress-related responses. To our knowledge, this is the first report of an amyloid formed from a plant protein. This suggests also the presence of functional amyloid in the plant kingdom.

  20. Ribosome-induced changes in elongation factor Tu conformation control GTP hydrolysis

    DEFF Research Database (Denmark)

    Villa, Elizabeth; Sengupta, Jayati; Trabuco, Leonard G.;

    2009-01-01

    .7-A cryo-electron microscopy map of the aminoacyl-tRNA x EF-Tu x GDP x kirromycin-bound Escherichia coli ribosome, together with an atomic model of the complex obtained through molecular dynamics flexible fitting. The model reveals the conformational changes in the conserved GTPase switch regions...