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Sample records for bacterial type iv

  1. Mechanism and structure of the bacterial type IV secretion systems.

    Science.gov (United States)

    Christie, Peter J; Whitaker, Neal; González-Rivera, Christian

    2014-08-01

    The bacterial type IV secretion systems (T4SSs) translocate DNA and protein substrates to bacterial or eukaryotic target cells generally by a mechanism dependent on direct cell-to-cell contact. The T4SSs encompass two large subfamilies, the conjugation systems and the effector translocators. The conjugation systems mediate interbacterial DNA transfer and are responsible for the rapid dissemination of antibiotic resistance genes and virulence determinants in clinical settings. The effector translocators are used by many Gram-negative bacterial pathogens for delivery of potentially hundreds of virulence proteins to eukaryotic cells for modulation of different physiological processes during infection. Recently, there has been considerable progress in defining the structures of T4SS machine subunits and large machine subassemblies. Additionally, the nature of substrate translocation sequences and the contributions of accessory proteins to substrate docking with the translocation channel have been elucidated. A DNA translocation route through the Agrobacterium tumefaciens VirB/VirD4 system was defined, and both intracellular (DNA ligand, ATP energy) and extracellular (phage binding) signals were shown to activate type IV-dependent translocation. Finally, phylogenetic studies have shed light on the evolution and distribution of T4SSs, and complementary structure-function studies of diverse systems have identified adaptations tailored for novel functions in pathogenic settings. This review summarizes the recent progress in our understanding of the architecture and mechanism of action of these fascinating machines, with emphasis on the 'archetypal' A. tumefaciens VirB/VirD4 T4SS and related conjugation systems. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey. PMID:24389247

  2. Bacterial secrets of secretion: EuroConference on the biology of type IV secretion processes.

    Science.gov (United States)

    Baron, Christian; OCallaghan, David; Lanka, Erich

    2002-03-01

    Type IV secretion systems (TFSS) mediate secretion or direct cell-to-cell transfer of virulence factors (proteins or protein-DNA complexes) from many Gram-negative animal, human and plant pathogens, such as Agrobacterium tumefaciens, Bartonella tribocorum, Bordetella pertussis, Brucella suis, Helicobacter pylori, Legionella pneumophila and Rickettsia prowazekii, into eukaryotic cells. Bacterial conjugation is also classified as a TFSS-like process mediating the spread of broad-host-range plasmids between Gram-negative bacteria such as RP4 and R388, which carry antibiotic resistance genes. Genetic, biochemical, cell biological and structural biology experiments led to significant progress in the understanding of several aspects of TFSS processes. X-ray crystallography revealed that homologues of the A. tumefaciens inner membrane-associated proteins VirB11 and VirD4 from H. pylori and R388, respectively, may form channels for substrate translocation or assembly of the transmembrane TFSS machinery. Biochemical and cell biological experiments revealed interactions between components of the periplasmic core components VirB8, VirB9 and VirB10, which may form the translocation channel. Analysis of A. tumefaciens virulence proteins VirE2 and VirF suggested that the periplasmic translocation route of the pertussis toxin from B. pertussis may be more generally valid than previously anticipated. Secretion and modification of toxins from H. pylori and L. pneumophila profoundly affect host cell metabolism, thus entering the discipline of cellular microbiology. Finally, results from genome sequencing projects revealed the presence of up to three TFSS in a single organism, and the analysis of their interplay and adaptation to different functions will be a future challenge. TFSS-carrying plasmids were discovered in different ecosystems, suggesting that genetic exchange may speed up their evolution and adaptation to different cell-cell interactions. PMID:11918819

  3. Parallel evolution of a type IV secretion system in radiating lineages of the host-restricted bacterial pathogen Bartonella.

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    Philipp Engel

    Full Text Available Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered to be responsible for the genesis of a great portion of the diversity of life. Bacteria have evolved enormous biological diversity by exploiting an exceptional range of environments, yet diversification of bacteria via adaptive radiation has been documented in a few cases only and the underlying molecular mechanisms are largely unknown. Here we show a compelling example of adaptive radiation in pathogenic bacteria and reveal their genetic basis. Our evolutionary genomic analyses of the α-proteobacterial genus Bartonella uncover two parallel adaptive radiations within these host-restricted mammalian pathogens. We identify a horizontally-acquired protein secretion system, which has evolved to target specific bacterial effector proteins into host cells as the evolutionary key innovation triggering these parallel adaptive radiations. We show that the functional versatility and adaptive potential of the VirB type IV secretion system (T4SS, and thereby translocated Bartonella effector proteins (Beps, evolved in parallel in the two lineages prior to their radiations. Independent chromosomal fixation of the virB operon and consecutive rounds of lineage-specific bep gene duplications followed by their functional diversification characterize these parallel evolutionary trajectories. Whereas most Beps maintained their ancestral domain constitution, strikingly, a novel type of effector protein emerged convergently in both lineages. This resulted in similar arrays of host cell-targeted effector proteins in the two lineages of Bartonella as the basis of their independent radiation. The parallel molecular evolution of the VirB/Bep system displays a striking example of a key innovation involved in independent adaptive processes and the emergence of bacterial

  4. Interplanetary Type IV Bursts

    CERN Document Server

    Hillaris, Alexander; Nindos, Alexander

    2016-01-01

    In this work we study the characteristics of moving type IV radio bursts which extend to the hectometric wavelengths (interplanetary type IV or type IV IP bursts) and their relationship with energetic phenomena on the Sun. Our dataset comprised 48 Interplanetary type IV bursts observed by the Wind/WAVES in the 13.825 MHz?20 KHz frequency range. The dynamic spec tra of the RSTN, DAM, ARTEMIS-IV, CULGOORA, Hiraiso and IZMIRAN Radio-spectrographs were used to track the evolution of the events in the low corona; these were supplemented with SXR ?ux recordings from GOES and CME data from LASCO. Positional information for the coronal bursts were obtained by the Nan\\c{c}ay radioheliograph (NRH). We examined the relationship of the type IV events with coronal radio bursts, CMEs and SXR ?ares. The majority of the events (45) were characterized as compact; their duration was on average 106 min. This type of events were, mostly, associated with M and X class ?ares (40 out of 45) and fast CMEs; 32 of these events had CME...

  5. Interplanetary Type IV Bursts

    Science.gov (United States)

    Hillaris, A.; Bouratzis, C.; Nindos, A.

    2016-08-01

    We study the characteristics of moving type IV radio bursts that extend to hectometric wavelengths (interplanetary type IV or type {IV}_{{IP}} bursts) and their relationship with energetic phenomena on the Sun. Our dataset comprises 48 interplanetary type IV bursts observed with the Radio and Plasma Wave Investigation (WAVES) instrument onboard Wind in the 13.825 MHz - 20 kHz frequency range. The dynamic spectra of the Radio Solar Telescope Network (RSTN), the Nançay Decametric Array (DAM), the Appareil de Routine pour le Traitement et l' Enregistrement Magnetique de l' Information Spectral (ARTEMIS-IV), the Culgoora, Hiraso, and the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) Radio Spectrographs were used to track the evolution of the events in the low corona. These were supplemented with soft X-ray (SXR) flux-measurements from the Geostationary Operational Environmental Satellite (GOES) and coronal mass ejections (CME) data from the Large Angle and Spectroscopic Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). Positional information of the coronal bursts was obtained by the Nançay Radioheliograph (NRH). We examined the relationship of the type IV events with coronal radio bursts, CMEs, and SXR flares. The majority of the events (45) were characterized as compact, their duration was on average 106 minutes. This type of events was, mostly, associated with M- and X-class flares (40 out of 45) and fast CMEs, 32 of these events had CMEs faster than 1000 km s^{-1}. Furthermore, in 43 compact events the CME was possibly subjected to reduced aerodynamic drag as it was propagating in the wake of a previous CME. A minority (three) of long-lived type {IV}_{{IP}} bursts was detected, with durations from 960 minutes to 115 hours. These events are referred to as extended or long duration and appear to replenish their energetic electron content, possibly from electrons escaping from the corresponding coronal

  6. T4SP Database 2.0: An Improved Database for Type IV Secretion Systems in Bacterial Genomes with New Online Analysis Tools

    Science.gov (United States)

    Han, Na; Yu, Weiwen; Qiang, Yujun

    2016-01-01

    Type IV secretion system (T4SS) can mediate the passage of macromolecules across cellular membranes and is essential for virulent and genetic material exchange among bacterial species. The Type IV Secretion Project 2.0 (T4SP 2.0) database is an improved and extended version of the platform released in 2013 aimed at assisting with the detection of Type IV secretion systems (T4SS) in bacterial genomes. This advanced version provides users with web server tools for detecting the existence and variations of T4SS genes online. The new interface for the genome browser provides a user-friendly access to the most complete and accurate resource of T4SS gene information (e.g., gene number, name, type, position, sequence, related articles, and quick links to other webs). Currently, this online database includes T4SS information of 5239 bacterial strains. Conclusions. T4SS is one of the most versatile secretion systems necessary for the virulence and survival of bacteria and the secretion of protein and/or DNA substrates from a donor to a recipient cell. This database on virB/D genes of the T4SS system will help scientists worldwide to improve their knowledge on secretion systems and also identify potential pathogenic mechanisms of various microbial species.

  7. Genetics Home Reference: mucopolysaccharidosis type IV

    Science.gov (United States)

    ... Understand Genetics Home Health Conditions mucopolysaccharidosis type IV mucopolysaccharidosis type IV Enable Javascript to view the expand/ ... boxes. Print All Open All Close All Description Mucopolysaccharidosis type IV (MPS IV), also known as Morquio ...

  8. Evidence of the presence of a functional Dot/Icm type IV-B secretion system in the fish bacterial pathogen Piscirickettsia salmonis.

    Directory of Open Access Journals (Sweden)

    Fernando A Gómez

    Full Text Available Piscirickettsia salmonis is a fish bacterial pathogen that has severely challenged the sustainability of the Chilean salmon industry since its appearance in 1989. As this Gram-negative bacterium has been poorly characterized, relevant aspects of its life cycle, virulence and pathogenesis must be identified in order to properly design prophylactic procedures. This report provides evidence of the functional presence in P. salmonis of four genes homologous to those described for Dot/Icm Type IV Secretion Systems. The Dot/Icm System, the major virulence mechanism of phylogenetically related pathogens Legionella pneumophila and Coxiella burnetii, is responsible for their intracellular survival and multiplication, conditions that may also apply to P. salmonis. Our results demonstrate that the four P. salmonis dot/icm homologues (dotB, dotA, icmK and icmE are expressed both during in vitro tissue culture cells infection and growing in cell-free media, suggestive of their putative constitutive expression. Additionally, as it happens in other referential bacterial systems, temporal acidification of cell-free media results in over expression of all four P. salmonis genes, a well-known strategy by which SSTIV-containing bacteria inhibit phagosome-lysosome fusion to survive. These findings are very important to understand the virulence mechanisms of P. salmonis in order to design new prophylactic alternatives to control the disease.

  9. Conjugative DNA transfer into human cells by the VirB/VirD4 type IV secretion system of the bacterial pathogen Bartonella henselae.

    Science.gov (United States)

    Schröder, Gunnar; Schuelein, Ralf; Quebatte, Maxime; Dehio, Christoph

    2011-08-30

    Bacterial type IV secretion systems (T4SS) mediate interbacterial conjugative DNA transfer and transkingdom protein transfer into eukaryotic host cells in bacterial pathogenesis. The sole bacterium known to naturally transfer DNA into eukaryotic host cells via a T4SS is the plant pathogen Agrobacterium tumefaciens. Here we demonstrate T4SS-mediated DNA transfer from a human bacterial pathogen into human cells. We show that the zoonotic pathogen Bartonella henselae can transfer a cryptic plasmid occurring in the bartonellae into the human endothelial cell line EA.hy926 via its T4SS VirB/VirD4. DNA transfer into EA.hy926 cells was demonstrated by using a reporter derivative of this Bartonella-specific mobilizable plasmid generated by insertion of a eukaryotic egfp-expression cassette. Fusion of the C-terminal secretion signal of the endogenous VirB/VirD4 protein substrate BepD with the plasmid-encoded DNA-transport protein Mob resulted in a 100-fold increased DNA transfer rate. Expression of the delivered egfp gene in EA.hy926 cells required cell division, suggesting that nuclear envelope breakdown may facilitate passive entry of the transferred ssDNA into the nucleus as prerequisite for complementary strand synthesis and transcription of the egfp gene. Addition of an eukaryotic neomycin phosphotransferase expression cassette to the reporter plasmid facilitated selection of stable transgenic EA.hy926 cell lines that display chromosomal integration of the transferred plasmid DNA. Our data suggest that T4SS-dependent DNA transfer into host cells may occur naturally during human infection with Bartonella and that these chronically infecting pathogens have potential for the engineering of in vivo gene-delivery vectors with applications in DNA vaccination and therapeutic gene therapy. PMID:21844337

  10. Fluctuations in type IV pilus retraction

    CERN Document Server

    Linden, M; Jonsson, A B; Wallin, M; Linden, Martin; Johansson, Emil; Jonsson, Ann-Beth; Wallin, Mats

    2005-01-01

    The type IV pilus retraction motor is found in many important bacterial pathogens. It is the strongest known linear motor protein and is required for bacterial infectivity. We characterize the dynamics of type IV pilus retraction in terms of a stochastic chemical reaction model. We find that a two state model can describe the experimental force velocity relation and qualitative dependence of ATP concentration. The results indicate that the dynamics is limited by an ATP-dependent step at low load and a force-dependent step at high load, and that at least one step is effectively irreversible in the measured range of forces. The irreversible nature of the sub-step(s) lead to interesting predictions for future experiments: We find different parameterizations with mathematically identical force velocity relations but different fluctuations (diffusion constant). We also find a longer elementary step compared to an earlier analysis, which agrees better with known facts about the structure of the pilus filament and e...

  11. Structure of a type IV secretion system.

    Science.gov (United States)

    Low, Harry H; Gubellini, Francesca; Rivera-Calzada, Angel; Braun, Nathalie; Connery, Sarah; Dujeancourt, Annick; Lu, Fang; Redzej, Adam; Fronzes, Rémi; Orlova, Elena V; Waksman, Gabriel

    2014-04-24

    Bacterial type IV secretion systems translocate virulence factors into eukaryotic cells, distribute genetic material between bacteria and have shown potential as a tool for the genetic modification of human cells. Given the complex choreography of the substrate through the secretion apparatus, the molecular mechanism of the type IV secretion system has proved difficult to dissect in the absence of structural data for the entire machinery. Here we use electron microscopy to reconstruct the type IV secretion system encoded by the Escherichia coli R388 conjugative plasmid. We show that eight proteins assemble in an intricate stoichiometric relationship to form an approximately 3 megadalton nanomachine that spans the entire cell envelope. The structure comprises an outer membrane-associated core complex connected by a central stalk to a substantial inner membrane complex that is dominated by a battery of 12 VirB4 ATPase subunits organized as side-by-side hexameric barrels. Our results show a secretion system with markedly different architecture, and consequently mechanism, to other known bacterial secretion systems. PMID:24670658

  12. Mucolipidosis Type IV: an Update

    OpenAIRE

    Wakabayashi, Kazuyo; Gustafson, Ann Marie; Sidransky, Ellen; Goldin, Ehud

    2011-01-01

    Mucolipidosis type IV (MLIV) is a neurodevelopmental as well as neurodegenerative disorder with severe psychomotor developmental delay, progressive visual impairment, and achlorydria. It is characterized by the presence of lysosomal inclusions in many cell types in patients. MLIV is an autosomal recessive disease caused by mutations in MCOLN1, which encodes for mucolipin-1, a member of the transient receptor potential (TRP) cation channel family. Although approximately 70-80% of patients iden...

  13. Nanoscale Adhesion Forces of Pseudomonas aeruginosa Type IV Pili

    OpenAIRE

    Beaussart, Audrey; Baker, Amy E.; Kuchma, Sherry L.; El-Kirat-Chatel, Sofiane; O’Toole, George A; Yves F Dufrêne

    2014-01-01

    A variety of bacterial pathogens use nanoscale protein fibers called type IV pili to mediate cell adhesion, a primary step leading to infection. Currently, how these nanofibers respond to mechanical stimuli and how this response is used to control adhesion is poorly understood. Here, we use atomic force microscopy techniques to quantify the forces guiding the adhesion of Pseudomonas aeruginosa type IV pili to surfaces. Using chemical force microscopy and single-cell force spectroscopy, we sho...

  14. Type IV Wind Turbine Model

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Margaris, Ioannis D.

    This document is created as part of the EaseWind project. The goal of this project is to develop and investigate new control features for primary response provided by wind power plants. New control features as inertial response, synchronising power and power system damping are of interest to EaseWind...... project to be incorporated in the wind power plant level. This document describes the Type 4 wind turbine simulation model, implemented in the EaseWind project. The implemented wind turbine model is one of the initial necessary steps toward integrating new control services in the wind power plant level....... In the project, this wind turbine model will be further incorporated in a wind power plant model together with the implementation in the wind power control level of the new control functionalities (inertial response, synchronising power and power system damping). For this purpose an aggregate wind power plant...

  15. Ehlers-Danlos syndrome type IV

    Directory of Open Access Journals (Sweden)

    Germain Dominique P

    2007-07-01

    Full Text Available Abstract Ehlers-Danlos syndrome type IV, the vascular type of Ehlers-Danlos syndromes (EDS, is an inherited connective tissue disorder defined by characteristic facial features (acrogeria in most patients, translucent skin with highly visible subcutaneous vessels on the trunk and lower back, easy bruising, and severe arterial, digestive and uterine complications, which are rarely, if at all, observed in the other forms of EDS. The estimated prevalence for all EDS varies between 1/10,000 and 1/25,000, EDS type IV representing approximately 5 to 10% of cases. The vascular complications may affect all anatomical areas, with a tendency toward arteries of large and medium diameter. Dissections of the vertebral arteries and the carotids in their extra- and intra-cranial segments (carotid-cavernous fistulae are typical. There is a high risk of recurrent colonic perforations. Pregnancy increases the likelihood of a uterine or vascular rupture. EDS type IV is inherited as an autosomal dominant trait that is caused by mutations in the COL3A1 gene coding for type III procollagen. Diagnosis is based on clinical signs, non-invasive imaging, and the identification of a mutation of the COL3A1 gene. In childhood, coagulation disorders and Silverman's syndrome are the main differential diagnoses; in adulthood, the differential diagnosis includes other Ehlers-Danlos syndromes, Marfan syndrome and Loeys-Dietz syndrome. Prenatal diagnosis can be considered in families where the mutation is known. Choriocentesis or amniocentesis, however, may entail risk for the pregnant woman. In the absence of specific treatment for EDS type IV, medical intervention should be focused on symptomatic treatment and prophylactic measures. Arterial, digestive or uterine complications require immediate hospitalisation, observation in an intensive care unit. Invasive imaging techniques are contraindicated. Conservative approach is usually recommended when caring for a vascular

  16. Echocardiographic abnormalities in type IV mucopolysaccharidosis.

    OpenAIRE

    John, R. M.; Hunter, D; Swanton, R. H.

    1990-01-01

    Cardiac involvement is well recognised in most forms of the mucopolysaccharidoses but there is poor documentation of abnormalities specific to Morquio's syndrome (type IV mucopolysaccharidosis). Ten patients with the classic form or type A Morquio's syndrome with a median age of 12.5 years underwent echocardiographic assessment. Abnormalities were detected in six (60%) cases with mitral valve involvement in five patients and aortic valve disease in four. One patient had severe mitral leaflet ...

  17. Dual (type IV left anterior descending artery

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    Ozdil Baskan

    2013-11-01

    Full Text Available Congenital coronary artery anomalies are uncommon. Dual left anterior descending coronary artery (LAD is defined as the presence of two LADs within the anterior interventricular sulcus (AIVS, and is classified into four types. Type IV is a rarely reported subtype and differs from the others, with a long LAD originating from the right coronary artery (RCA. Dual LAD is a benign coronary artery anomaly, but should be recognised especially before interventional procedures. With the increasing use of multidedector computed tomography (MDCT, it is essential for radiologists to be aware of this entity and the cross-sectional findings.

  18. Ratchet model for type IV pilus retraction

    Science.gov (United States)

    Lindén, Martin; Tuohimaa, Tomi; Jonsson, Ann-Beth; Wallin, Mats

    2004-03-01

    Type IV pilus rectraction is required for twitching motility in a wide range of bacteriae, including Neisseria gonorrhoeae, Myxococcus xanthus and Pseudomonas aeruginosa. The mechanism of retraction is believed to be filament disassembly mediated by PilT, a member of the AAA family of motor proteins. Recent laser tweezer measurements of the force-velocity relation of PilT in N. gonorrhoeae, reveal that single PilT complexes generate forces of over 100 pN. We assume that PilT forms a cyclic ATPase surrounding the base of the pilus and formulate a model of retraction in terms of coupled flashing ratchets. We obtain a force-velocity relation by numerical simulation of the model which is in qualitative agreement with the experimental results.

  19. Type IV pili promote early biofilm formation by Clostridium difficile.

    Science.gov (United States)

    Maldarelli, Grace A; Piepenbrink, Kurt H; Scott, Alison J; Freiberg, Jeffrey A; Song, Yang; Achermann, Yvonne; Ernst, Robert K; Shirtliff, Mark E; Sundberg, Eric J; Donnenberg, Michael S; von Rosenvinge, Erik C

    2016-08-01

    Increasing morbidity and mortality from Clostridium difficile infection (CDI) present an enormous challenge to healthcare systems. Clostridium difficile express type IV pili (T4P), but their function remains unclear. Many chronic and recurrent bacterial infections result from biofilms, surface-associated bacterial communities embedded in an extracellular matrix. CDI may be biofilm mediated; T4P are important for biofilm formation in a number of organisms. We evaluate the role of T4P in C. difficile biofilm formation using RNA sequencing, mutagenesis and complementation of the gene encoding the major pilin pilA1, and microscopy. RNA sequencing demonstrates that, in comparison to other growth phenotypes, C. difficile growing in a biofilm has a distinct RNA expression profile, with significant differences in T4P gene expression. Microscopy of T4P-expressing and T4P-deficient strains suggests that T4P play an important role in early biofilm formation. A non-piliated pilA1 mutant forms an initial biofilm of significantly reduced mass and thickness in comparison to the wild type. Complementation of the pilA1 mutant strain leads to formation of a biofilm which resembles the wild-type biofilm. These findings suggest that T4P play an important role in early biofilm formation. Novel strategies for confronting biofilm infections are emerging; our data suggest that similar strategies should be investigated in CDI. PMID:27369898

  20. High-resolution structure of a type IV pilin from the metal-reducing bacterium Shewanella oneidensis

    DEFF Research Database (Denmark)

    Gorgel, Manuela; Ulstrup, Jakob; Bøggild, Andreas;

    2015-01-01

    Background Type IV pili are widely expressed among Gram-negative bacteria, where they are involved in biofilm formation, serve in the transfer of DNA, motility and in the bacterial attachment to various surfaces. Type IV pili in Shewanella oneidensis are also supposed to play an important role in...

  1. Type IV collagen-degrading enzyme activity in human serum.

    Directory of Open Access Journals (Sweden)

    Hashimoto,Noriaki

    1988-02-01

    Full Text Available Type IV collagen-degrading enzyme activity was detected in human serum. Serum was preincubated with 4-aminophenylmercuric acetate and trypsin to activate the enzyme prior to assay. Type IV collagen, purified from human placentas and radiolabeled with [1-14C] acetic anhydride, was used as the substrate. The enzyme activity was measured at pH 7.5 and inhibited by treatment with ethylenediaminetetraacetic acid or heat. The assay of type IV collagen-degrading enzyme in human serum might be useful for estimating the degradation of type IV collagen.

  2. Type IV renal tubular acidosis associated with Alport's syndrome.

    OpenAIRE

    Tkácová, R.; Roland, R.; Böör, A.; Kovácová, A.; Lazúrová, I.; Tkác, I.; Hildebrand, T.; Sefara, P.

    1993-01-01

    A case of hereditary nephritis with mild reduction of renal function associated with renal tubular acidosis type IV is described. The patient was admitted with life-threatening hyperkalaemia. To our knowledge, type IV renal tubular acidosis has not been reported previously in association with Alport's syndrome in an adult patient.

  3. Type IV collagen-degrading enzyme activity in human serum.

    OpenAIRE

    Hashimoto, Noriaki; Kobayashi,Michio; Watanabe,Akiharu; Higashi,Toshiro; Tsuji, Takao

    1988-01-01

    Type IV collagen-degrading enzyme activity was detected in human serum. Serum was preincubated with 4-aminophenylmercuric acetate and trypsin to activate the enzyme prior to assay. Type IV collagen, purified from human placentas and radiolabeled with [1-14C] acetic anhydride, was used as the substrate. The enzyme activity was measured at pH 7.5 and inhibited by treatment with ethylenediaminetetraacetic acid or heat. The assay of type IV collagen-degrading enzyme in human serum might be useful...

  4. Type IV collagen-degrading enzyme activity in hepatocellular carcinoma.

    OpenAIRE

    Nakatsukasa,Harushige

    1986-01-01

    Type IV collagen-degrading enzyme activity was measured in liver homogenate obtained from 10 patients with hepatocellular carcinomas. Type IV collagen, the enzyme substrate, was extracted from human placenta with pepsin digestion, and labeled with [1-14C] acetic anhydride. The homogenate was preincubated with p-aminophenylmercuric acetate to activate the latent form of the enzyme, and then the enzyme activity was measured at pH 7.5 by adding a substrate mixture. Referring to previous reports,...

  5. Outcome of surgical treatment of type IV capitellum frac-

    OpenAIRE

    Singh Ajay Pal; Dhammi Ish Kumar; Garg Vipul; Singh Arun Pal

    2012-01-01

    【Abstract】 Objective: Fractures of the capitellum and trochlea constitute less than 1% of all elbow fractures and a shear fracture involving the capitellum and extending medially into most of the trochlea is rarely reported. Type IV capitellum fracture is still controversial in regard to its ra-diographic appearance, surgical approach and osteosynthesis. We report 10 cases of type IV capitellum fracture with a view to elucidating its clinical features and treatment...

  6. A case of hereditary sensory autonomic neuropathy type IV

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    G P Prashanth

    2012-01-01

    Full Text Available Hereditary sensory autonomic neuropathy type IV (HSAN -IV, also known as congenital insensitivity to pain with anhidrosis, is a very rare condition that presents in infancy with anhidrosis, absence of pain sensation and self -mutilation. Developmental delay and mental retardation are usually present. Ultrastructural study of the peripheral nerves demonstrates loss of the unmyelinated and small myelinated fibers. We here report a 8 year -old boy with HSAN IV with typical clinical features where the diagnosis was supported by nerve biopsy findings. However, our case was unusual since mental development was normal.

  7. Biofilm formation by Pseudomonas aeruginosa wild type, flagella and type IV pili mutants

    DEFF Research Database (Denmark)

    Klausen, M.; Heydorn, Arne; Ragas, Paula Cornelia;

    2003-01-01

    Biofilm formation by Gfp-tagged Pseudomonas aeruginosa PAO1 wild type, flagella and type IV pili mutants in flow chambers irrigated with citrate minimal medium was characterized by the use of confocal laser scanning microscopy and comstat image analysis. Flagella and type IV pili were not necessary...

  8. Evaluation of Different Disinfactants on Dimensional Accuracy and Surface Quality of Type IV Gypsum Casts Retrieved from Elastomeric Impression Materials

    OpenAIRE

    Pal, P K; Kamble, Suresh S.; Chaurasia, Ranjitkumar Rampratap; Chaurasia, Vishwajit Rampratap; Tiwari, Samarth; Bansal, Deepak

    2014-01-01

    Background: The present study was done to evaluate the dimensional stability and surface quality of Type IV gypsum casts retrieved from disinfected elastomeric impression materials. Materials and Methods: In an in vitro study contaminated impression material with known bacterial species was disinfected with disinfectants followed by culturing the swab sample to assess reduction in level of bacterial colony. Changes in surface detail reproduction of impression were a...

  9. Outcome of surgical treatment of type IV capitellum frac-

    Directory of Open Access Journals (Sweden)

    Singh Ajay Pal

    2012-08-01

    Full Text Available 【Abstract】 Objective: Fractures of the capitellum and trochlea constitute less than 1% of all elbow fractures and a shear fracture involving the capitellum and extending medially into most of the trochlea is rarely reported. Type IV capitellum fracture is still controversial in regard to its ra-diographic appearance, surgical approach and osteosynthesis. We report 10 cases of type IV capitellum fracture with a view to elucidating its clinical features and treatment outcome. Methods: We treated 10 patients of type IV capitellum fracture with a mean age of 32 years. A uniform surgical approach and postoperative rehabilitation were followed. Results: Nine patients presented to us after a mean of 4 days of injury and one patient was nonunion after 6 months of injury who had been treated conservatively by a bone setter. Double arc sign was absent in 6 cases. Intraopera-tively 6 capitellotrochlear fragments were devoid of soft Chin J Traumatol 2012;15(4:201-205 DOI: 10.3760/cma.j.issn.1008-1275.2012.04.002 Punjab Civil Medical Services-I Mukerian, Punjab, In-dia (Singh AP Department of Orthopaedics, UCMS & GTB Hospital, Delhi, India (Dhammi IK and Garg V Swami Premanand Hospital, Mukerian, Punjab, India (Singh AP *Corresponding author: Tel: 98-72069734, Email: docajaypal@gmail.com C oronal shear fractures of distal end of humeral articular surface involve the capitellum and trochlea. These fractures are difficult to assess accurately on plain radiographs and the limited amount of subchondral bone available for stable internal fixation makes the operative treatment equally difficult. 1 Joint stiffness, instability and osteoarthrosis are complications resulting from treatment failures. 2 The major classification systems are proposed by Bryan and Dubberley et al. 3,4 Type IV fracture is a fracture involving the capitellum and extends to more than lateral half of the trochlea. 1 We report an analysis of ten cases of type IV capi-tissue attachments. By

  10. Agrobacterium rhizogenes GALLS protein contains domains for ATP binding, nuclear localization, and type IV secretion.

    Science.gov (United States)

    Hodges, Larry D; Vergunst, Annette C; Neal-McKinney, Jason; den Dulk-Ras, Amke; Moyer, Deborah M; Hooykaas, Paul J J; Ream, Walt

    2006-12-01

    Agrobacterium tumefaciens and Agrobacterium rhizogenes are closely related plant pathogens that cause different diseases, crown gall and hairy root. Both diseases result from transfer, integration, and expression of plasmid-encoded bacterial genes located on the transferred DNA (T-DNA) in the plant genome. Bacterial virulence (Vir) proteins necessary for infection are also translocated into plant cells. Transfer of single-stranded DNA (ssDNA) and Vir proteins requires a type IV secretion system, a protein complex spanning the bacterial envelope. A. tumefaciens translocates the ssDNA-binding protein VirE2 into plant cells, where it binds single-stranded T-DNA and helps target it to the nucleus. Although some strains of A. rhizogenes lack VirE2, they are pathogenic and transfer T-DNA efficiently. Instead, these bacteria express the GALLS protein, which is essential for their virulence. The GALLS protein can complement an A. tumefaciens virE2 mutant for tumor formation, indicating that GALLS can substitute for VirE2. Unlike VirE2, GALLS contains ATP-binding and helicase motifs similar to those in TraA, a strand transferase involved in conjugation. Both GALLS and VirE2 contain nuclear localization sequences and a C-terminal type IV secretion signal. Here we show that mutations in any of these domains abolished the ability of GALLS to substitute for VirE2. PMID:17012398

  11. Ferroportin Disease (Haemochromatosis-type IV): a case report

    OpenAIRE

    Novo, Elena; Faria, Ricardo; Faustino, Paula; Fleming, Rita

    2016-01-01

    Introdution: Haemochromatosis-type IV, the ferroportin disease, is characterized by an autosomal-dominant transmission and early iron accumulation in macrophages. It is caused by mutations in the transmembrane iron exporter protein ferroportin1 (SLC40A1 gene). In form A (classic), ferroportin loss of function mutants are unable to export iron from cells leading to cellular iron accumulation with decreased availability of iron for serum transferrin (TS). We present a Portuguese rare clinical c...

  12. Glomerular Basement Membrane Type IV Collagen in Health and Disease

    OpenAIRE

    Fish, Alfred J.; Kashtan, Clifford E.; Matsukura, Hiro; Butkowski, Ralph J.

    1991-01-01

    Glomerular basement membrane is the major supporting structural element of the glomerular capillary wall. This is a highly complex locus which functionally serves as a filtration barrier, and has been the subject of detailed investigation. The composition of whole glomerular basement membrane suggests that collagen is a major component. Isolation and characterization of the collagenous domains has revealed that glomerular basement membrane is chiefly composed of type IV collagen. This molecul...

  13. Severe type IV hypersensitivity to ‘black henna’ tattoo

    OpenAIRE

    Vasilakis, Vasileios; Knight, Bernice; Lidder, Satnam; Frankton, Sarah

    2010-01-01

    A 16-year-old Bangladeshi girl presented with a 9-day history of an extensive pruritic, erythematous, papulovesicular skin eruption to both forearms. Appearance was 5 days following application of a home-made henna preparation. Examination revealed ulceration and scabbing along the whole henna pattern and early keloid formation. A diagnosis of type IV delayed hypersensitivity reaction superimposed by infection was initially made. As in this case, home-made henna preparations commonly combine ...

  14. New steel grade to overcome Type IV cracking

    Energy Technology Data Exchange (ETDEWEB)

    Mayr, P.; Cerjak, H.

    2007-07-01

    Type IV cracking in the fine-grained region of the heat affected zone is seen as the major failure mechanism for welded components of heat resistant martensitic chromium steels. By Type IV cracking, the creep rupture strength of cross-welds can be reduced to 50% of the base material creep strength. In thermal power plants, several premature failures of welded structures have been caused by Type IV cracking. Today, the reduced creep strength of cross-welds can only be taken into account by the introduction of a weld strength factor which is considered during the design stage of new components. Within this work, the heat affected zone of a new steel grade based on 9Cr-3W-3Co-VNb with controlled additions of boron and nitrogen is investigated by physical weld simulation. Phase transformations in the heat affected zone during characteristic weld thermal cycles are studied by in-situ X-ray diffraction using synchrotron radiation and dilatometry. The heat affected zone microstructure is studied by optical as well as most modern analytical electron microscopic methods. (orig.)

  15. Bacteria turn on surfaces by oversteering with Type IV pili

    Science.gov (United States)

    Jin, Fan; Conrad, Jacinta C.; Gibiansky, Maxsim L.; Wong, Gerard C. L.

    2011-03-01

    Type-IV pili (TFP) are linear nano-actuators that enable bacteria to crawl on surfaces. Analysis of TFP-mediated crawling in P. aeruginosa reveals that it always alternates between two types of distinct movements: a linear translation of constant velocity is followed by a combined translation-rotation that is ~ 10 x faster in instantaneous velocity. The latter process can turn the cell body by over-steering so that the rear of the cell loses traction with the surface. Orientational distributions of these movements suggest that the former is due to pulling by multiple TFP, whereas the latter is mostly due to release by single TFP.

  16. Association of systemic collagen type IV formation with survival among patients undergoing hemodialysis

    DEFF Research Database (Denmark)

    Leeming, Diana Julie; Karsdal, Morten A; Rasmussen, Lars M;

    2013-01-01

    The 7S domain of collagen type IV (P4NP_7S) assessed in plasma represents systemic collagen type IV formation. The objective of the study was to investigate the association of systemic collagen type IV formation with survival among patients undergoing hemodialysis.......The 7S domain of collagen type IV (P4NP_7S) assessed in plasma represents systemic collagen type IV formation. The objective of the study was to investigate the association of systemic collagen type IV formation with survival among patients undergoing hemodialysis....

  17. Type IV secretion-dependent activation of host MAP kinases induces an increased proinflammatory cytokine response to Legionella pneumophila.

    Directory of Open Access Journals (Sweden)

    Sunny Shin

    2008-11-01

    Full Text Available The immune system must discriminate between pathogenic and nonpathogenic microbes in order to initiate an appropriate response. Toll-like receptors (TLRs detect microbial components common to both pathogenic and nonpathogenic bacteria, whereas Nod-like receptors (NLRs sense microbial components introduced into the host cytosol by the specialized secretion systems or pore-forming toxins of bacterial pathogens. The host signaling pathways that respond to bacterial secretion systems remain poorly understood. Infection with the pathogen Legionella pneumophila, which utilizes a type IV secretion system (T4SS, induced an increased proinflammatory cytokine response compared to avirulent bacteria in which the T4SS was inactivated. This enhanced response involved NF-kappaB activation by TLR signaling as well as Nod1 and Nod2 detection of type IV secretion. Furthermore, a TLR- and RIP2-independent pathway leading to p38 and SAPK/JNK MAPK activation was found to play an equally important role in the host response to virulent L. pneumophila. Activation of this MAPK pathway was T4SS-dependent and coordinated with TLR signaling to mount a robust proinflammatory cytokine response to virulent L. pneumophila. These findings define a previously uncharacterized host response to bacterial type IV secretion that activates MAPK signaling and demonstrate that coincident detection of multiple bacterial components enables immune discrimination between virulent and avirulent bacteria.

  18. Mechanical stability study of type IV cryomodule (ILC prototype)

    Energy Technology Data Exchange (ETDEWEB)

    McGee, M.W.; Doremus, R.; Wands, C.R.; /Fermilab

    2007-06-01

    An ANSYS modal and harmonic finite element analysis (FEA) was performed in order to investigate cryomodule design mechanical stability for the proposed International Linear Collider (ILC). The current cryomodule, designated Type IV or (T4CM), closely follows the Type III TESLA Test Facility (TTF) version used at DESY, with the exception of a proposed location of the superconducting (SC) quadrupole at the center. This analysis considered the stringent stability criteria established for the ILC, where vertical motion for the SC quadrupole is limited to the micron range at a few Hz. Model validation was achieved through Type III cryomodule vibration measurement studies performed at DESY. The effect of support location, support stiffness and other important parameters were considered in a parametric sensitivity study. FEA results, fast motion investigations and stabilization techniques are discussed.

  19. Recruitment of conjugative DNA transfer substrate to Agrobacterium type IV secretion apparatus.

    Science.gov (United States)

    Guo, Minliang; Jin, Shouguang; Sun, Deying; Hew, Choy L; Pan, Shen Q

    2007-12-11

    Bacterial type IV secretion system (T4SS) belongs to a growing class of evolutionarily conserved transporters that translocate DNA and proteins into a wide variety of organisms including bacterial and eukaryotic cells. Archetypal is the Agrobacterium tumefaciens VirB/D4 T4SS that transfers oncogenic T-DNA to various eukaryotic cells, which is transferred as a nucleoprotein T-complex with VirD2 as the pilot protein. As a derivative of plasmid conjugation systems, the VirB/D4 T4SS can also transfer certain mobilizable plasmids and bacterial proteins like VirE2 and VirF, although it is unknown how the membrane-bound T4SS recruits different transfer substrates. Here, we show that a cytoplasmic VirD2-binding protein (VBP) is involved in the recruitment of the T-complex to the energizing components of the T4SS, including VirD4, VirB4, and VirB11. VBP is also important for the recruitment of a conjugative plasmid to a different transfer system independent of VirB/D4. These data indicate that VBP functions as a previously unrecognized recruiting protein that helps couple nucleoprotein substrates to the appropriate transport sites for conjugative DNA transfers. VBP has three functionally redundant homologs, and similar homologs can be found in different bacterial genomes, suggesting a previously uncharacterized class of proteins involved in conjugative DNA transfers. PMID:18056647

  20. Motility in cyanobacteria: polysaccharide tracks and Type IV pilus motors.

    Science.gov (United States)

    Wilde, Annegret; Mullineaux, Conrad W

    2015-12-01

    Motility in cyanobacteria is useful for purposes that range from seeking out favourable light environments to establishing symbioses with plants and fungi. No known cyanobacterium is equipped with flagella, but a diverse range of species is able to 'glide' or 'twitch' across surfaces. Cyanobacteria with this capacity range from unicellular species to complex filamentous forms, including species such as Nostoc punctiforme, which can generate specialised motile filaments called hormogonia. Recent work on the model unicellular cyanobacterium Synechocystis sp. PCC 6803 has shown that its means of propulsion has much in common with the twitching motility of heterotrophs such as Pseudomonas and Myxococcus. Movement depends on Type IV pili, which are extended, adhere to the substrate and then retract to pull the cell across the surface. Previous work on filamentous cyanobacteria suggested a very different mechanism, with movement powered by the directional extrusion of polysaccharide from pores close to the cell junctions. Now a new report by Khayatan and colleagues in this issue of Molecular Microbiology suggests that the motility of Nostoc hormogonia has much more in common with Synechocystis than was previously thought. In both cases, polysaccharide secretion is important for preparing the surface, but the directional motive force comes from Type IV pili.

  1. Cross-reactivity of cell-mediated immunity between interstitial (type I) and basement membrane (type IV) collagens

    OpenAIRE

    1982-01-01

    In the present study, we demonstrate delayed-type hypersensitivity (DTH) to homologous type I collagen that cross-reacts with type IV collagen. Mice immunized with native or denatured type I collagens and challenged with these same antigens or native type IV collagen develop a peak DTH response on day 7. Challenge with denatured type IV collagen or collagenase-treated type IV collagen failed to elicit DTH in type I collagen-sensitized mice. Type I collagen-sensitized spleen cells adoptively t...

  2. Identification of mutations in Type IV glycogen storage disease

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Y.; Kishnani, P.; Chen, Y.T. [Duke Univ. Medical Center, Durham, NC (United States)] [and others

    1994-09-01

    Type IV glycogen storage disease (GSD IV, Andersen disease) is caused by a deficiency of glycogen branching enzyme (GBE) activity, which results in the accumulation of glycogen with unbranched, long, outer chains in the tissues. The molecular basis of the disease is not known. We studied four patients with the disease; three with typical presentation of progressive liver cirrhosis and failure, and one with severe and fatal neonatal hypotonia and cardiomyopathy. Southern blot analysis with EcoRI or MspI did not detect gross DNA rearrangement, deletion or duplication in patients` glycogen branching enzyme genes. Northern analysis with total cellular RNAs isolated from skin fibroblast MI strains of three patients with typical clinical presentation showed a normal level and size (2.95 kb) of GBE mRNA hybridization band in two and absent mRNA hybridization band in the remaining one. The patient with atypical severe neonatal hypotonia demonstrated a less intense and smaller size (2.75 kb) of mRNA hybridization band. A 210 hp deletion from nucleotide sequence 873 to 1082 which causes 70 amino acids missing from amino acid sequence 262 to 331 was detected in all 17 clones sequenced from the fatal hypotonia patient. This deletion is located in the region which is highly conserved between prokaryotic, yeast and human GBE polypeptide sequences, and also includes the first of the four regions which constitute the catalytic active sites of most of amylolytic enzymes. A point mutation C-T (1633) which changes the amino acid from Arginine to Cystine was found in 19 of 20 cDNA clones from a patient with classical clinical presentation. This point mutation was unique to this patient and was not observed in three other patients or normal controls. This is the first report on the molecular basis of GSD IV and our data indicated the presence of extensive genetic heterogeneity in the disease.

  3. Xanthomonas citri subsp. citri type IV Pilus is required for twitching motility, biofilm development, and adherence.

    Science.gov (United States)

    Dunger, German; Guzzo, Cristiane R; Andrade, Maxuel O; Jones, Jeffrey B; Farah, Chuck S

    2014-10-01

    Bacterial type IV pili (T4P) are long, flexible surface filaments that consist of helical polymers of mostly pilin subunits. Cycles of polymerization, attachment, and depolymerization mediate several pilus-dependent bacterial behaviors, including twitching motility, surface adhesion, pathogenicity, natural transformation, escape from immune system defense mechanisms, and biofilm formation. The Xanthomonas citri subsp. citri strain 306 genome codes for a large set of genes involved in T4P biogenesis and regulation and includes several pilin homologs. We show that X. citri subsp. citri can exhibit twitching motility in a manner similar to that observed in other bacteria such as Pseudomonas aeruginosa and Xylella fastidiosa and that this motility is abolished in Xanthomonas citri subsp. citri knockout strains in the genes coding for the major pilin subunit PilAXAC3241, the ATPases PilBXAC3239 and PilTXAC2924, and the T4P biogenesis regulators PilZXAC1133 and FimXXAC2398. Microscopy analyses were performed to compare patterns of bacterial migration in the wild-type and knockout strains and we observed that the formation of mushroom-like structures in X. citri subsp. citri biofilm requires a functional T4P. Finally, infection of X. citri subsp. citri cells by the bacteriophage (ΦXacm4-11 is T4P dependent. The results of this study improve our understanding of how T4P influence Xanthomonas motility, biofilm formation, and susceptibility to phage infection. PMID:25180689

  4. Identification of Anaplasma marginale type IV secretion system effector proteins.

    Directory of Open Access Journals (Sweden)

    Svetlana Lockwood

    Full Text Available BACKGROUND: Anaplasma marginale, an obligate intracellular alphaproteobacterium in the order Rickettsiales, is a tick-borne pathogen and the leading cause of anaplasmosis in cattle worldwide. Complete genome sequencing of A. marginale revealed that it has a type IV secretion system (T4SS. The T4SS is one of seven known types of secretion systems utilized by bacteria, with the type III and IV secretion systems particularly prevalent among pathogenic Gram-negative bacteria. The T4SS is predicted to play an important role in the invasion and pathogenesis of A. marginale by translocating effector proteins across its membrane into eukaryotic target cells. However, T4SS effector proteins have not been identified and tested in the laboratory until now. RESULTS: By combining computational methods with phylogenetic analysis and sequence identity searches, we identified a subset of potential T4SS effectors in A. marginale strain St. Maries and chose six for laboratory testing. Four (AM185, AM470, AM705 [AnkA], and AM1141 of these six proteins were translocated in a T4SS-dependent manner using Legionella pneumophila as a reporter system. CONCLUSIONS: The algorithm employed to find T4SS effector proteins in A. marginale identified four such proteins that were verified by laboratory testing. L. pneumophila was shown to work as a model system for A. marginale and thus can be used as a screening tool for A. marginale effector proteins. The first T4SS effector proteins for A. marginale have been identified in this work.

  5. Severe type IV hypersensitivity to 'black henna' tattoo.

    Science.gov (United States)

    Vasilakis, Vasileios; Knight, Bernice; Lidder, Satnam; Frankton, Sarah

    2010-01-01

    A 16-year-old Bangladeshi girl presented with a 9-day history of an extensive pruritic, erythematous, papulovesicular skin eruption to both forearms. Appearance was 5 days following application of a home-made henna preparation. Examination revealed ulceration and scabbing along the whole henna pattern and early keloid formation. A diagnosis of type IV delayed hypersensitivity reaction superimposed by infection was initially made. As in this case, home-made henna preparations commonly combine commercial henna with black hair dye, paraphenylenediamine (PPD). PPD, widely known as 'black henna', darkens the pigment and precipitates the drying process. PPD is a potent contact allergen associated with a high incidence of hypersensitivity reactions. Despite treatment the patient was left with extensive keloid scarring in the pattern of the henna tattoo. PMID:22778139

  6. Hereditary sensory and autonomic neuropathies: types II, III, and IV.

    Science.gov (United States)

    Axelrod, Felicia B; Gold-von Simson, Gabrielle

    2007-10-03

    The hereditary sensory and autonomic neuropathies (HSAN) encompass a number of inherited disorders that are associated with sensory dysfunction (depressed reflexes, altered pain and temperature perception) and varying degrees of autonomic dysfunction (gastroesophageal reflux, postural hypotention, excessive sweating). Subsequent to the numerical classification of four distinct forms of HSAN that was proposed by Dyck and Ohta, additional entities continue to be described, so that identification and classification are ongoing. As a group, the HSAN are rare diseases that affect both sexes. HSAN III is almost exclusive to individuals of Eastern European Jewish extraction, with incidence of 1 per 3600 live births. Several hundred cases with HSAN IV have been reported. The worldwide prevalence of HSAN type II is very low. This review focuses on the description of three of the disorders, HSAN II through IV, that are characterized by autosomal recessive inheritance and onset at birth. These three forms of HSAN have been the most intensively studied, especially familial dysautonomia (Riley-Day syndrome or HSAN III), which is often used as a prototype for comparison to the other HSAN. Each HSAN disorder is likely caused by different genetic errors that affect specific aspects of small fiber neurodevelopment, which result in variable phenotypic expression. As genetic tests are routinely used for diagnostic confirmation of HSAN III only, other means of differentiating between the disorders is necessary. Diagnosis is based on the clinical features, the degree of both sensory and autonomic dysfunction, and biochemical evaluations, with pathologic examinations serving to further confirm differences. Treatments for all these disorders are supportive.

  7. Hereditary sensory and autonomic neuropathies: types II, III, and IV

    Directory of Open Access Journals (Sweden)

    Axelrod Felicia B

    2007-10-01

    Full Text Available Abstract The hereditary sensory and autonomic neuropathies (HSAN encompass a number of inherited disorders that are associated with sensory dysfunction (depressed reflexes, altered pain and temperature perception and varying degrees of autonomic dysfunction (gastroesophageal reflux, postural hypotention, excessive sweating. Subsequent to the numerical classification of four distinct forms of HSAN that was proposed by Dyck and Ohta, additional entities continue to be described, so that identification and classification are ongoing. As a group, the HSAN are rare diseases that affect both sexes. HSAN III is almost exclusive to individuals of Eastern European Jewish extraction, with incidence of 1 per 3600 live births. Several hundred cases with HSAN IV have been reported. The worldwide prevalence of HSAN type II is very low. This review focuses on the description of three of the disorders, HSAN II through IV, that are characterized by autosomal recessive inheritance and onset at birth. These three forms of HSAN have been the most intensively studied, especially familial dysautonomia (Riley-Day syndrome or HSAN III, which is often used as a prototype for comparison to the other HSAN. Each HSAN disorder is likely caused by different genetic errors that affect specific aspects of small fiber neurodevelopment, which result in variable phenotypic expression. As genetic tests are routinely used for diagnostic confirmation of HSAN III only, other means of differentiating between the disorders is necessary. Diagnosis is based on the clinical features, the degree of both sensory and autonomic dysfunction, and biochemical evaluations, with pathologic examinations serving to further confirm differences. Treatments for all these disorders are supportive.

  8. Attachment of cells to basement membrane collagen type IV

    OpenAIRE

    1986-01-01

    Of ten different cell lines examined, three showed distinct attachment and spreading on collagen IV substrates, and neither attachment nor spreading was enhanced by adding soluble laminin or fibronectin. This reaction was not inhibited by cycloheximide or antibodies to laminin, indicating a direct attachment to collagen IV without the need of mediator proteins. Cell-binding sites were localized to the major triple-helical domain of collagen IV and required an intact triple helical conformatio...

  9. Earthworm symbiont Verminephrobacter eiseniae mediates natural transformation within the host egg capsules using type IV pili

    Directory of Open Access Journals (Sweden)

    SEANA Kelyn DAVIDSON

    2014-10-01

    Full Text Available The dense microbial communities commonly associated with plants and animals should offer many opportunities for horizontal gene transfer (HGT through described mechanisms of DNA exchange including natural transformation. However, studies of the significance of natural transformation have focused primarily on pathogens. The study presented here demonstrates highly efficient DNA exchange by natural transformation in a common symbiont of earthworms. The obligate bacterial symbiont Verminephrobacter eiseniae is a member of a microbial consortium of the earthworm Eisenia fetida that is transmitted into the egg capsules to colonize the embryonic worms. In the study presented here, by testing for transformants under different conditions in culture, we demonstrate that V. eiseniae can incorporate free DNA from the environment, that competency is regulated by environmental factors, and that it is sequence specific. Mutations in the type IV pili of V. eiseniae resulted in loss of DNA uptake, implicating the type IV pilus (TFP apparatus in DNA uptake. Furthermore, injection of DNA carrying antibiotic-resistance genes into egg capsules resulted in transformants within the capsule, demonstrating the relevance of DNA uptake within the earthworm system. The ability to take up species-specific DNA from the environment may explain the maintenance of the relatively large, intact genome of this long-associated obligate symbiont, and provides a mechanism for acquisition of foreign genes within the earthworm system.

  10. A type IV pilus mediates DNA binding during natural transformation in Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Raphaël Laurenceau

    Full Text Available Natural genetic transformation is widely distributed in bacteria and generally occurs during a genetically programmed differentiated state called competence. This process promotes genome plasticity and adaptability in Gram-negative and Gram-positive bacteria. Transformation requires the binding and internalization of exogenous DNA, the mechanisms of which are unclear. Here, we report the discovery of a transformation pilus at the surface of competent Streptococcus pneumoniae cells. This Type IV-like pilus, which is primarily composed of the ComGC pilin, is required for transformation. We provide evidence that it directly binds DNA and propose that the transformation pilus is the primary DNA receptor on the bacterial cell during transformation in S. pneumoniae. Being a central component of the transformation apparatus, the transformation pilus enables S. pneumoniae, a major Gram-positive human pathogen, to acquire resistance to antibiotics and to escape vaccines through the binding and incorporation of new genetic material.

  11. New type IV pili-related genes involved in early stages of Ralstonia solanacearum potato infection.

    Science.gov (United States)

    Siri, María Inés; Sanabria, Analía; Boucher, Christian; Pianzzola, María Julia

    2014-07-01

    This study provides insights into the pathogenesis of Ralstonia solanacearum, in particular with regards to strains belonging to phylotype IIB, sequevar 1 (IIB-1) and their interaction with potato, its natural host. We performed a comparative genomic analysis among IIB-1 R. solanacearum strains with different levels of virulence in order to identify candidate virulence genes. With this approach, we identified a 33.7-kb deletion in a strain showing reduced virulence on potato. This region contains a cluster of six genes putatively involved in type IV pili (Tfp) biogenesis. Functional analysis suggests that these proteins contribute to several Tfp-related functions such as twitching motility and biofilm formation. In addition, this genetic cluster was found to contribute to early bacterial wilt pathogenesis and colonization fitness of potato roots. PMID:24625029

  12. Mechanical Properties of Type IV Pili in P. Aeruginosa

    Science.gov (United States)

    Lu, Shun; Touhami, Ahmed; Scheurwater, Edie; Harvey, Hanjeong; Burrows, Lori; Dutcher, John

    2009-03-01

    Type IV pili (Tfp) are thin flexible protein filaments that extend from the cell membrane of bacteria such as Pseudomonas aeruginosa and Neisseria gonorrhoeae. The mechanical properties of Tfp are of great importance since they allow bacteria to interact with and colonize various surfaces. In the present study, we have used atomic force microscopy (AFM) for both imaging and pulling on Tfp from P. aeruginosa (PAO1) and from its PilA, PilT, and FliC mutants. A single pilus filament was mechanically stretched and the resulting force-extension profiles were fitted using the worm-like-chain (WLC) model. The statistical distributions obtained for contour length, persistence length, and number of pili per bacteria pole, were used to evaluate the mechanical properties of a single pilus and the biogenesis functions of different proteins (PilA, PilT) involved in its assembly and disassembly. Importantly, the persistence length value of ˜ 1 μm measured in the present study, which is consistent with the curvature of the pili observed in our AFM images, is significantly lower than the value of 5 μm reported earlier by Skerker et al. (1). Our results shed new light on the role of mechanical forces that mediate bacteria-surface interactions and biofilm formation. 1- J.M. Skerker and H.C. Berg, Proc. Natl. Acad. Sci. USA, 98, 6901-6904 (2001).

  13. Type-IV Pilus Deformation Can Explain Retraction Behavior

    CERN Document Server

    Ghosh, Ranajay; Vaziri, Ashkan

    2014-01-01

    Polymeric filament like type IV Pilus (TFP) can transfer forces in excess of 100pN during their retraction before stalling, powering surface translocation(twitching). Single TFP level experiments have shown remarkable nonlinearity in the retraction behavior influenced by the external load as well as levels of PilT molecular motor protein. This includes reversal of motion near stall forces when the concentration of the PilT protein is lowered significantly. In order to explain this behavior, we analyze the coupling of TFP elasticity and interfacial behavior with PilT kinetics. We model retraction as reaction controlled and elongation as transport controlled process. The reaction rates vary with TFP deformation which is modeled as a compound elastic body consisting of multiple helical strands under axial load. Elongation is controlled by monomer transport which suffer entrapment due to excess PilT in the cell periplasm. Our analysis shows excellent agreement with a host of experimental observations and we prese...

  14. Type IV collagen stimulates pancreatic cancer cell proliferation, migration, and inhibits apoptosis through an autocrine loop

    International Nuclear Information System (INIS)

    Pancreatic cancer shows a highly aggressive and infiltrative growth pattern and is characterized by an abundant tumor stroma known to interact with the cancer cells, and to influence tumor growth and drug resistance. Cancer cells actively take part in the production of extracellular matrix proteins, which then become deposited into the tumor stroma. Type IV collagen, an important component of the basement membrane, is highly expressed by pancreatic cancer cells both in vivo and in vitro. In this study, the cellular effects of type IV collagen produced by the cancer cells were characterized. The expression of type IV collagen and its integrin receptors were examined in vivo in human pancreatic cancer tissue. The cellular effects of type IV collagen were studied in pancreatic cancer cell lines by reducing type IV collagen expression through RNA interference and by functional receptor blocking of integrins and their binding-sites on the type IV collagen molecule. We show that type IV collagen is expressed close to the cancer cells in vivo, forming basement membrane like structures on the cancer cell surface that colocalize with the integrin receptors. Furthermore, the interaction between type IV collagen produced by the cancer cell, and integrins on the surface of the cancer cells, are important for continuous cancer cell growth, maintenance of a migratory phenotype, and for avoiding apoptosis. We show that type IV collagen provides essential cell survival signals to the pancreatic cancer cells through an autocrine loop

  15. Genomic and Gene-Expression Comparisons among Phage-Resistant Type-IV Pilus Mutants of Pseudomonas syringae pathovar phaseolicola.

    Directory of Open Access Journals (Sweden)

    Mark Sistrom

    Full Text Available Pseudomonas syringae pv. phaseolicola (Pph is a significant bacterial pathogen of agricultural crops, and phage Φ6 and other members of the dsRNA virus family Cystoviridae undergo lytic (virulent infection of Pph, using the type IV pilus as the initial site of cellular attachment. Despite the popularity of Pph/phage Φ6 as a model system in evolutionary biology, Pph resistance to phage Φ6 remains poorly characterized. To investigate differences between phage Φ6 resistant Pph strains, we examined genomic and gene expression variation among three bacterial genotypes that differ in the number of type IV pili expressed per cell: ordinary (wild-type, non-piliated, and super-piliated. Genome sequencing of non-piliated and super-piliated Pph identified few mutations that separate these genotypes from wild type Pph--and none present in genes known to be directly involved in type IV pilus expression. Expression analysis revealed that 81.1% of gene ontology (GO terms up-regulated in the non-piliated strain were down-regulated in the super-piliated strain. This differential expression is particularly prevalent in genes associated with respiration--specifically genes in the tricarboxylic acid cycle (TCA cycle, aerobic respiration, and acetyl-CoA metabolism. The expression patterns of the TCA pathway appear to be generally up and down-regulated, in non-piliated and super-piliated Pph respectively. As pilus retraction is mediated by an ATP motor, loss of retraction ability might lead to a lower energy draw on the bacterial cell, leading to a different energy balance than wild type. The lower metabolic rate of the super-piliated strain is potentially a result of its loss of ability to retract.

  16. Structural Characterization of Novel Pseudomonas aeruginosa Type IV Pilins

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Y.; Jackson, S; Aidoo, F; Junop, M; Burrows, L

    2010-01-01

    Pseudomonas aeruginosa type IV pili, composed of PilA subunits, are used for attachment and twitching motility on surfaces. P. aeruginosa strains express one of five phylogenetically distinct PilA proteins, four of which are associated with accessory proteins that are involved either in pilin posttranslational modification or in modulation of pilus retraction dynamics. Full understanding of pilin diversity is crucial for the development of a broadly protective pilus-based vaccine. Here, we report the 1.6-{angstrom} X-ray crystal structure of an N-terminally truncated form of the novel PilA from strain Pa110594 (group V), which represents the first non-group II pilin structure solved. Although it maintains the typical T4a pilin fold, with a long N-terminal {alpha}-helix and four-stranded antiparallel {beta}-sheet connected to the C-terminus by a disulfide-bonded loop, the presence of an extra helix in the {alpha}{beta}-loop and a disulfide-bonded loop with helical character gives the structure T4b pilin characteristics. Despite the presence of T4b features, the structure of PilA from strain Pa110594 is most similar to the Neisseria gonorrhoeae pilin and is also predicted to assemble into a fiber similar to the GC pilus, based on our comparative pilus modeling. Interactions between surface-exposed areas of the pilin are suggested to contribute to pilus fiber stability. The non-synonymous sequence changes between group III and V pilins are clustered in the same surface-exposed areas, possibly having an effect on accessory protein interactions. However, based on our high-confidence model of group III PilA{sub PA14}, compensatory changes allow for maintenance of a similar shape.

  17. Dipeptidyl peptidase IV and its inhibitors: therapeutics for type 2 diabetes and what else?

    Science.gov (United States)

    Juillerat-Jeanneret, Lucienne

    2014-03-27

    The proline-specific dipeptidyl aminopeptidase IV (DPP IV, DPP-4, CD26), widely expressed in mammalians, releases X-Pro/Ala dipeptides from the N-terminus of peptides. DPP IV is responsible of the degradation of the incretin peptide hormones regulating blood glucose levels. Several families of DPP IV inhibitors have been synthesized and evaluated. Their positive effects on the degradation of the incretins and the control of blood glucose levels have been demonstrated in biological models and in clinical trials. Presently, several DPP IV inhibitors, the "gliptins", are approved for type 2 diabetes or are under clinical evaluation. However, the gliptins may also be of therapeutic interest for other diseases beyond the inhibition of incretin degradation. In this Perspective, the biological functions and potential substrates of DPP IV enzymes are reviewed and the characteristics of the DPP IV inhibitors are discussed in view of type 2 diabetes and further therapeutic interest. PMID:24099035

  18. Steered molecular dynamics simulations of a type IV pilus probe initial stages of a force-induced conformational transition.

    Directory of Open Access Journals (Sweden)

    Joseph L Baker

    2013-04-01

    Full Text Available Type IV pili are long, protein filaments built from a repeating subunit that protrudes from the surface of a wide variety of infectious bacteria. They are implicated in a vast array of functions, ranging from bacterial motility to microcolony formation to infection. One of the most well-studied type IV filaments is the gonococcal type IV pilus (GC-T4P from Neisseria gonorrhoeae, the causative agent of gonorrhea. Cryo-electron microscopy has been used to construct a model of this filament, offering insights into the structure of type IV pili. In addition, experiments have demonstrated that GC-T4P can withstand very large tension forces, and transition to a force-induced conformation. However, the details of force-generation, and the atomic-level characteristics of the force-induced conformation, are unknown. Here, steered molecular dynamics (SMD simulation was used to exert a force in silico on an 18 subunit segment of GC-T4P to address questions regarding the nature of the interactions that lead to the extraordinary strength of bacterial pili. SMD simulations revealed that the buried pilin α1 domains maintain hydrophobic contacts with one another within the core of the filament, leading to GC-T4P's structural stability. At the filament surface, gaps between pilin globular head domains in both the native and pulled states provide water accessible routes between the external environment and the interior of the filament, allowing water to access the pilin α1 domains as reported for VC-T4P in deuterium exchange experiments. Results were also compared to the experimentally observed force-induced conformation. In particular, an exposed amino acid sequence in the experimentally stretched filament was also found to become exposed during the SMD simulations, suggesting that initial stages of the force induced transition are well captured. Furthermore, a second sequence was shown to be initially hidden in the native filament and became exposed upon

  19. Modulation of C1-Inhibitor and Plasma Kallikrein Activities by Type IV Collagen

    Directory of Open Access Journals (Sweden)

    Sriram Ravindran

    2012-01-01

    Full Text Available The contact system of coagulation can be activated when in contact with biomaterials. As collagen is being tested in novel biomaterials in this study, we have investigated how type IV collagen affects plasma kallikrein and C1-inhibitor. Firstly, we showed C1-inhibitor binds to type IV collagen with a Kd of 0.86 μM. The effects of type IV collagen on plasma kallikrein, factor XIIa, and β-factor XIIa activity and on C1-inhibitor function were determined. Factor XIIa rapidly lost activity in the presence of type IV collagen, whereas plasma kallikrein and β-factor XIIa were more stable. The rate of inhibition of plasma kallikrein by C1-inhibitor was decreased by type IV collagen in a dose-dependent manner. These studies could be relevant to the properties of biomaterials, which contain collagen, and should be considered in the testing for biocompatibility.

  20. In silico identification of potential chaperone genes that belong to type III and type IV secretion systems in Xanthomonas axonopodis pv citri

    Directory of Open Access Journals (Sweden)

    Letícia Khater

    2005-01-01

    Full Text Available The secretion of bacterial virulence factors and flagellar components requires the assistance of specific type III and flagellar chaperones. Standard computational annotation of the genome of Xanthomonas axonopodis pv citri, a plant pathogen that causes citrus canker, initially did not identify any genes belonging to these chaperone categories since the primary sequence homology between them was very low. However, in a search for hypothetical proteins with characteristics similar to these chaperones, we have now identified 30 chromosomal and 10 plasmidial potential genes encoding chaperones belonging to types III/IV, and flagellar secretion systems in this organism. The significance of these findings is discussed.

  1. Reassessing the role of DotF in the Legionella pneumophila type IV secretion system.

    Directory of Open Access Journals (Sweden)

    Molly C Sutherland

    Full Text Available Legionella pneumophila, the causative agent of a severe pneumonia termed Legionnaires' Disease, survives and replicates within both protozoan hosts and human alveolar macrophages. Intracellular survival is dependent upon secretion of a plethora of protein effectors that function to form a replicative vacuole, evade the endocytic pathway and subvert host immune defenses. Export of these factors requires a type IV secretion system (T4SS called Dot/Icm that is composed of twenty-seven proteins. This report focuses on the DotF protein, which was previously postulated to have several different functions, one of which centered on binding Dot/Icm substrates. In this report, we examined if DotF functions as the T4SS inner membrane receptor for Dot/Icm substrates. Although we were able to recapitulate the previously published bacterial two-hybrid interaction between DotF and several substrates, the interaction was not dependent on the Dot/Icm substrates' signal sequences as predicted for a substrate:receptor interaction. In addition, binding did not require the cytoplasmic domain of DotF, which was anticipated to be involved in recognizing substrates in the cytoplasm. Finally, inactivation of dotF did not abolish intracellular growth of L. pneumophila or translocation of substrates, two phenotypes dependent on the T4SS receptor. These data strongly suggest that DotF does not act as the major receptor for Dot/Icm substrates and therefore likely performs an accessory function within the core-transmembrane subcomplex of the L. pneumophila Dot/Icm type IV secretion system.

  2. Localization of type V collagen and type IV collagen in human cornea, lung, and skin. Immunohistochemical evidence by anti-collagen antibodies characterized by immunoelectroblotting.

    OpenAIRE

    Konomi, H.; Hayashi, T.; NAKAYASU, K.; Arima, M.

    1984-01-01

    Tissue distribution of Type V collagen in comparison with Type IV collagen was investigated by indirect immunofluorescence microscopy. Affinity-purified rat antibodies to Type IV and Type V collagens obtained from human placenta reacted specifically only with the corresponding type of collagen in both native and denatured conformations. In indirect immunofluorescent stainings of human skin, lung, and cornea tissues, Type IV and Type V collagens showed distinct distributions. Type IV collagen ...

  3. Type IV Ehlers-Danlos Syndrome: A Surgical Emergency? A Case of Massive Retroperitoneal Hemorrhage

    OpenAIRE

    Chun, Stephen G.; Pedro, Patrick; Yu, Mihae; Takanishi, Danny M.

    2011-01-01

    Retroperitoneal hemorrhagic bleeding is a known manifestation of Type-IV Ehlers-Danlos Syndrome that is caused by loss-of-function mutations of the pro-alpha-1 chains of type III pro-collagen (COL3A1) resulting in vascular fragility. A number of previous reports describe futile surgical intervention for retroperitoneal bleeding in Type-IV Ehlers-Danlos Syndrome with high post-operative mortality, although the rarity of retroperitoneal bleeding associated with Type-IV Ehlers-Danlos Syndrome pr...

  4. Limited significance of curative surgery in Borrmann type IV gastric cancer.

    Science.gov (United States)

    Kim, Eun Young; Yoo, Han Mo; Song, Kyo Young; Park, Cho Hyun

    2016-07-01

    Borrmann type IV advanced gastric cancer has a poor prognosis. Although surgical resection remains the only hope for a cure, the role of curative surgery is questionable in this type of cancer. This study defined the role of curative surgery in the prognosis of type IV gastric cancer. We analyzed 168 patients with Borrmann type IV undergoing surgery at Seoul St. Mary's Hospital from 1989 to 2010. We categorized the patients into curative (R0) and non-curative (R1, R2, and non-resection) groups. The curative and non-curative groups comprised 88 and 80 patients, respectively. The preoperative predictive value of Borrmann type IV was 50.5, and 8.9 % of the patients had microscopic resection margin involvement. The 3- to 5-year overall survival (OS) of patients in the curative group was significantly higher than that of in the non-curative group (p peritoneum (85.7 %). Most recurrences occurred within 2 years. The role of surgery for Borrmann type IV is quite limited. Such cases have a poor prognosis even after curative surgery. In addition, microscopic resection margin involvement is frequent in type IV cancer because it is difficult to diagnose preoperatively. Therefore, multimodal diagnostic tools and treatment strategies should be developed for Borrmann type IV gastric cancer. PMID:27251378

  5. Specific cleavage of human type III and IV collagens by Pseudomonas aeruginosa elastase.

    OpenAIRE

    Heck, L W; Morihara, K; McRae, W B; Miller, E J

    1986-01-01

    Purified Pseudomonas aeruginosa elastase cleaved human type III and IV collagens with the formation of specific cleavage products. Furthermore, type I collagen appeared to be slowly cleaved by both P. aeruginosa elastase and alkaline protease. These cleavage fragments from type III and IV collagens were separated from the intact collagen chains by SDS polyacrylamide gradient gel electrophoresis run under reducing conditions, and they were detected by their characteristic Coomassie blue staini...

  6. Roles of type IV pili, flagellum-mediated motility and extracellular DNA in the formation of mature multicellular structures in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Barken, Kim B; Pamp, Sünje J; Yang, Liang;

    2008-01-01

    When grown as a biofilm in laboratory flow chambers Pseudomonas aeruginosa can develop mushroom-shaped multicellular structures consisting of distinct subpopulations in the cap and stalk portions. We have previously presented evidence that formation of the cap portion of the mushroom......-shaped structures in P. aeruginosa biofilms occurs via bacterial migration and depends on type IV pili (Mol Microbiol 50: 61-68). In the present study we examine additional factors involved in the formation of this multicellular substructure. While pilA mutants, lacking type IV pili, are deficient in mushroom cap...

  7. Modulation of C1-Inhibitor and Plasma Kallikrein Activities by Type IV Collagen

    OpenAIRE

    Sriram Ravindran; Marc Schapira; Patston, Philip A.

    2012-01-01

    The contact system of coagulation can be activated when in contact with biomaterials. As collagen is being tested in novel biomaterials in this study, we have investigated how type IV collagen affects plasma kallikrein and C1-inhibitor. Firstly, we showed C1-inhibitor binds to type IV collagen with a Kd of 0.86 μM. The effects of type IV collagen on plasma kallikrein, factor XIIa, and β-factor XIIa activity and on C1-inhibitor function were determined. Factor XIIa rapidly lost activity in the...

  8. Relativistic Modeling of Quark Stars with Tolman IV Type Potential

    CERN Document Server

    Malaver, Manuel

    2015-01-01

    In this paper, we studied the behavior of relativistic objects with anisotropic matter distribution considering Tolman IV form for the gravitational potential Z. The equation of state presents a quadratic relation between the energy density and the radial pressure. New exact solutions of the Einstein-Maxwell system are generated. A physical analysis of electromagnetic field indicates that is regular in the origin and well behaved. We show as the presence of an electrical field modifies the energy density, the radial pressure and the mass of the stellar object and generates a singular charge density.

  9. The Trw type IV secretion system of Bartonella mediates host-specific adhesion to erythrocytes.

    Directory of Open Access Journals (Sweden)

    Muriel Vayssier-Taussat

    Full Text Available Bacterial pathogens typically infect only a limited range of hosts; however, the genetic mechanisms governing host-specificity are poorly understood. The alpha-proteobacterial genus Bartonella comprises 21 species that cause host-specific intraerythrocytic bacteremia as hallmark of infection in their respective mammalian reservoirs, including the human-specific pathogens Bartonella quintana and Bartonella bacilliformis that cause trench fever and Oroya fever, respectively. Here, we have identified bacterial factors that mediate host-specific erythrocyte colonization in the mammalian reservoirs. Using mouse-specific Bartonella birtlesii, human-specific Bartonella quintana, cat-specific Bartonella henselae and rat-specific Bartonella tribocorum, we established in vitro adhesion and invasion assays with isolated erythrocytes that fully reproduce the host-specificity of erythrocyte infection as observed in vivo. By signature-tagged mutagenesis of B. birtlesii and mutant selection in a mouse infection model we identified mutants impaired in establishing intraerythrocytic bacteremia. Among 45 abacteremic mutants, five failed to adhere to and invade mouse erythrocytes in vitro. The corresponding genes encode components of the type IV secretion system (T4SS Trw, demonstrating that this virulence factor laterally acquired by the Bartonella lineage is directly involved in adherence to erythrocytes. Strikingly, ectopic expression of Trw of rat-specific B. tribocorum in cat-specific B. henselae or human-specific B. quintana expanded their host range for erythrocyte infection to rat, demonstrating that Trw mediates host-specific erythrocyte infection. A molecular evolutionary analysis of the trw locus further indicated that the variable, surface-located TrwL and TrwJ might represent the T4SS components that determine host-specificity of erythrocyte parasitism. In conclusion, we show that the laterally acquired Trw T4SS diversified in the Bartonella lineage

  10. Type IV secretion system of Brucella spp. and its effectors.

    Science.gov (United States)

    Ke, Yuehua; Wang, Yufei; Li, Wengfeng; Chen, Zeliang

    2015-01-01

    Brucella spp. are intracellular bacterial pathogens that cause infection in domestic and wild animals. They are often used as model organisms to study intracellular bacterial infections. Brucella VirB T4SS is a key virulence factor that plays important roles in mediating intracellular survival and manipulating host immune response to infection. In this review, we discuss the roles of Brucella VirB T4SS and 15 effectors that are proposed to be crucial for Brucella pathogenesis. VirB T4SS regulates the inflammation response and manipulates vesicle trafficking inside host cells. VirB T4SS also plays crucial roles in the inhibition of the host immune response and intracellular survival during infection. Here, we list the key molecular events in the intracellular life cycle of Brucella that are potentially targeted by the VirB T4SS effectors. Elucidating the functions of these effectors will help clarify the molecular role of T4SS during infection. Furthermore, studying the effectors secreted by Brucella spp. might provide insights into the mechanisms used by the bacteria to hijack the host signaling pathways and aid in the development of better vaccines and therapies against brucellosis.

  11. Cyclic di-GMP riboswitch-regulated type IV pili contribute to aggregation of Clostridium difficile.

    Science.gov (United States)

    Bordeleau, Eric; Purcell, Erin B; Lafontaine, Daniel A; Fortier, Louis-Charles; Tamayo, Rita; Burrus, Vincent

    2015-03-01

    Clostridium difficile is an anaerobic Gram-positive bacterium that causes intestinal infections with symptoms ranging from mild diarrhea to fulminant colitis. Cyclic diguanosine monophosphate (c-di-GMP) is a bacterial second messenger that typically regulates the switch from motile, free-living to sessile and multicellular behaviors in Gram-negative bacteria. Increased intracellular c-di-GMP concentration in C. difficile was recently shown to reduce flagellar motility and to increase cell aggregation. In this work, we investigated the role of the primary type IV pilus (T4P) locus in c-di-GMP-dependent cell aggregation. Inactivation of two T4P genes, pilA1 (CD3513) and pilB1 (CD3512), abolished pilus formation and significantly reduced cell aggregation under high c-di-GMP conditions. pilA1 is preceded by a putative c-di-GMP riboswitch, predicted to be transcriptionally active upon c-di-GMP binding. Consistent with our prediction, high intracellular c-di-GMP concentration increased transcript levels of T4P genes. In addition, single-round in vitro transcription assays confirmed that transcription downstream of the predicted transcription terminator was dose dependent and specific to c-di-GMP binding to the riboswitch aptamer. These results support a model in which T4P gene transcription is upregulated by c-di-GMP as a result of its binding to an upstream transcriptionally activating riboswitch, promoting cell aggregation in C. difficile.

  12. Serum type IV collagen-degrading enzyme in hepatocellular carcinoma with metastasis.

    OpenAIRE

    Hashimoto, Noriaki; Kobayashi, Michio; Tsuji, Takao

    1988-01-01

    The activity of serum type IV collagen-degrading enzyme was measured in 18 patients with hepatocellular carcinoma (HCC). The enzyme activity was significantly higher, in HCC patients with a tumor thrombus in the portal vein than in healthy controls, liver cirrhosis patients and HCC patients without a tumor thrombus. Moreover, the activity in HCC patients with lung metastasis tended to be higher than that in HCC patients without lung metastasis. The activity of serum type IV collagen-degrading...

  13. The spatial organization of Descemet's membrane-associated type IV collagen in the avian cornea

    OpenAIRE

    1990-01-01

    The organization of type IV collagen in the unconventional basement membrane of the corneal endothelium (Descemet's membrane) was investigated in developing chicken embryos using anti-collagen mAbs. Both immunofluorescence histochemistry and immunoelectron microscopy were performed. In mature embryos (greater than 15 d of development), the type IV collagen of Descemet's membrane was present as an array of discrete aggregates of amorphous material at the interface between Descemet's membrane a...

  14. Autoantibodies against basement membrane collagen type IV are associated with myocardial infarction

    OpenAIRE

    Olga McLeod; Pontus Dunér; Ann Samnegård; Per Tornvall; Jan Nilsson; Anders Hamsten; Eva Bengtsson

    2015-01-01

    Background: Collagen type IV is the major constituent of basement membranes underlying endothelial cells and is important for endothelial cell attachment and function. Autoantibodies against native collagen type IV have been found in various autoimmune diseases. Oxidation of LDL in the vascular wall results in the formation of reactive aldehydes, which could modify surrounding matrix proteins. Like oxidized LDL, these modified matrix proteins are likely to induce immune responses. We examined...

  15. Struggling with a Gastric Volvulus Secondary to a Type IV Hiatal Hernia

    Directory of Open Access Journals (Sweden)

    Dafnomilis George

    2010-01-01

    Full Text Available Type IV hiatal hernias are characterized by herniation of the stomach along with associated viscera such as the spleen, colon, small bowel, and pancreas through the esophageal hiatus. They are relatively rare, representing only about 5%–7% of all hernias, and can be associated with severe complications. We report a 71-year-old veteran wrestler who presented to our department with a type IV paraesophageal hernia containing a gastric volvulus and treated successfully with emergency operation.

  16. High resolution observations with Artemis-IV and the NRH. I. Type IV associated narrow-band bursts

    CERN Document Server

    Bouratzis, C; Alissandrakis, C E; Preka-Papadema, P; Moussas, X; Caroubalos, C; Tsitsipis, P; Kontogeorgos, A

    2016-01-01

    Narrow band bursts appear on dynamic spectra from microwave to decametric frequencies as fine structures with very small duration and bandwidth. They are thought to mark small scale magnetic reconnection. We analyzed 27 metric type-IV events with narrow band bursts observed by the ARTEMIS-IV radiospectrograph in 30/6/1999-1/8/2010. We examined the morphological characteristics of isolated narrow-band bursts and groups or chains of spikes. The events were recorded with the SAO (10 ms cadence) receiver of ARTEMIS-IV in the 270-450 MHz range. We measured the duration, spectral width, and frequency drift of ~12000 individual narrow-band bursts, groups, and chains. Spike sources were imaged with the NRH for the event of 21 April 2003. The mean duration of individual bursts at fixed frequency was ~100 ms, while the instantaneous relative bandwidth was ~2%. Some bursts had measurable frequency drift, positive or negative. Often spikes appeared in chains, which were closely spaced in time (column chains) or in freque...

  17. Cells that emerge from embryonic explants produce fibers of type IV collagen.

    Science.gov (United States)

    Chen, J M; Little, C D

    1985-10-01

    Double immunofluorescence staining experiments designed to examine the synthesis and deposition of collagen types I and IV in cultured explants of embryonic mouse lung revealed the presence of connective tissue-like fibers that were immunoreactive with anti-type IV collagen antibodies. This observation is contrary to the widely accepted belief that type IV collagen is found only in sheet-like arrangements beneath epithelia or as a sheath-like layer enveloping bundles of nerve or muscle cells. The extracellular matrix produced by cells that migrate from embryonic mouse lung rudiments in vitro was examined by double indirect immunofluorescence microscopy. Affinity-purified monospecific polyclonal antibodies were used to examine cells after growth on glass or native collagen substrata. The data show that embryonic mesenchymal cells can produce organized fibers of type IV collagen that are not contained within a basement membrane, and that embryonic epithelial cells deposit fibers and strands of type IV collagen beneath their basal surface when grown on glass; however, when grown on a rat tail collagen substratum the epithelial cells produce a fine meshwork. To our knowledge this work represents the first report that type IV collagen can be organized by cells into a fibrous extracellular matrix that is not a basement membrane.

  18. Agrobacterium type IV secretion system and its substrates form helical arrays around the circumference of virulence-induced cells.

    Science.gov (United States)

    Aguilar, Julieta; Zupan, John; Cameron, Todd A; Zambryski, Patricia C

    2010-02-23

    The genetic transformation of plant cells by Agrobacterium tumefaciens results from the transfer of DNA and proteins via a specific virulence (vir) -induced type IV secretion system (T4SS). To better understand T4SS function, we analyzed the localization of its structural components and substrates by deconvolution fluorescence microscopy. GFP fusions to T4SS proteins with cytoplasmic tails, VirB8 and VirD4, or cytoplasmic T4SS substrate proteins, VirD2, VirE2, and VirF, localize in a helical pattern of fluorescent foci around the perimeter of the bacterial cell. All fusion proteins were expressed at native levels of vir induction. Importantly, most fusion proteins are functional and do not exhibit dominant-negative effects on DNA transfer to plant cells. Further, GFP-VirB8 complements a virB8 deletion strain. We also detect native VirB8 localization as a helical array of foci by immunofluorescence microscopy. T4SS foci likely use an existing helical scaffold during their assembly. Indeed, the bacterial cytoskeletal component MinD colocalizes with GFP-VirB8. Helical arrays of foci are found at all times investigated between 12 and 48 h post vir induction at 19 degrees C. These data lead to a model with multiple T4SSs around the bacterial cell that likely facilitate host cell attachment and DNA transfer. In support, we find multiple T pili around vir-induced bacterial cells. PMID:20133577

  19. Assembly of the bacterial type III secretion machinery.

    Science.gov (United States)

    Diepold, Andreas; Wagner, Samuel

    2014-07-01

    Many bacteria that live in contact with eukaryotic hosts, whether as symbionts or as pathogens, have evolved mechanisms that manipulate host cell behaviour to their benefit. One such mechanism, the type III secretion system, is employed by Gram-negative bacterial species to inject effector proteins into host cells. This function is reflected by the overall shape of the machinery, which resembles a molecular syringe. Despite the simplicity of the concept, the type III secretion system is one of the most complex known bacterial nanomachines, incorporating one to more than hundred copies of up to twenty different proteins into a multi-MDa transmembrane complex. The structural core of the system is the so-called needle complex that spans the bacterial cell envelope as a tripartite ring system and culminates in a needle protruding from the bacterial cell surface. Substrate targeting and translocation are accomplished by an export machinery consisting of various inner membrane embedded and cytoplasmic components. The formation of such a multimembrane-spanning machinery is an intricate task that requires precise orchestration. This review gives an overview of recent findings on the assembly of type III secretion machines, discusses quality control and recycling of the system and proposes an integrated assembly model.

  20. Type-IV DCT, DST, and MDCT algorithms with reduced numbers of arithmetic operations

    CERN Document Server

    Shao, Xuancheng

    2007-01-01

    We present algorithms for the type-IV discrete cosine transform (DCT-IV) and discrete sine transform (DST-IV), as well as for the modified discrete cosine transform (MDCT) and its inverse, that achieve a lower count of real multiplications and additions than previously published algorithms, without sacrificing numerical accuracy. Asymptotically, the operation count is reduced from ~2NlogN to ~(17/9)NlogN for a power-of-two transform size N. These results are derived by considering the DCT to be a special case of a DFT of length 8N, with certain symmetries, and then pruning redundant operations from a recent improved fast Fourier transform algorithm (based on a recursive rescaling of the conjugate-pair split radix algorithm). The improved algorithms for DST-IV and MDCT follow immediately from the improved count for the DCT-IV.

  1. Type IV Ehlers-Danlos Syndrome: A Surgical Emergency? A Case of Massive Retroperitoneal Hemorrhage.

    Science.gov (United States)

    Chun, Stephen G; Pedro, Patrick; Yu, Mihae; Takanishi, Danny M

    2011-01-01

    Retroperitoneal hemorrhagic bleeding is a known manifestation of Type-IV Ehlers-Danlos Syndrome that is caused by loss-of-function mutations of the pro-alpha-1 chains of type III pro-collagen (COL3A1) resulting in vascular fragility. A number of previous reports describe futile surgical intervention for retroperitoneal bleeding in Type-IV Ehlers-Danlos Syndrome with high post-operative mortality, although the rarity of retroperitoneal bleeding associated with Type-IV Ehlers-Danlos Syndrome precludes an evidence-based approach to clinical management. We report a 23-year-old male with history of Type-IV Ehlers-Danlos Syndrome who presented with severe abdominal pain and tachycardia following an episode of vomiting. Further work-up of his abdominal pain revealed massive retroperitoneal bleeding by CT-scan of the abdomen. Given numerous cases of catastrophic injury caused by surgical intervention in Type-IV Ehlers-Danlos Syndrome, the patient was treated non-operatively, and the patient made a full recovery. This case suggests that even in cases of large retroperitoneal hemorrhages associated with Ehlers-Danlos Syndrome, it may not truly represent a surgical emergency. PMID:21966332

  2. Perisigmoid Abscess Leading to a Diagnosis of Ehlers-Danlos Syndrome Type IV.

    Science.gov (United States)

    Normatov, Inessa; Kesavan, Anil; Srikumar, Pillai B; McConnie, Randolph M

    2016-01-01

    The Ehlers-Danlos syndromes (EDS) are a group of connective tissue disorders characterized by triad of joint hypermobility, skin extensibility, and tissue fragility. Ehlers-Danlos syndrome type IV places patients at risk for life-threatening, spontaneous, vascular or visceral rupture due to reduced or abnormal secretion of type III collagen. We present an adolescent male who was found to have a perisigmoid abscess with a fistula connecting to adjacent sigmoid colon secondary to undiagnosed EDS type IV. Conservative management with antibiotics and bowel rest was pursued to allow for elective resection for his acute complicated diverticulitis at a safer time. PMID:26958560

  3. Type IV Cracking Susceptibility in Weld Joints of Different Grades of Cr-Mo Ferritic Steel

    Science.gov (United States)

    Laha, K.; Chandravathi, K. S.; Parameswaran, P.; Bhanu Sankara Rao, K.

    2009-02-01

    Relative type-IV cracking susceptibility in 2.25Cr-1Mo, 9Cr-1Mo, and 9Cr-1MoVNb ferritic steel weld joint has been assessed. The type-IV cracking was manifested as preferential accumulation of creep deformation and cavitation in the relatively soft intercritical region of heat affected zone of the weld joint. The type-IV cracking susceptibility has been defined as the reduction in creep-rupture strength of weld joint compared to its base metal. The 2.25Cr-1Mo steel exhibited more susceptibility to type-IV cracking at relatively lower temperatures; whereas, at higher temperatures, 9Cr-1MoVNb steel was more susceptible. The relative susceptibility to type-IV cracking in the weld joint of the Cr-Mo steels has been rationalized on the basis of creep-strengthening mechanisms operating in the steels and their venerability to change on intercritical heating during weld thermal cycle, subsequent postweld heat treatment, and creep exposure.

  4. High resolution observations with Artemis-IV and the NRH. I. Type IV associated narrow-band bursts

    Science.gov (United States)

    Bouratzis, C.; Hillaris, A.; Alissandrakis, C. E.; Preka-Papadema, P.; Moussas, X.; Caroubalos, C.; Tsitsipis, P.; Kontogeorgos, A.

    2016-02-01

    Context. Narrow-band bursts appear on dynamic spectra from microwave to decametric frequencies as fine structures with very small duration and bandwidth. They are believed to be manifestations of small scale energy release through magnetic reconnection. Aims: We analyzed 27 metric type IV events with embedded narrow-band bursts, which were observed by the ARTEMIS-IV radio spectrograph from 30 June 1999 to 1 August 2010. We examined the morphological characteristics of isolated narrow-band structures (mostly spikes) and groups or chains of structures. Methods: The events were recorded with the SAO high resolution (10 ms cadence) receiver of ARTEMIS-IV in the 270-450 MHz range. We measured the duration, spectral width, and frequency drift of ~12 000 individual narrow-band bursts, groups, and chains. Spike sources were imaged with the Nançay radioheliograph (NRH) for the event of 21 April 2003. Results: The mean duration of individual bursts at fixed frequency was ~100 ms, while the instantaneous relative bandwidth was ~2%. Some bursts had measurable frequency drift, either positive or negative. Quite often spikes appeared in chains, which were closely spaced in time (column chains) or in frequency (row chains). Column chains had frequency drifts similar to type-IIId bursts, while most of the row chains exhibited negative frequently drifts with a rate close to that of fiber bursts. From the analysis of NRH data, we found that spikes were superimposed on a larger, slowly varying, background component. They were polarized in the same sense as the background source, with a slightly higher degree of polarization of ~65%, and their size was about 60% of their size in total intensity. Conclusions: The duration and bandwidth distributions did not show any clear separation in groups. Some chains tended to assume the form of zebra, lace stripes, fiber bursts, or bursts of the type-III family, suggesting that such bursts might be resolved in spikes when viewed with high

  5. 布鲁氏菌的IV型分泌系统%Type IV secretion system of Brucella

    Institute of Scientific and Technical Information of China (English)

    刘倩宏

    2012-01-01

    Brucellosis, which is caused by Brucella, is one of the most important bacterial zoonoses. It brings serious harm to stock raising, human health and animal-derived food security. Type IV secretion system of Brucella is essential for survival and multiplication within the host cells, which also play an important role in pathogenicity of Brucella. Type IV secretion system that is encoded by the virB operon is described as a family of multi-protein and crossing-envelope complex, and regulated by the same promoter. Type IV secretion system is also affected by multi-factor, which may be PH, temperature, nutrition and the type of the cells infected and it plays an important role in regulation intracellular and extracellular survival of Brucella.%布鲁氏菌病是由布鲁氏菌引起的人兽共患病,给养殖业、人类健康和动物源性食品安全带来很大威胁.布鲁氏菌的IV型分泌系统在布鲁氏菌的致病力上发挥重要作用,与布鲁氏菌在宿主细胞内生存、复制有密切关系.IV型分泌系统由virB操纵子编码,由同一启动子调控,是一个多蛋白的跨膜复合物,受感染宿主细胞类型、生长温度、营养条件、pH值等多因素调控;并且对布鲁氏菌的胞内、胞外的生存产生重要影响.

  6. The Role of Type IV Collagen in Developing Lens in Mouse Fetuses

    Directory of Open Access Journals (Sweden)

    Mehdi Jalali

    2009-09-01

    Full Text Available Objective(sExtracellular matrix (ECM and basement membrane (BM play important roles in many developmental processes during development and after birth. Among the components of the BM, collagen fibers specially type IV are the most important parts. The aim of this study was to determine the time when collagen type IV appears in the BM of lens structure during mouse embryonic development.Materials and MethodsIn this experimental study, 22 female Balb/C mice were randomly selected and were kept under normal condition, finding vaginal plug was assumed as day zero of pregnancy. From embryonic day 10 to 20, all specimens were sacrificed by cervical dislocation and their heads were fixed, serially sectioned and immunohistochemistry study for tracing collagen type IV in lens were carried out.ResultsOur data revealed that collagen type IV appeared at the early stage of gestation day 12 in BM of anterior epithelial lens cells and the amount of this protein gradually increased until days 15-17 in ECM and posterior capsule epithelium. After this period, severe reaction was not observed in any part of the lens.ConclusionThese findings establish the important role of collagen IV in developing optic cup and any changes during critical period of pregnancy may be result in severe visual system defect

  7. Arrangement of type IV collagen on NH₂ and COOH functionalized surfaces.

    Science.gov (United States)

    Coelho, Nuno Miranda; González-García, Cristina; Salmerón-Sánchez, Manuel; Altankov, George

    2011-12-01

    Apart from the paradigm that cell-biomaterials interaction depends on the adsorption of soluble adhesive proteins we anticipate that upon distinct conditions also other, less soluble ECM proteins such as collagens, associate with the biomaterials interface with consequences for cellular response that might be of significant bioengineering interest. Using atomic force microscopy (AFM) we seek to follow the nanoscale behavior of adsorbed type IV collagen (Col IV)--a unique multifunctional matrix protein involved in the organization of basement membranes (BMs) including vascular ones. We have previously shown that substratum wettability significantly affects Col IV adsorption pattern, and in turn alters endothelial cells interaction. Here we introduce two new model surfaces based on self-assembled monolayers (SAMs), a positively charged -NH(2) , and negatively charged -COOH surface, to learn more about their particular effect on Col IV behavior. AFM studies revealed distinct pattern of Col IV assembly onto the two SAMs resembling different aspects of network-like structure or aggregates (suggesting altered protein conformation). Moreover, the amount of adsorbed FITC-labeled Col IV was quantified and showed about twice more protein on NH(2) substrata. Human umbilical vein endothelial cells attached less efficiently to Col IV adsorbed on negatively charged COOH surface judged by altered cell spreading, focal adhesions formation, and actin cytoskeleton development. Immunofluorescence studies also revealed better Col IV recognition by both α(1) and α(2) integrins on positively charged NH(2) substrata resulting in higher phosphorylated focal adhesion kinase recruitment in the focal adhesion complexes. On COOH surface, no integrin clustering was observed. Taken altogether these results, point to the possibility that combined NH(2) and Col IV functionalization may support endothelization of cardiovascular implants.

  8. CagI is an essential component of the Helicobacter pylori Cag type IV secretion system and forms a complex with CagL.

    Directory of Open Access Journals (Sweden)

    Kieu Thuy Pham

    Full Text Available Helicobacter pylori, the causative agent of type B gastritis, peptic ulcers, gastric adenocarcinoma and MALT lymphoma, uses the Cag type IV secretion system to induce a strong proinflammatory response in the gastric mucosa and to inject its effector protein CagA into gastric cells. CagA translocation results in altered host cell gene expression profiles and cytoskeletal rearrangements, and it is considered as a major bacterial virulence trait. Recently, it has been shown that binding of the type IV secretion apparatus to integrin receptors on target cells is a crucial step in the translocation process. Several bacterial proteins, including the Cag-specific components CagL and CagI, have been involved in this interaction. Here, we have examined the localization and interactions of CagI in the bacterial cell. Since the cagI gene overlaps and is co-transcribed with the cagL gene, the role of CagI for type IV secretion system function has been difficult to assess, and conflicting results have been reported regarding its involvement in the proinflammatory response. Using a marker-free gene deletion approach and genetic complementation, we show now that CagI is an essential component of the Cag type IV secretion apparatus for both CagA translocation and interleukin-8 induction. CagI is distributed over soluble and membrane-associated pools and seems to be partly surface-exposed. Deletion of several genes encoding essential Cag components has an impact on protein levels of CagI and CagL, suggesting that both proteins require partial assembly of the secretion apparatus. Finally, we show by co-immunoprecipitation that CagI and CagL interact with each other. Taken together, our results indicate that CagI and CagL form a functional complex which is formed at a late stage of secretion apparatus assembly.

  9. Expression and localization of collagen type IV α1 chain in medaka ovary

    OpenAIRE

    Kato, Yumiko; Ogiwara, Katsueki; Fujimori, Chika; KIMURA, Atsushi; Takahashi, Takayuki

    2010-01-01

    A cDNA clone coding for collagen type IV α1 chain was obtained from the ovary of the medaka, Oryzias latipes. The clone encodes a protein of 1639 amino acids including a putative 21-residue signal peptide, and the deduced amino acid sequence of the α1 chain was homologous to those of the proteins from other species. Collagen type IV α1 chain mRNA was expressed in various tissues of the adult fish. In situ hybridization analysis revealed that the α1 chain mRNA was localized in the follicle lay...

  10. Cardiac arrest after anesthetic management in a patient with hereditary sensory autonomic neuropathy type IV

    Directory of Open Access Journals (Sweden)

    Ergül Yakup

    2011-01-01

    Full Text Available Hereditary sensory autonomic neuropathy type IV is a rare disorder with an autosomal recessive transmission and characterized by self-mutilation due to a lack in pain and heat sensation. Recurrent hyperpyrexia and anhydrosis are seen in patients as a result of a lack of sweat gland innervation. Self-mutilation and insensitivity to pain result in orthopedic complications and patients undergone recurrent surgical interventions with anesthesia. However, these patients are prone to perioperative complications such as hyperthermia, hypothermia, and cardiac complications like bradycardia and hypotension. We report a 5-year-old boy with hereditary sensory autonomic neuropathy type IV, developing hyperpyrexia and cardiac arrest after anesthesia.

  11. Different assembly of type IV collagen on hydrophilic and hydrophobic substrata alters endothelial cells interaction

    Directory of Open Access Journals (Sweden)

    NM Coelho

    2010-06-01

    Full Text Available Considering the structural role of type IV collagen (Col IV in the assembly of the basement membrane (BM and the perspective of mimicking its organization for vascular tissue engineering purposes, we studied the adsorption pattern of this protein on model hydrophilic (clean glass and hydrophobic trichloro(octadecylsilane (ODS surfaces known to strongly affect the behavior of other matrix proteins. The amount of fluorescently labeled Col IV was quantified showing saturation of the surface for concentration of the adsorbing solution of about 50μg/ml, but with approximately twice more adsorbed protein on ODS. AFM studies revealed a fine – nearly single molecular size – network arrangement of Col IV on hydrophilic glass, which turns into a prominent and growing polygonal network consisting of molecular aggregates on hydrophobic ODS. The protein layer forms within minutes in a concentration-dependent manner. We further found that human umbilical vein endothelial cells (HUVEC attach less efficiently to the aggregated Col IV (on ODS, as judged by the significantly altered cell spreading, focal adhesions formation and the development of actin cytoskeleton. Conversely, the immunofluorescence studies for integrins revealed that the fine Col IV network formed on hydrophilic substrata is better recognized by the cells via both α1 and α2 heterodimers which support cellular interaction, apart from these on hydrophobic ODS where almost no clustering of integrins was observed.

  12. Conservative management of small bowel perforation in Ehlers-Danlos syndrome type IV.

    Science.gov (United States)

    Allaparthi, Satya; Verma, Himanshu; Burns, David L; Joyce, Ann M

    2013-08-16

    Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders caused by collagen synthesis defects. EDS type IV, or vascular EDS, is caused by loss-of-function mutations in the type III pro-collagen gene (COL3A1). Common complications of EDS type IV include gastrointestinal bleeding and bowel perforations, posing diagnostic and therapeutic dilemmas for both surgeons and gastroenterologists. Here, we describe a complicated case of EDS type IV in a 35-year-old caucasian female who presented with overt gastrointestinal bleeding. The patient had a prior history of spontaneous colonic perforation, and an uncomplicated upper endoscopy was performed. A careful ileoscopy was terminated early due to tachycardia and severe abdominal pain, and a subsequent computed tomography scan confirmed the diagnosis of ileal perforation. The patient was managed conservatively, and demonstrated daily improvement. At the time of hospital discharge, no further episodes of gastrointestinal blood loss had occurred. This case highlights the benefit of conservative management for EDS patients with gastrointestinal hemorrhage. It is recommended that surgical treatment should be reserved for patients who fail conservative treatment or in cases of hemodynamic instability. Finally, this case demonstrates the necessity for a higher threshold of operative or endoscopic interventions in EDS type IV patients. PMID:23951395

  13. Dipeptidyl peptidase IV inhibitors: a promising new therapeutic approach for the management of type 2 diabetes

    DEFF Research Database (Denmark)

    Deacon, Carolyn F; Holst, Jens J

    2005-01-01

    of appetite. Glucagon-like peptide-1 is, however, extremely rapidly inactivated by the serine peptidase, dipeptidyl peptidase IV, so that the native peptide is not useful clinically. A new approach to utilise the beneficial effects of glucagon-like peptide-1 in the treatment of type 2 diabetes has been......-12 months duration in patients with type 2 diabetes, dipeptidyl peptidase IV inhibitors have proved efficacious, both as monotherapy and when given in combination with metformin. Fasting and postprandial glucose concentrations were reduced, leading to reductions in glycosylated haemoglobin levels, while...... the development of orally active dipeptidyl peptidase IV inhibitors. Preclinical studies have demonstrated that this approach is effective in enhancing endogenous levels of glucagon-like peptide-1, resulting in improved glucose tolerance in glucose-intolerant and diabetic animal models. In recent studies of 3...

  14. Type IV renal tubular acidosis and spironolactone therapy in the elderly.

    OpenAIRE

    O'Connell, J. E.; Colledge, N. R.

    1993-01-01

    Spironolactone therapy is a well-known cause of hyperkalaemia, but in susceptible patient, it may also be associated with metabolic acidosis. We report a case of severe renal tubular acidosis (Type IV) with life-threatening hyperkalaemia caused by spironolactone, and discuss the mechanisms by which this may occur.

  15. Tibial lengthening for unilateral Crowe type-IV developmental dysplasia of the hip

    Directory of Open Access Journals (Sweden)

    Jun Wan

    2014-01-01

    Conclusions: Tibial lengthening may effectively correct gait and satisfactorily improve body image in young patients with unilateral Crowe type-IV DDH. Mono-lateral external fixator allows for accelerated postoperative rehabilitation and optimal preservation of ankle movements. Lengthening along with intramedullary nails may significantly reduce the external fixation time and the risk of fixator-related complications.

  16. Campylobacter fetus subspecies contain conserved type IV secretion systems on multiple genomic islands and plasmids

    Science.gov (United States)

    The features contributing to the differences in pathogenicity of the C. fetus subspecies are unknown. Putative factors involved in pathogenesis are located in genomic islands that encode type IV secretion system (T4SS) and fic-domain (filamentation induced by cyclic AMP) proteins. In the genomes of ...

  17. UV-inducible DNA exchange in hyperthermophilic archaea mediated by type IV pili

    NARCIS (Netherlands)

    Ajon, Malgorzata; Froels, Sabrina; van Wolferen, Marleen; Stoecker, Kilian; Teichmann, Daniela; Driessen, Arnold J. M.; Grogan, Dennis W.; Albers, Sonja-Verena; Schleper, Christa; Ajon, Małgorzata

    2011-01-01

    Archaea, like bacteria and eukaryotes, contain proteins involved in various mechanisms of DNA repair, highlighting the importance of these processes for all forms of life. Species of the order Sulfolobales of hyperthermophilic crenarchaeota are equipped with a strongly UV-inducible type IV pilus sys

  18. Multiwavelength Analysis of a Moving Type-IV Radio Burst on 4th March 2012

    Science.gov (United States)

    Veluchamy, V.; Chen, Y.; Feng, S.; Du, G.; Song, H.; Kong, X.

    2015-12-01

    We performed a multiwavelength analysis of a moving Type-IV radio burst on 4th march 2012. The Type-IV radio burst is observed between 10:39 - 11:00 UT in the frequency range of 300 - 20 MHz. From the radio heliographic observation, the radio source of the type-IV burst is traced and their sky plane speed is estimated as ~ 370 km/s. A plasmoid structure is ejected during the impulsive phase of the flare, at the same time of the type-IV burst and the structure is clearly observed at SDO/AIA 131 Å channel. From this, we find that the radio source moves with the plasmoid. The high brightness temperature profile in the range of 108 - 109 K and the moderate polarization between -50 - 30 % supports the plasma emission mechanism. Further the differential emission measure (DEM) analysis will be carried out and their results will be presented to provide more evidence of the emission mechanism.

  19. Liver transplantation for glycogen storage disease types I, III, and IV

    NARCIS (Netherlands)

    Matern, D; Starzl, TE; Arnaout, W; Barnard, J; Bynon, JS; Dhawan, A; Emond, J; Haagsma, EB; Hug, G; Lachaux, A; Smit, GPA; Chen, YT

    1999-01-01

    Glycogen storage disease (GSD) types I, III, and IV can be associated with severe liver disease. The possible development of hepatocellular carcinoma and/or hepatic failure make these GSDs potential candidates for liver transplantation. Early diagnosis and initiation of effective dietary therapy hav

  20. Tate twists of Hodge structures arising from abelian varieties of type IV

    CERN Document Server

    Abdulali, Salman

    2012-01-01

    We show that certain abelian varieties A have the property that for every Hodge structure V in the cohomology of A, every effective Tate twist of V occurs in the cohomology of some abelian variety. We deduce the general Hodge conjecture for certain non-simple abelian varieties of type IV.

  1. Serum type IV collagen level is predictive for esophageal varices in patients with severe alcoholic disease

    Institute of Scientific and Technical Information of China (English)

    Satoshi Mamori; Yasuyuki Searashi; Masato Matsushima; Kenichi Hashimoto; Shinichiro Uetake; Hiroshi Matsudaira; Shuji Ito; Hisato Nakajima; Hisao Tajiri

    2008-01-01

    AIM: To determine factors predictive for esophageal varices in severe alcoholic disease (SAD).METHODS: Abdominal ultrasonography (US) was performed on 444 patients suffering from alcoholism. Forty-four patients found to have splenomegaly and/ or withering of the right liver lobe were defined as those with SAD. SAD patients were examined by upper gastrointestinal (UGI) endoscopy for the presence of esophageal varices. The existence of esophageal varices was then related to clinical variables.RESULTS: Twenty-five patients (56.8%) had esophageal varices. A univariate analysis revealed a significant difference in age and type IV collagen levels between patients with and without esophageal varices. A logistic regression analysis identified type IV collagen as the only independent variable predictive for esophageal varices (P = 0.017). The area under the curve (AUC) for type IV collagen as determined by the receiver operating characteristic (ROC) for predicting esophageal varices was 0.78.CONCLUSION: This study suggests that the level of type IV collagen has a high diagnostic accuracy for the detection of esophageal varices in SAD.

  2. Elective reconstruction of thoracoabdominal aortic aneurysm type IV by transabdominal approach

    Directory of Open Access Journals (Sweden)

    Marjanović Ivan

    2012-01-01

    Full Text Available Introduction. Thoracoabdominal aortic aneurysm (TAAA type IV represents an aortic dilatation from the level of the diaphragmatic hiatus to the iliac arteries branches, including visceral branches of the aorta. In the traditional procedure of TAAA type IV repair, the body is opened using thoractomy and laparotomy in order to provide adequate exposure of the descending thoracic and abdominal aorta for safe aortic reconstruction. Case report. We reported a 71-yearold man with elective reconstruction of the TAAA type IV performed by transabdominal approach. Computed tomography scans angiography revealed a TAAA type IV with diameter of 62 mm in the region of celiac trunk and superior mesenteric artery branching, and the largest diameter of 75 mm in the infrarenal aortic level. The patient comorbidity included a chronic obstructive pulmonary disease and hypertension, therefore he was treated for a prolonged period. In preparation for the planned aortic reconstruction asymptomatic carotid disease (occlusion of the left internal carotid artery and subtotal stenosis of the right internal carotid artery was diagnosed. Within the same intervention percutaneous transluminal angioplasty with stent placement in right internal carotid artery was made. In general, under endotracheal anesthesia and epidural analgesia, with transabdominal approach performed aortic reconstruction with tubular dakron graft 24 mm were, and reimplantation of visceral aortic branches into the graft performed. Postoperative course was uneventful, and the patient was discharged on the postoperative day 17. Control computed tomography scan angiography performed three months after the operation showed vascular state of the patient to be in order. Conclusion. Complete transabdominal approach to TAAA type IV represents an appropriate substitute for thoracoabdominal approach, without compromising safety of the patient. This approach is less traumatic, especially in patients with impaired

  3. Spontaneous rupture of the spleen in type IV Ehlers-Danlos syndrome: report of a case.

    Science.gov (United States)

    Privitera, Antonio; Milkhu, Chaz; Datta, Vivek; Sayegh, Mazim; Cohen, Richard; Windsor, Alastair

    2009-01-01

    The vascular type of Ehlers-Danlos syndrome, type IV, is associated with severe complications, including arterial rupture and visceral perforation. However, to our knowledge, there has been only one previous report of splenic rupture caused by a spontaneous hemorrhage in type IV Ehlers-Danlos syndrome. We report another case of this uncommon complication, occurring in a 35-year-old woman who presented after the sudden onset of acute abdominal pain. Patients should be stabilized quickly in the intensive care unit and the most timesaving surgical techniques used. Moreover, tissues must be handled with great care intraoperatively in view of their extreme fragility. Despite prompt and appropriate treatment, the prognosis is often dismal. PMID:19132469

  4. The Prognostic and Predictive Value of Soluble Type IV Collagen in Colorectal Cancer

    DEFF Research Database (Denmark)

    Rolff, Hans Christian; Christensen, Ib Jarle; Vainer, Ben;

    2016-01-01

    validation set, respectively. The prognostic impact was present both in patients with metastatic and nonmetastatic disease. The predictive value of the marker was investigated in stage II and III patients. In the training set, type IV collagen was prognostic both in the subsets of patients receiving and not...... receiving adjuvant antineoplastic therapy. However, in the validation set, the prognostic effect of the marker vanished when looking at patients who received adjuvant antineoplatic therapy (HR 0.90; 95% CI, 0.42-1.93) but was still present in the group not receiving adjuvant chemotherapy (HR 2.88; 95% CI, 1.......98-4.21). CONCLUSIONS: The results indicate clinical validity of type IV collagen as a prognostic biomarker in colorectal cancer, although the suggested predictive role of the marker should be validated. Clin Cancer Res; 22(10); 2427-34. ©2015 AACR....

  5. Type IV Sacrococcygeal Teratoma Displacing the Urinary Bladder: Unique Magnetic Resonance Imaging

    Science.gov (United States)

    Eftekharzadeh, Sahar; Keihani, Sorena; Fareghi, Mehdi; Alamsahebpour, Alireza; Kajbafzadeh, Abdol-Mohammad

    2016-01-01

    Type IV sacrococcygeal teratoma is a rare pediatric tumor that is confined to the presacral area with no external component. The signs and symptoms often arise due to mass effect and compression of adjacent organs. Urinary retention is an uncommon presenting symptom in these patients. A wide spectrum of imaging findings may be encountered in cases with sacrococcygeal teratoma because of variability of tumor size and components. We hereby present a unique magnetic resonance urography finding in a type IV sacrococcygeal teratoma which caused bladder displacement. A meticulous and complete resection of tumor with special attention to the pelvic plexus led to preservation of normal voiding function and normal bowel function in this patient. PMID:27413571

  6. Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain

    International Nuclear Information System (INIS)

    Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy γ-rays or a fractionated dose of 40 Gy γ-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.

  7. Outcome of surgical treatment of type IV capitellum fractures in adults

    Institute of Scientific and Technical Information of China (English)

    Ajay Pal Singh; Ish Kumar Dhammi; Vipul Garg; Arun Pal Singh

    2012-01-01

    Objective:Fractures of the capitellum and trochlea constitute less than 1% of all elbow fractures and a shear fracture involving the capitellum and extending medially into most of the trochlea is rarely reported.Type IV capitellum fracture is still controversial in regard to its radiographic appearance,surgical approach and osteosynthesis.We report 10 cases of type IV capitellum fracture with a view to elucidating its clinical features and treatment outcome.Methods:We treated 10 patients of type IV capitellum fracture with a mean age of 32 years.A uniform surgical approach and postoperative rehabilitation were followed.Results:Nine patients presented to us after a mean of 4 days of injury and one patient was nonunion after 6 months of injury who had been treated conservatively by a bone setter.Double arc sign was absent in 6 cases.Intraoperatively 6 capitellotrochlear fragments were devoid of soft tissue attachments.By Mayo Elbow Performance Score evaluation,7 patients got excellent,2 good and l fair results.One patient with associated elbow dislocation developed heterotopic ossification.There was no case of avascular necrosis,osteoarthrosis or fixation failures.Conclusions:Type IV capitellum fractures are rare and belong to complex articular injuries.A good functional outcome can only be achieved with open reduction and stable internal fixation followed by early mobilization.Preoperative radiographic assessment and computed tomography help surgeons in choosing the right surgical approach and implants.Good surgical technique and stable internal fixation are the keys to early mobilization and good functional outcome.

  8. Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hee [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Warrington, Junie P.; Sonntag, William E. [Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Lee, Yong Woo, E-mail: ywlee@vt.edu [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States)

    2012-04-01

    Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy {gamma}-rays or a fractionated dose of 40 Gy {gamma}-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.

  9. N. elongata Produces Type IV Pili That Mediate Interspecies Gene Transfer with N. gonorrhoeae

    OpenAIRE

    Higashi, Dustin L.; Nicolas Biais; Weyand, Nathan J.; Al Agellon; Sisko, Jennifer L.; Brown, Lewis M.; Magdalene So

    2011-01-01

    The genus Neisseria contains at least eight commensal and two pathogenic species. According to the Neisseria phylogenetic tree, commensals are basal to the pathogens. N. elongata, which is at the opposite end of the tree from N. gonorrhoeae, has been observed to be fimbriated, and these fimbriae are correlated with genetic competence in this organism. We tested the hypothesis that the fimbriae of N. elongata are Type IV pili (Tfp), and that Tfp functions in genetic competence. We provide evid...

  10. Cystatin C and collagen type IV in diagnostics of chronic kidney disease in type 2 diabetic patients

    Directory of Open Access Journals (Sweden)

    Vadim Valer'evich Klimontov

    2015-03-01

    Full Text Available AimTo compare kidney disease markers: glomerular filtration rate (GFR, calculated upon creatinine and cystatin C, urinary cystatin C, collagen type IV and albumin in type 2 diabetic patients with normal and moderately reduced renal function.Materials and methods56 patients, aged 43–70 years, and 16 healthy controls, aged 40-72 years, were included in the study. GFR was calculated by equations based on creatinine (CKD-EPIcreat, cystatin C (CKD-EPIcys or both markers (CKD-EPIcreat-cys. Serum and urinary cystatin C was measured by immunoturbidimetric method, urinary albumin, albumin excretion rate (AER and collagen type IV excretion was determined by ELISA. The body composition was investigated in 24 patients by dual-energy X-ray absorptiometry.ResultsIn diabetic patients serum cystatin C level correlated positively with age (r=0.37, GFR calculated by CKD-EPIcreat (r=-0.43 and fat mass percentage (r=0.55. There was a positive correlation between GFR calculated by the CKD-EPIcys and GFR by CKD-EPIcreat (r=0.48. In multiple regression analysis the percentage of body fat influenced the GFR calculated by CKD-EPIcys or CKD-EPIcreat-cys. No correlation between urinary cystatin C and serum cystatin C level, GFR and AER was found. Collagen type IV excretion was increased in patients with decreased GFR, compared to those with normal GFR (p=0.002. Urinary collagen type IV correlated with both GFR and AER (r=-0.28 and r=0.47.ConclusionThe measurement of serum cystatin C with calculation of GFR by CKD-EPIcys and CKD-EPIcreat-cys, in addition to the CKD-EPIcreat, increases the accuracy of CKD diagnostics in type 2 diabetic patients. However, obesity and particularly body fat mass affect the results of estimation of GFR based on cystatin C. The increase in urinary collagen type IV, but not in cystatin C excretion, is related to GFR decline and AER elevation in these patients.

  11. Pathological personality traits can capture DSM-IV personality disorder types.

    Science.gov (United States)

    Miller, Joshua D; Few, Lauren R; Lynam, Donald R; MacKillop, James

    2015-01-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) includes an alternative diagnostic approach to the assessment of personality disorders (PDs) in Section III with the aim of stimulating further research. Diagnosis of a PD using this approach is predicated on the presence of personality impairment and pathological personality traits. The types of traits present (e.g., callousness vs. emotional lability) are used to derive DSM-IV PD scores. Concerns have been raised, however, that such a trait-based approach will yield PD constructs that differ substantially from those generated using the approaches articulated in previous iterations of the DSM. We empirically examined this issue in a sample of 109 adults who were currently receiving mental health treatment. More specifically, we examined the correlations between interview-based PD scores derived from DSM-IV to DSM-5 PD trait counts, and tested them in relation to the 30 specific facets of the five-factor model, as well as internalizing and externalizing symptoms. Overall, the DSM-IV PD scores and DSM-5 PD trait counts correlated significantly with one another (Mr = .63), demonstrated similar patterns of interrelations among the PDs, and manifested highly similar patterns of correlations with general personality traits and symptoms of psychopathology. These results indicate that the DSM-5 PD trait counts specified in the alternative DSM-5 PD diagnostic approach capture the same constructs as those measured using the more traditional DSM-IV diagnostic system.

  12. Microstructures and Type-IV Creep Damage of High Cr Steel Welds

    Science.gov (United States)

    Hongo, Hiromichi; Tabuchi, Masaaki; Takahashi, Yukio

    Creep strength of welded joints in high Cr steels decreases due to the formation of Type-IV creep damage in the heat-affected zone (HAZ) during long-term use at high temperatures. This paper aims to elucidate the processes and mechanisms of Type-IV failure. Creep tests for the welded joints with different groove configurations of Mod.9Cr-1Mo steel were conducted. Distributions of Type-IV creep damages in HAZ of these welds were measured quantitatively, and were compared with FEM computations using damage mechanics analysis. For the welded joints with double U groove, creep voids were observed mostly at 20% below the surface of the plate, and scarcely near surfaces and center of thickness. For the welded joints with single U groove, creep voids were observed inside the plate thickness more than 3mm below the surfaces. From the comparison of experimental damage distributions with FEM analysis, it is considered to be important to take the stress triaxiality into account for the prediction of damage location and fracture life of high Cr ferritic steel welds.

  13. Twenty-Two-Year Follow-up of Pronation External Rotation Type III-IV (OTA Type C) Ankle Fractures: A Retrospective Cohort Study.

    NARCIS (Netherlands)

    Donken, C.C.M.A.; Verhofstad, M.H.J.; Edwards, M.J.R.; Laarhoven, C.J.H.M. van

    2012-01-01

    OBJECTIVE: : Long-term evaluation protocolled treatment of pronation external rotation (PER) type III-IV (OTA type C) ankle fractures. DESIGN: : Level III retrospective cohort study. SETTING: : Level I trauma center. PATIENTS: : A consecutive series of 98 patients with PER III-IV ankle fractures bet

  14. Changes of serum or urine type IV collagen concentrations and GFR in DM2 patients complicated with nephropathy

    International Nuclear Information System (INIS)

    Objective: To investigate the changes of serum or urinary, type IV collagen concentration and GFR in patients with diabetic nephropathy (DN). Methods: Serum or urine type IV collagen concentrations (with RIA) and CFR (with SPECT) were determined in 136 DM2 patients with various degrees of albuminuria as well as in 30 controls. Results: Both the serum and urine type IV collagen concentrations were significantly higher in the diabetic patients than those in the controls, and the levels increased continuously as the renal involvement progressed (albuminuria from < 20 μg/min → 200 μg/min). The elevation of serum or urinary, type IV collagen occurred early, even before the increase of albuminuria. The CFR at this early stage was paradoxically higher than normal (135.6±41.4ml/min). Later, with progression of nephropathy, the albuminuria and serum/urine type IV collagen contents increased continuously but the CFR decreased to very low level. Successful control of blood sugar might reverse the increase of type IV collagen to certain degree. Conclusion: Determination of serum/urinary type IV collagen levels might be useful for early diagnosis and assessment of severity of the nephropathy complicating DM2. (authors)

  15. Comparative Analysis of Different Types of Bacterial Colonies from the Soils of Yusmarg Forest, Kashmir valley India

    Directory of Open Access Journals (Sweden)

    Gowhar Hamid Dar

    2013-06-01

    Full Text Available The present work was carried out in the soils of Yusmarg forest to study about the bacterial load (density and diversity, to identify and isolate the bacteria from the soils. During the study a total of thirty six isolates were obtained, among thirty-six different isolates obtained at the four sites B7 and B8 were present at all the four sites, B6 and B9 were present only at site I in November, B16 and B17 were present only at site II in November, B19, B22, B23 and B24 were present only at site III in November, B32, B33 and B34 were present only at site III in December and B35 was present only at site IV in December. Comparative analysis of different types of colonies found at the four sites during the study indicates that the bacterial load was dominant in the month of November.

  16. Alport familial nephritis. Absence of 28 kilodalton non-collagenous monomers of type IV collagen in glomerular basement membrane.

    OpenAIRE

    Kleppel, M M; Kashtan, C. E.; Butkowski, R J; Fish, A. J.; Michael, A. F.

    1987-01-01

    Alport-type familial nephritis (FN), a genetic disorder, results in progressive renal insufficiency and sensorineural hearing loss. Immunochemical and biochemical analyses of the non-collagenous (NC1) domain of type IV collagen isolated from the glomerular basement membranes (GBM) of three males with this disease demonstrate absence of the normally occurring 28-kilodalton (kD) NC1 monomers, but persistence of the 26- and 24-kD monomeric subunits derived from alpha 1 and 2 (both type IV) colla...

  17. Characterization of a synthetic peptide from type IV collagen that promotes melanoma cell adhesion, spreading, and motility

    OpenAIRE

    1990-01-01

    The adhesion and motility of tumor cells on basement membranes is a central consideration in tumor cell invasion and metastasis. Basement membrane type IV collagen directly promotes the adhesion and migration of various tumor cell types in vitro. Our previous studies demonstrated that tumor cells adhered and spread on surfaces coated with intact type IV collagen or either of the two major enzymatically purified domains of this protein. Only one of these major domains, the pepsin-generated maj...

  18. Alogliptin, a potent and selective dipeptidyl peptidase-IV inhibitor for the treatment of type 2 diabetes

    DEFF Research Database (Denmark)

    Deacon, Carolyn F

    2008-01-01

    Takeda San Diego Inc is developing alogliptin, a small-molecule, orally available dipeptidyl peptidase IV (DPP IV) inhibitor, for the potential treatment of type 2 diabetes. In January 2008, Takeda announced that an NDA for alogliptin had been submitted to the FDA....

  19. Galactose recognition by a tetrameric C-type lectin, CEL-IV, containing the EPN carbohydrate recognition motif.

    OpenAIRE

    Hatakeyama, Tomomitsu; Kamiya, Takuro; Kusunoki, Masami; Nakamura-Tsuruta, Sachiko; Hirabayashi, Jun; Goda, Shuichiro; Unno, Hideaki

    2011-01-01

    CEL-IV is a C-type lectin isolated from a sea cucumber, Cucumaria echinata. This lectin is composed of four identical C-type carbohydrate-recognition domains (CRDs). X-ray crystallographic analysis of CEL-IV revealed that its tetrameric structure was stabilized by multiple interchain disulfide bonds among the subunits. Although CEL-IV has the EPN motif in its carbohydrate-binding sites, which is known to be characteristic of mannose binding C-type CRDs, it showed preferential binding of galac...

  20. Galactose Recognition by a Tetrameric C-type Lectin, CEL-IV, Containing the EPN Carbohydrate Recognition Motif*

    OpenAIRE

    Hatakeyama, Tomomitsu; Kamiya, Takuro; Kusunoki, Masami; Nakamura-Tsuruta, Sachiko; Hirabayashi, Jun; Goda, Shuichiro; Unno, Hideaki

    2011-01-01

    CEL-IV is a C-type lectin isolated from a sea cucumber, Cucumaria echinata. This lectin is composed of four identical C-type carbohydrate-recognition domains (CRDs). X-ray crystallographic analysis of CEL-IV revealed that its tetrameric structure was stabilized by multiple interchain disulfide bonds among the subunits. Although CEL-IV has the EPN motif in its carbohydrate-binding sites, which is known to be characteristic of mannose binding C-type CRDs, it showed preferential binding of galac...

  1. Genetic Analysis of the Regulation of Type IV Pilus Function by the Chp Chemosensory System of Pseudomonas aeruginosa▿

    OpenAIRE

    Bertrand, Jacob J.; West, Joyce T.; Engel, Joanne N.

    2009-01-01

    The virulence of the opportunistic pathogen Pseudomonas aeruginosa involves the coordinate expression of many virulence factors, including type IV pili, which are required for colonization of host tissues and for twitching motility. Type IV pilus function is controlled in part by the Chp chemosensory system, which includes a histidine kinase, ChpA, and two CheY-like response regulators, PilG and PilH. How the Chp components interface with the type IV pilus motor proteins PilB, PilT, and PilU ...

  2. Cloning of Bovine herpesvirus type 1 and type 5 as infectious bacterial artifical chromosomes

    OpenAIRE

    Ackermann Mathias; Fraefel Cornel; Gabev Evgeni; Tobler Kurt

    2009-01-01

    Abstract Background Bovine herpesviruses type 1 (BoHV1) and type 5 (BoHV5) are two closely related pathogens of cattle. The identity of the two viruses on the amino acid level averages 82%. Despite their high antigenetic similarities the two pathogens induce distinctive clinical signs. BoHV1 causes respiratory and genital tract infections while BoHV5 leads to severe encephalitis in calves. Findings The viral genomes of BoHV1 and BoHV5 were cloned as infectious bacterial artificial chromosomes...

  3. The gonococcal genetic island and type IV secretion in the pathogenic Neisseria

    Directory of Open Access Journals (Sweden)

    Meghan E Ramsey

    2011-04-01

    Full Text Available Eighty percent of Neisseria gonorrhoeae strains and some Neisseria meningitidis strains encode a 57 kb gonococcal genetic island (GGI. The GGI was horizontally acquired and is inserted in the chromosome at the replication terminus. The GGI is flanked by direct repeats, and site-specific recombination at these sites results in excision of the GGI and may be responsible for its original acquisition. Although the role of the GGI in N. meningitidis is unclear, the GGI in N. gonorrhoeae encodes a type IV secretion system (T4SS. Type IV secretion systems are versatile multi-protein complexes and include both conjugation systems as well as effector systems that translocate either proteins or DNA-protein complexes. In N. gonorrhoeae, the T4SS secretes single-stranded chromosomal DNA into the extracellular milieu in a contact-independent manner. Importantly, the DNA secreted through the T4SS is effective in natural transformation and therefore contributes to the spread of genetic information through Neisseria populations. Mutagenesis experiments have identified genes for DNA secretion including those encoding putative structural components of the apparatus, peptidoglycanases which may act in assembly, and relaxosome components for processing the DNA and delivering it to the apparatus. The T4SS may also play a role in infection by N. gonorrhoeae. During intracellular infection, N. gonorrhoeae requires the Ton complex for iron acquisition and survival. However, N. gonorrhoeae strains that do not express the Ton complex can survive intracellularly if they express structural components of the T4SS. These data provide evidence that the T4SS is expressed during intracellular infection and suggest that the T4SS may provide an advantage for intracellular survival. Here we review our current understanding of how the GGI and type IV secretion affect natural transformation and pathogenesis in N. gonorrhoeae and N. meningitidis.

  4. Microstructure evolution in HAZ and suppression of Type IV fracture in advanced ferritic power plant steels

    International Nuclear Information System (INIS)

    The effect of boron and nitrogen on the microstructure evolution in heat affected zone (HAZ) of 9Cr steel during simulated heating and on the Type IV fracture in welded joints has been investigated at 650 oC. Gr.92 exhibits a significant decrease in time to rupture after thermal cycle to a peak temperature near AC3, while the creep life of Gr.92N, subjected to only normalizing but no tempering, and 9Cr-boron steel is substantially the same as that of the base metals. In Gr.92 after AC3 thermal cycle, very few precipitates are formed along PAGBs in the fine-grained microstructure. In the P92N and 9Cr-boron steel after AC3 heat cycle, on the other hand, not only PAGBs but also lath and block boundaries are covered by M23C6 carbides in the coarse-grained microstructure. It is concluded that the degradation in creep life in Gr.92 after the AC3 thermal cycle is not caused by grain refinement but that the reduction of boundary and sub-boundary hardening is the most important. Soluble boron is essential for the change in α/γ transformation behavior during heating and also for the suppression of Type IV fracture in welded joints. Newly alloy-designed 9Cr steel with 160 ppm boron and 85 ppm nitrogen exhibits much higher creep rupture strength of base metal than P92 and also no Type IV fracture in welded joints at 650 oC.

  5. A bipartite signal mediates the transfer of type IV secretion substrates of Bartonella henselae into human cells.

    Science.gov (United States)

    Schulein, Ralf; Guye, Patrick; Rhomberg, Thomas A; Schmid, Michael C; Schröder, Gunnar; Vergunst, Annette C; Carena, Ilaria; Dehio, Christoph

    2005-01-18

    Bacterial type IV secretion (T4S) systems mediate the transfer of macromolecular substrates into various target cells, e.g., the conjugative transfer of DNA into bacteria or the transfer of virulence proteins into eukaryotic host cells. The T4S apparatus VirB of the vascular tumor-inducing pathogen Bartonella henselae causes subversion of human endothelial cell (HEC) function. Here we report the identification of multiple protein substrates of VirB, which, upon translocation into HEC, mediate all known VirB-dependent cellular changes. These Bartonella-translocated effector proteins (Beps) A-G are encoded together with the VirB system and the T4S coupling protein VirD4 on a Bartonella-specific pathogenicity island. The Beps display a modular architecture, suggesting an evolution by extensive domain duplication and reshuffling. The C terminus of each Bep harbors at least one copy of the Bep-intracellular delivery domain and a short positively charged tail sequence. This biparte C terminus constitutes a transfer signal that is sufficient to mediate VirB/VirD4-dependent intracellular delivery of reporter protein fusions. The Bep-intracellular delivery domain is also present in conjugative relaxases of bacterial conjugation systems. We exemplarily show that the C terminus of such a conjugative relaxase mediates protein transfer through the Bartonella henselae VirB/VirD4 system into HEC. Conjugative relaxases may thus represent the evolutionary origin of the here defined T4S signal for protein transfer into human cells. PMID:15642951

  6. Chaos in periodically forced Holling type IV predator-prey system with impulsive perturbations

    International Nuclear Information System (INIS)

    The effect of periodic forcing and impulsive perturbations on predator-prey model with Holling type IV functional response is investigated. The periodic forcing is affected by assuming a periodic variation in the intrinsic growth rate of the prey. The impulsive perturbations are affected by introducing periodic constant impulsive immigration of predator. The dynamical behavior of the system is simulated and bifurcation diagrams are obtained for different parameters. The results show that periodic forcing and impulsive perturbation can easily give rise to complex dynamics, including (1) quasi-periodic oscillating, (2) period doubling cascade, (3) chaos, (4) period halfing cascade

  7. Type IV acromioclavicular joint dislocation associated with a mid-shaft clavicle malunion

    Directory of Open Access Journals (Sweden)

    Khalid D Mohammed

    2016-01-01

    Full Text Available This reports presents the case of a combined clavicle fracture malunion and chronic Type IV acromioclavicular (AC joint dislocation. The patient was seen acutely in the emergency department following a mountain bike accident at which time the clavicle fracture was identified and managed conservatively however the AC dislocation was not diagnosed. The patient presented 25 months following the injury with persistent pain and disability and was treated with clavicle osteotomy and AC stabilization. We document the clinical details, surgical treatment and outcome.

  8. Type IV acromioclavicular joint dislocation associated with a mid-shaft clavicle malunion.

    Science.gov (United States)

    Mohammed, Khalid D; Stachiw, Danielle; Malone, Alex A

    2016-01-01

    This reports presents the case of a combined clavicle fracture malunion and chronic Type IV acromioclavicular (AC) joint dislocation. The patient was seen acutely in the emergency department following a mountain bike accident at which time the clavicle fracture was identified and managed conservatively however the AC dislocation was not diagnosed. The patient presented 25 months following the injury with persistent pain and disability and was treated with clavicle osteotomy and AC stabilization. We document the clinical details, surgical treatment and outcome. PMID:26980988

  9. Surface detail reproduction of Type IV dental stones with selected polyvinyl siloxane impression materials.

    Science.gov (United States)

    Schelb, E; Cavazos, E; Troendle, K B; Prihoda, T J

    1991-01-01

    Four polyvinyl siloxane impression materials and 14 modified Type IV dental stones were evaluated for their abilities to reproduce surface detail. Each combination of impression material and dental stone was used to duplicate a 20-microns-wide line. Surface detail reproduction was observed by two paired-rater groups. The line was reproduced in all impression material specimens, but in only 32% of the stone cast specimens. Some combinations of impression material/dental stone reproduced the line all or most of the time, but 12 combinations did not reproduce the line at all.

  10. Structural characterization of outer membrane components of the type IV pili system in pathogenic Neisseria.

    Directory of Open Access Journals (Sweden)

    Samta Jain

    Full Text Available Structures of the type IV pili secretin complexes from Neisseria gonorrhoeae and Neisseria meningitidis, embedded in outer membranes were investigated by transmission electron microscopy. Single particle averaging revealed additional domains not observed previously. Secretin complexes of N. gonorrhoeae showed a double ring structure with a 14-15-fold symmetry in the central ring, and a 14-fold symmetry of the peripheral ring with 7 spikes protruding. In secretin complexes of N. meningitidis, the spikes were absent and the peripheral ring was partly or completely lacking. When present, it had a 19-fold symmetry. The structures of the complexes in several pil mutants were determined. Structures obtained from the pilC1/C2 adhesin and the pilW minor pilin deletion strains were similar to wild-type, whereas deletion of the homologue of N. meningitidis PilW resulted in the absence of secretin structures. Remarkably, the pilE pilin subunit and pilP lipoprotein deletion mutants showed a change in the symmetry of the peripheral ring from 14 to 19 and loss of spikes. The pilF ATPase mutant also lost the spikes, but maintained 14-fold symmetry. These results show that secretin complexes contain previously unidentified large and flexible extra domains with a probable role in stabilization or assembly of type IV pili.

  11. ROLE OF DPP-IV INHIBITORS IN TREATMENT OF TYPE II DIABETES

    Directory of Open Access Journals (Sweden)

    Patel Kishan D

    2010-12-01

    Full Text Available Emerging as an epidemic of the 21st century type II diabetes has become a major health problem throughout the globe. Known treatments of type II diabetes mellitus have limitations such as weight gain and hypoglycaemias. A new perspective is the use of incretin hormones and incretin enhancers. Incretin mimetics are a new class of pharmacological agents with multiple antihyperglycemic actions that mimic the actions of incretin hormones such as glucagon-like peptide (GLP-1. DPP-4, a protease that specifically cleaves dipeptides from proteins and oligopeptides after a penultimate N-terminal proline or alanine, is involved in the degradation of a number of neuropeptides, peptide hormones and cytokines, including the incretins GLP-1 and GIP. Based on preliminary clinical data, incretin mimetics and DPP-IV inhibitors show potential for treating type II diabetes.

  12. Atlas of fine structures of dynamic spectra of solar type IV-dm and some type II radio bursts

    International Nuclear Information System (INIS)

    The author presents an atlas of spectral fine structures of solar radio bursts of types IV and II around 1 m wavelength, as obtained with a multichannel spectrograph at Dwingeloo. The structures form largely a collection of observations of these events during late 1968 through 1974, thus covering almost entirely the declining branch of solar cycle 20. The spectrograph has an extra enhanced contrast output with properties quite different from those of the commonly used swept frequency spectrographs. The corresponding instrumental characteristics and effects are discussed. A classification of fine structures and an analysis of their statistical properties and of those of the pertinent radio events are also given. (Auth.)

  13. Commercial Application of the CTV-IV Type Catalyst for Synthesis of Vinyl Acetate Developed by Shanghai Petrochemical Research Instit

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The CTV-IV type catalyst for synthesis of vinyl acetate developed by the SINOPEC Shanghai Petrochemical Research Institute (SPRI) has been successfully applied on the #2 vinyl acetate unit at SINOPEC's Shanghai Petrochemical Company.

  14. Internal carotid artery dissection in a patient with Ehlers-Danlos syndrome type IV: diagnosis and management

    Directory of Open Access Journals (Sweden)

    Michel Nasser

    2013-06-01

    Full Text Available Ehlers-Danlos syndrome (EDS type IV, also known as vascular EDS, is an inherited connective tissue disorder with an estimated prevalence of 1/100,000 to 1/250,000. In EDS type IV, vascular complications may affect all anatomical areas, with a preference for large- and medium-sized arteries. Dissections of the vertebral and carotid arteries in their extra- and intra-cranial segments are typical. The authors report the case of a patient with EDS type IV for whom the diagnosis was established based on clinical signs and who developed internal carotid artery dissection at the age of 44 years. In the absence of a specific treatment for EDS type IV, medical interventions should focus on symptomatic relief, prophylactic measures, and genetic counseling. Invasive imaging techniques are contraindicated, and a conservative approach to vascular complications is usually recommended.

  15. Visualization of VirE2 protein translocation by the Agrobacterium type IV secretion system into host cells.

    Science.gov (United States)

    Sakalis, Philippe A; van Heusden, G Paul H; Hooykaas, Paul J J

    2014-02-01

    Type IV secretion systems (T4SS) can mediate the translocation of bacterial virulence proteins into host cells. The plant pathogen Agrobacterium tumefaciens uses a T4SS to deliver a VirD2-single stranded DNA complex as well as the virulence proteins VirD5, VirE2, VirE3, and VirF into host cells so that these become genetically transformed. Besides plant cells, yeast and fungi can efficiently be transformed by Agrobacterium. Translocation of virulence proteins by the T4SS has so far only been shown indirectly by genetic approaches. Here we report the direct visualization of VirE2 protein translocation by using bimolecular fluorescence complementation (BiFC) and Split GFP visualization strategies. To this end, we cocultivated Agrobacterium strains expressing VirE2 tagged with one part of a fluorescent protein with host cells expressing the complementary part, either fused to VirE2 (for BiFC) or not (Split GFP). Fluorescent filaments became visible in recipient cells 20-25 h after the start of the cocultivation indicative of VirE2 protein translocation. Evidence was obtained that filament formation was due to the association of VirE2 with the microtubuli. PMID:24376037

  16. Intercellular adhesion molecule 1 serves as a primary cognate receptor for the Type IV pilus of nontypeable Haemophilus influenzae.

    Science.gov (United States)

    Novotny, Laura A; Bakaletz, Lauren O

    2016-08-01

    Nontypeable Haemophilus influenzae (NTHI) utilizes the Type IV pilus (Tfp) to adhere to respiratory tract epithelial cells thus colonizing its human host; however, the host cell receptor to which this adhesive protein binds is unknown. From a panel of receptors engaged by Tfp expressed by other bacterial species, we showed that the majority subunit of NTHI Tfp, PilA, bound to intercellular adhesion molecule 1 (ICAM1) and that this interaction was both specific and of high affinity. Further, Tfp-expressing NTHI inoculated on to polarized respiratory tract epithelial cells that expressed ICAM1 were significantly more adherent compared to Tfp-deficient NTHI or NTHI inoculated on to epithelial cells to which ICAM1 gene expression was silenced. Moreover, pre-incubation of epithelial cells with recombinant soluble PilA (rsPilA) blocked adherence of NTHI, an outcome that was abrogated by admixing rsPilA with ICAM1 prior to application on to the target cells. Epithelial cells infected with adenovirus or respiratory syncytial virus showed increased expression of ICAM1; this outcome supported augmented adherence of Tfp-expressing NTHI. Collectively, these data revealed the cognate receptor for NTHI Tfp as ICAM1 and promote continued development of a Tfp-targeted vaccine for NTHI-induced diseases of the airway wherein upper respiratory tract viruses play a key predisposing role.

  17. Galactose recognition by a tetrameric C-type lectin, CEL-IV, containing the EPN carbohydrate recognition motif.

    Science.gov (United States)

    Hatakeyama, Tomomitsu; Kamiya, Takuro; Kusunoki, Masami; Nakamura-Tsuruta, Sachiko; Hirabayashi, Jun; Goda, Shuichiro; Unno, Hideaki

    2011-03-25

    CEL-IV is a C-type lectin isolated from a sea cucumber, Cucumaria echinata. This lectin is composed of four identical C-type carbohydrate-recognition domains (CRDs). X-ray crystallographic analysis of CEL-IV revealed that its tetrameric structure was stabilized by multiple interchain disulfide bonds among the subunits. Although CEL-IV has the EPN motif in its carbohydrate-binding sites, which is known to be characteristic of mannose binding C-type CRDs, it showed preferential binding of galactose and N-acetylgalactosamine. Structural analyses of CEL-IV-melibiose and CEL-IV-raffinose complexes revealed that their galactose residues were recognized in an inverted orientation compared with mannose binding C-type CRDs containing the EPN motif, by the aid of a stacking interaction with the side chain of Trp-79. Changes in the environment of Trp-79 induced by binding to galactose were detected by changes in the intrinsic fluorescence and UV absorption spectra of WT CEL-IV and its site-directed mutants. The binding specificity of CEL-IV toward complex oligosaccharides was analyzed by frontal affinity chromatography using various pyridylamino sugars, and the results indicate preferential binding to oligosaccharides containing Galβ1-3/4(Fucα1-3/4)GlcNAc structures. These findings suggest that the specificity for oligosaccharides may be largely affected by interactions with amino acid residues in the binding site other than those determining the monosaccharide specificity. PMID:21247895

  18. Decameter Stationary Type IV Burst in Imaging Observations on the 6th of September 2014

    CERN Document Server

    Koval, Artem; Chen, Yao; Feng, Shiwei; Konovalenko, Aleksander; Volvach, Yaroslav

    2016-01-01

    First-of-its-kind radio imaging of decameter solar stationary type IV radio burst has been presented in this paper. On 6 September 2014 the observations of type IV burst radio emission have been carried out with the two-dimensional heliograph based on the Ukrainian T-shaped radio telescope (UTR-2) together with other telescope arrays. Starting at 09:55 UT and throughout 3 hours, the radio emission was kept within the observational session of UTR-2. The interesting observation covered the full evolution of this burst, "from birth to death". During the event lifetime, two C-class solar X-ray flares with peak times 11:29 UT and 12:24 UT took place. The time profile of this burst in radio has a double-humped shape that can be explained by injection of energetic electrons, accelerated by the two flares, into the burst source. According to the heliographic observations we suggest the burst source was confined within a high coronal loop, which was a part of a relatively slow coronal mass ejection. The latter has bee...

  19. IMPROVEMENT OF TYPE IV CRACKING RESISTANCE OF 9Cr HEAT RESISTING STEEL WELDMENT BY BORON ADDITION

    Institute of Scientific and Technical Information of China (English)

    M.Tabuchi; M.Kondo; T.Watanabe; H.Hongo; F.Yin; F.Abe

    2004-01-01

    Creep lives of high Cr ferritic heat resisting steel weldments decrease due to Type IV fracture, which occurs as a result of formation and growth of creep voids and cracks on grain boundaries in fine-grained heat affected zone (HAZ). Because boron is considered to suppress the coarsening of grain boundary precipitates and growth of creep voids, we have investigated the effect of boron addition on the creep properties of 9Cr steel weldments. Four kinds of 9Cr3W3CoVNb steels with boron content varying from 4.7×10-5 to 1.8×10-4 and with nitrogen as low as 2.0×10-5 were prepared.The steel plates were welded by gas tungsten arc welding and crept at 923K. It was found that the microstructures of HAZ were quite different from those of conventional high Cr steels such as P91 and P92, namely the fine-grained HAZ did not exist in the present steel weldments. Boron addition also has the effect to suppress coarsening of grain boundary carbides in HAZ during creep. As a result of these phenomena,the welded joints of present steels showed no Type IV fractures and much better creep lives than those of conventional steels.

  20. Cloning of Bovine herpesvirus type 1 and type 5 as infectious bacterial artifical chromosomes

    Directory of Open Access Journals (Sweden)

    Ackermann Mathias

    2009-10-01

    Full Text Available Abstract Background Bovine herpesviruses type 1 (BoHV1 and type 5 (BoHV5 are two closely related pathogens of cattle. The identity of the two viruses on the amino acid level averages 82%. Despite their high antigenetic similarities the two pathogens induce distinctive clinical signs. BoHV1 causes respiratory and genital tract infections while BoHV5 leads to severe encephalitis in calves. Findings The viral genomes of BoHV1 and BoHV5 were cloned as infectious bacterial artificial chromosomes (BACs. First, recombinant viruses carrying the genetic elements for propagation in bacteria were generated. Second, DNA from these recombinant viruses were transferred into prokaryotic cells. Third, DNA from these bacteria were transferred into eukaryotic cells. Progeny viruses from BAC transfections showed similar kinetics as their corresponding wild types. Conclusion The two viral genomes of BoHV1 and BoHV5 cloned as BACs are accessible to the tools of bacterial genetics. The ability to easily manipulate the viral genomes on a molecular level in future experiments will lead to a better understanding of the difference in pathogenesis induced by these two closely related bovine herpesviruses.

  1. Molecular and structural analysis of Legionella DotI gives insights into an inner membrane complex essential for type IV secretion

    Science.gov (United States)

    Kuroda, Takuya; Kubori, Tomoko; Thanh Bui, Xuan; Hyakutake, Akihiro; Uchida, Yumiko; Imada, Katsumi; Nagai, Hiroki

    2015-01-01

    The human pathogen Legionella pneumophila delivers a large array of the effector proteins into host cells using the Dot/Icm type IVB secretion system. Among the proteins composing the Dot/Icm system, an inner membrane protein DotI is known to be crucial for the secretion function but its structure and role in type IV secretion had not been elucidated. We report here the crystal structures of the periplasmic domains of DotI and its ortholog in the conjugation system of plasmid R64, TraM. These structures reveal a striking similarity to VirB8, a component of type IVA secretion systems, suggesting that DotI/TraM is the type IVB counterpart of VirB8. We further show that DotI and its partial paralog DotJ form a stable heterocomplex. R64 TraM, encoded by the conjugative plasmid lacking DotJ ortholog, forms a homo-hexamer. The DotI-DotJ complex is distinct from the core complex, which spans both inner and outer membranes to form a substrate conduit, and seems not to stably associate with the core complex. These results give insight into VirB8-family inner membrane proteins essential for type IV secretion and aid towards understanding the molecular basis of secretion systems essential for bacterial pathogenesis. PMID:26039110

  2. Homozygous factor V Leiden mutation in type IV Ehlers-Danlos patient

    Science.gov (United States)

    Refaat, Marwan; Hotait, Mostafa; Winston, Brion

    2014-01-01

    Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders caused by collagen synthesis defects. Several hemostatic abnormalities have been described in EDS patients that increase the bleeding tendencies of these patients. This case report illustrates a patient with an unusual presentation of a patient with type IV EDS, platelet δ-storage pool disease and factor V Leiden mutation. Young woman having previous bilateral deep vein thrombosis and pulmonary emboli coexisting with ruptured splenic aneurysm and multiple other aneurysms now presented with myocardial infarction. Presence of factor V Leiden mutation raises the possibility that the infarct was due to acute coronary thrombosis, although coronary artery aneurysm and dissection with myocardial infarction is known to occur in vascular type EDS. This is the first report in the medical literature of factor V Leiden mutation in an EDS patient which made the management of our patient challenging with propensity to both bleeding and clotting. PMID:24653990

  3. Bright but slow - Type II supernovae from OGLE-IV - implications for magnitude-limited surveys

    Science.gov (United States)

    Poznanski, D.; Kostrzewa-Rutkowska, Z.; Wyrzykowski, L.; Blagorodnova, N.

    2015-05-01

    We study a sample of 11 Type II supernovae (SNe) discovered by the OGLE-IV survey. All objects have well-sampled I-band light curves, and at least one spectrum. We find that two or three of the 11 SNe have a declining light curve, and spectra consistent with other SNe II-L, while the rest have plateaus that can be as short as 70 d, unlike the 100 d typically found in nearby galaxies. The OGLE SNe are also brighter, and show that magnitude-limited surveys find SNe that are different than usually found in nearby galaxies. We discuss this sample in the context of understanding Type II SNe as a class and their suggested use as standard candles.

  4. Bright but slow - Type II supernovae from OGLE-IV & magnitude limited surveys

    CERN Document Server

    Poznanski, Dovi; Wyrzykowski, Lukasz; Blagorodnova, Nadejda

    2015-01-01

    We study a sample of 11 Type II supernovae (SNe) discovered by the OGLE-IV survey. All objects have well sampled I-band light curves, and at least one spectrum. We find that 3 or 4 of the 11 SNe have a declining light curve, making them SNe II-L, while the rest have plateaus that can be as short as 70d, unlike the 100d typically found in nearby galaxies. These SNe are also brighter than found in the local Universe, and show that magnitude limited surveys find SNe that are different than found in nearby galaxies. We discuss this sample in the context of understanding Type II SNe as a class and their suggested use as standard candles.

  5. Community-associated methicillin-resistant Staphylococcus aureus clonal complex 80 type IV (CC80-MRSA-IV isolated from the Middle East: a heterogeneous expanding clonal lineage.

    Directory of Open Access Journals (Sweden)

    Houda H Harastani

    Full Text Available The emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA has caused a change in MRSA epidemiology worldwide. In the Middle East, the persistent spread of CA-MRSA isolates that were associated with multilocus sequence type (MLST clonal complex 80 and with staphylococcal cassette chromosome mec (SCCmec type IV (CC80-MRSA-IV, calls for novel approaches for infection control that would limit its spread.In this study, the epidemiology of CC80-MRSA-IV was investigated in Jordan and Lebanon retrospectively covering the period from 2000 to 2011. Ninety-four S. aureus isolates, 63 (67% collected from Lebanon and 31 (33% collected from Jordan were included in this study. More than half of the isolates (56% were associated with skin and soft tissue infections (SSTIs, and 73 (78% were Panton-Valentine Leukocidin (PVL positive. Majority of the isolates (84% carried the gene for exofoliative toxin d (etd, 19% had the Toxic Shock Syndrome Toxin-1 gene (tst, and seven isolates from Jordan had a rare combination being positive for both tst and PVL genes. spa typing showed the prevalence of type t044 (85% and pulsed-field gel electrophoresis (PFGE recognized 21 different patterns. Antimicrobial susceptibility testing showed the prevalence (36% of a unique resistant profile, which included resistance to streptomycin, kanamycin, and fusidic acid (SKF profile.The genetic diversity among the CC80 isolates observed in this study poses an additional challenge to infection control of CA-MRSA epidemics. CA-MRSA related to ST80 in the Middle East was distinguished in this study from the ones described in other countries. Genetic diversity observed, which may be due to mutations and differences in the antibiotic regimens between countries may have led to the development of heterogeneous strains. Hence, it is difficult to maintain "the European CA-MRSA clone" as a uniform clone and it is better to designate as CC80-MRSA-IV isolates.

  6. Fine Structure of Metric Type-IV Radio Bursts Observed with the ARTEMIS-IV Radio Spectrograph: Association with Flares and Coronal Mass Ejections

    CERN Document Server

    Bouratzis, C; Alissandrakis, C E; Preka-Papadema, P; Moussas, X; Caroubalos, C; Tsitsipis, P; Kontogeorgos, A

    2014-01-01

    Fine structures embedded in type-IV burst continua may be used as diagnostics of the magnetic field restructuring and the corresponding energy release associated with the low corona development of flare/CME events. A catalog of 36 type-IV bursts observed with the SAO receiver of the ARTEMIS-IV solar radio-spectrograph in the 450--270 MHz range at high cadence (0.01 sec) was compiled; the fine structures were classified into five basic classes with two or more sub-classes each. The time of fine structure emission was compared with the injection of energetic electrons as evidenced by HXR and microwave emission, the SXR light-curves and the CME onset time. Our results indicate a very good temporal association between energy release episodes and pulsations, spikes, narrow-band bursts of the type-III family and zebra bursts. Of the remaining categories, the featureless broadband continuum starts near the time of the first energy release, between the CME onset and the SXR peak, but extends for several tens of minut...

  7. Identification of a Novel Conjugative Plasmid in Mycobacteria That Requires Both Type IV and Type VII Secretion

    KAUST Repository

    Ummels, R.

    2014-09-23

    Conjugative plasmids have been identified in a wide variety of different bacteria, ranging from proteobacteria to firmicutes, and conjugation is one of the most efficient routes for horizontal gene transfer. The most widespread mechanism of plasmid conjugation relies on different variants of the type IV secretion pathway. Here, we describe the identification of a novel type of conjugative plasmid that seems to be unique for mycobacteria. Interestingly, while this plasmid is efficiently exchanged between different species of slow-growing mycobacteria, including Mycobacterium tuberculosis, it could not be transferred to any of the fast-growing mycobacteria tested. Genetic analysis of the conjugative plasmid showed the presence of a locus containing homologues of three type IV secretion system components and a relaxase. In addition, a new type VII secretion locus was present. Using transposon insertion mutagenesis, we show that in fact both these secretion systems are essential for conjugation, indicating that this plasmid represents a new class of conjugative plasmids requiring two secretion machineries. This plasmid could form a useful new tool to exchange or introduce DNA in slow-growing mycobacteria. IMPORTANCE: Conjugative plasmids play an important role in horizontal gene transfer between different bacteria and, as such, in their adaptation and evolution. This effect is most obvious in the spread of antibiotic resistance genes. Thus far, conjugation of natural plasmids has been described only rarely for mycobacterial species. In fact, it is generally accepted that M. tuberculosis does not show any recent sign of horizontal gene transfer. In this study, we describe the identification of a new widespread conjugative plasmid that can also be efficiently transferred to M. tuberculosis. This plasmid therefore poses both a threat and an opportunity. The threat is that, through the acquisition of antibiotic resistance markers, this plasmid could start a rapid spread of

  8. Arthroscopically assisted treatment for Schatzker type I-V tibial plateau fractures

    Institute of Scientific and Technical Information of China (English)

    DUAN Xiao-jun; YANG Liu; GUO Lin; CHEN Guang-xing; DAI Gang

    2008-01-01

    Objective: To report the clinical outcome of arthroscopically assisted treatment for tibial plateau fractures.Methods: A total of 39 patients with tibial plateau fractures were treated by arthroscopic fixation from February 2002 to December 2005,including 11 patients with bony avulsion of the anterior cruciate ligament and 19 with meniscal injury.There were 4 cases of type I fracture,12 type II,9 type III,12 type IV and 2 type V according to Schatzker criteria.Firstly,the combined injuries were treated.Then the plateau fractures with the displacement over 3 mm or more were reduced and fixed.Finally,the internal fixation was observed by X-ray equipment.Postoperative management was early motion and delayed weight bearing.Results: All the fractures healed in 3 or 4 months.All patients were followed up for 1 to 5 years after operation.No case had severe complications,such as poor wound healing,infection,osteofascial compartment syndrome and osteoarthritis.According to the Rasmussen scoring system,36 cases obtained excellent or good results and the other 3 cases had moderate clinical results.The average score was 26 ± 3.Conclusions: As an adjuvant treatment of intraarticular fractures such as tibial plateau fracture,arthroscopy has many advantages.It can treat associated intraarticular soft tissue components,visualize the chondral surface reduction,lavage the hematoma and smaller loose fragments,decrease soft tissue dissection,reduce the risk of scarring and promote rapid recovery.

  9. Treatment of type 2 diabetes mellitus with agonists of the GLP-1 receptor or DPP-IV inhibitors

    DEFF Research Database (Denmark)

    Holst, Jens Juul

    2004-01-01

    in the treatment of Type 2 diabetes, causing marked improvements in glycaemic profile, insulin sensitivity and beta-cell performance, as well as weight reduction. The hormone is metabolised rapidly by the enzyme dipeptidyl peptidase IV (DPP-IV) and, therefore, cannot be easily used clinically. Instead, resistant...... with exendin have been carried out for > 6 months and have indicated efficacy in patients inadequately treated with oral antidiabetic agents. Orally active DPP-IV inhibitors, suitable for once-daily administration, have demonstrated similar efficacy. Diabetes therapy, based on GLP-1 receptor activation...

  10. Molecular characterization of collagen IV evidences early transcription expression related to the immune response against bacterial infection in the red abalone (Haliotis rufescens).

    Science.gov (United States)

    Chovar-Vera, Ornella; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2015-02-01

    Collagen IV has been described as a structural protein of the basement membrane, which as a whole forms a specialized extracellular matrix. Recent studies have indicated a possible relationship between collagen IV and the innate immune response of invertebrate organisms. The present study characterized the alpha-1 chain of collagen IV in the red abalone Haliotis rufescens (Hr-ColIV) and evaluated its association with the innate immune response against Vibrio anguillarum. To further evidence the immune response, the matrix metalloproteinase-1 (Hr-MMP-1) and C-type lectin (Hr-CLEC) genes were also assessed. The complete sequence of Hr-ColIV was composed of 6658 bp, with a 5'UTR of 154 bp, a 3'UTR of 1177 bp, and an ORF of 5327 bp that coded for 1776 amino acids. The innate immune response generated against V. anguillarum resulted in a significant increase in the transcript levels of Hr-ColIV between 3 and 6 hpi, whereas Hr-MMP-1 and Hr-CLEC had the highest transcript activity 6 and 12 hpi, respectively. The results obtained in this study propose a putative biological function for collagen IV involved in the early innate immune response of the red abalone H. rufescens. PMID:25463284

  11. Longevity of dental implants in type IV bone: a systematic review.

    Science.gov (United States)

    Goiato, M C; dos Santos, D M; Santiago, J F; Moreno, A; Pellizzer, E P

    2014-09-01

    Bone quality and quantity are important factors with regard to the survival rate of dental implants. The aim of this study was to conduct a systematic review of dental implants inserted in low-density bone and to determine the survival rate of dental implants with surface treatments over time. A systematic review of the literature was undertaken by two independent individuals; the Medline/PubMed database was searched for the period July 1975 to March 2013. Relevant reports on bone quality and osseointegration of dental implants were selected. The search retrieved 1018 references, and after inclusion and exclusion criteria were applied, 19 studies were selected for review. A total of 3937 patients, who had received a total of 12,465 dental implants, were analyzed. The survival rates of dental implants according to the bone density were: type I, 97.6%; type II, 96.2%; type III, 96.5%; and type IV, 88.8%. The survival rate of treated surface implants inserted in low-density bone was higher (97.1%) than that of machined surface implants (91.6%). Surface-treated dental implants inserted in low-density bone have a high survival rate and may be indicated for oral rehabilitation. However, more randomized studies are required to better evaluate this issue.

  12. A model to predict the permeation of type IV hydrogen tanks

    Energy Technology Data Exchange (ETDEWEB)

    Bayle, Julien; Perreux, Dominique; Chapelle, David; Thiebaud, Frederic [MaHyTec, Dole (France); Nardin, Philippe [Franche Comte Univ. (France)

    2010-07-01

    In the frame of the certification process of the type IV hydrogen storage tanks MaHyTec aims to manufacture, this innovative SME is developing a numerical model dedicated to the study of permeation issues. Such an approach aims at avoiding complicated, time-consuming and expensive testing. Experimental results obtained under real conditions can moreover be significantly influenced by the scattering of material properties and liner dimensions. From simple testing on small-size flat membranes, the model allows to predict the gas diffusion flow through the whole structure by means of numerous parameters. On every step, theory can be compared with the results obtained from the samples. This document presents a brief review of the mathematical theory describing gas diffusion and the different aspects of the study for better understanding the proposed approach. (orig.)

  13. Type IV FDP avulsion: lessons learned clinically and through review of the literature.

    Science.gov (United States)

    Henry, Steven L; Katz, Mark A; Green, David P

    2009-12-01

    The type IV flexor digitorum profundus avulsion is a rare injury involving fracture of the volar base of the distal phalanx and separation of the tendon from the fracture fragment. Recommendations for management are sparse and are substantiated only by a few isolated case reports. We recently encountered two of these injuries, both of which proved challenging, particularly with regard to joint incongruity and tendon adhesions. In reviewing the literature, it is apparent that no consensus exists regarding surgical strategies. However, based on our experience and that of other authors, we can suggest the following: (1) high index of suspicion of this potentially deceptive injury, with use of magnetic resonance imaging or ultrasound if preoperative confirmation is needed; (2) rigid bony fixation that prevents dorsal subluxation of the distal phalanx; (3) tendon repair that is independent of the bony fixation; and (4) early range of motion therapy. PMID:19399559

  14. Type IV hiatal hernia post laparoscopic Nissen fundoplication: report of a case.

    LENUS (Irish Health Repository)

    Awad, Z T

    2001-01-01

    A postoperative hiatal hernia is a rare but serious complication of fundoplication. We report herein a 62-year-old female who presented with abdominal pain and vomiting 2 years following laparoscopic Nissen fundoplication. At laparotomy, the stomach and the transverse colon were intrathoracic (type IV hiatal hernia); the esophageal hiatus was markedly dilated with no evidence that they had been approximated. At 18 months follow-up, she is doing very well apart from occasional heartburn. A high index of suspicion is needed to diagnose postoperative hiatal hernias. A routine closure of the crura with nonabsorbable suture material and an avoidance of iatrogenic pneumothorax may help to reduce the occurrence of this problem.

  15. Type IV secretion system in Helicobacter pylori: a new insight into pathogenicity

    Institute of Scientific and Technical Information of China (English)

    ZHONG Qiao; SHAO Shi-he; CUI Lei-lei; MU Run-hong; JU Xiao-li; DONG Su-rong

    2007-01-01

    Objective To review the research progress on Type IV secretion system (T4SS) in Helicobacter pylori.Data sources The data used in this review were identified by searching of PUBMED (1995-2007) online resources Study selection Mainly original articles and critical reviews written by major pioneer investigators of this field were selected.Results The research progress on T4SS in Helicobacter pylori was summarized.The structure and function was discussed.Conclusions T4SS is not only involved in toxin secretion and injection of virulence factors into eukaryotic host target cells,but also involved in horizontal DNA transfer to other bacteria and eukaryotic cells,through DNA uptake from or release into the extracellular milieu.It provides a new insight into the pathogenicity of Helicobacter pylori and a novel target for antimicrobials development.However,many challenges remain for us in understanding the biological role of T4SS in Helicobacter pylori.

  16. Type IV Creep Damage Behavior in Gr.91 Steel Welded Joints

    Science.gov (United States)

    Hongo, Hiromichi; Tabuchi, Masaaki; Watanabe, Takashi

    2012-04-01

    Modified 9Cr-1Mo steel (ASME Grade 91 steel) is used as a key structural material for boiler components in ultra-supercritical (USC) thermal power plants at approximately 873 K (600 °C). The creep strength of welded joints of this steel decreases as a result of Type IV creep cracking that forms in the heat-affected zone (HAZ) under long-term use at high temperatures. The current article aims to elucidate the damage processes and microstructural degradations that take place in the HAZ of these welded joints. Long-term creep tests for base metal, simulated HAZ, and welded joints were conducted at 823 K, 873 K, and 923 K (550 °C, 600 °C, and 650 °C). Furthermore, creep tests of thick welded joint specimens were interrupted at several time steps at 873 K (600 °C) and 90 MPa, after which the distribution and evolution of creep damage inside the plates were measured quantitatively. It was found that creep voids are initiated in the early stages (0.2 of life) of creep rupture life, which coalesce to form a crack at a later stage (0.8 of life). In a fine-grained HAZ, creep damage is concentrated chiefly in an area approximately 20 pct below the surface of the plate. The experimental creep damage distributions coincide closely with the computed results obtained by damage mechanics analysis using the creep properties of a simulated fine-grained HAZ. Both the concentration of creep strain and the high multiaxial stress conditions in the fine-grained HAZ influence the distribution of Type IV creep damage.

  17. Evaluation of the Various Drying Methods on Surface Hardness of Type IV Dental Stone

    Science.gov (United States)

    Sudhakar, A; Srivatsa, G; Shetty, Rohit; Rajeswari, C L; Manvi, Supriya

    2015-01-01

    Background: Studies regarding the effect of various methods to increase the surface hardness of Type IV dental stone are not conclusive. Therefore, this study was carried out to evaluate the effect of air drying, micro oven drying and die hardener on surface hardness of Type IV dental stone. Materials and Methods: A standard metal die was fabricated; polyvinyl siloxane impression material was used to make the molds of metal die. A total of 120 specimens were obtained from two different die stones and were grouped as Group A (kalrock) and Group B (pearl stone), and were subjected to air drying for 24 h, micro oven drying and application of die hardener. These models were then subjected to surface hardness testing using the knoop hardness instrument. The obtained data were subjected to statistical analysis. Results: The hardness of Group A specimens was 64 ± 0.54 Knoop hardness number (KHN) after application of die hardener, 60.47 ± 0.41 KHN after 24 h air drying, 58.2 ± 0.88 after microwave oven drying and 24.6 ± 0.4 after 1 h air drying. The hardness of Group B specimens was 45.59 ± 0.63 KHN after application of die hardener, 40.2 ± 0.63 KHN after 24 h air drying, 38.28 ± 0.55 KHN after microwave oven drying and 19.91 ± 0.64 KHN after 1 h air drying. Conclusion: Group A showed better results than Group B at all times. Application of the die hardener showed highest hardness values followed in the order by 24 h air drying, microwave oven drying and 1 h air drying in both groups. The study showed that air drying the dies for 24 h followed by application of a single layer of the die hardener produced the best surface hardness and is recommended to be followed in practice. PMID:26124610

  18. Role of 17 beta-estradiol on type IV collagen fibers volumetric density in the basement membrane of bladder wall.

    Science.gov (United States)

    de Fraga, Rogerio; Dambros, Miriam; Miyaoka, Ricardo; Riccetto, Cássio Luís Zanettini; Palma, Paulo César Rodrigues

    2007-10-01

    The authors quantified the type IV collagen fibers volumetric density in the basement membrane of bladder wall of ovariectomized rats with and without estradiol replacement. This study was conducted on 40 Wistar rats (3 months old) randomly divided in 4 groups: group 1, remained intact (control); group 2, submitted to bilateral oophorectomy and daily replacement 4 weeks later of 17 beta-estradiol for 12 weeks; group 3, sham operated and daily replacement 4 weeks later of sesame oil for 12 weeks; and group 4, submitted to bilateral oophorectomy and killed after 12 weeks. It was used in immunohistochemistry evaluation using type IV collagen polyclonal antibody to stain the fibers on paraffin rat bladder sections. The M-42 stereological grid system was used to analyze the fibers. Ovariectomy had an increase effect on the volumetric density of the type IV collagen fibers in the basement membrane of rat bladder wall. Estradiol replacement in castrated animals demonstrated a significative difference in the stereological parameters when compared to the castrated group without hormonal replacement. Surgical castration performed on rats induced an increasing volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall and the estradiol treatment had a significant effect in keeping a low volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall.

  19. Heterotrophic activity, bacterial types and abundance in different ecosystems of the Queen Maud Land

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Kodagali, J.; Nair, S.; Sheelu, G.; Chandramohan, D.

    Microbiological studies from the marine, limnetic, terrestrial and glacial ecosystems were carried out during the Ninth Indian Expedition (1989-90) to estimate the bacterial numbers, to characterise the generic types and also to estimate the uptake...

  20. Distinctive tomographic abnormalities of the craniocervical region in a patient with osteogenesis imperfecta type IV B

    Energy Technology Data Exchange (ETDEWEB)

    Kaissi, Ali Al; Klaushofer, Klaus, E-mail: ali.alkaissi@osteologie.a [Ludwig Boltzmann Institute of Osteology, Vienna (Austria); Grill, Franz [Orthopaedic Hospital of Speising, Vienna (Austria). Paediatric Dept.

    2010-07-01

    Osteogenesis imperfecta is a clinically and genetically heterogeneous group of heritable disorders of connective tissue characterized by reduced bone mass (osteopenia) with associated bone fragility. The resulting skeletal manifestations are due to a generalized deficiency in the development of both membranous and endochondral bone and include markedly thin calvarium with delayed closure of the fontanelles and the sutures and excessive Wormian bone formation. Sillence et al. developed a classification system of OI subtypes: OI type I, which is characterised by blue sclerae; perinatal lethal OI type II, also known as congenital OI; OI type III, a progressively deforming subtype with normal sclera; and OI type IV, which is characterized by a normal sclera. Levin et al. have suggested that OI subtypes could be further divided into type A and B based on the absence or presence of dentinogenesis imperfecta. Basilar impression involves the upward (vertical) migration of the odontoid process into the foramen magnum with a depression in the cranium. Basilar impression is a developmental defect and refers to the infolding of the occipital condyles, an elevation of the clivus, and the posterior cranial fossa of the skull. The soft bones of the skull base allow for progressive infolding of the dysplastic clivus and translocation of the odontoid into the posterior fossa. The combination of platybasia and basilar impression can lead to severe distortion of the spinal cord and the anterior brain stem. The specific structures that can be involved include the upper cervical cord, medulla, pons, mid-brain, cerebellum, as well as the vertebrobasilar system. (author)

  1. AN ASSESSMENT OF THE SERVICE HISTORY AND CORROSION SUSCEPTIBILITY OF TYPE IV WASTE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B

    2008-09-18

    Type IV waste tanks were designed and built to store waste that does not require auxiliary cooling. Each Type IV tank is a single-shell tank constructed of a steel-lined pre-stressed concrete tank in the form of a vertical cylinder with a concrete domed roof. There are four such tanks in F-area, Tanks 17-20F, and four in H-Area, Tanks 21-24H. Leak sites were discovered in the liners for Tanks 19 and 20F in the 1980's. Although these leaks were visually observed, the investigation to determine the mechanism by which the leaks had occurred was not completed at that time. Therefore, a concern was raised that the same mechanism which caused the leak sites in the Tanks in F-area may also be operable in the H-Area tanks. Data from the construction of the tanks (i.e., certified mill test reports for the steel, no stress-relief), the service history (i.e., waste sample data, temperature data), laboratory tests on actual wastes and simulants (i.e., electrochemical testing), and the results of the visual inspections were reviewed. The following observations and conclusions were made: (1) Comparison of the compositional and microstructural features indicate that the A212 material utilized for construction of the H-Area tanks are far more resistant to SCC than the A285 materials used for construction of the F-Area tanks. (2) A review of the materials of construction, temperature history, service histories concluded that F-Area tanks likely failed by caustic stress corrosion cracking. (3) The environment in the F-Area tanks was more aggressive than that experienced by the H-Area tanks. (4) Based on a review of the service history, the H-Area tanks have not been exposed to an environment that would render the tanks susceptible to either nitrate stress corrosion cracking (i.e., the cause of failures in the Type I and II tanks) or caustic stress corrosion cracking. (5) Due to the very dilute and uninhibited solutions that have been stored in Tank 23H, vapor space corrosion

  2. c-Type cytochrome-dependent formation of U(IV nanoparticles by Shewanella oneidensis.

    Directory of Open Access Journals (Sweden)

    Matthew J Marshall

    2006-09-01

    Full Text Available Modern approaches for bioremediation of radionuclide contaminated environments are based on the ability of microorganisms to effectively catalyze changes in the oxidation states of metals that in turn influence their solubility. Although microbial metal reduction has been identified as an effective means for immobilizing highly-soluble uranium(VI complexes in situ, the biomolecular mechanisms of U(VI reduction are not well understood. Here, we show that c-type cytochromes of a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, are essential for the reduction of U(VI and formation of extracellular UO(2 nanoparticles. In particular, the outer membrane (OM decaheme cytochrome MtrC (metal reduction, previously implicated in Mn(IV and Fe(III reduction, directly transferred electrons to U(VI. Additionally, deletions of mtrC and/or omcA significantly affected the in vivo U(VI reduction rate relative to wild-type MR-1. Similar to the wild-type, the mutants accumulated UO(2 nanoparticles extracellularly to high densities in association with an extracellular polymeric substance (EPS. In wild-type cells, this UO(2-EPS matrix exhibited glycocalyx-like properties and contained multiple elements of the OM, polysaccharide, and heme-containing proteins. Using a novel combination of methods including synchrotron-based X-ray fluorescence microscopy and high-resolution immune-electron microscopy, we demonstrate a close association of the extracellular UO(2 nanoparticles with MtrC and OmcA (outer membrane cytochrome. This is the first study to our knowledge to directly localize the OM-associated cytochromes with EPS, which contains biogenic UO(2 nanoparticles. In the environment, such association of UO(2 nanoparticles with biopolymers may exert a strong influence on subsequent behavior including susceptibility to oxidation by O(2 or transport in soils and sediments.

  3. Phorbol esters enhance attachment of NIH/3T3 cells to laminin and type IV collagen substrates

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Shigemi; Ben, T.L.; De Luca, L.M. (National Institutes of Health, Bethesda, MD (USA))

    1988-11-01

    The effect of phorbol esters on the adhesive properties of NIH/3T3 mouse fibroblasts was investigated using plastic substrates precoated with the extracellular matrix proteins fibronectin, collagen, and laminin. Treatment with phorbol 12-myristate 13-acetate (PMA) enhanced NIH/3T3 cell attachment to laminin and type IV collagen substrates but had little or no effect on attachment to fibronectin and type I collagen substrates. The effect of PMA in enhancing cell attachment to laminin and type IV collagen substrates was dose dependent between 10{sup {minus}9} and 10{sup {minus}7} M. PMA was effective as early as 30 min; the effect reached a maximum at 2 h and decreased gradually. Phorbol 12, 13-dibenzoate and phorbol 12, 13-diacetate were effective but to a lesser extent and phorbol 12-myristate and phorbol 13-acetate showed little or no effect. These results suggest that PMA may enhance NIH/3T3 cell adhesion through effects on laminin and type IV collagen receptors. Retinoic acid, which itself requires at least 6 h to show an effect on attachment, did not have any effect on cell attachment in 2 h and, if anything, slightly inhibited PMA-enhanced cell attachment to laminin and type IV collagen substrates.

  4. Type IV pili in Francisella – A virulence trait in an intracellular pathogen

    Directory of Open Access Journals (Sweden)

    Emelie eNäslund Salomonsson

    2011-02-01

    Full Text Available Francisella tularensis is a highly virulent intracellular human pathogen that is capable of rapid proliferation in the infected host. Mutants affected in intracellular survival and growth are highly attenuated which highlights the importance of the intracellular phase of the infection. Genomic analysis has revealed that Francisella encodes all genes required for expression of functional type IV pili (Tfp, and in this focused review we summarise recent findings regarding this system in the pathogenesis of tularemia. Tfp are dynamic adhesive structures that have been identified as major virulence determinants in several human pathogens, but it is not obvious what role these structures could have in an intracellular pathogen like Francisella. In the human pathogenic strains, genes required for secretion and assembly of Tfp and one pilin, PilA, have shown to be required for full virulence. Importantly, specific genetic differences have been identified between the different Francisella subspecies where in the most pathogenic type A variants all genes are intact while several Tfp genes are pseudogenes in the less pathogenic type B strains. This suggests that there has been a selection for expression of Tfp with different properties in the different subspecies. There is also a possibility that the genetic differences reflect adaption to different environmental niches of the subspecies and plays a role in transmission of tularemia. This is also in line with recent findings where Tfp pilins are found to be glycosylated which could reflect a role for Tfp in the environment to promote survival and transmission. We are still far from understanding the role of Tfp in virulence and transmission of tularemia, but with the genomic information and genetic tools available we are in a good position to address these issues in the future.

  5. Bacterial Flora Changes in Conjunctiva of Rats with Streptozotocin-Induced Type I Diabetes.

    Directory of Open Access Journals (Sweden)

    Chao Yang

    Full Text Available The microbiota of both humans and animals plays an important role in their health and the development of disease. Therefore, the bacterial flora of the conjunctiva may also be associated with some diseases. However, there are no reports on the alteration of bacterial flora in conjunctiva of diabetic rats in the literature. Therefore, we investigated the changes in bacterial flora in bulbar conjunctiva of rats with streptozotocin (STZ-induced type I diabetes.A high dose of STZ (60 mg/kg, i.p. was injected into Sprague-Dawley (SD rats to induce type I diabetes mellitus (T1DM. The diabetic rats were raised in the animal laboratory and at 8 months post-injection of STZ swab samples were taken from the bulbar conjunctiva for cultivation of aerobic bacteria. The bacterial isolates were identified by Gram staining and biochemical features. The identified bacteria from both diabetic and healthy rats were then compared.The diabetic and healthy rats had different bacterial flora present in their bulbar conjunctiva. In total, 10 and 8 bacterial species were found in the STZ and control groups, respectively, with only three species (Enterococcus faecium, Enterococcus gallinarum and Escherichia coli shared between the two groups. Gram-positive bacteria were common in both groups and the most abundant was Enterococcus faecium. However, after the development of T1DM, the bacterial flora in the rat bulbar conjunctiva changed considerably, with a reduced complexity evident.STZ-induced diabetes caused alterations of bacterial flora in the bulbar conjunctiva in rats, with some bacterial species disappearing and others emerging. Our results indicate that the conjunctival bacterial flora in diabetic humans should be surveyed for potential diagnostic markers or countermeasures to prevent eye infections in T1DM patients.

  6. Preparation and characterization of resistant starch type IV nanoparticles through ultrasonication and miniemulsion cross-linking.

    Science.gov (United States)

    Ding, Yongbo; Zheng, Jiong; Xia, Xuejuan; Ren, Tingyuan; Kan, Jianquan

    2016-05-01

    This study aimed to assess the properties of resistant starch type IV (chemically modified starch, RS4) prepared from a new and convenient synthesis route by using ultrasonication combined with water-in-oil miniemulsion cross-linking technique. A three-factor Box-Behnken design and optimization was used to minimize particle size through the developed RS4 nanoparticles. The predicted minimized Z-Avel (576.1nm) under the optimum conditions of the process variables (ultrasonic power, 214.57W; sonication time, 114.73min; and oil/water ratio, 10.54:1) was very close to the experimental value (651.0nm) determined in a batch experiment. After preparing the RS4 nanoparticles, morphological, physical, chemical, and functional properties were assessed. Results revealed that RS4 nanoparticle size reached about 600nm. Scanning electron microscopy images showed that ultrasonication induced notches and grooves on the surface. Under polarized light, the polarized cross was impaired. X-ray diffraction results revealed that the crystalline structure was disrupted. Smaller or no endotherms were exhibited in DSC analysis. In the FTIR graph, new peaks at 1532.91 and 1451.50cm(-1) were observed, and pasting properties were reduced. Amylose content, solubility, and SP increased, but RS content decreased. Anti-digestibility remained after ultrasonication. The prepared RS4 nanoparticles could be extensively used in biomedical applications and in the development of new medical materials. PMID:26877007

  7. Proximal spinal muscular atrophy types I-IV: Specific features of molecular genetic diagnosis

    Directory of Open Access Journals (Sweden)

    V. V. Zabnenkova

    2013-01-01

    Full Text Available Proximal spinal muscular atrophy (SMA types I-IV is the most common autosomal recessive neuromuscular disease caused by mutations in the SMN1 gene encoding the survival motor neuron protein. It is characterized by progressive muscle weakness due to injury of the motor neurons of the anterior horns of the spinal cord. The classification of the disease is based on the time of its onset, severity, and survival. The detection of the major mutation of exon 7 and/or 8 deletion in the SMN1 gene is a qualitative reliable and sensitive diagnostic test. The SMN1 gene has the almost complete homolog SMN2 gene, which hampers the analysis of heterozygous carriage of the disease. So the determination of the carriage status is based on the quantitative analysis of the number of SMN1 gene copies. The paper covers problems and new possibilities in themolecular genetic diagnosis of proximal SMA.

  8. N. elongata produces type IV pili that mediate interspecies gene transfer with N. gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Dustin L Higashi

    Full Text Available The genus Neisseria contains at least eight commensal and two pathogenic species. According to the Neisseria phylogenetic tree, commensals are basal to the pathogens. N. elongata, which is at the opposite end of the tree from N. gonorrhoeae, has been observed to be fimbriated, and these fimbriae are correlated with genetic competence in this organism. We tested the hypothesis that the fimbriae of N. elongata are Type IV pili (Tfp, and that Tfp functions in genetic competence. We provide evidence that the N. elongata fimbriae are indeed Tfp. Tfp, as well as the DNA Uptake Sequence (DUS, greatly enhance N. elongata DNA transformation. Tfp allows N. elongata to make intimate contact with N. gonorrhoeae and to mediate the transfer of antibiotic resistance markers between these two species. We conclude that Tfp functional for genetic competence is a trait of a commensal member of the Neisseria genus. Our findings provide a mechanism for the horizontal gene transfer that has been observed among Neisseria species.

  9. N. elongata produces type IV pili that mediate interspecies gene transfer with N. gonorrhoeae.

    Science.gov (United States)

    Higashi, Dustin L; Biais, Nicolas; Weyand, Nathan J; Agellon, Al; Sisko, Jennifer L; Brown, Lewis M; So, Magdalene

    2011-01-01

    The genus Neisseria contains at least eight commensal and two pathogenic species. According to the Neisseria phylogenetic tree, commensals are basal to the pathogens. N. elongata, which is at the opposite end of the tree from N. gonorrhoeae, has been observed to be fimbriated, and these fimbriae are correlated with genetic competence in this organism. We tested the hypothesis that the fimbriae of N. elongata are Type IV pili (Tfp), and that Tfp functions in genetic competence. We provide evidence that the N. elongata fimbriae are indeed Tfp. Tfp, as well as the DNA Uptake Sequence (DUS), greatly enhance N. elongata DNA transformation. Tfp allows N. elongata to make intimate contact with N. gonorrhoeae and to mediate the transfer of antibiotic resistance markers between these two species. We conclude that Tfp functional for genetic competence is a trait of a commensal member of the Neisseria genus. Our findings provide a mechanism for the horizontal gene transfer that has been observed among Neisseria species. PMID:21731720

  10. Pseudoaneurysm Accompanied by Crowe Type IV Developmental Dysplasia of the Hip: A Case Report

    Directory of Open Access Journals (Sweden)

    Hirotake Yo

    2012-01-01

    Full Text Available We report the case of a 72-year-old woman whose pseudoaneurysm was difficult to diagnose and treat. The patient had a history of congenital dislocated hip and was undergoing anticoagulation therapy with warfarin due to the mitral valve replacement. Her chief complaint was pain and enlargement of the left buttock, and the laboratory tests revealed severe anemia. However, her elderly depression confused her chief complaint, and she was transferred to a psychiatric hospital. Two months after the onset of the symptoms, she was finally diagnosed with a pseudoaneurysm by contrast-enhanced CT and angiography. IDC coils were used for embolization. A plain CT showed hemostasis as well as a reduced hematoma at 2 months after the embolization. The possible contributing factors for the pseudoaneurysm included bleeding due to warfarin combined with an intramuscular hematoma accompanied by Crowe type IV developmental dysplasia of the hip that led to an arterial rupture by impingement between pelvis and femoral head. Since the warfarin treatment could not be halted due to the valve replacement, embolization was chosen for her treatment, and the treatment outcome was favorable.

  11. Energy–momentum localization for Bianchi type-IV Universe in general relativity and teleparallel gravity

    Indian Academy of Sciences (India)

    Sezgin Aygün; İsmail Tarhan

    2012-04-01

    In this study we have investigated the energy–momentum distributions for homogeneous and anisotropic Bianchi type-IV in B class Universe. For this purpose, we have used energy–momentum complexes of Einstein, Bergmann–Thomson, Landau–Lifshitz (LL), Papapetrou, Tolman and Møller in general relativity (GR) as also Einstein, Bergmann–Thomson, Landau–Lifshitz and Møller in teleparallel gravity (TG). From the obtained results we have found that Einstein and Bergmann–Thomson distributions are exactly giving the same results in GR and TG but the Landau–Lifshitz, Papapetrou Tolman and Møller energy–momentum distributions do not provide the same results with Einstein and Bergmann–Thomson in GR and TG. Furthermore, Einstein, Bergmann–Thomson and LL results are the same in different gravitation theories and we get that both GR and TG are equivalent theories for these prescriptions. From the obtained solutions, we could say that these are equivalent theories. Also, Møller energy–momentum distributions do not give the same results in GR and TG. However, we have found that all energy prescriptions are negative and our results agree with Nester et al.

  12. Type IV Collagens and Basement Membrane Diseases: Cell Biology and Pathogenic Mechanisms.

    Science.gov (United States)

    Mao, Mao; Alavi, Marcel V; Labelle-Dumais, Cassandre; Gould, Douglas B

    2015-01-01

    Basement membranes are highly specialized extracellular matrices. Once considered inert scaffolds, basement membranes are now viewed as dynamic and versatile environments that modulate cellular behaviors to regulate tissue development, function, and repair. Increasing evidence suggests that, in addition to providing structural support to neighboring cells, basement membranes serve as reservoirs of growth factors that direct and fine-tune cellular functions. Type IV collagens are a major component of all basement membranes. They evolved along with the earliest multicellular organisms and have been integrated into diverse fundamental biological processes as time and evolution shaped the animal kingdom. The roles of basement membranes in humans are as complex and diverse as their distributions and molecular composition. As a result, basement membrane defects result in multisystem disorders with ambiguous and overlapping boundaries that likely reflect the simultaneous interplay and integration of multiple cellular pathways and processes. Consequently, there will be no single treatment for basement membrane disorders, and therapies are likely to be as varied as the phenotypes. Understanding tissue-specific pathology and the underlying molecular mechanism is the present challenge; personalized medicine will rely upon understanding how a given mutation impacts diverse cellular functions.

  13. Late onset pityriasis rubra pilaris type IV treated with low-dose acitretin.

    Science.gov (United States)

    Mota, Fernando; Carvalho, Sandrina; Sanches, Madalena; Selores, Manuela

    2016-01-01

    Pityriasis rubra pilaris is a chronic inflammatory dermatosis of unknown etiology and great clinical variability. It has been divided into six categories. Types III, IV, and V occur in childhood and are distinguished by their clinical presentation, age of onset, and course. We report a 19-year-old male patient with a 2-week history of pruritic, scaling dermatosis of the hands, feet, elbows, and knees. He had no family history of skin disease. On physical examination, we observed circumscribed, reddish-orange, scaling plaques affecting the elbows and knees and a waxy palmoplantar keratoderma. The skin biopsy showed acanthosis, alternating orthokeratosis, parakeratosis, and follicular plugging suggestive of pityriasis rubra pilaris. The patient started treatment with oral acitretin, 25 mg every other day. The treatment was tolerated well, and after 6 months the lesions had resolved completely. Pityriasis rubra pilaris is a chronic papulosquamous disorder of unknown pathogenesis, characterized by reddish-orange scaly plaques, palmoplantar keratoderma, and keratotic follicular papules. There is still no consensus regarding the treatment, but therapeutic options include systemic retinoids, particularly acitretin in the recommended dose of 0.5 to 0.75 mg/kg/day. In our case, the patient was treated with a low-dose regimen of acitretin, which was effective and well tolerated. PMID:27014774

  14. Frequency Dependence of Polarization of Zebra Pattern in Type-IV Solar Radio Bursts

    CERN Document Server

    Kaneda, Kazutaka; Iwai, Kazumasa; Tsuchiya, Fuminori; Obara, Takahiro

    2015-01-01

    We investigated the polarization characteristics of a zebra pattern (ZP) in a type-IV solar radio burst observed with AMATERAS on 2011 June 21 for the purpose of evaluating the generation processes of ZP. Analyzing highly resolved spectral and polarization data revealed the frequency dependence of the degree of circular polarization and the delay between two polarized components for the first time. The degree of circular polarization was 50-70 percent right-handed and it varied little as a function of frequency. Cross-correlation analysis determined that the left-handed circularly polarized component was delayed by 50-70 ms relative to the right-handed component over the entire frequency range of the ZP and this delay increased with the frequency. We examined the obtained polarization characteristics by using pre-existing ZP models and concluded that the ZP was generated by the double plasma resonance process. Our results suggest that the ZP emission was originally generated in a completely polarized state in...

  15. FREQUENCY DEPENDENCE OF POLARIZATION OF ZEBRA PATTERN IN TYPE-IV SOLAR RADIO BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Kaneda, Kazutaka; Misawa, H.; Tsuchiya, F.; Obara, T. [Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Iwai, K., E-mail: k.kaneda@pparc.gp.tohoku.ac.jp [National Institute of Information and Communications Technology, 4-2-1, Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan)

    2015-08-01

    We investigated the polarization characteristics of a zebra pattern (ZP) in a type-IV solar radio burst observed with AMATERAS on 2011 June 21 for the purpose of evaluating the generation processes of ZPs. Analyzing highly resolved spectral and polarization data revealed the frequency dependence of the degree of circular polarization and the delay between two polarized components for the first time. The degree of circular polarization was 50%–70% right-handed and it varied little as a function of frequency. Cross-correlation analysis determined that the left-handed circularly polarized component was delayed by 50–70 ms relative to the right-handed component over the entire frequency range of the ZP and this delay increased with the frequency. We examined the obtained polarization characteristics by using pre-existing ZP models and concluded that the ZP was generated by the double-plasma-resonance process. Our results suggest that the ZP emission was originally generated in a completely polarized state in the O-mode and was partly converted into the X-mode near the source. Subsequently, the difference between the group velocities of the O-mode and X-mode caused the temporal delay.

  16. Plasma dipeptidyl peptidase-IV activity in patients with type-2 diabetes mellitus correlates positively with HbAlc levels, but is not acutely affected by food intake

    DEFF Research Database (Denmark)

    Ryskjaer, Jakob; Deacon, Carolyn F.; Carr, Richard D;

    2006-01-01

    hormones are metabolized quickly by the enzyme dipeptidyl peptidase-IV (DPP-IV). It is well known that type-2 diabetic patients have an impaired incretin effect. Therefore, the aim of the present study was to investigate plasma DPP-IV activity in the fasting and the postprandial state in type-2 diabetic...... patients, DPP-IV activity was positively correlated to FPG and HbAlc and negatively to the duration of diabetes and age of the patients. No postprandial changes were seen in plasma DPP-IV activity in any of the groups. CONCLUSIONS: Plasma DPP-IVactivity increases in the fasting state and is positively...

  17. Cicaprost and the type IV phosphodiesterase inhibitor, rolipram, synergize in suppression of tumor necrosis factor-alpha synthesis

    NARCIS (Netherlands)

    Greten, T F; Sinha, B; Haslberger, C; Eigler, A; Endres, S

    1996-01-01

    Suppression of tumor necrosis factor-alpha (TNF) synthesis is one major target in pharmacological immunomodulation. We now showed the synergistic suppressive effect of the specific type IV phosphodiesterase inhibitor, rolipram, and of the stable prostacyclin analogue, cicaprost, on TNF synthesis. Th

  18. Traveling Wave Solution in a Diffusive Predator-Prey System with Holling Type-IV Functional Response

    OpenAIRE

    Deniu Yang; Lihan Liu; Hongyong Wang

    2014-01-01

    We establish the existence of traveling wave solution for a reaction-diffusion predator-prey system with Holling type-IV functional response. For simplicity, only one space dimension will be involved, the traveling solution equivalent to the heteroclinic orbits in ${R}^{\\mathrm{3}}$ . The methods used to prove the result are the shooting argument and the invariant manifold theory.

  19. Characterization and transcriptional analysis of two gene clusters for type IV secretion machinery in Wolbachia of Armadillidium vulgare

    DEFF Research Database (Denmark)

    Félix, Christine; Pichon, Samuel; Braquart-Varnier, Christine;

    2008-01-01

    Wolbachia are maternally inherited alpha-proteobacteria that induce feminization of genetic males in most terrestrial crustacean isopods. Two clusters of vir genes for a type IV secretion machinery have been identified at two separate loci and characterized for the first time in a feminizing Wolb...

  20. A novel relaxase homologue is involved in chromosomal DNA processing for type IV secretion in Neisseria gonorrhoeae

    NARCIS (Netherlands)

    Salgado-Pabon, Wilmara; Jain, Samta; Turner, Nicholas; van der Does, Chris; Dillard, Joseph P.

    2007-01-01

    The Neisseria gonorrhoeae type IV secretion system secretes chromosomal DNA that acts in natural transformation. To examine the mechanism of DNA processing for secretion, we made mutations in the putative relaxase gene traI and used nucleases to characterize the secreted DNA. The nuclease experiment

  1. Processing and Maturation of the Pilin of the Type IV Secretion System Encoded within the Gonococcal Genetic Island

    NARCIS (Netherlands)

    Jain, Samta; Kahnt, Joerg; van der Does, Chris

    2011-01-01

    The type IV secretion system (T4SS) encoded within the gonococcal genetic island (GGI) of Neisseria gonorrhoeae has homology to the T4SS encoded on the F plasmid. The GGI encodes the putative pilin protein TraA and a serine protease TrbI, which is homologous to the TraF protein of the RP4 plasmid in

  2. Influences of plant type on bacterial and archaeal communities in constructed wetland treating polluted river water.

    Science.gov (United States)

    Long, Yan; Yi, Hao; Chen, Sili; Zhang, Zhengke; Cui, Kai; Bing, Yongxin; Zhuo, Qiongfang; Li, Bingxin; Xie, Shuguang; Guo, Qingwei

    2016-10-01

    Both bacteria and archaeal communities can play important roles in biogeochemical processes in constructed wetland (CW) system. However, the influence of plant type on microbial community in surface water CW remains unclear. The present study investigated bacterial and archaeal communities in five surface water CW systems with different plant species. The abundance, richness, and diversity of both bacterial and archaeal communities considerably differed in these five CW systems. Compared with the other three CW systems, the CW systems planted with Vetiveria zizanioides or Juncus effusus L. showed much higher bacterial abundance but lower archaeal abundance. Bacteria outnumbered archaea in each CW system. Moreover, the CW systems planted with V. zizanioides or J. effusus L. had relatively lower archaeal but higher bacterial richness and diversity. In each CW system, bacterial community displayed much higher richness and diversity than archaeal community. In addition, a remarkable difference of both bacterial and archaeal community structures was observed in the five studied CW systems. Proteobacteria was the most abundant bacterial group (accounting for 33-60 %). Thaumarchaeota organisms (57 %) predominated in archaeal communities in CW systems planted with V. zizanioides or J. effusus L., while Woesearchaeota (23 or 24 %) and Euryarchaeota (23 or 15 %) were the major archaeal groups in CW systems planted with Cyperus papyrus or Canna indica L. Archaeal community in CW planted with Typha orientalis Presl was mainly composed of unclassified archaea. Therefore, plant type exerted a considerable influence on microbial community in surface water CW system. PMID:27392623

  3. [Reactivity of antibodies to collagen types I to IV and antibodies to chondroitin sulfate in the spleen].

    Science.gov (United States)

    Galbavý, S; Ruzicková, M; Surmíková, E; Danihel, L; Porubský, J; Papincák, J; Holesa, S; Trnka, J

    1996-02-01

    Antibodies to collagen type I and III reacted negatively, antibodies to collagen type IV positively with reticulin, trabeculae and circumferent reticulum of lymphatic sheaths, poorly positively with capsula, strongly positively with subcapsular zone. Antibodies to collagen type II reacted positively with capsula, poorly with subcapsular zone, strongly with sinus wall and poorly with trabeculae. They did not react with circumferent reticulum of periarterial lymphoid sheaths. Antibodies to collagen type II and IV reacted positively with central arteries. Antibodies to chondroitinsulphate C reacted poorly and antibodies to chondroitinsulphate B strongly positively with sinus walls and oval cells spread in the white and red pulpa. Antibodies to chondroitin sulphate A reacted similarly as antibodies to chondroitinsulphate B. PMID:9560890

  4. Clay mineral type effect on bacterial enteropathogen survival in soil.

    Science.gov (United States)

    Brennan, Fiona P; Moynihan, Emma; Griffiths, Bryan S; Hillier, Stephen; Owen, Jason; Pendlowski, Helen; Avery, Lisa M

    2014-01-15

    Enteropathogens released into the environment can represent a serious risk to public health. Soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. However, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. This work investigated the effect of clay materials, with a predominance of a particular mineral type (montmorillonite, kaolinite, or illite), on the survival in soil microcosms over 96 days of Listeria monocytogenes, Salmonella Dublin, and Escherichia coli O157. Clay mineral addition was found to alter a number of physicochemical parameters in soil, including cation exchange capacity and surface area, and this was specific to the mineral type. Clay mineral addition enhanced enteropathogen survival in soil. The type of clay mineral was found to differentially affect enteropathogen survival and the effect was enteropathogen-specific.

  5. Streptocollin, a type IV lanthipeptide produced by Streptomyces collinus Tü 365

    DEFF Research Database (Denmark)

    Iftime, Dumitrita; Jasyk, Martin; Kulik, Andreas;

    2015-01-01

    Lanthipeptides are ribosomally synthesized and posttranslationally modified microbial secondary metabolites. Here, we report the identification and isolation of streptocollin from Streptomyces collinus Tü 365, a new member of the class IV lanthipeptides. Insertion of the constitutive ermE* promoter...

  6. Colonoscopic perforation leading to a diagnosis of Ehlers Danlos syndrome type IV: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Wolfe John

    2011-06-01

    Full Text Available Abstract Introduction Colonoscopic perforation is a rare but serious complication of colonoscopy. Factors known to increase the risk of perforation include colonic strictures, extensive diverticulosis, and friable tissues. We describe the case of a man who was found to have perforation of the sigmoid colon secondary to an undiagnosed connective tissue disorder (Ehlers-Danlos syndrome type IV while undergoing surveillance for hereditary non-polyposis colorectal cancer. Case presentation A 33-year-old Caucasian man presented to our hospital with an acute abdomen following a colonoscopy five days earlier as part of hereditary non-polyposis colorectal cancer screening. His medical history included bilateral clubfoot. His physical examination findings suggested left iliac fossa peritonitis. A computed tomographic scan revealed perforation of the sigmoid colon and incidentally a right common iliac artery aneurysm as well. Hartmann's procedure was performed during laparotomy. The patient recovered well post-operatively and was discharged. Reversal of the Hartmann's procedure was performed six months later. This procedure was challenging because of dense adhesions and friable bowel. The histology of bowel specimens from this surgery revealed thinning and fibrosis of the muscularis externa. The patient was subsequently noted to have transparency of truncal skin with easily visible vessels. An underlying collagen vascular disorder was suspected, and genetic testing revealed a mutation in the collagen type III, α1 (COL3A1 gene, which is consistent with a diagnosis of Ehlers-Danlos syndrome type IV. Conclusions Ehlers-Danlos syndrome type IV, the vascular type, is a rare disorder caused by mutations in the COL3A1 gene on chromosome 2q31. It is characterized by translucent skin, clubfoot, and the potentially fatal complications of spontaneous large vessel rupture, although spontaneous uterine and colonic perforations have also been reported in the

  7. Chromosomal assignments of the genes coding for human types II, III, and IV collagen: a dispersed gene family.

    OpenAIRE

    Solomon, E; Hiorns, L R; Spurr, N; Kurkinen, M.; Barlow, D; Hogan, B L; Dalgleish, R.

    1985-01-01

    The human type II collagen gene, COL2A1, has been assigned to chromosome 12, the type III gene, COL3A1, to chromosome 2, and one of the type IV genes, COL4A1, to chromosome 13. These assignments were made by using cloned genes as probes on Southern blots of DNA from a panel of mouse/human somatic cell hybrids. The two genes of type I collagen, COL1A1 and COL2A1, have been mapped previously to chromosomes 17 and 7, respectively. This family of conserved genes seems therefore to be dispersed th...

  8. Efficacy of pulsed dye laser in cosmetically distressing facial dermatoses in skin types IV and V

    Directory of Open Access Journals (Sweden)

    Khandpur Sujay

    2008-01-01

    Full Text Available Background: Pulsed dye laser (PDL has revolutionized treatment of vascular dermatoses. It has been successfully employed to treat several non-vascular conditions in fair skinned individuals without producing significant pigmentary and textural complications. Aim: A preliminary study was undertaken to assess its efficacy in cosmetically distressing facial, vascular and non-vascular dermatoses in Indian patients with skin types IV and V. Materials and Methods: Nine patients of ages 7 to 55 years, with facial verruca plana (VP- 4 cases, angiofibromas (AF- 4 cases and multiple pyogenic granulomas (PG- one case were recruited. They had no systemic complaints. Laser parameters used were (spot size/fluence/wavelength/pulse duration:VP- 5mm/5.5-7.5J/585nm/0.45ms; AF-5mm/6-8.5J/585nm/0.45ms;PG- 5mm/7J/585 and 595nm alternately/1.5ms. Response was assessed clinically and photographically. Results and Conclusions: All VP lesions completely resolved after 2-4 sessions (mean 3.25 sessions, AF showed 50% regression in all cases after 2-3 sessions (mean 2.5 sessions and ≥75% subsidence after 3-7 sessions (mean 5.5 sessions and in PG, after 3 sessions, there was complete subsidence of small satellite lesions with moderate shrinkage of larger papules and complete resolution after 5 sessions. Complications included transient hyperpigmentation/hypopigmentation only. There was no recurrence during next 6 months. PDL offers significant cosmetic improvement in facial dermatoses in Indian patients.

  9. Cooperative retraction of bundled type IV pili enables nanonewton force generation.

    Directory of Open Access Journals (Sweden)

    Nicolas Biais

    2008-04-01

    Full Text Available The causative agent of gonorrhea, Neisseria gonorrhoeae, bears retractable filamentous appendages called type IV pili (Tfp. Tfp are used by many pathogenic and nonpathogenic bacteria to carry out a number of vital functions, including DNA uptake, twitching motility (crawling over surfaces, and attachment to host cells. In N. gonorrhoeae, Tfp binding to epithelial cells and the mechanical forces associated with this binding stimulate signaling cascades and gene expression that enhance infection. Retraction of a single Tfp filament generates forces of 50-100 piconewtons, but nothing is known, thus far, on the retraction force ability of multiple Tfp filaments, even though each bacterium expresses multiple Tfp and multiple bacteria interact during infection. We designed a micropillar assay system to measure Tfp retraction forces. This system consists of an array of force sensors made of elastic pillars that allow quantification of retraction forces from adherent N. gonorrhoeae bacteria. Electron microscopy and fluorescence microscopy were used in combination with this novel assay to assess the structures of Tfp. We show that Tfp can form bundles, which contain up to 8-10 Tfp filaments, that act as coordinated retractable units with forces up to 10 times greater than single filament retraction forces. Furthermore, single filament retraction forces are transient, whereas bundled filaments produce retraction forces that can be sustained. Alterations of noncovalent protein-protein interactions between Tfp can inhibit both bundle formation and high-amplitude retraction forces. Retraction forces build over time through the recruitment and bundling of multiple Tfp that pull cooperatively to generate forces in the nanonewton range. We propose that Tfp retraction can be synchronized through bundling, that Tfp bundle retraction can generate forces in the nanonewton range in vivo, and that such high forces could affect infection.

  10. Spectroscopic Studies of Abiotic and Biological Nanomaterials: Silver Nanoparticles, Rhodamine 6G Adsorbed on Graphene, and c-Type Cytochromes and Type IV Pili in Geobacter sulfurreducens

    Science.gov (United States)

    Thrall, Elizabeth S.

    This thesis describes spectroscopic studies of three different systems: silver nanoparticles, the dye molecule rhodamine 6G adsorbed on graphene, and the type IV pili and c-type cytochromes produced by the dissimilatory metal-reducing bacterium Geobacter sulfurreducens. Although these systems are quite different in some ways, they can all be considered examples of nanomaterials. A nanomaterial is generally defined as having at least one dimension below 100 nm in size. Silver nanoparticles, with sub-100 nm size in all dimensions, are examples of zero-dimensional nanomaterials. Graphene, a single atomic layer of carbon atoms, is the paradigmatic two-dimensional nanomaterial. And although bacterial cells are on the order of 1 μm in size, the type IV pili and multiheme c-type cytochromes produced by G. sulfurreducens can be considered to be one- and zero-dimensional nanomaterials respectively. A further connection between these systems is their strong interaction with visible light, allowing us to study them using similar spectroscopic tools. The first chapter of this thesis describes research on the plasmon-mediated photochemistry of silver nanoparticles. Silver nanoparticles support coherent electron oscillations, known as localized surface plasmons, at resonance frequencies that depend on the particle size and shape and the local dielectric environment. Nanoparticle absorption and scattering cross-sections are maximized at surface plasmon resonance frequencies, and the electromagnetic field is amplified near the particle surface. Plasmonic effects can enhance the photochemistry of silver particles alone or in conjunction with semiconductors according to several mechanisms. We study the photooxidation of citrate by silver nanoparticles in a photoelectrochemical cell, focusing on the wavelength-dependence of the reaction rate and the role of the semiconductor substrate. We find that the citrate photooxidation rate does not track the plasmon resonance of the silver

  11. Spine deformities in patients with Ehlers-Danlos syndrome, type IV - late results of surgical treatment

    Directory of Open Access Journals (Sweden)

    Tesiorowski Maciej

    2010-11-01

    Full Text Available Abstract Background Spinal deformities in Ehlers-Danlos syndrome are usually progressive and may require operative treatment. There is limited number of studies describing late results of surgery in this disease. Methods This is a retrospective study of the records of 11 patients with Ehlers-Danlos syndrome type IV, treated surgically between 1990 and 2007. All patients underwent surgical treatment for spinal deformity. Duration of operation, type of instrumentation, intraoperative blood loss, complications and number of additional surgeries were noted. Radiographic measurement was performed on standing AP and lateral radiographs acquired before surgery, just after and at final follow up. Results The mean follow up period was 5.5 ± 2.9 years (range 1-10 years. The mean preoperative thoracic and lumbar curve were 109.5 ± 19.9° (range 83° - 142° and 75.6 ± 26.7° (range 40° - 108° respectively. Posterior spine fusion alone was performed on 6 patients and combined anterior and posterior fusion (one- or two stage on 5 cases. Posterior segmental spinal instrumentation was applied with use of hooks, screws and wires. The mean postoperative thoracic and lumbar curve improved to 79.3 ± 16.1° (range 56° - 105° and 58.5 ± 27.7° (range 10° - 95° respectively, with a slight loss of correction during follow up. The average thoracic and lumbar correction was 26.4 ± 14.9% (range 5.3 - 50.4% and 26.3 ± 21.2% (range 7.9 - 75%. Postoperatively, the mean kyphosis was 79.5 ± 40.3° (range 21° -170°, and lordosis was 50.8 ± 18.6° (range 20° -79°. Hyperkyphosis increased during follow up while lordosis remained stable. Mean Th12-L2 angle was -3.5 ±9.9° (range -19° - 15° postoperatively and did not change significantly during follow up. Conclusions Huge spinal deformities in patients with Ehlers-Danlos syndrome require complex and extensive surgery. There is a big risk of sagittal imbalance in this group.

  12. Detection of bacterial biofilms in different types of chronic otitis media.

    Science.gov (United States)

    Gu, Xingzhi; Keyoumu, Youlidusi; Long, Li; Zhang, Hua

    2014-11-01

    Biofilms are organized bacterial communities that may be homogeneous or heterogeneous. They play a significant role in the pathogenesis of chronic nasal sinusitis, chronic tonsillitis, cholesteatomas, and device-related infections. Despite this, few studies have been done that examine the presence of bacterial biofilms in tissues from patients with different types of COM or middle ear cholesteatomas. In the current study, we examined the presence of biofilms in surgical tissue specimens from humans with chronic ear infections using scanning electron microscopy (SEM). We hypothesize that bacterial biofilms present differently in patients with different types of chronic otitis media. Our results provide new insights regarding treatment of chronic otitis media. A prospective study was conducted in which middle ear tissues were obtained from 38 patients who underwent tympanoplasty and/or tympanomastoid surgery due to chronic ear infections. A total of 50 middle and mastoid tissue samples were processed for SEM analysis. In addition, 38 middle ear secretion specimens were obtained for routine bacterial culture analysis. Bacterial biofilms were present in 85 % (11 of 13) of patients with middle ear cholesteatoma, 92 % (12/13) of patients with chronic otitis suppurative media (CSOM), and 16 % of patients (2/12) with tympanic membrane perforation (TMP). Fungal biofilms were found in two cases of cholesteatoma. The positive coincidence rate between bacterial biofilms visualized by SEM and bacteria detected by culture was 82 %. Our findings suggest that bacterial biofilms are very common in CSOM and middle ear cholesteatomas. Positive bacterial cultures imply the presence of biofilm formation in CSOM and cholesteatomas. As such, our results provide new insights regarding treatment of chronic otitis media.

  13. A New Type of Compositive Information Entropy for IvIFS and Its Applications

    Directory of Open Access Journals (Sweden)

    Junjun Mao

    2016-01-01

    Full Text Available We first show the interval-valued intuitionistic fuzzy entropy which reflects intuitionism and fuzziness of interval-valued intuitionistic fuzzy set (IvIFS based on interval-valued intuitionistic fuzzy cross-entropy. As for intuitionism and fuzziness of IvIFS, we propose interval-valued intuitionistic entropy and interval-valued fuzzy entropy, respectively. Furthermore, we establish the interval-valued span entropy describing the uncertainty of membership degree and nonmembership degree and show some concrete measure formulas. Combining intuitionistic factor, fuzzy factor, and span factor, we ultimately put forward the axiomatic definition of the compositive entropy and give a measure formula of compositive entropy. In addition, the effectiveness of the compositive entropy measure is illuminated by comparison with other entropy measures. Furthermore, the compositive entropy is applied to multiple attributes’ decision-making by using the weighted correlation coefficient between IvIFSs and pattern recognition by a similarity measure transformed from the compositive entropy.

  14. Behind the lines–actions of bacterial type III effector proteins in plant cells

    Science.gov (United States)

    Büttner, Daniela

    2016-01-01

    Pathogenicity of most Gram-negative plant-pathogenic bacteria depends on the type III secretion (T3S) system, which translocates bacterial effector proteins into plant cells. Type III effectors modulate plant cellular pathways to the benefit of the pathogen and promote bacterial multiplication. One major virulence function of type III effectors is the suppression of plant innate immunity, which is triggered upon recognition of pathogen-derived molecular patterns by plant receptor proteins. Type III effectors also interfere with additional plant cellular processes including proteasome-dependent protein degradation, phytohormone signaling, the formation of the cytoskeleton, vesicle transport and gene expression. This review summarizes our current knowledge on the molecular functions of type III effector proteins with known plant target molecules. Furthermore, plant defense strategies for the detection of effector protein activities or effector-triggered alterations in plant targets are discussed. PMID:27526699

  15. Endodontic Treatment of a Mandibular Second Premolar with Type IV Wiene’s Root Canal: A Case Report

    Directory of Open Access Journals (Sweden)

    Noushad Matavan Chalil

    2014-01-01

    Full Text Available This case report describes an endodontic treatment of a mandibular second premolar with type IV root canal. A 26-year-old male patient reported pain in right mandibular second premolar. Clinical examination showed a large carious lesion with pulp exposure. Radiographs showed minimal periapical changes and slight widening of periodontal ligament space. Mandibular second premolars usually have one canal. The mandibular second premolar may present large number of anatomic variations. The clinician should be aware of the configuration of the pulp system. This case presents the diagnosis and clinical management of a mandibular second premolar with two distinct canals in the apical third of root (Type IV Wiene’s canal configuration, drawing particular attention to tactile examination of all the canal walls and obturating it with calamus 3D obturation system.

  16. Antimicrobial peptide inhibition of fungalysin proteases that target plant type 19 Family IV defense chitinases

    Science.gov (United States)

    Cereal crops and other plants produce secreted seed chitinases that reduce pathogenic infection, most likely by targeting the fungal chitinous cell wall. We have shown that corn (Zea mays) produces three GH family 19, plant class IV chitinases, that help in protecting the plant against Fusarium and ...

  17. biochemistry physiological effects and the role of DDP-IV inhibitors in the management of type 2 diabetes mellitus

    OpenAIRE

    Andreani, Tatiana; Silva, Amélia M.; Souza, Ana Luiza R. de

    2010-01-01

    Type-2 diabetes mellitus (T2DM) is a metabolic disease characterized mainly by hyperglycemia, resulting from defects in β-cell function and/or insulin resistance. Treatment approaches include diet, exercise, and pharmacological agents these however can produce adverse effects such as weight gain and hypoglycemia. Glucagon-like peptide-1 (GLP-1) is a peptide hormone that controls glycaemia and preserves β-cell mass and function. Currently dipeptidyl peptidase (DDP-IV) inhibitors...

  18. An Eruptive Hot-Channel Structure Observed at Metric Wavelength as a Moving Type-IV Solar Radio Burst

    CERN Document Server

    Vasanth, V; Feng, Shiwei; Ma, Suli; Du, Guohui; Song, Hongqiang; Kong, Xiangliang; Wang, Bing

    2016-01-01

    Hot channel (HC) structure, observed in the high-temperature passbands of the AIA/SDO, is regarded as one candidate of coronal flux rope which is an essential element of solar eruptions. Here we present the first radio imaging study of an HC structure in the metric wavelength. The associated radio emission manifests as a moving type-IV (t-IVm) burst. We show that the radio sources co-move outwards with the HC, indicating that the t-IV emitting energetic electrons are efficiently trapped within the structure. The t-IV sources at different frequencies present no considerable spatial dispersion during the early stage of the event, while the sources spread gradually along the eruptive HC structure at later stage with significant spatial dispersion. The t-IV bursts are characterized by a relatively-high brightness temperature ($\\sim$ 10$^{7}$ $-$ 10$^{9}$ K), a moderate polarization, and a spectral shape that evolves considerably with time. This study demonstrates the possibility of imaging the eruptive HC structu...

  19. A bacterial pathogen uses distinct type III secretion systems to alternate between host kingdoms

    Science.gov (United States)

    Plant and animal-pathogenic bacteria utilize phylogenetically distinct type III secretion systems (T3SS) that produce needle-like injectisomes or pili for the delivery of effector proteins into host cells. Pantoea stewartii subsp. stewartii (Pnss), the causative agent of Stewart’s bacterial wilt and...

  20. VirE2, a type IV secretion substrate, interacts with the VirD4 transfer protein at cell poles of Agrobacterium tumefaciens.

    Science.gov (United States)

    Atmakuri, Krishnamohan; Ding, Zhiyong; Christie, Peter J

    2003-09-01

    Agrobacterium tumefaciens transfers oncogenic DNA and effector proteins to plant cells during the course of infection. Substrate translocation across the bacterial cell envelope is mediated by a type IV secretion (TFS) system composed of the VirB proteins, as well as VirD4, a member of a large family of inner membrane proteins implicated in the coupling of DNA transfer intermediates to the secretion machine. In this study, we demonstrate with novel cytological screens - a two-hybrid (C2H) assay and bimolecular fluorescence complementation (BiFC) - and by immunoprecipitation of chemically cross-linked protein complexes that the VirE2 effector protein interacts directly with the VirD4 coupling protein at cell poles of A. tumefaciens. Analyses of truncation derivatives showed that VirE2 interacts via its C terminus with VirD4, and, further, an NH2-terminal membrane-spanning domain of VirD4 is dispensable for complex formation. VirE2 interacts with VirD4 independently of the virB-encoded transfer machine and T pilus, the putative periplasmic chaperones AcvB and VirJ, and the T-DNA transfer intermediate. Finally, VirE2 is recruited to polar-localized VirD4 as a complex with its stabilizing secretion chaperone VirE1, yet the effector-coupling protein interaction is not dependent on chaperone binding. Together, our findings establish for the first time that a protein substrate of a type IV secretion system is recruited to a member of the coupling protein superfamily. PMID:12950931

  1. A novel arctigenin-containing latex glove prevents latex allergy by inhibiting type I/IV allergic reactions.

    Science.gov (United States)

    Wang, Yong-Xin; Xue, Dan-Ting; Liu, Meng; Zhou, Zheng-Min; Shang, Jing

    2016-03-01

    The present study aimed at developing a natural compound with anti-allergic effect and stability under latex glove manufacturing conditions and investigating whether its anti-allergic effect is maintained after its addition into the latex. The effects of nine natural compounds on growth of the RBL-2H3 cells and mouse primary spleen lymphocytes were determined using MTT assay. The compounds included glycyrrhizin, osthole, tetrandrine, tea polyphenol, catechin, arctigenin, oleanolic acid, baicalin and oxymatrine. An ELISA assay was used for the in vitro anti-type I/IV allergy screening; in this process β-hexosaminidase, histamine, and IL-4 released from RBL-2H3 cell lines and IFN-γ and IL-2 released from mouse primary spleen lymphocytes were taken as screening indices. The physical stability of eight natural compounds and the dissolubility of arctigenin, selected based on the in vitro pharnacodynamaic screening and the stability evaluation, were detected by HPLC. The in vivo pharmacodynamic confirmation of arctigenin and final latex product was evaluated with a passive cutaneous anaphylaxis (PCA) model and an allergen-specific skin response model. Nine natural compounds showed minor growth inhibition on RBL-2H3 cells and mouse primary spleen lymphocytes. Baicalin and arctigenin had the best anti-type I and IV allergic effects among the natural compounds based on the in vitro pharmacodynamic screening. Arctigenin and catechin had the best physical stability under different manufacturing conditions. Arctigenin was the selected for further evaluation and proven to have anti-type I and IV allergic effects in vivo in a dose-dependent manner. The final product of the arctigenin-containing latex glove had anti-type I and IV allergic effects in vivo which were mainly attributed to arctigenin as proved from the dissolubility results. Arctigenin showed anti-type I and IV allergic effects in vitro and in vivo, with a good stability under latex glove manufacturing conditions

  2. A novel arctigenin-containing latex glove prevents latex allergy by inhibiting type I/IV allergic reactions.

    Science.gov (United States)

    Wang, Yong-Xin; Xue, Dan-Ting; Liu, Meng; Zhou, Zheng-Min; Shang, Jing

    2016-03-01

    The present study aimed at developing a natural compound with anti-allergic effect and stability under latex glove manufacturing conditions and investigating whether its anti-allergic effect is maintained after its addition into the latex. The effects of nine natural compounds on growth of the RBL-2H3 cells and mouse primary spleen lymphocytes were determined using MTT assay. The compounds included glycyrrhizin, osthole, tetrandrine, tea polyphenol, catechin, arctigenin, oleanolic acid, baicalin and oxymatrine. An ELISA assay was used for the in vitro anti-type I/IV allergy screening; in this process β-hexosaminidase, histamine, and IL-4 released from RBL-2H3 cell lines and IFN-γ and IL-2 released from mouse primary spleen lymphocytes were taken as screening indices. The physical stability of eight natural compounds and the dissolubility of arctigenin, selected based on the in vitro pharnacodynamaic screening and the stability evaluation, were detected by HPLC. The in vivo pharmacodynamic confirmation of arctigenin and final latex product was evaluated with a passive cutaneous anaphylaxis (PCA) model and an allergen-specific skin response model. Nine natural compounds showed minor growth inhibition on RBL-2H3 cells and mouse primary spleen lymphocytes. Baicalin and arctigenin had the best anti-type I and IV allergic effects among the natural compounds based on the in vitro pharmacodynamic screening. Arctigenin and catechin had the best physical stability under different manufacturing conditions. Arctigenin was the selected for further evaluation and proven to have anti-type I and IV allergic effects in vivo in a dose-dependent manner. The final product of the arctigenin-containing latex glove had anti-type I and IV allergic effects in vivo which were mainly attributed to arctigenin as proved from the dissolubility results. Arctigenin showed anti-type I and IV allergic effects in vitro and in vivo, with a good stability under latex glove manufacturing conditions

  3. Impact of plasmids, including those encodingVirB4/D4 type IV secretion systems, on Salmonella enterica serovar Heidelberg virulence in macrophages and epithelial cells.

    Directory of Open Access Journals (Sweden)

    Kuppan Gokulan

    Full Text Available Salmonella enterica serovar Heidelberg (S. Heidelberg can cause foodborne illness in humans following the consumption of contaminated meat and poultry products. Recent studies from our laboratory have demonstrated that certain S. Heidelberg isolated from food-animal sources harbor multiple transmissible plasmids with genes that encode antimicrobial resistance, virulence and a VirB4/D4 type-IV secretion system. This study examines the potential role of these transmissible plasmids in bacterial uptake and survival in intestinal epithelial cells and macrophages, and the molecular basis of host immune system modulation that may be associated with disease progression. A series of transconjugant and transformant strains were developed with different combinations of the plasmids to determine the roles of the individual and combinations of plasmids on virulence. Overall the Salmonella strains containing the VirB/D4 T4SS plasmids entered and survived in epithelial cells and macrophages to a greater degree than those without the plasmid, even though they carried other plasmid types. During entry in macrophages, the VirB/D4 T4SS encoding genes are up-regulated in a time-dependent fashion. When the potential mechanisms for increased virulence were examined using an antibacterial Response PCR Array, the strain containing the T4SS down regulated several host innate immune response genes which likely contributed to the increased uptake and survival within macrophages and epithelial cells.

  4. Impact of plasmids, including those encodingVirB4/D4 type IV secretion systems, on Salmonella enterica serovar Heidelberg virulence in macrophages and epithelial cells.

    Science.gov (United States)

    Gokulan, Kuppan; Khare, Sangeeta; Rooney, Anthony W; Han, Jing; Lynne, Aaron M; Foley, Steven L

    2013-01-01

    Salmonella enterica serovar Heidelberg (S. Heidelberg) can cause foodborne illness in humans following the consumption of contaminated meat and poultry products. Recent studies from our laboratory have demonstrated that certain S. Heidelberg isolated from food-animal sources harbor multiple transmissible plasmids with genes that encode antimicrobial resistance, virulence and a VirB4/D4 type-IV secretion system. This study examines the potential role of these transmissible plasmids in bacterial uptake and survival in intestinal epithelial cells and macrophages, and the molecular basis of host immune system modulation that may be associated with disease progression. A series of transconjugant and transformant strains were developed with different combinations of the plasmids to determine the roles of the individual and combinations of plasmids on virulence. Overall the Salmonella strains containing the VirB/D4 T4SS plasmids entered and survived in epithelial cells and macrophages to a greater degree than those without the plasmid, even though they carried other plasmid types. During entry in macrophages, the VirB/D4 T4SS encoding genes are up-regulated in a time-dependent fashion. When the potential mechanisms for increased virulence were examined using an antibacterial Response PCR Array, the strain containing the T4SS down regulated several host innate immune response genes which likely contributed to the increased uptake and survival within macrophages and epithelial cells.

  5. Characterization of a recombinant C-type lectin, rCEL-IV, expressed in Escherichia coli cells using a synthetic gene.

    Science.gov (United States)

    Hatakeyama, Tomomitsu; Hozawa, Takao; Hirotani, Iyo; Tsuda, Nobuaki; Kusunoki, Masami; Shiba, Kohei

    2006-03-01

    The body fluid of marine invertebrate Cucumaria echinata (Holothuroidea) contains four Ca2+-dependent galactose-specific lectins. One of these lectins, CEL-IV, is composed of a C-type carbohydrate-recognition domain homotetramer. CEL-IV exhibits higher specificity for alpha-galactosides than for beta-galactosides, while other C. echinata lectins show preferential binding of beta-galactosides. We constructed an artificial synthetic gene for recombinant CEL-IV (rCEL-IV) based on the amino acid sequence previously determined from the purified protein. rCEL-IV was expressed in Escherichia coli cells as inclusion bodies. After the refolding process, most of rCEL-IV spontaneously formed a homotetramer structure having interchain disulfide bonds. The secondary structure of rCEL-IV was similar to that of the native one, as judged by the comparison of the far UV-circular dichroism spectra of rCEL-IV and native CEL-IV (nCEL-IV). Carbohydrate-binding specificity of rCEL-IV was confirmed to be similar to that of nCEL-IV from the results of the binding-inhibition assay using liposomes composed of rabbit erythrocyte lipids. Crystals of rCEL-IV were obtained in a few days by the sitting drop vapor diffusion method. These results indicate that rCEL-IV achieved essentially correct three-dimensional structure, including the carbohydrate-binding sites, and it would be very useful for further study on the carbohydrate-recognition mechanism by mutational and X-ray crystallographic analyses. PMID:16503091

  6. Combination of monoclonal antibodies and DPP-IV inhibitors in the treatment of type 1 diabetes: a plausible treatment modality?

    Science.gov (United States)

    Dubala, Anil; Gupta, Ankur; Samanta, Malay K

    2014-07-01

    Regulatory T cells (Tregs) are crucial for the maintenance of immunological tolerance. Type 1 diabetes (T1D) occurs when the immune-regulatory mechanism fails. In fact, T1D is reversed by islet transplantation but is associated with hostile effects of persistent immune suppression. T1D is believed to be dependent on the activation of type-1 helper T (Th1) cells. Immune tolerance is liable for the activation of the Th1 cells. The important role of Th1 cells in pathology of T1D entails the depletion of CD4(+) T cells, which initiated the use of monoclonal antibodies (mAbs) against CD4(+) T cells to interfere with induction of T1D. Prevention of autoimmunity is not only a step forward for the treatment of T1D, but could also restore the β-cell mass. Glucagon-like peptide (GLP)-1 stimulates β-cell proliferation and also has anti-apoptotic effects on them. However, the potential use of GLP-1 as a possible method to restore pancreatic β-cells is limited due to rapid degradation by dipeptidyl peptidase (DPP)-IV. We hypothesize that treatment with combination of CD4 mAbs and DPP-IV inhibitors could prevent/reverse T1D. CD4 mAbs have the ability to induce immune tolerance, thereby arresting further progression of T1D; DPP-IV inhibitors have the capability to regenerate the β-cell mass. Consequently, the combination of CD4 mAbs and DPP-IV inhibitor could avoid or at least minimize the constraints of intensive subcutaneous insulin therapy. We presume that if this hypothesis proves correct, it may become one of the plausible therapeutic options for T1D.

  7. T3_MM: A Markov Model Effectively Classifies Bacterial Type III Secretion Signals

    OpenAIRE

    Yejun Wang; Ming'an Sun; Hongxia Bao; Aaron P. White

    2013-01-01

    MOTIVATION: Type III Secretion Systems (T3SSs) play important roles in the interaction between gram-negative bacteria and their hosts. T3SSs function by translocating a group of bacterial effector proteins into the host cytoplasm. The details of specific type III secretion process are yet to be clarified. This research focused on comparing the amino acid composition within the N-terminal 100 amino acids from type III secretion (T3S) signal sequences or non-T3S proteins, specifically whether e...

  8. High serum laminin and type IV collagen levels in schistosomiasis mansoni Elevação dos níveis séricos de laminina e colágeno tipo IV na esquistossomose mansoni

    Directory of Open Access Journals (Sweden)

    Rozangela Maria de Almeida Fernandes Wyszomirska

    2005-12-01

    Full Text Available BACKGROUND: Fibrosis is the process of excessive deposition of collagen and other extra cellular matrix components and large amounts of these components have been shown in periovular schistosomal granulomas, especially in the liver. Laminin and type IV collagen have been investigated in various hepatic disorders but their accuracy in fibrosis detection and in the evaluation of its progression in schistosomiasis have not been fully explained. AIM: To measure the serum levels of two markers of fibrosis, laminin and type IV collagen in schistosomiasis. PATIENTS AND METHODS: Sixty-four patients with different clinical forms of schistosomiasis mansoni: intestinal (group I, hepatointestinal (group II, compensated (group III and decompensated hepatosplenic (group IV and 18 healthy volunteers were included. RESULTS: Serum type IV collagen and laminin levels were significantly increased in patients compared to controls. At about clinical forms, serum type IV collagen was increased in groups II and IV, compared to controls and was significantly higher in group IV than in group I. Serum laminin was significantly increased in groups II, III and IV and was significantly higher in group IV than in group II. Serum type IV collagen was closely correlated with serum laminin in groups II and IV. CONCLUSIONS: Connective tissue marker levels did not correlate with periportal thickness. In schistosomiasis mansoni there is an increase of type IV collagen and laminin levels at the initial stage of the disease, as well as in advanced forms. We also suggest that these markers may be a useful predictor of disease progression.RACIONAL: A fibrose hepática é caracterizada por um aumento progressivo na quantidade do tecido conjuntivo hepático, que é formado pelo aumento na deposição de componentes da matriz extracelular, tendo sido encontrada grande quantidade desses componentes no fígado de pacientes com esquistossomose mansoni. A laminina e o colágeno tipo IV t

  9. Formation Mechanism of Type IV Failure in High Cr Ferritic Heat-Resistant Steel-Welded Joint

    Science.gov (United States)

    Liu, Y.; Tsukamoto, S.; Shirane, T.; Abe, F.

    2013-10-01

    The mechanism of type IV failure has been investigated by using a conventional 9Cr ferritic heat-resistant steel Gr.92. In order to clarify the main cause of type IV failure, different heat treatments were performed on the base metal in order to change the prior austenite grain (PAG) size and precipitate distribution after applying the heat-affected zone (HAZ) simulated thermal cycle at the peak temperature of around A c3 ( A c3 HAZ thermal cycle) and postweld heat treatment (PWHT). The microstructural evolution during the A c3 HAZ thermal cycle and PWHT was investigated by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), electron probe microanalysis (EPMA), and transmission electron microscope (TEM). It was found that M23C6 carbides were scarcely precipitated at the newly formed fine PAG, block, and lath boundaries in A c3 HAZ-simulated Gr.92, because the carbide forming elements such as Cr and C were segregated at the former PAG and block boundaries of the base metal. On the other hand, if all the boundaries were covered by sufficient M23C6 carbides by homogenization of the alloying elements prior to applying the HAZ thermal cycle, the creep strength was much improved even if the fine PAG was formed. From these results, it is concluded that fine-grained microstructure cannot account for the occurrence of type IV failure, and it only has a small effect during long-term creep. The most important factor is the precipitate formation behavior at various boundaries. Without sufficient boundary strengthening by precipitates, the microstructure of A c3 HAZ undergoes severe changes even during PWHT and causes premature failure during creep.

  10. Bacterial microbiota compositions of naturally fermented milk are shaped by both geographic origin and sample type.

    Science.gov (United States)

    Zhong, Z; Hou, Q; Kwok, L; Yu, Z; Zheng, Y; Sun, Z; Menghe, B; Zhang, H

    2016-10-01

    Naturally fermented dairy products contain a rich microbial biodiversity. This study aimed to provide an overview on the bacterial microbiota biodiversity of 85 samples, previously collected across a wide region of China, Mongolia, and Russia. Data from these 85 samples, including 55 yogurts, 18 naturally fermented yak milks, 6 koumisses, and 6 cheeses, were retrieved and collectively analyzed. The most prevalent phyla shared across samples were Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria, which together accounted for 99% of bacterial sequences. The predominant genera were Lactobacillus, Lactococcus, Streptococcus, Acetobacter, Acinetobacter, Leuconostoc, and Macrococcus, which together corresponded to 96.63% of bacterial sequences. Further multivariate statistical analyses revealed significant differences in the microbiota structure across sample geographic origin and type. First, on the principal coordinate score plot, samples representing the 3 main sample collection regions (Russia, Xinjiang, and Tibet) were mostly located respectively in the upper left, lower right, and lower left quadrants, although slight overlapping occurred. In contrast, samples from the minor sampling areas (Inner Mongolia, Mongolia, Gansu, and Sichuan) were predominantly distributed in the lower left quadrant. These results suggest a possible association between sample geographical origin and microbiota composition. Second, bacterial microbiota structure was stratified by sample type. In particular, the microbiota of cheese was largely distinct from the other sample types due to its high abundances of Lactococcus and Streptococcus. The fermented yak milk microbiota was most like that of the yogurts. Koumiss samples had the lowest microbial diversity and richness. In conclusion, both geographic origin and sample type shape the microbial diversity of naturally fermented milk. PMID:27474988

  11. Haemophilus influenzae Type b Carriage and Novel Bacterial Population Structure among Children in Urban Kathmandu, Nepal▿

    OpenAIRE

    Williams, E. J.; Lewis, J.; John, T.; Hoe, J. C.; Yu, L.; Dongol, S.; Kelly, D. F.; Griffiths, D. T.; Shah, A; Limbu, B.; Pradhan, R.; Mawas, F.; Shrestha, S.; Thorson, S.; Werno, A. M.

    2011-01-01

    Haemophilus influenzae type b (Hib) is a major cause of invasive bacterial infection in children that can be prevented by a vaccine, but there is still uncertainty about its relative importance in Asia. This study investigated the age-specific prevalence of Hib carriage and its molecular epidemiology in carriage and disease in Nepal. Oropharyngeal swabs were collected from children in Kathmandu, Nepal, from 3 different settings: a hospital outpatient department (OPD), schools, and children's ...

  12. A Type VI Secretion System Is Involved in Pseudomonas fluorescens Bacterial Competition

    OpenAIRE

    Victorien Decoin; Corinne Barbey; Dorian Bergeau; Xavier Latour; Feuilloley, Marc G. J.; Nicole Orange; Annabelle Merieau

    2014-01-01

    Protein secretion systems are crucial mediators of bacterial interactions with other organisms. Among them, the type VI secretion system (T6SS) is widespread in Gram-negative bacteria and appears to inject toxins into competitor bacteria and/or eukaryotic cells. Major human pathogens, such as Vibrio cholerae, Burkholderia and Pseudomonas aeruginosa, express T6SSs. Bacteria prevent self-intoxication by their own T6SS toxins by producing immunity proteins, which interact with the cognate toxins...

  13. Dynamics of a delayed discrete semi-ratio-dependent predator-prey system with Holling type IV functional response

    Directory of Open Access Journals (Sweden)

    Lu Hongying

    2011-01-01

    Full Text Available Abstract A discrete semi-ratio-dependent predator-prey system with Holling type IV functional response and time delay is investigated. It is proved the general nonautonomous system is permanent and globally attractive under some appropriate conditions. Furthermore, if the system is periodic one, some sufficient conditions are established, which guarantee the existence and global attractivity of positive periodic solutions. We show that the conditions for the permanence of the system and the global attractivity of positive periodic solutions depend on the delay, so, we call it profitless.

  14. Comparative immunohistochemical study of group II (synovial-type) and group IV (cytosolic) phospholipases A2 in disc prolapse tissue

    OpenAIRE

    Habtemariam, A.; Grönblad, M; Virri, J.; Airaksinen, O.; Luukkonen, M; Turunen, V.; Savolainen, S; Karaharju, E.

    1998-01-01

    Phospholipase A2 (PLA2) has been suggested to be present in herniated disc tissue and it could possibly be involved in sciatica/ discogenic back pain mechanisms. In the present study the occurrence of two different phospholipase A2 enzymes, (1) low molecular weight (14 kDa) group II synovial-type (sPLA2) and (2) high molecular weight (85 kDa) group IV cytosolic (cPLA2), were compared. Fifty-three disc prolapses obtained at disc operations were analyzed by immunohistochemistry, using anti-huma...

  15. The N. gonorrhoeae Type IV Pilus Stimulates Mechanosensitive Pathways and Cytoprotection through a pilT-Dependent Mechanism

    Directory of Open Access Journals (Sweden)

    Howie Heather L

    2005-01-01

    Full Text Available The Neisseria gonorrhoeae type IV pilus is a retractile appendage that can generate forces near 100 pN. We tested the hypothesis that type IV pilus retraction influences epithelial cell gene expression by exerting tension on the host membrane. Wild-type and retraction-defective bacteria altered the expression of an identical set of epithelial cell genes during attachment. Interestingly, pilus retraction, per se, did not regulate novel gene expression but, rather, enhanced the expression of a subset of the infection-regulated genes. This is accomplished through mitogen-activated protein kinase activation and at least one other undefined stress-activated pathway. These results can be reproduced by applying artificial force on the epithelial membrane, using a magnet and magnetic beads. Importantly, this retraction-mediated signaling increases the ability of the cell to withstand apoptotic signals triggered by infection. We conclude that pilus retraction stimulates mechanosensitive pathways that enhance the expression of stress-responsive genes and activate cytoprotective signaling. A model for the role of pilus retraction in influencing host cell survival is presented.

  16. The N. gonorrhoeae type IV pilus stimulates mechanosensitive pathways and cytoprotection through a pilT-dependent mechanism.

    Directory of Open Access Journals (Sweden)

    Heather L Howie

    2005-04-01

    Full Text Available The Neisseria gonorrhoeae type IV pilus is a retractile appendage that can generate forces near 100 pN. We tested the hypothesis that type IV pilus retraction influences epithelial cell gene expression by exerting tension on the host membrane. Wild-type and retraction-defective bacteria altered the expression of an identical set of epithelial cell genes during attachment. Interestingly, pilus retraction, per se, did not regulate novel gene expression but, rather, enhanced the expression of a subset of the infection-regulated genes. This is accomplished through mitogen-activated protein kinase activation and at least one other undefined stress-activated pathway. These results can be reproduced by applying artificial force on the epithelial membrane, using a magnet and magnetic beads. Importantly, this retraction-mediated signaling increases the ability of the cell to withstand apoptotic signals triggered by infection. We conclude that pilus retraction stimulates mechanosensitive pathways that enhance the expression of stress-responsive genes and activate cytoprotective signaling. A model for the role of pilus retraction in influencing host cell survival is presented.

  17. The bacterial pathogen Listeria monocytogenes and the interferon family: type I, type II and type III interferons.

    Science.gov (United States)

    Dussurget, Olivier; Bierne, Hélène; Cossart, Pascale

    2014-01-01

    Interferons (IFNs) are secreted proteins of the cytokine family that regulate innate and adaptive immune responses to infection. Although the importance of IFNs in the antiviral response has long been appreciated, their role in bacterial infections is more complex and is currently a major focus of investigation. This review summarizes our current knowledge of the role of these cytokines in host defense against the bacterial pathogen Listeria monocytogenes and highlights recent discoveries on the molecular mechanisms evolved by this intracellular bacterium to subvert IFN responses.

  18. Hierarchical assembly of helicate-type dinuclear titanium(IV) complexes.

    Science.gov (United States)

    Albrecht, Markus; Mirtschin, Sebastian; de Groot, Marita; Janser, Ingo; Runsink, Jan; Raabe, Gerhard; Kogej, Michael; Schalley, Christoph A; Fröhlich, Roland

    2005-07-27

    The ligands 4-7-H(2) were used in coordination studies with titanium(IV) and gallium(III) ions to obtain dimeric complexes Li(4)[(4-7)(6)Ti(2)] and Li(6)[(4/5a)(6)Ga(2)]. The X-ray crystal structures of Li(4)[(4)(6)Ti(2)], Li(4)[(5b)(6)Ti(2)], and Li(4)[(7a)(6)Ti(2)] could be obtained. While these complexes are triply lithium-bridged dimers in the solid state, a monomer/dimer equilibrium is observed in solution by NMR spectroscopy and ESI FT-ICR MS. The stability of the dimer is enhanced by high negative charges (Ti(IV) versus Ga(III)) of the monomers, when the carbonyl units are good donors (aldehydes versus ketones and esters), when the solvent does not efficiently solvate the bridging lithium ions (DMSO versus acetone), and when sterical hindrance is minimized (methyl versus primary and secondary carbon substituents). The dimer is thermodynamically favored by enthalpy as well as entropy. ESI FT-ICR mass spectrometry provides detailed insight into the mechanisms with which monomeric triscatecholate complexes as well as single catechol ligands exchange in the dimers. Tandem mass spectrometric experiments in the gas phase show the dimers to decompose either in a symmetric (Ti) or in an unsymmetric (Ga) fashion when collisionally activated. The differences between the Ti and Ga complexes can be attributed to different electronic properties and a charge-controlled reactivity of the ions in the gas phase. The complexes represent an excellent example for hierarchical self-assembly, in which two different noncovalent interactions of well balanced strengths bring together eleven individual components into one well-defined aggregate.

  19. Legionella pneumophila Type IV Effectors YlfA and YlfB Are SNARE-Like Proteins that Form Homo- and Heteromeric Complexes and Enhance the Efficiency of Vacuole Remodeling.

    Directory of Open Access Journals (Sweden)

    Eva M Campodonico

    Full Text Available Legionella pneumophila is a Gram-negative bacterium that can colonize both freshwater protozoa and human alveolar macrophages, the latter infection resulting in Legionnaires' disease. The intracellular lifecycle of L. pneumophila requires extensive manipulation of its host cell, which is carried out by effector proteins that are translocated into the host cell through the Dot/Icm type IV secretion system. This study focuses on a pair of highly similar type IV substrates called YlfA/LegC7 and YlfB/LegC2 that were initially identified in a screen for proteins that cause growth inhibition in yeast. Analysis of truncation mutants revealed that the hydrophobic residues in the Ylf amino termini were required for localization of each protein to the membranes of host cells. Central and carboxy terminal coiled coil domains were found to mediate binding of YlfA and YlfB to themselves and to each other. In vivo, a ΔylfA ΔylfB double mutant strain of L. pneumophila was shown to be defective in establishing a vacuole that supports bacterial replication. This phenotype was subsequently correlated with a decrease in the association of endoplasmic reticulum (ER-derived vesicles with vacuoles containing ΔylfA ΔylfB mutant bacteria. These data suggest that the Ylf proteins are membrane-associated effectors that enhance remodeling of the L. pneumophila -containing vacuole by promoting association and possibly fusion of ER-derived membrane vesicles with the bacterial compartment.

  20. Legionella pneumophila Type IV Effectors YlfA and YlfB Are SNARE-Like Proteins that Form Homo- and Heteromeric Complexes and Enhance the Efficiency of Vacuole Remodeling

    Science.gov (United States)

    Campodonico, Eva M.; Roy, Craig R.; Ninio, Shira

    2016-01-01

    Legionella pneumophila is a Gram-negative bacterium that can colonize both freshwater protozoa and human alveolar macrophages, the latter infection resulting in Legionnaires’ disease. The intracellular lifecycle of L. pneumophila requires extensive manipulation of its host cell, which is carried out by effector proteins that are translocated into the host cell through the Dot/Icm type IV secretion system. This study focuses on a pair of highly similar type IV substrates called YlfA/LegC7 and YlfB/LegC2 that were initially identified in a screen for proteins that cause growth inhibition in yeast. Analysis of truncation mutants revealed that the hydrophobic residues in the Ylf amino termini were required for localization of each protein to the membranes of host cells. Central and carboxy terminal coiled coil domains were found to mediate binding of YlfA and YlfB to themselves and to each other. In vivo, a ΔylfA ΔylfB double mutant strain of L. pneumophila was shown to be defective in establishing a vacuole that supports bacterial replication. This phenotype was subsequently correlated with a decrease in the association of endoplasmic reticulum (ER)-derived vesicles with vacuoles containing ΔylfA ΔylfB mutant bacteria. These data suggest that the Ylf proteins are membrane-associated effectors that enhance remodeling of the L. pneumophila -containing vacuole by promoting association and possibly fusion of ER-derived membrane vesicles with the bacterial compartment. PMID:27459495

  1. Legionella pneumophila Type IV Effectors YlfA and YlfB Are SNARE-Like Proteins that Form Homo- and Heteromeric Complexes and Enhance the Efficiency of Vacuole Remodeling.

    Science.gov (United States)

    Campodonico, Eva M; Roy, Craig R; Ninio, Shira

    2016-01-01

    Legionella pneumophila is a Gram-negative bacterium that can colonize both freshwater protozoa and human alveolar macrophages, the latter infection resulting in Legionnaires' disease. The intracellular lifecycle of L. pneumophila requires extensive manipulation of its host cell, which is carried out by effector proteins that are translocated into the host cell through the Dot/Icm type IV secretion system. This study focuses on a pair of highly similar type IV substrates called YlfA/LegC7 and YlfB/LegC2 that were initially identified in a screen for proteins that cause growth inhibition in yeast. Analysis of truncation mutants revealed that the hydrophobic residues in the Ylf amino termini were required for localization of each protein to the membranes of host cells. Central and carboxy terminal coiled coil domains were found to mediate binding of YlfA and YlfB to themselves and to each other. In vivo, a ΔylfA ΔylfB double mutant strain of L. pneumophila was shown to be defective in establishing a vacuole that supports bacterial replication. This phenotype was subsequently correlated with a decrease in the association of endoplasmic reticulum (ER)-derived vesicles with vacuoles containing ΔylfA ΔylfB mutant bacteria. These data suggest that the Ylf proteins are membrane-associated effectors that enhance remodeling of the L. pneumophila -containing vacuole by promoting association and possibly fusion of ER-derived membrane vesicles with the bacterial compartment. PMID:27459495

  2. Disease-associated Neisseria meningitidis isolates inhibit wound repair in respiratory epithelial cells in a type IV pilus-independent manner.

    Science.gov (United States)

    Ren, Xiaoyun; MacKichan, Joanna K

    2014-12-01

    Neisseria meningitidis is the causative agent of meningococcal disease. Onset of meningococcal disease can be extremely rapid and can kill within a matter of hours. However, although a much-feared pathogen, Neisseria meningitidis is frequently found in the nasopharyngeal mucosae of healthy carriers. The bacterial factors that distinguish disease- from carriage-associated meningococci are incompletely understood. Evidence suggesting that disruptions to the nasopharynx may increase the risk of acquiring meningococcal disease led us to evaluate the ability of disease- and carriage-associated meningococcal isolates to inhibit cell migration, using an in vitro assay for wound repair. We found that disease-associated isolates in our collection inhibited wound closure, while carriage-associated isolates were more variable, with many isolates not inhibiting wound repair at all. For isolates selected for further study, we found that actin morphology, such as presence of lamellipodia, correlated with cell migration. We demonstrated that multiple meningococcal virulence factors, including the type IV pili, are dispensable for inhibition of wound repair. Inhibition of wound repair was also shown to be an active process, i.e., requiring live bacteria undergoing active protein synthesis. PMID:25225250

  3. Investigation of enhanced hemocompatibility and tissue compatibility associated with multi-functional coating based on hyaluronic acid and Type IV collagen.

    Science.gov (United States)

    Li, Jingan; Zhang, Kun; Ma, Wenyong; Wu, Feng; Yang, Ping; He, Zikun; Huang, Nan

    2016-09-01

    The biocompatibility of cardiovascular devices has always been considered crucial for their clinical efficacy. Therefore, a biofunctional coating composed of Type IV collagen (CoIV) and hyaluronan (HA) was previously fabricated onto the titanium (Ti) substrate for the application of promoting vascular smooth muscle cell contractile phenotype and improving surface endothelialization. However, the anti-inflammation property, blood compatibility and in vivo tissue compatibility of the HA/CoIV coating, as paramount consideration of cardiovascular materials surface coating, have not been investigated. Thus, in this study, the three crucial properties of the HA/CoIV coating were tested. The platelet adhesion/activation test and the dynamic whole blood experiment implied that the HA/CoIV coating had better blood compatibility compared with Ti substrate and pure CoIV coating. The macrophage adhesion/activation and inflammatory cytokine release (tumor necrosis factor-alpha and interleukin-1) results indicated that the HA/CoIV coating could significantly improve the anti-inflammation property of the Ti substrate. The in vivo implantation of SD rats for 3 weeks' results demonstrated that the HA/CoIV coating caused milder tissue response. All these results suggested that the multi-functional HA/CoIV coating possessed good biocompatibility. This research is anticipated to be potentially applied for the surface modification of cardiovascular stents. PMID:27252884

  4. Loss of Col3a1, the gene for Ehlers-Danlos syndrome type IV, results in neocortical dyslamination.

    Directory of Open Access Journals (Sweden)

    Sung-Jin Jeong

    Full Text Available It has recently been discovered that Collagen III, the encoded protein of the type IV Ehlers-Danlos Syndrome (EDS gene, is one of the major constituents of the pial basement membrane (BM and serves as the ligand for GPR56. Mutations in GPR56 cause a severe human brain malformation called bilateral frontoparietal polymicrogyria, in which neurons transmigrate through the BM causing severe mental retardation and frequent seizures. To further characterize the brain phenotype of Col3a1 knockout mice, we performed a detailed histological analysis. We observed a cobblestone-like cortical malformation, with BM breakdown and marginal zone heterotopias in Col3a1⁻/⁻ mouse brains. Surprisingly, the pial BM appeared intact at early stages of development but starting as early as embryonic day (E 11.5, prominent BM defects were observed and accompanied by neuronal overmigration. Although collagen III is expressed in meningeal fibroblasts (MFs, Col3a1⁻/⁻ MFs present no obvious defects. Furthermore, the expression and posttranslational modification of α-dystroglycan was undisturbed in Col3a1⁻/⁻ mice. Based on the previous finding that mutations in COL3A1 cause type IV EDS, our study indicates a possible common pathological pathway linking connective tissue diseases and brain malformations.

  5. Localization of type IV collagen a 1 to a 6 chains in basement membrane during mouse molar germ development.

    Science.gov (United States)

    Nagai, N; Nakano, K; Sado, Y; Naito, I; Gunduz, M; Tsujigiwa, H; Nagatsuka, H; Ninomiya, Y; Siar, C H

    2001-10-01

    The dental basement membrane (BM) putatively mediates epithelial-mesenchymal interactions during tooth morphogenesis and cytodifferentiation. Type IV collagen alpha chains, a major network-forming protein of the dental BM, was studied and results disclosed distinct expression patterns at different stages of mouse molar germ development. At the dental placode and bud stage, the BM of the oral epithelium expressed alpha 1, alpha 2, alpha 5 and alpha 6 chains while the gubernaculum dentis, in addition to the above four chains, also expressed a 4 chain. An asymmetrical expression for alpha 4, alpha 5 and alpha 6 chains was observed at the bud stage. At the early bell stage, the BM associated with the inner enamel epithelium (IEE) of molar germ expressed alpha 1, alpha 2 and alpha 4 chains while the BM of the outer enamel epithelium (OEE) expressed only alpha 1 and a 2 chains. With the onset of dentinogenesis, the collagen a chain profile of the IEE BM gradually disappeared. Howeverfrom the early to late bell stage, the gubernaculum dentis consistently expressed alpha 1, alpha 2, alpha 5 and a 6 chains resembling fetal oral mucosa. These findings suggest that stage- and position-specific distribution of type IV collagen alpha subunits occur during molar germ development and that these changes are essential for molar morphogenesis and cytodifferentiation. PMID:11732842

  6. The mucosal expression signatures of g-type lysozyme in turbot (Scophthalmus maximus) following bacterial challenge.

    Science.gov (United States)

    Gao, Chengbin; Fu, Qiang; Zhou, Shun; Song, Lin; Ren, Yichao; Dong, Xiaoyu; Su, Baofeng; Li, Chao

    2016-07-01

    The mucosal surfaces constitute the first line of host defense against infection, and also serve as the dynamic interfaces that simultaneously mediate a diverse array of critical physiological processes, while in constantly contact with a wide range of pathogens. The lysozymes are considered as key components for innate immune response to pathogen infection with their strong antibacterial activities. But their activities in mucosal immune responses were always overlooked, especially for g-type lysozymes, whose expression patterns in mucosal tissues following bacterial challenge are still limited. Towards to this end, here, we characterized the g-type lysozymes, Lyg1 and Lyg2 in turbot, and determined their expression patterns in mucosal barriers following different bacterial infection. The phylogenetic analysis revealed the turbot g-type lysozyme genes showed the closest relationship to Cynoglossus semilaevis. The two lysozyme genes showed different expression patterns following challenge. Lyg2 was significantly up-regulated in mucosal tissues following Vibrio anguillarum and Streptococcus iniae challenge, while Lyg1 showed a general trend of down-regulation. The significant mucosal expression signatures of g-type lysozyme genes indicated their key roles to prevent pathogen attachment and entry in the first line of host defense system. Further functional studies should be carried out to better characterize the availability of utilization of g-type lysozyme to increase the disease resistance in the mucosal surfaces and facilitate the disease resistant breeding selection. PMID:27189917

  7. Effects of bacterial cells and two types of extracellular polymers on bioclogging of sand columns

    Science.gov (United States)

    Xia, Lu; Zheng, Xilai; Shao, Haibing; Xin, Jia; Sun, Zhaoyue; Wang, Leyun

    2016-04-01

    Microbially induced reductions in the saturated hydraulic conductivity, Ks, of natural porous media, conventionally called bioclogging, occurs frequently in natural and engineered subsurface systems. Bioclogging can affect artificial groundwater recharge, in situ bioremediation of contaminated aquifers, or permeable reactive barriers. In this study, we designed a series of percolation experiments to simulate the growth and metabolism of bacteria in sand columns. The experimental results showed that the bacterial cell amount gradually increased to a maximum of 8.91 log10 CFU/g sand at 144 h during the bioclogging process, followed by a decrease to 7.89 log10 CFU/g sand until 336 h. The same variation pattern was found for the concentration of tightly bound extracellular polymeric substances (TB-EPS), which had a peak value of 220.76 μg/g sand at 144 h. In the same experiments, the concentration of loosely bound extracellular polymeric substances (LB-EPS) increased sharply from 54.45 to 575.57 μg/g sand in 192 h, followed by a slight decline to 505.04 μg/g sand. The increase of the bacterial cell amount along with the other two concentrations could reduce the Ks of porous media, but their relative contributions varied to a large degree during different percolation stages. At the beginning of the tests (e.g., 48 h before), bacterial cells were likely responsible for the Ks reduction of porous media because no increase was found for the other two concentrations. With the accumulation of cells and EPS production from 48 to 144 h, both were important for the reduction of Ks. However, in the late period of percolation tests from 144 to 192 h, LB-EPS was probably responsible for the further reduction of Ks, as the bacterial cell amount and TB-EPS concentration decreased. Quantitative contributions of bacterial cell amount and the two types of extracellular polymers to Ks reductions were also evaluated.

  8. Influence of silver additions to type 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Tseng, I-Sheng; Møller, Per;

    2010-01-01

    Bacterial contamination is a major concern in many areas. In this study, silver was added to type 316 stainless steels in order to obtain an expected bacteria inhibiting property to reduce the occurrence of bacterial contamination. Silver-bearing 316 stainless steels were prepared by vacuum melti...

  9. A spider toxin, ω-agatoxin IV A, binds to fixed as well as living tissues: cytochemical visualization of P/Q-type calcium channels.

    Science.gov (United States)

    Nakanishi, Setsuko

    2016-08-01

    ω-Agatoxin IV A, a peptidyl toxin from Agelenopsis aperta venom, selectively binds to voltage-gated P/Q-type calcium channels. ω-Agatoxin IV A has been used as a selective tool in pharmacological and electrophysiological studies. Visualization of P/Q-type calcium channels has previously been accomplished using biotin-conjugated ω-Agatoxin IV A in freshly prepared mouse cerebellar and hippocampal slices (Nakanishi et al, J. Neurosci. Res., 41: , 532, 1995). Here biotinylated ω-agatoxin IV A was applied to transcardially fixed brain slices prepared with various fixatives. ω-Agatoxin IV A did not bind to fixed tissues from P/Q-type calcium channel knockout mice, confirming that binding to normal, fixed tissues was not an artifact. Using transmission electron microscopy, locations of biotinylated ω-agatoxin IV A binding sites visualized with gold-conjugated streptavidin showed a similar pattern to those visualized with antibody. The ability of biotinylated ω-agatoxin IV A to bind to fixed tissue provides a new cytochemical technique to study molecular architecture of synapses. PMID:27095701

  10. Analyses of Bifurcations and Stability in a Predator-prey System with Holling Type-IV Functional Response

    Institute of Scientific and Technical Information of China (English)

    Ji-cai Huang; Dong-mei Xiao

    2004-01-01

    In this paper the dynamical behaviors of a predator-prey system with Holling Type-IV functional response are investigated in detail by using the analyses of qualitative method,bifurcation theory,and numerical simulation.The qualitative analyses and numerical simulation for the model indicate that it has a unique stable limit cycle.The bifurcation analyses of the system exhibit static and dynamical bifurcations including saddlenode bifurcation,Hopf bifurcation,homoclinic bifurcation and bifurcation of cusp-type with codimension two(ie,the Bogdanov-Takens bifurcation),and we show the existence of codimension three degenerated equilibrium and the existence of homoclinic orbit by using numerical simulation.

  11. The extracellular matrix of Gadus morhua muscle contains types III, V, VI and IV collagens in addition to type I

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline; Lawson, M.A.

    2005-01-01

    Confocal microscopy and immuno‐histochemistry were used to examine collagens in the extracellular matrix of cod Gadus morhua swimming muscle. In addition to the well known presence of type I fibrous collagen, types III and VI were also found in the myocommata and the endomysium. The beaded collagen...

  12. Molecular Epidemiologic Typing Systems of Bacterial Pathogens: Current Issues and Perpectives

    Directory of Open Access Journals (Sweden)

    Marc J Struelens

    1998-09-01

    Full Text Available The epidemiologic typing of bacterial pathogens can be applied to answer a number of different questions: in case of outbreak, what is the extent and mode of transmission of epidemic clone(s ? In case of long-term surveillance, what is the prevalence over time and the geographic spread of epidemic and endemic clones in the population? A number of molecular typing methods can be used to classify bacteria based on genomic diversity into groups of closely-related isolates (presumed to arise from a common ancestor in the same chain of transmission and divergent, epidemiologically-unrelated isolates (arising from independent sources of infection. Ribotyping, IS-RFLP fingerprinting, macrorestriction analysis of chromosomal DNA and PCR-fingerprinting using arbitrary sequence or repeat element primers are useful methods for outbreak investigations and regional surveillance. Library typing systems based on multilocus sequence-based analysis and strain-specific probe hybridization schemes are in development for the international surveillance of major pathogens like Mycobacterium tuberculosis. Accurate epidemiological interpretation of data obtained with molecular typing systems still requires additional research on the evolution rate of polymorphic loci in bacterial pathogens.

  13. Combined determination of serum type IV collagen with urine Tamm-Horsfall protein and albumin for early diagnosis in diabetic retinopathy

    International Nuclear Information System (INIS)

    Objective: To study the relationship between changes of serum type IV collagen, urine Tamm-horsfall protein, albumin and development of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus. Methods: Serum CIV, urine THP and Alb were determined with ELISA and RIA respectively in 76 patients with type 2 diabetes mellitus (NDR26, BDR26, PDR24) and 30 controls. Results: Values of the three markers were significantly different among the three groups of patients (p < 0.01; p < 0.01; p < 0.001 respectively). Conclusion: Serum type IV collagens, urine Tamm-Horsfall protein and albumin were sensitive indicators in predicting diabetic retinopathy

  14. Burkholderia type VI secretion systems have distinct roles in eukaryotic and bacterial cell interactions.

    Directory of Open Access Journals (Sweden)

    Sandra Schwarz

    Full Text Available Bacteria that live in the environment have evolved pathways specialized to defend against eukaryotic organisms or other bacteria. In this manuscript, we systematically examined the role of the five type VI secretion systems (T6SSs of Burkholderia thailandensis (B. thai in eukaryotic and bacterial cell interactions. Consistent with phylogenetic analyses comparing the distribution of the B. thai T6SSs with well-characterized bacterial and eukaryotic cell-targeting T6SSs, we found that T6SS-5 plays a critical role in the virulence of the organism in a murine melioidosis model, while a strain lacking the other four T6SSs remained as virulent as the wild-type. The function of T6SS-5 appeared to be specialized to the host and not related to an in vivo growth defect, as ΔT6SS-5 was fully virulent in mice lacking MyD88. Next we probed the role of the five systems in interbacterial interactions. From a group of 31 diverse bacteria, we identified several organisms that competed less effectively against wild-type B. thai than a strain lacking T6SS-1 function. Inactivation of T6SS-1 renders B. thai greatly more susceptible to cell contact-induced stasis by Pseudomonas putida, Pseudomonas fluorescens and Serratia proteamaculans-leaving it 100- to 1000-fold less fit than the wild-type in competition experiments with these organisms. Flow cell biofilm assays showed that T6S-dependent interbacterial interactions are likely relevant in the environment. B. thai cells lacking T6SS-1 were rapidly displaced in mixed biofilms with P. putida, whereas wild-type cells persisted and overran the competitor. Our data show that T6SSs within a single organism can have distinct functions in eukaryotic versus bacterial cell interactions. These systems are likely to be a decisive factor in the survival of bacterial cells of one species in intimate association with those of another, such as in polymicrobial communities present both in the environment and in many infections.

  15. The host type Ⅰ interferon response to viral and bacterial infections

    Institute of Scientific and Technical Information of China (English)

    Andrea K. PERRY; Gang CHEN; Dahai ZHENG; Hong TANG; Genhong CHENG

    2005-01-01

    Type Ⅰ interferons (IFN) are well studied cytokines with anti-viral and immune-modulating functions. Type Ⅰ IFNs are produced following viral infections, but until recently, the mechanisms of viral recognition leading to IFN production were largely unknown. Toll like receptors (TLRs) have emerged as key transducers of type Ⅰ IFN during viral infections by recognizing various viral components. Furthermore, much progress has been made in defining the signaling pathways downstream of TLRs for type Ⅰ IFN production. TLR7 and TLR9 have become apparent as universally important in inducing type Ⅰ IFN during infection with most viruses, particularly by plasmacytoid dendritic cells. New intracellular viral pattern recognition receptors leading to type Ⅰ IFN production have been identified. Many bacteria can also induce the up-regulation of these cytokines. Interestingly, recent studies have found a detrimental effect on host cells if type Ⅰ IFN is produced during infection with the intracellular gram-positive bacterial pathogen, Listeria monocytogenes. This review will discuss the recent advances made in defining the signaling pathways leading to type Ⅰ IFN production.

  16. Burkholderia type VI secretion systems have distinct roles in eukaryotic and bacterial cell interactions

    DEFF Research Database (Denmark)

    Schwarz, Sandra; West, T Eoin; Boyer, Frédéric;

    2010-01-01

    Bacteria that live in the environment have evolved pathways specialized to defend against eukaryotic organisms or other bacteria. In this manuscript, we systematically examined the role of the five type VI secretion systems (T6SSs) of Burkholderia thailandensis (B. thai) in eukaryotic and bacterial....... From a group of 31 diverse bacteria, we identified several organisms that competed less effectively against wild-type B. thai than a strain lacking T6SS-1 function. Inactivation of T6SS-1 renders B. thai greatly more susceptible to cell contact-induced stasis by Pseudomonas putida, Pseudomonas...... fluorescens and Serratia proteamaculans-leaving it 100- to 1000-fold less fit than the wild-type in competition experiments with these organisms. Flow cell biofilm assays showed that T6S-dependent interbacterial interactions are likely relevant in the environment. B. thai cells lacking T6SS-1 were rapidly...

  17. Structure of the type IVa major pilin from the electrically conductive bacterial nanowires of Geobacter sulfurreducens.

    Science.gov (United States)

    Reardon, Patrick N; Mueller, Karl T

    2013-10-11

    Several species of δ proteobacteria are capable of reducing insoluble metal oxides as well as other extracellular electron acceptors. These bacteria play a critical role in the cycling of minerals in subsurface environments, sediments, and groundwater. In some species of bacteria such as Geobacter sulfurreducens, the transport of electrons is proposed to be facilitated by filamentous fibers that are referred to as bacterial nanowires. These nanowires are polymeric assemblies of proteins belonging to the type IVa family of pilin proteins and are mainly comprised of one subunit protein, PilA. Here, we report the high resolution solution NMR structure of the PilA protein from G. sulfurreducens determined in detergent micelles. The protein is >85% α-helical and exhibits similar architecture to the N-terminal regions of other non-conductive type IVa pilins. The detergent micelle interacts with the first 21 amino acids of the protein, indicating that this region likely associates with the bacterial inner membrane prior to fiber formation. A model of the G. sulfurreducens pilus fiber is proposed based on docking of this structure into the fiber model of the type IVa pilin from Neisseria gonorrhoeae. This model provides insight into the organization of aromatic amino acids that are important for electrical conduction.

  18. The bacterial communities associated with fecal types and body weight of rex rabbits.

    Science.gov (United States)

    Zeng, Bo; Han, Shushu; Wang, Ping; Wen, Bin; Jian, Wensu; Guo, Wei; Yu, Zhiju; Du, Dan; Fu, Xiangchao; Kong, Fanli; Yang, Mingyao; Si, Xiaohui; Zhao, Jiangchao; Li, Ying

    2015-01-01

    Rex rabbit is an important small herbivore for fur and meat production. However, little is known about the gut microbiota in rex rabbit, especially regarding their relationship with different fecal types and growth of the hosts. We characterized the microbiota of both hard and soft feces from rex rabbits with high and low body weight by using the Illumina MiSeq platform targeting the V4 region of the 16S rDNA. High weight rex rabbits possess distinctive microbiota in hard feces, but not in soft feces, from the low weight group. We detected the overrepresentation of several genera such as YS2/Cyanobacteria, and Bacteroidales and underrepresentation of genera such as Anaeroplasma spp. and Clostridiaceae in high weight hard feces. Between fecal types, several bacterial taxa such as Ruminococcaceae, and Akkermansia spp. were enriched in soft feces. PICRUSt analysis revealed that metabolic pathways such as "stilbenoid, diarylheptanoid, gingerol biosynthesis" were enriched in high weight rabbits, and pathways related to "xenobiotics biodegradation" and "various types of N-glycan biosynthesis" were overrepresented in rabbit soft feces. Our study provides foundation to generate hypothesis aiming to test the roles that different bacterial taxa play in the growth and caecotrophy of rex rabbits. PMID:25791609

  19. Bacterial-type oxygen detoxification and iron-sulfur cluster assembly in amoebal relict mitochondria.

    Science.gov (United States)

    Maralikova, Barbora; Ali, Vahab; Nakada-Tsukui, Kumiko; Nozaki, Tomoyoshi; van der Giezen, Mark; Henze, Katrin; Tovar, Jorge

    2010-03-01

    The assembly of vital reactive iron-sulfur (Fe-S) cofactors in eukaryotes is mediated by proteins inherited from the original mitochondrial endosymbiont. Uniquely among eukaryotes, however, Entamoeba and Mastigamoeba lack such mitochondrial-type Fe-S cluster assembly proteins and possess instead an analogous bacterial-type system acquired by lateral gene transfer. Here we demonstrate, using immunomicroscopy and biochemical methods, that beyond their predicted cytosolic distribution the bacterial-type Fe-S cluster assembly proteins NifS and NifU have been recruited to function within the relict mitochondrial organelles (mitosomes) of Entamoeba histolytica. Both Nif proteins are 10-fold more concentrated within mitosomes compared with their cytosolic distribution suggesting that active Fe-S protein maturation occurs in these organelles. Quantitative immunoelectron microscopy showed that amoebal mitosomes are minute but highly abundant cellular structures that occupy up to 2% of the total cell volume. In addition, protein colocalization studies allowed identification of the amoebal hydroperoxide detoxification enzyme rubrerythrin as a mitosomal protein. This protein contains functional Fe-S centres and exhibits peroxidase activity in vitro. Our findings demonstrate the role of analogous protein replacement in mitochondrial organelle evolution and suggest that the relict mitochondrial organelles of Entamoeba are important sites of metabolic activity that function in Fe-S protein-mediated oxygen detoxification. PMID:19888992

  20. Structure of the Type IVa Major Pilin from the Electrically Conductive Bacterial Nanowires of Geobacter sulfurreducens

    Energy Technology Data Exchange (ETDEWEB)

    Reardon, Patrick N.; Mueller, Karl T.

    2013-10-11

    Several species of bacteria are capable of reducing insoluble metal oxides as well as other extracellular electron acceptors. These bacteria play a critical role in the cycling of minerals in subsurface environments, sediments, and groundwater. In some species of bacteria, such as Geobacter sulfurreducens, the transport of electrons is facilitated by filamentous fibers that are referred to as bacterial nanowires. These nanowires belong to the type IVa family of pilin proteins and are mainly comprised of one subunit protein, PilA. Here, we report the high resolution solution nuclear magnetic resonance (NMR) structure of the PilA protein from G. sulfurreducens determined in detergent micelles. The protein is over 85% α-helical and exhibits similar architecture to the N-terminal regions of other non-conductive type IVa pilins. The detergent micelle interacts with the first 21 amino acids of the protein, indicating that this region likely associates with the bacterial inner membrane prior to fiber formation. A model of the G. sulfurreducens pilus fiber is proposed based on docking of this structure into the fiber model of the type IVa pilin from Neisseria gonorrhoeae. This model provides insight into the organization of aromatic amino acids that are important for electrical conduction.

  1. Massive stars exploding in a He-rich circumstellar medium - IV. Transitional Type Ibn supernovae

    DEFF Research Database (Denmark)

    Pastorello, A.; Benetti, S.; Brown, P. J.;

    2015-01-01

    We present ultraviolet, optical and near-infrared data of the Type Ibn supernovae (SNe) 2010al and 2011hw. SN 2010al reaches an absolute magnitude at peak of M-R = -18.86 +/- 0.21. Its early light curve shows similarities with normal SNe Ib, with a rise to maximum slower than most SNe Ibn. The sp...

  2. Photon storage in ¿-type optically dense atomic media. IV. Optimal control using gradient ascent

    DEFF Research Database (Denmark)

    Gorshkov, Alexey V.; Calarco, Tomasso; Lukin, Mikhail D.;

    2008-01-01

    We use the numerical gradient ascent method from optimal control theory to extend efficient photon storage in -type media to previouslyinaccessible regimes and to provide simple intuitive explanations for our optimization techniques. In particular, by using gradient ascent to shape classical...

  3. Direct and Indirect Targeting of PP2A by Conserved Bacterial Type-III Effector Proteins

    OpenAIRE

    Lin Jin; Jong Hyun Ham; Rosemary Hage; Wanying Zhao; Jaricelis Soto-Hernández; Sang Yeol Lee; Seung-Mann Paek; Min Gab Kim; Charles Boone; Coplin, David L.; David Mackey

    2016-01-01

    Bacterial AvrE-family Type-III effector proteins (T3Es) contribute significantly to the virulence of plant-pathogenic species of Pseudomonas, Pantoea, Ralstonia, Erwinia, Dickeya and Pectobacterium, with hosts ranging from monocots to dicots. However, the mode of action of AvrE-family T3Es remains enigmatic, due in large part to their toxicity when expressed in plant or yeast cells. To search for targets of WtsE, an AvrE-family T3E from the maize pathogen Pantoea stewartii subsp. stewartii, w...

  4. Induction of delayed-type hypersensitivity by the T cell line specific to bacterial peptidoglycans

    International Nuclear Information System (INIS)

    A T cell line specific for the chemically well-defined peptidoglycan of bacterial cell wall, disaccharide tetrapeptide, was established from Lewis rats immunized with the antigen covalently linked to the autologous rat serum albumin. The antigen specificity was examined with various analogues or derivatives of the peptidoglycan. The cell line was reactive to analogues with the COOH-terminal D-amino acid, but least reactive to those with L-amino acid as COOH terminus. Transferring of the T cell line into X-irradiated normal Lewis rats induced delayed-type hypersensitivity in an antigen specific manner

  5. Human tandem-repeat-type galectins bind bacterial non-βGal polysaccharides

    DEFF Research Database (Denmark)

    Knirel, Yu A.; Gabius, H.-J.; Blixt, Klas Ola;

    2014-01-01

    ), prompted us to establish an array with bacterial polysaccharides. We addressed the question whether sugar determinants other than β-galactosides may be docking sites, using human galectins-4, -8, and -9. Positive controls with histo-blood group ABH-epitopes and the E. coli 086 polysaccharide ascertained...... the suitability of the set-up. Significant signal generation, depending on type of galectin and polysacchride, was obtained. Presence of cognate β-galactoside-related epitopes within a polysaccharide chain or its branch will not automatically establish binding properties, and structural constellations lacking...

  6. Residual lifetime calculations for the equipment and pipes of WWER type nuclear power plants (1st draft). Section IV

    International Nuclear Information System (INIS)

    The standards documentation of the Association of Mechanical Engineers, Section IV, 'Residual lifetime calculations for the equipment and pipes of WWER type nuclear power plants', provides guidelines and requirements for (i) residual lifetime assessment for apparatus, pipes and supports at WWER type nuclear power plants with respect to their resistance to sudden failure and fatigue damage and with respect to the occurrence of defects detected during in-service inspections; (ii) residual lifetime assessment for apparatus, pipes and supports at WWER type nuclear power plants after component repair, replacement or innovation; and (iii) preparation of documents relating to the continuous gradual exhaustion of the lifetime of apparatus, pipes, and supports at WWER 440 MW and WWER 1000 MW type nuclear power plants and assessment of their residual lifetime. The standards documentation is based on the philosophy of ASME Code Section XI and contains some additional guidelines. The report is divided into the following chapters: General principles, terminology, definitions; General requirements for residual lifetime calculations; Equipment residual lifetime calculation procedure; Equipment residual lifetime assessment with regard to resistance against sudden failure; Assessment of equipment 'fatigue' lifetime; Assessment of equipment 'corrosion mechanical lifetime'; Assessment of the tolerability of defects detected during in-service inspections and residual lifetime assessment for equipment containing such defects; and final assessment of the residual lifetime of equipment. Details are given in 12 Annexes. (P.A.)

  7. [Morquio disease (Mucopolysaccharidosis type IV-A): clinical aspects, diagnosis and new treatment with enzyme replacement therapy].

    Science.gov (United States)

    Politei, Juan; Schenone, Andrea B; Guelbert, Norberto; Fainboim, Alejandro; Szlago, Marina

    2015-08-01

    Mucopolysaccharidosis type IV-A (Morquio A disease) is an autosomal recessive lysosomal storage disease caused by mutations in the gene encoding the N-acetylgalactosamine-6-sulfate sulfatase, that results in impaired catabolism of two glycosaminoglycans, chondroitin-6-sulfate and keratan sulfate. Clinical presentations reflect a spectrum of progression from a severe phenotype to an attenuated expression. Accumulation of substrate manifests predominantly as short stature and skeletal dysplasia, including atlantoaxial instability and cervical cord compression. Other abnormalities in the visual, auditory, cardiovascular and respiratory systems can also affect individuals with Morquio disease. Elosulfase alfa showed in clinical trials in children and adults a significant and sustained improvement in endurance and urinary levels of keratan sulfate. Data from the ongoing observational, multinational Morquio A Registry Study will provide valuable information on the long-term efficacy and safety of elosulfase alfa in patients, as well as on the natural history of this very rare disease. PMID:26172013

  8. Intimal aortic sarcoma mimicking ruptured thoracoabdominal type IV aneurysm. a rare case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Dedeilias Panagiotis

    2011-12-01

    Full Text Available Abstract Primary intimal aortic sarcoma represents a very rare and highly lethal medical entity. Diagnosis is made either by embolic events caused by the tumor or by surrounding tissue symptoms such as pain. Herein we report an extremely rare case of a 51-year-old man previously operated for ascending aortic aneurysm, who presented with clinical and radiological findings suggestive of a ruptured thoracoabdominal type IV aneurysm. The patient underwent radical resection of the aorta and surrounding tissue with placement of a composite 4-branched graft. The diagnosis was made by frozen section and regular histopathologic examination of the specimen and the patient received adjuvant chemotherapy. Nine months after surgery the patient is still alive and has no signs of recurrence. We review the literature and discuss the option of postoperative chemotherapy.

  9. The ATLAS(3D) project : IV. The molecular gas content of early-type galaxies

    NARCIS (Netherlands)

    Young, Lisa M.; Bureau, Martin; Davis, Timothy A.; Combes, Francoise; McDermid, Richard M.; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Cappellari, Michele; Davies, Roger L.; de Zeeuw, P. T.; Emsellem, Eric; Khochfar, Sadegh; Krajnovic, Davor; Kuntschner, Harald; Lablanche, Pierre-Yves; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie

    2011-01-01

    We have carried out a survey for CO J = 1-0 and J = 2-1 emission in the 260 early-type galaxies of the volume-limited ATLAS(3D) sample, with the goal of connecting their star formation and assembly histories to their cold gas content. This is the largest volume-limited CO survey of its kind and is t

  10. Role of Boundary Strengthening on Prevention of Type IV Failure in High Cr Ferritic Heat-Resistant Steels

    Science.gov (United States)

    Liu, Yuan; Tsukamoto, Susumu; Sawada, Kota; Abe, Fujio

    2013-10-01

    Microstructure evolution of newly developed 9Cr-3W-3Co-V, Nb steel with boron addition (B steel) has been analyzed during HAZ thermal cycle at the peak temperature of around Ac3 (Ac3 HAZ) and post-weld heat treatment (PWHT) to elucidate the prevention mechanism of type IV failure by boron addition. It was found that enhancement of the boundary strengthening by precipitates is the main reason for prevention of type IV failure by boron addition. In B steel HAZ, original austenite is reconstituted through martensitic α to γ reverse transformation during the heating and original martensite is reconstituted through martensitic transformation during cooling of the Ac3 HAZ thermal cycle. This process allows M23C6 carbides to precipitate at the prior austenite grain (PAG) and block boundaries during PWHT even if the chemical segregation of carbide forming elements exists. The effect of boundary strengthening on the creep property has also been investigated. Microstructure evolution during creep was compared among Gr.92 with different Ac3 HAZ microstructures prepared by three kinds of heat treatments and B steel. The results revealed that both the boundary length and kernel average misorientation value decreased in all samples during creep. However, this process occurred very rapidly in Ac3 HAZ simulated Gr.92, whereas it was significantly retarded in the other samples with sufficient boundary strengthening by precipitates. This result confirms that the precipitates formed at PAG and block boundaries play the most important role to stabilize the microstructure of Ac3 HAZ simulated samples during creep and prolong the creep life.

  11. Evaluation of three analytical techniques used to determine high levels of volatile organic compounds in type IV sludge from Rocky Flats Plant

    International Nuclear Information System (INIS)

    Before disposal, radioactive sludge (Type IV) from Rocky Flats Plant (RFP) must be evaluated for volatile organic compound (VOC) content. The Type IV sludge consists of organic solvents, degreasers, cutting oils, and transuranic (TRU) waste mixed with calcium silicate (MicroCel E reg-sign) and Oil Dri reg-sign to form a grease or paste-like material. For laboratory testing, a simulated Type IV RFP sludge (nonradioactive) was prepared at Argonne National Laboratory-East. This sludge has a composition similar to that expected from field samples. On the basis of historical information, a typical Type IV sludge is expected to contain approximately 1-10 percent of three target VOCs. The objective of this work is to evaluate three proposed methods for the determination of high levels of these three VOCs in Type IV sludge. The three methods are (1) static headspace gas analysis, (2) methanol extraction, and (3) ethylene glycol extraction. All three methods employ gas chromatography/mass spectrometry (GC/MS). They were evaluated regarding general method performance criteria, ease of operation, and amounts of secondary mixed waste generated

  12. The Atlas3D project -- IV: the molecular gas content of early-type galaxies

    OpenAIRE

    Young, Lisa M.; Bureau, Martin; Davis, Timothy A.; Combes, Francoise; McDermid, Richard M.; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Cappellari, Michele; Davies, Roger L.; de Zeeuw, P. T.; Emsellem, Eric; Khochfar, Sadegh; Krajnovic, Davor

    2011-01-01

    We have carried out a survey for 12CO J=1-0 and J=2-1 emission in the 260 early-type galaxies of the volume-limited Atlas3D sample, with the goal of connecting their star formation and assembly histories to their cold gas content. This is the largest volume-limited CO survey of its kind and is the first to include many Virgo Cluster members. Sample members are dynamically hot galaxies with a median stellar mass 3\\times 10^{10} Msun; they are selected by morphology rather than colour, and the ...

  13. Pyrosequencing-Based Assessment of Bacterial Community Structure Along Different Management Types in German Forest and Grassland Soils

    Science.gov (United States)

    Nacke, Heiko; Thürmer, Andrea; Wollherr, Antje; Will, Christiane; Hodac, Ladislav; Herold, Nadine; Schöning, Ingo; Schrumpf, Marion; Daniel, Rolf

    2011-01-01

    Background Soil bacteria are important drivers for nearly all biogeochemical cycles in terrestrial ecosystems and participate in most nutrient transformations in soil. In contrast to the importance of soil bacteria for ecosystem functioning, we understand little how different management types affect the soil bacterial community composition. Methodology/Principal Findings We used pyrosequencing-based analysis of the V2-V3 16S rRNA gene region to identify changes in bacterial diversity and community structure in nine forest and nine grassland soils from the Schwäbische Alb that covered six different management types. The dataset comprised 598,962 sequences that were affiliated to the domain Bacteria. The number of classified sequences per sample ranged from 23,515 to 39,259. Bacterial diversity was more phylum rich in grassland soils than in forest soils. The dominant taxonomic groups across all samples (>1% of all sequences) were Acidobacteria, Alphaproteobacteria, Actinobacteria, Betaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, and Firmicutes. Significant variations in relative abundances of bacterial phyla and proteobacterial classes, including Actinobacteria, Firmicutes, Verrucomicrobia, Cyanobacteria, Gemmatimonadetes and Alphaproteobacteria, between the land use types forest and grassland were observed. At the genus level, significant differences were also recorded for the dominant genera Phenylobacter, Bacillus, Kribbella, Streptomyces, Agromyces, and Defluviicoccus. In addition, soil bacterial community structure showed significant differences between beech and spruce forest soils. The relative abundances of bacterial groups at different taxonomic levels correlated with soil pH, but little or no relationships to management type and other soil properties were found. Conclusions/Significance Soil bacterial community composition and diversity of the six analyzed management types showed significant differences between the land use types grassland

  14. Pyrosequencing-based assessment of bacterial community structure along different management types in German forest and grassland soils.

    Directory of Open Access Journals (Sweden)

    Heiko Nacke

    Full Text Available BACKGROUND: Soil bacteria are important drivers for nearly all biogeochemical cycles in terrestrial ecosystems and participate in most nutrient transformations in soil. In contrast to the importance of soil bacteria for ecosystem functioning, we understand little how different management types affect the soil bacterial community composition. METHODOLOGY/PRINCIPAL FINDINGS: We used pyrosequencing-based analysis of the V2-V3 16S rRNA gene region to identify changes in bacterial diversity and community structure in nine forest and nine grassland soils from the Schwäbische Alb that covered six different management types. The dataset comprised 598,962 sequences that were affiliated to the domain Bacteria. The number of classified sequences per sample ranged from 23,515 to 39,259. Bacterial diversity was more phylum rich in grassland soils than in forest soils. The dominant taxonomic groups across all samples (>1% of all sequences were Acidobacteria, Alphaproteobacteria, Actinobacteria, Betaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, and Firmicutes. Significant variations in relative abundances of bacterial phyla and proteobacterial classes, including Actinobacteria, Firmicutes, Verrucomicrobia, Cyanobacteria, Gemmatimonadetes and Alphaproteobacteria, between the land use types forest and grassland were observed. At the genus level, significant differences were also recorded for the dominant genera Phenylobacter, Bacillus, Kribbella, Streptomyces, Agromyces, and Defluviicoccus. In addition, soil bacterial community structure showed significant differences between beech and spruce forest soils. The relative abundances of bacterial groups at different taxonomic levels correlated with soil pH, but little or no relationships to management type and other soil properties were found. CONCLUSIONS/SIGNIFICANCE: Soil bacterial community composition and diversity of the six analyzed management types showed significant differences between the land

  15. Calcitonin gene-related peptide regulates type IV hypersensitivity through dendritic cell functions.

    Directory of Open Access Journals (Sweden)

    Norihisa Mikami

    Full Text Available Dendritic cells (DCs play essential roles in both innate and adaptive immune responses. In addition, mutual regulation of the nervous system and immune system is well studied. One of neuropeptides, calcitonin gene-related peptide (CGRP, is a potent regulator in immune responses; in particular, it has anti-inflammatory effects in innate immunity. For instance, a deficiency of the CGRP receptor component RAMP 1 (receptor activity-modifying protein 1 results in higher cytokine production in response to LPS (lipopolysaccharide. On the other hand, how CGRP affects DCs in adaptive immunity is largely unknown. In this study, we show that CGRP suppressed Th1 cell differentiation via inhibition of IL-12 production in DCs using an in vitro co-culture system and an in vivo ovalbumin-induced delayed-type hypersensitivity (DTH model. CGRP also down-regulated the expressions of chemokine receptor CCR2 and its ligands CCL2 and CCL12 in DCs. Intriguingly, the frequency of migrating CCR2(+ DCs in draining lymph nodes of RAMP1-deficient mice was higher after DTH immunization. Moreover, these CCR2(+ DCs highly expressed IL-12 and CD80, resulting in more effective induction of Th1 differentiation compared with CCR2(- DCs. These results indicate that CGRP regulates Th1 type reactions by regulating expression of cytokines, chemokines, and chemokine receptors in DCs.

  16. Development of variable number of tandem repeats typing schemes for Ralstonia solanacearum, the agent of bacterial wilt, banana Moko disease and potato brown rot.

    Science.gov (United States)

    N'guessan, Carine Aya; Brisse, Sylvain; Le Roux-Nio, Anne-Claire; Poussier, Stéphane; Koné, Daouda; Wicker, Emmanuel

    2013-03-01

    Ralstonia solanacearum is an important soil borne bacterial plant pathogen causing bacterial wilt on many important crops. To better monitor epidemics, efficient tools that can identify and discriminate populations are needed. In this study, we assessed variable number of tandem repeats (VNTR) genotyping as a new tool for epidemiological surveillance of R. solanacearum phylotypes, and more specifically for the monitoring of the monomorphic ecotypes "Moko" (banana-pathogenic) and "brown rot" (potato-pathogenic under cool conditions). Screening of six R. solanacearum genome sequences lead to select 36 VNTR loci that were preliminarily amplified on 24 strains. From this step, 26 single-locus primer pairs were multiplexed, and applied to a worldwide collection of 337 strains encompassing the whole phylogenetic diversity, with revelation on a capillary-electrophoresis genotype. Four loci were monomorphic within all phylotypes and were not retained; the other loci were highly polymorphic but displayed a clear phylotype-specificity. Phylotype-specific MLVA schemes were thus defined, based on 13 loci for phylotype I, 12 loci for phylotype II, 11 loci for phylotype III and 6 for phylotype IV. MLVA typing was significantly more discriminative than egl-based sequevar typing, particularly on monomorphic "brown rot" ecotype (phylotype IIB/sequevar 1) and "Moko disease" clade 4 (Phylotype IIB/sequevar 4). Our results raise promising prospects for studies of population genetic structures and epidemiological monitoring. PMID:23376194

  17. Transition of Crack from Type IV to Type II Resulting from Improved Utilization of Boron in the Modified 9Cr-1Mo Steel Weldment

    Science.gov (United States)

    Das, C. R.; Albert, S. K.; Swaminathan, J.; Raju, S.; Bhaduri, A. K.; Murty, B. S.

    2012-10-01

    The roles of boron and heat-treatment temperature in improving the type IV cracking resistance of modified 9Cr-1Mo steel weldment were studied. Two different heats of P91 steel, one without boron, designated as P91 and the other with controlled addition of boron with very low nitrogen, designated as P91B, were melted for the current study. The addition of Boron to modified 9Cr-1Mo steel has increased the resistance against softening in fine-grained heat-affected zones (FGHAZ) and intercritical heat-affected zones (ICHAZ) of the weldment. Creep rupture life of boron containing modified 9Cr-1Mo steel weldment, prepared from 1423 K (1150 °C) normalized base metal, was found to be much higher than that prepared from 1323 K (1050 °C) normalized base metal because of the stabilization of lath martensite by fine M23C6 precipitates. This finding is in contrast to the reduction in creep rupture life of P91 weldment prepared from 1423 K (1150 °C) normalized base metal compared with that of the weldment prepared from 1323 K (1050 °C) normalized base metal. The trace of failure path from the weld metal to ICHAZ in P91B weldment was indicative of type II failure in contrast to type IV failure outside the HAZ and base metal junction in P91 weldment, which suggested that boron strengthened the microstructure of the HAZ, whereby the utilization of boron at a higher normalizing temperature seemed to be significantly greater than that at the lower normalizing temperature.

  18. Development and application of pathovar-specific monoclonal antibodies that recognize the lipopolysaccharide O antigen and the type IV fimbriae of Xanthomonas hyacinthi

    Energy Technology Data Exchange (ETDEWEB)

    Doorn, J. van; Ojanen-Reuhs, T.; Hollinger, T.C.; Reuhs, B.L.; Schots, A.; Boonekamp, P.M.; Oudega, B.

    1999-09-01

    The objective of this study was to develop a specific immunological diagnostic assay for yellow disease in hyacinths, using monoclonal antibodies (MAbs). Mice were immunized with a crude cell wall preparation (shear fraction) from Xanthomonas hyacinthi and with purified type IV fimbriae. Hybridomas were screened for a positive reaction with X. hyacinthi cells or fimbriae and for a negative reaction with X. translucens pv. graminis or Erwinia carotovora subsp. carotovora. Nine MAbs recognized fimbrial epitopes, as shown by immunoblotting, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and immunoelectron microscopy; however, three of these MAbs had weak cross-reactions with two X. translucens pathovars in immunoblotting experiments. Seven MAbs reacted with lipopolysaccharides and yielded a low-mobility ladder pattern on immunoblots. Subsequent analysis of MAb 2E5 showed that it specifically recognized an epitope on the O antigen, which was found to consist of rhamnose and fucose in a 2:1 molar ratio. The cross-reaction of MAb 2E5 with all X. hyacinthi strains tested showed that this O antigen is highly conserved within this species. MAb 1B10 also reacted with lipopolysaccharides. MAbs 2E5 and 1B10 were further tested in ELISA and immunoblotting experiments with cells and extracts from other pathogens. No cross-reaction was found with 27 other Xanthomonas pathovars tested or with 14 other bacterial species from other genera, such as Erwinia and Pseudomonas, indicating the high specificity of these antibodies. MAbs 2E5 and 1B10 were shown to be useful in ELISA for the detection of X. hyacinthi in infected hyacinths.

  19. Microbial Diagnostic Microarrays for the Detection and Typing of Food- and Water-Borne (Bacterial) Pathogens.

    Science.gov (United States)

    Kostić, Tanja; Sessitsch, Angela

    2011-10-14

    Reliable and sensitive pathogen detection in clinical and environmental (including food and water) samples is of greatest importance for public health. Standard microbiological methods have several limitations and improved alternatives are needed. Most important requirements for reliable analysis include: (i) specificity; (ii) sensitivity; (iii) multiplexing potential; (iv) robustness; (v) speed; (vi) automation potential; and (vii) low cost. Microarray technology can, through its very nature, fulfill many of these requirements directly and the remaining challenges have been tackled. In this review, we attempt to compare performance characteristics of the microbial diagnostic microarrays developed for the detection and typing of food and water pathogens, and discuss limitations, points still to be addressed and issues specific for the analysis of food, water and environmental samples.

  20. Microbial Diagnostic Microarrays for the Detection and Typing of Food- and Water-Borne (Bacterial Pathogens

    Directory of Open Access Journals (Sweden)

    Tanja Kostić

    2011-10-01

    Full Text Available Reliable and sensitive pathogen detection in clinical and environmental (including food and water samples is of greatest importance for public health. Standard microbiological methods have several limitations and improved alternatives are needed. Most important requirements for reliable analysis include: (i specificity; (ii sensitivity; (iii multiplexing potential; (iv robustness; (v speed; (vi automation potential; and (vii low cost. Microarray technology can, through its very nature, fulfill many of these requirements directly and the remaining challenges have been tackled. In this review, we attempt to compare performance characteristics of the microbial diagnostic microarrays developed for the detection and typing of food and water pathogens, and discuss limitations, points still to be addressed and issues specific for the analysis of food, water and environmental samples.

  1. Dipeptidyl-Peptidase IV inhibitors and glycemic control in type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Lokendra Bahadur Sapkota

    2016-03-01

    Full Text Available Background & Objectives: Type 2 diabetes mellitus (T2DM is a progressive disease, characterized by insulin resistance, impaired glucose-induced insulin secretion, inappropriately elevated glucagon concentrations, and hyperglycemia. Many patients cannot obtain satisfactory glycemic control with current therapies. New and more effective agents, targeted not only at treatment, but also at prevention of the disease, its progression, and its associated complications, are, therefore, required. The dipeptidyl peptidase-4 (DPP-4 inhibitors are a newer class of oral drugs for the treatment of T2DM. They inhibit the breakdown of glucagon-like peptide-1 (GLP-1 and glucose-dependent insulinotropic polypeptide (GIP thereby increasing the incretin effect in patients with T2DM. In clinical practice they are associated with significant reductions in HbA1c, no weight gain and a low risk of hypoglycemia. Since incretin response is markedly diminished in Asian populations, these agents can be used to achieve satisfactory glycemic control in Nepalese T2DM patients.JCMS Nepal. 2016;12(1:28-32.

  2. Classification of bulimic-type eating disorders: from DSM-IV to DSM-5.

    Science.gov (United States)

    Mond, Jonathan M

    2013-01-01

    Proposed changes to the classification of bulimic-type eating disorders in the lead up to the publication of DSM-5 are reviewed. Several of the proposed changes, including according formal diagnostic status to binge eating disorder (BED), removing the separation of bulimia nervosa (BN) into purging and non-purging subtypes, and reducing the binge frequency threshold from twice per week to once per week for both BN and (BED), have considerable empirical evidence to support them and will likely have the effect of facilitating clinical practice, improving access to care, improving public and professional awareness and understanding of these disorders and stimulating the additional research needed to address at least some problematic issues. However, the omission of any reference to variants of BN characterized by subjective, but not objective, binge eating episodes, and to the undue influence of weight or shape on self-evaluation or similar cognitive criterion in relation to the diagnosis of BED, is regrettable, given their potential to inform clinical and research practice and given that there is considerable evidence to support specific reference to these distinctions. Other aspects of the proposed criteria, such as retention of behavioral indicators of impaired control associated with binge eating and the presence of marked distress regarding binge eating among the diagnostic for BED, appear anomalous in that there is little or no evidence to support their validity or clinical utility. It is hoped that these issues will be addressed in final phase of the DSM-5 development process. PMID:24999412

  3. SVBR-100 module-type fast reactor of the IV generation for regional power industry

    Science.gov (United States)

    Zrodnikov, A. V.; Toshinsky, G. I.; Komlev, O. G.; Stepanov, V. S.; Klimov, N. N.

    2011-08-01

    In the report the following is presented: basic conceptual provisions of the innovative nuclear power technology (NPT) based on modular fast reactors (FR) SVBR-100, summarized results of calculations of the reactor, analysis of the opportunities of multi-purpose application of such reactor facilities (RF) including export potentials with due account of nonproliferation requirements. The most important features of the proposed NPT analyzed in the report are as follows: (1) integral (monoblock) arrangement of the primary circuit equipment with entire elimination of the primary circuit pipelines and valves that considerably reduces the construction and assembly works period and coupling with high boiling point of lead-bismuth coolant (LBC) deterministically eliminates accidents of the LOCA type, (2) option for 100 MWe power and dimensions of the reactor provide: on the one hand, an opportunity to transport the reactor monoblock in factory-readiness by railway as well as other kinds of transport, on the other hand, core breeding ratio (CBR) exceeds 1 while MOX-fuel is used. The preferable area of application of RF SVBR-100 is regional and small power requiring power-units of electric power in a range of (100-600) MW, which could be used for cogeneration-based district heating while locating them nearby cities as well as for generation of electric power in a mode of load tracking in the regions with low network systems.

  4. IFU spectroscopy of 10 early-type galactic nuclei - IV. Properties of the circumnuclear stellar kinematics

    CERN Document Server

    Ricci, T V; Menezes, R B

    2016-01-01

    The study of stellar kinematic properties may provide hints on the formation and evolution of elliptical and lenticular galaxies. Although most previous studies have focused on the large scale of these galaxies, their central regions (scales of $\\sim$ 100 pc) may contain important clues about their structure, such as kinematically decoupled cores. This is the fourth paper on a sample of 10 massive ($\\sigma$ $>$ 200 km s$^{-1}$) and nearby ($d$ $<$ 31 Mpc) early-type galaxies, observed with the integral field unit of the Gemini South Multi Object Spectrograph. Here, we analyse the properties of the stellar kinematics in the circumnuclear region. We fitted the line-of-sight velocity distribution with a Gauss-Hermite function. In seven galaxies of the sample, we detected a rotation pattern in their radial velocity maps that are anti-correlated with $h_3$. We interpret this as stellar structures in rotation embedded in the bulges of the objects. Comparing the stellar kinematic results with the PCA Tomography r...

  5. The Atlas3D project -- IV: the molecular gas content of early-type galaxies

    CERN Document Server

    Young, Lisa M; Davis, Timothy A; Combes, Francoise; McDermid, Richard M; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Cappellari, Michele; Davies, Roger L; de Zeeuw, P T; Emsellem, Eric; Khockfar, Sadegh; Krajnovic, Davor; Kuntschner, Harald; Lablanche, Pierre-Yves; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie

    2011-01-01

    We have carried out a survey for 12CO J=1-0 and J=2-1 emission in the 260 early-type galaxies of the volume-limited Atlas3D sample, with the goal of connecting their star formation and assembly histories to their cold gas content. This is the largest volume-limited CO survey of its kind and is the first to include many Virgo Cluster members. Sample members are dynamically hot galaxies with a median stellar mass 3\\times 10^{10} Msun; they are selected by morphology rather than colour, and the bulk of them lie on the red sequence. The overall CO detection rate is 56/259 = 0.22 \\error 0.03, with no dependence on K luminosity and only a modest dependence on dynamical mass. There are a dozen CO detections among the Virgo Cluster members; statistical analysis of their H_2 mass distributions and their dynamical status within the cluster shows that the cluster's influence on their molecular masses is subtle at best, even though (unlike spirals) they seem to be virialized within the cluster. We suggest that the cluste...

  6. Early-type galaxies at z~1.3. IV. Scaling relations in different environments

    CERN Document Server

    Raichoor, A; Stanford, S A; Holden, B P; Nakata, F; Rosati, P; Shankar, F; Ford, H; Huertas-Company, M; Illingworth, G; Kodama, T; Postman, M; Rettura, A; Blakeslee, J P; Demarco, R; Jee, M J; Tanaka, M; White, R L

    2011-01-01

    We present the Kormendy and mass-size relations for early-type galaxies (ETGs) as a function of environment at z ~ 1.3. Our sample includes 76 ETGs in the Lynx supercluster and in the GOODS/CDF-S field, 31 ETGs in clusters, 18 in groups and 27 in the field, all with multi-wavelength photometry and HST/ACS observations and masses in the range 10^10 < M/Msun < 10^11.5. The Kormendy relation, in place at z ~ 1.3, does not depend on the environment. The mass-size relation reveals that ETGs overall appear to be more compact in denser environments: cluster ETGs have sizes on average twice as smaller than in the local universe, whereas field ETGs show a mass-size relation with a similar distribution than the local one. Our results imply that (1) the mass-size relation in the field did not evolve overall from z ~ 1.3 to present; (2) in denser environments, either ETGs sizes have evolved on average to twice their size, or more ETGs have been formed within the dense environment from not ETG progenitors or larger ...

  7. IFU spectroscopy of 10 early-type galactic nuclei - IV. Properties of the circumnuclear stellar kinematics

    Science.gov (United States)

    Ricci, T. V.; Steiner, J. E.; Menezes, R. B.

    2016-09-01

    The study of stellar kinematic properties may provide hints on the formation and evolution of elliptical and lenticular galaxies. Although most previous studies have focused on the large scale of these galaxies, their central regions (scales of ˜ 100 pc) may contain important clues about their structure, such as kinematically decoupled cores. This is the fourth paper on a sample of 10 massive (σ > 200 km s-1) and nearby (d < 31 Mpc) early-type galaxies, observed with the Integral Field Unit of the Gemini South Multi Object Spectrograph. Here, we analyse the properties of the stellar kinematics in the circumnuclear region. We fitted the line-of-sight velocity distribution with a Gauss-Hermite function. In seven galaxies of the sample, we detected a rotation pattern in their radial velocity maps that are anti-correlated with h3. We interpret this as stellar structures in rotation embedded in the bulges of the objects. Comparing the stellar kinematic results with the PCA Tomography results and also with the gas kinematic results of IC 5181, it seems that this object may have a non-axisymmetric potential at its centre. The velocity dispersion maps of four objects have a nuclear peak, which must correspond, in part, to unresolved stellar rotation. In NGC 1404, we detected a kinematic decoupled core with an extension of ˜ 200 pc. This galaxy also has a σ-drop in the centre, which may be related to both stellar components in counterrotation or with a kinematically cold star-forming region.

  8. Photometric Properties for Selected Algol-type Binaries. IV. AV Hydrae and DZ Cassiopeiae

    Science.gov (United States)

    Yang, Y.-G.; Li, L.-H.; Dai, H.-F.

    2012-08-01

    We present BVR photometric observations and several eclipsing times for AV Hya and DZ Cas from 2004 to 2011. Using the Wilson-Devinney method, the photometric solutions with hot spots were deduced from their asymmetric light curves. The results indicate that both stars are Algol-type binaries, whose mass ratio, q ph, and fill-out factor of the primary, f 1, are q ph = 0.255(± 0.002) and f 1 = 81.2(± 0.2)% for AV Hya, and q ph = 0.093(± 0.003) and f 1 = 98.7(± 0.3)% for DZ Cas. Based on all available light minimum times, it is discovered that the O - C curve of each star could be described by a light-time orbit overlying on a downward parabola. Their periods and amplitudes are P 3 = 37.2(± 0.7) yr and A = 0fd0095(±0fd0006) for AV Hya, and P 3 = 62.5(± 1.0) yr and A = 0fd0183(±0fd0007) for DZ Cas. Cyclic variations may result from the light-time effect due to the third body. The secular period decrease rates are dP/dt = -1.47(± 0.04) × 10-7 days yr-1 for AV Hya and dP/dt = -0.92(± 0.04) × 10-7 days yr-1 for DZ Cas. This may be interpreted using mass and angular momentum loss from the system. With decreasing period, the fill-out factor of the primary increases and it may finally fill its inner Roche lobe. Therefore, AV Hya and DZ Cas with a secular period decrease will evolve from semi-detached configurations into contact ones.

  9. Lack of association of the HMGA1 IVS5-13insC variant with type 2 diabetes in an ethnically diverse hypertensive case control cohort

    Directory of Open Access Journals (Sweden)

    Karnes Jason H

    2013-01-01

    Full Text Available Abstract Background Recently, the high-mobility group A1 gene (HMGA1 variant IVS5-13insC has been associated with type 2 diabetes, but reported associations are inconsistent and data are lacking in Hispanic and African American populations. We sought to investigate the HMGA1-diabetes association and to characterize IVS5-13insC allele frequencies and linkage disequilibrium (LD in 3,070 Caucasian, Hispanic, and African American patients from the INternational VErapamil SR-Trandolapril STudy (INVEST. Methods INVEST was a randomized, multicenter trial comparing two antihypertensive treatment strategies in an ethnically diverse cohort of hypertensive, coronary artery disease patients. Controls, who were diabetes-free throughout the study, and type 2 diabetes cases, either prevalent or incident, were genotyped for IVS5-13insC using Taqman®, confirmed with Pyrosequencing and Sanger sequencing. For LD analysis, genotyping for eight additional HMGA1 single nucleotide polymorphisms (SNPs was performed using the Illumina® HumanCVD BeadChip. We used logistic regression to test association of the HMGA1 IVS5-13insC and diabetes, adjusted for age, gender, body mass index, and percentage European, African, and Native American ancestry. Results We observed IVS5-13insC minor allele frequencies consistent with previous literature in Caucasians and African Americans (0.03 in cases and 0.04 in controls for both race/ethnic groups, and higher frequencies in Hispanics (0.07 in cases and 0.07 in controls. The IVS5-13insC was not associated with type 2 diabetes overall (odds ratio 0.98 [0.76-1.26], p=0.88 or in any race/ethnic group. Pairwise LD (r2 of IVS5-13insC and rs9394200, a SNP previously used as a tag SNP for IVS5-13insC, was low (r2=0.47 in Caucasians, r2=0.25 in Hispanics, and r2=0.06 in African Americans. Furthermore, in silico analysis suggested a lack of functional consequences for the IVS5-13insC variant. Conclusions Our results suggest that IVS5-13ins

  10. Identification and functional analysis of a novel mutation in the SOX10 gene associated with Waardenburg syndrome type IV.

    Science.gov (United States)

    Wang, Hong-Han; Chen, Hong-Sheng; Li, Hai-Bo; Zhang, Hua; Mei, Ling-Yun; He, Chu-Feng; Wang, Xing-Wei; Men, Mei-Chao; Jiang, Lu; Liao, Xin-Bin; Wu, Hong; Feng, Yong

    2014-03-15

    Waardenburg syndrome type IV (WS4) is a rare genetic disorder, characterized by auditory-pigmentary abnormalities and Hirschsprung disease. Mutations of the EDNRB gene, EDN3 gene, or SOX10 gene are responsible for WS4. In the present study, we reported a case of a Chinese patient with clinical features of WS4. In addition, the three genes mentioned above were sequenced in order to identify whether mutations are responsible for the case. We revealed a novel nonsense mutation, c.1063C>T (p.Q355*), in the last coding exon of SOX10. The same mutation was not found in three unaffected family members or 100 unrelated controls. Then, the function and mechanism of the mutation were investigated in vitro. We found both wild-type (WT) and mutant SOX10 p.Q355* were detected at the expected size and their expression levels are equivalent. The mutant protein also localized in the nucleus and retained the DNA-binding activity as WT counterpart; however, it lost its transactivation capability on the MITF promoter and acted as a dominant-negative repressor impairing function of the WT SOX10. PMID:24440785

  11. Fusion of lysosomes with secretory organelles leads to uncontrolled exocytosis in the lysosomal storage disease mucolipidosis type IV.

    Science.gov (United States)

    Park, Soonhong; Ahuja, Malini; Kim, Min Seuk; Brailoiu, G Cristina; Jha, Archana; Zeng, Mei; Baydyuk, Maryna; Wu, Ling-Gang; Wassif, Christopher A; Porter, Forbes D; Zerfas, Patricia M; Eckhaus, Michael A; Brailoiu, Eugen; Shin, Dong Min; Muallem, Shmuel

    2016-02-01

    Mutations in TRPML1 cause the lysosomal storage disease mucolipidosis type IV (MLIV). The role of TRPML1 in cell function and how the mutations cause the disease are not well understood. Most studies focus on the role of TRPML1 in constitutive membrane trafficking to and from the lysosomes. However, this cannot explain impaired neuromuscular and secretory cells' functions that mediate regulated exocytosis. Here, we analyzed several forms of regulated exocytosis in a mouse model of MLIV and, opposite to expectations, we found enhanced exocytosis in secretory glands due to enlargement of secretory granules in part due to fusion with lysosomes. Preliminary exploration of synaptic vesicle size, spontaneous mEPSCs, and glutamate secretion in neurons provided further evidence for enhanced exocytosis that was rescued by re-expression of TRPML1 in neurons. These features were not observed in Niemann-Pick type C1. These findings suggest that TRPML1 may guard against pathological fusion of lysosomes with secretory organelles and suggest a new approach toward developing treatment for MLIV. PMID:26682800

  12. Processing and maturation of the pilin of the type IV secretion system encoded within the gonococcal genetic island.

    Science.gov (United States)

    Jain, Samta; Kahnt, Jörg; van der Does, Chris

    2011-12-23

    The type IV secretion system (T4SS) encoded within the gonococcal genetic island (GGI) of Neisseria gonorrhoeae has homology to the T4SS encoded on the F plasmid. The GGI encodes the putative pilin protein TraA and a serine protease TrbI, which is homologous to the TraF protein of the RP4 plasmid involved in circularization of pilin subunits of P-type pili. TraA was processed to a 68-amino acid long circular peptide by leader peptidase and TrbI. Processing occurred after co-translational membrane insertion and was independent of other proteins. Circularization occurred after removal of three C-terminal amino acids. Mutational analysis of TraA revealed limited flexibility at the cleavage and joining sites. Mutagenesis of TrbI showed that the conserved Lys-93 and Asp-155 are essential, whereas mutagenesis of Ser-52, the putative catalytic serine did not influence circularization. Further mutagenesis of other serine residues did not identify a catalytic serine, indicating that TrbI either contains redundant catalytic serine residues or does not function via a serine-lysine dyad mechanism. In vitro studies revealed that circularization occurs via a covalent intermediate between the C terminus of TraA and TrbI. The intermediate is processed to the circular form after cleavage of the N-terminal signal sequence. This is the first demonstration of a covalent intermediate in the circularization mechanism of conjugative pili. PMID:22006923

  13. MMP Mediated Degradation of Type IV Collagen Alpha 1 and Alpha 3 Chains Reflects Basement Membrane Remodeling in Experimental and Clinical Fibrosis - Validation of Two Novel Biomarker Assays

    DEFF Research Database (Denmark)

    Sand, Jannie Marie; Larsen, Lise Skakkebæk; Hogaboam, Cory;

    2013-01-01

    Fibrosis is characterized by excessive tissue remodeling resulting from altered expression of various growth factors, cytokines and proteases. We hypothesized that matrix metalloproteinase (MMP) mediated degradation of type IV collagen, a main component of the basement membrane, will release...... peptide fragments (neo-epitopes) into the circulation. Here we present the development of two competitive enzyme-linked immunosorbent assays (ELISAs) for assessing the levels of specific fragments of type IV collagen α1 (C4M12a1) and α3 (C4M12a3) chains in serum as indicators of fibrosis....

  14. Pyrosequencing-Based Assessment of Bacterial Community Structure Along Different Management Types in German Forest and Grassland Soils

    OpenAIRE

    Nacke, Heiko; Thürmer, Andrea; Wollherr, Antje; Will, Christiane; Hodac, Ladislav; Herold, Nadine; Schöning, Ingo; Schrumpf, Marion; Daniel, Rolf

    2011-01-01

    Background: Soil bacteria are important drivers for nearly all biogeochemical cycles in terrestrial ecosystems and participate in most nutrient transformations in soil. In contrast to the importance of soil bacteria for ecosystem functioning, we understand little how different management types affect the soil bacterial community composition. Methodology/Principal Findings: We used pyrosequencing-based analysis of the V2-V3 16S rRNA gene region to identify changes in bacterial dive...

  15. Displacement of the predominant dengue virus from type 2 to type 1 with a subsequent genotype shift from IV to I in Surabaya, Indonesia 2008-2010.

    Directory of Open Access Journals (Sweden)

    Atsushi Yamanaka

    Full Text Available Indonesia has annually experienced approximately 100,000 reported cases of dengue fever (DF and dengue hemorrhagic fever (DHF in recent years. However, epidemiological surveys of dengue viruses (DENVs have been limited in this country. In Surabaya, the second largest city, a single report indicated that dengue virus type 2 (DENV2 was the predominant circulating virus in 2003-2005. We conducted three surveys in Surabaya during: (i April 2007, (ii June 2008 to April 2009, and (iii September 2009 to December 2010. A total of 231 isolates were obtained from dengue patients and examined by PCR typing. We found that the predominant DENV shifted from type 2 to type 1 between October and November 2008. Another survey using wild-caught mosquitoes in April 2009 confirmed that dengue type 1 virus (DENV1 was the predominant type in Surabaya. Phylogenetic analyses of the nucleotide sequences of the complete envelope gene of DENV1 indicated that all 22 selected isolates in the second survey belonged to genotype IV and all 17 selected isolates in the third survey belonged to genotype I, indicating a genotype shift between April and September 2009. Furthermore, in December 2010, isolates were grouped into a new clade of DENV1 genotype I, suggesting clade shift between September and December 2010. According to statistics reported by the Surabaya Health Office, the proportion of DHF cases among the total number of dengue cases increased about three times after the type shift in 2008. In addition, the subsequent genotype shift in 2009 was associated with the increased number of total dengue cases. This indicates the need for continuous surveillance of circulating viruses to predict the risk of DHF and DF.

  16. Structure of a bacterial type III secretion system in contact with a host membrane in situ

    Science.gov (United States)

    Nans, Andrea; Kudryashev, Mikhail; Saibil, Helen R.; Hayward, Richard D.

    2015-12-01

    Many bacterial pathogens of animals and plants use a conserved type III secretion system (T3SS) to inject virulence effector proteins directly into eukaryotic cells to subvert host functions. Contact with host membranes is critical for T3SS activation, yet little is known about T3SS architecture in this state or the conformational changes that drive effector translocation. Here we use cryo-electron tomography and sub-tomogram averaging to derive the intact structure of the primordial Chlamydia trachomatis T3SS in the presence and absence of host membrane contact. Comparison of the averaged structures demonstrates a marked compaction of the basal body (4 nm) occurs when the needle tip contacts the host cell membrane. This compaction is coupled to a stabilization of the cytosolic sorting platform-ATPase. Our findings reveal the first structure of a bacterial T3SS from a major human pathogen engaged with a eukaryotic host, and reveal striking `pump-action' conformational changes that underpin effector injection.

  17. Durability improvement assessment in different high strength bacterial structural concrete grades against different types of acids

    Indian Academy of Sciences (India)

    Ramin Andalib; M Zaimi Abd Majid; A Keyvanfar; Amirreza Talaiekhozan; Mohd Warid Hussin; A Shafaghat; Rosli Mohd Zin; Chew Tin Lee; Mohammad Ali Fulazzaky; Hasrul Haidar Ismail

    2014-12-01

    This paper provides an insight into a new biotechnological method based on calcite precipitation for achieving high strength bio-concrete durability. It is very clear that mineral precipitation has the potential to enhance construction material resistance towards degradation procedures. The appropriate microbial cell concentration (30 * 105 cells/ml) was introduced onto different structural concrete grades (40, 45 and 50 MPa) by mixing water. In order to study the durability of structural concrete against aggressive agents, specimens were immersed in different types of acids solution (5% H2SO4 and HCl) to compare their effects on 60th, 90th and 120th day. In general, sulphuric acid and hydrochloric acid are known to be the most aggressive natural threats from industrial waters which can penetrate concrete to transfer the soluble calcium salts away from the cement matrix. The experimental results demonstrated that bio-concrete has less weight and strength losses when compared to the ordinary Portland cement concrete without microorganism. It was also found that maximum compressive strength and weight loss occurred during H2SO4 acid immersion as compared to HCl immersion. The density and uniformity of bio-concrete were examined using ultrasonic pulse velocity (UPV) test. Microstructure chemical analysis was also quantified by energy dispersive spectrometer (EDS) to justify the durability improvement in bacterial concrete. It was observed that less sulphur and chloride were noticed in bacterial concrete against H2SO4 and HCl, respectively in comparison to the ordinary Portland cement concrete due to calcite deposition.

  18. A novel type bacterial flagellar motor that can use divalent cations as a coupling ion.

    Science.gov (United States)

    Imazawa, Riku; Takahashi, Yuka; Aoki, Wataru; Sano, Motohiko; Ito, Masahiro

    2016-01-01

    The bacterial flagellar motor is a sophisticated nanomachine embedded in the cell envelope and powered by an electrochemical gradient of H(+), Na(+), or K(+)across the cytoplasmic membrane. Here we describe a new member of the bacterial flagellar stator channel family (MotAB1 of Paenibacillus sp. TCA20 (TCA-MotAB1)) that is coupled to divalent cations (Ca(2+)and Mg(2+)). In the absence of divalent cations of alkaline earth metals, no swimming was observed in Paenibacillus sp. TCA20, which grows optimally in Ca(2+)-rich environments. This pattern was confirmed by swimming assays of a stator-free Bacillus subtilis mutant expressing TCA-MotAB1. Both a stator-free and major Mg(2+)uptake system-deleted B. subtilis mutant expressing TCA-MotAB1 complemented both growth and motility deficiency under low Mg(2+)conditions and exhibited [Mg(2+)]in identical to that of the wild-type. This is the first report of a flagellar motor that can use Ca(2+)and Mg(2+)as coupling ions. These findings will promote the understanding of the operating principles of flagellar motors and molecular mechanisms of ion selectivity. PMID:26794857

  19. Enhanced discrimination of highly clonal ST22-methicillin-resistant Staphylococcus aureus IV isolates achieved by combining spa, dru, and pulsed-field gel electrophoresis typing data.

    LENUS (Irish Health Repository)

    Shore, Anna C

    2010-05-01

    ST22-methicillin-resistant Staphylococcus aureus type IV (ST22-MRSA-IV) is endemic in Irish hospitals and is designated antibiogram-resistogram type-pulsed-field group (AR-PFG) 06-01. Isolates of this highly clonal strain exhibit limited numbers of pulsed-field gel electrophoresis (PFGE) patterns and spa types. This study investigated whether combining PFGE and spa typing with DNA sequencing of the staphylococcal cassette chromosome mec element (SCCmec)-associated direct repeat unit (dru typing) would improve isolate discrimination. A total of 173 MRSA isolates recovered in one Irish hospital during periods in 2007 and 2008 were investigated using antibiogram-resistogram (AR), PFGE, spa, dru, and SCCmec typing. Isolates representative of each of the 17 pulsed-field group 01 (PFG-01) spa types identified underwent multilocus sequence typing, and all isolates were ST22. Ninety-seven percent of isolates (168 of 173) exhibited AR-PFG 06-01 or closely related AR patterns, and 163 of these isolates harbored SCCmec type IVh. The combination of PFGE, spa, and dru typing methods significantly improved discrimination of the 168 PFG-01 isolates, yielding 65 type combinations with a Simpson\\'s index of diversity (SID) of 96.53, compared to (i) pairwise combinations of spa and dru typing, spa and PFGE typing, and dru and PFGE typing, which yielded 37, 44, and 43 type combinations with SIDs of 90.84, 91.00, and 93.57, respectively, or (ii) individual spa, dru, and PFGE typing methods, which yielded 17, 17, and 21 types with SIDs of 66.9, 77.83, and 81.34, respectively. Analysis of epidemiological information for a subset of PFG-01 isolates validated the relationships inferred using combined PFGE, spa, and dru typing data. This approach significantly enhances discrimination of ST22-MRSA-IV isolates and could be applied to epidemiological investigations of other highly clonal MRSA strains.

  20. Biological evaluation and molecular modelling study of thiosemicarbazide derivatives as bacterial type IIA topoisomerases inhibitors.

    Science.gov (United States)

    Paneth, Agata; Stączek, Paweł; Plech, Tomasz; Strzelczyk, Aleksandra; Dzitko, Katarzyna; Wujec, Monika; Kuśmierz, Edyta; Kosikowska, Urszula; Grzegorczyk, Agnieszka; Paneth, Piotr

    2016-01-01

    In the present article, we describe the inhibitory potency of nine thiosemicarbazide derivatives against bacterial type IIA topoisomerases, their antibacterial profile and molecular modelling evaluation. We found that one of the tested compounds, compound 7, significantly inhibits activity of Staphylococcus aureus DNA gyrase with an IC(50) below 15 μM. Besides, this compound displays antibacterial activity on reference Staphylococuss spp. and Enterococcus faecalis strains as well as clinical S. aureus isolates at non-cytotoxic concentrations in mammalian cells with MIC values ranging from 16 to 32 μg/mL thereby indicating, in some cases, equipotent or even more effective action than standard drugs such as vancomycin, ampicillin and nitrofurantoin. The computational studies showed that both molecular geometry and the electron density distribution have a great impact on antibacterial activity of thiosemicarbazide derivatives. PMID:25792505

  1. Vaccination for the control of childhood bacterial pneumonia - Haemophilus influenzae type b and pneumococcal vaccines

    Directory of Open Access Journals (Sweden)

    Diana C Otczyk

    2013-01-01

    Full Text Available Pneumonia in childhood is endemic in large parts of the world and in particular, in developing countries, as well as in many indigenous communities within developed nations. Haemophilus influenzae type b and Streptococcus pneumoniae conjugate vaccines are currently available against the leading bacterial causes of pneumonia.  The use of the vaccines in both industrialised and developing countries have shown a dramatic reduction in the burden of pneumonia and invasive disease in children.  However, the greatest threat facing pneumococcal conjugate vaccine effectiveness is serotype replacement.  The current vaccines provide serotype-specific, antibody–mediated protection against only a few of the 90+ capsule serotypes.  Therefore, there has been a focus in recent years to rapidly advance technologies that will result in broader disease coverage and more affordable vaccines that can be used in developing countries.  The next generation of pneumococcal vaccines have advanced to clinical trials.

  2. Inhibitors of dipeptidyl peptidase IV: a novel approach for the prevention and treatment of Type 2 diabetes?

    DEFF Research Database (Denmark)

    Deacon, Carolyn F; Ahrén, Bo; Holst, Jens J

    2004-01-01

    Inhibitors of the enzyme dipeptidyl peptidase IV (DPP IV) are of increasing interest to both diabetologists and the pharmaceutical industry alike, as they may become established as the next member of the oral antidiabetic class of therapeutic agents, designed to lower blood glucose and, possibly,...

  3. Computational prediction of secretion systems and secretomes of Brucella: identification of novel type IV effectors and their interaction with the host.

    Science.gov (United States)

    Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S; Dinakaran, Vasudevan; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash

    2016-01-01

    Brucella spp. are facultative intracellular pathogens that cause brucellosis in various mammals including humans. Brucella survive inside the host cells by forming vacuoles and subverting host defence systems. This study was aimed to predict the secretion systems and the secretomes of Brucella spp. from 39 complete genome sequences available in the databases. Furthermore, an attempt was made to identify the type IV secretion effectors and their interactions with host proteins. We predicted the secretion systems of Brucella by the KEGG pathway and SecReT4. Brucella secretomes and type IV effectors (T4SEs) were predicted through genome-wide screening using JVirGel and S4TE, respectively. Protein-protein interactions of Brucella T4SEs with their hosts were analyzed by HPIDB 2.0. Genes coding for Sec and Tat pathways of secretion and type I (T1SS), type IV (T4SS) and type V (T5SS) secretion systems were identified and they are conserved in all the species of Brucella. In addition to the well-known VirB operon coding for the type IV secretion system (T4SS), we have identified the presence of additional genes showing homology with T4SS of other organisms. On the whole, 10.26 to 14.94% of total proteomes were found to be either secreted (secretome) or membrane associated (membrane proteome). Approximately, 1.7 to 3.0% of total proteomes were identified as type IV secretion effectors (T4SEs). Prediction of protein-protein interactions showed 29 and 36 host-pathogen specific interactions between Bos taurus (cattle)-B. abortus and Ovis aries (sheep)-B. melitensis, respectively. Functional characterization of the predicted T4SEs and their interactions with their respective hosts may reveal the secrets of host specificity of Brucella.

  4. Evaluation of W/P Ratio, Setting Time and Compressive Strength of Dental Stone Type III and IV Marketed in Jakarta

    Directory of Open Access Journals (Sweden)

    Yosi Kusuma Eriwati

    2015-10-01

    Full Text Available Dental gypsum products in Indonesia are mainly imported from countries with non-tropical weather. Mostly, these gypsum products marketed in Jakarta are without adequate packaging, data or manipulative and maintenance instructions, which can cause misuse & abuse in the materials manipulation and handling. The purpose of this study was to evaluate the W/P ratio, setting time and compressive strength of dental stone type III and IV in relation with room temperature condition and relative humidity in Jakarta, Indonesia. One hundred and eighty dental stone Type III (unlabelled Blue Hard Stone; Giludur, Germany: Moldaroc, Germany and Type IV (New Fujirock, Japan; Glastone, USA; unlabelled Quickstone specimens were made as recommended by ISO 6873-1983 for setting time (with Vicat needle and compressive strength determination (Shimadzu mechanical testing machine with W/P ratio variables of 0.28; 0.29; 0.30 for Type III and 0.20; 0.21; 0.22 for type IV. The tests were conducted in 2 rooms with different temperature and humidity and with and without air-conditioned. Statistical analysis using T-test. The results shows that the increasing of W/P ratio will decrease the dental stone type III and IV setting time. Jakarta condition of high room temperature and relative humidity significantly shorten the setting time of Moldaroc and New Fujirock. The rest of the stones were reduced statistically insignificant. It can be concluded that the temperature and humidity in Jakarta can influence the setting time and compressive strength of dental stone type III and IV. However, since the setting time and strength values are still within the ISO standard, these stones can be accepted and used in Indonesia.

  5. The influence of surface soil physicochemistry on the edaphic bacterial communities in contrasting terrain types of the Central Namib Desert.

    Science.gov (United States)

    Gombeer, S; Ramond, J-B; Eckardt, F D; Seely, M; Cowan, D A

    2015-09-01

    Notwithstanding, the severe environmental conditions, deserts harbour a high diversity of adapted micro-organisms. In such oligotrophic environments, soil physicochemical characteristics play an important role in shaping indigenous microbial communities. This study investigates the edaphic bacterial communities of three contrasting desert terrain types (gravel plains, sand dunes and ephemeral rivers) with different surface geologies in the Central Namib Desert. For each site, we evaluated surface soil physicochemistries and used explorative T-RFLP methodology to get an indication of bacterial community diversities. While grain size was an important parameter in separating the three terrain types physicochemically and specific surface soil types could be distinguished, the desert edaphic bacterial communities displayed a high level of local spatial heterogeneity. Ten variables contributed significantly (P Namib Desert and stress the importance of recording a wide variety of environmental descriptors to comprehensively assess the role of edaphic parameters in shaping microbial communities. PMID:25939371

  6. Subtilisin-like protease-1 secreted through type IV secretion system contributes to high virulence of Streptococcus suis 2.

    Science.gov (United States)

    Yin, Supeng; Li, Ming; Rao, Xiancai; Yao, Xinyue; Zhong, Qiu; Wang, Min; Wang, Jing; Peng, Yizhi; Tang, Jiaqi; Hu, Fuquan; Zhao, Yan

    2016-01-01

    Streptococcus suis serotype 2 is an emerging zoonotic pathogen that triggered two outbreaks of streptococcal toxic shock syndrome (STSS) in China. Our previous research demonstrated that a type IV secretion system (T4SS) harbored in the 89K pathogenicity island contributes to the pathogenicity of S. suis 2. In the present study, a shotgun proteomics approach was employed to identify the effectors secreted by T4SS in S. suis 2, and surface-associated subtilisin-like protease-1 (SspA-1) was identified as a potential virulence effector. Western blot analysis and pull-down assay revealed that SspA-1 secretion depends on T4SS. Knockout mutations affecting sspA-1 attenuated S. suis 2 and impaired the pathogen's ability to trigger inflammatory response in mice. And purified SspA-1 induced the secretion of IL-6, TNF-α, and IL-12p70 in THP-1 cells directly. SspA-1 is the first T4SS virulence effector reported in Gram-positive bacteria. Overall, these findings allow us to gain further insights into the pathogenesis of T4SS and STSS. PMID:27270879

  7. Targeted mutagenesis of intergenic regions in the Neisseria gonorrhoeae gonococcal genetic island reveals multiple regulatory mechanisms controlling type IV secretion.

    Science.gov (United States)

    Ramsey, Meghan E; Bender, Tobias; Klimowicz, Amy K; Hackett, Kathleen T; Yamamoto, Ami; Jolicoeur, Adrienne; Callaghan, Melanie M; Wassarman, Karen M; van der Does, Chris; Dillard, Joseph P

    2015-09-01

    Gonococci secrete chromosomal DNA into the extracellular environment using a type IV secretion system (T4SS). The secreted DNA acts in natural transformation and initiates biofilm development. Although the DNA and its effects are detectable, structural components of the T4SS are present at very low levels, suggestive of uncharacterized regulatory control. We sought to better characterize the expression and regulation of T4SS genes and found that the four operons containing T4SS genes are transcribed at very different levels. Increasing transcription of two of the operons through targeted promoter mutagenesis did not increase DNA secretion. The stability and steady-state levels of two T4SS structural proteins were affected by a homolog of tail-specific protease. An RNA switch was also identified that regulates translation of a third T4SS operon. The switch mechanism relies on two putative stem-loop structures contained within the 5' untranslated region of the transcript, one of which occludes the ribosome binding site and start codon. Mutational analysis of these stem loops supports a model in which induction of an alternative structure relieves repression. Taken together, these results identify multiple layers of regulation, including transcriptional, translational and post-translational mechanisms controlling T4SS gene expression and DNA secretion. PMID:26076069

  8. Bacillus Calmette-Guérin enhances production and secretion of type IV collagenases in peripheral blood mononuclear cells.

    Science.gov (United States)

    Kageyama, Y; Kawakami, S; Fujii, Y; Kihara, K; Oshima, H

    1997-03-01

    Intravesical administration of bacillus Calmette-Guérin (BCG) is an effective and widely accepted treatment for superficial bladder cancer. Rapid progression of the disease after BCG therapy, however, has been reported in some cases refractory to the treatment. We examined whether BCG treatment and coexistence of peripheral blood mononuclear cells (PBMCs) alter the invasive potential of bladder cancer cells. Production and secretion of two type IV collagenases, matrix metalloproteinase (MMP) 2 and MMP 9, by PBMCs from five healthy donors or bladder cancer cells (T24, JTC 30, and JTC 32) were evaluated by gelatin zymography, western blot analysis, and northern blot analysis. Invasion of bladder cancer cells was also examined using reconstituted basement membrane (Matrigel). BCG (5, 50, and 500 micrograms/ml) had no effect on secretion of MMP 2 and MMP 9 by bladder cancer cells, but increased the production and secretion of MMP 9 by PBMCs in a dose-dependent manner. The coexistence of PBMCs increased invasion of T24 cells and BCG further enhanced the invasion. Thus, BCG promotes invasion of bladder cancer cells under certain conditions. An increase in the secretion of MMP 9 by PBMCs may account in part for the effect.

  9. Relationships between host phylogeny, host type and bacterial community diversity in cold-water coral reef sponges.

    Directory of Open Access Journals (Sweden)

    Sandra Schöttner

    Full Text Available Cold-water coral reefs are known to locally enhance the diversity of deep-sea fauna as well as of microbes. Sponges are among the most diverse faunal groups in these ecosystems, and many of them host large abundances of microbes in their tissues. In this study, twelve sponge species from three cold-water coral reefs off Norway were investigated for the relationship between sponge phylogenetic classification (species and family level, as well as sponge type (high versus low microbial abundance, and the diversity of sponge-associated bacterial communities, taking also geographic location and water depth into account. Community analysis by Automated Ribosomal Intergenic Spacer Analysis (ARISA showed that as many as 345 (79% of the 437 different bacterial operational taxonomic units (OTUs detected in the dataset were shared between sponges and sediments, while only 70 (16% appeared purely sponge-associated. Furthermore, changes in bacterial community structure were significantly related to sponge species (63% of explained community variation, sponge family (52% or sponge type (30%, whereas mesoscale geographic distances and water depth showed comparatively small effects (<5% each. In addition, a highly significant, positive relationship between bacterial community dissimilarity and sponge phylogenetic distance was observed within the ancient family of the Geodiidae. Overall, the high diversity of sponges in cold-water coral reefs, combined with the observed sponge-related variation in bacterial community structure, support the idea that sponges represent heterogeneous, yet structured microbial habitats that contribute significantly to enhancing bacterial diversity in deep-sea ecosystems.

  10. The dipeptidyl peptidase IV inhibitor vildagliptin suppresses endogenous glucose production and enhances islet function after single-dose administration in type 2 diabetic patients

    DEFF Research Database (Denmark)

    Balas, Bogdan; Baig, Muhammad R; Watson, Catherine;

    2007-01-01

    AIMS/HYPOTHESIS: Vildagliptin is a selective dipeptidyl peptidase IV inhibitor that augments meal-stimulated levels of biologically active glucagon-like peptide-1. Chronic vildagliptin treatment decreases postprandial glucose levels and reduces hemoglobin A1c in type 2 diabetic patients. However,...

  11. Vildagliptin, a dipeptidyl peptidase-IV inhibitor, improves model-assessed beta-cell function in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Mari, A; Sallas, W M; He, Y L;

    2005-01-01

    AIMS/HYPOTHESIS: The dipeptidyl peptidase IV inhibitor, vildagliptin, increases levels of intact glucagon-like peptide-1 (GLP-1) and improves glycemic control in patients with type 2 diabetes. Although GLP-1 is known to stimulate insulin secretion, vildagliptin does not affect plasma insulin leve...

  12. Finite element analysis of type IV cracking in 2.25Cr-1Mo steel weldment based on micro-mechanistic approach

    Science.gov (United States)

    Goyal, Sunil; Laha, K.; Chandravathi, K. S.; Parameswaran, P.; Mathew, M. D.

    2011-08-01

    Creep studies were carried out on 2.25Cr-1Mo steel base metal and its fusion-welded weldments at 823 K over the stress range 100-240 MPa. The weldment possessed lower creep rupture strength than the base metal due to type IV failure at the outer edge of the heat-affected zone (HAZ). Premature failure of the weldment was associated with pronounced creep cavitation accompanied with localized creep deformation in the soft intercritical region of the HAZ that was sandwiched between relatively higher creep deformation-resistant microstructural regions. The cavitation was associated with coarse intergranular precipitates in the intercritical region of the HAZ. The type IV cracking in the intercritical region of the HAZ was found to initiate deep inside the weldment and propagate towards the specimen surface. Finite element analysis of stress and strain distributions across the weldment was carried out considering the micro-mechanical strength inhomogeneity across it to explain the observed features of type IV cracking. The estimated higher von-Mises and principal stresses deep inside the intercritical region of the HAZ of the weldment led to the localized creep deformation and preferential cavity nucleation and growth, resulting in type IV failure of the weldment. The role of intergranular precipitate particles in the intercritical region of the HAZ in facilitating creep cavity nucleation by the exhaustion of creep ductility of the material close to the precipitate was corroborated from finite element analysis of stress and strain distribution around the precipitates.

  13. A novel method for measuring carrier lifetime and capture cross-section by using the negative resistance I-V characteristics of a barrier-type thyristor

    Energy Technology Data Exchange (ETDEWEB)

    Li Hairong; Li Siyuan, E-mail: hrli@lzu.edu.c [Institute of Microelectronics, Lanzhou University, Lanzhou 730000 (China)

    2010-08-15

    A brand new and feasible method for measuring the carrier lifetime and capture cross-section of a barrier by using the negative resistance segment of the I-V characteristics of a barrier-type thyristor (BTH) is put forward. The measuring principle and calculation method are given. The BTH samples are experimentally measured and the results are analyzed in detail. (semiconductor devices)

  14. Milder clinical course of Type IV 3-methylglutaconic aciduria due to a novel mutation in TMEM70.

    Science.gov (United States)

    Shchelochkov, Oleg A; Li, Fang-Yuan; Wang, Jing; Zhan, Hongli; Towbin, Jeffrey A; Jefferies, John Lynn; Wong, Lee-Jun; Scaglia, Fernando

    2010-01-01

    Mitochondrial disorders are a large and genetically heterogeneous group of disorders posing a significant diagnostic challenge. Only approximately 10-20% of patients have identifiable alterations in their mitochondrial DNA (mtDNA). The remaining ~80-90% of affected patients likely harbor mutations in nuclear genes, most of which are still poorly characterized, and therefore not amenable to efficient screening using currently available molecular methods. Here we present a patient, who has been followed since birth after presenting with neonatal hyperammonemia, lactic acidosis, Reye-like syndrome episodes, and ventricular tachyarrhythmia. Initial biochemical work-up revealed hyperalaninemia, normal plasma glutamine, mild orotic aciduria and significant amounts of urinary 3-methylglutaconic (3-MGC) and 3-methylglutaric (3-MGA) acids. Muscle biopsy demonstrated the presence of ragged-red fibers and non-specific structural abnormalities of mitochondria. The activities of respiratory chain enzymes (complexes I-IV) showed no deficiency. Mutational analysis of the entire mitochondrial genome did not reveal deleterious point mutations or large deletions. Long-term follow-up was significant for a later-onset hypertrophic cardiomyopathy, muscle weakness, and exercise intolerance. Although she had frequent episodes of Reye-like episodes in infancy and early childhood, mostly triggered by illnesses, these symptoms improved significantly with the onset of puberty. In the light of recent reports linking cases of type IV 3-methylglutaconic aciduria (3-MGCA) and hypertrophic cardiomyopathy to mutations in TMEM70, we proceeded with sequencing analysis of this gene. We identified one previously reported splice site mutation, c.317-2A>G and a novel mutation c.494G>A (p.G165D) in an evolutionarily conserved region predicted to be deleterious. This variant was not identified in 100 chromosomes of healthy control subjects and 200 chromosomes of patients with cardiomyopathies. Western

  15. Direct and Indirect Targeting of PP2A by Conserved Bacterial Type-III Effector Proteins.

    Science.gov (United States)

    Jin, Lin; Ham, Jong Hyun; Hage, Rosemary; Zhao, Wanying; Soto-Hernández, Jaricelis; Lee, Sang Yeol; Paek, Seung-Mann; Kim, Min Gab; Boone, Charles; Coplin, David L; Mackey, David

    2016-05-01

    Bacterial AvrE-family Type-III effector proteins (T3Es) contribute significantly to the virulence of plant-pathogenic species of Pseudomonas, Pantoea, Ralstonia, Erwinia, Dickeya and Pectobacterium, with hosts ranging from monocots to dicots. However, the mode of action of AvrE-family T3Es remains enigmatic, due in large part to their toxicity when expressed in plant or yeast cells. To search for targets of WtsE, an AvrE-family T3E from the maize pathogen Pantoea stewartii subsp. stewartii, we employed a yeast-two-hybrid screen with non-lethal fragments of WtsE and a synthetic genetic array with full-length WtsE. Together these screens indicate that WtsE targets maize protein phosphatase 2A (PP2A) heterotrimeric enzyme complexes via direct interaction with B' regulatory subunits. AvrE1, another AvrE-family T3E from Pseudomonas syringae pv. tomato strain DC3000 (Pto DC3000), associates with specific PP2A B' subunit proteins from its susceptible host Arabidopsis that are homologous to the maize B' subunits shown to interact with WtsE. Additionally, AvrE1 was observed to associate with the WtsE-interacting maize proteins, indicating that PP2A B' subunits are likely conserved targets of AvrE-family T3Es. Notably, the ability of AvrE1 to promote bacterial growth and/or suppress callose deposition was compromised in Arabidopsis plants with mutations of PP2A genes. Also, chemical inhibition of PP2A activity blocked the virulence activity of both WtsE and AvrE1 in planta. The function of HopM1, a Pto DC3000 T3E that is functionally redundant to AvrE1, was also impaired in specific PP2A mutant lines, although no direct interaction with B' subunits was observed. These results indicate that sub-component specific PP2A complexes are targeted by bacterial T3Es, including direct targeting by members of the widely conserved AvrE-family. PMID:27191168

  16. Evidence for alternative quaternary structure in a bacterial Type III secretion system chaperone

    Energy Technology Data Exchange (ETDEWEB)

    Barta, Michael L.; Zhang, Lingling; Picking, Wendy L.; Geisbrecht, Brian V. (UMKC); (OKLU)

    2010-10-05

    Type III secretion systems are a common virulence mechanism in many Gram-negative bacterial pathogens. These systems use a nanomachine resembling a molecular needle and syringe to provide an energized conduit for the translocation of effector proteins from the bacterial cytoplasm to the host cell cytoplasm for the benefit of the pathogen. Prior to translocation specialized chaperones maintain proper effector protein conformation. The class II chaperone, Invasion plasmid gene (Ipg) C, stabilizes two pore forming translocator proteins. IpgC exists as a functional dimer to facilitate the mutually exclusive binding of both translocators. In this study, we present the 3.3 {angstrom} crystal structure of an amino-terminally truncated form (residues 10-155, denoted IpgC10-155) of the class II chaperone IpgC from Shigella flexneri. Our structure demonstrates an alternative quaternary arrangement to that previously described for a carboxy-terminally truncated variant of IpgC (IpgC{sup 1-151}). Specifically, we observe a rotationally-symmetric 'head-to-head' dimerization interface that is far more similar to that previously described for SycD from Yersinia enterocolitica than to IpgC1-151. The IpgC structure presented here displays major differences in the amino terminal region, where extended coil-like structures are seen, as opposed to the short, ordered alpha helices and asymmetric dimerization interface seen within IpgC{sup 1-151}. Despite these differences, however, both modes of dimerization support chaperone activity, as judged by a copurification assay with a recombinant form of the translocator protein, IpaB. Conclusions: From primary to quaternary structure, these results presented here suggest that a symmetric dimerization interface is conserved across bacterial class II chaperones. In light of previous data which have described the structure and function of asymmetric dimerization, our results raise the possibility that class II chaperones may

  17. Direct and Indirect Targeting of PP2A by Conserved Bacterial Type-III Effector Proteins.

    Directory of Open Access Journals (Sweden)

    Lin Jin

    2016-05-01

    Full Text Available Bacterial AvrE-family Type-III effector proteins (T3Es contribute significantly to the virulence of plant-pathogenic species of Pseudomonas, Pantoea, Ralstonia, Erwinia, Dickeya and Pectobacterium, with hosts ranging from monocots to dicots. However, the mode of action of AvrE-family T3Es remains enigmatic, due in large part to their toxicity when expressed in plant or yeast cells. To search for targets of WtsE, an AvrE-family T3E from the maize pathogen Pantoea stewartii subsp. stewartii, we employed a yeast-two-hybrid screen with non-lethal fragments of WtsE and a synthetic genetic array with full-length WtsE. Together these screens indicate that WtsE targets maize protein phosphatase 2A (PP2A heterotrimeric enzyme complexes via direct interaction with B' regulatory subunits. AvrE1, another AvrE-family T3E from Pseudomonas syringae pv. tomato strain DC3000 (Pto DC3000, associates with specific PP2A B' subunit proteins from its susceptible host Arabidopsis that are homologous to the maize B' subunits shown to interact with WtsE. Additionally, AvrE1 was observed to associate with the WtsE-interacting maize proteins, indicating that PP2A B' subunits are likely conserved targets of AvrE-family T3Es. Notably, the ability of AvrE1 to promote bacterial growth and/or suppress callose deposition was compromised in Arabidopsis plants with mutations of PP2A genes. Also, chemical inhibition of PP2A activity blocked the virulence activity of both WtsE and AvrE1 in planta. The function of HopM1, a Pto DC3000 T3E that is functionally redundant to AvrE1, was also impaired in specific PP2A mutant lines, although no direct interaction with B' subunits was observed. These results indicate that sub-component specific PP2A complexes are targeted by bacterial T3Es, including direct targeting by members of the widely conserved AvrE-family.

  18. The bacterial cytoskeleton modulates motility, type 3 secretion, and colonization in Salmonella.

    Directory of Open Access Journals (Sweden)

    David M Bulmer

    2012-01-01

    Full Text Available Although there have been great advances in our understanding of the bacterial cytoskeleton, major gaps remain in our knowledge of its importance to virulence. In this study we have explored the contribution of the bacterial cytoskeleton to the ability of Salmonella to express and assemble virulence factors and cause disease. The bacterial actin-like protein MreB polymerises into helical filaments and interacts with other cytoskeletal elements including MreC to control cell-shape. As mreB appears to be an essential gene, we have constructed a viable ΔmreC depletion mutant in Salmonella. Using a broad range of independent biochemical, fluorescence and phenotypic screens we provide evidence that the Salmonella pathogenicity island-1 type three secretion system (SPI1-T3SS and flagella systems are down-regulated in the absence of MreC. In contrast the SPI-2 T3SS appears to remain functional. The phenotypes have been further validated using a chemical genetic approach to disrupt the functionality of MreB. Although the fitness of ΔmreC is reduced in vivo, we observed that this defect does not completely abrogate the ability of Salmonella to cause disease systemically. By forcing on expression of flagella and SPI-1 T3SS in trans with the master regulators FlhDC and HilA, it is clear that the cytoskeleton is dispensable for the assembly of these structures but essential for their expression. As two-component systems are involved in sensing and adapting to environmental and cell surface signals, we have constructed and screened a panel of such mutants and identified the sensor kinase RcsC as a key phenotypic regulator in ΔmreC. Further genetic analysis revealed the importance of the Rcs two-component system in modulating the expression of these virulence factors. Collectively, these results suggest that expression of virulence genes might be directly coordinated with cytoskeletal integrity, and this regulation is mediated by the two-component system

  19. Aminomethylenediphosphonate: A Potent Type-Specific Inhibitor of Both Plant and Phototrophic Bacterial H+-Pyrophosphatases.

    Science.gov (United States)

    Zhen, R. G.; Baykov, A. A.; Bakuleva, N. P.; Rea, P. A.

    1994-01-01

    The suitability of different pyrophosphate (PPi) analogs as inhibitors of the vacuolar H+-translocating inorganic pyrophosphatase (V-PPase; EC 3.6.1.1) of tonoplast vesicles isolated from etiolated hypocotyls of Vigna radiata was investigated. Five 1,1-diphosphonates and imidodiphosphate were tested for their effects on substrate hydrolysis by the V-PPase at a substrate concentration corresponding to the Km of the enzyme. The order of inhibitory potency (apparent inhibition constants, Kiapp values, [mu]M, in parentheses) of the compounds examined was aminomethylenediphosphonate (1.8) > hydroxymethylenediphosphonate (5.7) [almost equal to] ethane-1-hydroxy-1,1-diphosphonate (6.5) > imidodiphosphate (12) > methylenediphosphonate (68) > dichloromethylenediphosphonate (>500). The specificity of three of these compounds, aminomethylenediphosphonate, imidodiphosphate, and methylenediphosphonate, was determined by comparing their effects on the V-PPase and vacuolar H+-ATPase from Vigna, plasma membrane H+-ATPase from Beta vulgaris, H+-PPi synthase of chromatophores prepared from Rhodospirillum rubrum, soluble PPase from Saccharomyces cerevisiae, alkaline phosphatase from bovine intestinal mucosa, and nonspecific monophosphoesterase from Vigna at a PPi concentration equivalent to 10 times the Km of the V-PPase. Although all three PPi analogs inhibited the plant V-PPase and bacterial H+-PPi synthase with qualitatively similar kinetics, whether substrate hydrolysis or PPi-dependent H+-translocation was measured, neither the vacuolar H+-ATPase nor plasma membrane H+-ATPase nor any of the non-V-PPase-related PPi hydrolases were markedly inhibited under these conditions. It is concluded that 1, 1-diphosphonates, in general, and aminomethylenediphosphonate, in particular, are potent type-specific inhibitors of the V-PPase and its putative bacterial homolog, the H+-PPi synthase of Rhodospirillum. PMID:12232069

  20. The Mechanism for Type I Interferon Induction by Mycobacterium tuberculosis is Bacterial Strain-Dependent

    Science.gov (United States)

    Wiens, Kirsten E.; Ernst, Joel D.

    2016-01-01

    Type I interferons (including IFNαβ) are innate cytokines that may contribute to pathogenesis during Mycobacterium tuberculosis (Mtb) infection. To induce IFNβ, Mtb must gain access to the host cytosol and trigger stimulator of interferon genes (STING) signaling. A recently proposed model suggests that Mtb triggers STING signaling through bacterial DNA binding cyclic GMP-AMP synthase (cGAS) in the cytosol. The aim of this study was to test the generalizability of this model using phylogenetically distinct strains of the Mtb complex (MTBC). We infected bone marrow derived macrophages with strains from MTBC Lineages 2, 4 and 6. We found that the Lineage 6 strain induced less IFNβ, and that the Lineage 2 strain induced more IFNβ, than the Lineage 4 strain. The strains did not differ in their access to the host cytosol and IFNβ induction by each strain required both STING and cGAS. We also found that the three strains shed similar amounts of bacterial DNA. Interestingly, we found that the Lineage 6 strain was associated with less mitochondrial stress and less mitochondrial DNA (mtDNA) in the cytosol compared with the Lineage 4 strain. Treating macrophages with a mitochondria-specific antioxidant reduced cytosolic mtDNA and inhibited IFNβ induction by the Lineage 2 and 4 strains. We also found that the Lineage 2 strain did not induce more mitochondrial stress than the Lineage 4 strain, suggesting that additional pathways contribute to higher IFNβ induction. These results indicate that the mechanism for IFNβ by Mtb is more complex than the established model suggests. We show that mitochondrial dynamics and mtDNA contribute to IFNβ induction by Mtb. Moreover, we show that the contribution of mtDNA to the IFNβ response varies by MTBC strain and that additional mechanisms exist for Mtb to induce IFNβ. PMID:27500737

  1. Two different bacterial community types are linked with the low-methane emission trait in sheep.

    Directory of Open Access Journals (Sweden)

    Sandra Kittelmann

    Full Text Available The potent greenhouse gas methane (CH4 is produced in the rumens of ruminant animals from hydrogen produced during microbial degradation of ingested feed. The natural animal-to-animal variation in the amount of CH4 emitted and the heritability of this trait offer a means for reducing CH4 emissions by selecting low-CH4 emitting animals for breeding. We demonstrate that differences in rumen microbial community structure are linked to high and low CH4 emissions in sheep. Bacterial community structures in 236 rumen samples from 118 high- and low-CH4 emitting sheep formed gradual transitions between three ruminotypes. Two of these (Q and S were linked to significantly lower CH4 yields (14.4 and 13.6 g CH4/kg dry matter intake [DMI], respectively than the third type (H; 15.9 g CH4/kg DMI; p<0.001. Low-CH4 ruminotype Q was associated with a significantly lower ruminal acetate to propionate ratio (3.7±0.4 than S (4.4±0.7; p<0.001 and H (4.3±0.5; p<0.001, and harbored high relative abundances of the propionate-producing Quinella ovalis. Low-CH4 ruminotype S was characterized by lactate- and succinate-producing Fibrobacter spp., Kandleria vitulina, Olsenella spp., Prevotella bryantii, and Sharpea azabuensis. High-CH4 ruminotype H had higher relative abundances of species belonging to Ruminococcus, other Ruminococcaceae, Lachnospiraceae, Catabacteriaceae, Coprococcus, other Clostridiales, Prevotella, other Bacteroidales, and Alphaproteobacteria, many of which are known to form significant amounts of hydrogen. We hypothesize that lower CH4 yields are the result of bacterial communities that ferment ingested feed to relatively less hydrogen, which results in less CH4 being formed.

  2. Terminal reassortment drives the quantum evolution of type III effectors in bacterial pathogens.

    Directory of Open Access Journals (Sweden)

    John Stavrinides

    2006-10-01

    Full Text Available Many bacterial pathogens employ a type III secretion system to deliver type III secreted effectors (T3SEs into host cells, where they interact directly with host substrates to modulate defense pathways and promote disease. This interaction creates intense selective pressures on these secreted effectors, necessitating rapid evolution to overcome host surveillance systems and defenses. Using computational and evolutionary approaches, we have identified numerous mosaic and truncated T3SEs among animal and plant pathogens. We propose that these secreted virulence genes have evolved through a shuffling process we have called "terminal reassortment." In terminal reassortment, existing T3SE termini are mobilized within the genome, creating random genetic fusions that result in chimeric genes. Up to 32% of T3SE families in species with relatively large and well-characterized T3SE repertoires show evidence of terminal reassortment, as compared to only 7% of non-T3SE families. Terminal reassortment may permit the near instantaneous evolution of new T3SEs and appears responsible for major modifications to effector activity and function. Because this process plays a more significant role in the evolution of T3SEs than non-effectors, it provides insight into the evolutionary origins of T3SEs and may also help explain the rapid emergence of new infectious agents.

  3. Insufficient Folding of Type IV Collagen and Formation of Abnormal Basement Membrane-like Structure in Embryoid Bodies Derived from Hsp47-Null Embryonic Stem CellsD⃞

    OpenAIRE

    Matsuoka, Yasuhiro; Kubota, Hiroshi; Adachi, Eijiro; Nagai, Naoko; Marutani, Toshihiro; Hosokawa, Nobuko; Nagata, Kazuhiro

    2004-01-01

    Hsp47 is a molecular chaperone that specifically recognizes procollagen in the endoplasmic reticulum. Hsp47-null mouse embryos produce immature type I collagen and form discontinuous basement membranes. We established Hsp47-/- embryonic stem cell lines and examined formation of basement membrane and production of type IV collagen in embryoid bodies, a model for postimplantation egg-cylinder stage embryos. The visceral endodermal cell layers surrounding Hsp47-/- embryoid bodies were often diso...

  4. [Targeting of type IV carbonic anhydrases in Capan-1 human pancreatic duct cells is concomitant of the polarization].

    Science.gov (United States)

    Mairal, A; Fanjul, M; Hollande, E

    1996-01-01

    Carbonic anhydrases II and IV play an essential role in the synthesis and secretion of HCO3- ions in pancreatic duct cells. Secretion of these ions is regulated by the CFTR (cystic fibrosis transmembrane conductance regulator) chloride channel. In the present study, the expression of carbonic anhydrases IV and their targeting to plasma membranes were examined during the growth of human pancreatic duct cells in vitro. Human cancerous pancreatic duct cells of Capan-1 cell line which polarize during their growth were used. We show that: a) these cells express carbonic anhydrases IV continuously during growth in culture, and the expression depends on the stage of growth and the conformation of the cells; b) carbonic anhydrases IV are seen in the cytoplasm in non-polarized cells, but become progressively anchored to plasma membranes as the cells polarize, being targeted to the apical membranes of polarized cells; c) the subcellular distribution of carbonic anhydrases IV indicates that these enzymes are synthetized in rough endoplasmic reticulum and then transported towards the plasma membrane using the classical secretory pathway through the Golgi apparatus. The results indicated that targeting of carbonic anhydrases IV in Capan-1 cells is linked to cellular polarization. PMID:8881572

  5. Generation mechanism of the slowly drifting narrowband structure in the type IV solar radio bursts observed by AMATERAS

    International Nuclear Information System (INIS)

    We investigate the type IV burst event observed by AMATERAS on 2011 June 7, and reveal that the main component of the burst was emitted from the plasmoid eruption identified in the EUV images of the Solar Dynamics Observatory (SDO)/AIA. We show that a slowly drifting narrowband structure (SDNS) appeared in the burst's spectra. Using statistical analysis, we reveal that the SDNS appeared for a duration of tens to hundreds of milliseconds and had a typical bandwidth of 3 MHz. To explain the mechanism generating the SDNS, we propose wave-wave coupling between Langmuir waves and whistler-mode chorus emissions generated in a post-flare loop, which were inferred from the similarities in the plasma environments of a post-flare loop and the equatorial region of Earth's inner magnetosphere. We assume that a chorus element with a rising tone is generated at the top of a post-flare loop. Using the magnetic field and plasma density models, we quantitatively estimate the expected duration of radio emissions generated from coupling between Langmuir waves and chorus emissions during their propagation in the post-flare loop, and we find that the observed duration and bandwidth properties of the SDNS are consistently explained by the proposed generation mechanism. While observations in the terrestrial magnetosphere show that the chorus emissions are a group of large-amplitude wave elements generated naturally and intermittently, the mechanism proposed in the present study can explain both the intermittency and the frequency drift in the observed spectra.

  6. The Legionella pneumophila IcmSW complex interacts with multiple Dot/Icm effectors to facilitate type IV translocation.

    Directory of Open Access Journals (Sweden)

    Eric D Cambronne

    2007-12-01

    Full Text Available Many gram-negative pathogens use a type IV secretion system (T4SS to deliver effector proteins into eukaryotic host cells. The fidelity of protein translocation depends on the efficient recognition of effector proteins by the T4SS. Legionella pneumophila delivers a large number of effector proteins into eukaryotic cells using the Dot/Icm T4SS. How the Dot/Icm system is able to recognize and control the delivery of effectors is poorly understood. Recent studies suggest that the IcmS and IcmW proteins interact to form a stable complex that facilitates translocation of effector proteins by the Dot/Icm system by an unknown mechanism. Here we demonstrate that the IcmSW complex is necessary for the productive translocation of multiple Dot/Icm effector proteins. Effector proteins that were able to bind IcmSW in vitro required icmS and icmW for efficient translocation into eukaryotic cells during L. pneumophila infection. We identified regions in the effector protein SidG involved in icmSW-dependent translocation. Although the full-length SidG protein was translocated by an icmSW-dependent mechanism, deletion of amino terminal regions in the SidG protein resulted in icmSW-independent translocation, indicating that the IcmSW complex is not contributing directly to recognition of effector proteins by the Dot/Icm system. Biochemical and genetic studies showed that the IcmSW complex interacts with a central region of the SidG protein. The IcmSW interaction resulted in a conformational change in the SidG protein as determined by differences in protease sensitivity in vitro. These data suggest that IcmSW binding to effectors could enhance effector protein delivery by mediating a conformational change that facilitates T4SS recognition of a translocation domain located in the carboxyl region of the effector protein.

  7. Functional mapping of PilF and PilQ in the Pseudomonas aeruginosa type IV pilus system.

    Science.gov (United States)

    Koo, Jason; Tang, Tim; Harvey, Hanjeong; Tammam, Stephanie; Sampaleanu, Liliana; Burrows, Lori L; Howell, P Lynne

    2013-04-30

    Pseudomonas aeruginosa uses type IV pili (T4P) to interact with the environment and as key virulence factors when acting as an opportunistic pathogen. Assembly of the outer membrane PilQ secretin channel through which the pili are extruded is essential for pilus biogenesis. The P. aeruginosa T4P pilotin, PilF, is required for PilQ outer membrane localization and assembly into secretins and contains six tetratricopeptide (TPR) protein-protein interaction motifs, suggesting that the two proteins interact. In this study, we found that the first four TPR motifs of PilF are sufficient for PilQ outer membrane targeting, oligomerization, and function. Guided by our structure of PilF, site-directed mutagenesis of the protein surface revealed that a hydrophobic groove on the first TPR is required for PilF-mediated PilQ assembly. Deletion of individual domains within PilQ suggests that the N0, KH-like, or secretin domain, but not the C-terminus, interacts with PilF. Purified PilQ was found to pull down PilF from Pseudomonas cell lysates. Together, these data allow us to propose a model for PilF function in the T4P system. PilF interacts directly or indirectly with the PilQ monomer after translocation of both proteins through the inner membrane and acts as a co-chaperone with the Lol system to facilitate transit across the periplasm to the outer membrane. The mechanism of PilQ insertion and assembly, which appears to be independent of the Bam system, remains to be determined. PMID:23547883

  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. Crystallization and X-ray diffraction studies of a complete bacterial fatty-acid synthase type I

    Energy Technology Data Exchange (ETDEWEB)

    Enderle, Mathias [Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main (Germany); Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried (Germany); McCarthy, Andrew [EMBL Grenoble, 71 Avenue des Martyrs, 38042 Grenoble CEDEX 9 (France); Paithankar, Karthik Shivaji, E-mail: paithankar@em.uni-frankfurt.de [Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main (Germany); Grininger, Martin, E-mail: paithankar@em.uni-frankfurt.de [Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main (Germany); Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried (Germany)

    2015-10-23

    Bacterial and fungal type I fatty-acid synthases (FAS I) are evolutionarily connected, as bacterial FAS I is considered to be the ancestor of fungal FAS I. In this work, the production, crystallization and X-ray diffraction data analysis of a bacterial FAS I are reported. While a deep understanding of the fungal and mammalian multi-enzyme type I fatty-acid synthases (FAS I) has been achieved in recent years, the bacterial FAS I family, which is narrowly distributed within the Actinomycetales genera Mycobacterium, Corynebacterium and Nocardia, is still poorly understood. This is of particular relevance for two reasons: (i) although homologous to fungal FAS I, cryo-electron microscopic studies have shown that bacterial FAS I has unique structural and functional properties, and (ii) M. tuberculosis FAS I is a drug target for the therapeutic treatment of tuberculosis (TB) and therefore is of extraordinary importance as a drug target. Crystals of FAS I from C. efficiens, a homologue of M. tuberculosis FAS I, were produced and diffracted X-rays to about 4.5 Å resolution.

  10. Engineering de novo disulfide bond in bacterial α-type carbonic anhydrase for thermostable carbon sequestration

    Science.gov (United States)

    Jo, Byung Hoon; Park, Tae Yoon; Park, Hyun June; Yeon, Young Joo; Yoo, Young Je; Cha, Hyung Joon

    2016-01-01

    Exploiting carbonic anhydrase (CA), an enzyme that rapidly catalyzes carbon dioxide hydration, is an attractive biomimetic route for carbon sequestration due to its environmental compatibility and potential economic viability. However, the industrial applications of CA are strongly hampered by the unstable nature of enzymes. In this work, we introduced in silico designed, de novo disulfide bond in a bacterial α-type CA to enhance thermostability. Three variants were selected and expressed in Escherichia coli with an additional disulfide bridge. One of the variants showed great enhancement in terms of both kinetic and thermodynamic stabilities. This improvement could be attributed to the loss of conformational entropy of the unfolded state, showing increased rigidity. The variant showed an upward-shifted optimal temperature and appeared to be thermoactivated, which compensated for the lowered activity at 25 °C. Collectively, the variant constructed by the rapid and effective de novo disulfide engineering can be used as an efficient biocatalyst for carbon sequestration under high temperature conditions. PMID:27385052

  11. Effect of leaf type and pesticide exposure on abundance of bacterial taxa in mosquito larval habitats.

    Directory of Open Access Journals (Sweden)

    Ephantus J Muturi

    Full Text Available Lentic freshwater systems including those inhabited by aquatic stages of mosquitoes derive most of their carbon inputs from terrestrial organic matter mainly leaf litter. The leaf litter is colonized by microbial communities that provide the resource base for mosquito larvae. While the microbial biomass associated with different leaf species in container aquatic habitats is well documented, the taxonomic composition of these microbes and their response to common environmental stressors is poorly understood. We used indoor aquatic microcosms to determine the abundances of major taxonomic groups of bacteria in leaf litters from seven plant species and their responses to low concentrations of four pesticides with different modes of action on the target organisms; permethrin, malathion, atrazine and glyphosate. We tested the hypotheses that leaf species support different quantities of major taxonomic groups of bacteria and that exposure to pesticides at environmentally relevant concentrations alters bacterial abundance and community structure in mosquito larval habitats. We found support for both hypotheses suggesting that leaf litter identity and chemical contamination may alter the quality and quantity of mosquito food base (microbial communities in larval habitats. The effect of pesticides on microbial communities varied significantly among leaf types, suggesting that the impact of pesticides on natural microbial communities may be highly complex and difficult to predict. Collectively, these findings demonstrate the potential for detritus composition within mosquito larval habitats and exposure to pesticides to influence the quality of mosquito larval habitats.

  12. Engineering de novo disulfide bond in bacterial α-type carbonic anhydrase for thermostable carbon sequestration

    Science.gov (United States)

    Jo, Byung Hoon; Park, Tae Yoon; Park, Hyun June; Yeon, Young Joo; Yoo, Young Je; Cha, Hyung Joon

    2016-07-01

    Exploiting carbonic anhydrase (CA), an enzyme that rapidly catalyzes carbon dioxide hydration, is an attractive biomimetic route for carbon sequestration due to its environmental compatibility and potential economic viability. However, the industrial applications of CA are strongly hampered by the unstable nature of enzymes. In this work, we introduced in silico designed, de novo disulfide bond in a bacterial α-type CA to enhance thermostability. Three variants were selected and expressed in Escherichia coli with an additional disulfide bridge. One of the variants showed great enhancement in terms of both kinetic and thermodynamic stabilities. This improvement could be attributed to the loss of conformational entropy of the unfolded state, showing increased rigidity. The variant showed an upward-shifted optimal temperature and appeared to be thermoactivated, which compensated for the lowered activity at 25 °C. Collectively, the variant constructed by the rapid and effective de novo disulfide engineering can be used as an efficient biocatalyst for carbon sequestration under high temperature conditions.

  13. Bioactive compounds from culinary herbs inhibit a molecular target for type 2 diabetes management, dipeptidyl peptidase IV.

    Science.gov (United States)

    Bower, Allyson M; Real Hernandez, Luis M; Berhow, Mark A; de Mejia, Elvira Gonzalez

    2014-07-01

    Greek oregano (Origanum vulgare), marjoram (Origanum majorana), rosemary (Rosmarinus officinalis), and Mexican oregano (Lippia graveolens) are concentrated sources of bioactive compounds. The aims were to characterize and examine extracts from greenhouse-grown or commercially purchased herbs for their ability to inhibit dipeptidyl peptidase IV (DPP-IV) and protein tyrosine phosphatase 1B (PTP1B), enzymes that play a role in insulin secretion and insulin signaling, respectively. Greenhouse herbs contained more polyphenols (302.7-430.1 μg of gallic acid equivalents/mg of dry weight of extract (DWE)) and flavonoids (370.1-661.4 μg of rutin equivalents/mg of DWE) compared to the equivalent commercial herbs. Greenhouse rosemary, Mexican oregano, and marjoram extracts were the best inhibitors of DPP-IV (IC₅₀=16, 29, and 59 μM, respectively). Commercial rosemary, Mexican oregano, and marjoram were the best inhibitors of PTP1B (32.4-40.9% at 500 μM). The phytochemicals eriodictyol, naringenin, hispidulin, cirsimaritin, and carnosol were identified by LC-ESI-MS as being present in greenhouse-grown Mexican oregano and rosemary. Computational modeling indicated that hispidulin, carnosol, and eriodictyol would have the best binding affinities for DPP-IV. Biochemically, the best inhibitors of DPP-IV were cirsimaritin (IC₅₀=0.43±0.07 μM), hispidulin (IC₅₀=0.49±0.06 μM), and naringenin (IC₅₀=2.5±0.29 μM). Overall, herbs contain several flavonoids that inhibit DPP-IV and should be investigated further regarding their potential in diabetes management. PMID:24881464

  14. Characterization of transcription factors that regulate the type IV secretion system and riboflavin biosynthesis in Wolbachia of Brugia malayi.

    Directory of Open Access Journals (Sweden)

    Zhiru Li

    Full Text Available The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium Wolbachia (wBm that is required for parasite survival. Consequently, targeting wBm is a promising approach for anti-filarial drug development. The Type IV secretion system (T4SS plays an important role in bacteria-host interactions and is under stringent regulation by transcription factors. In wBm, most T4SS genes are contained in two operons. We show the wBm is active since the essential assembly factor virB8-1, is transcribed in adult worms and larval stages, and VirB8-1 is present in parasite lysates. We also identify two transcription factors (wBmxR1 and wBmxR2 that bind to the promoter region of several genes of the T4SS. Gel shift assays show binding of wBmxR1 to regions upstream of the virB9-2 and wBmxR2 genes, whereas wBmxR2 binds to virB4-2 and wBmxR1 promoter regions. Interestingly, both transcription factors bind to the promoter of the ribA gene that precedes virB8-1, the first gene in operon 1 of the wBm T4SS. RT-PCR reveals ribA and virB8-1 genes are co-transcribed as one operon, indicating the ribA gene and T4SS operon 1 are co-regulated by both wBmxR1 and wBmxR2. RibA encodes a bi-functional enzyme that catalyzes two essential steps in riboflavin (Vitamin B2 biosynthesis. Importantly, the riboflavin pathway is absent in B. malayi. We demonstrate the pathway is functional in wBm, and observe vitamin B2 supplementation partially rescues filarial parasites treated with doxycycline, indicating Wolbachia may supply the essential vitamin to its worm host. This is the first characterization of a transcription factor(s from wBm and first report of co-regulation of genes of the T4SS and riboflavin biosynthesis pathway. In addition, our results demonstrate a requirement of vitamin B2 for worm health and fertility, and imply a nutritional role of the symbiont for the filarial parasite host.

  15. Characterization of transcription factors that regulate the type IV secretion system and riboflavin biosynthesis in Wolbachia of Brugia malayi.

    Science.gov (United States)

    Li, Zhiru; Carlow, Clotilde K S

    2012-01-01

    The human filarial parasite Brugia malayi harbors an endosymbiotic bacterium Wolbachia (wBm) that is required for parasite survival. Consequently, targeting wBm is a promising approach for anti-filarial drug development. The Type IV secretion system (T4SS) plays an important role in bacteria-host interactions and is under stringent regulation by transcription factors. In wBm, most T4SS genes are contained in two operons. We show the wBm is active since the essential assembly factor virB8-1, is transcribed in adult worms and larval stages, and VirB8-1 is present in parasite lysates. We also identify two transcription factors (wBmxR1 and wBmxR2) that bind to the promoter region of several genes of the T4SS. Gel shift assays show binding of wBmxR1 to regions upstream of the virB9-2 and wBmxR2 genes, whereas wBmxR2 binds to virB4-2 and wBmxR1 promoter regions. Interestingly, both transcription factors bind to the promoter of the ribA gene that precedes virB8-1, the first gene in operon 1 of the wBm T4SS. RT-PCR reveals ribA and virB8-1 genes are co-transcribed as one operon, indicating the ribA gene and T4SS operon 1 are co-regulated by both wBmxR1 and wBmxR2. RibA encodes a bi-functional enzyme that catalyzes two essential steps in riboflavin (Vitamin B2) biosynthesis. Importantly, the riboflavin pathway is absent in B. malayi. We demonstrate the pathway is functional in wBm, and observe vitamin B2 supplementation partially rescues filarial parasites treated with doxycycline, indicating Wolbachia may supply the essential vitamin to its worm host. This is the first characterization of a transcription factor(s) from wBm and first report of co-regulation of genes of the T4SS and riboflavin biosynthesis pathway. In addition, our results demonstrate a requirement of vitamin B2 for worm health and fertility, and imply a nutritional role of the symbiont for the filarial parasite host.

  16. THE LIMIT CYCLES AND HOPF BIFURCATION OF A CLASS OF SIMPLIFIED HOLLING TYPE-IV PREDATOR-PREY SYSTEM WITH LINEAR STATE FEEDBACK

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper, a class of simplified Type-IV predator-prey system with linear state feedback is investigated. We prove the boundedness of the positive solutions to this system, and analyze the quality of the equilibria and the existence of limit cycles of the system surrounding the positive equilibra. By Hopf bifurcation theory, the result of having two limit cycles to the system is obtained.

  17. Assessment of proteolytic degradation of the basement membrane: a fragment of type IV collagen as a biochemical marker for liver fibrosis

    OpenAIRE

    Veidal Sanne S; Karsdal Morten A; Nawrocki Arkadiusz; Larsen Martin R; Dai Yueqin; Zheng Qinlong; Hägglund Per; Vainer Ben; Skjøt-Arkil Helene; Leeming Diana J

    2011-01-01

    Abstract Background Collagen deposition and an altered matrix metalloproteinase (MMP) expression profile are hallmarks of fibrosis. Type IV collagen is the most abundant structural basement membrane component of tissue, which increases 14-fold during fibrogenesis in the liver. Proteolytic degradation of collagens by proteases produces small fragments, so-called neoepitopes, which are released systemically. Technologies investigating MMP-generated fragments of collagens may provide more useful...

  18. The Goodpasture-like syndrome in mice induced by intravenous injections of anti-type IV collagen and anti-laminin antibody.

    OpenAIRE

    Yaar, M; Foidart, J. M.; Brown, K S; Rennard, S. I.; Martin, G R; Liotta, L.

    1982-01-01

    Laminin and Type IV collagen are both components of basement membrane. Antibodies to these two proteins, when injected into mice, were found to accumulate in all basement membranes examined, but at highest levels in kidney, liver, and spleen. An acute respiratory distress syndrome was noted shortly after injection. A transient segmental proliferative glomerulonephritis was observed both in the heterologous (early) and autologous (late) phase. The glomerular basement membrane of mice injected ...

  19. Phlorizin, an Active Ingredient of Eleutherococcus senticosus, Increases Proliferative Potential of Keratinocytes with Inhibition of MiR135b and Increased Expression of Type IV Collagen.

    Science.gov (United States)

    Choi, Hye-Ryung; Nam, Kyung-Mi; Lee, Hyun-Sun; Yang, Seung-Hye; Kim, Young-Soo; Lee, Jongsung; Date, Akira; Toyama, Kazumi; Park, Kyoung-Chan

    2016-01-01

    E. senticosus extract (ESE), known as antioxidant, has diverse pharmacologic effects. It is also used as an antiaging agent for the skin and phlorizin (PZ) is identified as a main ingredient. In this study, the effects of PZ on epidermal stem cells were investigated. Cultured normal human keratinocytes and skin equivalents are used to test whether PZ affects proliferative potential of keratinocytes and how it regulates these effects. Skin equivalents (SEs) were treated with ESE and the results showed that the epidermis became slightly thickened on addition of 0.002% ESE. The staining intensity of p63 as well as proliferating cell nuclear antigen (PCNA) is increased, and integrin α6 was upregulated. Analysis of ESE confirmed that PZ is the main ingredient. When SEs were treated with PZ, similar findings were observed. In particular, the expression of integrin α6, integrin β1, and type IV collagen was increased. Levels of mRNA for type IV collagen were increased and levels of miR135b were downregulated. All these findings suggested that PZ can affect the proliferative potential of epidermal cells in part by microenvironment changes via miR135b downregulation and following increased expression of type IV collagen. PMID:27042261

  20. Phlorizin, an Active Ingredient of Eleutherococcus senticosus, Increases Proliferative Potential of Keratinocytes with Inhibition of MiR135b and Increased Expression of Type IV Collagen

    Directory of Open Access Journals (Sweden)

    Hye-Ryung Choi

    2016-01-01

    Full Text Available E. senticosus extract (ESE, known as antioxidant, has diverse pharmacologic effects. It is also used as an antiaging agent for the skin and phlorizin (PZ is identified as a main ingredient. In this study, the effects of PZ on epidermal stem cells were investigated. Cultured normal human keratinocytes and skin equivalents are used to test whether PZ affects proliferative potential of keratinocytes and how it regulates these effects. Skin equivalents (SEs were treated with ESE and the results showed that the epidermis became slightly thickened on addition of 0.002% ESE. The staining intensity of p63 as well as proliferating cell nuclear antigen (PCNA is increased, and integrin α6 was upregulated. Analysis of ESE confirmed that PZ is the main ingredient. When SEs were treated with PZ, similar findings were observed. In particular, the expression of integrin α6, integrin β1, and type IV collagen was increased. Levels of mRNA for type IV collagen were increased and levels of miR135b were downregulated. All these findings suggested that PZ can affect the proliferative potential of epidermal cells in part by microenvironment changes via miR135b downregulation and following increased expression of type IV collagen.

  1. Endovenous surgery for recurrent varicose veins with a one-year follow up in a patient with Ehlers Danlos syndrome type IV.

    Science.gov (United States)

    Whiteley, Mark S; Holdstock, Judith M

    2015-08-01

    We present a woman with severe symptomatic recurrent varicose veins who was treated with endovenous laser ablation and transluminal occlusion of perforator with attempted phlebectomies for extensive varices. The phlebectomies turned out to be near impossible due to friability of the veins. Her treatment was completed with post-operative ultrasound guided foam sclerotherapy seven months later. She was subsequently diagnosed as Ehlers Danlos syndrome type IV. A duplex ultrasound scan 18 months post-endovenous laser ablation and transluminal occlusion of perforator and 11 months after ultrasound guided foam sclerotherapy confirmed successful closure with virtual atrophy of all treated veins. She was found to be reflux free and only showed a few scattered cosmetic reticular veins. Open varicose vein surgery has been reported as being hazardous in the past in a patient with Ehlers Danlos syndrome type IV. Our experience has shown that endovenous laser ablation, transluminal occlusion of perforator and ultrasound guided foam sclerotherapy appear to be effective in treating this patient with Ehlers Danlos syndrome type IV, although phlebectomies were technically impossible.

  2. Studying Coxiella burnetii Type IV Substrates in the Yeast Saccharomyces cerevisiae: Focus on Subcellular Localization and Protein Aggregation.

    Science.gov (United States)

    Rodríguez-Escudero, María; Cid, Víctor J; Molina, María; Schulze-Luehrmann, Jan; Lührmann, Anja; Rodríguez-Escudero, Isabel

    2016-01-01

    Coxiella burnetii is a Gram-negative obligate parasitic bacterium that causes the disease Q-fever in humans. To establish its intracellular niche, it utilizes the Icm/Dot type IVB secretion system (T4BSS) to inject protein effectors into the host cell cytoplasm. The host targets of most cognate and candidate T4BSS-translocated effectors remain obscure. We used the yeast Saccharomyces cerevisiae as a model to express and study six C. burnetii effectors, namely AnkA, AnkB, AnkF, CBU0077, CaeA and CaeB, in search for clues about their role in C. burnetii virulence. When ectopically expressed in HeLa cells, these effectors displayed distinct subcellular localizations. Accordingly, GFP fusions of these proteins produced in yeast also decorated distinct compartments, and most of them altered cell growth. CaeA was ubiquitinated both in yeast and mammalian cells and, in S. cerevisiae, accumulated at juxtanuclear quality-control compartments (JUNQs) and insoluble protein deposits (IPODs), characteristic of aggregative or misfolded proteins. AnkA, which was not ubiquitinated, accumulated exclusively at the IPOD. CaeA, but not AnkA or the other effectors, caused oxidative damage in yeast. We discuss that CaeA and AnkA behavior in yeast may rather reflect misfolding than recognition of conserved targets in the heterologous system. In contrast, CBU0077 accumulated at vacuolar membranes and abnormal ER extensions, suggesting that it interferes with vesicular traffic, whereas AnkB associated with the yeast nucleolus. Both effectors shared common localization features in HeLa and yeast cells. Our results support the idea that C. burnetii T4BSS effectors manipulate multiple host cell targets, which can be conserved in higher and lower eukaryotic cells. However, the behavior of CaeA and AnkA prompt us to conclude that heterologous protein aggregation and proteostatic stress can be a limitation to be considered when using the yeast model to assess the function of bacterial effectors.

  3. Linear dimensional change, compressive strength and detail reproduction in type IV dental stone dried at room temperature and in a microwave oven

    Directory of Open Access Journals (Sweden)

    Marcos Aurélio Bomfim da Silva

    2012-10-01

    Full Text Available The type IV dental stone is widely used for the fabrication of dyes and master casts for fixed and removable partial prostheses. It is typically normal to wait at least 24 hours for the casts to dry prior to beginning the laboratory procedures. The waiting time has been shown to be greatly reduced by using microwave drying. OBJECTIVE: This study evaluated the influence of drying techniques at room temperature and microwave oven on the linear dimensional change, compressive strength and detail reproduction in type IV dental stones. MATERIAL AND METHODS: Three type IV dental stone brands were selected; elite Rock, Shera Premium and Durone IV. Two different drying protocols were tested in 4 groups (n=10; G1 - room temperature (25±4ºC dried for 2 hours; G2 - room temperature dried for 24 hours; G3 - room temperature dried for 7 days and G4 - microwave oven dried at 800 W for 5 minutes and after 2 hours at room temperature. After drying, the samples were assayed for dimensional charges. The sample surface was submitted to the ImageTool 3.0 software for compressive strength in a universal testing machine with a cell load of 50 KN at a crosshead speed of 0.5 mm/minutes and the detail reproduction was analyzed with a stereomicroscope at 25x magnification. The statistical analysis of the linear dimensional change and compressive strength data were conducted by the ANOVA test followed by the Tukey test (p<0.05. Detailed reproduction values were reported in percentages. RESULTS: For the compressive strength test, Elite Rock and Durone IV did not present significant differences between G2 and G4, while Shera Premium did not present differences between G3 and G4. The best reproduction levels were observed for G3. CONCLUSIONS: Dental stone microwave oven drying showed a linear dimensional change similar to after room temperature drying for 24 hours and 7 days. The compressive strength of the stone dried in the microwave oven was similar to those dried at

  4. Are Isotopologue Signatures of N2O from Bacterial Denitrifiers Indicative of NOR Type?

    Science.gov (United States)

    Well, R.; Braker, G.; Giesemann, A.; Flessa, H.

    2010-12-01

    Nitrous oxide (N2O) fluxes from soils result from its production by nitrification and denitrification and reduction during denitrification. The structure of the denitrifying microbial community contributes to the control of net N2O fluxes. Although molecular techniques are promising for identifying the active community of N2O producers, there are few data until now because methods to explore gene expression of N2O production are laborious and disregard regulation of activity at the enzyme level. The isotopologue signatures of N2O including δ18O, average δ15N (δ15Nbulk) and 15N site preference (SP = difference in δ15N between the central and peripheral N positions of the asymmetric N2O molecule) have been used to estimate the contribution of partial processes to net N2O fluxes to the atmosphere. However, the use of this approach to study N2O dynamics in soils requires knowledge of isotopic signatures of N2O precursors and isotopologue fractionation factors (ɛ) of all processes of N2O production and consumption. In contrast to δ18O and δ15Nbulk, SP is independent of precursor signatures and hence is a promising parameter here. It is assumed that SP of produced N2O is almost exclusively controlled by the enzymatic isotope effects of NO reductases (NOR). These enzymes are known to be structurally different between certain classes of N2O producers with each class causing different isotope effects (Schmidt et al., 2004). The NH2OH-to-N2O step of nitrifiers and the NO3-to-N2O step of fungal denitrifiers are associated with large site-specific 15N effects with SP of 33 to 37 ‰ (Sutka et al., 2006, 2008) while the few tested species of gram-negative bacterial denitrifiers (cNOR group) exhibited low SP of -5 to 0‰ (Sutka et al., 2006; Toyoda et al., 2005). The aim of our study was to determine site-specific fractionation factors of the NO3-to-N2O step (ɛSP) for several species of denitrifiers representing each of the known NOR-types of bacteria, i.e. cNOR, q

  5. Transmission of endemic ST22-MRSA-IV on four acute hospital wards investigated using a combination of spa, dru and pulsed-field gel electrophoresis typing.

    LENUS (Irish Health Repository)

    Creamer, E

    2012-11-01

    The transmission of meticillin-resistant Staphylococcus aureus (MRSA) between individual patients is difficult to track in institutions where MRSA is endemic. We investigated the transmission of MRSA where ST22-MRSA-IV is endemic on four wards using demographic data, patient and environmental screening, and molecular typing of isolates. A total of 939 patients were screened, 636 within 72 h of admission (on admission) and 303 >72 h after admission, and 1,252 environmental samples were obtained. Isolates were typed by spa, dru and pulsed-field gel electrophoresis (PFGE) typing. A composite dendrogram generated from the three sets of typing data was used to divide isolates into \\'dendrogram groups\\' (DGs). Ten percent of patients (92\\/939) were MRSA-positive; 7 % (44\\/636) on admission and 16 % (48\\/303) >72 h after admission (p = 0.0007). MRSA was recovered from 5 % of environmental specimens (65\\/1,252). Most isolates from patients (97 %, 85\\/88) and the environment (97 %, 63\\/65) exhibited the ST22-MRSA-IV genotype. Four DGs (DG1, DG4, DG16 and DG17) accounted for 58 % of ST22-MRSA-IV isolates from patients. Epidemiological evidence suggested cross-transmission among 44\\/92 patients (48 %) but molecular typing confirmed probable cross-transmission in only 11 instances (13 %, 11\\/88), with the majority of cross-transmission (64 %; 7\\/11) occurring on one ward. In the setting of highly clonal endemic MRSA, the combination of local epidemiology, PFGE, spa and dru typing provided valuable insights into MRSA transmission.

  6. Antitumor effects of the molecule-downsized immunoconjugate composed of lidamycin and Fab' fragment of monoclonal antibody directed against type IV collagenase

    Institute of Scientific and Technical Information of China (English)

    WANG; Fengqiang; SHANG; Boyang; ZHEN; Yongsu

    2004-01-01

    Type IV collagenase plays an important role in tumor invasion and metastasis through cleaving type IV collagen in the basement membrane and extracellular matrix. In this study a molecule-downsized immunoconjugate (Fab′-LDM) was constructed by linking lidamycin (LDM), a highly potent antitumor antibiotic, to the Fab′ fragment of a monoclonal antibody directed against type IV collagenase and its antitumor effect was investigated. As assayed in 10% SDS-PAGE gel, the molecular weight of Fab′-LDM conjugate was 65 kD with a 1:1 molecular ratio of Fab′ and LDM. The Fab′-LDM conjugate maintained most part of the immunoreactivity of Fab′ fragment to both type IV collagense and mouse hepatoma 22 cells by ELISA. By MTT assay, Fab′-LDM conjugate showed more potent cytotoxicity to hepatoma 22 cells than that of LDM. Administered intravenously, Fab′-LDM conjugate proved to be more effective against the growth of subcutaneously transplanted hepatoma 22 in mice than free LDM in two experiment settings. In Experiment I, the drugs were given intravenously on day 1 and day 8. Fab′-LDM at the doses of 0.025 mg/kg, 0.05 mg/kg and 0.1 mg/kg inhibited tumor growth by 76.7%, 93.3% and 94.8%, while free LDM at 0.05 mg/kg inhibited tumor growth by 76.1%, respectively. In experiment II, the drugs were given intravenously on day 4 and day 11, Fab′-LDM at the doses of 0.025 mg/kg and 0.05 mg/kg inhibited tumor growth by 74.2%, 80.9%, while free LDM at 0.05 mg/kg inhibited tumor growth by 60.5%, respectively. In terms of survival time, Fab′-LDM was more effective than free LDM. The results suggest that the molecule-downsized immunoconjugate directed against type IV collagenase is of high efficacy in experimental cancer therapy.

  7. Effect of catchment land use and soil type on the concentration, quality, and bacterial degradation of riverine dissolved organic matter

    DEFF Research Database (Denmark)

    Autio, Iida; Soinne, Helena; Helin, Janne;

    2016-01-01

    of dissolved organic carbon, nitrogen, and phosphorus (DOC, DON, and DOP, respectively), and was linked to DOM quality. Soil type was more important than land use in determining the concentration and quality of riverine DOM. On average, 5–9 % of the DOC and 45 % of the DON were degraded by the bacterial......We studied the effects of catchment characteristics (soil type and land use) on the concentration and quality of dissolved organic matter (DOM) in river water and on the bacterial degradation of terrestrial DOM. The share of organic soil was the strongest predictor of high concentrations...... communities within 2–3 months. Simultaneously, the proportion of humic-like compounds in the DOM pool increased. Bioavailable DON accounted for approximately one-third of the total bioavailable dissolved nitrogen, and thus, terrestrial DON can markedly contribute to the coastal plankton dynamics and support...

  8. Dynamics of bacterial communities in two unpolluted soils after spiking with phenanthrene: soil type specific and common responders

    Directory of Open Access Journals (Sweden)

    Guo-Chun eDing

    2012-08-01

    Full Text Available Considering their key role for ecosystem processes, it is important to understand the response of microbial communities in unpolluted soils to pollution with polycyclic aromatic hydrocarbons (PAH. Phenanthrene, a model compound for PAH, was spiked to a Cambisol and a Luvisol soil. Total community DNA from phenanthrene-spiked and control soils collected on days 0, 21 and 63 were analyzed based on PCR-amplified 16S rRNA genefragments. Denaturing gradient gel electrophoresis (DGGE fingerprints of bacterial communities increasingly deviated with time between spiked and control soils. In taxon specific DGGE, significant responses of Alphaproteobacteria and Actinobacteria became only detectable after 63 days, while significant effects on Betaproteobacteria were detectable in both soils after 21 days. Comparison of the taxonomic distribution of bacteria in spiked and control soils on day 63 as revealed by pyrosequencing indicated soil type specific negative effects of phenanthrene on several taxa, many of them belonging to the Gamma-, Beta- or Deltaproteobacteria. Bacterial richness and evenness decreased in spiked soils. Despite the significant differences in the bacterial community structure between both soils on day 0, similar genera increased in relative abundance after PAH spiking, especially Sphingomonas and Polaromonas. However, this did not result in an increased overall similarity of the bacterial communities in both soils.

  9. A type VI secretion system is involved in Pseudomonas fluorescens bacterial competition.

    Directory of Open Access Journals (Sweden)

    Victorien Decoin

    Full Text Available Protein secretion systems are crucial mediators of bacterial interactions with other organisms. Among them, the type VI secretion system (T6SS is widespread in Gram-negative bacteria and appears to inject toxins into competitor bacteria and/or eukaryotic cells. Major human pathogens, such as Vibrio cholerae, Burkholderia and Pseudomonas aeruginosa, express T6SSs. Bacteria prevent self-intoxication by their own T6SS toxins by producing immunity proteins, which interact with the cognate toxins. We describe here an environmental P. fluorescens strain, MFE01, displaying an uncommon oversecretion of Hcp (hemolysin-coregulated protein and VgrG (valine-glycine repeat protein G into the culture medium. These proteins are characteristic components of a functional T6SS. The aim of this study was to attribute a role to this energy-consuming overexpression of the T6SS. The genome of MFE01 contains at least two hcp genes (hcp1 and hcp2, suggesting that there may be two putative T6SS clusters. Phenotypic studies have shown that MFE01 is avirulent against various eukaryotic cell models (amebas, plant or animal cell models, but has antibacterial activity against a wide range of competitor bacteria, including rhizobacteria and clinical bacteria. Depending on the prey cell, mutagenesis of the hcp2 gene in MFE01 abolishes or reduces this antibacterial killing activity. Moreover, the introduction of T6SS immunity proteins from S. marcescens, which is not killed by MFE01, protects E. coli against MFE01 killing. These findings suggest that the protein encoded by hcp2 is involved in the killing activity of MFE01 mediated by effectors of the T6SS targeting the peptidoglycan of Gram-negative bacteria. Our results indicate that MFE01 can protect potato tubers against Pectobacterium atrosepticum, which causes tuber soft rot. Pseudomonas fluorescens is often described as a major PGPR (plant growth-promoting rhizobacterium, and our results suggest that there may be a

  10. Optical fingerprinting in medical microbiology; Raman spectroscopy as a bacterial typing tool

    NARCIS (Netherlands)

    H.F.M. Willemse-Erix (Diana)

    2011-01-01

    textabstractBacteria are present everywhere on earth and form a large part of the world’s biomass (41). It has been estimated that there are approximately ten times as many bacterial cells as there are human cells in the body. The majority of bacteria present in or on the body are harmless and many

  11. Effects of Maternal Nicotine Exposure on Expression of Collagen Type IV and its Roles on Pulmonary Bronchogenesis and Alveolarization in Newborn Mice

    Directory of Open Access Journals (Sweden)

    Mehdi Jalali

    2010-09-01

    Full Text Available Nicotine is one the chemical substance with high level of toxically. It crosses the placenta and accumulates in the developing organs of fetus. Our previous investigations indicated that collagen type IV plays a key role in basement membrane of various embryonic organs. In this study we evaluated the effect of maternal nicotine exposure pre and postnatal period on collagen IV expression during bronchogenesis and alveolarization in the lungs of newborn mice. Female Balb/C mice were mated and Sperm positive in vaginal smear was designated as embryonic day zero. Pregnant mice were divided into 2 experimental and 2 control groups. Experimental group 1, received 3 mg/kg nicotine intrapritoneally from day 5 of gestation to last day of pregnancy. Experimental group 2 received the same amount of nicotine during the same gestational days as well as 2 first week after birth (lactation. The control groups received the same volume of normal saline during the same periods. At the end of exposure times, all of newborns were anesthetized and their lungs were removed for immunohistochemical method.Our finding indicated that collagen reaction in the bronchial basement membrane and extra cellular matrix of lung parenchyma in experimental groups increased significantly compared to control groups. Our results also showed alveolar remodeling and abnormal bronchogenesis were observed in experimental group especially group 2. These data indicate that maternal nicotine exposure may induce abnormal collagen IV expression and cause defects in bronchopulmonary development.

  12. Non-oxido divanadium(IV) and divanadium(V) thiolate complexes with a new type of chalcogenide bridging motif.

    Science.gov (United States)

    Wu, Hong-Ming; Chang, Ya-Ho; Tsai, Yi-Fang; Hsu, Kuei-Fang; Lee, Gene-Hsiang; Hsu, Hua-Fen

    2015-03-14

    In our effort to study vanadium chalcogenide chemistry, we have synthesized and characterized a class of non-oxido divanadium(IV) and divanadium(V) complexes with chalcogenide and dichalcogenide as bridges. All structures consist of a similar divanadium motif, in which two metal centers are bridged by one μ-chalcogenide and one μ-η(2):η(2)-dichalcogenide, forming a V2(μ-E)(μ-η(2):η(2)-E2) (E = S or Se) core structure. These compounds are [V(IV)2(PS3)2(μ-Se2)(μ-Se)][PPh4]2 (1), [V(V)2(PS3'')2(μ-Se2)(μ-Se)] (2), [V(V)2(PS3'')2(μ-S2)(μ-S)] (3a) and [V(V)2(PS3)2(μ-S2)(μ-S)] (3b) ([PS3](3-) = P(C6H4-2-S)3 and [PS3''](3-) = P(C6H3-3-SiMe3-2-S)3). Compound 1 exhibits diamagnetic behavior, indicating strong antiferromagnetic coupling between two d(1) centers. Compounds 2 and 3a-b have the highest oxidation states for vanadium ions (+5/+5) among those reported divanadium chalcogenide clusters. The work demonstrates that high-valent divanadium chalcogenide clusters can be obtained with the activation of elemental chalcogens by low-valent vanadium ions. PMID:25645817

  13. Ehlers-Danlos syndrome type IV and recurrent carotid-cavernous fistula: review of the literature, endovascular approach, technique and difficulties

    Energy Technology Data Exchange (ETDEWEB)

    Desal, H.A.; Toulgoat, F.; Raoul, S.; Guillon, B.; Bommard, S.; Naudou-Giron, E.; Auffary-Calvier, E.; Kersaint-Gilly, A. de [Department of Neuroradiology, Laennec Hospital, University of Nantes (France); 1

    2005-04-01

    We report the follow-up of a previously published case (Forlodou et al. Neuroradiology 38:595-597, 1996) of carotido-cavernous fistulas (CCFs) in a patient presenting with type IV Ehlers-Danlos syndrome (EDS 4) that were successfully treated twice by an endovascular approach. Initial treatment with a detachable balloon was in 1994 for a right CCF, and, 8 years later, a left CCF was treated by selective transarterial occlusion of the cavernous sinus with coils. Unfortunately, the patient suffered from a spontaneous post-operative intracranial haemorrhage in the left hemisphere and died. Review of the literature, technical considerations for bilateral CCF and complication are discussed.

  14. Production of the Type IV Secretion System Differs among Brucella Species as Revealed with VirB5- and VirB8-Specific Antisera

    OpenAIRE

    Rouot, Bruno; Alvarez-Martinez, Maria-Teresa; Marius, Carine; Menanteau, Pierrette; Guilloteau, Laurence; Boigegrain, Rose-Anne; Zumbihl, Robert; O'Callaghan, David; Domke, Natalie; Baron, Christian

    2003-01-01

    Expression of the virB operon, encoding the type IV secretion system required for Brucella suis virulence, occurred in the acidic phagocytic vacuoles of macrophages and could be induced in minimal medium at acidic pH values. To analyze the production of VirB proteins, polyclonal antisera against B. suis VirB5 and VirB8 were generated. Western blot analysis revealed that VirB5 and VirB8 were detected after 3 h in acidic minimal medium and that the amounts increased after prolonged incubation. ...

  15. Dynamics of bacterial communities during the ripening process of different Croatian cheese types derived from raw ewe's milk cheeses.

    Science.gov (United States)

    Fuka, Mirna Mrkonjić; Wallisch, Stefanie; Engel, Marion; Welzl, Gerhard; Havranek, Jasmina; Schloter, Michael

    2013-01-01

    Microbial communities play an important role in cheese ripening and determine the flavor and taste of different cheese types to a large extent. However, under adverse conditions human pathogens may colonize cheese samples during ripening and may thus cause severe outbreaks of diarrhoea and other diseases. Therefore in the present study we investigated the bacterial community structure of three raw ewe's milk cheese types, which are produced without the application of starter cultures during ripening from two production sites based on fingerprinting in combination with next generation sequencing of 16S rRNA gene amplicons. Overall a surprisingly high diversity was found in the analyzed samples and overall up to 213 OTU97 could be assigned. 20 of the major OTUs were present in all samples and include mostly lactic acid bacteria (LAB), mainly Lactococcus, and Enterococcus species. Abundance and diversity of these genera differed to a large extent between the 3 investigated cheese types and in response to the ripening process. Also a large number of non LAB genera could be identified based on phylogenetic alignments including mainly Enterobacteriaceae and Staphylococcacae. Some species belonging to these two families could be clearly assigned to species which are known as potential human pathogens like Staphylococcus saprophyticus or Salmonella spp. However, during cheese ripening their abundance was reduced. The bacterial genera, namely Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Corynebacterium, Clostridium, Staphylococcus, Thermoanerobacterium, E. coli, Hafnia, Pseudomonas, Janthinobacterium, Petrotoga, Kosmotoga, Megasphaera, Macrococcus, Mannheimia, Aerococcus, Vagococcus, Weissella and Pediococcus were identified at a relative low level and only in selected samples. Overall the microbial composition of the used milk and the management of the production units determined the bacterial community composition for all cheese types to a

  16. Dynamics of bacterial communities during the ripening process of different Croatian cheese types derived from raw ewe's milk cheeses.

    Directory of Open Access Journals (Sweden)

    Mirna Mrkonjić Fuka

    Full Text Available Microbial communities play an important role in cheese ripening and determine the flavor and taste of different cheese types to a large extent. However, under adverse conditions human pathogens may colonize cheese samples during ripening and may thus cause severe outbreaks of diarrhoea and other diseases. Therefore in the present study we investigated the bacterial community structure of three raw ewe's milk cheese types, which are produced without the application of starter cultures during ripening from two production sites based on fingerprinting in combination with next generation sequencing of 16S rRNA gene amplicons. Overall a surprisingly high diversity was found in the analyzed samples and overall up to 213 OTU97 could be assigned. 20 of the major OTUs were present in all samples and include mostly lactic acid bacteria (LAB, mainly Lactococcus, and Enterococcus species. Abundance and diversity of these genera differed to a large extent between the 3 investigated cheese types and in response to the ripening process. Also a large number of non LAB genera could be identified based on phylogenetic alignments including mainly Enterobacteriaceae and Staphylococcacae. Some species belonging to these two families could be clearly assigned to species which are known as potential human pathogens like Staphylococcus saprophyticus or Salmonella spp. However, during cheese ripening their abundance was reduced. The bacterial genera, namely Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Corynebacterium, Clostridium, Staphylococcus, Thermoanerobacterium, E. coli, Hafnia, Pseudomonas, Janthinobacterium, Petrotoga, Kosmotoga, Megasphaera, Macrococcus, Mannheimia, Aerococcus, Vagococcus, Weissella and Pediococcus were identified at a relative low level and only in selected samples. Overall the microbial composition of the used milk and the management of the production units determined the bacterial community composition for all

  17. Critical roles of sea cucumber C-type lectin in non-self recognition and bacterial clearance.

    Science.gov (United States)

    Wei, Xiumei; Liu, Xiangquan; Yang, Jianmin; Wang, Sheng; Sun, Guohua; Yang, Jialong

    2015-08-01

    C-type lectin is one important pattern recognition receptor (PRR) that plays crucial roles in multiple immune responses. A C-type lectin from sea cucumber Apostichopus japonicus (AjCTL-1) was characterized in the present study. The amino acid sequence of AjCTL-1 shared high similarities with other C-type lectins from invertebrates and vertebrates. The C-type lectin domain (CTLD) of AjCTL-1 contained a Ca(2+)-binding site 2 and four conserved cysteine residues. AjCTL-1 mRNA expression patterns in tissues and after bacterial challenge were then analysed. Quantitative PCR revealed that AjCTL-1 mRNA was widely expressed in the tested tissues of healthy sea cucumber. The highest expression level occurred in gonad followed by body wall, coelomocytes, tentacle, intestinum and longitudinal muscle, and the lowest expression level was in respiratory tree. AjCTL-1 mRNA expression in coelomocytes was significantly induced by gram-negative Listonella anguillarum and gram-positive Micrococcus luteus, with different up-regulation patterns post-challenge. Recombinant AjCTL-1 exhibited the ability to bind peptidoglycan directly, agglutinate M. luteus, Staphylococcus aureus and Escherichia coli, in a Ca(2+)-dependant manner, and enhance the phagocytosis of coelomocytes against E. coli in vitro. The results indicated that AjCTL-1 could act as a PRR in Apostichopus japonicus and had critical roles in non-self recognition and bacterial clearance against invading microbes. PMID:26052017

  18. A new multiplex PCR for easy screening of methicillin-resistant Staphylococcus aureus SCCmec types I-V

    DEFF Research Database (Denmark)

    Boye, Kit; Bartels, Mette Damkjær; Andersen, Ina S;

    2007-01-01

    A multiplex PCR with four primer-pairs was designed to identify the five main known SCCmec types. A clear and easily discriminated band pattern was obtained for all five types. The SCCmec type was identified for 98% of 312 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA...

  19. In vivo efficacy of azithromycin in treatment of systemic infection and septic arthritis induced by type IV group B Streptococcus strains in mice: comparative study with erythromycin and penicillin G.

    OpenAIRE

    Tissi, L; von Hunolstein, C; Mosci, P; Campanelli, C; Bistoni, F.; Orefici, G

    1995-01-01

    We compared the activities of azithromycin, erythromycin, and penicillin G in a mouse model of systemic infection and septic arthritis induced by type IV group B streptococci (GBS). The in vitro and in vivo efficacy data for these drugs were analyzed relative to the pharmacokinetics of the drugs in sera, joints, and kidneys. Adult CD-1 mice were infected intravenously with 10(7) CFU of type IV GBS. Intraperitoneal drug administration was initiated with different dose regimens at different tim...

  20. Cholesterol binding by the bacterial type III translocon is essential for virulence effector delivery into mammalian cells.

    Science.gov (United States)

    Hayward, Richard D; Cain, Robert J; McGhie, Emma J; Phillips, Neil; Garner, Matthew J; Koronakis, Vassilis

    2005-05-01

    A ubiquitous early step in infection of man and animals by enteric bacterial pathogens like Salmonella, Shigella and enteropathogenic Escherichia coli (EPEC) is the translocation of virulence effector proteins into mammalian cells via specialized type III secretion systems (TTSSs). Translocated effectors subvert the host cytoskeleton and stimulate signalling to promote bacterial internalization or survival. Target cell plasma membrane cholesterol is central to pathogen-host cross-talk, but the precise nature of its critical contribution remains unknown. Using in vitro cholesterol-binding assays, we demonstrate that Salmonella (SipB) and Shigella (IpaB) TTSS translocon components bind cholesterol with high affinity. Direct visualization of cell-associated fluorescently labelled SipB and parallel immunogold transmission electron microscopy revealed that cholesterol levels limit both the amount and distribution of plasma membrane-integrated translocon. Correspondingly, cholesterol depletion blocked effector translocation into cultured mammalian cells by not only the related Salmonella and Shigella TTSSs, but also the more divergent EPEC system. The data reveal that cholesterol-dependent association of the bacterial TTSS translocon with the target cell plasma membrane is essential for translocon activation and effector delivery into mammalian cells.

  1. Secondary flow structures in the presence of Type-IV stent fractures through a bent tube model for curved arteries: Effect of circulation thresholding

    Science.gov (United States)

    Hussain, Shadman; Bulusu, Kartik V.; Plesniak, Michael W.

    2013-11-01

    A common treatment for atherosclerosis is the opening of narrowed arteries resulting from obstructive lesions by angioplasty and stent implantation to restore unrestricted blood flow. ``Type-IV'' stent fractures involve complete transverse, linear fracture of stent struts, along with displacement of the stent fragments. Experimental data pertaining to secondary flows in the presence of stents that underwent ``Type-IV'' fractures in a bent artery model under physiological inflow conditions were obtained through a two-component, two-dimensional (2C-2D) PIV technique. Concomitant stent-induced flow perturbations result in secondary flow structures with complex, multi-scale morphologies and varying size-strength characteristics. Ultimately, these flow structures may have a role to play in restenosis and progression of atherosclerotic plaque. Vortex circulation thresholds were established with the goal of resolving and tracking iso-circulation secondary flow vortical structures and their morphological changes. This allowed for a parametric evaluation and quantitative representation of secondary flow structures undergoing deformation and spatial reorganization. Supported by NSF Grant No. CBET- 0828903 and GW Center for Biomimetics and Bioinspired Engineering.

  2. Characterization of Microstructures across the Heat-Affected Zone of the Modified 9Cr-1Mo Weld Joint to Understand Its Role in Promoting Type IV Cracking

    Science.gov (United States)

    Laha, K.; Chandravathi, K. S.; Parameswaran, P.; Rao, K. Bhanu Sankara; Mannan, S. L.

    2007-01-01

    In the postweld heat-treated (PWHT) fusion welded modified 9Cr-1Mo steel joint, a soft zone was identified at the outer edge of the heat-affected zone (HAZ) of the base metal adjacent to the deposited weld metal. Hardness and tensile tests were performed on the base metal subjected to soaking for 5 minutes at temperatures below Ac1 to above Ac3 and tempering at the PWHT condition. These tests indicated that the soft zone in the weld joint corresponds to the intercritical region of HAZ. Creep tests were conducted on the base metal and cross weld joint. At relatively lower stresses and higher test temperatures, the weld joint possessed lower creep rupture life than the base metal, and the difference in creep rupture life increased with the decrease in stress and increase in temperature. Preferential accumulation of creep deformation coupled with extensive creep cavitation in the intercritical region of HAZ led to the premature failure of the weld joint in the intercritical region of the HAZ, commonly known as type IV cracking. The microstructures across the HAZ of the weld joint have been characterized to understand the role of microstructure in promoting type IV cracking. Strength reduction in the intercritical HAZ of the joint resulted from the combined effects of coarsening of dislocation substructures and precipitates. Constrained deformation of the soft intercritical HAZ sandwich between relatively stronger constitutes of the joint induced creep cavitation in the soft zone resulting in premature failure.

  3. A survey of biofilms on wastewater aeration diffusers suggests bacterial community composition and function vary by substrate type and time.

    Science.gov (United States)

    Noble, Peter A; Park, Hee-Deung; Olson, Betty H; Asvapathanagul, Pitiporn; Hunter, M Colby; Garrido-Baserba, Manel; Lee, Sang-Hoon; Rosso, Diego

    2016-07-01

    Aeration diffusers in wastewater treatment plants generate air bubbles that promote mixing, distribution of dissolved oxygen, and microbial processing of dissolved and suspended matter in bulk solution. Biofouling of diffusers represents a significant problem to wastewater treatment plants because biofilms decrease oxygen transfer efficiency and increase backpressure on the blower. To better understand biofouling, we conducted a pilot study to survey the bacterial community composition and function of biofilms on different diffuser substrates and compare them to those in the bulk solution. DNA was extracted from the surface of ethylene-propylene-diene monomer (EPDM), polyurethane, and silicone diffusers operated for 15 months in a municipal treatment plant and sampled at 3 and 9 months. The bacterial community composition and function of the biofilms and bulk solution were determined by amplifying the 16S rRNA genes and pyrosequencing the amplicons and raw metagenomic DNA. The ordination plots and dendrograms of the 16S rRNA and functional genes showed that while the bacterial community composition and function of the bulk solution was independent of sampling time, the composition and function of the biofilms differed by diffuser type and testing time. For the EPDM and silicone diffusers, the biofilm communities were more similar in composition to the bulk solution at 3 months than 9 months. In contrast, the bacteria on the polyurethane diffusers were more dissimilar to the bulk solution at 3 months than 9 months. Taken together, the survey showed that the community composition and function of bacterial biofilms depend on the diffuser substrate and testing time, which warrants further elucidation. PMID:27294381

  4. Genomic Encyclopedia of Bacterial and Archaeal Type Strains, Phase III: the genomes of soil and plant-associated and newly described type strains.

    Science.gov (United States)

    Whitman, William B; Woyke, Tanja; Klenk, Hans-Peter; Zhou, Yuguang; Lilburn, Timothy G; Beck, Brian J; De Vos, Paul; Vandamme, Peter; Eisen, Jonathan A; Garrity, George; Hugenholtz, Philip; Kyrpides, Nikos C

    2015-01-01

    The Genomic Encyclopedia of Bacteria and Archaea (GEBA) project was launched by the JGI in 2007 as a pilot project to sequence about 250 bacterial and archaeal genomes of elevated phylogenetic diversity. Herein, we propose to extend this approach to type strains of prokaryotes associated with soil or plants and their close relatives as well as type strains from newly described species. Understanding the microbiology of soil and plants is critical to many DOE mission areas, such as biofuel production from biomass, biogeochemistry, and carbon cycling. We are also targeting type strains of novel species while they are being described. Since 2006, about 630 new species have been described per year, many of which are closely aligned to DOE areas of interest in soil, agriculture, degradation of pollutants, biofuel production, biogeochemical transformation, and biodiversity.

  5. Two Different Bacterial Community Types Are Linked with the Low-Methane Emission Trait in Sheep

    OpenAIRE

    Kittelmann, Sandra; Cesar S Pinares-Patiño; Seedorf, Henning; Kirk, Michelle R.; Ganesh, Siva; McEwan, John C; Janssen, Peter H.

    2014-01-01

    The potent greenhouse gas methane (CH4) is produced in the rumens of ruminant animals from hydrogen produced during microbial degradation of ingested feed. The natural animal-to-animal variation in the amount of CH4 emitted and the heritability of this trait offer a means for reducing CH4 emissions by selecting low-CH4 emitting animals for breeding. We demonstrate that differences in rumen microbial community structure are linked to high and low CH4 emissions in sheep. Bacterial community str...

  6. Impact of transgenic potatoes expressing anti-bacterial agents on bacterial endophytes is comparable with the effects of plant genotype, soil type and pathogen infection

    NARCIS (Netherlands)

    Rasche, F; Velvis, H; Zachow, C; Berg, G; Van Elsas, JD; Sessitsch, A

    2006-01-01

    1. Blackleg and soft rot disease of potatoes Solanum tuberosum L., mainly caused by the bacterial pathogen Erwinia carotovora ssp. atrospetica (Eca), lead to enormous yield losses world-wide. Genetically modified (GM) potatoes producing anti-bacterial agents, such as cecropin/attacin and T4 lysozyme

  7. Salter-Harris type III and IV displaced fracture of the hallux in young gymnasts: A series of four cases at 1-year follow-up.

    Science.gov (United States)

    Perugia, Dario; Fabbri, Mattia; Guidi, Marco; Lepri, Marco; Masi, Vincenzo

    2014-12-01

    The purpose of this study was to describe four exceptional cases of Salter-Harris type III and IV fractures of the proximal phalanx of the hallux in young high-level gymnasts. All gymnasts underwent the same mechanism of injury of hyperadduction, which indicates a role of the abductor hallucis muscle in the genesis and displacement of these fractures. An open reduction and internal fixation was performed to achieve an anatomical reduction and avoid chronic disability. At 1-year follow-up, all patients had an excellent American Orthopaedic Foot and Ankle Society (AOFAS) score (100 points), and there was no shortening or angulation of the first ray and no evidence of degenerative joint disease on X-ray. Moreover, all the gymnasts had returned to pre-injury levels of sporting activity. To our knowledge, there are no previous studies that address these types of injuries and how they are handled in gymnasts. PMID:25457317

  8. Inactivation of Selected Bacterial Pathogens in Dairy Cattle Manure by Mesophilic Anaerobic Digestion (Balloon Type Digester

    Directory of Open Access Journals (Sweden)

    Christy E. Manyi-Loh

    2014-07-01

    Full Text Available Anaerobic digestion of animal manure in biogas digesters has shown promise as a technology in reducing the microbial load to safe and recommended levels. We sought to treat dairy manure obtained from the Fort Hare Dairy Farm by investigating the survival rates of bacterial pathogens, through a total viable plate count method, before, during and after mesophilic anaerobic digestion. Different microbiological media were inoculated with different serial dilutions of manure samples that were withdrawn from the biogas digester at 3, 7 and 14 day intervals to determine the viable cells. Data obtained indicated that the pathogens of public health importance were 90%–99% reduced in the order: Campylobacter sp. (18 days < Escherichia coli sp. (62 days < Salmonella sp. (133 days from a viable count of 10.1 × 103, 3.6 × 105, 7.4 × 103 to concentrations below the detection limit (DL = 102 cfu/g manure, respectively. This disparity in survival rates may be influenced by the inherent characteristics of these bacteria, available nutrients as well as the stages of the anaerobic digestion process. In addition, the highest p-value i.e., 0.957 for E. coli showed the statistical significance of its model and the strongest correlation between its reductions with days of digestion. In conclusion, the results demonstrated that the specific bacterial pathogens in manure can be considerably reduced through anaerobic digestion after 133 days.

  9. Inactivation of selected bacterial pathogens in dairy cattle manure by mesophilic anaerobic digestion (balloon type digester).

    Science.gov (United States)

    Manyi-Loh, Christy E; Mamphweli, Sampson N; Meyer, Edson L; Okoh, Anthony I; Makaka, Golden; Simon, Michael

    2014-07-14

    Anaerobic digestion of animal manure in biogas digesters has shown promise as a technology in reducing the microbial load to safe and recommended levels. We sought to treat dairy manure obtained from the Fort Hare Dairy Farm by investigating the survival rates of bacterial pathogens, through a total viable plate count method, before, during and after mesophilic anaerobic digestion. Different microbiological media were inoculated with different serial dilutions of manure samples that were withdrawn from the biogas digester at 3, 7 and 14 day intervals to determine the viable cells. Data obtained indicated that the pathogens of public health importance were 90%-99% reduced in the order: Campylobacter sp. (18 days) count of 10.1 × 103, 3.6 × 105, 7.4 × 103 to concentrations below the detection limit (DL = 102 cfu/g manure), respectively. This disparity in survival rates may be influenced by the inherent characteristics of these bacteria, available nutrients as well as the stages of the anaerobic digestion process. In addition, the highest p-value i.e., 0.957 for E. coli showed the statistical significance of its model and the strongest correlation between its reductions with days of digestion. In conclusion, the results demonstrated that the specific bacterial pathogens in manure can be considerably reduced through anaerobic digestion after 133 days.

  10. Crystal Structure of a Bacterial Type IB DNA Topoisomerase Reveals a Preassembled Active Site in the Absence of DNA

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Asmita; Shuman, Stewart; Mondragon, Alfonso (NWU); (SKI)

    2010-03-08

    Type IB DNA topoisomerases are found in all eukarya, two families of eukaryotic viruses (poxviruses and mimivirus), and many genera of bacteria. They alter DNA topology by cleaving and resealing one strand of duplex DNA via a covalent DNA-(3-phosphotyrosyl)-enzyme intermediate. Bacterial type IB enzymes were discovered recently and are described as poxvirus-like with respect to their small size, primary structures, and bipartite domain organization. Here we report the 1.75-{angstrom} crystal structure of Deinococcus radiodurans topoisomerase IB (DraTopIB), a prototype of the bacterial clade. DraTopIB consists of an amino-terminal (N) {beta}-sheet domain (amino acids 1-90) and a predominantly {alpha}-helical carboxyl-terminal (C) domain (amino acids 91-346) that closely resemble the corresponding domains of vaccinia virus topoisomerase IB. The five amino acids of DraTopIB that comprise the catalytic pentad (Arg-137, Lys-174, Arg-239, Asn-280, and Tyr-289) are preassembled into the active site in the absence of DNA in a manner nearly identical to the pentad configuration in human topoisomerase I bound to DNA. This contrasts with the apoenzyme of vaccinia topoisomerase, in which three of the active site constituents are either displaced or disordered. The N and C domains of DraTopIB are splayed apart in an 'open' conformation, in which the surface of the catalytic domain containing the active site is exposed for DNA binding. A comparison with the human topoisomerase I-DNA cocrystal structure suggests how viral and bacterial topoisomerase IB enzymes might bind DNA circumferentially via movement of the N domain into the major groove and clamping of a disordered loop of the C domain around the helix.

  11. Welding IV.

    Science.gov (United States)

    Allegheny County Community Coll., Pittsburgh, PA.

    Instructional objectives and performance requirements are outlined in this course guide for Welding IV, a competency-based course in advanced arc welding offered at the Community College of Allegheny County to provide students with proficiency in: (1) single vee groove welding using code specifications established by the American Welding Society…

  12. Type 3 fimbriae of Klebsiella sp.: molecular characterization and role in bacterial adhesion to plant roots.

    OpenAIRE

    Korhonen, T K; Tarkka, E; Ranta, H; Haahtela, K

    1983-01-01

    Type 3 fimbriae of Klebsiella were purified and characterized. The fimbriae were 4 to 5 nm in diameter and 0.5 to 2 microns long. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the fimbrillin had an apparent molecular weight of 23,500, and it differed from enterobacterial type 1 fimbrillins in its amino acid composition. Hydrophobic amino acids comprised 33.6% of all amino acids in the fimbrillin, which lacked cystine, phenylalanine, and arginine. Serologically, the type 3 fimb...

  13. Determination of the Stoichiometry of the Complete Bacterial Type III Secretion Needle Complex Using a Combined Quantitative Proteomic Approach.

    Science.gov (United States)

    Zilkenat, Susann; Franz-Wachtel, Mirita; Stierhof, York-Dieter; Galán, Jorge E; Macek, Boris; Wagner, Samuel

    2016-05-01

    Precisely knowing the stoichiometry of their components is critical for investigating structure, assembly, and function of macromolecular machines. This has remained a technical challenge in particular for large, hydrophobic membrane-spanning protein complexes. Here, we determined the stoichiometry of a type III secretion system of Salmonella enterica serovar Typhimurium using two complementary protocols of gentle complex purification combined with peptide concatenated standard and synthetic stable isotope-labeled peptide-based mass spectrometry. Bacterial type III secretion systems are cell envelope-spanning effector protein-delivery machines essential for colonization and survival of many Gram-negative pathogens and symbionts. The membrane-embedded core unit of these secretion systems, termed the needle complex, is composed of a base that anchors the machinery to the inner and outer membranes, a hollow filament formed by inner rod and needle subunits that serves as conduit for substrate proteins, and a membrane-embedded export apparatus facilitating substrate translocation. Structural analyses have revealed the stoichiometry of the components of the base, but the stoichiometry of the essential hydrophobic export apparatus components and of the inner rod protein remain unknown. Here, we provide evidence that the export apparatus of type III secretion systems contains five SpaP, one SpaQ, one SpaR, and one SpaS. We confirmed that the previously suggested stoichiometry of nine InvA is valid for assembled needle complexes and describe a loose association of InvA with other needle complex components that may reflect its function. Furthermore, we present evidence that not more than six PrgJ form the inner rod of the needle complex. Providing this structural information will facilitate efforts to obtain an atomic view of type III secretion systems and foster our understanding of the function of these and related flagellar machines. Given that other virulence

  14. Identification and Characterization of a Candidate Wolbachia pipientis Type IV Effector That Interacts with the Actin Cytoskeleton

    Directory of Open Access Journals (Sweden)

    Kathy B. Sheehan

    2016-07-01

    Full Text Available Many bacteria live as intracellular symbionts, causing persistent infections within insects. One extraordinarily common infection is that of Wolbachia pipientis, which infects 40% of insect species and induces reproductive effects. The bacteria are passed from generation to generation both vertically (through the oocyte and horizontally (by environmental transmission. Maintenance of the infection within Drosophila melanogaster is sensitive to the regulation of actin, as Wolbachia inefficiently colonizes strains hemizygous for the profilin or villin genes. Therefore, we hypothesized that Wolbachia must depend on the host actin cytoskeleton. In this study, we identify and characterize a Wolbachia protein (WD0830 that is predicted to be secreted by the bacterial parasite. Expression of WD0830 in a model eukaryote (the yeast Saccharomyces cerevisiae induces a growth defect associated with the appearance of aberrant, filamentous structures which colocalize with rhodamine-phalloidin-stained actin. Purified WD0830 bundles actin in vitro and cosediments with actin filaments, suggesting a direct interaction of the two proteins. We characterized the expression of WD0830 throughout Drosophila development and found it to be upregulated in third-instar larvae, peaking in early pupation, during the critical formation of adult tissues, including the reproductive system. In transgenic flies, heterologously expressed WD0830 localizes to the developing oocyte. Additionally, overexpression of WD0830 results in increased Wolbachia titers in whole flies, in stage 9 and 10 oocytes, and in embryos, compared to controls, suggesting that the protein may facilitate Wolbachia’s replication or transmission. Therefore, this candidate secreted effector may play a role in Wolbachia’s infection of and persistence within host niches.

  15. Mineral Type and Solution Chemistry Affect the Structure and Composition of Actively Growing Bacterial Communities as Revealed by Bromodeoxyuridine Immunocapture and 16S rRNA Pyrosequencing.

    Science.gov (United States)

    Kelly, L C; Colin, Y; Turpault, M-P; Uroz, S

    2016-08-01

    Understanding how minerals affect bacterial communities and their in situ activities in relation to environmental conditions are central issues in soil microbial ecology, as minerals represent essential reservoirs of inorganic nutrients for the biosphere. To determine the impact of mineral type and solution chemistry on soil bacterial communities, we compared the diversity, composition, and functional abilities of a soil bacterial community incubated in presence/absence of different mineral types (apatite, biotite, obsidian). Microcosms were prepared containing different liquid culture media devoid of particular essential nutrients, the nutrients provided only in the introduced minerals and therefore only available to the microbial community through mineral dissolution by biotic and/or abiotic processes. By combining functional screening of bacterial isolates and community analysis by bromodeoxyuridine DNA immunocapture and 16S rRNA gene pyrosequencing, we demonstrated that bacterial communities were mainly impacted by the solution chemistry at the taxonomic level and by the mineral type at the functional level. Metabolically active bacterial communities varied with solution chemistry and mineral type. Burkholderia were significantly enriched in the obsidian treatment compared to the biotite treatment and were the most effective isolates at solubilizing phosphorous or mobilizing iron, in all the treatments. A detailed analysis revealed that the 16S rRNA gene sequences of the OTUs or isolated strains assigned as Burkholderia in our study showed high homology with effective mineral-weathering bacteria previously recovered from the same experimental site. PMID:27138048

  16. The Sloan Lens ACS survey. IV. The mass density profile of early-type galaxies out to 100 effective radii

    NARCIS (Netherlands)

    Gavazzi, Raphael; Treu, Tommaso; Rhodes, Jason D.; Koopmans, Leon V. E.; Bolton, Adam S.; Burles, Scott; Massey, Richard J.; Moustakas, Leonidas A.

    2007-01-01

    We present a weak-lensing analysis of 22 early-type (strong) lens galaxies, based on deep HST images obtained as part of the Sloan Lens ACS Survey. Using advanced techniques to control systematic uncertainties, we show that weak-lensing signal is detected out to similar to 300 h(-1) kpc (at the mean

  17. SPIDER - IV. Optical and NIR color gradients in Early-type galaxies: New Insights into Correlations with Galaxy Properties

    CERN Document Server

    La Barbera, F; de la Rosa, I G; Gal, R R; Swindle, R; Lopes, P A A

    2010-01-01

    We present an analysis of stellar population gradients in 4,546 Early-Type Galaxies with photometry in $grizYHJK$ along with optical spectroscopy. A new approach is described which utilizes color information to constrain age and metallicity gradients. Defining an effective color gradient, $\

  18. Increased searching and handling effort in tall swards lead to a Type IV functional response in small grazing herbivores

    NARCIS (Netherlands)

    Heuermann, N.; Langevelde, van F.; Wieren, van S.E.; Prins, H.H.T.

    2011-01-01

    Understanding the functional response of species is important in comprehending the species’ population dynamics and the functioning of multi-species assemblages. A Type II functional response, where instantaneous intake rate increases asymptotically with sward biomass, is thought to be common in gra

  19. Glucagon-like peptide 1 and inhibitors of dipeptidyl peptidase IV in the treatment of type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Deacon, Carolyn F

    2004-01-01

    Proof-of-concept for the efficacy of a glucagon-like peptide 1 (GLP-1)-based therapy of patients with type 2 diabetes was provided in 2002 by means of prolonged continuous subcutaneous infusion of native GLP-1. Since then, several long-acting analogues of GLP-1, as well as inhibitors of dipeptidyl...

  20. New lethal disease involving type I and III collagen defect resembling geroderma osteodysplastica, De Barsy syndrome, and Ehlers-Danlos syndrome IV.

    Science.gov (United States)

    Jukkola, A; Kauppila, S; Risteli, L; Vuopala, K; Risteli, J; Leisti, J; Pajunen, L

    1998-06-01

    We describe the clinical findings and biochemical features of a male child suffering from a so far undescribed lethal connective tissue disorder characterised by extreme hypermobility of the joints, lax skin, cataracts, severe growth retardation, and insufficient production of type I and type III procollagens. His features are compared with Ehlers-Danlos type IV, De Barsy syndrome, and geroderma osteodysplastica, as these disorders show some symptoms and signs shared with our patient. The child died because of failure of the connective tissue structures joining the skull and the spine, leading to progressive spinal stenosis. The aortic valve was translucent and insufficient. The clinical symptoms and signs, together with histological findings, suggested a collagen defect. Studies on both skin fibroblast cultures and the patient's serum showed reduced synthesis of collagen types I and III at the protein and RNA levels. The sizes of the mRNAs and newly synthesised proteins were normal, excluding gross structural abnormalities. These findings are not in accordance with any other collagen defect characterised so far.

  1. Enzyme-linked immunosorbent serum assay specific for the 7S domain of Collagen Type IV (P4NP 7S)

    DEFF Research Database (Denmark)

    Leeming, Diana J; Nielsen, Mette J; Dai, Yueqin;

    2012-01-01

    Aim:  The present study describes the ability of a newly developed N-terminal pro-peptides of type IV collagen 7S domain (P4NP 7S) competitive enzyme-linked immunosorbent assay (ELISA) for describing liver fibrosis. The assay applies a monoclonal antibody specific for a PIVNP 7S epitope 100...... preclinical liver fibrosis models; the bile duct ligation model (BDL) and the carbon tetrachloride model (CCL4) both performed in rats. Results:  A technically robust P4NP 7S ELISA assay using a monoclonal antibody was produced. In the BDL and CCL4 liver fibrosis models it was observed that the P4NP 7S levels...... were significantly elevated in rat with liver fibrosis as seen by histology (CCL4: 283% elevated in the highest quartile of total hepatic collagen compared with controls, P = 0.001; BDL: 183% elevated at week 4 compared with sham, P 

  2. Non-thermal radio emission from O-type stars. IV. Cygnus OB2 No. 8A

    OpenAIRE

    Blomme, R.; De Becker, Michaël; Volpi, D.; Rauw, Grégor

    2010-01-01

    Context. Several early-type colliding-wind binaries are known to emit synchrotron radiation due to relativistic electrons, which are most probably accelerated by the Fermi mechanism. By studying such systems we can learn more about this mechanism, which is also relevant in other astrophysical contexts. Colliding-wind binaries are furthermore important for binary frequency determination in clusters and for understanding clumping and porosity in stellar winds. Aims: We study the non-thermal ...

  3. Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section.

    Science.gov (United States)

    Bulusu, Kartik V; Plesniak, Michael W

    2016-01-01

    The arterial network in the human vasculature comprises of ubiquitously present blood vessels with complex geometries (branches, curvatures and tortuosity). Secondary flow structures are vortical flow patterns that occur in curved arteries due to the combined action of centrifugal forces, adverse pressure gradients and inflow characteristics. Such flow morphologies are greatly affected by pulsatility and multiple harmonics of physiological inflow conditions and vary greatly in size-strength-shape characteristics compared to non-physiological (steady and oscillatory) flows (1 - 7). Secondary flow structures may ultimately influence the wall shear stress and exposure time of blood-borne particles toward progression of atherosclerosis, restenosis, sensitization of platelets and thrombosis (4 - 6, 8 - 13). Therefore, the ability to detect and characterize these structures under laboratory-controlled conditions is precursor to further clinical investigations. A common surgical treatment to atherosclerosis is stent implantation, to open up stenosed arteries for unobstructed blood flow. But the concomitant flow perturbations due to stent installations result in multi-scale secondary flow morphologies (4 - 6). Progressively higher order complexities such as asymmetry and loss in coherence can be induced by ensuing stent failures vis-à-vis those under unperturbed flows (5). These stent failures have been classified as "Types I-to-IV" based on failure considerations and clinical severity (14). This study presents a protocol for the experimental investigation of the complex secondary flow structures due to complete transverse stent fracture and linear displacement of fractured parts ("Type IV") in a curved artery model. The experimental method involves the implementation of particle image velocimetry (2C-2D PIV) techniques with an archetypal carotid artery inflow waveform, a refractive index matched blood-analog working fluid for phase-averaged measurements (15 - 18

  4. Use of colony-based bacterial strain typing for tracking the fate of Lactobacillus strains during human consumption

    Directory of Open Access Journals (Sweden)

    Drevinek Pavel

    2009-12-01

    Full Text Available Abstract Background The Lactic Acid Bacteria (LAB are important components of the healthy gut flora and have been used extensively as probiotics. Understanding the cultivable diversity of LAB before and after probiotic administration, and being able to track the fate of administered probiotic isolates during feeding are important parameters to consider in the design of clinical trials to assess probiotic efficacy. Several methods may be used to identify bacteria at the strain level, however, PCR-based methods such as Random Amplified Polymorphic DNA (RAPD are particularly suited to rapid analysis. We examined the cultivable diversity of LAB in the human gut before and after feeding with two Lactobacillus strains, and also tracked the fate of these two administered strains using a RAPD technique. Results A RAPD typing scheme was developed to genetically type LAB isolates from a wide range of species, and optimised for direct application to bacterial colony growth. A high-throughput strategy for fingerprinting the cultivable diversity of human faeces was developed and used to determine: (i the initial cultivable LAB strain diversity in the human gut, and (ii the fate of two Lactobacillus strains (Lactobacillus salivarius NCIMB 30211 and Lactobacillus acidophilus NCIMB 30156 contained within a capsule that was administered in a small-scale human feeding study. The L. salivarius strain was not cultivated from the faeces of any of the 12 volunteers prior to capsule administration, but appeared post-feeding in four. Strains matching the L. acidophilus NCIMB 30156 feeding strain were found in the faeces of three volunteers prior to consumption; after taking the Lactobacillus capsule, 10 of the 12 volunteers were culture positive for this strain. The appearance of both Lactobacillus strains during capsule consumption was statistically significant (p Conclusion We have shown that genetic strain typing of the cultivable human gut microbiota can be

  5. Effects of inoculation sources on the enrichment and performance of anode bacterial consortia in sensor typed microbial fuel cells

    Directory of Open Access Journals (Sweden)

    Phuong Tran

    2016-01-01

    Full Text Available Microbial fuel cells are a recently emerging technology that promises a number of applications in energy recovery, environmental treatment and monitoring. In this study, we investigated the effect of inoculating sources on the enrichment of electrochemically active bacterial consortia in sensor-typed microbial fuel cells (MFCs. Several MFCs were constructed, operated with modified artificial wastewater and inoculated with different microbial sources from natural soil, natural mud, activated sludge, wastewater and a mixture of those sources. After enrichment, the MFCs inoculated with the natural soil source generated higher and more stable currents (0.53±0.03 mA, in comparisons with the MFCs inoculated with the other sources. The results from denaturing gradient gel electrophoresis (DGGE showed that there were significant changes in bacterial composition from the original inocula to the enriched consortia. Even more interestingly, Pseudomonas sp. was found dominant in the natural soil source and also in the corresponding enriched consortium. The interactions between Pseudomonas sp. and other species in such a community are probably the key for the effective and stable performance of the MFCs.

  6. Parental somatic and germ-line mosaicism for a multiexon deletion with unusual endpoints in a type III collagen (COL3Al) allele produces ehlers-danlos syndrome type IV in the heterozygous offspring

    Energy Technology Data Exchange (ETDEWEB)

    McGookey Milewicz, D.; Witz, A.M.; Byers, P.H. (Univ of Washington, Seattle (United States)); Smith, A.C.M.; Manchester, D.K.; Waldstein, G. (Children' s Hospital, Denver, CO (United States))

    1993-07-01

    Ehlers-Danlos syndrome (EDS) type IV is a dominantly inherited disorder that results from mutation in the type III collagen gene (COL3A1). The authors studied the structure of the COL3A1 gene of an individual with EDS type IV and that of her phenotypically normal parents. The proband was heterozygous for a 2-kb deletion in COL3A1, while her father was mosaic for the same deletion in somatic and germ cells. In fibroblasts from the father, approximately two-fifths of the COL3A1 alleles carried the deletion, but only 10% of the COL3A1 alleles in white blood cells were of the mutant species. The deletion in the mutant allele extended from intron 7 into intron 11. There was a 12-bp direct repeat in intron 7 and intron 11, the latter about 60 bp 5' to the junction. At the breakpoint there was a duplication of 10 bp from intron 11 separated by an insertion of 4 bp contained within the duplicated sequence. The father was mosaic for the deletion so that the gene rearrangement occurred during his early embryonic development prior to lineage allocation. These findings suggest that at least some of the deletions seen in human genes may occur during replication, rather than as a consequence of meiotic crossing-over, and that they thus have a risk for recurrence when observed de novo. 71 refs., 4 figs., 2 tabs.

  7. Platelet half-life in patients with primary hyperlipoproteinemia type IIa, IIb, and IV according to Fredrickson with and without clinical signs of atherosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, E.; Sinzinger, H.; Widhalm, K.; Kaliman, J.; Hoefer, R. (Vienna Univ. (Austria). 2. Medizinische Klinik; Ludwig Boltzmann-Institut fuer Nuklearmedizin, Vienna (Austria); Vienna Univ. (Austria). Kinderklinik; Vienna Univ. (Austria). Kardiologische Klinik)

    1982-09-01

    It is generally accepted that platelet half-life is shortened in atherosclerotic vascular diseases. Concerning changes due to hyperlipoproteinemia (HLP), however, there exist only few data. Therefore, we examined the platelet-half life in 60 patients with recently discovered HLP type IIa, IIb and IV according to Fredrickson before treatment in comparison to 60 controls. 33 of the HLP-patients had no clinical symptoms of angiopathy. 27 patients suffered from peripheral vascular disease or from coronary heart disease as verified by angiography. The labelling of autologous platelets was performed with 100..mu..Ci of /sup 111/Indium-oxine-sulfate at 37/sup 0/C for 5 minutes. The mean labelling efficiency was 90%, the recovery after 2 hours about 70%. Serum lipoproteins were estimated by means of ultracentrifugation and polyanionprecipitation according to Lipid Research Clinic Methods. In the patients with HLP platelet half-life was significantly shortened in comparison to the control group (p < 0.01). These changes were most pronounced in patients with HLP-type IIa and with atherosclerotic lesions, respectively. In patients with HLP-type IIa a very close correlation could be demonstrated between platelet half-life and LDL-cholesterol (r = -0.72; p < 0.001) as well as total cholesterol (r = -0.73; p < 0.001). These data prove that in HLP in-vivo platelet function as measured by platelet survival is significantly influenced even before the occurrence of clinically relevant symptoms of atherosclerosis.

  8. Agrobacterium tumefaciens VirB6 protein participates in formation of VirB7 and VirB9 complexes required for type IV secretion.

    Science.gov (United States)

    Jakubowski, Simon J; Krishnamoorthy, Vidhya; Christie, Peter J

    2003-05-01

    This study characterized the contribution of Agrobacterium tumefaciens VirB6, a polytopic inner membrane protein, to the formation of outer membrane VirB7 lipoprotein and VirB9 protein multimers required for type IV secretion. VirB7 assembles as a disulfide cross-linked homodimer that associates with the T pilus and a VirB7-VirB9 heterodimer that stabilizes other VirB proteins during biogenesis of the secretion machine. Two presumptive VirB protein complexes, composed of VirB6, VirB7, and VirB9 and of VirB7, VirB9, and VirB10, were isolated by immunoprecipitation or glutathione S-transferase pulldown assays from detergent-solubilized membrane extracts of wild-type A348 and a strain producing only VirB6 through VirB10 among the VirB proteins. To examine the biological importance of VirB6 complex formation for type IV secretion, we monitored the effects of nonstoichiometric VirB6 production and the synthesis of VirB6 derivatives with 4-residue insertions (VirB6.i4) on VirB7 and VirB9 multimerization, T-pilus assembly, and substrate transfer. A virB6 gene deletion mutant accumulated VirB7 dimers at diminished steady-state levels, whereas complementation with a plasmid bearing wild-type virB6 partially restored accumulation of the dimers. VirB6 overproduction was correlated with formation of higher-order VirB9 complexes or aggregates and also blocked substrate transfer without a detectable disruption of T-pilus production; these phenotypes were displayed by cells grown at 28 degrees C, a temperature that favors VirB protein turnover, but not by cells grown at 20 degrees C. Strains producing several VirB6.i4 mutant proteins assembled novel VirB7 and VirB9 complexes detectable by nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and two strains producing the D60.i4 and L191.i4 mutant proteins translocated IncQ plasmid and VirE2 effector protein substrates in the absence of a detectable T pilus. Our findings support a model that VirB6 mediates

  9. Uncovering the Transmembrane Metal Binding Site of the Novel Bacterial Major Facilitator Superfamily-Type Copper Importer CcoA

    Directory of Open Access Journals (Sweden)

    Bahia Khalfaoui-Hassani

    2016-01-01

    Full Text Available Uptake and trafficking of metals and their delivery to their respective metalloproteins are important processes. Cells need precise control of each step to avoid exposure to excessive metal concentrations and their harmful consequences. Copper (Cu is a required micronutrient used as a cofactor in proteins. However, in large amounts, it can induce oxidative damage; hence, Cu homeostasis is indispensable for cell survival. Biogenesis of respiratory heme-Cu oxygen (HCO reductases includes insertion of Cu into their catalytic subunits to form heme-Cu binuclear centers. Previously, we had shown that CcoA is a major facilitator superfamily (MFS-type bacterial Cu importer required for biogenesis of cbb3-type cytochrome c oxidase (cbb3-Cox. Here, using Rhodobacter capsulatus, we focused on the import and delivery of Cu to cbb3-Cox. By comparing the CcoA amino acid sequence with its homologues from other bacterial species, we located several well-conserved Met, His, and Tyr residues that might be important for Cu transport. We determined the topology of the transmembrane helices that carry these residues to establish that they are membrane embedded, and substituted for them amino acids that do not ligand metal atoms. Characterization of these mutants for their uptake of radioactive 64Cu and cbb3-Cox activities demonstrated that Met233 and His261 of CcoA are essential and Met237 and Met265 are important, whereas Tyr230 has no role for Cu uptake or cbb3-Cox biogenesis. These findings show for the first time that CcoA-mediated Cu import relies on conserved Met and His residues that could act as metal ligands at the membrane-embedded Cu binding domain of this transporter.

  10. A Gram-Negative Bacterial Secreted Protein Types Prediction Method Based on PSI-BLAST Profile

    Science.gov (United States)

    2016-01-01

    Prediction of secreted protein types based solely on sequence data remains to be a challenging problem. In this study, we extract the long-range correlation information and linear correlation information from position-specific score matrix (PSSM). A total of 6800 features are extracted at 17 different gaps; then, 309 features are selected by a filter feature selection method based on the training set. To verify the performance of our method, jackknife and independent dataset tests are performed on the test set and the reported overall accuracies are 93.60% and 100%, respectively. Comparison of our results with the existing method shows that our method provides the favorable performance for secreted protein type prediction.

  11. Construction of a bacterial artificial chromosome library of S-type CMS maize mitochondria

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to isolate mitochondrial genes easily, we have developed a new method to construct S-type CMS maize mitochondrial gene library by means of embedding mitochondria and enzymatic digesting mitochondria in situ, preparing mtDNA by electrophoresis, digesting LMP agarose with β-agarase, using BAC vector and electroporation. About 2 500 white clones of Mo17 CMS-J mitochondrial gene library were obtained with the average size of 18.24 kb, ranging from 5 to 40 kb, 63.6% inserts came from mitochondrial genome and represented 48 ′ mitochondrial genome equivalents. All the probes had detected the positive clones in the gene library. It is helpful to elucidating the maize mitochondrial genome structure and mechanism of S-type CMS, and may give some valuable reference to the construction of other plant mitochondrial genome library.

  12. Bacterial Bile Metabolising Gene Abundance in Crohn's, Ulcerative Colitis and Type 2 Diabetes Metagenomes

    OpenAIRE

    Labbé, Alain; Ganopolsky, Jorge G.; Martoni, Christopher J.; Prakash, Satya; Jones, Mitchell L.

    2014-01-01

    We performed an analysis to determine the importance of bile acid modification genes in the gut microbiome of inflammatory bowel disease and type 2 diabetic patients. We used publicly available metagenomic datasets from the Human Microbiome Project and the MetaHIT consortium, and determined the abundance of bile salt hydrolase gene (bsh), 7 alpha-dehydroxylase gene (adh) and 7-alpha hydroxysteroid dehydrogenase gene (hsdh) in fecal bacteria in diseased populations of Crohn's disease (CD), Ulc...

  13. A Pseudomonas fluorescens type 6 secretion system is related to mucoidy, motility and bacterial competition

    OpenAIRE

    Decoin, Victorien; Gallique, Mathias; Barbey, Corinne; Le Mauff, Francois; Poc, Cecile Duclairoir; Feuilloley, Marc GJ; Orange, Nicole; Merieau, Annabelle

    2015-01-01

    Background Pseudomonas fluorescens strain MFE01 secretes in abundance two Hcp proteins (haemolysin co-regulated proteins) Hcp1 and Hcp2, characteristic of a functional type 6 secretion system. Phenotypic studies have shown that MFE01 has antibacterial activity against a wide range of competitor bacteria, including rhizobacteria and clinically relevant bacteria. Mutagenesis of the hcp2 gene abolishes or reduces, depending on the target strain, MFE01 antibacterial activity. Hcp1, encoded by hcp...

  14. Variability in Proto-Planetary Nebulae: IV. Light Curve Analyses of Four Oxygen-Rich, F Spectral-Type Objects

    CERN Document Server

    Hrivnak, Bruce J; Nault, Kristie A

    2015-01-01

    We present new light curves covering 14 to 19 years of observations of four bright proto-planetary nebulae (PPNs), all O-rich and of F spectral type. They each display cyclical light curves with significant variations in amplitude. All four were previously known to vary in light. Our data were combined with published data and searched for periodicity. The results are as follows: IRAS 19475+3119 (HD 331319; 41.0 days), 17436+5003 (HD 161796; 45.2 days), 19386+0155 (101.8 days), and 18095+2704 (113.3 days). The two longer periods are in agreement with previous studies while the two shorter periods each reveal for the first time reveal a dominant period over these long observing intervals. Multiple periods were also found for each object. The secondary periods were all close to the dominant periods, with P2/P1 ranging from 0.86 to 1.06. The variations in color reveal maximum variations in T(eff) of 400 to 770 K. These variations are due to pulsations in these post-AGB objects. Maximum seasonal light variations a...

  15. A comprehensive survey of the laminins and collagens type IV expressed in mouse Leydig cells and their regulation by LH/hCG.

    Science.gov (United States)

    Mazaud Guittot, Séverine; Vérot, Adélie; Odet, Fanny; Chauvin, Marie-Agnès; le Magueresse-Battistoni, Brigitte

    2008-04-01

    Extracellular matrix (ECM) proteins have been shown to alter Leydig cell steroidogenesis in vitro, substantiating the hypothesis that Leydig cell steroidogenic activity and matrix environment are interdependent events. However, the nature of the ECM components synthesized by Leydig cells and their regulation by LH/human chorionic gonadotropin (hCG) remain unknown. Here, we examine the occurrence of the 11 laminin subunits and the 6 alpha chains of collagen IV (COL4A1-6) by RT-PCR in Leydig cells cultured with or without LH/hCG. Leydig cells were a tumor Leydig cell line (mLTC-1) or 8-week-old mice Leydig cells. Based on PCR data, it is suggested that normal Leydig cells may synthesize a maximum of 11 laminin heterotrimers and the 6 alpha chains of collagen IV. They also may synthesize various proteases and inhibitors of the metzincin family. The mLTC-1 cells have a limited repertoire as compared with normal Leydig cells. Interestingly, none of the ten proteases and inhibitors monitored is under LH-hCG regulation whereas every protease and inhibitor of the serine protease family yet identified in Leydig cells is under gonadotropin regulation. In addition, a few laminin and collagen subunit genes are regulated by LH/hCG. These are laminins alpha3 and gamma3 (Lama3 and Lamc3), Col4a3, and Col4a6, which are negatively regulated by LH/hCG in both Leydig cell types, and Col4a4, which was downregulated in primary cultures but not in mLTC-1 cells. Collectively, the present study suggests that Leydig cells modulate in a selective fashion their matrix environment in response to their trophic hormone. This may alter the steroidogenic outcome of Leydig cells. PMID:18367508

  16. A novel COL4A1 frameshift mutation in familial kidney disease: the importance of the C-terminal NC1 domain of type IV collagen

    Science.gov (United States)

    Gale, Daniel P.; Oygar, D. Deren; Lin, Fujun; Oygar, P. Derin; Khan, Nadia; Connor, Thomas M.F.; Lapsley, Marta; Maxwell, Patrick H.; Neild, Guy H.

    2016-01-01

    Background Hereditary microscopic haematuria often segregates with mutations of COL4A3, COL4A4 or COL4A5 but in half of families a gene is not identified. We investigated a Cypriot family with autosomal dominant microscopic haematuria with renal failure and kidney cysts. Methods We used genome-wide linkage analysis, whole exome sequencing and cosegregation analyses. Results We identified a novel frameshift mutation, c.4611_4612insG:p.T1537fs, in exon 49 of COL4A1. This mutation predicts truncation of the protein with disruption of the C-terminal part of the NC1 domain. We confirmed its presence in 20 family members, 17 with confirmed haematuria, 5 of whom also had stage 4 or 5 chronic kidney disease. Eleven family members exhibited kidney cysts (55% of those with the mutation), but muscle cramps or cerebral aneurysms were not observed and serum creatine kinase was normal in all individuals tested. Conclusions Missense mutations of COL4A1 that encode the CB3 [IV] segment of the triple helical domain (exons 24 and 25) are associated with HANAC syndrome (hereditary angiopathy, nephropathy, aneurysms and cramps). Missense mutations of COL4A1 that disrupt the NC1 domain are associated with antenatal cerebral haemorrhage and porencephaly, but not kidney disease. Our findings extend the spectrum of COL4A1 mutations linked with renal disease and demonstrate that the highly conserved C-terminal part of the NC1 domain of the α1 chain of type IV collagen is important in the integrity of glomerular basement membrane in humans. PMID:27190376

  17. TraK and TraB are conserved outer membrane proteins of the Neisseria gonorrhoeae Type IV secretion system and are expressed at low levels in wild-type cells.

    Science.gov (United States)

    Ramsey, Meghan E; Hackett, Kathleen T; Bender, Tobias; Kotha, Chaitra; van der Does, Chris; Dillard, Joseph P

    2014-08-15

    Neisseria gonorrhoeae uses a type IV secretion system (T4SS) to secrete chromosomal DNA into the medium, and this DNA is effective in transforming other gonococci via natural transformation. In addition, the T4SS is important in the initial stages of biofilm development and mediates intracellular iron uptake in the absence of TonB. To better understand the mechanism of type IV secretion in N. gonorrhoeae, we examined the expression levels and localization of two predicted T4SS outer membrane proteins, TraK and TraB, in the wild-type strain as well as in overexpression strains and in a strain lacking all of the T4SS proteins. Despite very low sequence similarity to known homologues, TraB (VirB10 homolog) and TraK (VirB9 homolog) localized similarly to related proteins in other systems. Additionally, we found that TraV (a VirB7 homolog) interacts with TraK, as in other T4SSs. However, unlike in other systems, neither TraK nor TraB required the presence of other T4SS components for proper localization. Unlike other gonococcal T4SS proteins we have investigated, protein levels of the outer membrane proteins TraK and TraB were extremely low in wild-type cells and were undetectable by Western blotting unless overexpressed or tagged with a FLAG3 triple-epitope tag. Localization of TraK-FLAG3 in otherwise wild-type cells using immunogold electron microscopy of thin sections revealed a single gold particle on some cells. These results suggest that the gonococcal T4SS may be present in single copy per cell and that small amounts of T4SS proteins TraK and TraB are sufficient for DNA secretion. PMID:24914183

  18. The bacterial communities associated with fecal types and body weight of rex rabbits

    OpenAIRE

    Bo Zeng; Shushu Han; Ping Wang; Bin Wen; Wensu Jian; Wei Guo; Zhiju Yu; Dan Du; Xiangchao Fu; Fanli Kong; Mingyao Yang; Xiaohui Si; Jiangchao Zhao; Ying Li

    2015-01-01

    Rex rabbit is an important small herbivore for fur and meat production. However, little is known about the gut microbiota in rex rabbit, especially regarding their relationship with different fecal types and growth of the hosts. We characterized the microbiota of both hard and soft feces from rex rabbits with high and low body weight by using the Illumina MiSeq platform targeting the V4 region of the 16S rDNA. High weight rex rabbits possess distinctive microbiota in hard feces, but not in so...

  19. Ehlers-Danlos Syndrome type IV: a multi-exon deletion in one of the two COL3A1 alleles affecting structure, stability, and processing of type III procollagen

    Energy Technology Data Exchange (ETDEWEB)

    Superti-Furga, A.; Gugler, E.; Gitzelmann, R.; Steinmann, B.

    1988-05-05

    The authors have studied a patient with severe, dominantly inherited Ehlers-Danlos syndrome type IV. The results indicate that this patient carries a deletion of 3.3 kilobase pairs in the triple helical coding domain of one of the two alleles for the pro-..cap alpha..-chains of type III collagen (COL3A1). His cultured skin fibroblasts contain equal amounts of normal length mRNA and of mRNA shortened by approximately 600 bases, and synthesize both normal and shortened pro-..cap alpha..1(III)-chains. In procollagen molecules containing one or more shortened chains, a triple helix is formed with a length of only about 780 amino acids. The mutant procollagen molecules have decreased thermal stability, are less efficiently secreted, and are not processed as their normal counterpart. The deletion in this family is the first mutation to be described in COL3A1.

  20. Improved detection limits of bacterial endotoxins using new type of planar interdigital sensors

    KAUST Repository

    Syaifudin, A. R Mohd

    2012-10-01

    New types of planar interdigital sensors were fabricated by photolithography and etching techniques on a Silicon/Silicon Dioxide (Si/SiO2) wafer (single side polished). The sensors were then coated with APTES (3-aminopropyltrietoxysilane) a cross linker used to bind Polymyxin B (PmB) molecules on electrodes surface. PmB is an antimicrobial peptide produced by the Gram-positive bacterium-Bacillus which has specific binding properties to Lipopolysaccharide (LPS). This paper will discuss the fabrication process, coating and immobilization procedures and analysis of sensors\\' performance based on Impedance Spectroscopy method. The sensor sensitivity was compared to standard ToxinSensor Chromogenic LAL Endotoxin Assay Kit for verification. © 2012 IEEE.

  1. Targeting bacterial topoisomerases: how to counter mechanisms of resistance.

    Science.gov (United States)

    Tse-Dinh, Yuk-Ching

    2016-06-01

    DNA gyrase and topoisomerase IV are type IIA bacterial topoisomerases that are targeted by highly effective antibiotics. However, resistance via multiple mechanisms arises to limit the efficacies of these drugs. Continued research on type IIA bacterial topoisomerases has provided novel approaches to counter the most common resistance mechanism for utilization of these proven targets in antibacterial therapy. Bacterial topoisomerase I is being explored as an alternative target that is not expected to show cross-resistance. Dual targeting or combination therapy could be strategies for circumventing the development of resistance to topoisomerase-targeting antibiotics. Bacterial topoisomerases are high-value bactericidal targets that could continue to be exploited for antibacterial therapy, if new tactics to counter resistance can be adopted. PMID:27285067

  2. Bacterial bile metabolising gene abundance in Crohn's, ulcerative colitis and type 2 diabetes metagenomes.

    Directory of Open Access Journals (Sweden)

    Alain Labbé

    Full Text Available We performed an analysis to determine the importance of bile acid modification genes in the gut microbiome of inflammatory bowel disease and type 2 diabetic patients. We used publicly available metagenomic datasets from the Human Microbiome Project and the MetaHIT consortium, and determined the abundance of bile salt hydrolase gene (bsh, 7 alpha-dehydroxylase gene (adh and 7-alpha hydroxysteroid dehydrogenase gene (hsdh in fecal bacteria in diseased populations of Crohn's disease (CD, Ulcerative Colitis (UC and Type 2 diabetes mellitus (T2DM. Phylum level abundance analysis showed a significant reduction in Firmicute-derived bsh in UC and T2DM patients but not in CD patients, relative to healthy controls. Reduction of adh and hsdh genes was also seen in UC and T2DM patients, while an increase was observed in the CD population as compared to healthy controls. A further analysis of the bsh genes showed significant differences in the correlations of certain Firmicutes families with disease or healthy populations. From this observation we proceeded to analyse BSH protein sequences and identified BSH proteins clusters representing the most abundant strains in our analysis of Firmicute bsh genes. The abundance of the bsh genes corresponding to one of these protein clusters was significantly reduced in all disease states relative to healthy controls. This cluster includes bsh genes derived from Lachospiraceae, Clostridiaceae, Erysipelotrichaceae and Ruminococcaceae families. This metagenomic analysis provides evidence of the importance of bile acid modifying enzymes in health and disease. It further highlights the importance of identifying gene and protein clusters, as the same gene may be associated with health or disease, depending on the strains expressing the enzyme, and differences in the enzymes themselves.

  3. Construction of an Excisable Bacterial Artificial Chromosome Containing a Full-Length Infectious Clone of Herpes Simplex Virus Type 1: Viruses Reconstituted from the Clone Exhibit Wild-Type Properties In Vitro and In Vivo

    OpenAIRE

    Tanaka, Michiko; Kagawa, Hiroyuki; Yamanashi, Yuji; Sata, Tetsutaro; Kawaguchi, Yasushi

    2003-01-01

    In recent years, several laboratories have reported on the cloning of herpes simplex virus type 1 (HSV-1) genomes as bacterial artificial chromosomes (BACs) in Escherichia coli and on procedures to manipulate these genomes by using the bacterial recombination machinery. However, the HSV-BACs reported so far are either replication incompetent or infectious, with a deletion of one or more viral genes due to the BAC vector insertion. For use as a multipurpose clone in research on HSV-1, we attem...

  4. High-throughput bacterial SNP typing identifies distinct clusters of Salmonella Typhi causing typhoid in Nepalese children

    LENUS (Irish Health Repository)

    Holt, Kathryn E

    2010-05-31

    Abstract Background Salmonella Typhi (S. Typhi) causes typhoid fever, which remains an important public health issue in many developing countries. Kathmandu, the capital of Nepal, is an area of high incidence and the pediatric population appears to be at high risk of exposure and infection. Methods We recently defined the population structure of S. Typhi, using new sequencing technologies to identify nearly 2,000 single nucleotide polymorphisms (SNPs) that can be used as unequivocal phylogenetic markers. Here we have used the GoldenGate (Illumina) platform to simultaneously type 1,500 of these SNPs in 62 S. Typhi isolates causing severe typhoid in children admitted to Patan Hospital in Kathmandu. Results Eight distinct S. Typhi haplotypes were identified during the 20-month study period, with 68% of isolates belonging to a subclone of the previously defined H58 S. Typhi. This subclone was closely associated with resistance to nalidixic acid, with all isolates from this group demonstrating a resistant phenotype and harbouring the same resistance-associated SNP in GyrA (Phe83). A secondary clone, comprising 19% of isolates, was observed only during the second half of the study. Conclusions Our data demonstrate the utility of SNP typing for monitoring bacterial populations over a defined period in a single endemic setting. We provide evidence for genotype introduction and define a nalidixic acid resistant subclone of S. Typhi, which appears to be the dominant cause of severe pediatric typhoid in Kathmandu during the study period.

  5. PG1058 Is a Novel Multidomain Protein Component of the Bacterial Type IX Secretion System

    Science.gov (United States)

    Veith, Paul D.; Butler, Catherine A.; Nor Muhammad, Nor A.; Chen, Yu-Yen; Slakeski, Nada; Peng, Benjamin; Zhang, Lianyi; Dashper, Stuart G.; Cross, Keith J.; Cleal, Steven M.; Moore, Caroline; Reynolds, Eric C.

    2016-01-01

    Porphyromonas gingivalis utilises the Bacteroidetes-specific type IX secretion system (T9SS) to export proteins across the outer membrane (OM), including virulence factors such as the gingipains. The secreted proteins have a conserved carboxy-terminal domain essential for type IX secretion that is cleaved upon export. In P. gingivalis the T9SS substrates undergo glycosylation with anionic lipopolysaccharide (A-LPS) and are attached to the OM. In this study, comparative analyses of 24 Bacteroidetes genomes identified ten putative novel components of the T9SS in P. gingivalis, one of which was PG1058. Computer modelling of the PG1058 structure predicted a novel N- to C-terminal architecture comprising a tetratricopeptide repeat (TPR) domain, a β-propeller domain, a carboxypeptidase regulatory domain-like fold (CRD) and an OmpA_C-like putative peptidoglycan binding domain. Inactivation of pg1058 in P. gingivalis resulted in loss of both colonial pigmentation and surface-associated proteolytic activity; a phenotype common to T9SS mutants. Immunoblot and LC-MS/MS analyses of subcellular fractions revealed T9SS substrates accumulated within the pg1058 mutant periplasm whilst whole-cell ELISA showed the Kgp gingipain was absent from the cell surface, confirming perturbed T9SS function. Immunoblot, TEM and whole-cell ELISA analyses indicated A-LPS was produced and present on the pg1058 mutant cell surface although it was not linked to T9SS substrate proteins. This indicated that PG1058 is crucial for export of T9SS substrates but not for the translocation of A-LPS. PG1058 is a predicted lipoprotein and was localised to the periplasmic side of the OM using whole-cell ELISA, immunoblot and LC-MS/MS analyses of subcellular fractions. The structural prediction and localisation of PG1058 suggests that it may have a role as an essential scaffold linking the periplasmic and OM components of the T9SS. PMID:27711252

  6. Cell compartmentalisation in planctomycetes: novel types of structural organisation for the bacterial cell.

    Science.gov (United States)

    Lindsay, M R; Webb, R I; Strous, M; Jetten, M S; Butler, M K; Forde, R J; Fuerst, J A

    2001-06-01

    The organisation of cells of the planctomycete species Pirellula marina, Isosphaera pallida, Gemmata obscuriglobus, Planctomyces maris and "Candidatus Brocadia anammoxidans" was investigated based on ultrastructure derived from thin-sections of cryosubstituted cells, freeze-fracture replicas, and in the case of Gemmata obscuriglobus and Pirellula marina, computer-aided 3-D reconstructions from serial sections of cryosubstituted cells. All planctomycete cells display a peripheral ribosome-free region, termed here the paryphoplasm, surrounding the perimeter of the cell, and an interior region including any nucleoid regions as well as ribosome-like particles, bounded by a single intracytoplasmic membrane (ICM), and termed the pirellulosome in Pirellula species. Immunogold labelling and RNase-gold cytochemistry indicates that in planctomycetes all the cell DNA is contained wholly within the interior region bounded by the ICM, and the paryphoplasm contains no DNA but at least some of the cell's RNA. The ICM in Isosphaera pallida and Planctomyces maris is invaginated such that the paryphoplasm forms a major portion of the cell interior in sections, but in other planctomycetes it remains as a peripheral zone. In the anaerobic ammonium-oxidising ("anammox" process) chemoautotroph "Candidatus Brocadia anammoxidans" the interior region bounded by ICM contains a further internal single-membrane-bounded region, the anammoxosome. In Gemmata obscuriglobus, the interior ICM-bounded region contains the nuclear body, a double-membrane-bounded region containing the cell's nucleoid and all genomic DNA in addition to some RNA. Shared features of cell compartmentalisation in different planctomycetes are consistent with the monophyletic nature of the planctomycetes as a distinct division of the Bacteria. The shared organisational plan for the planctomycete cell constitutes a new type not known in cells of other bacteria. PMID:11491082

  7. Wild-type phosphoribosylpyrophosphate synthase (PRS from Mycobacterium tuberculosis: a bacterial class II PRS?

    Directory of Open Access Journals (Sweden)

    Ardala Breda

    Full Text Available The 5-phospho-α-D-ribose 1-diphosphate (PRPP metabolite plays essential roles in several biosynthetic pathways, including histidine, tryptophan, nucleotides, and, in mycobacteria, cell wall precursors. PRPP is synthesized from α-D-ribose 5-phosphate (R5P and ATP by the Mycobacterium tuberculosis prsA gene product, phosphoribosylpyrophosphate synthase (MtPRS. Here, we report amplification, cloning, expression and purification of wild-type MtPRS. Glutaraldehyde cross-linking results suggest that MtPRS predominates as a hexamer, presenting varied oligomeric states due to distinct ligand binding. MtPRS activity measurements were carried out by a novel coupled continuous spectrophotometric assay. MtPRS enzyme activity could be detected in the absence of P(i. ADP, GDP and UMP inhibit MtPRS activity. Steady-state kinetics results indicate that MtPRS has broad substrate specificity, being able to accept ATP, GTP, CTP, and UTP as diphosphoryl group donors. Fluorescence spectroscopy data suggest that the enzyme mechanism for purine diphosphoryl donors follows a random order of substrate addition, and for pyrimidine diphosphoryl donors follows an ordered mechanism of substrate addition in which R5P binds first to free enzyme. An ordered mechanism for product dissociation is followed by MtPRS, in which PRPP is the first product to be released followed by the nucleoside monophosphate products to yield free enzyme for the next round of catalysis. The broad specificity for diphosphoryl group donors and detection of enzyme activity in the absence of P(i would suggest that MtPRS belongs to Class II PRS proteins. On the other hand, the hexameric quaternary structure and allosteric ADP inhibition would place MtPRS in Class I PRSs. Further data are needed to classify MtPRS as belonging to a particular family of PRS proteins. The data here presented should help augment our understanding of MtPRS mode of action. Current efforts are toward experimental structure

  8. The elusive third subunit IIa of the bacterial B-type oxidases: the enzyme from the hyperthermophile Aquifex aeolicus.

    Directory of Open Access Journals (Sweden)

    Laurence Prunetti

    Full Text Available The reduction of molecular oxygen to water is catalyzed by complicated membrane-bound metallo-enzymes containing variable numbers of subunits, called cytochrome c oxidases or quinol oxidases. We previously described the cytochrome c oxidase II from the hyperthermophilic bacterium Aquifex aeolicus as a ba(3-type two-subunit (subunits I and II enzyme and showed that it is included in a supercomplex involved in the sulfide-oxygen respiration pathway. It belongs to the B-family of the heme-copper oxidases, enzymes that are far less studied than the ones from family A. Here, we describe the presence in this enzyme of an additional transmembrane helix "subunit IIa", which is composed of 41 amino acid residues with a measured molecular mass of 5105 Da. Moreover, we show that subunit II, as expected, is in fact longer than the originally annotated protein (from the genome and contains a transmembrane domain. Using Aquifex aeolicus genomic sequence analyses, N-terminal sequencing, peptide mass fingerprinting and mass spectrometry analysis on entire subunits, we conclude that the B-type enzyme from this bacterium is a three-subunit complex. It is composed of subunit I (encoded by coxA(2 of 59000 Da, subunit II (encoded by coxB(2 of 16700 Da and subunit IIa which contain 12, 1 and 1 transmembrane helices respectively. A structural model indicates that the structural organization of the complex strongly resembles that of the ba(3 cytochrome c oxidase from the bacterium Thermus thermophilus, the IIa helical subunit being structurally the lacking N-terminal transmembrane helix of subunit II present in the A-type oxidases. Analysis of the genomic context of genes encoding oxidases indicates that this third subunit is present in many of the bacterial oxidases from B-family, enzymes that have been described as two-subunit complexes.

  9. Two novel splicing mutations in the SLC45A2 gene cause Oculocutaneous Albinism Type IV by unmasking cryptic splice sites.

    Science.gov (United States)

    Straniero, Letizia; Rimoldi, Valeria; Soldà, Giulia; Mauri, Lucia; Manfredini, Emanuela; Andreucci, Elena; Bargiacchi, Sara; Penco, Silvana; Gesu, Giovanni P; Del Longo, Alessandra; Piozzi, Elena; Asselta, Rosanna; Primignani, Paola

    2015-09-01

    Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin, hair and eye, and by ophthalmologic abnormalities caused by a deficiency in melanin biosynthesis. OCA type IV (OCA4) is one of the four commonly recognized forms of albinism, and is determined by mutation in the SLC45A2 gene. Here, we investigated the genetic basis of OCA4 in an Italian child. The mutational screening of the SLC45A2 gene identified two novel potentially pathogenic splicing mutations: a synonymous transition (c.888G>A) involving the last nucleotide of exon 3 and a single-nucleotide insertion (c.1156+2dupT) within the consensus sequence of the donor splice site of intron 5. As computer-assisted analysis for mutant splice-site prediction was not conclusive, we investigated the effects on pre-mRNA splicing of these two variants by using an in vitro minigene approach. Production of mutant transcripts in HeLa cells demonstrated that both mutations cause the almost complete abolishment of the physiologic donor splice site, with the concomitant unmasking of cryptic donor splice sites. To our knowledge, this work represents the first in-depth molecular characterization of splicing defects in a OCA4 patient. PMID:26016411

  10. Treatment of a direct carotid-cavernous fistula in a patient with type IV Ehlers-Danlos syndrome: a novel approach

    Energy Technology Data Exchange (ETDEWEB)

    Hollands, J.K.; Santarius, T.; Kirkpatrick, P.J. [Addenbrooke' s Hospital, Department of Neurosurgery, Cambridge (United Kingdom); Higgins, J.N. [Addenbrooke' s Hospital, Department of Neuroradiology, Cambridge (United Kingdom)

    2006-07-15

    We report a case of a 34-year-old female with type IV Ehlers-Danlos syndrome diagnosed with a carotid cavernous fistula presenting with progressive proptosis. Endovascular embolization using balloons or coils carries a high risk of complications in this group of patients, owing to the extreme fragility of the blood vessels. Initial treatment was conservative until an intracerebral haemorrhage occurred. To avoid transfemoral angiography, the ipsilateral carotid arteries and the internal jugular vein were surgically exposed for insertion of two endovascular sheaths. The patient was transferred from theatre to the angiography suite and the sheaths were used for embolization access. The fistula was closed, with preservation of the carotid artery, using Guglielmi detachable coils deployed in the cavernous sinus from the arterial and venous sides. Rapid resolution of symptoms and signs followed, which was sustained at 6-month follow-up. This technique offers alternative access for endovascular treatment, which may reduce the high incidence of mortality associated with catheter angiography in this condition. (orig.)

  11. NMR structure of a complex between the VirB9/VirB7 interaction domains of the pKM101 type IV secretion system.

    Science.gov (United States)

    Bayliss, Richard; Harris, Richard; Coutte, Loic; Monier, Amy; Fronzes, Remi; Christie, Peter J; Driscoll, Paul C; Waksman, Gabriel

    2007-01-30

    Type IV secretion (T4S) systems translocate DNA and protein effectors through the double membrane of Gram-negative bacteria. The paradigmatic T4S system in Agrobacterium tumefaciens is assembled from 11 VirB subunits and VirD4. Two subunits, VirB9 and VirB7, form an important stabilizing complex in the outer membrane. We describe here the NMR structure of a complex between the C-terminal domain of the VirB9 homolog TraO (TraO(CT)), bound to VirB7-like TraN from plasmid pKM101. TraO(CT) forms a beta-sandwich around which TraN winds. Structure-based mutations in VirB7 and VirB9 of A. tumefaciens show that the heterodimer interface is conserved. Opposite this interface, the TraO structure shows a protruding three-stranded beta-appendage, and here, we supply evidence that the corresponding region of VirB9 of A. tumefaciens inserts in the membrane and protrudes extracellularly. This complex structure elucidates the molecular basis for the interaction between two essential components of a T4S system. PMID:17244707

  12. Two novel splicing mutations in the SLC45A2 gene cause Oculocutaneous Albinism Type IV by unmasking cryptic splice sites.

    Science.gov (United States)

    Straniero, Letizia; Rimoldi, Valeria; Soldà, Giulia; Mauri, Lucia; Manfredini, Emanuela; Andreucci, Elena; Bargiacchi, Sara; Penco, Silvana; Gesu, Giovanni P; Del Longo, Alessandra; Piozzi, Elena; Asselta, Rosanna; Primignani, Paola

    2015-09-01

    Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin, hair and eye, and by ophthalmologic abnormalities caused by a deficiency in melanin biosynthesis. OCA type IV (OCA4) is one of the four commonly recognized forms of albinism, and is determined by mutation in the SLC45A2 gene. Here, we investigated the genetic basis of OCA4 in an Italian child. The mutational screening of the SLC45A2 gene identified two novel potentially pathogenic splicing mutations: a synonymous transition (c.888G>A) involving the last nucleotide of exon 3 and a single-nucleotide insertion (c.1156+2dupT) within the consensus sequence of the donor splice site of intron 5. As computer-assisted analysis for mutant splice-site prediction was not conclusive, we investigated the effects on pre-mRNA splicing of these two variants by using an in vitro minigene approach. Production of mutant transcripts in HeLa cells demonstrated that both mutations cause the almost complete abolishment of the physiologic donor splice site, with the concomitant unmasking of cryptic donor splice sites. To our knowledge, this work represents the first in-depth molecular characterization of splicing defects in a OCA4 patient.

  13. The predicted ABC transporter AbcEDCBA is required for type IV secretion system expression and lysosomal evasion by Brucella ovis.

    Directory of Open Access Journals (Sweden)

    Teane M A Silva

    Full Text Available Brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described Brucella species that is not zoonotic. Previous work showed that a B. ovis mutant lacking a species-specific ABC transporter (ΔabcBA was attenuated in mice and was unable to survive in macrophages. The aim of this study was to evaluate the role of this ABC transporter during intracellular survival of B. ovis. In HeLa cells, B. ovis WT was able to survive and replicate at later time point (48 hpi, whereas an ΔabcBA mutant was attenuated at 24 hpi. The reduced survival of the ΔabcBA mutant was associated with a decreased ability to exclude the lysosomal marker LAMP1 from its vacuolar membrane, suggesting a failure to establish a replicative niche. The ΔabcBA mutant showed a reduced abundance of the Type IV secretion system (T4SS proteins VirB8 and VirB11 in both rich and acid media, when compared to WT B. ovis. However, mRNA levels of virB1, virB8, hutC, and vjbR were similar in both strains. These results support the notion that the ABC transporter encoded by abcEDCBA or its transported substrate acts at a post-transcriptional level to promote the optimal expression of the B. ovis T4SS within infected host cells.

  14. Identification of VceA and VceC, two members of the VjbR regulon that are translocated into macrophages by the Brucella type IV secretion system

    NARCIS (Netherlands)

    de Jong, Maarten F.; Sun, Yao-Hui; den Hartigh, Andreas B.; van Dijl, Jan Maarten; Tsolis, Renee M.

    2008-01-01

    Survival and replication inside host cells by Brucella spp. requires a type IV secretion system (T4SS), encoded by the virB locus. However, the identity of the molecules secreted by the T4SS has remained elusive. We hypothesized that proteins translocated by the T4SS would be co-regulated with the v

  15. Asteroids IV

    Science.gov (United States)

    Michel, Patrick; DeMeo, Francesca E.; Bottke, William F.

    . Asteroids, like planets, are driven by a great variety of both dynamical and physical mechanisms. In fact, images sent back by space missions show a collection of small worlds whose characteristics seem designed to overthrow our preconceived notions. Given their wide range of sizes and surface compositions, it is clear that many formed in very different places and at different times within the solar nebula. These characteristics make them an exciting challenge for researchers who crave complex problems. The return of samples from these bodies may ultimately be needed to provide us with solutions. In the book Asteroids IV, the editors and authors have taken major strides in the long journey toward a much deeper understanding of our fascinating planetary ancestors. This book reviews major advances in 43 chapters that have been written and reviewed by a team of more than 200 international authorities in asteroids. It is aimed to be as comprehensive as possible while also remaining accessible to students and researchers who are interested in learning about these small but nonetheless important worlds. We hope this volume will serve as a leading reference on the topic of asteroids for the decade to come. We are deeply indebted to the many authors and referees for their tremendous efforts in helping us create Asteroids IV. We also thank the members of the Asteroids IV scientific organizing committee for helping us shape the structure and content of the book. The conference associated with the book, "Asteroids Comets Meteors 2014" held June 30-July 4, 2014, in Helsinki, Finland, did an outstanding job of demonstrating how much progress we have made in the field over the last decade. We are extremely grateful to our host Karri Muinonnen and his team. The editors are also grateful to the Asteroids IV production staff, namely Renée Dotson and her colleagues at the Lunar and Planetary Institute, for their efforts, their invaluable assistance, and their enthusiasm; they made life as

  16. Neisseria meningitidis differentially controls host cell motility through PilC1 and PilC2 components of type IV Pili.

    Directory of Open Access Journals (Sweden)

    Philippe C Morand

    Full Text Available Neisseria meningitidis is a strictly human pathogen that has two facets since asymptomatic carriage can unpredictably turn into fulminant forms of infection. Meningococcal pathogenesis relies on the ability of the bacteria to break host epithelial or endothelial cellular barriers. Highly restrictive, yet poorly understood, mechanisms allow meningococcal adhesion to cells of only human origin. Adhesion of encapsulated and virulent meningococci to human cells relies on the expression of bacterial type four pili (T4P that trigger intense host cell signalling. Among the components of the meningococcal T4P, the concomitantly expressed PilC1 and PilC2 proteins regulate pili exposure at the bacterial surface, and until now, PilC1 was believed to be specifically responsible for T4P-mediated meningococcal adhesion to human cells. Contrary to previous reports, we show that, like PilC1, the meningococcal PilC2 component is capable of mediating adhesion to human ME180 epithelial cells, with cortical plaque formation and F-actin condensation. However, PilC1 and PilC2 promote different effects on infected cells. Cellular tracking analysis revealed that PilC1-expressing meningococci caused a severe reduction in the motility of infected cells, which was not the case when cells were infected with PilC2-expressing strains. The amount of both total and phosphorylated forms of EGFR was dramatically reduced in cells upon PilC1-mediated infection. In contrast, PilC2-mediated infection did not notably affect the EGFR pathway, and these specificities were shared among unrelated meningococcal strains. These results suggest that meningococci have evolved a highly discriminative tool for differential adhesion in specific microenvironments where different cell types are present. Moreover, the fine-tuning of cellular control through the combined action of two concomitantly expressed, but distinctly regulated, T4P-associated variants of the same molecule (i.e. PilC1 and Pil

  17. Structure of the ent-Copalyl Diphosphate Synthase PtmT2 from Streptomyces platensis CB00739, a Bacterial Type II Diterpene Synthase.

    Science.gov (United States)

    Rudolf, Jeffrey D; Dong, Liao-Bin; Cao, Hongnan; Hatzos-Skintges, Catherine; Osipiuk, Jerzy; Endres, Michael; Chang, Chin-Yuan; Ma, Ming; Babnigg, Gyorgy; Joachimiak, Andrzej; Phillips, George N; Shen, Ben

    2016-08-31

    Terpenoids are the largest and most structurally diverse family of natural products found in nature, yet their presence in bacteria is underappreciated. The carbon skeletons of terpenoids are generated through carbocation-dependent cyclization cascades catalyzed by terpene synthases (TSs). Type I and type II TSs initiate cyclization via diphosphate ionization and protonation, respectively, and protein structures of both types are known. Most plant diterpene synthases (DTSs) possess three α-helical domains (αβγ), which are thought to have arisen from the fusion of discrete, ancestral bacterial type I TSs (α) and type II TSs (βγ). Type II DTSs of bacterial origin, of which there are no structurally characterized members, are a missing piece in the structural evolution of TSs. Here, we report the first crystal structure of a type II DTS from bacteria. PtmT2 from Streptomyces platensis CB00739 was verified as an ent-copalyl diphosphate synthase involved in the biosynthesis of platensimycin and platencin. The crystal structure of PtmT2 was solved at a resolution of 1.80 Å, and docking studies suggest the catalytically active conformation of geranylgeranyl diphosphate (GGPP). Site-directed mutagenesis confirmed residues involved in binding the diphosphate moiety of GGPP and identified DxxxxE as a potential Mg(2+)-binding motif for type II DTSs of bacterial origin. Finally, both the shape and physicochemical properties of the active sites are responsible for determining specific catalytic outcomes of TSs. The structure of PtmT2 fundamentally advances the knowledge of bacterial TSs, their mechanisms, and their role in the evolution of TSs. PMID:27490479

  18. Structure of the ent-Copalyl Diphosphate Synthase PtmT2 from Streptomyces platensis CB00739, a Bacterial Type II Diterpene Synthase.

    Science.gov (United States)

    Rudolf, Jeffrey D; Dong, Liao-Bin; Cao, Hongnan; Hatzos-Skintges, Catherine; Osipiuk, Jerzy; Endres, Michael; Chang, Chin-Yuan; Ma, Ming; Babnigg, Gyorgy; Joachimiak, Andrzej; Phillips, George N; Shen, Ben

    2016-08-31

    Terpenoids are the largest and most structurally diverse family of natural products found in nature, yet their presence in bacteria is underappreciated. The carbon skeletons of terpenoids are generated through carbocation-dependent cyclization cascades catalyzed by terpene synthases (TSs). Type I and type II TSs initiate cyclization via diphosphate ionization and protonation, respectively, and protein structures of both types are known. Most plant diterpene synthases (DTSs) possess three α-helical domains (αβγ), which are thought to have arisen from the fusion of discrete, ancestral bacterial type I TSs (α) and type II TSs (βγ). Type II DTSs of bacterial origin, of which there are no structurally characterized members, are a missing piece in the structural evolution of TSs. Here, we report the first crystal structure of a type II DTS from bacteria. PtmT2 from Streptomyces platensis CB00739 was verified as an ent-copalyl diphosphate synthase involved in the biosynthesis of platensimycin and platencin. The crystal structure of PtmT2 was solved at a resolution of 1.80 Å, and docking studies suggest the catalytically active conformation of geranylgeranyl diphosphate (GGPP). Site-directed mutagenesis confirmed residues involved in binding the diphosphate moiety of GGPP and identified DxxxxE as a potential Mg(2+)-binding motif for type II DTSs of bacterial origin. Finally, both the shape and physicochemical properties of the active sites are responsible for determining specific catalytic outcomes of TSs. The structure of PtmT2 fundamentally advances the knowledge of bacterial TSs, their mechanisms, and their role in the evolution of TSs.

  19. Structural basis for entropy-driven cellulose binding by a type-A cellulose-binding module (CBM) and bacterial expansin

    OpenAIRE

    Georgelis, Nikolaos; Yennawar, Neela H.; Cosgrove, Daniel J.

    2012-01-01

    Components of modular cellulases, type-A cellulose-binding modules (CBMs) bind to crystalline cellulose and enhance enzyme effectiveness, but structural details of the interaction are uncertain. We analyzed cellulose binding by EXLX1, a bacterial expansin with ability to loosen plant cell walls and whose domain D2 has type-A CBM characteristics. EXLX1 strongly binds to crystalline cellulose via D2, whereas its affinity for soluble cellooligosaccharides is weak. Calorimetry indicated cellulose...

  20. Agrobacterium tumefaciens VirB9, an outer-membrane-associated component of a type IV secretion system, regulates substrate selection and T-pilus biogenesis.

    Science.gov (United States)

    Jakubowski, Simon J; Cascales, Eric; Krishnamoorthy, Vidhya; Christie, Peter J

    2005-05-01

    Agrobacterium tumefaciens translocates DNA and protein substrates between cells via a type IV secretion system (T4SS) whose channel subunits include the VirD4 coupling protein, VirB11 ATPase, VirB6, VirB8, VirB2, and VirB9. In this study, we used linker insertion mutagenesis to characterize the contribution of the outer-membrane-associated VirB9 to assembly and function of the VirB/D4 T4SS. Twenty-five dipeptide insertion mutations were classified as permissive for intercellular substrate transfer (Tra+), completely transfer defective (Tra-), or substrate discriminating, e.g., selectively permissive for transfer only of the oncogenic transfer DNA and the VirE2 protein substrates or of a mobilizable IncQ plasmid substrate. Mutations inhibiting transfer of DNA substrates did not affect formation of close contacts of the substrate with inner membrane channel subunits but blocked formation of contacts with the VirB2 and VirB9 channel subunits, which is indicative of a defect in assembly or function of the distal portion of the secretion channel. Several mutations in the N- and C-terminal regions disrupted VirB9 complex formation with the outer-membrane-associated lipoprotein VirB7 or the inner membrane energy sensor VirB10. Several VirB9.i2-producing Tra+ strains failed to elaborate T pilus at detectable levels (Pil-), and three such Tra+ Pil- mutant strains were rendered Tra- upon deletion of virB2, indicating that the cellular form of pilin protein is essential for substrate translocation. Our findings, together with computer-based analyses, support a model in which distinct domains of VirB9 contribute to substrate selection and translocation, establishment of channel subunit contacts, and T-pilus biogenesis. PMID:15866936

  1. Mating pair formation homologue TraG is a variable membrane protein essential for contact-independent type IV secretion of chromosomal DNA by Neisseria gonorrhoeae.

    Science.gov (United States)

    Kohler, Petra L; Chan, Yolande A; Hackett, Kathleen T; Turner, Nicholas; Hamilton, Holly L; Cloud-Hansen, Karen A; Dillard, Joseph P

    2013-04-01

    Neisseria gonorrhoeae uses a type IV secretion system (T4SS) to secrete chromosomal DNA into the surrounding milieu. The DNA is effective in transforming gonococci in the population, and this mechanism of DNA donation may contribute to the high degree of genetic diversity in this species. Similar to other F-like T4SSs, the gonococcal T4SS requires a putative membrane protein, TraG, for DNA transfer. In F-plasmid and related systems, the homologous protein acts in pilus production, mating pair stabilization, and entry exclusion. We characterized the localization, membrane topology, and variation of TraG in N. gonorrhoeae. TraG was found to be an inner-membrane protein with one large periplasmic region and one large cytoplasmic region. Each gonococcal strain carried one of three different alleles of traG. Strains that carried the smallest allele of traG were found to lack the peptidoglycanase gene atlA but carried a peptidoglycan endopeptidase gene in place of atlA. The purified endopeptidase degraded gonococcal peptidoglycan in vitro, cutting the peptide cross-links. Although the other two traG alleles functioned for DNA secretion in strain MS11, the smallest traG did not support DNA secretion. Despite the requirement for a mating pair stabilization homologue, static coculture transformation experiments demonstrated that DNA transfer was nuclease sensitive and required active uptake by the recipient, thus demonstrating that transfer occurred by transformation and not conjugation. Together, these results demonstrate the TraG acts in a process of DNA export not specific to conjugation and that different forms of TraG affect what substrates can be transported. PMID:23378511

  2. Bacterial community variation and microbial mechanism of triclosan (TCS) removal by constructed wetlands with different types of plants.

    Science.gov (United States)

    Zhao, Congcong; Xie, HuiJun; Xu, Jingtao; Xu, Xiaoli; Zhang, Jian; Hu, Zhen; Liu, Cui; Liang, Shuang; Wang, Qian; Wang, Jingmin

    2015-02-01

    Triclosan (TCS) is a broad-spectrum synthetic antimicrobial agent that is toxic to microbes and other aquatic organisms. Constructed wetlands (CWs) are now popular in TCS removal. However, knowledge on the effects of TCS on the bacterial community and microbial removal mechanism in CWs is lacking. The effects of TCS (60 μg L(-1)) on bacterial communities in batch-loaded CWs with emergent (Typha angustifolia), submerged (Hydrilla verticillata), and floating plant (Salvinia natans) were analyzed by 454 pyrosequencing technology. After six periods of experiment, the TCS removal efficiencies were over 90% in CWs, and negative effects of TCS on bacterial community richness and diversity were observed. Moreover, plant species effect existed. Bacterial strains that contributed to TCS biodegradation in CWs were successfully identified. In TCS-treated T. angustifolia and H. verticillata CWs, beta-Proteobacteria increased by 16.63% and 18.20%, respectively. In TCS-treated S. natans CWs, delta- and gamma-Proteobacteria and Sphingobacteria increased by 9.36%, 19.49%, and 31.37%, respectively, and could relate to TCS biodegradation. TCS affected the development of certain bacteria, and eventually, the bacterial community structures in CWs. This research provided ecologically relevant information on bacterial community and microbial removal mechanism in CWs under TCS treatment. PMID:25461066

  3. Detergent extraction identifies different VirB protein subassemblies of the type IV secretion machinery in the membranes of Agrobacterium tumefaciens.

    Science.gov (United States)

    Krall, Lilian; Wiedemann, Urs; Unsin, Gabriele; Weiss, Sabine; Domke, Natalie; Baron, Christian

    2002-08-20

    The VirB/D4 type IV secretion system of Agrobacterium tumefaciens translocates virulence factors (VirE2, VirF, and the VirD2-T-DNA complex) to plant cells. The membrane-bound translocation machinery consists of 12 proteins (VirB1-11 and VirD4) required for substrate translocation. Protein-protein interactions in the membranes were analyzed after extraction with the mild detergent dodecyl-beta-d-maltoside followed by separation under native conditions. Incubation of the membranes with increasing concentrations of the detergent differentially extracted virulence proteins. Separation of the solubilized proteins by blue native electrophoresis revealed cofractionation between two classes of protein complexes containing VirB7. The first class, consisting of major T-pilus component VirB2 and associated proteins VirB5 and VirB7, comigrated in the low molecular mass portion of the gel of about 100 kDa. The second class contains putative translocation complex core components VirB8, VirB9, and VirB10 in the high molecular mass portion of the gel larger than 232 kDa, as well as VirB7. Solubilized proteins were characterized further by gel filtration chromatography. This procedure separated T-pilus-associated proteins VirB2, VirB5, and VirB7 in the low molecular mass range from the other components of the translocation machinery and the substrates VirE2 and VirD2. Fractionation of VirB7-containing complexes (VirB7-VirB7 homodimers and VirB7-VirB9 heterodimers) suggested that they may link the T-pilus components to the core of the translocation machinery. Based on previously described VirB protein interactions and biochemical analysis of C58 wild type as well as of virB5 and virB6 deletion mutants, a model of T-pilus assembly in A. tumefaciens is suggested. PMID:12177443

  4. 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.

  5. 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....

  6. Combinative effects of a bacterial type-III effector and a biocontrol bacterium on rice growth and disease resistance

    Indian Academy of Sciences (India)

    Haiying Ren; Ganyu Gu; Juying Long; Qian Yin; Tingquan Wu; Tao Song; Shujian Zhang; Zhiyi Chen; Hansong Dong

    2006-12-01

    Expression of HpaGXoo, a bacterial type-III effector, in transgenic plants induces disease resistance. Resistance also can be elicited by biocontrol bacteria. In both cases, plant growth is often promoted. Here we address whether biocontrol bacteria and HpaGXoo can act together to provide better results in crop improvement. We studied effects of Pseudomonas cepacia on the rice variety R109 and the hpaGXoo-expressing rice line HER1. Compared to R109, HER1 showed increased growth, grain yield, and defense responses toward diseases and salinity stress. Colonization of roots by P. cepacia caused 20% and 13% increase, in contrast to controls, in root growth of R109 and HER1. Growth of leaves and stems also increased in R109 but that of HER1 was inhibited. When P. cepacia colonization was subsequent to plant inoculation with Rhizoctonia solani, a pathogen that causes sheath blight, the disease was less severe than controls in both R109 and HER1; HER1, nevertheless, was more resistant, suggesting that P. cepacia and HpaGXoo cooperate in inducing disease resistance. Several genes that critically regulate growth and defense behaved differentially in HER1 and R109 while responding to P. cepacia. In R109 leaves, the OsARF1 gene, which regulates plant growth, was expressed in consistence with growth promotion by P. cepacia. Inversely, OsARF1 expression was coincident with inhibition in growth of HER1 leaves. In both plants, the expression of OsEXP1, which encodes an expansin protein involved in plant growth, was concomitant with growth promotion in leaves instead of roots, in response to P. cepacia. We also studied OsMAPK, a gene that encodes a mitogen-activated protein kinase and controls defense responses toward salinity and infection by pathogens in rice. In response to P. cepacia, an early expression of OsMAPK was coincident with R109 resistance to the disease, while HER1 expressed the gene similarly whether P. cepacia was present or not. Evidently, P. cepacia and GXoo

  7. Influence of organic waste type and soil structure on the bacterial filtration rates in unsaturated intact soil columns.

    Science.gov (United States)

    Mosaddeghi, M R; Mahboubi, A A; Zandsalimi, S; Unc, A

    2009-02-01

    Organic wastes are considered to be a source for the potentially pathogenic microorganisms found in surface and sub-surface water resources. Following their release from the organic waste matrix, bacteria often infiltrate into soil and may be transported to significant depths contaminating aquifers. We investigated the influence of soil texture and structure and most importantly the organic waste properties on the transport and filtration coefficients of Escherichia coli and total bacteria in undisturbed soil columns. Intact soil columns (diameter 16 cm and height 25 cm) were collected from two soils: sandy clay loam (SCL) and loamy sand (LS) in Hamadan, western Iran. The cores were amended with cow manure, poultry manure and sewage sludge at a rate of 10 Mg ha(-1) (dry basis). The amended soil cores were leached at a steady-state flux of 4.8 cm h(-1) (i.e. 0.12 of saturated hydraulic conductivity of the SCL) to a total volume of up to 4 times the pore volume of the columns. The influent (C(0)) and effluent (C) were sampled at similar time intervals during the experiments and bacterial concentrations were measured by the plate count method. Cumulative numbers of the leached bacteria, filtration coefficient (lambda(f)), and relative adsorption index (S(R)) were calculated. The preferential pathways and stable structure of the SCL facilitated the rapid transport and early appearance of the bacteria in the effluent. The LS filtered more bacteria when compared with the SCL. The effluent contamination of poultry manure-treated columns was greater than the cow manure- and sewage sludge-treated ones. The difference between cow manure and sewage sludge was negligible. The lambda(f) and S(R) values for E. coli and total bacteria were greater in the LS than in the SCL. This indicates a predominant role for the physical pore-obstruction filtration mechanisms as present in the poorly structured LS vs. the retention at adsorptive sites (chemical filtration) more likely in the

  8. Substitution of Aspartate for glycine 1018 in the Type III procollagen (COL3AI) gene causes type IV Ehlers-Danlos Syndrome: The mutated allele is present in most blood leukocytes of the asymptomatic and mosaic mother

    Energy Technology Data Exchange (ETDEWEB)

    Kontusaari, S.; Tromp, G.; Kuivaniemi, H.; Prockop, D.J. (Thomas Jefferson Univ., Philadelphia, PA (United States)); Stolle, C. (Robert Wood Johnson Medical School, Piscataway, NJ (United States)); Pope, F.M.

    1992-09-01

    A proband with arterial ruptures and skin changes characteristic of the type IV variant of Ehlers-Danlos syndrome was found to have a single-base mutation in the type III procollagen gene, which converted the codon for glycine at amino position 1018 to a codon for aspartate. (Amino acid positions are numbered by the standard convention in which the first glycine of the triple-helical domain of an [alpha] chain is number 1. The numbers of positions in the [alpha]1(III) chains can be converted to positions in the human pro[alpha](III) chain by adding 167.). Nucleotide sequencing of overlapping PCR products in which the two alleles were distinguished demonstrated that the mutation of glycine 1018 was the only mutation that changed the primary structure of type III procollagen. The glycine substitution markedly decreased the amount of type III procollagen secreted into the medium by cultured skin fibroblasts from the proband. It is surprising that the same mutation was found in about 94% of the peripheral blood leukocytes from the proband's asymptomatic 72-year-old mother. Other tissues from the mother contained the mutated allele; it was present in 0%-100% of different samples of hair cells and in about 40% of cells from the oral epithelium. Therefore, the mother was a mosaic for the mutation. Since the mutated allele was present in cells derived from all three germ layers, the results indicated that the mutation arose by the late blastocyst stage of development. The results also indicate that assays of blood leukocytes do not always reveal mosaicism or predict phenotypic involvement of tissues, such as blood vessels, that are derived from the same embryonic cells as are leukocytes. 66 refs., 6 figs., 1 tab.

  9. Raman spectra of Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} magnetic quaternary semiconductor compounds with tetragonal stannite type structure

    Energy Technology Data Exchange (ETDEWEB)

    Rincón, C., E-mail: crincon@ula.ve; Quintero, M.; Power, Ch.; Moreno, E.; Quintero, E.; Morocoima, M. [Centro de Estudios de Semiconductores, Departamento de Física, Facultad de Ciencias, Universidad de Los Andes, Mérida (Venezuela, Bolivarian Republic of); Henao, J. A.; Macías, M. A. [Grupo de Investigación en Química Estructural, Facultad de Ciencias, Escuela de Química, Universidad Industrial de Santander, Apartado Aéreo 678, Bucaramanga (Colombia)

    2015-05-28

    A comparative study of the Raman spectra of Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} and Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI}(where B = Mn or Fe) magnetic quaternary semiconductor compounds with stannite-type structure (I4{sup ¯}2m) has been done. Most of the fourteen Raman lines expected for these materials were observed in the spectra. The two strongest lines observed have been assigned to the IR inactive A{sub 1}{sup 1} and A{sub 1}{sup 2} stannite modes that originated from the motion of the S or Se anion around the Cu and C{sup IV} cations remaining at rest. The shift in the frequency of these two lines of about 150 cm{sup −1} to lower energies observed in Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI} compounds as compared to those in Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} ones, can then be explained as due to the anion mass effect. Based on the fact that values of these frequencies depend mainly on anion mass and bond-stretching forces between nearest-neighbor atoms, the vibrational frequencies v{sup ¯}(A{sub 1}{sup 2}) and v{sup ¯}(A{sub 1}{sup 2}) of both modes for several Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} stannite compounds (where X = S, Se, or Te) very close to the experimental data reported for these materials were calculated from a simple model that relates these stretching forces to the anion-cation bond-distances.

  10. Surface Display of Metal Fixation Motifs of Bacterial P1-Type ATPases Specifically Promotes Biosorption of Pb2+ by Saccharomyces cerevisiae▿

    OpenAIRE

    Kotrba, Pavel; Ruml, Tomas

    2010-01-01

    Biosorption of metal ions may take place by different passive metal-sequestering processes such as ion exchange, complexation, physical entrapment, and inorganic microprecipitation or by a combination of these. To improve the biosorption capacity of the potential yeast biosorbent, short metal-binding NP peptides (harboring the CXXEE metal fixation motif of the bacterial Pb2+-transporting P1-type ATPases) were efficiently displayed and covalently anchored to the cell wall of Saccharomyces cere...

  11. Effects of wild-type (Trp72) and mutant (Arg72) apolipoprotein(a) kringle IV-10 on the proliferation of human arterial smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    喻红; 洪嘉玲; 汪炳华; 彭芳芳; 李小明; 何春燕

    2003-01-01

    Objective To assess the atherogenicity of lipoprotein(a), the effect of the heterogeneity of lysine binding of apolipoprotein(a) [apo(a)], a plasminogen-like glycoprotein component on the proliferation of human arterial smooth muscle cells (SMCs).Results Apo(a) wt-kringle IV-10 that has lysine binding properties possessed a growth-stimulating activity to SMCs on a dose-dependence manner by stimulating cells in the G1/G0 phase of cell cycle to S and G2/M phase, and reduced significantly the amounts of endogenous active TGF-β1 in culture when compared with the control medium and the GST group (2.4±0.5 vs 8.6±1.6 and 9.1±1.7 ng/ml, P<0.01). The growth-stimulating effect of apo(a) mut-kringle IV-10 deficient in lysine binding was negligible. Conclusions Apo(a) induces SMCs growth by inhibiting the activation of latent TGF-β1, an activity that may involve the ability of apo(a) kringle IV-10 to bind lysine. The mitogenic effect of apo(a) wt-kringle IV-10 on SMCs might play an active role in the atherogenic function of lipoprotein(a).

  12. 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.

  13. Influence of silver additions to type 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Tseng, I-Sheng; Møller, Per;

    2010-01-01

    techniques. The microstructure of these 316 stainless steels was examined, and the influences of silver additions to 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance were investigated. This study suggested that silver-bearing 316 stainless steels could be used in...

  14. Bacterial community composition in relation to bedrock type and macrobiota in soils from the Sør Rondane Mountains, East Antarctica.

    Science.gov (United States)

    Tytgat, Bjorn; Verleyen, Elie; Sweetlove, Maxime; D'hondt, Sofie; Clercx, Pia; Van Ranst, Eric; Peeters, Karolien; Roberts, Stephen; Namsaraev, Zorigto; Wilmotte, Annick; Vyverman, Wim; Willems, Anne

    2016-09-01

    Antarctic soils are known to be oligotrophic and of having low buffering capacities. It is expected that this is particularly the case for inland high-altitude regions. We hypothesized that the bedrock type and the presence of macrobiota in these soils enforce a high selective pressure on their bacterial communities. To test this, we analyzed the bacterial community structure in 52 soil samples from the western Sør Rondane Mountains (Dronning Maud Land, East Antarctica), using the Illumina MiSeq platform in combination with ARISA fingerprinting. The samples were taken along broad environmental gradients in an area covering nearly 1000 km(2) Ordination and variation partitioning analyses revealed that the total organic carbon content was the most significant variable in structuring the bacterial communities, followed by pH, electric conductivity, bedrock type and the moisture content, while spatial distance was of relatively minor importance. Acidobacteria (Chloracidobacteria) and Actinobacteria (Actinomycetales) dominated gneiss derived mineral soil samples, while Proteobacteria (Sphingomonadaceae), Cyanobacteria, Armatimonadetes and candidate division FBP-dominated soil samples with a high total organic carbon content that were mainly situated on granite derived bedrock. PMID:27402710

  15. Mapping Topoisomerase IV Binding and Activity Sites on the E. coli Genome.

    Science.gov (United States)

    El Sayyed, Hafez; Le Chat, Ludovic; Lebailly, Elise; Vickridge, Elise; Pages, Carine; Cornet, Francois; Cosentino Lagomarsino, Marco; Espéli, Olivier

    2016-05-01

    Catenation links between sister chromatids are formed progressively during DNA replication and are involved in the establishment of sister chromatid cohesion. Topo IV is a bacterial type II topoisomerase involved in the removal of catenation links both behind replication forks and after replication during the final separation of sister chromosomes. We have investigated the global DNA-binding and catalytic activity of Topo IV in E. coli using genomic and molecular biology approaches. ChIP-seq revealed that Topo IV interaction with the E. coli chromosome is controlled by DNA replication. During replication, Topo IV has access to most of the genome but only selects a few hundred specific sites for its activity. Local chromatin and gene expression context influence site selection. Moreover strong DNA-binding and catalytic activities are found at the chromosome dimer resolution site, dif, located opposite the origin of replication. We reveal a physical and functional interaction between Topo IV and the XerCD recombinases acting at the dif site. This interaction is modulated by MatP, a protein involved in the organization of the Ter macrodomain. These results show that Topo IV, XerCD/dif and MatP are part of a network dedicated to the final step of chromosome management during the cell cycle. PMID:27171414

  16. Pederin-type pathways of uncultivated bacterial symbionts: analysis of o-methyltransferases and generation of a biosynthetic hybrid.

    Science.gov (United States)

    Zimmermann, Katrin; Engeser, Marianne; Blunt, John W; Munro, Murray H G; Piel, Jörn

    2009-03-01

    The complex polyketide pederin is a potent antitumor agent isolated from Paederus spp. rove beetles. We have previously isolated a set of genes from a bacterial endosymbiont that are good candidates for pederin biosynthesis. To biochemically study this pathway, we expressed three methyltransferases from the putative pederin pathway and used the partially unmethylated analogue mycalamide A from the marine sponge Mycale hentscheli as test substrate. Analysis by high-resolution MS/MS and NMR revealed that PedO regiospecifically methylates the marine compound to generate the nonnatural hybrid compound 18-O-methylmycalamide A with increased cytotoxicity. To our knowledge, this is the first biochemical evidence that invertebrates can obtain defensive complex polyketides from bacterial symbionts. PMID:19206228

  17. Pederin-type pathways of uncultivated bacterial symbionts: analysis of o-methyltransferases and generation of a biosynthetic hybrid.

    Science.gov (United States)

    Zimmermann, Katrin; Engeser, Marianne; Blunt, John W; Munro, Murray H G; Piel, Jörn

    2009-03-01

    The complex polyketide pederin is a potent antitumor agent isolated from Paederus spp. rove beetles. We have previously isolated a set of genes from a bacterial endosymbiont that are good candidates for pederin biosynthesis. To biochemically study this pathway, we expressed three methyltransferases from the putative pederin pathway and used the partially unmethylated analogue mycalamide A from the marine sponge Mycale hentscheli as test substrate. Analysis by high-resolution MS/MS and NMR revealed that PedO regiospecifically methylates the marine compound to generate the nonnatural hybrid compound 18-O-methylmycalamide A with increased cytotoxicity. To our knowledge, this is the first biochemical evidence that invertebrates can obtain defensive complex polyketides from bacterial symbionts.

  18. Characterization of a novel arginine catabolic mobile element (ACME) and staphylococcal chromosomal cassette mec composite island with significant homology to Staphylococcus epidermidis ACME type II in methicillin-resistant Staphylococcus aureus genotype ST22-MRSA-IV.

    LENUS (Irish Health Repository)

    Shore, Anna C

    2011-05-01

    The arginine catabolic mobile element (ACME) is prevalent among methicillin-resistant Staphylococcus aureus (MRSA) isolates of sequence type 8 (ST8) and staphylococcal chromosomal cassette mec (SCCmec) type IVa (USA300) (ST8-MRSA-IVa isolates), and evidence suggests that ACME enhances the ability of ST8-MRSA-IVa to grow and survive on its host. ACME has been identified in a small number of isolates belonging to other MRSA clones but is widespread among coagulase-negative staphylococci (CoNS). This study reports the first description of ACME in two distinct strains of the pandemic ST22-MRSA-IV clone. A total of 238 MRSA isolates recovered in Ireland between 1971 and 2008 were investigated for ACME using a DNA microarray. Twenty-three isolates (9.7%) were ACME positive, and all were either MRSA genotype ST8-MRSA-IVa (7\\/23, 30%) or MRSA genotype ST22-MRSA-IV (16\\/23, 70%). Whole-genome sequencing and comprehensive molecular characterization revealed the presence of a novel 46-kb ACME and staphylococcal chromosomal cassette mec (SCCmec) composite island (ACME\\/SCCmec-CI) in ST22-MRSA-IVh isolates (n=15). This ACME\\/SCCmec-CI consists of a 12-kb DNA region previously identified in ACME type II in S. epidermidis ATCC 12228, a truncated copy of the J1 region of SCCmec type I, and a complete SCCmec type IVh element. The composite island has a novel genetic organization, with ACME located within orfX and SCCmec located downstream of ACME. One PVL locus-positive ST22-MRSA-IVa isolate carried ACME located downstream of SCCmec type IVa, as previously described in ST8-MRSA-IVa. These results suggest that ACME has been acquired by ST22-MRSA-IV on two independent occasions. At least one of these instances may have involved horizontal transfer and recombination events between MRSA and CoNS. The presence of ACME may enhance dissemination of ST22-MRSA-IV, an already successful MRSA clone.

  19. Type III-IV muscle afferents are not required for steady-state exercise hyperpnea in healthy subjects and patients with COPD or heart failure.

    Science.gov (United States)

    Poon, Chi-Sang; Song, Gang

    2015-09-15

    Blockade of group III-IV muscle afferents by intrathecal injection of the μ-opioid agonist fentanyl (IF) in humans has been variously reported to depress exercise hyperpnea in some studies but not others. A key unanswered question is whether such an effect is transient or persists in the steady state. Here we show that in healthy subjects undergoing constant-load cycling exercise IF significantly slows the transient exercise ventilatory kinetics but has no discernible effect on the ventilatory response when exercise is sufficiently prolonged. Thus, the ventilatory response to group III-IV muscle afferents input in healthy subjects is not a simple reflex but acts like a high-pass filter with maximum sensitivity during early-phase exercise and is reset in the late phase. In patients with chronic heart failure (CHF) IF causes sustained CO2 retention not only during exercise but also in the resting state, where muscle afferents feedback is minimal. In patients with chronic obstructive pulmonary disease (COPD), IF also elicits sustained decreases in the exercise ventilatory response but with little or no resultant CO2 retention due to concomitant decreases in physiological VD/VT (dead space-to-ventilation ratio). These results support the proposition that optimal long-term regulation of exercise hyperpnea in health and in disease is determined centrally by the respiratory controller through the continuing adaptation of an internal model which dynamically tracks the metabolic CO2 load and the ventilatory inefficiency 1/1-VD/VT that must be overcome for the maintenance of arterial PCO2 homeostasis, rather than being reflexively driven by group III-IV muscle afferents feedback per se. PMID:25911558

  20. Diversity of Clinical and Environmental Isolates of Vibrio cholerae in Natural Transformation and Contact-Dependent Bacterial Killing Indicative of Type VI Secretion System Activity.

    Science.gov (United States)

    Bernardy, Eryn E; Turnsek, Maryann A; Wilson, Sarah K; Tarr, Cheryl L; Hammer, Brian K

    2016-05-01

    The bacterial pathogen Vibrio cholerae can occupy both the human gut and aquatic reservoirs, where it may colonize chitinous surfaces that induce the expression of factors for three phenotypes: chitin utilization, DNA uptake by natural transformation, and contact-dependent bacterial killing via a type VI secretion system (T6SS). In this study, we surveyed a diverse set of 53 isolates from different geographic locales collected over the past century from human clinical and environmental specimens for each phenotype outlined above. The set included pandemic isolates of serogroup O1, as well as several serogroup O139 and non-O1/non-O139 strains. We found that while chitin utilization was common, only 22.6% of the isolates tested were proficient at chitin-induced natural transformation, suggesting that transformation is expendable. Constitutive contact-dependent killing of Escherichia coli prey, which is indicative of a functional T6SS, was rare among clinical isolates (only 4 of 29) but common among environmental isolates (22 of 24). These results bolster the pathoadaptive model in which tight regulation of T6SS-mediated bacterial killing is beneficial in a human host, whereas constitutive killing by environmental isolates may give a competitive advantage in natural settings. Future sequence analysis of this set of diverse isolates may identify previously unknown regulators and structural components for both natural transformation and T6SS. PMID:26944842

  1. GDP (Gemcitabine, Dexamethasone, and Cisplatin) Is Highly Effective and Well-Tolerated for Newly Diagnosed Stage IV and Relapsed/Refractory Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type.

    Science.gov (United States)

    Wang, Jing-Jing; Dong, Mei; He, Xiao-Hui; Li, Ye-Xiong; Wang, Wei-Hu; Liu, Peng; Yang, Jian-Liang; Gui, Lin; Zhang, Chang-Gong; Yang, Sheng; Zhou, Sheng-Yu; Shi, Yuan-Kai

    2016-02-01

    This study was conducted to evaluate the effectiveness and tolerance of GDP (gemcitabine, dexamethasone, and cisplatin) regimen in patients with newly diagnosed stage IV and relapsed/refractory extranodal natural killer/T-cell lymphoma, nasal type (ENKTL).The study enrolled 41 ENKTL patients who received GDP regimen at the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between January 2008 and January 2015.The disease status was newly diagnosed stage IV in 15 patients and relapsed/refractory in 26 patients. The median number of cycles of chemotherapy per patient was 6 (range, 2-8 cycles). The overall response rate and complete-remission rate were 83.0% (34/41) and 41.5% (17/41), respectively. After a median follow-up of 16.2 months, 1-year progression-free survival rate and 1-year overall survival rate for the whole cohort were 54.5% and 72.7%. Grade 3 to 4 adverse events included neutropenia (34.1%), thrombocytopenia (19.5%), and anemia (14.6%).Our study has suggested high efficacy and low toxicity profile of GDP regimen in patients with newly diagnosed stage IV and relapsed/refractory ENKTL.

  2. Characterization of a Novel Arginine Catabolic Mobile Element (ACME) and Staphylococcal Chromosomal Cassette mec Composite Island with Significant Homology to Staphylococcus epidermidis ACME type II in Methicillin-Resistant Staphylococcus aureus Genotype ST22-MRSA-IV.

    LENUS (Irish Health Repository)

    Shore, Anna C

    2011-02-22

    The arginine catabolic mobile element (ACME) is prevalent among ST8-MRSA-IVa (USA300) isolates and evidence suggests that ACME enhances the ability of ST8-MRSA-IVa to grow and survive on its host. ACME has been identified in a small number of isolates belonging to other MRSA clones but is widespread among coagulase-negative staphylococci (CoNS). This study reports the first description of ACME in two distinct strains of the pandemic ST22-MRSA-IV clone. A total of 238 MRSA isolates recovered in Ireland between 1971 and 2008 were investigated for ACME using a DNA microarray. Twenty-three isolates (9.7%) were ACME-positive, all were either MRSA genotype ST8-MRSA-IVa (7\\/23, 30%) or ST22-MRSA-IV (16\\/23, 70%). Whole-genome sequencing and comprehensive molecular characterization revealed the presence of a novel 46-kb ACME and SCCmec composite island (ACME\\/SCCmec-CI) in ST22-MRSA-IVh isolates (n = 15). This ACME\\/SCCmec-CI consists of a 12-kb DNA region previously identified in ACME type II in S. epidermidis ATCC 12228, a truncated copy of the J1 region of SCCmec I and a complete SCCmec IVh element. The composite island has a novel genetic organization with ACME located within orfX and SCCmec located downstream of ACME. One pvl-positive ST22-MRSA-IVa isolate carried ACME located downstream of SCCmec IVa as previously described in ST8-MRSA-IVa. These results suggest that ACME has been acquired by ST22-MRSA-IV on two independent occasions. At least one of these instances may have involved horizontal transfer and recombination events between MRSA and CoNS. The presence of ACME may enhance dissemination of ST22-MRSA-IV, an already successful MRSA clone.

  3. Bacterial Leakage Assessment for Different Types of Resin-Based Dental Restorations Applied Using Various Placement Methods

    Directory of Open Access Journals (Sweden)

    Horieh Moosavi

    2014-09-01

    Full Text Available Introduction: Although composite resins have improved greatly since their introduction, microleakage is one of the most frequently encountered problems. This study compared the effects of different monomer systems and layering techniques on the bacterial leakage of Cl I composite resin restorations. Methods: Eighty-two sound human third molars were used. The teeth were randomly divided into six groups of 12 teeth each and two positive and negative control groups of five teeth. Class I cavities, measuring 4×4×2 mm, were prepared. The first three groups were filled with a silorane-based composite (Filtek P90 using three different methods of filling (bulk, incremental and snowplow and the remaining three groups were filled with a methacrylate-based composite (Clearfil AP-X using the same techniques. The specimens were stored for 24 hours at 37°C and then thermocycled up to 1000 cycles. The bacterial leakage of the specimens was assessed in a microbiological laboratory and statistical analyses of data were performed by Fisher’s exact and chi-squared tests (P0.05. Conclusion: Leakage occurred similarly in both silorane- and methacrylate-based composite resins and three filling techniques.  

  4. Evaluation of bacterial communities by bacteriome analysis targeting 16S rRNA genes and quantitative analysis of ammonia monooxygenase gene in different types of compost.

    Science.gov (United States)

    Kitamura, Rika; Ishii, Kazuo; Maeda, Isamu; Kozaki, Toshinori; Iwabuchi, Kazunori; Saito, Takahiro

    2016-01-01

    Biofiltration technology based on microbial degradation and assimilation is used for the removal of malodorous compounds, such as ammonia. Microbes that degrade malodorous and/or organic substances are involved in composting and are retained after composting; therefore, mature composts can serve as an ideal candidate for a biofilter medium. In this study, we focused on different types of raw compost materials, as these are important factors determining the bacterial community profile and the chemical component of the compost. Therefore, bacterial community profiles, the abundance of the bacterial ammonia monooxygenase gene (amoA), and the quantities of chemical components were analyzed in composts produced from either food waste or cattle manure. The community profiles with the lowest beta diversity were obtained from single type of cattle manure compost. However, cattle manure composts showed greater alpha diversity, contained higher amounts of various rRNA gene fragments than those of food waste composts and contained the amoA gene by relative quantification, and Proteobacteria were abundantly found and nitrifying bacteria were detected in it. Nitrifying bacteria are responsible for ammonia oxidation and mainly belong to the Proteobacteria or Nitrospira phyla. The quantities of chemical components, such as salt, phosphorus, and nitrogen, differed between the cattle manure and food waste composts, indicating that the raw materials provided different fermentation environments that were crucial for the formation of different community profiles. The results also suggest that cattle manure might be a more suitable raw material for the production of composts to be used in the biofiltration of ammonia.

  5. Evaluation of bacterial communities by bacteriome analysis targeting 16S rRNA genes and quantitative analysis of ammonia monooxygenase gene in different types of compost.

    Science.gov (United States)

    Kitamura, Rika; Ishii, Kazuo; Maeda, Isamu; Kozaki, Toshinori; Iwabuchi, Kazunori; Saito, Takahiro

    2016-01-01

    Biofiltration technology based on microbial degradation and assimilation is used for the removal of malodorous compounds, such as ammonia. Microbes that degrade malodorous and/or organic substances are involved in composting and are retained after composting; therefore, mature composts can serve as an ideal candidate for a biofilter medium. In this study, we focused on different types of raw compost materials, as these are important factors determining the bacterial community profile and the chemical component of the compost. Therefore, bacterial community profiles, the abundance of the bacterial ammonia monooxygenase gene (amoA), and the quantities of chemical components were analyzed in composts produced from either food waste or cattle manure. The community profiles with the lowest beta diversity were obtained from single type of cattle manure compost. However, cattle manure composts showed greater alpha diversity, contained higher amounts of various rRNA gene fragments than those of food waste composts and contained the amoA gene by relative quantification, and Proteobacteria were abundantly found and nitrifying bacteria were detected in it. Nitrifying bacteria are responsible for ammonia oxidation and mainly belong to the Proteobacteria or Nitrospira phyla. The quantities of chemical components, such as salt, phosphorus, and nitrogen, differed between the cattle manure and food waste composts, indicating that the raw materials provided different fermentation environments that were crucial for the formation of different community profiles. The results also suggest that cattle manure might be a more suitable raw material for the production of composts to be used in the biofiltration of ammonia. PMID:26111599

  6. The bacterial-type phosphoenolpyruvate carboxylase isozyme from developing castor oil seeds is subject to in vivo regulatory phosphorylation at serine-451.

    Science.gov (United States)

    Dalziel, Katie J; O'Leary, Brendan; Brikis, Carolyne; Rao, Srinath K; She, Yi-Min; Cyr, Terry; Plaxton, William C

    2012-04-01

    Phosphoenolpyruvate carboxylase (PEPC) is a tightly controlled anaplerotic enzyme situated at a pivotal branch point of plant carbohydrate-metabolism. In developing castor oil seeds (COS) a novel allosterically-densensitized 910-kDa Class-2 PEPC hetero-octameric complex arises from a tight interaction between 107-kDa plant-type PEPC and 118-kDa bacterial-type PEPC (BTPC) subunits. Mass spectrometry and immunoblotting with anti-phosphoSer451 specific antibodies established that COS BTPC is in vivo phosphorylated at Ser451, a highly conserved target residue that occurs within an intrinsically disordered region. This phosphorylation was enhanced during COS development or in response to depodding. Kinetic characterization of a phosphomimetic (S451D) mutant indicated that Ser451 phosphorylation inhibits the catalytic activity of BTPC subunits within the Class-2 PEPC complex.

  7. A bacterial type III effector family uses the papain-like hydrolytic activity to arrest the host cell cycle

    OpenAIRE

    Yao, Qing; Cui, Jixin; Zhu, Yongqun; Wang, Guolun; Hu, Liyan; Long, Chengzu; Cao, Ran; Liu, Xinqi; Huang, Niu; Chen, She; Liu, LiPing; Shao, Feng

    2009-01-01

    Pathogenic bacteria deliver effector proteins into host cells through the type III secretion apparatus to modulate the host function. We identify a family of proteins, homologous to the type III effector Cif from enteropathogenic Escherichia coli, in pathogens including Yersinia, Photorhabdus, and Burkholderia that contain functional type III secretion systems. Like Cif, this family of proteins is capable of arresting the host cell cycle at G2/M. Structure of one of the family members, Cif ho...

  8. On the role of Mn(IV) vacancies in the photoreductive dissolution of hexagonal birnessite

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, K.D.; Refson, K.; Sposito, G.

    2009-06-01

    Photoreductive dissolution of layer type Mn(IV) oxides (birnessite) under sunlight illumination to form soluble Mn(II) has been observed in both field and laboratory settings, leading to a consensus that this process is a key driver of the biogeochemical cycling of Mn in the euphotic zones of marine and freshwater ecosystems. However, the underlying mechanisms for the process remain unknown, although they have been linked to the semiconducting characteristics of hexagonal birnessite, the ubiquitous Mn(IV) oxide produced mainly by bacterial oxidation of soluble Mn(II). One of the universal properties of this biogenic mineral is the presence of Mn(IV) vacancies, long-identified as strong adsorption sites for metal cations. In this paper, the possible role of Mn vacancies in photoreductive dissolution is investigated theoretically using quantum mechanical calculations based on spin-polarized density functional theory (DFT). Our DFT study demonstrates unequivocally that Mn vacancies significantly reduce the band-gap energy for hexagonal birnessite relative to a hypothetical vacancy-free MnO{sub 2} and thus would increase the concentration of photo-induced electrons available for Mn(IV) reduction upon illumination of the mineral by sunlight. Calculations of the charge distribution in the presence of vacancies, although not fully conclusive, show a clear separation of photo-induced electrons and holes, implying a slow recombination of these charge-carriers that facilitates the two-electron reduction of Mn(IV) to Mn(II).

  9. 新型数字化智能输液仪的研制及应用%The research and application of a new type of digitalized intelligent IV monitoring device.

    Institute of Scientific and Technical Information of China (English)

    华嘉临; 何茗芳; 缪学明; 冯钧; 支杨

    2011-01-01

    Objective:The goal of this research is to study and to develop a new type of digitized intelligent IV monitoring device in order to robotize the IV infusion process, to increase the safety factor, to reduce the working load of nurses, and to make patient having better rest. Methods:The method of such a device is described as the followings. The device which applies the principle of electronic load sensor consists of 5 parts: load sensor, data collector, data processor,data display including a liquid crystal display screen,a wireless transmitter and an alarming device. Results:The device can automatically monitor the whole process of an IV infusion process, including measuring the volume of the medical liquid in an IV bottle, the infusion rate, the required infusion time, and automatic alarming. Conclusions: This device applies high technology with low cost, high market demand, ease to use, and ease for market development; It would become the first candidate candidate for an IV infusion monitoring system.%目的:研制一种新型数字化智能输液监测仪,自动监测输液过程,提高安全系数,减轻护士工作负担,保证患者休息.方法:该输液监测仪采用电子称重的原理,由五部分构成:传感器、数据采集部件、数据处理部件、液晶面板显示和无线发送并报警.结果:实现对输液全过程进行自动化测试,测试输液容器容量、输液速度、需要时间、自动报警.结论:该装置技术含量高、成本低廉、实用性强、使用简便、易于推广,可成为输液监测系统的首选装置.

  10. EGFR、PCNA、LN、IV型胶原在SACC中的表达及临床意义%The clinical significance of EGFR,PCNA,LN and type IV collagen expression in salivary adenoid cystic carcinoma

    Institute of Scientific and Technical Information of China (English)

    杜贵霞; 张凡; 霍秀英; 李立恒; 李瑞平; 刘博; 张九鸿; 白睿; 赵秀芳

    2014-01-01

    Objective:To investigate the clinical significance of epidermal growth factor receptor(EGFR),proliferating cell nuclear antigen(PCNA),laminin(LN)and type IV collagen expression in salivary adenoid cystic carcinoma(SACC).Methods:EGFR gene in 78 cases of SACC with complete clinical data was detected by fluorescence in situ hybridization(FISH)technique,the expression of EGFR,PCNA,LN and type IV collagen protein was detected by immunohistochemistry technique(IHC),their correlation with the clin-icopathological parameters was analysed by SPSS 13.00 software.Results:EGFR gene amplification levels(69.2%)was positively related to the ratio of EGFR protein positive expression(7 1 .8%),the expression of EGFR,PCNA,LN and type IV collagen was posi-tively related to the clinical pathological parameters(P<0.05).There was a positive correlation between EGFR and PCNA expression (P<0.05),a negative correlation between LN protein and type IV collagen protein expression(P<0.05).Conclusion:EGFR gene is amplified in SACC.EGFR,PCNA,LN and type IV collagen take part in the occurrence and development of SACC.%目的:探讨表皮生长因子受体(EGFR)、增殖细胞核抗原(PCNA)、层黏连蛋白(LN)和IV型胶原蛋白在唾液腺腺样囊性癌(SACC)中的表达及临床意义。方法:选取临床病例资料齐全的SACC 78例,用荧光原位杂交技术检测EGFR基因表达,免疫组织化学技术检测 EGFR、PCNA、LN和Ⅳ型胶原蛋白的表达,分析其与临床病理参数的相关性。结果:SACC中EG-FR基因扩增率(69.2%)与蛋白的阳性表达率(71.8%)存在明显正相关(P<0.05),且EGFR、PCNA、LN、Ⅳ型胶原蛋白表达与临床病理参数密切相关。EGFR、PCNA表达水平间存在明显正相关(P<0.05);LN蛋白、Ⅳ型胶原表达水平间存在明显负相关(P<0.05)。结论:EGFR基因在SACC中明显扩增,EGFR、PCNA、LN、Ⅳ型胶原蛋白共同参与SACC发生、发展。

  11. Putative resolution of the EEEE selectivity paradox in L-type Ca2+ and bacterial Na+ biological ion channels

    Science.gov (United States)

    Kaufman, I. Kh; Luchinsky, D. G.; Gibby, W. A. T.; McClintock, P. V. E.; Eisenberg, R. S.

    2016-05-01

    The highly selective permeation of ions through biological ion channels can be described and explained in terms of fluctuational dynamics under the influence of powerful electrostatic forces. Hence valence selectivity, e.g. between Ca2+ and Na+ in calcium and sodium channels, can be described in terms of ionic Coulomb blockade, which gives rise to distinct conduction bands and stop-bands as the fixed negative charge Q f at the selectivity filter of the channel is varied. This picture accounts successfully for a wide range of conduction phenomena in a diversity of ion channels. A disturbing anomaly, however, is that what appears to be the same electrostatic charge and structure (the so-called EEEE motif) seems to select Na+ conduction in bacterial channels but Ca2+ conduction in mammalian channels. As a possible resolution of this paradox it is hypothesised that an additional charged protein residue on the permeation path of the mammalian channel increases |{{Q}f}| by e, thereby altering the selectivity from Na+ to Ca2+. Experiments are proposed that will enable the hypothesis to be tested.

  12. Crystallization and preliminary X-ray analysis of the FliH–FliI complex responsible for bacterial flagellar type III protein export

    International Nuclear Information System (INIS)

    The FliH–FliI complex from the bacterial flagellar type III export apparatus has been expressed, purified and crystallized, and the crystals have been characterized by X-ray diffraction. The bacterial flagellar proteins are translocated into the central channel of the flagellum by a specific protein-export apparatus for self-assembly at the distal growing end. FliH and FliI are soluble components of the export apparatus and form an FliH2–FliI heterotrimer in the cytoplasm. FliI is an ATPase and the FliH2–FliI complex delivers export substrates from the cytoplasm to an export gate made up of six integral membrane proteins of the export apparatus. In this study, an FliHC fragment consisting of residues 99–235 was co-purified with FliI and the FliHC2–FliI complex was crystallized. Crystals were obtained using the hanging-drop vapour-diffusion technique with PEG 400 as a precipitant. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 133.7, b = 147.3, c = 164.2 Å, and diffracted to 3.0 Å resolution

  13. Catalogue of the Type Specimens of Amphibians and Reptiles in the Herpetological Museum of the Chengdu Institute of Biology, Chinese Academy of Sciences:IV. Lizards (Reptilia, Sauria)

    Institute of Scientific and Technical Information of China (English)

    Bo WANG; Ke JIANG; Jiatang LI; Yuezhao WANG; Daode YANG

    2015-01-01

    In the present study, we report the six type specimens and two paratypes of eight lizard species in the Herpetological Museum of the Chengdu Institute of Biology (CIB), Chinese Academy of Sciences (CAS). Each entry provides the information of the original description, the catalog number of the holotype, sex, type locality, and information of allotype and paratype (if any), number and distribution of deposited specimens, and comments. Additionally, two invalid species and one invalid subspecies are discussed.

  14. IL-1RI (interleukin-1 receptor type I signalling is essential for host defence and hemichannel activity during acute central nervous system bacterial infection

    Directory of Open Access Journals (Sweden)

    Tammy Kielian

    2012-04-01

    Full Text Available Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1 response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood–brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I KO (knockout animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared with WT (wild-type animals. Loss of IL-1RI signalling also dampened the expression of select cytokines and chemokines, concomitant with significant reductions in neutrophil and macrophage infiltrates into the brain. In addition, the opening of astrocyte hemichannels during acute infection was shown to be dependent on IL-1RI activity. Collectively, these results demonstrate that IL-1RI signalling plays a pivotal role in the genesis of immune responses during the acute stage of brain abscess development through S. aureus containment, inflammatory mediator production, peripheral immune cell recruitment, and regulation of astrocyte hemichannel activity. Taken in the context of previous studies with MyD88 (myeloid differentiation primary response gene 88 and TLR2 (Toll-like receptor 2 KO animals, the current report advances our understanding of MyD88-dependent cascades and implicates IL-1RI signalling as a major antimicrobial effector pathway during acute brain-abscess formation.

  15. RND type efflux pump system MexAB-OprM of pseudomonas aeruginosa selects bacterial languages, 3-oxo-acyl-homoserine lactones, for cell-to-cell communication

    Directory of Open Access Journals (Sweden)

    Minagawa Shu

    2012-05-01

    Full Text Available Abstract Background Bacteria release a wide variety of small molecules including cell-to-cell signaling compounds. Gram-negative bacteria use a variety of self-produced autoinducers such as acylated homoserine lactones (acyl-HSLs as signal compounds for quorum sensing (QS within and between bacterial species. QS plays a significant role in the pathogenesis of infectious diseases and in beneficial symbiosis by responding to acyl-HSLs in Pseudomonas aeruginosa. It is considered that the selection of bacterial languages is necessary to regulate gene expression and thus it leads to the regulation of virulence and provides a growth advantage in several environments. In this study, we hypothesized that RND-type efflux pump system MexAB-OprM of P. aeruginosa might function in the selection of acyl-HSLs, and we provide evidence to support this hypothesis. Results Loss of MexAB-OprM due to deletion of mexB caused increases in QS responses, as shown by the expression of gfp located downstream of the lasB promoter and LasB elastase activity, which is regulated by a LasR-3-oxo-C12-HSL complex. Either complementation with a plasmid containing wild-type mexB or the addition of a LasR-specific inhibitor, patulin, repressed these high responses to 3-oxo-acyl-HSLs. Furthermore, it was shown that the acyl-HSLs-dependent response of P. aeruginosa was affected by the inhibition of MexB transport activity and the mexB mutant. The P. aeruginosa MexAB-OprM deletion mutant showed a strong QS response to 3-oxo-C10-HSL produced by Vibrio anguillarum in a bacterial cross-talk experiment. Conclusion This work demonstrated that MexAB-OprM does not control the binding of LasR to 3-oxo-Cn-HSLs but rather accessibility of non-cognate acyl-HSLs to LasR in P. aeruginosa. MexAB-OprM not only influences multidrug resistance, but also selects acyl-HSLs and regulates QS in P. aeruginosa. The results demonstrate a new QS regulation mechanism via the efflux system MexAB-OprM in P

  16. A novel cytology-based, two-hybrid screen for bacteria applied to protein-protein interaction studies of a type IV secretion system.

    Science.gov (United States)

    Ding, Zhiyong; Zhao, Zhenming; Jakubowski, Simon J; Krishnamohan, Atmakuri; Margolin, William; Christie, Peter J

    2002-10-01

    DivIVA of Bacillus subtilis and FtsZ of Escherichia coli were used to target heterologous protein complexes to cell division sites of E. coli and Agrobacterium tumefaciens. DivIVA and FtsZ that were fused to the dimerizing leucine zipper (LZ) domain of the yeast transcription activator GCN4 directed the green fluorescent protein (GFP) that was fused to an LZ domain to E. coli division sites, resulting in fluorescence patterns identical to those observed with DivIVA::GFP and FtsZ::GFP. These cell division proteins also targeted the VirE1 chaperone and VirE2 secretion substrate complex to division sites of E. coli and A. tumefaciens. Coproduction of the native VirE1 or VirE2 proteins inhibited the dihybrid interaction in both species, as judged by loss of GFP targeting to division sites. The VirE1 chaperone bound independently to N- and C-terminal regions of VirE2, with a requirement for residues 84 to 147 and 331 to 405 for these interactions, as shown by dihybrid studies with VirE1::GFP and DivIVA fused to N- and C-terminal VirE2 fragments. DivIVA also targeted homo- and heterotypic complexes of VirB8 and VirB10, two bitopic inner membrane subunits of the A. tumefaciens T-DNA transfer system, in E. coli and homotypic complexes of VirB10 in A. tumefaciens. VirB10 self-association in bacteria was mediated by the C-terminal periplasmic domain, as shown by dihybrid studies with fusions to VirB10 truncation derivatives. Together, our findings establish a proof-of-concept for the use of cell-location-specific proteins for studies of interactions among cytosolic and membrane proteins in diverse bacterial species. PMID:12270814

  17. Contamination with bacterial zoonotic pathogen genes in U.S. streams influenced by varying types of animal agriculture.

    Science.gov (United States)

    Haack, Sheridan K; Duris, Joseph W; Kolpin, Dana W; Focazio, Michael J; Meyer, Michael T; Johnson, Heather E; Oster, Ryan J; Foreman, William T

    2016-09-01

    Animal waste, stream water, and streambed sediment from 19 small (water or sediment sample in any control watershed. Post-rainfall pathogen gene numbers in stream water were significantly correlated with FIB, cholesterol and coprostanol concentrations, and were most highly correlated in dairy watershed samples collected from 3 different states. Although collected across multiple states and ecoregions, animal-waste gene profiles were distinctive via discriminant analysis. Stream water gene profiles could also be discriminated by the watershed animal type. Although pathogen genes were not abundant in stream water or streambed samples, PCR on enrichments indicated that many genes were from viable organisms, including several (shiga-toxin producing or enterotoxigenic E. coli, Salmonella, vancomycin-resistant enterococci) that could potentially affect either human or animal health. Pathogen gene numbers and types in stream water samples were influenced most by animal type, by local factors such as whether animals had stream access, and by the amount of local rainfall, and not by studied watershed soil or physical characteristics. Our results indicated that stream water in small agricultural U.S. watersheds was susceptible to pathogen gene inputs under typical agricultural practices and environmental conditions. Pathogen gene profiles may offer the potential to address both source of, and risks associated with, fecal pollution. PMID:27139306

  18. 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.

  19. Alternative Agents in Type 1 Diabetes in Addition to Insulin Therapy: Metformin, Alpha-Glucosidase Inhibitors, Pioglitazone, GLP-1 Agonists, DPP-IV Inhibitors, and SGLT-2 Inhibitors.

    Science.gov (United States)

    DeGeeter, Michelle; Williamson, Bobbie

    2016-04-01

    Insulin is the mainstay of current treatment for patients with type 1 diabetes mellitus (T1DM). Due to increasing insulin resistance, insulin doses are often continually increased, which may result in weight gain for patients. Medications currently approved for the treatment of type 2 diabetes offer varying mechanisms of action that can help to reduce insulin resistance and prevent or deter weight gain. A MEDLINE search was conducted to review literature evaluating the use of metformin, alpha-glucosidase inhibitors, pioglitazone, glucagon-like peptide 1 agonists, dipeptidyl peptidase, and sodium-dependent glucose transporter 2 inhibitors, in patients with T1DM. Varying results were found with some benefits including reductions in hemoglobin A1c, decreased insulin doses, and favorable effects on weight. Of significance, a common fear of utilizing multiple therapies for diabetes treatment is the risk of hypoglycemia, and this review displayed limited evidence of hypoglycemia with multiple agents. PMID:25312263

  20. The MASSIVE Survey. IV. The X-ray Halos of the Most Massive Early-type Galaxies in the Nearby Universe

    Science.gov (United States)

    Goulding, Andy D.; Greene, Jenny E.; Ma, Chung-Pei; Veale, Melanie; Bogdan, Akos; Nyland, Kristina; Blakeslee, John P.; McConnell, Nicholas J.; Thomas, Jens

    2016-08-01

    Studies of the physical properties of local elliptical galaxies are shedding new light on galaxy formation. Here we present the hot-gas properties of 33 early-type systems within the MASSIVE galaxy survey that have archival Chandra X-ray observations, and we use these data to derive X-ray luminosities ({L}{{X,gas}}) and plasma temperatures ({T}{{gas}}) for the diffuse gas components. We combine this with the {{ATLAS}}{{3D}} survey to investigate the X-ray-optical properties of a statistically significant sample of early-type galaxies across a wide range of environments. When X-ray measurements are performed consistently in apertures set by the galaxy stellar content, we deduce that all early types (independent of galaxy mass, environment, and rotational support) follow a universal scaling law such that {L}{{X,gas}}\\propto {T}{{gas}}˜ 4.5. We further demonstrate that the scatter in {L}{{X,gas}} around both K-band luminosity (L K ) and the galaxy stellar velocity dispersion ({σ }e) is primarily driven by {T}{{gas}}, with no clear trends with halo mass, radio power, or angular momentum of the stars. It is not trivial to tie the gas origin directly to either stellar mass or galaxy potential. Indeed, our data require a steeper relation between {L}{{X,gas}},{L}K, and {σ }e than predicted by standard mass-loss models. Finally, we find that {T}{{gas}} is set by the galaxy potential inside the optical effective radius. We conclude that within the innermost 10-30 kpc region, early types maintain pressure-supported hot gas, with a minimum {T}{{gas}} set by the virial temperature, but the majority show evidence for additional heating.

  1. A Geobacter sulfurreducens Strain Expressing Pseudomonas aeruginosa Type IV Pili Localizes OmcS on Pili but Is Deficient in Fe(III) Oxide Reduction and Current Production

    Science.gov (United States)

    Liu, Xing; Tremblay, Pier-Luc; Malvankar, Nikhil S.; Nevin, Kelly P.; Vargas, Madeline

    2014-01-01

    The conductive pili of Geobacter species play an important role in electron transfer to Fe(III) oxides, in long-range electron transport through current-producing biofilms, and in direct interspecies electron transfer. Although multiple lines of evidence have indicated that the pili of Geobacter sulfurreducens have a metal-like conductivity, independent of the presence of c-type cytochromes, this claim is still controversial. In order to further investigate this phenomenon, a strain of G. sulfurreducens, designated strain PA, was constructed in which the gene for the native PilA, the structural pilin protein, was replaced with the PilA gene of Pseudomonas aeruginosa PAO1. Strain PA expressed and properly assembled P. aeruginosa PilA subunits into pili and exhibited a profile of outer surface c-type cytochromes similar to that of a control strain expressing the G. sulfurreducens PilA. Surprisingly, the strain PA pili were decorated with the c-type cytochrome OmcS in a manner similar to the control strain. However, the strain PA pili were 14-fold less conductive than the pili of the control strain, and strain PA was severely impaired in Fe(III) oxide reduction and current production. These results demonstrate that the presence of OmcS on pili is not sufficient to confer conductivity to pili and suggest that there are unique structural features of the G. sulfurreducens PilA that are necessary for conductivity. PMID:24296506

  2. Neptunium (IV) oxalate solubility

    International Nuclear Information System (INIS)

    The equilibrium solubility of neptunium (IV) oxalate in nitric/oxalic acid solutions was determined at 220C, 450C, and 600C. The concentrations of nitric/oxalic acid solutions represented a wide range of free oxalate ion concentration. A mathematical solubility model was developed which is based on the formation of the known complexes of neptunium (IV) oxalate. the solubility model uses a simplified concentration parameter which is proportional to the free oxalate ion concentration. The solubility model can be used to estimate the equilibrium solubility of neptunium (IV) oxalate over a wide range of oxalic and nitric acid concentrations at each temperature

  3. The Bacterial Flagellar Type III Export Gate Complex Is a Dual Fuel Engine That Can Use Both H+ and Na+ for Flagellar Protein Export.

    Science.gov (United States)

    Minamino, Tohru; Morimoto, Yusuke V; Hara, Noritaka; Aldridge, Phillip D; Namba, Keiichi

    2016-03-01

    The bacterial flagellar type III export apparatus utilizes ATP and proton motive force (PMF) to transport flagellar proteins to the distal end of the growing flagellar structure for self-assembly. The transmembrane export gate complex is a H+-protein antiporter, of which activity is greatly augmented by an associated cytoplasmic ATPase complex. Here, we report that the export gate complex can use sodium motive force (SMF) in addition to PMF across the cytoplasmic membrane to drive protein export. Protein export was considerably reduced in the absence of the ATPase complex and a pH gradient across the membrane, but Na+ increased it dramatically. Phenamil, a blocker of Na+ translocation, inhibited protein export. Overexpression of FlhA increased the intracellular Na+ concentration in the presence of 100 mM NaCl but not in its absence, suggesting that FlhA acts as a Na+ channel. In wild-type cells, however, neither Na+ nor phenamil affected protein export, indicating that the Na+ channel activity of FlhA is suppressed by the ATPase complex. We propose that the export gate by itself is a dual fuel engine that uses both PMF and SMF for protein export and that the ATPase complex switches this dual fuel engine into a PMF-driven export machinery to become much more robust against environmental changes in external pH and Na+ concentration.

  4. The Bacterial Flagellar Type III Export Gate Complex Is a Dual Fuel Engine That Can Use Both H+ and Na+ for Flagellar Protein Export.

    Directory of Open Access Journals (Sweden)

    Tohru Minamino

    2016-03-01

    Full Text Available The bacterial flagellar type III export apparatus utilizes ATP and proton motive force (PMF to transport flagellar proteins to the distal end of the growing flagellar structure for self-assembly. The transmembrane export gate complex is a H+-protein antiporter, of which activity is greatly augmented by an associated cytoplasmic ATPase complex. Here, we report that the export gate complex can use sodium motive force (SMF in addition to PMF across the cytoplasmic membrane to drive protein export. Protein export was considerably reduced in the absence of the ATPase complex and a pH gradient across the membrane, but Na+ increased it dramatically. Phenamil, a blocker of Na+ translocation, inhibited protein export. Overexpression of FlhA increased the intracellular Na+ concentration in the presence of 100 mM NaCl but not in its absence, suggesting that FlhA acts as a Na+ channel. In wild-type cells, however, neither Na+ nor phenamil affected protein export, indicating that the Na+ channel activity of FlhA is suppressed by the ATPase complex. We propose that the export gate by itself is a dual fuel engine that uses both PMF and SMF for protein export and that the ATPase complex switches this dual fuel engine into a PMF-driven export machinery to become much more robust against environmental changes in external pH and Na+ concentration.

  5. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2015.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  6. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2016.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  7. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2014.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  8. Charge recombination kinetics and protein dynamics in wild type and carotenoid-less bacterial reaction centers: studies in trehalose glasses.

    Science.gov (United States)

    Francia, Francesco; Malferrari, Marco; Sacquin-Mora, Sophie; Venturoli, Giovanni

    2009-07-30

    The coupling between electron transfer and protein dynamics has been investigated in reaction centers (RCs) from the wild type (wt) and the carotenoid-less strain R26 of the photosynthetic bacterium Rhodobacter sphaeroides. Recombination kinetics between the primary photoreduced quinone acceptor (QA-) and photoxidized donor (P+) have been analyzed at room temperature in RCs incorporated into glassy trehalose matrices of different water/sugar ratios. As previously found in R26 RCs, also in the wt RC, upon matrix dehydration, P+QA- recombination accelerates and becomes broadly distributed, reflecting the inhibition of protein relaxation from the dark-adapted to the light-adapted conformation and the hindrance of interconversion between conformational substates. While in wet trehalose matrices (down to approximately one water per trehalose molecule) P+QA- recombination kinetics are essentially coincident in wt and R26 RCs, more extensive dehydration leads to two-times faster and more distributed kinetics in the carotenoid-containing RC, indicating a stronger inhibition of the internal protein dynamics in the wt RC. Coarse-grained Brownian dynamics simulations performed on the two RC structures reveal a markedly larger flexibility of the R26 RC, showing that a rigid core of residues, close to the quinone acceptors, is specifically softened in the absence of the carotenoid. These experimental and computational results concur to indicate that removal of the carotenoid molecule has long-range effects on protein dynamics and that the structural/dynamical coupling between the protein and the glassy matrix depends strongly upon the local mechanical properties of the protein interior. The data also suggest that the conformational change stabilizing P+QA- is localized around the QA binding pocket.

  9. Evaluation of bacterial leakage of four root- end filling materials: Gray Pro Root MTA, White Pro Root MTA, Root MTA and Portland Cement (type I

    Directory of Open Access Journals (Sweden)

    Zarabian M.

    2005-07-01

    Full Text Available Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro Root MTA in in-vitro and in-vivo studies has been proven. On the other hand, based on some studies, Root MTA (Iranian Pro Root MTA and Portland cement are similar to Pro Root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time of four root- end filling materials. Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro Root MTA, white Pro Root MTA, Root MTA (Iranian Pro Root MTA, Portland Cement (type I and positive and negative control groups. Root canals were instrumented using the step- back technique. Root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556. Culture media were observed every 24h for colour change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance. Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro Root MTA, White Pro Root MTA. Root MTA and Portland Cement (type I had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time of the four tested root- end filling materials (P=0.9958. Conclusion: Based on the results of this study, there were no significant differences in leakage among the four

  10. Genes encoding putative effector proteins of the type III secretion system of Salmonella pathogenicity island 2 are required for bacterial virulence and proliferation in macrophages.

    Science.gov (United States)

    Hensel, M; Shea, J E; Waterman, S R; Mundy, R; Nikolaus, T; Banks, G; Vazquez-Torres, A; Gleeson, C; Fang, F C; Holden, D W

    1998-10-01

    The type III secretion system of Salmonella pathogenicity island 2 (SPI-2) is required for systemic infection of this pathogen in mice. Cloning and sequencing of a central region of SPI-2 revealed the presence of genes encoding putative chaperones and effector proteins of the secretion system. The predicted products of the sseB, sseC and sseD genes display weak but significant similarity to amino acid sequences of EspA, EspD and EspB, which are secreted by the type III secretion system encoded by the locus of enterocyte effacement of enteropathogenic Escherichia coli. The transcriptional activity of an sseA::luc fusion gene was shown to be dependent on ssrA, which is required for the expression of genes encoding components of the secretion system apparatus. Strains carrying nonpolar mutations in sseA, sseB or sseC were severely attenuated in virulence, strains carrying mutations in sseF or sseG were weakly attenuated, and a strain with a mutation in sseE had no detectable virulence defect. These phenotypes were reflected in the ability of mutant strains to grow within a variety of macrophage cell types: strains carrying mutations in sseA, sseB or sseC failed to accumulate, whereas the growth rates of strains carrying mutations in sseE, sseF or sseG were only modestly reduced. These data suggest that, in vivo, one of the functions of the SPI-2 secretion system is to enable intracellular bacterial proliferation.

  11. Spider. IV. Optical and Near-infrared Color Gradients in Early-type Galaxies: New Insight into Correlations with Galaxy Properties

    Science.gov (United States)

    La Barbera, F.; De Carvalho, R. R.; De La Rosa, I. G.; Gal, R. R.; Swindle, R.; Lopes, P. A. A.

    2010-11-01

    We present an analysis of stellar population gradients in 4546 early-type galaxies (ETGs) with photometry in grizYHJK along with optical spectroscopy. ETGs were selected as bulge-dominated systems, displaying passive spectra within the SDSS fibers. A new approach is described which utilizes color information to constrain age and metallicity gradients. Defining an effective color gradient, ∇sstarf, which incorporates all of the available color indices, we investigate how ∇sstarf varies with galaxy mass proxies, i.e., velocity dispersion, stellar (M sstarf) and dynamical (M dyn) masses, as well as age, metallicity, and [α/Fe]. ETGs with M dyn larger than 8.5 × 1010 M sun have increasing age gradients and decreasing metallicity gradients with respect to mass, metallicity, and enhancement. We find that velocity dispersion and [α/Fe] are the main drivers of these correlations. ETGs with 2.5 × 1010 M sun population parameters, and these correlations are independent of each other. In both mass regimes, the striking anti-correlation between color gradient and α-enhancement is significant at ~5σ and results from the fact that metallicity gradient decreases with [α/Fe]. This anti-correlation may reflect the fact that star formation and metallicity enrichment are regulated by the interplay between the energy input from supernovae, and the temperature and pressure of the hot X-ray gas in ETGs. For all mass ranges, positive age gradients are associated with old galaxies (>5-7 Gyr). For galaxies younger than ~5 Gyr, mostly at low mass, the age gradient tends to be anti-correlated with the Age parameter, with more positive gradients at younger ages.

  12. A low-luminosity type-1 QSO sample . IV. Molecular gas contents and conditions of star formation in three nearby Seyfert galaxies

    Science.gov (United States)

    Moser, Lydia; Krips, Melanie; Busch, Gerold; Scharwächter, Julia; König, Sabine; Eckart, Andreas; Smajić, Semir; García-Marin, Macarena; Valencia-S., Mónica; Fischer, Sebastian; Dierkes, Jens

    2016-03-01

    We present a pilot study of ~3'' resolution observations of low CO transitions with the Submillimeter Array in three nearby Seyfert galaxies, which are part of the low-luminosity quasi-stellar object (LLQSOs) sample consisting of 99 nearby (z = 0.06) type-1 active galactic nuclei (AGN) taken from the Hamburg/ESO quasi-stellar object (QSO) survey. Two sources were observed in 12CO(2-1) and 13CO(2-1) and the third in 12CO(3-2) and HCO+(4-3). None of the sources is detected in continuum emission. More than 80% of the 12CO detected molecular gas is concentrated within a diameter (FWHM) 1.5 × 109M⊙ and for the dust masses of Mdust> 1.6 × 106M⊙. The R21 = 12CO/13CO(2-1) line luminosity ratios show Galactic values of R21 ~ 5-7 in the outskirts and R21 ≳ 20 in the central region, similar to starbursts and (ultra)luminous infrared galaxies ((U)LIRGs; i.e. LIRGs and ULIRGs), implying higher temperatures and stronger turbulence. All three sources show indications of 12CO(2-1)/12CO(1-0) ratios of ~0.5, suggesting a cold or diffuse gas phase. Strikingly, the 12CO(3-2)/(1-0) ratio of ~1 also indicates a higher excited phase. Since these galaxies have high infrared luminosities of LIR ≥ 1011L⊙ and seem to contain a circumnuclear starburst with minimum surface densities of gas and star formation rate (SFR) around Σmol = 50-550 M⊙pc-2 and ΣSFR = 1.1-3.1 M⊙ kpc-2 yr-1, we conclude that the interstellar medium in the centers of these LIRG Seyferts is strongly affected by violent star formation and better described by the ULIRG mass conversion factor.

  13. Collagen IV in normal skin and in pathological processes

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu-Velez

    2012-01-01

    Full Text Available Context: Type IV collagen is a type of collagen found primarily in the skin within the basement membrane zone. The type IV collagen C4 domain at the C-terminus is not removed in post-translational processing, and the fibers are thus link head-to-head, rather than in a parallel fashion. Also, type IV collagen lacks a glycine in every third amino-acid residue necessary for the tight collagen helix. Thus, the overall collagen-IV conformation is structurally more pliable and kinked, relative to other collagen subtypes. These structural features allow collagen IV to form sheets, which is the primary structural form found in the cutaneous basal lamina. There are six human genes associated with collagen IV, specifically COL4A1, COL4A2, COL4A3, COL4A4, COL4A5 and COL4A6. The aim of this review is to highlight the significance of this protein in normal skin, and in selected diseases. Results: The alpha 3 protein constituent of type IV collagen is thought to be the antigen implicated in Goodpasture′s syndrome, wherein the immune system attacks the basement membranes of the renal glomeruli and pulmonary alveoli. In addition, mutations to the genes coding for type IV collagen lead to the Alport syndrome. Furthermore, autoantibodies directed against denatured human type IV collagen have been described in rheumatoid arthritis, scleroderma, and SLE. Structural studies of collagen IV have been utilized to differentiate between subepidermal blistering diseases, including bullous pemphigoid, acquired epidermolysis bullosa, anti-epiligrin cicatricial pemphigoid, and bullous lupus erythematosus. Collagen IV is also of importance in wound healing and in embryogenesis. Conclusions: Pathological studies have demonstrated that minor structural differences in collagen IV can lead to distinct, clinically different diseases.

  14. Peptides Derived from Type IV Collagen, CXC Chemokines, and Thrombospondin-1 Domain-Containing Proteins Inhibit Neovascularization and Suppress Tumor Growth in MDA-MB-231 Breast Cancer Xenografts

    Directory of Open Access Journals (Sweden)

    Jacob E. Koskimaki

    2009-12-01

    Full Text Available Angiogenesis or neovascularization, the process of new blood vessel formation from preexisting microvasculature, involves interactions among several cell types including parenchymal, endothelial cells, and immune cells. The formation of new vessels is tightly regulated by a balance between endogenous proangiogenic and antiangiogenic factors to maintain homeostasis in tissue; tumor progression and metastasis in breast cancer have been shown to be angiogenesis-dependent. We previously introduced a systematic methodology to identify putative endogenous antiangiogenic peptides and validated these predictions in vitro in human umbilical vein endothelial cell proliferation and migration assays. These peptides are derived from several protein families including type IV collagen, CXC chemokines, and thrombospondin-1 domain-containing proteins. On the basis of the results from the in vitro screening, we have evaluated the ability of one peptide selected from each family named pentastatin-1, chemokinostatin-1, and properdistatin, respectively, to suppress angiogenesis in an MDA-MB-231 human breast cancer orthotopic xenograft model in severe combined immunodeficient mice. Peptides were administered intraperitoneally once per day. We have demonstrated significant suppression of tumor growth in vivo and subsequent reductions in microvascular density, indicating the potential of these peptides as therapeutic agents for breast cancer.

  15. Responding to the challenge of untreatable gonorrhea: ETX0914, a first-in-class agent with a distinct mechanism-of-action against bacterial Type II topoisomerases.

    Science.gov (United States)

    Basarab, Gregory S; Kern, Gunther H; McNulty, John; Mueller, John P; Lawrence, Kenneth; Vishwanathan, Karthick; Alm, Richard A; Barvian, Kevin; Doig, Peter; Galullo, Vincent; Gardner, Humphrey; Gowravaram, Madhusudhan; Huband, Michael; Kimzey, Amy; Morningstar, Marshall; Kutschke, Amy; Lahiri, Sushmita D; Perros, Manos; Singh, Renu; Schuck, Virna J A; Tommasi, Ruben; Walkup, Grant; Newman, Joseph V

    2015-01-01

    With the diminishing effectiveness of current antibacterial therapies, it is critically important to discover agents that operate by a mechanism that circumvents existing resistance. ETX0914, the first of a new class of antibacterial agent targeted for the treatment of gonorrhea, operates by a novel mode-of-inhibition against bacterial type II topoisomerases. Incorporating an oxazolidinone on the scaffold mitigated toxicological issues often seen with topoisomerase inhibitors. Organisms resistant to other topoisomerase inhibitors were not cross-resistant with ETX0914 nor were spontaneous resistant mutants to ETX0914 cross-resistant with other topoisomerase inhibitor classes, including the widely used fluoroquinolone class. Preclinical evaluation of ETX0914 pharmacokinetics and pharmacodynamics showed distribution into vascular tissues and efficacy in a murine Staphylococcus aureus infection model that served as a surrogate for predicting efficacious exposures for the treatment of Neisseria gonorrhoeae infections. A wide safety margin to the efficacious exposure in toxicological evaluations supported progression to Phase 1. Dosing ETX0914 in human volunteers showed sufficient exposure and minimal adverse effects to expect a highly efficacious anti-gonorrhea therapy. PMID:26168713

  16. Bacterial Type I Glutamine Synthetase of the Rifamycin SV Producing Actinomycete, Amycolatopsis mediterranei U32, is the Only Enzyme Responsible for Glutamine Synthesis under Physiological Conditions

    Institute of Scientific and Technical Information of China (English)

    Wen-Tao PENG; Jin WANG; Ting WU; Jian-Qiang HUANG; Jui-Shen CHIAO; Guo-Ping ZHAO

    2006-01-01

    The structural gene for glutamine synthetase, glnA, from Amycolatopsis mediterranei U32 was cloned via screening a genomic library using the analog gene from Streptomyces coelicolor. The clone was functionally verified by complementing for glutamine requirement of an Escherichia coli glnA null mutant under the control of a lac promoter. Sequence analysis showed an open reading frame encoding a protein of466 amino acid residues. The deduced amino acid sequence bears significant homologies to other bacterial type I glutamine synthetases, specifically, 71% and 72% identical to the enzymes of S. coelicolor and Mycobacterium tuberculosis, respectively. Disruption of this glnA gene in A. mediterranei U32 led to glutamine auxotrophy with no detectable glutamine synthetase activity in vivo. In contrast, the cloned glnA+ gene can complement for both phenotypes in trans. It thus suggested that in A. mediterranei U32, the glnA gene encoding glutamine synthetase is uniquely responsible for in vivo glutamine synthesis under our laboratory defined physiological conditions.

  17. IV access in dental practice.

    LENUS (Irish Health Repository)

    Fitzpatrick, J J

    2009-04-01

    Intravenous (IV) access is a valuable skill for dental practitioners in emergency situations and in IV sedation. However, many people feel some apprehension about performing this procedure. This article explains the basic principles behind IV access, and the relevant anatomy and physiology, as well as giving a step-by-step guide to placing an IV cannula.

  18. Bacterial- and plant-type phosphoenolpyruvate carboxylase isozymes from developing castor oil seeds interact in vivo and associate with the surface of mitochondria.

    Science.gov (United States)

    Park, Joonho; Khuu, Nicholas; Howard, Alexander S M; Mullen, Robert T; Plaxton, William C

    2012-07-01

    Phosphoenolpyruvate carboxylase (PEPC) from developing castor oil seeds (COS) exists as two distinct oligomeric isoforms. The typical class-1 PEPC homotetramer consists of 107-kDa plant-type PEPC (PTPC) subunits, whereas the allosterically desensitized 910-kDa class-2 PEPC hetero-octamer arises from the association of class-1 PEPC with 118-kDa bacterial-type PEPC (BTPC) subunits. The in vivo interaction and subcellular location of COS BTPC and PTPC were assessed by imaging fluorescent protein (FP)-tagged PEPCs in tobacco suspension-cultured cells. The BTPC-FP mainly localized to cytoplasmic punctate/globular structures, identified as mitochondria by co-immunostaining of endogenous cytochrome oxidase. Inhibition of respiration with KCN resulted in proportional decreases and increases in mitochondrial versus cytosolic BTPC-FP, respectively. The FP-PTPC and NLS-FP-PTPC (containing an appended nuclear localization signal, NLS) localized to the cytosol and nucleus, respectively, but both co-localized with mitochondrial-associated BTPC when co-expressed with BTPC-FP. Transmission electron microscopy of immunogold-labeled developing COS revealed that BTPC and PTPC are localized at the mitochondrial (outer) envelope, as well as the cytosol. Moreover, thermolysin-sensitive BTPC and PTPC polypeptides were detected on immunoblots of purified COS mitochondria. Overall, our results demonstrate that: (i) COS BTPC and PTPC interact in vivo as a class-2 PEPC complex that associates with the surface of mitochondria, (ii) BTPC's unique and divergent intrinsically disordered region mediates its interaction with PTPC, whereas (iii) the PTPC-containing class-1 PEPC is entirely cytosolic. We hypothesize that mitochondrial-associated class-2 PEPC facilitates rapid refixation of respiratory CO(2) while sustaining a large anaplerotic flux to replenish tricarboxylic acid cycle C-skeletons withdrawn for biosynthesis.

  19. Fratura extra-articular da extremidade medial da clavícula associada à luxação acromioclavicular tipo IV: relato de caso Extra-articular fracture of the medial end of the clavicle associated with type IV acromioclavicular dislocation: case report

    Directory of Open Access Journals (Sweden)

    Mário Chaves Correa

    2011-10-01

    Full Text Available Ocorrendo isoladamente, as fraturas da clavícula e as luxações acromioclaviculares são lesões muito comuns. A combinação de uma luxação acromioclavicular e de uma fratura do terço lateral da clavícula não é rara. Entretanto, existem muito poucos casos descritos de luxações acromioclaviculares associadas a fraturas do terço médio da clavícula; aquelas associadas a fraturas do terço medial são ainda mais raras. Nós reportamos o caso de um indivíduo adulto do sexo masculino que sofreu uma luxação acromioclavicular (tipo IV associada a uma fratura extra-articular desviada da extremidade medial da clavícula (grupo 3 de Almann em um acidente ciclístico. O paciente foi tratado na fase aguda com redução aberta e fixação interna das duas lesões. Na avaliação clínica, 12 meses após a cirurgia, o paciente apresentava-se assintomático, com mobilidade ativa e passiva completa, força e resistência normais e simetria das cinturas escapulares. As radiografias e a tomografia computadorizada tridimensional mostravam subluxação posterossuperior persistente da articulação acromioclavicular e consolidação anatômica da fratura clavicular.Fractures of the clavicle and acromioclavicular dislocations are very common injuries when they occur separately. The combination of an acromioclavicular dislocation and a fracture of the lateral third of the clavicle is not rare. However, there are very few reported cases of acromioclavicular dislocations associated with fractures of the middle third of the clavicle; those associated with fractures of the medial third are even rarer. We report the case of an adult male who suffered an acromioclavicular dislocation (type IV associated with a displaced extra-articular fracture of the medial end of the clavicle (Almann group 3 in a cycling accident. The patient was treated during the acute phase with open reduction and internal fixation of the two lesions. At the clinical evaluation 12

  20. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  1. Comparison of bacterial biomass and PRP production between different isolation of Haemophilus influenza type-b (Hib under different culture conditions

    Directory of Open Access Journals (Sweden)

    Hadi, A.

    2011-06-01

    Full Text Available Heamophilus influenzae type-b (Hib is a gram - negative pleomorphic bacterium that causes meningitis infections in children with the age of less than 5 years particularly in two years old infants. In the present study various isolates of Heamophilus influenzae from infants suspected to meningitis were collected, identified, characterized and were used throughout our experiments. Different culture media namely Brain Heart Infusion Broth (BHIB, Tryptic Soy Broth (TSB and GC medium Base (GCB which this medium was modified and prepared in our own laboratory, were compared to determine the highest bacterial yield. All media were added supplements 10mg/ml hemin & 0.01/ml IsovitaleX containing V factor. The bacterial yield for all Hib strains present in our laboratory were measured with an initial inoculums of 104 cfu per ml. The result showed very closed amount of biomass for all isolates however, GCB had slightly higher yield and ultimately we chose this medium for cultivation and extraction of capsular polysaccharide (CPS-b. In our laboratory we have adapted the PRP production according to our technical and instrumental availabilities which exists in our laboratories replacing ultra centrifugation to phenol chloroform to remove contaminants like endotoxin and proteins to the minimum level and also decreased the number of some chemical treatments while some steps were added in purification process. Our study showed although there were not significant differences between the PRP extract of the three isolates with average amount of 108 mg/lit, however, isolate ATCC10210 (ATF2 showed the highest amount with 192mg/lit and the least PRP was produced by isolate H.inf.1, with 16 mg/lit. It seems that the data can be categorized to a normal distribution with the mean of 106.4 and standard deviation of 6.25. This result was confirmed by one sample kolmogorov-Smirnov test, hence the PRP ≥192 mg/lit is statistically significant at a significant level of α =0

  2. Targeting bacterial secretion systems: benefits of disarmament in the microcosm.

    Science.gov (United States)

    Baron, Christian; Coombes, Brian

    2007-03-01

    Secretion systems are used by many bacterial pathogens for the delivery of virulence factors to the extracellular space or directly into host cells. They are attractive targets for the development of novel anti-virulence drugs as their inactivation would lead to pathogen attenuation or avirulence, followed by clearance of the bacteria by the immune system. This review will present the state of knowledge on the assembly and function of type II, type III and type IV secretion systems in Gram-negative bacteria focusing on insights provided by structural analyses of several key components. The suitability of transcription factors regulating the expression of secretion system components and of ATPases, lytic transglycosylases and protein assembly factors as drug targets will be discussed. Recent progress using innovative in vivo as well as in vitro screening strategies led to a first set of secretion system inhibitors with potential for further development as anti-infectives. The discovery of such inhibitors offers exciting and innovative opportunities to further develop these anti-virulence drugs into monotherapy or in combination with classical antibiotics. Bacterial growth per se would not be inhibited by such drugs so that the selection for mutations causing resistance could be reduced. Secretion system inhibitors may therefore avoid many of the problems associated with classical antibiotics and may constitute a valuable addition to our arsenal for the treatment of bacterial infections. PMID:17346208

  3. (2R)-4-Oxo-4[3-(Trifluoromethyl)-5,6-diihydro:1,2,4}triazolo[4,3-a}pyrazin-7(8H)-y1]-1-(2,4,5-trifluorophenyl)butan-2-amine: A Potent, Orally Active Dipeptidyl Peptidase IV Inhibitor for the Treatment of Type 2 Diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.; Wang, L.; Beconi, M.; Eiermann, G.; Fisher, M.; He, H.; Hickey, G.; Kowalchick, Jennifer; Leiting, Barbara; Lyons, K.; Marsilio, F.; McCann, F.; Patel, R.; Petrov, A.; Scapin, G.; Patel, S.; Roy, R.; Wu, J.; Wyvratt, M.; Zhang, B.; Zhu, L.; Thornberry, N.; Weber, A. (Merck)

    2010-11-10

    A novel series of {beta}-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC{sub 50} = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes.

  4. 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 ...

  5. 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, ...

  6. Dipeptidyl peptidase-IV (DPP-IV inhibitory activity of parotid exudate of Bufo melanostictus

    Directory of Open Access Journals (Sweden)

    Allenki Venkatesham

    2009-01-01

    Full Text Available Type 2 diabetes arises as a result of β-cell failure combined with concomitant insulin resistance. Glucagon-like peptide-1 is a gastrointestinal hormone that is released postprandially from the L cells of the gut and exerts a glucose- dependent and direct insulinotropic effect on the pancreatic β cell. Which activate adenylate cyclase and enhances insulin secretion. GLP-1 is rapidly degraded by DPP-IV to GLP-1(9-37 amide following release from gut L cells. GLP-1 directly enhances glucose-dependent insulin secretion via an increase in β-cell cAMP. Dipeptidyl peptidase IV (DPP-IV is a plasma membrane glycoprotein ectopeptidase. In mammals, DPP-IV was widely expressed on the surface of endothelial and epithelial cells and highest levels in humans have been reported to occur in the intestine, bone marrow and kidney. Inhibiting DPP-IV reduces its rapid degradation of GLP-1, increasing circulating levels of the active hormone in vivo and prolonging its beneficial effects. The IC 50 value of parotid exudate was found to be 9.4 μg/ml. The maximum % inhibition (61.8 was showed at a concentration of 12μg/ml. Parotid exudate through inhibition of DPP-IV, improves glucose tolerance and enhances insulin secretion. DPP-IV inhibitors are a novel class of oral hypoglycemic agents with a potential to improve pancreatic beta cell function and the clinical course of type 2 diabetes.

  7. Dibromidodimethyldipyridineplatinum(IV

    Directory of Open Access Journals (Sweden)

    Mairéad E. Kelly

    2008-11-01

    Full Text Available In the title complex, [PtBr2(CH32(C5H5N2], the PtIV metal centre lies on a twofold rotation axis and adopts a slightly distorted octahedral coordination geometry. The structure displays weak intramolecular C—H...Br hydrogen-bonding interactions.

  8. The PLATO IV Architecture.

    Science.gov (United States)

    Stifle, Jack

    The PLATO IV computer-based instructional system consists of a large scale centrally located CDC 6400 computer and a large number of remote student terminals. This is a brief and general description of the proposed input/output hardware necessary to interface the student terminals with the computer's central processing unit (CPU) using available…

  9. PLATO IV Accountancy Index.

    Science.gov (United States)

    Pondy, Dorothy, Comp.

    The catalog was compiled to assist instructors in planning community college and university curricula using the 48 computer-assisted accountancy lessons available on PLATO IV (Programmed Logic for Automatic Teaching Operation) for first semester accounting courses. It contains information on lesson access, lists of acceptable abbreviations for…

  10. Marketing produktu Karel IV.

    OpenAIRE

    Mikšů, Šárka

    2009-01-01

    Goal of the thesis Marketing of the product Karel IV. is to propose chanels of marketing communication and indicate possibilities of next product's development. Theoretical part is based on marketing plan and it's partition. In the practical part you can find market analysis and competing products analysis, product's evolution description and marketing research.

  11. Optimal and safe treatment of spider leg veins measuring less than 1.5 mm on skin type IV patients, using repeated low-fluence Nd:YAG laser pulses after polidocanol injection.

    Science.gov (United States)

    Moreno-Moraga, Javier; Hernández, Esteban; Royo, Josefina; Alcolea, Justo; Isarría, M Jose; Pascu, Mihail Lucian; Smarandache, Adriana; Trelles, Mario

    2013-05-01

    Treatment of micro-veins of less than 1.5 mm with laser and with chemical sclerosis is technically challenging because of their difficulty to remedy. Laser treatment is even more difficult when dark phototypes are involved.Three groups of 30 patients each, skin type IV, and vessels measuring less than 1.5 mm in diameter, were enrolled for two treatment sessions 8 weeks apart: group A, polidocanol (POL) micro-foam injection; group B, Nd:YAG laser alone; and group C, laser after POL injection. Repeated 8-Hz low-fluence pulses, moving the hand piece over a 3-cm vein segment with an average of five laser passes maximum and with a total time irradiation of 1 s were used. Sixteen weeks after the second treatment, statistically, degree of clearance after examining photographs and patients satisfaction index, plotted on a visual analogue scale and comparing results of all three groups, results were significantly better for group C (p<0.0001). No significant differences in complications were noticed between the three groups. Efficacy of combining POL and laser proved safe and satisfactory in 96 % of patients using low-fluence laser pulses with a total cumulative energy in the 3 cm venous segment, lower than that of conventional treatment. Very few and transient complications were observed. POL foam injection followed by laser pulses is safe and efficient for vein treatment in dark-skinned patients.

  12. The effect of pure water and tap-water on the expansion of type IV gesso after curing%3种水质对Ⅳ型石膏固化后膨胀的影响

    Institute of Scientific and Technical Information of China (English)

    杨磊; 张力; 张勇; 杜艳峰

    2014-01-01

    Type IV gesso was cured by laboratory distilled water,tap water and commercially obtained pure water respectively.2 h,12 h and 24 h after curing,linear expansion of the gesso samples was measured and compared.Tap-water curing produced the greatest linear ex-pansion,followed by laboratory distilled water and then pure water(P<0.05).The mineral components in the common tap-water may con-tribute to the larger expansion.%用实验室净水机制备蒸馏水、自来水和市售瓶装纯净水分别调拌的IV型石膏,固化2、12、24 h后测试线性膨胀率,2组纯净水调拌的Ⅳ型石膏比自来水调拌的Ⅳ型石膏线固化膨胀率小(P<0.05)。自来水中的矿物质成分含量远超过2种纯净水,调拌的Ⅳ型石膏产生了更多的非结晶水,导致较高的线固化膨胀率。

  13. 全髋关节置换治疗CroweⅣ型成人髋关节发育性不良%Total hip arthroplasty for Crowe type IV developmental dysplasia of hip in adults

    Institute of Scientific and Technical Information of China (English)

    齐小鹏; 张元凯; 李德强; 李明

    2014-01-01

    BACKGROUND:Total hip arthroplasty is an optimal choice for patients with late hip dysplasia. Crowe type IV developmental dysplasia of the hip increases the difficulty of the operation, and the surgery is controversial. OBJECTIVE:To evaluate the clinical effects of total hip arthroplasty on Crowe type IV developmental dysplasia of the hip and the method of reconstruction of acetabulum and the treatment of proximal femur. METHODS:A total of 12 patients (14 hips) with Crowe type IV developmental dysplasia of the hip underwent total hip arthroplasty. Preoperative Harris hip score was averagely (35.0±6.8) points. Al hips were treated with smal acetabular components combined with medial protrusion technique in acetabular reconstruction, as wel as subtrochanteric shortening osteotomy in femur. Joint function of hips was evaluated according to the Harris hip score. RESULTS AND CONCLUSION:Al patients were fol owed up with an average of 4.6 years (ranged 1 to 7 years). Two cases (two hips) suffered from infraction of greater trochanter of femur during replacement, and it was fixed with wire. There was complete sciatic nerve injury in one case, which partial y restored after conservative treatment for 1 month. No infection, prosthesis loosening, or deep venous thrombosis with obvious clinical manifestations was visible. Bone union was observed at the site undergoing osteotomy at the side of femur. After replacement, final fol ow-up showed that Harris hip score was averagely (84.0±7.0) points. The mean amount of postoperative leg lengthening was 5 cm (range 4-6 cm). Shortened limbs were corrected satisfactorily. These results suggested that total hip arthroplasty using smal acetabular component, medial protrusion, and femoral subtrochanteric shortening osteotomy technique for the Crowe type IV developmental dysplasia of the hip can effectively restore hip function and leg length. The long-term curative effects require further investigations.%背景:人工全髋关节置

  14. Respiratory Viruses Augment the Adhesion of Bacterial Pathogens to Respiratory Epithelium in a Viral Species- and Cell Type-Dependent Manner

    OpenAIRE

    Avadhanula, Vasanthi; Rodriguez, Carina A.; DeVincenzo, John P.; Wang, Yan; Webby, Richard J; Ulett, Glen C.; Adderson, Elisabeth E.

    2006-01-01

    Secondary bacterial infections often complicate respiratory viral infections, but the mechanisms whereby viruses predispose to bacterial disease are not completely understood. We determined the effects of infection with respiratory syncytial virus (RSV), human parainfluenza virus 3 (HPIV-3), and influenza virus on the abilities of nontypeable Haemophilus influenzae and Streptococcus pneumoniae to adhere to respiratory epithelial cells and how these viruses alter the expression of known recept...

  15. The non-flagellar type III secretion system evolved from the bacterial flagellum and diversified into host-cell adapted systems.

    Directory of Open Access Journals (Sweden)

    Sophie S Abby

    2012-09-01

    Full Text Available Type 3 secretion systems (T3SSs are essential components of two complex bacterial machineries: the flagellum, which drives cell motility, and the non-flagellar T3SS (NF-T3SS, which delivers effectors into eukaryotic cells. Yet the origin, specialization, and diversification of these machineries remained unclear. We developed computational tools to identify homologous components of the two systems and to discriminate between them. Our analysis of >1,000 genomes identified 921 T3SSs, including 222 NF-T3SSs. Phylogenomic and comparative analyses of these systems argue that the NF-T3SS arose from an exaptation of the flagellum, i.e. the recruitment of part of the flagellum structure for the evolution of the new protein delivery function. This reconstructed chronology of the exaptation process proceeded in at least two steps. An intermediate ancestral form of NF-T3SS, whose descendants still exist in Myxococcales, lacked elements that are essential for motility and included a subset of NF-T3SS features. We argue that this ancestral version was involved in protein translocation. A second major step in the evolution of NF-T3SSs occurred via recruitment of secretins to the NF-T3SS, an event that occurred at least three times from different systems. In rhizobiales, a partial homologous gene replacement of the secretin resulted in two genes of complementary function. Acquisition of a secretin was followed by the rapid adaptation of the resulting NF-T3SSs to multiple, distinct eukaryotic cell envelopes where they became key in parasitic and mutualistic associations between prokaryotes and eukaryotes. Our work elucidates major steps of the evolutionary scenario leading to extant NF-T3SSs. It demonstrates how molecular evolution can convert one complex molecular machine into a second, equally complex machine by successive deletions, innovations, and recruitment from other molecular systems.

  16. Tissue-specific expression and post-translational modifications of plant- and bacterial-type phosphoenolpyruvate carboxylase isozymes of the castor oil plant, Ricinus communis L.

    Science.gov (United States)

    O'Leary, Brendan; Fedosejevs, Eric T; Hill, Allyson T; Bettridge, James; Park, Joonho; Rao, Srinath K; Leach, Craig A; Plaxton, William C

    2011-11-01

    This study employs transcript profiling together with immunoblotting and co-immunopurification to assess the tissue-specific expression, protein:protein interactions, and post-translational modifications (PTMs) of plant- and bacterial-type phosphoenolpyruvate carboxylase (PEPC) isozymes (PTPC and BTPC, respectively) in the castor plant, Ricinus communis. Previous studies established that the Class-1 PEPC (PTPC homotetramer) of castor oil seeds (COS) is activated by phosphorylation at Ser-11 and inhibited by monoubiquitination at Lys-628 during endosperm development and germination, respectively. Elimination of photosynthate supply to developing COS by depodding caused the PTPC of the endosperm and cotyledon to be dephosphorylated, and then subsequently monoubiquitinated in vivo. PTPC monoubiquitination rather than phosphorylation is widespread throughout the castor plant and appears to be the predominant PTM of Class-1 PEPC that occurs in planta. The distinctive developmental patterns of PTPC phosphorylation versus monoubiquitination indicates that these two PTMs are mutually exclusive. By contrast, the BTPC: (i) is abundant in the inner integument, cotyledon, and endosperm of developing COS, but occurs at low levels in roots and cotyledons of germinated COS, (ii) shows a unique developmental pattern in leaves such that it is present in leaf buds and young expanding leaves, but undetectable in fully expanded leaves, and (iii) tightly interacts with co-expressed PTPC to form the novel and allosterically-desensitized Class-2 PEPC heteromeric complex. BTPC and thus Class-2 PEPC up-regulation appears to be a distinctive feature of rapidly growing and/or biosynthetically active tissues that require a large anaplerotic flux from phosphoenolpyruvate to replenish tricarboxylic acid cycle C-skeletons being withdrawn for anabolism.

  17. Comparison and Interpretation of Taxonomical Structure of Bacterial Communities in Two Types of Lakes on Yun-Gui plateau of China.

    Science.gov (United States)

    Han, Maozhen; Gong, Yanhai; Zhou, Chunyu; Zhang, Junqian; Wang, Zhi; Ning, Kang

    2016-01-01

    Bacterial communities from freshwater lakes are shaped by various factors such as nutrients, pH value, temperature, etc. Their compositions and relative abundances would undergo changes to adapt the changing environments, and in turn could affect the environments of freshwater lakes. Analyses of the freshwater lake's bacterial communities under different environments would be of pivotal importance to monitor the condition of waterbody. In this study, we have collected freshwater samples from two lakes on Yun-Gui plateau of China, Lake Dianchi and Lake Haixihai, and analyzed the bacterial community structures from these samples based on 16S rRNA sequencing. Results have shown that: Firstly, the bacterial community of these samples have very different taxonomical structures, not only between two lakes but also among the intra-groups for samples collected from Dianchi. Secondly, the differences between samples from two lakes are highly associated with the chemical-geographical properties of the two lakes. Thirdly, for samples of Dianchi and Haixihai, analytical results of physicochemical, taxonomical structure and relative abundance of community revealed that extreme physicochemical factors caused by human activities have strongly affected the bacterial ecosystem in Dianchi. These results have clearly indicated the importance of combining biological profiling and chemical-geographical properties for monitoring Chinese plateau freshwater bacterial ecosystem, which could provide clues for Chinese freshwater ecosystem remediation on plateau. PMID:27461070

  18. Identification of novel splice site mutation IVS9 + 1(G > A) and novel complex allele G355R/R359X in Type 1 Gaucher patients heterozygous for mutation N370S.

    Science.gov (United States)

    Hoitsema, Kourtnee; Amato, Dominick; Khan, Aneal; Sirrs, Sandra; Choy, Francis Y M

    2016-09-01

    Gaucher disease is an autosomal recessive lysosomal storage disorder resulting from deficient glucocerebrosidase activity. More than 350 mutations that cause Gaucher disease have been described to date. Novel mutations can potentially provide insight into the glucocerebrosidase structure-function relationship and biochemical basis of the disease. Here, we report the identification of two novel mutations in two unrelated patients with type I (non-neuronopathic) Gaucher disease: 1) a splice site mutation IVS9 + 1G > A; and (2) a complex allele (cis) G355R/R359X. Both patients have a common N370S mutation in the other allele. The splice site mutation results from an intronic base substitution (G to A, c.1328 + 1, g.5005) at the donor splice site of exon and intron 9. The complex allele results from two point mutations in exon 8 of glucocerebrosidase (G to C at c.1180, g.4396, and T to C at c. 1192, g.4408) substituting glycine by arginine (G355R) and arginine by a premature termination (R359X), respectively. In order to demonstrate that G355R/R359X are in cis arrangement, PCR-amplified glucocerebrosidase exon 8 genomic DNA from the patient was cloned into the vector pJET1.2 in Escherichia coli TOP10® strain. Out of the 15 clones that were sequence analyzed, 10 contained the normal allele sequence and 5 contained the complex allele G355R/R359X sequence showing both mutations in cis arrangement. Restriction fragment length polymorphism analysis using Hph1 restriction endonuclease digest was established for the IVS9 + 1G > A mutation for confirmation and efficient identification of this mutation in future patients. Past literature suggests that mutations affecting splicing patterns of the glucocerebrosidase transcript as well as mutations in Gaucher complex alleles are detrimental to enzyme activity. However, compound heterozygosity with N370S, a mild mutation, will lead to a mild phenotype. The cases reported here support these past findings. PMID:27222815

  19. The carboxy-terminus of VirE2 from Agrobacterium tumefaciens is required for its transport to host cells by the virB-encoded type IV transport system.

    Science.gov (United States)

    Simone, M; McCullen, C A; Stahl, L E; Binns, A N

    2001-09-01

    Agrobacterium tumefaciens transfers DNA from the resident 'tumour-inducing' (Ti) plasmid into plant cells, where it can be stably integrated into the plant genome, ultimately resulting in crown gall tumour formation. The mobilized DNA molecule is a single-stranded intermediate with VirD2 covalently bound to its 5' end. Successful transport of the transferred DNA (T-DNA) and integration of the DNA into the genome requires that additional proteins be transported to the plant as well, including the single-stranded (ss)DNA-binding protein, VirE2. The transport of these two different substrates occurs as a result of the activities of a type IV secretion system encoded by the virB operon. Although the substrates have been identified, the mechanism of their transport remains unknown. In the experiments described here, a region in one of these substrates, VirE2, necessary for transport is identified. The addition of a C-terminal FLAG epitope tag to VirE2, or the deletion of its C-terminal 18 amino acids, renders it non-functional in A. tumefaciens. However, transgenic plants expressing either of these virE2 genes respond to virE2 mutants of A. tumefaciens by forming wild-type tumours. These results indicate that this region of VirE2 is necessary for the protein to be transported into the plant cells, but is not necessary for its function within the plant. Additionally, these studies demonstrate that mutant forms of VirE2 lacking this region do not disrupt the activities of the VirB transporter and support the hypothesis that VirE2 and the VirD2 T-strand are transported independently, even when they co-exist in the same cell. PMID:11580834

  20. 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)

  1. Bacterial glycosyltransferase toxins.

    Science.gov (United States)

    Jank, Thomas; Belyi, Yury; Aktories, Klaus

    2015-12-01

    Mono-glycosylation of host proteins is a common mechanism by which bacterial protein toxins manipulate cellular functions of eukaryotic target host cells. Prototypic for this group of glycosyltransferase toxins are Clostridium difficile toxins A and B, which modify guanine nucleotide-binding proteins of the Rho family. However, toxin-induced glycosylation is not restricted to the Clostridia. Various types of bacterial pathogens including Escherichia coli, Yersinia, Photorhabdus and Legionella species produce glycosyltransferase toxins. Recent studies discovered novel unexpected variations in host protein targets and amino acid acceptors of toxin-catalysed glycosylation. These findings open new perspectives in toxin as well as in carbohydrate research.

  2. DNA repair in bacterial cultures and plasmid DNA exposed to infrared laser for treatment of pain

    International Nuclear Information System (INIS)

    Biostimulation of tissues by low intensity lasers has been described on a photobiological basis and clinical protocols are recommended for treatment of various diseases, but their effects on DNA are controversial. The objective of this work was to evaluate effects of low intensity infrared laser exposure on survival and bacterial filamentation in Escherichia coli cultures, and induction of DNA lesions in bacterial plasmids. In E. coli cultures and plasmids exposed to an infrared laser at fluences used to treat pain, bacterial survival and filamentation and DNA lesions in plasmids were evaluated by electrophoretic profile. Data indicate that the infrared laser (i) increases survival of E. coli wild type in 24 h of stationary growth phase, (ii) induces bacterial filamentation, (iii) does not alter topological forms of plasmids and (iv) does not alter the electrophoretic profile of plasmids incubated with exonuclease III or formamidopyrimidine DNA glycosylase. A low intensity infrared laser at the therapeutic fluences used to treat pain can alter survival of E. coli wild type, induce filamentation in bacterial cells, depending on physiologic conditions and DNA repair, and induce DNA lesions other than single or double DNA strand breaks or alkali-labile sites, which are not targeted by exonuclease III or formamidopyrimidine DNA glycosylase. (letter)

  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. Equilibrium between Different Coordination Geometries in Oxidovanadium(IV) Complexes

    Science.gov (United States)

    Ugone, Valeria; Garribba, Eugenio; Micera, Giovanni; Sanna, Daniele

    2015-01-01

    In this laboratory activity, the equilibrium between square pyramidal and octahedral V(IV)O[superscript 2+] complexes is described. We propose a set of experiments to synthesize and characterize two types of V(IV)O[superscript 2+] complexes. The experiment allows great flexibility and may be effectively used at a variety of levels and the activity…

  5. 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

  6. The abcEDCBA-Encoded ABC Transporter and the virB Operon-Encoded Type IV Secretion System of Brucella ovis Are Critical for Intracellular Trafficking and Survival in Ovine Monocyte-Derived Macrophages.

    Directory of Open Access Journals (Sweden)

    Auricelio A Macedo

    Full Text Available Brucella ovis infection is associated with epididymitis, orchitis and infertility in rams. Most of the information available on B. ovis and host cell interaction has been generated using murine macrophages or epithelial cell lines, but the interaction between B. ovis and primary ovine macrophages has not been studied. The aim of this study was to evaluate the role of the B. ovis abcEDCBA-encoded ABC transporter and the virB operon-encoded Type IV Secretion System (T4SS during intracellular survival of B. ovis in ovine peripheral blood monocyte-derived macrophages. ΔabcBA and ΔvirB2 mutant strains were unable to survive in the intracellular environment when compared to the WT B. ovis at 48 hours post infection (hpi. In addition, these mutant strains cannot exclude the lysosomal marker LAMP1 from its vacuolar membrane, and their vacuoles do not acquire the endoplasmic reticulum marker calreticulin, which takes place in the WT B. ovis containing vacuole. Higher levels of nitric oxide production were observed in macrophages infected with WT B. ovis at 48 hpi when compared to macrophages infected with the ΔabcBA or ΔvirB2 mutant strains. Conversely, higher levels of reactive oxygen species were detected in macrophages infected with the ΔabcBA or ΔvirB2 mutant strains at 48 hpi when compared to macrophages infected with the WT strain. Our results demonstrate that B. ovis is able to persist and multiply in ovine macrophages, while ΔabcBA and ΔvirB2 mutations prevent intracellular multiplication, favor phagolysosome fusion, and impair maturation of the B. ovis vacuole towards an endoplasmic reticulum-derived compartment.

  7. Dipeptidyl peptidase-IV inhibitors used in type-2 diabetes inhibit a phospholipase C: a case of promiscuous scaffolds in proteins [v2; ref status: indexed, http://f1000r.es/4wz

    Directory of Open Access Journals (Sweden)

    Sandeep Chakraborty

    2015-01-01

    Full Text Available The long term side effects of any newly introduced drug is a subject of intense research, and often raging controversies. One such example is the dipeptidyl peptidase-IV (DPP4 inhibitor used for treating type 2 diabetes, which is inconclusively implicated in increased susceptibility to acute pancreatitis. Previously, based on a computational analysis of the spatial and electrostatic properties of active site residues, we have demonstrated that phosphoinositide-specific phospholipase C (PI-PLC from Bacillus cereus is a prolyl peptidase using in vivo experiments. In the current work, we first report the inhibition of the native activity of PI-PLC by two DPP4 inhibitors - vildagliptin (LAF-237 and K-579. While vildagliptin inhibited PI-PLC at micromolar concentrations, K-579 was a potent inhibitor even at nanomolar concentrations. Subsequently, we queried a comprehensive, non-redundant set of 5000 human proteins (50% similarity cutoff with known structures using serine protease (SPASE motifs derived from trypsin and DPP4. A pancreatic lipase and a gastric lipase are among the proteins that are identified as proteins having promiscuous SPASE scaffolds that could interact with DPP4 inhibitors. The presence of such scaffolds in human lipases is expected since they share the same catalytic mechanism with PI-PLC. However our methodology also detects other proteins, often with a completely different enzymatic mechanism, that have significantly congruent domains with the SPASE motifs. The reported elevated levels of serum lipase, although contested, could be rationalized by inhibition of lipases reported here. In an effort to further our understanding of the spatial and electrostatic basis of DPP4 inhibitors, we have also done a comprehensive analysis of all 76 known DPP4 structures liganded to inhibitors till date. Also, the methodology presented here can be easily adopted for other drugs, and provide the first line of filtering in the identification of

  8. Clinico-pathological Responses of Calves Associated with Infection of Pasteurella multocida Type B and the Bacterial Lipopolysaccharide and Outer Membrane Protein Immunogens

    Directory of Open Access Journals (Sweden)

    Faez Firdaus Jesse Abdullah

    2013-10-01

    Full Text Available The current study aims to investigate the Clinico-pathological responses of calves associated with the infections of Pasteurella multocida type B and the bacterial lipopolysaccharide and outer membrane protein immunogens. Alterations in the behavior of animals and pathological lesions observed following innate or experimental infections usually divulge extensive and detrimental changes in the clinical signs, organs and tissues of the animals afflicted with the disease. These alterations are imperative for Veterinary evaluation of herd health. Eight clinically healthy, non-pregnant and non-lactating Brangus cross heifers weighing 150±50 kg were used in the study. The heifers (n = 8 were divided into 4 groups of 2 calves per group. The control calves in group 1 were inoculated intramuscularly with 10 mL of sterile Phosphate Buffered Saline (PBS. Calves in group 2 were inoculated intramuscularly with 10 mL of 1012 colony forming unit (cfu of wild-type P. multocida and calves in group 3 were inoculated intravenously with 10 mL of LPS broth extract. Calves in group 4 were inoculated intramuscularly with 10 mL of OMP broth extract. All animals were observed for 48 h for clinical signs, changes in behavior and mortality pattern, including the time of death. The results divulged significant differences in the Clinico-pathological alterations. Calves inoculated with whole cell P. multocida type B: 2 showed a significant (p<0.05 increased in rectal temperature. The affected calves showed significant severe dullness (p<0.000 and significant rumen hypomotility (p<0.000 was also exhibited. The calves showed signs of hypersalivation at 14 h. There is no significant difference (p = 0.240 in pulmonary oedema in the Calves of group 2 compared to control group 1. Calves of group 4 also showed no significant difference in pulmonary oedema (p = 0.612 compared to control group 1. Calves of group 3 showed significantly moderate pulmonary oedema (p<0.000. All the

  9. Structural and functional similarity between the bacterial type III secretion system needle protein PrgI and the eukaryotic apoptosis Bcl-2 proteins.

    Directory of Open Access Journals (Sweden)

    Matthew D Shortridge

    Full Text Available BACKGROUND: Functional similarity is challenging to identify when global sequence and structure similarity is low. Active-sites or functionally relevant regions are evolutionarily more stable relative to the remainder of a protein structure and provide an alternative means to identify potential functional similarity between proteins. We recently developed the FAST-NMR methodology to discover biochemical functions or functional hypotheses of proteins of unknown function by experimentally identifying ligand binding sites. FAST-NMR utilizes our CPASS software and database to assign a function based on a similarity in the structure and sequence of ligand binding sites between proteins of known and unknown function. METHODOLOGY/PRINCIPAL FINDINGS: The PrgI protein from Salmonella typhimurium forms the needle complex in the type III secretion system (T3SS. A FAST-NMR screen identified a similarity between the ligand binding sites of PrgI and the Bcl-2 apoptosis protein Bcl-xL. These ligand binding sites correlate with known protein-protein binding interfaces required for oligomerization. Both proteins form membrane pores through this oligomerization to release effector proteins to stimulate cell death. Structural analysis indicates an overlap between the PrgI structure and the pore forming motif of Bcl-xL. A sequence alignment indicates conservation between the PrgI and Bcl-xL ligand binding sites and pore formation regions. This active-site similarity was then used to verify that chelerythrine, a known Bcl-xL inhibitor, also binds PrgI. CONCLUSIONS/SIGNIFICANCE: A structural and functional relationship between the bacterial T3SS and eukaryotic apoptosis was identified using our FAST-NMR ligand affinity screen in combination with a bioinformatic analysis based on our CPASS program. A similarity between PrgI and Bcl-xL is not readily apparent using traditional global sequence and structure analysis, but was only identified because of conservation in

  10. Assembly of respiratory complexes I, III, and IV into NADH oxidase supercomplex stabilizes complex I in Paracoccus denitrificans.

    Science.gov (United States)

    Stroh, Anke; Anderka, Oliver; Pfeiffer, Kathy; Yagi, Takao; Finel, Moshe; Ludwig, Bernd; Schägger, Hermann

    2004-02-01

    Stable supercomplexes of bacterial respiratory chain complexes III (ubiquinol:cytochrome c oxidoreductase) and IV (cytochrome c oxidase) have been isolated as early as 1985 (Berry, E. A., and Trumpower, B. L. (1985) J. Biol. Chem. 260, 2458-2467). However, these assemblies did not comprise complex I (NADH:ubiquinone oxidoreductase). Using the mild detergent digitonin for solubilization of Paracoccus denitrificans membranes we could isolate NADH oxidase, assembled from complexes I, III, and IV in a 1:4:4 stoichiometry. This is the first chromatographic isolation of a complete "respirasome." Inactivation of the gene for tightly bound cytochrome c552 did not prevent formation of this supercomplex, indicating that this electron carrier protein is not essential for structurally linking complexes III and IV. Complex I activity was also found in the membranes of mutant strains lacking complexes III or IV. However, no assembled complex I but only dissociated subunits were observed following the same protocols used for electrophoretic separation or chromatographic isolation of the supercomplex from the wild-type strain. This indicates that the P. denitrificans complex I is stabilized by assembly into the NADH oxidase supercomplex. In addition to substrate channeling, structural stabilization of a membrane protein complex thus appears as one of the major functions of respiratory chain supercomplexes.

  11. Activities of virE1 and the VirE1 secretion chaperone in export of the multifunctional VirE2 effector via an Agrobacterium type IV secretion pathway.

    Science.gov (United States)

    Zhao, Z; Sagulenko, E; Ding, Z; Christie, P J

    2001-07-01

    Agrobacterium tumefaciens uses a type IV secretion system to deliver oncogenic nucleoprotein particles and effector proteins, such as the multifunctional VirE2 protein, to plant cells. In this study, we examined the function of virE1 and its product, the VirE1 secretion chaperone, in mediating VirE2 export. A nonpolar virE1 null mutant accumulated low levels of VirE2, and trans expression of virE1 in this mutant only partially restored VirE2 abundance. Deletion of virE1 did not affect transcription but decreased translation of virE2, as shown by analysis of lacZ transcriptional and translational fusions. VirE2 was stable for a prolonged period, more than 6 h, when it was expressed in cis with virE1, and it exhibited half-lives of about 2 h when it was expressed in trans with virE1 and less than 10 min when it was expressed in the absence of virE1, as shown by pulse-chase experiments. VirE1 stabilized VirE2 via an interaction with a domain near the N terminus of VirE2, as shown by analyses of VirE2 truncation and insertion mutants synthesized in A. tumefaciens. VirE1 self-association was demonstrated by using bacteriophage lambda cI repressor fusion and pull-down assays, and evidence of VirE1 homomultimerization in vivo was obtained by native polyacrylamide gel electrophoresis and gel filtration chromatography. A putative VirE1-VirE2 complex with a molecular mass of about 70 to 80 kDa was detected by gel filtration chromatography of extracts from wild-type cells, whereas higher-order VirE2 complexes or aggregates were detected in extracts from a virE1 mutant. Taken together, our findings show that virE1 contributes in several ways to VirE2 export:(i) virE1 regulates efficient virE2 translation in the context of expression from the native P(virE) promoter; (ii) the VirE1 secretion chaperone stabilizes VirE2, most probably via an interaction with an N-terminal domain; and (iii) VirE1 forms a VirE1-VirE2 complex with a predicted 2:1 stoichiometry that inhibits assembly

  12. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  13. Analysis of bacterial culture results of two types of platelet products%两种血小板制品细菌培养结果分析

    Institute of Scientific and Technical Information of China (English)

    林栋; 崔四平; 苏婉兰; 陈宝婵; 叶柱江

    2014-01-01

    目的:探讨单采血小板与混合血小板在血液采集制备过程中细菌污染的危险程度,为血小板的采集制备过程中改良工艺,提高输血安全性提供可靠数据。方法采用生物梅里埃公司生产的BaeT/Alert 3D 全自动细菌培养仪及应用需氧瓶(BPA Culture Bottle)、厌氧瓶(BPN Culture Bottle)对5210例单采血小板,1653例混合血小板进行了细菌培养,细菌培养阳性者转种,转种阳性者进行细菌鉴定。结果在5210例单采血小板细菌培养经确定阳性6例,阳性率为1.15‰;1653例混合血小板中细菌培养经确定阳性10例,阳性率6.05‰。结论混合血小板细菌培养阳性率(6.05‰)高于单采血小板(1.15‰),两者比较差异有统计学意义(P<0.01);血小板细菌污染情况仍然严峻,应引起注意。%Objective To investigate the criticality of bacterial pollution in the blood collection and preparation process of single donor platelets and mixed platelets in order to provide reliable data for improving the technology in the collection and preparation process of platelets and improving the blood transfusion safety. Methods The BaeT/Alert 3D Full-Automatic Bacterial Culture System produced by BioMérieux and the BPA Culture Bottle and BPN Culture Bottle were used for the bacterial culture of 5210 cases of single donor platelets and 1653 cases of mixed platelets.The samples showing g positive bacterial culture results received subcultivation and the subcultivated sample showing positive results received bacterial identification. Results Of the 5210 cases of single donor platelets,bacterial culture confirmed 6 positive cases,with the positive rate of 1.15‰.Of the 1653 cases of mixed platelets,bacterial culture confirmed 10 positive cases,with the positive rate of 6.05‰. Conclusion The positive bacterial culture rate of mixed platelets (6.05‰)is higher than that of the single donor platelets (1.15

  14. [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

  15. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten;

    2010-01-01

    in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by tyrosine......Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  16. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  17. Social behavior and decision making in bacterial conjugation.

    Science.gov (United States)

    Koraimann, Günther; Wagner, Maria A

    2014-01-01

    Bacteria frequently acquire novel genes by horizontal gene transfer (HGT). HGT through the process of bacterial conjugation is highly efficient and depends on the presence of conjugative plasmids (CPs) or integrated conjugative elements (ICEs) that provide the necessary genes for DNA transmission. This review focuses on recent advancements in our understanding of ssDNA transfer systems and regulatory networks ensuring timely and spatially controlled DNA transfer (tra) gene expression. As will become obvious by comparing different systems, by default, tra genes are shut off in cells in which conjugative elements are present. Only when conditions are optimal, donor cells-through epigenetic alleviation of negatively acting roadblocks and direct stimulation of DNA transfer genes-become transfer competent. These transfer competent cells have developmentally transformed into specialized cells capable of secreting ssDNA via a T4S (type IV secretion) complex directly into recipient cells. Intriguingly, even under optimal conditions, only a fraction of the population undergoes this transition, a finding that indicates specialization and cooperative, social behavior. Thereby, at the population level, the metabolic burden and other negative consequences of tra gene expression are greatly reduced without compromising the ability to horizontally transfer genes to novel bacterial hosts. This undoubtedly intelligent strategy may explain why conjugative elements-CPs and ICEs-have been successfully kept in and evolved with bacteria to constitute a major driving force of bacterial evolution.

  18. Spatial scales of bacterial diversity in cold-water coral reef ecosystems.

    Directory of Open Access Journals (Sweden)

    Sandra Schöttner

    Full Text Available BACKGROUND: Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning. METHODOLOGY/PRINCIPAL FINDINGS: Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA, was investigated with respect to (i microbial habitat type and (ii coral species and color, as well as the three spatial components (iii geomorphologic reef zoning, (iv reef boundary, and (v reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus and ambient microbial habitats (seawater, sediments. This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity. CONCLUSIONS/SIGNIFICANCE: This study presents the first multi-scale survey of bacterial diversity in cold-water coral reefs, spanning a total of five observational levels including three spatial scales. It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has

  19. THE TWENTIETH CENTURY DEVELOPMENT OF DIFFERENT TYPES OF BACTERIAL, BIOLOGICAL AND CHEMICAL WEAPONS AND THE PRESENT CAPABILITIES OF NATO AND THE WARSAW PACT IN THIS RESPECT

    OpenAIRE

    A.L.S. Hudson

    2012-01-01

    Over the last twenty years increased attention has been focused on the military uses of Bacterial, Biological and Chemical agents (BBC weapons). This phenomenon can be attributed to a number of reasons. Firstly, BBC weapons are comparatively cheap and simple to produce, they are easy to use as conventional weapons and their effects are short-lived. The mutual deterrence effect of nuclear weapons, furthermore, has necessitated the exploration of other fields of warfare of which - BBC warfare i...

  20. The feather-degrading bacterial community in two soils as revealed by a specific primer targeting serine-type keratinolytic proteases.

    Science.gov (United States)

    Gu, Zhenhong; Zhu, Honghui; Xie, Xiaolin; Wang, Yonghong; Liu, Xiaodi; Yao, Qing

    2016-10-01

    Feather waste represents a huge resource of protein, but is underutilized due to its recalcitrant nature. Feather-degrading bacteria can biologically degrade feathers and have great potential for industries. In this study, we first designed a primer set (BC) suitable for exploring the diversity of the keratinolytic bacterial community with denatured gradient gel electrophoresis (DGGE). With the BC primer set, the difference in the keratinolytic bacterial community between a feather-dumping (FD) soil and a non feather-dumping (NFD) soil and the influence of feather addition (enrichment culture) on the keratinolytic bacterial community were investigated. DGGE and sequencing showed that keratinolytic bacteria in these soils belong to 2 phyla (Actinobacteria and Proteobacteria) and 9 genera (Micromonospora, Verrucosispora, Actinopolymorpha, Knoellia, Hyalangium, Stigmatella, Archangium, Cystobacter, and Luteimonas). Feather addition decreased the species richness of the keratinolytic bacteria in FD soil, but greatly increased the diversity, species richness and abundance in NFD soil. Moreover, feather addition to NFD soil induced some keratinolytic bacteria that were absent in all of the other soils. Collectively, these data indicate that keratinolytic bacteria are diverse in both FD and NFD soil, and some novel keratinolytic bacteria taxa might be revealed by using the BC primer set. PMID:27562599