These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

FY2003 LDRD Final Annual Report Article: Pathogen Pathway Project  

SciTech Connect

Understanding virulence mechanisms of bacterial pathogens is vital to anticipating biological threats and to improving detectors, vaccines, and treatments. This project will characterize factors responsible for virulence of Yersinia pestis, the causative agent of plague and a biothreat agent, which has an inducible Type III secretion virulence mechanism also found in other animal, plant, and human pathogens. Our approach relies on genomic and proteomic characterization of Y. pestis in addition to a bioinformatic infrastructure. Scientific and technical capabilities developed in this project can be applied to other microbes of interest. This work will establish a significant new direction for biodefense at LLNL and expand our national and international scientific collaborations.

Fitch, J P; McCutchen-Maloney, S L

2003-11-10

2

Review article Pathogenic diversity of Escherichia coli  

E-print Network

Review article Pathogenic diversity of Escherichia coli and the emergence of 'exotic' islands December 1998) Abstract - Escherichia coli is a highly adaptive bacterial species that is both a member and other bacteria are presented. © Inra/Elsevier, Paris. Escherichia coli / pathogenicity island

Boyer, Edmond

3

Review article Avian pathogenic Escherichia coli (APEC)  

E-print Network

Review article Avian pathogenic Escherichia coli (APEC) Maryvonne Dho-Moulina John Morris Inra/Elscvier, Paris. avian / Escherichia coli / virulence / fimbriae / capsule / aerobactin.int-a. li- #12;Résumé-Escherichia coli pathogènes aviaires (APEC). Les Escherichia coli pathogènes aviaires

Paris-Sud XI, Université de

4

Innate immunity in Drosophila: Pathogens and pathways  

PubMed Central

Following in the footsteps of traditional developmental genetics, research over the last 15 years has shown that innate immunity against bacteria and fungi is governed largely by two NF-?B signal transduction pathways, Toll and IMD. Antiviral immunity appears to stem from RNA interference, whereas resistance against parasitoids is conferred by Toll signaling. The identification of these post-transcriptional regulatory mechanisms and the annotation of most Drosophila immunity genes have derived from functional genomic studies using “model” pathogens, intact animals and cell lines. The D. melanogaster host has thus provided the core information that can be used to study responses to natural microbial and metazoan pathogens as they become identified, as well as to test ideas of selection and evolutionary change. These analyses are of general importance to understanding mechanisms of other insect host–pathogen interactions and determinants of variation in host resistance. PMID:20485470

Govind, Shubha

2009-01-01

5

Intervention of Phytohormone Pathways by Pathogen Effectors[OPEN  

PubMed Central

The constant struggle between plants and microbes has driven the evolution of multiple defense strategies in the host as well as offense strategies in the pathogen. To defend themselves from pathogen attack, plants often rely on elaborate signaling networks regulated by phytohormones. In turn, pathogens have adopted innovative strategies to manipulate phytohormone-regulated defenses. Tactics frequently employed by plant pathogens involve hijacking, evading, or disrupting hormone signaling pathways and/or crosstalk. As reviewed here, this is achieved mechanistically via pathogen-derived molecules known as effectors, which target phytohormone receptors, transcriptional activators and repressors, and other components of phytohormone signaling in the host plant. Herbivores and sap-sucking insects employ obligate pathogens such as viruses, phytoplasma, or symbiotic bacteria to intervene with phytohormone-regulated defenses. Overall, an improved understanding of phytohormone intervention strategies employed by pests and pathogens during their interactions with plants will ultimately lead to the development of new crop protection strategies. PMID:24920334

Kazan, Kemal; Lyons, Rebecca

2014-01-01

6

Stress signaling pathways for the pathogenicity of Cryptococcus.  

PubMed

Sensing, responding, and adapting to the surrounding environment are crucial for all living organisms to survive, proliferate, and differentiate in their biological niches. This ability is also essential for Cryptococcus neoformans and its sibling species Cryptococcus gattii, as these pathogens have saprobic and parasitic life cycles in natural and animal host environments. The ability of Cryptococcus to cause fatal meningoencephalitis is highly related to its capability to remodel and optimize its metabolic and physiological status according to external cues. These cues act through multiple stress signaling pathways through a panoply of signaling components, including receptors/sensors, small GTPases, secondary messengers, kinases, transcription factors, and other miscellaneous adaptors or regulators. In this minireview, we summarize and highlight the importance of several stress signaling pathways that influence the pathogenicity of Cryptococcus and discuss future challenges in these areas. PMID:24078305

Bahn, Yong-Sun; Jung, Kwang-Woo

2013-12-01

7

Stress Signaling Pathways for the Pathogenicity of Cryptococcus  

PubMed Central

Sensing, responding, and adapting to the surrounding environment are crucial for all living organisms to survive, proliferate, and differentiate in their biological niches. This ability is also essential for Cryptococcus neoformans and its sibling species Cryptococcus gattii, as these pathogens have saprobic and parasitic life cycles in natural and animal host environments. The ability of Cryptococcus to cause fatal meningoencephalitis is highly related to its capability to remodel and optimize its metabolic and physiological status according to external cues. These cues act through multiple stress signaling pathways through a panoply of signaling components, including receptors/sensors, small GTPases, secondary messengers, kinases, transcription factors, and other miscellaneous adaptors or regulators. In this minireview, we summarize and highlight the importance of several stress signaling pathways that influence the pathogenicity of Cryptococcus and discuss future challenges in these areas. PMID:24078305

Jung, Kwang-Woo

2013-01-01

8

Original article Signaling pathways involved in liver injury  

E-print Network

Original article Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 · 104 hemagglutination. The current findings suggest that activation of JNK is an essential component in liver injury mediated

Paris-Sud XI, Université de

9

Original article Enteric bacterial pathogen detection in southern sea otters  

E-print Network

and Game, Marine Wildlife Veterinary Care and Research Center, 1451 Shaffer Road, Santa Cruz, CA, 95060 contact-associated illness and shellfish harvest restrictions [17, 19]. In some countries, identifying and protozoa enter the ocean, invertebrates can efficiently concentrate these potential pathogens through

Paris-Sud XI, Université de

10

The Spore Differentiation Pathway in the Enteric Pathogen Clostridium difficile  

PubMed Central

Endosporulation is an ancient bacterial developmental program that culminates with the differentiation of a highly resistant endospore. In the model organism Bacillus subtilis, gene expression in the forespore and in the mother cell, the two cells that participate in endospore development, is governed by cell type-specific RNA polymerase sigma subunits. ?F in the forespore, and ?E in the mother cell control early stages of development and are replaced, at later stages, by ?G and ?K, respectively. Starting with ?F, the activation of the sigma factors is sequential, requires the preceding factor, and involves cell-cell signaling pathways that operate at key morphological stages. Here, we have studied the function and regulation of the sporulation sigma factors in the intestinal pathogen Clostridium difficile, an obligate anaerobe in which the endospores are central to the infectious cycle. The morphological characterization of mutants for the sporulation sigma factors, in parallel with use of a fluorescence reporter for single cell analysis of gene expression, unraveled important deviations from the B. subtilis paradigm. While the main periods of activity of the sigma factors are conserved, we show that the activity of ?E is partially independent of ?F, that ?G activity is not dependent on ?E, and that the activity of ?K does not require ?G. We also show that ?K is not strictly required for heat resistant spore formation. In all, our results indicate reduced temporal segregation between the activities of the early and late sigma factors, and reduced requirement for the ?F-to-?E, ?E-to-?G, and ?G-to-?K cell-cell signaling pathways. Nevertheless, our results support the view that the top level of the endosporulation network is conserved in evolution, with the sigma factors acting as the key regulators of the pathway, established some 2.5 billion years ago upon its emergence at the base of the Firmicutes Phylum. PMID:24098139

Pereira, Fatima C.; Saujet, Laure; Tome, Ana R.; Serrano, Monica; Monot, Marc; Couture-Tosi, Evelyne; Martin-Verstraete, Isabelle; Dupuy, Bruno; Henriques, Adriano O.

2013-01-01

11

Review article Escherichia coli as a pathogen in dogs and cats  

E-print Network

Review article Escherichia coli as a pathogen in dogs and cats Lothar Beutin Robert Koch; accepted 17December 1998) Abstraet-Certain strains of Escherichia coli behave as pathogens in dogs and cats. © Inra/Elsevier, Paris. Escherichia coli infections / dogs / cats / humans / diarrhoea / extra

Paris-Sud XI, Université de

12

The Arginine Decarboxylase Pathways of Host and Pathogen Interact to Impact Inflammatory Pathways in the Lung  

PubMed Central

The arginine decarboxylase pathway, which converts arginine to agmatine, is present in both humans and most bacterial pathogens. In humans agmatine is a neurotransmitter with affinities towards ?2-adrenoreceptors, serotonin receptors, and may inhibit nitric oxide synthase. In bacteria agmatine serves as a precursor to polyamine synthesis and was recently shown to enhance biofilm development in some strains of the respiratory pathogen Pseudomonas aeruginosa. We determined agmatine is at the center of a competing metabolism in the human lung during airways infections and is influenced by the metabolic phenotypes of the infecting pathogens. Ultra performance liquid chromatography with mass spectrometry detection was used to measure agmatine in human sputum samples from patients with cystic fibrosis, spent supernatant from clinical sputum isolates, and from bronchoalvelolar lavage fluid from mice infected with P. aeruginosa agmatine mutants. Agmatine in human sputum peaks during illness, decreased with treatment and is positively correlated with inflammatory cytokines. Analysis of the agmatine metabolic phenotype in clinical sputum isolates revealed most deplete agmatine when grown in its presence; however a minority appeared to generate large amounts of agmatine presumably driving sputum agmatine to high levels. Agmatine exposure to inflammatory cells and in mice demonstrated its role as a direct immune activator with effects on TNF-? production, likely through NF-?B activation. P. aeruginosa mutants for agmatine detection and metabolism were constructed and show the real-time evolution of host-derived agmatine in the airways during acute lung infection. These experiments also demonstrated pathogen agmatine production can upregulate the inflammatory response. As some clinical isolates have adapted to hypersecrete agmatine, these combined data would suggest agmatine is a novel target for immune modulation in the host-pathogen dynamic. PMID:25350753

Dalluge, Joseph J.; Welchlin, Cole W.; Hughes, John; Han, Wei; Blackwell, Timothy S.; Laguna, Theresa A.; Williams, Bryan J.

2014-01-01

13

Multiple Transmission Pathways and Disease Dynamics in a Waterborne Pathogen Model  

Microsoft Academic Search

Multiple transmission pathways exist for many waterborne diseases, including cholera, Giardia, Cryptosporidium, and Campylobacter. Theoretical work exploring the effects of multiple transmission pathways on disease dynamics is incomplete. Here, we consider\\u000a a simple ODE model that extends the classical SIR framework by adding a compartment (W) that tracks pathogen concentration in the water. Infected individuals shed pathogen into the water compartment,

Joseph H. Tien; David J. D. Earn

2010-01-01

14

Bacterium induces cryptic meroterpenoid pathway in the pathogenic fungus Aspergillus fumigatus.  

PubMed

Stimulating encounter: The intimate, physical interaction between the soil-derived bacterium Streptomyces rapamycinicus and the human pathogenic fungus Aspergillus fumigatus led to the activation of an otherwise silent polyketide synthase (PKS) gene cluster coding for an unusual prenylated polyphenol (fumicycline A). The meroterpenoid pathway is regulated by a pathway-specific activator gene as well as by epigenetic factors. PMID:23649940

König, Claudia C; Scherlach, Kirstin; Schroeckh, Volker; Horn, Fabian; Nietzsche, Sandor; Brakhage, Axel A; Hertweck, Christian

2013-05-27

15

Polyprenyl-dependent glycan assembly pathways in microbial pathogens  

E-print Network

Polyisoprenyl-dependent glycan assembly pathways form the basis for the biosynthesis of many complex glycoconjugates. This thesis addresses key aspects of undecaprenyl-phosphate related processes; undecaprenol is the linear ...

Hartley, Meredith Diane

2011-01-01

16

Comparative Analysis of Protein Glycosylation Pathways in Humans and the Fungal Pathogen Candida albicans  

PubMed Central

Protein glycosylation pathways are present in all kingdoms of life and are metabolic pathways found in all the life kingdoms. Despite sharing commonalities in their synthesis, glycans attached to glycoproteins have species-specific structures generated by the presence of different sets of enzymes and acceptor substrates in each organism. In this review, we present a comparative analysis of the main glycosylation pathways shared by humans and the fungal pathogen Candida albicans: N-linked glycosylation, O-linked mannosylation and glycosylphosphatidylinositol-anchorage. The knowledge of similarities and divergences between these metabolic pathways could help find new pharmacological targets for C. albicans infection. PMID:25104959

Martinez-Duncker, Ivan; Diaz-Jimenez, Diana F.; Mora-Montes, Hector M.

2014-01-01

17

Convergent pathogenic pathways in Alzheimer's and Huntington's diseases: shared targets for drug development  

Microsoft Academic Search

Neurodegenerative diseases, exemplified by Alzheimer's disease and Huntington's disease, are characterized by progressive neuropsychiatric dysfunction and loss of specific neuronal subtypes. Although there are differences in the exact sites of pathology, and the clinical profiles of these two conditions only partially overlap, considerable similarities in disease mechanisms and pathogenic pathways can be observed. These shared mechanisms raise the possibility of

Dagmar E. Ehrnhoefer; Bibiana K. Y. Wong; Michael R. Hayden

2011-01-01

18

Multiple transmission pathways and disease dynamics in a waterborne pathogen model.  

PubMed

Multiple transmission pathways exist for many waterborne diseases, including cholera, Giardia, Cryptosporidium, and Campylobacter. Theoretical work exploring the effects of multiple transmission pathways on disease dynamics is incomplete. Here, we consider a simple ODE model that extends the classical SIR framework by adding a compartment (W) that tracks pathogen concentration in the water. Infected individuals shed pathogen into the water compartment, and new infections arise both through exposure to contaminated water, as well as by the classical SIR person-person transmission pathway. We compute the basic reproductive number ([Symbol: see text](0)), epidemic growth rate, and final outbreak size for the resulting "SIWR" model, and examine how these fundamental quantities depend upon the transmission parameters for the different pathways. We prove that the endemic disease equilibrium for the SIWR model is globally stable. We identify the pathogen decay rate in the water compartment as a key parameter determining when the distinction between the different transmission routes in the SIWR model is important. When the decay rate is slow, using an SIR model rather than the SIWR model can lead to under-estimates of the basic reproductive number and over-estimates of the infectious period. PMID:20143271

Tien, Joseph H; Earn, David J D

2010-08-01

19

Pathogens penetrating the central nervous system: infection pathways and the cellular and molecular mechanisms of invasion.  

PubMed

The brain is well protected against microbial invasion by cellular barriers, such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). In addition, cells within the central nervous system (CNS) are capable of producing an immune response against invading pathogens. Nonetheless, a range of pathogenic microbes make their way to the CNS, and the resulting infections can cause significant morbidity and mortality. Bacteria, amoebae, fungi, and viruses are capable of CNS invasion, with the latter using axonal transport as a common route of infection. In this review, we compare the mechanisms by which bacterial pathogens reach the CNS and infect the brain. In particular, we focus on recent data regarding mechanisms of bacterial translocation from the nasal mucosa to the brain, which represents a little explored pathway of bacterial invasion but has been proposed as being particularly important in explaining how infection with Burkholderia pseudomallei can result in melioidosis encephalomyelitis. PMID:25278572

Dando, Samantha J; Mackay-Sim, Alan; Norton, Robert; Currie, Bart J; St John, James A; Ekberg, Jenny A K; Batzloff, Michael; Ulett, Glen C; Beacham, Ifor R

2014-10-01

20

IntPath--an integrated pathway gene relationship database for model organisms and important pathogens  

PubMed Central

Background Pathway data are important for understanding the relationship between genes, proteins and many other molecules in living organisms. Pathway gene relationships are crucial information for guidance, prediction, reference and assessment in biochemistry, computational biology, and medicine. Many well-established databases--e.g., KEGG, WikiPathways, and BioCyc--are dedicated to collecting pathway data for public access. However, the effectiveness of these databases is hindered by issues such as incompatible data formats, inconsistent molecular representations, inconsistent molecular relationship representations, inconsistent referrals to pathway names, and incomprehensive data from different databases. Results In this paper, we overcome these issues through extraction, normalization and integration of pathway data from several major public databases (KEGG, WikiPathways, BioCyc, etc). We build a database that not only hosts our integrated pathway gene relationship data for public access but also maintains the necessary updates in the long run. This public repository is named IntPath (Integrated Pathway gene relationship database for model organisms and important pathogens). Four organisms--S. cerevisiae, M. tuberculosis H37Rv, H. Sapiens and M. musculus--are included in this version (V2.0) of IntPath. IntPath uses the "full unification" approach to ensure no deletion and no introduced noise in this process. Therefore, IntPath contains much richer pathway-gene and pathway-gene pair relationships and much larger number of non-redundant genes and gene pairs than any of the single-source databases. The gene relationships of each gene (measured by average node degree) per pathway are significantly richer. The gene relationships in each pathway (measured by average number of gene pairs per pathway) are also considerably richer in the integrated pathways. Moderate manual curation are involved to get rid of errors and noises from source data (e.g., the gene ID errors in WikiPathways and relationship errors in KEGG). We turn complicated and incompatible xml data formats and inconsistent gene and gene relationship representations from different source databases into normalized and unified pathway-gene and pathway-gene pair relationships neatly recorded in simple tab-delimited text format and MySQL tables, which facilitates convenient automatic computation and large-scale referencing in many related studies. IntPath data can be downloaded in text format or MySQL dump. IntPath data can also be retrieved and analyzed conveniently through web service by local programs or through web interface by mouse clicks. Several useful analysis tools are also provided in IntPath. Conclusions We have overcome in IntPath the issues of compatibility, consistency, and comprehensiveness that often hamper effective use of pathway databases. We have included four organisms in the current release of IntPath. Our methodology and programs described in this work can be easily applied to other organisms; and we will include more model organisms and important pathogens in future releases of IntPath. IntPath maintains regular updates and is freely available at http://compbio.ddns.comp.nus.edu.sg:8080/IntPath. PMID:23282057

2012-01-01

21

Dothistroma pini, a Forest Pathogen, Contains Homologs of Aflatoxin Biosynthetic Pathway Genes  

PubMed Central

Homologs of aflatoxin biosynthetic genes have been identified in the pine needle pathogen Dothistroma pini. D. pini produces dothistromin, a difuranoanthraquinone toxin with structural similarity to the aflatoxin precursor versicolorin B. Previous studies with purified dothistromin suggest a possible role for this toxin in pathogenicity. By using an aflatoxin gene as a hybridization probe, a genomic D. pini clone was identified that contained four dot genes with similarity to genes in aflatoxin and sterigmatocystin gene clusters with predicted activities of a ketoreductase (dotA), oxidase (dotB), major facilitator superfamily transporter (dotC), and thioesterase (dotD). A D. pini dotA mutant was made by targeted gene replacement and shown to be severely impaired in dothistromin production, confirming that dotA is involved in dothistromin biosynthesis. Accumulation of versicolorin A (a precursor of aflatoxin) by the dotA mutant confirms that the dotA gene product is involved in an aflatoxin-like biosynthetic pathway. Since toxin genes have been found to be clustered in fungi in every case analyzed so far, it is speculated that the four dot genes may comprise part of a dothistromin biosynthetic gene cluster. A fifth gene, ddhA, is not a homolog of aflatoxin genes and could be at one end of the dothistromin cluster. These genes will allow comparative biochemical and genetic studies of the aflatoxin and dothistromin biosynthetic pathways and may also lead to new ways to control Dothistroma needle blight. PMID:12039746

Bradshaw, Rosie E.; Bhatnagar, Deepak; Ganley, Rebecca J.; Gillman, Carmel J.; Monahan, Brendon J.; Seconi, Janet M.

2002-01-01

22

ORIGINAL ARTICLE New enzymes, new pathways and an alternative view on starch  

E-print Network

. In addition, we describe many overlooked aspects of both ADPG and starch metabolism. With the overall data we by means of an ADPG synthesizing SuSy activity. According to this new view, starch metabolism embodiesORIGINAL ARTICLE New enzymes, new pathways and an alternative view on starch biosynthesis in both

Etxeberria, Edgardo

23

ORIGINAL ARTICLE Cell-to-cell pathway dominates xylem-epidermis hydraulic  

E-print Network

ORIGINAL ARTICLE Cell-to-cell pathway dominates xylem-epidermis hydraulic connection the hydraulic linkage between xylem and epidermis, epidermal cell turgor pressure (Pt) in leaves of Tradescantia- tutes a significant part of the leaf hydraulic path from xylem to epidermis. Furthermore, perfusion of H

Holbrook, N. Michele

24

A Model of an Integrated Immune System Pathway in Homo sapiens and Its Interaction with Superantigen Producing Expression Regulatory Pathway in Staphylococcus aureus: Comparing Behavior of Pathogen Perturbed and Unperturbed Pathway  

PubMed Central

Response of an immune system to a pathogen attack depends on the balance between the host immune defense and the virulence of the pathogen. Investigation of molecular interactions between the proteins of a host and a pathogen helps in identifying the pathogenic proteins. It is necessary to understand the dynamics of a normally behaved host system to evaluate the capacity of its immune system upon pathogen attack. In this study, we have compared the behavior of an unperturbed and pathogen perturbed host system. Moreover, we have developed a formalism under Flux Balance Analysis (FBA) for the optimization of conflicting objective functions. We have constructed an integrated pathway system, which includes Staphylococcal Superantigen (SAg) expression regulatory pathway and TCR signaling pathway of Homo sapiens. We have implemented the method on this pathway system and observed the behavior of host signaling molecules upon pathogen attack. The entire study has been divided into six different cases, based on the perturbed/unperturbed conditions. In other words, we have investigated unperturbed and pathogen perturbed human TCR signaling pathway, with different combinations of optimization of concentrations of regulatory and signaling molecules. One of these cases has aimed at finding out whether minimization of the toxin production in a pathogen leads to the change in the concentration levels of the proteins coded by TCR signaling pathway genes in the infected host. Based on the computed results, we have hypothesized that the balance between TCR signaling inhibitory and stimulatory molecules can keep TCR signaling system into resting/stimulating state, depending upon the perturbation. The proposed integrated host-pathogen interaction pathway model has accurately reflected the experimental evidences, which we have used for validation purpose. The significance of this kind of investigation lies in revealing the susceptible interaction points that can take back the Staphylococcal Enterotoxin (SE)-challenged system within the range of normal behavior. PMID:24324645

Tomar, Namrata; De, Rajat K.

2013-01-01

25

A novel pathogenic pathway of immune activation detectable before clinical onset in Huntington's disease  

PubMed Central

Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by both neurological and systemic abnormalities. We examined the peripheral immune system and found widespread evidence of innate immune activation detectable in plasma throughout the course of HD. Interleukin 6 levels were increased in HD gene carriers with a mean of 16 years before the predicted onset of clinical symptoms. To our knowledge, this is the earliest plasma abnormality identified in HD. Monocytes from HD subjects expressed mutant huntingtin and were pathologically hyperactive in response to stimulation, suggesting that the mutant protein triggers a cell-autonomous immune activation. A similar pattern was seen in macrophages and microglia from HD mouse models, and the cerebrospinal fluid and striatum of HD patients exhibited abnormal immune activation, suggesting that immune dysfunction plays a role in brain pathology. Collectively, our data suggest parallel central nervous system and peripheral pathogenic pathways of immune activation in HD. PMID:18625748

Bjorkqvist, Maria; Wild, Edward J.; Thiele, Jenny; Silvestroni, Aurelio; Andre, Ralph; Lahiri, Nayana; Raibon, Elsa; Lee, Richard V.; Benn, Caroline L.; Soulet, Denis; Magnusson, Anna; Woodman, Ben; Landles, Christian; Pouladi, Mahmoud A.; Hayden, Michael R.; Khalili-Shirazi, Azadeh; Lowdell, Mark W.; Brundin, Patrik; Bates, Gillian P.; Leavitt, Blair R.; Moller, Thomas; Tabrizi, Sarah J.

2008-01-01

26

Characterization of the Complete Uric Acid Degradation Pathway in the Fungal Pathogen Cryptococcus neoformans  

PubMed Central

Degradation of purines to uric acid is generally conserved among organisms, however, the end product of uric acid degradation varies from species to species depending on the presence of active catabolic enzymes. In humans, most higher primates and birds, the urate oxidase gene is non-functional and hence uric acid is not further broken down. Uric acid in human blood plasma serves as an antioxidant and an immune enhancer; conversely, excessive amounts cause the common affliction gout. In contrast, uric acid is completely degraded to ammonia in most fungi. Currently, relatively little is known about uric acid catabolism in the fungal pathogen Cryptococcus neoformans even though this yeast is commonly isolated from uric acid-rich pigeon guano. In addition, uric acid utilization enhances the production of the cryptococcal virulence factors capsule and urease, and may potentially modulate the host immune response during infection. Based on these important observations, we employed both Agrobacterium-mediated insertional mutagenesis and bioinformatics to predict all the uric acid catabolic enzyme-encoding genes in the H99 genome. The candidate C. neoformans uric acid catabolic genes identified were named: URO1 (urate oxidase), URO2 (HIU hydrolase), URO3 (OHCU decarboxylase), DAL1 (allantoinase), DAL2,3,3 (allantoicase-ureidoglycolate hydrolase fusion protein), and URE1 (urease). All six ORFs were then deleted via homologous recombination; assaying of the deletion mutants' ability to assimilate uric acid and its pathway intermediates as the sole nitrogen source validated their enzymatic functions. While Uro1, Uro2, Uro3, Dal1 and Dal2,3,3 were demonstrated to be dispensable for virulence, the significance of using a modified animal model system of cryptococcosis for improved mimicking of human pathogenicity is discussed. PMID:23667704

Lee, I. Russel; Yang, Liting; Sebetso, Gaseene; Allen, Rebecca; Doan, Thi H. N.; Blundell, Ross; Lui, Edmund Y. L.; Morrow, Carl A.; Fraser, James A.

2013-01-01

27

The evolution of alternative biofilms in an opportunistic fungal pathogen: an explanation for how new signal transduction pathways may evolve.  

PubMed

The evolution of two types of biofilms, one pathogenic and one sexual, is unique for Candidaalbicans, the most pervasive fungal pathogen in humans. When in the predominant a/? configuration, cells can form a traditional biofilm made up of a basal layer of yeast cells and an extensive upper layer of hyphae and dense matrix. This a/? biofilm is impermeable, impenetrable and drug-resistant. When in the a/a or ?/? configuration, white cells form a biofilm of similar architecture, but which is permeable, penetrable and drug-susceptible. The latter biofilm facilitates mating between minority opaque a/a and ?/? cells. The two biofilms are regulated by different signal transduction pathways that provide clues for deducing not only how the sexual a/a or ?/? biofilms evolved, but how the pathogenic a/? biofilm evolved as well. In the deduced evolutionary models, regulatory molecules, including components of the signal transduction pathways and transcription factors, are recruited from conserved pathways. The evolution of the alternative biofilms of C. albicans provides a rare glimpse into how new regulatory pathways may evolve in general. PMID:23871837

Soll, David R

2014-03-01

28

Two functional type VI secretion systems in avian pathogenic Escherichia coli are involved in different pathogenic pathways.  

PubMed

Type VI secretion systems (T6SSs) are involved in the pathogenicity of several Gram-negative bacteria. The VgrG protein, a core component and effector of T6SS, has been demonstrated to perform diverse functions. The N-terminal domain of VgrG protein is a homologue of tail fiber protein gp27 of phage T4, which performs a receptor binding function and determines the host specificity. Based on sequence analysis, we found that two putative T6SS loci exist in the genome of the avian pathogenic Escherichia coli (APEC) strain TW-XM. To assess the contribution of these two T6SSs to TW-XM pathogenesis, the crucial clpV clusters of these two T6SS loci and their vgrG genes were deleted to generate a series of mutants. Consequently, T6SS1-associated mutants presented diminished adherence to and invasion of several host cell lines cultured in vitro, decreased pathogenicity in duck and mouse infection models in vivo, and decreased biofilm formation and bacterial competitive advantage. In contrast, T6SS2-associated mutants presented a significant decrease only in the adherence to and invasion of mouse brain microvascular endothelial cell (BMEC) line bEnd.3 and brain tissue of the duck infection model. These results suggested that T6SS1 was involved in the proliferation of APEC in systemic infection, whereas VgrG-T6SS2 was responsible only for cerebral infection. Further study demonstrated that VgrG-T6SS2 was able to bind to the surface of bEnd.3 cells, whereas it did not bind to DF-1 (chicken embryo fibroblast) cells, which further proved the interaction of VgrG-T6SS2 with the surface of BMECs. PMID:24980972

Ma, Jiale; Bao, Yinli; Sun, Min; Dong, Wenyang; Pan, Zihao; Zhang, Wei; Lu, Chengping; Yao, Huochun

2014-09-01

29

Differential involvement of indole-3-acetic acid biosynthetic pathways in pathogenicity and epiphytic fitness of Erwinia herbicola pv. gypsophilae.  

PubMed

Erwinia herbicola pv. gypsophilae (Ehg), which induces galls on Gypsophila paniculata, harbors two major pathways for indole-3-acetic acid (IAA) synthesis, the indole-3-acetamide (IAM) and indole-3-pyruvate (IPyA) routes, as well as cytokinin biosynthetic genes. Mutants were generated in which the various biosynthetic routes were disrupted separately or jointly in order to assess the contribution of IAA of various origins and cytokinins to pathogenicity and epiphytic fitness. Inactivation of the IAM pathway or cytokinin biosynthesis caused the largest reduction in gall size. Inactivation of the IPyA pathway caused a minor, nonsignificant decrease in pathogenicity. No further reduction in gall size was observed by the simultaneous inactivation of both IAA pathways only or in combination with that of cytokinin production. However, inactivation of the IPyA pathway caused a 14-fold reduction in the population of Ehg on bean plants. Inactivation of the IAM pathway or cytokinin production did not affect epiphytic fitness. While the apparent transcriptional activity of iaaM-inaZ fusion increased slightly in cells of Ehg on bean and gypsophila leaves, compared with that in culture, very high levels of induction were observed in cells injected into gypsophila stems. In contrast, moderate levels of induction of ipdC-inaZ in Ehg were observed on leaves of these plants and in gypsophila stems, when compared with that in culture. These results suggest that the IAM pathway is involved primarily in gall formation and support the main contribution of the IpyA pathway to the epiphytic fitness of this bacterial species. PMID:9650296

Manulis, S; Haviv-Chesner, A; Brandl, M T; Lindow, S E; Barash, I

1998-07-01

30

Utilization of the nitrate reductase enzymatic pathway to reduce enteric pathogens in chickens.  

PubMed

Previous reports have shown that some bacteria, including Salmonella, use a dissimilatory nitrate reductase enzyme pathway (NREP) in anaerobic environments. This enzyme reduces nitrate to nitrite and has been shown to cometabolize chlorate to cytotoxic chlorite. The present investigations were performed to evaluate the susceptibility of a competitive exclusion culture (CE) to the experimental chlorate product (ECP). A commercially available CE product was evaluated for its nitrate reductase activity and therefore its chlorate sensitivity. Individual isolates (in triplicate) were cultured in 10 mL of Viande Levure broth containing 5 mM sodium nitrate or 10 mM sodium chlorate. Bacterial growth (optical density at 625 nm) was measured and 1-mL aliquots were removed concurrently for colorimetric determination of nitrate content at 0, 3, 6, and 24 h. Of the 15 different facultative strains, 11 had slight NREP utilization, 3 had moderate NREP utilization, and the remainder were NREP negative (with slight and moderate NREP utilization: >0.1 to <1.0 mM and >1.0 mM nitrate used within 6 h, respectively). Of the obligate anaerobes evaluated, 3 had slight NREP utilization and the remainder were NREP negative. In vivo studies utilizing both products (CE and ECP) in a horizontal transmission challenge model (seeders + contacts) showed significant reductions in Salmonella from 5.37 to 1.76 log10 cfu/g and 3.94 to 0.07 log10 cfu/g, respectively. The combined effect of the CE culture and an ECP are effective in killing these food-borne pathogens. PMID:15554062

McReynolds, J L; Byrd, J A; Moore, R W; Anderson, R C; Poole, T L; Edrington, T S; Kubena, L F; Nisbet, D J

2004-11-01

31

Relationships between calcium and sphingolipid-dependent signalling pathways during the early steps of plant-pathogen interactions.  

PubMed

An increase in cellular calcium ion (Ca(2+)) concentration is now acknowledged to be one of the earliest events occurring during the induction of plant defence responses to a wide variety of pathogens. Sphingoid long-chain bases (LCBs) have also been recently demonstrated to be important mediators of defence-related programmed cell death during pathogen attack. Here, we present recent data highlighting how Ca(2+) and LCBs may be interconnected to regulate cellular processes which lead either to plant susceptibility or to resistance mechanisms. This article is part of a Special Issue entitled: 12th European Symposium on Calcium. PMID:23219859

Thuleau, Patrice; Aldon, Didier; Cotelle, Valérie; Brière, Christian; Ranty, Benoit; Galaud, Jean-Philippe; Mazars, Christian

2013-07-01

32

The PD-1/PD-L costimulatory pathway critically affects host resistance to the pathogenic fungus Histoplasma capsulatum.  

PubMed

The PD-1 costimulatory receptor inhibits T cell receptor signaling upon interacting with its ligands PD-L1 and PD-L2. The PD-1/PD-L pathway is critical in maintaining self-tolerance. In this study, we examined the role of PD-1 in a mouse model of acute infection with Histoplasma capsulatum, a major human pathogenic fungus. In a lethal model of histoplasmosis, all PD-1-deficient mice survived infection, whereas the wild-type mice died with disseminated disease. PD-L expression on macrophages and splenocytes was up-regulated during infection, and macrophages from infected mice inhibited in vitro T cell activation. Of interest, antibody blocking of PD-1 significantly increased survival of lethally infected wild-type mice. Thus, our studies extend the role of the PD-1/PD-L pathway in regulating antimicrobial immunity to fungal pathogens. The results show that the PD-1/PD-L pathway has a key role in the regulation of antifungal immunity, and suggest that manipulation of this pathway represents a strategy of immunotherapy for histoplasmosis. PMID:18268348

Lázár-Molnár, Eszter; Gácser, Attila; Freeman, Gordon J; Almo, Steven C; Nathenson, Stanley G; Nosanchuk, Joshua D

2008-02-19

33

The PD-1/PD-L costimulatory pathway critically affects host resistance to the pathogenic fungus Histoplasma capsulatum  

PubMed Central

The PD-1 costimulatory receptor inhibits T cell receptor signaling upon interacting with its ligands PD-L1 and PD-L2. The PD-1/PD-L pathway is critical in maintaining self-tolerance. In this study, we examined the role of PD-1 in a mouse model of acute infection with Histoplasma capsulatum, a major human pathogenic fungus. In a lethal model of histoplasmosis, all PD-1-deficient mice survived infection, whereas the wild-type mice died with disseminated disease. PD-L expression on macrophages and splenocytes was up-regulated during infection, and macrophages from infected mice inhibited in vitro T cell activation. Of interest, antibody blocking of PD-1 significantly increased survival of lethally infected wild-type mice. Thus, our studies extend the role of the PD-1/PD-L pathway in regulating antimicrobial immunity to fungal pathogens. The results show that the PD-1/PD-L pathway has a key role in the regulation of antifungal immunity, and suggest that manipulation of this pathway represents a strategy of immunotherapy for histoplasmosis. PMID:18268348

Lazar-Molnar, Eszter; Gacser, Attila; Freeman, Gordon J.; Almo, Steven C.; Nathenson, Stanley G.; Nosanchuk, Joshua D.

2008-01-01

34

ARTicle  

NSDL National Science Digital Library

ARTicle is yet another entry in the arena of museum blogs, this time from the Art Institute of Chicago (AIC). ARTicle is intended to cover all sorts of subjects related to the AIC, and its six staff writers ask readers to, "Think of it as a little peek behind the scenes." The blog dates back to October of 2009, and visitors will find recent entries that include a staff picks entry, an entry on saints and symbols, and a short video featuring Robby S., a media assistant in Communications. In the video, Robby discusses Chilean painter Matta's The Earth Is a Man, 1942, which he describes as looking like a bunch of things floating in soup. Another recent post by Sarah M. investigates a piece currently on view in the modern wing, Shade by London-based Dutch designer Simon Heijdens, taking a look at how the work was installed and the possible meaning behind the work. If a "little peek behind the scenes" means the opportunity to hear people talking about art in an accessible and straightforward fashion, then ARTicle certainly achieves its stated goal.

35

Transcriptome of Aphanomyces euteiches: New Oomycete Putative Pathogenicity Factors and Metabolic Pathways  

Microsoft Academic Search

Aphanomyces euteiches is an oomycete pathogen that causes seedling blight and root rot of legumes, such as alfalfa and pea. The genus Aphanomyces is phylogenically distinct from well-studied oomycetes such as Phytophthora sp., and contains species pathogenic on plants and aquatic animals. To provide the first foray into gene diversity of A. euteiches, two cDNA libraries were constructed using mRNA

Elodie Gaulin; Mohammed-Amine Madoui; Arnaud Bottin; Christophe Jacquet; Catherine Mathe ´; Arnaud Couloux; Patrick Wincker; Bernard Dumas

2008-01-01

36

The Cpc1 regulator of the cross-pathway control of amino acid biosynthesis is required for pathogenicity of the vascular pathogen Verticillium longisporum.  

PubMed

The plant-pathogenic fungus Verticillium longisporum is a causal agent of early senescence and ripening in cruciferous crops like Brassica napus. Verticillium wilts have become serious agricultural threats in recent decades. Verticillium species infect host plants through the roots and colonize xylem vessels of the host plant. The xylem fluid provides an environment with limited carbon sources and unbalanced amino acid supply, which requires V. longisporum to induce the cross-pathway control of amino acid biosynthesis. RNA-mediated gene silencing reduced the expression of the two CPC1 isogenes (VlCPC1-1 and VlCPC1-2) of the allodiploid V. longisporum up to 85%. VlCPC1 encodes the conserved transcription factor of the cross-pathway control. The silenced mutants were highly sensitive to amino-acid starvation, and the infected plants showed significantly fewer symptoms such as stunting or early senescence in oilseed rape plant infection assays. Consistently, deletion of single CPC1 of the haploid V. dahliae resulted in strains that are sensitive to amino-acid starvation and cause strongly reduced symptoms in the plant-host tomato (Solanum lycopersicum). The allodiploid V. longisporum and the haploid V. dahliae are the first phytopathogenic fungi that were shown to require CPC1 for infection and colonization of their respective host plants, oilseed rape and tomato. PMID:23883358

Timpner, Christian; Braus-Stromeyer, Susanna A; Tran, Van Tuan; Braus, Gerhard H

2013-11-01

37

Population History and Pathways of Spread of the Plant Pathogen Phytophthora plurivora  

E-print Network

.pone.0085368 Editor: Mark Gijzen, Agriculture and Agri-Food Canada, Canada Received September 24, 2013 environments. It is supposed to be native to Europe while resident populations are also present in the US. We trade has allowed the pathogen to colonize new environments and/or hosts, resulting in population growth

Grünwald, Niklaus J.

38

Genetic Interactions of DNA Repair Pathways in the Pathogen Neisseria meningitidis  

Microsoft Academic Search

The current increase in the incidence and severity of infectious diseases mandates improved understanding of the basic biology and DNA repair profiles of virulent microbes. In our studies of the major pathogen and model organism Neisseria meningitidis, we constructed a panel of mutants inactivating genes involved in base excision repair, mismatch repair, nucleotide excision repair (NER), translesion synthesis, and recombinational

Tonje Davidsen; Hanne K. Tuven; M. Bjoras; E. A. Rodland; T. Tonjum

2007-01-01

39

Crosstalk between the Unfolded Protein Response and Pathways That Regulate Pathogenic Development in Ustilago maydis[C][W  

PubMed Central

The unfolded protein response (UPR) is a conserved eukaryotic signaling pathway regulating endoplasmic reticulum (ER) homeostasis during ER stress, which results, for example, from an increased demand for protein secretion. Here, we characterize the homologs of the central UPR regulatory proteins Hac1 (for Homologous to ATF/CREB1) and Inositol Requiring Enzyme1 in the plant pathogenic fungus Ustilago maydis and demonstrate that the UPR is tightly interlinked with the b mating-type-dependent signaling pathway that regulates pathogenic development. Exact timing of UPR is required for virulence, since premature activation interferes with the b-dependent switch from budding to filamentous growth. In addition, we found crosstalk between UPR and the b target Clampless1 (Clp1), which is essential for cell cycle release and proliferation in planta. The unusual C-terminal extension of the U. maydis Hac1 homolog, Cib1 (for Clp1 interacting bZIP1), mediates direct interaction with Clp1. The interaction between Clp1 and Cib1 promotes stabilization of Clp1, resulting in enhanced ER stress tolerance that prevents deleterious UPR hyperactivation. Thus, the interaction between Cib1 and Clp1 constitutes a checkpoint to time developmental progression and increased secretion of effector proteins at the onset of biotrophic development. Crosstalk between UPR and the b mating-type regulated developmental program adapts ER homeostasis to the changing demands during biotrophy. PMID:24179126

Heimel, Kai; Freitag, Johannes; Hampel, Martin; Ast, Julia; Bolker, Michael; Kamper, Jorg

2013-01-01

40

The Drosophila melanogaster Toll Pathway Participates in Resistance to Infection by the Gram-Negative Human Pathogen Pseudomonas aeruginosa  

PubMed Central

Pseudomonas aeruginosa is a gram-negative pathogen that infects immunocompromised and cystic fibrosis patients. The molecular basis of the host-P. aeruginosa interaction and the effect of specific P. aeruginosa virulence factors on various components of the innate immunity pathways are largely unknown. We examine interactions between P. aeruginosa virulence factors and components of innate immunity response in the Drosophila melanogaster model system to reveal the importance of the Toll signaling pathway in resistance to infection by the P. aeruginosa human isolate PA14. Using the two PA14-isogenic mutants plcS and dsbA, we show that Drosophila loss-of-function mutants of Spatzle, the extracellular ligand of Toll, and Dorsal and Dif, two NF-?B-like transcription factors, allow increased P. aeruginosa infectivity within fly tissues. In contrast, a constitutively active Toll mutant and a loss-of-function mutant of Cactus, an I?B-like factor that inhibits the Toll signaling, reduce infectivity. Our finding that Dorsal activity is required to restrict P. aeruginosa infectivity in Drosophila provides direct in vivo evidence for Dorsal function in adult fly immunity. Additionally, our results provide the basis for future studies into interactions between P. aeruginosa virulence factors and components of the Toll signaling pathway, which is functionally conserved between flies and humans. PMID:12819096

Lau, Gee W.; Goumnerov, Boyan C.; Walendziewicz, Cynthia L.; Hewitson, Jennifer; Xiao, Wenzhong; Mahajan-Miklos, Shalina; Tompkins, Ronald G.; Perkins, Lizabeth A.; Rahme, Laurence G.

2003-01-01

41

Conidial Dihydroxynaphthalene Melanin of the Human Pathogenic Fungus Aspergillus fumigatus Interferes with the Host Endocytosis Pathway.  

PubMed

Aspergillus fumigatus is the most important air-borne fungal pathogen of humans. The interaction of the pathogen with the host's immune system represents a key process to understand pathogenicity. For elimination of invading microorganisms, they need to be efficiently phagocytosed and located in acidified phagolysosomes. However, as shown previously, A. fumigatus is able to manipulate the formation of functional phagolysosomes. Here, we demonstrate that in contrast to pigmentless pksP mutant conidia of A. fumigatus, the gray-green wild-type conidia inhibit the acidification of phagolysosomes of alveolar macrophages, monocyte-derived macrophages, and human neutrophil granulocytes. Therefore, this inhibition is independent of the cell type and applies to the major immune effector cells required for defense against A. fumigatus. Studies with melanin ghosts indicate that the inhibitory effect of wild-type conidia is due to their dihydroxynaphthalene (DHN)-melanin covering the conidia, whereas the hydrophobin RodA rodlet layer plays no role in this process. This is also supported by the observation that pksP conidia still exhibit the RodA hydrophobin layer, as shown by scanning electron microscopy. Mutants defective in different steps of the DHN-melanin biosynthesis showed stronger inhibition than pksP mutant conidia but lower inhibition than wild-type conidia. Moreover, A. fumigatus and A. flavus led to a stronger inhibition of phagolysosomal acidification than A. nidulans and A. terreus. These data indicate that a certain type of DHN-melanin that is different in the various Aspergillus species, is required for maximal inhibition of phagolysosomal acidification. Finally, we identified the vacuolar ATPase (vATPase) as potential target for A. fumigatus based on the finding that addition of bafilomycin which inhibits vATPase, led to complete inhibition of the acidification whereas the fusion of phagosomes containing wild-type conidia and lysosomes was not affected. PMID:21747802

Thywißen, Andreas; Heinekamp, Thorsten; Dahse, Hans-Martin; Schmaler-Ripcke, Jeannette; Nietzsche, Sandor; Zipfel, Peter F; Brakhage, Axel A

2011-01-01

42

Conidial Dihydroxynaphthalene Melanin of the Human Pathogenic Fungus Aspergillus fumigatus Interferes with the Host Endocytosis Pathway  

PubMed Central

Aspergillus fumigatus is the most important air-borne fungal pathogen of humans. The interaction of the pathogen with the host's immune system represents a key process to understand pathogenicity. For elimination of invading microorganisms, they need to be efficiently phagocytosed and located in acidified phagolysosomes. However, as shown previously, A. fumigatus is able to manipulate the formation of functional phagolysosomes. Here, we demonstrate that in contrast to pigmentless pksP mutant conidia of A. fumigatus, the gray-green wild-type conidia inhibit the acidification of phagolysosomes of alveolar macrophages, monocyte-derived macrophages, and human neutrophil granulocytes. Therefore, this inhibition is independent of the cell type and applies to the major immune effector cells required for defense against A. fumigatus. Studies with melanin ghosts indicate that the inhibitory effect of wild-type conidia is due to their dihydroxynaphthalene (DHN)-melanin covering the conidia, whereas the hydrophobin RodA rodlet layer plays no role in this process. This is also supported by the observation that pksP conidia still exhibit the RodA hydrophobin layer, as shown by scanning electron microscopy. Mutants defective in different steps of the DHN-melanin biosynthesis showed stronger inhibition than pksP mutant conidia but lower inhibition than wild-type conidia. Moreover, A. fumigatus and A. flavus led to a stronger inhibition of phagolysosomal acidification than A. nidulans and A. terreus. These data indicate that a certain type of DHN-melanin that is different in the various Aspergillus species, is required for maximal inhibition of phagolysosomal acidification. Finally, we identified the vacuolar ATPase (vATPase) as potential target for A. fumigatus based on the finding that addition of bafilomycin which inhibits vATPase, led to complete inhibition of the acidification whereas the fusion of phagosomes containing wild-type conidia and lysosomes was not affected. PMID:21747802

Thywißen, Andreas; Heinekamp, Thorsten; Dahse, Hans-Martin; Schmaler-Ripcke, Jeannette; Nietzsche, Sandor; Zipfel, Peter F.; Brakhage, Axel A.

2011-01-01

43

Highly Pathogenic H5N1 Avian Influenza: Entry Pathways into North America via Bird Migration  

PubMed Central

Given the possibility of highly pathogenic H5N1 avian influenza arriving in North America and monitoring programs that have been established to detect and track it, we review intercontinental movements of birds. We divided 157 bird species showing regular intercontinental movements into four groups based on patterns of movement—one of these groups (breed Holarctic, winter Eurasia) fits well with the design of the monitoring programs (i.e., western Alaska), but the other groups have quite different movement patterns, which would suggest the importance of H5N1 monitoring along the Pacific, Atlantic, and Gulf coasts of North America. PMID:17330144

Peterson, A. Townsend; Benz, Brett W.; Papes, Monica

2007-01-01

44

AUTOANTIBODY PROFILING TO IDENTIFY BIOMARKERS OF KEY PATHOGENIC PATHWAYS IN MUCINOUS OVARIAN CANCER  

PubMed Central

Mucinous epithelial ovarian cancers are clinically and morphologically distinct from the other histopathologic subtypes of ovarian cancer. Unlike other ovarian subtypes, epidemiologic studies have indicated that tobacco exposure is a significant risk factor for developing mucinous ovarian cancer. Detection of autoantibody reactivity is useful in biomarker discovery and for explaining the role of important pathophysiologic pathways in disease. In order to study if there are specific antibody biomarkers in the plasma samples of mucinous ovarian cancer patients, we have initiated a screen by employing a “reverse capture antibody microarray” platform that uses native host antigens derived from mucinous ovarian tissues as “baits” for the capture of differentially labeled patient and control autoantibodies. 35 autoantibodies that were significantly elevated in the cancer plasma samples compared with healthy controls, and six autoantibodies that segregated smoking and nonsmoking patients were identified. Functional annotation of the antibody targets has identified nine target antigens involved in integrin and Wnt signaling pathways. Immunohistochemistry of archived ovarian specimens showed significant overexpression of eight of the nine target antigens in mucinous ovarian tumor tissues, suggesting that plasma autoantibodies from mucinous ovarian cancer patients might have heightened reactivities with epitopes presented by these overexpressed antigens. Autoantibody profiling may have an unexpected utility in uncovering key signaling pathways that are dysregulated in the system of interest. PMID:19926475

Tang, Liangdan; Yang, Junzheng; Ng, Shu-Kay; Rodriguez, Noah; Choi, Pui-Wah; Vitonis, Allison; Wang, Kui; McLachlan, Geoffrey J.; Caiazzo, Robert J.; Liu, Brian C.-S.; Welch, William R.; Cramer, Daniel W.; Berkowitz, Ross S.; Ng, Shu-Wing

2009-01-01

45

Unraveling Unique Structure and Biosynthesis Pathway of N-Linked Glycans in Human Fungal Pathogen Cryptococcus neoformans by Glycomics Analysis*  

PubMed Central

The encapsulated fungal pathogen Cryptococcus neoformans causes cryptococcosis in immunocompromised individuals. Although cell surface mannoproteins have been implicated in C. neoformans pathogenicity, the structure of N-linked glycans assembled on mannoproteins has not yet been elucidated. By analyzing oligosaccharide profiles combined with exoglycosidase treatment, we report here that C. neoformans has serotype-specific high mannose-type N-glycans with or without a ?1,2-xylose residue, which is attached to the trimannosyl core of N-glycans. Interestingly, the neutral N-glycans of serotypes A and D were shown to contain a xylose residue, whereas those of serotype B appeared to be much shorter and devoid of a xylose residue. Moreover, analysis of the C. neoformans uxs1? mutant demonstrated that UDP-xylose is utilized as a donor sugar in N-glycan biosynthesis. We also constructed and analyzed a set of C. neoformans mutant strains lacking genes putatively assigned to the reconstructed N-glycan biosynthesis pathway. It was shown that the outer chain of N-glycan is initiated by CnOch1p with addition of an ?1,6-mannose residue and then subsequently extended by CnMnn2p with multiple additions of ?1,2-mannose residues. Finally, comparative analysis of acidic N-glycans from wild-type, Cnoch1?, Cnmnn2?, and Cnuxs1? strains strongly indicated the presence of xylose phosphate attached to mannose residues in the core and outer region of N-glycans. Our data present the first report on the unique structure and biosynthesis pathway of N-glycans in C. neoformans. PMID:22500028

Park, Jeong-Nam; Lee, Dong-Jik; Kwon, Ohsuk; Oh, Doo-Byoung; Bahn, Yong-Sun; Kang, Hyun Ah

2012-01-01

46

Linkage of cold acclimation and disease resistance through plant-pathogen interaction pathway in Vitis amurensis grapevine.  

PubMed

Low temperatures cause severe damage to none cold hardy grapevines. A preliminary survey with Solexa sequencing technology was used to analyze gene expression profiles of cold hardy Vitis amurensis 'Zuoshan-1' after cold acclimation at 4 °C for 48 h. A total of 16,750 and 18,068 putative genes were annotated for 4 °C-treated and control library, respectively. Among them, 393 genes were upregulated for at least 20-fold, while 69 genes were downregulated for at least 20-fold under the 4 °C treatment for 48 h. A subset of 101 genes from this survey was investigated further using reverse transcription polymerase chain reaction (RT-PCR). Genes associated with signaling events in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), including generation of calcium signals (CNGC, CMLs), jasmonic acid signal (JAZ1), oxidative burst (Rboh), and phosphorylation (FLS2, BAK, MEKK1, MKKs) cascades, were upregulated after cold acclimation. Disease resistance genes (RPM1, RPS5, RIN4, PBS1) in the process of effector-triggered immunity (ETI) were also upregulated in the current condition. Defense-related genes (WRKYs, PR1, MIN7) involved in both PTI and ETI processes were abundantly expressed after cold acclimation. Our results indicated that plant-pathogen interaction pathways were linked to the cold acclimation in V. amurensis grapevine. Other biotic- and abiotic-related genes, such as defense (protein phosphatase 2C, U-box domain proteins, NCED1, stilbene synthase), transcription (DREBs, MYBs, ERFs, ZFPs), signal transduction (kinase, calcium, and auxin signaling), transport (ATP-binding cassette (ABC) transporters, auxin:hydrogen symporter), and various metabolism, were also abundantly expressed in the cold acclimation of V. Amurensis 'Zuoshan-1' grapevine. This study revealed a series of critical genes and pathways to delineate important biological processes affected by low temperature in 'Zuoshan-1'. PMID:25154381

Wu, Jiao; Zhang, Yali; Yin, Ling; Qu, Junjie; Lu, Jiang

2014-12-01

47

METHODOLOGY ARTICLE Open Access SNP-based pathway enrichment analysis for  

E-print Network

in using genome-wide association studies (GWAS) to discover the genetic basis of complex diseases. Many from these studies is that the genetic variations discovered by GWAS can only explain a small fraction variations underlying a biological pathway, rather than separately as in the traditional GWAS studies

Yu, Zhaoxia

48

Evolution of a Pathogen: A Comparative Genomics Analysis Identifies a Genetic Pathway to Pathogenesis in Acinetobacter  

PubMed Central

Acinetobacter baumannii is an emergent and global nosocomial pathogen. In addition to A. baumannii, other Acinetobacter species, especially those in the Acinetobacter calcoaceticus-baumannii (Acb) complex, have also been associated with serious human infection. Although mechanisms of attachment, persistence on abiotic surfaces, and pathogenesis in A. baumannii have been identified, the genetic mechanisms that explain the emergence of A. baumannii as the most widespread and virulent Acinetobacter species are not fully understood. Recent whole genome sequencing has provided insight into the phylogenetic structure of the genus Acinetobacter. However, a global comparison of genomic features between Acinetobacter spp. has not been described in the literature. In this study, 136 Acinetobacter genomes, including 67 sequenced in this study, were compared to identify the acquisition and loss of genes in the expansion of the Acinetobacter genus. A whole genome phylogeny confirmed that A. baumannii is a monophyletic clade and that the larger Acb complex is also a well-supported monophyletic group. The whole genome phylogeny provided the framework for a global genomic comparison based on a blast score ratio (BSR) analysis. The BSR analysis demonstrated that specific genes have been both lost and acquired in the evolution of A. baumannii. In addition, several genes associated with A. baumannii pathogenesis were found to be more conserved in the Acb complex, and especially in A. baumannii, than in other Acinetobacter genomes; until recently, a global analysis of the distribution and conservation of virulence factors across the genus was not possible. The results demonstrate that the acquisition of specific virulence factors has likely contributed to the widespread persistence and virulence of A. baumannii. The identification of novel features associated with transcriptional regulation and acquired by clades in the Acb complex presents targets for better understanding the evolution of pathogenesis and virulence in the expansion of the genus. PMID:23365658

Sahl, Jason W.; Gillece, John D.; Schupp, James M.; Waddell, Victor G.; Driebe, Elizabeth M.; Engelthaler, David M.; Keim, Paul

2013-01-01

49

Evolution of a pathogen: a comparative genomics analysis identifies a genetic pathway to pathogenesis in Acinetobacter.  

PubMed

Acinetobacter baumannii is an emergent and global nosocomial pathogen. In addition to A. baumannii, other Acinetobacter species, especially those in the Acinetobacter calcoaceticus-baumannii (Acb) complex, have also been associated with serious human infection. Although mechanisms of attachment, persistence on abiotic surfaces, and pathogenesis in A. baumannii have been identified, the genetic mechanisms that explain the emergence of A. baumannii as the most widespread and virulent Acinetobacter species are not fully understood. Recent whole genome sequencing has provided insight into the phylogenetic structure of the genus Acinetobacter. However, a global comparison of genomic features between Acinetobacter spp. has not been described in the literature. In this study, 136 Acinetobacter genomes, including 67 sequenced in this study, were compared to identify the acquisition and loss of genes in the expansion of the Acinetobacter genus. A whole genome phylogeny confirmed that A. baumannii is a monophyletic clade and that the larger Acb complex is also a well-supported monophyletic group. The whole genome phylogeny provided the framework for a global genomic comparison based on a blast score ratio (BSR) analysis. The BSR analysis demonstrated that specific genes have been both lost and acquired in the evolution of A. baumannii. In addition, several genes associated with A. baumannii pathogenesis were found to be more conserved in the Acb complex, and especially in A. baumannii, than in other Acinetobacter genomes; until recently, a global analysis of the distribution and conservation of virulence factors across the genus was not possible. The results demonstrate that the acquisition of specific virulence factors has likely contributed to the widespread persistence and virulence of A. baumannii. The identification of novel features associated with transcriptional regulation and acquired by clades in the Acb complex presents targets for better understanding the evolution of pathogenesis and virulence in the expansion of the genus. PMID:23365658

Sahl, Jason W; Gillece, John D; Schupp, James M; Waddell, Victor G; Driebe, Elizabeth M; Engelthaler, David M; Keim, Paul

2013-01-01

50

Trypanosoma cruzi Infection and Endothelin-1 Cooperatively Activate Pathogenic Inflammatory Pathways in Cardiomyocytes  

PubMed Central

Trypanosoma cruzi, the causative agent of Chagas' disease, induces multiple responses in the heart, a critical organ of infection and pathology in the host. Among diverse factors, eicosanoids and the vasoactive peptide endothelin-1 (ET-1) have been implicated in the pathogenesis of chronic chagasic cardiomyopathy. In the present study, we found that T. cruzi infection in mice induces myocardial gene expression of cyclooxygenase-2 (Cox2) and thromboxane synthase (Tbxas1) as well as endothelin-1 (Edn1) and atrial natriuretic peptide (Nppa). T. cruzi infection and ET-1 cooperatively activated the Ca2+/calcineurin (Cn)/nuclear factor of activated T cells (NFAT) signaling pathway in atrial myocytes, leading to COX-2 protein expression and increased eicosanoid (prostaglandins E2 and F2?, thromboxane A2) release. Moreover, T. cruzi infection of ET-1-stimulated cardiomyocytes resulted in significantly enhanced production of atrial natriuretic peptide (ANP), a prognostic marker for impairment in cardiac function of chagasic patients. Our findings support an important role for the Ca2+/Cn/NFAT cascade in T. cruzi-mediated myocardial production of inflammatory mediators and may help define novel therapeutic targets. PMID:23409199

Corral, Ricardo S.; Guerrero, Nestor A.; Cuervo, Henar; Girones, Nuria; Fresno, Manuel

2013-01-01

51

Pathogenic mechanisms of bradykinin mediated diseases: dysregulation of an innate inflammatory pathway.  

PubMed

Binding of negatively charged macromolecules to factor XII induces a conformational change such that it becomes a substrate for trace amounts of activated factor present in plasma (less than 0.01%). As activated factor XII (factor XIIa or factor XIIf) forms, it converts prekallikrein (PK) to kallikrein and kallikrein cleaves high molecular weight kininogen (HK) to release bradykinin. A far more rapid activation of the remaining unactivated factor XII occurs by enzymatic cleavage by kallikrein (kallikrein-feedback) and sequential cleavage yields two forms of activated factor XII; namely, factor XIIa followed by factor XII fragment (factor XIIf). PK circulates bound to HK and binding induces a conformational change in PK so that it acquires enzymatic activity and can stoichiometrically cleave HK to produce bradykinin. This reaction is prevented from occurring in plasma by the presence of C1 inhibitor (C1 INH). The same active site leads to autoactivation of the PK-HK complex to generate kallikrein if a phosphate containing buffer is used. Theoretically, formation of kallikrein by this factor XII-independent route can activate surface-bound factor XII to generate factor XIIa resulting in a marked increase in the rate of bradykinin formation as stoichiometric reactions are replaced by Michaelis-Menton, enzyme-substrate, kinetics. Zinc-dependent binding of the constituents of the bradykinin-forming cascade to the surface of endothelial cells is mediated by gC1qR and bimolecular complexes of gC1qR-cytokeratin 1 and cytokeratin 1-u-PAR (urokinase plasminogen activator receptor). Factor XII and HK compete for binding to free gC1qR (present in excess) while cytokeratin 1-u-PAR preferentially binds factor XII and gC1qR-cytokeratin 1 preferentially binds HK. Autoactivation of factor XII can be initiated as a result of binding to gC1qR but is prevented by C1 INH. Yet stoichiometric activation of PK-HK to yield kallikrein in the absence of factor XII can be initiated by heat shock protein 90 (HSP-90) which forms a zinc-dependent trimolecular complex by binding to HK. Thus, endothelial cell-dependent activation can be initiated by activation of factor XII or by activation of PK-HK. Hereditary angioedema (HAE), types I and II, are due to autosomal dominant mutations of the C1 INH gene. In type I disease, the level of C1 INH protein and function is proportionately low, while type II disease has a normal protein level but diminished function. There is trans-inhibition of the one normal gene so that functional levels are 30% or less and severe angioedema affecting peripheral structures, the gastrointestinal tract, and the larynx results. Prolonged incubation of plasma of HAE patients (but not normal controls) leads to bradykinin formation and conversion of PK to kallikrein which is reversed by reconstitution with C1 INH. The disorder can be treated by C1 INH replacement, inhibition of plasma kallikrein, or blockade at the bradykinin B-2 receptor. A recently described HAE with normal C1 INH (based on inhibition of activated C1s) presents similarly; the defect is not yet clear, however one-third of patients have a mutant factor XII gene. We have shown that this HAE has a defect in bradykinin overproduction whether the factor XII mutation is present or not, that patients' C1 INH is capable of inhibiting factor XIIa and kallikrein (and not just activated C1) but the functional level is approximately 40-60% of normal, and that ?2 macroglobulin protein levels are normal. In vitro abnormalities can be suppressed by raising C1 INH to twice normal levels. Finally, aggregated proteins have been shown to activate the bradykinin-forming pathway by catalyzing factor XII autoactivation. Those include the amyloid ? protein of Alzheimer's disease and cryoglobulins. This may represent a new avenue for kinin-dependent research in human disease. In allergy (anaphylaxis; perhaps other mast cell-dependent reactions), the oversulfated proteoglycan of mast cells, liberated along with histamine, also catalyze factor XII autoactivation. PMID:24388213

Kaplan, Allen P; Joseph, Kusumam

2014-01-01

52

Elucidation of the pathways responsible for the biosynthesis of UDP-N,N'-diacetylbacillosamine in bacterial pathogens  

E-print Network

The highly-modified, bacterial sugar N,N'-diacetylbacillosamine (diNAcBac) has been implicated in the pathogenicity of certain microbes through its incorporation onto various protein virulence factors. In particular, ...

Morrison, Michael James

2014-01-01

53

Biosecurity and Vector Behaviour: Evaluating the Potential Threat Posed by Anglers and Canoeists as Pathways for the Spread of Invasive Non-Native Species and Pathogens  

PubMed Central

Invasive non-native species (INNS) endanger native biodiversity and are a major economic problem. The management of pathways to prevent their introduction and establishment is a key target in the Convention on Biological Diversity's Aichi biodiversity targets for 2020. Freshwater environments are particularly susceptible to invasions as they are exposed to multiple introduction pathways, including non-native fish stocking and the release of boat ballast water. Since many freshwater INNS and aquatic pathogens can survive for several days in damp environments, there is potential for transport between water catchments on the equipment used by recreational anglers and canoeists. To quantify this biosecurity risk, we conducted an online questionnaire with 960 anglers and 599 canoeists to investigate their locations of activity, equipment used, and how frequently equipment was cleaned and/or dried after use. Anglers were also asked about their use and disposal of live bait. Our results indicate that 64% of anglers and 78.5% of canoeists use their equipment/boat in more than one catchment within a fortnight, the survival time of many of the INNS and pathogens considered in this study and that 12% of anglers and 50% of canoeists do so without either cleaning or drying their kit between uses. Furthermore, 8% of anglers and 28% of canoeists had used their equipment overseas without cleaning or drying it after each use which could facilitate both the introduction and secondary spread of INNS in the UK. Our results provide a baseline against which to evaluate the effectiveness of future biosecurity awareness campaigns, and identify groups to target with biosecurity awareness information. Our results also indicate that the biosecurity practices of these groups must improve to reduce the likelihood of inadvertently spreading INNS and pathogens through these activities. PMID:24717714

Anderson, Lucy G.; White, Piran C. L.; Stebbing, Paul D.; Stentiford, Grant D.; Dunn, Alison M.

2014-01-01

54

Specialized and shared functions of the histidine kinase- and HOG1 MAP kinase-mediated signaling pathways in Alternaria alternata, a filamentous fungal pathogen of citrus.  

PubMed

Signal transduction pathways are critical for the coordination of complex cellular processes in cells. In Alternaria alternata, a necrotrophic fungal pathogen of citrus, cloning and characterization of a gene coding a Group III histidine kinase (AaHSK1) and the yeast HOG1 ortholog (AaHOG1) showed the two genes to operate, both uniquely and synergistically, in a number of physiological and pathological functions. Systemic loss-of-function genetics in A. alternata revealed that AaHSK1 is a primary regulator for cellular resistance to sugar osmotic stress and for sensitivity to dicarboximide or phenylpyrrole fungicides. These functions were likely modulated by unknown mechanisms rather than solely by the AaHOG1-mediated pathway. AaHOG1, which conferred cellular resistance to salts and oxidative stress, also bypassed AaHSK1, even though deletion of AaHSK1 affected AaHOG1 phosphorylation. Phosphorylation of AaHOG1 was increased when the fungus was treated with osmotic stress, fungicides or H(2)O(2). Fungal mutants impaired in AaHSK1, AaHOG1, AaAP1 (encoding a redox-responsive transcription factor) or AaFUS3 (encoding a MAP kinase) were all hypersensitive to 2-chloro-5-hydroxypyridine (CHP) or 2,3,5-triiodobenzoic acid (TIBA). An AaHOG1::sGFP (synthetic green fluorescent protein) fusion protein became localized in the nucleus in response to H(2)O(2), CHP, TIBA, fungicides, but not glucose. Glucose, however, enhanced AaHOG1 phosphorylation and nuclear localization in the AaHSK1 deficient background. Accumulation of the AaHSK1 gene transcript was negatively regulated by AaHOG1, AaAP1 or AaFUS3. AaHOG1 was necessary for fungal pathogenicity, yet AaHSK1 was completely dispensable for pathogenicity. Our results highlight a dramatic flexibility and uniqueness in the signaling pathways that are involved in responding to diverse environmental stimuli in A. alternata. PMID:20601043

Lin, Ching-Hsuan; Chung, Kuang-Ren

2010-10-01

55

Phenotypic characterization of mutants of the citrus pathogen Colletotrichum acutatum defective in a PacC-mediated pH regulatory pathway.  

PubMed

Environmental pH plays an important role in the growth and differentiation of microorganisms. In fungi, one well-studied pH-response pathway is controlled by the transcriptional regulator PacC. The PacC(KLAP2) gene of the citrus pathogen Colletotrichum acutatum is required for virulence. Here, the phenotypes of C. acutatum mutants obtained by targeted disruption of PacC(KLAP2) are characterized. The PacC(KLAP2) null mutants displayed hypersensitivity to a wide range of compounds but were more tolerant than wild type to cell wall-degrading enzymes (CWDEs). The null mutants have lower cell-wall chitin content as well as lower cellulase, cutinase, xylanase, and catalase activities, but markedly increased pecteolytic activities. Expression of the genes encoding endo-polygalacturonase and cellulase is higher in the null mutants compared with wild type, whereas expression of the gene for cutinase is almost completely abolished, suggesting that cutinase and other CWDEs may play a role in fungal pathogenicity. PMID:17986091

You, Bang-Jau; Chung, Kuang-Ren

2007-12-01

56

WATERBORNE PATHOGENS IN URBAN WATERSHEDS  

EPA Science Inventory

Pathogens are microorganisms that can cause sickness or even death. A serious concern for managers of water resources, pathogens in the urban environment easily enter waters through a number of pathways, including discharge of inadequately treated sewage, stormwater runoff, combi...

57

Pathogen Sensing Pathways in Human Embryonic Stem Cell Derived-Endothelial Cells: Role of NOD1 Receptors  

PubMed Central

Human embryonic stem cell-derived endothelial cells (hESC-EC), as well as other stem cell derived endothelial cells, have a range of applications in cardiovascular research and disease treatment. Endothelial cells sense Gram-negative bacteria via the pattern recognition receptors (PRR) Toll-like receptor (TLR)-4 and nucleotide-binding oligomerisation domain-containing protein (NOD)-1. These pathways are important in terms of sensing infection, but TLR4 is also associated with vascular inflammation and atherosclerosis. Here, we have compared TLR4 and NOD1 responses in hESC-EC with those of endothelial cells derived from other stem cells and with human umbilical vein endothelial cells (HUVEC). HUVEC, endothelial cells derived from blood progenitors (blood outgrowth endothelial cells; BOEC), and from induced pluripotent stem cells all displayed both a TLR4 and NOD1 response. However, hESC-EC had no TLR4 function, but did have functional NOD1 receptors. In vivo conditioning in nude rats did not confer TLR4 expression in hESC-EC. Despite having no TLR4 function, hESC-EC sensed Gram-negative bacteria, a response that was found to be mediated by NOD1 and the associated RIP2 signalling pathways. Thus, hESC-EC are TLR4 deficient but respond to bacteria via NOD1. This data suggests that hESC-EC may be protected from unwanted TLR4-mediated vascular inflammation, thus offering a potential therapeutic advantage. PMID:24690886

Reed, Daniel M.; Foldes, Gabor; Gatheral, Timothy; Paschalaki, Koralia E.; Lendvai, Zsuzsanna; Bagyura, Zsolt; Nemeth, Tamas; Skopal, Judit; Merkely, Bela; Telcian, Aurica G.; Gogsadze, Leila; Edwards, Michael R.; Gough, Peter J.; Bertin, John; Johnston, Sebastian L.; Harding, Sian E.; Mitchell, Jane A.

2014-01-01

58

Research article Activity of two catabolic enzymes of the phosphogluconate pathway in mesquite roots inoculated with Azospirillum brasilense Cd  

Microsoft Academic Search

The mesquite amargo (Prosopis articulate), one of the main nurse trees of the Sonoran Desert in Mexico, is responsible for major, natural re- vegetation processes. It exudes gluconic acid in root exudates, a favorite carbon source for the plant growth-promoting bacterium Azospirillum bra- silense. Two enzymes, gluconokinase (EC 2.7.1.12) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44), participating in the phosphogluconate pathway, are

Luis A. Leyva; Yoav Bashan

59

Reactive oxygen species homeostasis and virulence of the fungal pathogen Cryptococcus neoformans requires an intact proline catabolism pathway.  

PubMed

Degradation of the multifunctional amino acid proline is associated with mitochondrial oxidative respiration. The two-step oxidation of proline is catalyzed by proline oxidase and ?(1)-pyrroline-5-carboxylate (P5C) dehydrogenase, which produce P5C and glutamate, respectively. In animal and plant cells, impairment of P5C dehydrogenase activity results in P5C-proline cycling when exogenous proline is supplied via the actions of proline oxidase and P5C reductase (the enzyme that converts P5C to proline). This proline is oxidized by the proline oxidase-FAD complex that delivers electrons to the electron transport chain and to O2, leading to mitochondrial reactive oxygen species (ROS) overproduction. Coupled activity of proline oxidase and P5C dehydrogenase is therefore important for maintaining ROS homeostasis. In the genome of the fungal pathogen Cryptococcus neoformans, there are two paralogs (PUT1 and PUT5) that encode proline oxidases and a single ortholog (PUT2) that encodes P5C dehydrogenase. Transcription of all three catabolic genes is inducible by the presence of proline. However, through the creation of deletion mutants, only Put5 and Put2 were found to be required for proline utilization. The put2? mutant also generates excessive mitochondrial superoxide when exposed to proline. Intracellular accumulation of ROS is a critical feature of cell death; consistent with this fact, the put2? mutant exhibits a slight, general growth defect. Furthermore, Put2 is required for optimal production of the major cryptococcal virulence factors. During murine infection, the put2? mutant was discovered to be avirulent; this is the first report highlighting the importance of P5C dehydrogenase in enabling pathogenesis of a microorganism. PMID:23564202

Lee, I Russel; Lui, Edmund Y L; Chow, Eve W L; Arras, Samantha D M; Morrow, Carl A; Fraser, James A

2013-06-01

60

Reactive Oxygen Species Homeostasis and Virulence of the Fungal Pathogen Cryptococcus neoformans Requires an Intact Proline Catabolism Pathway  

PubMed Central

Degradation of the multifunctional amino acid proline is associated with mitochondrial oxidative respiration. The two-step oxidation of proline is catalyzed by proline oxidase and ?1-pyrroline-5-carboxylate (P5C) dehydrogenase, which produce P5C and glutamate, respectively. In animal and plant cells, impairment of P5C dehydrogenase activity results in P5C-proline cycling when exogenous proline is supplied via the actions of proline oxidase and P5C reductase (the enzyme that converts P5C to proline). This proline is oxidized by the proline oxidase-FAD complex that delivers electrons to the electron transport chain and to O2, leading to mitochondrial reactive oxygen species (ROS) overproduction. Coupled activity of proline oxidase and P5C dehydrogenase is therefore important for maintaining ROS homeostasis. In the genome of the fungal pathogen Cryptococcus neoformans, there are two paralogs (PUT1 and PUT5) that encode proline oxidases and a single ortholog (PUT2) that encodes P5C dehydrogenase. Transcription of all three catabolic genes is inducible by the presence of proline. However, through the creation of deletion mutants, only Put5 and Put2 were found to be required for proline utilization. The put2? mutant also generates excessive mitochondrial superoxide when exposed to proline. Intracellular accumulation of ROS is a critical feature of cell death; consistent with this fact, the put2? mutant exhibits a slight, general growth defect. Furthermore, Put2 is required for optimal production of the major cryptococcal virulence factors. During murine infection, the put2? mutant was discovered to be avirulent; this is the first report highlighting the importance of P5C dehydrogenase in enabling pathogenesis of a microorganism. PMID:23564202

Lee, I. Russel; Lui, Edmund Y. L.; Chow, Eve W. L.; Arras, Samantha D. M.; Morrow, Carl A.; Fraser, James A.

2013-01-01

61

Featured Article: Selective blockade of the OGF-OGFr pathway by naltrexone accelerates fibroblast proliferation and wound healing.  

PubMed

Naltrexone (NTX) is an opioid receptor antagonist that acts at classical and non-classical opioid receptors including the opioid growth factor receptor (OGFr). Animal models of type 1 and type 2 diabetes, as well as normal rodents, have shown that topical NTX enhances the healing rates of corneal epithelium and full-thickness cutaneous wounds. The mechanism of this general opioid antagonist on growth, and in particular the specific receptor pathway involved, is not understood. Tissue culture studies using NIH 3T3 fibroblasts and primary rat auricular fibroblasts were established to evaluate growth following opioid receptor antagonist treatment. Treatment of cells with CTOP, naltrindole, or nalmefene, selective antagonists for mu, delta, and kappa opioid receptors, respectively, did not accelerate cell replication. Addition of the classical opioid receptor peptides DAMGO, DPDPE, or EKC did not alter cell growth, suggesting that the classical opioid receptors were not involved in cutaneous wound healing. However, NTX (10(-6?)M) increased the growth of NIH 3T3 fibroblasts in culture over a 96-h period, and the specific ligand OGF decreased cell growth, supporting that the OGF-OGFr axis is tonically active and constitutively expressed in fibroblasts, the primary cell type in granulation tissue of the skin. Transfection of NIH 3T3 cells with OGFr siRNA reduced receptor protein; subsequent treatment with NTX did not accelerate cell proliferation. These data indicate that blockade of the OGFr pathway enhances proliferation of fibroblasts in vitro, and in a primary culture of auricular fibroblasts, suggesting that the effect of NTX on growth is mediated through the OGF-OGFr axis. Finally, antagonists for classical opioid receptors as well as NTX were topically applied to cutaneous wounds in type 1 diabetic rats; only NTX accelerated wound closure. These studies indicate that the mechanistic pathway underlying the effects of NTX to enhance cutaneous wound closure in diabetic and nondiabetic subjects is specific blockade of the OGF-OGFr regulatory axis. PMID:25030485

Immonen, Jessica A; Zagon, Ian S; McLaughlin, Patricia J

2014-10-01

62

MICROBIOLOGY: A Bacterial Pathogen Sees the Light  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Photosensitive proteins abound in the bacterial kingdom, but their cellular functions often remain a mystery. In this Perspective Kennis and Crosson discuss how Swartz et al. identified a functional role for a new type of light sensor in bacteria--light, oxygen, or voltage (LOV) histidine kinase. In the notorious pathogen Brucella abortus, light increases the enzymatic activity of this kinase, which, remarkably, increases virulence of the bacterium. Related LOV histidine kinases are conserved across a range of bacterial taxa, suggesting that this virulence pathway could be one of many new photosensory pathways regulating bacterial physiology.

John T. M. Kennis (Faculty of Sciences, Vrije Universiteit;Biophysics Department); Sean Crosson (The University of Chicago;Department of Biochemistry and Molecular Biology)

2007-08-24

63

RESEARCH ARTICLE Open Access Comparisons of resistance of CF and Non-CF pathogens to Hydrogen Peroxide and Hypochlorous Acid Oxidants In Vitro  

E-print Network

Background: Cystic fibrosis (CF) lung disease has a unique profile of pathogens predominated by Pseudomonas aeruginosa (PsA) and Staphylococcus aureus (SA). These microorganisms must overcome host immune defense to colonize the CF lungs. Polymorphonuclear neutrophils are a major component of the host defense against bacterial infection. A crucial microbicidal mechanism is the production of oxidants including hydrogen peroxide (H2O2) and hypochlorous acid (HOCl) by neutrophils to achieve efficient bacterial killing. To determine to what degrees various CF pathogens resist the oxidants relative to non-CF pathogens, we compared the susceptibility of PsA, SA, Burkholderia cepacia (BC), Klebsiella pneumoniae (KP), and Escherichia coli (EC) to various concentrations of H2O2 or HOCl, in vitro. The comparative oxidant-resistant profiles were established. Oxidant-induced damage to ATP production and cell membrane integrity of the microbes were quantitatively assessed. Correlation of membrane permeability and ATP levels with bacterial viability was statistically evaluated. Results: PsA was relatively resistant to both H2O2 (LD50 = 1.5 mM) and HOCl (LD50 = 0.035 mM). SA was susceptible to H2O2 (LD50 = 0.1 mM) but resistant to HOCl (LD50 = 0.035 mM). Interestingly, KP was extremely resistant to high doses of H2O2 (LD50 = 2.5-5.0 mM) but was very sensitive to low doses of HOCl (LD50 = 0.015 mM). BC was intermediate to resist both oxidants: H2O2 (LD50 = 0.3-0.4 mM) and HOCl (LD50 = 0.025 mM). EC

Ryan W Bonvillain; Richard G Painter; Elisa M Ledet; Guoshun Wang

64

Bacterial Pathogens Induce Abscess Formation by CD41 T-Cell Activation via the CD28B7-2 Costimulatory Pathway  

Microsoft Academic Search

Abscesses are a classic host response to infection by many pathogenic bacteria. The immunopathogenesis of this tissue response to infection has not been fully elucidated. Previous studies have suggested that T cells are involved in the pathologic process, but the role of these cells remains unclear. To delineate the mechanism by which T cells mediate abscess formation associated with intra-abdominal

ARTHUR O. TZIANABOS; ANIL CHANDRAKER; WILTRUD KALKA-MOLL; FRANCESCA STINGELE; VICTOR M. DONG; ROBERT W. FINBERG; ROBERT PEACH; MOHAMED H. SAYEGH

65

The FUS3 MAPK signaling pathway of the citrus pathogen Alternaria alternata functions independently or cooperatively with the fungal redox-responsive AP1 regulator for diverse developmental, physiological and pathogenic processes.  

PubMed

Alternaria alternata, the fungus that causes citrus brown spot, invades its hosts primarily through the production and action of a host-selective ACT toxin that kills citrus cells prior to invasion. In this study, we show that, in the tangerine pathotype of A. alternata, a mitogen-activated protein kinase (MAPK)-mediated signaling pathway governs a number of biological functions, either separately or in a cooperative manner, with the AaAP1 gene encoding a transcription regulator. The reported MAPK is encoded by the AaFUS3 gene, which we show to be necessary for conidial development, resistance to copper fungicides, melanin biosynthesis, and particularly, for elaboration of the penetration process. In contrast, AaFUS3 negatively controls salt tolerance and production of several hydrolytic enzymes. AaFUS3 has no apparent role in the biosynthesis of host-selective toxin or in resistance to oxidative stress. Both AaAP1 and AaFUS3 are required for fungal resistance to 2,3,5-triiodobenzoic acid (TIBA), 2-chloro-5-hydroxypyridine (CHP), diethyl maleate (DEM), and many pyridine-containing compounds. A strain with mutations in both AaAP1 and AaFUS3 displayed an increased sensitivity to these compounds. Expression of the AaAP1 and AaFUS3 genes and phosphorylation of AaFUS3 were also induced by CHP, DEM, or TIBA. Expression of two genes coding for a putative MFS transporter was coordinately regulated by AaAP1 and AaFUS3. The AaAP1::sGFP (synthetic green fluorescent protein) fusion protein became localized in the nucleus in response to CHP or TIBA. Inactivation of the AaAP1 gene, however, promoted phosphorylation of AaFUS3. Taken together, our results indicate that A. alternata utilizes specialized or synergistic regulatory interactions between the AP1 and MAPK signaling pathways for diverse physiological functions. PMID:20036749

Lin, Ching-Hsuan; Yang, Siwy Ling; Wang, Nan-Yi; Chung, Kuang-Ren

2010-04-01

66

Antibiotic targeting of the bacterial secretory pathway.  

PubMed

Finding new, effective antibiotics is a challenging research area driven by novel approaches required to tackle unconventional targets. In this review we focus on the bacterial protein secretion pathway as a target for eliminating or disarming pathogens. We discuss the latest developments in targeting the Sec-pathway for novel antibiotics focusing on two key components: SecA, the ATP-driven motor protein responsible for driving preproteins across the cytoplasmic membrane and the Type I signal peptidase that is responsible for the removal of the signal peptide allowing the release of the mature protein from the membrane. We take a bird's-eye view of other potential targets in the Sec-pathway as well as other Sec-dependent or Sec-independent protein secretion pathways as targets for the development of novel antibiotics. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey. PMID:24534745

Rao C V, Smitha; De Waelheyns, Evelien; Economou, Anastassios; Anné, Jozef

2014-08-01

67

Identification of novel molecules and pathogenic pathways in primary biliary cirrhosis: cDNA array analysis of intrahepatic differential gene expression  

PubMed Central

BACKGROUND—Primary biliary cirrhosis (PBC) is an autoimmune disease in which the pathogenesis of progressive liver injury is poorly understood.?AIM—To provide novel insights into the pathogenesis of PBC related liver injury using cDNA array analysis, which simultaneously examines expression of many genes.?METHODS—Utilising cDNA arrays of 874 genes, PBC was compared with primary sclerosing cholangitis (PSC) associated cirrhosis and non-diseased liver. Differential expression of 10 genes was confirmed by real time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).?RESULTS—Array analysis identified many differentially expressed genes that are important in inflammation, fibrosis, proliferation, signalling, apoptosis, and oxidative stress. PBC was associated with increased expression of both Th1 and Th2 type molecules of the immune response. Fibrosis related gene expression featured upregulation of connective tissue growth factor and transforming growth factor beta3. Many more apoptosis associated molecules exhibited increased expression, consistent with apoptosis being a more active and regulated process, in PSC associated cirrhosis than in PBC. Increased expression of many genes of the Wnt and notch pathways implicated these highly conserved and linked pathways in PBC pathogenesis. The observed increases in expression of c-jun, c-myc, and c-fos related antigen 1 are consistent with increased Wnt pathway activity in PBC. Differential expression of four components of the Wnt pathway, Wnt-5a, Wnt-13, FRITZ, and beta-catenin, was confirmed by quantitative RT-PCR.?CONCLUSION—Many genes implicated in intrahepatic inflammation, fibrosis, and regeneration were upregulated in PBC cirrhosis. In particular, increased expression of a number of Drosophila homologues was seen in PBC.???Keywords: primary sclerosing cholangitis; apoptosis; fibrosis; connective tissue growth factor; Wnt; Th1/Th2; brain derived neurotrophic factor; notch PMID:11559656

Shackel, N; McGuinness, P; Abbott, C; Gorrell, M; McCaughan, G

2001-01-01

68

Non-nucleoside Inhibitors of BasE, An Adenylating Enzyme in the Siderophore Biosynthetic Pathway of the Opportunistic Pathogen Acinetobacter baumannii  

PubMed Central

Siderophores are small-molecule iron chelators produced by bacteria and other microorganisms for survival under iron limiting conditions, such as found in a mammalian host. Siderophore biosynthesis is essential for the virulence of many important Gram-negative pathogens including Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. We performed high-throughput screening of against BasE, which is involved in siderophore biosynthesis in A. baumannii and identified 6-phenyl-1-(pyridin-4-ylmethyl)-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid 15. Herein we report the synthesis, biochemical, and microbiological evaluation of a systematic series of analogues of the HTS hit 15. Analogue 67 is the most potent analogue with a KD of 2 nM against BasE. Structural characterization of the inhibitors with BasE reveal they bind in a unique orientation in the active site occupying all three substrate binding sites, and thus can be considered multisubstrate inhibitors. These results provide a foundation for future studies aimed at both increasing enzyme potency and antibacterial activity. PMID:23437866

Neres, Joao; Engelhart, Curtis A.; Drake, Eric J.; Wilson, Daniel J.; Fu, Peng; Boshoff, Helena I.; Barry, Clifton E.; Gulick, Andrew M.; Aldrich, Courtney C.

2013-01-01

69

Publications: ____ Original article  

E-print Network

(2009) Activity of the novel peptide Arminin against multiresistant human pathogens shows Epithelial Cells for Host Defence. Dev Comp Immunol. 33, 559-569 Augustin R, A Franke, K Khalturin, R Kiko force microscopy. Journal of Computer- Assisted Microscopy 10(2):71-76 Review article: Augustin R

McFall-Ngai, Margaret

70

Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Induces Prostaglandin E2 Production through Cyclooxygenase 1, Which Is Dependent on the ERK1/2-p-C/EBP-? Pathway  

PubMed Central

ABSTRACT Atypical porcine reproductive and respiratory syndrome (PRRS) caused by highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) is characterized by high fever and high mortality. However, the mechanism underlying the fever induction is still unknown. Prostaglandin E2 (PGE2), synthesized by cyclooxygenase type 1/2 (COX-1/2) enzymes, is essential for inducing fever. In this study, we found that PGE2, together with COX-1, was significantly elevated by HP-PRRSV. We subsequently demonstrated that extracellular signal-regulated kinase 1/2 (ERK1/2) and phosphorylated ERK (p-ERK) were the key nodes to trigger COX-1 expression after HP-PRRSV infection. Furthermore, we proved the direct binding of p-C/EBP-? to the COX-1 promoter by luciferase reporter and chromatin immunoprecipitation assays. In addition, silencing of C/EBP-? remarkably impaired the enhancement of COX-1 production induced by HP-PRRSV infection. Taken together, our results indicate that HP-PPRSV elicits the expression of COX-1 through the ERK1/2-p-C/EBP-? signaling pathway, resulting in the increase of PGE2, which might be the cause of high fever in infected pigs. Our findings might provide new insights into the molecular mechanisms underlying the pathogenesis of HP-PRRSV infection. IMPORTANCE The atypical PRRS caused by HP-PRRSV was characterized by high fever, high morbidity, and high mortality in pigs of all ages, yet how HP-PRRSV induces high fever in pigs remains unknown. In the present study, we found out that HP-PRRSV infection could increase PGE2 production by upregulation of COX-1, and we subsequently characterized the underlying mechanisms about how HP-PRRSV enhances COX-1 production. PGE2 plays a critical role in inducing high temperature in hosts during pathogen infections. Thus, our findings here could help us have a better understanding of HP-PRRSV pathogenesis. PMID:24352469

Bi, Yanmin; Guo, Xue-kun; Zhao, Haiyan; Gao, Li; Wang, Lianghai; Tang, Jun

2014-01-01

71

Leukocyte-subset counts in idiopathic parkinsonism provide clues to a pathogenic pathway involving small intestinal bacterial overgrowth. A surveillance study  

PubMed Central

Background Following Helicobacter pylori eradication in idiopathic parkinsonism (IP), hypokinesia improved but flexor-rigidity increased. Small intestinal bacterial-overgrowth (SIBO) is a candidate driver of the rigidity: hydrogen-breath-test-positivity is common in IP and case histories suggest that Helicobacter keeps SIBO at bay. Methods In a surveillance study, we explore relationships of IP-facets to peripheral immune/inflammatory-activation, in light of presence/absence of Helicobacter infection (urea-breath- and/or stool-antigen-test: positivity confirmed by gastric-biopsy) and hydrogen-breath-test status for SIBO (positivity: >20 ppm increment, 2 consecutive 15-min readings, within 2h of 25G lactulose). We question whether any relationships found between facets and blood leukocyte subset counts stand in patients free from anti-parkinsonian drugs, and are robust enough to defy fluctuations in performance consequent on short t½ therapy. Results Of 51 IP-probands, 36 had current or past Helicobacter infection on entry, 25 having undergone successful eradication (median 3.4 years before). Thirty-four were hydrogen-breath-test-positive initially, 42 at sometime (343 tests) during surveillance (2.8 years). Hydrogen-breath-test-positivity was associated inversely with Helicobacter-positivity (OR 0.20 (95% CI 0.04, 0.99), p<0.05). In 38 patients (untreated (17) or on stable long-t½ IP-medication), the higher the natural-killer count, the shorter stride, slower gait and greater flexor-rigidity (by mean 49 (14, 85) mm, 54 (3, 104) mm.s-1, 89 (2, 177) Nm.10-3, per 100 cells.?l-1 increment, p=0.007, 0.04 & 0.04 respectively, adjusted for patient characteristics). T-helper count was inversely associated with flexor-rigidity before (p=0.01) and after adjustment for natural-killer count (-36(-63, -10) Nm.10-3 per 100 cells.?l-1, p=0.007). Neutrophil count was inversely associated with tremor (visual analogue scale, p=0.01). Effect-sizes were independent of IP-medication, and not masked by including 13 patients receiving levodopa (except natural-killer count on flexor-rigidity). Cellular associations held after allowing for potentially confounding effect of hydrogen-breath-test or Helicobacter status. Moreover, additional reduction in stride and speed (68 (24, 112) mm & 103 (38, 168) mm.s-1, each p=0.002) was seen with Helicobacter-positivity. Hydrogen-breath-test-positivity, itself, was associated with higher natural-killer and T-helper counts, lower neutrophils (p=0.005, 0.02 & 0.008). Conclusion We propose a rigidity-associated subordinate pathway, flagged by a higher natural-killer count, tempered by a higher T-helper, against which Helicobacter protects by keeping SIBO at bay. PMID:23083400

2012-01-01

72

SEWAGE SLUDGE PATHOGEN TRANSPORT MODEL PROJECT  

EPA Science Inventory

The sewage sludge pathogen transport model predicts the number of Salmonella, Ascaris, and polioviruses which might be expected to occur at various points in the environment along 13 defined pathways. These pathways describe the use of dried or liquid, raw or anaerobically digest...

73

Detection of enteric pathogens by the nodosome.  

PubMed

Nucleotide-binding oligomerization domain protein (NOD)1 and NOD2 participate in signaling pathways that detect pathogen-induced processes, such as the presence of peptidoglycan fragments in the host cell cytosol, as danger signals. Recent work suggests that peptidoglycan fragments activate NOD1 indirectly, through activation of the small Rho GTPase Ras-related C3 botulinum toxin substrate 1 (RAC1). Excessive activation of small Rho GTPases by virulence factors of enteric pathogens also triggers the NOD1 signaling pathway. Many enteric pathogens use virulence factors that alter the activation state of small Rho GTPases, thereby manipulating the host cell cytoskeleton of intestinal epithelial cells to promote bacterial attachment or entry. These data suggest that the NOD1 signaling pathway in intestinal epithelial cells provides an important sentinel function for detecting 'breaking and entering' by enteric pathogens. PMID:24268520

Keestra, A Marijke; Bäumler, Andreas J

2014-03-01

74

Article Review  

NSDL National Science Digital Library

During the semester, students must complete two article reviews. They are required to summarize and critically evaluate a recent article pertaining to a topic in Earth Science. Articles may include topics such as global warming, ocean water chemistry, magnetic field wander, hurricane formation, etc. Articles are generally from popular science magazines (Discover, ScienceNews, GeoTimes)but may include artiticles from peer reviewed journals. Students must, in their 2-3 page paper summarize the article, but the most important part I look for is their critical assessment of the science process with an explicit description of how the evidence in the article supports their conclusion.

Bridges, Karen

75

Bioterrorism Articles  

NSDL National Science Digital Library

The Journal of the American Medical Association (JAMA) is offering free access to a large number of its previously published articles related to bioterrorism. Among the articles are five pieces by the Working Group on Civilian Biodefense, which are focused on Anthrax, Smallpox, Plague, Botulinum Toxin, and Tularemia. The remainder of the articles are sorted by subject, including these diseases plus Ebola and Brucella, as well as Clinical Articles, Epidemiologic Investigations, articles on Preparedness, and a section devoted to Policy, Historical, and Editorial Perspectives. Articles are available in HTML or .pdf formats.

1995-01-01

76

1807RESEARCH ARTICLE INTRODUCTION  

E-print Network

1807RESEARCH ARTICLE INTRODUCTION Ectodermal organs such as teeth, hair, vibrissae and feathers that binding of Sostdc1 to Lrp4 inhibits the Wnt pathway could explain the identical tooth phenotype in Sostdc1­/­ and Lrp4­/­ mice (Ohazama et al., 2008). Multiple supernumerary teeth develop in K14-Cre;Ctnnb1(Ex3)fl

Maini, Philip K.

77

Signalling pathway in appressorium formation in Magnaporthe grisea  

E-print Network

and the cAMP pathway, regulate filamentous growth. Homologous pathways regulating growth polarity also have been defined in the fission yeast, Schizosaccharomyces pombe. These pathways are conserved in the human pathogens Candida albicans... and the cAMP pathway, regulate filamentous growth. Homologous pathways regulating growth polarity also have been defined in the fission yeast, Schizosaccharomyces pombe. These pathways are conserved in the human pathogens Candida albicans...

Filippi, Marta Cristina

2004-11-15

78

ORIGINAL ARTICLE Alternative pathways for phosphonate metabolism  

E-print Network

) appear to constitute a signifi- cant fraction of dissolved organic P in the oceans. In parts of the Pacific Ocean, Phns can constitute as much as 25% of the dissolved, high-molecular- weight organic P and oxygen gradients. These thermophiles engage in photosynthesis and aerobic respiration during the day

79

Review article Chemical architecture of antennal pathways  

E-print Network

circuits for proboscis extension seem to include cholinergic projection and local interneurons, GABAergic interneurons, glutamatergic motoneurons, and aminergic neurons which link with extensive arborisations the neu cellular analysis of neural plasticity will depend on the identifi- cation of transmitter substances

Boyer, Edmond

80

Bacterial itaconate degradation promotes pathogenicity.  

PubMed

Itaconate (methylenesuccinate) was recently identified as a mammalian metabolite whose production is substantially induced during macrophage activation. This compound is a potent inhibitor of isocitrate lyase, a key enzyme of the glyoxylate cycle, which is a pathway required for the survival of many pathogens inside the eukaryotic host. Here we show that numerous bacteria, notably many pathogens such as Yersinia pestis and Pseudomonas aeruginosa, have three genes for itaconate degradation. They encode itaconate coenzyme A (CoA) transferase, itaconyl-CoA hydratase and (S)-citramalyl-CoA lyase, formerly referred to as CitE-like protein. These genes are known to be crucial for survival of some pathogens in macrophages. The corresponding enzymes convert itaconate into the cellular building blocks pyruvate and acetyl-CoA, thus enabling the bacteria to metabolize itaconate and survive in macrophages. The itaconate degradation and detoxification pathways of Yersinia and Pseudomonas are the result of convergent evolution. This work revealed a common persistence factor operating in many pathogenic bacteria. PMID:24657929

Sasikaran, Jahminy; Ziemski, Micha?; Zadora, Piotr K; Fleig, Angela; Berg, Ivan A

2014-05-01

81

The Landscape of Human Proteins Interacting with Viruses and Other Pathogens  

Microsoft Academic Search

Infectious diseases result in millions of deaths each year. Mechanisms of infection have been studied in detail for many pathogens. However, many questions are relatively unexplored. What are the properties of human proteins that interact with pathogens? Do pathogens interact with certain functional classes of human proteins? Which infection mechanisms and pathways are commonly triggered by multiple pathogens? In this

Matthew D Dyer; T. M Murali; Bruno W Sobral

2008-01-01

82

Article URL  

E-print Network

PDF corresponds to the article as it appeared upon acceptance. Fully formatted PDF and full text (HTML) versions will be made available soon. Validity and reliability of Turkish version of "Hospital Survey on Patient Safety Culture " and perception of patient safety in public hospitals in Turkey

Emel Filiz; Said Bodur; Emel Filiz

2010-01-01

83

Article URL  

E-print Network

PDF corresponds to the article as it appeared upon acceptance. Fully formatted PDF and full text (HTML) versions will be made available soon. A comparative study on the traditional Indian Shodhana and Chinese processing methods for aconite roots by characterization and determination of the major components

Yogini Jaiswal; Zhitao Liang; Peng Yong; Hubiao Chen; Zhongzhen Zhao; Yogini Jaiswal; Zhitao Liang; Peng Yong; Hubiao Chen

2013-01-01

84

Laminate article  

DOEpatents

A laminate article comprises a substrate and a biaxially textured (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer over the substrate, wherein 0article can include a layer of YBCO over the (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer. A layer of CeO.sub.2 between the YBCO layer and the (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer can also be include. Further included can be a layer of YSZ between the CeO.sub.2 layer and the (RE.sub.x A.sub.(1-x)).sub.2 O.sub.2-(x/2) buffer layer. The substrate can be a biaxially textured metal, such as nickel. A method of forming the laminate article is also disclosed.

Williams, Robert K. (Knoxville, TN); Paranthaman, Mariappan (Knoxville, TN); Chirayil, Thomas G. (Knoxville, TN); Lee, Dominic F. (Knoxville, TN); Goyal, Amit (Knoxville, TN); Feenstra, Roeland (Knoxville, TN)

2002-01-01

85

MAIT cells and pathogen defense.  

PubMed

Mucosa-associated invariant T (MAIT) cells are a unique population of innate T cells that are abundant in humans. These cells possess an evolutionarily conserved invariant T cell receptor ? chain restricted by the nonpolymorphic class Ib major histocompatibility (MHC) molecule, MHC class I-related protein (MR1). The recent discovery that MAIT cells are activated by MR1-bound riboflavin metabolite derivatives distinguishes MAIT cells from all other ?? T cells in the immune system. Since mammals lack the capacity to synthesize riboflavin, intermediates from the riboflavin biosynthetic pathway are distinct microbial molecular patterns that provide a unique signal to the immune system. Multiple lines of evidence suggest that MAIT cells, which produce important cytokines such as IFN-?, TNF, and IL-17A, have the potential to influence immune responses to a broad range of pathogens. Here we will discuss our current understanding of MAIT cell biology and their role in pathogen defense. PMID:25164578

Cowley, Siobhán C

2014-12-01

86

Protein signaling via type III secretion pathways in phytopathogenic bacteria  

E-print Network

109 Protein signaling via type III secretion pathways in phytopathogenic bacteria Mary Beth Mudgett secretion pathway has revealed new mechanisms by which phytopathogenic bacteria infect plants are continually exposed to a number of potentially pathogenic bacteria. Phytopathogenic bacteria, in general

Mudgettt, Mary Beth

87

BIOSYNTHETIC PATHWAYS: Biosynthesis Meets Bioinformatics  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. In his Perspective, Cane discusses the increasing importance of the study of biosynthetic pathways in the discovery of biochemical reactions and pathways. Two recent papers (Rohdich et al. and Khaleeli et al.) highlight the increasing role of molecular biology and genomics in the study of biosynthetic pathways.

David E. Cane (Brown University;Department of Chemistry)

2000-02-04

88

The cuticle and plant defense to pathogens  

PubMed Central

The cuticle provides a physical barrier against water loss and protects against irradiation, xenobiotics, and pathogens. Components of the cuticle are perceived by invading fungi and activate developmental processes during pathogenesis. In addition, cuticle alterations of various types induce a syndrome of reactions that often results in resistance to necrotrophs. This article reviews the current knowledge on the role of the cuticle in relation to the perception of pathogens and activation of defenses. PMID:24982666

Serrano, Mario; Coluccia, Fania; Torres, Martha; L'Haridon, Floriane; Metraux, Jean-Pierre

2014-01-01

89

Taxonomy of bacterial fish pathogens  

PubMed Central

Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens. PMID:21314902

2011-01-01

90

Molecular Pathways: The Hedgehog Signaling Pathway in Cancer  

PubMed Central

The Hedgehog (Hh) signaling pathway regulates embryonic development and may be aberrantly activated in a wide variety of human cancers. Efforts to target pathogenic Hh signaling have steadily progressed from the laboratory to the clinic, and the recent approval of the Hh pathway inhibitor vismodegib for patients with advanced basal cell carcinoma (BCC) represents an important milestone. On the other hand, Hh pathway antagonists have failed to demonstrate significant clinical activity in other solid tumors. The reasons for these negative results are not precisely understood, but it is possible that the impact of Hh pathway inhibition has not been adequately measured by the clinical endpoints used thus far or that aberrancies in Hh signal transduction limit the activity of currently available pathway antagonists. Further basic and correlative studies to better understand Hh signaling in human tumors and validate putative anti-tumor mechanisms in the clinical setting may ultimately improve the success of Hh pathway inhibition to other tumor types. PMID:22718857

McMillan, Ross; Matsui, William

2012-01-01

91

Manipulation of Rab GTPase Function by Intracellular Bacterial Pathogens  

PubMed Central

Summary: Intracellular bacterial pathogens have evolved highly specialized mechanisms to enter and survive within their eukaryotic hosts. In order to do this, bacterial pathogens need to avoid host cell degradation and obtain nutrients and biosynthetic precursors, as well as evade detection by the host immune system. To create an intracellular niche that is favorable for replication, some intracellular pathogens inhibit the maturation of the phagosome or exit the endocytic pathway by modifying the identity of their phagosome through the exploitation of host cell trafficking pathways. In eukaryotic cells, organelle identity is determined, in part, by the composition of active Rab GTPases on the membranes of each organelle. This review describes our current understanding of how selected bacterial pathogens regulate host trafficking pathways by the selective inclusion or retention of Rab GTPases on membranes of the vacuoles that they occupy in host cells during infection. PMID:18063721

Brumell, John H.; Scidmore, Marci A.

2007-01-01

92

Pathogen-Responsive Expression of a Putative ATP-Binding Cassette Transporter Gene Conferring Resistance to the Diterpenoid Sclareol Is Regulated by Multiple Defense Signaling Pathways in Arabidopsis1  

PubMed Central

The ATP-binding cassette (ABC) transporters are encoded by large gene families in plants. Although these proteins are potentially involved in a number of diverse plant processes, currently, very little is known about their actual functions. In this paper, through a cDNA microarray screening of anonymous cDNA clones from a subtractive library, we identified an Arabidopsis gene (AtPDR12) putatively encoding a member of the pleiotropic drug resistance (PDR) subfamily of ABC transporters. AtPDR12 displayed distinct induction profiles after inoculation of plants with compatible and incompatible fungal pathogens and treatments with salicylic acid, ethylene, or methyl jasmonate. Analysis of AtPDR12 expression in a number of Arabidopsis defense signaling mutants further revealed that salicylic acid accumulation, NPR1 function, and sensitivity to jasmonates and ethylene were all required for pathogen-responsive expression of AtPDR12. Germination assays using seeds from an AtPDR12 insertion line in the presence of sclareol resulted in lower germination rates and much stronger inhibition of root elongation in the AtPDR12 insertion line than in wild-type plants. These results suggest that AtPDR12 may be functionally related to the previously identified ABC transporters SpTUR2 and NpABC1, which transport sclareol. Our data also point to a potential role for terpenoids in the Arabidopsis defensive armory. PMID:14526118

Campbell, Emma J.; Schenk, Peer M.; Kazan, Kemal; Penninckx, Iris A.M.A.; Anderson, Jonathan P.; Maclean, Don J.; Cammue, Bruno P.A.; Ebert, Paul R.; Manners, John M.

2003-01-01

93

Pathways for Cytokine Secretion  

NSDL National Science Digital Library

Cytokine secretion is a widely studied process, although little is known regarding the specific mechanisms that regulate cytokine release. Recent findings have shed light on some of the precise molecular pathways that regulate the packaging of newly synthesized cytokines from immune cells. These findings begin to elucidate pathways and mechanisms that underpin cytokine release in all cells. In this article, we review the highlights of some of these novel discoveries.

Amanda Stanley (Institute for Molecular Bioscience)

2010-08-01

94

Modularity analysis based on predicted protein-protein interactions provides new insights into pathogenicity and cellular process of Escherichia coli O157:H7  

PubMed Central

Background With the development of experimental techniques and bioinformatics, the quantity of data available from protein-protein interactions (PPIs) is increasing exponentially. Functional modules can be identified from protein interaction networks. It follows that the investigation of functional modules will generate a better understanding of cellular organization, processes, and functions. However, experimental PPI data are still limited, and no modularity analysis of PPIs in pathogens has been published to date. Results In this study, we predict and analyze the functional modules of E. coli O157:H7 systemically by integrating several bioinformatics methods. After evaluation, most of the predicted modules are found to be biologically significant and functionally homogeneous. Six pathogenicity-related modules were discovered and analyzed, including novel modules. These modules provided new information on the pathogenicity of O157:H7. The modularity of cellular function and cooperativity between modules are also discussed. Moreover, modularity analysis of O157:H7 can provide possible candidates for biological pathway extension and clues for discovering new pathways of cross-talk. Conclusions This article provides the first modularity analysis of a pathogen and sheds new light on the study of pathogens and cellular processes. Our study also provides a strategy for applying modularity analysis to any sequenced organism. PMID:22188601

2011-01-01

95

ORIGINAL ARTICLE Multiple introductions of highly pathogenic avian  

E-print Network

.2.1 (Egypt); 2.3.2.1 (Bangladesh, China, India, Indonesia, Korea, Nepal and Vietnam); 2.3.4.2 (China); and 7 on poultry as a source of meat and household income.8 Thus, there is a high risk of rapid disease spread

Cai, Long

96

Vaccines against dangerous pathogens  

Microsoft Academic Search

Dangerous pathogens are defined by the UK Health and Safety Executive's advisory committee as category 3 (those which cause severe human disease for which prophylaxis or therapy is usually available) or category 4 (as for category 3, but for which prophylaxis or therapy is not available). Research and development of vaccines for such pathogens is challenging, due to the safety

E D Williamson; R W Titball

2002-01-01

97

Emerging Escherichia pathogen.  

PubMed

Escherichia hermannii was first identified as a new species in 1982. It has rarely been reported as a human pathogen. We report the first case of E. hermannii as the sole pathogen in a catheter-related bloodstream infection. PMID:23740732

Kaewpoowat, Quanhathai; Permpalung, Nitipong; Sentochnik, Deborah E

2013-08-01

98

Emerging Escherichia Pathogen  

PubMed Central

Escherichia hermannii was first identified as a new species in 1982. It has rarely been reported as a human pathogen. We report the first case of E. hermannii as the sole pathogen in a catheter-related bloodstream infection. PMID:23740732

Permpalung, Nitipong; Sentochnik, Deborah E.

2013-01-01

99

BACTERIAL WATERBORNE PATHOGENS  

EPA Science Inventory

Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

100

Plant pathogen resistance  

DOEpatents

Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

Greenberg, Jean T; Jung, Ho Won; Tschaplinski, Timothy

2012-11-27

101

Genetic characteristics and pathogenic mechanisms of periodontal pathogens.  

PubMed

Periodontal disease is caused by a group of bacteria that utilize a variety of strategies and molecular mechanisms to evade or overcome host defenses. Recent research has uncovered new evidence illuminating interesting aspects of the virulence of these bacteria and their genomic variability. This paper summarizes some of the strategies utilized by the major species - Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Porphyromonas gingivalis - implicated in the pathogenesis of periodontal disease. Whole-genome sequencing of 14 diverse A. actinomycetemcomitans strains has revealed variations in their genetic content (ranging between 0.4% and 19.5%) and organization. Strikingly, isolates from human periodontal sites showed no genomic changes during persistent colonization. T. forsythia manipulates the cytokine responses of macrophages and monocytes through its surface glycosylation. Studies have revealed that bacterial surface-expressed O-linked glycans modulate T-cell responses during periodontal inflammation. Periodontal pathogens belonging to the "red complex" consortium express neuraminidases, which enables them to scavenge sialic acid from host glycoconjugates. Analysis of recent data has demonstrated that the cleaved sialic acid acts as an important nutrient for bacterial growth and a molecule for the decoration of bacteria surfaces to help evade the host immune attack. In addition, bacterial entry into host cells is also an important prerequisite for the lifestyle of periodontal pathogens such as P. gingivalis. Studies have shown that, after its entry into the cell, this bacterium uses multiple sorting pathways destined for autophagy, lysosomes, or recycling pathways. In addition, P. gingivalis releases outer membrane vesicles which enter cells via endocytosis and cause cellular functional impairment. PMID:24736700

Amano, A; Chen, C; Honma, K; Li, C; Settem, R P; Sharma, A

2014-05-01

102

CELL SIGNALING: Mitochondrial Longevity Pathways  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. A cytosolic protein that translocates into the mitochondria may serve as an integration point for signaling pathways that control longevity and cell death.

György Hajnóczky (Thomas Jefferson University;Department of Pathology, Anatomy and Cell Biology); Jan B. Hoek (Thomas Jefferson University;Department of Pathology, Anatomy and Cell Biology)

2007-02-02

103

What are bloodborne pathogens? Bloodborne pathogens are infectious materials  

E-print Network

available Hepatitis B vaccinations to all employees with occupational exposure to bloodborne pathogens receive regular training that covers the dangers of bloodborne pathogens, preventive practices, and post

Pawlowski, Wojtek

104

A putative twin-arginine translocation pathway in Legionella pneumophila  

Microsoft Academic Search

Legionella pneumophila is a facultative intracellular human pathogen causing Legionnaires’ disease, a severe form of pneumonia. Because of the importance of secretion pathways in virulence, we were interested in the possible presence of the twin-arginine translocation (Tat) pathway in L. pneumophila. This secretion pathway is used to transport folded proteins, characterized by two arginines in their signal peptide, across the

Emmy De Buck; Ilya Lebeau; Liesbeth Maes; Nick Geukens; Eef Meyen; Lieve Van Mellaert; Jozef Anné; Elke Lammertyn

2004-01-01

105

Global Expression Studies of Yersinia Pestis Pathogenicity  

SciTech Connect

The aim of these studies continues to be the investigation into the molecular mechanisms that underlie the virulence process in Yersinia pestis. In particular, the focus of this work centers on the identification of novel genes and pathways responsible for the pathogenic properties of this organism. In spite of more than four decades of intense investigation in this field, the dilemma as to what makes Y. pestis such a virulent and lethal pathogen remains unanswered. The method being employed makes use microarray technology (DNA chip) that enables the examination of the global activities of the whole complement of genes in this pathogen. Two primary resources available to the investigators (one directly obtained from a separate CBNP-funded project) make these studies possible: (1) Whole genome comparisons of the genes in Y. pestis and its near neighbors with attenuated or non pathogenic characteristics, and (2) the ability to duplicate in vitro, conditions that mimic the infection process of this pathogen. This year we have extended our studies from the original work of characterizing the global transcriptional regulation in Y. pestis triggered during temperature transition from 26 C to 37 C (roughly conditions found in the flea vector and the mammalian host, respectively) to studies of regulation encountered during shift between growth from conditions of neutral pH to acidic pH (the latter conditions, those mimic the environment found inside macrophages, a likely environment found by these cells during infection.). For this work, DNA arrays containing some 5,000 genes (the entire genome of Y. pestis plus those genes found uniquely in the enteropathogen, and near neighbor, Y. pseudotuberculosis) are used to monitor the simultaneous expression levels of each gene of known and unknown function in Y. pestis. Those genes that are up-regulate under the experimental conditions represent genes potentially involved in the pathogenic process. The ultimate role in pathogenicity of those candidate genes uncovered from these studies will be further ascertained by direct knock outs (gene inactivation) and by in vivo studies using an animal model. Discovery of new virulence factors in Y. pestis will directly impact the development of new signatures for detection and geo-location since it will help us to understand and identify those genes that are essential in making the organism pathogenic. These are genes that cannot be altered or removed from the pathogen and as such constitute the best type of signature that we can utilize in their detection and identification. Applications such as this will also enable the utilization of similar technologies to study other pathogens such as Francisella and Brucella, for which we know substantially less in terms of their modality of virulence.

Garcia, E; Motin, V; Brubaker, R; Fitch, P

2002-10-15

106

Salicylate-mediated interactions between pathogens and herbivores.  

PubMed

Plants employ hormone-mediated signaling pathways to defend against pathogens and insects. We tested predictions about the relative effect of jasmonate and salicylate pathways and how they mediate interactions between pathogens and herbivores. We employed two pathogens of tomato, Pseudomonas syringae (Pst) and tobacco mosaic virus (TMV), that are known to elicit distinct components of the two pathways, and we address the consequences of their induction for resistance in wild-type and salicylate-deficient transgenic plants in field experiments. We report that Pst infection induced jasmonic acid and proteinase inhibitors (PIs), and reduced the growth of Spodoptera exigua caterpillars on wild-type and salicylate-deficient plants. Pst and TMV both induced salicylic acid in wild-type but not salicylate-deficient plants. Although TMV did not affect jasmonic acid or PIs, infection increased caterpillar growth on wild-type plants, but not on salicylate-deficient plants. Aphid population growth was higher on salicylate-deficient compared to wild-type plants, and lower on salicylate-induced plants compared to controls. Natural aphid colonization was reduced on TMV-infected wild types, but not on salicylate-deficient plants. In sum, jasmonate-mediated resistance is induced by some pathogens, independent of salicylate, and salicylate-mediated induction by other pathogens results in induced susceptibility to a chewer and resistance to an aphid. We conclude with a predictive model for the expression of defense pathways and their consequences. PMID:20462121

Thaler, Jennifer S; Agrawal, Anurag A; Halitschke, Rayko

2010-04-01

107

Human Pathogen Importation Importing "Human" Pathogens from Outside Canada  

E-print Network

Human Pathogen Importation Importing "Human" Pathogens from Outside Canada 1) Permits.gc.ca/ols-bsl/pathogen/index.html and scroll to the bottom of the page where you can download the "Application for Permit to Import Human Human Pathogens" and "CL2 Checklist" to PHAC at (613) 941-0596. There are no fees for this service. 5

108

ORIGINAL ARTICLE A major effect quantitative trait locus for whirling  

E-print Network

and freshwater ecosystems (Bartholomew and Reno, 2002). Whirling disease has negatively impacted survival ratesORIGINAL ARTICLE A major effect quantitative trait locus for whirling disease resistance identified disease, caused by the pathogen Myxobolus cerebralis, leads to skeletal deformation, neurological

May, Bernie

109

RESEARCH ARTICLE Open Access Klebsiella pneumoniae related community-  

E-print Network

RESEARCH ARTICLE Open Access Klebsiella pneumoniae related community- acquired acute lower, Klebsiella pneumoniae (KP) is the second pathogen responsible for community-acquired pneumonia. Yet, very-sector hospitals. Keywords: Klebsiella pneumoniae, Community-acquired, Pneumonia, Extended-spectrum betalactamases

Paris-Sud XI, Université de

110

Microbial risk assessment in heterogeneous aquifers: 1. Pathogen transport  

NASA Astrophysics Data System (ADS)

Pathogen transport in heterogeneous aquifers is investigated for microbial risk assessment. A point source with time-dependent input of pathogens is assumed, exemplified as a simple on-site sanitation installation, intermingled with water supply wells. Any pathogen transmission pathway (realization) to the receptor from a postulated infection hazard is viewed as a random event, with the hydraulic conductivity varying spatially. For aquifers where VAR[lnK] < 1 and the integral scale is finite, we provide relatively simple semianalytical expressions for pathogen transport that incorporate the colloid filtration theory. We test a wide range of Damkohler numbers in order to assess the significance of rate limitations on the aquifer barrier function. Even slow immobile inactivation may notably affect the retention of pathogens. Analytical estimators for microbial peak discharge are evaluated and are shown to be applicable using parameters representative of rotavirus and Hepatitis A with input of 10-20 days duration.

Molin, S.; Cvetkovic, V.

2010-05-01

111

RAB11-mediated trafficking in host-pathogen interactions.  

PubMed

Many bacterial and viral pathogens block or subvert host cellular processes to promote successful infection. One host protein that is targeted by invading pathogens is the small GTPase RAB11, which functions in vesicular trafficking. RAB11 functions in conjunction with a protein complex known as the exocyst to mediate terminal steps in cargo transport via the recycling endosome to cell-cell junctions, phagosomes and cellular protrusions. These processes contribute to host innate immunity by promoting epithelial and endothelial barrier integrity, sensing and immobilizing pathogens and repairing pathogen-induced cellular damage. In this Review, we discuss the various mechanisms that pathogens have evolved to disrupt or subvert RAB11-dependent pathways as part of their infection strategy. PMID:25118884

Guichard, Annabel; Nizet, Victor; Bier, Ethan

2014-09-01

112

Animal models for highly pathogenic emerging viruses  

PubMed Central

Exotic and emerging viral pathogens associated with high morbidity and mortality in humans are being identified annually with recent examples including Lujo virus in southern Africa, Severe fever with Thrombocytopenia virus in China and a SARS-like coronavirus in the Middle East. The sporadic nature of these infections hampers our understanding of these diseases and limits the opportunities to design appropriate medical countermeasures against them. Due to this, animal models are utilized to gain insight into the pathogenesis of disease with the overall goal of identifying potential targets for intervention and evaluating specific therapeutics and vaccines. For these reasons it is imperative that animal models of disease recapitulate the human condition as closely as possible in order to provide the best predictive data with respect to the potential efficacy in humans. In this article we review the current status of disease models for highly pathogenic and emerging viral pathogens. PMID:23403208

Safronetz, David; Geisbert, Thomas W.; Feldmann, Heinz

2013-01-01

113

Microarrays for Pathogen Detection and Analysis  

PubMed Central

DNA microarrays have emerged as a viable platform for detection of pathogenic organisms in clinical and environmental samples. These microbial detection arrays occupy a middle ground between low cost, narrowly focused assays such as multiplex PCR and more expensive, broad-spectrum technologies like high-throughput sequencing. While pathogen detection arrays have been used primarily in a research context, several groups are aggressively working to develop arrays for clinical diagnostics, food safety testing, environmental monitoring and biodefense. Statistical algorithms that can analyze data from microbial detection arrays and provide easily interpretable results are absolutely required in order for these efforts to succeed. In this article, we will review the most promising array designs and analysis algorithms that have been developed to date, comparing their strengths and weaknesses for pathogen detection and discovery. PMID:21930658

2011-01-01

114

Pathway Analysis  

Cancer.gov

Surprising failures of new cancer treatments have made it clear that we do not know enough about how molecules in RAS signaling pathways interact with each other. For example, in the context of mutant KRAS, inhibitors of BRAF increase signaling through ERK. RAS Program scientists at the FNLCR are expanding our knowledge of signaling through RAS pathways using in silico and wet lab methods.

115

Community support one pathway for small farmers to make a go of it in Vermont | Burlington Free Press | burlingtonfreepress.com http://www.burlingtonfreepress.com/article/20120531/BUSINESS08/120530041/1003/NEWS01/Community-support-one-pathway-small-farmer  

E-print Network

and energetic Vermont farmer -- full of passion and creative ideas for how she can provide good and healthy food] ADVERTISEMENT May 31, 2012 | Community support one pathway for small farmers to make a go of it in Vermont Comments A A Emily Curtis-Murphy of Fair Food Farm in Calais in many ways is your typical young

Hayden, Nancy J.

116

Evolution of microbial pathogens.  

PubMed Central

Various genetic mechanisms including point mutations, genetic rearrangements and lateral gene transfer processes contribute to the evolution of microbes. Long-term processes leading to the development of new species or subspecies are termed macroevolution, and short-term developments, which occur during days or weeks, are considered as microevolution. Both processes, macro- and microevolution need horizontal gene transfer, which is particularly important for the development of pathogenic microorganisms. Plasmids, bacteriophages and so-called pathogenicity islands (PAIs) play a crucial role in the evolution of pathogens. During microevolution, genome variability of pathogenic microbes leads to new phenotypes, which play an important role in the acute development of an infectious disease. Infections due to Staphylococcus epidermidis, Candida albicans and Escherichia coli will be described with special emphasis on processes of microevolution. In contrast, the development of PAIs is a process involved in macroevolution. PAIs are especially important in processes leading to new pathotypes or even species. In this review, particular attention will be given to the fact that the evolution of pathogenic microbes can be considered as a specific example for microbial evolution in general. PMID:10874741

Morschhauser, J; Kohler, G; Ziebuhr, W; Blum-Oehler, G; Dobrindt, U; Hacker, J

2000-01-01

117

Pathogens: raft hijackers.  

PubMed

Throughout evolution, organisms have developed immune-surveillance networks to protect themselves from potential pathogens. At the cellular level, the signalling events that regulate these defensive responses take place in membrane rafts--dynamic microdomains that are enriched in cholesterol and glycosphingolipids--that facilitate many protein-protein and lipid-protein interactions at the cell surface. Pathogens have evolved many strategies to ensure their own survival and to evade the host immune system, in some cases by hijacking rafts. However, understanding the means by which pathogens exploit rafts might lead to new therapeutic strategies to prevent or alleviate certain infectious diseases, such as those caused by HIV-1 or Ebola virus. PMID:12876558

Mañes, Santos; del Real, Gustavo; Martínez-A, Carlos

2003-07-01

118

Neopolyploidy and pathogen resistance  

PubMed Central

Despite the well-documented historical importance of polyploidy, the mechanisms responsible for the establishment and evolutionary success of novel polyploid lineages remain unresolved. One possibility, which has not been previously evaluated theoretically, is that novel polyploid lineages are initially more resistant to pathogens than the diploid progenitor species. Here, we explore this possibility by developing and analysing mathematical models of interactions between newly formed polyploid lineages and their pathogens. We find that for the genetic mechanisms of pathogen resistance with the best empirical support, newly formed polyploid populations of hosts are expected to be more resistant than their diploid progenitors. This effect can be quite strong and, in the case of perennial species with recurrent polyploid formation, may last indefinitely, potentially providing a general explanation for the successful establishment of novel polyploid lineages. PMID:17686733

Oswald, Benjamin P; Nuismer, Scott L

2007-01-01

119

Emerging Pathogens - How Safe is Blood?  

PubMed Central

Summary During the last few decades, blood safety efforts were mainly focused on preventing viral infections. However, humanity's increased mobility and improved migration pathways necessitate a global perspective regarding other transfusion-transmitted pathogens. This review focuses on the general infection risk of blood components for malaria, dengue virus, Trypanosoma cruzi (Chagas disease) and Babesia spp. Approximately 250 million people become infected by Plasmodium spp. per year. Dengue virus affects more than 50 million people annually in more than 100 countries; clinically, it can cause serious diseases, such as dengue haemorrhagic fever and dengue shock syndrome. Chagas disease, which is caused by Trypanosoma cruzi, mainly occurs in South America and infects approximately 10 million people annually. Babesia spp. is a parasitic infection that infects red blood cells; although many infections are asymptomatic, severe clinical disease has been reported, especially in the elderly. Screening assays are available for all considered pathogens but make screening strategies more complex and more expensive. A general pathogen inactivation for all blood components (whole blood) promises to be a long-term, sustainable solution for both known and unknown pathogens. Transfusion medicine therefore eagerly awaits such a system. PMID:24659943

Schmidt, Michael; Geilenkeuser, Wolf-Jochen; Sireis, Walid; Seifried, Erhard; Hourfar, Kai

2014-01-01

120

ICT Pathways  

NSDL National Science Digital Library

This page, from the Mid-Pacific Information and Communications Technology Center, provides a useful diagram for ICT educators that highlights employment pathways for students pursuing this career track. Users may click on the diagram to view a larger version.

2011-07-28

121

Rapid Detection of Pathogens  

Microsoft Academic Search

Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents.

David Perlin

2005-01-01

122

Studying host-pathogen interactions and innate immunity in Caenorhabditis elegans  

E-print Network

The genetic analysis of mechanisms of pathogen resistance in the nematode Caenorhabditis elegans has revealed a role for evolutionarily conserved signaling pathways that are required for innate immunity in a wide range of ...

Kim, Dennis H.

123

Stress adaptation in a pathogenic fungus  

PubMed Central

Candida albicans is a major fungal pathogen of humans. This yeast is carried by many individuals as a harmless commensal, but when immune defences are perturbed it causes mucosal infections (thrush). Additionally, when the immune system becomes severely compromised, C. albicans often causes life-threatening systemic infections. A battery of virulence factors and fitness attributes promote the pathogenicity of C. albicans. Fitness attributes include robust responses to local environmental stresses, the inactivation of which attenuates virulence. Stress signalling pathways in C. albicans include evolutionarily conserved modules. However, there has been rewiring of some stress regulatory circuitry such that the roles of a number of regulators in C. albicans have diverged relative to the benign model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. This reflects the specific evolution of C. albicans as an opportunistic pathogen obligately associated with warm-blooded animals, compared with other yeasts that are found across diverse environmental niches. Our understanding of C. albicans stress signalling is based primarily on the in vitro responses of glucose-grown cells to individual stresses. However, in vivo this pathogen occupies complex and dynamic host niches characterised by alternative carbon sources and simultaneous exposure to combinations of stresses (rather than individual stresses). It has become apparent that changes in carbon source strongly influence stress resistance, and that some combinatorial stresses exert non-additive effects upon C. albicans. These effects, which are relevant to fungus–host interactions during disease progression, are mediated by multiple mechanisms that include signalling and chemical crosstalk, stress pathway interference and a biological transistor. PMID:24353214

Brown, Alistair J. P.; Budge, Susan; Kaloriti, Despoina; Tillmann, Anna; Jacobsen, Mette D.; Yin, Zhikang; Ene, Iuliana V.; Bohovych, Iryna; Sandai, Doblin; Kastora, Stavroula; Potrykus, Joanna; Ballou, Elizabeth R.; Childers, Delma S.; Shahana, Shahida; Leach, Michelle D.

2014-01-01

124

Silicon and plant disease resistance against pathogenic fungi  

Microsoft Academic Search

Silicon (Si) is a bioactive element associated with beneficial effects on mechanical and physiological properties of plants. Silicon alleviates abiotic and biotic stresses, and increases the resistance of plants to pathogenic fungi. Several studies have suggested that Si activates plant defense mechanisms, yet the exact nature of the interaction between the element and biochemical pathways leading to resistance remains unclear.

James G. Menzies; Richard R. Bélanger

2005-01-01

125

Draft Genome Sequence of the Sexually Transmitted Pathogen Trichomonas vaginalis  

Microsoft Academic Search

We describe the genome sequence of the protist Trichomonas vaginalis, a sexually transmitted human pathogen. Repeats and transposable elements comprise about two-thirds of the ~160-megabase genome, reflecting a recent massive expansion of genetic material. This expansion, in conjunction with the shaping of metabolic pathways that likely transpired through lateral gene transfer from bacteria, and amplification of specific gene families implicated

J. M. Carlton; R. P. Hirt; J. C. Silva; A. L. Delcher; Michael Schatz; Qi Zhao; J. R. Wortman; S. L. Bidwell; U. C. M. Alsmark; Sébastien Besteiro; Thomas Sicheritz-Ponten; C. J. Noel; J. B. Dacks; P. G. Foster; Cedric Simillion; Y. Van de Peer; Diego Miranda-Saavedra; G. J. Barton; G. D. Westrop; S. Muller; Daniele Dessi; P. L. Fiori; Qinghu Ren; Ian Paulsen; Hanbang Zhang; F. D. Bastida-Corcuera; Augusto Simoes-Barbosa; M. T. Brown; R. D. Hayes; Mandira Mukherjee; C. Y. Okumura; Rachel Schneider; A. J. Smith; Stepanka Vanacova; Maria Villalvazo; B. J. Haas; Mihaela Pertea; Tamara V. Feldblyum; T. R. Utterback; Chung-Li Shu; Kazutoyo Osoegawa; P. J. de Jong; Ivan Hrdy; Lenka Horvathova; Zuzana Zubacova; Pavel Dolezal; Shehre-Banoo Malik; J. M. Logsdon; Katrin Henze; Arti Gupta; Ching C. Wang; R. L. Dunne; J. A. Upcroft; Peter Upcroft; Owen White; S. L. Salzberg; Petrus Tang; Cheng-Hsun Chiu; Ying-Shiung Lee; T. M. Embley; G. H. Coombs; J. C. Mottram; Jan Tachezy; C. M. Fraser-Liggett; P. J. Johnson

2007-01-01

126

Original research article (regular article) Title : MYC+  

E-print Network

by R-ICE or R-DHAP followed by high-dose therapy and autologous stem cell transplantation. Twenty is not salvaged by classical R- ICE or R-DHAP followed by BEAM plus autologous stem cell transplantation Running1 Original research article (regular article) Title : MYC+ diffuse large B-cell lymphoma

Boyer, Edmond

127

ArticleLinker ArticleLinker  

E-print Network

://edb.kulib.kyoto-u.ac.jp/erhelp/al.html) ArticleLinker ISSN( ID) DOI( ID) Journal presented by Article Journal (2) : Google Scholar, OAIster Services Abstracts, Sociological Abstracts, Periodical Index Online, EBSCOhost, EconLit with Fulltext, LISTA, Scirus, MLA International Bibliography, OCLC First Search, WorldCat.org, Biosis Previews, Sports

Takada, Shoji

128

ARTICLE IN PRESS UNCORRECTEDPROOF  

E-print Network

ARTICLE IN PRESS UNCORRECTEDPROOF Please cite this article as: V. Guerra, R. de Abreu, Comment on Communicated by P.R. Holland Abstract In a recent article [M. Consoli, E. Costanzo, Phys. Lett. A 333 (2004 a growing number of articles questioning the standard interpretation of special rela- tivity is appearing

Guerra, Vasco

129

Article Search Advanced Search  

E-print Network

-Entertainment Film TV Music Gossip Dining Features EMAIL ARTICLE LINK TO ARTICLE PRINT ARTICLE Article Published in the current issue of the British scientific journal Nature, may lead to therapies for people with disorders such as autism who have difficulty recognizing emotion in others, Adolphs said. The group has studied an unusual

Gosselin, Frédéric

130

Olive knot and its pathogens  

Microsoft Academic Search

Olive knot, caused by a pathogen or pathogens within the group of bacterial pathogens currently known as Pseudomonas savastanoi, is described. The ecology, transmission and methods of control of the pathogens are discussed. Strategies to minimise the\\u000a effects of infection are recommended and these depend on attention to specific details in programs for pruning, irrigation\\u000a and use of fertiliser. Introduction

J. M. Young

2004-01-01

131

Multiplex detection of agricultural pathogens  

DOEpatents

Described are kits and methods useful for detection of agricultural pathogens in a sample. Genomic sequence information from agricultural pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay and/or an array assay to successfully identify the presence or absence of pathogens in a sample.

Siezak, Thomas R.; Gardner, Shea; Torres, Clinton; Vitalis, Elizabeth; Lenhoff, Raymond J.

2013-01-15

132

Microbiota-mediated colonization resistance against intestinal pathogens  

PubMed Central

Commensal bacteria inhabit mucosal and epidermal surfaces in mice and humans, and have effects on metabolic and immune pathways in their hosts. Recent studies indicate that the commensal microbiota can be manipulated to prevent and even to cure infections that are caused by pathogenic bacteria, particularly pathogens that are broadly resistant to antibiotics, such as vancomycin-resistant Enterococcus faecium, Gram-negative Enterobacteriaceae and Clostridium difficile. In this Review, we discuss how immune- mediated colonization resistance against antibiotic-resistant intestinal pathogens is influenced by the composition of the commensal microbiota. We also review recent advances characterizing the ability of different commensal bacterial families, genera and species to restore colonization resistance to intestinal pathogens in antibiotic-treated hosts. PMID:24096337

Buffie, Charlie G.; Pamer, Eric G.

2014-01-01

133

Chitosan against cutaneous pathogens.  

PubMed

Propionibacterium acnes and Staphylococcus aureus are cutaneous pathogens that have become increasingly resistant to antibiotics. We sought to determine if chitosan, a polymer of deacetylated chitin, could be used as a potential treatment against these bacteria. We found that higher molecular weight chitosan had superior antimicrobial properties compared to lower molecular weights, and that this activity occurred in a pH dependent manner. Electron and fluorescence microscopy revealed that chitosan forms aggregates and binds to the surface of bacteria, causing shrinkage of the bacterial membrane from the cell wall. Of special relevance, clinical isolates of P. acnes were vulnerable to chitosan, which could be combined with benzoyl peroxide for additive antibacterial effect. Chitosan also demonstrated significantly less cytotoxicity to monocytes than benzoyl peroxide. Overall, chitosan demonstrates many promising qualities for treatment of cutaneous pathogens. PMID:23829873

Champer, Jackson; Patel, Julie; Fernando, Nathalie; Salehi, Elaheh; Wong, Victoria; Kim, Jenny

2013-01-01

134

Lipid-derived signals that discriminate wound- and pathogen-responsive isoprenoid pathways in plants: methyl jasmonate and the fungal elicitor arachidonic acid induce different 3-hydroxy-3-methylglutaryl-coenzyme A reductase genes and antimicrobial isoprenoids in Solanum tuberosum L.  

PubMed Central

Induction of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR; EC 1.1.1.34) is essential for the synthesis of steroid derivatives and sesquiterpenoid phytoalexins in solanaceous plants following mechanical injury or pathogen infection. Gene-specific probes corresponding to different HMGR genes (hmg1 and hmg2) were used to study HMGR expression in potato tissue following treatment with methyl jasmonate, a lipoxygenase product of linolenic acid, or arachidonic acid, an elicitor present in the lipids of the potato late blight fungus Phytophthora infestans. Treatment of potato discs (2.2 cm in diameter) with low concentrations (0.45-45 nmol per disc surface) of methyl jasmonate nearly doubled the wound-induced accumulation of hmg1 transcripts and steroid-glycoalkaloid (SGA) accumulation, reduced the abundance of hmg2 transcripts, and did not induce phytoalexins. High concentrations of methyl jasmonate (2-4.5 mol per disc surface) suppressed hmg1 mRNA and SGA accumulation but did not affect hmg2 mRNA abundance or induce phytoalexins. In contrast, arachidonate treatment strongly suppressed hmg1 and strongly induced hmg2 mRNA in a concentration-dependent manner. There was a corresponding suppression of SGA accumulation and an induction of sesquiterpene phytoalexin accumulation by this elicitor. Lipoxygenase inhibitors reduced the wound-induced accumulation of hmg1 transcripts and suppressed SGA levels, effects that were overcome by exogenous methyl jasmonate (45 nmol per disc surface). The results (i) suggest that methyl jasmonate can function as a signal for hmg1 expression and SGA induction following wounding and (ii) indicate that the arachidonate- and jasmonate-response pathways are distinct in relation to HMGR gene expression and isoprenoid product accumulation. The results also are consistent with placement of the HMGR activities encoded by hmg1 and hmg2 within discrete steroid and sesquiterpenoid biosynthetic channels. Images PMID:11607466

Choi, D; Bostock, R M; Avdiushko, S; Hildebrand, D F

1994-01-01

135

Adhesion by Pathogenic Corynebacteria  

Microsoft Academic Search

\\u000a Pathogenic members of the genus Corynebacterium cause a wide range of serious infections in humans including diphtheria. Adhesion to host cells is a crucial step during\\u000a infection. In Corynebacterium diphtheriae, adhesion is mediated primarily by filamentous structures called pili or fimbriae that are covalently attached to the bacterial\\u000a cell wall. C. diphtheriae produces three distinct pilus structures, SpaA-, SpaD- and

Elizabeth A. Rogers; Asis Das; Hung Ton-That

136

Pathogenic agents in freshwater resources  

Microsoft Academic Search

Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and

Edwin E. Geldreich

1996-01-01

137

Microbial Pathogens in the Fungal Kingdom  

PubMed Central

The fungal kingdom is vast, spanning ~1.5 to as many as 5 million species diverse as unicellular yeasts, filamentous fungi, mushrooms, lichens, and both plant and animal pathogens. The fungi are closely aligned with animals in one of the six to eight supergroups of eukaryotes, the opisthokonts. The animal and fungal kingdoms last shared a common ancestor ~1 billion years ago, more recently than other groups of eukaryotes. As a consequence of their close evolutionary history and shared cellular machinery with metazoans, fungi are exceptional models for mammalian biology, but prove more difficult to treat in infected animals. The last common ancestor to the fungal/metazoan lineages is thought to have been unicellular, aquatic, and motile with a posterior flagellum, and certain extant species closely resemble this hypothesized ancestor. Species within the fungal kingdom were traditionally assigned to four phyla, including the basal fungi (Chytridiomycota, Zygomycota) and the more recently derived monophyletic lineage, the dikarya (Ascomycota, Basidiomycota). The fungal tree of life project has revealed that the basal lineages are polyphyletic, and thus there are as many as eight to ten fungal phyla. Fungi that infect vertebrates are found in all of the major lineages, and virulence arose multiple times independently. A sobering recent development involves the species Batrachochytrium dendrobatidis from the basal fungal phylum, the Chytridiomycota, which has emerged to cause global amphibian declines and extinctions. Genomics is revolutionizing our view of the fungal kingdom, and genome sequences for zygomycete pathogens (Rhizopus, Mucor), skin-associated fungi (dermatophytes, Malassezia), and the Candida pathogenic species clade promise to provide insights into the origins of virulence. Here we survey the diversity of fungal pathogens and illustrate key principles revealed by genomics involving sexual reproduction and sex determination, loss of conserved pathways in derived fungal lineages that are retained in basal fungi, and shared and divergent virulence strategies of successful human pathogens, including dimorphic and trimorphic transitions in form. The overarching conclusion is that fungal pathogens of animals have arisen repeatedly and independently throughout the fungal tree of life, and while they share general properties, there are also unique features to the virulence strategies of each successful microbial pathogen. PMID:21528015

Heitman, Joseph

2011-01-01

138

Aquatic eutrophication promotes pathogenic infection in amphibians  

PubMed Central

The widespread emergence of human and wildlife diseases has challenged ecologists to understand how large-scale agents of environmental change affect host–pathogen interactions. Accelerated eutrophication of aquatic ecosystems owing to nitrogen and phosphorus enrichment is a pervasive form of environmental change that has been implicated in the emergence of diseases through direct and indirect pathways. We provide experimental evidence linking eutrophication and disease in a multihost parasite system. The trematode parasite Ribeiroia ondatrae sequentially infects birds, snails, and amphibian larvae, frequently causing severe limb deformities and mortality. Eutrophication has been implicated in the emergence of this parasite, but definitive evidence, as well as a mechanistic understanding, have been lacking until now. We show that the effects of eutrophication cascade through the parasite life cycle to promote algal production, the density of snail hosts, and, ultimately, the intensity of infection in amphibians. Infection also negatively affected the survival of developing amphibians. Mechanistically, eutrophication promoted amphibian disease through two distinctive pathways: by increasing the density of infected snail hosts and by enhancing per-snail production of infectious parasites. Given forecasted increases in global eutrophication, amphibian extinctions, and similarities between Ribeiroia and important human and wildlife pathogens, our results have broad epidemiological and ecological significance. PMID:17893332

Johnson, Pieter T. J.; Chase, Jonathan M.; Dosch, Katherine L.; Hartson, Richard B.; Gross, Jackson A.; Larson, Don J.; Sutherland, Daniel R.; Carpenter, Stephen R.

2007-01-01

139

Review article Cardioprotective signaling to mitochondria  

E-print Network

Review article Cardioprotective signaling to mitochondria Keith D. Garlid a, , Alexandre D.T. Costa species Permeability transition Signaling pathways Mitochondria are central players in the pathophysiology the plasma membrane and migrate to mitochondria. The signalosome­mitochondria interaction then initiates

Brand, Paul H.

140

In silico metabolic pathway modeling and analysis of Mycoplasma pneumoniae  

E-print Network

In silico metabolic pathway modeling and analysis of Mycoplasma pneumoniae Jin Sik Kim Sang Yup Lee-gu, Taejon 305-701, Korea Keywords: metabolic pathway modeling, Mycoplasma pneumoniae 1 Introduction of the metabolic model [2, 5]. Mycoplasma pneumoniae is a pathogen causing atypical pneumonia in human beings

141

BK polyomavirus: emerging pathogen  

PubMed Central

BK polyomavirus (BKPyV) is a small double-stranded DNA virus that is an emerging pathogen in immunocompromised individuals. BKPyV is widespread in the general population, but primarily causes disease when immune suppression leads to reactivation of latent virus. Polyomavirus-associated nephropathy and hemorrhagic cystitis in renal and bone marrow transplant patients, respectively, are the most common diseases associated with BKPyV reactivation and lytic infection. In this review, we discuss the clinical relevance, effects on the host, virus life cycle, and current treatment protocols. PMID:22402031

Bennett, Shauna M.; Broekema, Nicole M.; Imperiale, Michael J.

2013-01-01

142

Host-Pathogen Interactions  

PubMed Central

A polysaccharide from the fungal pathogen Colletotrichum lindemuthianum causes browning and phytoalexin production when applied to the cut surfaces of bean (Phaseolus vulgaris) cotyledons and hypocotyls. The application of an amount of polysaccharide equivalent to less than 100 ng of glucose will elicit this response in the bean tissues. The polysaccharide has been isolated both from culture filtrates and from the mycelial walls of the fungus. Purification of the polysaccharide involved anion and cation exchange chromatography and gel filtration. The polysaccharide has an apparent molecular weight between 1,000,000 and 5,000,000 daltons, and consists predominantly of 3- and 4-linked glucosyl residues. PMID:16659289

Anderson-Prouty, Anne J.; Albersheim, Peter

1975-01-01

143

1081Research Article Introduction  

E-print Network

. This pathogen, spread by the tsetse fly, causes both a devastating human disease, African Sleeping Sickness of glycosylphosphatidylinositol (GPI)-anchored surface proteins, such as procyclin (the major surface protein of the tsetse midgut and function of bloodstream and `procyclic' cell (tsetse midgut form) pockets are similar. Although

Schnaufer, Achim

144

Stress Response and Pathogenicity of the Necrotrophic Fungal Pathogen Alternaria alternata  

PubMed Central

The production of host-selective toxins by the necrotrophic fungus Alternaria alternata is essential for the pathogenesis. A. alternata infection in citrus leaves induces rapid lipid peroxidation, accumulation of hydrogen peroxide (H2O2), and cell death. The mechanisms by which A. alternata avoids killing by reactive oxygen species (ROS) after invasion have begun to be elucidated. The ability to coordinate of signaling pathways is essential for the detoxification of cellular stresses induced by ROS and for pathogenicity in A. alternata. A low level of H2O2, produced by the NADPH oxidase (NOX) complex, modulates ROS resistance and triggers conidiation partially via regulating the redox-responsive regulators (YAP1 and SKN7) and the mitogen-activated protein (MAP) kinase (HOG1) mediated pathways, which subsequently regulate the genes required for the biosynthesis of siderophore, an iron-chelating compound. Siderophore-mediated iron acquisition plays a key role in ROS detoxification because of the requirement of iron for the activities of antioxidants (e.g., catalase and SOD). Fungal strains impaired for the ROS-detoxifying system severely reduce the virulence on susceptible citrus cultivars. This paper summarizes the current state of knowledge of signaling pathways associated with cellular responses to multidrugs, oxidative and osmotic stress, and fungicides, as well as the pathogenicity/virulence in the tangerine pathotype of A. alternata. PMID:24278721

Chung, Kuang-Ren

2012-01-01

145

Stress Response and Pathogenicity of the Necrotrophic Fungal Pathogen Alternaria alternata.  

PubMed

The production of host-selective toxins by the necrotrophic fungus Alternaria alternata is essential for the pathogenesis. A. alternata infection in citrus leaves induces rapid lipid peroxidation, accumulation of hydrogen peroxide (H2O2), and cell death. The mechanisms by which A. alternata avoids killing by reactive oxygen species (ROS) after invasion have begun to be elucidated. The ability to coordinate of signaling pathways is essential for the detoxification of cellular stresses induced by ROS and for pathogenicity in A. alternata. A low level of H2O2, produced by the NADPH oxidase (NOX) complex, modulates ROS resistance and triggers conidiation partially via regulating the redox-responsive regulators (YAP1 and SKN7) and the mitogen-activated protein (MAP) kinase (HOG1) mediated pathways, which subsequently regulate the genes required for the biosynthesis of siderophore, an iron-chelating compound. Siderophore-mediated iron acquisition plays a key role in ROS detoxification because of the requirement of iron for the activities of antioxidants (e.g., catalase and SOD). Fungal strains impaired for the ROS-detoxifying system severely reduce the virulence on susceptible citrus cultivars. This paper summarizes the current state of knowledge of signaling pathways associated with cellular responses to multidrugs, oxidative and osmotic stress, and fungicides, as well as the pathogenicity/virulence in the tangerine pathotype of A. alternata. PMID:24278721

Chung, Kuang-Ren

2012-01-01

146

PID: the Pathway Interaction Database.  

PubMed

The Pathway Interaction Database (PID, http://pid.nci.nih.gov) is a freely available collection of curated and peer-reviewed pathways composed of human molecular signaling and regulatory events and key cellular processes. Created in a collaboration between the US National Cancer Institute and Nature Publishing Group, the database serves as a research tool for the cancer research community and others interested in cellular pathways, such as neuroscientists, developmental biologists and immunologists. PID offers a range of search features to facilitate pathway exploration. Users can browse the predefined set of pathways or create interaction network maps centered on a single molecule or cellular process of interest. In addition, the batch query tool allows users to upload long list(s) of molecules, such as those derived from microarray experiments, and either overlay these molecules onto predefined pathways or visualize the complete molecular connectivity map. Users can also download molecule lists, citation lists and complete database content in extensible markup language (XML) and Biological Pathways Exchange (BioPAX) Level 2 format. The database is updated with new pathway content every month and supplemented by specially commissioned articles on the practical uses of other relevant online tools. PMID:18832364

Schaefer, Carl F; Anthony, Kira; Krupa, Shiva; Buchoff, Jeffrey; Day, Matthew; Hannay, Timo; Buetow, Kenneth H

2009-01-01

147

DEVELOPMENT 547RESEARCH ARTICLE  

E-print Network

successive phases. First, the vegetal plate, which is composed of specified endodermal cells and secondary a review, see Weidinger and Moon, 2003). The Wnt/Ca2+ pathway acts by means of a G protein to stimulate

Villefranche sur mer

148

Molecular Pathways  

PubMed Central

The Rad52 protein was largely ignored in humans and other mammals when the mouse knockout revealed a largely “no-effect” phenotype. However, using synthetic lethal approaches to investigate context dependent function, new studies have shown that Rad52 plays a key survival role in cells lacking the function of the BRCA1-BRCA2 pathway of homologous recombination. Biochemical studies also showed significant differences between yeast and human Rad52, in which yeast Rad52 can promote strand invasion of RPA-coated single-stranded DNA in the presence of Rad51, but human Rad52 cannot. This results in the paradox of how is human Rad52 providing Rad51 function: presumably there is something missing in the biochemical assays that exists in-vivo, but the nature of this missing factor is currently unknown. Recent studies have suggested that Rad52 provides back-up Rad51 function for all members of the BRCA1-BRCA2 pathway, suggesting that Rad52 may be a target for therapy in BRCA pathway deficient cancers. Screening for ways to inhibit Rad52 would potentially provide a complementary strategy for targeting BRCA-deficient cancers in addition to PARP inhibitors. PMID:23071261

Lok, Benjamin H.; Powell, Simon N.

2012-01-01

149

Cryptosporidium Pathogenicity and Virulence  

PubMed Central

Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence among Cryptosporidium species and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation of Cryptosporidium virulence factors have been hindered by the renowned difficulties pertaining to the in vitro culture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors for Cryptosporidium. This progress has been accelerated since the publication of the Cryptosporidium parvum and C. hominis genomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge on Cryptosporidium infectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence. PMID:23297262

Bouzid, Maha; Chalmers, Rachel M.; Tyler, Kevin M.

2013-01-01

150

Host-Pathogen Interactions  

PubMed Central

An elicitor of glyceollin accumulation in soybeans (Glycine max L.) has been isolated from a commercially available extract of brewers' yeast. Yeast is not a known pathogen of plants. The elicitor was isolated by precipitation in 80% (v/v) ethanol followed by column chromatography on DEAE-cellulose, sulfopropyl-Sephadex, and concanavalin A-Sepharose. Compositional and structural analysis showed the elicitor to be a glucan containing terminal, 3-, 6-, and 3,6-linked glucosyl residues. The yeast elicitor stimulates the accumulation of glyceollin in the cotyledons and hypocotyls of soybeans when as little as 15 nanograms or 100 nanograms of the elicitor is applied to the respective tissues. The yeast elicitor is very similar in both structure and absolute elicitor activity to an elicitor isolated from the mycelial walls of Phytophthora megasperma var. sojae, a pathogen of soybeans. These and other results of this laboratory suggest that plants are able to respond to the presence of a wide range of fungi by recognizing, as foreign to the plant, structural polysaccharides of the mycelial walls of the fungi. PMID:16660446

Hahn, Michael G.; Albersheim, Peter

1978-01-01

151

Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms  

PubMed Central

Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance. PMID:24137567

Mansilla Pareja, Maria Eugenia; Colombo, Maria I.

2013-01-01

152

Luteovirus: insights into pathogenicity.  

PubMed

Luteoviruses are economically important plant viruses, infecting almost all cereals throughout the world. Idiosyncrasies related to this virus group may be a strategic consequence of viral genome compression. However, many fundamental questions have yet to be resolved. This review summarizes selected findings covering molecular aspects of pathogenesis relating to plant-infecting RNA viruses in general, and luteoviruses in specific. These studies enhance our understanding of the replication structures and the virus infection pathways. PMID:25091739

Ali, Muhammad; Hameed, Shahid; Tahir, Muhammad

2014-11-01

153

MICROBIOLOGY: Enhanced: A Furtive Pathogen Revealed  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required: The pathogenic bacterium Neisseria meningitidis is the cause of meningococcal meningitis. Although a vaccine is available for Neisseria of serogroups A and C, there is no vaccine available for serogroup B. In a Perspective, Nassif reports on the sequencing of the complete genome of N. meningitidis type B strain MC58 (Tettelin et al.) and the mining of this genome to identify highly conserved surface proteins that may be valuable as vaccine antigens (Pizza et al.).

Xavier Nassif (Faculté de Médecine Necker-Enfants Malades;INSERM Unit 411)

2000-03-10

154

MICROBIOLOGY: Enhanced: Pathogenic Bacteria Prefer Heme  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Bloodletting by physicians before the era of antibiotics may seem like a barbaric practice, but it may have been of some benefit to patients suffering from bacterial infections. In her Perspective, Rouault explains that most bacteria depend on a source of iron to grow and survive inside their animal hosts. A new study (Skaar et al.) shows that the pathogenic bacterium Staphylococcus aureus uses several ingenious strategies to obtain iron from heme stored as hemoglobin in the red blood cells of its mammalian hosts.

Tracey A. Rouault (National Institute of Child Health and Human Development;Human Iron Metabolism, Cell Biology and Metabolism Branch)

2004-09-10

155

Tick vaccines and the control of tick-borne pathogens  

PubMed Central

Ticks are obligate hematophagous ectoparasites that transmit a wide variety of pathogens to humans and animals. The incidence of tick-borne diseases has increased worldwide in both humans and domestic animals over the past years resulting in greater interest in the study of tick-host-pathogen interactions. Advances in vector and pathogen genomics and proteomics have moved forward our knowledge of the vector-pathogen interactions that take place during the colonization and transmission of arthropod-borne microbes. Tick-borne pathogens adapt from the vector to the mammalian host by differential gene expression thus modulating host processes. In recent years, studies have shown that targeting tick proteins by vaccination can not only reduce tick feeding and reproduction, but also the infection and transmission of pathogens from the tick to the vertebrate host. In this article, we review the tick-protective antigens that have been identified for the formulation of tick vaccines and the effect of these vaccines on the control of tick-borne pathogens. PMID:23847771

Merino, Octavio; Alberdi, Pilar; Pérez de la Lastra, José M.; de la Fuente, José

2013-01-01

156

Fungal pathogens of Proteaceae.  

PubMed

Species of Leucadendron, Leucospermum and Protea (Proteaceae) are in high demand for the international floriculture market due to their brightly coloured and textured flowers or bracts. Fungal pathogens, however, create a serious problem in cultivating flawless blooms. The aim of the present study was to characterise several of these pathogens using morphology, culture characteristics, and DNA sequence data of the rRNA-ITS and LSU genes. In some cases additional genes such as TEF 1-? and CHS were also sequenced. Based on the results of this study, several novel species and genera are described. Brunneosphaerella leaf blight is shown to be caused by three species, namely B. jonkershoekensis on Protea repens, B. nitidae sp. nov. on Protea nitida and B. protearum on a wide host range of Protea spp. (South Africa). Coniothyrium-like species associated with Coniothyrium leaf spot are allocated to other genera, namely Curreya grandicipis on Protea grandiceps, and Microsphaeropsis proteae on P. nitida (South Africa). Diaporthe leucospermi is described on Leucospermum sp. (Australia), and Diplodina microsperma newly reported on Protea sp. (New Zealand). Pyrenophora blight is caused by a novel species, Pyrenophora leucospermi, and not Drechslera biseptata or D. dematoidea as previously reported. Fusicladium proteae is described on Protea sp. (South Africa), Pestalotiopsis protearum on Leucospermum cuneiforme (Zimbabwe), Ramularia vizellae and R. stellenboschensis on Protea spp. (South Africa), and Teratosphaeria capensis on Protea spp. (Portugal, South Africa). Aureobasidium leaf spot is shown to be caused by two species, namely A. proteae comb. nov. on Protea spp. (South Africa), and A. leucospermi sp. nov. on Leucospermum spp. (Indonesia, Portugal, South Africa). Novel genera and species elucidated in this study include Gordonomyces mucovaginatus and Pseudopassalora gouriqua (hyphomycetes), and Xenoconiothyrium catenata (coelomycete), all on Protea spp. (South Africa). PMID:22403475

Crous, P W; Summerell, B A; Swart, L; Denman, S; Taylor, J E; Bezuidenhout, C M; Palm, M E; Marincowitz, S; Groenewald, J Z

2011-12-01

157

Rapid Detection of Pathogens  

SciTech Connect

Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleic acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development and the Perlin lab in sample preparation and testing in animal models.

David Perlin

2005-08-14

158

Pathways mediating resolution of inflammation: when enough is too much.  

PubMed

Patients with critical illness, and in particular sepsis, are now recognized to undergo unifying, pathogenic disturbances of immune function. Whilst scientific and therapeutic focus has traditionally been on understanding and modulating the initial pro-inflammatory limb, recent years have witnessed a refocusing on the development and importance of immunosuppressive 'anti-inflammatory' pathways. Several mechanisms are known to drive this phenomenon; however, no overriding conceptual framework justifies them. In this article we review the contribution of pro-resolution pathways to this phenotype, describing the observed immune alterations in terms of either a failure of resolution of inflammation or the persistence of pro-resolution processes causing inappropriate 'injurious resolution'-a novel hypothesis. The dysregulation of key processes in critical illness, including apoptosis of infiltrating neutrophils and their efferocytosis by macrophages, are discussed, along with the emerging role of specialized cell subtypes Gr1(+) CD11b(+) myeloid-derived suppressor cells and CD4(+) CD25(+) FoxP3(+) T-regulatory cells. PMID:23794437

Fullerton, James N; O'Brien, Alastair J; Gilroy, Derek W

2013-09-01

159

Inflammatory Monocytes Are Required for Mucosal Resistance to the Pathogen  

E-print Network

this barrier to cause systemic infection. Mucosal immunity relies on dendritic cells (DCs) that are residentImmunity Article Gr1+ Inflammatory Monocytes Are Required for Mucosal Resistance to the Pathogen, 2005). CCR6+ DCs are important in regulating mucosal responses to antigens sampled by M cells, which

Arnold, Jonathan

160

REVIEW ARTICLE Molecular Anions  

E-print Network

REVIEW ARTICLE Molecular Anions Jack Simons Chemistry Department, Henry Eyring Center for Theoretical Chemistry, UniVersity of Utah, Salt Lake City, Utah ReceiVed: December 5, 2007; ReVised Manuscript in close collaboration with experiment in this field. In this article, many of the experimental

Simons, Jack

161

Cultures & Conflits Articles indits  

E-print Network

Cultures & Conflits Articles in). ................................................................................................................................................................................................................................................................................................ R�f�rence �lectronique Didier BIGO, � L'impossible cartographie du terrorisme �, Cultures & Conflits [En ligne], Articles in�dits, mis en ligne le 25 f�vrier 2005, consult� le 27 juin 2014. URL : http://conflits

Boyer, Edmond

162

Cultures & Conflits Articles indits  

E-print Network

Cultures & Conflits Articles in (French) �, Cultures & Conflits [En ligne], Articles in�dits, mis en ligne le , consult� le 29 juin 2014. URL : http://conflits.revues.org/1175 �diteur : Centre d'�tudes sur les conflits http://conflits

Paris-Sud XI, Université de

163

Permaculture Magazine Articles  

NSDL National Science Digital Library

This website from Permaculture Magazine offers a selection of gratis online articles. According to the site, this section "has sample articles from previous issues of Permaculture Magazine. These have been chosen primarily to give an idea of the broad range of subjects covered by the magazine" back to issue number nine. Topics include ecofarming, bird management, earthen huts, and pollution control.

2008-04-03

164

PDF Article Metadata Harvester  

Microsoft Academic Search

Scientific journals are very important in recording the finding from researchers around the world. The recent media to disseminate scientific journals is PDF. On scheme to find the scientific journals over the internet is via metadata. Metadata stores information about article summary. Embedding metadata into PDF of scientific article will grant the consistency of metadata readness. Harvesting the metadata from

Leon Andretti Abdillah

2012-01-01

165

Bacterial subversion of host innate immune pathways.  

PubMed

The pathogenesis of infection is a continuously evolving battle between the human host and the infecting microbe. The past decade has brought a burst of insights into the molecular mechanisms of innate immune responses to bacterial pathogens. In parallel, multiple specific mechanisms by which microorganisms subvert these host responses have been uncovered. This Review highlights recently characterized mechanisms by which bacterial pathogens avoid killing by innate host responses, including autophagy pathways and a proinflammatory cytokine transcriptional response, and by the manipulation of vesicular trafficking to avoid the toxicity of lysosomal enzymes. PMID:23661751

Baxt, Leigh A; Garza-Mayers, Anna Cristina; Goldberg, Marcia B

2013-05-10

166

Common themes in microbial pathogenicity.  

PubMed Central

A bacterial pathogen is a highly adapted microorganism which has the capacity to cause disease. The mechanisms used by pathogenic bacteria to cause infection and disease usually include an interactive group of virulence determinants, sometimes coregulated, which are suited for the interaction of a particular microorganism with a specific host. Because pathogens must overcome similar host barriers, common themes in microbial pathogenesis have evolved. However, these mechanisms are diverse between species and not necessarily conserved; instead, convergent evolution has developed several different mechanisms to overcome host barriers. The success of a bacterial pathogen can be measured by the degree with which it replicates after entering the host and reaching its specific niche. Successful microbial infection reflects persistence within a host and avoidance or neutralization of the specific and nonspecific defense mechanisms of the host. The degree of success of a pathogen is dependent upon the status of the host. As pathogens pass through a host, they are exposed to new environments. Highly adapted pathogenic organisms have developed biochemical sensors exquisitely designed to measure and respond to such environmental stimuli and accordingly to regulate a cascade of virulence determinants essential for life within the host. The pathogenic state is the product of dynamic selective pressures on microbial populations. PMID:2569162

Finlay, B B; Falkow, S

1989-01-01

167

Proteomics of Foodborne Bacterial Pathogens  

NASA Astrophysics Data System (ADS)

This chapter is intended to be a relatively brief overview of proteomic techniques currently in use for the identification and analysis of microorganisms with a special emphasis on foodborne pathogens. The chapter is organized as follows. First, proteomic techniques are introduced and discussed. Second, proteomic applications are presented specifically as they relate to the identification and qualitative/quantitative analysis of foodborne pathogens.

Fagerquist, Clifton K.

168

Cell Host & Microbe Autophagy Induction by the Pathogen Receptor CD46  

E-print Network

Cell Host & Microbe Article Autophagy Induction by the Pathogen Receptor CD46 Pierre.09.006 SUMMARY Autophagy is a highly regulated self-degradative mechanism required at a basal level for intracellular clearance and recycling of cytoplasmic contents. Upon intracellular pathogen invasion, autophagy

169

Biological Control of Plant Pathogens: Research, Commercialization, and Application in the USA  

NSDL National Science Digital Library

This article describes the current status of research, commercial development, and application of biocontrol strategies targeted at plant pathogens. Also included is a description of future prospects for using biological control to limit the damage of plant pathogens in both conventional and organic agriculture.

Brian B. McSpadden Gardener (The Ohio State University-OARDC;); Deborah R. Fravel (USDA, ARS;)

2002-05-10

170

Glacial refugia in pathogens: European genetic structure of anther smut pathogens on Silene latifolia and Silene dioica.  

PubMed

Climate warming is predicted to increase the frequency of invasions by pathogens and to cause the large-scale redistribution of native host species, with dramatic consequences on the health of domesticated and wild populations of plants and animals. The study of historic range shifts in response to climate change, such as during interglacial cycles, can help in the prediction of the routes and dynamics of infectious diseases during the impending ecosystem changes. Here we studied the population structure in Europe of two Microbotryum species causing anther smut disease on the plants Silene latifolia and Silene dioica. Clustering analyses revealed the existence of genetically distinct groups for the pathogen on S. latifolia, providing a clear-cut example of European phylogeography reflecting recolonization from southern refugia after glaciation. The pathogen genetic structure was congruent with the genetic structure of its host species S. latifolia, suggesting dependence of the migration pathway of the anther smut fungus on its host. The fungus, however, appeared to have persisted in more numerous and smaller refugia than its host and to have experienced fewer events of large-scale dispersal. The anther smut pathogen on S. dioica also showed a strong phylogeographic structure that might be related to more northern glacial refugia. Differences in host ecology probably played a role in these differences in the pathogen population structure. Very high selfing rates were inferred in both fungal species, explaining the low levels of admixture between the genetic clusters. The systems studied here indicate that migration patterns caused by climate change can be expected to include pathogen invasions that follow the redistribution of their host species at continental scales, but also that the recolonization by pathogens is not simply a mirror of their hosts, even for obligate biotrophs, and that the ecology of hosts and pathogen mating systems likely affects recolonization patterns. PMID:21187901

Vercken, Elodie; Fontaine, Michael C; Gladieux, Pierre; Hood, Michael E; Jonot, Odile; Giraud, Tatiana

2010-01-01

171

Glacial Refugia in Pathogens: European Genetic Structure of Anther Smut Pathogens on Silene latifolia and Silene dioica  

PubMed Central

Climate warming is predicted to increase the frequency of invasions by pathogens and to cause the large-scale redistribution of native host species, with dramatic consequences on the health of domesticated and wild populations of plants and animals. The study of historic range shifts in response to climate change, such as during interglacial cycles, can help in the prediction of the routes and dynamics of infectious diseases during the impending ecosystem changes. Here we studied the population structure in Europe of two Microbotryum species causing anther smut disease on the plants Silene latifolia and Silene dioica. Clustering analyses revealed the existence of genetically distinct groups for the pathogen on S. latifolia, providing a clear-cut example of European phylogeography reflecting recolonization from southern refugia after glaciation. The pathogen genetic structure was congruent with the genetic structure of its host species S. latifolia, suggesting dependence of the migration pathway of the anther smut fungus on its host. The fungus, however, appeared to have persisted in more numerous and smaller refugia than its host and to have experienced fewer events of large-scale dispersal. The anther smut pathogen on S. dioica also showed a strong phylogeographic structure that might be related to more northern glacial refugia. Differences in host ecology probably played a role in these differences in the pathogen population structure. Very high selfing rates were inferred in both fungal species, explaining the low levels of admixture between the genetic clusters. The systems studied here indicate that migration patterns caused by climate change can be expected to include pathogen invasions that follow the redistribution of their host species at continental scales, but also that the recolonization by pathogens is not simply a mirror of their hosts, even for obligate biotrophs, and that the ecology of hosts and pathogen mating systems likely affects recolonization patterns. PMID:21187901

Vercken, Elodie; Fontaine, Michael C.; Gladieux, Pierre; Hood, Michael E.; Jonot, Odile; Giraud, Tatiana

2010-01-01

172

Original article Comparative influence  

E-print Network

of adaptation. The adaptive genetic response can be easily assayed at different levels of the relevant environmental factor. Fruit flies breed in the wild in decaying plant material [8], where different alcohols can ethanol tolerance are very complex. They involve a series of metabolic pathways, i

Paris-Sud XI, Université de

173

THEJOURNALOFCELLBIOLOGY JCB: ARTICLE  

E-print Network

of replicative stress Anna M. Woodward,1 Thomas Göhler,1 M. Gloria Luciani,1 Maren Oehlmann,1 Xinquan Ge,1 Anton during unperturbed S phases because of suppression by a caffeine-sensitive checkpoint pathway. Use, most of which normally remain dormant unless cells experience replicative stress. Consistent

Gartner, Anton

174

THEJOURNALOFCELLBIOLOGY JCB: ARTICLE  

E-print Network

and induces homotrimerization of E1. The final lowest-energy forms of E1, HA, and many other fusion proteins 167­177 http://www.jcb.org/cgi/doi/10.1083/jcb.200412059 JCB 167 Class II fusion protein of alphaviruses drives membrane fusion through the same pathway as class I proteins Elena Zaitseva,1 Aditya Mittal

Mittal, Aditya

175

Pathogenicity islands: the tip of the iceberg  

Microsoft Academic Search

Pathogenicity islands represent distinct genetic elements encoding virulence factors of pathogenic bacteria. Pathogenicity islands belong to the class of genomic islands, which are common genetic elements sharing a set of unifying features. Genomic islands have been acquired by horizontal gene transfer. In recent years many different genomic islands have been discovered in a variety of pathogenic as well as non-pathogenic

Ute Hentschel; Jörg Hacker

2001-01-01

176

The Oxylipin Pathway in Arabidopsis  

PubMed Central

Oxylipins are acyclic or cyclic oxidation products derived from the catabolism of fatty acids which regulate many defense and developmental pathways in plants. The dramatic increase in the volume of publications and reviews on these compounds since 1997 documents the increasing interest in this compound and its role in plants. Research on this topic has solidified our understanding of the chemistry and biosynthetic pathways for oxylipin production. However, more information is still needed on how free fatty acids are produced and the role of beta-oxidation in the biosynthetic pathway for oxylipins. It is also becoming apparent that oxylipin content and composition changes during growth and development and during pathogen or insect attack. Oxylipins such as jasmonic acid (JA) or 12-oxo-phytodienoic acid modulate the expression of numerous genes and influence specific aspects of plant growth, development and responses to abiotic and biotic stresses. Although oxylipins are believed to act alone, several examples were presented to illustrate that JA-induced responses are modulated by the type and the nature of crosstalk with other signaling molecules such as ethylene and salicylic acid. How oxylipins cause changes in gene expression and instigate a physiological response is becoming understood with the isolation of mutations in both positive and negative regulators in the jasmonate signaling pathway and the use of cDNA microarrays. PMID:22303193

Creelman, Robert A.; Mulpuri, Rao

2002-01-01

177

Filamentous pathogen effector functions: of pathogens, hosts and microbiomes.  

PubMed

Microorganisms play essential roles in almost every environment on earth. For instance, microbes decompose organic material, or establish symbiotic relationships that range from pathogenic to mutualistic. Symbiotic relationships have been particularly well studied for microbial plant pathogens and have emphasized the role of effectors; secreted molecules that support host colonization. Most effectors characterized thus far play roles in deregulation of host immunity. Arguably, however, pathogens not only deal with immune responses during host colonization, but also encounter other microbes including competitors, (myco)parasites and even potential co-operators. Thus, part of the effector catalog may target microbiome co-inhabitants rather than host physiology. PMID:24879450

Rovenich, Hanna; Boshoven, Jordi C; Thomma, Bart P H J

2014-08-01

178

Host-Pathogen Interactions  

PubMed Central

A ?-glucan isolated from the mycelial walls of Phytophthora megasperma var. sojae and a glucan purified from yeast extract stimulate the accumulation of phytoalexins in red kidney bean, Phaseolus vulgaris, and stimulate the accumulation of the phytoalexin, rishitin, in potato tubers, Solanum tuberosum. These glucans have previously been shown to be potent elicitors of glyceollin accumulation in soybean, Glycine max. Treatment of kidney bean cotyledons with the glucan elicitors resulted in the accumulation of at least five fungistatic compounds. These compounds migrate during thin layer chromatography identically to the fungistatic compounds which accumulate in kidney beans which have been inoculated with Colletotrichum lindemuthianum, a fungal pathogen of kidney beans. Potatoes accumulate as much as 29 micrograms of rishitin per gram fresh weight following exposure to the glucan from Phytophthora megasperma var. sojae and as much as 19.5 micrograms of rishitin per gram fresh weight following exposure to yeast glucan. Potatoes accumulated 28 micrograms of rishitin per gram fresh weight following inoculation with live Phytophthora megasperma var. sojae. ImagesFig. 1 PMID:16660638

Cline, Kenneth; Wade, Mark; Albersheim, Peter

1978-01-01

179

Bacterial pathogen manipulation of host membrane trafficking.  

PubMed

Pathogens use a vast number of strategies to alter host membrane dynamics. Targeting the host membrane machinery is important for the survival and pathogenesis of several extracellular, vacuolar, and cytosolic bacteria. Membrane manipulation promotes bacterial replication while suppressing host responses, allowing the bacterium to thrive in a hostile environment. This review provides a comprehensive summary of various strategies used by both extracellular and intracellular bacteria to hijack host membrane trafficking machinery. We start with mechanisms used by bacteria to alter the plasma membrane, delve into the hijacking of various vesicle trafficking pathways, and conclude by summarizing bacterial adaptation to host immune responses. Understanding bacterial manipulation of host membrane trafficking provides insights into bacterial pathogenesis and uncovers the molecular mechanisms behind various processes within a eukaryotic cell. PMID:25103867

Asrat, Seblewongel; de Jesús, Dennise A; Hempstead, Andrew D; Ramabhadran, Vinay; Isberg, Ralph R

2014-10-11

180

Article Watch, April 2012  

PubMed Central

This column highlights recently published articles that are of interest to the readership of this publication. We encourage ABRF members to forward information on articles they feel are important and useful to Clive Slaughter, Georgia Health Sciences University-University of Georgia Medical Partnership, 279 William St., Athens GA 30607-1777. Phone: 706-369-5945; Fax: 706-369-5936; E-mail: cslaught@uga.edu; or to any member of the editorial board. Article summaries reflect the reviewer's opinions and not necessarily those of the association.

Slaughter, Clive

2012-01-01

181

Article Watch: December 2014  

PubMed Central

This column highlights recently published articles that are of interest to the readership of this publication. We encourage ABRF members to forward information on articles they feel are important and useful to Clive Slaughter, Georgia Regents University-University of Georgia Medical Partnership, 1425 Prince Ave., Athens, GA 30606, USA. Phone: 706-713-2216; Fax: 706-713-2221; E-mail: cslaught@uga.edu; or to any member of the Editorial Board. Article summaries reflect the reviewer's opinions and not necessarily those of the association. PMID:25365791

Slaughter, Clive A.

2014-01-01

182

Article Watch: April 2014  

PubMed Central

This column highlights recently published articles that are of interest to the readership of this publication. We encourage ABRF members to forward information on articles they feel are important and useful to Clive Slaughter, Georgia Regents University/University of Georgia Medical Partnership, 1425 Prince Ave., Athens, GA 30606, USA (Phone: 706-713-2216; Fax: 706-713-2221; E-mail; cslaught@uga.edu), or to any member of the editorial board. Article summaries reflect the reviewer's opinions and not necessarily those of the association.

Slaughter, Clive A.

2014-01-01

183

Article Watch, April 2010  

PubMed Central

This column highlights recently published articles that are of interest to the readership of this publication. We encourage ABRF members to forward information about articles they feel are important and useful to Clive Slaughter, MCG-UGA Medical Partnership, 279 William St., Athens, GA 30607-1777, USA. Tel.: (706) 369-5945: Fax: (706) 369-5936; E-mail: cslaughter@mail.mcg.edu; or to any member of the editorial board. Article summaries reflect the reviewer's opinions and not necessarily those of the association.

Slaughter, Clive

2010-01-01

184

A critical role of autophagy in plant resistance to necrotrophic fungal pathogens.  

PubMed

Autophagy is a pathway for degradation of cytoplasmic components. In plants, autophagy plays an important role in nutrient recycling during nitrogen or carbon starvation, and in responses to abiotic stress. Autophagy also regulates age- and immunity-related programmed cell death, which is important in plant defense against biotrophic pathogens. Here we show that autophagy plays a critical role in plant resistance to necrotrophic pathogens. ATG18a, a critical autophagy protein in Arabidopsis, interacts with WRKY33, a transcription factor that is required for resistance to necrotrophic pathogens. Expression of autophagy genes and formation of autophagosomes are induced in Arabidopsis by the necrotrophic fungal pathogen Botrytis cinerea. Induction of ATG18a and autophagy by B. cinerea was compromised in the wrky33 mutant, which is highly susceptible to necrotrophic pathogens. Arabidopsis mutants defective in autophagy exhibit enhanced susceptibility to the necrotrophic fungal pathogens B. cinerea and Alternaria brassicicola based on increased pathogen growth in the mutants. The hypersusceptibility of the autophagy mutants was associated with reduced expression of the jasmonate-regulated PFD1.2 gene, accelerated development of senescence-like chlorotic symptoms, and increased protein degradation in infected plant tissues. These results strongly suggest that autophagy cooperates with jasmonate- and WRKY33-mediated signaling pathways in the regulation of plant defense responses to necrotrophic pathogens. PMID:21395886

Lai, Zhibing; Wang, Fei; Zheng, Zuyu; Fan, Baofang; Chen, Zhixiang

2011-06-01

185

Transient virulence of emerging pathogens  

PubMed Central

Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution. PMID:19864267

Bolker, Benjamin M.; Nanda, Arjun; Shah, Dharmini

2010-01-01

186

1371RESEARCH ARTICLE INTRODUCTION  

E-print Network

morphologies in response to sensory deprivation (Mukhopadhyay et al., 2008), and perturbation of sensory1371RESEARCH ARTICLE INTRODUCTION Dendritic spines and sensory neuron protrusions are examples evoked by presynaptic release of neurotransmitters, and sensory receptive endings process and interpret

Shaham, Shai

187

Research Articles REBECCA HARDIN  

E-print Network

Research Articles REBECCA HARDIN MELISSA J. REMIS Biological and Cultural Anthropology approaches from biological and cultural anthropology to describe changing relationships between humans, environmental anthropology] BIOLOGICAL AND CULTURAL ANTHROPOLOGY IN AN AFRICAN FOREST SITE The collaborative

Hardin, Rebecca D.

188

Original article Reproductive biotechnologies  

E-print Network

Original article Reproductive biotechnologies for endangered mammalian species Pierre COMIZZOLIa, France b INRA, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France (Received 2 June 2000; accepted 16 August 2000) Abstract -- Assisted reproductive techniques (gamete

Paris-Sud XI, Université de

189

Transactions Dynamic Article Links  

E-print Network

Dalton Transactions Dynamic Article Links Cite this: Dalton Trans., 2012, 41, 1742 www.rsc.org/dalton adducts Casie R. Hilliard, Nattamai Bhuvanesh, John A. Gladysz and Janet Bl¨umel* Received 3rd October

Bluemel, Janet

190

Original article Amylase polymorphism  

E-print Network

Original article Amylase polymorphism in Drosophila melanogaster: haplotype frequencies in tropical December 1992) Summary - The frequencies of phenotypic haplotypes at the Amylase loci of D melanogaster by demographic bottlenecks related to recent colonizations. amylase / polymorphism / tropical populations

Boyer, Edmond

191

BTI Pathogen Use Committee BTI Pathogen Use Form  

E-print Network

, grafting, seed, nematode, insect) and favorable environmental conditions for pathogen spread. 14. Describe/7/04 4 16. Provide reference(s) (including page numbers), which describes containment procedures

Pawlowski, Wojtek

192

Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens  

PubMed Central

Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

Harwood, Catherine G.; Rao, Reeta P.

2014-01-01

193

Lipolytic enzymes involved in the virulence of human pathogenic fungi.  

PubMed

Pathogenic microbes secrete various enzymes with lipolytic activities to facilitate their survival within the host. Lipolytic enzymes include extracellular lipases and phospholipases, and several lines of evidence have suggested that these enzymes contribute to the virulence of pathogenic fungi. Candida albicans and Cryptococcus neoformans are the most commonly isolated human fungal pathogens, and several biochemical and molecular approaches have identified their extracellular lipolytic enzymes. The role of lipases and phospholipases in the virulence of C. albicans has been extensively studied, and these enzymes have been shown to contribute to C. albicans morphological transition, colonization, cytotoxicity, and penetration to the host. While not much is known about the lipases in C. neoformans, the roles of phospholipases in the dissemination of fungal cells in the host and in signaling pathways have been described. Lipolytic enzymes may also influence the survival of the lipophilic cutaneous pathogenic yeast Malassezia species within the host, and an unusually high number of lipase-coding genes may complement the lipid dependency of this fungus. This review briefly describes the current understanding of the lipolytic enzymes in major human fungal pathogens, namely C. albicans, C. neoformans, and Malassezia spp. PMID:23874127

Park, Minji; Do, Eunsoo; Jung, Won Hee

2013-06-01

194

Pathogen Recognition and Inflammatory Signaling in Innate Immune Defenses  

PubMed Central

Summary: The innate immune system constitutes the first line of defense against invading microbial pathogens and relies on a large family of pattern recognition receptors (PRRs), which detect distinct evolutionarily conserved structures on pathogens, termed pathogen-associated molecular patterns (PAMPs). Among the PRRs, the Toll-like receptors have been studied most extensively. Upon PAMP engagement, PRRs trigger intracellular signaling cascades ultimately culminating in the expression of a variety of proinflammatory molecules, which together orchestrate the early host response to infection, and also is a prerequisite for the subsequent activation and shaping of adaptive immunity. In order to avoid immunopathology, this system is tightly regulated by a number of endogenous molecules that limit the magnitude and duration of the inflammatory response. Moreover, pathogenic microbes have developed sophisticated molecular strategies to subvert host defenses by interfering with molecules involved in inflammatory signaling. This review presents current knowledge on pathogen recognition through different families of PRRs and the increasingly complex signaling pathways responsible for activation of an inflammatory and antimicrobial response. Moreover, medical implications are discussed, including the role of PRRs in primary immunodeficiencies and in the pathogenesis of infectious and autoimmune diseases, as well as the possibilities for translation into clinical and therapeutic applications. PMID:19366914

Mogensen, Trine H.

2009-01-01

195

Impact of the UPR on the virulence of the plant fungal pathogen A. brassicicola  

PubMed Central

The fungal genus Alternaria contains many destructive plant pathogens, including Alternaria brassicicola, which causes black spot disease on a wide range of Brassicaceae plants and which is routinely used as a model necrotrophic pathogen in studies with Arabidopsis thaliana. During host infection, many fungal proteins that are critical for disease progression are processed in the endoplasmic reticulum (ER)/Golgi system and secreted in planta. The unfolded protein response (UPR) is an essential part of ER protein quality control that ensures efficient maturation of secreted and membrane-bound proteins in eukaryotes. This review highlights the importance of the UPR signaling pathway with respect to the ability of A. brassicicola to efficiently accomplish key steps of its pathogenic life cycle. Understanding the pathogenicity mechanisms that fungi uses during infection is crucial for the development of new antifungal therapies. Therefore the UPR pathway has emerged as a promising drug target for plant disease control. PMID:24189567

Guillemette, Thomas; Calmes, Benoit; Simoneau, Philippe

2014-01-01

196

Optimization of proteomic sample preparation procedures for comprehensive protein characterization of pathogenic systems  

SciTech Connect

The elucidation of critical functional pathways employed by pathogens and hosts during an infectious cycle is both challenging and central to our understanding of infectious diseases. In recent years, mass spectrometry-based proteomics has been used as a powerful tool to identify key pathogenesis-related proteins and pathways. Despite the analytical power of mass spectrometry-based technologies, samples must be appropriately prepared to characterize the functions of interest (e.g. host-response to a pathogen or a pathogen-response to a host). The preparation of these protein samples requires multiple decisions about what aspect of infection is being studied, and it may require the isolation of either host and/or pathogen cellular material.

Brewer, Heather M.; Norbeck, Angela D.; Adkins, Joshua N.; Manes, Nathan P.; Ansong, Charles; Shi, Liang; Rikihisa, Yasuko; Kikuchi, Takane; Wong, Scott; Estep, Ryan D.; Heffron, Fred; Pasa-Tolic, Ljiljana; Smith, Richard D.

2008-12-19

197

Original article title: \\  

Microsoft Academic Search

Background  Vitiligo is the most prevalent pigmentary disorder which occurs worldwide, with an incidence rate between 0.1-4 percent. It\\u000a is anticipated that the discovery of biological pathways of vitiligo pathogenesis will provide novel therapeutic and prophylactic\\u000a targets for future approaches to the treatment and prevention of vitiligo. The purposes of this study were evaluating the\\u000a efficacy of supplemental zinc on the

Reza Yaghoobi; Mohammad Omidian; Nooshin Bagherani

2011-01-01

198

Developmental Pathways in Juvenile Externalizing and Internalizing Problems  

ERIC Educational Resources Information Center

This article summarizes the empirical studies showing pathways in the development of externalizing and delinquent behaviors. Pathways are defined as the orderly temporal development between more than two problem behaviors. The paper addresses the following questions: (1) What are the developmental pathways between different diagnoses of Disruptive…

Loeber, Rolf; Burke, Jeffrey D.

2011-01-01

199

Pathogens in Dairy Farming: Source Characterization and Groundwater Impacts  

NASA Astrophysics Data System (ADS)

Intense animal husbandry is of growing concern as a potential contamination source of enteric pathogens as well as antibiotics. To assess the public health risk from pathogens and their hydrologic pathways, we hypothesize that the animal farm is not a homogeneous diffuse source, but that pathogen loading to the soil and, therefore, to groundwater varies significantly between the various management units of a farm. A dairy farm, for example, may include an area with calf hutches, corrals for heifers of various ages, freestalls and exercise yards for milking cows, separate freestalls for dry cows, a hospital barn, a yard for collection of solid manure, a liquid manure storage lagoon, and fields receiving various amounts of liquid and solid manure. Pathogen shedding and, hence, therapeutic and preventive pharmaceutical treatments vary between these management units. We are implementing a field reconnaissance program to determine the occurrence of three different pathogens ( E. coli, Salmonella, Campylobacter) and one indicator organism ( Enterococcus) at the ground-surface and in shallow groundwater of seven different management units on each of two farms, and in each of four seasons (spring/dry season, summer/irrigation season, fall/dry season, winter/rainy season). Initial results indicate that significant differences exist in the occurrence of these pathogens between management units and between organisms. These differences are weakly reflected in their occurrence in groundwater, despite the similarity of the shallow geologic environment across these sites. Our results indicate the importance of differentiating sources within a dairy farm and the importance of understanding subsurface transport processes for these pathogens.

Atwill, E. R.; Watanabe, N.; Li, X.; Hou, L.; Harter, T.; Bergamaschi, B.

2007-12-01

200

insight review articles 826 NATURE | VOL 411 | 14 JUNE 2001 | www.nature.com  

E-print Network

developmental responses on the plant cells, leading to the appearance of galls, root knots or cysts. The plantinsight review articles 826 NATURE | VOL 411 | 14 JUNE 2001 | www.nature.com M ost plants are resistant to most plant pathogens. Passive protection against pathogens that are not specialized to attack

Dangl, Jeff

201

RESEARCH ARTICLE Open Access Meta-analysis of Chicken Salmonella infection  

E-print Network

RESEARCH ARTICLE Open Access Meta-analysis of Chicken ­ Salmonella infection experiments Marinus FW zoonotic pathogens, especially Salmonella species. These food items contain a potential hazard for humans. Chickens lines differ in susceptibility for Salmonella and can harbor Salmonella pathogens without showing

202

Review article Reviewing molecular adaptations of Lyme borreliosis  

E-print Network

disease risk ­ either through vaccinating humans or reducing the risk of contacting infected ticksReview article Reviewing molecular adaptations of Lyme borreliosis spirochetes in the context) Abstract ­ Lyme borreliosis (LB) is caused by a group of pathogenic spirochetes ­ most often Borrelia

Paris-Sud XI, Université de

203

Review article Secretion of virulence factors by Escherichia coli  

E-print Network

Review article Secretion of virulence factors by Escherichia coli Bernard China* Fréderic Goffaux with their host, pathogenic strains of E. coli need to secrete some virulence factors which can modify the metabolism of host cells, contributing to disease. Since E. coli is a Gram-negative bacteria, this secretion

Paris-Sud XI, Université de

204

Original article Evidence of long distance airborne transport  

E-print Network

/ Mycoplasma 1. INTRODUCTION The ability of livestock pathogens to be transported over long distances viaOriginal article Evidence of long distance airborne transport of porcine reproductive (PRRSV) and Mycoplasma hyopneumoniae to be transported over long distances via the airborne route

Paris-Sud XI, Université de

205

How Do Filamentous Pathogens Deliver Effector Proteins into Plant Cells?  

PubMed Central

Fungal and oomycete plant parasites are among the most devastating pathogens of food crops. These microbes secrete effector proteins inside plant cells to manipulate host processes and facilitate colonization. How these effectors reach the host cytoplasm remains an unclear and debated area of plant research. In this article, we examine recent conflicting findings that have generated discussion in the field. We also highlight promising approaches based on studies of both parasite and host during infection. Ultimately, this knowledge may inform future broad spectrum strategies for protecting crops from such pathogens. PMID:24586116

Petre, Benjamin; Kamoun, Sophien

2014-01-01

206

Legless pathogens: how bacterial physiology provides the key to understanding pathogenicity.  

PubMed

This review argues that knowledge of microbial physiology and metabolism is a prerequisite to understanding mechanisms of pathogenicity. The ability of Neisseria gonorrhoeae to cope with stresses such as those found during infection requires a sialyltransferase to sialylate its lipopolysaccharide using host-derived CMP-NANA in the human bloodstream, the ability to oxidize lactate that is abundant in the human body, outer-membrane lipoproteins that provide the first line of protection against oxidative and nitrosative stress, regulation of NO reduction independently from the nitrite reductase that forms NO, an extra haem group on the C-terminal extension of a cytochrome oxidase subunit, and a respiratory capacity far in excess of metabolic requirements. These properties are all normal components of neisserial physiology; they would all fail rigid definitions of a pathogenicity determinant. In anaerobic cultures of enteric bacteria, duplicate pathways for nitrate reduction to ammonia provide a selective advantage when nitrate is either abundant or scarce. Selection of these alternative pathways is in part regulated by two parallel two-component regulatory systems. NarX-NarL primarily ensures that nitrate is reduced in preference to thermodynamically less favourable terminal electron acceptors, but NarQ-NarP facilitates reduction of limited quantities of nitrate or other, less favourable, terminal electron acceptors in preference to fermentative growth. How enteric bacteria repair damage caused by nitrosative and oxidative damage inflicted by host defences is less well understood. In both N. gonorrhoeae and Escherichia coli, parallel pathways that duplicate particular biochemical functions are far from redundant, but fulfil specific physiological roles. PMID:22493300

Cole, Jeffrey A

2012-06-01

207

Will the package contain pathogens  

E-print Network

Will the package contain pathogens OR dry ice ? Is the material considered hazardous by the DOT? Do: Shipping Biological Goods or Dry Ice" before packing and shipping this material. EH&S April 09, 2008

208

NLR functions beyond pathogen recognition  

Microsoft Academic Search

The last 10 years have witnessed the identification of a new class of intracellular pattern-recognition molecules—the nucleotide-binding domain and leucine-rich repeat–containing family (NLR). Members of this family garnered interest as pattern-recognition receptors able to trigger inflammatory responses against pathogens. Many studies support a pathogen-recognition function for human NLR proteins and shed light on their role in the broader control of

Thomas A Kufer; Philippe J Sansonetti

2011-01-01

209

Host–Pathogen Systems Biology  

Microsoft Academic Search

\\u000a Unlike traditional biological research that focuses on a small set of components, systems biology studies the complex interactions\\u000a among a large number of genes, proteins, and other elements of biological networks and systems. Host-pathogen systems biology\\u000a examines the interactions between the components of two distinct organisms: a microbial or viral pathogen and its animal host.\\u000a With the availability of complete

Christian V. Forst

210

Ameobal Pathogen Mimivirus Infects Macrophages through Phagocytosis  

PubMed Central

Mimivirus, or Acanthamoeba polyphaga mimivirus (APMV), a giant double-stranded DNA virus that grows in amoeba, was identified for the first time in 2003. Entry by phagocytosis within amoeba has been suggested but not demonstrated. We demonstrate here that APMV was internalized by macrophages but not by non-phagocytic cells, leading to productive APMV replication. Clathrin- and caveolin-mediated endocytosis pathways, as well as degradative endosome-mediated endocytosis, were not used by APMV to invade macrophages. Ultrastructural analysis showed that protrusions were formed around the entering virus, suggesting that macropinocytosis or phagocytosis was involved in APMV entry. Reorganization of the actin cytoskeleton and activation of phosphatidylinositol 3-kinases were required for APMV entry. Blocking macropinocytosis and the lack of APMV colocalization with rabankyrin-5 showed that macropinocytosis was not involved in viral entry. Overexpression of a dominant-negative form of dynamin-II, a regulator of phagocytosis, inhibited APMV entry. Altogether, our data demonstrated that APMV enters macrophages through phagocytosis, a new pathway for virus entry in cells. This reinforces the paradigm that intra-amoebal pathogens have the potential to infect macrophages. PMID:18551172

Ghigo, Eric; Kartenbeck, Jurgen; Lien, Pham; Pelkmans, Lucas; Capo, Christian; Mege, Jean-Louis; Raoult, Didier

2008-01-01

211

Arachidonic acid metabolites in pathogenic yeasts  

PubMed Central

Although most of what is known about the biology and function of arachidonic acid metabolites comes from the study of mammalian biology, these compounds can also be produced by lower eukaryotes, including yeasts and other fungi. It is also in this group of organisms that the least is known about the metabolic pathways leading to the production of these compounds as well as the functions of these compounds in the biology of fungi and yeasts. This review will deal with the discovery of oxylipins from polyunsaturated fatty acids, and more specifically the arachidonic acid derived eicosanoids, such as 3-hydroxy eicosatetraenoic acid, prostaglandin F2? and prostaglandin E2, in yeasts starting in the early 1990s. This review will also focus on what is known about the metabolic pathways and/or proteins involved in the production of these compounds in pathogenic yeasts. The possible roles of these compounds in the biology, including the pathology, of these organisms will be discussed. PMID:22873782

2012-01-01

212

Fungal pathogens: an overview.  

PubMed

Of all the classes of infectious agents--bacteria, viruses, parasites, worms and prions--fungi are perhaps the last to come to mind and the least understood by most health care providers. Although they rarely cause fatal disease, fungi can cause significant injury and illness. Fungal infections are both difficult to prevent and difficult to treat. In addition, fungal infections are likely to become more common because of the ongoing human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic, the aging population and the growth of treatments that alter patients' immune status. This review introduces fungi, the infections they cause, the risk factors involved, diagnosis and treatment. This article is a Directed Reading. Your access to Directed Reading quizzes for continuing education credit is determined by your continuing education preference. For access to other quizzes, go to www.asrt.org/store. PMID:21406709

Faguy, David M

2011-01-01

213

This Article Full Text (PDF)  

E-print Network

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues Articles by LOPEZ, J. M. Articles by MURPHY, J. O. Search for Related Content Social Bookmarking What

Lopez, John M.

214

Emergence of new pathogens as a function of changes in host susceptibility.  

PubMed Central

A pathogen may emerge as an important public health problem because of changes in itself or its transmission pathways. Alternatively, a microorganism may emerge as a pathogen or acquire new public health importance because of changes in host susceptibility to infection. Factors influencing host susceptibility within the population as a whole include increases in the number of immunocompromised patients; increased use of immunosuppressive agents, particularly among persons receiving cancer chemotherapy or undergoing organ transplantation; aging of the population; and malnutrition. In considering the emergence of foodborne pathogens and designing interventions to limit their spread, the susceptibility of these population subgroups to specific infections should be taken into account. PMID:9368786

Morris, J. G.; Potter, M.

1997-01-01

215

Emergence of New Pathogens as a Function of Changes in Host Susceptibility  

PubMed Central

A pathogen may emerge as an important public health problem because of changes in itself or its transmission pathways. Alternatively, a microorganism may emerge as a pathogen or acquire new public health importance because of changes in host susceptibility to infection. Factors influencing host susceptibility within the population as a whole include increases in the number of immunocompromised patients; increased use of immunosuppressive agents, particularly among persons receiving cancer chemotherapy or undergoing organ transplantation; aging of the population; and malnutrition. In considering the emergence of foodborne pathogens and designing interventions to limit their spread, the susceptibility of these population subgroups to specific infections should be taken into account. PMID:9366594

Morris, JG; Potter, M

1997-01-01

216

Biomolecular Dynamic Article Links  

E-print Network

Organic & Biomolecular Chemistry Dynamic Article Links Cite this: DOI: 10.1039/c1ob05735a www.rsc.org/obc PAPER Click chemistry from organic halides, diazonium salts and anilines in water catalysed by copper of click chemistry1 and green chemistry2 share a series of stringent criteria in order to design

Escolano, Francisco

217

Original article Microsatellite markers  

E-print Network

Original article Microsatellite markers and management of brown trout Salmo trutta fario, Salmo trutta fario, dans le sud-ouest de la France. La truite commune peu- plant l'ouest des Pyrénées fish, and especially the brown trout (Salmo trutta fario L.), present some interesting biological

Boyer, Edmond

218

Research Article Signaling Threat  

E-print Network

Research Article Signaling Threat How Situational Cues Affect Women in Math, Science an MSE con- ference video depicting either an unbalanced ratio of men to women or a balanced ratio. Women a lower sense of belonging and less desire to participate in the conference, than did women who viewed

Gross, James J.

219

Response to Trachtman's Article  

ERIC Educational Resources Information Center

This response to Trachtman's article (TM 510 399) argues that the Trachtman paper is inappropriate due to the time elapsed since the original Bardon proposal. The author acknowledges the difference in perspective between Trachtman and himself. He expresses the hope that discussion concerning this aspect of school psychology politics may be ended.…

Bardon, Jack I.

1985-01-01

220

Articles Index Patron Saints  

E-print Network

to form a shock troop for the Papacy, a small, mobile, well-educated, group of men who had mobilityHome Articles Index Audio Patron Saints of Education Recommended Reading USA Directory Contact THE JESUIT MODEL OF EDUCATION By Fr. Michael McMahon This conference was given by Fr. Michael Mc

Carter, John

221

1107RESEARCH ARTICLE INTRODUCTION  

E-print Network

1107RESEARCH ARTICLE INTRODUCTION The vertebrate kidney is essential to conserve water (Saxén, 1987; Vize et al., 2002). These three kidney forms appear very different, but all rely conserved (Mobjerg et al., 2000; Zhou and Vize, 2004; Dressler, 2006; Raciti et al., 2008). The kidney

De Robertis, Eddy M.

222

DEVELOPMENT 3827RESEARCH ARTICLE  

E-print Network

DEVELOPMENT 3827RESEARCH ARTICLE INTRODUCTION Motoneuron axons project out of the central nervous and maintenance (for a review, see Sanes and Lichtman, 2001). These findings have led to the traditional view is the voltage-gated Na+ channel. A spontaneously occurring mouse mutant, med (motor endplate disease), displays

Betz, William J.

223

Comment on Holland's Article  

ERIC Educational Resources Information Center

Authors describes Holland's article as "...an extraordinary act of moral perception and intellectual courage." However, he continues, in the case of behavior modification methods, it may not be a matter of warning against abuse of a good thing, but rather a matter of warning against use of a bad thing. (Author/RW)

Matson, Floyd W.

1976-01-01

224

Response to Wong's Article.  

ERIC Educational Resources Information Center

In response to a paper on risk and resilience models in learning disabilities (LD) research, this article supports the author and suggests areas of research, especially identification of risk and protective factors in children with LD. Application to analysis of friendship strategies is described. Also noted is longitudinal research to identify…

Cosden, Merith

2003-01-01

225

Research Article Temporally Nonadjacent  

E-print Network

that acoustic histo- ries composed of sine-wave tones drawn from spectral distributions with different mean they are preceded by /ar/ (with more low-frequency energy; Mann, 1980). High- and low-frequency nonlinguistic sine-waveResearch Article Temporally Nonadjacent Nonlinguistic Sounds Affect Speech Categorization Lori L

Holt, Lori L.

226

Wisconsin Agriculture SPECIAL ARTICLE  

E-print Network

STATUS OF Wisconsin Agriculture 2009 · SPECIAL ARTICLE: Bioenergy and Agriculture in Wisconsin Economy Department of Agricultural and Applied Economics College of Agricultural and Life Sciences of Wisconsin Agriculture, 2009 An annual report by the University of Wisconsin-Madison Department

Radeloff, Volker C.

227

Focus Article Nuclear winter  

E-print Network

Focus Article Nuclear winter Alan Robock Nuclear winter is the term for a theory describing the climatic effects of nuclear war. Smoke from the fires started by nuclear weapons, especially the black of these indirect effects. Nuclear proliferation is now expanding the threat. A nuclear war between India

Robock, Alan

228

2223RESEARCH ARTICLE INTRODUCTION  

E-print Network

2223RESEARCH ARTICLE INTRODUCTION Stem cells achieve self-renewal through both the execution of mitotic cell division and maintenance of stem cell fate. Different stem cell types display distinct patterns of self-renewal and differentiation. For example, hematopoetic stem cells divide infrequently

229

2739RESEARCH ARTICLE INTRODUCTION  

E-print Network

2739RESEARCH ARTICLE INTRODUCTION Asymmetric cell division has been proposed as a mechanism for maintaining stem cell numbers while allowing the generation of differentiated cell types (Morrison and Kimble, 2006). It is also been proposed that asymmetric cell division of a small number of tumor stem cells may

Oregon, University of

230

PSYCHOLOGICAL SCIENCE Research Article  

E-print Network

of what makes a face attractive is currently the subject of a lively debate. What standards of beauty doPSYCHOLOGICAL SCIENCE Research Article 558 Copyright © 2003 American Psychological Society VOL. 14 people have, and what sets those standards? Traits that contribute to attractiveness include symmetry

Nakayama, Ken

231

Research Article Phonological Dyslexia  

E-print Network

Research Article Phonological Dyslexia A Test Case for Reading Models Elise Caccappolo-van Vliet,1 words, a type of deficit referred to as phonological dyslexia. We report on 2 individuals with Alzheimer's disease who show phonological dyslexia. Although highly accurate in reading familiar words aloud (even

232

3221RESEARCH ARTICLE INTRODUCTION  

E-print Network

signaling center, called the enamel knot, is induced at the tip of the tooth bud and it regulates tooth3221RESEARCH ARTICLE INTRODUCTION The extensive variation in tooth number and morphology of tooth development is characterized by thickening of the oral ectoderm and subsequent condensation

Klein, Ophir

233

ORIGINAL ARTICLE Andrew Storfer  

E-print Network

ORIGINAL ARTICLE Andrew Storfer Gene ¯ow and local adaptation in a sun®sh-salamander system There is increasing evidence that populations may not be well adapted to their local environments, and as a result presents data suggesting gene ¯ow may constrain the ability of larvae of the streamside salamander

Storfer, Andrew

234

Review article Genetic transformation  

E-print Network

Review article Genetic transformation: a short review of methods and their applications, results of phenotypic traits has been examined. Agrobacterium I biotechnology I forest tree I genetic transformation Biotechnology includes tissue culture, mo- lecular biology and genetic transformation. This field of research

Paris-Sud XI, Université de

235

Volatile metabolites of pathogens: a systematic review.  

PubMed

Ideally, invading bacteria are detected as early as possible in critically ill patients: the strain of morbific pathogens is identified rapidly, and antimicrobial sensitivity is known well before the start of new antimicrobial therapy. Bacteria have a distinct metabolism, part of which results in the production of bacteria-specific volatile organic compounds (VOCs), which might be used for diagnostic purposes. Volatile metabolites can be investigated directly in exhaled air, allowing for noninvasive monitoring. The aim of this review is to provide an overview of VOCs produced by the six most abundant and pathogenic bacteria in sepsis, including Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Such VOCs could be used as biological markers in the diagnostic approach of critically ill patients. A systematic review of existing literature revealed 31 articles. All six bacteria of interest produce isopentanol, formaldehyde, methyl mercaptan, and trimethylamine. Since humans do not produce these VOCs, they could serve as biological markers for presence of these pathogens. The following volatile biomarkers were found for identification of specific strains: isovaleric acid and 2-methyl-butanal for Staphylococcus aureus; 1-undecene, 2,4-dimethyl-1-heptane, 2-butanone, 4-methyl-quinazoline, hydrogen cyanide, and methyl thiocyanide for Pseudomonas aeruginosa; and methanol, pentanol, ethyl acetate, and indole for Escherichia coli. Notably, several factors that may effect VOC production were not controlled for, including used culture media, bacterial growth phase, and genomic variation within bacterial strains. In conclusion, VOCs produced by bacteria may serve as biological markers for their presence. Goal-targeted studies should be performed to identify potential sets of volatile biological markers and evaluate the diagnostic accuracy of these markers in critically ill patients. PMID:23675295

Bos, Lieuwe D J; Sterk, Peter J; Schultz, Marcus J

2013-05-01

236

Volatile Metabolites of Pathogens: A Systematic Review  

PubMed Central

Ideally, invading bacteria are detected as early as possible in critically ill patients: the strain of morbific pathogens is identified rapidly, and antimicrobial sensitivity is known well before the start of new antimicrobial therapy. Bacteria have a distinct metabolism, part of which results in the production of bacteria-specific volatile organic compounds (VOCs), which might be used for diagnostic purposes. Volatile metabolites can be investigated directly in exhaled air, allowing for noninvasive monitoring. The aim of this review is to provide an overview of VOCs produced by the six most abundant and pathogenic bacteria in sepsis, including Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Such VOCs could be used as biological markers in the diagnostic approach of critically ill patients. A systematic review of existing literature revealed 31 articles. All six bacteria of interest produce isopentanol, formaldehyde, methyl mercaptan, and trimethylamine. Since humans do not produce these VOCs, they could serve as biological markers for presence of these pathogens. The following volatile biomarkers were found for identification of specific strains: isovaleric acid and 2-methyl-butanal for Staphylococcus aureus; 1-undecene, 2,4-dimethyl-1-heptane, 2-butanone, 4-methyl-quinazoline, hydrogen cyanide, and methyl thiocyanide for Pseudomonas aeruginosa; and methanol, pentanol, ethyl acetate, and indole for Escherichia coli. Notably, several factors that may effect VOC production were not controlled for, including used culture media, bacterial growth phase, and genomic variation within bacterial strains. In conclusion, VOCs produced by bacteria may serve as biological markers for their presence. Goal-targeted studies should be performed to identify potential sets of volatile biological markers and evaluate the diagnostic accuracy of these markers in critically ill patients. PMID:23675295

Bos, Lieuwe D. J.; Sterk, Peter J.; Schultz, Marcus J.

2013-01-01

237

Waterborne protozoan pathogens.  

PubMed Central

Protozoan parasites were the most frequently identified etiologic agents in waterborne disease outbreak from 1991 to 1994. The waterborne parasites Giardia lamblia, Naegleria fowleri, Acanthamoeba spp., Entamoeba histolytica, Cryptosporidium parvum, Cyclospora cayetanesis, Isospora belli, and the microsporidia are reviewed. For each parasite, the review includes history, life cycle, incidence, symptoms, and therapy. Clinical detection methods are compared, and emerging technologies are discussed. Information on the association of these parasites with waterborne outbreaks is reviewed. Current information on protozoan parasites identified as etiological agents in waterborne outbreaks is discussed. Water industry issues related to recent disease outbreaks are examined in the context of water quality testing regulations for G. lamblia and those proposed for C. parvum. The review identifies the limitations of the American Society of Testing and Materials water-testing method for these parasites. An overview of federal regulations affecting the water industry and laboratories that test for water quality is also provided. The article highlights the importance of the clinical laboratory as a frontline defense for the detection of infectious organisms. The review points to the need for clinical laboratories, physicians, and public health personnel to cooperatively plan and assess the challenge of meeting this potential public health threat. PMID:8993859

Marshall, M M; Naumovitz, D; Ortega, Y; Sterling, C R

1997-01-01

238

Microbial Exposure Assessment of Waterborne Pathogens  

Microsoft Academic Search

The large number of waterborne illnesses in Ireland and worldwide has highlighted the need to enhance strategies that minimize human exposure to pathogens in drinking water supplies. Waterborne pathogens of public concern together with relevant national and international legislation are reviewed in this study. Cryptosporidium species and pathogenic Escherichia coli are among pathogens of primary concern. The organisms originate from

Rory Coffey; Enda Cummins; Martin Cormican; Vincent O Flaherty; Stephen Kelly

2007-01-01

239

Pathogen prevalence and human mate preferences  

Microsoft Academic Search

Members of host species in pathogen-host coevolutionary races may be selected to choose mates who possess features of physical appearance associated with pathogen resistance. Human data from 29 cultures indicate that people in geographical areas carrying rela- tively greater prevalences of pathogens value a mate's physical attractiveness more than people in areas with relatively little pathogen incidence. The relationship between

Steven W. Gangestad; David M. Buss

1993-01-01

240

WRKY70 modulates the selection of signaling pathways in plant defense  

Microsoft Academic Search

Summary Cross-talk between signal transduction pathways is a central feature of the tightly regulated plant defense signaling network. The potential synergism or antagonism between defense pathways is determined by recognition of the type of pathogen or pathogen-derived elicitor. Our studies have identified WRKY70 as a node of convergence for integrating salicylic acid (SA)- and jasmonic acid (JA)-mediated signaling events during

Jing Li; Günter Brader; Tarja Kariola; E. Tapio Palva

2006-01-01

241

Molecular Responses to Aphid Feeding in Arabidopsis in Relation to Plant Defense Pathways  

Microsoft Academic Search

Little is known about molecular responses in plants to phloem feeding by insects. The induction of genes associated with wound and pathogen response pathways was investigated following green peach aphid (Myzus persicae) feeding on Arabidopsis. Aphid feeding on rosette leaves induced transcription of two genes associated with salicylic acid (SA)- dependent responses to pathogens (PR-1 and BGL2) 10- and 23-fold,

Patrick J. Moran; Gary A. Thompson

2001-01-01

242

Cross-talk between jasmonate and salicylate plant defense pathways: effects on several plant parasites  

Microsoft Academic Search

Plants are often attacked by many herbivorous insects and pathogens at the same time. Two important suites of responses to attack are mediated by plant hormones, jasmonate and salicylate, which independently provide resistance to herbivorous insects and pathogens, respectively. Several lines of evidence suggest that there is negative cross-talk between the jasmonate and salicylate response pathways. This biochemical link between

Jennifer S. Thaler; Richard Karban; Diane E. Ullman; Karina Boege; Richard M. Bostock

2002-01-01

243

Article de Synthse RLE ET STRUCTURE DES ARTICLES SCIENTIFIQUES, ARTICLES DE  

E-print Network

Article de Synthèse RÃ?LE ET STRUCTURE DES ARTICLES SCIENTIFIQUES, ARTICLES DE RECHERCHE, COURTES NOTES, ARTICLES DE SYNTHÃ?SE, RÃ?SUMÃ?S DE RÃ?UNION LE LOUÃ?DEC Christiane CHARLEY-POULAIN Joëlle2 1 : INRA OF SCIENTIFIC ARTICLES. ― This review analyses structure and definition of content of research articles

Paris-Sud XI, Université de

244

Article Critique For each article we read, submit your article critique to eagle before class.  

E-print Network

Article Critique For each article we read, submit your article critique to eagle before class. Put your name on the top along with the name of the article you are reviewing. The Article Critique will consist of the following sections a) Overview: What are they trying to do? How well does the article

Allan, Vicki H.

245

Article original Pollution fluore  

E-print Network

Article original Pollution fluorée et croissance radiale des conifères en Maurienne (Savoie, France; accepté le 24 juillet 1989) Résumé - La recherche de l'impact de la pollution fluorée sur la croissance en en fonction de l'éloignement des sources de pollution, l'exposition et l'altitude. L'é- tude porte

Paris-Sud XI, Université de

246

Xylella Genomics and Bacterial Pathogenicity to Plants  

PubMed Central

Xylella fastidiosa, a pathogen of citrus, is the first plant pathogenic bacterium for which the complete genome sequence has been published. Inspection of the sequence reveals high relatedness to many genes of other pathogens, notably Xanthomonas campestris. Based on this, we suggest that Xylella possesses certain easily testable properties that contribute to pathogenicity. We also present some general considerations for deriving information on pathogenicity from bacterial genomics. PMID:11119303

Dow, J. M.

2000-01-01

247

The Main Aeromonas Pathogenic Factors  

PubMed Central

The members of the Aeromonas genus are ubiquitous, water-borne bacteria. They have been isolated from marine waters, rivers, lakes, swamps, sediments, chlorine water, water distribution systems, drinking water and residual waters; different types of food, such as meat, fish, seafood, vegetables, and processed foods. Aeromonas strains are predominantly pathogenic to poikilothermic animals, and the mesophilic strains are emerging as important pathogens in humans, causing a variety of extraintestinal and systemic infections as well as gastrointestinal infections. The most commonly described disease caused by Aeromonas is the gastroenteritis; however, no adequate animal model is available to reproduce this illness caused by Aeromonas. The main pathogenic factors associated with Aeromonas are: surface polysaccharides (capsule, lipopolysaccharide, and glucan), S-layers, iron-binding systems, exotoxins and extracellular enzymes, secretion systems, fimbriae and other nonfilamentous adhesins, motility and flagella. PMID:23724321

Tomas, J. M.

2012-01-01

248

Lessons learned from mice deficient in lectin complement pathway molecules.  

PubMed

The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite differences in the genetic arrangements of murine and human orthologues of lectin pathway molecules, the knockout mice have proven to be valuable models to explore the effect of deficiency states in humans. In addition, new insight and unexpected findings on the diverse roles of lectin pathway molecules in complement activation, pathogen infection, coagulation, host tissue injury and developmental biology have been revealed by in vivo investigations. This review provides an overview of the mice deficient in lectin pathway molecules and highlights some of the most important findings that have resulted from studies of these. PMID:25060538

Genster, Ninette; Takahashi, Minoru; Sekine, Hideharu; Endo, Yuichi; Garred, Peter; Fujita, Teizo

2014-10-01

249

New trends in emerging pathogens.  

PubMed

The emergence of pathogens is the result of a number of impact in all parts of the food chain. The emerging technologies in food production explain how new pathogens can establish themselves in the food chain and compromise food safety. The impact of the food technology is analysed for several bacteria, such as Yersinia, Campylobacter, Arcobacter, Helicobacter pullorum, Enterobacter sakazakii, Mycobacterium avium spp. paratuberculosis, prions related to vCJD and others. The importance of the ability of many microbes to form VBNC forms is elaborated on. Research on culture independent methods may address this outstanding issue to the better understanding of emerging pathogens. The "demerging" of pathogens also occur, and examples of this are explained. The reaction of bacteria to stresses and sublethal treatments, and how exposure to one stress factor can confer resistance to other stresses, literally speaking causing contagious resistance, are explained. The implication of this e.g. in modern approaches of food preservation, such as Minimally processed Foods, is considerable. Intestinal colonization of EHEC may be regulated by Quorum sensing, and this ability of microbes plays an important role in the colonization of microbes in food and on food processing equipment, an important factor in the emergence of pathogens. The emergence of Saccharomyces cerevisiae, as an opportunistic human pathogen, used for centuries for food and production of alcoholic beverages, calls for research in molecular tools to distinguish between probiotic and clinical strains. Cyclospora cayetanensis and Norovirus outbreaks can no longer be designated as emerging pathogens, they share however one characteristic in the epidemiology of emerging nature, the importance of the hygiene in the primary production stage, including supply of potable water, and the application of GMP and the HACCP principles in the beginning of the food chain. Hepatitis E virus is a potential emerging food borne pathogen and swine may serve as a source of infection in human, a most challenging issue in greater part of the world raising pigs. Tick-borne encephalitis virus infection, either thick borne or caused by consumption of raw milk, is an increasing trend in the industrialized part of the world. Consumer awareness, ethics of food, sustainability in food production, and trust in foods, are of growing importance to the consumer. The reaction of the consumer to new technology, such as nanotechnology, is unpredictable. Many efforts should be devoted to communication of non-biased information to both the food producers as well as the consumer. PMID:17976849

Skovgaard, Niels

2007-12-15

250

Modulation of iron homeostasis in macrophages by bacterial intracellular pathogens  

PubMed Central

Background Intracellular bacterial pathogens depend on acquisition of iron for their success as pathogens. The host cell requires iron as an essential component for cellular functions that include innate immune defense mechanisms. The transferrin receptor TfR1 plays an important part for delivering iron to the host cell during infection. Its expression can be modulated by infection, but its essentiality for bacterial intracellular survival has not been directly investigated. Results We identified two distinct iron-handling scenarios for two different bacterial pathogens. Francisella tularensis drives an active iron acquisition program via the TfR1 pathway program with induction of ferrireductase (Steap3), iron membrane transporter Dmt1, and iron regulatory proteins IRP1 and IRP2, which is associated with a sustained increase of the labile iron pool inside the macrophage. Expression of TfR1 is critical for Francisella's intracellular proliferation. This contrasts with infection of macrophages by wild-type Salmonella typhimurium, which does not require expression of TfR1 for successful intracellular survival. Macrophages infected with Salmonella lack significant induction of Dmt1, Steap3, and IRP1, and maintain their labile iron pool at normal levels. Conclusion The distinction between two different phenotypes of iron utilization by intracellular pathogens will allow further characterization and understanding of host-cell iron metabolism and its modulation by intracellular bacteria. PMID:20184753

2010-01-01

251

Host Response to Respiratory Bacterial Pathogens as Identified by Integrated Analysis of Human Gene Expression Data  

PubMed Central

Respiratory bacterial pathogens are one of the leading causes of infectious death in the world and a major health concern complicated by the rise of multi-antibiotic resistant strains. Therapeutics that modulate host genes essential for pathogen infectivity could potentially avoid multi-drug resistance and provide a wider scope of treatment options. Here, we perform an integrative analysis of published human gene expression data generated under challenges from the gram-negative and Gram-positive bacteria pathogens, Pseudomonas aeruginosa and Streptococcus pneumoniae, respectively. We applied a previously described differential gene and pathway enrichment analysis pipeline to publicly available host mRNA GEO datasets resulting from exposure to bacterial infection. We found 72 canonical human pathways common between four GEO datasets, representing P. aeruginosa and S. pneumoniae. Although the majority of these pathways are known to be involved with immune response, we found several interesting new interactions such as the SUMO1 pathway that might have a role in bacterial infections. Furthermore, 36 host-bacterial pathways were also shared with our previous results for respiratory virus host gene expression. Based on our pathway analysis we propose several drug-repurposing opportunities supported by the literature. PMID:24086587

Smith, Steven B.; Magid-Slav, Michal; Brown, James R.

2013-01-01

252

Effects of chitosan particles in periodontal pathogens and gingival fibroblasts.  

PubMed

Chitosan is a naturally derived polymer with antimicrobial and anti-inflammatory properties. However, studies evaluating the role of chitosan in the control of periodontal pathogens and the responses of fibroblasts to inflammatory stimuli are lacking. In the present study, we analyzed whether chitosan particles may inhibit the growth of periodontal pathogens and modulate the inflammatory response in human gingival fibroblasts. Chitosan particles were generated through ionic gelation. They inhibited the growth of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans at 5 mg/mL. Conversely, IL-1? strongly stimulated PGE2 protein levels in gingival fibroblasts, and chitosan inhibited this response at 50 µg/mL. IL-1?-stimulated PGE2 production was dependent on the JNK pathway, and chitosan strongly inhibited this response. IL-1? stimulated NF-?B activation, another signaling pathway involved in PGE2 production. However, chitosan particles were unable to modify NF-?B signaling. The present study shows that chitosan exerts a predominantly anti-inflammatory activity by modulating PGE2 levels through the JNK pathway, which may be useful in the prevention or treatment of periodontal inflammation. PMID:23788611

Arancibia, R; Maturana, C; Silva, D; Tobar, N; Tapia, C; Salazar, J C; Martínez, J; Smith, P C

2013-08-01

253

Hepcidin Induction by Pathogens and Pathogen-Derived Molecules Is Strongly Dependent on Interleukin-6  

PubMed Central

Hepcidin, the iron-regulatory hormone, is increased during infection or inflammation, causing hypoferremia. This response is thought to be a host defense mechanism that restricts iron availability to invading pathogens. It is not known if hepcidin is differentially induced by bacterial versus viral infections, whether the stimulation of pattern recognition receptors directly regulates hepcidin transcription, or which of the proposed signaling pathways are essential for hepcidin increase during infection. We analyzed hepcidin induction and its dependence on interleukin-6 (IL-6) in response to common bacterial or viral infections in mice or in response to a panel of pathogen-derived molecules (PAMPs) in mice and human primary hepatocytes. In wild-type (WT) mice, hepcidin mRNA was induced several hundred-fold both by a bacterial (Streptococcus pneumoniae) and a viral infection (influenza virus PR8) within 2 to 5 days. Treatment of mice and human primary hepatocytes with most Toll-like receptor ligands increased hepcidin mRNA within 6 h. Hepcidin induction by microbial stimuli was IL-6 dependent. IL-6 knockout mice failed to increase hepcidin in response to S. pneumoniae or influenza infection and had greatly diminished hepcidin response to PAMPs. In vitro, hepcidin induction by PAMPs in primary human hepatocytes was abolished by the addition of neutralizing IL-6 antibodies. Our results support the key role of IL-6 in hepcidin regulation in response to a variety of infectious and inflammatory stimuli. PMID:24478088

Rodriguez, Richard; Jung, Chun-Ling; Gabayan, Victoria; Deng, Jane C.; Ganz, Tomas; Nemeth, Elizabeta

2014-01-01

254

Human pathogenic bacteria, fungi, and viruses in Drosophila  

PubMed Central

Drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. Many Drosophila–microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. Here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. We discuss studies of human pathogens in flies revealing not only the elicitation and avoidance of immune response but also mechanisms of tolerance, host tissue homeostasis, regeneration, and predisposition to cancer. Prominent among those is the emerging pattern of intestinal regeneration as a defense response induced by pathogenic and innocuous bacteria. Immunopathology mechanisms and many microbial virulence factors have been elucidated, but their relevance to human health conventionally necessitates validation in mammalian models of infection. PMID:24398387

Panayidou, Stavria; Ioannidou, Eleni; Apidianakis, Yiorgos

2014-01-01

255

SIGNAL TRANSDUCTION: Nuclear Fusion of Signaling Pathways  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. There is often crosstalk between signal transduction pathways activated by different cytokines. In this issue, Nakashima and colleagues report on one way in which signaling pathways communicate. They show that the signaling pathways for two cytokines (LIF and BMP2), which are necessary for astrocyte differentiation, can interact synergistically through the binding of their transcription factor targets (STAT3 and Smad1, respectively) to a common transcriptional coactivator molecule called p300.

Ralf Janknecht (Mayo Clinic;Department of Biochemistry and Molecular Biology); Tony Hunter (The Salk Institute;Molecular Biology and Virology Laboratory)

1999-04-16

256

The pathogenicity of avian mycoplasmas.  

PubMed

Based on literature data and own experiences the author gives an outlook about pathogenicity of avian mycoplasmas. In chickens and turkeys M. gallisepticum and M. synoviae (in addition to it M. meleagridis exclusively in turkeys) are the most important mycoplasmas producing respiratory disease, inflamation of synovial membranes and other lesions. Their pathogenic effect is very much influenced by dose of agent, route of entry of microorganism, age of birds, virulence and tropism of organism as well as associated other mycoplasma or virus or bacterial or fungal infections and conditions of environment. These facts rise difficulties in serological diagnostic and erradication program. Recently ureaplasma infection was also established in chickens and turkeys which can also be associated with respiratory disease. From ducks A. laidlawii, M. anatis and various unclassified strains were isolated, among these M. anatis and unclassified arginine splitting mycoplasma strains proved to be pathogenic. In geese M. gallinarum, A. laidlawii and A. axanthum were detected. A. axanthum showed pathogenicity for goslings and goose embryos. Its effect is exacerbated by associated parvovirus infection. PMID:44612

Stipkovits, L

1979-10-01

257

Pathogenicity of aseptic Bursaphelenchus xylophilus.  

PubMed

Pine wilt is a disease of pine (Pinus spp.) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus. However, the pathogenic mechanism of pine wilt disease (PWD) remains unclear. Although the PWN was thought to be the only pathogenic agent associated with this disease, a potential role for bacterial symbionts in the disease process was recently proposed. Studies have indicated that aseptic PWNs do not cause PWD in aseptic pine trees, while PWNs associated with bacteria cause wilting symptoms. To investigate the pathogenicity of the PWN and its associated bacteria, 3-month-old microcuttings derived from certain clones of Pinus densiflora Siebold & Zucc. produced in vitro were inoculated under aseptic conditions with aseptic PWNs, non-aseptic PWNs and bacteria isolated from the nematodes. Six-month-old aseptic P. densiflora microcuttings and 7-month-old P. massoniana seedlings were also inoculated under aseptic conditions with aseptic PWNs and non-aseptic PWNs. The results showed that the aseptic microcuttings and seedlings inoculated with aseptic PWNs or non-aseptic PWNs wilted, while those inoculated with bacterial isolates did not wilt. Nematodes were recovered from wilted microcuttings and seedlings inoculated with aseptic PWNs and non-aseptic PWNs, and the asepsis of nematodes recovered from aseptic PWN-inoculated microcuttings and seedlings was reconfirmed by culturing them in NB liquid medium at 30°C for more than 7 days. Taken together, the results indicate that the asepsis of PWN did not cause the loss of pathogenicity. PMID:22662271

Zhu, Li-hua; Ye, Jianren; Negi, Sapna; Xu, Xu-ling; Wang, Zhang-li; Ji, Jin-yi

2012-01-01

258

USEPA PERSPECTIVE ON CONTROLLING PATHOGENS  

EPA Science Inventory

EPA minimizes the risk of infectious diseases from the beneficial use of sludge by requiring its treatment to reduce pathogen levels below the detection limit. How new treatment processes can be shown equivalent to ones specified in 40CFR503 will be discussed together with ways t...

259

PATHOGEN QUIESCENCE IN POSTHARVEST DISEASES  

Microsoft Academic Search

This chapter examines the quiescence period during different stages of fungal attack of postharvest pathogens: quiescence during spore germination and initial hyphal development, during and after appressorium formation, and quiescence of germinated appressorium and subcuticular hyphae. The different mechanisms for quiescence are reviewed: factors affecting quiescence of germinated spores, appressoria formation and germination, and fungal colonization. Special empha- sis is

Dov Prusky

1996-01-01

260

PATHOGENIC 'NAEGLERIA': DISTRIBUTION IN NATURE  

EPA Science Inventory

Infection in man with pathogenic Naegleria, a free-living soil amoeba, results in a usually fatal disease entity known as primary amoebic meningoencephalitis. Epidemiological data usually included exposure to freshwater lakes or streams within the week prior to onset. However, no...

261

An imprinted rheumatoid arthritis methylome signature reflects pathogenic phenotype  

PubMed Central

Background A DNA methylation signature has been characterized that distinguishes rheumatoid arthritis (RA) fibroblast like synoviocytes (FLS) from osteoarthritis (OA) FLS. The presence of epigenetic changes in long-term cultured cells suggest that rheumatoid FLS imprinting might contribute to pathogenic behavior. To understand how differentially methylated genes (DMGs) might participate in the pathogenesis of RA, we evaluated the stability of the RA signature and whether DMGs are enriched in specific pathways and ontology categories. Methods To assess the RA methylation signatures the Illumina HumanMethylation450 chip was used to compare methylation levels in RA, OA, and normal (NL) FLS at passage 3, 5, and 7. Then methylation frequencies at CpGs within the signature were compared between passages. To assess the enrichment of DMGs in specific pathways, DMGs were identified as genes that possess significantly differential methylated loci within their promoter regions. These sets of DMGs were then compared to pathway and ontology databases to establish enrichment in specific categories. Results Initial studies compared passage 3, 5, and 7 FLS from RA, OA, and NL. The patterns of differential methylation of each individual FLS line were very similar regardless of passage number. Using the most robust analysis, 20 out of 272 KEGG pathways and 43 out of 34,400 GO pathways were significantly altered for RA compared with OA and NL FLS. Most interestingly, we found that the KEGG 'Rheumatoid Arthritis' pathway was consistently the most significantly enriched with differentially methylated loci. Additional pathways involved with innate immunity (Complement and Coagulation, Toll-like Receptors, NOD-like Receptors, and Cytosolic DNA-sensing), cell adhesion (Focal Adhesion, Cell Adhesion Molecule), and cytokines (Cytokine-cytokine Receptor). Taken together, KEGG and GO pathway analysis demonstrates non-random epigenetic imprinting of RA FLS. Conclusions The DNA methylation patterns include anomalies in key genes implicated in the pathogenesis of RA and are stable for multiple cell passages. Persistent epigenetic alterations could contribute to the aggressive phenotype of RA synoviocytes and identify potential therapeutic targets that could modulate the pathogenic behavior. PMID:23631487

2013-01-01

262

Exotic insect pests and pathogens pose the most serious current threat to the forests of eastern North  

E-print Network

Articles Exotic insect pests and pathogens pose the most serious current threat to the forests States,the primary animal pests are insects, but this analysis could also apply to other types of animal to repeated introductions of exotic insect pests and pathogens over the last century, and several new pests

Berkowitz, Alan R.

263

Cellular defense processes regulated by pathogen-elicited receptor signaling  

NASA Astrophysics Data System (ADS)

Vertebrates are constantly threatened by the invasion of microorganisms and have evolved systems of immunity to eliminate infectious pathogens in the body. Initial sensing of microbial agents is mediated by the recognition of pathogens by means of molecular structures expressed uniquely by microbes of a given type. So-called 'Toll-like receptors' are expressed on host epithelial barrier cells play an essential role in the host defense against microbial pathogens by inducing cell responses (e.g., proliferation, death, cytokine secretion) via activation of intracellular signaling networks. As these networks, comprising multiple interconnecting dynamic pathways, represent highly complex multi-variate "information processing" systems, the signaling activities particularly critical for governing the host cell responses are poorly understood and not easily ascertained by a priori theoretical notions. We have developed over the past half-decade a "data-driven" computational modeling approach, on a 'cue-signal-response' combined experiment/computation paradigm, to elucidate key multi-variate signaling relationships governing the cell responses. In an example presented here, we study how a canonical set of six kinase pathways combine to effect microbial agent-induced apoptotic death of a macrophage cell line. One modeling technique, partial least-squares regression, yielded the following key insights: {a} signal combinations most strongly correlated to apoptotic death are orthogonal to those most strongly correlated with release of inflammatory cytokines; {b} the ratio of two key pathway activities is the most powerful predictor of microbe-induced macrophage apoptotic death; {c} the most influential time-window of this signaling activity ratio is surprisingly fast: less than one hour after microbe stimulation.

Wu, Rongcong; Goldsipe, Arthur; Schauer, David B.; Lauffenburger, Douglas A.

2011-06-01

264

Constraint-based analysis of metabolic capacity of Salmonella typhimurium during host-pathogen interaction  

Microsoft Academic Search

BACKGROUND: Infections with Salmonella cause significant morbidity and mortality worldwide. Replication of Salmonella typhimurium inside its host cell is a model system for studying the pathogenesis of intracellular bacterial infections. Genome-scale modeling of bacterial metabolic networks provides a powerful tool to identify and analyze pathways required for successful intracellular replication during host-pathogen interaction. RESULTS: We have developed and validated a

Anu Raghunathan; Jennifer Reed; Sookil Shin; Bernhard Palsson; Simon Daefler

2009-01-01

265

Manipulation of small Rho GTPases is a pathogen-induced process detected by Nod1  

PubMed Central

Our innate immune system distinguishes microbes from self by detecting conserved pathogen-associated molecular patterns (PAMPs) 1. However, all microbes produce PAMPs, regardless of their pathogenic potential. To distinguish virulent microbes from ones with lower disease-causing potential the innate immune system detects conserved pathogen-induced processes 2, such as the presence of microbial products in the host cytosol, by mechanisms that are not fully resolved. Here we show that Nod1 senses cytosolic microbial products by monitoring the activation state of small Rho GTPases. Activation of Rac1 and Cdc42 by bacterial delivery or ectopic expression of a Salmonella virulence factor, SopE, triggered the Nod1 signaling pathway with consequent Rip2-mediated induction of NF-?B-dependent inflammatory responses. Similarly, activation of the Nod1 signaling pathway by peptidoglycan required Rac1 activity. Furthermore, constitutively active forms of Rac1, Cdc42 and RhoA activated the Nod1 signaling pathway. Our data identify activation of small Rho GTPases as a pathogen-induced process sensed through the Nod1 signaling pathway (Fig. S1). PMID:23542589

Keestra, A. Marijke; Winter, Maria G.; Auburger, Josef J.; Frassle, Simon P.; Xavier, Mariana N.; Winter, Sebastian E.; Kim, Anita; Poon, Victor; Ravesloot, Marietta M.; Waldenmaier, Julian; Tsolis, Renee M.; Eigenheer, Richard A.; Baumler, Andreas J.

2013-01-01

266

Rab5b localization to early endosomes in the protozoan human pathogen Leishmania donovani  

Microsoft Academic Search

Leishmania donovani is a primitive trypanosomatid pathogen of humans. This protozoan is apically polarized such that the flagellar reservoir, the exclusive site of endocytosis and exocytosis, is situated at the anterior end. Recent evidence for the existence of an endocytic pathway in Leishmania has prompted us to investigate candidate temporal markers for endocytosis. In this study we identify the L.

Diane E. Marotta; Noel Gerald; Dennis M. Dwyer

2006-01-01

267

Role of periodontal pathogenic bacteria in RANKL-mediated bone destruction in periodontal disease  

PubMed Central

Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal bacteria in the onset and progression of periodontal disease (PD) are well documented. However, the mechanism underlying the engagement of periodontal bacteria in RANKL-mediated alveolar bone resorption remains unclear. Therefore, this review article addresses three critical subjects. First, we discuss earlier studies of immune intervention, ultimately leading to the identification of bacteria-reactive lymphocytes as the cellular source of osteoclast-induction factor lymphokine (now called RANKL) in the context of periodontal bone resorption. Next, we consider (1) the effects of periodontal bacteria on RANKL production from a variety of adaptive immune effector cells, as well as fibroblasts, in inflamed periodontal tissue and (2) the bifunctional roles (upregulation vs. downregulation) of LPS produced from periodontal bacteria in a RANKL-induced osteoclast-signal pathway. Future studies in these two areas could lead to new therapeutic approaches for the management of PD by down-modulating RANKL production and/or RANKL-mediated osteoclastogenesis in the context of host immune responses against periodontal pathogenic bacteria. PMID:21523224

Kajiya, Mikihito; Giro, Gabriela; Taubman, Martin A.; Han, Xiaozhe; Mayer, Marcia P.A.; Kawai, Toshihisa

2010-01-01

268

Glucanase Induces Filamentation of the Fungal Pathogen Candida albicans  

PubMed Central

Candida albicans is the most common human fungal pathogen. Many organisms, including C. albicans, secrete glucanases under different environmental conditions. Here, we report a novel role for beta-1, 3- glucanase in inducing Candida albicans to form filaments at 22°C and enhancing filamentation at 37°C in nutrient-rich medium. Quorum sensing, the efg1-signaling and cek1 MAP kinase pathways are involved in this process. Our data suggest that the natural antifungal agent beta–glucanase may support morphologic transformation of Candida albicans at a wide range of ambient temperatures. PMID:23737947

Xu, Hongbin; Nobile, Clarissa J.; Dongari-Bagtzoglou, Anna

2013-01-01

269

Autophagy in the regulation of pathogen replication and adaptive immunity.  

PubMed

Autophagy is an evolutionarily conserved homeostatic process by which cells deliver cytoplasmic material for degradation into lysosomes. Autophagy may have evolved as a nutrient-providing homeostatic pathway induced upon starvation, but with the acquisition of cargo receptors, autophagy has become an important cellular defence mechanism as well as a generator of antigenic peptides for major histocompatibility complex (MHC) presentation. We propose that autophagy efficiently protects against microbes encountering the cytosolic environment accidentally, for example, upon phagosomal damage, whereas pathogens routinely accessing the host cytosol have evolved to avoid or even benefit from autophagy. PMID:22796170

Randow, Felix; Münz, Christian

2012-10-01

270

Draft genome sequence of the sexually transmitted pathogen Trichomonas vaginalis.  

PubMed

We describe the genome sequence of the protist Trichomonas vaginalis, a sexually transmitted human pathogen. Repeats and transposable elements comprise about two-thirds of the approximately 160-megabase genome, reflecting a recent massive expansion of genetic material. This expansion, in conjunction with the shaping of metabolic pathways that likely transpired through lateral gene transfer from bacteria, and amplification of specific gene families implicated in pathogenesis and phagocytosis of host proteins may exemplify adaptations of the parasite during its transition to a urogenital environment. The genome sequence predicts previously unknown functions for the hydrogenosome, which support a common evolutionary origin of this unusual organelle with mitochondria. PMID:17218520

Carlton, Jane M; Hirt, Robert P; Silva, Joana C; Delcher, Arthur L; Schatz, Michael; Zhao, Qi; Wortman, Jennifer R; Bidwell, Shelby L; Alsmark, U Cecilia M; Besteiro, Sébastien; Sicheritz-Ponten, Thomas; Noel, Christophe J; Dacks, Joel B; Foster, Peter G; Simillion, Cedric; Van de Peer, Yves; Miranda-Saavedra, Diego; Barton, Geoffrey J; Westrop, Gareth D; Müller, Sylke; Dessi, Daniele; Fiori, Pier Luigi; Ren, Qinghu; Paulsen, Ian; Zhang, Hanbang; Bastida-Corcuera, Felix D; Simoes-Barbosa, Augusto; Brown, Mark T; Hayes, Richard D; Mukherjee, Mandira; Okumura, Cheryl Y; Schneider, Rachel; Smith, Alias J; Vanacova, Stepanka; Villalvazo, Maria; Haas, Brian J; Pertea, Mihaela; Feldblyum, Tamara V; Utterback, Terry R; Shu, Chung-Li; Osoegawa, Kazutoyo; de Jong, Pieter J; Hrdy, Ivan; Horvathova, Lenka; Zubacova, Zuzana; Dolezal, Pavel; Malik, Shehre-Banoo; Logsdon, John M; Henze, Katrin; Gupta, Arti; Wang, Ching C; Dunne, Rebecca L; Upcroft, Jacqueline A; Upcroft, Peter; White, Owen; Salzberg, Steven L; Tang, Petrus; Chiu, Cheng-Hsun; Lee, Ying-Shiung; Embley, T Martin; Coombs, Graham H; Mottram, Jeremy C; Tachezy, Jan; Fraser-Liggett, Claire M; Johnson, Patricia J

2007-01-12

271

Draft Genome Sequence of the Sexually Transmitted Pathogen Trichomonas vaginalis  

PubMed Central

We describe the genome sequence of the protist Trichomonas vaginalis, a sexually transmitted human pathogen. Repeats and transposable elements comprise about two-thirds of the ~160-megabase genome, reflecting a recent massive expansion of genetic material. This expansion, in conjunction with the shaping of metabolic pathways that likely transpired through lateral gene transfer from bacteria, and amplification of specific gene families implicated in pathogenesis and phagocytosis of host proteins may exemplify adaptations of the parasite during its transition to a urogenital environment. The genome sequence predicts previously unknown functions for the hydrogenosome, which support a common evolutionary origin of this unusual organelle with mitochondria. PMID:17218520

Carlton, Jane M.; Hirt, Robert P.; Silva, Joana C.; Delcher, Arthur L.; Schatz, Michael; Zhao, Qi; Wortman, Jennifer R.; Bidwell, Shelby L.; Alsmark, U. Cecilia M.; Besteiro, Sébastien; Sicheritz-Ponten, Thomas; Noel, Christophe J.; Dacks, Joel B.; Foster, Peter G.; Simillion, Cedric; Van de Peer, Yves; Miranda-Saavedra, Diego; Barton, Geoffrey J.; Westrop, Gareth D.; Müller, Sylke; Dessi, Daniele; Fiori, Pier Luigi; Ren, Qinghu; Paulsen, Ian; Zhang, Hanbang; Bastida-Corcuera, Felix D.; Simoes-Barbosa, Augusto; Brown, Mark T.; Hayes, Richard D.; Mukherjee, Mandira; Okumura, Cheryl Y.; Schneider, Rachel; Smith, Alias J.; Vanacova, Stepanka; Villalvazo, Maria; Haas, Brian J.; Pertea, Mihaela; Feldblyum, Tamara V.; Utterback, Terry R.; Shu, Chung-Li; Osoegawa, Kazutoyo; de Jong, Pieter J.; Hrdy, Ivan; Horvathova, Lenka; Zubacova, Zuzana; Dolezal, Pavel; Malik, Shehre-Banoo; Logsdon, John M.; Henze, Katrin; Gupta, Arti; Wang, Ching C.; Dunne, Rebecca L.; Upcroft, Jacqueline A.; Upcroft, Peter; White, Owen; Salzberg, Steven L.; Tang, Petrus; Chiu, Cheng-Hsun; Lee, Ying-Shiung; Embley, T. Martin; Coombs, Graham H.; Mottram, Jeremy C.; Tachezy, Jan; Fraser-Liggett, Claire M.; Johnson, Patricia J.

2007-01-01

272

Modeling the effects of a Staphylococcal Enterotoxin B (SEB) on the apoptosis pathway  

Microsoft Academic Search

BACKGROUND: The lack of detailed understanding of the mechanism of action of many biowarfare agents poses an immediate challenge to biodefense efforts. Many potential bioweapons have been shown to affect the cellular pathways controlling apoptosis 1234. For example, pathogen-produced exotoxins such as Staphylococcal Enterotoxin B (SEB) and Anthrax Lethal Factor (LF) have been shown to disrupt the Fas-mediated apoptotic pathway

Brandon W Higgs; John Dileo; Wenling E Chang; Haley B Smith; Olivia J Peters; Rasha Hammamieh; Marti Jett; Jordan C Feidler

2006-01-01

273

Modifying lignin to improve bioenergy feedstocks: strengthening the barrier against pathogens  

PubMed Central

Lignin is a ubiquitous polymer present in cell walls of all vascular plants, where it rigidifies and strengthens the cell wall structure through covalent cross-linkages to cell wall polysaccharides. The presence of lignin makes the cell wall recalcitrant to conversion into fermentable sugars for bioenergy uses. Therefore, reducing lignin content and modifying its linkages have become major targets for bioenergy feedstock development through either biotechnology or traditional plant breeding. In addition, lignin synthesis has long been implicated as an important plant defense mechanism against pathogens, because lignin synthesis is often induced at the site of pathogen attack. This article explores the impact of lignin modifications on the susceptibility of a range of plant species to their associated pathogens, and the implications for development of feedstocks for the second-generation biofuels industry. Surprisingly, there are some instances where plants modified in lignin synthesis may display increased resistance to associated pathogens, which is explored in this article. PMID:23577013

Sattler, Scott E.; Funnell-Harris, Deanna L.

2013-01-01

274

Overviews of Pathogen Emergence: Which Pathogens Emerge, When and Why?  

Microsoft Academic Search

An emerging pathogen has been defined as the causative agent of an infectious disease whose incidence is increasing following\\u000a its appearance in a new host population or whose incidence is increasing in an existing population as a result of long-term\\u000a changes in its underlying epidemiology (Woolhouse and Dye 2001). Although we appear to be in a period where novel diseases

S. Cleaveland; D. T. Haydon; L. Taylor

275

Comparative Phylogenomics of Pathogenic and Non-Pathogenic Mycobacterium  

PubMed Central

Mycobacterium species are the source of a variety of infectious diseases in a range of hosts. Genome based methods are used to understand the adaptation of each pathogenic species to its unique niche. In this work, we report the comparison of pathogenic and non-pathogenic Mycobacterium genomes. Phylogenetic trees were constructed using sequence of core orthologs, gene content and gene order. It is found that the genome based methods can better resolve the inter-species evolutionary distances compared to the conventional 16S based tree. Phylogeny based on gene order highlights distinct evolutionary characteristics as compared to the methods based on sequence, as illustrated by the shift in the relative position of M. abscessus. This difference in gene order among the Mycobacterium species is further investigated using a detailed synteny analysis. It is found that while rearrangements between some Mycobacterium genomes are local within synteny blocks, few possess global rearrangements across the genomes. The study illustrates how a combination of different genome based methods is essential to build a robust phylogenetic relationship between closely related organisms. PMID:24015186

Prasanna, Arun N.; Mehra, Sarika

2013-01-01

276

Finding Articles Social Sciences Inquiry  

E-print Network

Finding Articles Social Sciences Inquiry Info Lit @ Mac Nora Gaskin Reference Librarian Mills Articles in the Social Sciences 1. Finding references to articles 2. Getting the articles 3. Downloading and Social Sciences INNIS -- Business THODE -- Science and Engineering HEALTH Sciences #12;Inquiry 1SS3 Mills

Haykin, Simon

277

Genome of the Opportunistic Pathogen Streptococcus sanguinis? †  

PubMed Central

The genome of Streptococcus sanguinis is a circular DNA molecule consisting of 2,388,435 bp and is 177 to 590 kb larger than the other 21 streptococcal genomes that have been sequenced. The G+C content of the S. sanguinis genome is 43.4%, which is considerably higher than the G+C contents of other streptococci. The genome encodes 2,274 predicted proteins, 61 tRNAs, and four rRNA operons. A 70-kb region encoding pathways for vitamin B12 biosynthesis and degradation of ethanolamine and propanediol was apparently acquired by horizontal gene transfer. The gene complement suggests new hypotheses for the pathogenesis and virulence of S. sanguinis and differs from the gene complements of other pathogenic and nonpathogenic streptococci. In particular, S. sanguinis possesses a remarkable abundance of putative surface proteins, which may permit it to be a primary colonizer of the oral cavity and agent of streptococcal endocarditis and infection in neutropenic patients. PMID:17277061

Xu, Ping; Alves, Joao M.; Kitten, Todd; Brown, Arunsri; Chen, Zhenming; Ozaki, Luiz S.; Manque, Patricio; Ge, Xiuchun; Serrano, Myrna G.; Puiu, Daniela; Hendricks, Stephanie; Wang, Yingping; Chaplin, Michael D.; Akan, Doruk; Paik, Sehmi; Peterson, Darrell L.; Macrina, Francis L.; Buck, Gregory A.

2007-01-01

278

OSHA's bloodborne pathogens standard: a review of physician office compliance after the first year.  

PubMed

In May 1993, medical practices for the first time were required to review their bloodborne pathogens programs for compliance with a 1991 standard issued by the Occupational Safety and Health Administration. The standard has a commendable purpose--to enhance the protection afforded workers exposed to potentially infectious materials. Yet its requirements have caused fear and confusion among physicians. This article details the provisions of the bloodborne pathogens standard and outlines some of the reasons physicians have found its implementation troublesome. PMID:10128456

Smith, P W

1993-01-01

279

Toll-like receptors (TLRs) in aquatic animals: signaling pathways, expressions and immune responses.  

PubMed

The innate system's recognition of non-self and danger signals is mediated by a limited number of germ-line encoded pattern recognition receptors (PRRs) that recognize pathogen associated molecular patterns (PAMPs). Toll-like receptors (TLRs) are single, non-catalytic, membrane-spanning PRRs present in invertebrates and vertebrates. They act by specifically recognizing PAMPs of a variety of microbes and activate signaling cascades to induce innate immunity. A large number of TLRs have been identified in various aquatic animals of phyla Cnidaria, Annelida, Mollusca, Arthropoda, Echinodermata and Chordata. TLRs of aquatic and warm-blooded higher animals exhibit some distinctive features due to their diverse evolutionary lineages. However, majority of them share conserve signaling pathways in pathogen recognition and innate immunity. Functional analysis of novel TLRs in aquatic animals is very important in understanding the comparative immunology between warm-blooded and aquatic animals. In additions to innate immunity, recent reports have highlighted the additional roles of TLRs in adaptive immunity. Therefore, vaccines against many critical diseases of aquatic animals may be made more effective by supplementing TLR activators which will stimulate dendritic cells. This article describes updated information of TLRs in aquatic animals and their structural and functional relationship with warm-blooded animals. PMID:24291116

Rauta, Pradipta R; Samanta, Mrinal; Dash, Hirak R; Nayak, Bismita; Das, Surajit

2014-01-01

280

Assembly Test Article (ATA)  

NASA Technical Reports Server (NTRS)

The assembly test article (ATA) consisted of two live loaded redesigned solid rocket motor (RSRM) segments which were assembled and disassembled to simulate the actual flight segment stacking process. The test assembly joint was flight RSRM design, which included the J-joint insulation design and metal capture feature. The ATA test was performed mid-November through 24 December 1987, at Kennedy Space Center (KSC), Florida. The purpose of the test was: certification that vertical RSRM segment mating and separation could be accomplished without any damage; verification and modification of the procedures in the segment stacking/destacking documents; and certification of various GSE to be used for flight assembly and inspection. The RSRM vertical segment assembly/disassembly is possible without any damage to the insulation, metal parts, or seals. The insulation J-joint contact area was very close to the predicted values. Numerous deviations and changes to the planning documents were made to ensure the flight segments are effectively and correctly stacked. Various GSE were also certified for use on flight segments, and are discussed in detail.

Ricks, Glen A.

1988-01-01

281

DC-SIGN: escape mechanism for pathogens  

Microsoft Academic Search

Dendritic cells (DCs) are crucial in the defence against pathogens. Invading pathogens are recognized by Toll-like receptors (TLRs) and receptors such as C-type lectins expressed on the surface of DCs. However, it is becoming evident that some pathogens, including viruses, such as HIV-1, and non-viral pathogens, such as Mycobacterium tuberculosis, subvert DC functions to escape immune surveillance by targeting the

Teunis B. H. Geijtenbeek; Yvette van Kooyk

2003-01-01

282

RNA silencing suppression by plant pathogens: defence, counter-defence and counter-counter-defence.  

PubMed

RNA silencing is a central regulator of gene expression in most eukaryotes and acts both at the transcriptional level through DNA methylation and at the post-transcriptional level through direct mRNA interference mediated by small RNAs. In plants and invertebrates, the same pathways also function directly in host defence against viruses by targeting viral RNA for degradation. Successful viruses have consequently evolved diverse mechanisms to avoid silencing, most notably through the expression of viral suppressors of RNA silencing. RNA silencing suppressors have also been recently identified in plant pathogenic bacteria and oomycetes, suggesting that disruption of host silencing is a general virulence strategy across several kingdoms of plant pathogens. There is also increasing evidence that plants have evolved specific defences against RNA-silencing suppression by pathogens, providing yet another illustration of the never-ending molecular arms race between plant pathogens and their hosts. PMID:24129510

Pumplin, Nathan; Voinnet, Olivier

2013-11-01

283

APDS: Autonomous Pathogen Detection System  

SciTech Connect

An early warning system to counter bioterrorism, the Autonomous Pathogen Detection System (APDS) continuously monitors the environment for the presence of biological pathogens (e.g., anthrax) and once detected, it sounds an alarm much like a smoke detector warns of a fire. Long before September 11, 2001, this system was being developed to protect domestic venues and events including performing arts centers, mass transit systems, major sporting and entertainment events, and other high profile situations in which the public is at risk of becoming a target of bioterrorist attacks. Customizing off-the-shelf components and developing new components, a multidisciplinary team developed APDS, a stand-alone system for rapid, continuous monitoring of multiple airborne biological threat agents in the environment. The completely automated APDS samples the air, prepares fluid samples in-line, and performs two orthogonal tests: immunoassay and nucleic acid detection. When compared to competing technologies, APDS is unprecedented in terms of flexibility and system performance.

Langlois, R G; Brown, S; Burris, L; Colston, B; Jones, L; Makarewicz, T; Mariella, R; Masquelier, D; McBride, M; Milanovich, F; Masarabadi, S; Venkateswaran, K; Marshall, G; Olson, D; Wolcott, D

2002-02-14

284

NCI DTP Pathways Services  

Cancer.gov

Pathways to Development Services Home Discovery Development Pathways Grants/Contracts Books/Publications Site Search Data Search What's New Section under development. Please direct inquiries to NCIDTPINFO@mail.nih.gov

285

Identifying pathogenic processes by integrating microarray data with prior knowledge  

PubMed Central

Background It is of great importance to identify molecular processes and pathways that are involved in disease etiology. Although there has been an extensive use of various high-throughput methods for this task, pathogenic pathways are still not completely understood. Often the set of genes or proteins identified as altered in genome-wide screens show a poor overlap with canonical disease pathways. These findings are difficult to interpret, yet crucial in order to improve the understanding of the molecular processes underlying the disease progression. We present a novel method for identifying groups of connected molecules from a set of differentially expressed genes. These groups represent functional modules sharing common cellular function and involve signaling and regulatory events. Specifically, our method makes use of Bayesian statistics to identify groups of co-regulated genes based on the microarray data, where external information about molecular interactions and connections are used as priors in the group assignments. Markov chain Monte Carlo sampling is used to search for the most reliable grouping. Results Simulation results showed that the method improved the ability of identifying correct groups compared to traditional clustering, especially for small sample sizes. Applied to a microarray heart failure dataset the method found one large cluster with several genes important for the structure of the extracellular matrix and a smaller group with many genes involved in carbohydrate metabolism. The method was also applied to a microarray dataset on melanoma cancer patients with or without metastasis, where the main cluster was dominated by genes related to keratinocyte differentiation. Conclusion Our method found clusters overlapping with known pathogenic processes, but also pointed to new connections extending beyond the classical pathways. PMID:24758699

2014-01-01

286

Phylogeography of the fungal pathogen Histoplasma capsulatum  

Microsoft Academic Search

Until recently, Histoplasma capsulatum was believed to harbour three varieties, var. capsulatum (chiefly a New World human pathogen), var. duboisii (an African human pathogen) and var. farciminosum (an Old World horse pathogen), which varied in clinical manifestations and geographical distribution. We analysed the phylogenetic relationships of 137 individuals representing the three varieties from six continents using DNA sequence variation in

Takao Kasuga; Thomas J. White; Gina Koenig; Juan Mcewen; Angela Restrepo; Elizabetha Castaneda; Carlos Da Silva Lacaz; Elisabeth M. Heins-Vaccari; Roseli S. De Freitas; Rosely M. Zancope-Oliveira; Zhenyu Qin; Ricardo Negroni; Deidre A. Carter; Yuzuru Mikami; Miki Tamura; Maria Lucia Taylor; Georgina F. Miller; Natteewan Poonwan; John W. Taylor

2003-01-01

287

Genomic islands in pathogenic and environmental microorganisms  

Microsoft Academic Search

Horizontal gene transfer is an important mechanism for the evolution of microbial genomes. Pathogenicity islands — mobile genetic elements that contribute to rapid changes in virulence potential — are known to have contributed to genome evolution by horizontal gene transfer in many bacterial pathogens. Increasing evidence indicates that equivalent elements in non-pathogenic species — genomic islands — are important in

Ulrich Dobrindt; Bianca Hochhut; Ute Hentschel; Jörg Hacker

2004-01-01

288

Molecular Mechanisms of Bacterial Pathogenicity  

NASA Astrophysics Data System (ADS)

Cautious optimism has arisen over recent decades with respect to the long struggle against bacteria, viruses, and parasites. This has been offset, however, by a fatal complacency stemming from previous successes such as the development of antimicrobial drugs, the eradication of smallpox, and global immunization programs. Infectious diseases nevertheless remain the world's leading cause of death, killing at least 17 million persons annually [61]. Diarrheal diseases caused by Vibrio cholerae or Shigella dysenteriae kill about 3 million persons every year, most of them young children: Another 4 million die of tuberculosis or tetanus. Outbreaks of diphtheria in Eastern Europe threatens the population with a disease that had previously seemed to be overcome. Efforts to control infectious diseases more comprehensively are undermined not only by socioeconomic conditions but also by the nature of the pathogenic organisms itself; some isolates of Staphylococcus aureus and Enterobacter have become so resistant to drugs by horizontal gene transfer that they are almost untreatable. In addition, the mechanism of genetic variability helps pathogens to evade the human immune system, thus compromising the development of powerful vaccines. Therefore detailed knowledge of the molecular mechanisms of microbial pathogenicity is absolutely necessary to develop new strategies against infectious diseases and thus to lower their impact on human health and social development.

Fuchs, Thilo Martin

289

Metabolic profiling reveals PAFAH1B3 as a critical driver of breast cancer pathogenicity.  

PubMed

Many studies have identified metabolic pathways that underlie cellular transformation, but the metabolic drivers of cancer progression remain less well understood. The Hippo transducer pathway has been shown to confer malignant traits on breast cancer cells. In this study, we used metabolic mapping platforms to identify biochemical drivers of cellular transformation and malignant progression driven through RAS and the Hippo pathway in breast cancer and identified platelet-activating factor acetylhydrolase 1B3 (PAFAH1B3) as a key metabolic driver of breast cancer pathogenicity that is upregulated in primary human breast tumors and correlated with poor prognosis. Metabolomic profiling suggests that PAFAH1B3 inactivation attenuates cancer pathogenicity through enhancing tumor-suppressing signaling lipids. Our studies provide a map of altered metabolism that underlies breast cancer progression and put forth PAFAH1B3 as a critical metabolic node in breast cancer. PMID:24954006

Mulvihill, Melinda M; Benjamin, Daniel I; Ji, Xiaodan; Le Scolan, Erwan; Louie, Sharon M; Shieh, Alice; Green, McKenna; Narasimhalu, Tara; Morris, Patrick J; Luo, Kunxin; Nomura, Daniel K

2014-07-17

290

Impacts of Climate Change on Indirect Human Exposure to Pathogens and Chemicals from Agriculture  

PubMed Central

Objective Climate change is likely to affect the nature of pathogens and chemicals in the environment and their fate and transport. Future risks of pathogens and chemicals could therefore be very different from those of today. In this review, we assess the implications of climate change for changes in human exposures to pathogens and chemicals in agricultural systems in the United Kingdom and discuss the subsequent effects on health impacts. Data sources In this review, we used expert input and considered literature on climate change; health effects resulting from exposure to pathogens and chemicals arising from agriculture; inputs of chemicals and pathogens to agricultural systems; and human exposure pathways for pathogens and chemicals in agricultural systems. Data synthesis We established the current evidence base for health effects of chemicals and pathogens in the agricultural environment; determined the potential implications of climate change on chemical and pathogen inputs in agricultural systems; and explored the effects of climate change on environmental transport and fate of different contaminant types. We combined these data to assess the implications of climate change in terms of indirect human exposure to pathogens and chemicals in agricultural systems. We then developed recommendations on future research and policy changes to manage any adverse increases in risks. Conclusions Overall, climate change is likely to increase human exposures to agricultural contaminants. The magnitude of the increases will be highly dependent on the contaminant type. Risks from many pathogens and particulate and particle-associated contaminants could increase significantly. These increases in exposure can, however, be managed for the most part through targeted research and policy changes. PMID:19440487

Boxall, Alistair B.A.; Hardy, Anthony; Beulke, Sabine; Boucard, Tatiana; Burgin, Laura; Falloon, Peter D.; Haygarth, Philip M.; Hutchinson, Thomas; Kovats, R. Sari; Leonardi, Giovanni; Levy, Leonard S.; Nichols, Gordon; Parsons, Simon A.; Potts, Laura; Stone, David; Topp, Edward; Turley, David B.; Walsh, Kerry; Wellington, Elizabeth M.H.; Williams, Richard J.

2009-01-01

291

Hedgehog Signaling Pathway  

NSDL National Science Digital Library

The Hedgehog (Hh) signaling pathway is essential for development and tissue homeostasis in metazoans. Probably as a result of its potent influence on cell-fate outcomes, the Hh pathway when corrupted results in malformations and diseases such as cancer. Many of the pathway components that contribute to Hh-mediated signal transduction are presented.

Leni Jacob (University of Texas Southwestern Medical Center;Department of Cell Biology REV); Lawrence Lum (University of Texas Southwestern Medical Center;Department of Cell Biology REV)

2007-10-09

292

Animal Pathogen/Product Import Importing "Animal" Pathogens from Outside Canada  

E-print Network

Animal Pathogen/Product Import Importing "Animal" Pathogens from Outside Canada 1) Permits) Complete the three-page "Facility Certification for the Importation of Animal Pathogens" located the appropriate checklist and complete it. Complete only one of either the "Inspection Checklist ­ Animal Pathogen

293

COCEBI-656; NO OF PAGES 7 Please cite this article in press as: Lecuyer E, et al. Global implications of mRNA localization pathways in cellular organization, Curr Opin Cell Biol (2009), doi:10.1016/j.ceb.2009.01.027  

E-print Network

, however, the advent of functional genomic approaches such as biochemical fractionations combined reveal the breadth of mRNA localization pathways The combination of cellular fractionation and microarray], the mitotic apparatus [9 ], dendrites [10], and pseu- dopodia [11 ]. In each case, many of the co-fractionating

Krause, Henry M.

294

Response Ability Pathways: A Curriculum for Connecting  

ERIC Educational Resources Information Center

This article describes a new training curriculum for educators, youth workers, and mentors which draws from research and best practices in positive youth development and positive behavior support. Response Ability Pathways or RAP focuses on three practical interventions: connect to others for support, clarify challenging problems, and restore…

Koehler, Nancy; Seger, Vikki

2005-01-01

295

RESEARCH ARTICLE Open Access DNA methylation in glioblastoma: impact on  

E-print Network

RESEARCH ARTICLE Open Access DNA methylation in glioblastoma: impact on gene expression methylation pattern of genes involved in key biological pathways have been reported in glioblastoma. Genome in the aggressive phenotype of glioblastoma, and to guide new treatment strategies. Results: We performed a whole

Paris-Sud XI, Université de

296

ORIGINAL ARTICLE Visualization of Oleic Acid-induced Transdermal Diusion  

E-print Network

£uores- cence and the transdermal £uorescent model drug spatial distributions were imaged simultaneously overORIGINAL ARTICLE Visualization of Oleic Acid-induced Transdermal Di¡usion Pathways Using Two-based model drug intensity emission at a di¡erent wavelength range of the £uorescence emission spectrum

So, Peter

297

Epigenetic control of effectors in plant pathogens  

PubMed Central

Plant pathogens display impressive versatility in adapting to host immune systems. Pathogen effector proteins facilitate disease but can become avirulence (Avr) factors when the host acquires discrete recognition capabilities that trigger immunity. The mechanisms that lead to changes to pathogen Avr factors that enable escape from host immunity are diverse, and include epigenetic switches that allow for reuse or recycling of effectors. This perspective outlines possibilities of how epigenetic control of Avr effector gene expression may have arisen and persisted in filamentous plant pathogens, and how it presents special problems for diagnosis and detection of specific pathogen strains or pathotypes.

Gijzen, Mark; Ishmael, Chelsea; Shrestha, Sirjana D.

2014-01-01

298

Organomercury Pathway Map  

NSDL National Science Digital Library

The University of Minnesota Biocatalysis/Biodegradation Database (UM/BBD) contains "microbial biocatalytic reactions and biodegradation pathways primarily for xenobiotic, chemical compounds." A new microbial enzyme-catalyzed reactions has been posted for Organomercury. The Organomercury pathway map highlights mercury, a highly toxic heavy metal used "as a pesticide, herbicide, fungicide, disinfectant and a preservative in cosmetics." The organomercury pathway map includes organisms which can initiate the pathway. The pathway map provides detailed information on each hyperlinked step, including graphics, product/substrate reactions, and external links to further information.

Nasevicius, Aidas.; Ouyang, Jun.; Stephens, Stephen.; Sun, Zhifu.

2001-01-01

299

Constraint-Based Modeling and Scheduling of Clinical Pathways  

NASA Astrophysics Data System (ADS)

In this article a constraint-based modeling of clinical pathways, in particular of surgical pathways, is introduced and used for an optimized scheduling of their tasks. The addressed optimization criteria are based on practical experiences in the area of Constraint Programming applications in medical work flow management. Objective functions having empirical evidence for their adequacy in the considered use cases are formally presented. It is shown how they are respected while scheduling clinical pathways.

Wolf, Armin

300

Contamination of water resources by pathogenic bacteria  

PubMed Central

Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed. PMID:25006540

2014-01-01

301

Automated creation of Wikipedia articles  

E-print Network

This thesis describes an automatic approach for producing Wikipedia articles. The wealth of information present on the Internet is currently untapped for many topics of secondary concern. Creating articles requires a great ...

Sauper, Christina (Christina Joan)

2009-01-01

302

Bankruptcy and Revised Article 9.  

National Technical Information Service (NTIS)

On July 1, 2001 revisions to Article 9 of the Uniform Commercial Code became effective in almost every state. David Lander Esq., moderates a discussion of the Article 9 changes and their ramifications for bankruptcy judges and practitioners. Nationally re...

2001-01-01

303

The chemical arsenal of Burkholderia pseudomallei is essential for pathogenicity.  

PubMed

Increasing evidence has shown that small-molecule chemistry in microbes (i.e., secondary metabolism) can modulate the microbe-host response in infection and pathogenicity. The bacterial disease melioidosis is conferred by the highly virulent, antibiotic-resistant pathogen Burkholderia pseudomallei (BP). Whereas some macromolecular structures have been shown to influence BP virulence (e.g., secretion systems, cellular capsule, pili), the role of the large cryptic secondary metabolome encoded within its genome has been largely unexplored for its importance to virulence. Herein we demonstrate that BP-encoded small-molecule biosynthesis is indispensible for in vivo BP pathogenicity. Promoter exchange experiments were used to induce high-level molecule production from two gene clusters (MPN and SYR) found to be essential for in vivo virulence. NMR structural characterization of these metabolites identified a new class of lipopeptide biosurfactants/biofilm modulators (the malleipeptins) and syrbactin-type proteasome inhibitors, both of which represent overlooked small-molecule virulence factors for BP. Disruption of Burkholderia virulence by inhibiting the biosynthesis of these small-molecule biosynthetic pathways may prove to be an effective strategy for developing novel melioidosis-specific therapeutics. PMID:24884988

Biggins, John B; Kang, Hahk-Soo; Ternei, Melinda A; DeShazer, David; Brady, Sean F

2014-07-01

304

Immunity to intestinal pathogens: lessons learned from Salmonella.  

PubMed

Salmonella are a common source of food- or water-borne infection and cause a wide range of clinical disease in human and animal hosts. Salmonella are relatively easy to culture and manipulate in a laboratory setting, and the infection of laboratory animals induces robust innate and adaptive immune responses. Thus, immunologists have frequently turned to Salmonella infection models to expand understanding of host immunity to intestinal pathogens. In this review, I summarize current knowledge of innate and adaptive immunity to Salmonella and highlight features of this response that have emerged from recent studies. These include the heterogeneity of the antigen-specific T-cell response to intestinal infection, the prominence of microbial mechanisms to impede T- and B-cell responses, and the contribution of non-cognate pathways for elicitation of T-cell effector functions. Together, these different issues challenge an overly simplistic view of host-pathogen interaction during mucosal infection, but also allow deeper insight into the real-world dynamic of protective immunity to intestinal pathogens. PMID:24942689

McSorley, Stephen J

2014-07-01

305

Gating by Cyclic AMP: Expanded Role for an Old Signaling Pathway  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. The intracellular signal transduction pathway that utilizes cyclic AMP as a key messenger was the first such pathway to be described and has served as a model for many other transducing systems. Now Iyengar illustrates how this classic pathway has yet another function--in a number of different biological systems, the cyclic AMP pathway appears to gate (either negatively or positively) other signal transduction pathways.

Ravi Iyengar (City University of New York;Department of Pharmacology, Mount Sinai School of Medicine)

1996-01-26

306

Pathways of Youth Development in a Rural Trailer Park  

ERIC Educational Resources Information Center

Limited empirical documentation exists for the developmental pathways available to "rural" youth growing up in low-resource community settings. Drawing on ethnographic data, this article examines the developmental pathways experienced by youth in a rural trailer park. Findings reveal how various factors, some inherent to working poor class status…

MacTavish, Katherine A.; Salamon, Sonya

2006-01-01

307

ORIGINAL ARTICLES Disease Limits Populations  

E-print Network

vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100 pestis. Introduction Plague, caused by the bacterium Yersinia pestis, has occurred in black). Yersinia pestis is an exotic pathogen in the prairie dog system, and its impacts on populations of all four

Collinge, Sharon K.

308

Original article Ecopathology in aquaculture  

E-print Network

factors associated with disease outbreaks in fish species of fish farms and rivers of north-east Spain. We focused our work on the isolation of fish pathogens (bacteria, virus), the water quality (physicochemical that there are some potential risk factors associated with the main diseases of fish, such as fish age, fish species

Paris-Sud XI, Université de

309

Detection of pathogenic gram negative bacteria using infrared thermography  

NASA Astrophysics Data System (ADS)

Detection of viable bacteria is of prime importance in all fields of microbiology and biotechnology. Conventional methods of enumerating bacteria are often time consuming and labor-intensive. All living organisms generate heat due to metabolic activities and hence, measurement of heat energy is a viable tool for detection and quantification of bacteria. In this article, we employ a non-contact and real time method - infrared thermography (IRT) for measurement of temperature variations in four clinically significant gram negative pathogenic bacteria, viz. Vibrio cholerae, Vibrio mimicus, Proteus mirabilis and Pseudomonas aeruginosa. We observe that, the energy content, defined as the ratio of heat generated by bacterial metabolic activities to the heat lost from the liquid medium to the surrounding, vary linearly with the bacterial concentration in all the four pathogenic bacteria. The amount of energy content observed in different species is attributed to their metabolisms and morphologies that affect the convection velocity and hence heat transport in the medium.

Lahiri, B. B.; Divya, M. P.; Bagavathiappan, S.; Thomas, Sabu; Philip, John

2012-11-01

310

Caspase-11 activation requires lysis of pathogen-containing vacuoles by IFN-induced GTPases.  

PubMed

Lipopolysaccharide from Gram-negative bacteria is sensed in the host cell cytoplasm by a non-canonical inflammasome pathway that ultimately results in caspase-11 activation and cell death. In mouse macrophages, activation of this pathway requires the production of type-I interferons, indicating that interferon-induced genes have a critical role in initiating this pathway. Here we report that a cluster of small interferon-inducible GTPases, the so-called guanylate-binding proteins, is required for the full activity of the non-canonical caspase-11 inflammasome during infections with vacuolar Gram-negative bacteria. We show that guanylate-binding proteins are recruited to intracellular bacterial pathogens and are necessary to induce the lysis of the pathogen-containing vacuole. Lysis of the vacuole releases bacteria into the cytosol, thus allowing the detection of their lipopolysaccharide by a yet unknown lipopolysaccharide sensor. Moreover, recognition of the lysed vacuole by the danger sensor galectin-8 initiates the uptake of bacteria into autophagosomes, which results in a reduction of caspase-11 activation. These results indicate that host-mediated lysis of pathogen-containing vacuoles is an essential immune function and is necessary for efficient recognition of pathogens by inflammasome complexes in the cytosol. PMID:24739961

Meunier, Etienne; Dick, Mathias S; Dreier, Roland F; Schürmann, Nura; Kenzelmann Broz, Daniela; Warming, Søren; Roose-Girma, Merone; Bumann, Dirk; Kayagaki, Nobuhiko; Takeda, Kiyoshi; Yamamoto, Masahiro; Broz, Petr

2014-05-15

311

Differential Host Response, Rather Than Early Viral Replication Efficiency, Correlates with Pathogenicity Caused by Influenza Viruses  

PubMed Central

Influenza viruses exhibit large, strain-dependent differences in pathogenicity in mammalian hosts. Although the characteristics of severe disease, including uncontrolled viral replication, infection of the lower airway, and highly inflammatory cytokine responses have been extensively documented, the specific virulence mechanisms that distinguish highly pathogenic strains remain elusive. In this study, we focused on the early events in influenza infection, measuring the growth rate of three strains of varying pathogenicity in the mouse airway epithelium and simultaneously examining the global host transcriptional response over the first 24 hours. Although all strains replicated equally rapidly over the first viral life-cycle, their growth rates in both lung and tracheal tissue strongly diverged at later times, resulting in nearly 10-fold differences in viral load by 24 hours following infection. We identified separate networks of genes in both the lung and tracheal tissues whose rapid up-regulation at early time points by specific strains correlated with a reduced viral replication rate of those strains. The set of early-induced genes in the lung that led to viral growth restriction is enriched for both NF-?B binding site motifs and members of the TREM1 and IL-17 signaling pathways, suggesting that rapid, NF-?B –mediated activation of these pathways may contribute to control of viral replication. Because influenza infection extending into the lung generally results in severe disease, early activation of these pathways may be one factor distinguishing high- and low-pathogenicity strains. PMID:24073225

Askovich, Peter S.; Sanders, Catherine J.; Rosenberger, Carrie M.; Diercks, Alan H.; Dash, Pradyot; Navarro, Garnet; Vogel, Peter; Doherty, Peter C.; Thomas, Paul G.; Aderem, Alan

2013-01-01

312

Switch Region for Pathogenic Structural Change in Conformational Disease and Its Prediction  

PubMed Central

Many diseases are believed to be related to abnormal protein folding. In the first step of such pathogenic structural changes, misfolding occurs in regions important for the stability of the native structure. This destabilizes the normal protein conformation, while exposing the previously hidden aggregation-prone regions, leading to subsequent errors in the folding pathway. Sites involved in this first stage can be deemed switch regions of the protein, and can represent perfect binding targets for drugs to block the abnormal folding pathway and prevent pathogenic conformational changes. In this study, a prediction algorithm for the switch regions responsible for the start of pathogenic structural changes is introduced. With an accuracy of 94%, this algorithm can successfully find short segments covering sites significant in triggering conformational diseases (CDs) and is the first that can predict switch regions for various CDs. To illustrate its effectiveness in dealing with urgent public health problems, the reason of the increased pathogenicity of H5N1 influenza virus is analyzed; the mechanisms of the pandemic swine-origin 2009 A(H1N1) influenza virus in overcoming species barriers and in infecting large number of potential patients are also suggested. It is shown that the algorithm is a potential tool useful in the study of the pathology of CDs because: (1) it can identify the origin of pathogenic structural conversion with high sensitivity and specificity, and (2) it provides an ideal target for clinical treatment. PMID:20111584

Liu, Xin; Zhao, Ya-Pu

2010-01-01

313

Molecular neurodegeneration: basic biology and disease pathways.  

PubMed

The field of neurodegeneration research has been advancing rapidly over the past few years, and has provided intriguing new insights into the normal physiological functions and pathogenic roles of a wide range of molecules associated with several devastating neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, Huntington's disease, and Down syndrome. Recent developments have also facilitated initial efforts to translate preclinical discoveries toward novel therapeutic approaches and clinical trials in humans. These recent developments are reviewed in the current Review Series on "Molecular Neurodegeneration: Basic Biology and Disease Pathways" in a number of state-of-the-art manuscripts that cover themes presented at the Third International Conference on Molecular Neurodegeneration: "Basic biology and disease pathways" held in Cannes, France, September, 2013. PMID:25248568

Vassar, Robert; Zheng, Hui

2014-01-01

314

Molecular Epidemiology of Foodborne Pathogens  

NASA Astrophysics Data System (ADS)

The purpose of this chapter is to describe the basic principles and advancements in the molecular epidemiology of foodborne pathogens. Epidemiology is the study of the distribution and determinants of infectious diseases and/or the dynamics of disease transmission. The goals of epidemiology include the identification of physical sources, routes of transmission of infectious agents, and distribution and relationships of different subgroups. Molecular epidemiology is the study of epidemiology at the molecular level. It has been defined as "a science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution and prevention of diseases within families and across populations".

Chen, Yi; Brown, Eric; Knabel, Stephen J.

315

Surface treatment of ceramic articles  

DOEpatents

A process is disclosed for producing an article with improved ceramic surface properties including providing an article having a ceramic surface, and placing the article onto a conductive substrate holder in a hermetic enclosure. Thereafter a low pressure ambient is provided in the hermetic enclosure. A plasma including ions of solid materials is produced the ceramic surface of the article being at least partially immersed in a macroparticle free region of the plasma. While the article is immersed in the macroparticle free region, a bias of the substrate holder is biased between a low voltage at which material from the plasma condenses on the surface of the article and a high negative voltage at which ions from the plasma are implanted into the article. 15 figs.

Komvopoulos, K.; Brown, I.G.; Wei, B.; Anders, S.; Anders, A.; Bhatia, C.S.

1998-12-22

316

PATHWAYS - ELECTRON TUNNELING PATHWAYS IN PROTEINS  

NASA Technical Reports Server (NTRS)

The key to understanding the mechanisms of many important biological processes such as photosynthesis and respiration is a better understanding of the electron transfer processes which take place between metal atoms (and other groups) fixed within large protein molecules. Research is currently focused on the rate of electron transfer and the factors that influence it, such as protein composition and the distance between metal atoms. Current models explain the swift transfer of electrons over considerable distances by postulating bridge-mediated tunneling, or physical tunneling pathways, made up of interacting bonds in the medium around and between donor and acceptor sites. The program PATHWAYS is designed to predict the route along which electrons travel in the transfer processes. The basic strategy of PATHWAYS is to begin by recording each possible path element on a connectivity list, including in each entry which two atoms are connected and what contribution the connection would make to the overall rate if it were included in a pathway. The list begins with the bonded molecular structure (including the backbone sequence and side chain connectivity), and then adds probable hydrogen bond links and through-space contacts. Once this list is completed, the program runs a tree search from the donor to the acceptor site to find the dominant pathways. The speed and efficiency of the computer search offers an improvement over manual techniques. PATHWAYS is written in FORTRAN 77 for execution on DEC VAX series computers running VMS. The program inputs data from four data sets and one structure file. The software was written to input BIOGRAF (old format) structure files based on x-ray crystal structures and outputs ASCII files listing the best pathways and BIOGRAF vector files containing the paths. Relatively minor changes could be made in the input format statements for compatibility with other graphics software. The executable and source code are included with the distribution. The main memory requirement for execution is 2.6 Mb. This program is available in DEC VAX BACKUP format on a 9-track 1600 BPI magnetic tape (standard distribution) or on a TK50 tape cartridge. PATHWAYS was developed in 1988. PATHWAYS is a copyrighted work with all copyright vested in NASA. DEC, VAX, VMS, and TK50 are trademarks of Digital Equipment Corporation. BIOGRAF is a trademark of Molecular Simulations, Inc., Sunnyvale, CA.

Beratan, D. N.

1994-01-01

317

APDS: The Autonomous Pathogen Detection System  

SciTech Connect

We have developed and tested a fully autonomous pathogen detection system (APDS) capable of continuously monitoring the environment for airborne biological threat agents. The system was developed to provide early warning to civilians in the event of a bioterrorism incident and can be used at high profile events for short-term, intensive monitoring or in major public buildings or transportation nodes for long-term monitoring. The APDS is completely automated, offering continuous aerosol sampling, in-line sample preparation fluidics, multiplexed detection and identification immunoassays, and nucleic-acid based polymerase chain reaction (PCR) amplification and detection. Highly multiplexed antibody-based and duplex nucleic acid-based assays are combined to reduce false positives to a very low level, lower reagent costs, and significantly expand the detection capabilities of this biosensor. This article provides an overview of the current design and operation of the APDS. Certain sub-components of the ADPS are described in detail, including the aerosol collector, the automated sample preparation module that performs multiplexed immunoassays with confirmatory PCR, and the data monitoring and communications system. Data obtained from an APDS that operated continuously for seven days in a major U.S. transportation hub is reported.

Hindson, B; Makarewicz, A; Setlur, U; Henderer, B; McBride, M; Dzenitis, J

2004-10-04

318

The intrinsic resistome of bacterial pathogens  

PubMed Central

Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice. PMID:23641241

Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B. Sanchez, Maria; Martinez, Jose L.

2013-01-01

319

The Genus Aeromonas: Taxonomy, Pathogenicity, and Infection  

PubMed Central

Summary: Over the past decade, the genus Aeromonas has undergone a number of significant changes of practical importance to clinical microbiologists and scientists alike. In parallel with the molecular revolution in microbiology, several new species have been identified on a phylogenetic basis, and the genome of the type species, A. hydrophila ATCC 7966, has been sequenced. In addition to established disease associations, Aeromonas has been shown to be a significant cause of infections associated with natural disasters (hurricanes, tsunamis, and earthquakes) and has been linked to emerging or new illnesses, including near-drowning events, prostatitis, and hemolytic-uremic syndrome. Despite these achievements, issues still remain regarding the role that Aeromonas plays in bacterial gastroenteritis, the extent to which species identification should be attempted in the clinical laboratory, and laboratory reporting of test results from contaminated body sites containing aeromonads. This article provides an extensive review of these topics, in addition to others, such as taxonomic issues, microbial pathogenicity, and antimicrobial resistance markers. PMID:20065325

Janda, J. Michael; Abbott, Sharon L.

2010-01-01

320

Bacteriophage-Based Pathogen Detection  

NASA Astrophysics Data System (ADS)

Considered the most abundant organism on Earth, at a population approaching 1031, bacteriophage, or phage for short, mediate interactions with myriad bacterial hosts that has for decades been exploited in phage typing schemes for signature identification of clinical, food-borne, and water-borne pathogens. With over 5,000 phage being morphologically characterized and grouped as to susceptible host, there exists an enormous cache of bacterial-specific sensors that has more recently been incorporated into novel bio-recognition assays with heightened sensitivity, specificity, and speed. These assays take many forms, ranging from straightforward visualization of labeled phage as they attach to their specific bacterial hosts to reporter phage that genetically deposit trackable signals within their bacterial hosts to the detection of progeny phage or other uniquely identifiable elements released from infected host cells. A comprehensive review of these and other phage-based detection assays, as directed towards the detection and monitoring of bacterial pathogens, will be provided in this chapter.

Ripp, Steven

321

SAGPAR: structural grammar-based automated pathway reconstruction.  

PubMed

In-silico metabolic engineering is a very useful branch of systems biology for modeling, analysis and prediction of various outcomes of metabolic pathways. It can also be used for detecting interactions and dynamics within a network. Various protocols have been proposed for modeling a pathway. But most of these protocols have various disadvantages and shortcomings with respect to automated pathway modeling and analysis. In the present article, we have proposed a novel algorithm for automated pathway reconstruction. We have also made a comparative study of our algorithm with other standard protocols and discussed its advantages over others. We present StructurAl Grammar-based automated PAthway Reconstruction (SAGPAR), a fast and robust algorithm that generates any metabolic pathway using some given structural representations of metabolites. Users can model any pathway based on some pre-required features that are asked as an input by the algorithm. The algorithm also takes into considerations various thermodynamic thresholds and structural properties while modeling a pathway. The given algorithm has been tested on the standard pathway datasets of 25 pathways of Mycoplasma pneumoniae M129 and 24 pathways of Homo sapiens. The dataset is taken from KEGG and PubChem Compound data repositories. SAGPAR performs much better than some already present metabolic pathway analysis tools like Copasi, PHT, Gepasi, Jarnac and Path-A. PMID:22843234

Tagore, Somnath; De, Rajat K

2012-06-01

322

Fluorene Degradation Pathway Map  

NSDL National Science Digital Library

The University of Minnesota Biocatalysis/Biodegradation Database (UM/BBD) contains "microbial biocatalytic reactions and biodegradation pathways primarily for xenobiotic, chemical compounds." A new microbial enzyme-catalyzed reactions has been posted for Flourene. Flourene is commonly found in vehicle exhaust emissions, motor oils, crude oils, coal and oil combustion products, industrial effluents, and waste incineration, and is a major component of "fossil fuels and their derivatives." The Fluorene pathway map includes organisms which initiate the pathway, as well as organisms that carry out later steps. The pathway map provides detailed information on each hyperlinked step, including graphics, product/substrate reactions, and external links to further information.

Feng, Jingfeng.; Solanas, Anna M.

2001-01-01

323

Article type: Focus Article Replaying History on Process Models for  

E-print Network

mining on the one hand, and process modeling and analysis on the other hand [1]. Starting point as a starting point for other types of analysis. · Conformance: an existing process model is comparedArticle type: Focus Article Replaying History on Process Models for Conformance Checking

van der Aalst, Wil

324

Selected Gymnastics Articles. Sports Articles Reprint Series. First Edition.  

ERIC Educational Resources Information Center

This is a collection of the best articles in the "DGWS (Division for Girls and Women's Sports) Gymnastics Guide" from 1963 to 1972. Included are the current Federation of International Gymnastics rule interpretations from the 1972-74 Gymnastics Guide. The articles have been edited to conform with the new rules and regulations from the Federation…

Bowers, Carolyn O., Ed.

325

Comment & analysis / Editorial comment Print article | Email article  

E-print Network

Comment & analysis / Editorial comment Print article | Email article Published: November 25 2004 02 and industrial powers agreed to spend $10bn (£5.4bn) over the next 30 years on a nuclear fusion experiment that could provide another energy option for the middle of this century. Sadly, the International

326

Print This Article Print this article Close This Window  

E-print Network

Print This Article Print this article Close This Window TOKYO (Reuters) - Japan's science minister France. Media have suggested the deadlock over the multi-billion dollar project reflected Washington content or of any content used on this site, including by framing or similar means, is expressly

327

Guidelines for evaluating research articles.  

PubMed

The article describes the components and composition of journal articles that report empirical research findings in the field of rehabilitation. The authors delineate technical writing strategies and discuss the contents of research manuscripts, including the Title, Abstract, Introduction, Method, Results, Discussion, and References. The article concludes with a scale that practitioners, manuscript reviewers, educators, and students can use in critically analyzing the content and scientific merits of published rehabilitation research. PMID:12441522

Rumrill, Phillip; Fitzgerald, Shawn; Ware, Megen

2000-01-01

328

The emerging role of photorespiration and non-photorespiratory peroxisomal metabolism in pathogen defence.  

PubMed

Photorespiration represents one of the major highways of primary plant metabolism and is the most prominent example of metabolic cell organelle integration, since the pathway requires the concerted action of plastidial, peroxisomal, mitochondrial and cytosolic enzymes and organellar transport proteins. Oxygenation of ribulose-1,5-bisphosphate by Rubisco leads to the formation of large amounts of 2-phosphoglycolate, which are recycled to 3-phosphoglycerate by the photorespiratory C2 cycle, concomitant with stoichiometric production rates of H2 O2 in peroxisomes. Apart from its significance for agricultural productivity, a secondary function of photorespiration in pathogen defence has emerged only recently. Here, we summarise literature data supporting the crosstalk between photorespiration and pathogen defence and perform a meta-expression analysis of photorespiratory genes during pathogen attack. Moreover, we screened Arabidopsis proteins newly predicted using machine learning methods to be targeted to peroxisomes, the central H2 O2 -producing organelle of photorespiration, for homologues of known pathogen defence proteins and analysed their expression during pathogen infection. The analyses further support the idea that photorespiration and non-photorespiratory peroxisomal metabolism play multi-faceted roles in pathogen defence beyond metabolism of reactive oxygen species. PMID:23506300

Sørhagen, K; Laxa, M; Peterhänsel, C; Reumann, S

2013-07-01

329

Sumoylation at the Host-Pathogen Interface  

PubMed Central

Many viral proteins have been shown to be sumoylated with corresponding regulatory effects on their protein function, indicating that this host cell modification process is widely exploited by viral pathogens to control viral activity. In addition to using sumoylation to regulate their own proteins, several viral pathogens have been shown to modulate overall host sumoylation levels. Given the large number of cellular targets for SUMO addition and the breadth of critical cellular processes that are regulated via sumoylation, viral modulation of overall sumoylation presumably alters the cellular environment to ensure that it is favorable for viral reproduction and/or persistence. Like some viruses, certain bacterial plant pathogens also target the sumoylation system, usually decreasing sumoylation to disrupt host anti-pathogen responses. The recent demonstration that Listeria monocytogenes also disrupts host sumoylation, and that this is required for efficient infection, extends the plant pathogen observations to a human pathogen and suggests that pathogen modulation of host sumoylation may be more widespread than previously appreciated. This review will focus on recent aspects of how pathogens modulate the host sumoylation system and how this benefits the pathogen. PMID:23795346

Wilson, Van G.

2012-01-01

330

The roles of pathogen small RNAs.  

PubMed

Regulatory small RNAs (sRNAs), also known as non-coding RNA, are not translated into proteins and widespread in prokaryotes and eukaryotes. sRNAs involve in multiple fundamental cellular events. They are emerging regulatory elements that are gaining momentum. Knowledge of sRNA largely originates from eukaryotes. Prokaryotic sRNAs, particularly those of pathogen are only recently explored. The main types, function, and methodology to predict pathogen sRNAs are summarized in this review. Special focus is sRNAs regulating pathogen gene expression, particularly that of Mycobacterium tuberculosis, which is hitherto the most successful pathogen afflicting mankind. PMID:20945366

Zhou, Yexin; Xie, Jianping

2011-04-01

331

Forest Ecosystem Responses to Exotic Pests and Pathogens in Eastern North America  

NSDL National Science Digital Library

This peer-reviewed article from BioScience investigates exotic pests and pathogens in eastern North America.The forests of eastern North America have been subjected to repeated introductions of exotic insect pests and pathogens over the last century, and several new pests are currently invading, or threatening to invade, the region. These pests and pathogens can have major short- and long-term impacts on forest ecosystem processes such as productivity, nutrient cycling, and support of consumer food webs. We identify six key features of the biology of exotic animal pests and the ecology of their hosts that are critical to predicting the general nature and severity of those impacts. Using three examples of introduced pests and pathogens in eastern forest ecosystems, we provide a conceptual framework for assessing potential ecosystem-scale effects.

GARY M. LOVETT, CHARLES D. CANHAM, MARY A. ARTHUR, KATHLEEN C. WEATHERS, and ROSS D. FITZHUGH (;)

2006-05-01

332

Insect Behavior: Student Review Articles  

NSDL National Science Digital Library

Colorado State University entomology professor Dr. Louis Bjostad provides this interesting resource of review articles on insect behavior. Each review article was written by a student as part of a graduate level course held in Spring 1999; review articles consist of a three to six paragraph summary of research, followed by a dozen or more recent references. Titles include "Communal Roosting in Insects" and "Behavioral Aspects of Biological Control of Spider Mites," among dozens of others. For those interested in reading summaries of (and finding references to) recent scientific articles on insect behavior, this is an excellent starting place.

333

UV signaling pathways within the skin.  

PubMed

The effects of UVR on the skin include tanning, carcinogenesis, immunomodulation, and synthesis of vitamin D, among others. Melanocortin 1 receptor polymorphisms correlate with skin pigmentation, UV sensitivity, and skin cancer risk. This article reviews pathways through which UVR induces cutaneous stress and the pigmentation response. Modulators of the UV-tanning pathway include sunscreen agents, melanocortin 1 receptor activators, adenylate cyclase activators, phosphodiesterase 4D3 inhibitors, T-oligos, and microphthalmia-associated transcription factor regulators such as histone deacetylase inhibitors. UVR, as one of the most ubiquitous carcinogens, represents both a challenge and an enormous opportunity in skin cancer prevention. PMID:24759085

Chen, Hongxiang; Weng, Qing Y; Fisher, David E

2014-08-01

334

Contribution of Small RNA Pathway Components in Plant Immunity  

PubMed Central

Small RNAs regulate a multitude of cellular processes, including development, stress responses, metabolism, and maintenance of genome integrity, in a sequence-specific manner. Accumulating evidence reveals that host endogenous small RNAs and small RNA pathway components play important roles in plant immune responses against various pathogens, including bacteria, fungi, oomycetes, and viruses. Small-RNA-mediated defense responses are regulated through diverse pathways and the components of these pathways, including Dicer-like proteins, RNA-dependent RNA polymerases, Argonaute proteins, and RNA polymerase IV and V, exhibit functional specificities as well as redundancy. In this review, we summarize the recent insights revealed mainly through the examination of two model plants, Arabidopsis and rice, with a primary focus on our emerging understanding of how these small RNA pathway components contribute to plant immunity. PMID:23489060

Seo, Jang-Kyun; Wu, Jianguo; Lii, Yifan; Li, Yi; Jin, Hailing

2013-01-01

335

National Microbial Pathogen Data Resource  

NSDL National Science Digital Library

Overview on searching, navigating, and teaching with NMPDR. Presentations on connecting bioinformatics to the bench, and subsystems annotation. Assignments exploring biosynthesis and pathogenesis. Documents on using GBrowse, and SEED. ***Notice to NMPDR Users*** The NMPDR BRC contract ended in December 2009. At that time we ceased maintenance of the NMPDR web resource and data. The PATRIC team, located at the Virginia Bioinformatics Institute, created and maintains a new consolidated BRC for all of the NIAID category A-C priority pathogenic bacteria. NMPDR is transferring data and software associated to PATRIC for incorporation into their new Web-based bioinformatics resource. Please feel free to contact us if you have any questions about this transition.

Nmpdr

336

Growth Requirements of Pathogenic Leptospira  

PubMed Central

Nutritional requirements for growth at 30 C of Leptospira pomona and L. canicola have been determined. Both pathogenic serotypes initially required bovine serum albumin (BSA) for growth in a medium (SM-4) which permitted growth of the water isolate B-16. Requirement for BSA was eliminated by (i) removing much of the apparent toxicity of free fatty acids in Tween 80 on an anion exchange column, (ii) decreasing extended lag periods observed from small inocula by incorporation of pyruvate into the medium, (iii) the addition of acetate to permit full utilization of substrate fatty acids in Tween 80, and (iv) the addition of glycerol to decrease generation times. Physiologic significance of these findings is discussed, and the possibility is suggested that apparent toxicity of fatty acids for leptospires may result from their auto-oxidation products. The resulting protein-free medium (SM-5) permitted the growth of pathogens at 30 C to high cell yields in low inocula. Highly virulent and avirulent strains from the same clone of L. canicola Moulton were used to determine additional growth requirements associated with virulence. As incubation temperatures were increased from 30 C to those of mammalian hosts, virulent cells required biotin at 35 C and higher levels of K+ and Mg2+ at 37 C. Additional Fe2+ eliminated the necessity for removing the toxicity of Tween 80 by anion exchange. Significance of these physiologic studies are discussed in relationship to virulence. The final protein-free medium (SM-6) grew highly virulent L. canicola from tissue to high yields from low inocula at 37 C with no loss in virulence over several transfers. PMID:4716547

Staneck, Joseph L.; Henneberry, Richard C.; Cox, C. D.

1973-01-01

337

Pathogenic Roles for Fungal Melanins  

PubMed Central

Melanins represent virulence factors for several pathogenic fungi; the number of examples is growing. Thus, albino mutants of several genera (in one case, mutated precisely in the melanizing enzyme) exhibit decreased virulence in mice. We consider the phenomenon in relation to known chemical properties of melanin, beginning with biosynthesis from ortho-hydroquinone precursors which, when oxidized enzymatically to quinones, polymerize spontaneously to melanin. It follows that melanizing intermediates are cross-linking reagents; melanization stabilizes the external cell wall against hydrolysis and is thought to determine semipermeability in the osmotic ram (the appressorium) of certain plant pathogens. Polymeric melanins undergo reversible oxidation-reduction reactions between cell wall-penetrating quinone and hydroquinone oxidation states and thus represent polymeric redox buffers; using strong oxidants, it is possible to titrate the melanin on living cells and thereby demonstrate protection conferred by melanin in several species. The amount of buffering per cell approximately neutralizes the amount of oxidant generated by a single macrophage. Moreover, the intermediate oxidation state, the semiquinone, is a very stable free radical and is thought to trap unpaired electrons. We have suggested that the oxidation state of external melanin may be regulated by external Fe(II). An independent hypothesis holds that in Cryptococcus neoformans, an important function of the melanizing enzyme (apart from melanization) is the oxidation of Fe(II) to Fe(III), thereby forestalling generation of the harmful hydroxyl radical from H2O2. Thus, problems in fungal pathogenesis have led to evolving hypotheses regarding melanin functioning. PMID:11023965

Jacobson, Eric S.

2000-01-01

338

IDENTIFICATION OF PEPTIDASES IN HIGHLY-PATHOGENIC VERSUS WEAKLY-PATHOGENIC NAEGLERIA FOWLERI AMEBAE.  

E-print Network

??Naegleria fowleri, a free-living ameba, is the causative agent of Primary Amebic Meningoencephalitis. Highly-pathogenic mouse-passaged amebae (Mp) and weakly-pathogenic axenically-grown (Ax) N. fowleri were examined… (more)

Vyas, Ishan

2014-01-01

339

Pathways with Friends  

NSDL National Science Digital Library

Directed by instructional cards, learners kinesthetically model cell communication by acting as components in a cell signaling pathway. Learners discover that cell communication is a multi-step process and that cells communicate via signaling pathways made of interacting components that sometimes change shape as a result of their interaction (conformational change).

Davies, Christian; Egan, Barbara; Hoelscher, Mary; Kuka, Chris; Malone, Molly; Starr, Harmony

2008-01-01

340

SUSTAINABLE TRANSPORTATION ENERGY PATHWAYS  

E-print Network

and Sustainable Transportation 249 11: Toward a Universal Low-Carbon Fuel Standard 251 Daniel Sperling and SoniaSUSTAINABLE TRANSPORTATION ENERGY PATHWAYS A Research Summary for Decision Makers Edited by Joan Ogden and Lorraine Anderson #12;SUSTAINABLE TRANSPORTATION ENERGY PATHWAYS #12;SUSTAINABLE

California at Davis, University of

341

ARTICLES  

Microsoft Academic Search

ABSTRACTThis paper considers what should be done about offers of organs for transplant that come with racist strings attached. Saving lives or improving their quality seem powerful reasons to accept the offer. Fairness, justice, and rejecting racism seem like powerful reasons against. This paper argues that conditional allocation should occur when it would provide access to organs for at least

T. M. WILKINSON

2007-01-01

342

CONSTITUTION Article I--NAME  

E-print Network

CONSTITUTION Article I--NAME The Botany Club Article II--PURPOSE The Botany Club will foster--MEMBERSHIP Membership is open to all students, faculty, and staff that have an interest in Botany. Size is unlimited. We The Botany Club will elect a President, Vice President, and Treasurer once each year during the spring

343

Do TEFL Articles Solve Problems?  

ERIC Educational Resources Information Center

Discusses the problem which English-as-a-foreign-language (EFL) teacher trainees who are nonnative English speakers have in reading articles about EFL teaching methods. As a solution to this problem, the author produced a worksheet for the students to fill in while reading the articles which followed Hoey's…

Edge, Julian

1985-01-01

344

Therapeutic targeting of STAT pathways in CNS autoimmune diseases  

PubMed Central

Signal transducers and activators of transcription (STATs) transduce extracellular signals that regulate the initiation, duration and intensity of immune responses. However, unbridled activation of STATs by pro-inflammatory cytokines or growth factors contributes to pathogenic autoimmunity. In this review, we briefly discuss STAT pathways that promote the development and expansion of T cells that mediate two CNS inflammatory diseases, multiple sclerosis (MS) and uveitis. Particular focus is on animal models of MS and uveitis and new approaches to the treatment of CNS autoimmune diseases based on therapeutic targeting of Th17 cells and STAT pathways. PMID:24058800

Egwuagu, Charles E.; Larkin, III, Joseph

2013-01-01

345

Therapeutic targeting of STAT pathways in CNS autoimmune diseases.  

PubMed

Signal transducers and activators of transcription (STATs) transduce extracellular signals that regulate the initiation, duration and intensity of immune responses. However, unbridled activation of STATs by pro-inflammatory cytokines or growth factors contributes to pathogenic autoimmunity. In this review, we briefly discuss STAT pathways that promote the development and expansion of T cells that mediate two CNS inflammatory diseases, multiple sclerosis (MS) and uveitis. Particular focus is on animal models of MS and uveitis and new approaches to the treatment of CNS autoimmune diseases based on therapeutic targeting of Th17 cells and STAT pathways. PMID:24058800

Egwuagu, Charles E; Larkin Iii, Joseph

2013-01-01

346

Metabolic Pathway Analysis: Basic Concepts and Scientific Applications in the Post-genomic Era  

Microsoft Academic Search

This article reviews the relatively short history of metabolic pathway analysis. Computer-aided algorithms for the synthesis of metabolic pathways are discussed. Important algebraic concepts used in pathway analysis, such as null space and convex cone, are explained. It is demonstrated how these concepts can be translated into meaningful metabolic concepts. For example, it is shown that the simplest vectors spanning

Christophe H. Schilling; Stefan Schuster; Bernhard O. Palsson; Reinhart Heinrich

1999-01-01

347

Pathways of fear and anxiety in dentistry: A review  

PubMed Central

The aim of this article was to analyze the theories underpinning dental fear, anxiety and phobias. To be included, articles must have been published between the years of 1949 and 2013 concerning fears and phobias within dentistry and/or psychiatry. Of 200 articles originally under review, 140 were included and reviewed by the authors.Five specific pathways relating to dental fear and anxiety were identified; Cognitive Conditioning, Informative, Visual Vicarious, Verbal Threat, and Parental. Eight currently accepted management techniques across all dental disciplines for dental fear and anxiety were identified. Further research is required to identify clinical diagnosis and treatment for fears originating from different pathways. PMID:25405187

Carter, Ava Elizabeth; Carter, Geoff; Boschen, Mark; AlShwaimi, Emad; George, Roy

2014-01-01

348

Plant-pathogen interactions and elevated CO2: morphological changes in favour of pathogens  

Microsoft Academic Search

Crop losses caused by pests and weeds have been estimated at 42% worldwide, with plant pathogens responsible for almost $10 billion worth of damage in the USA in 1994 alone. Elevated carbon dioxide (ECO2) and associated climate change have the potential to accelerate plant pathogen evolution, which may, in turn, affect virulence. Plant- pathogen interactions under increasing CO2 concentrations have

Janice Ann Lake; Ruth Nicola Wade

2009-01-01

349

OSHA's bloodborne pathogens standard: new job-safety requirements for healthcare.  

PubMed

This article outlines the OSHA requirements set forth by the new Occupational Exposure to Bloodborne Pathogens Standard. While some states administer their own occupational safety and health programs, they must adopt standards and enforce requirements that are at least as effective as federal requirements. PMID:10120123

Dohms, J A

1992-01-01

350

ER stress response mechanisms in the pathogenic yeast Candida glabrata and their roles in virulence  

PubMed Central

The maintenance of endoplasmic reticulum (ER) homeostasis is critical for numerous aspects of cell physiology. Eukaryotic cells respond to the accumulation of misfolded proteins in the ER (ER stress) by activating the unfolded protein response (UPR), an intracellular signaling pathway that adjusts the folding capacity of the ER. Recent studies of several pathogenic fungi have revealed that the UPR is important for antifungal resistance and virulence; therefore, the pathway has attracted much attention as a potential therapeutic target. While the UPR is highly conserved among eukaryotes, our group recently discovered that the pathogenic yeast Candida glabrata lacks the typical fungal UPR, but possesses alternative mechanisms to cope with ER stress. This review summarizes how C. glabrata responds to ER stress and discusses the impacts of ER quality control systems on antifungal resistance and virulence. PMID:24335436

Miyazaki, Taiga; Kohno, Shigeru

2014-01-01

351

Viroids: petite RNA pathogens with distinguished talents  

Microsoft Academic Search

Viroids are small, circular, single-stranded RNA molecules that cause several infectious plant diseases. Viroids do not encode any pathogen-specific peptides but nonetheless, the subviral pathogens replicate autonomously and spread in the plant by recruiting host proteins via functional motifs encoded in their RNA genome. During the past couple of years, considerable progress has been made towards comprehending how viroids interact

Martin Tabler; Mina Tsagris

2004-01-01

352

Design and Analysis of Pathogen Surveillance Studies  

E-print Network

1 Design and Analysis of Pathogen Surveillance Studies University of Tennessee Center for Wildlife Stratified Random Sampling Systematic Sampling All individuals within a specified location or category have Type/Condition; Gender; Age Class Biased if Not a Uniform Distribution #12;5 Detect a Pathogen

Gray, Matthew

353

Vibrio parahaemolyticus cell biology and pathogenicity determinants  

Microsoft Academic Search

Vibrio parahaemolyticus is a significant cause of gastroenteritis worldwide. Characterization of this pathogen has revealed a unique repertoire of virulence factors that allow for colonization of the human host and disease. The following describes the known pathogenicity determinants while establishing the need for continued research.

Christopher A. Broberg; Thomas J. Calder; Kim Orth

2011-01-01

354

Assessment of source water pathogen contamination.  

PubMed

During the last decade, the source to tap risk-based approach to pathogens in drinking water has been largely promoted. This paper addresses the issue of source water pathogen contamination, which is the first step of quantitative microbial risk assessment. It is focused on a selection of pathogens considered to be a major risk to human health. Source water quality is highly variable and understanding the reasons for this variability is important as it will influence the requirements for treatment, treatment efficiency and the resulting health risk associated with the finished water. A framework for source water microbial quality assessment based on catchment surveys and monitoring programmes was set and tested on ten water sources. The monitoring programmes included faecal indicators and pathogens, during both baseline and hazardous event conditions. Concentrations varied greatly within and between systems. Faecal indicators were shown to be poor surrogates for pathogen presence and concentrations. There was no recurring evidence that the pathogens correlated together and links between microbial parameters appeared to be very site specific. Such variability between systems shows the importance of running local monitoring programs for use in risk assessment. Finally, pathogen detection methods are not yet optimal due to their sensitivity and to the lack of knowledge on viability and infectivity of pathogens. A great effort needs to be made in the future to ensure better quality data as this may have large implications in the statistical risk assessment calculations. PMID:17890835

Dechesne, Magali; Soyeux, Emmanuel

2007-01-01

355

Signal perception in plant pathogen defense  

Microsoft Academic Search

Highly sensitive and specific recognition systems for microbial pathogens are essential for disease resistance in plants. Structurally diverse elicitors from various pathogens have been identified and shown to trigger plant defense mechanisms. Elicitor recognition by the plant is assumed to be mediated by receptors. Plant receptors for fungus-derived elicitors appear to reside preferentially in the plasma membrane, whereas viral and

T. Nürnberger

1999-01-01

356

Arthropods vector grapevine trunk disease pathogens.  

PubMed

ABSTRACT Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases. PMID:24624953

Moyo, P; Allsopp, E; Roets, F; Mostert, L; Halleen, F

2014-10-01

357

The evolutionary conundrum of pathogen mimicry  

Microsoft Academic Search

Evolutionary conflicts involving mimicry are found throughout nature. Diverse pathogens produce a range of 'mimics' that resemble host components in both form and function. Such mimics subvert crucial cellular processes, including the cell cycle, apoptosis, cytoskeletal dynamics and immunity. Here, we review the mounting evidence that mimicry of host processes is a highly successful strategy for pathogens. Discriminating mimics can

Harmit S. Malik; Nels C. Elde

2009-01-01

358

WORKSHOP ON EMERGING PATHOGENS IN RESIDUALS  

EPA Science Inventory

There is considerable concern among regulatory authorities, the agricultural community and the public as a whole about the scientific community's ability to measure the level(s) of known pathogens in residuals. There is also concern for whether we are aware of all the pathogens t...

359

An extracellular bacterial pathogen modulates host metabolism to regulate its own sensing and proliferation.  

PubMed

Successful infection depends on the ability of the pathogen to gain nutrients from the host. The extracellular pathogenic bacterium group A Streptococcus (GAS) causes a vast array of human diseases. By using the quorum-sensing sil system as a reporter, we found that, during adherence to host cells, GAS delivers streptolysin toxins, creating endoplasmic reticulum stress. This, in turn, increases asparagine (ASN) synthetase expression and the production of ASN. The released ASN is sensed by the bacteria, altering the expression of ?17% of GAS genes of which about one-third are dependent on the two-component system TrxSR. The expression of the streptolysin toxins is strongly upregulated, whereas genes linked to proliferation are downregulated in ASN absence. Asparaginase, a widely used chemotherapeutic agent, arrests GAS growth in human blood and blocks GAS proliferation in a mouse model of human bacteremia. These results delineate a pathogenic pathway and propose a therapeutic strategy against GAS infections. PMID:24439371

Baruch, Moshe; Belotserkovsky, Ilia; Hertzog, Baruch B; Ravins, Miriam; Dov, Eran; McIver, Kevin S; Le Breton, Yoann S; Zhou, Yiting; Cheng, Catherine Youting; Chen, Catherine Youting; Hanski, Emanuel

2014-01-16

360

Very long chain fatty acid and lipid signaling in the response of plants to pathogens.  

PubMed

Recent findings indicate that lipid signaling is essential for plant resistance to pathogens. Besides oxylipins and unsaturated fatty acids known to play important signaling functions during plant-pathogen interactions, the very long chain fatty acid (VLCFA) biosynthesis pathway has been recently associated to plant defense through different aspects. VLCFAs are indeed required for the biosynthesis of the plant cuticle and the generation of sphingolipids. Elucidation of the roles of these lipids in biotic stress responses is the result of the use of genetic approaches together with the identification of the genes/proteins involved in their biosynthesis. This review focuses on recent observations which revealed the complex function of the cuticle and cuticle-derived signals, and the key role of sphingolipids as bioactive molecules involved in signal transduction and cell death regulation during plant-pathogen interactions. PMID:19649180

Raffaele, Sylvain; Leger, Amandine; Roby, Dominique

2009-02-01

361

PLEASE SCROLL DOWN FOR ARTICLE This article was downloaded by  

E-print Network

briefly introduce the articles, which address the areas of child sexual abuse, traumatic loss, complex into intervention approaches. Keywords child trauma, adolescent trauma, ecology, culture, child sexual abuse of Child & Adolescent Trauma Publication details, including instructions for authors and subscription

Huang, Jianyu

362

Modulation of Intestinal TLR4-Inflammatory Signaling Pathways by Probiotic Microorganisms: Lessons Learned from Lactobacillus jensenii TL2937  

PubMed Central

The intestinal mucosa plays a critical role in the host’s interactions with innocuous commensal microbiota and invading pathogenic microorganisms. Intestinal epithelial cells (IECs) and gut associated immune cells recognize the bacterial components via pattern-recognition receptors (PRRs) and are responsible for maintaining tolerance to the large communities of resident luminal bacteria while being also able to mount inflammatory responses against pathogens. Toll-like receptors (TLRs) are a major class of PRRs that are present on IECs and immune cells which are involved in the induction of both tolerance and inflammation. A growing body of experimental and clinical evidence supports the therapeutic and preventive application of probiotics for several gastrointestinal inflammatory disorders in which?TLRs exert a significant role. This review aims to summarize the current knowledge of the beneficial effects of probiotic microorganisms with the capacity to modulate the immune system (immunobiotics) in the regulation of intestinal inflammation in pigs, which are very important as both livestock and human model. Especially we discuss the role of?TLRs, their signaling pathways, and their negative regulators in both the inflammatory intestinal injury and the beneficial effects of immunobiotics in general, and Lactobacillus jensenii?TL2937 in particular. This review article emphasizes the cellular and molecular interactions of immunobiotics with IECs and immune cells through?TLRs and their application for improving animal and human health. PMID:24459463

Villena, Julio; Kitazawa, Haruki

2014-01-01

363

Modulation of Intestinal TLR4-Inflammatory Signaling Pathways by Probiotic Microorganisms: Lessons Learned from Lactobacillus jensenii TL2937.  

PubMed

The intestinal mucosa plays a critical role in the host's interactions with innocuous commensal microbiota and invading pathogenic microorganisms. Intestinal epithelial cells (IECs) and gut associated immune cells recognize the bacterial components via pattern-recognition receptors (PRRs) and are responsible for maintaining tolerance to the large communities of resident luminal bacteria while being also able to mount inflammatory responses against pathogens. Toll-like receptors (TLRs) are a major class of PRRs that are present on IECs and immune cells which are involved in the induction of both tolerance and inflammation. A growing body of experimental and clinical evidence supports the therapeutic and preventive application of probiotics for several gastrointestinal inflammatory disorders in which?TLRs exert a significant role. This review aims to summarize the current knowledge of the beneficial effects of probiotic microorganisms with the capacity to modulate the immune system (immunobiotics) in the regulation of intestinal inflammation in pigs, which are very important as both livestock and human model. Especially we discuss the role of?TLRs, their signaling pathways, and their negative regulators in both the inflammatory intestinal injury and the beneficial effects of immunobiotics in general, and Lactobacillus jensenii?TL2937 in particular. This review article emphasizes the cellular and molecular interactions of immunobiotics with IECs and immune cells through?TLRs and their application for improving animal and human health. PMID:24459463

Villena, Julio; Kitazawa, Haruki

2014-01-14

364

Probabilistic Quality Assessment Based on Article’s Revision History  

Microsoft Academic Search

\\u000a The collaborative efforts of users in social media services such as Wikipedia have led to an explosion in user-generated content\\u000a and how to automatically tag the quality of the content is an eminent concern now. Actually each article is usually undergoing\\u000a a series of revision phases and the articles of different quality classes exhibit specific revision cycle patterns. We propose

Jingyu Han; Chuandong Wang; Dawei Jiang

365

The Role of the Jasmonate Response in Plant Susceptibility to Diverse Pathogens with a Range of Lifestyles  

Microsoft Academic Search

Plants defend themselves against attack from insects and pathogens with various resistance strategies. The jasmonate and salicylate signaling pathways are two induced responses that protect plants against these attackers. Knowledge of the range of organisms that are affected by each response is important for understanding how plants coordinate their defenses against multiple attackers and the generality of effect of different

Jennifer S. Thaler; Blythe Owen; Verna J. Higgins

2004-01-01

366

PINT: Pathways INtegration Tool.  

PubMed

New pathway databases generally display pathways by retrieving information from a database dynamically. Some of them even provide their pathways in SBML or other exchangeable formats. Integrating these models is a challenging work, because these models were not built in the same way. Pathways integration Tool (PINT) may integrate the standard SBML files. Since these files may be obtained from different sources, any inconsistency in component names can be revised by using an annotation editor upon uploading a pathway model. This integration function greatly simplifies the building of a complex model from small models. To get new users started, about 190 curated public models of human pathways were collected by PINT. Relevant models can be selected and sent to the workbench by using a user-friendly query interface, which also accepts a gene list derived from high-throughput experiments. The models on the workbench, from either a public or a private source, can be integrated and painted. The painting function is useful for highlighting important genes or even their expression level on a merged pathway diagram, so that the biological significance can be revealed. This tool is freely available at http://csb2.ym.edu.tw/pint/. PMID:20538652

Wang, Y-T; Huang, Y-H; Chen, Y-C; Hsu, C-L; Yang, U-C

2010-07-01

367

Phytophthora parasitica: a model oomycete plant pathogen  

PubMed Central

Oomycetes are eukaryotic microorganisms morphologically similar to but phylogenetically distant from true fungi. Most species in the genus Phytophthora of oomycetes are devastating plant pathogens, causing damages to both agricultural production and natural ecosystems. Tremendous progress has been achieved in recent years in diversity, evolution and lifestyles of oomycete plant pathogens, as well as on the understanding of genetic and molecular basis of oomycete-plant interactions. Phytophthora parasitica is a soilborne pathogen with a wide range of host plants and represents most species in the genus Phytophthora. In this review, we present some recent progress of P. parasitica research by highlighting important features that make it emerge as a model species of oomycete pathogens. The emerged model pathogen will facilitate improved understanding of oomycete biology and pathology that are crucial to the development of novel disease-control strategies and improved disease-control measures. PMID:24999436

Meng, Yuling; Zhang, Qiang; Ding, Wei; Shan, Weixing

2014-01-01

368

Botrytis cinerea Manipulates the Antagonistic Effects between Immune Pathways to Promote Disease Development in Tomato[C][W][OA  

PubMed Central

Plants have evolved sophisticated mechanisms to sense and respond to pathogen attacks. Resistance against necrotrophic pathogens generally requires the activation of the jasmonic acid (JA) signaling pathway, whereas the salicylic acid (SA) signaling pathway is mainly activated against biotrophic pathogens. SA can antagonize JA signaling and vice versa. Here, we report that the necrotrophic pathogen Botrytis cinerea exploits this antagonism as a strategy to cause disease development. We show that B. cinerea produces an exopolysaccharide, which acts as an elicitor of the SA pathway. In turn, the SA pathway antagonizes the JA signaling pathway, thereby allowing the fungus to develop its disease in tomato (Solanum lycopersicum). SA-promoted disease development occurs through Nonexpressed Pathogen Related1. We also show that the JA signaling pathway required for tomato resistance against B. cinerea is mediated by the systemin elicitor. These data highlight a new strategy used by B. cinerea to overcome the plant’s defense system and to spread within the host. PMID:21665999

El Oirdi, Mohamed; El Rahman, Taha Abd; Rigano, Luciano; El Hadrami, Abdelbasset; Rodriguez, María Cecilia; Daayf, Fouad; Vojnov, Adrian; Bouarab, Kamal

2011-01-01

369

Engineering complex metabolic pathways in plants.  

PubMed

Metabolic engineering can be used to modulate endogenous metabolic pathways in plants or introduce new metabolic capabilities in order to increase the production of a desirable compound or reduce the accumulation of an undesirable one. In practice, there are several major challenges that need to be overcome, such as gaining enough knowledge about the endogenous pathways to understand the best intervention points, identifying and sourcing the most suitable metabolic genes, expressing those genes in such a way as to produce a functional enzyme in a heterologous background, and, finally, achieving the accumulation of target compounds without harming the host plant. This article discusses the strategies that have been developed to engineer complex metabolic pathways in plants, focusing on recent technological developments that allow the most significant bottlenecks to be overcome. PMID:24579989

Farré, Gemma; Blancquaert, Dieter; Capell, Teresa; Van Der Straeten, Dominique; Christou, Paul; Zhu, Changfu

2014-01-01

370

Capsicum annuum WRKY protein CaWRKY1 is a negative regulator of pathogen defense  

Microsoft Academic Search

Summary • Plants respond to pathogens by regulating a network of signaling pathways that fine-tune transcriptional activation of defense-related genes.  The aim of this study was to determine the role of Capsicum annuum WRKY zinc finger-domain transcription factor 1 (CaWRKY1) in defense. In previous studies, CaWRKY1 was found to be rapidly induced in C. annuum (chili pepper) leaves by

Sang-Keun Oh; Kwang-Hyun Baek; Jeong Mee Park; So Young Yi; Seung Hun Yu; Sophien Kamoun; Doil Choi

2007-01-01

371

Melanin as a virulence factor of Paracoccidioides brasiliensis and other dimorphic pathogenic fungi: a minireview  

Microsoft Academic Search

Melanin pigments are substances produced by a broad variety of pathogenic microorganisms, including bacteria, fungi, and helminths.\\u000a Microbes predominantly produce melanin pigment via tyrosinases, laccases, catecholases, and the polyketide synthase pathway.\\u000a In fungi, melanin is deposited in the cell wall and cytoplasm, and melanin particles (“ghosts”) can be isolated from these\\u000a fungi that have the same size and shape of

Carlos P. Taborda; Marcelo B. da Silva; Joshua D. Nosanchuk; Luiz R. Travassos

2008-01-01

372

Algae as Reservoirs for Coral Pathogens  

PubMed Central

Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS) in the Indo-Pacific and Yellow Band Disease (YBD) in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively). Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is most likely a prerequisite to potential transmission of these pathogens. PMID:23936086

Sweet, Michael J.; Bythell, John C.; Nugues, Maggy M.

2013-01-01

373

Microbiota-liberated host sugars facilitate post-antibiotic expansion of enteric pathogens  

PubMed Central

The human intestine, colonized by a dense community of resident microbes, is a frequent target of bacterial pathogens. Undisturbed, this intestinal microbiota provides protection from bacterial infections. Conversely, disruption of the microbiota with oral antibiotics often precedes the emergence of several enteric pathogens1–4. How pathogens capitalize upon the failure of microbiota-afforded protection is largely unknown. Here we show that two antibiotic-associated pathogens, Salmonella typhimurium and Clostridium difficile, employ a common strategy of catabolizing microbiota-liberated mucosal carbohydrates during their expansion within the gut. S. typhimurium accesses fucose and sialic acid within the lumen of the gut in a microbiota-dependent manner, and genetic ablation of the respective catabolic pathways reduces its competitiveness in vivo. Similarly, C. difficile expansion is aided by microbiota-induced elevation of sialic acid levels in vivo. Colonization of gnotobiotic mice with a sialidase-deficient mutant of the model gut symbiont Bacteroides thetaiotaomicron (Bt) reduces free sialic acid levels resulting in a downregulation of C. difficile’s sialic acid catabolic pathway and impaired expansion. These effects are reversed by exogenous dietary administration of free sialic acid. Furthermore, antibiotic treatment of conventional mice induces a spike in free sialic acid and mutants of both Salmonella and C. difficile that are unable to catabolize sialic acid exhibit impaired expansion. These data show that antibiotic-induced disruption of the resident microbiota and subsequent alteration in mucosal carbohydrate availability are exploited by these two distantly related enteric pathogens in a similar manner. This insight suggests new possibilities for therapeutic approaches for preventing diseases caused by antibiotic-associated pathogens. PMID:23995682

Ng, Katharine M.; Ferreyra, Jessica A.; Higginbottom, Steven K.; Lynch, Jonathan B.; Kashyap, Purna C.; Gopinath, Smita; Naidu, Natasha; Choudhury, Biswa; Weimer, Bart C.; Monack, Denise M.; Sonnenburg, Justin L.

2013-01-01

374

Identifying proteins controlling key disease signaling pathways  

PubMed Central

Motivation: Several types of studies, including genome-wide association studies and RNA interference screens, strive to link genes to diseases. Although these approaches have had some success, genetic variants are often only present in a small subset of the population, and screens are noisy with low overlap between experiments in different labs. Neither provides a mechanistic model explaining how identified genes impact the disease of interest or the dynamics of the pathways those genes regulate. Such mechanistic models could be used to accurately predict downstream effects of knocking down pathway members and allow comprehensive exploration of the effects of targeting pairs or higher-order combinations of genes. Results: We developed methods to model the activation of signaling and dynamic regulatory networks involved in disease progression. Our model, SDREM, integrates static and time series data to link proteins and the pathways they regulate in these networks. SDREM uses prior information about proteins’ likelihood of involvement in a disease (e.g. from screens) to improve the quality of the predicted signaling pathways. We used our algorithms to study the human immune response to H1N1 influenza infection. The resulting networks correctly identified many of the known pathways and transcriptional regulators of this disease. Furthermore, they accurately predict RNA interference effects and can be used to infer genetic interactions, greatly improving over other methods suggested for this task. Applying our method to the more pathogenic H5N1 influenza allowed us to identify several strain-specific targets of this infection. Availability: SDREM is available from http://sb.cs.cmu.edu/sdrem Contact: zivbj@cs.cmu.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23812988

Gitter, Anthony; Bar-Joseph, Ziv

2013-01-01

375

Seaweed Polysaccharides and Derived Oligosaccharides Stimulate Defense Responses and Protection Against Pathogens in Plants  

PubMed Central

Plants interact with the environment by sensing “non-self” molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants. PMID:22363237

Vera, Jeannette; Castro, Jorge; Gonzalez, Alberto; Moenne, Alejandra

2011-01-01

376

DNA Mutations Mediate Microevolution between Host-Adapted Forms of the Pathogenic Fungus Cryptococcus neoformans  

PubMed Central

The disease cryptococcosis, caused by the fungus Cryptococcus neoformans, is acquired directly from environmental exposure rather than transmitted person-to-person. One explanation for the pathogenicity of this species is that interactions with environmental predators select for virulence. However, co-incubation of C. neoformans with amoeba can cause a “switch” from the normal yeast morphology to a pseudohyphal form, enabling fungi to survive exposure to amoeba, yet conversely reducing virulence in mammalian models of cryptococcosis. Like other human pathogenic fungi, C. neoformans is capable of microevolutionary changes that influence the biology of the organism and outcome of the host-pathogen interaction. A yeast-pseudohyphal phenotypic switch also happens under in vitro conditions. Here, we demonstrate that this morphological switch, rather than being under epigenetic control, is controlled by DNA mutation since all pseudohyphal strains bear mutations within genes encoding components of the RAM pathway. High rates of isolation of pseudohyphal strains can be explained by the physical size of RAM pathway genes and a hypermutator phenotype of the strain used in phenotypic switching studies. Reversion to wild type yeast morphology in vitro or within a mammalian host can occur through different mechanisms, with one being counter-acting mutations. Infection of mice with RAM mutants reveals several outcomes: clearance of the infection, asymptomatic maintenance of the strains, or reversion to wild type forms and progression of disease. These findings demonstrate a key role of mutation events in microevolution to modulate the ability of a fungal pathogen to cause disease. PMID:23055925

Magditch, Denise A.; Liu, Tong-Bao; Xue, Chaoyang; Idnurm, Alexander

2012-01-01

377

Seaweed polysaccharides and derived oligosaccharides stimulate defense responses and protection against pathogens in plants.  

PubMed

Plants interact with the environment by sensing "non-self" molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants. PMID:22363237

Vera, Jeannette; Castro, Jorge; Gonzalez, Alberto; Moenne, Alejandra

2011-12-01

378

A Nod to disease vectors: mitigation of pathogen sensing by arthropod saliva  

PubMed Central

Arthropod saliva possesses anti-hemostatic, anesthetic, and anti-inflammatory properties that facilitate feeding and, inadvertently, dissemination of pathogens. Vector-borne diseases caused by these pathogens affect millions of people each year. Many studies address the impact of arthropod salivary proteins on various immunological components. However, whether and how arthropod saliva counters Nod-like (NLR) sensing remains elusive. NLRs are innate immune pattern recognition molecules involved in detecting microbial molecules and danger signals. Nod1/2 signaling results in activation of the nuclear factor-?B and the mitogen-activated protein kinase pathways. Caspase-1 NLRs regulate the inflammasome~– a protein scaffold that governs the maturation of interleukin (IL)-1? and IL-18. Recently, several vector-borne pathogens have been shown to induce NLR activation in immune cells. Here, we provide a brief overview of NLR signaling and discuss clinically relevant vector-borne pathogens recognized by NLR pathways. We also elaborate on possible anti-inflammatory effects of arthropod saliva on NLR signaling and microbial pathogenesis for the purpose of exchanging research perspectives. PMID:24155744

Sakhon, Olivia S.; Severo, Maiara S.; Kotsyfakis, Michail; Pedra, Joao H. F.

2013-01-01

379

Caenorhabditis elegans pathways that surveil and defend mitochondria  

PubMed Central

Mitochondrial function is challenged by toxic byproducts of metabolism as well as by pathogen attack1,2. Caenorhabditis elegans normally responds to mitochondrial dysfunction with activation of mitochondrial repair, drug detoxification, and pathogen-response pathways1–7. From a genome-wide RNAi screen, we identified 45 C. elegans genes that are required to upregulate detoxification, pathogen-response, and mitochondrial repair pathways after inhibition of mitochondrial function by drugs or genetic disruption. Animals defective in ceramide biosynthesis are deficient in mitochondrial surveillance, and addition of particular ceramides can rescue the surveillance defects. Ceramide can also rescue the mitochondrial surveillance defects of other gene inactivations, mapping these gene activities upstream of ceramide. Inhibition of the mevalonate pathway, either by RNAi or statin drugs also disrupts mitochondrial surveillance. Growth of C. elegans with a significant fraction of bacterial species from their natural habitat causes mitochondrial dysfunction. Other bacterial species inhibit C. elegans defense responses to a mitochondrial toxin, revealing bacterial countermeasures to animal defense. PMID:24695221

Liu, Ying; Samuel, Buck S.; Breen, Peter C.; Ruvkun, Gary

2014-01-01

380

Evolution of Pathogen Specialisation in a Host Metapopulation: Joint Effects of Host and Pathogen Dispersal  

PubMed Central

Metapopulation processes are important determinants of epidemiological and evolutionary dynamics in host-pathogen systems, and are therefore central to explaining observed patterns of disease or genetic diversity. In particular, the spatial scale of interactions between pathogens and their hosts is of primary importance because migration rates of one species can affect both spatial and temporal heterogeneity of selection on the other. In this study we developed a stochastic and discrete time simulation model to specifically examine the joint effects of host and pathogen dispersal on the evolution of pathogen specialisation in a spatially explicit metapopulation. We consider a plant-pathogen system in which the host metapopulation is composed of two plant genotypes. The pathogen is dispersed by air-borne spores on the host metapopulation. The pathogen population is characterised by a single life-history trait under selection, the infection efficacy. We found that restricted host dispersal can lead to high amount of pathogen diversity and that the extent of pathogen specialisation varied according to the spatial scale of host-pathogen dispersal. We also discuss the role of population asynchrony in determining pathogen evolutionary outcomes. PMID:24853675

Papaix, Julien; Burdon, Jeremy J.; Lannou, Christian; Thrall, Peter H.

2014-01-01

381

New and emerging yeast pathogens.  

PubMed Central

The most common yeast species that act as agents of human disease are Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. The incidence of infections by other yeasts has increased during the past decade. The most evident emerging pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. Organisms once considered environmental contaminants or only industrially important, such as Candida utilis and Candida lipolytica, have now been implicated as agents of fungemia, onychomycosis, and systemic disease. The unusual yeasts primarily infect immunocompromised patients, newborns, and the elderly. The role of central venous catheter removal and antifungal therapy in patient management is controversial. The antibiograms of the unusual yeasts range from resistant to the most recent azoles and amphotericin B to highly susceptible to all antifungal agents. Current routine methods for yeast identification may be insufficient to identify the unusual yeasts within 2 days after isolation. The recognition of unusual yeasts as agents of sometimes life-threatening infection and their unpredictable antifungal susceptibilities increase the burden on the clinical mycology laboratory to pursue complete species identification and MIC determinations. Given the current and evolving medical practices for management of seriously ill patients, further evaluations of the clinically important data about these yeasts are needed. PMID:8665465

Hazen, K C

1995-01-01

382

Review article Molecular characterization, spread  

E-print Network

Review article Molecular characterization, spread and evolution of multidrug resistance developments in the characterization of S. enterica Typhimurium DT104, its chromosomal antibiotic resistance (Received 23 November 2000; accepted 6 February 2001) Abstract ­ Multidrug-resistant Salmonella enterica

Boyer, Edmond

383

AgricultureandEnvironment Review article  

E-print Network

AgricultureandEnvironment Review article The taxonomy of Pseudomonas fluorescens and Pseudomonas studies are devoted to the ecology of Pseudomonas fluorescens and Pseudomonas putida. Indeed, bacteria. fluorescens and P. putida. taxonomy / Pseudomonas fluorescens / P. putida / phenotypic characterization

Paris-Sud XI, Université de

384

Article having good wear resistance  

US Patent & Trademark Office Database

An article having good wear resistance includes a first component including a boride coating and a second component including a cobalt-chromium-molybdenum coating that is in sliding contact with the boride coating of the first component.

2014-09-16

385

Constitution1 ARTICLE I3  

E-print Network

, by unanimous vote, by secret ballot, confer an honorary32 membership of the Indiana Memorial Union to any.34 35 ARTICLE III36 Section 1. GOVERNMENT37 The government of the Indiana Memorial Union shall

Indiana University

386

Original article Chlorophyll fluorescence characteristics,  

E-print Network

Original article Chlorophyll fluorescence characteristics, performance and survival of freshly was eval- uated in situ using determinations of chlorophyll fluorescence and plant water status. Pre growth potential (RGP), root electrolyte leakage (REL), shoot water content and chlorophyll fluorescence

Boyer, Edmond

387

ORIGINAL ARTICLE Ambient Air Pollution  

E-print Network

ORIGINAL ARTICLE Ambient Air Pollution and Cardiovascular Emergency Department Visits Kristi Busico ambient air pollutants and cardiovascular disease (CVD), the roles of the physicochemical components the relation between ambient air pollution and cardiovascular conditions using ambient air quality data

Mulholland, James A.

388

Molecular Pathways: Targeted ?-Particle Radiation Therapy  

PubMed Central

An ?-particle, a 4He nucleus, is exquisitely cytotoxic, and indifferent to many limitations associated with conventional chemo- and radiotherapy. The exquisite cytotoxicity of ? radiation, the result of its high mean energy deposition (high linear energy transfer, LET) and limited range in tissue, provides for a highly controlled therapeutic modality that can be targeted to selected malignant cells (targeted ?-therapy (TAT)) with minimal normal tissue effects. There is a burgeoning interest in the development of TAT that is buoyed by the increasing number of ongoing clinical trials worldwide. The short path length renders ?-emitters suitable for treatment and management of minimal disease such as micrometastases or residual tumor after surgical debulking, hematological cancers, infections, and compartmental cancers such as ovarian cancer or neoplastic meningitis. Yet, despite decades of study of high-LET radiation, the mechanistic pathways of the effects of this modality remain not well defined. The modality is effectively presumed to follow a simple therapeutic mechanism centered on catastrophic double strand (ds) DNA breaks without full examination of the actual molecular pathways and targets that are activated that directly impact cell survival or death. This Molecular Pathways article provides an overview of the mechanisms and pathways that are involved in the response to and repair of TAT induced DNA damage as currently understood. Finally, this article highlights the current state of clinical translation of TAT as well as other high-LET radionuclide radiation therapy using ?-emitters such as 225Ac, 211At, 213Bi, 212Pb and 223Ra. PMID:23230321

Baidoo, Kwamena E.; Yong, Kwon; Brechbiel, Martin W.

2012-01-01

389

Neural Pathways of Stress Integration  

PubMed Central

Stress is a critical component in the development, maintenance, and reinstatement of addictive behaviors, including alcohol use. This article reviews the current state of the literature on the brain’s stress response, focusing on the hypothalamic–pituitary–adrenal (HPA) axis. Stress responses can occur as a reaction to physiological (or systemic) challenge or threat; signals from multiple parts of the brain send input to the paraventricular nucleus (PVN) within the hypothalamus. However, responses also occur to stressors that predict potential threats (psychogenic stressors). Psychogenic responses are mediated by a series of nerve cell connections in the limbic–PVN pathway, with amygdalar and infralimbic cortex circuits signaling excitation and prelimbic cortex and hippocampal neurons signaling stress inhibition. Limbic–PVN connections are relayed by predominantly GABAergic neurons in regions such as the bed nucleus of the stria terminalis and preoptic area. Chronic stress affects the structure and function of limbic stress circuitry and results in enhanced PVN excitability, although the exact mechanism is unknown. Of importance, acute and chronic alcohol exposure are known to affect both systemic and psychogenic stress pathways and may be linked to stress dysregulation by precipitating chronic stress–like changes in amygdalar and prefrontal components of the limbic stress control network. PMID:23584110

Herman, James P.

2012-01-01

390

Impairment of p38 MAPK-mediated cytosolic phospholipase A2 activation in the kidneys is associated with pathogenicity of Candida albicans  

PubMed Central

In studying the mechanisms underlying the susceptibility of the kidney to candidal infection, we previously reported that the reduced production of cytokines [i.e. tumour necrosis factor-? (TNF-?)] via platelet-activating factor (PAF)-induced activation of nuclear factor-?B (NF-?B) renders the organ susceptible to the fungal burden. In this study, we investigated the possibility that pathogenic Candida albicans may evade clearance and perhaps even multiply by inhibiting elements in the signalling pathway that lead to the production of TNF-?. The fungal burden of pathogenic C. albicans in the kidneys was 104?105-fold higher than that of a non-pathogenic strain. PAF-induced early activation of NF-?B and TNF-? mRNA expression were both observed in the kidneys of mice infected with non-pathogenic strains of C. albicans, but not in mice infected with pathogenic strains. Impairment of PAF-mediated early NF-?B activation following infection with pathogenic C. albicans was associated with the prevention of activation of the enzyme cytosolic phospholipase A2 (cPLA2) as well as the upstream pathway of cPLA2, p38 mitogen-activated protein kinase. Collectively, these findings indicate that C. albicans exerts its pathogenicity through impairing the production of anticandidal cytokines by preventing cPLA2 activity. This novel mechanism provides insight into understanding pathogenic C. albicans and perhaps identifies a target for its treatment. PMID:17054728

Choi, Jung-Hwa; Choi, Eun Kyoung; Park, Sung Jun; Ko, Hyun-Mi; Kim, Kyoung-Jin; Han, Su-Ji; Choi, Il-Whan; Im, Suhn-Young

2007-01-01

391

Updating the Wnt pathways.  

PubMed

In the three decades since the discovery of the Wnt1 proto-oncogene in virus-induced mouse mammary tumours, our understanding of the signalling pathways that are regulated by the Wnt proteins has progressively expanded. Wnts are involved in an complex signalling network that governs multiple biological processes and cross-talk with multiple additional signalling cascades, including the Notch, FGF (fibroblast growth factor), SHH (Sonic hedgehog), EGF (epidermal growth factor) and Hippo pathways. The Wnt signalling pathway also illustrates the link between abnormal regulation of the developmental processes and disease manifestation. Here we provide an overview of Wnt-regulated signalling cascades and highlight recent advances. We focus on new findings regarding the dedicated Wnt production and secretion pathway with potential therapeutic targets that might be beneficial for patients with Wnt-related diseases. PMID:25208913

Yu, Jia; Virshup, David M

2014-01-01

392

Updating the Wnt pathways  

PubMed Central

In the three decades since the discovery of the Wnt1 proto-oncogene in virus-induced mouse mammary tumours, our understanding of the signalling pathways that are regulated by the Wnt proteins has progressively expanded. Wnts are involved in an complex signalling network that governs multiple biological processes and cross-talk with multiple additional signalling cascades, including the Notch, FGF (fibroblast growth factor), SHH (Sonic hedgehog), EGF (epidermal growth factor) and Hippo pathways. The Wnt signalling pathway also illustrates the link between abnormal regulation of the developmental processes and disease manifestation. Here we provide an overview of Wnt-regulated signalling cascades and highlight recent advances. We focus on new findings regarding the dedicated Wnt production and secretion pathway with potential therapeutic targets that might be beneficial for patients with Wnt-related diseases. PMID:25208913

Yu, Jia; Virshup, David M.

2014-01-01

393

Pathway Commons, a web resource for biological pathway data.  

PubMed

Pathway Commons (http://www.pathwaycommons.org) is a collection of publicly available pathway data from multiple organisms. Pathway Commons provides a web-based interface that enables biologists to browse and search a comprehensive collection of pathways from multiple sources represented in a common language, a download site that provides integrated bulk sets of pathway information in standard or convenient formats and a web service that software developers can use to conveniently query and access all data. Database providers can share their pathway data via a common repository. Pathways include biochemical reactions, complex assembly, transport and catalysis events and physical interactions involving proteins, DNA, RNA, small molecules and complexes. Pathway Commons aims to collect and integrate all public pathway data available in standard formats. Pathway Commons currently contains data from nine databases with over 1400 pathways and 687,000 interactions and will be continually expanded and updated. PMID:21071392

Cerami, Ethan G; Gross, Benjamin E; Demir, Emek; Rodchenkov, Igor; Babur, Ozgün; Anwar, Nadia; Schultz, Nikolaus; Bader, Gary D; Sander, Chris

2011-01-01

394

Analysis of proline reduction in the nosocomial pathogen Clostridium difficile.  

PubMed

Clostridium difficile, a proteolytic strict anaerobe, has emerged as a clinically significant nosocomial pathogen in recent years. Pathogenesis is due to the production of lethal toxins, A and B, members of the large clostridial cytotoxin family. Although it has been established that alterations in the amino acid content of the growth medium affect toxin production, the molecular mechanism for this observed effect is not yet known. Since there is a paucity of information on the amino acid fermentation pathways used by this pathogen, we investigated whether Stickland reactions might be at the heart of its bioenergetic pathways. Growth of C. difficile on Stickland pairs yielded large increases in cell density in a limiting basal medium, demonstrating that these reactions are tied to ATP production. Selenium supplementation was required for this increase in cell yield. Analysis of genome sequence data reveals genes encoding the protein components of two key selenoenzyme reductases, glycine reductase and d-proline reductase (PR). These selenoenzymes were expressed upon the addition of the corresponding Stickland acceptor (glycine, proline, or hydroxyproline). Purification of the selenoenzyme d-proline reductase revealed a mixed complex of PrdA and PrdB (SeCys-containing) proteins. PR utilized only d-proline but not l-hydroxyproline, even in the presence of an expressed and purified proline racemase. PR was found to be independent of divalent cations, and zinc was a potent inhibitor of PR. These results show that Stickland reactions are key to the growth of C. difficile and that the mechanism of PR may differ significantly from that of previously studied PR from nonpathogenic species. PMID:17041035

Jackson, Sarah; Calos, Mary; Myers, Andrew; Self, William T

2006-12-01

395

Analysis of Proline Reduction in the Nosocomial Pathogen Clostridium difficile?  

PubMed Central

Clostridium difficile, a proteolytic strict anaerobe, has emerged as a clinically significant nosocomial pathogen in recent years. Pathogenesis is due to the production of lethal toxins, A and B, members of the large clostridial cytotoxin family. Although it has been established that alterations in the amino acid content of the growth medium affect toxin production, the molecular mechanism for this observed effect is not yet known. Since there is a paucity of information on the amino acid fermentation pathways used by this pathogen, we investigated whether Stickland reactions might be at the heart of its bioenergetic pathways. Growth of C. difficile on Stickland pairs yielded large increases in cell density in a limiting basal medium, demonstrating that these reactions are tied to ATP production. Selenium supplementation was required for this increase in cell yield. Analysis of genome sequence data reveals genes encoding the protein components of two key selenoenzyme reductases, glycine reductase and d-proline reductase (PR). These selenoenzymes were expressed upon the addition of the corresponding Stickland acceptor (glycine, proline, or hydroxyproline). Purification of the selenoenzyme d-proline reductase revealed a mixed complex of PrdA and PrdB (SeCys-containing) proteins. PR utilized only d-proline but not l-hydroxyproline, even in the presence of an expressed and purified proline racemase. PR was found to be independent of divalent cations, and zinc was a potent inhibitor of PR. These results show that Stickland reactions are key to the growth of C. difficile and that the mechanism of PR may differ significantly from that of previously studied PR from nonpathogenic species. PMID:17041035

Jackson, Sarah; Calos, Mary; Myers, Andrew; Self, William T.

2006-01-01

396

Probing Pathways Periodically  

NSDL National Science Digital Library

Signal transduction pathways are used by cells to process and transmit information about their external surroundings. These systems are dynamic, interconnected molecular networks. Therefore, full characterization of their behavior requires a systems-level analysis. Investigations with temporally oscillating input signals probed the dynamic properties of the high-osmolarity glycerol (HOG) pathway of the budding yeast Saccharomyces cerevisiae. These studies shed light on how the network functions as a whole to respond to changing environmental conditions.

Timothy C. Elston (Chapel Hill;University of North Carolina REV)

2008-10-21

397

Intestinal barrier: Molecular pathways and modifiers  

PubMed Central

The gastrointestinal tract is frequently challenged by pathogens/antigens contained in food and water and the intestinal epithelium must be capable of rapid regeneration in the event of tissue damage. Disruption of the intestinal barrier leads to a number of immune-mediated diseases, including inflammatory bowel disease, food allergy, and celiac disease. The intestinal mucosa is composed of different types of epithelial cells in specific barrier functions. Epithelial cells control surface-associated bacterial populations without disrupting the intestinal microflora that is crucial for host health. They are also capable of modulating mucosal immune system, and are thus essential in maintaining homeostasis in the gut. Thus, the regulation of intestinal epithelial homeostasis is crucial for the maintenance of the structure of the mucosa and the defensive barrier functions. Recent studies have demonstrated that multiple molecular pathways are involved in the regulation of intestinal epithelial cell polarity. These include the Wnt, Notch, Hippo, transforming growth factor-? (TGF-?)/bone morphogenetic protein (BMP) and Hedgehog pathways, most of which were identified in lower organisms where they play important roles during embryogenesis. These pathways are also used in adult organisms to regulate multiple self-renewing organs. Understanding the interactions between these molecular mechanisms and intestinal barrier function will therefore provide important insight into the pathogenesis of intestinal-based immune-mediated diseases. PMID:24244877

Jeon, Min Kyung; Klaus, Christina; Kaemmerer, Elke; Gassler, Nikolaus

2013-01-01

398

Competition for zinc binding in the host-pathogen interaction.  

PubMed

Due to its favorable chemical properties, zinc is used as a structural or catalytic cofactor in a very large number of proteins. Despite the apparent abundance of this metal in all cell types, the intracellular pool of loosely bound zinc ions available for biological exchanges is in the picomolar range and nearly all zinc is tightly bound to proteins. In addition, to limit bacterial growth, some zinc-sequestering proteins are produced by eukaryotic hosts in response to infections. Therefore, to grow and multiply in the infected host, bacterial pathogens must produce high affinity zinc importers, such as the ZnuABC transporter which is present in most Gram-negative bacteria. Studies carried in different bacterial species have established that disruption of ZnuABC is usually associated with a remarkable loss of pathogenicity. The critical involvement of zinc in a plethora of metabolic and virulence pathways and the presence of very low number of zinc importers in most bacterial species mark zinc homeostasis as a very promising target for the development of novel antimicrobial strategies. PMID:24400228

Cerasi, Mauro; Ammendola, Serena; Battistoni, Andrea

2013-01-01

399

Competition for zinc binding in the host-pathogen interaction  

PubMed Central

Due to its favorable chemical properties, zinc is used as a structural or catalytic cofactor in a very large number of proteins. Despite the apparent abundance of this metal in all cell types, the intracellular pool of loosely bound zinc ions available for biological exchanges is in the picomolar range and nearly all zinc is tightly bound to proteins. In addition, to limit bacterial growth, some zinc-sequestering proteins are produced by eukaryotic hosts in response to infections. Therefore, to grow and multiply in the infected host, bacterial pathogens must produce high affinity zinc importers, such as the ZnuABC transporter which is present in most Gram-negative bacteria. Studies carried in different bacterial species have established that disruption of ZnuABC is usually associated with a remarkable loss of pathogenicity. The critical involvement of zinc in a plethora of metabolic and virulence pathways and the presence of very low number of zinc importers in most bacterial species mark zinc homeostasis as a very promising target for the development of novel antimicrobial strategies. PMID:24400228

Cerasi, Mauro; Ammendola, Serena; Battistoni, Andrea

2013-01-01

400

Experimental Evolution of a Plant Pathogen into a Legume Symbiont  

PubMed Central

Rhizobia are phylogenetically disparate ?- and ?-proteobacteria that have achieved the environmentally essential function of fixing atmospheric nitrogen in symbiosis with legumes. Ample evidence indicates that horizontal transfer of symbiotic plasmids/islands has played a crucial role in rhizobia evolution. However, adaptive mechanisms that allow the recipient genomes to express symbiotic traits are unknown. Here, we report on the experimental evolution of a pathogenic Ralstonia solanacearum chimera carrying the symbiotic plasmid of the rhizobium Cupriavidus taiwanensis into Mimosa nodulating and infecting symbionts. Two types of adaptive mutations in the hrpG-controlled virulence pathway of R. solanacearum were identified that are crucial for the transition from pathogenicity towards mutualism. Inactivation of the hrcV structural gene of the type III secretion system allowed nodulation and early infection to take place, whereas inactivation of the master virulence regulator hrpG allowed intracellular infection of nodule cells. Our findings predict that natural selection of adaptive changes in the legume environment following horizontal transfer has been a major driving force in rhizobia evolution and diversification and show the potential of experimental evolution to decipher the mechanisms leading to symbiosis. PMID:20084095

Cruveiller, Stephane; Chane-Woon-Ming, Beatrice; Gris, Carine; Timmers, Ton; Poinsot, Verena; Gilbert, Luz B.; Heeb, Philipp; Medigue, Claudine; Batut, Jacques; Masson-Boivin, Catherine

2010-01-01

401

Targeting the PI3-kinase/Akt/mTOR Signaling Pathway  

PubMed Central

Synopsis This article presents an overview of the PI3K/Akt/mTOR signaling pathway. As a central regulator of cell growth, protein translation, survival, and metabolism, activation of this signaling pathway contributes to the pathogenesis of many tumor types. Biochemical and genetic aberrations of this pathway observed in various cancer types will be explored. Lastly, pathway inhibitors both in development and already FDA-approved will be discussed. PMID:24012393

Hassan, Burhan; Akcakanat, Argun; Holder, Ashley M.; Meric-Bernstam, Funda

2013-01-01

402

Ras Signaling Gets Fine-Tuned: Regulation of Multiple Pathogenic Traits of Candida albicans  

PubMed Central

Candida albicans is an opportunistic fungal pathogen that can cause disseminated infection in patients with indwelling catheters or other implanted medical devices. A common resident of the human microbiome, C. albicans responds to environmental signals, such as cell contact with catheter materials and exposure to serum or CO2, by triggering the expression of a variety of traits, some of which are known to contribute to its pathogenic lifestyle. Such traits include adhesion, biofilm formation, filamentation, white-to-opaque (W-O) switching, and two recently described phenotypes, finger and tentacle formation. Under distinct sets of environmental conditions and in specific cell types (mating type-like a [MTLa]/alpha cells, MTL homozygotes, or daughter cells), C. albicans utilizes (or reutilizes) a single signal transduction pathway—the Ras pathway—to affect these phenotypes. Ras1, Cyr1, Tpk2, and Pde2, the proteins of the Ras signaling pathway, are the only nontranscriptional regulatory proteins that are known to be essential for regulating all of these processes. How does C. albicans utilize this one pathway to regulate all of these phenotypes? The regulation of distinct and yet related processes by a single, evolutionarily conserved pathway is accomplished through the use of downstream transcription factors that are active under specific environmental conditions and in different cell types. In this minireview, we discuss the role of Ras signaling pathway components and Ras pathway-regulated transcription factors as well as the transcriptional regulatory networks that fine-tune gene expression in diverse biological contexts to generate specific phenotypes that impact the virulence of C. albicans. PMID:23913542

Inglis, Diane O.

2013-01-01

403

RESEARCH ARTICLE Nucleotide Sequence of Yellow Fever  

E-print Network

related human or veterinary pathogens causing many serious illness- es, including dengue fever, Japanese en- cephalitis, St. Louis encephalitis, Mur- ray Valley encephalitis, tick-borne en- cephalitis

Eddy, Sean

404

www.landesbioscience.com Plant Signaling & Behavior 1 article addendumarticle addendum  

E-print Network

, including the second messenger PA.13 Thus, although the lipid stimuli are different, animal and plant PDK1www.landesbioscience.com Plant Signaling & Behavior 1 article addendumarticle addendum Plant species, plant stress, plant microbe interaction, plant pathogen Submitted: 03/22/11 Accepted: 03

Hirt, Heribert

405

Real Time Detection of Foodborne Pathogens  

NASA Astrophysics Data System (ADS)

Contamination of foods by harmful bacteria by natural events or malicious intent poses a serious threat to public health and safety. This review introduces current technologies in detecting pathogens in food and foodborne illnesses. Causes of foodborne diseases and trends impacting foodborne diseases such as globalization and changes in micro-organisms, human populations, lifestyles, and climates are addressed. In addition, a review of the limitations in detecting pathogens with conventional technologies is presented. Finally, a review of nanostructured and nanomaterials based sensing technologies by pathogen, detection limits, and advantages is described.

Velusamy, V.; Arshak, K.; Korostynka, O.; Vaseashta, Ashok; Adley, C.

406

Haemoglobin modulates salicylate and jasmonate/ethylene-mediated resistance mechanisms against pathogens  

PubMed Central

Nitric oxide (NO) plays a role in defence against hemibiotrophic pathogens mediated by salicylate (SA) and also necrotrophic pathogens influenced by jasmonate/ethylene (JA/Et). This study examined how NO-oxidizing haemoglobins (Hb) encoded by GLB1, GLB2, and GLB3 in Arabidopsis could influence both defence pathways. The impact of Hb on responses to the hemibiotrophic Pseudomonas syringae pathovar tomato (Pst) AvrRpm1 and the necrotrophic Botrytis cinerea were investigated using glb1, glb2, and glb3 mutant lines and also CaMV 35S GLB1 and GLB2 overexpression lines. In glb1, but not glb2 and glb3, increased resistance was observed to both pathogens but was compromised in the 35S-GLB1. A quantum cascade laser-based sensor measured elevated NO production in glb1 infected with Pst AvrRpm1 and B. cinerea, which was reduced in 35S-GLB1 compared to Col-0. SA accumulation was increased in glb1 and reduced in 35S-GLB1 compared to controls following attack by Pst AvrRpm1. Similarly, JA and Et levels were increased in glb1 but decreased in 35S-GLB1 in response to attack by B. cinerea. Quantitative PCR assays indicated reduced GLB1 expression during challenge with either pathogen, thus this may elevate NO concentration and promote a wide-ranging defence against pathogens. PMID:22641422

Mur, Luis A. J.

2012-01-01

407

Cgl-SLT2 is required for appressorium formation, sporulation and pathogenicity in Colletotrichum gloeosporioides  

PubMed Central

The mitogen-activated protein (MAP) kinase pathways has been implicated in the pathogenicity of various pathogenic fungi and plays important roles in regulating pathogenicity-related morphogenesis. This work describes the isolation and characterization of MAP kinase gene, Cgl-SLT2, from Colletotrichum gloeosporioides. A DNA sequence, including 1,633 bp of Cgl-SLT2 open-reading frame and its promoter and terminator regions, was isolated via DNA walking and cloned. To analyze gene function, a gene disruption cassette containing hygromycin-resistant gene was constructed, and Cgl-SLT2 was inactivated via gene deletion. Analysis on Cgl-slt2 mutant revealed a defect in vegetative growth and sporulation as compared to the wild-type strain. When grown under nutrient-limiting conditions, hyperbranched hyphal morphology was observed in the mutant. Conidia induction for germination on rubber wax-coated hard surfaces revealed no differences in the percentage of conidial germination between the wild-type and Cgl-slt2 mutant. However, the percentage of appressorium formation in the mutant was greatly reduced. Bipolar germination in the mutant was higher than in the wild-type at 8-h post-induction. A pathogenicity assay revealed that the mutant was unable to infect either wounded or unwounded mangoes. These results suggest that the Cgl-SLT2 MAP kinase is required for C. gloeosporioides conidiation, polarized growth, appressorium formation and pathogenicity. PMID:24688518

Yong, H.Y.; Bakar, F.D.A.; Illias, R.M.; Mahadi, N.M.; Murad, A.M.A.

2013-01-01

408

Metabolic environments and genomic features associated with pathogenic and mutualistic interactions between bacteria and plants.  

PubMed

Genomic characteristics discriminating parasitic and mutualistic relationship of bacterial symbionts with plants are poorly understood. This study comparatively analyzed the genomes of 54 mutualists and pathogens to discover genomic markers associated with the different phenotypes. Using metabolic network models, we predict external environments associated with free-living and symbiotic lifestyles and quantify dependences of symbionts on the host in terms of the consumed metabolites. We show that specific differences between the phenotypes are pronounced at the levels of metabolic enzymes, especially carbohydrate active, and protein functions. Overall, biosynthetic functions are enriched and more diverse in plant mutualists whereas processes and functions involved in degradation and host invasion are enriched and more diverse in pathogens. A distinctive characteristic of plant pathogens is a putative novel secretion system with a circadian rhythm regulator. A specific marker of plant mutualists is the co-residence of genes encoding nitrogenase and ribulose bisphosphate carboxylase/oxygenase (RuBisCO). We predict that RuBisCO is likely used in a putative metabolic pathway to supplement carbon obtained heterotrophically with low-cost assimilation of carbon from CO2. We validate results of the comparative analysis by predicting correct phenotype, pathogenic or mutualistic, for 20 symbionts in an independent set of 30 pathogens, mutualists, and commensals. PMID:24580106

Karpinets, Tatiana V; Park, Byung H; Syed, Mustafa H; Klotz, Martin G; Uberbacher, Edward C

2014-07-01

409

Cgl-SLT2 is required for appressorium formation, sporulation and pathogenicity in Colletotrichum gloeosporioides.  

PubMed

The mitogen-activated protein (MAP) kinase pathways has been implicated in the pathogenicity of various pathogenic fungi and plays important roles in regulating pathogenicity-related morphogenesis. This work describes the isolation and characterization of MAP kinase gene, Cgl-SLT2, from Colletotrichum gloeosporioides. A DNA sequence, including 1,633 bp of Cgl-SLT2 open-reading frame and its promoter and terminator regions, was isolated via DNA walking and cloned. To analyze gene function, a gene disruption cassette containing hygromycin-resistant gene was constructed, and Cgl-SLT2 was inactivated via gene deletion. Analysis on Cgl-slt2 mutant revealed a defect in vegetative growth and sporulation as compared to the wild-type strain. When grown under nutrient-limiting conditions, hyperbranched hyphal morphology was observed in the mutant. Conidia induction for germination on rubber wax-coated hard surfaces revealed no differences in the percentage of conidial germination between the wild-type and Cgl-slt2 mutant. However, the percentage of appressorium formation in the mutant was greatly reduced. Bipolar germination in the mutant was higher than in the wild-type at 8-h post-induction. A pathogenicity assay revealed that the mutant was unable to infect either wounded or unwounded mangoes. These results suggest that the Cgl-SLT2 MAP kinase is required for C. gloeosporioides conidiation, polarized growth, appressorium formation and pathogenicity. PMID:24688518

Yong, H Y; Bakar, F D A; Illias, R M; Mahadi, N M; Murad, A M A

2013-12-01

410

Susceptibility of Intact Germinating Arabidopsis thaliana to Human Fungal Pathogens Cryptococcus neoformans and C. gattii  

PubMed Central

The fungus Cryptococcus contributes a large global burden of infectious death in both HIV-infected and healthy individuals. As Cryptococcus is an opportunistic pathogen, much of the evolutionary pressure shaping virulence occurs in environments in contact with plants and soil. The present studies investigated inoculation of intact seeds of the common weed Arabidopsis thaliana with fungal cells over a 21-day period. C. gattii was the more virulent plant pathogen, resulting in disrupted germination as well as increased stem lodging, fungal burden, and plant tissue colocalization. C. neoformans was a less virulent plant pathogen but exhibited prolonged tissue residence within the cuticle and vascular spaces. Arabidopsis mutants of the PRN1 gene, which is involved in abiotic and biotic signaling affecting phenylalanine-derived flavonoids, showed altered susceptibility to cryptoccocal infections, suggesting roles for this pathway in cryptococcal defense. The fungal virulence factor laccase was also implicated in plant pathogenesis, as a cryptococcal lac1? strain was less virulent than wild-type fungi and was unable to colonize seedlings. In conclusion, these studies expand knowledge concerning the ecological niche of Cryptococcus by demonstrating the pathogenic capacity of the anamorphic form of cryptococcal cells against healthy seedlings under physiologically relevant conditions. In addition, an important role of laccase in plant as well as human virulence may suggest mechanisms for laccase retention and optimization during evolution of this fungal pathogen. PMID:23435895

Park, Yoon-Dong

2013-01-01

411

Multiplexed Activity-based Protein Profiling of the Human Pathogen Aspergillus fumigatus Reveals Large Functional Changes upon Exposure to Human Serum  

SciTech Connect

Environmental and metabolic adaptability is critical for survival of the fungal human pathogen Aspergillus fumigatus in the immunocompromised lung. We employed an activity-based protein profiling (ABPP) approach utilizing a new aryl vinyl sulfonate probe and a serine hydrolase probe combined with quantitative LC-MS based accurate mass and time (AMT) tag proteomics for the identification of functional pathway adaptation of A. fumigatus to environmental variability relevant to pulmonary Invasive Aspergillosis. When the fungal pathogen was grown with human serum, metabolism and energy processes were markedly decreased compared to no serum culture. Additionally, functional pathways associated with amino acid and protein biosynthesis were limited as the fungus scavenged from the serum to obtain essential nutrients. Our approach revealed significant metabolic adaptation by A. fumigatus, and provides direct insight into this pathogen’s ability to survive and proliferate.

Wiedner, Susan D.; Burnum, Kristin E.; Pederson, Leeanna M.; Anderson, Lindsey N.; Fortuin, Suereta; Chauvigne-Hines, Lacie M.; Shukla, Anil K.; Ansong, Charles; Panisko, Ellen A.; Smith, Richard D.; Wright, Aaron T.

2012-08-03

412

The Interaction of Human Enteric Pathogens with Plants  

PubMed Central

There are an increasing number of outbreaks of human pathogens related to fresh produce. Thus, the growth of human pathogens on plants should be explored. Human pathogens can survive under the harsh environments in plants, and can adhere and actively invade plants. Plant-associated microbiota or insects contribute to the survival and transmission of enteric pathogens in plants. Human enteric pathogens also trigger plant innate immunity, but some pathogens–such as Salmonella–can overcome this defense mechanism.

Lim, Jeong-A; Lee, Dong Hwan; Heu, Sunggi

2014-01-01

413

ETHYLENE RESPONSE FACTOR1 Integrates Signals from Ethylene and Jasmonate Pathways in Plant Defense  

Microsoft Academic Search

Cross-talk between ethylene and jasmonate signaling pathways determines the activation of a set of defense re- sponses against pathogens and herbivores. However, the molecular mechanisms that underlie this cross-talk are poorly understood. Here, we show that ethylene and jasmonate pathways converge in the transcriptional activation of ETHYLENE RESPONSE FACTOR1 (ERF1), which encodes a transcription factor that regulates the expression of

Oscar Lorenzo; Raquel Piqueras; Jose J. Sánchez-Serrano; Roberto Solano

2003-01-01

414

Predicting pathogen transport and risk of infection from land-applied biosolids  

NASA Astrophysics Data System (ADS)

Biosolids have been recycled as fertilizer to sustainably improve and maintain productive soils and to stimulate plant growth for over forty years, but may contain low levels of microbial pathogens. The Spreadsheet Microbial Assessment of Risk: Tool for Biosolids ("SMART Biosolids") is an environmental transport, exposure and risk model that compiles knowledge on the occurrence, environmental dispersion and attenuation of biosolids-associated pathogens to estimate microbial risk from biosolids land application. The SMART Biosolids model calculates environmental pathogen concentrations and assesses risk associated with exposure to pathogens from land-applied biosolids through five pathways: 1) inhalation of aerosols from land application sites, 2) consumption of groundwater contaminated by land-applied biosolids, 3) direct ingestion of biosolids-amended soils, 4) ingestion of plants contaminated by land-applied biosolids, and 5) consumption of surface water contaminated by runoff from a land application site. The SMART Biosolids model can be applied under a variety of scenarios, thereby providing insight into effective management practices. This study presents example results of the SMART Biosolids model, focusing on the groundwater and surface water pathways, following biosolids application to a typical site in Michigan. Volumes of infiltration and surface water runoff are calculated following a 100-year storm event. Pathogen transport and attenuation through the subsurface and via surface runoff are modeled, and pathogen concentrations in a downstream well and an adjacent pond are calculated. Risks are calculated for residents of nearby properties. For a 100-year storm event occurring immediately after biosolids application, the surface water pathway produces risks that may be of some concern, but best estimates do not exceed the bounds of what has been considered acceptable risk for recreational water use (Table 1); groundwater risks are very uncertain and at the upper bound may exceed both drinking water and recreational standards, but these risks would be associated with very shallow groundwater (depth of 3 feet), which would not typically be used as a potable water source. Comparisons across pathogens are presented, as are the effects of different site management practices.
Risk from Surface Water Recreational Swimming Following a 1 in 100 Year Storm Event Values displayed are based on nominal input parameter values with 5-95th percentiles of a Monte Carlo simulation given in parentheses. NA - not available as value was below reporting threshold of 10-2

Olson, M. S.; Teng, J.; Kumar, A.; Gurian, P.

2011-12-01

415

Ophthalmic Parasitosis: A Review Article  

PubMed Central

Ocular parasitosis in human is more prevalent in geographical areas where environmental factors and poor sanitary conditions favor the parasitism between man and animals. Lesions in the eye can be due to damage directly caused by the infectious pathogen, indirect pathology caused by toxic products, or the immune response incited by infections or ectopic parasitism. The epidemiology of parasitic ocular diseases reflects the habitat of the causative parasites as well as the habits and health status of the patient. An ocular examination may provide clues to the underlying disease/infection, and an awareness of the possibilities of travel-related pathology may shed light on an ocular presentation. This paper is a comprehensive review of the parasitic diseases of the eye. The majority of the clinically important species of parasites involved in eye infection are reviewed in this paper. Parasites are discussed by the disease or infection they cause. PMID:23024652

Nimir, Amal R.; Saliem, Ahmed; Ibrahim, Ibrahim Abdel Aziz

2012-01-01

416

Salicylic Acid InductionDeficient Mutants of Arabidopsis Express PR2 and PR5 and Accumulate High Levels of Camalexin after Pathogen Inoculation  

Microsoft Academic Search

In Arabidopsis, systemic acquired resistance against pathogens has been associated with the accumulation of salicylic acid (SA) and the expression of the pathogenesis-related proteins PR-1, PR-2, and PR-5. We report here the isolation of two nonallelic mutants impaired in the pathway leading to SA biosynthesis. These SA induction-deficient ( sid ) mutants do not accumulate SA after pathogen inoculation and

Christiane Nawrath; Jean-Pierre Métraux

1999-01-01

417

Genetic variation in Drosophila melanogaster pathogen susceptibility  

E-print Network

Genetic variation in Drosophila melanogaster pathogen susceptibility M. C. TINSLEY*, S. BLANFORD: Drosophila melanogaster, Beauveria bassiana, immunity, genetic variation, malaria, resistance evolution). Drosophila melanogaster is the principal model system for study of the invertebrate immune system and has

Jiggins, Francis

418

PATHOGEN EQUIVALENCY COMMITTEE UPDATE: PFRP EQUIVALENCY DETERMINATIONS  

EPA Science Inventory

This presentation will: Review the mandate of the Pathogen Equivalency Committee Review the PEC's current membership of 10 Discuss how a typical application is evaluated Note where information can be found List present deliberations/applications and describe t...

419

Page 1 of 16 Bloodborne Pathogens Program  

E-print Network

cause disease in humans. These pathogens include, but are not limited to, hepatitis B virus (HBV) and human immunodeficiency virus (HIV). The following methods are outlined to eliminate or control exposure

420

YAPI, a New Yersinia pseudotuberculosis Pathogenicity Island  

Microsoft Academic Search

Pathogenicity islands (PAIs) are chromosomal clusters of pathogen-specific virulence genes often found at tRNA loci. In the Yersinia pseudotuberculosis 32777 chromosome, we characterized a 98-kb segment that has all of the characteristic features of a PAI, including insertion in a (phenylalanine) tRNA gene, the presence of a bacteriophage-like integrase-encoding gene, and direct repeats at the integration sites. The GC content

Francois Collyn; Alain Billault; Chantal Mullet; Michel Simonet; Michael Marceau

2004-01-01

421

Probiotic-Pathogen Interactions and Enteric Cytoprotection  

Microsoft Academic Search

\\u000a The intestinal epithelium forms a physicochemical barrier that impedes enteric pathogens from invading the epithelium and\\u000a cause disease. In order for a particular pathogen to colonise the intestinal mucosa, it needs to break and cross this barrier.\\u000a The barrier consists of a low pH area mainly resulting from carbohydrate fermentation, a mucus layer along the epithelial\\u000a surface, an epithelial mechanical

Joshua J. Malago; Jos F. J. G. Koninkx

422

Detection of foodborne pathogens using bioconjugated nanomaterials  

Microsoft Academic Search

This review focuses on applying nanotechnology to foodborne pathogen detection. Because of low infectious doses for most foodborne\\u000a pathogens, the rapid and sensitive detection methods are essential to ensure the food safety. The advances in the development\\u000a of nanomaterials have stimulated worldwide research interests in their applications for bioanalysis. The conjugation of biomolecules\\u000a with nanomaterials is the foundation of nano-biorecognition.

Hua Yang; Huaping Li; Xiuping Jiang

2008-01-01

423

Distribution of pathogenic Yersinia enterocolitica in China  

Microsoft Academic Search

Yersinia enterocolitica (1,295 strains) was isolated from diarrhea patients, livestock, poultry, wild animals, insect vectors, food, and the environment.\\u000a They were studied for epidemiology distribution using bacterial biochemical metabolism tests, their virulence genes, and pulsed-field\\u000a gel electrophoresis (PFGE) sub-typing. The data showed that 416 of the 1,295 strains were pathogenic, where the pathogenic\\u000a Chinese isolates were of serotypes O:3 and

X. Wang; Z. Cui; D. Jin; L. Tang; S. Xia; H. Wang; Y. Xiao; H. Qiu; Q. Hao; B. Kan; J. Xu; H. Jing

2009-01-01

424

Development of DNA microarray for pathogen detection  

Microsoft Academic Search

Pathogens pose a significant threat to humans, animals, and plants. Consequently, a considerable effort has been devoted to\\u000a developing rapid, convenient, and accurate assays for the detection of these unfavorable organisms. Recently, DNA-microarray\\u000a based technology is receiving much attention as a powerful tool for pathogen detection. After the target gene is first selected\\u000a for the unique identification of microorganisms, species-specific

Seung Min Yoo; Ki Chang Keum; So Young Yoo; Jun Yong Choi; Kyung Hee Chang; Nae Choon Yoo; Won Min Yoo; June Myung Kim; Duke Lee; Sang Yup Lee

2004-01-01

425

Enteric pathogens and cellular transformation: bridging the gaps  

PubMed Central

Cancer patients in general, either due to the nature of their underlying illness or because of being on chemotherapeutic regimens, are at increased risk of infection. Indeed, microbes can exploit the innate plasticity of the epithelial cells to promote their trans-differentiation into a mesenchymal phenotype in a process called epithelial-to-mesenchymal transition (EMT). This process as well as the reverse, mesenchymal-epithelial transition, occurs repeatedly during normal embryonic development and is recapitulated during pathologies such as tissue fibrosis or tumor metastasis. Multiple signaling pathways including TGF?, Wnt and Notch working together with transcription factors such as Slug, Snail, Twist, Zeb1 and 2 suppress E-cadherin, induce EMT and result in loss of cell-cell adhesion, increased tumor progression and migration. In addition, in approximately 20% of all cases, microbial organisms including pathobionts of the commensal microbiota, have been implicated in inflammatory processes that promote tumor growth. Thus, the dynamic process of EMT serves to enhance tumor progression and is also involved in the generation of cancer stem cells (CSCs) across multiple organ systems including colon cancer. Suffice to say, EMT and CSC molecular pathways activated by pathogens, may represent a unique therapeutic alternative to conventional anti-neoplastic strategy to mitigate early stage metastasis and/or frank malignancy. PMID:25216513

Umar, Shahid

2014-01-01

426

MicroRNAs: New Regulators of Toll-Like Receptor Signalling Pathways  

PubMed Central

Toll-like receptors (TLRs), a critical family of pattern recognition receptors (PRRs), are responsible for the innate immune responses via signalling pathways to provide effective host defence against pathogen infections. However, TLR-signalling pathways are also likely to stringently regulate tissue maintenance and homeostasis by elaborate modulatory mechanisms. MicroRNAs (miRNAs) have emerged as key regulators and as an essential part of the networks involved in regulating TLR-signalling pathways. In this review, we highlight our understanding of the regulation of miRNA expression profiles by TLR-signalling pathways and the regulation of TLR-signalling pathways by miRNAs. We focus on the roles of miRNAs in regulating TLR-signalling pathways by targeting multiple molecules, including TLRs themselves, their associated signalling proteins and regulatory molecules, and transcription factors and functional cytokines induced by them, at multiple levels. PMID:24772440

He, Xiaobing; Jing, Zhizhong; Cheng, Guofeng

2014-01-01

427

Pathway Tools version 13.0: integrated software for pathway/genome informatics and systems biology  

PubMed Central

Pathway Tools is a production-quality software environment for creating a type of model-organism database called a Pathway/Genome Database (PGDB). A PGDB such as EcoCyc integrates the evolving understanding of the genes, proteins, metabolic network and regulatory network of an organism. This article provides an overview of Pathway Tools capabilities. The software performs multiple computational inferences including prediction of metabolic pathways, prediction of metabolic pathway hole fillers and prediction of operons. It enables interactive editing of PGDBs by DB curators. It supports web publishing of PGDBs, and provides a large number of query and visualization tools. The software also supports comparative analyses of PGDBs, and provides several systems biology analyses of PGDBs including reachability analysis of metabolic networks, and interactive tracing of metabolites through a metabolic network. More than 800 PGDBs have been created using Pathway Tools by scientists around the world, many of which are curated DBs for important model organisms. Those PGDBs can be exchanged using a peer-to-peer DB sharing system called the PGDB Registry. PMID:19955237

Paley, Suzanne M.; Krummenacker, Markus; Latendresse, Mario; Dale, Joseph M.; Lee, Thomas J.; Kaipa, Pallavi; Gilham, Fred; Spaulding, Aaron; Popescu, Liviu; Altman, Tomer; Paulsen, Ian; Keseler, Ingrid M.; Caspi, Ron

2010-01-01

428

Sexual reproduction of human fungal pathogens.  

PubMed

We review here recent advances in our understanding of sexual reproduction in fungal pathogens that commonly infect humans, including Candida albicans, Cryptococcus neoformans/gattii, and Aspergillus fumigatus. Where appropriate or relevant, we introduce findings on other species associated with human infections. In particular, we focus on rapid advances involving genetic, genomic, and population genetic approaches that have reshaped our view of how fungal pathogens evolve. Rather than being asexual, mitotic, and largely clonal, as was thought to be prevalent as recently as a decade ago, we now appreciate that the vast majority of pathogenic fungi have retained extant sexual, or parasexual, cycles. In some examples, sexual and parasexual unions of pathogenic fungi involve closely related individuals, generating diversity in the population but with more restricted recombination than expected from fertile, sexual, outcrossing and recombining populations. In other cases, species and isolates participate in global outcrossing populations with the capacity for considerable levels of gene flow. These findings illustrate general principles of eukaryotic pathogen emergence with relevance for other fungi, parasitic eukaryotic pathogens, and both unicellular and multicellular eukaryotic organisms. PMID:25085958

Heitman, Joseph; Carter, Dee A; Dyer, Paul S; Soll, David R

2014-08-01

429

Lactobacillus fermentum, a pathogen in documented cholecystitis  

PubMed Central

INTRODUCTION Lactobacillus species are probiotics proven to exhibit various preventative as well as therapeutic properties. While lactobacillus species have been implicated in the formation of dental caries, endocarditis and bacteremia, their role as pathogens in cholecystitis has not been reported. We present a rare case of Lactobacillus fermentum working as a pathogen in cholecystitis. PRESENTATION OF CASE An 81-year old male was admitted with right upper quadrant abdominal pain. His signs, symptoms, laboratory values and imaging were consistent with a diagnosis of cholecystitis with ascending cholangitis. In view of his co-morbidity and severe sepsis, the patient was treated non-operatively with antibiotics and cholecystostomy. L. fermentum, which was vancomycin resistant, was identified from the cholecystostomy aspirate and from anaerobic blood culture. The patient went into septic shock, developed multi-organ dysfunction syndrome and eventually died. DISCUSSION Commensal bacteria such as L. fermentum are known to modulate immunity, reduce the pathogenicity of gastrointestinal organisms and play a therapeutic role in various disease processes. We isolated L. fermentum as a pathogen in a documented case of cholecystitis with ascending cholangitis. CONCLUSION While the routine use lactobacillus species as a probiotic is supported in the literature, understanding its potential role as a pathogen may allow more judicious use of these bacteria and encourage research to elucidate the pathogenicity of lactobacillus species. PMID:23792476

Chery, Josue; Dvoskin, Dmitriy; Morato, Fernando P.; Fahoum, Bashar

2013-01-01

430

Signaling network of dendritic cells in response to pathogens: a community-input supported knowledgebase  

PubMed Central

Background Dendritic cells are antigen-presenting cells that play an essential role in linking the innate and adaptive immune systems. Much research has focused on the signaling pathways triggered upon infection of dendritic cells by various pathogens. The high level of activity in the field makes it desirable to have a pathway-based resource to access the information in the literature. Current pathway diagrams lack either comprehensiveness, or an open-access editorial interface. Hence, there is a need for a dependable, expertly curated knowledgebase that integrates this information into a map of signaling networks. Description We have built a detailed diagram of the dendritic cell signaling network, with the goal of providing researchers with a valuable resource and a facile method for community input. Network construction has relied on comprehensive review of the literature and regular updates. The diagram includes detailed depictions of pathways activated downstream of different pathogen recognition receptors such as Toll-like receptors, retinoic acid-inducible gene-I-like receptors, C-type lectin receptors and nucleotide-binding oligomerization domain-like receptors. Initially assembled using CellDesigner software, it provides an annotated graphical representation of interactions stored in Systems Biology Mark-up Language. The network, which comprises 249 nodes and 213 edges, has been web-published through the Biological Pathway Publisher software suite. Nodes are annotated with PubMed references and gene-related information, and linked to a public wiki, providing a discussion forum for updates and corrections. To gain more insight into regulatory patterns of dendritic cell signaling, we analyzed the network using graph-theory methods: bifan, feedforward and multi-input convergence motifs were enriched. This emphasis on activating control mechanisms is consonant with a network that subserves persistent and coordinated responses to pathogen detection. Conclusions This map represents a navigable aid for presenting a consensus view of the current knowledge on dendritic cell signaling that can be continuously improved through contributions of research community experts. Because the map is available in a machine readable format, it can be edited and may assist researchers in data analysis. Furthermore, the availability of a comprehensive knowledgebase might help further research in this area such as vaccine development. The dendritic cell signaling knowledgebase is accessible at http://tsb.mssm.edu/pathwayPublisher/DC_pathway/DC_pathway_index.html. PMID:20929569

2010-01-01

431

Children’s Health | Article  

E-print Network

The prevalence of dental fluorosis in the United States has increased during the last 30 years. In this study, we used a mathematical model commonly employed by the U.S. Environmental Protection Agency to estimate average daily intake of fluoride via all applicable exposure pathways contributing to fluorosis risk for infants and children living in hypothetical fluoridated and nonfluoridated communities. We also estimated hazard quotients for each exposure pathway and hazard indices for exposure conditions representative of central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. The exposure pathways considered were uptake of fluoride via fluoridated drinking water, beverages, cow’s milk, foods, and fluoride supplements for both age groups. Additionally, consumption of infant formula for infants and inadvertent swallowing of toothpaste while brushing and incidental ingestion of soil for children were also considered. The cumulative daily fluoride intake in fluoridated areas was estimated as 0.20 and 0.11 mg/kg-day for RME and CTE scenarios, respectively, for infants. On the other hand, the RME and CTE estimates for children were 0.23 and 0.06 mg/kg-day, respectively. In areas where municipal water is not fluoridated, our RME and CTE estimates for cumulative daily average intake were, respectively, 0.11 and 0.08 mg/kg-day for infants and 0.21 and 0.06 mg/kg-day for children. Our theoretical estimates are in good agreement with measurement-based estimates reported in the literature. Although CTE estimates were within the optimum range for dental caries prevention, the RME estimates were above the upper tolerable intake limit. This suggests that some children may be at risk for fluorosis. Key words: children, exposure, fluoride, multipathway, risk. Environ Health Perspect 113:111–117 (2005). doi:10.1289/ehp.7077 available via

Serap Erdal; Susan N. Buchanan

432

ORIGINAL ARTICLE Molecular phylogeny of Armillaria  

E-print Network

aggressive pathogens when the native forest is replaced by introduced plantation tree species such as Pinus Mycological Society and Springer-Verlag 2009 Abstract A number of species in the plant pathogen genus. Knowledge pertaining to phylogenetic relationships of these species with those of other Armillaria species

433

Myocyte Adrenoceptor Signaling Pathways  

NSDL National Science Digital Library

Adrenoceptors (ARs), members of the G proteinâÂÂcoupled receptor superfamily, form the interface between the sympathetic nervous system and the cardiovascular system, with integral roles in the rapid regulation of myocardial function. However, in heart failure, chronic catecholamine stimulation of adrenoceptors has been linked to pathologic cardiac remodeling, including myocyte apoptosis and hypertrophy. In cardiac myocytes, activation of AR subtypes results in coupling to different G proteins and induction of specific signaling pathways, which is partly regulated by the subtype-specific distribution of receptors in plasma membrane compartments containing distinct complexes of signaling molecules. The Connections Maps of the Adrenergic and Myocyte Adrenergic Signaling Pathways bring into focus the specific signaling pathways of individual AR subtypes and their relevant functions in vivo.

Yang Xiang (Stanford Medical Center;Department of Molecular and Cellular Physiology); Brian Kobilka (Stanford Medical Center;Department of Molecular and Cellular Physiology)

2003-06-06

434

Original article Dietary antioxidant supplementation  

E-print Network

Original article Dietary antioxidant supplementation did not affect declining sperm function a control or antioxidant diet. Aged males showed a sig- nificant decrease in number of spermatozoa. The mechanism involved may be associated with either the antioxidant properties of vitamins C and E

Paris-Sud XI, Université de

435

Original article Lipogenic enzyme activities  

E-print Network

Original article Lipogenic enzyme activities in subcutaneous adipose tissue and skeletal muscle, lipogenic enzyme activities and expression of GLUT4 mRNA were determined in subcutaneous adipose tissue. In adipose tissue, acetyl-CoA-carboxylase (CBX), fatty acid synthase (FAS), malic enzyme (ME), glucose-6

Paris-Sud XI, Université de

436

AgricultureandEnvironment Original article  

E-print Network

may be removed, probably by precipitation with the organic matter. aluminium / water quality / organic and fulvic acids are chemically stable [19]. In stream water, aluminium bound to organic matter may stayAgricultureandEnvironment Original article Role of natural organic matter in the mobility

Paris-Sud XI, Université de

437

COMPUTATIONAL NEUROSCIENCE ORIGINAL RESEARCH ARTICLE  

E-print Network

COMPUTATIONAL NEUROSCIENCE ORIGINAL RESEARCH ARTICLE published: 09 May 2013 doi: 10.3389/fncom.2013 depression Paul Miller* Volen National Center for Complex Systems and Department of Biology, Brandeis University, Waltham, MA, USA Edited by: Si Wu, Beijing Normal University, China Reviewed by: Louis Tao

Miller, Paul

438

Review article Taxonomy of rhizobia  

E-print Network

Review article Taxonomy of rhizobia Frédéric ZAKHIA, Philippe de LAJUDIE* Laboratoire des Symbioses on their characterisation by polypha- sic taxonomy, their classification has undergone great changes in recent years. The current six rhizobium genera and 28 recognised species are reviewed here. Rhizobium / taxonomy Résumé

Paris-Sud XI, Université de

439

FEATURE ARTICLE 2 Empirical quagmires  

E-print Network

FEATURE ARTICLE 2 Empirical quagmires WORK IN PROGRESS 5 Plantation medicine in Malaya ARV therapy were reluctant to vaccinate children who were sickly, had skin irritations or rashes, or were teething, and it was not clear whether or not the higher death rate among the unvaccinated (who were primarily young children

Rambaut, Andrew

440

ORIGINAL ARTICLE Kidney Cancer Mortality  

E-print Network

ORIGINAL ARTICLE Kidney Cancer Mortality Fifty-year Latency Patterns Related to Arsenic Exposure,e and Allan H. Smitha Background: Arsenic in drinking water is associated with kidney cancer. Beginning obtained computerized mortality data for all of Chile for 1971­2000. Results: Kidney cancer risks

California at Berkeley, University of

441

Original article Soybean impairs Na  

E-print Network

Original article Soybean impairs Na + -dependent glucose absorption and Cl ­ secretion in porcine -- Recent evidence indicates that soybean, which is widely used in animal nutrition, could directly alter of the study was to investigate the effect of three differently treated soybean prod- ucts on the glucose

Boyer, Edmond

442

HUMAN NEUROSCIENCE ORIGINAL RESEARCH ARTICLE  

E-print Network

HUMAN NEUROSCIENCE ORIGINAL RESEARCH ARTICLE published: 02 February 2012 doi: 10.3389/fnhum.2012 ,Vijeth Iyengar3 , MatthewThornburg4 , Jaap Weel5 , Mingkuan Lin2 , Ellen Clarke2 , Kevin McCabe5 Department of Neurosciences, Inova Fairfax Hospital, Inova Health System, Falls Church, VA, USA Edited by

Parasuraman, Raja

443

ORIGINAL ARTICLE Blood pressure, antihypertensive  

E-print Network

ORIGINAL ARTICLE Blood pressure, antihypertensive treatment and factors associated with good blood and that intensive antihypertensive treatment is more beneficial to diabetic than to nondiabetic hypertensive and the effects of antihypertensive drugs in the medical management of hypertension in diabetic patients

Cai, Long

444

ARTICLE IN PRESS Pattern Recognition ( ) --  

E-print Network

of Birmingham, UK d Laboratory of Computer and Information Science, Helsinki University of Technology, Finland A R T I C L E I N F O A B S T R A C T Article history: Received 16 October 2007 Received in revised signals that originate from the same source but travel along different paths to the observer, is a real

Yao, Xin

445

Index of 1991 Professional Articles.  

ERIC Educational Resources Information Center

This bibliography for school library media specialists lists periodical articles published in 1991 on information service (censorship, CD-ROM and online searching, networking, resource sharing, reading guidance, and reference service); instructional consulting; management; National Education Goals; teaching (computer applications, information…

Morris, Betty J.

1992-01-01

446

Article de synthse Escherichia coli  

E-print Network

Article de synthèse Escherichia coli entéropathogènes du lapin D Licois INRA, Station de pathologie diarrhée, chez l'homme ou l'animal. Escherichia coli/ entéropathogène / entérohémorragique / lapin Summary ― Enteropathogenic Escherichia coli from the rabbit. Intestinal pathology is the main cause

Paris-Sud XI, Université de

447

Research Article Pigeons See Correspondence  

E-print Network

Research Article Pigeons See Correspondence Between Objects and Their Pictures Marcia L. Spetch in pictures have produced mixed and inconclusive results. We trained pigeons to discrim- inate between two to pictures occurred even when pigeons were trained with 12 views and only novel views of the objects were

Cook, Robert

448

Author's personal copy Review Article  

E-print Network

Author's personal copy Review Article Middle atmosphere dynamics with gravity wave interactions in the numerical spectral model: Tides and planetary waves H.G. Mayr a,n , J.G. Mengel 1,b , K.L. Chan c , F, Greenbelt, MD 20771, USA b Science Systems and Applications Inc., Lanham, MD, USA c University of Science

Chan, Kwing Lam

449

NEURAL CIRCUITS ORIGINAL RESEARCH ARTICLE  

E-print Network

.,2009) have used quantitative methods, with unsupervised clustering algorithms to seek an objectiveNEURAL CIRCUITS ORIGINAL RESEARCH ARTICLE published: 14 May 2010 doi: 10.3389/fncir.2010 features (Sabo and Sceniak, 2006). To better understand this variability, we took advantage of a transgenic

Columbia University

450

Research Article Inhibition Versus Switching  

E-print Network

information. We used a task-switching paradigm that can distinguish between these two processes. Two rumination are associated with difficulties in switching to a new task set, but not with inhibitionResearch Article Inhibition Versus Switching Deficits in Different Forms of Rumination Anson J

Banich, Marie T.

451

Original article Effect of dehydration  

E-print Network

Original article Effect of dehydration on ruminal degradability of lucerne José Luis REPETTO 28 October 1999; accepted 17 February 2000) Abstract -- The effects of industrial dehydration obtained at harvest or after the process of dehydration and compression of this forage. Rumen degradability

Paris-Sud XI, Université de

452

Author's personal copy Research article  

E-print Network

Author's personal copy Research article Characterization of glutathione reductase and catalase charac- terized two antioxidant enzymes, glutathione reductase (GR) and catalase (CAT), in the fronds but much smaller increases were observed for P. ensiformis and purified bovine liver catalase (133% and 120

Ma, Lena

453

Review Article RADIATION SHIELDING TECHNOLOGY  

E-print Network

Review Article RADIATION SHIELDING TECHNOLOGY J. Kenneth Shultis and Richard E. Faw* Abstract Physics Society INTRODUCTION THIS IS a review of the technology of shielding against the effects to the review. The first treats the evolution of radiation-shielding technology from the beginning of the 20th

Shultis, J. Kenneth

454

Original article Salmonella typhimurium contamination  

E-print Network

Original article Salmonella typhimurium contamination from farm to meat in adult cattle by salmonella in cattle between the farm and slaughterhouse and to explore the possible relationship between included in each group because they had been shown to excrete Salmonella 1Bphil11uriul11 Idays before

Paris-Sud XI, Université de

455