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Sample records for abc paulista nos

  1. ABC transporters: bacterial exporters.

    PubMed Central

    Fath, M J; Kolter, R

    1993-01-01

    The ABC transporters (also called traffic ATPases) make up a large superfamily of proteins which share a common function and a common ATP-binding domain. ABC transporters are classified into three major groups: bacterial importers (the periplasmic permeases), eukaryotic transporters, and bacterial exporters. We present a comprehensive review of the bacterial ABC exporter group, which currently includes over 40 systems. The bacterial ABC exporter systems are functionally subdivided on the basis of the type of substrate that each translocates. We describe three main groups: protein exporters, peptide exporters, and systems that transport nonprotein substrates. Prototype exporters from each group are described in detail to illustrate our current understanding of this protein family. The prototype systems include the alpha-hemolysin, colicin V, and capsular polysaccharide exporters from Escherichia coli, the protease exporter from Erwinia chrysanthemi, and the glucan exporters from Agrobacterium tumefaciens and Rhizobium meliloti. Phylogenetic analysis of the ATP-binding domains from 29 bacterial ABC exporters indicates that the bacterial ABC exporters can be divided into two primary branches. One branch contains the transport systems where the ATP-binding domain and the membrane-spanning domain are present on the same polypeptide, and the other branch contains the systems where these domains are found on separate polypeptides. Differences in substrate specificity do not correlate with evolutionary relatedness. A complete survey of the known and putative bacterial ABC exporters is included at the end of the review. PMID:8302219

  2. Plant ABC Transporters

    PubMed Central

    Kang, Joohyun; Park, Jiyoung; Choi, Hyunju; Burla, Bo; Kretzschmar, Tobias; Lee, Youngsook; Martinoia, Enrico

    2011-01-01

    ABC transporters constitute one of the largest protein families found in all living organisms. ABC transporters are driven by ATP hydrolysis and can act as exporters as well as importers. The plant genome encodes for more than 100 ABC transporters, largely exceeding that of other organisms. In Arabidopsis, only 22 out of 130 have been functionally analyzed. They are localized in most membranes of a plant cell such as the plasma membrane, the tonoplast, chloroplasts, mitochondria and peroxisomes and fulfill a multitude of functions. Originally identified as transporters involved in detoxification processes, they have later been shown to be required for organ growth, plant nutrition, plant development, response to abiotic stresses, pathogen resistance and the interaction of the plant with its environment. To fulfill these roles they exhibit different substrate specifies by e.g. depositing surface lipids, accumulating phytate in seeds, and transporting the phytohormones auxin and abscisic acid. The aim of this review is to give an insight into the functions of plant ABC transporters and to show their importance for plant development and survival. PMID:22303277

  3. ABC's of Being Smart

    ERIC Educational Resources Information Center

    Foster, Joanne

    2011-01-01

    Determining what giftedness is all about means focusing on many aspects of the individual. In this paper, the author focuses on letter D of the ABC's of being smart. She starts with specifics about giftedness (details), and then moves on to some ways of thinking (dispositions).

  4. The ABC of ABCS: a phylogenetic and functional classification of ABC systems in living organisms.

    PubMed

    Dassa, E; Bouige, P

    2001-01-01

    ATP binding cassette (ABC) systems constitute one of the most abundant superfamilies of proteins. They are involved not only in the transport of a wide variety of substances, but also in many cellular processes and in their regulation. In this paper, we made a comparative analysis of the properties of ABC systems and we provide a phylogenetic and functional classification. This analysis will be helpful to accurately annotate ABC systems discovered during the sequencing of the genome of living organisms and to identify the partners of the ABC ATPases. PMID:11421270

  5. Do You Know Your ABC?

    ERIC Educational Resources Information Center

    Neale, Claire

    2013-01-01

    Within primary schools, the core subjects of literacy and numeracy are highly regarded, and rightly so, as children need to learn to read, write and be numerically literate. This means that all children learn their ABCs at an early age, But, what about the "other ABC"--"Airway, Breathing and Circulation?" Accidents and medical…

  6. ABC Technology Development Program

    SciTech Connect

    1994-10-14

    The Accelerator-Based Conversion (ABC) facility will be designed to accomplish the following mission: `Provide a weapon`s grade plutonium disposition capability in a safe, economical, and environmentally sound manner on a prudent schedule for [50] tons of weapon`s grade plutonium to be disposed on in [20] years.` This mission is supported by four major objectives: provide a reliable plutonium disposition capability within the next [15] years; provide a level of safety and of safety assurance that meets or exceeds that afforded to the public by modern commercial nuclear power plants; meet or exceed all applicable federal, state, and local regulations or standards for environmental compliance; manage the program in a cost effective manner. The ABC Technology Development Program defines the technology development activities that are required to accomplish this mission. The technology development tasks are related to the following topics: blanket system; vessel systems; reactivity control systems; heat transport system components; energy conversion systems; shutdown heat transport systems components; auxiliary systems; technology demonstrations - large scale experiments.

  7. The ABCs of Sex Ed.

    ERIC Educational Resources Information Center

    Sroka, Stephen R.

    2002-01-01

    Cites statistics on extent of sexually transmitted diseases and pregnancies among adolescents; describes ideological dispute over how to teach sex education; advocates teaching the ABCs of sex education: Abstinence, Be Monogamous, and Condoms. (PKP)

  8. The ABCs of Safe BBQing

    MedlinePlus

    ... 158343.html The ABCs of Safe BBQing National Fire Protection Association offers tips for outdoor cooking To ... well-seasoned meats also comes a risk of fires and burns, the National Fire Protection Association (NFPA) ...

  9. ABC transporters and neuroblastoma.

    PubMed

    Yu, Denise M T; Huynh, Tony; Truong, Alan M; Haber, Michelle; Norris, Murray D

    2015-01-01

    Neuroblastoma is the most common cancer of infancy and accounts for 15% of all pediatric oncology deaths. Survival rates of high-risk neuroblastoma remain less than 50%, with amplification of the MYCN oncogene the most important aberration associated with poor outcome. Direct transcriptional targets of MYCN include a number of ATP-binding cassette (ABC) transporters, of which ABCC1 (MRP1), ABCC3 (MRP3), and ABCC4 (MRP4) are the best characterized. These three transporter genes have been shown to be strongly prognostic of neuroblastoma outcome in primary untreated neuroblastoma. In addition to their ability to efflux a number of chemotherapeutic drugs, evidence suggests that these transporters also contribute to neuroblastoma outcome independent of any role in cytotoxic drug efflux. Endogenous substrates of ABCC1 and ABCC4 that may be potential candidates affecting neuroblastoma biology include molecules such as prostaglandins and leukotrienes. These bioactive lipid mediators have the ability to influence biological processes contributing to cancer initiation and progression, such as angiogenesis, cell signaling, inflammation, proliferation, and migration and invasion. ABCC1 and ABCC4 are thus potential targets for therapeutic suppression in high-risk neuroblastoma, and recently developed small-molecule inhibitors may be an effective strategy in treating aggressive forms of this cancer, as well as other cancers that express high levels of these transporters. PMID:25640269

  10. The ABCs of Student Engagement

    ERIC Educational Resources Information Center

    Parsons, Seth A.; Nuland, Leila Richey; Parsons, Allison Ward

    2014-01-01

    Student engagement is an important consideration for teachers and administrators because it is explicitly associated with achievement. What the authors call the ABC's of engagement they outline as: Affective engagement, Behavioral engagement, and Cognitive engagement. They also present "Three Things Every Teacher Needs to Know about…

  11. Mapping the functional yeast ABC transporter interactome.

    PubMed

    Snider, Jamie; Hanif, Asad; Lee, Mid Eum; Jin, Ke; Yu, Analyn R; Graham, Chris; Chuk, Matthew; Damjanovic, Dunja; Wierzbicka, Marta; Tang, Priscilla; Balderes, Dina; Wong, Victoria; Jessulat, Matthew; Darowski, Katelyn D; San Luis, Bryan-Joseph; Shevelev, Igor; Sturley, Stephen L; Boone, Charles; Greenblatt, Jack F; Zhang, Zhaolei; Paumi, Christian M; Babu, Mohan; Park, Hay-Oak; Michaelis, Susan; Stagljar, Igor

    2013-09-01

    ATP-binding cassette (ABC) transporters are a ubiquitous class of integral membrane proteins of immense clinical interest because of their strong association with human disease and pharmacology. To improve our understanding of these proteins, we used membrane yeast two-hybrid technology to map the protein interactome of all of the nonmitochondrial ABC transporters in the model organism Saccharomyces cerevisiae and combined this data with previously reported yeast ABC transporter interactions in the BioGRID database to generate a comprehensive, integrated 'interactome'. We show that ABC transporters physically associate with proteins involved in an unexpectedly diverse range of functions. We specifically examine the importance of the physical interactions of ABC transporters in both the regulation of one another and in the modulation of proteins involved in zinc homeostasis. The interaction network presented here will be a powerful resource for increasing our fundamental understanding of the cellular role and regulation of ABC transporters. PMID:23831759

  12. ABC transporters: The power to change

    PubMed Central

    Rees, Douglas C.; Johnson, Eric; Lewinson, Oded

    2010-01-01

    ATP binding cassette (ABC) transporters constitute a ubiquitous superfamily of integral membrane proteins that are responsible for the ATP powered translocation of many substrates across membranes. The highly conserved ABC domains provide the nucleotide dependent engine that drives transport. By contrast, the transmembrane domains that create the translocation pathway are more variable. Recent structural advances with prokaryotic ABC transporters have provided a qualitative molecular framework for deciphering the transport cycle; an important goal is to develop quantitative models that detail the kinetic and molecular mechanisms by which ABC transporters couple the binding and hydrolysis of ATP to substrate translocation. PMID:19234479

  13. Bioinformatic survey of ABC transporters in dermatophytes.

    PubMed

    Gadzalski, Marek; Ciesielska, Anita; Stączek, Paweł

    2016-01-15

    ATP binding cassette (ABC) transporters constitute a very large and ubiquitous superfamily of membrane proteins. They are responsible for ATP hydrolysis driven translocation of countless substrates. Being a very old and diverse group of proteins present in all organisms they share a common feature, which is the presence of an evolutionary conservative nucleotide binding domain (NBD)--the engine that drives the transport. Another common domain is a transmembrane domain (TMD) which consists of several membrane-spanning helices. This part of protein is substrate-specific, thus it is much more variable. ABC transporters are known for driving drug efflux in many pathogens and cancer cells, therefore they are the subject of extensive studies. There are many examples of conferring a drug resistance phenotype in fungal pathogens by ABC transporters, however, little is known about these proteins in dermatophytes--a group of fungi causing superficial mycoses. So far only a single ABC transporter has been extensively studied in this group of pathogens. We analyzed available genomic sequences of seven dermatophyte species in order to provide an insight into dermatophyte ABC protein inventory. Phylogenetic studies of ABC transporter genes and their products were conducted and included ABC transporters of other fungi. Our results show that each dermatophyte genome studied possesses a great variety of ABC transporter genes. Detailed analysis of selected genes and their products indicates that relatively recent duplication of ABC transporter genes could lead to novel substrate specificity. PMID:26524502

  14. Identification and functional characterization of Penicillium marneffei pleiotropic drug resistance transporters ABC1 and ABC2.

    PubMed

    Panapruksachat, Siribun; Iwatani, Shun; Oura, Takahiro; Vanittanakom, Nongnuch; Chindamporn, Ariya; Niimi, Kyoko; Niimi, Masakazu; Lamping, Erwin; Cannon, Richard D; Kajiwara, Susumu

    2016-07-01

    Penicilliosis caused by the dimorphic fungus Penicillium marneffei is an endemic, AIDS-defining illness and, after tuberculosis and cryptococcosis, the third most common opportunistic infection of AIDS patients in tropical Southeast Asia. Untreated, patients have poor prognosis; however, primary amphotericin B treatment followed by prolonged itraconazole prophylaxis is effective. To identify ATP-binding cassette (ABC) transporters that may play a role in potential multidrug resistance of P. marneffei, we identified and classified all 46 P. marneffei ABC transporters from the genome sequence. PmABC1 and PmABC2 were most similar to the archetype Candida albicans multidrug efflux pump gene CDR1. P. marneffei Abc1p (PmAbc1p) was functionally expressed in Saccharomyces cerevisiae, although at rather low levels, and correctly localized to the plasma membrane, causing cells to be fourfold to eightfold more resistant to azoles and many other xenobiotics than untransformed cells. P. marneffei Abc2p (PmAbc2p) was expressed at similarly low levels, but it had no efflux activity and did not properly localize to the plasma membrane. Interestingly, PmAbc1p mislocalized and lost its transport activity when cells were shifted to 37 °C. We conclude that expression of PmAbc1p in S. cerevisiae confers resistance to several xenobiotics indicating that PmAbc1p may be a multidrug efflux pump. PMID:26782644

  15. The ABC transporters in Candidatus Liberibacter asiaticus

    PubMed Central

    Li, Wenlin; Cong, Qian; Pei, Jimin; Kinch, Lisa N; Grishin, Nick V

    2012-01-01

    Candidatus Liberibacter asiaticus (Ca. L. asiaticus) is a Gram-negative bacterium and the pathogen of Citrus Greening disease (Huanglongbing, HLB). As a parasitic bacterium, Ca. L. asiaticus harbors ABC transporters that play important roles in exchanging chemical compounds between Ca. L. asiaticus and its host. Here, we analyzed all the ABC transporter-related proteins in Ca. L. asiaticus. We identified 14 ABC transporter systems and predicted their structures and substrate specificities. In-depth sequence and structure analysis including multiple sequence alignment, phylogenetic tree reconstruction, and structure comparison further support their function predictions. Our study shows that this bacterium could use these ABC transporters to import metabolites (amino acids and phosphates) and enzyme cofactors (choline, thiamine, iron, manganese, and zinc), resist to organic solvent, heavy metal, and lipid-like drugs, maintain the composition of the outer membrane (OM), and secrete virulence factors. Although the features of most ABC systems could be deduced from the abundant experimental data on their orthologs, we reported several novel observations within ABC system proteins. Moreover, we identified seven nontransport ABC systems that are likely involved in virulence gene expression regulation, transposon excision regulation, and DNA repair. Our analysis reveals several candidates for further studies to understand and control the disease, including the type I virulence factor secretion system and its substrate that are likely related to Ca. L. asiaticus pathogenicity and the ABC transporter systems responsible for bacterial OM biosynthesis that are good drug targets. PMID:22807026

  16. K-ABC Subtest Specificity Recalculated.

    ERIC Educational Resources Information Center

    Bracken, Bruce A.; Howell, Karen Kuehn

    1989-01-01

    Provides recalculated subtest specificity figures for Kaufman Assessment Battery for Children (K-ABC) and corrects original calculation errors made during determination of subtests specificity when instrument was first published. Recalculated figures indicate that K-ABC has more specific variance than was originally thought. Questions about…

  17. The ABC transporters in Candidatus Liberibacter asiaticus.

    PubMed

    Li, Wenlin; Cong, Qian; Pei, Jimin; Kinch, Lisa N; Grishin, Nick V

    2012-11-01

    Candidatus Liberibacter asiaticus (Ca. L. asiaticus) is a Gram-negative bacterium and the pathogen of Citrus Greening disease (Huanglongbing, HLB). As a parasitic bacterium, Ca. L. asiaticus harbors ABC transporters that play important roles in exchanging chemical compounds between Ca. L. asiaticus and its host. Here, we analyzed all the ABC transporter-related proteins in Ca. L. asiaticus. We identified 14 ABC transporter systems and predicted their structures and substrate specificities. In-depth sequence and structure analysis including multiple sequence alignment, phylogenetic tree reconstruction, and structure comparison further support their function predictions. Our study shows that this bacterium could use these ABC transporters to import metabolites (amino acids and phosphates) and enzyme cofactors (choline, thiamine, iron, manganese, and zinc), resist to organic solvent, heavy metal, and lipid-like drugs, maintain the composition of the outer membrane (OM), and secrete virulence factors. Although the features of most ABC systems could be deduced from the abundant experimental data on their orthologs, we reported several novel observations within ABC system proteins. Moreover, we identified seven nontransport ABC systems that are likely involved in virulence gene expression regulation, transposon excision regulation, and DNA repair. Our analysis reveals several candidates for further studies to understand and control the disease, including the type I virulence factor secretion system and its substrate that are likely related to Ca. L. asiaticus pathogenicity and the ABC transporter systems responsible for bacterial OM biosynthesis that are good drug targets. PMID:22807026

  18. An ABC for decision making.

    PubMed

    Garcia, Luiz Henrique Costa; Ferreira, Bruna Cortez

    2015-01-01

    The present study was aimed at proposing a systematic evaluation of cranial computed tomography, identifying the main aspects to be analyzed in order to facilitate the decision making process regarding diagnosis and management in emergency settings. The present descriptive study comprised a literature review at the following databases: Access Medicine and Access Emergency Medicine (McGraw- Hill Education); British Medical Journal Evidence Center; UptoDate; Bireme; PubMed; Lilacs; SciELO; ProQuest; Micromedex (Thomson Reuters); Embase. Once the literature review was completed, the authors identified the main diseases with tomographic repercussions and proposed the present system to evaluate cranial computed tomography images. An easy-to-memorize ABC system will facilitate the decision making in emergency settings, as it covers the main diseases encountered by intensivists and emergency physicians, and provides a sequential guidance about anatomical structures to be investigated as well as their respective alterations. PMID:25987751

  19. An ABC for decision making*

    PubMed Central

    Garcia, Luiz Henrique Costa; Ferreira, Bruna Cortez

    2015-01-01

    The present study was aimed at proposing a systematic evaluation of cranial computed tomography, identifying the main aspects to be analyzed in order to facilitate the decision making process regarding diagnosis and management in emergency settings. The present descriptive study comprised a literature review at the following databases: Access Medicine and Access Emergency Medicine (McGraw- Hill Education); British Medical Journal Evidence Center; UptoDate; Bireme; PubMed; Lilacs; SciELO; ProQuest; Micromedex (Thomson Reuters); Embase. Once the literature review was completed, the authors identified the main diseases with tomographic repercussions and proposed the present system to evaluate cranial computed tomography images. An easy-to-memorize ABC system will facilitate the decision making in emergency settings, as it covers the main diseases encountered by intensivists and emergency physicians, and provides a sequential guidance about anatomical structures to be investigated as well as their respective alterations. PMID:25987751

  20. Identification of ABC transporters in Sarcoptes scabiei.

    PubMed

    Mounsey, K E; Holt, D C; McCarthy, J; Walton, S F

    2006-06-01

    We have identified and partially sequenced 8 ABC transporters from an EST dataset of Sarcoptes scabiei var. hominis, the causative agent of scabies. Analysis confirmed that most of the known ABC subfamilies are represented in the EST dataset including several members of the multidrug resistance protein subfamily (ABC-C). Although P-glycoprotein (ABC-B) sequences were not found in the EST dataset, a partial P-glycoprotein sequence was subsequently obtained using a degenerate PCR strategy and library screening. Thus a total of 9 potential S. scabiei ABC transporters representing the subfamilies A, B, C, E, F and H have been identified. Ivermectin is currently used in the treatment of hyper-infested (crusted) scabies, and has also been identified as a potentially effective acaricide for mass treatment programmes in scabies-endemic communities. The observation of clinical and in vitro ivermectin resistance in 2 crusted scabies patients who received multiple treatments has raised serious concerns regarding the sustainability of such programmes. One possible mechanism for ivermectin resistance is through ABC transporters such as P-glycoprotein. This work forms an important foundation for further studies to elucidate the potential role of ABC transporters in ivermectin resistance of S. scabiei. PMID:16454864

  1. Applying the ABCs in provider organizations.

    PubMed

    Pandey, Seema

    2012-11-01

    Activity-based costing (ABC) is an accounting technique designed to guard against potentially serious financial problems that can arise when an organization's accounting costs deviate significantly from its actual costs. In general, an ABC analysis considers two factors: a cost element (a directly measurable unit of cost, such as the cost of an item) and a cost driver (a directly measurable feature of the service, such as how often the item is used). ABC is best applied to specific service areas, orservice packages, for which consumption of resources is largely predictable and atomic units of services can be accurately identified. PMID:23173369

  2. Isolation and Characterization of the Colletotrichum acutatum ABC Transporter CaABC1

    PubMed Central

    Kim, Suyoung; Park, Sook-Young; Kim, Hyejeong; Kim, Dongyoung; Lee, Seon-Woo; Kim, Heung Tae; Lee, Jong-Hwan; Choi, Woobong

    2014-01-01

    Fungi tolerate exposure to various abiotic stresses, including cytotoxic compounds and fungicides, via their ATP-driven efflux pumps belonging to ATP-binding cassette (ABC) transporters. To clarify the molecular basis of interaction between the fungus and various abiotic stresses including fungicides, we constructed a cDNA library from germinated conidia of Colletotrichum acutatum, a major anthracnose pathogen of pepper (Capsicum annum L.). Over 1,000 cDNA clones were sequenced, of which single clone exhibited significant nucleotide sequence homology to ABC transporter genes. We isolated three fosmid clones containing the C. acutatum ABC1 (CaABC1) gene in full-length from genomic DNA library screening. The CaABC1 gene consists of 4,059 bp transcript, predicting a 1,353-aa protein. The gene contains the typical ABC signature and Walker A and B motifs. The 5′-flanking region contains a CAAT motif, a TATA box, and a Kozak region. Phylogenetic and structural analysis suggested that the CaABC1 is a typical ABC transporter gene highly conserved in various fungal species, as well as in Chromista, Metazoans, and Viridiplantae. We also found that CaABC1 was up-regulated during conidiation and a minimal medium condition. Moreover, CaABC1 was induced in iprobenfos, kresoxim-methyl, thiophanate-methyl, and hygromycin B. These results demonstrate that CaABC1 is necessary for conidiation, abiotic stress, and various fungicide resistances. These results will provide the basis for further study on the function of ABC transporter genes in C. acutatum. PMID:25506302

  3. Isolation and Characterization of the Colletotrichum acutatum ABC Transporter CaABC1.

    PubMed

    Kim, Suyoung; Park, Sook-Young; Kim, Hyejeong; Kim, Dongyoung; Lee, Seon-Woo; Kim, Heung Tae; Lee, Jong-Hwan; Choi, Woobong

    2014-12-01

    Fungi tolerate exposure to various abiotic stresses, including cytotoxic compounds and fungicides, via their ATP-driven efflux pumps belonging to ATP-binding cassette (ABC) transporters. To clarify the molecular basis of interaction between the fungus and various abiotic stresses including fungicides, we constructed a cDNA library from germinated conidia of Colletotrichum acutatum, a major anthracnose pathogen of pepper (Capsicum annum L.). Over 1,000 cDNA clones were sequenced, of which single clone exhibited significant nucleotide sequence homology to ABC transporter genes. We isolated three fosmid clones containing the C. acutatum ABC1 (CaABC1) gene in full-length from genomic DNA library screening. The CaABC1 gene consists of 4,059 bp transcript, predicting a 1,353-aa protein. The gene contains the typical ABC signature and Walker A and B motifs. The 5'-flanking region contains a CAAT motif, a TATA box, and a Kozak region. Phylogenetic and structural analysis suggested that the CaABC1 is a typical ABC transporter gene highly conserved in various fungal species, as well as in Chromista, Metazoans, and Viridiplantae. We also found that CaABC1 was up-regulated during conidiation and a minimal medium condition. Moreover, CaABC1 was induced in iprobenfos, kresoxim-methyl, thiophanate-methyl, and hygromycin B. These results demonstrate that CaABC1 is necessary for conidiation, abiotic stress, and various fungicide resistances. These results will provide the basis for further study on the function of ABC transporter genes in C. acutatum. PMID:25506302

  4. The ABC`s of nuclear science workshop

    SciTech Connect

    McMahn, P.; Carlock, M.S.; Mattis, H.; Norman, E.; Seaborg, G.

    1997-12-31

    Over the last several years the Contemporary Physics Education Project (CPEP) has developed two wall charts which illustrate contemporary aspects of particle and plasma physics for high school and undergraduate students. We are now working with CPEP on the development of a similar chart for nuclear science. This chart will illustrate the basics of nuclear science coupled with the exciting research which is being done in this field. This workshop will explore the wall chart, along with materials and experiments that have been developed to accompany it. The set of experiments have been developed by high school teachers, chemists, and physicists working together, and include experiments such as, {open_quotes}the ABCs of Nuclear Science,{close_quotes} and experiments exploring the various kinds of radioactive decay, radioactivity in common household products, half-live measurements, radiography, etc. Teachers who join the project as chart field testers will receive a poster size chart and accompanying materials free of charge. The materials also include a video about cosmic rays has also been produced for the classroom.

  5. Yeast ABC proteins involved in multidrug resistance.

    PubMed

    Piecuch, Agata; Obłąk, Ewa

    2014-03-01

    Pleiotropic drug resistance is a complex phenomenon that involves many proteins that together create a network. One of the common mechanisms of multidrug resistance in eukaryotic cells is the active efflux of a broad range of xenobiotics through ATP-binding cassette (ABC) transporters. Saccharomyces cerevisiae is often used as a model to study such activity because of the functional and structural similarities of its ABC transporters to mammalian ones. Numerous ABC transporters are found in humans and some are associated with the resistance of tumors to chemotherapeutics. Efflux pump modulators that change the activity of ABC proteins are the most promising candidate drugs to overcome such resistance. These modulators can be chemically synthesized or isolated from natural sources (e.g., plant alkaloids) and might also be used in the treatment of fungal infections. There are several generations of synthetic modulators that differ in specificity, toxicity and effectiveness, and are often used for other clinical effects. PMID:24297686

  6. Quasi-Biennial Oscillation signatures in the diurnal tidal winds over Cachoeira Paulista

    NASA Astrophysics Data System (ADS)

    Rodrigues de Araujo, Luciana; Jacobi, Christoph; Batista, Paulo; Lima, Lourivaldo

    2016-07-01

    The solar diurnal tidal plays an important role in the Mesosphere and Lower Thermosphere (MLT) region at low latitudes, in which its amplitude for horizontal winds maximizes around 20 degrees. The tides are excited in the lower atmosphere and stratosphere and can be affected by short and long-term local variations during their upward propagation. In this work, the meteor winds obtained over Cachoeira Paulista (22.7° S, 45.0° W), Brazil, have been used to investigate interannual variability in the amplitude of the diurnal tidal winds. The monthly diurnal tidal displays year to year variations. Amplitudes are strongest when the equatorial quasi-biennial oscillation (QBO) at the 30 mb level is eastward. This behavior can be observed in all seasons in the meridional component, whilst it is more clearly expressed during austral autumn in the zonal component, just when the diurnal tidal is strongest at this latitude.

  7. Yeast ABC transporters in lipid trafficking.

    PubMed

    Prasad, Rajendra; Khandelwal, Nitesh Kumar; Banerjee, Atanu

    2016-08-01

    Throughout its evolution, the ATP-binding cassette (ABC) transporter superfamily has experienced a rapid expansion in its substrate repertoire and functions. Of the diverse functions that these pumps offer, their drug transport properties have attracted considerable attention primarily owing to their clinical significance. Despite this fact, emerging evidence suggests that physiological substrates of transporters also affect the overall functioning of an organism. Lipids, as substrates of ABC transporters, constitute one feature found in all representative groups of the living kingdom. Due to the importance of lipid species in the cellular physiology of an organism, their proper distribution within cells is crucial. This fact is well exemplified by the vast number of medical conditions that have been caused as a result of perturbations in ABC transporter-mediated lipid transport in higher organisms. In yeasts, apart from providing transport functions, ABC transporters also coordinate regulatory networks with lipids. This review focuses on yeast ABC transporters involved in the transport of lipids and briefly discusses the integration of their regulatory network with that of the lipid species. PMID:27259587

  8. [Population and labor force: the case of coffee growing in the West Paulista].

    PubMed

    De Oliveira, M C; Madeira, F R

    1986-01-01

    Fertility rates in Brazil have dropped at an increasingly rapid rate since 1940; this has occurred in the absence of an explicit, official policy on population control, and without a notable increase in quality of life. The context for analysis of this change in population dynamics is the colonato, the coffee plantation labor system which was prevalent in the Western portion of the state of Sao Paulo, or Paulista West unitl 1930; work organization here was based on the family as a unit of labor force. This study reconsiders the importance of the family in the labor force under the colonato, and the demographic implications of this organizational pattern. European immigrant colonists contracted with coffee growers to do subsistence farming; in exchange, they were granted land in proportion to the number of coffee trees tended. An increase in the number of family members resulted in an increase in productive capacity of the head of the family. The high fertility rate among these immigrants may have been a natural response to the existing institutional control of the labor system, high mortality rates and abundance of land; however, it may not have been a deliberate, planned response based on economic essentials. Also significant is the fact that the average family size in the Paulista West has changed little in the last 60 years. Immigrant families may have received contracts based on their favorable demographic composition rather than on their size alone. The elimination of contracted, guaranteed land-for-subsistence farming is sufficient to explain the changes in fertility patterns. Additional research is needed and should be based on empirical evidence. PMID:12268885

  9. The cloning of a human ABC gene (ABC3) mapping to chromosome 16p13.3

    SciTech Connect

    Connors, T.D.; Van Raay, T.J.; Petry, L.R.

    1997-01-15

    The ATP binding cassette (ABC) transporters, or traffic ATPases, constitute a large family of proteins responsible for the transport of a wide variety of substrates across cell membranes in both prokaryotic and eukaryotic cells. We describe a human ABC protein with regions of strong homology to the recently described murine ABC1 and ABC2 transporters. The gene for this novel protein, human ABC3, maps near the polycystic kidney disease type 1 (PKD1) gene on chromosome 16p13.3. The ABC3 gene is expressed at highest levels in lung compared to other tissues. 19 refs., 3 figs.

  10. Structural insights into ABC transporter mechanism

    SciTech Connect

    Oldham, Michael L.; Davidson, Amy L.; Chen, Jue

    2010-07-27

    ATP-binding cassette (ABC) transporters utilize the energy from ATP hydrolysis to transport substances across the membrane. In recent years, crystal structures of several ABC transporters have become available. These structures show that both importers and exporters oscillate between two conformations: an inward-facing conformation with the substrate translocation pathway open to the cytoplasm and an outward-facing conformation with the translocation pathway facing the opposite side of the membrane. In this review, conformational differences found in the structures of homologous ABC transporters are analyzed to understand how alternating-access is achieved. It appears that rigid-body rotations of the transmembrane subunits, coinciding with the opening and closing of the nucleotide-binding subunits, couples ATP hydrolysis to substrate translocation.

  11. Communicating a New ABC: Advocacy, Partnerships, and Implementing Change.

    ERIC Educational Resources Information Center

    Ryan, Cathy

    2001-01-01

    Reiterates some key points and responds to challenges issued by the speakers to the Association for Business Communication (ABC) conference. Notes that Paula Pomerenke spoke about formalizing support of Plain Language across the continents and about ABC's continuing need to strengthen relationships with practitioners. Suggests the ABC build…

  12. THE ABC TRANSPORTER, AbcB3, MEDIATES cAMP EXPORT IN D. DISCOIDEUM DEVELOPMENT

    PubMed Central

    Miranda, Edward Roshan; Nam, Edward A.; Kuspa, Adam; Shaulsky, Gad

    2014-01-01

    Extracellular cAMP functions as a primary ligand for cell surface cAMP receptors throughout Dictyostelium discoideum development, controlling chemotaxis and morphogenesis. The developmental consequences of cAMP signaling and the metabolism of cAMP have been studied in great detail, but it has been unclear how cells export cAMP across the plasma membrane. Here we show pharmacologically and genetically that ABC transporters mediate cAMP export. Using an evolutionary-developmental biology approach, we identified several candidate abc genes and characterized one of them, abcB3, in more detail. Genetic and biochemical evidence suggest that AbcB3 is a component of the cAMP export mechanism in D. discoideum development. PMID:25448698

  13. The K-ABC and Ability Training.

    ERIC Educational Resources Information Center

    Salvia, John; Hritcko, Terese

    1984-01-01

    Nine questions that link performance on the Kaufman Assessment Battery for Children to classroom teaching and pupil learning were posed. Results revealed the absence of empirical validation for linking K-ABC scores and altered teaching methods to known and desirable outcomes. (Author/CL)

  14. The ABC's of Learning in Infancy.

    ERIC Educational Resources Information Center

    Saunders, Minta M.

    Learning in infancy is based on activity, beginnings, and curiosity, the so-called ABC's. Earliest behavior consists of mass activity, the period from birth to 24 months of sensory-motor development which provides the foundation for all future learning. Adults must provide space, toys, and affectionate care to help infants proceed through…

  15. ABC--Me Teacher, You Student.

    ERIC Educational Resources Information Center

    Ames, Dianne M.

    As the world has moved from the industrial age to a technology-based society in which individual and societal competence is paramount, the focus of educational systems must shift from the basic ABC's to Competency-Based Education (CBE). Educational priorities must be continually revised to meet competitive and ever-changing workplace demands and…

  16. The New ABC of the Arts

    ERIC Educational Resources Information Center

    Tusa, John

    2007-01-01

    This article presents a new alphabet of the arts that shows how the arts world has been transformed the past five years. Beginning with "A" for assessment and continuing through "Y" for year end, the ABC of the arts illustrates the ways in which the arts world is judged, managed, and evaluated, and shows that the skill of arts management is to…

  17. The ABCs of Managing Teacher Stress.

    ERIC Educational Resources Information Center

    Nagel, Liza; Brown, Sheri

    2003-01-01

    Describes stress management for teachers and presents strategies that teachers can use to lessen the impact of stress. Outlines the ABCs of stress: Acknowledge, Behavior Modification, and Communication. Notes that stress can motivate teachers to explore new instructional strategies, adopt innovative approaches to increasing student motivation, and…

  18. ABC transporters in fish species: a review

    PubMed Central

    Ferreira, Marta; Costa, Joana; Reis-Henriques, Maria A.

    2014-01-01

    ATP-binding cassette (ABC) proteins were first recognized for their role in multidrug resistance (MDR) in chemotherapeutic treatments, which is a major impediment for the successful treatment of many forms of malignant tumors in humans. These proteins, highly conserved throughout vertebrate species, were later related to cellular detoxification and accounted as responsible for protecting aquatic organisms from xenobiotic insults in the so-called multixenobiotic resistance mechanism (MXR). In recent years, research on these proteins in aquatic species has highlighted their importance in the detoxification mechanisms in fish thus it is necessary to continue these studies. Several transporters have been pointed out as relevant in the ecotoxicological context associated to the transport of xenobiotics, such as P-glycoproteins (Pgps), multidrug-resistance-associated proteins (MRPs 1-5) and breast cancer resistance associated protein (BCRP). In mammals, several nuclear receptors have been identified as mediators of phase I and II metabolizing enzymes and ABC transporters. In aquatic species, knowledge on co-regulation of the detoxification mechanism is scarce and needs to be addressed. The interaction of emergent contaminants that can act as chemosensitizers, with ABC transporters in aquatic organisms can compromise detoxification processes and have population effects and should be studied in more detail. This review intends to summarize the recent advances in research on MXR mechanisms in fish species, focusing in (1) regulation and functioning of ABC proteins; (2) cooperation with phase I and II biotransformation enzymes; and (3) ecotoxicological relevance and information on emergent pollutants with ability to modulate ABC transporters expression and activity. Several lines of evidence are clearly suggesting the important role of these transporters in detoxification mechanisms and must be further investigated in fish to underlay the mechanism to consider their use as

  19. Loss of plastoglobule kinases ABC1K1 and ABC1K3 causes conditional degreening, modified prenyl-lipids, and recruitment of the jasmonic acid pathway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plastoglobules (PGs) are plastid lipid-protein particles. This study examines the function of PG-localized kinases ABC1K1 and ABC1K3 in Arabidopsis thaliana. Several lines of evidence suggested that ABC1K1 and ABC1K3 form a protein complex. Null mutants for both genes (abc1k1 and abc1k3) and the dou...

  20. ABC Transporters and the Alzheimer's Disease Enigma.

    PubMed

    Wolf, Andrea; Bauer, Björn; Hartz, Anika M S

    2012-01-01

    Alzheimer's disease (AD) is considered the "disease of the twenty-first century." With a 10-fold increase in global incidence over the past 100 years, AD is now reaching epidemic proportions and by all projections, AD patient numbers will continue to rise. Despite intense research efforts, AD remains a mystery and effective therapies are still unavailable. This represents an unmet need resulting in clinical, social, and economic problems. Over the last decade, a new AD research focus has emerged: ATP-binding cassette (ABC) transporters. In this article, we provide an overview of the ABC transporters ABCA1, ABCA2, P-glycoprotein (ABCB1), MRP1 (ABCC1), and BCRP (ABCG2), all of which are expressed in the brain and have been implicated in AD. We summarize recent findings on the role of these five transporters in AD, and discuss their potential to serve as therapeutic targets. PMID:22675311

  1. Three ways to learn the ABCs.

    PubMed

    Ng, M; Yanofsky, M F

    2000-02-01

    The ABC model of flower development represents a milestone in explaining how the fate of emerging floral organ primordia is specified. This model states that organ identity is specified by different combinations of the activities of the A, B and C class homeotic genes. In spite of the remarkable simplicity of this model, the complex regulatory interactions that establish the initial pattern of A, B and C gene activity have yet to be fully explained. It has been shown that the LEAFY gene functions early to promote flower meristem identity, and that it is subsequently required for the normal expression of the ABC genes. Recently, LEAFY has been identified as an immediate upstream regulator of the floral homeotic genes, thus opening up an avenue to examine the transcriptional interactions that underlie floral patterning. PMID:10679448

  2. Nanostructured assemblies from amphiphilic ABC multiblock polymers

    NASA Astrophysics Data System (ADS)

    Hillmyer, Marc A.

    2012-02-01

    Amphiphilic AB diblock copolymers containing a water compatible segment can self-assemble in aqueous media to give supramolecular structures that include simple spherical micelles and macromolecular vesicles termed polymersomes. Amphiphilic ABA triblocks with hydrophobic end blocks can adopt analogous structures but can also form gels at high polymer concentrations. The structural and chemical diversity demonstrated in block copolymer micelles and gels makes them attractive for applications ranging from drug delivery to personal care products to nanoreactors. The inclusion of a third block in amphiphilic ABC triblock systems can lead to a much wider array of self-assembled structures that depend not only on composition but also on block sequence, architecture and incompatibility considerations. I will present our recent efforts on tuning micelle and gel structure and behavior using controlled architecture ABC triblocks. The combination of diverse polymer segments into a single macromolecule is a powerful method for development of self-assembled structures with both new form and new function.

  3. Adhesion to chondroitinase ABC treated dentin

    PubMed Central

    Mazzoni, Annalisa; Pashley, David H.; Ruggeri, Alessandra; Vita, Francesca; Falconi, Mirella; Di Lenarda, Roberto; Breschi, Lorenzo

    2013-01-01

    Dentin bonding relies on complete resin impregnation throughout the demineralised hydrophilic collagen mesh. Chondroitin sulphate-glycosaminoglycans are claimed to regulate the three-dimensional arrangement of the dentin organic matrix and its hydrophilicity. The aim of this study was to investigate bond strength of two etch-and-rinse adhesives to chondroitinase ABC treated dentin. Human extracted molars were treated with chondroitinase ABC and a double labelling immunohistochemical technique was applied to reveal type I collagen and chondroitin 4/6 sulphate distribution under field emission in-lens scanning electron microscope. The immunohistochemical technique confirmed the effective removal of chondroitin 4/6 sulphate after the enzymatic treatment. Dentin surfaces exposed to chondroitinase ABC and untreated specimens prepared on untreated acid-etched dentin were bonded with Adper Scotchbond Multi-Purpose or Prime & Bond NT. Bonded specimens were submitted to microtensile testing and nanoleakage interfacial analysis under transmission electron microscope. Increased mean values of microtensile bond strength and reduced nanoleakage expression were found for both adhesives after chondroitinase ABC treatment of the dentin surface. Adper Scotchbond Multi-Purpose increased its bond strength about 28%, while bonding made with Prime & Bond NT almost doubled (92% increase) compared to untreated specimens. This study supports the hypothesis that adhesion can be enhanced by removal of chondroitin 4/6 sulphate and dermatan sulphate, probably due to a reduced amount of water content and enlarged interfibrillar spaces. Further studies should validate this hypothesis investigating the stability of chondroitin 4/6 and dermatan sulphate-depleted dentin bonded interface over time. PMID:18161809

  4. Pharmacological correction of misfolding of ABC proteins.

    PubMed

    Rudashevskaya, Elena L; Stockner, Thomas; Trauner, Michael; Freissmuth, Michael; Chiba, Peter

    2014-06-01

    The endoplasmic reticulum (ER) quality control system distinguishes between correctly and incorrectly folded proteins to prevent processing of aberrantly folded conformations along the secretory pathway. Non-synonymous mutations can lead to misfolding of ABC proteins and associated disease phenotypes. Specific phenotypes may at least partially be corrected by small molecules, so-called pharmacological chaperones. Screening for folding correctors is expected to open an avenue for treatment of diseases such as cystic fibrosis and intrahepatic cholestasis. PMID:25027379

  5. Pharmacological correction of misfolding of ABC proteins☆

    PubMed Central

    Rudashevskaya, Elena L.; Stockner, Thomas; Trauner, Michael; Freissmuth, Michael; Chiba, Peter

    2014-01-01

    The endoplasmic reticulum (ER) quality control system distinguishes between correctly and incorrectly folded proteins to prevent processing of aberrantly folded conformations along the secretory pathway. Non-synonymous mutations can lead to misfolding of ABC proteins and associated disease phenotypes. Specific phenotypes may at least partially be corrected by small molecules, so-called pharmacological chaperones. Screening for folding correctors is expected to open an avenue for treatment of diseases such as cystic fibrosis and intrahepatic cholestasis. PMID:25027379

  6. Analyzing health care operations using ABC.

    PubMed

    Ross, Thomas K

    2004-01-01

    The evolution of health care created a climate in which cost was subordinate to medical treatment. Current reimbursement constraints have increased the need for providers to be cost conscious, but they have discovered that current accounting practices do not provide the appropriate information to determine the cost of service or make decisions. This article argues that activity-based costing (ABC) can bridge the gap between the medical and financial communities and provide a foundation for performance improvement. PMID:15151193

  7. Peroxisomal ABC transporters: functions and mechanism

    PubMed Central

    Baker, Alison; Carrier, David J.; Schaedler, Theresia; Waterham, Hans R.; van Roermund, Carlo W.; Theodoulou, Frederica L.

    2015-01-01

    Peroxisomes are arguably the most biochemically versatile of all eukaryotic organelles. Their metabolic functions vary between different organisms, between different tissue types of the same organism and even between different developmental stages or in response to changed environmental conditions. New functions for peroxisomes are still being discovered and their importance is underscored by the severe phenotypes that can arise as a result of peroxisome dysfunction. The β-oxidation pathway is central to peroxisomal metabolism, but the substrates processed are very diverse, reflecting the diversity of peroxisomes across species. Substrates for β-oxidation enter peroxisomes via ATP-binding cassette (ABC) transporters of subfamily D; (ABCD) and are activated by specific acyl CoA synthetases for further metabolism. Humans have three peroxisomal ABCD family members, which are half transporters that homodimerize and have distinct but partially overlapping substrate specificity; Saccharomyces cerevisiae has two half transporters that heterodimerize and plants have a single peroxisomal ABC transporter that is a fused heterodimer and which appears to be the single entry point into peroxisomes for a very wide variety of β-oxidation substrates. Our studies suggest that the Arabidopsis peroxisomal ABC transporter AtABCD1 accepts acyl CoA substrates, cleaves them before or during transport followed by reactivation by peroxisomal synthetases. We propose that this is a general mechanism to provide specificity to this class of transporters and by which amphipathic compounds are moved across peroxisome membranes. PMID:26517910

  8. Phase behavior of model ABC triblock copolymers

    NASA Astrophysics Data System (ADS)

    Chatterjee, Joon

    The phase behavior of poly(isoprene-b-styrene- b-ethylene oxide) (ISO), a model ABC triblock copolymer has been studied. This class of materials exhibit self-assembly, forming a large array of ordered morphologies at length scales of 5-100 nm. The formation of stable three-dimensionally continuous network morphologies is of special interest in this study. Since these nanostructures considerably impact the material properties, fundamental knowledge for designing ABC systems have high technological importance for realizing applications in the areas of nanofabrication, nanoporous media, separation membranes, drug delivery and high surface area catalysts. A comprehensive framework was developed to describe the phase behavior of the ISO triblock copolymers at weak to intermediate segregation strengths spanning a wide range of composition. Phases were characterized through a combination of characterization techniques, including small angle x-ray scattering, dynamic mechanical spectroscopy, transmission electron microscopy, and birefringence measurements. Combined with previous investigations on ISO, six different stable ordered state symmetries have been identified: lamellae (LAM), Fddd orthorhombic network (O70), double gyroid (Q230), alternating gyroid (Q214), hexagonal (HEX), and body-centered cubic (BCC). The phase map was found to be somewhat asymmetric around the fI = fO isopleth. This work provides a guide for theoretical studies and gives insight into the intricate effects of various parameters on the self-assembly of ABC triblock copolymers. Experimental SAXS data evaluated with a simple scattering intensity model show that local mixing varies continuously across the phase map between states of two- and three-domain segregation. Strategies of blending homopolymers with ISO triblock copolymer were employed for studying the swelling properties of a lamellar state. Results demonstrate that lamellar domains swell or shrink depending upon the type of homopolymer that

  9. Revisiting the ABCs of multidrug resistance in cancer chemotherapy.

    PubMed

    Tiwari, Amit K; Sodani, Kamlesh; Dai, Chun-Ling; Ashby, Charles R; Chen, Zhe-Sheng

    2011-04-01

    The adenosine tri-phosphate binding cassette (ABC) transporters are one of the largest transmembrane gene families in humans. The ABC transporters are present in a number of tissues, providing protection against xenobiotics and certain endogenous molecules. Unfortunately, their presence produces suboptimal chemotherapeutic outcomes in cancer patient tumor cells. It is well established that they actively efflux antineoplastic agents from cancer cells, producing the multidrug resistance (MDR) phenotype. The inadequate response to chemotherapy and subsequent poor prognosis in cancer patients can be in part the result of the clinical overexpression of ABC transporters. In fact, one of the targeted approaches for overcoming MDR in cancer cells is that directed towards blocking or inhibiting ABC transporters. Indeed, for almost three decades, research has been conducted to overcome MDR through pharmacological inhibition of ABC transporters with limited clinical success. Therefore, contemporary strategies to identify or to synthesize selective "resensitizers" of ABC transporters with limited nonspecific toxicity have been undertaken. Innovative approaches en route to understanding specific biochemical role of ABC transporters in MDR and tumorigenesis will prove essential to direct our knowledge towards more effective targeted therapies. This review briefly discusses the current knowledge regarding the clinical involvement of ABC transporters in MDR to antineoplastic drugs and highlights approaches undertaken so far to overcome ABC transporter-mediated MDR in cancer. PMID:21118094

  10. The Role of the Atypical Kinases ABC1K7 and ABC1K8 in Abscisic Acid Responses

    PubMed Central

    Manara, Anna; DalCorso, Giovanni; Furini, Antonella

    2016-01-01

    The ABC1K family of atypical kinases (activity of bc1 complex kinase) is represented in bacteria, archaea, and eukaryotes. In plants they regulate diverse physiological processes in the chloroplasts and mitochondria, but their precise functions are poorly defined. ABC1K7 and ABC1K8 are probably involved in oxidative stress responses, isoprenyl lipid synthesis and distribution of iron within chloroplasts. Because reactive oxygen species take part in abscisic acid (ABA)-mediated processes, we investigated the functions of ABC1K7 and ABC1K8 during germination, stomatal movement, and leaf senescence. Both genes were upregulated by ABA treatment and some ABA-responsive physiological processes were affected in abc1k7 and abc1k8 mutants. Germination was more severely affected by ABA, osmotic stress and salt stress in the single and double mutants; the stomatal aperture was smaller in the mutants under standard growth conditions and was not further reduced by exogenous ABA application; ABA-induced senescence symptoms were more severe in the leaves of the single and double mutants compared to wild type leaves. Taken together, our results suggest that ABC1K7 and ABC1K8 might be involved in the cross-talk between ABA and ROS signaling. PMID:27047531

  11. APOLLO 13: A News Bulletin from ABC

    NASA Technical Reports Server (NTRS)

    1974-01-01

    APOLLO 13: ABC breaks the news of a mishap aboard the spacecraft From the film documentary 'APOLLO 13: 'Houston, We've got a problem'', part of a documentary series on the APOLLO missions made in the early '70's and narrated by Burgess Meredith. APOLO 13 : Third manned lunar landing attempt with James A. Lovell, Jr., John L. Swigert, Jr., and Fred W. Haise, Jr. Pressure lost in SM oxygen system; mission aborted; LM used for life support. Mission Duration 142hrs 54mins 41sec

  12. ABCs of Being Smart: S Is for Supporting

    ERIC Educational Resources Information Center

    Foster, Joanne

    2014-01-01

    Joanne Foster's article "R We There Yet?" was first published in "Parenting for High Potential" ("PHP") in 2006, which became the springboard for the "ABCs of Being Smart" series of columns. At that time, Foster invited "PHP" readers to think about their own versions of the "ABCs of Being…

  13. How heterogeneous is the involvement of ABC transporters against insecticides?

    PubMed

    Porretta, Daniele; Epis, Sara; Mastrantonio, Valentina; Ferrari, Marco; Bellini, Romeo; Favia, Guido; Urbanelli, Sandra

    2016-05-01

    Understanding the molecular mechanisms underlying cellular defense against xenobiotic compounds is a main research issue in medical and veterinary entomology, as insecticide/acaricide resistance is a major threat in the control of arthropods. ABC transporters are recognized as a component of the detoxifying mechanism in arthropods. We investigated the possible involvement of ABC transporters in defense to the organophosphate insecticide temephos in the malarial vector Anopheles stephensi. We performed bioassays on larvae of An. stephensi, using insecticide alone and in combination with ABC-transporter inhibitors, to assess synergism between these compounds. Next, we investigated the expression profiles of six ABC transporter genes in larvae exposed to temephos. Surprisingly, neither bioassays nor gene expression analyses provided any evidence for a major role of ABC transporters in defense against temephos in An. stephensi. We thus decided to review existing literature to generate a record of other studies that failed to reveal a role for ABC transporters against particular insecticides/acaricides. A review of the scientific literature led to the recovery of 569 papers about ABC transporters; among these, 50 involved arthropods, and 10 reported negative results. Our study on An. stephensi and accompanying literature review highlight the heterogeneity that exists in ABC transporter involvement in defense/resistance mechanisms in arthropods. PMID:26855383

  14. The ABCs of School Choice, 2009-2010 Edition

    ERIC Educational Resources Information Center

    Friedman Foundation for Educational Choice, 2010

    2010-01-01

    This publication presents the 2009-2010 edition of the Friedman Foundation for Educational Choice's "ABCs of School Choice". The "ABCs of School Choice" provides the latest in up-to-date and accurate information about the many school choice success stories taking place throughout the country. Readers will find this guide an essential resource on…

  15. Measuring Academic Behavioural Confidence: The ABC Scale Revisited

    ERIC Educational Resources Information Center

    Sander, Paul; Sanders, Lalage

    2009-01-01

    The Academic Behavioural Confidence (ABC) scale has been shown to be valid and can be useful to teachers in understanding their students, enabling the design of more effective teaching sessions with large cohorts. However, some of the between-group differences have been smaller than expected, leading to the hypothesis that the ABC scale many not…

  16. The NOS Challenge

    ERIC Educational Resources Information Center

    Quigley, Cassie; Buck, Gayle; Akerson, Valarie

    2011-01-01

    "The picture of a scientist is me!" exclaims first grader Kendra during a nature of science (NOS) lesson. She drew a picture of a scientist and explained that she was going to be a scientist when she grew up because she "loved to observe like a scientist." Kendra's experience was a part of a 30-day unit designed specifically for first graders.…

  17. The ABC transporter gene family of Daphnia pulex

    PubMed Central

    Sturm, Armin; Cunningham, Phil; Dean, Michael

    2009-01-01

    Background The large gene superfamily of ABC (ATP-binding cassette) transporters encodes membrane proteins involved in trafficking processes across biological membranes and further essential cell biological functions. ABC transporters are evolutionary ancient and involved in the biochemical defence against toxicants. We report here a genome-wide survey of ABC proteins of Daphnia pulex, providing for the first time information on ABC proteins in crustacea, a primarily aquatic arthropod subphylum of high ecological and economical importance. Results We identified 64 ABC proteins in the Daphnia genome, which possesses members of all current ABC subfamilies A to H. To unravel phylogenetic relationships, ABC proteins of Daphnia were compared to those from yeast, worm, fruit fly and human. A high conservation of Daphnia of ABC transporters was observed for proteins involved in fundamental cellular processes, including the mitochondrial half transporters of the ABCB subfamily, which function in iron metabolism and transport of Fe/S protein precursors, and the members of subfamilies ABCD, ABCE and ABCF, which have roles in very long chain fatty acid transport, initiation of gene transcription and protein translation, respectively. A number of Daphnia proteins showed one-to-one orthologous relationships to Drosophila ABC proteins including the sulfonyl urea receptor (SUR), the ecdysone transporter ET23, and the eye pigment precursor transporter scarlet. As the fruit fly, Daphnia lacked homologues to the TAP protein, which plays a role in antigene processing, and the cystic fibrosis transmembrane conductance regulator (CFTR), which functions as a chloride channel. Daphnia showed two proteins homologous to MDR (multidrug resistance) P-glycoproteins (ABCB subfamily) and six proteins homologous to MRPs (multidrug resistance-associated proteins) (ABCC subfamily). However, lineage specific gene duplications in the ABCB and ABCC subfamilies complicated the inference of function. A

  18. Evolutionary relationships of ATP-Binding Cassette (ABC) uptake porters

    PubMed Central

    2013-01-01

    Background The ATP-Binding Cassette (ABC) functional superfamily includes integral transmembrane exporters that have evolved three times independently, forming three families termed ABC1, ABC2 and ABC3, upon which monophyletic ATPases have been superimposed for energy-coupling purposes [e.g., J Membr Biol 231(1):1-10, 2009]. The goal of the work reported in this communication was to understand how the integral membrane constituents of ABC uptake transporters with different numbers of predicted or established transmembrane segments (TMSs) evolved. In a few cases, high resolution 3-dimensional structures were available, and in these cases, their structures plus primary sequence analyses allowed us to predict evolutionary pathways of origin. Results All of the 35 currently recognized families of ABC uptake proteins except for one (family 21) were shown to be homologous using quantitative statistical methods. These methods involved using established programs that compare native protein sequences with each other, after having compared each sequence with thousands of its own shuffled sequences, to gain evidence for homology. Topological analyses suggested that these porters contain numbers of TMSs ranging from four or five to twenty. Intragenic duplication events occurred multiple times during the evolution of these porters. They originated from a simple primordial protein containing 3 TMSs which duplicated to 6 TMSs, and then produced porters of the various topologies via insertions, deletions and further duplications. Except for family 21 which proved to be related to ABC1 exporters, they are all related to members of the previously identified ABC2 exporter family. Duplications that occurred in addition to the primordial 3 → 6 duplication included 5 → 10, 6 → 12 and 10 → 20 TMSs. In one case, protein topologies were uncertain as different programs gave discrepant predictions. It could not be concluded with certainty whether a 4 TMS ancestral

  19. Women: the ABC of food security.

    PubMed

    Arcellana, N P

    1997-12-01

    While the 1996 World Food Summit Plan of Action was being approved, a companion NGO (nongovernmental organization) Forum provided opportunities for rural women from 29 countries to relay their perspectives and recommendations. The Rural Women's Workshop was organized by four NGOs: Isis International-Manila, La Via Campesina, the People-Centred Development Forum, and the Women's Food and Agriculture Working Group. Isis International-Manila seeks to create spaces, facilitate processes, and disseminate information for rural women to voice concerns, network, and plan responses. The La Via Campesina network operates in Latin American and the Caribbean where it applies a strong gender perspective to all of its activities. Ultimate progress on the World Food Summit Plan of Action can be evaluated using the ABCs of food security: does the program or policy assure 1) access for women to the total means of production; 2) benefits for women; and 3) community-based resource management and sustainable agriculture. PMID:12321562

  20. Human ATP-binding cassette (ABC) transporter family

    PubMed Central

    2009-01-01

    There exist four fundamentally different classes of membrane-bound transport proteins: ion channels; transporters; aquaporins; and ATP-powered pumps. ATP-binding cassette (ABC) transporters are an example of ATP-dependent pumps. ABC transporters are ubiquitous membrane-bound proteins, present in all prokaryotes, as well as plants, fungi, yeast and animals. These pumps can move substrates in (influx) or out (efflux) of cells. In mammals, ABC transporters are expressed predominantly in the liver, intestine, blood-brain barrier, blood-testis barrier, placenta and kidney. ABC proteins transport a number of endogenous substrates, including inorganic anions, metal ions, peptides, amino acids, sugars and a large number of hydrophobic compounds and metabolites across the plasma membrane, and also across intracellular membranes. The human genome contains 49 ABC genes, arranged in eight subfamilies and named via divergent evolution. That ABC genes are important is underscored by the fact that mutations in at least I I of these genes are already known to cause severe inherited diseases (eg cystic fibrosis and X-linked adrenoleukodystrophy [X-ALD]). ABC transporters also participate in the movement of most drugs and their metabolites across cell surface and cellular organelle membranes; thus, defects in these genes can be important in terms of cancer therapy, pharmacokinetics and innumerable pharmacogenetic disorders. PMID:19403462

  1. Role of the ABCE1 gene in human lung adenocarcinoma

    PubMed Central

    REN, YI; LI, YINGHUI; TIAN, DALI

    2012-01-01

    ATP-binding cassette transporter E1 (ABCE1), also known as RLI (RNase L inhibitor), is a new type of endoribonuclease inhibitor, which can specifically bind to RNase L and abolish its effect. ABCE1 binds to eIF2α and eIF5 to form a pre-translation initiation complex, suggesting its crucial role in cell growth, development and certain pathological processes. To probe the role of ABCE1 in the development and progress of human lung adenocarcinoma, we first detected the changes of its mRNA and protein expression in tissues, and found a high expression level of ABCE1 in human lung adenocarcinoma tissues and metastatic lymph nodes, which was also correlated with clinical stages. Moreover, human lung adenocarcinoma A549 cells were infected with lentiviral vectors containing ABCE1-specific shRNA, and resulted in significant inhibition of cell growth. Using microarray assay, a number of differentially expressed genes were found after ABCE1 suppression. Our results demonstrated the potential role of ABCE1 in human lung adenocarcinoma, which may provide some molecular basis for the mechanisms of development and progress of human lung adenocarcinoma, and help to find new pharmacological targets. PMID:22267055

  2. Diversity in ABC transporters: Type I, II and III importers

    PubMed Central

    Rice, Austin J.; Park, Aekyung

    2014-01-01

    ATP-binding cassette transporters are multi-subunit membrane pumps that transport substrates across membranes. While significant in the transport process, transporter architecture exhibits a range of diversity that we are only beginning to recognize. This divergence may provide insight into the mechanisms of substrate transport and homeostasis. Until recently, ABC importers have been classified into two types, but with the emergence of energy-coupling factor (ECF) transporters there are potentially three types of ABC importers. In this review, we summarize an expansive body of research on the three types of importers with an emphasis on the basics that underlie ABC importers, such as structure, subunit composition and mechanism. PMID:25155087

  3. ABC's of Being Smart: I Can "C" Clearly Now

    ERIC Educational Resources Information Center

    Foster, Joanne

    2011-01-01

    In this paper, the author focuses on C of the ABC's of being smart. She continues to categorize the points for readers. These categories include the following: (1) being; (2) doing; and (3) stretching.

  4. ABC-B transporter genes in Dirofilaria immitis.

    PubMed

    Bourguinat, Catherine; Che, Hua; Mani, Thangadurai; Keller, Kathy; Prichard, Roger K

    2016-08-01

    Dirofilaria immitis is a filarial nematode causing infection and heartworm disease in dogs and other canids, cats, and occasionally in humans. Prevention with macrocyclic lactones (ML) is recommended during the mosquito transmission season. Recently, ML resistance has been reported. ABC-B transporter genes are thought to be involved in the mechanism of ML resistance in other nematodes. This study aimed to identify all the ABC-B transporter genes in D. immitis using as a reference the nDi.2.2 D. immitis whole genome, which is not completely annotated. Using bioinformatic tools and PCR amplification on pooled D. immitis genomic DNA and on pooled cDNA, nine ABC transporter genes including one pseudogene were characterized. Bioinformatic and phylogenetic analyses allowed identification of three P-glycoproteins (Pgps) (Dim-pgp-3 Dim-pgp-10, Dim-pgp-11), of two ABC-B half transporter genes (one ortholog of Cel-haf-4 and Cel-haf-9; and one ortholog of Cel-haf-1 and Cel-haf-3), of one ABC half transporter gene (ortholog of Cel-haf-5) that contained an ABC-C motif, and of one additional half transporter that would require functional study for characterization. The number of ABC-B transporter genes identified was lower than in Caenorhabditis elegans and Haemonchus contortus. Further studies are needed to understand their possible role in ML resistance in D. immitis. These ABC transporters constitute a base for ML resistance investigation in D. immitis and advance our understanding of the molecular biology of this parasite. PMID:27164440

  5. Regulation of ABC Transporter Function Via Phosphorylation by Protein Kinases

    PubMed Central

    Stolarczyk, Elzbieta I.; Reiling, Cassandra J.; Paumi, Christian M.

    2011-01-01

    ATP-binding cassette (ABC) transporters are multispanning membrane proteins that utilize ATP to move a broad range of substrates across cellular membranes. ABC transporters are involved in a number of human disorders and diseases [1]. Overexpression of a subset of the transporters has been closely linked to multidrug resistance in both bacteria and viruses and in cancer. A poorly understood and important aspect of ABC transporter biology is the role of phosphorylation as a mechanism to regulate transporter function. In this review, we summarize the current literature addressing the role of phosphorylation in regulating ABC transporter function. A comprehensive list of all the phosphorylation sites that have been identified for the human ABC transporters is presented, and we discuss the role of individual kinases in regulating transporter function. We address the potential pitfalls and difficulties associated with identifying phosphorylation sites and the corresponding kinase(s), and we discuss novel techniques that may circumvent these problems. We conclude by providing a brief perspective on studying ABC transporter phosphorylation. PMID:21118091

  6. ABC transporter research: going strong 40 years on

    PubMed Central

    Theodoulou, Frederica L.; Kerr, Ian D.

    2015-01-01

    In most organisms, ABC transporters constitute one of the largest families of membrane proteins. In humans, their functions are diverse and underpin numerous key physiological processes, as well as being causative factors in a number of clinically relevant pathologies. Advances in our understanding of these diseases have come about through combinations of genetic and protein biochemical investigations of these transporters and the power of in vitro and in vivo investigations is helping to develop genotype–phenotype understanding. However, the importance of ABC transporter research goes far beyond human biology; microbial ABC transporters are of great interest in terms of understanding virulence and drug resistance and industrial biotechnology researchers are exploring the potential of prokaryotic ABC exporters to increase the capacity of synthetic biology systems. Plant ABC transporters play important roles in transport of hormones, xenobiotics, metals and secondary metabolites, pathogen responses and numerous aspects of development, all of which are important in the global food security area. For 3 days in Chester, this Biochemical Society Focused Meeting brought together researchers with diverse experimental approaches and with different fundamental questions, all of which are linked by the commonality of ABC transporters. PMID:26517919

  7. Fungal ABC transporter deletion and localization analysis.

    PubMed

    Kovalchuk, Andriy; Weber, Stefan S; Nijland, Jeroen G; Bovenberg, Roel A L; Driessen, Arnold J M

    2012-01-01

    Fungal cells are highly complex as their metabolism is compartmentalized harboring various types of subcellular organelles that are bordered by one or more membranes. Knowledge about the intracellular localization of transporter proteins is often required for the understanding of their biological function. Among different approaches available, the localization analysis based on the expression of GFP fusions is commonly used as a relatively fast and cost-efficient method that allows visualization of proteins of interest in both live and fixed cells. In addition, inactivation of transporter genes is an important tool to resolve their specific function. Here we provide a detailed protocol for the deletion and localization analysis of ABC transporters in the filamentous fungus Penicillium chrysogenum. It includes construction of expression plasmids, their transformation into fungal strains, cultivation of transformants, microscopy analysis, as well as additional protocols on staining of fungal cells with organelle-specific dyes like Hoechst 33342, MitoTracker DeepRed, and FM4-64. PMID:22183644

  8. The 'ABC' of examining foot radiographs.

    PubMed Central

    Pearse, Eyiyemi O.; Klass, Benjamin; Bendall, Stephen P.

    2005-01-01

    INTRODUCTION: We report a simple systematic method of assessing foot radiographs that improves diagnostic accuracy and can reduce the incidence of inappropriate management of serious forefoot and midfoot injuries, particularly the Lisfranc-type injury. STUDY GROUP AND METHODS: Five recently appointed senior house officers (SHOs), with no casualty or Orthopaedic experience prior to their appointment, were shown a set of 10 foot radiographs and told the history and examination findings recorded in the casualty notes of each patient within 6 weeks of taking up their posts. They were informed that the radiographs might or might not demonstrate an abnormality. They were asked to make a diagnosis and decide on a management plan. The test was repeated after they were taught the 'ABC' method of evaluating foot radiographs. RESULTS: Diagnostic accuracy improved after SHOs were taught a systematic method of assessing foot radiographs. The proportion of correct diagnoses increased from 0.64 to 0.78 and the probability of recognising Lisfranc injuries increased from 0 to 0.6. CONCLUSIONS: The use of this simple method of assessing foot radiographs can reduce the incidence of inappropriate management of serious foot injuries by casualty SHOs, in particular the Lisfranc type injury. PMID:16263015

  9. Optimal ABC inventory classification using interval programming

    NASA Astrophysics Data System (ADS)

    Rezaei, Jafar; Salimi, Negin

    2015-08-01

    Inventory classification is one of the most important activities in inventory management, whereby inventories are classified into three or more classes. Several inventory classifications have been proposed in the literature, almost all of which have two main shortcomings in common. That is, the previous methods mainly rely on an expert opinion to derive the importance of the classification criteria which results in subjective classification, and they need precise item parameters before implementing the classification. While the problem has been predominantly considered as a multi-criteria, we examine the problem from a different perspective, proposing a novel optimisation model for ABC inventory classification in the form of an interval programming problem. The proposed interval programming model has two important features compared to the existing methods: it provides optimal results instead of an expert-based classification and it does not require precise values of item parameters, which are not almost always available before classification. Finally, by illustrating the proposed classification model in the form of numerical example, conclusion and suggestions for future works are presented.

  10. A Drosophila ABC transporter regulates lifespan.

    PubMed

    Huang, He; Lu-Bo, Ying; Haddad, Gabriel G

    2014-12-01

    MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling. PMID:25474322

  11. Know your ABCs: Characterization and gene expression dynamics of ABC transporters in the polyphagous herbivore Helicoverpa armigera.

    PubMed

    Bretschneider, Anne; Heckel, David G; Vogel, Heiko

    2016-05-01

    Polyphagous insect herbivores are adapted to many different secondary metabolites of their host plants. However, little is known about the role of ATP-binding cassette (ABC) transporters, a multigene family involved in detoxification processes. To study the larval response of the generalist Helicoverpa armigera (Lepidoptera) and the putative role of ABC transporters, we performed developmental assays on artificial diet supplemented with secondary metabolites from host plants (atropine-scopolamine, nicotine and tomatine) and non-host plants (taxol) in combination with a replicated RNAseq experiment. A maximum likelihood phylogeny identified the subfamily affiliations of the ABC transporter sequences. Larval performance was equal on the atropine-scopolamine diet and the tomatine diet. For the latter we could identify a treatment-specific upregulation of five ABC transporters in the gut. No significant developmental difference was detected between larvae fed on nicotine or taxol. This was also mirrored in the upregulation of five ABC transporters when fed on either of the two diets. The highest number of differentially expressed genes was recorded in the gut samples in response to feeding on secondary metabolites. Our results are consistent with the expectation of a general detoxification response in a polyphagous herbivore. This is the first study to characterize the multigene family of ABC transporters and identify gene expression changes across different developmental stages and tissues, as well as the impact of secondary metabolites in the agricultural pest H. armigera. PMID:26951878

  12. Lunar tides in the mesosphere and lower thermosphere over Cachoeira Paulista (22.7°S; 45.0°W)

    NASA Astrophysics Data System (ADS)

    Paulino, A. R.; Batista, P. P.; Clemesha, R.

    2012-04-01

    Using data from a meteor radar at Cachoeira Paulista (22.7°S; 45.0°W), the atmospheric lunar semidiurnal tide in the mesosphere and lower thermosphere was studied from January 2000 to October 2008. Monthly tidal amplitudes and phases were estimated using hourly mean winds in seven layers of 4 km thickness each. Several amplitude and phase profiles of the lunar semidiurnal tide over Cachoeira Paulista showed characteristics of vertically propagating waves. The mean amplitudes over all heights were greater in the northward wind in January, February, May, June, July, August, November and December, but taken into account the error bars this behavior can be different in certain months. The mean phases presented characteristics appropriate to the Southern Hemisphere throughout the year, except in July. In some aspects, the results presented similarities with the Vial and Forbes (1994) atmospheric lunar semidiurnal tidal model.

  13. Function of prokaryotic and eukaryotic ABC proteins in lipid transport.

    PubMed

    Pohl, Antje; Devaux, Philippe F; Herrmann, Andreas

    2005-03-21

    ATP binding cassette (ABC) proteins of both eukaryotic and prokaryotic origins are implicated in the transport of lipids. In humans, members of the ABC protein families A, B, C, D and G are mutated in a number of lipid transport and metabolism disorders, such as Tangier disease, Stargardt syndrome, progressive familial intrahepatic cholestasis, pseudoxanthoma elasticum, adrenoleukodystrophy or sitosterolemia. Studies employing transfection, overexpression, reconstitution, deletion and inhibition indicate the transbilayer transport of endogenous lipids and their analogs by some of these proteins, modulating lipid transbilayer asymmetry. Other proteins appear to be involved in the exposure of specific lipids on the exoplasmic leaflet, allowing their uptake by acceptors and further transport to specific sites. Additionally, lipid transport by ABC proteins is currently being studied in non-human eukaryotes, e.g. in sea urchin, trypanosomatides, arabidopsis and yeast, as well as in prokaryotes such as Escherichia coli and Lactococcus lactis. Here, we review current information about the (putative) role of both pro- and eukaryotic ABC proteins in the various phenomena associated with lipid transport. Besides providing a better understanding of phenomena like lipid metabolism, circulation, multidrug resistance, hormonal processes, fertilization, vision and signalling, studies on pro- and eukaryotic ABC proteins might eventually enable us to put a name on some of the proteins mediating transbilayer lipid transport in various membranes of cells and organelles. It must be emphasized, however, that there are still many uncertainties concerning the functions and mechanisms of ABC proteins interacting with lipids. In particular, further purification and reconstitution experiments with an unambiguous role of ATP hydrolysis are needed to demonstrate a clear involvement of ABC proteins in lipid transbilayer asymmetry. PMID:15749056

  14. ABC3 Consensus: Assessment by a German Group of Experts.

    PubMed

    Thomssen, Christoph; Augustin, Doris; Ettl, Johannes; Haidinger, Renate; Lück, Hans-Joachim; Lüftner, Diana; Marmé, Frederik; Marschner, Norbert; Müller, Lothar; Overkamp, Friedrich; Ruckhäberle, Eugen; Thill, Marc; Untch, Michael; Wuerstlein, Rachel; Harbeck, Nadia

    2016-02-01

    The Advanced Breast Cancer Third International Consensus Conference on the diagnosis and treatment of advanced breast cancer took place in Lisbon, Portugal, on November 5-7, 2015. This year's conference (ABC3) was focused on the treatment of metastatic breast cancer (stage IV), as it was 4 years ago at the first consensus meeting (ABC1). A matter of particular interest was the patients' perspective. Thus, patient-relevant issues were addressed by the consensus discussions, such as those on treatment goals, quality of life, care of long-term survivors ('survivorship issues'), and coping with disease-related symptoms and the side effects of treatment. Further important issues on the agenda were the use of standardized instruments for the assessment of individual treatment success ('patient-reported outcome measures') and the evaluation of the benefit of novel drugs (e.g. the European Society for Medical Oncology (ESMO) Magnitude of Clinical Benefit Scale). Diagnosis and treatment of inoperable locally advanced breast cancer had already been discussed 2 years earlier at the ABC2 Consensus and were not dealt with in the framework of this year's ABC3 Consensus. With regard to country-specific peculiarities, which unavoidably found their way into the ABC Consensus, a working group of German breast cancer experts commented on the voting results of the ABC panelists. As for the past consensus, the group specially considered the German guidelines for the diagnosis and treatment of breast cancer (AGO (Gyneco-Oncology Working Group), S3, DGHO (German Society of Hematology and Medical Oncology)) in order to adapt the ABC3 consensus for everyday therapy in Germany. PMID:27051399

  15. Cloning of two novel ABC transporters mapping on human chromosome 9

    SciTech Connect

    Luciani, M.F.; Savary, S.; Chimini, G. ); Denizot, F. ); Mattei, M.G. )

    1994-05-01

    The family of ATP binding cassette (ABC) transporters or traffic ATPases is composed of several membrane-associated proteins that transport a great variety of solutes across cellular membranes. Two novel mammalian members of the family, ABC1 and ABC2, have been identified by a PCR-based approach. They belong to a group of traffic ATPases encoded as a single multifunctional protein, such as CFTR, STE 6, and P-glycoproteins. Their peculiar structural features and close relationship to ABC transporters involved in nodulation suggest that ABC1 and ABC2 define a novel subgroup of mammalian traffic ATPases. 51 refs., 7 figs.

  16. Independent Activity of the Homologous Small Regulatory RNAs AbcR1 and AbcR2 in the Legume Symbiont Sinorhizobium meliloti

    PubMed Central

    Torres-Quesada, Omar; Millán, Vicenta; Nisa-Martínez, Rafael; Bardou, Florian; Crespi, Martín; Toro, Nicolás; Jiménez-Zurdo, José I.

    2013-01-01

    The legume symbiont Sinorhizobium meliloti expresses a plethora of small noncoding RNAs (sRNAs) whose function is mostly unknown. Here, we have functionally characterized two tandemly encoded S. meliloti Rm1021 sRNAs that are similar in sequence and structure. Homologous sRNAs (designated AbcR1 and AbcR2) have been shown to regulate several ABC transporters in the related α-proteobacteria Agrobacterium tumefaciens and Brucella abortus. In Rm1021, AbcR1 and AbcR2 exhibit divergent unlinked regulation and are stabilized by the RNA chaperone Hfq. AbcR1 is transcribed in actively dividing bacteria, either in culture, rhizosphere or within the invasion zone of mature alfalfa nodules. Conversely, AbcR2 expression is induced upon entry into stationary phase and under abiotic stress. Only deletion of AbcR1 resulted into a discrete growth delay in rich medium, but both are dispensable for symbiosis. Periplasmic proteome profiling revealed down-regulation of the branched-chain amino acid binding protein LivK by AbcR1, but not by AbcR2. A double-plasmid reporter assay confirmed the predicted specific targeting of the 5′-untranslated region of the livK mRNA by AbcR1 in vivo. Our findings provide evidences of independent regulatory functions of these sRNAs, probably to fine-tune nutrient uptake in free-living and undifferentiated symbiotic rhizobia. PMID:23869210

  17. Independent activity of the homologous small regulatory RNAs AbcR1 and AbcR2 in the legume symbiont Sinorhizobium meliloti.

    PubMed

    Torres-Quesada, Omar; Millán, Vicenta; Nisa-Martínez, Rafael; Bardou, Florian; Crespi, Martín; Toro, Nicolás; Jiménez-Zurdo, José I

    2013-01-01

    The legume symbiont Sinorhizobium meliloti expresses a plethora of small noncoding RNAs (sRNAs) whose function is mostly unknown. Here, we have functionally characterized two tandemly encoded S. meliloti Rm1021 sRNAs that are similar in sequence and structure. Homologous sRNAs (designated AbcR1 and AbcR2) have been shown to regulate several ABC transporters in the related α-proteobacteria Agrobacterium tumefaciens and Brucella abortus. In Rm1021, AbcR1 and AbcR2 exhibit divergent unlinked regulation and are stabilized by the RNA chaperone Hfq. AbcR1 is transcribed in actively dividing bacteria, either in culture, rhizosphere or within the invasion zone of mature alfalfa nodules. Conversely, AbcR2 expression is induced upon entry into stationary phase and under abiotic stress. Only deletion of AbcR1 resulted into a discrete growth delay in rich medium, but both are dispensable for symbiosis. Periplasmic proteome profiling revealed down-regulation of the branched-chain amino acid binding protein LivK by AbcR1, but not by AbcR2. A double-plasmid reporter assay confirmed the predicted specific targeting of the 5'-untranslated region of the livK mRNA by AbcR1 in vivo. Our findings provide evidences of independent regulatory functions of these sRNAs, probably to fine-tune nutrient uptake in free-living and undifferentiated symbiotic rhizobia. PMID:23869210

  18. ABC multidrug transporters in schistosomes and other parasitic flatworms

    PubMed Central

    Greenberg, Robert M.

    2013-01-01

    Schistosomiasis, a neglected tropical disease affecting hundreds of millions, is caused by parasitic flatworms of the genus Schistosoma. Treatment and control of schistosomiasis relies almost exclusively on a single drug, praziquantel (PZQ), a dangerous situation for a disease of this magnitude. Though PZQ is highly effective overall, it has drawbacks, and reports of worms showing PZQ resistance, either induced in the laboratory or isolated from the field, are disconcerting. Multidrug transporters underlie multidrug resistance (MDR), a phenomenon in which resistance to a single drug is accompanied by unexpected cross-resistance to several structurally unrelated compounds. Some of the best studied multidrug transporters are members of the ancient and very large ATP-binding cassette (ABC) superfamily of efflux transporters. ABC multidrug transporters such as P-glycoprotein (Pgp; ABCB1) are also associated with drug resistance in parasites, including helminths such as schistosomes. In addition to their association with drug resistance, however, ABC transporters also function in a wide variety of physiological processes in metazoans. In this review, we examine recent studies that help define the role of schistosome ABC transporters in regulating drug susceptibility, and in normal schistosome physiology, including reproduction and excretory activity. We postulate that schistosome ABC transporters could be useful targets for compounds that enhance the effectiveness of current therapeutics as well as for agents that act as antischistosomals on their own. PMID:23474413

  19. The ABC of Ribosome-Related Antibiotic Resistance

    PubMed Central

    Wilson, Daniel N.

    2016-01-01

    ABSTRACT The increase in multidrug-resistant pathogenic bacteria is limiting the utility of our current arsenal of antimicrobial agents. Mechanistically understanding how bacteria obtain antibiotic resistance is a critical first step to the development of improved inhibitors. One common mechanism for bacteria to obtain antibiotic resistance is by employing ATP-binding cassette (ABC) transporters to actively pump the drug from the cell. The ABC-F family includes proteins conferring resistance to a variety of clinically important ribosome-targeting antibiotics; however, controversy remains as to whether resistance is conferred via efflux like other ABC transporters or whether another mechanism, such as ribosome protection, is at play. A recent study by Sharkey and coworkers (L. K. Sharkey, T. A. Edwards, and A. J. O’Neill, mBio 7:e01975-15, 2016, http://dx.doi.org/10.1128/mBio.01975-15) provides strong evidence that ABC-F proteins conferring antibiotic resistance utilize ribosome protection mechanisms, namely, by interacting with the ribosome and displacing the drug from its binding site, thus revealing a novel role for ABC-F proteins in antibiotic resistance. PMID:27143393

  20. Membrane-Active Action Mode of Polybia-CP, a Novel Antimicrobial Peptide Isolated from the Venom of Polybia paulista

    PubMed Central

    Wang, Kairong; Yan, Jiexi; Chen, Ru; Dang, Wen; Zhang, Bangzhi; Zhang, Wei; Song, Jingjing

    2012-01-01

    The extensive use of antibiotics in medicine, the food industry, and agriculture has resulted in the frequent emergence of multidrug-resistant bacteria, which creates an urgent need for new antibiotics. It is now widely recognized that antimicrobial peptides (AMPs) could play a promising role in fighting multidrug-resistant bacteria. Antimicrobial peptide polybia-CP was purified from the venom of the social wasp Polybia paulista. In this study, we synthesized polybia-CP and studied its action mode of antibacterial activity. Our results revealed that polybia-CP has potent antibacterial activity against both Gram-positive and Gram-negative bacteria. The results from both the real bacterial membrane and the in vitro model membrane showed that polybia-CP is membrane active and that its action target is the membrane of bacteria. It is difficult for bacteria to develop resistance to polybia-CP, which may thus offer a new strategy for defending against resistant bacteria in medicine and the food and farming industries. PMID:22450985

  1. A note on the first integrals of the ABC system

    NASA Astrophysics Data System (ADS)

    Llibre, Jaume; Valls, Clàudia

    2012-02-01

    Without loss of generality the ABC systems reduce to two cases: either A = 0 and B, C ⩾ 0, or A = 1 and 0 < B, C ⩽ 1. In the first case it is known that the ABC system is completely integrable, here we provide its explicit first integrals. In the second case Ziglin ["Dichotomy of the separatrices and the nonexistence of first integrals in systems of differential equations of Hamiltonian type with two degrees of freedom," Izv. Akad. Nauk SSSR, Ser. Mat. 51, 1088 (1987)] proved that the ABC system with 0 < B < 1 and C > 0 sufficiently small has no real meromorphic first integrals. We improve Ziglin's result showing that there are no C1 first integrals under convenient assumptions.

  2. Warped resolved L{sup a,b,c} cones

    SciTech Connect

    Cvetic, Mirjam; Vazquez-Poritz, J. F.

    2008-06-15

    We construct supergravity solutions describing a stack of D3-branes localized at a point on a blown-up cycle of a resolved L{sup a,b,c} cone. The geometry flows from AdS{sub 5}xL{sup a,b,c} to AdS{sub 5}xS{sup 5}/Z{sub k}. The corresponding quiver gauge theory undergoes a renormalization group flow between two superconformal fixed points, which leads to semi-infinite chains of flows between the various L{sup a,b,c} fixed points. The general system is described by a triplet of Heun equations, which can each be solved by an expansion with a three-term recursion relation, though there are closed-form solutions for certain cases. This enables us to read off the operators that acquire nonzero vacuum expectation values as the quiver gauge theory flows away from a fixed point.

  3. Acoustic velocity sensor for the NRL ABC research platform

    SciTech Connect

    Corsaro, R.D.; Houston, B.

    1996-04-01

    A new research platform has been constructed for general underwater structural-acoustics studies of sensor/actuator coupling mechanisms, and in particular for active acoustic boundary control (ABC) studies. It consists of an array of 15 {open_quote}{open_quote}ABC{close_quote}{close_quote} tiles arranged in a 5{times}3 pattern on a backing structure (an air-backed steel plate). Tiles are 10 inches square, and each tile contains a large area actuator, pressure sensor, and (acoustic particle) velocity sensor. While the actuator and pressure sensor could be constructed of commercially available transducer material, the selection of a suitable acoustic velocity sensor proved more difficult. This paper describes the velocity sensor system selected and its impact on the resulting performance and characteristics of the ABC Platform. {copyright} {ital 1996 American Institute of Physics.}

  4. Tumor metastatic promoter ABCE1 interacts with the cytoskeleton protein actin and increases cell motility.

    PubMed

    Han, Xu; Tian, Ye; Tian, Dali

    2016-06-01

    ABCE1, a member of the ATP-binding cassette (ABC) family, is a candidate tumor metastatic promoter in lung cancer. Overexpression of ABCE1 is correlated with aggressive growth and metastasis in lung cancer cells. However, the exact mechanism remains unclear. In the present study, GST pull-down assay provided evidence of the possible interaction between ABCE1 and β-actin using GST-ABCE1 as a bait protein. Co-immunoprecipitation manifested ABCE1 formed complexes with β-actin in vivo. ABCE1 overexpression significantly increased the migration of lung cancer cells which may be attributed to the promotion of F-actin rearrangements. Taken together, these data suggest that overexpression of ABCE1 produces an obvious effect on the motility of lung cancer cells through cytoskeleton rearrangement. PMID:27109616

  5. ABC estimation of unit costs for emergency department services.

    PubMed

    Holmes, R L; Schroeder, R E

    1996-04-01

    Rapid evolution of the health care industry forces managers to make cost-effective decisions. Typical hospital cost accounting systems do not provide emergency department managers with the information needed, but emergency department settings are so complex and dynamic as to make the more accurate activity-based costing (ABC) system prohibitively expensive. Through judicious use of the available traditional cost accounting information and simple computer spreadsheets. managers may approximate the decision-guiding information that would result from the much more costly and time-consuming implementation of ABC. PMID:10156656

  6. Migration of Adipose-derived Mesenchymal Stem Cells Stably Expressing Chondroitinase ABC In vitro

    PubMed Central

    Wu, Jian-Huang; Li, Miao; Liang, Yan; Lu, Tao; Duan, Chun-Yue

    2016-01-01

    Background: Several studies have revealed that adipose-derived mesenchymal stem cells (ADSCs) can be used as seed cells for the treatment of spinal cord injury (SCI). Chondroitinase ABC (ChABC) decomposes chondroitin sulfate proteoglycans in the glial scar that forms following SCI, allowing stem cells to penetrate through the scar and promote recovery of nerve function. This study aimed to establish ADSCs that stably express ChABC (ChABC-ADSCs) and evaluate the migratory capability of ChABC-ADSCs in vitro. Methods: ADSCs were obtained from Sprague-Dawley rats using secondary collagenase digestion. Their phenotypes were characterized using flow cytometry detection of cell surface antigens and their stem cell properties were confirmed by induction of differentiation. After successful culture, ADSCs were transfected with lentiviral vectors and ChABC-ADSCs were obtained. Proliferation curves of ChABC-ADSCs were determined using the Cell Counting Kit-8 method, ChABC expression was verified using Western blotting, and the migration of ChABC-ADSCs was analyzed using the transwell assay. Results: Secondary collagenase digestion increased the isolation efficiency of primary ADSCs. Following transfection using lentiviral vectors, the proliferation of ChABC-ADSCs was reduced in comparison with control ADSCs at 48 h (P < 0.05). And the level of ChABC expression in the ChABC-ADSC group was significantly higher than that of the ADSC group (P < 0.05). Moreover, ChABC-ADSC migration in matrigel was significantly enhanced in comparison with the control (P < 0.05). Conclusions: Secondary collagenase digestion can be used to effectively isolate ADSCs. ChABC-ADSCs constructed using lentiviral vector transfection stably express ChABC, and ChABC expression significantly enhances the migratory capacity of ADSCs. PMID:27364797

  7. Tonoplast-localized Abc2 Transporter Mediates Phytochelatin Accumulation in Vacuoles and Confers Cadmium Tolerance*

    PubMed Central

    Mendoza-Cózatl, David G.; Zhai, Zhiyang; Jobe, Timothy O.; Akmakjian, Garo Z.; Song, Won-Yong; Limbo, Oliver; Russell, Matthew R.; Kozlovskyy, Volodymyr I.; Martinoia, Enrico; Vatamaniuk, Olena K.; Russell, Paul; Schroeder, Julian I.

    2010-01-01

    Phytochelatins mediate tolerance to heavy metals in plants and some fungi by sequestering phytochelatin-metal complexes into vacuoles. To date, only Schizosaccharomyces pombe Hmt1 has been described as a phytochelatin transporter and attempts to identify orthologous phytochelatin transporters in plants and other organisms have failed. Furthermore, recent data indicate that the hmt1 mutant accumulates significant phytochelatin levels in vacuoles, suggesting that unidentified phytochelatin transporters exist in fungi. Here, we show that deletion of all vacuolar ABC transporters abolishes phytochelatin accumulation in S. pombe vacuoles and abrogates 35S-PC2 uptake into S. pombe microsomal vesicles. Systematic analysis of the entire S. pombe ABC transporter family identified Abc2 as a full-size ABC transporter (ABCC-type) that mediates phytochelatin transport into vacuoles. The S. pombe abc1 abc2 abc3 abc4 hmt1 quintuple and abc2 hmt1 double mutant show no detectable phytochelatins in vacuoles. Abc2 expression restores phytochelatin accumulation into vacuoles and suppresses the cadmium sensitivity of the abc quintuple mutant. A novel, unexpected, function of Hmt1 in GS-conjugate transport is also shown. In contrast to Hmt1, Abc2 orthologs are widely distributed among kingdoms and are proposed as the long-sought vacuolar phytochelatin transporters in plants and other organisms. PMID:20937798

  8. The ABCs for Pre-Service Teacher Cultural Competency Development

    ERIC Educational Resources Information Center

    He, Ye; Cooper, Jewell E.

    2009-01-01

    In an effort to combine pre-service teachers' self-reflection with their field experiences to enhance their cultural competency, this study adopted Schmidt's ABC's (Autobiography, Biography, and Cross-cultural Comparison) Model in two courses in a pre-service teacher education program. Through group comparisons, this study measured the impact that…

  9. The Library ABC's Game: Sneaking in Learning through Gaming

    ERIC Educational Resources Information Center

    Maxwell, D. Jackson

    2007-01-01

    Teaching library terminology and definitions can be a real bore. Unfortunately, no matter how one looks at it, students need to learn a set of basic library words and their meanings. The Library ABC's game teaches elementary age students library terms and definitions, and it is effective, efficient, easy, exciting, and fun. Introduce the Library…

  10. Dissociations among ABA, ABC, and AAB Recovery Effects

    ERIC Educational Resources Information Center

    Ungor, Metin; Lachnit, Harald

    2008-01-01

    In a human predictive learning experiment, the strengths of ABA, ABC, and AAB recovery effects after discrimination reversal learning were compared. Initially, a discrimination between two stimuli (X+, Y-) was trained in Context A. During Phase 2, participants received discrimination reversal training (X-, Y+) either in Context A (Group AAB) or in…

  11. The Value of Green Technology at ABC Community College

    ERIC Educational Resources Information Center

    McAllister, Bernadette

    2012-01-01

    A challenge facing community colleges nationwide is to reduce the carbon footprint of campuses by initiating green technology initiatives. This case study assessed the effect of switching from paper assignments to a learning management system at ABC Community College. The topic is important because federal and state funding, as well as…

  12. Electronic excitation spectrum of ABC-stacked multilayer graphene

    NASA Astrophysics Data System (ADS)

    Henni, Y.; Nogajewski, K.; Ojeda Collado, H. P.; Usaj, G.; Balseiro, C. A.; Potemski, M.; Faugeras, C.

    The electronic properties of ABC graphene trilayers has attracted lot of attention recently due to their potential applications in engineering carbon-based devices with gate tunable electrical conductivity. Morever,ABC-stacked thin layers of graphite are predicted to host peculiar surface electronic states, with a flat dispersion over most of the Brillouin zone. The associated high density of states is likely to favour the emergence of exotic electronic phases, such as charge density waves or even superconductivity. We present a micro-magneto-Raman scattering study of a thin graphite flake produced by exfoliation of natural graphite, composed of ~15graphene layers, and including a large ABC-stacked domain. Exploring the low temperature Raman scattering spectrum of this domain up to B=29T,we identify inter Landau level electronic excitations within the surface flat bands,together with electronic excitations involving the gapped states in the bulk. This interband electronic excitation at B=0T can be observed,up to room temperature, directly in the Raman scattering spectrum as a broad(~ 180 cm-1) feature. Because the energy gap strongly depends on the number of layers,this electronic excitation can be used to identify and characterize ABC-stacked graphite thin layers.

  13. Selections from the ABC 2009 Annual Convention, Portsmouth, Virginia

    ERIC Educational Resources Information Center

    Whalen, D. Joel

    2010-01-01

    The "My Favorite Assignment" Session at the 2009 Association for Business Communication (ABC) annual convention in Portsmouth, Virginia, featured over a dozen teachers sharing pedagogical innovations in a fast-paced, 4-minute format designed by Dan Dietrich. The wide variety of ideas and techniques presented makes these sessions popular ABC…

  14. ABCs of Being Smart... G Is for Gifted!

    ERIC Educational Resources Information Center

    Foster, Joanne

    2012-01-01

    Giftedness can generate speculation, misconceptions, expectations, pride, innuendo, apprehension, puzzlement--and the list goes on. What does it mean to be a gifted learner? In this installment of the series "ABCs of Being Smart," the author grapples with the term gifted, giving a glimpse into giftedness, along with some general guidelines for…

  15. Selections from the ABC 2011 Annual Convention, Montreal, Canada

    ERIC Educational Resources Information Center

    Whalen, D. Joel; Andersen, Ken; Campbell, Gloria; Crenshaw, Cheri; Cross, Geoffrey A.; Grinols, Anne Bradstreet; Hildebrand, John; Newman, Amy; Ortiz, Lorelei A.; Paulson, Edward; Phillabaum, Melinda; Powell, Elizabeth A.; Sloan, Ryan

    2012-01-01

    The 12 Favorite Assignments featured in this article were presented at the 2011 Annual Convention of the Association for Business Communication (ABC), Montreal, Canada. A variety of learning objectives are featured: delivering bad news, handling difficult people, persuasion, reporting financial analysis, electronic media, face-to-face…

  16. Selections from the ABC 2012 Annual Convention, Honolulu, Hawaii

    ERIC Educational Resources Information Center

    Whalen, D. Joel

    2013-01-01

    The 13 Favorite Assignments featured here were presented at the 2012 Association for Business Communication (ABC) Annual Convention, Honolulu, Hawaii. A variety of learning objectives are featured, including the following: enhancing resume's visual impact, interpersonal skills, social media, team building, web design, community service…

  17. The K-ABC in Historical and Contemporary Perspective.

    ERIC Educational Resources Information Center

    Anastasi, Anne

    1984-01-01

    The Kaufman Assessment Battery for Children is examined with particular attention to evolution of current psychometric concepts and methods, as well as the historical sources of popular misconceptions. The K-ABC reveals sophisticated applications of current test construction methodology but requires knowledgeable examiners. (Author/CL)

  18. Multidrug resistance ABC transporter structure predictions by homology modeling approaches.

    PubMed

    Honorat, Mylène; Falson, Pierre; Terreux, Raphael; Di Pietro, Attilio; Dumontet, Charles; Payen, Léa

    2011-03-01

    Human multidrug resistance ABC transporters are ubiquitous membrane proteins responsible for the efflux of multiple, endogenous or exogenous, compounds out of the cells, and therefore they are involved in multi-drug resistance phenotype (MDR). They thus deeply impact the pharmacokinetic parameters and toxicity properties of drugs. A great pressure to develop inhibitors of these pumps is carried out, by either ligand-based drug design or (more ideally) structure-based drug design. In that goal, many biochemical studies have been carried out to characterize their transport functions, and many efforts have been spent to get high-resolution structures. Currently, beside the 3D-structures of bacterial ABC transporters Sav1866 and MsbA, only the mouse ABCB1 complete structure has been published at high-resolution, illustrating the tremendous difficulty in getting such information, taking into account that the human genome accounts for 48 ABC transporters encoding genes. Homology modeling is consequently a reasonable approach to overcome this obstacle. The present review describes, in the first part, the different approaches which have been published to set up human ABC pump 3D-homology models allowing the localization of binding sites for drug candidates, and the identification of critical residues therein. In a second part, the review proposes a more accurate strategy and practical keys to use such biological tools for initiating structure-based drug design. PMID:21470105

  19. Delayed treatment with chondroitinase ABC promotes sensorimotor recovery and plasticity after stroke in aged rats.

    PubMed

    Soleman, Sara; Yip, Ping K; Duricki, Denise A; Moon, Lawrence D F

    2012-04-01

    Stroke is the dominant cause of sensorimotor disability that primarily affects the elderly. We now show that neuroplasticity and functional recovery after stroke is constrained by inhibitory chondroitin sulphates. In two blinded, randomized preclinical trials, degradation of chondroitin sulphate using chondroitinase ABC reactivated neuroplasticity and promoted sensorimotor recovery after stroke in elderly rats. Three days after stroke, chondroitinase ABC was microinjected into the cervical spinal cord to induce localized plasticity of forelimb sensorimotor spinal circuitry. Chondroitinase ABC effectively removed chondroitin sulphate from the extracellular matrix and perineuronal nets. Three different tests of sensorimotor function showed that chondroitinase ABC promoted recovery of forelimb function. Anterograde and retrograde tracing showed that chondroitinase ABC also induced sprouting of the contralesional corticospinal tract in the aged treated hemicord. Chondroitinase ABC did not neuroprotect the peri-infarct region. We show for the first time delayed chondroitinase ABC treatment promotes neuroanatomical and functional recovery after focal ischaemic stroke in an elderly nervous system. PMID:22396394

  20. 75 FR 49549 - ABC & D Recycling, Inc.-Lease and Operation Exemption-a Line of Railroad in Ware, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... Surface Transportation Board ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line of Railroad in Ware, MA ABC & D Recycling, Inc. (ABC & D), a noncarrier, has filed a verified notice of exemption... operation of this trackage in FD 35356, ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line...

  1. A burst of ABC genes in the genome of the polyphagous spider mite Tetranychus urticae

    PubMed Central

    2013-01-01

    Background The ABC (ATP-binding cassette) gene superfamily is widespread across all living species. The majority of ABC genes encode ABC transporters, which are membrane-spanning proteins capable of transferring substrates across biological membranes by hydrolyzing ATP. Although ABC transporters have often been associated with resistance to drugs and toxic compounds, within the Arthropoda ABC gene families have only been characterized in detail in several insects and a crustacean. In this study, we report a genome-wide survey and expression analysis of the ABC gene superfamily in the spider mite, Tetranychus urticae, a chelicerate ~ 450 million years diverged from other Arthropod lineages. T. urticae is a major agricultural pest, and is among of the most polyphagous arthropod herbivores known. The species resists a staggering array of toxic plant secondary metabolites, and has developed resistance to all major classes of pesticides in use for its control. Results We identified 103 ABC genes in the T. urticae genome, the highest number discovered in a metazoan species to date. Within the T. urticae ABC gene set, all members of the eight currently described subfamilies (A to H) were detected. A phylogenetic analysis revealed that the high number of ABC genes in T. urticae is due primarily to lineage-specific expansions of ABC genes within the ABCC, ABCG and ABCH subfamilies. In particular, the ABCC subfamily harbors the highest number of T. urticae ABC genes (39). In a comparative genomic analysis, we found clear orthologous relationships between a subset of T. urticae ABC proteins and ABC proteins in both vertebrates and invertebrates known to be involved in fundamental cellular processes. These included members of the ABCB-half transporters, and the ABCD, ABCE and ABCF families. Furthermore, one-to-one orthologues could be distinguished between T. urticae proteins and human ABCC10, ABCG5 and ABCG8, the Drosophila melanogaster sulfonylurea receptor and ecdysone

  2. Les abcès froids pariétaux thoraciques chez les sujets immunocompétents

    PubMed Central

    Benjelloun, Hanane; Morad, Sanaa; Zaghba, Nahid; Bakhatar, Abdelaziz; Yassine, Najiba; Bahlaoui, Abdelkrim

    2015-01-01

    Les abcès froids de la paroi thoracique représentent une forme rare et inhabituelle de tuberculose extrapulmonaire. Sa fréquence est estimée à moins de 5% des tuberculoses ostéoarticulaires, évaluées elles-mêmes à 15% des tuberculoses extrapulmonaires. L'objectif de ce travail est de rapporter la prise en charge diagnostique et thérapeutique de cette localisation dans notre structure. Etude rétrospective portant sur 18 cas colligés au service des maladies respiratoires du centre hospitalier universitaire Ibn Rochd de Casablanca, sur une période de 13 ans. La moyenne d’âge était de 34 ans (21-57). Un antécédent de tuberculose traitée était relevé dans un cas. Le tableau clinique était révélé par l'apparition insidieuse d'une masse pariétale de taille, de consistance et de siège variables. A l'imagerie thoracique, l'abcès pariétal était associé à une lyse osseuse dans sept cas, une atteinte parenchymateuse et pleurale dans quatre cas chacune et des adénopathies médiastinales dans deux cas. La confirmation diagnostique était bactériologique et/ou histologique dans tous les cas. La sérologie du virus de l'immunodéficience humaineétait négative chez tous nos malades. L’évolution sous traitement antibacillaire couplé ou non à une résection chirurgicale était favorable chez tous nos malades. Malgré la fréquence de la tuberculose dans notre contexte, la localisation pariétale thoracique reste rare, survenant chez une population non immunodéprimée et non toxicomane, contrairement à ce qui est souvent rapporté dans la littérature. Les abcès froids tuberculeux représentent une forme rare de tuberculose extrapulmonaire dont l’évolution reste favorable sous traitement précoce et bien conduit. PMID:26113904

  3. Insights into how nucleotide-binding domains power ABC transport.

    PubMed

    Newstead, Simon; Fowler, Philip W; Bilton, Paul; Carpenter, Elisabeth P; Sadler, Peter J; Campopiano, Dominic J; Sansom, Mark S P; Iwata, So

    2009-09-01

    The mechanism by which nucleotide-binding domains (NBDs) of ABC transporters power the transport of substrates across cell membranes is currently unclear. Here we report the crystal structure of an NBD, FbpC, from the Neisseria gonorrhoeae ferric iron uptake transporter with an unusual and substantial domain swap in the C-terminal regulatory domain. This entanglement suggests that FbpC is unable to open to the same extent as the homologous protein MalK. Using molecular dynamics we demonstrate that this is not the case: both NBDs open rapidly once ATP is removed. We conclude from this result that the closed structures of FbpC and MalK have higher free energies than their respective open states. This result has important implications for our understanding of the mechanism of power generation in ABC transporters, because the unwinding of this free energy ensures that the opening of these two NBDs is also powered. PMID:19748342

  4. TaAbc1, a Member of Abc1-Like Family Involved in Hypersensitive Response against the Stripe Rust Fungal Pathogen in Wheat

    PubMed Central

    Wang, Xiaojing; Wang, Xiaojie; Duan, Yinghui; Yin, Shuining; Zhang, Hongchang; Huang, Li; Kang, Zhensheng

    2013-01-01

    To search for genes involved in wheat (Triticum aestivum L.) defense response to the infection of stripe rust pathogen Puccinia striiformis f. sp. tritici (Pst), we identified and cloned a new wheat gene similar to the genes in the Abc1-like gene family. The new gene, designated as TaAbc1, encodes a 717-amino acid, 80.35 kD protein. The TaAbc1 protein contains two conserved domains shared by Abc1-like proteins, two trans-membrane domains at the C-terminal, and a 36-amino acid chloroplast targeting presequence at the N-terminal. Characterization of TaAbc1 expression revealed that gene expression was tissue-specific and could be up-regulated by biotic agents (e.g., stripe rust pathogen) and/or by an abiotic stress like wounding. High-fold induction was associated with the hypersensitive response (HR) triggered only by avirulent stripe rust pathotypes, suggesting that TaAbc1 is a rust-pathotype specific HR-mediator. Down-regulating TaAbc1 reduced HR but not the overall resistance level in Suwon11 to CYR23, suggesting TaAbc1 was involved in HR against stripe rust, but overall host resistance is not HR-dependent. PMID:23527058

  5. The Predicted ABC Transporter AbcEDCBA Is Required for Type IV Secretion System Expression and Lysosomal Evasion by Brucella ovis

    PubMed Central

    Silva, Teane M. A.; Mol, Juliana P. S.; Winter, Maria G.; Atluri, Vidya; Xavier, Mariana N.; Pires, Simone F.; Paixão, Tatiane A.; Andrade, Hélida M.; Santos, Renato L.; Tsolis, Renee M.

    2014-01-01

    Brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described Brucella species that is not zoonotic. Previous work showed that a B. ovis mutant lacking a species-specific ABC transporter (ΔabcBA) was attenuated in mice and was unable to survive in macrophages. The aim of this study was to evaluate the role of this ABC transporter during intracellular survival of B. ovis. In HeLa cells, B. ovis WT was able to survive and replicate at later time point (48 hpi), whereas an ΔabcBA mutant was attenuated at 24 hpi. The reduced survival of the ΔabcBA mutant was associated with a decreased ability to exclude the lysosomal marker LAMP1 from its vacuolar membrane, suggesting a failure to establish a replicative niche. The ΔabcBA mutant showed a reduced abundance of the Type IV secretion system (T4SS) proteins VirB8 and VirB11 in both rich and acid media, when compared to WT B. ovis. However, mRNA levels of virB1, virB8, hutC, and vjbR were similar in both strains. These results support the notion that the ABC transporter encoded by abcEDCBA or its transported substrate acts at a post-transcriptional level to promote the optimal expression of the B. ovis T4SS within infected host cells. PMID:25474545

  6. Apical ABC transporters and cancer chemotherapeutic drug disposition.

    PubMed

    Durmus, Selvi; Hendrikx, Jeroen J M A; Schinkel, Alfred H

    2015-01-01

    ATP-binding cassette (ABC) transporters are transmembrane efflux transporters that mediate cellular extrusion of a broad range of substrates ranging from amino acids, lipids, and ions to xenobiotics including many anticancer drugs. ABCB1 (P-GP) and ABCG2 (BCRP) are the most extensively studied apical ABC drug efflux transporters. They are highly expressed in apical membranes of many pharmacokinetically relevant tissues such as epithelial cells of the small intestine and endothelial cells of the blood capillaries in brain and testis, and in the placental maternal-fetal barrier. In these tissues, they have a protective function as they efflux their substrates back to the intestinal lumen or blood and thus restrict the intestinal uptake and tissue disposition of many compounds. This presents a major challenge for the use of many (anticancer) drugs, as most currently used anticancer drugs are substrates of these transporters. Herein, we review the latest findings on the role of apical ABC transporters in the disposition of anticancer drugs. We discuss that many new, rationally designed anticancer drugs are substrates of these transporters and that their oral availability and/or brain disposition are affected by this interaction. We also summarize studies that investigate the improvement of oral availability and brain disposition of many cytotoxic (e.g., taxanes) and rationally designed (e.g., tyrosine kinase inhibitor) anticancer drugs, using chemical inhibitors of these transporters. These findings provide a better understanding of the importance of apical ABC transporters in chemotherapy and may therefore advance translation of promising preclinical insights and approaches to clinical studies. PMID:25640265

  7. Fungal ABC transporters and microbial interactions in natural environments.

    PubMed

    Schoonbeek, Henk-jan; Raaijmakers, Jos M; De Waard, Maarten A

    2002-11-01

    In natural environments, microorganisms are exposed to a wide variety of antibiotic compounds produced by competing organisms. Target organisms have evolved various mechanisms of natural resistance to these metabolites. In this study, the role of ATP-binding cassette (ABC) transporters in interactions between the plant-pathogenic fungus Botrytis cinerea and antibiotic-producing Pseudomonas bacteria was investigated in detail. We discovered that 2,4-diacetylphloroglucinol, phenazine-1-carboxylic acid and phenazine-1-carboxamide (PCN), broad-spectrum antibiotics produced by Pseudomonas spp., induced expression of several ABC transporter genes in B. cinerea. Phenazines strongly induced expression of BcatrB, and deltaBcatrB mutants were significantly more sensitive to these antibiotics than their parental strain. Treatment of B. cinerea germlings with PCN strongly affected the accumulation of [14C]fludioxonil, a phenylpyrrole fungicide known to be transported by BcatrB, indicating that phenazines also are transported by BcatrB. Pseudomonas strains producing phenazines displayed a stronger antagonistic activity in vitro toward ABcatrB mutants than to the parental B. cinerea strain. On tomato leaves, phenazine-producing Pseudomonas strains were significantly more effective in reducing gray mold symptoms incited by a ABcatrB mutant than by the parental strain. We conclude that the ABC transporter BcatrB provides protection to B. cinerea in phenazine-mediated interactions with Pseudomonas spp. Collectively, these results indicate that fungal ABC transporters can play an important role in antibiotic-mediated interactions between bacteria and fungi in plant-associated environments. The implications of these findings for the implementation and sustainability of crop protection by antagonistic microorganisms are discussed. PMID:12423022

  8. Genome-wide comparative analysis of ABC systems in the Bdellovibrio-and-like organisms.

    PubMed

    Li, Nan; Chen, Huan; Williams, Henry N

    2015-05-10

    Bdellovibrio-and-like organisms (BALOs) are gram-negative, predatory bacteria with wide variations in genome sizes and GC content and ecological habitats. The ATP-binding cassette (ABC) systems have been identified in several prokaryotes, fungi and plants and have a role in transport of materials in and out of cells and in cellular processes. However, knowledge of the ABC systems of BALOs remains obscure. A total of 269 putative ABC proteins were identified in BALOs. The genes encoding these ABC systems occupy nearly 1.3% of the gene content in freshwater Bdellovibrio strains and about 0.7% in their saltwater counterparts. The proteins found belong to 25 ABC system families based on their structural characteristics and functions. Among these, 16 families function as importers, 6 as exporters and 3 are involved in various cellular processes. Eight of these 25 ABC system families were deduced to be the core set of ABC systems conserved in all BALOs. All Bacteriovorax strains have 28 or less ABC systems. On the contrary, the freshwater Bdellovibrio strains have more ABC systems, typically around 51. In the genome of Bdellovibrio exovorus JSS (CP003537.1), 53 putative ABC systems were detected, representing the highest number among all the BALO genomes examined in this study. Unexpected high numbers of ABC systems involved in cellular processes were found in all BALOs. Phylogenetic analysis suggests that the majority of ABC proteins can be assigned into many separate families with high bootstrap supports (>50%). In this study, a general framework of sequence-structure-function connections for the ABC systems in BALOs was revealed providing novel insights for future investigations. PMID:25707746

  9. Genome-wide comparative analysis of ABC systems in the Bdellovibrio-and-like organisms

    PubMed Central

    Li, Nan; Chen, Huan; Williams, Henry N.

    2015-01-01

    Bdellovibrio -and-like organisms (BALOs) are gram-negative, predatory bacteria with wide variations in genome sizes and GC content and ecological habitats. The ATP-binding cassette (ABC) systems have been identified in several prokaryotes, fungi and plants and have a role in transport of materials in and out of cells and in cellular processes. However, knowledge of the ABC systems of BALOs remains obscure. A total of 269 putative ABC proteins were identified in BALOs. The genes encoding these ABC systems occupy nearly 1.3% of the gene content in freshwater Bdellovibrio strains and about 0.7% in their saltwater counterparts. The proteins found belong to 25 ABC system families based on their structural characteristics and functions. Among these, 16 families function as importers, 6 as exporters and 3 are involved in various cellular processes. Eight of these 25 ABC system families were deduced to be the core set of ABC systems conserved in all BALOs. All Bacteriovorax strains have 28 or less ABC systems. On the contrary, the freshwater Bdellovibrio strains have more ABC systems, typically around 51. In the genome of Bdellovibrio exovorus JSS (CP003537.1), 53 putative ABC systems were detected, representing the highest number among all the BALO genomes examined in this study. Unexpected high numbers of ABC systems involved in cellular processes were found in all BALOs. Phylogenetic analysis suggests that the majority of ABC proteins can be assigned into many separate families with high bootstrap supports (>50%). In this study, a general framework of sequence–structure–function connections for the ABC systems in BALOs was revealed providing novel insights for future investigations. PMID:25707746

  10. Extinction treatment in multiple contexts attenuates ABC renewal in humans.

    PubMed

    Balooch, Siavash Bandarian; Neumann, David L; Boschen, Mark J

    2012-10-01

    Renewal has been implicated as one of the underlying mechanisms in return of fear following exposure therapy. ABC renewal is clinically more relevant than ABA renewal and yet it is a weaker form of renewal, suggesting that conducting extinction treatment in multiple contexts may be sufficient to attenuate ABC renewal. Using self-reported expectancy of shock and startle blink responses the current study examined the effects of conducting extinction treatment in multiple contexts on ABC fear renewal. Participants (N = 68) received conditional stimulus (CS) and unconditional stimulus (US) pairings in one context (A) followed by extinction treatment (CS presentations alone) in either one other context (B) or three other contexts (BCD). Non-reinforced test trials in a novel context (E) resulted in renewal of extinguished conditioned behaviour for those who received extinction in only one context. However, renewal was attenuated for those who received extinction treatment in three contexts. No renewal was found for the control group that received the test trial in the same context as during extinction. Suggestions are provided for clinicians seeking to prevent or attenuate return of fear following exposure therapy. PMID:22835841

  11. The ABCs of Candida albicans Multidrug Transporter Cdr1

    PubMed Central

    Banerjee, Atanu; Khandelwal, Nitesh Kumar; Dhamgaye, Sanjiveeni

    2015-01-01

    In the light of multidrug resistance (MDR) among pathogenic microbes and cancer cells, membrane transporters have gained profound clinical significance. Chemotherapeutic failure, by far, has been attributed mainly to the robust and diverse array of these proteins, which are omnipresent in every stratum of the living world. Candida albicans, one of the major fungal pathogens affecting immunocompromised patients, also develops MDR during the course of chemotherapy. The pivotal membrane transporters that C. albicans has exploited as one of the strategies to develop MDR belongs to either the ATP binding cassette (ABC) or the major facilitator superfamily (MFS) class of proteins. The ABC transporter Candida drug resistance 1 protein (Cdr1p) is a major player among these transporters that enables the pathogen to outplay the battery of antifungals encountered by it. The promiscuous Cdr1 protein fulfills the quintessential need of a model to study molecular mechanisms of multidrug transporter regulation and structure-function analyses of asymmetric ABC transporters. In this review, we cover the highlights of two decades of research on Cdr1p that has provided a platform to study its structure-function relationships and regulatory circuitry for a better understanding of MDR not only in yeast but also in other organisms. PMID:26407965

  12. The ABCs of Candida albicans Multidrug Transporter Cdr1.

    PubMed

    Prasad, Rajendra; Banerjee, Atanu; Khandelwal, Nitesh Kumar; Dhamgaye, Sanjiveeni

    2015-12-01

    In the light of multidrug resistance (MDR) among pathogenic microbes and cancer cells, membrane transporters have gained profound clinical significance. Chemotherapeutic failure, by far, has been attributed mainly to the robust and diverse array of these proteins, which are omnipresent in every stratum of the living world. Candida albicans, one of the major fungal pathogens affecting immunocompromised patients, also develops MDR during the course of chemotherapy. The pivotal membrane transporters that C. albicans has exploited as one of the strategies to develop MDR belongs to either the ATP binding cassette (ABC) or the major facilitator superfamily (MFS) class of proteins. The ABC transporter Candida drug resistance 1 protein (Cdr1p) is a major player among these transporters that enables the pathogen to outplay the battery of antifungals encountered by it. The promiscuous Cdr1 protein fulfills the quintessential need of a model to study molecular mechanisms of multidrug transporter regulation and structure-function analyses of asymmetric ABC transporters. In this review, we cover the highlights of two decades of research on Cdr1p that has provided a platform to study its structure-function relationships and regulatory circuitry for a better understanding of MDR not only in yeast but also in other organisms. PMID:26407965

  13. Second-order nonlinear optical metamaterials: ABC-type nanolaminates

    SciTech Connect

    Alloatti, L. Kieninger, C.; Lauermann, M.; Köhnle, K.; Froelich, A.; Wegener, M.; Frenzel, T.; Freude, W.; Leuthold, J.; Koos, C.

    2015-09-21

    We demonstrate a concept for second-order nonlinear metamaterials that can be obtained from non-metallic centrosymmetric constituents with inherently low optical absorption. The concept is based on iterative atomic-layer deposition of three different materials, A = Al{sub 2}O{sub 3}, B = TiO{sub 2}, and C = HfO{sub 2}. The centrosymmetry of the resulting ABC stack is broken since the ABC and the inverted CBA sequences are not equivalent—a necessary condition for non-zero second-order nonlinearity. In our experiments, we find that the bulk second-order nonlinear susceptibility depends on the density of interfaces, leading to a nonlinear susceptibility of 0.26 pm/V at a wavelength of 800 nm. ABC-type nanolaminates can be deposited on virtually any substrate and offer a promising route towards engineering of second-order optical nonlinearities at both infrared and visible wavelengths.

  14. ABC-F Proteins Mediate Antibiotic Resistance through Ribosomal Protection

    PubMed Central

    Sharkey, Liam K. R.; Edwards, Thomas A.

    2016-01-01

    ABSTRACT Members of the ABC-F subfamily of ATP-binding cassette proteins mediate resistance to a broad array of clinically important antibiotic classes that target the ribosome of Gram-positive pathogens. The mechanism by which these proteins act has been a subject of long-standing controversy, with two competing hypotheses each having gained considerable support: antibiotic efflux versus ribosomal protection. Here, we report on studies employing a combination of bacteriological and biochemical techniques to unravel the mechanism of resistance of these proteins, and provide several lines of evidence that together offer clear support to the ribosomal protection hypothesis. Of particular note, we show that addition of purified ABC-F proteins to an in vitro translation assay prompts dose-dependent rescue of translation, and demonstrate that such proteins are capable of displacing antibiotic from the ribosome in vitro. To our knowledge, these experiments constitute the first direct evidence that ABC-F proteins mediate antibiotic resistance through ribosomal protection. PMID:27006457

  15. High-level assessment of LANL ABC Design

    SciTech Connect

    Not Available

    1994-04-15

    An annual weapon`s grade Pu disposition goal should be stated and related to the amount of Pu that needs to be disposed of. It needs to be determined to what extent it is possible to destroy Pu without building up any new Pu, i.e., how realistic this goal is. The strong positive Doppler coefficient for a Pu core might require the addition of some fertile material to ensure a negative Doppler coefficient. This in turn will affect the net Pu disposition rate. If a fertile material is required throughout the life of the ABC to ensure a negative Doppler coefficient, the difference between the molten salt ABC and other reactors in regard to Pu disposition is not a principled difference anymore but one of degree. A rationale has then to be developed that explains why {open_quotes}x{close_quotes} kg production of fissile material are acceptable but {open_quotes}y{close_quotes} kg are not. It is important to determine how a requirement for electricity production will impact on the ABC design choices. It is conceivable that DOE will not insist on electricity generation. In this case advantage has to be taken in terms of design simplifications and relaxed operating conditions.

  16. A reciprocating twin-channel model for ABC transporters.

    PubMed

    Jones, Peter M; George, Anthony M

    2014-08-01

    ABC transporters comprise a large, diverse, and ubiquitous superfamily of membrane active transporters. Their core architecture is a dimer of dimers, comprising two transmembrane (TM) domains that bind substrate, and two ATP-binding cassettes, which use the cell's energy currency to couple substrate translocation to ATP hydrolysis. Despite the availability of over a dozen resolved structures and a wealth of biochemical and biophysical data, this field is bedeviled by controversy and long-standing mechanistic questions remain unresolved. The prevailing paradigm for the ABC transport mechanism is the Switch Model, in which the ATP-binding cassettes dimerize upon binding two ATP molecules, and thence dissociate upon sequential ATP hydrolysis. This cycle of nucleotide-binding domain (NBD) dimerization and dissociation is coupled to a switch between inward- or outward facing conformations of a single TM channel; this alternating access enables substrate binding on one face of the membrane and its release at the other. Notwithstanding widespread acceptance of the Switch Model, there is substantial evidence that the NBDs do not separate very much, if at all, and thus physical separation of the ATP cassettes observed in crystallographic structures may be an artefact. An alternative Constant Contact Model has been proposed, in which ATP hydrolysis occurs alternately at the two ATP-binding sites, with one of the sites remaining closed and containing occluded nucleotide at all times. In this model, the cassettes remain in contact and the active sites swing open in an alternately seesawing motion. Whilst the concept of NBD association/dissociation in the Switch Model is naturally compatible with a single alternating-access channel, the asymmetric functioning proposed by the Constant Contact model suggests an alternating or reciprocating function in the TMDs. Here, a new model for the function of ABC transporters is proposed in which the sequence of ATP binding, hydrolysis, and

  17. Object detection based on template matching through use of best-so-far ABC.

    PubMed

    Banharnsakun, Anan; Tanathong, Supannee

    2014-01-01

    Best-so-far ABC is a modified version of the artificial bee colony (ABC) algorithm used for optimization tasks. This algorithm is one of the swarm intelligence (SI) algorithms proposed in recent literature, in which the results demonstrated that the best-so-far ABC can produce higher quality solutions with faster convergence than either the ordinary ABC or the current state-of-the-art ABC-based algorithm. In this work, we aim to apply the best-so-far ABC-based approach for object detection based on template matching by using the difference between the RGB level histograms corresponding to the target object and the template object as the objective function. Results confirm that the proposed method was successful in both detecting objects and optimizing the time used to reach the solution. PMID:24812556

  18. Object Detection Based on Template Matching through Use of Best-So-Far ABC

    PubMed Central

    2014-01-01

    Best-so-far ABC is a modified version of the artificial bee colony (ABC) algorithm used for optimization tasks. This algorithm is one of the swarm intelligence (SI) algorithms proposed in recent literature, in which the results demonstrated that the best-so-far ABC can produce higher quality solutions with faster convergence than either the ordinary ABC or the current state-of-the-art ABC-based algorithm. In this work, we aim to apply the best-so-far ABC-based approach for object detection based on template matching by using the difference between the RGB level histograms corresponding to the target object and the template object as the objective function. Results confirm that the proposed method was successful in both detecting objects and optimizing the time used to reach the solution. PMID:24812556

  19. Phylogenetic and functional classification of ATP-binding cassette (ABC) systems.

    PubMed

    Bouige, Philippe; Laurent, David; Piloyan, Linda; Dassa, Elie

    2002-10-01

    ATP binding cassette (ABC) systems constitute one of the most abundant superfamilies of proteins. They are involved in the transport of a wide variety of substances, but also in many cellular processes and in their regulation. In this paper, we made a comparative analysis of the properties of ABC systems and we provide a phylogenetic and functional classification. This analysis will be helpful to accurately annotate ABC systems discovered during the sequencing of the genome of living organisms and to identify the partners of the ABC ATPases. PMID:12370001

  20. MdsABC-Mediated Pathway for Pathogenicity in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Song, Saemee; Lee, Boeun; Yeom, Ji-Hyun; Hwang, Soonhye; Kang, Ilnam; Cho, Jang-Cheon; Ha, Nam-Chul; Bae, Jeehyeon

    2015-01-01

    MdsABC is a Salmonella-specific tripartite efflux pump that has been implicated in the virulence of Salmonella enterica serovar Typhimurium; however, little is known about the virulence factors associated with this pump. We observed MdsABC expression-dependent alterations in the degree of resistance to extracellular oxidative stress and macrophage-mediated killing. Thin-layer chromatography and tandem mass spectrometry analyses revealed that overexpression of MdsABC led to increased secretion of 1-palmitoyl-2-stearoyl-phosphatidylserine (PSPS), affecting the ability of the bacteria to invade and survive in host cells. Overexpression of MdsABC and external addition of PSPS similarly rendered the mdsABC deletion strain resistant to diamide. Diagonal gel analysis showed that PSPS treatment reduced the diamide-mediated formation of disulfide bonds, particularly in the membrane fraction of the bacteria. Salmonella infection of macrophages induced the upregulation of MdsABC expression and led to an increase of intracellular bacterial number and host cell death, similar to the effects of MdsABC overexpression and PSPS pretreatment on the mdsABC deletion strain. Our study shows that MdsABC mediates a previously uncharacterized pathway that involves PSPS as a key factor for the survival and virulence of S. Typhimurium in phagocytic cells. PMID:26283336

  1. Improvement of proteolytic and oxidative stability of Chondroitinase ABC I by cosolvents.

    PubMed

    Nazari-Robati, Mahdieh; Golestani, Abolfazl; Asadikaram, GholamReza

    2016-10-01

    Recently, utilization of the enzyme Chondroitinase ABC I (cABC I) has received considerable attention in treatment of spinal cord injury. cABC I removes chondroitin sulfate proteoglycans which are inhibitory to axon growth and enhances nerve regeneration. Therefore, determination of cABC I resistance to proteolysis and oxidation provides valuable information for optimizing its clinical application. In this work, proteolytic stability of cABC I to trypsin and chymotrypsin as well as its oxidative resistance to H2O2 was measured. Moreover, the effect of cosolvents glycerol, sorbitol and trehalose on cABC I proteolytic and oxidative stability was determined. The results indicated that cABC I is highly susceptible to proteolysis and oxidation. Comparison of proteolytic patterns demonstrated a high degree of similarity which confirmed the exposure of specific regions of cABC I to proteolysis. However, proteolytic degradation was significantly reduced in the presence of cosolvents. In addition, cosolvents decreased the rate of both cABC I proteolytic and oxidative inactivation. Notably, the degree of stabilization provided by these cosolvents varied greatly. These findings indicated the high potential of cosolvents in protein stabilization to proteolysis and oxidative inactivation. PMID:27311501

  2. Schistosome ABC multidrug transporters: From pharmacology to physiology

    PubMed Central

    Greenberg, Robert M.

    2014-01-01

    Praziquantel (PZQ) is essentially the only drug currently available for treatment and control of schistosomiasis, a disease affecting hundreds of millions worldwide. Though highly effective overall, PZQ has limitations, most notably its significant lack of activity against immature schistosomes. Furthermore, the availability of only a single drug for a disease of this magnitude makes reports of PZQ-resistant isolates particularly troubling. ATP-binding cassette (ABC) multidrug transporters such as P-glycoprotein (Pgp; ABCB1) are efflux transporters that underlie multidrug resistance (MDR); changes in their expression or structure are also associated with drug resistance in parasites, including helminths. This review will discuss the role these transporters might play in modulating schistosome susceptibility to PZQ, and the implications for developing new or repurposed treatments that enhance the efficacy of PZQ. However, in addition to influencing drug susceptibility, ABC transporters play important roles in several critical physiological functions such as excretion and maintenance of permeability barriers. They also transport signaling molecules with high affinity, and several lines of evidence implicate mammalian transporters in a diverse array of physiological functions, including regulation of immune responses. Like their mammalian counterparts, schistosome ABC transporters appear to be involved in functions critical to the parasite, including excretory activity and reproduction, and we hypothesize that they underlie at least some aspects of parasite–host interactions. Thus, in addition to their potential as targets for enhancers of PZQ susceptibility, these transporters might also serve as candidate targets for agents that disrupt the parasite life cycle and act as antischistosomals on their own. PMID:25516841

  3. Accelerator-based conversion (ABC) of reactor and weapons plutonium

    SciTech Connect

    Jensen, R.J.; Trapp, T.J.; Arthur, E.D.; Bowman, C.D.; Davidson, J.W.; Linford, R.K.

    1993-06-01

    An accelerator-based conversion (ABC) system is presented that is capable of rapidly burning plutonium in a low-inventory sub-critical system. The system also returns fission power to the grid and transmutes troublesome long-lived fission products to short lived or stable products. Higher actinides are totally fissioned. The system is suited not only to controlled, rapid burning of excess weapons plutonium, but to the long range application of eliminating or drastically reducing the world total inventory of plutonium. Deployment of the system will require the successful resolution of a broad range of technical issues introduced in the paper.

  4. Design of the storage location based on the ABC analyses

    NASA Astrophysics Data System (ADS)

    Jemelka, Milan; Chramcov, Bronislav; Kříž, Pavel

    2016-06-01

    The paper focuses on process efficiency and saving storage costs. Maintaining inventory through putaway strategy takes personnel time and costs money. The aim is to control inventory in the best way. The ABC classification based on Villefredo Pareto theory is used for a design of warehouse layout. New design of storage location reduces the distance of fork-lifters, total costs and it increases inventory process efficiency. The suggested solutions and evaluation of achieved results are described in detail. Proposed solutions were realized in real warehouse operation.

  5. SU-E-T-401: Feasibility Study of Using ABC to Gate Lung SBRT Treatment

    SciTech Connect

    Cao, D; Xie, X; Shepard, D

    2014-06-01

    Purpose: The current SBRT treatment techniques include free breathing (FB) SBRT and gated FB SBRT. Gated FB SBRT has smaller target and less lung toxicity with longer treatment time. The recent development of direct connectivity between the ABC and linac allowing for automated beam gating. In this study, we have examined the feasibility of using ABC system to gate the lung SBRT treatment. Methods: A CIRS lung phantom with a 3cm sphere-insert and a moving chest plate was used in this study. Sinusoidal motion was used for the FB pattern. An ABC signal was imported to simulate breath holds. 4D-CT was taken in FB mode and average-intensity-projection (AIP) was used to create FB and 50% gated FB SBRT planning CT. A manually gated 3D CT scan was acquired for ABC gated SBRT planning.An SBRT plan was created for each treatment option. A surface-mapping system was used for 50% gating and ABC system was used for ABC gating. A manually gated CBCT scan was also performed to verify setup. Results: Among three options, the ABC gated plan has the smallest PTV of 35.94cc, which is 35% smaller comparing to that of the FB plan. Consequently, the V20 of the left lung reduced by 15% and 23% comparing to the 50% gated FB and FB plans, respectively. The FB plan took 4.7 minutes to deliver, while the 50% gated FB plan took 18.5 minutes. The ABC gated plan delivery took only 10.6 minutes. A stationary target with 3cm diameter was also obtained from the manually gated CBCT scan. Conclusion: A strategy for ABC gated lung SBRT was developed. ABC gating can significantly reduce the lung toxicity while maintaining the target coverage. Comparing to the 50% gated FB SBRT, ABC gated treatment can also provide less lung toxicity as well as improved delivery efficiency. This research is funded by Elekta.

  6. The ABC gene family in arthropods: comparative genomics and role in insecticide transport and resistance.

    PubMed

    Dermauw, Wannes; Van Leeuwen, Thomas

    2014-02-01

    About a 100 years ago, the Drosophila white mutant marked the birth of Drosophila genetics. The white gene turned out to encode the first well studied ABC transporter in arthropods. The ABC gene family is now recognized as one of the largest transporter families in all kingdoms of life. The majority of ABC proteins function as primary-active transporters that bind and hydrolyze ATP while transporting a large diversity of substrates across lipid membranes. Although extremely well studied in vertebrates for their role in drug resistance, less is known about the role of this family in the transport of endogenous and exogenous substances in arthropods. The ABC families of five insect species, a crustacean and a chelicerate have been annotated in some detail. We conducted a thorough phylogenetic analysis of the seven arthropod and human ABC protein subfamilies, to infer orthologous relationships that might suggest conserved function. Most orthologous relationships were found in the ABCB half transporter, ABCD, ABCE and ABCF subfamilies, but specific expansions within species and lineages are frequently observed and discussed. We next surveyed the role of ABC transporters in the transport of xenobiotics/plant allelochemicals and their involvement in insecticide resistance. The involvement of ABC transporters in xenobiotic resistance in arthropods is historically not well documented, but an increasing number of studies using unbiased differential gene expression analysis now points to their importance. We give an overview of methods that can be used to link ABC transporters to resistance. ABC proteins have also recently been implicated in the mode of action and resistance to Bt toxins in Lepidoptera. Given the enormous interest in Bt toxicology in transgenic crops, such findings will provide an impetus to further reveal the role of ABC transporters in arthropods. PMID:24291285

  7. ABCE1 is essential for S phase progression in human cells.

    PubMed

    Toompuu, Marina; Kärblane, Kairi; Pata, Pille; Truve, Erkki; Sarmiento, Cecilia

    2016-05-01

    ABCE1 is a highly conserved protein universally present in eukaryotes and archaea, which is crucial for the viability of different organisms. First identified as RNase L inhibitor, ABCE1 is currently recognized as an essential translation factor involved in several stages of eukaryotic translation and ribosome biogenesis. The nature of vital functions of ABCE1, however, remains unexplained. Here, we study the role of ABCE1 in human cell proliferation and its possible connection to translation. We show that ABCE1 depletion by siRNA results in a decreased rate of cell growth due to accumulation of cells in S phase, which is accompanied by inefficient DNA synthesis and reduced histone mRNA and protein levels. We infer that in addition to the role in general translation, ABCE1 is involved in histone biosynthesis and DNA replication and therefore is essential for normal S phase progression. In addition, we analyze whether ABCE1 is implicated in transcript-specific translation via its association with the eIF3 complex subunits known to control the synthesis of cell proliferation-related proteins. The expression levels of a few such targets regulated by eIF3A, however, were not consistently affected by ABCE1 depletion. PMID:26985706

  8. Movement Assessment Battery for Children (M-ABC): Establishing Construct Validity for Israeli Children

    ERIC Educational Resources Information Center

    Engel-Yeger, Batya; Rosenblum, Sara; Josman, Naomi

    2010-01-01

    The Movement Assessment Battery for Children (M-ABC) is one of the most accepted tools, both in clinical practice and in research, for the diagnosis of Developmental Coordination Disorders (DCDs) in children. The present study aimed to: (1) establish the construct validity of M-ABC in Israel by comparing the motor performance of typically…

  9. Parents' Perspectives on Braille Literacy: Results from the ABC Braille Study

    ERIC Educational Resources Information Center

    Kamei-Hannan, Cheryl; Sacks, Sharon Zell

    2012-01-01

    Introduction: Parents who were the primary caretakers of children in the Alphabetic and Contracted Braille Study (ABC Braille Study) revealed their perspectives about braille literacy. Methods: A 30-item questionnaire was constructed by the ABC Braille research team, and researchers conducted telephone interviews with 31 parents who were the…

  10. ABCs of Public Education in North Carolina: A Journey toward Excellence.

    ERIC Educational Resources Information Center

    North Carolina State Board of Education, Raleigh.

    In 1995, the North Carolina General Assembly directed the North Carolina State Board of Education to develop a plan to bolster student growth and performance in grades 4-8 throughout the state. In response, the board developed the ABCs of Public Education. (ABC stands for Accountability; teaching the Basics of reading, writing, and mathematics;…

  11. Applying the Post-Modern Double ABC-X Model to Family Food Insecurity

    ERIC Educational Resources Information Center

    Hutson, Samantha; Anderson, Melinda; Swafford, Melinda

    2015-01-01

    This paper develops the argument that using the Double ABC-X model in family and consumer sciences (FCS) curricula is a way to educate nutrition and dietetics students regarding a family's perceptions of food insecurity. The Double ABC-X model incorporates ecological theory as a basis to explain family stress and the resulting adjustment and…

  12. 40 CFR Table 3 to Subpart II of... - Summary of Recordkeeping and Reporting Requirements abc

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Summary of Recordkeeping and Reporting Requirements abc 3 Table 3 to Subpart II of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... abc Requirement All Opts. Rec Rep Option 1 Rec Rep Option 2 Rec Rep Option 3 Rec Rep...

  13. 40 CFR Table 3 to Subpart II of... - Summary of Recordkeeping and Reporting Requirements abc

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Summary of Recordkeeping and Reporting Requirements abc 3 Table 3 to Subpart II of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... abc Requirement All Opts. Rec Rep Option 1 Rec Rep Option 2 Rec Rep Option 3 Rec Rep...

  14. A Comparison of the K-ABC and WISC-R: A Validity Study.

    ERIC Educational Resources Information Center

    Sapp, Gary L.; And Others

    The concurrent validity of the Kaufman Assessment Battery for Children (K-ABC) was examined by comparing K-ABC scores and Weschler Intelligence Scale for Children--Revised (WISC-R) scores for 58 school children in primary and intermediate grades. Thirty-seven of these children had either educable mental retardation, learning disabilities, or…

  15. Regulation of IL-10 by chondroitinase ABC promotes a distinct immune response following spinal cord injury.

    PubMed

    Didangelos, Athanasios; Iberl, Michaela; Vinsland, Elin; Bartus, Katalin; Bradbury, Elizabeth J

    2014-12-01

    Chondroitinase ABC (ChABC) has striking effects on promoting neuronal plasticity after spinal cord injury (SCI), but little is known about its involvement in other pathological mechanisms. Recent work showed that ChABC might also modulate the immune response by promoting M2 macrophage polarization. Here we investigate in detail the immunoregulatory effects of ChABC after SCI in rats. Initially, we examined the expression profile of 16 M1/M2 macrophage polarization markers at 3 h and 7 d postinjury. ChABC treatment had a clear effect on the immune signature after SCI. More specifically, ChABC increased the expression of the anti-inflammatory cytokine IL-10, accompanied by a reduction in the proinflammatory cytokine IL-12B in injured spinal tissue. These effects were associated with a distinct, IL-10-mediated anti-inflammatory response in ChABC-treated spinal cords. Mechanistically, we show that IL-10 expression is driven by tissue injury and macrophage infiltration, while the p38 MAPK is the central regulator of IL-10 expression in vivo. These findings provide novel insights into the effects of ChABC in the injured spinal cord and explain its immunoregulatory activity. PMID:25471580

  16. Structural Validity of the Movement ABC-2 Test: Factor Structure Comparisons across Three Age Groups

    ERIC Educational Resources Information Center

    Schulz, Joerg; Henderson, Sheila E.; Sugden, David A.; Barnett, Anna L.

    2011-01-01

    Background: The Movement ABC test is one of the most widely used assessments in the field of Developmental Coordination Disorder (DCD). Improvements to the 2nd edition of the test (M-ABC-2) include an extension of the age range and reduction in the number of age bands as well as revision of tasks. The total test score provides a measure of motor…

  17. Characterization of Two ABC Transporters from Biocontrol and Phytopathogenic Fusarium oxysporus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ABC transporter genes from four strains of Fusarium oxysporum [two biocontrol and two phytopathogenic (f. sp. lycopersici Race 1) isolates] indicated that this gene is well conserved. However, sequences of promoter regions of FoABC1 differed between 8 phytopathogenic and 11 biocontrol strains of F....

  18. When Does Rank(ABC)= Rank(AB) + Rank(BC) - Rank(B) Hold?

    ERIC Educational Resources Information Center

    Tian, Yongge; Styan, George P. H.

    2002-01-01

    The well-known Frobenius rank inequality established by Frobenius in 1911 states that the rank of the product ABC of three matrices satisfies the inequality rank(ABC) [greater than or equal]rank(AB) + rank(BC) - rank(B) A new necessary and sufficient condition for equality to hold is presented and then some interesting consequences and…

  19. The ABCs of Activity-Based Costing: A Cost Containment and Reallocation Tool.

    ERIC Educational Resources Information Center

    Turk, Frederick J.

    1992-01-01

    This article describes activity-based costing (ABC) and how this tool may help management understand the costs of major activities and identify possible alternatives. Also discussed are the traditional costing systems used by higher education and ways of applying ABC to higher education. (GLR)

  20. So, You Need To Justify Your Existing ABC Program (or Lobby for a New One).

    ERIC Educational Resources Information Center

    Walsh, Jean Terry; Gillis, Lee

    1998-01-01

    Advice for adventure-based counseling (ABC) programs seeking funding includes setting realistic goals, designing an evaluation that matches program resources, and keeping it simple. Low recidivism is most important to grantors. Published research on ABC is scarce, but on-site process research generates useful data, and local schools and agencies…

  1. Nucleobase-functionalized ABC triblock copolymers: self-assembly of supramolecular architectures.

    PubMed

    Zhang, Keren; Fahs, Gregory B; Aiba, Motohiro; Moore, Robert B; Long, Timothy E

    2014-08-21

    RAFT polymerization afforded acrylic ABC triblock copolymers with self-complementary nucleobase-functionalized external blocks and a low-Tg soft central block. ABC triblock copolymers self-assembled into well-defined lamellar microphase-separated morphologies for potential applications as thermoplastic elastomers. Complementary hydrogen bonding within the hard phase facilitated self-assembly and enhanced mechanical performance. PMID:24984613

  2. Creating an iPhone Application for Collecting Continuous ABC Data

    ERIC Educational Resources Information Center

    Whiting, Seth W.; Dixon, Mark R.

    2012-01-01

    This paper provides an overview and task analysis for creating a continuous ABC data- collection application using Xcode on a Mac computer. Behavior analysts can program an ABC data collection system, complete with a customized list of target clients, antecedents, behaviors, and consequences to be recorded, and have the data automatically sent to…

  3. The Role of Activity Based Costing (ABC) in Educational Support Services: A White Paper.

    ERIC Educational Resources Information Center

    Edds, Daniel B.

    Many front-line managers who are assuming more financial responsibility for their organizations find traditional cost accounting inadequate for their needs and are turning to Activity Based Costing (ABC). ABC is not a financial reporting system to serve the needs of regulatory agencies, but a tool that tracks costs from the general ledger…

  4. Abrasive wear behavior of heat-treated ABC-silicon carbide

    SciTech Connect

    Zhang, Xiao Feng; Lee, Gun Y.; Chen, Da; Ritchie, Robert O.; De Jonghe, Lutgard C.

    2002-06-17

    Hot-pressed silicon carbide, containing aluminum, boron, and carbon additives (ABC-SiC), was subjected to three-body and two-body wear testing using diamond abrasives over a range of sizes. In general, the wear resistance of ABC-SiC, with suitable heat treatment, was superior to that of commercial SiC.

  5. Hydroxyproline-free single composition ABC collagen heterotrimer.

    PubMed

    Jalan, Abhishek A; Demeler, Borries; Hartgerink, Jeffrey D

    2013-04-24

    Hydroxyproline plays a major role in stabilizing collagenous domains in eukaryotic organisms. Lack of this modification is associated with significant lowering in the thermal stability of the collagen triple helix and may also affect fibrillogenesis and folding of the peptide chains. In contrast, even though bacterial collagens lack hydroxyproline, their thermal stability is comparable to that of fibrillar collagen. This has been attributed to the high frequency of charged amino acids found in bacterial collagen. Here we report a thermally stable hydroxyproline-free ABC heterotrimeric collagen mimetic system composed of decapositive and decanegative peptides and a zwitterionic peptide. None of the peptides contain hydroxyproline, and furthermore the zwitterionic peptide does not even contain proline. The heterotrimer is electrostatically stabilized via multiple interpeptide lysine-aspartate and lysine-glutamate salt bridges and maintains good thermal stability with a melting temperature of 37 °C. The ternary peptide mixture also populates a single composition ABC heterotrimer as confirmed by circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. This system illustrates the power of axial salt bridges to direct and stabilize the self-assembly of a triple helix and may be useful in analogous designs in expression systems where the incorporation of hydroxyproline is challenging. PMID:23574286

  6. Environment sensing and response mediated by ABC transporters

    SciTech Connect

    Giuliani, Sarah E; Frank, Ashley M; Corgliano, Danielle M; Siefert, Catherine; Hauser, Loren John; Collart, Frank

    2011-01-01

    Abstract Background: Transporter proteins are one of an organism s primary interfaces with the environment. The expressed set of transporters mediates cellular metabolic capabilities and influences signal transduction pathways and regulatory networks. The functional annotation of most transporters is currently limited to general classification into families. The development of capabilities to map ligands with specific transporters would improve our knowledge of the function of these proteins, improve the annotation of related genomes, and facilitate predictions for their role in cellular responses to environmental changes. Results: To improve the utility of the functional annotation for ABC transporters, we expressed and purified the set of solute binding proteins from Rhodopseudomonas palustris and characterized their ligand-binding specificity. Our approach utilized ligand libraries consisting of environmental and cellular metabolic compounds, and fluorescence thermal shift based high throughput ligand binding screens. This process resulted in the identification of specific binding ligands for approximately 64% of the purified and screened proteins. The collection of binding ligands is representative of common functionalities associated with many bacterial organisms as well as specific capabilities linked to the ecological niche occupied by R. palustris. Conclusion: The functional screen identified specific ligands that bound to ABC transporter periplasmic binding subunits from R. palustris. These assignments provide unique insight for the metabolic capabilities of this organism and are consistent with the ecological niche of strain isolation. This functional insight can be used to improve the annotation of related organisms and provides a route to evaluate the evolution of this important and diverse group of transporter proteins.

  7. [Structural and Pharmacological Studies of an ABC Multidrug Transporter].

    PubMed

    Yamaguchi, Tomohiro

    2016-01-01

    A drug's effectiveness against a disease depends not only on its interaction with receptors but also its pharmacokinetics (absorption, distribution, metabolism, and extrusion; ADME). ATP binding cassette (ABC) multidrug transporters are important proteins that influence the ADME properties of a drug, especially the ABC transporter subfamily B member 1 (ABCB1). Elucidation of the molecular mechanisms of ABCB1 will contribute to our understanding of the molecular basis of ADME. Human ABCB1 is expressed in many organelles, and exports various substrates from cells using energy generated by its ATP hydrolase (ATPase) activity. The ATPase activity depends on the concentration of the transport substrates, and the characteristic behavior of the substrate-dependent ATPase activity can be related to the molecular mechanism of ABCB1. Recently, we have revealed the molecular mechanisms of a eukaryotic ABCB1 homolog, CmABCB1, based on structural and functional studies. In this review, I discuss the relationship between key structural features and the behavior of transport substrate-dependent ATPase activity of CmABCB1, including its role in determining the molecular basis of ADME. PMID:26831793

  8. Accuracy of the ABC/2 score for intracerebral hemorrhage: Systematic review and analysis of MISTIE, CLEAR-IVH, CLEAR III

    PubMed Central

    Webb, Alastair JS; Ullman, Natalie L; Morgan, Tim C; Muschelli, John; Kornbluth, Joshua; Awad, Issam A; Mayo, Stephen; Rosenblum, Michael; Ziai, Wendy; Zuccarrello, Mario; Aldrich, Francois; John, Sayona; Harnof, Sagi; Lopez, George; Broaddus, William C; Wijman, Christine; Vespa, Paul; Bullock, Ross; Haines, Stephen J; Cruz-Flores, Salvador; Tuhrim, Stan; Hill, Michael D; Narayan, Raj; Hanley, Daniel F

    2015-01-01

    Background and Purpose The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized Reading Center (RC-ABC) or local site (site-ABC) versus the reference-standard CT-based planimetry (CTP). Methods In MISTIE-II, CLEAR-IVH and CLEAR-III trials, ICH volume was prospectively calculated by CTP, RC-ABC and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5ml and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression. Results In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC (r2=0.93) than site-ABC (r2=0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC=15.2cm3, CTP=12.7cm3), agreement was reasonable when categorised into mild, moderate and severe ICH (kappa 0.75, p<0.001). This was consistent with overestimation of ICH volume in 6/8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5ml; 48% of scans within 20%) than for site-ABC (81% within 5ml; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥ 5ml change in CTP volume between consecutive scans (sensitivity 0.76, specificity 0.86) and was more accurate with smaller ICH, thalamic haemorrhage and homogeneous clots. Conclusions ABC/2 scores at local or central sites are sufficiently accurate to categorise ICH volume and assess eligibility for the CLEAR III and MISTIE III studies, and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular or lobar clots. Clinical Trial Registration MISTIE-II NCT00224770; CLEAR-III NCT00784134; www.clinicaltrials.gov PMID:26243227

  9. Application of activity-based costing (ABC) for a Peruvian NGO healthcare provider.

    PubMed

    Waters, H; Abdallah, H; Santillán, D

    2001-01-01

    This article describes the application of activity-based costing (ABC) to calculate the unit costs of the services for a health care provider in Peru. While traditional costing allocates overhead and indirect costs in proportion to production volume or to direct costs, ABC assigns costs through activities within an organization. ABC uses personnel interviews to determine principal activities and the distribution of individual's time among these activities. Indirect costs are linked to services through time allocation and other tracing methods, and the result is a more accurate estimate of unit costs. The study concludes that applying ABC in a developing country setting is feasible, yielding results that are directly applicable to pricing and management. ABC determines costs for individual clinics, departments and services according to the activities that originate these costs, showing where an organization spends its money. With this information, it is possible to identify services that are generating extra revenue and those operating at a loss, and to calculate cross subsidies across services. ABC also highlights areas in the health care process where efficiency improvements are possible. Conclusions about the ultimate impact of the methodology are not drawn here, since the study was not repeated and changes in utilization patterns and the addition of new clinics affected applicability of the results. A potential constraint to implementing ABC is the availability and organization of cost information. Applying ABC efficiently requires information to be readily available, by cost category and department, since the greatest benefits of ABC come from frequent, systematic application of the methodology in order to monitor efficiency and provide feedback for management. The article concludes with a discussion of the potential applications of ABC in the health sector in developing countries. PMID:11326572

  10. The replication origin of a repABC plasmid

    PubMed Central

    2011-01-01

    Background repABC operons are present on large, low copy-number plasmids and on some secondary chromosomes in at least 19 α-proteobacterial genera, and are responsible for the replication and segregation properties of these replicons. These operons consist, with some variations, of three genes: repA, repB, and repC. RepA and RepB are involved in plasmid partitioning and in the negative regulation of their own transcription, and RepC is the limiting factor for replication. An antisense RNA encoded between the repB-repC genes modulates repC expression. Results To identify the minimal region of the Rhizobium etli p42d plasmid that is capable of autonomous replication, we amplified different regions of the repABC operon using PCR and cloned the regions into a suicide vector. The resulting vectors were then introduced into R. etli strains that did or did not contain p42d. The minimal replicon consisted of a repC open reading frame under the control of a constitutive promoter with a Shine-Dalgarno sequence that we designed. A sequence analysis of repC revealed the presence of a large A+T-rich region but no iterons or DnaA boxes. Silent mutations that modified the A+T content of this region eliminated the replication capability of the plasmid. The minimal replicon could not be introduced into R. etli strain containing p42d, but similar constructs that carried repC from Sinorhizobium meliloti pSymA or the linear chromosome of Agrobacterium tumefaciens replicated in the presence or absence of p42d, indicating that RepC is an incompatibility factor. A hybrid gene construct expressing a RepC protein with the first 362 amino acid residues from p42d RepC and the last 39 amino acid residues of RepC from SymA was able to replicate in the presence of p42d. Conclusions RepC is the only element encoded in the repABC operon of the R. etli p42d plasmid that is necessary and sufficient for plasmid replication and is probably the initiator protein. The oriV of this plasmid resides

  11. An ABC Transporter Plays a Developmental Aggregation Role in Myxococcus xanthus

    PubMed Central

    Ward, Mandy J.; Mok, Kenny C.; Astling, David P.; Lew, Helen; Zusman, David R.

    1998-01-01

    Myxococcus xanthus is a gram-negative bacterium which has a complex life cycle. Autochemotaxis, a process whereby cells release a self-generated signaling molecule, may be the principal mechanism facilitating directed motility in both the vegetative swarming and developmental aggregation stages of this life cycle. The process requires the Frz signal transduction system, including FrzZ, a protein which is composed of two domains, both showing homology to the enteric chemotaxis response regulator CheY. The first domain of FrzZ (FrzZ1), when expressed as bait in the yeast two-hybrid system and screened against a library, was shown to potentially interact with the C-terminal portion of a protein encoding an ATP-binding cassette (AbcA). The activation domain-AbcA fusion protein did not interact with the second domain of FrzZ (FrzZ2) or with two other M. xanthus response regulator-containing proteins presented as bait, suggesting that the FrzZ1-AbcA interaction may be specific. Cloning and sequencing of the upstream region of the abcA gene showed the ATP-binding cassette to be linked to a large hydrophobic, potentially membrane-spanning domain. This domain organization is characteristic of a subgroup of ABC transporters which perform export functions. Cloning and sequencing downstream of abcA indicated that the ABC transporter is at the start of an operon containing three open reading frames. An insertion mutation in the abcA gene resulted in cells displaying the frizzy aggregation phenotype, providing additional evidence that FrzZ and AbcA may be part of the same signal transduction pathway. Cells with mutations in genes downstream of abcA showed no developmental defects. Analysis of the proposed exporter role of AbcA in cell mixing experiments showed that the ABC transporter mutant could be rescued by extracellular complementation. We speculate that the AbcA protein may be involved in the export of a molecule required for the autochemotactic process. PMID:9791121

  12. Multifunctional nanoarchitectures from DNA-based ABC monomers

    NASA Astrophysics Data System (ADS)

    Lee, Jong B.; Roh, Young H.; Um, Soong Ho; Funabashi, Hisakage; Cheng, Wenlong; Cha, Judy J.; Kiatwuthinon, Pichamon; Muller, David A.; Luo, Dan

    2009-07-01

    The ability to attach different functional moieties to a molecular building block could lead to applications in nanoelectronics, nanophotonics, intelligent sensing and drug delivery. The building unit needs to be both multivalent and anisotropic, and although many anisotropic building blocks have been created, these have not been universally applicable. Recently, DNA has been used to generate various nanostructures or hybrid systems, and as a generic building block for various applications. Here, we report the creation of anisotropic, branched and crosslinkable building blocks (ABC monomers) from which multifunctional nanoarchitectures have been assembled. In particular, we demonstrate a target-driven polymerization process in which polymers are generated only in the presence of a specific DNA molecule, leading to highly sensitive pathogen detection. Using this monomer system, we have also designed a biocompatible nanovector that delivers both drugs and tracers simultaneously. Our approach provides a general yet versatile route towards the creation of a range of multifunctional nanoarchitectures.

  13. Monte Carlo simulations of ABC stacked kagome lattice films

    NASA Astrophysics Data System (ADS)

    Yerzhakov, H. V.; Plumer, M. L.; Whitehead, J. P.

    2016-05-01

    Properties of films of geometrically frustrated ABC stacked antiferromagnetic kagome layers are examined using Metropolis Monte Carlo simulations. The impact of having an easy-axis anisotropy on the surface layers and cubic anisotropy in the interior layers is explored. The spin structure at the surface is shown to be different from that of the bulk 3D fcc system, where surface axial anisotropy tends to align spins along the surface [1 1 1] normal axis. This alignment then propagates only weakly to the interior layers through exchange coupling. Results are shown for the specific heat, magnetization and sub-lattice order parameters for both surface and interior spins in three and six layer films as a function of increasing axial surface anisotropy. Relevance to the exchange bias phenomenon in IrMn3 films is discussed.

  14. The Arabidopsis nectary is an ABC-independent floral structure.

    PubMed

    Baum, S F; Eshed, Y; Bowman, J L

    2001-11-01

    In contrast to the conservation of floral organ order in angiosperm flowers, nectary glands can be found in various floral and extrafloral positions. Since in Arabidopsis, the nectary develops only at the base of stamens, its specification was assayed with regard to the floral homeotic ABC selector genes. We show that the nectary can form independently of any floral organ identity gene but is restricted to the 'third whorl' domain in the flower. This domain is, in part, specified redundantly by LEAFY and UNUSUAL FLORAL ORGANS. Even though nectary glands arise from cells previously expressing the B class genes, their proper development requires the down-regulation of B class gene activity. While CRABS CLAW is essential for nectary gland formation, its ectopic expression is not sufficient to induce ectopic nectary formation. We show that in Arabidopsis multiple factors act to restrict the nectary to the flower, and surprisingly, some of these factors are LEAFY and UNUSUAL FLORAL ORGANS. PMID:11714690

  15. Monte Carlo simulations of ABC stacked kagome lattice films.

    PubMed

    Yerzhakov, H V; Plumer, M L; Whitehead, J P

    2016-05-18

    Properties of films of geometrically frustrated ABC stacked antiferromagnetic kagome layers are examined using Metropolis Monte Carlo simulations. The impact of having an easy-axis anisotropy on the surface layers and cubic anisotropy in the interior layers is explored. The spin structure at the surface is shown to be different from that of the bulk 3D fcc system, where surface axial anisotropy tends to align spins along the surface [1 1 1] normal axis. This alignment then propagates only weakly to the interior layers through exchange coupling. Results are shown for the specific heat, magnetization and sub-lattice order parameters for both surface and interior spins in three and six layer films as a function of increasing axial surface anisotropy. Relevance to the exchange bias phenomenon in IrMn3 films is discussed. PMID:27092744

  16. Similarities between the antABC-Encoded Anthranilate Dioxygenase and the benABC-Encoded Benzoate Dioxygenase of Acinetobacter sp. Strain ADP1

    PubMed Central

    Bundy, Becky M.; Campbell, Alan L.; Neidle, Ellen L.

    1998-01-01

    Acinetobacter sp. strain ADP1 can use benzoate or anthranilate as a sole carbon source. These structurally similar compounds are independently converted to catechol, allowing further degradation to proceed via the β-ketoadipate pathway. In this study, the first step in anthranilate catabolism was characterized. A mutant unable to grow on anthranilate, ACN26, was selected. The sequence of a wild-type DNA fragment that restored growth revealed the antABC genes, encoding 54-, 19-, and 39-kDa proteins, respectively. The deduced AntABC sequences were homologous to those of class IB multicomponent aromatic ring-dihydroxylating enzymes, including the dioxygenase that initiates benzoate catabolism. Expression of antABC in Escherichia coli, a bacterium that normally does not degrade anthranilate, enabled the conversion of anthranilate to catechol. Unlike benzoate dioxygenase (BenABC), anthranilate dioxygenase (AntABC) catalyzed catechol formation without requiring a dehydrogenase. In Acinetobacter mutants, benC substituted for antC during growth on anthranilate, suggesting relatively broad substrate specificity of the BenC reductase, which transfers electrons from NADH to the terminal oxygenase. In contrast, the benAB genes did not substitute for antAB. An antA point mutation in ACN26 prevented anthranilate degradation, and this mutation was independent of a mucK mutation in the same strain that prevented exogenous muconate degradation. Anthranilate induced expression of antA, although no associated transcriptional regulators were identified. Disruption of three open reading frames in the immediate vicinity of antABC did not prevent the use of anthranilate as a sole carbon source. The antABC genes were mapped on the ADP1 chromosome and were not linked to the two known supraoperonic gene clusters involved in aromatic compound degradation. PMID:9721284

  17. Research Progress on the Role of ABC Transporters in the Drug Resistance Mechanism of Intractable Epilepsy

    PubMed Central

    Xiong, Jie; Mao, Ding-an; Liu, Li-qun

    2015-01-01

    The pathogenesis of intractable epilepsy is not fully clear. In recent years, both animal and clinical trials have shown that the expression of ATP-binding cassette (ABC) transporters is increased in patients with intractable epilepsy; additionally, epileptic seizures can lead to an increase in the number of sites that express ABC transporters. These findings suggest that ABC transporters play an important role in the drug resistance mechanism of epilepsy. ABC transporters can perform the funcions of a drug efflux pump, which can reduce the effective drug concentration at epilepsy lesions by reducing the permeability of the blood brain barrier to antiepileptic drugs, thus causing resistance to antiepileptic drugs. Given the important role of ABC transporters in refractory epilepsy drug resistance, antiepileptic drugs that are not substrates of ABC transporters were used to obtain ABC transporter inhibitors with strong specificity, high safety, and few side effects, making them suitable for long-term use; therefore, these drugs can be used for future clinical treatment of intractable epilepsy. PMID:26491660

  18. Genetic identification of three ABC transporters as essential elements for nitrate respiration in Haloferax volcanii.

    PubMed Central

    Wanner, C; Soppa, J

    1999-01-01

    More than 40 nitrate respiration-deficient mutants of Haloferax volcanii belonging to three different phenotypic classes were isolated. All 15 mutants of the null phenotype were complemented with a genomic library of the wild type. Wild-type copies of mutated genes were recovered from complemented mutants using two different approaches. The DNA sequences of 13 isolated fragments were determined. Five fragments were found to overlap; therefore nine different genomic regions containing genes essential for nitrate respiration could be identified. Three genomic regions containing genes coding for subunits of ABC transporters were further characterized. In two cases, genes coding for an ATP-binding subunit and a permease subunit were clustered and overlapped by four nucleotides. The third gene for a permease subunit had no additional ABC transporter gene in proximity. One ABC transporter was found to be glucose specific. The mutant reveals that the ABC transporter solely mediates anaerobic glucose transport. Based on sequence similarity, the second ABC transporter is proposed to be molybdate specific, explaining its essential role in nitrate respiration. The third ABC transporter is proposed to be anion specific. Genome sequencing has shown that ABC transporters are widespread in Archaea. Nevertheless, this study represents only the second example of a functional characterization. PMID:10430572

  19. Affinity-based release of chondroitinase ABC from a modified methylcellulose hydrogel.

    PubMed

    Pakulska, Malgosia M; Vulic, Katarina; Shoichet, Molly S

    2013-10-10

    Chondroitinase ABC (ChABC) is a promising therapeutic for spinal cord injury as it can degrade the glial scar that is detrimental to regrowth and repair. However, the sustained delivery of bioactive ChABC is a challenge requiring highly invasive methods such as intra-spinal injections, insertion of intrathecal catheters, or implantation of delivery vehicles directly into the tissue. ChABC is thermally unstable, further complicating its delivery. Moreover, there are no commercial antibodies available for its detection. To achieve controlled release, we designed an affinity-based system that sustained the release of bioactive ChABC for at least 7days. ChABC was recombinantly expressed as a fusion protein with Src homology domain 3 (SH3) with an N-terminal histidine (HIS) tag and a C-terminal FLAG tag (ChABC-SH3). Protein purification was achieved using a nickel affinity column and, for the first time, direct quantification of ChABC down to 0.1nM was attained using an in-house HIS/FLAG double tag ELISA. The release of active ChABC-SH3 was sustained from a methylcellulose hydrogel covalently modified with an SH3 binding peptide. The rate of release was tunable by varying either the binding strength of the SH3-protein/SH3-peptide pair or the SH3-peptide to SH3-protein ratio. This innovative system has the potential to be used as a platform technology for the release and detection of other proteins that can be expressed using a similar construct. PMID:23831055

  20. The ABC protein turned chloride channel whose failure causes cystic fibrosis

    NASA Astrophysics Data System (ADS)

    Gadsby, David C.; Vergani, Paola; Csanády, László

    2006-03-01

    CFTR chloride channels are encoded by the gene mutated in patients with cystic fibrosis. These channels belong to the superfamily of ABC transporter ATPases. ATP-driven conformational changes, which in other ABC proteins fuel uphill substrate transport across cellular membranes, in CFTR open and close a gate to allow transmembrane flow of anions down their electrochemical gradient. New structural and biochemical information from prokaryotic ABC proteins and functional information from CFTR channels has led to a unifying mechanism explaining those ATP-driven conformational changes.

  1. ABC transporters as multidrug resistance mechanisms and the development of chemosensitizers for their reversal

    PubMed Central

    Choi, Cheol-Hee

    2005-01-01

    One of the major problems related with anticancer chemotherapy is resistance against anticancer drugs. The ATP-binding cassette (ABC) transporters are a family of transporter proteins that are responsible for drug resistance and a low bioavailability of drugs by pumping a variety of drugs out cells at the expense of ATP hydrolysis. One strategy for reversal of the resistance of tumor cells expressing ABC transporters is combined use of anticancer drugs with chemosensitizers. In this review, the physiological functions and structures of ABC transporters, and the development of chemosensitizers are described focusing on well-known proteins including P-glycoprotein, multidrug resistance associated protein, and breast cancer resistance protein. PMID:16202168

  2. The ABC protein turned chloride channel whose failure causes cystic fibrosis

    PubMed Central

    Gadsby, David C.; Vergani, Paola; Csanády, László

    2009-01-01

    CFTR chloride channels are encoded by the gene mutated in patients with cystic fibrosis. These channels belong to the superfamily of ABC transporter ATPases. ATP-driven conformational changes, which in other ABC proteins fuel uphill substrate transport across cellular membranes, in CFTR open and close a gate to allow transmembrane flow of anions down their electrochemical gradient. New structural and biochemical information from prokaryotic ABC proteins and functional information from CFTR channels has led to a unifying mechanism explaining those ATP-driven conformational changes. PMID:16554808

  3. ABC1 Consensus Conference - a German Perspective: First International Consensus Conference on Advanced Breast Cancer (ABC1), Lisbon, November 5, 2011.

    PubMed

    Thomssen, Christoph; Marschner, Norbert; Untch, Michael; Decker, Thomas; Hegewisch-Becker, Susanna; Jackisch, Christian; Janni, Wolfgang; Hans-Joachim, Lück; von Minckwitz, Gunter; Scharl, Anton; Schneeweiss, Andreas; Tesch, Hans; Welt, Anja; Harbeck, Nadia

    2012-02-01

    A group of German breast cancer experts (medical oncologists and gynaecologists) reviewed and commented on the results of the first international 'Advanced Breast Cancer First Consensus Conference' (ABC1) for the diagnosis and treatment of advanced breast cancer. The ABC1 Conference is an initiative of the European School of Oncology (ESO) Metastatic Breast Cancer Task Force in cooperation with the EBCC (European Breast Cancer Conference), ESMO (European Society of Medical Oncology) and the American JNCI (Journal of the National Cancer Institute). The main focus of the ABC1 Conference was metastatic breast cancer (stage IV). The ABC1 consensus is based on the vote of 33 breast cancer experts from different countries and has been specified as a guideline for therapeutic practice by the German expert group. It is the objective of the ABC1 consensus as well as of the German comments to provide an internationally standardized and evidence-based foundation for qualified decision-making in the treatment of metastatic breast cancer. PMID:22553474

  4. Screening of Streptococcus pneumoniae ABC transporter mutants demonstrates that LivJHMGF, a branched-chain amino acid ABC transporter, is necessary for disease pathogenesis.

    PubMed

    Basavanna, Shilpa; Khandavilli, Suneeta; Yuste, Jose; Cohen, Jonathan M; Hosie, Arthur H F; Webb, Alexander J; Thomas, Gavin H; Brown, Jeremy S

    2009-08-01

    Bacterial ABC transporters are an important class of transmembrane transporters that have a wide variety of substrates and are important for the virulence of several bacterial pathogens, including Streptococcus pneumoniae. However, many S. pneumoniae ABC transporters have yet to be investigated for their role in virulence. Using insertional duplication mutagenesis mutants, we investigated the effects on virulence and in vitro growth of disruption of 9 S. pneumoniae ABC transporters. Several were partially attenuated in virulence compared to the wild-type parental strain in mouse models of infection. For one ABC transporter, required for full virulence and termed LivJHMGF due to its similarity to branched-chain amino acid (BCAA) transporters, a deletion mutant (DeltalivHMGF) was constructed to investigate its phenotype in more detail. When tested by competitive infection, the DeltalivHMGF strain had reduced virulence in models of both pneumonia and septicemia but was fully virulent when tested using noncompetitive experiments. The DeltalivHMGF strain had no detectable growth defect in defined or complete laboratory media. Recombinant LivJ, the substrate binding component of the LivJHMGF, was shown by both radioactive binding experiments and tryptophan fluorescence spectroscopy to specifically bind to leucine, isoleucine, and valine, confirming that the LivJHMGF substrates are BCAAs. These data demonstrate a previously unsuspected role for BCAA transport during infection for S. pneumoniae and provide more evidence that functioning ABC transporters are required for the full virulence of bacterial pathogens. PMID:19470745

  5. 1st International consensus guidelines for advanced breast cancer (ABC 1).

    PubMed

    Cardoso, F; Costa, A; Norton, L; Cameron, D; Cufer, T; Fallowfield, L; Francis, P; Gligorov, J; Kyriakides, S; Lin, N; Pagani, O; Senkus, E; Thomssen, C; Aapro, M; Bergh, J; Di Leo, A; El Saghir, N; Ganz, P A; Gelmon, K; Goldhirsch, A; Harbeck, N; Houssami, N; Hudis, C; Kaufman, B; Leadbeater, M; Mayer, M; Rodger, A; Rugo, H; Sacchini, V; Sledge, G; van't Veer, L; Viale, G; Krop, I; Winer, E

    2012-06-01

    The 1st international Consensus Conference for Advanced Breast Cancer (ABC 1) took place on November 2011, in Lisbon. Consensus guidelines for the management of this disease were developed. This manuscript summarizes these international consensus guidelines. PMID:22425534

  6. Plant ABC Transporters Enable Many Unique Aspects of a Terrestrial Plant's Lifestyle.

    PubMed

    Hwang, Jae-Ung; Song, Won-Yong; Hong, Daewoong; Ko, Donghwi; Yamaoka, Yasuyo; Jang, Sunghoon; Yim, Sojeong; Lee, Eunjung; Khare, Deepa; Kim, Kyungyoon; Palmgren, Michael; Yoon, Hwan Su; Martinoia, Enrico; Lee, Youngsook

    2016-03-01

    Terrestrial plants have two to four times more ATP-binding cassette (ABC) transporter genes than other organisms, including their ancestral microalgae. Recent studies found that plants harboring mutations in these transporters exhibit dramatic phenotypes, many of which are related to developmental processes and functions necessary for life on dry land. These results suggest that ABC transporters multiplied during evolution and assumed novel functions that allowed plants to adapt to terrestrial environmental conditions. Examining the literature on plant ABC transporters from this viewpoint led us to propose that diverse ABC transporters enabled many unique and essential aspects of a terrestrial plant's lifestyle, by transporting various compounds across specific membranes of the plant. PMID:26902186

  7. Brassboard Astrometric Beam Combiner (ABC) Development for the Space Interferometry Mission (SIM)

    NASA Technical Reports Server (NTRS)

    Jeganathan, Muthu; Kuan, Gary; Rud, Mike; Lin, Sean; Sutherland, Kristen; Moore, James; An, Xin

    2008-01-01

    The Astrometric Beam Combiner (ABC) is a critical element of the Space Interferometry Mission (SIM) that performs three key functions: coherently combine starlight from two siderostats; individually detect starlight for angle tracking; and disperse and detect the interferometric fringes. In addition, the ABC contains: a stimulus, cornercubes and shutters for in-orbit calibration; several tip/tilt mirror mechanisms for in-orbit alignment; and internal metrology beam launcher for pathlength monitoring. The detailed design of the brassboard ABC (which has the form, fit and function of the flight unit) is complete, procurement of long-lead items is underway, and assembly and testing is expected to be completed in Spring 2009. In this paper, we present the key requirements for the ABC, details of the completed optical and mechanical design as well as plans for assembly and alignment.

  8. Selection of optimal artificial boundary condition (ABC) frequencies for structural damage identification

    NASA Astrophysics Data System (ADS)

    Mao, Lei; Lu, Yong

    2016-07-01

    In this paper, the sensitivities of artificial boundary condition (ABC) frequencies to the damages are investigated, and the optimal sensors are selected to provide the reliable structural damage identification. The sensitivity expressions for one-pin and two-pin ABC frequencies, which are the natural frequencies from structures with one and two additional constraints to its original boundary condition, respectively, are proposed. Based on the expressions, the contributions of the underlying mode shapes in the ABC frequencies can be calculated and used to select more sensitive ABC frequencies. Selection criteria are then defined for different conditions, and their performance in structural damage identification is examined with numerical studies. From the findings, conclusions are given.

  9. New Enhanced Artificial Bee Colony (JA-ABC5) Algorithm with Application for Reactive Power Optimization

    PubMed Central

    2015-01-01

    The standard artificial bee colony (ABC) algorithm involves exploration and exploitation processes which need to be balanced for enhanced performance. This paper proposes a new modified ABC algorithm named JA-ABC5 to enhance convergence speed and improve the ability to reach the global optimum by balancing exploration and exploitation processes. New stages have been proposed at the earlier stages of the algorithm to increase the exploitation process. Besides that, modified mutation equations have also been introduced in the employed and onlooker-bees phases to balance the two processes. The performance of JA-ABC5 has been analyzed on 27 commonly used benchmark functions and tested to optimize the reactive power optimization problem. The performance results have clearly shown that the newly proposed algorithm has outperformed other compared algorithms in terms of convergence speed and global optimum achievement. PMID:25879054

  10. Preliminary lifetime predictions for 304 stainless steel as the LANL ABC blanket material

    SciTech Connect

    Park, J.J.; Buksa, J.J.; Houts, M.G.; Arthur, E.D.

    1997-11-01

    The prediction of materials lifetime in the preconceptual Los Alamos National Laboratory (LANL) Accelerator-Based Conversion of Plutonium (ABC) is of utmost interest. Because Hastelloy N showed good corrosion resistance to the Oak Ridge National Laboratory Molten Salt Reactor Experiment fuel salt that is similar to the LANL ABC fuel salt, Hastelloy N was originally proposed for the LANL ABC blanket material. In this paper, the possibility of using 304 stainless steel as a replacement for the Hastelloy N is investigated in terms of corrosion issues and fluence-limit considerations. An attempt is made, based on the previous Fast Flux Test Facility design data, to predict the preliminary lifetime estimate of the 304 stainless steel used in the blanket region of the LANL ABC.

  11. The Assessment of Burden of COPD (ABC) Scale: A Reliable and Valid Questionnaire.

    PubMed

    Slok, Annerika H M; Bemelmans, Thomas C H; Kotz, Daniel; van der Molen, Thys; Kerstjens, Huib A M; In 't Veen, Johannes C C M; Chavannes, Niels H; Asijee, Guus M; Rutten-van Mölken, Maureen P M H; van Schayck, Onno C P

    2016-08-01

    The newly developed Assessment of Burden of COPD (ABC) scale is a 14-item self-administered questionnaire which measures the physical, psychological, emotional and/or social burden as experienced by patients with chronic obstructive pulmonary disease (COPD). The ABC scale is part of the ABC tool that visualises the outcomes of the questionnaire. The aim of this study was to assess the reliability and construct validity of the ABC scale. This multi-centre survey study was conducted in the practices of 19 general practitioners and 9 pulmonologists throughout the Netherlands. Next to the ABC scale, patients with COPD completed the Saint George Respiratory Questionnaire (SGRQ). Reliability analyses were performed with data from 162 cases. Cronbach's alpha was 0.91 for the total scale. Test-retest reliability, measured at a two week interval (n = 137), had an intra-class correlation coefficient of 0.92. Analyses for convergent validity were performed with data from 133 cases. Discriminant and known-groups validity was analysed with data from 162 cases. The ABC scale total score had a strong correlation with the total score of the SGRQ (r = 0.72, p < 0.001) but a weak correlation with the forced expired volume in 1 second predicted (r = -0.28, p < 0.001). Subgroups with more severe disease, defined by GOLD-stage, frequency of exacerbations, activity level and depression scored statistically significantly (p < 0.05) worse on almost all domains of the ABC scale than the less severe subgroups. The ABC scale seems a valid and reliable tool with good discriminative properties. PMID:26788838

  12. Aerosol Comparisons Between Observations and Models: AeroCom and ABC

    NASA Technical Reports Server (NTRS)

    Chin, Mian; Schulz, Michael; Kinne, Stefan

    2011-01-01

    I will represent the AeroCom community to the Atmospheric Brown Cloud (ABC) workshop. I will summarize the activities and results from AeroCom Phase I activities in the past 8 years and introduce the new results and activities in the current AeroCom Phase II. We hope to coordinate some activities with the ABC community to share model output and data access for model evaluations, comparisons, and assessment.

  13. ATP-binding cassette (ABC) transporters in normal and pathological lung

    PubMed Central

    van der Deen, Margaretha; de Vries, Elisabeth GE; Timens, Wim; Scheper, Rik J; Timmer-Bosscha, Hetty; Postma, Dirkje S

    2005-01-01

    ATP-binding cassette (ABC) transporters are a family of transmembrane proteins that can transport a wide variety of substrates across biological membranes in an energy-dependent manner. Many ABC transporters such as P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP) are highly expressed in bronchial epithelium. This review aims to give new insights in the possible functions of ABC molecules in the lung in view of their expression in different cell types. Furthermore, their role in protection against noxious compounds, e.g. air pollutants and cigarette smoke components, will be discussed as well as the (mal)function in normal and pathological lung. Several pulmonary drugs are substrates for ABC transporters and therefore, the delivery of these drugs to the site of action may be highly dependent on the presence and activity of many ABC transporters in several cell types. Three ABC transporters are known to play an important role in lung functioning. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene can cause cystic fibrosis, and mutations in ABCA1 and ABCA3 are responsible for respectively Tangier disease and fatal surfactant deficiency. The role of altered function of ABC transporters in highly prevalent pulmonary diseases such as asthma or chronic obstructive pulmonary disease (COPD) have hardly been investigated so far. We especially focused on polymorphisms, knock-out mice models and in vitro results of pulmonary research. Insight in the function of ABC transporters in the lung may open new ways to facilitate treatment of lung diseases. PMID:15967026

  14. Transcriptome-Based Identification of ABC Transporters in the Western Tarnished Plant Bug Lygus hesperus

    PubMed Central

    Hull, J. Joe; Chaney, Kendrick; Geib, Scott M.; Fabrick, Jeffrey A.; Brent, Colin S.; Walsh, Douglas; Lavine, Laura Corley

    2014-01-01

    ATP-binding cassette (ABC) transporters are a large superfamily of proteins that mediate diverse physiological functions by coupling ATP hydrolysis with substrate transport across lipid membranes. In insects, these proteins play roles in metabolism, development, eye pigmentation, and xenobiotic clearance. While ABC transporters have been extensively studied in vertebrates, less is known concerning this superfamily in insects, particularly hemipteran pests. We used RNA-Seq transcriptome sequencing to identify 65 putative ABC transporter sequences (including 36 full-length sequences) from the eight ABC subfamilies in the western tarnished plant bug (Lygus hesperus), a polyphagous agricultural pest. Phylogenetic analyses revealed clear orthologous relationships with ABC transporters linked to insecticide/xenobiotic clearance and indicated lineage specific expansion of the L. hesperus ABCG and ABCH subfamilies. The transcriptional profile of 13 LhABCs representative of the ABCA, ABCB, ABCC, ABCG, and ABCH subfamilies was examined across L. hesperus development and within sex-specific adult tissues. All of the transcripts were amplified from both reproductively immature and mature adults and all but LhABCA8 were expressed to some degree in eggs. Expression of LhABCA8 was spatially localized to the testis and temporally timed with male reproductive development, suggesting a potential role in sexual maturation and/or spermatozoa protection. Elevated expression of LhABCC5 in Malpighian tubules suggests a possible role in xenobiotic clearance. Our results provide the first transcriptome-wide analysis of ABC transporters in an agriculturally important hemipteran pest and, because ABC transporters are known to be important mediators of insecticidal resistance, will provide the basis for future biochemical and toxicological studies on the role of this protein family in insecticide resistance in Lygus species. PMID:25401762

  15. LARS Artificial Ligament Versus ABC Purely Polyester Ligament for Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Iliadis, Dimitrios Ph.; Bourlos, Dimitrios N.; Mastrokalos, Dimitrios S.; Chronopoulos, Efstathios; Babis, George C.

    2016-01-01

    Background: Graft choice for anterior cruciate ligament (ACL) reconstruction is of critical importance. Various grafts have been used so far, with autografts long considered the optimal solution for the treatment of ACL-deficient knees. Limited data are available on the long-term survivorship of synthetic grafts. Purpose: To compare the functional outcome and survivorship of ACL reconstructions performed using the LARS (ligament augmentation and reconstruction system) ligament and the ABC (active biosynthetic composite) purely polyester ligament. Study Design: Case series; Level of evidence, 4. Methods: The results of 72 patients who underwent primary arthroscopic ACL reconstruction with the LARS ligament and 31 cases with an ABC purely polyester ligament were reviewed. The mean follow-up periods for the LARS and ABC groups were 9.5 and 5.1 years, respectively. A survivorship analysis of the 2 synthetic grafts was performed using the Kaplan-Meier method with a log-rank test (Mantel-Cox, 95% CI). Lysholm, Tegner activity, Knee injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) scores as well as laxity measurements obtained using a KT-1000 arthrometer were recorded for all intact grafts, and a Mann-Whitney U test was used for comparison reasons. Results: The rupture rates for LARS and ABC grafts were 31% (95% CI, 20%-42%) and 42% (95% CI, 25%-59%), respectively. For intact grafts, the mean Lysholm score was good for both groups (90 for the LARS group and 89 for the ABC group), with the majority of patients returning to their preinjury level of activities, and the mean IKDC score was 90 for the LARS group and 86 for the ABC group. Conclusion: The rupture rates of both LARS and ABC grafts were both high. However, the LARS ligament provided significantly better survivorship compared with the ABC ligament at short- to midterm follow-up (95% CI). PMID:27453894

  16. Neuroprotective effect of chondroitinase ABC on primary and secondary brain injury after stroke in hypertensive rats.

    PubMed

    Chen, Xin-ran; Liao, Song-jie; Ye, Lan-xiang; Gong, Qiong; Ding, Qiao; Zeng, Jin-sheng; Yu, Jian

    2014-01-16

    Focal cerebral infarction causes secondary damage in the ipsilateral ventroposterior thalamic nucleus (VPN). Chondroitin sulfate proteoglycans (CSPGs) are a family of putative inhibitory components, and its degradation by chondroitinase ABC (ChABC) promotes post-injury neurogenesis. This study investigated the role of ChABC in the primary and secondary injury post stroke in hypertension. Renovascular hypertensive Sprague-Dawley rats underwent middle cerebral artery occlusion (MCAO), and were subjected to continuous intra-infarct infusion of ChABC (0.12 U/d for 7 days) 24 h later. Neurological function was evaluated by a modified neurologic severity score. Neurons were counted in the peri-infarct region and the ipsilateral VPN 8 and 14 days after MCAO by Nissl staining and NeuN labeling. The expressions of CSPGs, growth-associated protein-43 (GAP-43) and synaptophysin (SYN) were detected with immunofluorescence or Western blotting. The intra-infarct infusion of ChABC, by degrading accumulated CSPGs, rescued neuronal loss and increased the levels of GAP-43 and SYN in both the ipsilateral cortex and VPN, indicating enhancd neuron survival as well as augmented axonal growth and synaptic plasticity, eventually improving overall neurological function. The study demonstrated that intra-infarct ChABC infusion could salvage the brain from both primary and secondary injury by the intervention on the neuroinhibitory environment post focal cerebral infarction. PMID:24326094

  17. Approximate Bayesian Computation using Markov Chain Monte Carlo simulation: DREAM(ABC)

    NASA Astrophysics Data System (ADS)

    Sadegh, Mojtaba; Vrugt, Jasper A.

    2014-08-01

    The quest for a more powerful method for model evaluation has inspired Vrugt and Sadegh (2013) to introduce "likelihood-free" inference as vehicle for diagnostic model evaluation. This class of methods is also referred to as Approximate Bayesian Computation (ABC) and relaxes the need for a residual-based likelihood function in favor of one or multiple different summary statistics that exhibit superior diagnostic power. Here we propose several methodological improvements over commonly used ABC sampling methods to permit inference of complex system models. Our methodology entitled DREAM(ABC) uses the DiffeRential Evolution Adaptive Metropolis algorithm as its main building block and takes advantage of a continuous fitness function to efficiently explore the behavioral model space. Three case studies demonstrate that DREAM(ABC) is at least an order of magnitude more efficient than commonly used ABC sampling methods for more complex models. DREAM(ABC) is also more amenable to distributed, multi-processor, implementation, a prerequisite to diagnostic inference of CPU-intensive system models.

  18. Optimization of Straight Cylindrical Turning Using Artificial Bee Colony (ABC) Algorithm

    NASA Astrophysics Data System (ADS)

    Prasanth, Rajanampalli Seshasai Srinivasa; Hans Raj, Kandikonda

    2016-06-01

    Artificial bee colony (ABC) algorithm, that mimics the intelligent foraging behavior of honey bees, is increasingly gaining acceptance in the field of process optimization, as it is capable of handling nonlinearity, complexity and uncertainty. Straight cylindrical turning is a complex and nonlinear machining process which involves the selection of appropriate cutting parameters that affect the quality of the workpiece. This paper presents the estimation of optimal cutting parameters of the straight cylindrical turning process using the ABC algorithm. The ABC algorithm is first tested on four benchmark problems of numerical optimization and its performance is compared with genetic algorithm (GA) and ant colony optimization (ACO) algorithm. Results indicate that, the rate of convergence of ABC algorithm is better than GA and ACO. Then, the ABC algorithm is used to predict optimal cutting parameters such as cutting speed, feed rate, depth of cut and tool nose radius to achieve good surface finish. Results indicate that, the ABC algorithm estimated a comparable surface finish when compared with real coded genetic algorithm and differential evolution algorithm.

  19. Abc Amino Acids: Design, Synthesis, and Properties of New Photoelastic Amino Acids

    SciTech Connect

    Standaert, Robert F; Park, Dr Seung Bum

    2006-01-01

    Photoisomerizable amino acids provide a direct avenue to the experimental manipulation of bioactive polypeptides, potentially allowing real-time, remote control of biological systems and enabling useful applications in nanobiotechnology. Herein, we report a new class of photoisomerizable amino acids intended to cause pronounced expansion and contraction in the polypeptide backbone, i.e., to be photoelastic. These compounds, termed Abc amino acids, employ a photoisomerizable azobiphenyl chromophore to control the relative disposition of aminomethyl and carboxyl substituents. Molecular modeling of nine Abc isomers led to the identification of one with particularly attractive properties, including the ability to induce contractions up to 13A in the backbone upon transa?cis photoisomerization. This isomer, designated mpAbc, has substituents at meta and para positions on the inner (azo-linked) and outer rings, respectively. An efficient synthesis of Fmoc-protected mpAbc was executed in which the biaryl components were formed via Suzuki couplings and the azo linkage was formed via amine/nitroso condensation; protected forms of three other Abc isomers were prepared similarly. A decapeptide incorporating mpAbc was synthesized by conventional solid-phase methods and displayed characteristic azobenzene photochemical behavior with optimal conversion to the cis isomer at 360 nm and a thermal cisa?trans half life of 100 min. at 80 AoC.

  20. Multidrug resistance in parasites: ABC transporters, P-glycoproteins and molecular modelling.

    PubMed

    Jones, P M; George, A M

    2005-04-30

    Parasitic diseases, caused by protozoa, helminths and arthropods, rank among the most important problems in human and veterinary medicine, and in agriculture, leading to debilitating sicknesses and loss of life. In the absence of vaccines and with the general failure of vector eradication programs, drugs are the main line of defence, but the newest drugs are being tracked by the emergence of resistance in parasites, sharing ominous parallels with multidrug resistance in bacterial pathogens. Any of a number of mechanisms will elicit a drug resistance phenotype in parasites, including: active efflux, reduced uptake, target modification, drug modification, drug sequestration, by-pass shunting, or substrate competition. The role of ABC transporters in parasitic multidrug resistance mechanisms is being subjected to more scrutiny, due in part to the established roles of certain ABC transporters in human diseases, and also to an increasing portfolio of ABC transporters from parasite genome sequencing projects. For example, over 100 ABC transporters have been identified in the Escherichia coli genome, but to date only about 65 in all parasitic genomes. Long established laboratory investigations are now being assisted by molecular biology, bioinformatics, and computational modelling, and it is in these areas that the role of ABC transporters in parasitic multidrug resistance mechanisms may be defined and put in perspective with that of other proteins. We discuss ABC transporters in parasites, and conclude with an example of molecular modelling that identifies a new interaction between the structural domains of a parasite P-glycoprotein. PMID:15826647

  1. Study on ADI CD bias correlating ABC function

    NASA Astrophysics Data System (ADS)

    Deng, Guogui; Hao, Jingan; Xing, Bin; Jiang, Yuntao; Li, Gaorong; Zhang, Qiang; Yue, Liwan; Zu, Yanlei; Hu, Huayong; Liu, Chang; Shen, Manhua; Zhang, Shijian; He, Weiming; Zhang, Nannan; Lin, Yi-Shih; Wu, Qiang; Shi, Xuelong

    2015-03-01

    As the technology node of semiconductor industry is being driven into more advanced 28 nm and beyond, the critical dimension (CD) error budget at after-development inspection (ADI) stage and its control are more and more important and difficult (1-4). 1 nm or even 0.5 nm CD difference is critical for process control. 0.5~1 nm drift of poly linewidth will result in a detectable off-target drift of device performance. The 0.5~1 nm CD drift of hole or metal linewidth on the backend interconnecting layers can potentially contribute to the bridging of metal patterns to vias, and thereby impact yield. In this paper, we studied one function in the scanning electron microscope (SEM) measurement, i.e. the adjustment of brightness and contrast (ABC). We revealed how the step of addressing focus and even the choice of addressing pattern may bring in a systematic error into the CD measurement. This provides a unique insight in the CD measurement and the measurement consistency of through-pitch (TP) patterns and functional patterns.

  2. Additives Induced Structural Transformation of ABC Triblock Copolymer Particles.

    PubMed

    Xu, Jiangping; Yang, Yi; Wang, Ke; Li, Jingyi; Zhou, Huamin; Xie, Xiaolin; Zhu, Jintao

    2015-10-13

    Here we report the structural control of polystyrene-b-polyisoprene-b-poly(2-vinylpyridine) (PS-b-PI-b-P2VP) asymmetric ABC triblock copolymer particles under 3D confinement by tuning the interactions among blocks. The additives, including 3-n-pentadecylphenol, homopolystyrene, and solvents, which can modulate the interactions among polymer blocks, play significant roles in the particle morphology. Moreover, the structured particles can be disassembled into isolated micellar aggregates with novel morphologies or mesoporous particles with tunable pore shape. Interestingly, the formed pupa-like PS-b-PI-b-P2VP particles display interesting dynamic stretch-retraction behavior when the solvent property is changed after partial cross-linking of the P2VP block. We further prove that such dynamic behavior is closely related to the density of cross-linking. The strategies presented here are believed to be promising routes to rationally design and fabricate block copolymer particles with desirable shape and internal structure. PMID:26388457

  3. Nitric Oxide Synthase Enzymes in the Airways of Mice Exposed to Ovalbumin: NOS2 Expression Is NOS3 Dependent

    PubMed Central

    Bratt, Jennifer M.; Williams, Keisha; Rabowsky, Michelle F.; Last, Michael S.; Franzi, Lisa M.; Last, Jerold A.; Kenyon, Nicholas J.

    2010-01-01

    Objectives and Design. The function of the airway nitric oxide synthase (NOS) isoforms and the lung cell types responsible for its production are not fully understood. We hypothesized that NO homeostasis in the airway is important to control inflammation, which requires upregulation, of NOS2 protein expression by an NOS3-dependent mechanism. Materials or Subjects. Mice from a C57BL/6 wild-type, NOS1−/−, NOS2−/−, and NOS3−/− genotypes were used. All mice strains were systemically sensitized and exposed to filtered air or ovalbumin (OVA) aerosol for two weeks to create a subchronic model of allergen-induced airway inflammation. Methods. We measured lung function, lung lavage inflammatory and airway epithelial goblet cell count, exhaled NO, nitrate and nitrite concentration, and airway NOS1, NOS2, and NOS3 protein content. Results. Deletion of NOS1 or NOS3 increases NOS2 protein present in the airway epithelium and smooth muscle of air-exposed animals. Exposure to allergen significantly reduced the expression of NOS2 protein in the airway epithelium and smooth muscle of the NOS3−/− strain only. This reduction in NOS2 expression was not due to the replacement of epithelial cells with goblet cells as remaining epithelial cells did not express NOS2. NOS1−/− animals had significantly reduced goblet cell metaplasia compared to C57Bl/6 wt, NOS2−/−, and NOS3−/− allergen-exposed mice. Conclusion. The airway epithelial and smooth muscle cells maintain a stable airway NO concentration under noninflammatory conditions. This “homeostatic” mechanism is unable to distinguish between NOS derived from the different constitutive NOS isoforms. NOS3 is essential for the expression of NOS2 under inflammatory conditions, while NOS1 expression contributes to allergen-induced goblet cell metaplasia. PMID:20953358

  4. A Survey of the ATP-Binding Cassette (ABC) Gene Superfamily in the Salmon Louse (Lepeophtheirus salmonis)

    PubMed Central

    Heumann, Jan; Taggart, John B.; Gharbi, Karim; Bron, James E.; Bekaert, Michaël; Sturm, Armin

    2015-01-01

    Salmon lice, Lepeophtheirus salmonis (Krøyer, 1837), are fish ectoparasites causing significant economic damage in the mariculture of Atlantic salmon, Salmo salar Linnaeus, 1758. The control of L. salmonis at fish farms relies to a large extent on treatment with anti-parasitic drugs. A problem related to chemical control is the potential for development of resistance, which in L. salmonis is documented for a number of drug classes including organophosphates, pyrethroids and avermectins. The ATP-binding cassette (ABC) gene superfamily is found in all biota and includes a range of drug efflux transporters that can confer drug resistance to cancers and pathogens. Furthermore, some ABC transporters are recognised to be involved in conferral of insecticide resistance. While a number of studies have investigated ABC transporters in L. salmonis, no systematic analysis of the ABC gene family exists for this species. This study presents a genome-wide survey of ABC genes in L. salmonis for which, ABC superfamily members were identified through homology searching of the L. salmonis genome. In addition, ABC proteins were identified in a reference transcriptome of the parasite generated by high-throughput RNA sequencing (RNA-seq) of a multi-stage RNA library. Searches of both genome and transcriptome allowed the identification of a total of 33 genes / transcripts coding for ABC proteins, of which 3 were represented only in the genome and 4 only in the transcriptome. Eighteen sequences were assigned to ABC subfamilies known to contain drug transporters, i.e. subfamilies B (4 sequences), C (11) and G (2). The results suggest that the ABC gene family of L. salmonis possesses fewer members than recorded for other arthropods. The present survey of the L. salmonis ABC gene superfamily will provide the basis for further research into potential roles of ABC transporters in the toxicity of salmon delousing agents and as potential mechanisms of drug resistance. PMID:26418738

  5. Characterization of the Oxygen-Responsive NreABC Regulon of Staphylococcus aureus▿ †

    PubMed Central

    Schlag, Steffen; Fuchs, Stephan; Nerz, Christiane; Gaupp, Rosmarie; Engelmann, Susanne; Liebeke, Manuel; Lalk, Michael; Hecker, Michael; Götz, Friedrich

    2008-01-01

    Here, we investigate the functionality of the oxygen-responsive nitrogen regulation system NreABC in the human pathogen Staphylococcus aureus and evaluate its role in anaerobic gene regulation and virulence factor expression. Deletion of nreABC resulted in severe impairment of dissimilatory nitrate and nitrite reduction and led to a small-colony phenotype in the presence of nitrate during anaerobic growth. For characterization of the NreABC regulon, comparative DNA microarray and proteomic analyses between the wild type and nreABC mutant were performed under anoxic conditions in the absence and presence of nitrate. A reduced expression of virulence factors was not observed in the mutant. However, both the transcription of genes involved in nitrate and nitrite reduction and the accumulation of corresponding proteins were highly decreased in the nreABC mutant, which was unable to utilize nitrate as a respiratory oxidant and, hence, was forced to use fermentative pathways. These data were corroborated by the quantification of the extracellular metabolites lactate and acetate. Using an Escherichia coli-compatible two-plasmid system, the activation of the promoters of the nitrate and nitrite reductase operons and of the putative nitrate/nitrite transporter gene narK by NreBC was confirmed. Overall, our data indicate that NreABC is very likely a specific regulation system that is essential for the transcriptional activation of genes involved in dissimilatory reduction and transport of nitrate and nitrite. The study underscores the importance of NreABC as a fitness factor for S. aureus in anoxic environments. PMID:18820014

  6. A PhoPQ-Regulated ABC Transporter System Exports Tetracycline in Pseudomonas aeruginosa.

    PubMed

    Chen, Lin; Duan, Kangmin

    2016-05-01

    Pseudomonas aeruginosa is an important human pathogen whose infections are difficult to treat due to its high intrinsic resistance to many antibiotics. Here, we show that the disruption of PA4456, encoding the ATP binding component of a putative ATP-binding cassette (ABC) transporter, increased the bacterium's susceptible to tetracycline and other antibiotics or toxic chemicals. Fluorescence spectroscopy and antibiotic accumulation tests showed that the interruption of the ABC transporter caused increased intracellular accumulation of tetracycline, demonstrating a role of the ABC transporter in tetracycline expulsion. Site-directed mutagenesis proved that the conserved residues of E170 in the Walker B motif and H203 in the H-loop, which are important for ATP hydrolysis, were essential for the function of PA4456. Through a genome-wide search, the PhoPQ two-component system was identified as a regulator of the computationally predicted PA4456-4452 operon that encodes the ABC transporter system. A >5-fold increase of the expression of this operon was observed in the phoQ mutant. The results obtained also show that the expression of the phzA1B1C1D1E1 operon and the production of pyocyanin were significantly higher in the ABC transporter mutant, signifying a connection between the ABC transporter and pyocyanin production. These results indicated that the PhoPQ-regulated ABC transporter is associated with intrinsic resistance to antibiotics and other adverse compounds in P. aeruginosa, probably by extruding them out of the cell. PMID:26953208

  7. Genome organisation and expression profiling of ABC protein-encoding genes in Heterobasidion annosum s.l. complex.

    PubMed

    Baral, Bikash; Kovalchuk, Andriy; Asiegbu, Fred O

    2016-03-01

    Members of Heterobasidion annosum species complex are widely regarded as the most destructive fungal pathogens of conifer trees in the boreal and temperate zones of Northern hemisphere. To invade and colonise their host trees, Heterobasidion fungi must overcome components of host chemical defence, including terpenoid oleoresin and phenolic compounds. ABC transporters may play an important role in this process participating in the export of toxic host metabolites and maintaining their intracellular concentration below the critical level. We have identified and phylogenetically classified Heterobasidion genes encoding ABC transporters and closely related ABC proteins. The number of ABC proteins in the Heterobasidion genome is one of the lowest among analysed species of Agaricomycotina. Using quantitative RT-PCR, we have analysed transcriptional response of Heterobasidion ABC transporter-encoding genes to monoterpenes as well as their expression profile during growth on pine wood in comparison to the growth on defined media. Several ABC transporters were up-regulated during growth on pine wood. The ABC-transporter encoding gene ABCG1.1 was induced both during growth of H. annosum on pine wood and upon exposure to monoterpenes. Our experimental data demonstrate the differential responses of Heterobasidion ABC genes to growth conditions and chemical stressors. The presented results suggest a potential role of Heterobasidion ABC-G transporters in the resistance to the components of conifer chemical defence. PMID:26895866

  8. Cellodextrin and Laminaribiose ABC Transporters in Clostridium thermocellum▿

    PubMed Central

    Nataf, Yakir; Yaron, Sima; Stahl, Frank; Lamed, Raphael; Bayer, Edward A.; Scheper, Thomas-Helmut; Sonenshein, Abraham L.; Shoham, Yuval

    2009-01-01

    Clostridium thermocellum is an anaerobic thermophilic bacterium that grows efficiently on cellulosic biomass. This bacterium produces and secretes a highly active multienzyme complex, the cellulosome, that mediates the cell attachment to and hydrolysis of the crystalline cellulosic substrate. C. thermocellum can efficiently utilize only β-1,3 and β-1,4 glucans and prefers long cellodextrins. Since the bacterium can also produce ethanol, it is considered an attractive candidate for a consolidated fermentation process in which cellulose hydrolysis and ethanol fermentation occur in a single process. In this study, we have identified and characterized five sugar ABC transporter systems in C. thermocellum. The putative transporters were identified by sequence homology of the putative solute-binding lipoprotein to known sugar-binding proteins. Each of these systems is transcribed from a gene cluster, which includes an extracellular solute-binding protein, one or two integral membrane proteins, and, in most cases, an ATP-binding protein. The genes of the five solute-binding proteins were cloned, fused to His tags, overexpressed, and purified, and their abilities to interact with different sugars was examined by isothermal titration calorimetry. Three of the sugar-binding lipoproteins (CbpB to -D) interacted with different lengths of cellodextrins (G2 to G5), with disassociation constants in the micromolar range. One protein, CbpA, binds only cellotriose (G3), while another protein, Lbp (laminaribiose-binding protein) interacts with laminaribiose. The sugar specificity of the different binding lipoproteins is consistent with the observed substrate preference of C. thermocellum, in which cellodextrins (G3 to G5) are assimilated faster than cellobiose. PMID:18952792

  9. Control of Plasma Membrane Permeability by ABC Transporters.

    PubMed

    Khakhina, Svetlana; Johnson, Soraya S; Manoharlal, Raman; Russo, Sarah B; Blugeon, Corinne; Lemoine, Sophie; Sunshine, Anna B; Dunham, Maitreya J; Cowart, L Ashley; Devaux, Frédéric; Moye-Rowley, W Scott

    2015-05-01

    ATP-binding cassette transporters Pdr5 and Yor1 from Saccharomyces cerevisiae control the asymmetric distribution of phospholipids across the plasma membrane as well as serving as ATP-dependent drug efflux pumps. Mutant strains lacking these transporter proteins were found to exhibit very different resistance phenotypes to two inhibitors of sphingolipid biosynthesis that act either late (aureobasidin A [AbA]) or early (myriocin [Myr]) in the pathway leading to production of these important plasma membrane lipids. These pdr5Δ yor1 strains were highly AbA resistant but extremely sensitive to Myr. We provide evidence that these phenotypic changes are likely due to modulation of the plasma membrane flippase complexes, Dnf1/Lem3 and Dnf2/Lem3. Flippases act to move phospholipids from the outer to the inner leaflet of the plasma membrane. Genetic analyses indicate that lem3Δ mutant strains are highly AbA sensitive and Myr resistant. These phenotypes are fully epistatic to those seen in pdr5Δ yor1 strains. Direct analysis of AbA-induced signaling demonstrated that loss of Pdr5 and Yor1 inhibited the AbA-triggered phosphorylation of the AGC kinase Ypk1 and its substrate Orm1. Microarray experiments found that a pdr5Δ yor1 strain induced a Pdr1-dependent induction of the entire Pdr regulon. Our data support the view that Pdr5/Yor1 negatively regulate flippase function and activity of the nuclear Pdr1 transcription factor. Together, these data argue that the interaction of the ABC transporters Pdr5 and Yor1 with the Lem3-dependent flippases regulates permeability of AbA via control of plasma membrane protein function as seen for the high-affinity tryptophan permease Tat2. PMID:25724885

  10. Band structure of ABC-trilayer graphene superlattice

    SciTech Connect

    Uddin, Salah Chan, K. S.

    2014-11-28

    We investigate the effect of one-dimensional periodic potentials on the low energy band structure of ABC trilayer graphene first by assuming that all the three layers have the same potential. Extra Dirac points having the same electron hole crossing energy as that of the original Dirac point are generated by superlattice potentials with equal well and barrier widths. When the potential height is increased, the numbers of extra Dirac points are increased. The dispersions around the Dirac points are not isotropic. It is noted that the dispersion along the k{sub y} direction for k{sub x} = 0 oscillates between a non-linear dispersion and a linear dispersion when the potential height is increased. When the well and barrier widths are not identical, the symmetry of the conduction and valence bands is broken. The extra Dirac points are shifted either upward or downward depending on the barrier and well widths from the zero energy, while the position of the central Dirac point oscillates with the superlattice potential height. By considering different potentials for different layers, extra Dirac points are generated not from the original Dirac points but from the valleys formed in the energy spectrum. Two extra Dirac points appear from each pair of touched valleys, so four Dirac points appeared in the spectrum at particular barrier height. By increasing the barrier height of superlattice potential two Dirac points merge into the original Dirac point. This emerging and merging of extra Dirac points is different from the equal potential case.

  11. On the selectivity of neuronal NOS inhibitors

    PubMed Central

    Pigott, B; Bartus, K; Garthwaite, J

    2013-01-01

    Background and Purpose Isoform-selective inhibitors of NOS enzymes are desirable as research tools and for potential therapeutic purposes. Vinyl-l-N-5-(1-imino-3-butenyl)-l-ornithine (l-VNIO) and Nω-propyl-l-arginine (NPA) purportedly have good selectivity for neuronal over endothelial NOS under cell-free conditions, as does N-[(3-aminomethyl)benzyl]acetamidine (1400W), which is primarily an inducible NOS inhibitor. Although used in numerous investigations in vitro and in vivo, there have been surprisingly few tests of the potency and selectivity of these compounds in cells. This study addresses this deficiency and evaluates the activity of new and potentially better pyrrolidine-based compounds. Experimental Approach The inhibitors were evaluated by measuring their effect on NMDA-evoked cGMP accumulation in rodent hippocampal slices, a response dependent on neuronal NOS, and ACh-evoked cGMP synthesis in aortic rings of the same animals, an endothelial NOS-dependent phenomenon. Key Results l-VNIO, NPA and 1400W inhibited responses in both tissues but all showed less than fivefold higher potency in the hippocampus than in the aorta, implying useless selectivity for neuronal over endothelial NOS at the tissue level. In addition, the inhibitors had a 25-fold lower potency in the hippocampus than reported previously, the IC50 values being approximately 1 μM for l-VNIO and NPA, and 150 μM for 1400W. Pyrrolidine-based inhibitors were similarly weak and nonselective. Conclusion and Implications The results suggest that l-VNIO, NPA and 1400W, as well as the newer pyrrolidine-type inhibitors, cannot be used as neuronal NOS inhibitors in cells without stringent verification. The identification of inhibitors with useable selectivity in cells and tissues remains an important goal. PMID:23072468

  12. Marine medaka ATP-binding cassette (ABC) superfamily and new insight into teleost Abch nomenclature

    PubMed Central

    Jeong, Chang-Bum; Kim, Bo-Mi; Kang, Hye-Min; Choi, Ik-Young; Rhee, Jae-Sung; Lee, Jae-Seong

    2015-01-01

    The ABC gene family is recognized as one of the largest gene families in all kingdoms of life. Although many genes involved in the ABC superfamily have been annotated from several fish species, information on large sets of the ABC superfamily and their evolutionary characterization are still unclear. In the marine medaka Oryzias melastigma, 50 ABC transporters were identified with bioinformatics-aided in silico analyses, and their full-length cDNA sequences were characterized. Phylogenetic analysis revealed that they could be classified into the eight subfamilies (A–H) that include all members of all ABC subfamilies. Interestingly, several teleosts’ Abcg members were closely clustered with Abch members in a distinctive clade. The abch gene was also observed in the coelacanth and the spotted gar, suggesting that this gene was retained from a bilaterian ancestor and that a gene loss event recently occurred in the tetrapod lineage. In teleosts, the nomenclature of previously annotated abcg genes should be considered carefully, as they form a distinctive clade with the marine medaka abch subfamily and other teleost abch genes, but not with the members of the Abcg subfamily. PMID:26472499

  13. ABC transporter and metallothionein expression affected by NI and Epichloe endophyte infection in tall fescue.

    PubMed

    Mirzahossini, Zahra; Shabani, Leila; Sabzalian, Mohammad R; Sharifi-Tehrani, Majid

    2015-10-01

    Epichloe endophytes are symbiotic fungi which unlike mycorrhiza grow within aerial parts of host plants. The fungi may increase host tolerance to both biotic and abiotic stresses. In this study, the effect of endophyte infection on growth and tolerance, carbohydrate contents and ABC (ABC transporter) and MET (metallothionein) expression in the leaves of tall fescue (Festuca arundinacea) plants cultivated in Ni polluted soil were evaluated. The endophyte infected (E+) and non-infected (E-) fescue plants were cultivated in soil under different Ni concentrations (30, 90 and 180mgkg(-1)). Growth parameters including root, shoot, total biomass, tiller number and total chlorophyll content of plants and H2O2 content of shoots were measured at the end of experiment. Ni translocation to the shoots, carbohydrate contents in roots and expression of ABC and MET of the leaves were also measured after 10 weeks of growth. Results demonstrated the beneficial effect of endophyte association on growth and Ni tolerance of tall fescue under Ni stress through an avoidance mechanism (reduction of Ni accumulation and translocation to the shoots). Endophyte infected plants showed less ABC and MET expression compared to the endophyte free plants. In endophyte free plants, H2O2 production had a significant positive correlation with genes expression, indicating that an increase in H2O2 might be involved in the up-regulation of ABC and MET under Ni stress. PMID:26024809

  14. Accelerator-based conversion (ABC) of weapons plutonium: Plant layout study and related design issues

    SciTech Connect

    Cowell, B.S.; Fontana, M.H.; Krakowski, R.A.; Beard, C.A.; Buksa, J.J.; Davidson, J.W.; Sailor, W.C.; Williamson, M.A.

    1995-04-01

    In preparation for and in support of a detailed R and D Plan for the Accelerator-Based Conversion (ABC) of weapons plutonium, an ABC Plant Layout Study was conducted at the level of a pre-conceptual engineering design. The plant layout is based on an adaptation of the Molten-Salt Breeder Reactor (MSBR) detailed conceptual design that was completed in the early 1070s. Although the ABC Plant Layout Study included the Accelerator Equipment as an essential element, the engineering assessment focused primarily on the Target; Primary System (blanket and all systems containing plutonium-bearing fuel salt); the Heat-Removal System (secondary-coolant-salt and supercritical-steam systems); Chemical Processing; Operation and Maintenance; Containment and Safety; and Instrumentation and Control systems. Although constrained primarily to a reflection of an accelerator-driven (subcritical) variant of MSBR system, unique features and added flexibilities of the ABC suggest improved or alternative approaches to each of the above-listed subsystems; these, along with the key technical issues in need of resolution through a detailed R&D plan for ABC are described on the bases of the ``strawman`` or ``point-of-departure`` plant layout that resulted from this study.

  15. Phylogenetic, Expression, and Bioinformatic Analysis of the ABC1 Gene Family in Populus trichocarpa

    PubMed Central

    Zhang, Haizhen; Chen, Yunlin; Xu, Xuemei; Mao, Xuliang; Li, Chenghao

    2013-01-01

    We studied 17 ABC1 genes in Populus trichocarpa, all of which contained an ABC1 domain consisting of about 120 amino acid residues. Most of the ABC1 gene products were located in the mitochondria or chloroplasts. All had a conserved VAVK-like motif and a DFG motif. Phylogenetic analysis grouped the genes into three subgroups. In addition, the chromosomal locations of the genes on the 19 Populus chromosomes were determined. Gene structure was studied through exon/intron organization and the MEME motif finder, while heatmap was used to study the expression diversity using EST libraries. According to the heatmap, PtrABC1P14 was highlighted because of the high expression in tension wood which related to secondary cell wall formation and cellulose synthesis, thus making a contribution to follow-up experiment in wood formation. Promoter cis-element analysis indicated that almost all of the ABC1 genes contained one or two cis-elements related to ABA signal transduction pathway and drought stress. Quantitative real-time PCR was carried out to evaluate the expression of all of the genes under abiotic stress conditions (ABA, CdCl2, high temperature, high salinity, and drought); the results showed that some of the genes were affected by these stresses and confirmed the results of promoter cis-element analysis. PMID:24163630

  16. Phylodynamic Inference with Kernel ABC and Its Application to HIV Epidemiology

    PubMed Central

    Poon, Art F.Y.

    2015-01-01

    The shapes of phylogenetic trees relating virus populations are determined by the adaptation of viruses within each host, and by the transmission of viruses among hosts. Phylodynamic inference attempts to reverse this flow of information, estimating parameters of these processes from the shape of a virus phylogeny reconstructed from a sample of genetic sequences from the epidemic. A key challenge to phylodynamic inference is quantifying the similarity between two trees in an efficient and comprehensive way. In this study, I demonstrate that a new distance measure, based on a subset tree kernel function from computational linguistics, confers a significant improvement over previous measures of tree shape for classifying trees generated under different epidemiological scenarios. Next, I incorporate this kernel-based distance measure into an approximate Bayesian computation (ABC) framework for phylodynamic inference. ABC bypasses the need for an analytical solution of model likelihood, as it only requires the ability to simulate data from the model. I validate this “kernel-ABC” method for phylodynamic inference by estimating parameters from data simulated under a simple epidemiological model. Results indicate that kernel-ABC attained greater accuracy for parameters associated with virus transmission than leading software on the same data sets. Finally, I apply the kernel-ABC framework to study a recent outbreak of a recombinant HIV subtype in China. Kernel-ABC provides a versatile framework for phylodynamic inference because it can fit a broader range of models than methods that rely on the computation of exact likelihoods. PMID:26006189

  17. Efficient processing of TFO-directed psoralen DNA interstrand crosslinks by the UvrABC nuclease.

    PubMed

    Christensen, Laura A; Wang, Hong; Van Houten, Bennett; Vasquez, Karen M

    2008-12-01

    Photoreactive psoralens can form interstrand crosslinks (ICLs) in double-stranded DNA. In eubacteria, the endonuclease UvrABC plays a key role in processing psoralen ICLs. Psoralen-modified triplex-forming oligonucleotides (TFOs) can be used to direct ICLs to specific genomic sites. Previous studies of pyrimidine-rich methoxypsoralen-modified TFOs indicated that the TFO inhibits cleavage by UvrABC. Because different chemistries may alter the processing of TFO-directed ICLs, we investigated the effect of another type of triplex formed by purine-rich TFOs on the processing of 4'-(hydroxymethyl)-4,5',8-trimethylpsoralen (HMT) ICLs by the UvrABC nuclease. Using an HMT-modified TFO to direct ICLs to a specific site, we found that UvrABC made incisions on the purine-rich strand of the duplex approximately 3 bases from the 3'-side and approximately 9 bases from the 5'-side of the ICL, within the TFO-binding region. In contrast to previous reports, the UvrABC nuclease cleaved the TFO-directed psoralen ICL with a greater efficiency than that of the psoralen ICL alone. Furthermore, the TFO was dissociated from its duplex binding site by UvrA and UvrB. As mutagenesis by TFO-directed ICLs requires nucleotide excision repair, the efficient processing of these lesions supports the use of triplex technology to direct DNA damage for genome modification. PMID:18996898

  18. Electron transfer between the QmoABC membrane complex and adenosine 5'-phosphosulfate reductase.

    PubMed

    Duarte, Américo G; Santos, André A; Pereira, Inês A C

    2016-04-01

    The dissimilatory adenosine 5'-phosphosulfate reductase (AprAB) is a key enzyme in the sulfate reduction pathway that catalyzes the reversible two electron reduction of adenosine 5'-phosphosulfate (APS) to sulfite and adenosine monophosphate (AMP). The physiological electron donor for AprAB is proposed to be the QmoABC membrane complex, coupling the quinone-pool to sulfate reduction. However, direct electron transfer between these two proteins has never been observed. In this work we demonstrate for the first time direct electron transfer between the Desulfovibrio desulfuricans ATCC 27774 QmoABC complex and AprAB. Cyclic voltammetry conducted with the modified Qmo electrode and AprAB in the electrolyte solution presented the Qmo electrochemical signature with two additional well-defined one electron redox processes, attributed to the AprAB FAD redox behavior. Moreover, experiments performed under catalytic conditions using the QmoABC modified electrode, with AprAB and APS in solution, show a catalytic current peak develop in the cathodic wave, attributed to substrate reduction, and which is not observed in the absence of QmoABC. Substrate dependence conducted with different electrode preparations (with and without immobilized Qmo) demonstrated that the QmoABC complex is essential for efficient electron delivery to AprAB, in order to sustain catalysis. These results confirm the role of Qmo in electron transfer to AprAB. PMID:26768116

  19. Easy as ABC: A System to Stratify Category II Fetal Heart Rate Tracings.

    PubMed

    Penfield, Christina A; Hong, Connie; Ibrahim, Samia El Haj; Kilpatrick, Sarah J; Gregory, Kimberly D

    2016-06-01

    Objective To evaluate whether a subcategory system for category II tracings can improve team communication and perinatal outcomes. Study Design We collected data prospectively for 15 months, first using the NICHD system, followed by the ABC system, which divides category II tracings into subcategories A, B, and C, each representing increased risk for metabolic acidemia. We surveyed providers about communication effectiveness and agreement on tracing interpretation for each system. In cases where the communication system was used to alert an off-site physician about a category II tracing, we compared arrival to L&D and NICU admissions. Results The ABC system was preferred (69%, n = 152) and considered a more effective tool for communicating concerning fetal status (80% vs. 43%, p < 0.01). Participants also reported greater agreement on tracing interpretation (79% for ABC vs. 64% for NICHD, p = 0.046). When an off-site physician was contacted about a category II tracing (n = 95), they were more likely to arrive to L&D (44% vs. 20%, p < 0.01) and have fewer NICU admissions (0% vs. 6%, p < 0.01) with the ABC system. Conclusion The ABC system resulted in improved team communication, increased physician response, and decreased NICU admissions. Using standardized communication may offer a useful strategy for identifying and expediting care. PMID:26871906

  20. Subnanometer resolution cryo-EM structure of a nucleotide free heterodimeric ABC exporter

    PubMed Central

    Kim, JungMin; Wu, Shenping; Tomasiak, Thomas; Mergel, Claudia; Winter, Michael B.; Stiller, Sebastian B.; Robles-Colmanares, Yaneth; Stroud, Robert M.; Tampé, Robert; Craik, Charles S.; Cheng, Yifan

    2015-01-01

    ATP-binding cassette (ABC) transporters translocate substrates across cell membranes, using energy harnessed from ATP binding and hydrolysis at their nucleotide binding domains (NBDs)1,2. ABC exporters are present in both prokaryotes and eukaryotes with examples implicated in multidrug resistance of pathogens and cancer cells, as well as in many human diseases3,4. TmrAB is a heterodimeric ABC exporter from the thermophilic Gram-negative eubacterium Thermus thermophilus homologous to various multidrug transporters and containing one degenerate site with a non-catalytic residue next to the Walker B motif5. Here we report a subnanometer resolution structure of detergent-solubilized TmrAB in a nucleotide-free, inward-facing conformation by single particle electron cryomicroscopy (cryo-EM). The reconstructions clearly resolved characteristic features of ABC transporters, including helices in the transmembrane domain (TMD) and NBDs. A cavity in the TMD is accessible laterally from the cytoplasmic side of the membrane as well as from the cytoplasm, indicating that the transporter lies in an inward-facing open conformation. The two NBDs remain in contact via their C-terminal helices. Furthermore, comparison between our structure and the crystal structures of other ABC transporters suggests a possible trajectory of conformational changes that involves a sliding and rotating motion between the two NBDs during the transition from the inward facing to outward facing conformations. PMID:25363761

  1. Overcoming ABC transporter-mediated multidrug resistance: Molecular mechanisms and novel therapeutic drug strategies.

    PubMed

    Li, Wen; Zhang, Han; Assaraf, Yehuda G; Zhao, Kun; Xu, Xiaojun; Xie, Jinbing; Yang, Dong-Hua; Chen, Zhe-Sheng

    2016-07-01

    Multidrug resistance is a key determinant of cancer chemotherapy failure. One of the major causes of multidrug resistance is the enhanced efflux of drugs by membrane ABC transporters. Targeting ABC transporters projects a promising approach to eliminating or suppressing drug resistance in cancer treatment. To reveal the functional mechanisms of ABC transporters in drug resistance, extensive studies have been conducted from identifying drug binding sites to elucidating structural dynamics. In this review article, we examined the recent crystal structures of ABC proteins to depict the functionally important structural elements, such as domains, conserved motifs, and critical amino acids that are involved in ATP-binding and drug efflux. We inspected the drug-binding sites on ABC proteins and the molecular mechanisms of various substrate interactions with the drug binding pocket. While our continuous battle against drug resistance is far from over, new approaches and technologies have emerged to push forward our frontier. Most recent developments in anti-MDR strategies include P-gp inhibitors, RNA-interference, nano-medicines, and delivering combination strategies. With the advent of the 'Omics' era - genomics, epigenomics, transcriptomics, proteomics, and metabolomics - these disciplines play an important role in fighting the battle against chemoresistance by further unraveling the molecular mechanisms of drug resistance and shed light on medical therapies that specifically target MDR. PMID:27449595

  2. Co-solvent mediated thermal stabilization of chondroitinase ABC I form Proteus vulgaris.

    PubMed

    Nazari-Robati, Mahdieh; Khajeh, Khosro; Aminian, Mahdi; Fathi-Roudsari, Mehrnoosh; Golestani, Abolfazl

    2012-04-01

    Chondroitinase ABC I (cABC I) from Proteus vulgaris cleaves glycosaminoglycan chains which are responsible for most of the inhibition of axon regrowth in spinal cord injury. The clinical utilization of this enzyme is mainly limited by its thermal instability. This study has been undertaken to determine the effects of glycerol, sorbitol and trehalose on cABC I activity and thermal stability. The results indicated that the enzyme catalytic activity and intrinsic fluorescence intensity increased in the presence of these cosolvents whereas no considerable conformational changes observed in far-UV CD spectra. Thermal CD experiment revealed an increase in T(m) of cABC I in the presence of cosolvents which was significant for trehalose. Our results support the idea that cABC I has stabilized in the presence of glycerol, sorbitol and trehalose. Therefore, the use of these cosolvents seems to be promising for improvement in shelf-life and clinical applications of this drug enzyme. PMID:22274395

  3. Expression, purification and thermostability of MBP-chondroitinase ABC I from Proteus vulgaris.

    PubMed

    Chen, Zhenya; Li, Ye; Yuan, Qipeng

    2015-01-01

    Chondroitinase ABC I (ChSase ABC I) which can degrade chondroitin sulfate (CS) and other glycosaminoglycan to oligosaccharide or unsaturated disaccharide, was fusionally expressed with maltose-binding protein (MBP) in Escherichia coli BL21(DE3) (E. coli BL21(DE3)) and purified for the first time in this study. The result showed that the productivity of recombinant MBP-ChSase ABC I was 3180 IU/(L fermentation liquor) with CS A as substrate, and the productivity might be the highest level when compared to the reported ones. The specific activity of recombinant MBP-ChSase ABC I was 76 IU/(mg protein) after purification. The Vmax, Km and kcat were 18.7 ± 0.3 μmol/Ls, 73.1 ± 4.1 μmol/L and 586.7 ± 10.8 s(-1), respectively. Enzyme activity of the purified enzyme remained about 78% after 210 min when the enzyme incubated at 30 °C. This study introduces a rapid method for highly expressing ChSase ABC I, and the method could be adopted in the process of industrial production. Furthermore the investigation of thermostability might lead to an important guide in clinical treatment. PMID:25077839

  4. Multifaceted NOS Instruction: Contextualizing Nature of Science with Documentary Films

    ERIC Educational Resources Information Center

    Bloom, Mark; Binns, Ian C.; Koehler, Catherine

    2015-01-01

    This research focuses on inservice science teachers' conceptions of nature of science (NOS) before and after a two-week intensive summer professional development (PD). The PD combined traditional explicit NOS instruction, numerous interactive interventions that highlighted NOS aspects, along with documentary films that portrayed NOS in context of…

  5. mNos2 Deletion and Human NOS2 Replacement in Alzheimer Disease Models

    PubMed Central

    Colton, Carol A.; Wilson, Joan G.; Everhart, Angela; Wilcock, Donna M.; Puoliväli, Jukka; Heikkinen, Taneli; Oksman, Juho; Jääskeläinen, Olli; Lehtimäki, Kimmo; Laitinen, Teemu; Vartiainen, Nina; Vitek, Michael P.

    2014-01-01

    Abstract Understanding the pathophysiologic mechanisms underlying Alzheimer disease relies on knowledge of disease onset and the sequence of development of brain pathologies. We present a comprehensive analysis of early and progressive changes in a mouse model that demonstrates a full spectrum of characteristic Alzheimer disease–like pathologies. This model demonstrates an altered immune redox state reminiscent of the human disease and capitalizes on data indicating critical differences between human and mouse immune responses, particularly in nitric oxide levels produced by immune activation of the NOS2 gene. Using the APPSwDI+/+/mNos2−/− (CVN-AD) mouse strain, we show a sequence of pathologic events leading to neurodegeneration,which include pathologically hyperphosphorylated tau in the perforant pathway at 6 weeks of age progressing to insoluble tau, early appearance of β-amyloid peptides in perivascular deposits around blood vessels in brain regions known to be vulnerable to Alzheimer disease, and progression to damage and overt loss in select vulnerable neuronal populations in these regions. The role of species differences between hNOS2 and mNos2 was supported by generating mice in which the human NOS2 gene replaced mNos2. When crossed with CVN-AD mice, pathologic characteristics of this new strain (APPSwDI+/−/HuNOS2tg+/+/mNos2−/−) mimicked the pathologic phenotypes found in the CVN-AD strain. PMID:25003233

  6. mNos2 deletion and human NOS2 replacement in Alzheimer disease models.

    PubMed

    Colton, Carol A; Wilson, Joan G; Everhart, Angela; Wilcock, Donna M; Puoliväli, Jukka; Heikkinen, Taneli; Oksman, Juho; Jääskeläinen, Olli; Lehtimäki, Kimmo; Laitinen, Teemu; Vartiainen, Nina; Vitek, Michael P

    2014-08-01

    Understanding the pathophysiologic mechanisms underlying Alzheimer disease relies on knowledge of disease onset and the sequence of development of brain pathologies. We present a comprehensive analysis of early and progressive changes in a mouse model that demonstrates a full spectrum of characteristic Alzheimer disease-like pathologies. This model demonstrates an altered immune redox state reminiscent of the human disease and capitalizes on data indicating critical differences between human and mouse immune responses, particularly in nitric oxide levels produced by immune activation of the NOS2 gene. Using the APPSwDI(+)/(+)mNos2(-/-) (CVN-AD) mouse strain, we show a sequence of pathologic events leading to neurodegeneration,which include pathologically hyperphosphorylated tau in the perforant pathway at 6 weeks of age progressing to insoluble tau, early appearance of β-amyloid peptides in perivascular deposits around blood vessels in brain regions known to be vulnerable to Alzheimer disease, and progression to damage and overt loss in select vulnerable neuronal populations in these regions. The role of species differences between hNOS2 and mNos2 was supported by generating mice in which the human NOS2 gene replaced mNos2. When crossed with CVN-AD mice, pathologic characteristics of this new strain (APPSwDI(+)/(-)/HuNOS2(tg+)/(+)/mNos2(-/-)) mimicked the pathologic phenotypes found in the CVN-AD strain. PMID:25003233

  7. Identification and expression analysis of ABC protein-encoding genes in Toxoplasma gondii. Toxoplasma gondii ATP-binding cassette superfamily.

    PubMed

    Sauvage, Virginie; Millot, Jean-Marc; Aubert, Dominique; Visneux, Vincent; Marle-Plistat, Maggy; Pinon, Jean-Michel; Villena, Isabelle

    2006-06-01

    The ATP-binding cassette (ABC) transporters are one of the largest evolutionarily conserved families of proteins. They are characterized by the presence of nucleotide-binding domains (NBDs), which are highly conserved among organisms. In the present study, we used human and protozoan ABC sequences, and ATP-binding consensus motifs to screen the Toxoplasma gondii TwinScan2 predicted proteins database. We identified 24 ABC open reading frames (ORFs), whose deduced amino acid sequences exhibited all the typical biochemical features of the ABC family members. Fifteen of them clustered into five of the seven families of human ABC proteins: six ABCBs (drug, peptides and lipid export), two ABCCs (organic anion conjugates and drug export), one ABCE (Rnase L inhibitor, RLI, antibiotic resistance and translation regulation), one ABCF (drug resistance and regulation of gene expression) and five ABCGs (drug export and resistance). The nine other ORFs were represented by four ABCHs (energy-generating subunits), four SMCs (structural maintenance of chromosomes) and one member of unclear origin, whose closest homologue was the yeast Elf1 protein (mRNA export factor). A notable feature of the Toxoplasma ABC superfamily seems to be the absence of genes encoding ABCA and ABCD members. Expression analysis of ABC genes in tachyzoite and bradyzoite stages revealed the presence of ABC transcripts for all genes studied. Further research on the implication of these ABC proteins will increase our knowledge of the basic biology of Toxoplasma and provide the opportunity to identify novel therapeutic targets. To our knowledge, this is the first report of ABC transporters in T. gondii. PMID:16600400

  8. Tissue-Specific Transcript Profiling for ABC Transporters in the Sequestering Larvae of the Phytophagous Leaf Beetle Chrysomela populi

    PubMed Central

    Gretscher, René R.; Groth, Marco; Boland, Wilhelm; Burse, Antje

    2014-01-01

    Background Insects evolved ingenious adaptations to use extraordinary food sources. Particularly, the diet of herbivores enriched with noxious plant secondary metabolites requires detoxification mechanisms. Sequestration, which involves the uptake, transfer, and concentration of occasionally modified phytochemicals into specialized tissues or hemolymph, is one of the most successful detoxification strategies found in most insect orders. Due to the ability of ATP-binding cassette (ABC) carriers to transport a wide range of molecules including phytochemicals and xenobiotics, it is highly likely that they play a role in this sequestration process. To shed light on the role of ABC proteins in sequestration, we describe an inventory of putative ABC transporters in various tissues in the sequestering juvenile poplar leaf beetle, Chrysomela populi. Results In the transcriptome of C. populi, we predicted 65 ABC transporters. To link the proteins with a possible function, we performed comparative phylogenetic analyses with ABC transporters of other insects and of humans. While tissue-specific profiling of each ABC transporter subfamily suggests that ABCB, C and G influence the plant metabolite absorption in the gut, ABCC with 14 members is the preferred subfamily responsible for the excretion of these metabolites via Malpighian tubules. Moreover, salicin, which is sequestered from poplar plants, is translocated into the defensive glands for further deterrent production. In these glands and among all identified ABC transporters, an exceptionally high transcript level was observed only for Cpabc35 (Cpmrp). RNAi revealed the deficiency of other ABC pumps to compensate the function of CpABC35, demonstrating its key role during sequestration. Conclusion We provide the first comprehensive phylogenetic study of the ABC family in a phytophagous beetle species. RNA-seq data from different larval tissues propose the importance of ABC pumps to achieve a homeostasis of plant

  9. ABC transporters: one, two or four extracytoplasmic substrate-binding sites?

    PubMed Central

    van der Heide, Tiemen; Poolman, Bert

    2002-01-01

    Two families of ATP-binding cassette (ABC) transporters in which one or two extracytoplasmic substrate-binding domains are fused to either the N- or C-terminus of the translocator protein have been detected. This suggests that two, or even four, substrate-binding sites may function in the ABC transporter complex. This domain organization in ABC transporters, widely represented among microorganisms, raises new possibilities for how the substrate-binding protein(s) (SBPs) might interact with the translocator. One appealing hypothesis is that multiple substrate-binding sites in proximity to the entry site of the translocation pore enhance the transport capacity. We also discuss the implications of multiple substrate-binding sites in close proximity to the translocator in terms of broadened substrate specificity and possible cooperative interactions between SBPs and the translocator. PMID:12370206

  10. Application of edge-based finite elements and vector ABCs in 3D scattering

    NASA Technical Reports Server (NTRS)

    Chatterjee, A.; Jin, J. M.; Volakis, John L.

    1992-01-01

    A finite element absorbing boundary condition (FE-ABC) solution of the scattering by arbitrary 3-D structures is considered. The computational domain is discretized using edge-based tetrahedral elements. In contrast to the node-based elements, edge elements can treat geometries with sharp edges, are divergence-less, and easily satisfy the field continuity condition across dielectric interfaces. They do, however, lead to a higher unknown count but this is balanced by the greater sparsity of the resulting finite element matrix. Thus, the computation time required to solve such a system iteratively with a given degree of accuracy is less than the traditional node-based approach. The purpose is to examine the derivation and performance of the ABC's when applied to 2-D and 3-D problems and to discuss the specifics of our FE-ABC implementation.

  11. The ABC Schizophrenia Study: a preliminary overview of the results.

    PubMed

    Häfner, H; Maurer, K; Löffler, W; an der Heiden, W; Munk-Jørgensen, P; Hambrecht, M; Riecher-Rössler, A

    1998-08-01

    The ABC Schizophrenia Study, a large-scale epidemiological and neurobiological research project commenced in 1987, initially pursued two aims: (1) to elucidate the possible causes of the sex difference in age at first admission for schizophrenia and (2) to analyse the early course of the disorder from onset until first contact and its implications for further course and outcome. First, transnational case-register data (for Denmark and Germany) were compared, second, a population-based sample of first-episode cases of schizophrenia (n = 232) were selected and third, the results obtained were compared with data from the WHO Determinants of Outcome Study by using a systematic methodology. A consistent result was a 3-4 years higher age of onset for women by any definition of onset, which was not explainable by social variables, such as differences in the male-female societal roles. A sensitivity-reducing effect of oestrogen on central D2 receptors was identified as the underlying neurobiological mechanism in animal experiments. Applicability to humans with schizophrenia was established in a controlled clinical study. A comparison of familial and sporadic cases showed that in cases with a high genetic load, the sex difference in age of onset disappeared due to a clearly reduced age of onset in women, whereas in sporadic cases it increased. To analyse early course retrospectively, a semistructured interview, IRAOS, was developed. The early stages of the disorder were reconstructed in comparison with age- and sex-matched controls from the same population of origin. The initial signs consisted mainly of negative and affective symptoms, which accumulated exponentially until the first episode, as did the later emerging positive symptoms. Social disability appeared 2-4 years before first admission on average. In early-onset cases, social course and outcome, studied prospectively over 5 years, was determined by the level of social development at onset through social stagnation

  12. Canine olfactory ensheathing cells from the olfactory mucosa can be engineered to produce active chondroitinase ABC.

    PubMed

    Carwardine, Darren; Wong, Liang-Fong; Fawcett, James W; Muir, Elizabeth M; Granger, Nicolas

    2016-08-15

    A multitude of factors must be overcome following spinal cord injury (SCI) in order to achieve clinical improvement in patients. It is thought that by combining promising therapies these diverse factors could be combatted with the aim of producing an overall improvement in function. Chondroitin sulphate proteoglycans (CSPGs) present in the glial scar that forms following SCI present a significant block to axon regeneration. Digestion of CSPGs by chondroitinase ABC (ChABC) leads to axon regeneration, neuronal plasticity and functional improvement in preclinical models of SCI. However, the enzyme activity decays at body temperature within 24-72h, limiting the translational potential of ChABC as a therapy. Olfactory ensheathing cells (OECs) have shown huge promise as a cell transplant therapy in SCI. Their beneficial effects have been demonstrated in multiple small animal SCI models as well as in naturally occurring SCI in canine patients. In the present study, we have genetically modified canine OECs from the mucosa to constitutively produce enzymatically active ChABC. We have developed a lentiviral vector that can deliver a mammalian modified version of the ChABC gene to mammalian cells, including OECs. Enzyme production was quantified using the Morgan-Elson assay that detects the breakdown products of CSPG digestion in cell supernatants. We confirmed our findings by immunolabelling cell supernatant samples using Western blotting. OECs normal cell function was unaffected by genetic modification as demonstrated by normal microscopic morphology and the presence of the low affinity neurotrophin receptor (p75(NGF)) following viral transduction. We have developed the means to allow production of active ChABC in combination with a promising cell transplant therapy for SCI repair. PMID:27423610

  13. Nonrigid registration method to assess reproducibility of breath-holding with ABC in lung cancer

    SciTech Connect

    Sarrut, David . E-mail: dsarrut@univ-lyon2.fr; Boldea, Vlad; Ayadi, Myriam; Badel, Jean-Noel; Ginestet, Chantal; Clippe, Sebastien; Carrie, Christian

    2005-02-01

    Purpose: To study the interfraction reproducibility of breath-holding using active breath control (ABC), and to develop computerized tools to evaluate three-dimensional (3D) intrathoracic motion in each patient. Methods and materials: Since June 2002, 11 patients with non-small-cell lung cancer enrolled in a Phase II trial have undergone four CT scans: one during free-breathing (reference) and three using ABC. Patients left the room between breath-hold scans. The patient's breath was held at the same predefined phase of the breathing cycle (about 70% of the vital capacity) using the ABC device, then patients received 3D-conformal radiotherapy. Automated computerized tools for breath-hold CT scans were developed to analyze lung and tumor interfraction residual motions with 3D nonrigid registration. Results: All patients but one were safely treated with ABC for 7 weeks. For 6 patients, the lung volume differences were <5%. The mean 3D displacement inside the lungs was between 2.3 mm (SD 1.4) and 4 mm (SD 3.3), and the gross tumor volume residual motion was 0.9 mm (SD 0.4) to 5.9 mm (SD 0.7). The residual motion was slightly greater in the inferior part of the lung than the superior. For 2 patients, we detected volume changes >300 cm{sup 3} and displacements >10 mm, probably owing to atelectasia and emphysema. One patient was excluded, and two others had incomplete data sets. Conclusion: Breath-holding with ABC was effective in 6 patients, and discrepancies were clinically accountable in 2. The proposed 3D nonrigid registration method allows for personalized evaluation of breath-holding reproducibility with ABC. It will be used to adapt the patient-specific internal margins.

  14. H-ABC syndrome and DYT4: Variable expressivity or pleiotropy of TUBB4 mutations?

    PubMed

    Erro, Roberto; Hersheson, Joshua; Ganos, Christos; Mencacci, Niccoló E; Stamelou, Maria; Batla, Amit; Thust, Stefanie Catherine; Bras, Jose M; Guerreiro, Rita J; Hardy, John; Quinn, Niall P; Houlden, Henry; Bhatia, Kailash P

    2015-05-01

    Recently, mutations in the TUBB4A gene have been found to underlie hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) syndrome, a rare neurodegenerative disorder of infancy and childhood. TUBB4A mutations also have been described as causative of DYT4 ("hereditary whispering dysphonia"). However, in DYT4, brain imaging has been reported to be normal and, therefore, H-ABC syndrome and DYT4 have been construed to be different disorders, despite some phenotypic overlap. Hence, the question of whether these disorders reflect variable expressivity or pleiotropy of TUBB4A mutations has been raised. We report four unrelated patients with imaging findings either partially or totally consistent with H-ABC syndrome, who were found to have TUBB4A mutations. All four subjects had a relatively homogenous phenotype characterized by severe generalized dystonia with superimposed pyramidal and cerebellar signs, and also bulbar involvement leading to complete aphonia and swallowing difficulties, even though one of the cases had an intermediate phenotype between H-ABC syndrome and DYT4. Genetic analysis of the TUBB4A gene showed one previously described and two novel mutations (c.941C>T; p.Ala314Val and c.900G>T; p.Met300Ile) in the exon 4 of the gene. While expanding the genetic spectrum of H-ABC syndrome, we confirm its radiological heterogeneity and demonstrate that phenotypic overlap with DYT4. Moreover, reappraisal of previously reported cases would also argue against pleiotropy of TUBB4A mutations. We therefore suggest that H-ABC and DYT4 belong to a continuous phenotypic spectrum associated with TUBB4A mutations. PMID:25545912

  15. Sialidase, chondroitinase ABC, and combination therapy after spinal cord contusion injury.

    PubMed

    Mountney, Andrea; Zahner, Matthew R; Sturgill, Elizabeth R; Riley, Christopher J; Aston, Jeffrey W; Oudega, Martin; Schramm, Lawrence P; Hurtado, Andres; Schnaar, Ronald L

    2013-02-01

    Axon regeneration in the central nervous system is severely hampered, limiting functional recovery. This is in part because of endogenous axon regeneration inhibitors that accumulate at the injury site. Therapeutic targeting of these inhibitors and their receptors may facilitate axon outgrowth and enhance recovery. A rat model of spinal cord contusion injury was used to test the effects of two bacterial enzyme therapies that target independent axon regeneration inhibitors, sialidase (Vibrio cholerae) and chondroitinase ABC (ChABC, Proteus vulgaris). The two enzymes, individually and in combination, were infused for 2 weeks via implanted osmotic pumps to the site of a moderate thoracic spinal cord contusion injury. Sialidase was completely stable, whereas ChABC retained>30% of its activity in vivo over the 2 week infusion period. Immunohistochemistry revealed that infused sialidase acted robustly throughout the spinal cord gray and white matter, whereas ChABC activity was more intense superficially. Sialidase treatment alone resulted in improved behavioral and anatomical outcomes. Rats treated exclusively with sialidase showed significantly increased hindlimb motor function, evidenced by higher Basso Beattie and Bresnahan (BBB) and BBB subscores, and fewer stepping errors on a horizontal ladder. Sialidase-treated rats also had increased serotonergic axons caudal to the injury. ChABC treatment, in contrast, did not enhance functional recovery or alter axon numbers after moderate spinal cord contusion injury, and dampened the response of sialidase in the dual enzyme treatment group. We conclude that sialidase infusion enhanced recovery from spinal cord contusion injury, and that combining sialidase with ChABC failed to improve outcomes. PMID:22934782

  16. Adaptive Evolution of Thermotoga maritima Reveals Plasticity of the ABC Transporter Network

    PubMed Central

    Latif, Haythem; Sahin, Merve; Tarasova, Janna; Tarasova, Yekaterina; Portnoy, Vasiliy A.; Nogales, Juan

    2015-01-01

    Thermotoga maritima is a hyperthermophilic anaerobe that utilizes a vast network of ABC transporters to efficiently metabolize a variety of carbon sources to produce hydrogen. For unknown reasons, this organism does not metabolize glucose as readily as it does glucose di- and polysaccharides. The leading hypothesis implicates the thermolability of glucose at the physiological temperatures at which T. maritima lives. After a 25-day laboratory evolution, phenotypes were observed with growth rates up to 1.4 times higher than and glucose utilization rates exceeding 50% those of the wild type. Genome resequencing revealed mutations in evolved cultures related to glucose-responsive ABC transporters. The native glucose ABC transporter, GluEFK, has more abundant transcripts either as a result of gene duplication-amplification or through mutations to the operator sequence regulating this operon. Conversely, BglEFGKL, a transporter of beta-glucosides, is substantially downregulated due to a nonsense mutation to the solute binding protein or due to a deletion of the upstream promoter. Analysis of the ABC2 uptake porter families for carbohydrate and peptide transport revealed that the solute binding protein, often among the transcripts detected at the highest levels, is predominantly downregulated in the evolved cultures, while the membrane-spanning domain and nucleotide binding components are less varied. Similar trends were observed in evolved strains grown on glycerol, a substrate that is not dependent on ABC transporters. Therefore, improved growth on glucose is achieved through mutations favoring GluEFK expression over BglEFGKL, and in lieu of carbon catabolite repression, the ABC transporter network is modulated to achieve improved growth fitness. PMID:26048924

  17. mRMR-ABC: A Hybrid Gene Selection Algorithm for Cancer Classification Using Microarray Gene Expression Profiling.

    PubMed

    Alshamlan, Hala; Badr, Ghada; Alohali, Yousef

    2015-01-01

    An artificial bee colony (ABC) is a relatively recent swarm intelligence optimization approach. In this paper, we propose the first attempt at applying ABC algorithm in analyzing a microarray gene expression profile. In addition, we propose an innovative feature selection algorithm, minimum redundancy maximum relevance (mRMR), and combine it with an ABC algorithm, mRMR-ABC, to select informative genes from microarray profile. The new approach is based on a support vector machine (SVM) algorithm to measure the classification accuracy for selected genes. We evaluate the performance of the proposed mRMR-ABC algorithm by conducting extensive experiments on six binary and multiclass gene expression microarray datasets. Furthermore, we compare our proposed mRMR-ABC algorithm with previously known techniques. We reimplemented two of these techniques for the sake of a fair comparison using the same parameters. These two techniques are mRMR when combined with a genetic algorithm (mRMR-GA) and mRMR when combined with a particle swarm optimization algorithm (mRMR-PSO). The experimental results prove that the proposed mRMR-ABC algorithm achieves accurate classification performance using small number of predictive genes when tested using both datasets and compared to previously suggested methods. This shows that mRMR-ABC is a promising approach for solving gene selection and cancer classification problems. PMID:25961028

  18. mRMR-ABC: A Hybrid Gene Selection Algorithm for Cancer Classification Using Microarray Gene Expression Profiling

    PubMed Central

    Alshamlan, Hala; Badr, Ghada; Alohali, Yousef

    2015-01-01

    An artificial bee colony (ABC) is a relatively recent swarm intelligence optimization approach. In this paper, we propose the first attempt at applying ABC algorithm in analyzing a microarray gene expression profile. In addition, we propose an innovative feature selection algorithm, minimum redundancy maximum relevance (mRMR), and combine it with an ABC algorithm, mRMR-ABC, to select informative genes from microarray profile. The new approach is based on a support vector machine (SVM) algorithm to measure the classification accuracy for selected genes. We evaluate the performance of the proposed mRMR-ABC algorithm by conducting extensive experiments on six binary and multiclass gene expression microarray datasets. Furthermore, we compare our proposed mRMR-ABC algorithm with previously known techniques. We reimplemented two of these techniques for the sake of a fair comparison using the same parameters. These two techniques are mRMR when combined with a genetic algorithm (mRMR-GA) and mRMR when combined with a particle swarm optimization algorithm (mRMR-PSO). The experimental results prove that the proposed mRMR-ABC algorithm achieves accurate classification performance using small number of predictive genes when tested using both datasets and compared to previously suggested methods. This shows that mRMR-ABC is a promising approach for solving gene selection and cancer classification problems. PMID:25961028

  19. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... failure to meet the requirements of the regulations in 50 CFR part 648. Upon denial of an application to... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Acceptable biological catch (ABC), annual... Measures for the Atlantic Sea Scallop Fishery § 648.53 Acceptable biological catch (ABC), annual...

  20. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... failure to meet the requirements of the regulations in 50 CFR part 648. Upon denial of an application to... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Acceptable biological catch (ABC), annual... Measures for the Atlantic Sea Scallop Fishery § 648.53 Acceptable biological catch (ABC), annual...

  1. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... requirements of the regulations in 50 CFR part 648. Upon denial of an application to transfer IFQ, the Regional... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Acceptable biological catch (ABC), annual... Measures for the Atlantic Sea Scallop Fishery § 648.53 Acceptable biological catch (ABC), annual...

  2. 75 FR 11991 - ABC & D Recycling, Inc.-Lease and Operation Exemption-a Line of Railroad in Ware, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... Surface Transportation Board ABC & D Recycling, Inc.--Lease and Operation Exemption--a Line of Railroad in... under 49 CFR 1150.31 to lease from O'Riley Family Trust (O'Riley), and to operate 773 feet of rail line... lease and operate the railroad trackage owned by O'Riley. ABC & D states that it has and intends...

  3. The ABCs of School Choice: The Comprehensive Guide to Every Private School Choice Program in America. 2013 Edition

    ERIC Educational Resources Information Center

    Friedman Foundation for Educational Choice, 2013

    2013-01-01

    "The ABCs of School Choice" is the most comprehensive guide to every private school choice program in America, showcasing the voucher, tax-credit scholarship, education savings accounts, and individual tax credit/deduction programs currently operating in 21 states and Washington, D.C. "The ABCs of School Choice" provides policymakers, advocates,…

  4. 78 FR 54464 - ABC Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-04

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission ABC Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing...-referenced proceeding, of ABC Energy, LLC's application for market-based rate authority, with an...

  5. Starting with ABC and Finishing with XYZ: What Financial Reporting Model Best Fits a Faculty and Why?

    ERIC Educational Resources Information Center

    Berry, Prudence Jane

    2014-01-01

    This article looks at the range of financial reporting models available for use in the Australian higher education sector, the possible application of activity-based costing (ABC) in faculties and the eventual rejection of ABC in favour of a more qualitative model designed specifically for use in one institution, in a particular Faculty. The…

  6. Networks of ABA and ABC stacked graphene on mica observed by scanning tunneling microscopy

    NASA Astrophysics Data System (ADS)

    Hattendorf, S.; Georgi, A.; Liebmann, M.; Morgenstern, M.

    2013-04-01

    Graphene flakes are prepared on freshly cleaved mica by exfoliation and studied by scanning tunneling microscopy in ultra high vacuum. On few-layer graphene, a triangular network of partial dislocations separating ABC stacked and ABA stacked graphene was found similar to the networks occasionally visible on freshly cleaved HOPG. We found differences in the electronic structure of ABC and ABA stacked areas by scanning tunneling spectroscopy, i.e., a pronounced peak at 0.25 eV above the Fermi level exclusively in the ABA areas, which is shown to be responsible for the different apparent heights observed in STM images.

  7. Second-harmonic generation from atomic-scale ABC-type laminate optical metamaterials (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Alloatti, Luca; Kieninger, Clemens M.; Frölich, Andreas M.; Lauermann, Matthias; Frenzel, Tobias; Köhnle, Kira; Freude, Wolfgang; Leuthold, Juerg; Koos, Christian; Wegener, Martin

    2015-09-01

    [invited] We introduce ABC laminate metamaterials composed of layers of three different dielectrics. Each layer has zero bulk second-order optical nonlinearity, yet centro-symmetry is broken locally at each inner interface. To achieve appreciable effective bulk metamaterial second-order nonlinear optical susceptibilities, we densely pack many inner surfaces to a stack of atomically thin layers grown by conformal atomic-layer deposition. For the ABC stack, centro-symmetry is also broken macroscopically. Our experimental results for excitation at around 800 nm wavelength indicate interesting application perspectives for frequency conversion or electro-optic modulation in silicon photonics.

  8. Conformational coupling of the nucleotide-binding and the transmembrane domains in ABC transporters.

    PubMed

    Wen, Po-Chao; Tajkhorshid, Emad

    2011-08-01

    Basic architecture of ABC transporters includes two transmembrane domains (TMDs) and two nucleotide-binding domains (NBDs). Although the transport process takes place in the TMDs, which provide the substrate translocation pathway across the cell membrane and control its accessibility between the two sides of the membrane, the energy required for the process is provided by conformational changes induced in the NBDs by binding and hydrolysis of ATP. Nucleotide-dependent conformational changes in the NBDs, therefore, need to be coupled to structural changes in the TMDs. Using molecular dynamics simulations, we have investigated the structural elements involved in the conformational coupling between the NBDs and the TMDs in the Escherichia coli maltose transporter, an ABC importer for which an intact structure is available both in inward-facing and outward-facing conformations. The prevailing model of coupling is primarily based on a single structural motif, known as the coupling helices, as the main structural element for the NBD-TMD coupling. Surprisingly, we find that in the absence of the NBDs the coupling helices can be conformationally decoupled from the rest of the TMDs, despite their covalent connection. That is, the structural integrity of the coupling helices and their tight coupling to the core of the TMDs rely on the contacts provided by the NBDs. Based on the conformational and dynamical analysis of the simulation trajectories, we propose that the core coupling elements in the maltose transporter involve contributions from several structural motifs located at the NBD-TMD interface, namely, the EAA loops from the TMDs, and the Q-loop and the ENI motifs from the NBDs. These three structural motifs in small ABC importers show a high degree of correlation in motion and mediate the necessary conformational coupling between the core of TMDs and the helical subdomains of NBDs. A comprehensive analysis of the structurally known ABC transporters shows a high degree

  9. Temporal dynamics of the ABC transporter response to insecticide treatment: insights from the malaria vector Anopheles stephensi

    PubMed Central

    Epis, Sara; Porretta, Daniele; Mastrantonio, Valentina; Urbanelli, Sandra; Sassera, Davide; De Marco, Leone; Mereghetti, Valeria; Montagna, Matteo; Ricci, Irene; Favia, Guido; Bandi, Claudio

    2014-01-01

    In insects, ABC transporters have been shown to contribute to defence/resistance to insecticides by reducing toxic concentrations in cells/tissues. Despite the extensive studies about this detoxifying mechanism, the temporal patterns of ABC transporter activation have been poorly investigated. Using the malaria vector Anopheles stephensi as a study system, we investigated the expression profile of ABC genes belonging to different subfamilies in permethrin-treated larvae at different time points (30 min to 48 h). Our results showed that the expression of ABCB and ABCG subfamily genes was upregulated at 1 h after treatment, with the highest expression observed at 6 h. Therefore, future investigations on the temporal dynamics of ABC gene expression will allow a better implementation of insecticide treatment regimens, including the use of specific inhibitors of ABC efflux pumps. PMID:25504146

  10. Temporal dynamics of the ABC transporter response to insecticide treatment: insights from the malaria vector Anopheles stephensi.

    PubMed

    Epis, Sara; Porretta, Daniele; Mastrantonio, Valentina; Urbanelli, Sandra; Sassera, Davide; De Marco, Leone; Mereghetti, Valeria; Montagna, Matteo; Ricci, Irene; Favia, Guido; Bandi, Claudio

    2014-01-01

    In insects, ABC transporters have been shown to contribute to defence/resistance to insecticides by reducing toxic concentrations in cells/tissues. Despite the extensive studies about this detoxifying mechanism, the temporal patterns of ABC transporter activation have been poorly investigated. Using the malaria vector Anopheles stephensi as a study system, we investigated the expression profile of ABC genes belonging to different subfamilies in permethrin-treated larvae at different time points (30 min to 48 h). Our results showed that the expression of ABCB and ABCG subfamily genes was upregulated at 1 h after treatment, with the highest expression observed at 6 h. Therefore, future investigations on the temporal dynamics of ABC gene expression will allow a better implementation of insecticide treatment regimens, including the use of specific inhibitors of ABC efflux pumps. PMID:25504146

  11. Temporal dynamics of the ABC transporter response to insecticide treatment: insights from the malaria vector Anopheles stephensi

    NASA Astrophysics Data System (ADS)

    Epis, Sara; Porretta, Daniele; Mastrantonio, Valentina; Urbanelli, Sandra; Sassera, Davide; De Marco, Leone; Mereghetti, Valeria; Montagna, Matteo; Ricci, Irene; Favia, Guido; Bandi, Claudio

    2014-12-01

    In insects, ABC transporters have been shown to contribute to defence/resistance to insecticides by reducing toxic concentrations in cells/tissues. Despite the extensive studies about this detoxifying mechanism, the temporal patterns of ABC transporter activation have been poorly investigated. Using the malaria vector Anopheles stephensi as a study system, we investigated the expression profile of ABC genes belonging to different subfamilies in permethrin-treated larvae at different time points (30 min to 48 h). Our results showed that the expression of ABCB and ABCG subfamily genes was upregulated at 1 h after treatment, with the highest expression observed at 6 h. Therefore, future investigations on the temporal dynamics of ABC gene expression will allow a better implementation of insecticide treatment regimens, including the use of specific inhibitors of ABC efflux pumps.

  12. Second International Consensus Conference on Advanced Breast Cancer (ABC2), Lisbon, 11/09/2013: The German Perspective

    PubMed Central

    Harbeck, Nadia; Marschner, Norbert; Untch, Michael; Decker, Thomas; Hegewisch-Becker, Susanna; Jackisch, Christian; Huober, Jens; Lück, Hans-Joachim; von Minckwitz, Gunter; Scharl, Anton; Schneeweiss, Andreas; Tesch, Hans; Welt, Anja; Wuerstlein, Rachel; Thomssen, Christoph

    2014-01-01

    Summary The Advanced Breast Cancer Second International Consensus Conference (ABC2) on diagnosis and treatment of advanced breast cancer took place in Lisbon, Portugal, on November 7–9, 2013. The focus of the conference was inoperable, locally advanced breast cancer. The diagnosis and treatment of metastatic breast cancer had already been discussed 2 years before at the ABC1 Consensus and were only updated regarding special issues as part of this year's ABC2 Consensus. Like 2 years ago, a working group of German breast cancer experts commented on the voting results of the ABC panelists, with special consideration of the German guidelines for the diagnosis and treatment of breast cancer (German Gynecological Oncology Working Group (AGO) recommendations, S3 Guideline) in order to adapt them for daily clinical practice in Germany. The goal of both the ABC Consensus and the German comments is to facilitate evidence-based therapy decisions. PMID:24803888

  13. A wheat ABC transporter contributes to both grain formation and mycotoxin tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Deoxynivalenol (DON) is a mycotoxin produced by Fusarium fungi which acts as a disease virulence factor, aiding fungal pathogenesis of cereals spikelets and spread of the economically important Fusarium head blight (FHB) disease. Previously, a fragment of a wheat ABC transporter gene was shown to be...

  14. Transcriptome-based identification of ABC transporters in the western tarnished plant bug lygus hesperus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ATP-binding cassette (ABC) transporters are a large superfamily of proteins that mediate diverse physiological functions by coupling ATP hydrolysis with substrate transport across lipid membranes. In insects, these proteins play roles in metabolism, development, eye pigmentation, and xenobiotic cle...

  15. My Favorite Assignment: Selections from the ABC 2008 Annual Convention, Lake Tahoe, Nevada

    ERIC Educational Resources Information Center

    Whalen, D. Joel, Ed.

    2009-01-01

    At the 2008 Association for Business Communication (ABC) annual convention in Lake Tahoe, Nevada, many attendees stood at the back of a crowded room to hear over a dozen teachers describe "My Favorite Assignment." As is customary in these lively sessions, the chair, Dan Dieterich, orchestrated a fast, efficient presentation pace; each participant…

  16. Step 2: Know Your Diabetes ABCs | NIH MedlinePlus the Magazine

    MedlinePlus

    ... page please turn JavaScript on. Feature: Type 2 Diabetes Step 2: Know Your Diabetes ABCs Past Issues / Fall 2014 Table of Contents ... cholesterol helps remove cholesterol from your blood vessels. Diabetes HealthSense Find tools and programs that can help ...

  17. As Easy as ABC: Re-engineering the Cost Accounting System.

    ERIC Educational Resources Information Center

    Trussel, John M.; Bitner, Larry N.

    1996-01-01

    To be useful for management decision making, the college or university's cost accounting system must capture and measure improvements. Activity-based costing (ABC), which determines more accurately the full costs of services and products, tracks improvements and should proceed alongside reengineering of institutional accounting. Guidelines are…

  18. My Favorite Assignment: From the ABC 2010 Annual Convention, Chicago, Illinois

    ERIC Educational Resources Information Center

    Whalen, D. Joel

    2011-01-01

    The seven Favorite Assignments featured in this article were originally presented at the 2010 ABC Annual Convention, Chicago, Illinois. The reader can consider a variety of learning objectives from team building to persuasion, application of electronic media to face-to-face communication, and much more. Some Favorite Assignments take a full…

  19. ABCs of Being Smart: T Is for Tips for Working with Teachers

    ERIC Educational Resources Information Center

    Foster, Joanne

    2015-01-01

    As part of her series, "ABCs of Being Smart," Joanne Foster presents time-tested tips for parents of toddlers to teens. Categories include: traits to tap when meeting with teachers to strengthen home and school connections or resolve any issues; strategies for parents to add to their "toolbox"; and tactical measures to consider…

  20. FRICTIONAL RESPONSE OF BOVINE ARTICULAR CARTILAGE UNDER CREEP LOADING FOLLOWING PROTEOGLYCAN DIGESTION WITH CHONDROITINASE ABC

    PubMed Central

    Basalo, Ines M.; Chen, Faye Hui; Hung, Clark T.; Ateshian, Gerard A.

    2010-01-01

    Summary The specific aim of this study was to investigate the effect of chondroitinase ABC treatment on the frictional response of bovine articular cartilage against glass, under creep loading. The hypothesis is that chondroitinase ABC treatment increases the friction coefficient of bovine articular cartilage under creep. Articular cartilage samples (n=12) harvested from two bovine knee joints (1–3 months-old) were divided into a control group (intact specimens) and a treated group (chondroitinase ABC digestion), and tested in unconfined compression with simultaneous continuous sliding (±4 mm at 1 mm/s) under a constant applied stress of 0.5 MPa, for 2,500 s. The time-dependent response of the friction coefficient was measured. With increasing duration of loading, treated samples exhibited a significantly higher friction coefficient than control samples as assessed by the equilibrium value (treated: μeq = 0.19 ± 0.02; control: μeq = 0.12 ± 0.03; p=0.002), though the coefficient achieved immediately upon loading did not increase significantly (treated: μmin = 0.0053 ± 0.0025; control: μmin = 0.037 ± 0.0013; p=0.19). Our results demonstrate that removal of the cartilage glycosaminoglycans using chondroitinase ABC significantly increases the overall time-dependent friction coefficient of articular cartilage. These findings strengthen the motivation for developing chondroprotective strategies by increasing cartilage chondroitin sulfate content in osteoarthritic joints. PMID:16532626

  1. ABC Analysis for Inventory Management: Bridging the Gap between Research and Classroom

    ERIC Educational Resources Information Center

    Ravinder, Handanhal; Misra, Ram B.

    2014-01-01

    ABC analysis is a well-established categorization technique based on the Pareto Principle for determining which items should get priority in the management of a company's inventory. In discussing this topic, today's operations management and supply chain textbooks focus on dollar volume as the sole criterion for performing the categorization. The…

  2. The ABC's of Financing Church and Synagogue Libraries. Acquiring Funds, Budgeting, Cash Accounting.

    ERIC Educational Resources Information Center

    Hannaford, Claudia

    The ABCs of financing church and synagogue libraries are presented in this guide as Acquiring Funds, Budgeting, and Cash Accounting. Acquiring funds and the basic means needed to start a library are described, including resources such as books, shelves, office supplies, and financial resources; ideas and methods are presented for soliciting both…

  3. Genetic Characterization of Vga ABC Proteins Conferring Reduced Susceptibility to Pleuromutilins in Staphylococcus aureus▿

    PubMed Central

    Gentry, Daniel R.; McCloskey, Lynn; Gwynn, Michael N.; Rittenhouse, Stephen F.; Scangarella, Nicole; Shawar, Ribhi; Holmes, David J.

    2008-01-01

    Retapamulin MICs of ≥2 μg/ml were noted for 6 of 5,676 S. aureus recent clinical isolates evaluated. The ABC proteins VgaAv and VgaA were found to be responsible for the reduced susceptibility to pleuromutilins exhibited by these six isolates. PMID:18838584

  4. Psychometric Properties and Norms of the German ABC-Community and PAS-ADD Checklist

    ERIC Educational Resources Information Center

    Zeilinger, Elisabeth L.; Weber, Germain; Haveman, Meindert J.

    2011-01-01

    Aim: The aim of the present study was to standardize and generate psychometric evidence of the German language versions of two well-established English language mental health instruments: the "Aberrant Behavior Checklist-Community" (ABC-C) and the "Psychiatric Assessment Schedule for Adults with Developmental Disabilities" (PAS-ADD) Checklist. New…

  5. The Impact of ABC Canada's LEARN Campaign. Results of a National Research Study.

    ERIC Educational Resources Information Center

    Long, Ellen

    An impact study was conducted of ABC CANADA's LEARN campaign, a national media effort aimed at linking potential literacy learners with literacy groups. Two questionnaires were administered to 94 literacy groups, with 3,557 respondents. Findings included the following: (1) 70 percent of calls to literacy groups were from adult learners aged 16-44;…

  6. The ABC-F protein EttA gates ribosome entry into the translation elongation cycle.

    PubMed

    Boël, Grégory; Smith, Paul C; Ning, Wei; Englander, Michael T; Chen, Bo; Hashem, Yaser; Testa, Anthony J; Fischer, Jeffrey J; Wieden, Hans-Joachim; Frank, Joachim; Gonzalez, Ruben L; Hunt, John F

    2014-02-01

    ABC-F proteins have evaded functional characterization even though they compose one of the most widely distributed branches of the ATP-binding cassette (ABC) superfamily. Herein, we demonstrate that YjjK, the most prevalent eubacterial ABC-F protein, gates ribosome entry into the translation elongation cycle through a nucleotide-dependent interaction sensitive to ATP/ADP ratio. Accordingly, we rename this protein energy-dependent translational throttle A (EttA). We determined the crystal structure of Escherichia coli EttA and used it to design mutants for biochemical studies including enzymological assays of the initial steps of protein synthesis. These studies suggest that EttA may regulate protein synthesis in energy-depleted cells, which have a low ATP/ADP ratio. Consistently with this inference, EttA-deleted cells exhibit a severe fitness defect in long-term stationary phase. These studies demonstrate that an ABC-F protein regulates protein synthesis via a new mechanism sensitive to cellular energy status. PMID:24389466

  7. The ABC-F protein EttA gates ribosome entry into the translation elongation cycle

    PubMed Central

    Boël, Grégory; Smith, Paul C.; Ning, Wei; Englander, Michael T.; Chen, Bo; Hashem, Yaser; Testa, Anthony J.; Fischer, Jeffrey J.; Wieden, Hans-Joachim; Frank, Joachim; Gonzalez, Ruben L.; Hunt, John F.

    2014-01-01

    ABC-F proteins have evaded functional characterization even though they comprise one of the most widely distributed branches of the ATP-binding cassette (ABC) superfamily. Herein, we demonstrate that YjjK, the most prevalent eubacterial ABC-F protein, gates ribosome entry into the translation elongation cycle through a nucleotide-dependent interaction sensitive to ATP/ADP ratio. Accordingly, we rename this protein Energy-dependent Translational Throttle A (EttA). We determined the crystal structure of Escherichia coli EttA and used it to design mutants for biochemical studies, including enzymological assays of the initial steps of protein synthesis. These studies suggest that EttA may regulate protein synthesis in energy-depleted cells, which have a low ATP/ADP ratio. Consistent with this inference, ΔettA cells exhibit a severe fitness defect in long-term stationary phase. These studies demonstrate that an ABC-F protein regulates protein synthesis via a novel mechanism sensitive to cellular energy status. PMID:24389466

  8. Armpits, Belly Buttons and Chronic Wounds: The ABCs of Our Body Bacteria

    MedlinePlus

    ... The ABCs of Our Body Bacteria Inside Life Science View All Articles | Inside Life Science Home Page Armpits, Belly Buttons and Chronic Wounds: ... Findings About Our Resident Microbes This Inside Life Science article also appears on LiveScience . Learn about related ...

  9. The ABCs of Engagement in Out-of-School-Time Programs

    ERIC Educational Resources Information Center

    Bartko, W. Todd

    2005-01-01

    How do out-of-school-time (OST) programs get from attendance to active engagement? School researchers propose that engagement is composed of three "ABC" components, affect, behavior, and cognition, which can also be applied to OST programs. Affective engagement refers to positive and negative reactions to teachers, classmates, the academic…

  10. What Does the K-ABC Tell Us about Students with Learning Disabilities?

    ERIC Educational Resources Information Center

    Smith, Douglas K.

    Three studies were designed to explore the pattern of scores on the Kaufman Assessment Battery for Children (K-ABC) by 18 students in elementary level learning disability (LD) resource programs (Study 1), 133 elementary level students referred for learning problems (Study 2), and 67 elementary students referred for severe learning disabilities…