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Sample records for displays selective infection

  1. Mimotope peptides selected from phage display combinatorial library by serum antibodies of pigs experimentally infected with Taenia solium as leads to developing diagnostic antigens for human neurocysticercosis.

    PubMed

    Gazarian, Karlen; Rowlay, Merril; Gazarian, Tatiana; Vazquez Buchelli, Jorge Enrique; Hernández Gonzáles, Marisela

    2012-12-01

    Neurocysticercosis is caused by penetration of the tapeworm Taenia solium larvae into the central nervous system resulting in a diverse range of neurologic complications including epilepsy in endemic areas that globalization spreads worldwide. Sensitive and specific immunodiagnosis is needed for the early detection and elimination of the parasite, but the lack of standardized, readily obtainable antigens is a challenge. Here, we used the phage display for resolving the problem. The rationale of the strategy rests on the concept that the screening of combinatorial libraries with polyclonal serum to pathogens reveals families of peptides mimicking the pathogen most immunodominant epitopes indispensable for the successful diagnosis. The screening of a 7mer library with serum IgG of four pigs experimentally infected with parasite followed by computer aided segregation of the selected sequences resulted in the discovery of four clusters of homologous sequences of which one presented a family of ten mimotopes selected by three infected pig serum IgGs; the common motif sequence LSPF carried by the family was considered to be the core of an immunodominant epitope of the parasite critical for the binding with the antibody that selected the mimotopes. The immunoassay testing permitted to select a mimotope whose synthetic peptide free of the phage with the amino acid sequence Leu-Ser-Fen-Pro-Ser-Val-Val that distinguished well a panel of 21 cerebrospinal fluids of neurocysticercosis patients from the fluids of individuals with neurological complications of other etiology. This peptide is proposed as a lead for developing a novel molecularly defined diagnostic antigen(s) for the neurocysticercosis.

  2. Monitor selection criteria for stereoscopic displays

    NASA Astrophysics Data System (ADS)

    Meyer, Lhary

    1992-06-01

    Existing high-resolution monitors are optimized for display of non-stereoscopic images with field refresh rates of 60 to 80 hertz. Almost all existing graphics systems utilize refresh rates in this range. Stereoscopic field-sequential displays present alternate left and right images, with each eye seeing half the displayed fields by use of electronic shuttering systems. This image selection is accomplished by optical shutters that are alternately clear and opaque operating synchronously with the display. To maintain flicker-free display for each eye requires at least the doubling of the existing field rate. An idealized monitor for stereoscopic display adds several new demands on the performance of monitors that extend beyond existing requirements. Some of the new requirements may be contrary to existing needs, calling for engineering compromises to be considered. The paper addresses the electronic and perceptual requirements of stereoscopic monitors in the areas of scan ranges, phosphors, and interfaces. Success in utilizing existing commercial monitors and projectors and possible future directions are discussed.

  3. Response terminated displays unload selective attention.

    PubMed

    Roper, Zachary J J; Vecera, Shaun P

    2013-01-01

    Perceptual load theory successfully replaced the early vs. late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load) is sufficiently low to grant attentional "spill-over" to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional "spill-over" by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented. PMID:24399983

  4. Response terminated displays unload selective attention

    PubMed Central

    Roper, Zachary J. J.; Vecera, Shaun P.

    2013-01-01

    Perceptual load theory successfully replaced the early vs. late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load) is sufficiently low to grant attentional “spill-over” to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional “spill-over” by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented. PMID:24399983

  5. Immunodiagnosis of Canine Visceral Leishmaniasis Using Mimotope Peptides Selected from Phage Displayed Combinatorial Libraries

    PubMed Central

    Toledo-Machado, Christina Monerat; Machado de Avila, Ricardo Andrez; NGuyen, Christophe; Granier, Claude; Bueno, Lilian Lacerda; Carneiro, Claudia Martins; Menezes-Souza, Daniel; Carneiro, Rubens Antonio; Chávez-Olórtegui, Carlos; Fujiwara, Ricardo Toshio

    2015-01-01

    ELISA and RIFI are currently used for serodiagnosis of canine visceral leishmaniasis (CVL). The accuracy of these tests is controversial in endemic areas where canine infections by Trypanosoma cruzi may occur. We evaluated the usefulness of synthetic peptides that were selected through phage display technique in the serodiagnosis of CVL. Peptides were chosen based on their ability to bind to IgGs purified from infected dogs pooled sera. We selected three phage clones that reacted only with those IgGs. Peptides were synthesized, polymerized with glutaraldehyde, and used as antigens in ELISA assays. Each individual peptide or a mix of them was reactive with infected dogs serum. The assay was highly sensitive and specific when compared to soluble Leishmania antigen that showed cross-reactivity with anti-T. cruzi IgGs. Our results demonstrate that phage display technique is useful for selection of peptides that may represent valuable synthetic antigens for an improved serodiagnosis of CVL. PMID:25710003

  6. Selective posttranslational modification of phage-displayed polypeptides

    DOEpatents

    Tsao, Meng-Lin; Tian, Feng; Schultz, Peter

    2013-02-05

    The invention relates to posttranslational modification of phage-displayed polypeptides. These displayed polypeptides comprise at least one unnatural amino acid, e.g., an aryl-azide amino acid such as p-azido-L-phenylalanine, or an alkynyl-amino acid such as para-propargyloxyphenylalanine, which are incorporated into the phage-displayed fusion polypeptide at a selected position by using an in vivo orthogonal translation system comprising a suitable orthogonal aminoacyl-tRNA synthetase and a suitable orthogonal tRNA species. These unnatural amino acids advantageously provide targets for posttranslational modifications such as azide-alkyne [3+2]cycloaddition reactions and Staudinger modifications.

  7. Selective posttranslational modification of phage-displayed polypeptides

    DOEpatents

    Tsao, Meng-Lin; Tian, Feng; Schultz, Peter

    2013-11-19

    The invention relates to posttranslational modification of phage-displayed polypeptides. These displayed polypeptides comprise at least one unnatural amino acid, e.g., an aryl-azide amino acid such as p-azido-L-phenylalanine, or an alkynyl-amino acid such as para-propargyloxyphenylalanine, which are incorporated into the phage-displayed fusion polypeptide at a selected position by using an in vivo orthogonal translation system comprising a suitable orthogonal aminoacyl-tRNA synthetase and a suitable orthogonal tRNA species. These unnatural amino acids advantageously provide targets for posttranslational modifications such as azide-alkyne [3+2] cycloaddition reactions and Staudinger modifications.

  8. Protein Engineering and Selection Using Yeast Surface Display.

    PubMed

    Angelini, Alessandro; Chen, Tiffany F; de Picciotto, Seymour; Yang, Nicole J; Tzeng, Alice; Santos, Michael S; Van Deventer, James A; Traxlmayr, Michael W; Wittrup, K Dane

    2015-01-01

    Yeast surface display is a powerful technology for engineering a broad range of protein scaffolds. This protocol describes the process for de novo isolation of protein binders from large combinatorial libraries displayed on yeast by using magnetic bead separation followed by flow cytometry-based selection. The biophysical properties of isolated single clones are subsequently characterized, and desired properties are further enhanced through successive rounds of mutagenesis and flow cytometry selections, resulting in protein binders with increased stability, affinity, and specificity for target proteins of interest. PMID:26060067

  9. Development of Anti-Infectives Using Phage Display: Biological Agents against Bacteria, Viruses, and Parasites

    PubMed Central

    Huang, Johnny X.; Bishop-Hurley, Sharon L.

    2012-01-01

    The vast majority of anti-infective therapeutics on the market or in development are small molecules; however, there is now a nascent pipeline of biological agents in development. Until recently, phage display technologies were used mainly to produce monoclonal antibodies (MAbs) targeted against cancer or inflammatory disease targets. Patent disputes impeded broad use of these methods and contributed to the dearth of candidates in the clinic during the 1990s. Today, however, phage display is recognized as a powerful tool for selecting novel peptides and antibodies that can bind to a wide range of antigens, ranging from whole cells to proteins and lipid targets. In this review, we highlight research that exploits phage display technology as a means of discovering novel therapeutics against infectious diseases, with a focus on antimicrobial peptides and antibodies in clinical or preclinical development. We discuss the different strategies and methods used to derive, select, and develop anti-infectives from phage display libraries and then highlight case studies of drug candidates in the process of development and commercialization. Advances in screening, manufacturing, and humanization technologies now mean that phage display can make a significant contribution in the fight against clinically important pathogens. PMID:22664969

  10. Avoidance maneuevers selected while viewing cockpit traffic displays

    NASA Technical Reports Server (NTRS)

    Smith, J. D.; Ellis, S. R.; Lee, E.

    1982-01-01

    Ten airline pilots rates the collision danger of air traffic presented on cockpit displays of traffic information while they monitored simulated departures from Denver. They selected avoidance maneuvers when necessary for separation. Most evasive maneuvers were turns rather than vertical maneuvers. Evasive maneuvers chosen for encounters with low or moderate collision danger were generally toward the intruding aircraft. This tendency lessened as the perceived threat level increased. In the highest threst situations pilots turned toward the intruder only at chance levels. Intruders coming from positions in front of the pilot's own ship were more frequently avoided by turns toward than when intruders approached laterally or from behind. Some of the implications of the pilots' turning-toward tendencies are discussed with respect to automatic collision avoidance systems and coordination of avoidance maneuvers of conflicting aircraft.

  11. Content dependent selection of image enhancement parameters for mobile displays

    NASA Astrophysics Data System (ADS)

    Lee, Yoon-Gyoo; Kang, Yoo-Jin; Kim, Han-Eol; Kim, Ka-Hee; Kim, Choon-Woo

    2011-01-01

    Mobile devices such as cellular phones and portable multimedia player with capability of playing terrestrial digital multimedia broadcasting (T-DMB) contents have been introduced into consumer market. In this paper, content dependent image quality enhancement method for sharpness and colorfulness and noise reduction is presented to improve perceived image quality on mobile displays. Human visual experiments are performed to analyze viewers' preference. Relationship between the objective measures and the optimal values of image control parameters are modeled by simple lookup tables based on the results of human visual experiments. Content dependent values of image control parameters are determined based on the calculated measures and predetermined lookup tables. Experimental results indicate that dynamic selection of image control parameters yields better image quality.

  12. Selection of bead-displayed, PNA-encoded chemicals

    PubMed Central

    Gassman, Natalie R.; Nelli, J. Patrick; Dutta, Samrat; Kuhn, Adam; Bonin, Keith; Pianowski, Zbigniew; Winssinger, Nicolas; Guthold, Martin; Macosko, Jed C.

    2010-01-01

    The lack of efficient identification and isolation methods for specific molecular binders has fundamentally limited drug discovery. Here, we have developed a method to select peptide nucleic acid (PNA) encoded molecules with specific functional properties from combinatorially generated libraries. This method consists of three essential stages: (1) creation of a Lab-on-Bead™ library, a one-bead, one-sequence library that, in turn, displays a library of candidate molecules, (2) fluorescence microscopy-aided identification of single target-bound beads and the extraction – wet or dry – of these beads and their attached candidate molecules by a micropipette manipulator, and (3) identification of the target-binding candidate molecules via amplification and sequencing. This novel integration of techniques harnesses the sensitivity of DNA detection methods and the multiplexed and miniaturized nature of molecule screening to efficiently select and identify target-binding molecules from large nucleic acid encoded chemical libraries. Beyond its potential to accelerate assays currently used for the discovery of new drug candidates, its simple bead-based design allows for easy screening over a variety of prepared surfaces that can extend this technique's application to the discovery of diagnostic reagents and disease markers. PMID:19957300

  13. Selective attention and performance with a multidimensional visual display.

    PubMed

    Lambert, A; Hockey, R

    1986-11-01

    Selective attention was studied in four experiments in which stimuli varied in both spatial location and visual form. In Experiment 1 the likely location and likely form of targets were both precued. An advantage was found for cued over uncued forms at both cued and uncued locations. In Experiments 2, 3, and 4, different forms tended to occur at different locations. Regardless of whether a location was cued or uncued, form selective effects were found in accordance with form probability for that location. It was not the case that selective attention simply favored certain locations or certain stimulus forms in preference to others. Rather, selective attention was sensitive to precise combinations of form and location. These results could not be reconciled with mental spotlight notions of spatial selectivity. PMID:2946805

  14. Selection dynamic of Escherichia coli host in M13 combinatorial peptide phage display libraries.

    PubMed

    Zanconato, Stefano; Minervini, Giovanni; Poli, Irene; De Lucrezia, Davide

    2011-01-01

    Phage display relies on an iterative cycle of selection and amplification of random combinatorial libraries to enrich the initial population of those peptides that satisfy a priori chosen criteria. The effectiveness of any phage display protocol depends directly on library amino acid sequence diversity and the strength of the selection procedure. In this study we monitored the dynamics of the selective pressure exerted by the host organism on a random peptide library in the absence of any additional selection pressure. The results indicate that sequence censorship exerted by Escherichia coli dramatically reduces library diversity and can significantly impair phage display effectiveness. PMID:21512219

  15. Escherichia coli surface display of single-chain antibody VRC01 against HIV-1 infection

    SciTech Connect

    Wang, Lin-Xu; Mellon, Michael; Bowder, Dane; Quinn, Meghan; Shea, Danielle; Wood, Charles; Xiang, Shi-Hua

    2015-01-15

    Human immunodeficiency virus type 1 (HIV-1) transmission and infection occur mainly via the mucosal surfaces. The commensal bacteria residing in these surfaces can potentially be employed as a vehicle for delivering inhibitors to prevent HIV-1 infection. In this study, we have employed a bacteria-based strategy to display a broadly neutralizing antibody VRC01, which could potentially be used to prevent HIV-1 infection. The VRC01 antibody mimics CD4-binding to gp120 and has broadly neutralization activities against HIV-1. We have designed a construct that can express the fusion peptide of the scFv-VRC01 antibody together with the autotransporter β-barrel domain of IgAP gene from Neisseria gonorrhoeae, which enabled surface display of the antibody molecule. Our results indicate that the scFv-VRC01 antibody molecule was displayed on the surface of the bacteria as demonstrated by flow cytometry and immunofluorescence microscopy. The engineered bacteria can capture HIV-1 particles via surface-binding and inhibit HIV-1 infection in cell culture. - Highlights: • Designed single-chain VRC01 antibody was demonstrated to bind HIV-1 envelope gp120. • Single-chain VRC01 antibody was successfully displayed on the surface of E. coli. • Engineered bacteria can absorb HIV-1 particles and prevent HIV-1 infection in cell culture.

  16. Local interactions select for lower pathogen infectivity.

    PubMed

    Boots, Michael; Mealor, Michael

    2007-03-01

    Theory suggests that the current rapid increase in connectivity and consequential changes in the structure of human, agricultural, and wildlife populations may select for parasite strains with higher infectivity. We carried out a test of this spatial theory by experimentally altering individual host movement rates in a model host/pathogen system by altering the viscosity of their environment. In our microevolutionary selection experiments, the infectivity of the virus was, as predicted by the theory, reduced in the most viscous populations. We therefore provide empirical support for the theory that population structure affects the evolution of infectious organisms.

  17. Blocking peptides against HBV: PreS1 protein selected from a phage display library

    SciTech Connect

    Wang, Wei; Liu, Yang; Zu, Xiangyang; Jin, Rui; Xiao, Gengfu

    2011-09-09

    Highlights: {yields} Successfully selected specific PreS1-interacting peptides by using phage displayed library. {yields} Alignment of the positive phage clones revealed a consensus PreS1 binding motif. {yields} A highly enriched peptide named P7 had a strong binding ability for PreS1. {yields} P7 could block PreS1 attachment. -- Abstract: The PreS1 protein is present on the outermost part of the hepatitis B virus (HBV) surface and has been shown to have a pivotal function in viral infectivity and assembly. The development of reagents with high affinity and specificity for PreS1 is of great significance for early diagnosis and treatment of HBV infection. A phage display library of dodecapeptide was screened for interactions with purified PreS1 protein. Alignment of the positive phage clones revealed a putative consensus PreS1 binding motif of HX{sub n}HX{sub m}HP/R. Moreover, a peptide named P7 (KHMHWHPPALNT) was highly enriched and occurred with a surprisingly high frequency of 72%. A thermodynamic study revealed that P7 has a higher binding affinity to PreS1 than the other peptides. Furthermore, P7 was able to abrogate the binding of HBV virions to the PreS1 antibody, suggesting that P7 covers key functional sites on the native PreS1 protein. This newly isolated peptide may, therefore, be a new therapeutic candidate for the treatment of HBV. The consensus motif could be modified to deliver imaging, diagnostic, and therapeutic agents to tissues affected by HBV.

  18. Phage-displayed peptides selected for binding to Campylobacter jejuni are antimicrobial.

    PubMed

    Bishop-Hurley, Sharon L; Rea, Philippa J; McSweeney, Christopher S

    2010-10-01

    In developed countries, Campylobacter jejuni is a leading cause of zoonotic bacterial gastroenteritis in humans with chicken meat implicated as a source of infection. Campylobacter jejuni colonises the lower gastrointestinal tract of poultry and during processing is spread from the gastrointestinal tract onto the surface of dressed carcasses. Controlling or eliminating C.jejuni on-farm is considered to be one of the best strategies for reducing human infection. Molecules on the cell surface of C.jejuni interact with the host to facilitate its colonisation and persistence in the gastrointestinal tract of poultry. We used a subtractive phage-display protocol to affinity select for peptides binding to the cell surface of a poultry isolate of C.jejuni with the aim of finding peptides that could be used to control this microorganism in chickens. In total, 27 phage peptides, representing 11 unique clones, were found to inhibit the growth of C.jejuni by up to 99.9% in vitro. One clone was bactericidal, reducing the viability of C.jejuni by 87% in vitro. The phage peptides were highly specific. They completely inhibited the growth of two of the four poultry isolates of C.jejuni tested with no activity detected towards other Gram-negative and Gram-positive bacteria.

  19. Autostereoscopic display concept with time-sequential wavelength-selective filter-barrier

    NASA Astrophysics Data System (ADS)

    Jurk, Silvio; Kuhlmey, Mathias; Bartmann, Roland; Duckstein, Bernd; de la Barré, René

    2016-03-01

    A spatially multiplexed autostereoscopic 3D display design with a strip barrier consisting of RGB-color filters is presented. The wavelength selective filter barrier emits the light from a display area larger than that of common autostereoscopic barrier displays. However, such construction is still used rather rarely. The time sequential operation mode is a supplemental option. Wavelength selective filter barrier arrangements exhibit characteristics different from common barrier displays with similar barrier pitch and ascent. In particular these constructions show strong angular luminance dependency under barrier inclination specified by correspondent slant angle. In time sequential implementation it is important to avoid that quick eye or eyelid movement lead to visible color artifacts. Those circumstances limit the possibility to find well working and usable display designs superior to usual barrier displays. The newly introduced design is usable as a multi user display as well as a single user system with user adaptive control. In case of tracked single user mode the adaption in x-z-direction is continuously. The design has been modelled with simulation software developed for that purpose. The modelling of wavelength-selective barriers was used to calculate the light ray distribution properties of that arrangement. For the experimental verification of the image separation and evaluation of image quality, commercially available display components were combined for a display demonstrator.

  20. An experimental framework for improved selection of binding proteins using SNAP display.

    PubMed

    Houlihan, Gillian; Gatti-Lafranconi, Pietro; Kaltenbach, Miriam; Lowe, David; Hollfelder, Florian

    2014-03-01

    Display technologies (e.g. phage and ribosome display) are powerful tools for selecting and evolving protein binders against various target molecules. SNAP display is a DNA display technology that is conducted entirely in vitro: DNA encoding a library of variants is encapsulated in water-in-oil droplets wherein in vitro protein expression and covalent coupling to the encoding DNA occurs. Here, we explore critical factors for the successful performance of SNAP display based on a set of experiments designed to measure and quantify to what extent they affect selection efficiency. We find that, in SNAP display, the reconstituted cell free expression system PURExpress led to 1.5-fold more active protein and achieved 3.5-fold greater DNA recovery in model selections compared to the RTS 100 Escherichia coli lysate based expression system. We report on the influence parameters including droplet occupancy, valency and selection stringency have on recovery and enrichment. An improved procedure involving bivalent display and stringent selection against a model target, Her2, led to a 10(7)-fold enrichment of a DARPin (H10-2-G3, known to bind Her2 with picomolar affinity) over a non-binding DARPin after three rounds of selection. Furthermore, when spiked into a mixture of DARPins with different affinities, DARPin H10-2-G3 outcompeted all other variants demonstrating SNAP display's ability to efficiently resolve clones with affinities in the nano- to picomolar range. These data establish SNAP display as an in vitro protein engineering tool for isolating protein binders and provide a framework for troubleshooting affinity selections.

  1. In Vitro Selection of Proteins with Desired Characteristics Using mRNA-display

    PubMed Central

    Valencia, C. Alexander; Zou, Jianwei; Liu, Rihe

    2013-01-01

    mRNA-display is an amplification-based, iterative rounds of in vitro protein selection technique that circumvents a number of difficulties associated with yeast two-hybrid and phage display. Because of the covalent linkage between the genotype and the phenotype, mRNA-display provides a powerful means for reading and amplifying a peptide or protein sequence after it has been selected from a library with very high diversity. The purpose of this article is to provide a summary of the field and practical framework of mRNA-display-based selections. We summarize the advantages and limitations of selections using mRNA-display as well as the recent applications, namely, the identification of novel affinity reagents, target-binding partners, and enzyme substrates from synthetic peptide or natural proteome libraries. Practically, we provide a detailed procedure for performing mRNA-display-based selections with the aim of identifying protease substrates and binding partners of a target protein. Furthermore, we describe how to confirm the function of the selected protein sequences by biochemical assays and bioinformatic tools. PMID:23201412

  2. Subtractive Phage Display Selection from Canine Visceral Leishmaniasis Identifies Novel Epitopes That Mimic Leishmania infantum Antigens with Potential Serodiagnosis Applications

    PubMed Central

    Costa, Lourena E.; Lima, Mayara I. S.; Chávez-Fumagalli, Miguel A.; Menezes-Souza, Daniel; Martins, Vivian T.; Duarte, Mariana C.; Lage, Paula S.; Lopes, Eliane G. P.; Lage, Daniela P.; Ribeiro, Tatiana G.; Andrade, Pedro H. R.; de Magalhães-Soares, Danielle F.; Soto, Manuel; Tavares, Carlos A. P.; Goulart, Luiz R.

    2014-01-01

    Visceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy and Trypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected with Leishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n = 31) compared to those from vaccinated dogs (n = 21), experimentally infected dogs with cross-reactive parasites (n = 23), and healthy controls (n = 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no cross-reactivity with T. cruzi- or Ehrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes of L. infantum antigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programs. PMID:24256622

  3. Ribosome display for selection of active dihydrofolate reductase mutants using immobilized methotrexate on agarose beads.

    PubMed

    Takahashi, Fumio; Ebihara, Takashi; Mie, Masayasu; Yanagida, Yasuko; Endo, Yaeta; Kobatake, Eiry; Aizawa, Masuo

    2002-03-01

    Ribosome display was applied to the selection of an enzyme. As a model, we selected and amplified the dihydrofolate reductase (DHFR) gene by ribosome display utilizing a wheat germ cell-free protein synthesis system based on binding affinity to its substrate analog, methotrexate, immobilized on agarose beads. After three rounds of selection, the DHFR gene could be effectively selected and preferentially amplified from a small proportion in a mixture also containing competitive genes. Active enzymes were expressed and amplified and by sequence analysis, four mutants of DHFR were identified. These mutants showed as much activity as the wild-type enzyme.

  4. Pigeon circoviruses display patterns of recombination, genomic secondary structure and selection similar to those of beak and feather disease viruses.

    PubMed

    Stenzel, Tomasz; Piasecki, Tomasz; Chrząstek, Klaudia; Julian, Laurel; Muhire, Brejnev M; Golden, Michael; Martin, Darren P; Varsani, Arvind

    2014-06-01

    Pigeon circovirus (PiCV) has a ~2 kb genome circular ssDNA genome. All but one of the known PiCV isolates have been found infecting pigeons in various parts of the world. In this study, we screened 324 swab and tissue samples from Polish pigeons and recovered 30 complete genomes, 16 of which came from birds displaying no obvious pathology. Together with 17 other publicly available PiCV complete genomes sampled throughout the Northern Hemisphere and Australia, we find that PiCV displays a similar degree of genetic diversity to that of the related psittacine-infecting circovirus species, beak and feather disease virus (BFDV). We show that, as is the case with its pathology and epidemiology, PiCV also displays patterns of recombination, genomic secondary structure and natural selection that are generally very similar to those of BFDV. It is likely that breeding facilities play a significant role in the emergence of new recombinant PiCV variants and given that ~50 % of the domestic pigeon population is infected subclinically, all pigeon breeding stocks should be screened routinely for this virus.

  5. Combinatorially selected defense peptides protect plant roots from pathogen infection

    PubMed Central

    Fang, Zhiwei David; Laskey, James G.; Huang, Shaoxing; Bilyeu, Kristin D.; Morris, Roy O.; Schmidt, Francis J.; English, James T.

    2006-01-01

    Agricultural productivity and sustainability are continually challenged by emerging and indigenous pathogens. Currently, many pathogens can be combated only with biocides or environmentally dangerous fumigants. Here, we report a rapid and pathogen-specific strategy to reduce infection by organisms that target plant roots. Combinatorially selected defense peptides, previously shown to effect premature encystment of Phytophthora capsici zoospores, were fused to maize cytokinin oxidase/dehydrogenase as a display scaffold. When expressed in tomato roots, the peptide-scaffold constructs were secreted and accumulated to sufficient concentrations in the rhizosphere to induce zoospore encystment and thereby deter taxis to the root surface. Pathogen infection was significantly inhibited in roots expressing bioactive peptides fused to the maize cytokinin oxidase/dehydrogenase scaffold. This peptide-delivery technology is broadly applicable for rapid development of plant defense attributes against plant pathogens. PMID:17030803

  6. Coupling Binding to Catalysis: Using Yeast Cell Surface Display to Select Enzymatic Activities.

    PubMed

    Zhang, Keya; Bhuripanyo, Karan; Wang, Yiyang; Yin, Jun

    2015-01-01

    We find yeast cell surface display can be used to engineer enzymes by selecting the enzyme library for high affinity binding to reaction intermediates. Here we cover key steps of enzyme engineering on the yeast cell surface including library design, construction, and selection based on magnetic and fluorescence-activated cell sorting. PMID:26060080

  7. Coupling Binding to Catalysis: Using Yeast Cell Surface Display to Select Enzymatic Activities.

    PubMed

    Zhang, Keya; Bhuripanyo, Karan; Wang, Yiyang; Yin, Jun

    2015-01-01

    We find yeast cell surface display can be used to engineer enzymes by selecting the enzyme library for high affinity binding to reaction intermediates. Here we cover key steps of enzyme engineering on the yeast cell surface including library design, construction, and selection based on magnetic and fluorescence-activated cell sorting.

  8. Phage display selects for amylases with improved low pH starch-binding.

    PubMed

    Verhaert, Raymond M D; Beekwilder, Jules; Olsthoorn, René; van Duin, Jan; Quax, Wim J

    2002-06-13

    Directed evolution of secreted industrial enzymes is hampered by the lack of powerful selection techniques. We have explored surface display to select for enzyme variants with improved binding performance on complex polymeric substrates. By a combination of saturation mutagenesis and phage display we selected alpha-amylase variants, which have the ability to bind starch substrate at industrially preferred low pH conditions. First we displayed active alpha-amylase on the surface of phage fd. Secondly we developed a selection system that is based on the ability of alpha-amylase displaying phages to bind to cross-linked starch. This system was used to probe the involvement of specific beta-strands in substrate interaction. Finally, a saturated library of alpha-amylase mutants with one or more amino acid residues changed in their Cbeta4 starch-binding domain was subjected to phage display selection. Mutant molecules with good starch-binding and hydrolytic capacity could be isolated from the phage library by repeated binding and elution of phage particles at lowered pH value. Apart from the wild type alpha-amylase a specific subset of variants, with only changes in three out of the seven possible positions, was selected. All selected variants could hydrolyse starch and heptamaltose at low pH. Interestingly, variants were found with a starch hydrolysis ratio at pH 4.5/7.5 that is improved relative to the wild type alpha-amylase. These data demonstrate that useful alpha-amylase mutants can be selected via surface display on the basis of their binding properties to starch at lowered pH values.

  9. [2011 news in infections diseases: selected readings].

    PubMed

    Baumgartner, J-D; Christin, L

    2012-01-11

    A study published in 1998 linking MMR vaccine and autism was recently retracted by the Lancet because the data were falsified. The impressive reduction of invasive pneumococcal diseases with the 7-valent pneumococcal conjugate vaccine is due to a more than 90% reduction in rates of infections due to vaccinal serotypes at the expense of a slight increase in non-vaccinal serotypes. Genes encoding resistance factors to several antibiotic classes were detected in 30000-year-old samples. New Delhi metallo-beta-lactamase 1 was frequently detected in street water in New Dehli. Azithromycin decreased COPD exacerbations in a select group of patients with COPD at the cost of more frequent small decrements in hearing. Cranberry juice did not prevent recurrent urinary tract infections. Some patients with persistent symptoms after Lyme disease had higher levels of anti-Borrelia antibodies than cured patients. PMID:22303737

  10. Picomolar affinity antibodies from a fully synthetic naive library selected and evolved by ribosome display.

    PubMed

    Hanes, J; Schaffitzel, C; Knappik, A; Plückthun, A

    2000-12-01

    Here we applied ribosome display to in vitro selection and evolution of single-chain antibody fragments (scFvs) from a large synthetic library (Human Combinatorial Antibody Library; HuCAL) against bovine insulin. In three independent ribosome display experiments different clusters of closely related scFvs were selected, all of which bound the antigen with high affinity and specificity. All selected scFvs had affinity-matured up to 40-fold compared to their HuCAL progenitors, by accumulating point mutations during the ribosome display cycles. The dissociation constants of the isolated scFvs were as low as 82 pM, which validates the design of the naïve library and the power of this evolutionary method. We have thus mimicked the process of antibody generation and affinity maturation with a synthetic library in a cell-free system in just a few days, obtaining molecules with higher affinities than most natural antibodies.

  11. High affinity nanobodies against human epidermal growth factor receptor selected on cells by E. coli display

    PubMed Central

    Salema, Valencio; Mañas, Carmen; Cerdán, Lidia; Piñero-Lambea, Carlos; Marín, Elvira; Roovers, Rob C.; Van Bergen en Henegouwen, Paul M.P.; Fernández, Luis Ángel

    2016-01-01

    ABSTRACT Most therapeutic antibodies (Abs) target cell surface proteins on tumor and immune cells. Cloning of Ab gene libraries in E. coli and their display on bacteriophages is commonly used to select novel therapeutic Abs binding target antigens, either purified or expressed on cells. However, the sticky nature of bacteriophages renders phage display selections on cells challenging. We previously reported an E. coli display system for expression of VHHs (i.e., nanobodies, Nbs) on the surface of bacteria and selection of high-affinity clones by magnetic cell sorting (MACS). Here, we demonstrate that E. coli display is also an attractive method for isolation of Nbs against cell surface antigens, such as the epidermal growth factor receptor (EGFR), upon direct selection and screening of Ab libraries on live cells. We employ a whole cell-based strategy using a VHH library obtained by immunization with human tumor cells over-expressing EGFR (i.e., A431), and selection of bacterial clones bound to murine fibroblast NIH-3T3 cells transfected with human EGFR, after depletion of non-specific clones on untransfected cells. This strategy resulted in the isolation of high-affinity Nbs binding distinct epitopes of EGFR, including Nbs competing with the ligand, EGF, as characterized by flow cytometry of bacteria displaying the Nbs and binding assays with purified Nbs using surface plasmon resonance. Hence, our study demonstrates that E. coli display of VHH libraries and selection on cells enables efficient isolation and characterization of high-affinity Nbs against cell surface antigens. PMID:27472381

  12. Phage Display Selection of Cyclic Peptides That Inhibit Andes Virus Infection▿

    PubMed Central

    Hall, Pamela R.; Hjelle, Brian; Njus, Hadya; Ye, Chunyan; Bondu-Hawkins, Virginie; Brown, David C.; Kilpatrick, Kathleen A.; Larson, Richard S.

    2009-01-01

    Specific therapy is not available for hantavirus cardiopulmonary syndrome caused by Andes virus (ANDV). Peptides capable of blocking ANDV infection in vitro were identified using antibodies against ANDV surface glycoproteins Gn and Gc to competitively elute a cyclic nonapeptide-bearing phage display library from purified ANDV particles. Phage was examined for ANDV infection inhibition in vitro, and nonapeptides were synthesized based on the most-potent phage sequences. Three peptides showed levels of viral inhibition which were significantly increased by combination treatment with anti-Gn- and anti-Gc-targeting peptides. These peptides will be valuable tools for further development of both peptide and nonpeptide therapeutic agents. PMID:19515773

  13. Phage-displayed peptides as capture antigens in an innovative assay for Taenia saginata-infected cattle.

    PubMed

    Fogaça, Rafaela L; Capelli-Peixoto, Janaína; Yamanaka, Isabel B; de Almeida, Rodrigo P M; Muzzi, João Carlos D; Borges, Mariangela; Costa, Alvimar J; Chávez-Olortegui, Carlos; Thomaz-Soccol, Vanete; Alvarenga, Larissa M; de Moura, Juliana

    2014-11-01

    Bovine cysticercosis is detected during the routine post mortem examination of carcasses by visual inspection (knife and eye method). However, the sensitivity of this procedure is several times lower than immunoassays, even when it is performed by qualified professionals. In the present study, a new generation capture antigens were screened from a phage display peptide library using antibodies from Taenia saginata-infected animals. Eight phage clones were selected, and one, Tsag 3 (VHTSIRPRCQPRAITPR), produced similar results to the T. saginata metacestode crude antigen (TsCa) when used as a capture antigen in an ELISA. The phage-displayed peptides competed with TsCa for binding sites, reducing the reactivity by approximately 30 %. Alanine scanning indicated that proline, arginine, and serine are important residues for antibody binding. Tsag 1 (HFYQITWLPNTFPAR), the most frequent affinity-selected clone, and Tsag 6 (YRWPSTPSASRQATL) shared similarity with highly conserved proteins from the Taeniidae family with known immunogenicity. Due to their epitopic or mimotopic properties, these affinity-selected phages could contribute to the rational design of an ante mortem immunodiagnosis method for bovine cysticercosis, as well as an epitope-based vaccine to interrupt the taeniosis/cysticercosis complex. PMID:25081558

  14. Nanodiscs allow phage display selection for ligands to non-linear epitopes on membrane proteins.

    PubMed

    Pavlidou, Marina; Hänel, Karen; Möckel, Luis; Willbold, Dieter

    2013-01-01

    In this work, we exploited a method that uses polytopic membrane proteins as targets for phage display selections. Membrane proteins represent the largest class of drug targets and drug discovery is mostly based on the identification of ligands binding to target molecules. The screening of a phage display library for ligands against membrane proteins is typically hindered by the requirement of these proteins for a membrane environment, which is necessary to retain correct folding and epitope formation. Especially in proteins with multiple transmembrane domains, epitopes often are non-linear and consist of a combination of loops between transmembrane stretches of the proteins. Here, we have used bacteriorhodopsin (bR) as a model of polytopic membrane protein, assembled into nanoscale phospholipid bilayers, so called nanodiscs, to screen a phage display library for potential ligands. Nanodiscs provide a native-like environment to membrane proteins and thus selection of ligands can take place in a near physiological state. Screening a 12-mer phage display peptide library against bR nanodiscs led to the isolation of phage clones binding specifically to bR. We were further able to identify the binding site of selected phage clones proving that the clones bind to extramembranous, non-linear epitopes of bR. Thus, nanodiscs provide a suitable and general tool that allows screening of a phage display library against membrane proteins in a near native environment.

  15. Pseudo-nitzschia Challenged with Co-occurring Viral Communities Display Diverse Infection Phenotypes.

    PubMed

    Carlson, Michael C G; McCary, Nicolette D; Leach, Terence S; Rocap, Gabrielle

    2016-01-01

    Viruses are catalysts of biogeochemical cycling, architects of microbial community structure, and terminators of phytoplankton blooms. Viral lysis of diatoms, a key group of eukaryotic phytoplankton, has the potential to impact carbon export and marine food webs. However, the impact of viruses on diatom abundance and community composition is unknown. Diatom-virus dynamics were explored by sampling every month at two coastal and estuarine locations in Washington state, USA resulting in 41 new isolates of the pennate diatom Pseudo-nitzschia and 20 environmental virus samples. We conducted a total of 820 pair-wise crosses of the Pseudo-nitzschia isolates and viral communities. Viral communities infected Pseudo-nitzschia isolates in 8% of the crosses overall and 16% of crosses when the host and viral communities were isolated from the same sample. Isolates ranged in their permissivity to infection with some isolates not infected by any viral samples and others infected by up to 10 viral communities. Isolates that were infected by the most viral communities also had the highest maximum observed viral titers (as high as 16000 infectious units ml(-1)). Titers of the viral communities were host dependent, as titers for one viral sample on eight different hosts spanned four orders of magnitude. Sequencing of the Pseudo-nitzschia Internal Transcribed Spacer 1 (ITS1) of the revealed multiple subgroups of hosts with 100% ITS1 identities that were infected by different viral communities. Indeed, we repeatedly isolated groups of isolates with identical ITS1 sequences from the same water sample that displayed different viral infection phenotypes. The interactions between Pseudo-nitzschia and the viral communities highlight the diversity of diatoms and emphasize the complexity and variability of diatom-virus dynamics in the ocean.

  16. Pseudo-nitzschia Challenged with Co-occurring Viral Communities Display Diverse Infection Phenotypes.

    PubMed

    Carlson, Michael C G; McCary, Nicolette D; Leach, Terence S; Rocap, Gabrielle

    2016-01-01

    Viruses are catalysts of biogeochemical cycling, architects of microbial community structure, and terminators of phytoplankton blooms. Viral lysis of diatoms, a key group of eukaryotic phytoplankton, has the potential to impact carbon export and marine food webs. However, the impact of viruses on diatom abundance and community composition is unknown. Diatom-virus dynamics were explored by sampling every month at two coastal and estuarine locations in Washington state, USA resulting in 41 new isolates of the pennate diatom Pseudo-nitzschia and 20 environmental virus samples. We conducted a total of 820 pair-wise crosses of the Pseudo-nitzschia isolates and viral communities. Viral communities infected Pseudo-nitzschia isolates in 8% of the crosses overall and 16% of crosses when the host and viral communities were isolated from the same sample. Isolates ranged in their permissivity to infection with some isolates not infected by any viral samples and others infected by up to 10 viral communities. Isolates that were infected by the most viral communities also had the highest maximum observed viral titers (as high as 16000 infectious units ml(-1)). Titers of the viral communities were host dependent, as titers for one viral sample on eight different hosts spanned four orders of magnitude. Sequencing of the Pseudo-nitzschia Internal Transcribed Spacer 1 (ITS1) of the revealed multiple subgroups of hosts with 100% ITS1 identities that were infected by different viral communities. Indeed, we repeatedly isolated groups of isolates with identical ITS1 sequences from the same water sample that displayed different viral infection phenotypes. The interactions between Pseudo-nitzschia and the viral communities highlight the diversity of diatoms and emphasize the complexity and variability of diatom-virus dynamics in the ocean. PMID:27148216

  17. Pseudo-nitzschia Challenged with Co-occurring Viral Communities Display Diverse Infection Phenotypes

    PubMed Central

    Carlson, Michael C. G.; McCary, Nicolette D.; Leach, Terence S.; Rocap, Gabrielle

    2016-01-01

    Viruses are catalysts of biogeochemical cycling, architects of microbial community structure, and terminators of phytoplankton blooms. Viral lysis of diatoms, a key group of eukaryotic phytoplankton, has the potential to impact carbon export and marine food webs. However, the impact of viruses on diatom abundance and community composition is unknown. Diatom-virus dynamics were explored by sampling every month at two coastal and estuarine locations in Washington state, USA resulting in 41 new isolates of the pennate diatom Pseudo-nitzschia and 20 environmental virus samples. We conducted a total of 820 pair-wise crosses of the Pseudo-nitzschia isolates and viral communities. Viral communities infected Pseudo-nitzschia isolates in 8% of the crosses overall and 16% of crosses when the host and viral communities were isolated from the same sample. Isolates ranged in their permissivity to infection with some isolates not infected by any viral samples and others infected by up to 10 viral communities. Isolates that were infected by the most viral communities also had the highest maximum observed viral titers (as high as 16000 infectious units ml-1). Titers of the viral communities were host dependent, as titers for one viral sample on eight different hosts spanned four orders of magnitude. Sequencing of the Pseudo-nitzschia Internal Transcribed Spacer 1 (ITS1) of the revealed multiple subgroups of hosts with 100% ITS1 identities that were infected by different viral communities. Indeed, we repeatedly isolated groups of isolates with identical ITS1 sequences from the same water sample that displayed different viral infection phenotypes. The interactions between Pseudo-nitzschia and the viral communities highlight the diversity of diatoms and emphasize the complexity and variability of diatom-virus dynamics in the ocean. PMID:27148216

  18. Direct selection and phage display of a Gram-positive secretome

    PubMed Central

    Jankovic, Dragana; Collett, Michael A; Lubbers, Mark W; Rakonjac, Jasna

    2007-01-01

    Surface, secreted and transmembrane protein-encoding open reading frames, collectively the secretome, can be identified in bacterial genome sequences using bioinformatics. However, functional analysis of translated secretomes is possible only if many secretome proteins are expressed and purified individually. We have now developed and applied a phage display system for direct selection, identification, expression and purification of bacterial secretome proteins. PMID:18078523

  19. Individual Plasmodium vivax msp1 Variants within Polyclonal P. vivax Infections Display Different Propensities for Relapse

    PubMed Central

    Juliano, Jonathan J.; Kharabora, Oksana; Sem, Rithy; Lin, Feng-Chang; Muth, Sinuon; Ménard, Didier; Wongsrichanalai, Chansuda; Rogers, William O.; Meshnick, Steven R.

    2012-01-01

    Using a newly developed Plasmodium vivax merozoite surface protein 1 gene (Pvmsp1) heteroduplex tracking assay, we genotyped 107 P. vivax infections in individuals from Cambodia, 45 of whom developed recurrent parasitemia within 42 days. The majority of isolates were polyclonal, but recurrent parasitemias displayed fewer variants compared to initial parasitemias. Two Pvmsp1 gene variants occurred more frequently in the initial genotypes of those who developed recurrent parasitemia, representing the first time P. vivax variants associated with a higher risk of relapse have been described. PMID:22205791

  20. Identification of a copper chaperone from tomato fruits infected with Botrytis cinerea by differential display.

    PubMed

    Company, Patricia; González-Bosch, Carmen

    2003-05-16

    Differential display was used to isolate tomato genes responding to fungal infection. Here we describe the isolation and characterization of a gene that is down-regulated in tomato fruits infected with the phytopathogen Botrytis cinerea. The cDNA identified encodes a protein that shares sequence similarity to the amino terminal region of CCH, a copper chaperone from Arabidopsis thaliana, that participates in intracellular copper homeostasis by delivering Cu to the secretory pathway. The fact that this newly characterized tomato gene, referred to as LeCCH (Lycopersicon esculentum copper chaperone), be differentially expressed after fungal infection, suggests an interesting relationship between copper homeostasis and plant defense responses. LeCCH contains the conserved metal-binding domain MXCXGC but interestingly, lacks the C-terminal extension present in previously described plant members of this copper chaperone family, that seems to be involved in metallochaperone intercellular transport. This fact indicates that LeCCH is a novel plant copper chaperone that could act locally at the infection site, affecting the copper homeostasis in this particular stress situation.

  1. The use of scFv-displaying yeast in mammalian cell surface selections.

    PubMed

    Wang, Xin Xiang; Shusta, Eric V

    2005-09-01

    Yeast surface display has proven to be a powerful tool for the directed evolution of immunological proteins when soluble ligands are available (Cho, B.K., Kieke, M.C., Boder, E.T., Wittrup, K.D., Kranz, D.M., 1998. A yeast surface display system for the discovery of ligands that trigger cell activation. J. Immunol. Methods 220, 179; Boder, E.T., Midelfort, K.S., Wittrup, K.D., 2000. Directed evolution of antibody fragments with monovalent femtomolar antigen-binding affinity. Proc. Natl. Acad. Sci. U. S. A. 97, 10701; Shusta, E.V., Holler, P.D., Kieke, M.C., Kranz, D.M., Wittrup, K.D., 2000. Directed evolution of a stable scaffold for T-cell receptor engineering. Nat. Biotechnol. 18, 754; Esteban, O., Zhao, H., 2004. Directed evolution of soluble single-chain human class II MHC molecules. J. Mol. Biol. 340, 81). This investigation extends the utility of this display platform by demonstrating its capacity for use in cell panning selections. This was accomplished by employing a model single-chain antibody (scFv)-hapten system that allowed for detailed investigation of the factors governing panning success. Yeast displaying anti-fluorescein scFv (4-4-20) exhibited specific interactions with the fluoresceinated endothelial cells and could be recovered from large backgrounds of irrelevant yeast in just three rounds. Successful selections required as few as 1700 fluorescein ligands per cell, and a three-round enrichment ratio of 10(6) was possible. These results indicate that yeast surface display is a viable option for use in cell or tissue-based selections.

  2. Selection of functional T cell receptor mutants from a yeast surface-display library.

    PubMed

    Kieke, M C; Shusta, E V; Boder, E T; Teyton, L; Wittrup, K D; Kranz, D M

    1999-05-11

    The heterodimeric alphabeta T cell receptor (TCR) for antigen is the key determinant of T cell specificity. The structure of the TCR is very similar to that of antibodies, but the engineering of TCRs by directed evolution with combinatorial display libraries has not been accomplished to date. Here, we report that yeast surface display of a TCR was achieved only after the mutation of specific variable region residues. These residues are located in two regions of the TCR, at the interface of the alpha- and beta-chains and in the beta-chain framework region that is thought to be in proximity to the CD3 signal-transduction complex. The mutations are encoded naturally in many antibody variable regions, indicating specific functional differences that have not been appreciated between TCRs and antibodies. The identification of these residues provides an explanation for the inherent difficulties in the display of wild-type TCRs compared with antibodies. Yeast-displayed mutant TCRs bind specifically to the peptide/MHC antigen, enabling engineering of soluble T cell receptors as specific T cell antagonists. This strategy of random mutagenesis followed by selection for surface expression may be of general use in the directed evolution of other eukaryotic proteins that are refractory to display.

  3. Identification of a Novel Lysosomal Trafficking Peptide using Phage Display Biopanning Coupled with Endocytic Selection Pressure

    PubMed Central

    2015-01-01

    Methods to select ligands that accumulate specifically in cancer cells and traffic through a defined endocytic pathway may facilitate rapid pairing of ligands with linkers suitable for drug conjugate therapies. We performed phage display biopanning on cancer cells that are treated with selective inhibitors of a given mechanism of endocytosis. Using chlorpromazine to inhibit clathrin-mediated endocytosis in H1299 nonsmall cell lung cancer cells, we identified two clones, ATEPRKQYATPRVFWTDAPG (15.1) and a novel peptide LQWRRDDNVHNFGVWARYRL (H1299.3). The peptides segregate by mechanism of endocytosis and subsequent location of subcellular accumulation. The H1299.3 peptide primarily utilizes clathrin-mediated endocytosis and colocalizes with Lamp1, a lysosomal marker. Conversely, the 15.1 peptide is clathrin-independent and localizes to a perinuclear region. Thus, this novel phage display scheme allows for selection of peptides that selectively internalize into cells via a known mechanism of endocytosis. These types of selections may allow for better matching of linker with targeting ligand by selecting ligands that internalize and traffic to known subcellular locations. PMID:25188559

  4. Advanced display object selection methods for enhancing user-computer productivity

    NASA Technical Reports Server (NTRS)

    Osga, Glenn A.

    1993-01-01

    The User-Interface Technology Branch at NCCOSC RDT&E Division has been conducting a series of studies to address the suitability of commercial off-the-shelf (COTS) graphic user-interface (GUI) methods for efficiency and performance in critical naval combat systems. This paper presents an advanced selection algorithm and method developed to increase user performance when making selections on tactical displays. The method has also been applied with considerable success to a variety of cursor and pointing tasks. Typical GUI's allow user selection by: (1) moving a cursor with a pointing device such as a mouse, trackball, joystick, touchscreen; and (2) placing the cursor on the object. Examples of GUI objects are the buttons, icons, folders, scroll bars, etc. used in many personal computer and workstation applications. This paper presents an improved method of selection and the theoretical basis for the significant performance gains achieved with various input devices tested. The method is applicable to all GUI styles and display sizes, and is particularly useful for selections on small screens such as notebook computers. Considering the amount of work-hours spent pointing and clicking across all styles of available graphic user-interfaces, the cost/benefit in applying this method to graphic user-interfaces is substantial, with the potential for increasing productivity across thousands of users and applications.

  5. Selection of Ceratitis capitata (Diptera: Tephritidae) Specific Recombinant Monoclonal Phage Display Antibodies for Prey Detection Analysis

    PubMed Central

    Monzó, César; Urbaneja, Alberto; Ximénez-Embún, Miguel; García-Fernández, Julia; García, José Luis; Castañera, Pedro

    2012-01-01

    Several recombinant antibodies against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), one of the most important pests in agriculture worldwide, were selected for the first time from a commercial phage display library of human scFv antibodies. The specificity and sensitivity of the selected recombinant antibodies were compared with that of a rabbit polyclonal serum raised in parallel using a wide range of arthropod species as controls. The selected recombinant monoclonal antibodies had a similar or greater specificity when compared with classical monoclonal antibodies. The selected recombinant antibodies were successfully used to detect the target antigen in the gut of predators and the scFv antibodies were sequenced and compared. These results demonstrate the potential for recombinant scFv antibodies to be used as an alternative to the classical monoclonal antibodies or even molecular probes in the post-mortem analysis studies of generalist predators. PMID:23272105

  6. Molecular epidemiology of selected sexually transmitted infections.

    PubMed

    Jalal, Hamid; Delaney, Andrew; Bentley, Neil; Sonnex, Christopher; Carne, Christopher A

    2013-01-01

    Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG) are established pathogens for human genital tract. However, the role of Ureaplasma urealyticum (UU) and Ureaplasma parvum (UP) in genital pathology is poorly unerstood. A prospective study to investigate the prevalence of above infections was performed on a cohort of 1,718 consecutive patients attending a Genitourinary Medicine (GUM) clinic. A previously published in-house real-time PCR assay, for the detection of CT DNA in genital swabs, was modified for this study. Two amplification reactions detected the DNAs of TV, NG, MG, CT, UU and UP in genital swabs from 4 (0.2%), 11 (0.6%), 17 (1%), 129 (8%), 282 (16%) and 636 (37%) patients, respectively. 594 (70%) of 848 women and 333 (38%) of 870 men were infected with at least one type of microorganism. Among 594 infected females, 485 (82%) had a single infection, 97 (16%) had a double infection, and 12 (2%) had a triple infection. Of the 333 infected men, 304 (91%) had a single infection, 27 (8%) had a double infection, and 2 (1%) had a triple infection. The prevalence of infection in both genders decreased with increasing age. The prevalence proportion of UP was significantly higher in women (54%) compared with men (18%). The high prevalence of UU and UP suggests that these bacteria are commensals of genital tract.

  7. Molecular epidemiology of selected sexually transmitted infections.

    PubMed

    Jalal, Hamid; Delaney, Andrew; Bentley, Neil; Sonnex, Christopher; Carne, Christopher A

    2013-01-01

    Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG) are established pathogens for human genital tract. However, the role of Ureaplasma urealyticum (UU) and Ureaplasma parvum (UP) in genital pathology is poorly unerstood. A prospective study to investigate the prevalence of above infections was performed on a cohort of 1,718 consecutive patients attending a Genitourinary Medicine (GUM) clinic. A previously published in-house real-time PCR assay, for the detection of CT DNA in genital swabs, was modified for this study. Two amplification reactions detected the DNAs of TV, NG, MG, CT, UU and UP in genital swabs from 4 (0.2%), 11 (0.6%), 17 (1%), 129 (8%), 282 (16%) and 636 (37%) patients, respectively. 594 (70%) of 848 women and 333 (38%) of 870 men were infected with at least one type of microorganism. Among 594 infected females, 485 (82%) had a single infection, 97 (16%) had a double infection, and 12 (2%) had a triple infection. Of the 333 infected men, 304 (91%) had a single infection, 27 (8%) had a double infection, and 2 (1%) had a triple infection. The prevalence of infection in both genders decreased with increasing age. The prevalence proportion of UP was significantly higher in women (54%) compared with men (18%). The high prevalence of UU and UP suggests that these bacteria are commensals of genital tract. PMID:24046809

  8. Preferential germline usage and VH/VL pairing observed in human antibodies selected by mRNA display.

    PubMed

    Chen, Lei; Kutskova, Yuliya A; Hong, Feng; Memmott, John E; Zhong, Suju; Jenkinson, Megan D; Hsieh, Chung-Ming

    2015-10-01

    Since the invention of phage display, in vitro antibody display technologies have revolutionized the field of antibody discovery. In combination with antibody libraries constructed with sequences of human origin, such technologies enable accelerated therapeutic antibody discovery while bypassing the laborious animal immunization and hybridoma generation processes. Many in vitro display technologies developed since aim to differentiate from phage display by displaying full-length IgG proteins, utilizing eukaryotic translation system and codons, increasing library size or real-time kinetic selection by fluorescent activated cell sorting. We report here the development of an mRNA display technology and an accompanying HCDR3 size spectratyping monitor for human antibody discovery. Importantly, the mRNA display technology maintains a monovalent linkage between the mRNA (genotype) and display binding protein (phenotype), which minimizes avidity effect common in other display systems and allows for a stringent affinity and off-rate selection. The mRNA display technology successfully identified 100 human antibodies in 15 different selections against various targets from naïve human antibody libraries. These antibodies in general have high affinity and diversity. By analyzing the germline usage and combination of antibodies selected by the mRNA display technology, we identified trends and determined the productivity of each germline subgroup in the libraries that could serve as the knowledge base for constructing fully synthetic, next generation antibody libraries.

  9. Affinity and folding properties both influence the selection of antibodies with the selectively infective phage (SIP) methodology.

    PubMed

    Pedrazzi, G; Schwesinger, F; Honegger, A; Krebber, C; Plückthun, A

    1997-10-01

    We investigated which molecules are selected from a model library by the selectively infective phage (SIP) methodology. As a model system, we used the fluorescein binding single-chain Fv fragment FITC-E2, and from a 3D-model, we identified 11 residues potentially involved in hapten binding and mutated them individually to alanines. The binding constant of each mutant was determined by fluorescence titration, and each mutant was tested individually as well as in competitive SIP experiments for infectivity. After three rounds of SIP, only molecules with KD values within a factor of 2 of the tightest binder remain, and among those, a mutant no longer carrying an unnecessary exposed tryptophan residue is preferentially selected. SIP is shown to select for the best overall properties of the displayed molecules, including folding behavior, stability and affinity.

  10. Differential display analysis of gene expression in Etrog citron leaves infected by Citrus viroid III.

    PubMed

    Tessitori, Matilde; Maria, Giovanna; Capasso, Clemente; Catara, Giuliana; Rizza, Serena; De Luca, Viviana; Catara, Antonino; Capasso, Antonio; Carginale, Vincenzo

    2007-04-01

    Citrus are natural hosts of several viroids, which are plant pathogens composed exclusively of a non-protein-coding, small single-stranded circular RNA that is able to replicate autonomously in susceptible hosts. They are responsible for symptoms such as stunting, leaf epinasty, and chlorosis. Citrus viroid III (CVd-III) has been long regarded as a possible dwarfing agent of citrus grafted on trifoliate orange and its hybrids. To investigate molecular mechanisms involved in pathogenesis, the messenger RNA (mRNA) differential display technique was here applied to identify genes whose transcription was significantly altered in leaves of Etrog citron (Citrus medica) infected by CVd-III (variant b). Of eighteen genes identified, thirteen were up-regulated by viroid infection, while five were down-regulated. Except for two genes that encode proteins of unknown function, the remaining genes are mainly involved in plant defence/stress responses, signal transduction, amino acid transport, and cell wall structure. Among the up-regulated genes, it is noteworthy a suppressor of RNA silencing that might be involved in viroid and virus pathogenicity. The functions of these genes are discussed.

  11. A DNA-based system for selecting and displaying the combined result of two input variables

    PubMed Central

    Liu, Huajie; Wang, Jianbang; Song, Shiping; Fan, Chunhai; Gothelf, Kurt V.

    2015-01-01

    Oligonucleotide-based technologies for biosensing or bio-regulation produce huge amounts of rich high-dimensional information. There is a consequent need for flexible means to combine diverse pieces of such information to form useful derivative outputs, and to display those immediately. Here we demonstrate this capability in a DNA-based system that takes two input numbers, represented in DNA strands, and returns the result of their multiplication, writing this as a number in a display. Unlike a conventional calculator, this system operates by selecting the result from a library of solutions rather than through logic operations. The multiplicative example demonstrated here illustrates a much more general capability—to generate a unique output for any distinct pair of DNA inputs. The system thereby functions as a lookup table and could be a key component in future, more powerful data-processing systems for diagnostics and sensing. PMID:26646059

  12. Highly Selective Salicylketoxime-Based Estrogen Receptor β Agonists Display Antiproliferative Activities in a Glioma Model

    PubMed Central

    2016-01-01

    Estrogen receptor β (ERβ) selective agonists are considered potential therapeutic agents for a variety of pathological conditions, including several types of cancer. Their development is particularly challenging, since differences in the ligand binding cavities of the two ER subtypes α and β are minimal. We have carried out a rational design of new salicylketoxime derivatives which display unprecedentedly high levels of ERβ selectivity for this class of compounds, both in binding affinity and in cell-based functional assays. An endogenous gene expression assay was used to further characterize the pharmacological action of these compounds. Finally, these ERβ-selective agonists were found to inhibit proliferation of a glioma cell line in vitro. Most importantly, one of these compounds also proved to be active in an in vivo xenograft model of human glioma, thus demonstrating the high potential of this type of compounds against this devastating disease. PMID:25559213

  13. Combining Phage and Yeast Cell Surface Antibody Display to Identify Novel Cell Type-Selective Internalizing Human Monoclonal Antibodies.

    PubMed

    Bidlingmaier, Scott; Su, Yang; Liu, Bin

    2015-01-01

    Using phage antibody display, large libraries can be generated and screened to identify monoclonal antibodies with affinity for target antigens. However, while library size and diversity is an advantage of the phage display method, there is limited ability to quantitatively enrich for specific binding properties such as affinity. One way of overcoming this limitation is to combine the scale of phage display selections with the flexibility and quantitativeness of FACS-based yeast surface display selections. In this chapter we describe protocols for generating yeast surface antibody display libraries using phage antibody display selection outputs as starting material and FACS-based enrichment of target antigen-binding clones from these libraries. These methods should be widely applicable for the identification of monoclonal antibodies with specific binding properties. PMID:26060069

  14. Directed Selection of Recombinant Human Monoclonal Antibodies to Herpes Simplex Virus Glycoproteins from Phage Display Libraries

    NASA Astrophysics Data System (ADS)

    Sanna, Pietro Paolo; Williamson, R. Anthony; de Logu, Alessandro; Bloom, Floyd E.; Burton, Dennis R.

    1995-07-01

    Human monoclonal antibodies have considerable potential in the prophylaxis and treatment of viral disease. However, only a few such antibodies suitable for clinical use have been produced to date. We have previously shown that large panels of human recombinant monoclonal antibodies against a plethora of infectious agents, including herpes simplex virus types 1 and 2, can be established from phage display libraries. Here we demonstrate that facile cloning of recombinant Fab fragments against specific viral proteins in their native conformation can be accomplished by panning phage display libraries against viral glycoproteins "captured" from infected cell extracts by specific monoclonal antibodies immobilized on ELISA plates. We have tested this strategy by isolating six neutralizing recombinant antibodies specific for herpes simplex glycoprotein gD or gB, some of which are against conformationally sensitive epitopes. By using defined monoclonal antibodies for the antigen-capture step, this method can be used for the isolation of antibodies to specific regions and epitopes within the target viral protein. For instance, monoclonal antibodies to a nonneutralizing epitope can be used in the capture step to clone antibodies to neutralizing epitopes, or antibodies to a neutralizing epitope can be used to clone antibodies to a different neutralizing epitope. Furthermore, by using capturing antibodies to more immunodominant epitopes, one can direct the cloning to less immunogenic ones. This method should be of value in generating antibodies to be used both in the prophylaxis and treatment of viral infections and in the characterization of the mechanisms of antibody protective actions at the molecular level.

  15. Selection of binding targets in parasites using phage-display and aptamer libraries in vivo and in vitro

    PubMed Central

    Tonelli, R. R.; Colli, W.; Alves, M. J. M.

    2012-01-01

    Parasite infections are largely dependent on interactions between pathogen and different host cell populations to guarantee a successful infectious process. This is particularly true for obligatory intracellular parasites as Plasmodium, Toxoplasma, and Leishmania, to name a few. Adhesion to and entry into the cell are essential steps requiring specific parasite and host cell molecules. The large amount of possible involved molecules poses additional difficulties for their identification by the classical biochemical approaches. In this respect, the search for alternative techniques should be pursued. Among them two powerful methodologies can be employed, both relying upon the construction of highly diverse combinatorial libraries of peptides or oligonucleotides that randomly bind with high affinity to targets on the cell surface and are selectively displaced by putative ligands. These are, respectively, the peptide-based phage display and the oligonucleotide-based aptamer techniques. The phage display technique has been extensively employed for the identification of novel ligands in vitro and in vivo in different areas such as cancer, vaccine development, and epitope mapping. Particularly, phage display has been employed in the investigation of pathogen–host interactions. Although this methodology has been used for some parasites with encouraging results, in trypanosomatids its use is, as yet, scanty. RNA and DNA aptamers, developed by the SELEX process (Systematic Evolution of Ligands by Exponential Enrichment), were described over two decades ago and since then contributed to a large number of structured nucleic acids for diagnostic or therapeutic purposes or for the understanding of the cell biology. Similarly to the phage display technique scarce use of the SELEX process has been used in the probing of parasite–host interaction. In this review, an overall survey on the use of both phage display and aptamer technologies in different pathogenic organisms will

  16. Selection of phage-displayed human antibody fragments on Dengue virus particles captured by a monoclonal antibody: application to the four serotypes.

    PubMed

    Cabezas, Sheila; Rojas, Gertrudis; Pavon, Alequis; Alvarez, Mayling; Pupo, Maritza; Guillen, Gerardo; Guzman, Maria G

    2008-02-01

    Antibody fragments to the four Dengue virus serotypes were isolated from a human universal naïve library using phage display technology. Phage-displayed antibody fragments were selected on Dengue virus particles directly captured from infected Vero cells supernatant by an anti-dengue monoclonal antibody, in order to avoid laborious virus concentration/purification procedures. A total of nine phage-displayed antibody fragments were obtained. Seven of them were highly specific for three of the selector serotypes (two for Dengue 1, four for Dengue 3 and one for Dengue 4). One clone (Dengue 3-selected) cross-reacted with Dengue 1, whereas another (selected with Dengue 2) cross-reacted with the three remaining serotypes. The soluble variants of six antibody fragments recognized their target viruses when used at nanomolar and even subnanomolar concentrations. All phage-displayed antibody fragments were cross-reactive against several strains of distinct genotypes within the corresponding serotype(s). These antibody fragments are potentially useful for the future development of tools for viral diagnosis and serotype identification. The simple phage selection method on captured virus could be applied in a high throughput way to obtain larger panels of antibody fragments to Dengue virus for multiple applications.

  17. Accelerating phage-display library selection by reversible and site-specific biotinylation.

    PubMed

    Koide, Akiko; Wojcik, John; Gilbreth, Ryan N; Reichel, Annett; Piehler, Jacob; Koide, Shohei

    2009-11-01

    Immobilization of a target molecule to a solid support is an indispensable step in phage display library sorting. Here we describe an immobilization method that addresses shortcomings of existing strategies. Our method is based on the use of a polyhistidine-tagged (His-tagged) target molecule and (BT)tris-NTA, a high-affinity capture reagent for His-tags that also contains a biotin moiety. (BT)tris-NTA provides a stable and reversible linkage between a His-tag and a streptavidin-coated solid support. Because His-tags are the de facto standard for recombinant protein purification, this method dramatically simplifies target preparation for phage display library sorting. Here, we demonstrate the utility of this method by selecting high-affinity binding proteins based on the fibronectin type III (FN3) scaffold to two His-tagged protein targets, yeast small ubiquitin-like modifier and maltose-binding protein. Notably, a significant number of FN3 clones binding either targets selected using the new immobilization method exhibited only very weak binding when the same target was immobilized by coating on a polystyrene surface. This suggests that the His-tag-mediated immobilization exposes epitopes that are masked by commonly used passive adsorption methods. Together, these results establish a method with the potential to streamline and enhance many binding-protein engineering experiments. PMID:19737805

  18. Selection of recombinant anti-SH3 domain antibodies by high-throughput phage display.

    PubMed

    Huang, Haiming; Economopoulos, Nicolas O; Liu, Bernard A; Uetrecht, Andrea; Gu, Jun; Jarvik, Nick; Nadeem, Vincent; Pawson, Tony; Moffat, Jason; Miersch, Shane; Sidhu, Sachdev S

    2015-11-01

    Antibodies are indispensable tools in biochemical research and play an expanding role as therapeutics. While hybridoma technology is the dominant method for antibody production, phage display is an emerging technology. Here, we developed and employed a high-throughput pipeline that enables selection of antibodies against hundreds of antigens in parallel. Binding selections using a phage-displayed synthetic antigen-binding fragment (Fab) library against 110 human SH3 domains yielded hundreds of Fabs targeting 58 antigens. Affinity assays demonstrated that representative Fabs bind tightly and specifically to their targets. Furthermore, we developed an efficient affinity maturation strategy adaptable to high-throughput, which increased affinity dramatically but did not compromise specificity. Finally, we tested Fabs in common cell biology applications and confirmed recognition of the full-length antigen in immunoprecipitation, immunoblotting and immunofluorescence assays. In summary, we have established a rapid and robust high-throughput methodology that can be applied to generate highly functional and renewable antibodies targeting protein domains on a proteome-wide scale.

  19. Bombyx mori nucleopolyhedrovirus displaying neospora caninum antigens as a vaccine candidate against N. caninum infection in mice.

    PubMed

    Kato, Tatsuya; Otsuki, Takahiro; Yoshimoto, Mai; Itagaki, Kohei; Kohsaka, Tetsuya; Matsumoto, Yumino; Ike, Kazunori; Park, Enoch Y

    2015-02-01

    Baculovirus display systems have been utilized for cell-specific gene transfer, regenerative medicine, and as vaccine vectors. In particular, baculovirus particles displaying surface antigens have been used as vaccines against some parasites and viruses. In this study, Bombyx mori nucleopolyhedrovirus (BmNPV) particles displaying Neospora caninum antigens (NcSAG1, NcSRS2, and NcMIC3) purified from the hemolymph or fat body of silkworm larvae were prepared to vaccinate mice against N. caninum. Each antigen was expressed on the surface of BmNPV particles through glycoprotein 64 transmembrane and cytoplasmic domains. Antigen-specific antibody production was induced in mice by immunization with each recombinant BmNPV particle. NcMIC3-displaying BmNPV particles purified from the fat body induced a lower antibody titer than particles purified from the hemolymph. Antigen-specific IgG2a was predominantly produced in mice by immunization with NcSAG1-displaying BmNPV particles compared to IgG1, and induction of IFN-γ was dominant, indicating that antigen-displaying BmNPV particles can elicit a Th1 immune response in mice. Semi-quantitative PCR analysis revealed that immunization with each antigen-displaying BmNPV particle partially protected mice from cerebral N. caninum infection. These results suggest that antigen-displaying BmNPV particles can provide an alternative method of controlling neosporosis in cattle and represent a new generation of N. caninum vaccines.

  20. Female discrimination thresholds frequently exceed local male display variation: implications for mate choice dynamics and sexual selection.

    PubMed

    Höbel, G

    2016-03-01

    Among the factors that can influence female mate choice decisions is the degree to which females differentiate among similar displays: as differences decrease, females are expected to eventually stop discriminating. This discrimination threshold, in conjunction with the magnitude of male trait variation females regularly encounter while making mate choice decisions, may have important consequences for sexual selection. If local display variation is above the discrimination threshold, female preferences should translate into higher mating success for the more attractive male. But if display variation is frequently below the threshold, the resulting increased pattern of random mating may obscure the existence of female mate choice. I investigated the interplay between female discrimination and male display variation in green treefrogs (Hyla cinerea) and found that call trait differences between nearest neighbour males were frequently smaller than what females are expected to discriminate. This finding has two important consequences for our understanding of sexual selection in the wild: first, low display variation should weaken the strength of selection on male display traits, but the direction of selection should mirror the one predicted from females choice trials. Second, caution is needed when interpreting data on realized mating success in the wild: a pattern of random mating with respect to male display traits does not always mean that female preferences are weak or that conditions are too challenging for females to express their preferences. Rather, insufficient display variation can generate the same pattern. PMID:26663413

  1. Selective inhibitors of digestive enzymes from Aedes aegypti larvae identified by phage display.

    PubMed

    Soares, Tatiane Sanches; Soares Torquato, Ricardo Jose; Alves Lemos, Francisco Jose; Tanaka, Aparecida Sadae

    2013-01-01

    Dengue is a serious disease transmitted by the mosquito Aedes aegypti during blood meal feeding. It is estimated that the dengue virus is transmitted to millions of individuals each year in tropical and subtropical areas. Dengue control strategies have been based on controlling the vector, Ae. aegypti, using insecticide, but the emergence of resistance poses new challenges. The aim of this study was the identification of specific protease inhibitors of the digestive enzymes from Ae. aegypti larvae, which may serve as a prospective alternative biocontrol method. High affinity protein inhibitors were selected by all of the digestive serine proteases of the 4th instar larval midgut, and the specificity of these inhibitors was characterized. These inhibitors were obtained from a phage library displaying variants of HiTI, a trypsin inhibitor from Haematobia irritans, that are mutated in the reactive loop (P1-P4'). Based on the selected amino acid sequence pattern, seven HiTI inhibitor variants were cloned, expressed and purified. The results indicate that the HiTI variants named T6 (RGGAV) and T128 (WNEGL) were selected by larval trypsin-like (IC(50) of 1.1 nM) and chymotrypsin-like enzymes (IC(50) of 11.6 nM), respectively. The variants T23 (LLGGL) and T149 (GGVWR) inhibited both larval chymotrypsin-like (IC(50) of 4.2 nM and 29.0 nM, respectively) and elastase-like enzymes (IC(50) of 1.2 nM for both). Specific inhibitors were successfully obtained for the digestive enzymes of Ae. aegypti larvae by phage display. Our data also strongly suggest the presence of elastase-like enzymes in Ae. aegypti larvae. The HiTI variants T6 and T23 are good candidates for the development as a larvicide to control the vector.

  2. Selective and Sensitive Sensing of Flame Retardant Chemicals Through Phage Display Discovered Recognition Peptide.

    PubMed

    Jin, Hyo-Eon; Zueger, Chris; Chung, Woo-Jae; Wong, Winnie; Lee, Byung Yang; Lee, Seung-Wuk

    2015-11-11

    We report a highly selective and sensitive biosensor for the detection of an environmentally toxic molecule, decabrominated diphenyl ether (DBDE), one of the most common congeners of the polybrominated frame retardants (polybrominated diphenyl ether (PBDE)), using newly discovered DBDE peptide receptors integrated with carbon nanotube field-effect transistors (CNT-FET). The specific DBDE peptide receptor was identified using a high-throughput screening process of phage library display. The resulting binding peptide carries an interesting consensus binding pocket with two Trp-His/Asn-Trp repeats, which binds to the DBDE in a multivalent manner. We integrated the novel DBDE binding peptide onto the CNT-FET using polydiacetylene coating materials linked through cysteine-maleimide click chemistry. The resulting biosensor could detect the desired DBDE selectively with a 1 fM detection limit. Our combined approaches of selective receptor discovery, material nanocoating through click chemistry, and integration onto a sensitive CNT-FET electronic sensor for desired target chemicals will pave the way toward the rapid development of portable and easy-to-use biosensors for desired chemicals to protect our health and environment. PMID:26455834

  3. Identification of peptides that selectively bind to myoglobin by biopanning of phage displayed-peptide library.

    PubMed

    Padmanaban, Guruprasath; Park, Hyekyung; Choi, Ji Suk; Cho, Yong-Woo; Kang, Woong Chol; Moon, Chan-Il; Kim, In-San; Lee, Byung-Heon

    2014-10-10

    Biopanning of phage displayed-peptide library was performed against myoglobin, a marker for the early assessment of acute myocardial infarction (AMI), to identify peptides that selectively bind to myoglobin. Using myoglobin-conjugated magnetic beads, phages that bound to myoglobin were collected and amplified for the next round of screening. A 148-fold enrichment of phage titer was observed after five rounds of screening relative to the first round. After phage binding ELISA, three phage clones were selected (3R1, 3R7 and 3R10) and the inserted peptides were chemically synthesized. The analysis of binding affinity showed that the 3R7 (CPSTLGASC) peptide had higher binding affinity (Kd=57 nM) than did the 3R1 (CNLSSSWIC) and 3R10 (CVPRLSAPC) peptide (Kd=125 nM and 293 nM, respectively). Cross binding activity to other proteins, such as bovine serum albumin, troponin I, and creatine kinase-MB, was minimal. In a peptide-antibody sandwich ELISA, the selected peptides efficiently captured myoglobin. Moreover, the concentrations of myoglobin in serum samples measured by a peptide-peptide sandwich assay were comparable to those measured by a commercial antibody-based kit. These results indicate that the identified peptides can be used for the detection of myoglobin and may be a cost effective alternative to antibodies.

  4. Nanoparticles and phage display selected peptides for imaging and therapy of cancer.

    PubMed

    Cutler, Cathy S; Chanda, Nripen; Shukla, Ravi; Sisay, Nebiat; Cantorias, Melchor; Zambre, Ajit; McLaughlin, Mark; Kelsey, James; Upenandran, Anandhi; Robertson, Dave; Deutscher, Susan; Kannan, Raghuraman; Katti, Kattesh

    2013-01-01

    Molecular imaging probes are a special class of pharmaceuticals that target specific biochemical signatures associated with disease and allow for noninvasive imaging on the molecular level. Because changes in biochemistry occur before diseases reach an advanced stage, molecular imaging probes make it possible to locate and stage disease, track the effectiveness of drugs, treat disease, monitor response, and select patients to allow for more personalized diagnosis and treatment of disease. Targeting agents radiolabeled with positron emitters are of interest due to their ability to quantitatively measure biodistribution and receptor expression to allow for optimal dose determinations. (68)Ga is a positron emitter, which allows for quantitative imaging through positron emission chromatography (PET). The availability of (68)Ga from a generator and its ability to form stable complexes with a variety of chelates hold promise for expanding PET utilization to facilities unable to afford their own cyclotron. Nanoparticles conjugated with various proteins and peptides derived from phage display that can be selectively targeted are being developed and evaluated for guided imaging and therapy. Herein we highlight some initial efforts in combining the enhanced selectivity of nanoparticles and peptides with (68)Ga for use as molecular imaging probes. PMID:22918758

  5. Selective and Sensitive Sensing of Flame Retardant Chemicals Through Phage Display Discovered Recognition Peptide.

    PubMed

    Jin, Hyo-Eon; Zueger, Chris; Chung, Woo-Jae; Wong, Winnie; Lee, Byung Yang; Lee, Seung-Wuk

    2015-11-11

    We report a highly selective and sensitive biosensor for the detection of an environmentally toxic molecule, decabrominated diphenyl ether (DBDE), one of the most common congeners of the polybrominated frame retardants (polybrominated diphenyl ether (PBDE)), using newly discovered DBDE peptide receptors integrated with carbon nanotube field-effect transistors (CNT-FET). The specific DBDE peptide receptor was identified using a high-throughput screening process of phage library display. The resulting binding peptide carries an interesting consensus binding pocket with two Trp-His/Asn-Trp repeats, which binds to the DBDE in a multivalent manner. We integrated the novel DBDE binding peptide onto the CNT-FET using polydiacetylene coating materials linked through cysteine-maleimide click chemistry. The resulting biosensor could detect the desired DBDE selectively with a 1 fM detection limit. Our combined approaches of selective receptor discovery, material nanocoating through click chemistry, and integration onto a sensitive CNT-FET electronic sensor for desired target chemicals will pave the way toward the rapid development of portable and easy-to-use biosensors for desired chemicals to protect our health and environment.

  6. Selection of specific interactors from phage display library based on sea lamprey variable lymphocyte receptor sequences.

    PubMed

    Wezner-Ptasinska, Magdalena; Otlewski, Jacek

    2015-12-01

    Variable lymphocyte receptors (VLRs) are non-immunoglobulin components of adaptive immunity in jawless vertebrates. These proteins composed of leucine-rich repeat modules offer some advantages over antibodies in target binding and therefore are attractive candidates for biotechnological applications. In this paper we report the design and characterization of a phage display library based on a previously proposed dVLR scaffold containing six LRR modules [Wezner-Ptasinska et al., 2011]. Our library was designed based on a consensus approach in which the randomization scheme reflects the frequencies of amino acids naturally occurring in respective positions responsible for antigen recognition. We demonstrate general applicability of the scaffold by selecting dVLRs specific for lysozyme and S100A7 protein with KD values in the micromolar range. The dVLR library could be used as a convenient alternative to antibodies for effective isolation of high affinity binders.

  7. X-33 Telemetry Best Source Selection, Processing, Display, and Simulation Model Comparison

    NASA Technical Reports Server (NTRS)

    Burkes, Darryl A.

    1998-01-01

    The X-33 program requires the use of multiple telemetry ground stations to cover the launch, ascent, transition, descent, and approach phases for the flights from Edwards AFB to landings at Dugway Proving Grounds, UT and Malmstrom AFB, MT. This paper will discuss the X-33 telemetry requirements and design, including information on fixed and mobile telemetry systems, best source selection, and support for Range Safety Officers. A best source selection system will be utilized to automatically determine the best source based on the frame synchronization status of the incoming telemetry streams. These systems will be used to select the best source at the landing sites and at NASA Dryden Flight Research Center to determine the overall best source between the launch site, intermediate sites, and landing site sources. The best source at the landing sites will be decommutated to display critical flight safety parameters for the Range Safety Officers. The overall best source will be sent to the Lockheed Martin's Operational Control Center at Edwards AFB for performance monitoring by X-33 program personnel and for monitoring of critical flight safety parameters by the primary Range Safety Officer. The real-time telemetry data (received signal strength, etc.) from each of the primary ground stations will also be compared during each nu'ssion with simulation data generated using the Dynamic Ground Station Analysis software program. An overall assessment of the accuracy of the model will occur after each mission. Acknowledgment: The work described in this paper was NASA supported through cooperative agreement NCC8-115 with Lockheed Martin Skunk Works.

  8. Mapping polyclonal antibody responses to bacterial infection using next generation phage display.

    PubMed

    Naqid, Ibrahim A; Owen, Jonathan P; Maddison, Ben C; Spiliotopoulos, Anastasios; Emes, Richard D; Warry, Andrew; Tchórzewska, Monika A; Martelli, Francesca; Gosling, Rebecca J; Davies, Robert H; La Ragione, Roberto M; Gough, Kevin C

    2016-01-01

    Mapping polyclonal antibody responses to infectious diseases to identify individual epitopes has the potential to underpin the development of novel serological assays and vaccines. Here, phage-peptide library panning coupled with screening using next generation sequencing was used to map antibody responses to bacterial infections. In the first instance, pigs experimentally infected with Salmonella enterica serovar Typhimurium was investigated. IgG samples from twelve infected pigs were probed in parallel and phage binding compared to that with equivalent IgG from pre-infected animals. Seventy-seven peptide mimotopes were enriched specifically against sera from multiple infected animals. Twenty-seven of these peptides were tested in ELISA and twenty-two were highly discriminatory for sera taken from pigs post-infection (P < 0.05) indicating that these peptides are mimicking epitopes from the bacteria. In order to further test this methodology, it was applied to differentiate antibody responses in poultry to infections with distinct serovars of Salmonella enterica. Twenty-seven peptides were identified as being enriched specifically against IgY from multiple animals infected with S. Enteritidis compared to those infected with S. Hadar. Nine of fifteen peptides tested in ELISA were highly discriminatory for IgY following S. Enteritidis infection (p < 0.05) compared to infections with S. Hadar or S. Typhimurium. PMID:27072017

  9. Mapping polyclonal antibody responses to bacterial infection using next generation phage display

    PubMed Central

    Naqid, Ibrahim A.; Owen, Jonathan P.; Maddison, Ben C.; Spiliotopoulos, Anastasios; Emes, Richard D.; Warry, Andrew; Tchórzewska, Monika A.; Martelli, Francesca; Gosling, Rebecca J.; Davies, Robert H.; La Ragione, Roberto M.; Gough, Kevin C.

    2016-01-01

    Mapping polyclonal antibody responses to infectious diseases to identify individual epitopes has the potential to underpin the development of novel serological assays and vaccines. Here, phage-peptide library panning coupled with screening using next generation sequencing was used to map antibody responses to bacterial infections. In the first instance, pigs experimentally infected with Salmonella enterica serovar Typhimurium was investigated. IgG samples from twelve infected pigs were probed in parallel and phage binding compared to that with equivalent IgG from pre-infected animals. Seventy-seven peptide mimotopes were enriched specifically against sera from multiple infected animals. Twenty-seven of these peptides were tested in ELISA and twenty-two were highly discriminatory for sera taken from pigs post-infection (P < 0.05) indicating that these peptides are mimicking epitopes from the bacteria. In order to further test this methodology, it was applied to differentiate antibody responses in poultry to infections with distinct serovars of Salmonella enterica. Twenty-seven peptides were identified as being enriched specifically against IgY from multiple animals infected with S. Enteritidis compared to those infected with S. Hadar. Nine of fifteen peptides tested in ELISA were highly discriminatory for IgY following S. Enteritidis infection (p < 0.05) compared to infections with S. Hadar or S. Typhimurium. PMID:27072017

  10. Selection of peptides binding to metallic borides by screening M13 phage display libraries

    PubMed Central

    2014-01-01

    Background Metal borides are a class of inorganic solids that is much less known and investigated than for example metal oxides or intermetallics. At the same time it is a highly versatile and interesting class of compounds in terms of physical and chemical properties, like semiconductivity, ferromagnetism, or catalytic activity. This makes these substances attractive for the generation of new materials. Very little is known about the interaction between organic materials and borides. To generate nanostructured and composite materials which consist of metal borides and organic modifiers it is necessary to develop new synthetic strategies. Phage peptide display libraries are commonly used to select peptides that bind specifically to metals, metal oxides, and semiconductors. Further, these binding peptides can serve as templates to control the nucleation and growth of inorganic nanoparticles. Additionally, the combination of two different binding motifs into a single bifunctional phage could be useful for the generation of new composite materials. Results In this study, we have identified a unique set of sequences that bind to amorphous and crystalline nickel boride (Ni3B) nanoparticles, from a random peptide library using the phage display technique. Using this technique, strong binders were identified that are selective for nickel boride. Sequence analysis of the peptides revealed that the sequences exhibit similar, yet subtle different patterns of amino acid usage. Although a predominant binding motif was not observed, certain charged amino acids emerged as essential in specific binding to both substrates. The 7-mer peptide sequence LGFREKE, isolated on amorphous Ni3B emerged as the best binder for both substrates. Fluorescence microscopy and atomic force microscopy confirmed the specific binding affinity of LGFREKE expressing phage to amorphous and crystalline Ni3B nanoparticles. Conclusions This study is, to our knowledge, the first to identify peptides that

  11. From shunting inhibition to dynamic normalization: Attentional selection and decision-making in brief visual displays.

    PubMed

    Smith, Philip L; Sewell, David K; Lilburn, Simon D

    2015-11-01

    Normalization models of visual sensitivity assume that the response of a visual mechanism is scaled divisively by the sum of the activity in the excitatory and inhibitory mechanisms in its neighborhood. Normalization models of attention assume that the weighting of excitatory and inhibitory mechanisms is modulated by attention. Such models have provided explanations of the effects of attention in both behavioral and single-cell recording studies. We show how normalization models can be obtained as the asymptotic solutions of shunting differential equations, in which stimulus inputs and the activity in the mechanism control growth rates multiplicatively rather than additively. The value of the shunting equation approach is that it characterizes the entire time course of the response, not just its asymptotic strength. We describe two models of attention based on shunting dynamics, the integrated system model of Smith and Ratcliff (2009) and the competitive interaction theory of Smith and Sewell (2013). These models assume that attention, stimulus salience, and the observer's strategy for the task jointly determine the selection of stimuli into visual short-term memory (VSTM) and the way in which stimulus representations are weighted. The quality of the VSTM representation determines the speed and accuracy of the decision. The models provide a unified account of a variety of attentional phenomena found in psychophysical tasks using single-element and multi-element displays. Our results show the generality and utility of the normalization approach to modeling attention.

  12. Engineering phage materials with desired peptide display: rational design sustained through natural selection.

    PubMed

    Merzlyak, Anna; Lee, Seung-Wuk

    2009-12-01

    Genetic engineering of phage provides novel opportunities to build various nanomaterials by displaying functional peptide motifs on its surface coat protein. However, any genetic modifications of phage coat proteins must be able to accommodate their many biological roles in the phage replication process. To express functional but inherently unfavorable peptide motifs on major coat protein pVIII, we devised a novel genetic conjugation method to circumvent bacterial biological censorship. Constraining the designed peptides among the degenerate flanking residues, we obtained a pVIII library of phage that retained the desired sequences yet could navigate through the phage replication process due to the naturally selected flanking residues. Further, we systematically analyzed the biochemical and size-related compensation mechanisms of the pVIII expressed peptides by constructing four chemically diverse (His, Trp, Glu, Lys) partial library series. Described genetic conjugation methodology can serve to improve the design of engineered phage and allow further exploitation of these particles as functional nanobiomaterials for various applications. PMID:19842621

  13. Identification of genes expressed in response to phytoplasma infection in leaves of Prunus armeniaca by messenger RNA differential display.

    PubMed

    Carginale, Vincenzo; Maria, Giovanna; Capasso, Clemente; Ionata, Elena; La Cara, Francesco; Pastore, Maria; Bertaccini, Assunta; Capasso, Antonio

    2004-05-12

    The messenger RNA (mRNA) differential display technique was applied to the identification and isolation of genes whose transcription was altered in leaves of Prunus armeniaca infected by European stone fruit yellows (ESFY) phytoplasma belonging to ribosomal subgroup 16SrX-B. Four genes whose steady-state levels of expression significantly changed in response to phytoplasma infection were isolated and identified. The results obtained show that two group of genes are affected by phytoplasma infection in apricot leaves. The first group comprises genes that are up-regulated by phytoplasma presence: in particular, a gene encoding the heat-shock protein HSP-70, a gene encoding a metallothionein (MT) and another homologous to the EST 673 cDNA clone of P. armeniaca, whose function was unknown. The other gene identified in our analysis is down-regulated by phytoplasma presence. It encodes a protein having homology to an amino acid transporter of Arabidopsis thaliana. Our findings demonstrate the usefulness of mRNA differential display approach for the detection of plant metabolic pathways affected by phytoplasma infection.

  14. Identification of genes expressed in response to phytoplasma infection in leaves of Prunus armeniaca by messenger RNA differential display.

    PubMed

    Carginale, Vincenzo; Maria, Giovanna; Capasso, Clemente; Ionata, Elena; La Cara, Francesco; Pastore, Maria; Bertaccini, Assunta; Capasso, Antonio

    2004-05-12

    The messenger RNA (mRNA) differential display technique was applied to the identification and isolation of genes whose transcription was altered in leaves of Prunus armeniaca infected by European stone fruit yellows (ESFY) phytoplasma belonging to ribosomal subgroup 16SrX-B. Four genes whose steady-state levels of expression significantly changed in response to phytoplasma infection were isolated and identified. The results obtained show that two group of genes are affected by phytoplasma infection in apricot leaves. The first group comprises genes that are up-regulated by phytoplasma presence: in particular, a gene encoding the heat-shock protein HSP-70, a gene encoding a metallothionein (MT) and another homologous to the EST 673 cDNA clone of P. armeniaca, whose function was unknown. The other gene identified in our analysis is down-regulated by phytoplasma presence. It encodes a protein having homology to an amino acid transporter of Arabidopsis thaliana. Our findings demonstrate the usefulness of mRNA differential display approach for the detection of plant metabolic pathways affected by phytoplasma infection. PMID:15145051

  15. Spatial variation in pollinator-mediated selection on phenology, floral display and spur length in the orchid Gymnadenia conopsea.

    PubMed

    Chapurlat, Elodie; Ågren, Jon; Sletvold, Nina

    2015-12-01

    Spatial variation in plant-pollinator interactions may cause variation in pollinator-mediated selection on floral traits, but to establish this link conclusively experimental studies are needed. We quantified pollinator-mediated selection on flowering phenology and morphology in four populations of the fragrant orchid Gymnadenia conopsea, and compared selection mediated by diurnal and nocturnal pollinators in two of the populations. Variation in pollinator-mediated selection explained most of the among-population variation in the strength of directional and correlational selection. Pollinators mediated correlational selection on pairs of display traits, and on one display trait and spur length, a trait affecting pollination efficiency. Only nocturnal pollinators selected for longer spurs, and mediated stronger selection on the number of flowers compared with diurnal pollinators in one population. The two types of pollinators caused correlational selection on different pairs of traits and selected for different combinations of spur length and number of flowers. The results demonstrate that spatial variation in interactions with pollinators may result in differences in directional and correlational selection on floral traits in a plant with a semi-generalized pollination system, and suggest that differences in the relative importance of diurnal and nocturnal pollinators can cause variation in selection. PMID:26183369

  16. Spatial variation in pollinator-mediated selection on phenology, floral display and spur length in the orchid Gymnadenia conopsea.

    PubMed

    Chapurlat, Elodie; Ågren, Jon; Sletvold, Nina

    2015-12-01

    Spatial variation in plant-pollinator interactions may cause variation in pollinator-mediated selection on floral traits, but to establish this link conclusively experimental studies are needed. We quantified pollinator-mediated selection on flowering phenology and morphology in four populations of the fragrant orchid Gymnadenia conopsea, and compared selection mediated by diurnal and nocturnal pollinators in two of the populations. Variation in pollinator-mediated selection explained most of the among-population variation in the strength of directional and correlational selection. Pollinators mediated correlational selection on pairs of display traits, and on one display trait and spur length, a trait affecting pollination efficiency. Only nocturnal pollinators selected for longer spurs, and mediated stronger selection on the number of flowers compared with diurnal pollinators in one population. The two types of pollinators caused correlational selection on different pairs of traits and selected for different combinations of spur length and number of flowers. The results demonstrate that spatial variation in interactions with pollinators may result in differences in directional and correlational selection on floral traits in a plant with a semi-generalized pollination system, and suggest that differences in the relative importance of diurnal and nocturnal pollinators can cause variation in selection.

  17. Combining Yeast Display and Competitive FACS to Select Rare Hapten-Specific Clones from Recombinant Antibody Libraries

    PubMed Central

    2016-01-01

    The development of antibodies to low molecular weight haptens remains challenging due to both the low immunogenicity of many haptens and the cross-reactivity of the protein carriers used to generate the immune response. Recombinant antibodies and novel display technologies have greatly advanced antibody development; however, new techniques are still required to select rare hapten-specific antibodies from large recombinant libraries. In the present study, we used a combination of phage and yeast display to screen an immune antibody library (size, 4.4 × 106) against hapten markers for petroleum contamination (phenanthrene and methylphenanthrenes). Selection via phage display was used first to enrich the library between 20- and 100-fold for clones that bound to phenanthrene–protein conjugates. The enriched libraries were subsequently transferred to a yeast display system and a newly developed competitive FACS procedure was employed to select rare hapten-specific clones. Competitive FACS increased the frequency of hapten-specific scFvs in our yeast-displayed scFvs from 0.025 to 0.005% in the original library to between 13 and 35% in selected pools. The presence of hapten-specific scFvs was confirmed by competitive ELISA using periplasmic protein. Three distinct antibody clones that recognize phenanthrene and methylphenanthrenes were selected, and their distinctive binding properties were characterized. To our knowledge, these are first antibodies that can distinguish between methylated (petrogenic) versus unmethylated (pyrogenic) phenanthrenes; such antibodies will be useful in detecting the sources of environmental contamination. This selection method could be generally adopted in the selection of other hapten-specific recombinant antibodies. PMID:27571429

  18. Combining Yeast Display and Competitive FACS to Select Rare Hapten-Specific Clones from Recombinant Antibody Libraries.

    PubMed

    Sun, Yue; Ban, Bhupal; Bradbury, Andrew; Ansari, G A Shakeel; Blake, Diane A

    2016-09-20

    The development of antibodies to low molecular weight haptens remains challenging due to both the low immunogenicity of many haptens and the cross-reactivity of the protein carriers used to generate the immune response. Recombinant antibodies and novel display technologies have greatly advanced antibody development; however, new techniques are still required to select rare hapten-specific antibodies from large recombinant libraries. In the present study, we used a combination of phage and yeast display to screen an immune antibody library (size, 4.4 × 10(6)) against hapten markers for petroleum contamination (phenanthrene and methylphenanthrenes). Selection via phage display was used first to enrich the library between 20- and 100-fold for clones that bound to phenanthrene-protein conjugates. The enriched libraries were subsequently transferred to a yeast display system and a newly developed competitive FACS procedure was employed to select rare hapten-specific clones. Competitive FACS increased the frequency of hapten-specific scFvs in our yeast-displayed scFvs from 0.025 to 0.005% in the original library to between 13 and 35% in selected pools. The presence of hapten-specific scFvs was confirmed by competitive ELISA using periplasmic protein. Three distinct antibody clones that recognize phenanthrene and methylphenanthrenes were selected, and their distinctive binding properties were characterized. To our knowledge, these are first antibodies that can distinguish between methylated (petrogenic) versus unmethylated (pyrogenic) phenanthrenes; such antibodies will be useful in detecting the sources of environmental contamination. This selection method could be generally adopted in the selection of other hapten-specific recombinant antibodies.

  19. Combining Yeast Display and Competitive FACS to Select Rare Hapten-Specific Clones from Recombinant Antibody Libraries.

    PubMed

    Sun, Yue; Ban, Bhupal; Bradbury, Andrew; Ansari, G A Shakeel; Blake, Diane A

    2016-09-20

    The development of antibodies to low molecular weight haptens remains challenging due to both the low immunogenicity of many haptens and the cross-reactivity of the protein carriers used to generate the immune response. Recombinant antibodies and novel display technologies have greatly advanced antibody development; however, new techniques are still required to select rare hapten-specific antibodies from large recombinant libraries. In the present study, we used a combination of phage and yeast display to screen an immune antibody library (size, 4.4 × 10(6)) against hapten markers for petroleum contamination (phenanthrene and methylphenanthrenes). Selection via phage display was used first to enrich the library between 20- and 100-fold for clones that bound to phenanthrene-protein conjugates. The enriched libraries were subsequently transferred to a yeast display system and a newly developed competitive FACS procedure was employed to select rare hapten-specific clones. Competitive FACS increased the frequency of hapten-specific scFvs in our yeast-displayed scFvs from 0.025 to 0.005% in the original library to between 13 and 35% in selected pools. The presence of hapten-specific scFvs was confirmed by competitive ELISA using periplasmic protein. Three distinct antibody clones that recognize phenanthrene and methylphenanthrenes were selected, and their distinctive binding properties were characterized. To our knowledge, these are first antibodies that can distinguish between methylated (petrogenic) versus unmethylated (pyrogenic) phenanthrenes; such antibodies will be useful in detecting the sources of environmental contamination. This selection method could be generally adopted in the selection of other hapten-specific recombinant antibodies. PMID:27571429

  20. Analysis and Selection of a Remote Docking Simulation Visual Display System

    NASA Technical Reports Server (NTRS)

    Shields, N., Jr.; Fagg, M. F.

    1984-01-01

    The development of a remote docking simulation visual display system is examined. Video system and operator performance are discussed as well as operator command and control requirements and a design analysis of the reconfigurable work station.

  1. Injected phage-displayed-VP28 vaccine reduces shrimp Litopenaeus vannamei mortality by white spot syndrome virus infection.

    PubMed

    Solís-Lucero, G; Manoutcharian, K; Hernández-López, J; Ascencio, F

    2016-08-01

    White spot syndrome virus (WSSV) is the most important viral pathogen for the global shrimp industry causing mass mortalities with huge economic losses. Recombinant phages are capable of expressing foreign peptides on viral coat surface and act as antigenic peptide carriers bearing a phage-displayed vaccine. In this study, the full-length VP28 protein of WSSV, widely known as potential vaccine against infection in shrimp, was successfully cloned and expressed on M13 filamentous phage. The functionality and efficacy of this vaccine immunogen was demonstrated through immunoassay and in vivo challenge studies. In ELISA assay phage-displayed VP28 was bind to Litopenaeus vannamei immobilized hemocyte in contrast to wild-type M13 phage. Shrimps were injected with 2 × 10(10) cfu animal(-1) single dose of VP28-M13 and M13 once and 48 h later intramuscularly challenged with WSSV to test the efficacy of the vaccine against the infection. All dead challenged shrimps were PCR WSSV-positive. The accumulative mortality of the vaccinated and challenged shrimp groups was significantly lower (36.67%) than the unvaccinated group (66.67%). Individual phenoloxidase and superoxide dismutase activity was assayed on 8 and 48 h post-vaccination. No significant difference was found in those immunological parameters among groups at any sampled time evaluated. For the first time, phage display technology was used to express a recombinant vaccine for shrimp. The highest percentage of relative survival in vaccinated shrimp (RPS = 44.99%) suggest that the recombinant phage can be used successfully to display and deliver VP28 for farmed marine crustaceans.

  2. Selection of IgE-binding aptameric green fluorescent protein (Ap-GFP) by the ribosome display (RD) platform

    SciTech Connect

    Chen, S.-S. Yang Yongmin; Barankiewicz, Teresa J.

    2008-09-26

    GFP-C{kappa} fusion protein was previously shown selectable on ribosome display platform with solid phase antibodies against GFP determinant [Y.-M. Yang, T.J. Barankiewicz, M. He, M. Taussig, S.-S. Chen, Selection of antigenic markers on a GFP-C{kappa} fusion scaffold with high sensitivity by eukaryotic ribosome display, Biochem. Biophys. Res. Commun. 359 (2007) 251-257]. Herein, we show that members of aptameric peptide library constructed within the site 6 and site 8/9 loops of GFP of the ribosome display construct are selectable upon binding to the solid phase IgE antigen. An input of 1.0 {mu}g of the dual site aptameric GFP library exhibiting a diversity of 7.5 x 10{sup 11} was transcribed, translated and incubated with solid phase IgE. RT-PCR products were amplified from mRNA of the aptamer-ribosome-mRNA (ARM) complex captured on the solid phase IgE. Clones of aptameric GFP were prepared from RT-PCR product of ARM complex following repetitive selection. Recombinant aptameric GFP proteins from the selected clones bind IgE coated on the 96-well plate, and the binding was abrogated by incubation with soluble human IgE but not human IgG. Selected aptameric GFP proteins also exhibit binding to three different sources of human IgE (IgE PS, BED, and JW8) but not irrelevant proteins. These observations indicate that appropriately selected aptameric GFP on a solid phase ligand by ribosome display may serve as an affinity reagent for blocking reactivity of a biological ligand.

  3. Effectiveness of a neonatal intensive care unit access intercom linked audiovisual display monitor highlighting infection control procedures.

    PubMed

    El-Kafrawy, Ula; Taylor, Robert J; Francis, Natalie; Boussabaine, Emaan; Badrideen, Maysoon

    2013-08-01

    This prospective interventional study aimed at increasing knowledge and adherence to 4 infection control standards by visitors to a neonatal intensive care unit. Visitors were interviewed and observed for knowledge of and adherence to the standards pre- and postinstallation of an audiovisual display monitor, which demonstrates handwashing and delivers an auditory and written list of the standards. Handwashing adherence and watch removal improved from 79.2% to 100% and 67% to 89.7%, respectively. Recall of the standards increased from 19% to 81%.

  4. Mountain lions prey selectively on prion-infected mule deer.

    PubMed

    Krumm, Caroline E; Conner, Mary M; Hobbs, N Thompson; Hunter, Don O; Miller, Michael W

    2010-04-23

    The possibility that predators choose prey selectively based on age or condition has been suggested but rarely tested. We examined whether mountain lions (Puma concolor) selectively prey upon mule deer (Odocoileus hemionus) infected with chronic wasting disease, a prion disease. We located kill sites of mountain lions in the northern Front Range of Colorado, USA, and compared disease prevalence among lion-killed adult (> or =2 years old) deer with prevalence among sympatric deer taken by hunters in the vicinity of kill sites. Hunter-killed female deer were less likely to be infected than males (odds ratios (OR) = 0.2, 95% confidence intervals (CI) = 0.1-0.6; p = 0.015). However, both female (OR = 8.5, 95% CI = 2.3-30.9) and male deer (OR = 3.2, 95% CI = 1-10) killed by a mountain lion were more likely to be infected than same-sex deer killed in the vicinity by a hunter (p < 0.001), suggesting that mountain lions in this area actively selected prion-infected individuals when targeting adult mule deer as prey items. PMID:19864271

  5. Mountain lions prey selectively on prion-infected mule deer.

    PubMed

    Krumm, Caroline E; Conner, Mary M; Hobbs, N Thompson; Hunter, Don O; Miller, Michael W

    2010-04-23

    The possibility that predators choose prey selectively based on age or condition has been suggested but rarely tested. We examined whether mountain lions (Puma concolor) selectively prey upon mule deer (Odocoileus hemionus) infected with chronic wasting disease, a prion disease. We located kill sites of mountain lions in the northern Front Range of Colorado, USA, and compared disease prevalence among lion-killed adult (> or =2 years old) deer with prevalence among sympatric deer taken by hunters in the vicinity of kill sites. Hunter-killed female deer were less likely to be infected than males (odds ratios (OR) = 0.2, 95% confidence intervals (CI) = 0.1-0.6; p = 0.015). However, both female (OR = 8.5, 95% CI = 2.3-30.9) and male deer (OR = 3.2, 95% CI = 1-10) killed by a mountain lion were more likely to be infected than same-sex deer killed in the vicinity by a hunter (p < 0.001), suggesting that mountain lions in this area actively selected prion-infected individuals when targeting adult mule deer as prey items.

  6. DARPins recognizing the tumor-associated antigen EpCAM selected by phage and ribosome display and engineered for multivalency.

    PubMed

    Stefan, Nikolas; Martin-Killias, Patricia; Wyss-Stoeckle, Sascha; Honegger, Annemarie; Zangemeister-Wittke, Uwe; Plückthun, Andreas

    2011-11-01

    Designed Ankyrin Repeat Proteins (DARPins) represent a novel class of binding molecules. Their favorable biophysical properties such as high affinity, stability and expression yields make them ideal candidates for tumor targeting. Here, we describe the selection of DARPins specific for the tumor-associated antigen epithelial cell adhesion molecule (EpCAM), an approved therapeutic target on solid tumors. We selected DARPins from combinatorial libraries by both phage display and ribosome display and compared their binding on tumor cells. By further rounds of random mutagenesis and ribosome display selection, binders with picomolar affinity were obtained that were entirely monomeric and could be expressed at high yields in the cytoplasm of Escherichia coli. One of the binders, denoted Ec1, bound to EpCAM with picomolar affinity (K(d)=68 pM), and another selected DARPin (Ac2) recognized a different epitope on EpCAM. Through the use of a variety of bivalent and tetravalent arrangements with these DARPins, the off-rate on cells was further improved by up to 47-fold. All EpCAM-specific DARPins were efficiently internalized by receptor-mediated endocytosis, which is essential for intracellular delivery of anticancer agents to tumor cells. Thus, using EpCAM as a target, we provide evidence that DARPins can be conveniently selected and rationally engineered to high-affinity binders of various formats for tumor targeting.

  7. REAL-Select: Full-Length Antibody Display and Library Screening by Surface Capture on Yeast Cells

    PubMed Central

    Günther, Ralf; Becker, Stefan; Kolmar, Harald; Hock, Björn

    2014-01-01

    We describe a novel approach named REAL-Select for the non-covalent display of IgG-molecules on the surface of yeast cells for the purpose of antibody engineering and selection. It relies on the capture of secreted native full-length antibodies on the cell surface via binding to an externally immobilized ZZ domain, which tightly binds antibody Fc. It is beneficial for high-throughput screening of yeast-displayed IgG-libraries during antibody discovery and development. In a model experiment, antibody-displaying yeast cells were isolated from a 1∶1,000,000 mixture with control cells confirming the maintenance of genotype-phenotype linkage. Antibodies with improved binding characteristics were obtained by affinity maturation using REAL-Select, demonstrating the ability of this system to display antibodies in their native form and to detect subtle changes in affinity by flow cytometry. The biotinylation of the cell surface followed by functionalization with a streptavidin-ZZ fusion protein is an approach that is independent of the genetic background of the antibody-producing host and therefore can be expected to be compatible with other eukaryotic expression hosts such as P. pastoris or mammalian cells. PMID:25501029

  8. Immunoadjuvant activity of amphotericin B as displayed in mice infected with Candida albicans.

    PubMed Central

    Bistoni, F; Vecchiarelli, A; Mazzolla, R; Puccetti, P; Marconi, P; Garaci, E

    1985-01-01

    Mice receiving a single intraperitoneal injection of amphotericin B showed increased resistance to subsequent challenge with either Candida albicans or Staphylococcus aureus. This enhancement of resistance was obvious in terms of both survival criteria and clearance of the intravenously injected organism from different organs. The protective effect of amphotericin B was conditioned by dose, time of drug administration, and size of yeast or bacterial inoculum and was reversed by cyclophosphamide. Effector cells from mice treated with amphotericin B displayed enhanced fungicidal activity in vitro as measured in a short-term 51Cr release assay. Macrophages from intact animals exposed in vitro to amphotericin B also acquired strong candidacidal reactivity. PMID:3890731

  9. Display and selection of scFv antibodies on HEK-293T cells

    PubMed Central

    Ho, Mitchell; Pastan, Ira

    2009-01-01

    We describe a human cell display strategy to isolate high affinity single chain antibody fragments (scFvs) specific for CD22 for the treatment of B-cell malignancies. Our strategy uses flow cytometry and human embryonic kidney 293T (HEK-293T) cells that are widely used for transient protein expression. Flow cytometry enhances the screen's sensitivity thereby allowing us to isolate high affinity scFvs. Using human cell display one could isolate and engineer scFvs, single domains, Fabs or whole IgGs for increased affinity and other biological functions. PMID:19554290

  10. Anopheles darlingi (Diptera: Culicidae) displays increased attractiveness to infected individuals with Plasmodium vivax gametocytes

    PubMed Central

    2014-01-01

    Background Most hematophagous insects use host odours as chemical cues. The odour components, some physiological parameters and host attractiveness are affected by several conditions, including infection by parasites, e.g., plasmodia and, therefore, change the epidemiological scenario. This study evaluated the attractiveness of individuals with vivax malaria before, during (7 days) and after treatment (14 days) with specific antimalarial drugs. Findings Mosquito attractiveness to vivax-infected patients was assessed using a vertical olfactometer using the foot as a source of body odour. The ratio of Anopheles darlingi mosquitoes in the lower chamber of the olfactometer was used to calculate the attractiveness, and patient temperature was measured using a digital thermometer. An increased attractiveness was found only in patients bearing vivax gametocytes during the first experiment (early infection) (P < 0.001). Patients in the first experiment tended to have a higher body temperature, but grouping patients into fever and non-fever resulted in a higher attractiveness only in the fever group of gametocyte carriers, suggesting a synergistic effect of temperature and gametocytes in the host attractiveness to A. darlingi. Conclusions Gametocyte presence and fever in vivax malaria patients increased short distance host attractiveness to An. darlingi. PMID:24885914

  11. Selection of dental procedures for antibiotic prophylaxis against infective endocarditis.

    PubMed

    Tan, S Y; Gill, G

    1992-12-01

    A dental source of infection remains the most common identifiable risk factor in infective endocarditis and this may be particularly important in patients at 'high risk'. We therefore performed a questionnaire survey of dental practitioners to assess acceptance of The British Society of Antimicrobial Chemotherapy (BSAC) recommendations, especially with regards to selection of dental procedures for antibiotic prophylaxis. The results showed that the dental practitioners surveyed treated the 'high risk' patient group differently by extending the range of dental procedures covered by antibiotics but the BSAC only recommend that they be treated differently by hospital treatment and/or parenteral antibiotics. This must be an area of concern and deserves further attention, especially with regards to the need for wider publicity and the range of dental procedures that should be covered in the 'high risk' group where morbidity and mortality from infective endocarditis are higher.

  12. Selection of dental procedures for antibiotic prophylaxis against infective endocarditis.

    PubMed

    Tan, S Y; Gill, G

    1992-12-01

    A dental source of infection remains the most common identifiable risk factor in infective endocarditis and this may be particularly important in patients at 'high risk'. We therefore performed a questionnaire survey of dental practitioners to assess acceptance of The British Society of Antimicrobial Chemotherapy (BSAC) recommendations, especially with regards to selection of dental procedures for antibiotic prophylaxis. The results showed that the dental practitioners surveyed treated the 'high risk' patient group differently by extending the range of dental procedures covered by antibiotics but the BSAC only recommend that they be treated differently by hospital treatment and/or parenteral antibiotics. This must be an area of concern and deserves further attention, especially with regards to the need for wider publicity and the range of dental procedures that should be covered in the 'high risk' group where morbidity and mortality from infective endocarditis are higher. PMID:1452880

  13. Select forelimb muscles have evolved superfast contractile speed to support acrobatic social displays

    PubMed Central

    Fuxjager, Matthew J; Goller, Franz; Dirkse, Annika; Sanin, Gloria D; Garcia, Sarah

    2016-01-01

    Many species perform rapid limb movements as part of their elaborate courtship displays. However, because muscle performance is constrained by trade-offs between contraction speed and force, it is unclear how animals evolve the ability to produce both unusually fast appendage movement and limb force needed for locomotion. To address this issue, we compare the twitch speeds of forelimb muscles in a group of volant passerine birds, which produce different courtship displays. Our results show that the two taxa that perform exceptionally fast wing displays have evolved 'superfast' contractile kinetics in their main humeral retractor muscle. By contrast, the two muscles that generate the majority of aerodynamic force for flight show unmodified contractile kinetics. Altogether, these results suggest that muscle-specific adaptations in contractile speed allow certain birds to circumvent the intrinsic trade-off between muscular speed and force, and thereby use their forelimbs for both rapid gestural displays and powered locomotion. DOI: http://dx.doi.org/10.7554/eLife.13544.001 PMID:27067379

  14. Dissecting children's observational learning of complex actions through selective video displays.

    PubMed

    Flynn, Emma; Whiten, Andrew

    2013-10-01

    Children can learn how to use complex objects by watching others, yet the relative importance of different elements they may observe, such as the interactions of the individual parts of the apparatus, a model's movements, and desirable outcomes, remains unclear. In total, 140 3-year-olds and 140 5-year-olds participated in a study where they observed a video showing tools being used to extract a reward item from a complex puzzle box. Conditions varied according to the elements that could be seen in the video: (a) the whole display, including the model's hands, the tools, and the box; (b) the tools and the box but not the model's hands; (c) the model's hands and the tools but not the box; (d) only the end state with the box opened; and (e) no demonstration. Children's later attempts at the task were coded to establish whether they imitated the hierarchically organized sequence of the model's actions, the action details, and/or the outcome. Children's successful retrieval of the reward from the box and the replication of hierarchical sequence information were reduced in all but the whole display condition. Only once children had attempted the task and witnessed a second demonstration did the display focused on the tools and box prove to be better for hierarchical sequence information than the display focused on the tools and hands only.

  15. Selection of antigenic markers on a GFP-C{kappa} fusion scaffold with high sensitivity by eukaryotic ribosome display

    SciTech Connect

    Yang Yongmin; Barankiewicz, Teresa J.; He Mingyue; Taussig, Michael J.; Chen, Swey-Shen . E-mail: alexchen.IGE.com@gmail.com

    2007-07-27

    Ribosome display is a cell-free system permitting gene selection through the physical association of genetic material (mRNA) and its phenotypic (protein) product. While often used to select single-chain antibodies from large libraries by panning against immobilized antigens, we have adapted ribosome display for use in the 'reverse' format in order to select high affinity antigenic determinants against solid-phase antibody. To create an antigenic scaffold, DNA encoding green fluorescent protein (GFP) was fused to a light chain constant domain (C{kappa}) with stop codon deleted, and with 5' signals (T7 promoter, Kozak) enabling coupled transcription/translation in a eukaryotic cell-free system. Epitopes on either GFP (5') or C{kappa} (3') were selected by anti-GFP or anti-C{kappa} antibodies, respectively, coupled to magnetic beads. After selection, mRNA was amplified directly from protein-ribosome-mRNA (PRM) complexes by in situ PCR followed by internal amplification and reassembly PCR. As little as 10 fg of the 1 kb DNA construct, i.e. approximately 7500 molecules, could be recovered following a single round of interaction with solid-phase anti-GFP antibody. This platform is highly specific and sensitive for the antigen-antibody interaction and may permit selection and reshaping of high affinity antigenic variants of scaffold proteins.

  16. On the selection and evaluation of visual display symbology Factors influencing search and identification times

    NASA Technical Reports Server (NTRS)

    Remington, Roger; Williams, Douglas

    1986-01-01

    Three single-target visual search tasks were used to evaluate a set of cathode-ray tube (CRT) symbols for a helicopter situation display. The search tasks were representative of the information extraction required in practice, and reaction time was used to measure the efficiency with which symbols could be located and identified. Familiar numeric symbols were responded to more quickly than graphic symbols. The addition of modifier symbols, such as a nearby flashing dot or surrounding square, had a greater disruptive effect on the graphic symbols than did the numeric characters. The results suggest that a symbol set is, in some respects, like a list that must be learned. Factors that affect the time to identify items in a memory task, such as familiarity and visual discriminability, also affect the time to identify symbols. This analogy has broad implications for the design of symbol sets. An attempt was made to model information access with this class of display.

  17. Surgical video displays and booms. We answer your questions about selection and installation.

    PubMed

    2011-05-01

    If you're renovating your operating rooms or constructing new ones, you probably have a lot of basic questions about device requirements and the purchasing process. Do devices need to meet electrical safety standards? Is equipment described as "medical grade" better? Is it important to buy your displays from your surgical boom vendor or your integration provider? Here are answers to those and other questions we're often asked.

  18. Inhibition of G1P3 expression found in the differential display study on respiratory syncytial virus infection

    PubMed Central

    Zhao, Dongchi; Peng, Dan; Li, Lei; Zhang, Qiwei; Zhang, Chuyu

    2008-01-01

    Background Respiratory syncytial virus (RSV) is the leading viral pathogen associated with bronchiolitis and lower respiratory tract disease in infants and young children worldwide. The respiratory epithelium is the primary initiator of pulmonary inflammation in RSV infections, which cause significant perturbations of global gene expression controlling multiple cellular processes. In this study, differential display reverse transcription polymerase chain reaction amplification was performed to examine mRNA expression in a human alveolar cell line (SPC-A1) infected with RSV. Results Of the 2,500 interpretable bands on denaturing polyacrylamide gels, 40 (1.6%) cDNA bands were differentially regulated by RSV, in which 28 (70%) appeared to be upregulated and another 12 (30%) appeared to be downregulated. Forty of the expressed sequence tags (EST) were isolated, and 20 matched homologs in GenBank. RSV infection upregulated the mRNA expression of chemokines CC and CXC and interfered with type α/β interferon-inducible gene expression by upregulation of MG11 and downregulation of G1P3. Conclusion RSV replication could induce widespread changes in gene expression including both positive and negative regulation and play a different role in the down-regulation of IFN-α and up-regulation of IFN-γ inducible gene expression, which suggests that RSV interferes with the innate antiviral response of epithelial cells by multiple mechanisms. PMID:18838000

  19. In vitro selection of state-specific peptide modulators of G protein signaling using mRNA display.

    PubMed

    Ja, William W; Roberts, Richard W

    2004-07-20

    The G protein regulatory (GPR) motif is a approximately 20-residue conserved domain that acts as a guanine dissociation inhibitor (GDI) for G(i/o)(alpha) subunits. Here, we describe the isolation of peptides derived from a GPR consensus sequence using mRNA display selection libraries. Biotinylated G(i)(alpha)(1), modified at either the N or C terminus, serves as a high-affinity binding target for mRNA-displayed GPR peptides. In vitro selection using mRNA display libraries based on the C terminus of the GPR motif revealed novel peptide sequences with conserved residues. Surprisingly, selected peptides contain mutations to a highly conserved Arg in the GPR motif, previously shown to be crucial for binding and inhibition activities. The dominant peptide from the selection, R6A, and a minimal 9-mer peptide, R6A-1, do not contain Arg residues yet retain high affinity (K(D) = 60 and 200 nM, respectively) and specificity for the GDP-bound state of G(i)(alpha)(1), as measured by surface plasmon resonance. The selected peptides also maintain GDI activity for G(i)(alpha)(1), inhibiting both the exchange of GDP in GTPgammaS binding assays and the AlF(4)(-)-stimulated enhancement of intrinsic tryptophan fluorescence. The kinetics of GDI activity, however, are different for the selected peptides and demonstrate biphasic kinetics, suggesting a complex mechanism for inhibition. Like the GPR motif, the R6A and R6A-1 peptides compete with G(betagamma) subunits for binding to G(i)(alpha)(1), suggesting their use as activators of G(betagamma) signaling. PMID:15248784

  20. Masked selection: a straightforward and flexible approach for the selection of binders against specific epitopes and differentially expressed proteins by phage display.

    PubMed

    Even-Desrumeaux, Klervi; Nevoltris, Damien; Lavaut, Marie Noelle; Alim, Karima; Borg, Jean-Paul; Audebert, Stéphane; Kerfelec, Brigitte; Baty, Daniel; Chames, Patrick

    2014-02-01

    Phage display is a well-established procedure to isolate binders against a wide variety of antigens that can be performed on purified antigens, but also on intact cells. As selection steps are performed in vitro, it is possible to focus the outcome of the selection on relevant epitopes by performing some additional steps, such as depletion or competitive elutions. However in practice, the efficiency of these steps is often limited and can lead to inconsistent results. We have designed a new selection method named masked selection, based on the blockade of unwanted epitopes to favor the targeting of relevant ones. We demonstrate the efficiency and flexibility of this method by selecting single-domain antibodies against a specific portion of a fusion protein, by selecting binders against several members of the seven transmembrane receptor family using transfected HEK cells, or by selecting binders against unknown breast cancer markers not expressed on normal samples. The relevance of this approach for antibody-based therapies was further validated by the identification of four of these markers, Epithelial cell adhesion molecule, Transferrin receptor 1, Metastasis cell adhesion molecule, and Sushi containing domain 2, using immunoprecipitation and mass spectrometry. This new phage display strategy can be applied to any type of antibody fragments or alternative scaffolds, and is especially suited for the rapid discovery and identification of cell surface markers. PMID:24361863

  1. Masked Selection: A Straightforward and Flexible Approach for the Selection of Binders Against Specific Epitopes and Differentially Expressed Proteins by Phage Display*

    PubMed Central

    Even-Desrumeaux, Klervi; Nevoltris, Damien; Lavaut, Marie Noelle; Alim, Karima; Borg, Jean-Paul; Audebert, Stéphane; Kerfelec, Brigitte; Baty, Daniel; Chames, Patrick

    2014-01-01

    Phage display is a well-established procedure to isolate binders against a wide variety of antigens that can be performed on purified antigens, but also on intact cells. As selection steps are performed in vitro, it is possible to focus the outcome of the selection on relevant epitopes by performing some additional steps, such as depletion or competitive elutions. However in practice, the efficiency of these steps is often limited and can lead to inconsistent results. We have designed a new selection method named masked selection, based on the blockade of unwanted epitopes to favor the targeting of relevant ones. We demonstrate the efficiency and flexibility of this method by selecting single-domain antibodies against a specific portion of a fusion protein, by selecting binders against several members of the seven transmembrane receptor family using transfected HEK cells, or by selecting binders against unknown breast cancer markers not expressed on normal samples. The relevance of this approach for antibody-based therapies was further validated by the identification of four of these markers, Epithelial cell adhesion molecule, Transferrin receptor 1, Metastasis cell adhesion molecule, and Sushi containing domain 2, using immunoprecipitation and mass spectrometry. This new phage display strategy can be applied to any type of antibody fragments or alternative scaffolds, and is especially suited for the rapid discovery and identification of cell surface markers. PMID:24361863

  2. Novel fusion antigen displayed-bacterial ghosts vaccine candidate against infection of Escherichia coli O157:H7.

    PubMed

    Cai, Kun; Tu, Wei; Liu, Yuenan; Li, Tao; Wang, Hui

    2015-01-01

    Infection with Escherichia coli O157:H7 may develop into hemorrhagic colitis, or hemolytic uremic syndrome (HUS), which usually causes kidney failure or even death. The adhesion and toxins are the important virulent factors. In this study, a novel vaccine candidate rSOBGs was constructed based on the bacterial ghost (BG). rSOBGs maintained the integrity of cellular morphology and displayed the linear Stx2Am-Stx1B antigen on the surface of outer membrane. rSOBGs induced Stxs-specific IgA/IgG antibodies and stronger intimin-specific IgA/IgG antibodies effectively in sera in this study. In vivo, the rSOBGs provided the higher protection rate (52%) than native bacterial ghost-OBGs (12%) when challenged intragastricly with high dose (500 LD50) viable E. coli O157:H7. Meanwhile, the rSOBGs provided higher protection rate (73.33%) than OBGs when challenged with 2 LD50 even to 5 LD50 lysed E. coli O157:H7. In vitro, the rSOBGs-immunized sera possessed neutralizing activity to lysed pathogenic bacteria. Furthermore, the results of histopathology also displayed that the administration of rSOBGs have the ability to reduce or inhibit the adhesion lesions and toxins damages of organs. The novel vaccine candidate rSOBGs induced both anti-toxin and anti-adhesion immune protection, suggesting the possibility to prevent the infectious diseases caused by Escherichia coli O157:H7.

  3. Highly Avid Magnetic Bead Capture: An Efficient Selection Method for de novo Protein Engineering Utilizing Yeast Surface Display

    PubMed Central

    Ackerman, Margaret; Levary, David; Tobon, Gabriel; Hackel, Benjamin; Davis Orcutt, Kelly; Wittrup, K. Dane

    2010-01-01

    Protein engineering relies on the selective capture of members of a protein library with desired properties. Yeast surface display technology routinely enables as much as million-fold improvements in binding affinity by alternating rounds of diversification and flow cytometry-based selection. However, flow cytometry is not well suited for isolating de novo binding clones from naïve libraries due to limitations in the size of the population that can be analyzed, the minimum binding affinity of clones that can be reliably captured, the amount of target antigen required, and the likelihood of capturing artifactual binders to the reagents. Here, we demonstrate a method for capturing rare clones that maintains the advantages of yeast as the expression host, while avoiding the disadvantages of FACS in isolating de novo binders from naïve libraries. The multivalency of yeast surface display is intentionally coupled with multivalent target presentation on magnetic beads—allowing isolation of extremely weak binders from billions of non-binding clones, and requiring far less target antigen for each selection, while minimizing the likelihood of isolating undesirable alternative solutions to the selective pressure. Multivalent surface selection allows 30,000-fold enrichment and almost quantitative capture of micromolar binders in a single pass using less than one microgram of target antigen. We further validate the robust nature of this selection method by isolation of de novo binders against lysozyme as well as its utility in negative selections by isolating binders to streptavidin-biotin that do not cross-react to streptavidin alone. PMID:19363813

  4. Summarized Costs, Placement Of Quality Stars, And Other Online Displays Can Help Consumers Select High-Value Health Plans.

    PubMed

    Greene, Jessica; Hibbard, Judith H; Sacks, Rebecca M

    2016-04-01

    Starting in 2017, all state and federal health insurance exchanges will present quality data on health plans in addition to cost information. We analyzed variations in the current design of information on state exchanges to identify presentation approaches that encourage consumers to take quality as well as cost into account when selecting a health plan. Using an online sample of 1,025 adults, we randomly assigned participants to view the same comparative information on health plans, displayed in different ways. We found that consumers were much more likely to select a high-value plan when cost information was summarized instead of detailed, when quality stars were displayed adjacent to cost information, when consumers understood that quality stars signified the quality of medical care, and when high-value plans were highlighted with a check mark or blue ribbon. These approaches, which were equally effective for participants with higher and lower numeracy, can inform the development of future displays of plan information in the exchanges.

  5. Human antibody fragments specific for the epidermal growth factor receptor selected from large non-immunised phage display libraries.

    PubMed

    Souriau, Christelle; Rothacker, Julie; Hoogenboom, Hennie R; Nice, Edouard

    2004-09-01

    Antibodies to EGFR have been shown to display anti-tumour effects mediated in part by inhibition of cellular proliferation and angiogenesis, and by enhancement of apoptosis. Humanised antibodies are preferred for clinical use to reduce complications with HAMA and HAHA responses frequently seen with murine and chimaeric antibodies. We have used depletion and subtractive selection strategies on cells expressing the EGFR to sample two large antibody fragment phage display libraries for the presence of human antibodies which are specific for the EGFR. Four Fab fragments and six scFv fragments were identified, with affinities of up to 2.2nM as determined by BIAcore analysis using global fitting of the binding curves to obtain the individual rate constants (ka and kd). This overall approach offers a generic screening method for the identification of growth factor specific antibodies and antibody fragments from large expression libraries and has potential for the rapid development of new therapeutic and diagnostic reagents.

  6. Virus-like glycodendrinanoparticles displaying quasi-equivalent nested polyvalency upon glycoprotein platforms potently block viral infection

    PubMed Central

    Ribeiro-Viana, Renato; Sánchez-Navarro, Macarena; Luczkowiak, Joanna; Koeppe, Julia R.; Delgado, Rafael; Rojo, Javier; Davis, Benjamin G.

    2012-01-01

    Ligand polyvalency is a powerful modulator of protein–receptor interactions. Host–pathogen infection interactions are often mediated by glycan ligand–protein interactions, yet its interrogation with very high copy number ligands has been limited to heterogenous systems. Here we report that through the use of nested layers of multivalency we are able to assemble the most highly valent glycodendrimeric constructs yet seen (bearing up to 1,620 glycans). These constructs are pure and well-defined single entities that at diameters of up to 32 nm are capable of mimicking pathogens both in size and in their highly glycosylated surfaces. Through this mimicry these glyco-dendri-protein-nano-particles are capable of blocking (at picomolar concentrations) a model of the infection of T-lymphocytes and human dendritic cells by Ebola virus. The high associated polyvalency effects (β>106, β/N ~102–103) displayed on an unprecedented surface area by precise clusters suggest a general strategy for modulation of such interactions. PMID:23250433

  7. PHASTpep: Analysis Software for Discovery of Cell-Selective Peptides via Phage Display and Next-Generation Sequencing

    PubMed Central

    Dasa, Siva Sai Krishna; Kelly, Kimberly A.

    2016-01-01

    Next-generation sequencing has enhanced the phage display process, allowing for the quantification of millions of sequences resulting from the biopanning process. In response, many valuable analysis programs focused on specificity and finding targeted motifs or consensus sequences were developed. For targeted drug delivery and molecular imaging, it is also necessary to find peptides that are selective—targeting only the cell type or tissue of interest. We present a new analysis strategy and accompanying software, PHage Analysis for Selective Targeted PEPtides (PHASTpep), which identifies highly specific and selective peptides. Using this process, we discovered and validated, both in vitro and in vivo in mice, two sequences (HTTIPKV and APPIMSV) targeted to pancreatic cancer-associated fibroblasts that escaped identification using previously existing software. Our selectivity analysis makes it possible to discover peptides that target a specific cell type and avoid other cell types, enhancing clinical translatability by circumventing complications with systemic use. PMID:27186887

  8. Toward a Code for the Interactions of Zinc Fingers with DNA: Selection of Randomized Fingers Displayed on Phage

    NASA Astrophysics Data System (ADS)

    Choo, Yen; Klug, Aaron

    1994-11-01

    We have used two selection techniques to study sequence-specific DNA recognition by the zinc finger, a small, modular DNA-binding minidomain. We have chosen zinc fingers because they bind as independent modules and so can be linked together in a peptide designed to bind a predetermined DNA site. In this paper, we describe how a library of zinc fingers displayed on the surface of bacteriophage enables selection of fingers capable of binding to given DNA triplets. The amino acid sequences of selected fingers which bind the same triplet are compared to examine how sequence-specific DNA recognition occurs. Our results can be rationalized in terms of coded interactions between zinc fingers and DNA, involving base contacts from a few α-helical positions. In the paper following this one, we describe a complementary technique which confirms the identity of amino acids capable of DNA sequence discrimination from these positions.

  9. An engineered scorpion toxin analogue with improved Kv1.3 selectivity displays reduced conformational flexibility

    PubMed Central

    Bartok, Adam; Fehér, Krisztina; Bodor, Andrea; Rákosi, Kinga; Tóth, Gábor K.; Kövér, Katalin E.; Panyi, Gyorgy; Varga, Zoltan

    2015-01-01

    The voltage-gated Kv1.3 K+ channel plays a key role in the activation of T lymphocytes. Kv1.3 blockers selectively suppress immune responses mediated by effector memory T cells, which indicates the great potential of selective Kv1.3 inhibitors in the therapy of certain autoimmune diseases. Anuroctoxin (AnTx), a 35-amino-acid scorpion toxin is a high affinity blocker of Kv1.3, but also blocks Kv1.2 with similar potency. We designed and produced three AnTx variants: ([F32T]-AnTx, [N17A]-AnTx, [N17A/F32T]-AnTx) using solid-phase synthesis with the goal of improving the selectivity of the toxin for Kv1.3 over Kv1.2 while keeping the high affinity for Kv1.3. We used the patch-clamp technique to determine the blocking potency of the synthetic toxins on hKv1.3, mKv1.1, hKv1.2 and hKCa3.1 channels. Of the three variants [N17A/F32T]-AnTx maintained the high affinity of the natural peptide for Kv1.3 but became more than 16000-fold selective over Kv1.2. NMR data and molecular dynamics simulations suggest that the more rigid structure with restricted conformational space of the double substituted toxin compared to the flexible wild-type one is an important determinant of toxin selectivity. Our results provide the foundation for the possibility of the production and future therapeutic application of additional, even more selective toxins targeting various ion channels. PMID:26689143

  10. Selection of bisphenol A - single-chain antibodies from a non-immunized mouse library by ribosome display.

    PubMed

    Zhao, Li; Ning, Baoan; Bai, Jialei; Chen, Xiang; Peng, Yuan; Sun, Siming; Li, Guimin; Fan, Xianjun; Liu, Yuanyuan; Liu, Jianqing; Sun, Yanan; Gao, Zhixian; Zhang, Juankun

    2015-11-01

    Developing reagents with high affinity and specificity are critical to detect the environmental hormones or toxicants. Ribosome display technology has been widely used in functional protein or peptide screening and in directed evolution of protein molecules in vitro. In this study, single-chain variable fragments (scFvs) against bisphenol A (BPA) were selected from a library constructed from splenocytes of non-immunized mice. After five rounds of selection, the selected scFvs bound to BPA with high affinity. Indirect competitive enzyme-linked immunosorbent assay (ELISA) was introduced to screen the antibody affinity and specificity to BPA. The equilibrium dissociation constants (KDS) of one clone was 1.76μM as determined by surface plasmon resonance (SPR). This study indicated that ribosome display can isolate binders to small molecules from a non-immunized naive library without any in vivo steps and can generate recombinant antibodies efficiently and rapidly. In addition, this study provides a methodological framework for detection of small molecules using recombinant antibodies.

  11. Fingerprint-like Analysis of “Nanoantibody” Selection by Phage Display Using Two Helper Phage Variants

    PubMed Central

    Tillib, S.V.; Ivanova, T.I.; Vasilev, L.A.

    2010-01-01

    This paper discusses the selection of mini-antibody (nanoantibody, nanobody® or single domain antibody) sequences of desired specificity by phage display-based method using a generated library of antigen-binding domains of special heavy-chain only antibodies (single-stranded antibodies) of immunized camel. A comprehensive comparison of the efficiency of parallel selection procedures was performed by using the traditional (M13KO7) and modified (with N-terminal deletion in the surface gIII protein) helper phages. These two methods are partly complementary, and by using them in parallel one can significantly improve the selection efficiency. Parallel restriction analysis (fingerprinting) of PCR-amplified cloned sequences coding for mini-antibodies (HMR-analysis) is proposed for identifying individual clones, as a replacement to sequencing (to a certain extent). Using this method, unique data were collected on the selection of mini-antibody variants with the required specificity at various stages of a multi-stage selection procedure. It has been shown that different sequences coding for mini-antibodies are selected in different ways, and that, if this feature is not taken into account, some mini-antibody variants may be lost. PMID:22649655

  12. A phage display-selected peptide inhibitor of Agrobacterium vitis polygalacturonase.

    PubMed

    Warren, Jeremy G; Kasun, George W; Leonard, Takara; Kirkpatrick, Bruce C

    2016-05-01

    Agrobacterium vitis, the causal agent of crown gall of grapevine, is a threat to viticulture worldwide. A major virulence factor of this pathogen is polygalacturonase, an enzyme that degrades pectin components of the xylem cell wall. A single gene encodes for the polygalacturonase gene. Disruption of the polygalacturonase gene results in a mutant that is less pathogenic and produces significantly fewer root lesions on grapevines. Thus, the identification of peptides or proteins that could inhibit the activity of polygalacturonase could be part of a strategy for the protection of plants against this pathogen. A phage-displayed combinatorial peptide library was used to isolate peptides with a high binding affinity to A. vitis polygalacturonase. These peptides showed sequence similarity to regions of Oryza sativa (EMS66324, Japonica) and Triticum urartu (NP_001054402, wild wheat) polygalacturonase-inhibiting proteins (PGIPs). Furthermore, these panning experiments identified a peptide, SVTIHHLGGGS, which was able to reduce A. vitis polygalacturonase activity by 35% in vitro. Truncation studies showed that the IHHL motif alone is sufficient to inhibit A. vitis polygalacturonase activity. PMID:26177065

  13. Immunodiagnosis of human neurocysticercosis using a synthetic peptide selected by phage-display.

    PubMed

    Hell, R C R; Amim, P; de Andrade, H M; de Avila, R A M; Felicori, L; Oliveira, A G; Oliveira, C A; Nascimento, E; Tavares, C A P; Granier, C; Chávez-Olórtegui, C

    2009-04-01

    The usefulness of a synthetic peptide in the serodiagnosis of Taenia solium human neurocysticercosis (NC) has been evaluated. Phage-displayed peptides were screened with human antibodies to scolex protein antigen from cysticercus cellulosae (SPACc). One clone was found to interact specifically with anti-SPACc IgGs. The corresponding synthetic peptide was found to be recognized in ELISA by NC patient's sera. The study was carried out with sera from 28 confirmed NC patients, 13 control sera and 73 sera from patients suffering from other infectious diseases. A 93% sensibility and a 94.3% specificity was achieved. Figures of 89% and 31.4% of sensibility and specificity were obtained in a SPACc-based ELISA. Immunoblotting of SPACc with anti-peptide antibodies revealed a single band of approximately 45 kDa in 1D and four 45 kDa isoforms in 2D-gel electrophoresis. A strong and specific immunostaining in the fibers beneath the suckers, at the base of the rostellum, and in the tissue surrounding the scolex of cysticerci was observed by immunomicroscopy. Our results show that a peptide-based immunodiagnostic of neurocisticercosis can be envisioned.

  14. Novel strategy for the selection of human recombinant Fab fragments to membrane proteins from a phage-display library.

    PubMed

    Labrijn, Aran F; Koppelman, Marco H G M; Verhagen, Janneke; Brouwer, Mieke C; Schuitemaker, Hanneke; Hack, C Erik; Huisman, Han G

    2002-03-01

    Traditionally, the selection of phage-display libraries is performed on purified antigens (Ags), immobilized to a solid substrate. However, this approach may not be applicable for some Ags, such as membrane proteins, which for structural integrity strongly rely on their native environment. Here we describe an approach for the selection of phage-libraries against membrane proteins. The envelope glycoproteins (Env) of the Human Immunodeficiency Virus type-1 (HIV-1) were used as a model for a type-1 integral membrane protein. HIV-1IHI Env, expressed on the surface of Rabbit Kidney cells (RK13) with a recombinant vaccinia virus (rVV), was solubilized using the non-ionic detergent n-Octyl beta-D-glucopyranoside (OG). Membrane associated Env was reconstituted into vesicles by the simultaneous removal of detergent and free monomeric Env subunits by gel-filtration. The resulting antigen preparation, termed OG-P1IHI, was captured on microtiter plates coated with Galanthus nivalis agglutinin (GNA) and used for rounds of selection (panning) of a well-characterized phage-display library derived from an HIV-1 seropositive donor. Simultaneously, an identical experiment was performed with OG-P1IHI vesicles disrupted by Nonidet P-40 (NP-P1IHI). Both membrane-associated and soluble Ags were selected for vaccinia-specific clones (OG-P1IHI: 59/75 and NP-P1IHI: 1/75) and HIV-1-specific clones (OG-P1IHI: 11/75 and NP-P1IHI: 65/75) using our approach. Hence, the novel panning strategy described here may be applicable for selection of phage-libraries against membrane proteins.

  15. Selection of ceramic fluorapatite-binding peptides from a phage display combinatorial peptide library: optimum affinity tags for fluorapatite chromatography.

    PubMed

    Islam, Tuhidul; Bibi, Noor Shad; Vennapusa, Rami Reddy; Fernandez-Lahore, Marcelo

    2013-08-01

    Peptide affinity tags have become efficient tools for the purification of recombinant proteins from biological mixtures. The most commonly used ligands in this type of affinity chromatography are immobilized metal ions, proteins, antibodies, and complementary peptides. However, the major bottlenecks of this technique are still related to the ligands, including their low stability, difficulties in immobilization, and leakage into the final products. A model approach is presented here to overcome these bottlenecks by utilizing macroporous ceramic fluorapatite (CFA) as the stationary phase in chromatography and the CFA-specific short peptides as tags. The CFA chromatographic materials act as both the support matrix and the ligand. Peptides that bind with affinity to CFA were identified from a randomized phage display heptapeptide library. A total of five rounds of phage selection were performed. A common N-terminal sequence was found in two selected peptides: F4-2 (KPRSMLH) and F5-4 (KPRSVSG). The peptide F5-4, displayed by more than 40% of the phages analyzed in the fifth round of selection, was subjected to further studies. Selectivity of the peptide for the chemical composition and morphology of CFA was assured by the adsorption studies. The dissociation constant, obtained from the F5-4/CFA adsorption isotherm, was in the micromolar range, and the maximum capacity was 39.4 nmol/mg. The chromatographic behavior of the peptides was characterized on a CFA stationary phase with different buffers. Preferential affinity and specific retention properties suggest the possible application of the phage-derived peptides as a tag in CFA affinity chromatography for enhancing the selective recovery of proteins.

  16. Development of an HIV-1 Microbicide Based on Caulobacter crescentus: Blocking Infection by High-Density Display of Virus Entry Inhibitors.

    PubMed

    Farr, Christina; Nomellini, John F; Ailon, Evan; Shanina, Iryna; Sangsari, Sassan; Cavacini, Lisa A; Smit, John; Horwitz, Marc S

    2013-01-01

    The HIV/AIDS pandemic remains an enormous global health concern. Despite effective prevention options, 2.6 million new infections occur annually, with women in developing countries accounting for more than half of these infections. New prevention strategies that can be used by women are urgently needed. Topical microbicides specific for HIV-1 represent a promising prevention strategy. Conceptually, using harmless bacteria to display peptides or proteins capable of blocking entry provides an inexpensive approach to microbicide development. To avoid the potential pitfalls of engineering commensal bacteria, our strategy is to genetically display infection inhibitors on a non-native bacterium and rely on topical application of stabilized bacteria before potential virus exposure. Due to the high density cell-surface display capabilities and the inherent low toxicity of the bacterium, the S-layer mediated protein display capabilities of the non-pathogenic bacterium Caulobacter crescentus has been exploited for this approach. We have demonstrated that C. crescentus displaying MIP1α or CD4 interfered with the virus entry pathway and provided significant protection from HIV-1 pseudovirus representing clade B in a standard single cycle infection assay. Here we have expanded our C. crescentus based microbicide approach with additional and diverse classes of natural and synthetic inhibitors of the HIV-1 entry pathway. All display constructs provided variable but significant protection from HIV-1 infection; some with protection as high as 70%. Further, we describe protection from infection with additional viral clades. These findings indicate the significant potential for engineering C. crescentus to be an effective and readily adaptable HIV-1 microbicide platform. PMID:23840383

  17. Next-Generation Sequencing of a Single Domain Antibody Repertoire Reveals Quality of Phage Display Selected Candidates.

    PubMed

    Turner, Kendrick B; Naciri, Jennifer; Liu, Jinny L; Anderson, George P; Goldman, Ellen R; Zabetakis, Dan

    2016-01-01

    Next-Generation Sequencing and bioinformatics are powerful tools for analyzing the large number of DNA sequences present in an immune library. In this work, we constructed a cDNA library of single domain antibodies from a llama immunized with staphylococcal enterotoxin B. The resulting library was sequenced, resulting in approximately 8.5 million sequences with 5.4 million representing intact, useful sequences. The sequenced library was interrogated using sequences of known SEB-binding single domain antibodies from the library obtained through phage display panning methods in a previous study. New antibodies were identified, produced, and characterized, and were shown to have affinities and melting temperatures comparable to those obtained by traditional panning methods. This demonstrates the utility of using NGS as a complementary tool to phage-displayed biopanning as a means for rapidly obtaining additional antibodies from an immune library. It also shows that phage display, using a library of high diversity, is able to select high quality antibodies even when they are low in frequency. PMID:26895405

  18. Next-Generation Sequencing of a Single Domain Antibody Repertoire Reveals Quality of Phage Display Selected Candidates

    PubMed Central

    Turner, Kendrick B.; Naciri, Jennifer; Liu, Jinny L.; Anderson, George P.; Goldman, Ellen R.; Zabetakis, Dan

    2016-01-01

    Next-Generation Sequencing and bioinformatics are powerful tools for analyzing the large number of DNA sequences present in an immune library. In this work, we constructed a cDNA library of single domain antibodies from a llama immunized with staphylococcal enterotoxin B. The resulting library was sequenced, resulting in approximately 8.5 million sequences with 5.4 million representing intact, useful sequences. The sequenced library was interrogated using sequences of known SEB-binding single domain antibodies from the library obtained through phage display panning methods in a previous study. New antibodies were identified, produced, and characterized, and were shown to have affinities and melting temperatures comparable to those obtained by traditional panning methods. This demonstrates the utility of using NGS as a complementary tool to phage-displayed biopanning as a means for rapidly obtaining additional antibodies from an immune library. It also shows that phage display, using a library of high diversity, is able to select high quality antibodies even when they are low in frequency. PMID:26895405

  19. Prophylaxis with enteral antibiotics in ventilated patients: selective decontamination or selective cross-infection?

    PubMed Central

    Hurley, J C

    1995-01-01

    Selective decontamination of the digestive tract (SDD) has been evaluated as a method to prevent colonization and infection in ventilated patients in 40 trials. On the basis of an assumption that cross-infection would be reduced as a consequence of SDD and that this would distort the results of SDD studies that used concurrent controls, 14 studies used historic controls. To test this assumption, three observations from the two types of studies were compared. (i) The differences between observed and expected event rates for each study were used to perform a meta-analysis. This revealed that the summary odds ratios for bacteremia and respiratory infection were marked by significant heterogeneity (P > 0.95) and inconsistencies between those derived from studies with concurrent versus studies with historic controls. (ii) Where the data were available, the rates of acquisition of colonization in control groups were higher in studies with concurrent controls than in studies with historic controls. (iii) At least four studies with concurrent controls have shown a pattern of pathogenic isolates consistent with cross-infection between groups. These results are contrary to the initial assumption and suggest the possibility that SDD represents a major cross-infection hazard. PMID:7786000

  20. Solid-phase differential display and bacterial expression systems in selection and functional analysis of cDNAs.

    PubMed

    Ståhl, S; Odeberg, J; Larsson, M; Røsok, O; Ree, A H; Lundeberg, J

    1999-01-01

    Differential gene expression can be expected during activation and differentiation of cells as well as during pathological conditions, such as cancer. A number of strategies have been described to identify and understand isolated differentially expressed genes. The differential display methodology has rapidly become a widely used technique to identify differentially expressed mRNAs. In this chapter we described a variant of the differential display method based on solid-phase technology. The solid-phase procedure offers an attractive alternative to solution-based differential display because minute amounts of sample can be analyzed in considerably less time than previously. The employed solid support, monodisperse super paramagnetic beads, which circumvents precipitation and centrifugations steps, has also allowed for optimization of the critical enzymatic and preparative steps in the differential display methodology. We also described how bacterial expression can be used as a means to elucidate gene function. An efficient dual-expression system was presented, together with a basic concept describing how parallel expression of selected portions of cDNAs can be used for production of cDNA-encoded proteins as parts of affinity-tagged fusion proteins. The fusion proteins are suitable both for the generation of antibodies reactive to the target cDNA-encoded protein and for the subsequent affinity enrichment of such antibodies. Affinity-enriched antibodies have proved to be valuable tools in various assays, including immunoblotting and immunocytochemical staining, and can thus be used to localize the target cDNA-encoded protein to certain cells in a tissue section or even to a specific cell compartment or organelle within a cell. High-resolution localization of a cDNA-encoded protein would provide valuable information toward the understanding of protein function. PMID:10349662

  1. Naive CD8+ T-cell precursors display structured TCR repertoires and composite antigen-driven selection dynamics

    PubMed Central

    Neller, Michelle A; Ladell, Kristin; McLaren, James E; Matthews, Katherine K; Gostick, Emma; Pentier, Johanne M; Dolton, Garry; Schauenburg, Andrea JA; Koning, Dan; Fontaine Costa, Ana Isabel CA; Watkins, Thomas S; Venturi, Vanessa; Smith, Corey; Khanna, Rajiv; Miners, Kelly; Clement, Mathew; Wooldridge, Linda; Cole, David K; van Baarle, Debbie; Sewell, Andrew K; Burrows, Scott R; Price, David A; Miles, John J

    2015-01-01

    Basic parameters of the naive antigen (Ag)-specific T-cell repertoire in humans remain poorly defined. Systematic characterization of this ‘ground state' immunity in comparison with memory will allow a better understanding of clonal selection during immune challenge. Here, we used high-definition cell isolation from umbilical cord blood samples to establish the baseline frequency, phenotype and T-cell antigen receptor (TCR) repertoire of CD8+ T-cell precursor populations specific for a range of viral and self-derived Ags. Across the board, these precursor populations were phenotypically naive and occurred with hierarchical frequencies clustered by Ag specificity. The corresponding patterns of TCR architecture were highly ordered and displayed partial overlap with adult memory, indicating biased structuring of the T-cell repertoire during Ag-driven selection. Collectively, these results provide new insights into the complex nature and dynamics of the naive T-cell compartment. PMID:25801351

  2. Helicobacter pylori infection in patients with selective immunoglobulin E deficiency

    PubMed Central

    Magen, Eli; Schlesinger, Menachem; Ben-Zion, Itzhak; Vardy, Daniel

    2015-01-01

    AIM: To investigate the prevalence and clinical characteristics of Helicobacter pylori (H. pylori)-infected dyspeptic patients with selective immunoglobulin E deficiency (IgEd). METHODS: All individuals who underwent serum total immunoglobulin E (IgE) measurement at the Leumit Healthcare Services (Israel) in 2012 were identified in an electronic database search (n = 18487). From these, selected case group subjects were ≥ 12 years of age and had serum total IgE < 2 kIU/L (n = 158). The control group was selected from a random sampling of the remaining subjects ≥ 12 years of age to obtain a case-control ratio of 1:20 (n = 3160). Dyspeptic diseases, diagnosed no more than 5 years before serum total IgE testing, were identified and retrieved from the electronic database using specific International Classification of Diseases diagnostic codes. Results of C13-urea breath tests were used to identify subjects infected with H. pylori. Categorical variables between case and control subjects were analyzed using Fisher’s exact tests, whereas continuous variables were analyzed using χ2 tests. RESULTS: Dyspepsia was present in 27.2% (43/158) of case subjects and 22.7% (718/3160) of controls. Of these, significantly more case subjects (32/43, 74.4%) than controls (223/718, 31.1%) were positive for H. pylori (P < 0.01). Esophagogastroduodenoscopy was performed in 19 case and 94 control subjects, revealing that gastritis was more prevalent in IgEd case subjects than in controls (57.9% vs 29.8%, P < 0.05). Furthermore, a significantly greater proportion of case subjects presented with peptic duodenal ulcers (63.2% vs 15.9%, P < 0.01). Histopathologic examination showed marked chronic inflammation, lymphoid follicle formation and prominent germinal centers, with polymorphonuclear cell infiltration of gastric glands, that was similar in case and control biopsy tissues. Finally, IgEd case subjects that underwent esophagogastroduodenoscopy were more likely to exhibit treatment

  3. An antibody Fab selected from a recombinant phage display library detects deesterified pectic polysaccharide rhamnogalacturonan II in plant cells.

    PubMed Central

    Williams, M N; Freshour, G; Darvill, A G; Albersheim, P; Hahn, M G

    1996-01-01

    Rhamnogalacturonan II (RG-II) is a structurally complex, low molecular weight pectic polysaccharide that is released from primary cell walls of higher plants by treatment with endopolygalacturonase and is chromatographically purified after alkaline deesterification. A recombinant monovalent antibody fragment (Fab) that specifically recognizes RG-II has been obtained by selection from a phage display library of mouse immunoglobulin genes. By itself, RG-II is not immunogenic. Therefore, mice were immunized with a neoglycoprotein prepared by covalent attachment of RG-II to modified BSA. A cDNA library of the mouse IgG1/kappa antibody repertoire was constructed in the phage display vector pComb3. Selection of antigen-binding phage particles resulted in the isolation of an antibody Fab, CCRC-R1, that binds alkali-treated RG-II with high specificity. CCRC-R1 binds an epitope found primarily at sites proximal to the plasma membrane of suspension-cultured sycamore maple cells. In cells deesterified by alkali, CCRC-R1 labels the entire wall, suggesting that the RG-II epitope recognized by CCRC-R1 is masked by esterification in most of the wall and tha such RG-II esterification is absent near the plasma membrane. PMID:8624441

  4. Cell adhesion and invasion inhibitory effect of an ovarian cancer targeting peptide selected via phage display in vivo.

    PubMed

    Pu, Ximing; Ma, Chuying; Yin, Guangfu; You, Fei; Wei, Yan

    2014-01-17

    Organ-specific metastasis is of great importance since most of the cancer deaths are caused by spread of the primary cancer to distant sites. Therefore, targeted anti-metastases therapies are needed to prevent cancer cells from metastasizing to different organs. The phage clone pc3-1 displaying peptide WSGPGVWGASVK selected by phage display had been identified which have high binding efficiency and remarkable cell specificity to SK-OV-3 cells. In the present work, the effects of selected cell-binding phage and cognate peptide on the cell adhesion and invasion of targeted cells were investigated. Results showed that the adhesive ability of SK-OV-3 to extracellular matrix was inhibited by pc3-1 and peptide WSGPGVWGASVK, and pc3-1 blocked SK-OV-3 cells attachment more effective than the cognate peptide. The peptide WSGPGVWGASVK suppressed the cell number of SK-OV-3 that attached to HUVECs monolayer up to 24% and could block the spreading of the attaching cells. Forthermore, the cognate peptide could inhibit the invasion of SK-OV-3 significantly. The number of invaded SK-OV-3 cells and invaded SK-OV-3-activated HUVECs pretreated with peptide WSGPGVWGASVK was decreased by 24.3% and 36.6%, respectively. All these results suggested that peptide WSGPGVWGASVK might possess anti-metastasis against SK-OV-3 cells. PMID:24342617

  5. Extract of Pelargonium sidoides (EPs 7630) displays anti-infective properties by enhanced phagocytosis and differential modulation of host-bacteria interactions.

    PubMed

    Conrad, Andreas; Frank, Uwe

    2008-05-01

    EPs 7630 is an aqueous-ethanolic extract of the roots of PELARGONIUM SIDOIDES that displays well-documented benefits in the treatment of upper respiratory tract infections (URTI). IN VITRO and animal investigations have revealed various anti-infective properties of EPs 7630. The present review sums up recently published IN VITRO investigations that have shown positive effects on the activity of human peripheral blood phagocytes (PBP) and differential modulation of the interactions between group A streptococci and the host's epithelial barrier.

  6. Cardiac glycosides display selective efficacy for STK11 mutant lung cancer

    PubMed Central

    Kim, Nayoung; Yim, Hwa Young; He, Ningning; Lee, Cheol-Jung; Kim, Ju Hyun; Choi, Jin-Sung; Lee, Hye Suk; Kim, Somin; Jeong, Euna; Song, Mee; Jeon, Sang-Min; Kim, Woo-Young; Mills, Gordon B.; Cho, Yong-Yeon; Yoon, Sukjoon

    2016-01-01

    Although STK11 (LKB1) mutation is a major mediator of lung cancer progression, targeted therapy has not been implemented due to STK11 mutations being loss-of-function. Here, we report that targeting the Na+/K+-ATPase (ATP1A1) is synthetic lethal with STK11 mutations in lung cancer. The cardiac glycosides (CGs) digoxin, digitoxin and ouabain, which directly inhibit ATP1A1 function, exhibited selective anticancer effects on STK11 mutant lung cancer cell lines. Restoring STK11 function reduced the efficacy of CGs. Clinically relevant doses of digoxin decreased the growth of STK11 mutant xenografts compared to wild type STK11 xenografts. Increased cellular stress was associated with the STK11-specific efficacy of CGs. Inhibiting ROS production attenuated the efficacy of CGs, and STK11-AMPK signaling was important in overcoming the stress induced by CGs. Taken together, these results show that STK11 mutation is a novel biomarker for responsiveness to CGs. Inhibition of ATP1A1 using CGs warrants exploration as a targeted therapy for STK11 mutant lung cancer. PMID:27431571

  7. Zeta-crystallin displays strong selectivity for salicylic acid over aspirin.

    PubMed

    Bazzi, Mohammad D

    2002-04-26

    Interaction of camel lens zeta-crystallin with aspirin was investigated by activity and fluorescence measurements. Aspirin minimally inhibited the oxidoreductase activity of the enzyme and weakly quenched its fluorescence. However, significant fluorescence quenching of zeta-crystallin coincided with the appearance of a fluorescence signal characteristic of salicylic acid thereby raising the possibility that salicylic acid might have been the moiety responsible for inhibition and fluorescence quenching. Direct fluorescence measurements showed that zeta-crystallin had a much higher affinity for salicylic acid than aspirin (K(i) of about 24 microM for salicylic acid versus 630 microM for aspirin). Salicylic acid was also far more effective in inhibiting zeta-crystallin than aspirin (K(i) values were 23 microM versus 820 microM, respectively). Inhibition kinetics suggested that salicylic acid interacted with zeta-crystallin via a binding site that was distinct from that of NADPH. Salicylic acid also interacted with and quenched the fluorescence of camel lens alpha-crystallin suggesting a general mode of interaction with lens proteins. Within the normal therapeutic concentrations of salicylic acid or aspirin, only crystallin-salicylic acid interactions might be significant. These results showed that camel lens zeta- and alpha-crystallin exhibited remarkable selectivity for salicylic acid over aspirin, and thus, could be considered as salicylate-binding proteins.

  8. Cardiac glycosides display selective efficacy for STK11 mutant lung cancer.

    PubMed

    Kim, Nayoung; Yim, Hwa Young; He, Ningning; Lee, Cheol-Jung; Kim, Ju Hyun; Choi, Jin-Sung; Lee, Hye Suk; Kim, Somin; Jeong, Euna; Song, Mee; Jeon, Sang-Min; Kim, Woo-Young; Mills, Gordon B; Cho, Yong-Yeon; Yoon, Sukjoon

    2016-01-01

    Although STK11 (LKB1) mutation is a major mediator of lung cancer progression, targeted therapy has not been implemented due to STK11 mutations being loss-of-function. Here, we report that targeting the Na(+)/K(+)-ATPase (ATP1A1) is synthetic lethal with STK11 mutations in lung cancer. The cardiac glycosides (CGs) digoxin, digitoxin and ouabain, which directly inhibit ATP1A1 function, exhibited selective anticancer effects on STK11 mutant lung cancer cell lines. Restoring STK11 function reduced the efficacy of CGs. Clinically relevant doses of digoxin decreased the growth of STK11 mutant xenografts compared to wild type STK11 xenografts. Increased cellular stress was associated with the STK11-specific efficacy of CGs. Inhibiting ROS production attenuated the efficacy of CGs, and STK11-AMPK signaling was important in overcoming the stress induced by CGs. Taken together, these results show that STK11 mutation is a novel biomarker for responsiveness to CGs. Inhibition of ATP1A1 using CGs warrants exploration as a targeted therapy for STK11 mutant lung cancer. PMID:27431571

  9. Selection of high expressing mammalian cells by surface display of reporters.

    PubMed

    DeMaria, Christine T

    2012-01-01

    A flow cytometry method using a nonfluorescent reporter protein was developed for rapid, early-stage identification of cells producing high levels of a recombinant protein of interest. A cell surface reporter protein is coexpressed with the protein of interest, and the reporter protein is detected using a fluorescently labeled antibody. The genes encoding the reporter protein and the protein of interest are linked by an IRES so that they are transcribed in the same mRNA but are translated independently. Since they each arise from a common mRNA, the reporter protein's expression level accurately predicts, on a per cell basis, the relative expression level of the protein of interest. This method provides an effective process for selecting cells that express high levels of recombinant proteins, with the benefits of rapid and accurate 96-well plate clone screening (that is both quantitative and qualitative) and elimination of unstable clones during subsequent scale up and culture. Furthermore, because this method does not rely on the availability of a detection reagent specific for the protein of interest that is expressed, it can be easily implemented into any cell line development process. PMID:21987245

  10. Phage display selection of Affibody molecules with specific binding to the extracellular domain of the epidermal growth factor receptor.

    PubMed

    Friedman, M; Nordberg, E; Höidén-Guthenberg, I; Brismar, H; Adams, G P; Nilsson, F Y; Carlsson, J; Ståhl, S

    2007-04-01

    Affibody molecules specific for the epidermal growth factor receptor (EGFR) have been selected by phage display technology from a combinatorial protein library based on the 58-residue, protein A-derived Z domain. EGFR is overexpressed in various malignancies and is frequently associated with poor patient prognosis, and the information provided by targeting this receptor could facilitate both patient diagnostics and treatment. Three selected Affibody variants were shown to selectively bind to the extracellular domain of EGFR (EGFR-ECD). Kinetic biosensor analysis revealed that the three monomeric Affibody molecules bound with similar affinity, ranging from 130 to 185 nM. Head-to-tail dimers of the Affibody molecules were compared for their binding to recombinant EGFR-ECD in biosensor analysis and in human epithelial cancer A431 cells. Although the dimeric Affibody variants were found to bind in a range of 25-50 nM affinities in biosensor analysis, they were found to be low nanomolar binders in the cellular assays. Competition assays using radiolabeled Affibody dimers confirmed specific EGFR-binding and demonstrated that the three Affibody molecules competed for the same epitope. Immunofluorescence microscopy demonstrated that the selected Affibody dimers were initially binding to EGFR at the cell surface of A431, and confocal microscopy analysis showed that the Affibody dimers could thereafter be internalized. The potential use of the described Affibody molecules as targeting agents for radionuclide based imaging applications in various carcinomas is discussed. PMID:17452435

  11. Phage display selection of tight specific binding variants from a hyperthermostable Sso7d scaffold protein library.

    PubMed

    Zhao, Ning; Schmitt, Margaret A; Fisk, John D

    2016-04-01

    Antibodies, the quintessential biological recognition molecules, are not ideal for many applications because of their large size, complex modifications, and thermal and chemical instability. Identifying alternative scaffolds that may be evolved into tight, specific binding molecules with improved physical properties is of increasing interest, particularly for biomedical applications in resource-limited environments. Hyperthermophilic organisms, such as Sulfolobus solfataricus, are an attractive source of highly stable proteins that may serve as starting points for alternative molecular recognition scaffolds. We describe the first application of phage display to identify binding proteins based on the S. solfataricus protein Sso7d scaffold. Sso7d is a small cysteine-free DNA-binding protein (approximately 7 kDa, 63 amino acids), with a melting temperature of nearly 100 °C. Tight-binding Sso7d variants were selected for a diverse set of protein targets from a 10(10) member library, demonstrating the versatility of the scaffold. These Sso7d variants are able to discriminate among closely related human, bovine and rabbit serum albumins. Equilibrium dissociation constants in the nanomolar to low micromolar range were measured via competitive ELISA. Importantly, the Sso7d variants continue to bind their targets in the absence of the phage context. Furthermore, phage-displayed Sso7d variants retain their binding affinity after exposure to temperatures up to 70 °C. Taken together, our results suggest that the Sso7d scaffold will be a complementary addition to the range of non-antibody scaffold proteins that may be utilized in phage display. Variants of hyperthermostable binding proteins have potential applications in diagnostics and therapeutics for environments with extreme conditions of storage and deployment. PMID:26835881

  12. Phage display selection of tight specific binding variants from a hyperthermostable Sso7d scaffold protein library.

    PubMed

    Zhao, Ning; Schmitt, Margaret A; Fisk, John D

    2016-04-01

    Antibodies, the quintessential biological recognition molecules, are not ideal for many applications because of their large size, complex modifications, and thermal and chemical instability. Identifying alternative scaffolds that may be evolved into tight, specific binding molecules with improved physical properties is of increasing interest, particularly for biomedical applications in resource-limited environments. Hyperthermophilic organisms, such as Sulfolobus solfataricus, are an attractive source of highly stable proteins that may serve as starting points for alternative molecular recognition scaffolds. We describe the first application of phage display to identify binding proteins based on the S. solfataricus protein Sso7d scaffold. Sso7d is a small cysteine-free DNA-binding protein (approximately 7 kDa, 63 amino acids), with a melting temperature of nearly 100 °C. Tight-binding Sso7d variants were selected for a diverse set of protein targets from a 10(10) member library, demonstrating the versatility of the scaffold. These Sso7d variants are able to discriminate among closely related human, bovine and rabbit serum albumins. Equilibrium dissociation constants in the nanomolar to low micromolar range were measured via competitive ELISA. Importantly, the Sso7d variants continue to bind their targets in the absence of the phage context. Furthermore, phage-displayed Sso7d variants retain their binding affinity after exposure to temperatures up to 70 °C. Taken together, our results suggest that the Sso7d scaffold will be a complementary addition to the range of non-antibody scaffold proteins that may be utilized in phage display. Variants of hyperthermostable binding proteins have potential applications in diagnostics and therapeutics for environments with extreme conditions of storage and deployment.

  13. CARbodies: Human Antibodies Against Cell Surface Tumor Antigens Selected From Repertoires Displayed on T Cell Chimeric Antigen Receptors

    PubMed Central

    Alonso-Camino, Vanesa; Sánchez-Martín, David; Compte, Marta; Nuñez-Prado, Natalia; Diaz, Rosa M; Vile, Richard; Alvarez-Vallina, Luis

    2013-01-01

    A human single-chain variable fragment (scFv) antibody library was expressed on the surface of human T cells after transduction with lentiviral vectors (LVs). The repertoire was fused to a first-generation T cell receptor ζ (TCRζ)-based chimeric antigen receptor (CAR). We used this library to isolate antibodies termed CARbodies that recognize antigens expressed on the tumor cell surface in a proof-of-principle system. After three rounds of activation-selection there was a clear repertoire restriction, with the emergence dominant clones. The CARbodies were purified from bacterial cultures as soluble and active proteins. Furthermore, to validate its potential application for adoptive cell therapy, human T cells were transduced with a LV encoding a second-generation costimulatory CAR (CARv2) bearing the selected CARbodies. Transduced human primary T cells expressed significant levels of the CARbodies-based CARv2 fusion protein on the cell surface, and importantly could be specifically activated, after stimulation with tumor cells. This approach is a promising tool for the generation of antibodies fully adapted to the display format (CAR) and the selection context (cell synapse), which could extend the scope of current adoptive cell therapy strategies with CAR-redirected T cells. PMID:23695536

  14. [Selected bacterial infections of the skin in childhood].

    PubMed

    Mempel, M; Schnopp, C

    2015-04-01

    Bacterial infections of the skin are often seen by dermatologists. The majority of infections are caused by the gram-positive bacteria Staphylococcus aureus and Streptococcus pyogenes. These induce blistering/erosive (impetigo, ecthymata) and abceeding (folliculitis) infections of the skin, respectively. Owing to their differences in virulence factors and host immunity, these strains can lead to varying presentations and courses of the infections. This review focuses on impetigo, folliculitis, perianal streptococcal dermatitis, and ecthymata. PMID:25783212

  15. Type 1 cannabinoid receptor ligands display functional selectivity in a cell culture model of striatal medium spiny projection neurons.

    PubMed

    Laprairie, Robert B; Bagher, Amina M; Kelly, Melanie E M; Dupré, Denis J; Denovan-Wright, Eileen M

    2014-09-01

    Modulation of type 1 cannabinoid receptor (CB1) activity has been touted as a potential means of treating addiction, anxiety, depression, and neurodegeneration. Different agonists of CB1 are known to evoke varied responses in vivo. Functional selectivity is the ligand-specific activation of certain signal transduction pathways at a receptor that can signal through multiple pathways. To understand cannabinoid-specific functional selectivity, different groups have examined the effect of individual cannabinoids on various signaling pathways in heterologous expression systems. In the current study, we compared the functional selectivity of six cannabinoids, including two endocannabinoids (2-arachidonyl glycerol (2-AG) and anandamide (AEA)), two synthetic cannabinoids (WIN55,212-2 and CP55,940), and two phytocannabinoids (cannabidiol (CBD) and Δ(9)-tetrahydrocannabinol (THC)) on arrestin2-, Gα(i/o)-, Gβγ-, Gα(s)-, and Gα(q)-mediated intracellular signaling in the mouse STHdh(Q7/Q7) cell culture model of striatal medium spiny projection neurons that endogenously express CB1. In this system, 2-AG, THC, and CP55,940 were more potent mediators of arrestin2 recruitment than other cannabinoids tested. 2-AG, AEA, and WIN55,212-2, enhanced Gα(i/o) and Gβγ signaling, with 2-AG and AEA treatment leading to increased total CB1 levels. 2-AG, AEA, THC, and WIN55,212-2 also activated Gα(q)-dependent pathways. CP55,940 and CBD both signaled through Gα(s). CP55,940, but not CBD, activated downstream Gα(s) pathways via CB1 targets. THC and CP55,940 promoted CB1 internalization and decreased CB1 protein levels over an 18-h period. These data demonstrate that individual cannabinoids display functional selectivity at CB1 leading to activation of distinct signaling pathways. To effectively match cannabinoids with therapeutic goals, these compounds must be screened for their signaling bias.

  16. Type 1 cannabinoid receptor ligands display functional selectivity in a cell culture model of striatal medium spiny projection neurons.

    PubMed

    Laprairie, Robert B; Bagher, Amina M; Kelly, Melanie E M; Dupré, Denis J; Denovan-Wright, Eileen M

    2014-09-01

    Modulation of type 1 cannabinoid receptor (CB1) activity has been touted as a potential means of treating addiction, anxiety, depression, and neurodegeneration. Different agonists of CB1 are known to evoke varied responses in vivo. Functional selectivity is the ligand-specific activation of certain signal transduction pathways at a receptor that can signal through multiple pathways. To understand cannabinoid-specific functional selectivity, different groups have examined the effect of individual cannabinoids on various signaling pathways in heterologous expression systems. In the current study, we compared the functional selectivity of six cannabinoids, including two endocannabinoids (2-arachidonyl glycerol (2-AG) and anandamide (AEA)), two synthetic cannabinoids (WIN55,212-2 and CP55,940), and two phytocannabinoids (cannabidiol (CBD) and Δ(9)-tetrahydrocannabinol (THC)) on arrestin2-, Gα(i/o)-, Gβγ-, Gα(s)-, and Gα(q)-mediated intracellular signaling in the mouse STHdh(Q7/Q7) cell culture model of striatal medium spiny projection neurons that endogenously express CB1. In this system, 2-AG, THC, and CP55,940 were more potent mediators of arrestin2 recruitment than other cannabinoids tested. 2-AG, AEA, and WIN55,212-2, enhanced Gα(i/o) and Gβγ signaling, with 2-AG and AEA treatment leading to increased total CB1 levels. 2-AG, AEA, THC, and WIN55,212-2 also activated Gα(q)-dependent pathways. CP55,940 and CBD both signaled through Gα(s). CP55,940, but not CBD, activated downstream Gα(s) pathways via CB1 targets. THC and CP55,940 promoted CB1 internalization and decreased CB1 protein levels over an 18-h period. These data demonstrate that individual cannabinoids display functional selectivity at CB1 leading to activation of distinct signaling pathways. To effectively match cannabinoids with therapeutic goals, these compounds must be screened for their signaling bias. PMID:25037227

  17. The first caprine rotavirus detected in Argentina displays genomic features resembling virus strains infecting members of the Bovidae and Camelidae.

    PubMed

    Louge Uriarte, Enrique L; Badaracco, Alejandra; Matthijnssens, Jelle; Zeller, Mark; Heylen, Elizabeth; Manazza, Jorge; Miño, Samuel; Van Ranst, Marc; Odeón, Anselmo; Parreño, Viviana

    2014-06-25

    Rotavirus group A (RVA) is a major cause of diarrhea in humans and young animals including small ruminants. The purpose of this study was to identify RVA in dairy goat kids, and to characterize the complete genomic constellation and genetic relatedness with other RVA strains. Four out of twenty fecal samples from diarrheic and non-diarrheic goat kids were positive for RVA by ELISA. A representative sample was selected for further genome analyses. The RVA strain RVA/Goat-wt/ARG/0040/2011/G8P[1] displayed the following genomic constellation: G8-P[1]-I2-R5-C2-M2-A3-N2-T6-E12-H3, reminiscent to guanaco and other bovine-like RVA strains detected in Argentina. Phylogenetic analyses revealed that most of the genome segments had a rather close relatedness with RVA strains typically obtained from cattle, sheep, South American camelids and goats. Interestingly, strain 0040 possessed the R5 and E12 genotypes which have up to date only been found in different animal species from Argentina. Overall, these findings suggest that strain 0040 could represent a typical goat RVA genome constellation similar to those previously found in other animal species within the order Artiodactyla.

  18. Potential of Peptides as Inhibitors and Mimotopes: Selection of Carbohydrate-Mimetic Peptides from Phage Display Libraries

    PubMed Central

    Matsubara, Teruhiko

    2012-01-01

    Glycoconjugates play various roles in biological processes. In particular, oligosaccharides on the surface of animal cells are involved in virus infection and cell-cell communication. Inhibitors of carbohydrate-protein interactions are potential antiviral drugs. Several anti-influenza drugs such as oseltamivir and zanamivir are derivatives of sialic acid, which inhibits neuraminidase. However, it is very difficult to prepare a diverse range of sugar derivatives by chemical synthesis or by the isolation of natural products. In addition, the pathogenic capsular polysaccharides of bacteria are carbohydrate antigens, for which a safe and efficacious method of vaccination is required. Phage-display technology has been improved to enable the identification of peptides that bind to carbohydrate-binding proteins, such as lectins and antibodies, from a large repertoire of peptide sequences. These peptides are known as “carbohydrate-mimetic peptides (CMPs)” because they mimic carbohydrate structures. Compared to carbohydrate derivatives, it is easy to prepare mono- and multivalent peptides and then to modify them to create various derivatives. Such mimetic peptides are available as peptide inhibitors of carbohydrate-protein interactions and peptide mimotopes that are conjugated with adjuvant for vaccination. PMID:23094142

  19. Selective destruction of cells infected with human immunodeficiency virus

    DOEpatents

    Keener, William K.; Ward, Thomas E.

    2003-09-30

    Compositions and methods for selectively killing a cell containing a viral protease are disclosed. The composition is a variant of a protein synthesis inactivating toxin wherein a viral protease cleavage site is interposed between the A and B chains. The variant of the type II ribosome-inactivating protein is activated by digestion of the viral protease cleavage site by the specific viral protease. The activated ribosome-inactivating protein then kills the cell by inactivating cellular ribosomes. A preferred embodiment of the invention is specific for human immunodeficiency virus (HIV) and uses ricin as the ribosome-inactivating protein. In another preferred embodiment of the invention, the variant of the ribosome-inactivating protein is modified by attachment of one or more hydrophobic agents. The hydrophobic agent facilitates entry of the variant of the ribosome-inactivating protein into cells and can lead to incorporation of the ribosome-inactivating protein into viral particles. Still another preferred embodiment of the invention includes a targeting moiety attached to the variants of the ribosome-inactivating protein to target the agent to HIV infectable cells.

  20. Selective Destruction Of Cells Infected With The Human Immunodeficiency Virus

    DOEpatents

    Keener, William K.; Ward, Thomas E.

    2006-03-28

    Compositions and methods for selectively killing a cell containing a viral protease are disclosed. The composition is a varient of a protein synthesis inactivating toxin wherein a viral protease cleavage site is interposed between the A and B chains. The variant of the type II ribosome-inactivating protein is activated by digestion of the viral protease cleavage site by the specific viral protease. The activated ribosome-inactivating protein then kills the cell by inactivating cellular ribosomes. A preferred embodiment of the invention is specific for human immunodeficiency virus (HIV) and uses ricin as the ribosome-inactivating protein. In another preferred embodiment of the invention, the variant of the ribosome-inactivating protein is modified by attachment of one or more hydrophobic agents. The hydrophobic agent facilitates entry of the variant of the ribosome-inactivating protein into cells and can lead to incorporation of the ribosome-inactivating protein into viral particles. Still another preferred embodiment of the invention includes a targeting moiety attached to the variants of the ribosome-inactivating protein to target the agent to HIV infectable cells.

  1. Tetrahydro-2-naphthyl and 2-Indanyl Triazolopyrimidines Targeting Plasmodium falciparum Dihydroorotate Dehydrogenase Display Potent and Selective Antimalarial Activity

    PubMed Central

    2016-01-01

    Malaria persists as one of the most devastating global infectious diseases. The pyrimidine biosynthetic enzyme dihydroorotate dehydrogenase (DHODH) has been identified as a new malaria drug target, and a triazolopyrimidine-based DHODH inhibitor 1 (DSM265) is in clinical development. We sought to identify compounds with higher potency against Plasmodium DHODH while showing greater selectivity toward animal DHODHs. Herein we describe a series of novel triazolopyrimidines wherein the p-SF5-aniline was replaced with substituted 1,2,3,4-tetrahydro-2-naphthyl or 2-indanyl amines. These compounds showed strong species selectivity, and several highly potent tetrahydro-2-naphthyl derivatives were identified. Compounds with halogen substitutions displayed sustained plasma levels after oral dosing in rodents leading to efficacy in the P. falciparum SCID mouse malaria model. These data suggest that tetrahydro-2-naphthyl derivatives have the potential to be efficacious for the treatment of malaria, but due to higher metabolic clearance than 1, they most likely would need to be part of a multidose regimen. PMID:27127993

  2. Tetrahydro-2-naphthyl and 2-Indanyl Triazolopyrimidines Targeting Plasmodium falciparum Dihydroorotate Dehydrogenase Display Potent and Selective Antimalarial Activity.

    PubMed

    Kokkonda, Sreekanth; Deng, Xiaoyi; White, Karen L; Coteron, Jose M; Marco, Maria; de Las Heras, Laura; White, John; El Mazouni, Farah; Tomchick, Diana R; Manjalanagara, Krishne; Rudra, Kakali Rani; Chen, Gong; Morizzi, Julia; Ryan, Eileen; Kaminsky, Werner; Leroy, Didier; Martínez-Martínez, María Santos; Jimenez-Diaz, Maria Belen; Bazaga, Santiago Ferrer; Angulo-Barturen, Iñigo; Waterson, David; Burrows, Jeremy N; Matthews, Dave; Charman, Susan A; Phillips, Margaret A; Rathod, Pradipsinh K

    2016-06-01

    Malaria persists as one of the most devastating global infectious diseases. The pyrimidine biosynthetic enzyme dihydroorotate dehydrogenase (DHODH) has been identified as a new malaria drug target, and a triazolopyrimidine-based DHODH inhibitor 1 (DSM265) is in clinical development. We sought to identify compounds with higher potency against Plasmodium DHODH while showing greater selectivity toward animal DHODHs. Herein we describe a series of novel triazolopyrimidines wherein the p-SF5-aniline was replaced with substituted 1,2,3,4-tetrahydro-2-naphthyl or 2-indanyl amines. These compounds showed strong species selectivity, and several highly potent tetrahydro-2-naphthyl derivatives were identified. Compounds with halogen substitutions displayed sustained plasma levels after oral dosing in rodents leading to efficacy in the P. falciparum SCID mouse malaria model. These data suggest that tetrahydro-2-naphthyl derivatives have the potential to be efficacious for the treatment of malaria, but due to higher metabolic clearance than 1, they most likely would need to be part of a multidose regimen. PMID:27127993

  3. A compact phage display human scFv library for selection of antibodies to a wide variety of antigens

    PubMed Central

    Pansri, Potjamas; Jaruseranee, Nanthnit; Rangnoi, Kuntalee; Kristensen, Peter; Yamabhai, Montarop

    2009-01-01

    Background Phage display technology is a powerful new tool for making antibodies outside the immune system, thus avoiding the use of experimental animals. In the early days, it was postulated that this technique would eventually replace hybridoma technology and animal immunisations. However, since this technology emerged more than 20 years ago, there have only been a handful reports on the construction and application of phage display antibody libraries world-wide. Results Here we report the simplest and highly efficient method for the construction of a highly useful human single chain variable fragment (scFv) library. The least number of oligonucleotide primers, electroporations and ligation reactions were used to generate a library of 1.5 × 108 individual clones, without generation of sub-libraries. All possible combinations of heavy and light chains, among all immunoglobulin isotypes, were included by using a mixture of primers and overlapping extension PCR. The key difference from other similar libraries was the highest diversity of variable gene repertoires, which was derived from 140 non-immunized human donors. A wide variety of antigens were successfully used to affinity select specific binders. These included pure recombinant proteins, a hapten and complex antigens such as viral coat proteins, crude snake venom and cancer cell surface antigens. In particular, we were able to use standard bio-panning method to isolate antibody that can bind to soluble Aflatoxin B1, when using BSA-conjugated toxin as a target, as demonstrated by inhibition ELISA. Conclusion These results suggested that by using an optimized protocol and very high repertoire diversity, a compact and efficient phage antibody library can be generated. This advanced method could be adopted by any molecular biology laboratory to generate both naïve or immunized libraries for particular targets as well as for high-throughput applications. PMID:19175944

  4. Identification of Novel Protein-Ligand Interactions by Exon Microarray Analysis of Yeast Surface Displayed cDNA Library Selection Outputs.

    PubMed

    Bidlingmaier, Scott; Liu, Bin

    2015-01-01

    Yeast surface display is widely utilized to screen large libraries for proteins or protein fragments with specific binding properties. We have previously constructed and utilized yeast surface displayed human cDNA libraries to identify protein fragments that bind to various target ligands. Conventional approaches employ monoclonal screening and sequencing of polyclonal outputs that have been enriched for binding to a target molecule by several rounds of affinity-based selection. Frequently, a small number of clones will dominate the selection output, making it difficult to comprehensively identify potentially important interactions due to low representation in the selection output. We have developed a novel method to address this problem. By analyzing selection outputs using high-density human exon microarrays, the full potential of selection output diversity can be revealed in one experiment. FACS-based selection using yeast surface displayed human cDNA libraries combined with exon microarray analysis of the selection outputs is a powerful way of rapidly identifying protein fragments with affinity for any soluble ligand that can be fluorescently detected, including small biological molecules and drugs. In this report we present protocols for exon microarray-based analysis of yeast surface display human cDNA library selection outputs. PMID:26060075

  5. Phage-displayed antibody fragments recognizing dengue 3 and dengue 4 viruses as tools for viral serotyping in sera from infected individuals.

    PubMed

    Cabezas, Sheila; Rojas, Gertrudis; Pavon, Alequis; Bernardo, Lidice; Castellanos, Yinet; Alvarez, Mayling; Pupo, Maritza; Guillen, Gerardo; Guzman, Maria G

    2009-01-01

    The current study shows the usefulness of dengue-3- and dengue-4-specific phage-displayed antibody fragments as tools for viral detection and serotyping in sera from infected individuals. C6/36 HT cells were inoculated with acute-phase sera from patients, and supernatants were collected daily and analyzed by ELISA using phage-displayed antibody fragments as serotype-specific detector reagents. Serotyping of most samples was possible as early as two to three days postinoculation. Results were comparable with those obtained by indirect immunofluorescence assay but were obtained in a shorter period of time (<1 week). Phage-displayed antibody fragments were better tools for diagnosis and serotyping than their soluble counterparts. Our approach combines the advantages of viral isolation and ELISA techniques. These results could be the basis for the development of a high-throughput method for identifying dengue virus serotypes, which is crucial for the management and control of the disease.

  6. Two allelic isoforms of the serotonin transporter from Schistosoma mansoni display electrogenic transport and high selectivity for serotonin

    PubMed Central

    Fontana, Andréia C. K.; Sonders, Mark S.; Pereira-Junior, Olavo S.; Knight, Matty; Javitch, Jonathan A.; Rodrigues, Vanderlei; Amara, Susan G.; Mortensen, Ole V.

    2009-01-01

    The human blood fluke Schistosoma mansoni is the primary cause of schistosomiasis, a debilitating disease that affects 200 million individuals in over 70 countries. The biogenic amine serotonin is essential for the survival of the parasite and serotonergic proteins are potential novel drug targets for treating schistosomiasis. Here we characterize two novel serotonin transporter gene transcripts, SmSERT-A and SmSERT-B, from Schistosoma mansoni. Southern blot analysis shows that the two mRNAs are the products of different alleles of a single SmSERT gene locus. The two SmSERT forms differ in three amino acid positions near the N-terminus of the protein. Both SmSERTs are expressed in the adult form and in the sporocyst form (infected snails) of the parasite, but are absent from all other stages of the parasite’s complex life cycle. Heterologous expression of the two cDNAs in mammalian cells resulted in saturable, sodium-dependent serotonin transport activity with an apparent affinity for serotonin comparable to that of the human serotonin transporter. Although the two SmSERTs are pharmacologically indistinguishable from each other, efflux experiments reveal notably higher substrate selectivity for serotonin compared with their mammalian counterparts. Several well-established substrates for human SERT including (±)MDMA, S-(+)amphetamine, RU 24969, and m-CPP are not transported by SmSERTs, underscoring the higher selectivity of the schistosomal isoforms. Voltage clamp recordings of SmSERT substrate-elicited currents confirm the substrate selectivity observed in efflux experiments and suggest that it may be possible to exploit the electrogenic nature of SmSERT to screen for compounds that target the parasite in vivo. PMID:19549517

  7. System status display information

    NASA Technical Reports Server (NTRS)

    Summers, L. G.; Erickson, J. B.

    1984-01-01

    The system Status Display is an electronic display system which provides the flight crew with enhanced capabilities for monitoring and managing aircraft systems. Guidelines for the design of the electronic system displays were established. The technical approach involved the application of a system engineering approach to the design of candidate displays and the evaluation of a Hernative concepts by part-task simulation. The system engineering and selection of candidate displays are covered.

  8. A novel screen design for anti-ambient light front projection display with angle-selective absorber

    NASA Astrophysics Data System (ADS)

    Liao, Tianju; Chen, Weigang; He, Kebo; Zhang, Zhaoyu

    2016-03-01

    Ambient light is destructive to the reflective type projection system's contrast ratio which has great influence on the image quality. In contrast to the conventional front projection, short-throw projection has its advantage to reject the ambient light. Fresnel lens-shaped reflection layer is adapted to direct light from a large angle due to the low lens throw ratio to the viewing area. The structure separates the path of the ambient light and projection light, creating the chance to solve the problem that ambient light is mixed with projection light. However, with solely the lens-shaped reflection layer is not good enough to improve the contrast ratio due to the scattering layer, which contributes a necessarily wide viewing angle, could interfere with both light paths before hitting the layer. So we propose a new design that sets the draft angle surface with absorption layer and adds an angle-selective absorber to separate these two kinds of light. The absorber is designed to fit the direction of the projection light, leading to a small absorption cross section for the projection light and respectfully big absorption cross section for the ambient light. We have calculated the design with Tracepro, a ray tracing program and find a nearly 8 times contrast ratio improvement against the current design in theory. This design can hopefully provide efficient display in bright lit situation with better viewer satisfaction.

  9. Selective intestinal malabsorption of vitamin B12 displays recessive Mendelian inheritance: Assignment of a locus to chromosome 10 by linkage

    SciTech Connect

    Aminoff, M.; Tahvanainen, E.; Chapelle, A. de la

    1995-10-01

    Juvenile megaloblastic anemia caused by selective intestinal malabsorption of vitamin B12 has been considered a distinct condition displaying autosomal recessive inheritance. It appears to have a worldwide distribution, and comparatively high incidences were reported 30 years ago in Finland and Norway. More recently, the Mendelian inheritance of the condition has been questioned because almost no new cases have occurred in these populations. Here we report linkage studies assigning a recessive-gene locus for the disease to chromosome 10 in previously diagnosed multiplex families from Finland and Norway, proving the Mendelian mode of inheritance. The locus is tentatively assigned to the 6-cM interval between markers D10S548 and D10S466, with a multipoint maximum lod score (Z{sub max}) of 5.36 near marker D10S1477. By haplotype analysis, the healthy sibs in these families did not appear to constitute any examples of nonpenetrance. We hypothesize that the paucity of new cases in these populations is due either to a dietary effect on the gene penetrance that has changed with time, or to a drop in the birth rate in subpopulations showing enrichment of the mutation, or to both of these causes. 38 refs., 4 figs., 2 tabs.

  10. Antagonistic effect of disulfide-rich peptide aptamers selected by cDNA display on interleukin-6-dependent cell proliferation

    SciTech Connect

    Nemoto, Naoto; Tsutsui, Chihiro; Yamaguchi, Junichi; Ueno, Shingo; Machida, Masayuki; Kobayashi, Toshikatsu; Sakai, Takafumi

    2012-04-27

    Highlights: Black-Right-Pointing-Pointer Disulfide-rich peptide aptamer inhibits IL-6-dependent cell proliferation. Black-Right-Pointing-Pointer Disulfide bond of peptide aptamer is essential for its affinity to IL-6R. Black-Right-Pointing-Pointer Inhibitory effect of peptide depends on number and pattern of its disulfide bonds. -- Abstract: Several engineered protein scaffolds have been developed recently to circumvent particular disadvantages of antibodies such as their large size and complex composition, low stability, and high production costs. We previously identified peptide aptamers containing one or two disulfide-bonds as an alternative ligand to the interleukin-6 receptor (IL-6R). Peptide aptamers (32 amino acids in length) were screened from a random peptide library by in vitro peptide selection using the evolutionary molecular engineering method 'cDNA display'. In this report, the antagonistic activity of the peptide aptamers were examined by an in vitro competition enzyme-linked immunosorbent assay (ELISA) and an IL-6-dependent cell proliferation assay. The results revealed that a disulfide-rich peptide aptamer inhibited IL-6-dependent cell proliferation with similar efficacy to an anti-IL-6R monoclonal antibody.

  11. Lipocalin 2 Imparts Selective Pressure on Bacterial Growth in the Bladder and Is Elevated in Women with Urinary Tract Infection

    PubMed Central

    Steigedal, Magnus; Marstad, Anne; Haug, Markus; Damås, Jan K.; Strong, Roland K.; Roberts, Pacita L.; Himpsl, Stephanie D.; Stapleton, Ann; Hooton, Thomas M.; Mobley, Harry L. T.; Hawn, Thomas R.

    2014-01-01

    Competition for iron is a critical component of successful bacterial infections, but the underlying in vivo mechanisms are poorly understood. We have previously demonstrated that lipocalin 2 (LCN2) is an innate immunity protein that binds to bacterial siderophores and starves them for iron, thus representing a novel host defense mechanism to infection. In the present study we show that LCN2 is secreted by the urinary tract mucosa and protects against urinary tract infection (UTI). We found that LCN2 was expressed in the bladder, ureters, and kidneys of mice subject to UTI. LCN2 was protective with higher bacterial numbers retrieved from bladders of Lcn2-deficient mice than from wild-type mice infected with the LCN2-sensitive Escherichia coli strain H9049. Uropathogenic E. coli mutants in siderophore receptors for salmochelin, aerobactin, or yersiniabactin displayed reduced fitness in wild-type mice, but not in mice deficient of LCN2, demonstrating that LCN2 imparts a selective pressure on bacterial growth in the bladder. In a human cohort of women with recurrent E. coli UTIs, urine LCN2 levels were associated with UTI episodes and with levels of bacteriuria. The number of siderophore systems was associated with increasing bacteriuria during cystitis. Our data demonstrate that LCN2 is secreted by the urinary tract mucosa in response to uropathogenic E. coli challenge and acts in innate immune defenses as a colonization barrier that pathogens must overcome to establish infection. PMID:25398327

  12. Infrainguinal anastomotic arterial graft infections treated by selective graft preservation.

    PubMed Central

    Calligaro, K D; Westcott, C J; Buckley, R M; Savarese, R P; DeLaurentis, D A

    1992-01-01

    The purpose of this study was to determine whether the type of graft material and bacteria involved in an infrainguinal arterial anastomotic infection can be used as guidelines for graft preservation. Between 1972 and 1990, the authors treated 35 anastomotic infections involving a common femoral or distal artery. The graft material was Dacron in 14 patients, polytetrafluoroethylene (PTFE) in 14, and vein in 7. Of the 14 Dacron grafts, immediate graft excision was required for overwhelming infection in eight patients (bleeding in five, sepsis in three) and for an occluded graft in one patient. Three of five patients failed attempted graft preservation because of nonhealing wounds. Thus, 12 of the 14 Dacron grafts ultimately required graft excision. Of the 21 "smooth-walled" vein and PTFE grafts, 10 required immediate graft excision for occluded grafts (five PTFE, one vein) or bleeding (three PTFE, one vein). Ten of the remaining 11 (91%) patients with patent "smooth-walled" grafts, intact anastomoses, and absence of sepsis managed by graft preservation healed their wounds and maintained distal arterial perfusion. Wound cultures grew pure gram-positive cocci in 17 of 21 "smooth-walled" graft infections versus 8 of 14 Dacron graft infections. In the absence of systemic sepsis, graft preservation is the treatment of choice for gram-positive infections involving an intact anastomosis of patent PTFE and vein grafts. Regardless of the bacterial cause, the authors recommend that any infrainguinal anastomotic infection of a Dacron graft be treated by immediate excision of all infected graft material. PMID:1632705

  13. Infection of Brachypodium distachyon with selected grass rust pathogens.

    PubMed

    Ayliffe, Michael; Singh, Davinder; Park, Robert; Moscou, Matthew; Pryor, Tony

    2013-08-01

    The model temperate grass Brachypodium distachyon is considered a nonhost for wheat rust diseases caused by Puccinia graminis f. sp. tritici, P. triticina, and P. striiformis. Up to 140 Brachypodium accessions were infected with these three rust species, in addition to P. graminis ff. spp. avena and phalaridis. Related B. distachyon lines showed similar cytological nonhost resistance (NHR) phenotypes, and an inverse relationship between P. graminis f. sp. tritici and P. striiformis growth was observed in many lines, with accessions that allowed the most growth of P. graminis f. sp. tritici showing the least P. striiformis development and vice versa. Callose deposition patterns during infection by all three rust species showed similarity to the wheat basal defense response while cell death that resulted in autofluorescence did not appear to be a major component of the defense response. Infection of B. distachyon with P. graminis f. sp. avena and P. graminis f. sp. phalaridis produced much greater colonization, indicating that P. graminis rusts with Poeae hosts show greater ability to infect B. distachyon than those with Triticeae hosts. P. striiformis infection of progeny from two B. distachyon families demonstrated that these NHR phenotypes are highly heritable and appear to be under relatively simple genetic control, making this species a powerful tool for elucidating the molecular basis of NHR to cereal rust pathogens.

  14. Dogs infected with the blood trypomastigote form of Trypanosoma cruzi display an increase expression of cytokines and chemokines plus an intense cardiac parasitism during acute infection.

    PubMed

    de Souza, Sheler Martins; Vieira, Paula Melo de Abreu; Roatt, Bruno Mendes; Reis, Levi Eduardo Soares; da Silva Fonseca, Kátia; Nogueira, Nívia Carolina; Reis, Alexandre Barbosa; Tafuri, Washington Luiz; Carneiro, Cláudia Martins

    2014-03-01

    The recent increase in immigration of people from areas endemic for Chagas disease (Trypanosoma cruzi) to the United States and Europe has raised concerns about the transmission via blood transfusion and organ transplants in these countries. Infection by these pathways occurs through blood trypomastigotes (BT), and these forms of T. cruzi are completely distinct of metacyclic trypomastigotes (MT), released by triatomine vector, in relation to parasite-host interaction. Thus, research comparing infection with these different infective forms is important for explaining the potential impacts on the disease course. Here, we investigated tissue parasitism and relative mRNA expression of cytokines, chemokines, and chemokine receptors in the heart during acute infection by MT or BT forms in dogs. BT-infected dogs presented a higher cardiac parasitism, increased relative mRNA expression of pro-inflammatory and immunomodulatory cytokines and of the chemokines CCL3/MIP-1α, CCL5/RANTES, and the chemokine receptor CCR5 during the acute phase of infection, as compared to MT-infected dogs. These results suggest that infection with BT forms may lead to an increased immune response, as revealed by the cytokines ratio, but this kind of immune response was not able to control the cardiac parasitism. Infection with the MT form presented an increase in the relative mRNA expression of IL-12p40 as compared to that of IL-10 or TGF-β1. Correlation analysis showed increased relative mRNA expression of IFN-γ as well as IL-10, which may be an immunomodulatory response, as well as an increase in the correlation of CCL5/RANTES and its CCR5 receptor. Our findings revealed a difference between inoculum sources of T. cruzi, as vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase, which may influence immunopathological aspects of Chagas disease.

  15. Identification of selected respiratory pathogens in endodontic infections

    PubMed Central

    Nandakumar, R.; Whiting, J.; Fouad, A. F.

    2008-01-01

    Objective To determine whether endodontic infections could harbor common etiologic agents of respiratory infections such as Streptococcus pneumoniae and Chlamydia pneumoniae. Methods Specimens were aseptically obtained from 40 patients with endodontic infections. For the detection of C. pneumoniae, a single step 16S rRNA based PCR and a nested PCR targeting aromatic amino acid hydroxylase were used. For the identification of S. pneumoniae, primers targeting 16S rRNA gene and autolysin (lytA) were used. Results Of 21 patient samples tested with the 16S rRNA-based PCR for S. pneumoniae, positive amplification was observed in all except three specimens. However, sequencing and phylogenetic analysis revealed that the product belonged to other bacterial phylotypes. The lytA-based PCR for S. pneumoniae and both PCR assays for C. pneumoniae failed to detect these organisms in all the specimens tested. Conclusions S. pneumoniae and C. pneumoniae were not present in endodontic infections. PCR primers with less stringent specificity will inaccurately identify respiratory pathogens. PMID:18585629

  16. Prevalence of selected rickettsial infections in cats in Southern Germany.

    PubMed

    Bergmann, Michèle; Englert, Theresa; Stuetzer, Bianca; Hawley, Jennifer R; Lappin, Michael R; Hartmann, Katrin

    2015-10-01

    Prevalence of Anaplasma, Ehrlichia, Neorickettsia, and Wolbachia DNA in blood of 479 cats collected in different veterinary clinics in Southern Germany was determined using a previously published conventional PCR using 16S-23S intergenic spacer primers (5' CTG GGG ACT ACG GTC GCA AGA C 3' - forward; 5' CTC CAG TTT ATC ACT GGA AGT T 3' - reverse). Purified amplicons were sequenced to confirm genus and species. Associations between rickettsial infections, and feline immunodeficiency virus (FIV), as well as feline leukemia virus (FeLV) status were evaluated. Rickettsial prevalence was 0.4% (2/479; CI: 0.01-1.62%). In the two infected cats, Anaplasma phagocytophilum DNA was amplified. These cats came from different environment and had outdoor access. Both were ill with many of their problems likely related to other diseases. However, one cat had neutrophilia with left shift and the other thrombocytopenia potentially caused by their A. phagocytophilum infection. There was no significant difference in the FIV and FeLV status between A. phagocytophilum-negative and -positive cats. A. phagocytophilum can cause infection in cats in Southern Germany, and appropriate tick control is recommended. PMID:26387062

  17. Prevalence of selected rickettsial infections in cats in Southern Germany.

    PubMed

    Bergmann, Michèle; Englert, Theresa; Stuetzer, Bianca; Hawley, Jennifer R; Lappin, Michael R; Hartmann, Katrin

    2015-10-01

    Prevalence of Anaplasma, Ehrlichia, Neorickettsia, and Wolbachia DNA in blood of 479 cats collected in different veterinary clinics in Southern Germany was determined using a previously published conventional PCR using 16S-23S intergenic spacer primers (5' CTG GGG ACT ACG GTC GCA AGA C 3' - forward; 5' CTC CAG TTT ATC ACT GGA AGT T 3' - reverse). Purified amplicons were sequenced to confirm genus and species. Associations between rickettsial infections, and feline immunodeficiency virus (FIV), as well as feline leukemia virus (FeLV) status were evaluated. Rickettsial prevalence was 0.4% (2/479; CI: 0.01-1.62%). In the two infected cats, Anaplasma phagocytophilum DNA was amplified. These cats came from different environment and had outdoor access. Both were ill with many of their problems likely related to other diseases. However, one cat had neutrophilia with left shift and the other thrombocytopenia potentially caused by their A. phagocytophilum infection. There was no significant difference in the FIV and FeLV status between A. phagocytophilum-negative and -positive cats. A. phagocytophilum can cause infection in cats in Southern Germany, and appropriate tick control is recommended.

  18. Phenotypes selected during chronic lung infection in cystic fibrosis patients: implications for the treatment of Pseudomonas aeruginosa biofilm infections.

    PubMed

    Ciofu, Oana; Mandsberg, Lotte F; Wang, Hengzhuang; Høiby, Niels

    2012-07-01

    During chronic lung infection of patients with cystic fibrosis, Pseudomonas aeruginosa can survive for long periods of time under the challenging selective pressure imposed by the immune system and antibiotic treatment as a result of its biofilm mode of growth and adaptive evolution mediated by genetic variation. Mucoidy, hypermutability and acquirement of mutational antibiotic resistance are important adaptive phenotypes that are selected during chronic P. aeruginosa infection. This review dicsusses the role played by these phenotypes for the tolerance of biofilms to antibiotics and show that mucoidy and hypermutability change the architecture of in vitro formed biofilms and lead to increase tolerance to antibiotics. Production of high levels of beta-lactamase impairs penetration of beta-lactam antibiotics due to inactivation of the antibiotic. In conclusion, these data underline the importance of biofilm prevention strategies by early aggressive antibiotic prophylaxis or therapy before phenotypic diversification during chronic lung infection of patients with cystic fibrosis.

  19. Directed evolution of anti-HER2 DARPins by SNAP display reveals stability/function trade-offs in the selection process.

    PubMed

    Houlihan, Gillian; Gatti-Lafranconi, Pietro; Lowe, David; Hollfelder, Florian

    2015-09-01

    In vitro display technologies have proved to be powerful tools for obtaining high-affinity protein binders. We recently described SNAP display, an entirely in vitro DNA display system that uses the SNAP-tag to link protein with its encoding DNA in water-in-oil emulsions. Here, we apply SNAP display for the affinity maturation of a designed ankyrin repeat proteins (DARPin) that binds to the extracellular domain of HER2 previously isolated by ribosome display. After four SNAP display selection cycles, proteins that bound specifically to HER2 in vitro, with dissociation constants in the low- to sub-nanomolar range, were isolated. In vitro affinities of the panel of evolved DARPins directly correlated with the fluorescence intensities of evolved DARPins bound to HER2 on a breast cancer cell line. A stability trade-off is observed as the most improved DARPins have decreased thermostability, when compared with the parent DARPin used as a starting point for affinity maturation. Dissection of the framework mutations of the highest affinity variant, DARPin F1, shows that functionally destabilising and compensatory mutations accumulated throughout the four rounds of evolution.

  20. Epidemiological investigation of selected pigeon viral infections in Poland.

    PubMed

    Stenzel, T A; Pestka, D; Tykałowski, B; Śmiałek, M; Koncicki, A

    2012-12-01

    Due to a lack of data in regard to the spread of viral infections in Polish pigeon populations, studies were undertaken to assess the frequency of adeno-, circo- and herpesvirus infections in flocks of pigeons across the entire country. In total, 107 flocks were examined, of which 61 per cent consisted of racing and 39 per cent of fancy pigeons. The flocks were divided into groups according to breed (racing and fancy pigeons) as well as physical condition (healthy and sick). In the studied pigeon flocks, the pigeon circovirus (PiCV) genetic material was the most frequently detected (44.5-100 per cent depending on the group), pigeon herpesvirus genetic material was second in frequency (0-30 per cent depending on the group), while genetic material of pigeon adenovirus was found only in two flocks of young birds with clinical symptoms of Young Pigeon Disease Syndrome (YPDS). The presence of fowl adenovirus (FAdV) genetic material was not detected in any of the studied flocks. Results obtained demonstrate a wide spread of circovirus in pigeon flocks in Poland, and substantiate earlier theories proposed by other authors, that immunosuppression evoked by PiCV infection is one of the main causative agents of YPDS.

  1. Chlamydia trachomatis-infected patients display variable antibody profiles against the nine-member polymorphic membrane protein family.

    PubMed

    Tan, Chun; Hsia, Ru-ching; Shou, Huizhong; Haggerty, Catherine L; Ness, Roberta B; Gaydos, Charlotte A; Dean, Deborah; Scurlock, Amy M; Wilson, David P; Bavoil, Patrik M

    2009-08-01

    Genomic analysis of the Chlamydiaceae has revealed a multigene family encoding large, putatively autotransported polymorphic membrane proteins (Pmps) with nine members in the sexually transmitted pathogen Chlamydia trachomatis. While various pathogenesis-related functions are emerging for the Pmps, observed genotypic and phenotypic variation among several chlamydial Pmps in various Chlamydia species has led us to hypothesize that the pmp gene repertoire is the basis of a previously undetected mechanism of antigenic variation. To test this hypothesis, we chose to examine the serologic response of C. trachomatis-infected patients to each Pmp subtype. Immune serum samples were collected from four populations of patients with confirmed C. trachomatis genital infection: 40 women with pelvic inflammatory disease from Pittsburgh, PA; 27 and 34 adolescent/young females from Oakland, CA, and Little Rock, AR, respectively; and 58 adult male patients from Baltimore, MD. The Pmp-specific antibody response was obtained using immunoblot analysis against each of the nine recombinantly expressed Pmps and quantified by densitometry. Our results show that nearly all C. trachomatis-infected patients mount a strong serologic response against individual or multiple Pmp subtypes and that the antibody specificity profile varies between patients. Moreover, our analysis reveals differences in the strengths and specificities of the Pmp subtype-specific antibody reactivity relating to gender and clinical outcome. Overall, our results indicate that the Pmps elicit various serologic responses in C. trachomatis-infected patients and are consistent with the pmp gene family being the basis of a mechanism of antigenic variation.

  2. Chlamydia trachomatis-Infected Patients Display Variable Antibody Profiles against the Nine-Member Polymorphic Membrane Protein Family▿ §

    PubMed Central

    Tan, Chun; Hsia, Ru-ching; Shou, Huizhong; Haggerty, Catherine L.; Ness, Roberta B.; Gaydos, Charlotte A.; Dean, Deborah; Scurlock, Amy M.; Wilson, David P.; Bavoil, Patrik M.

    2009-01-01

    Genomic analysis of the Chlamydiaceae has revealed a multigene family encoding large, putatively autotransported polymorphic membrane proteins (Pmps) with nine members in the sexually transmitted pathogen Chlamydia trachomatis. While various pathogenesis-related functions are emerging for the Pmps, observed genotypic and phenotypic variation among several chlamydial Pmps in various Chlamydia species has led us to hypothesize that the pmp gene repertoire is the basis of a previously undetected mechanism of antigenic variation. To test this hypothesis, we chose to examine the serologic response of C. trachomatis-infected patients to each Pmp subtype. Immune serum samples were collected from four populations of patients with confirmed C. trachomatis genital infection: 40 women with pelvic inflammatory disease from Pittsburgh, PA; 27 and 34 adolescent/young females from Oakland, CA, and Little Rock, AR, respectively; and 58 adult male patients from Baltimore, MD. The Pmp-specific antibody response was obtained using immunoblot analysis against each of the nine recombinantly expressed Pmps and quantified by densitometry. Our results show that nearly all C. trachomatis-infected patients mount a strong serologic response against individual or multiple Pmp subtypes and that the antibody specificity profile varies between patients. Moreover, our analysis reveals differences in the strengths and specificities of the Pmp subtype-specific antibody reactivity relating to gender and clinical outcome. Overall, our results indicate that the Pmps elicit various serologic responses in C. trachomatis-infected patients and are consistent with the pmp gene family being the basis of a mechanism of antigenic variation. PMID:19487469

  3. GC–MS-Based Metabonomic Profiling Displayed Differing Effects of Borna Disease Virus Natural Strain Hu-H1 and Laboratory Strain V Infection in Rat Cortical Neurons

    PubMed Central

    Liu, Siwen; Bode, Liv; Zhang, Lujun; He, Peng; Huang, Rongzhong; Sun, Lin; Chen, Shigang; Zhang, Hong; Guo, Yujie; Zhou, Jingjing; Fu, Yuying; Zhu, Dan; Xie, Peng

    2015-01-01

    Borna disease virus (BDV) persists in the central nervous systems of a wide variety of vertebrates and causes behavioral disorders. Previous studies have revealed that metabolic perturbations are associated with BDV infection. However, the pathophysiological effects of different viral strains remain largely unknown. Rat cortical neurons infected with human strain BDV Hu-H1, laboratory BDV Strain V, and non-infected control (CON) cells were cultured in vitro. At day 12 post-infection, a gas chromatography coupled with mass spectrometry (GC–MS) metabonomic approach was used to differentiate the metabonomic profiles of 35 independent intracellular samples from Hu-H1-infected cells (n = 12), Strain V-infected cells (n = 12), and CON cells (n = 11). Partial least squares discriminant analysis (PLS-DA) was performed to demonstrate discrimination between the three groups. Further statistical testing determined which individual metabolites displayed significant differences between groups. PLS-DA demonstrated that the whole metabolic pattern enabled statistical discrimination between groups. We identified 31 differential metabolites in the Hu-H1 and CON groups (21 decreased and 10 increased in Hu-H1 relative to CON), 35 differential metabolites in the Strain V and CON groups (30 decreased and 5 increased in Strain V relative to CON), and 21 differential metabolites in the Hu-H1 and Strain V groups (8 decreased and 13 increased in Hu-H1 relative to Strain V). Comparative metabonomic profiling revealed divergent perturbations in key energy and amino acid metabolites between natural strain Hu-H1 and laboratory Strain V of BDV. The two BDV strains differentially alter metabolic pathways of rat cortical neurons in vitro. Their systematic classification provides a valuable template for improved BDV strain definition in future studies. PMID:26287181

  4. Infection Profiles of Selected Aquabirnavirus Isolates in CHSE Cells

    PubMed Central

    Gamil, Amr A. A.; Evensen, Øystein; Mutoloki, Stephen

    2015-01-01

    The wide host range and antigenic diversity of aquabirnaviruses are reflected by the presence of a collection of isolates with different sero- and genotypic properties that have previously been classified as such. Differences in cytopathogenic mechanisms and host responses induced by these isolates have not been previously examined. In the present study, we investigated infection profiles induced by genetically and serologically closely related as well as distant isolates in-vitro. CHSE-214 cells were infected with either E1S (serotype A3, genogroup 3), VR-299 (serotype A1, genogroup 1), highly virulent Sp (TA) or avirulent Sp (PT) (serotype A2, genogroup 5). The experiments were performed at temperatures most optimum for each of the isolates namely 15°C for VR-299, TA and PT strains and 20°C for E1S. Differences in virus loads and ability to induce cytopathic effect, inhibition of protein synthesis, apoptosis, and induction of IFNa, Mx1, PKR or TNFα gene expression at different times post infection were examined. The results showed on one hand, E1S with the highest ability to replicate, induce apoptosis and IFNa gene expression while VR-299 inhibited protein synthesis and induced Mx1 and PKR gene expression the most. The two Sp isolates induced the highest TNFα gene expression but differed in their ability to replicate, inhibit protein synthesis, and induce gene expression, with TA being more superior. Collectively, these findings point towards the adaptation by different virus isolates to suit environments and hosts that they patronize. Furthermore, the results also suggest that genetic identity is not prerequisite to functional similarities thus results of one aquabirnavirus isolate cannot necessarily be extrapolated to another. PMID:26263557

  5. Experimental evolution can unravel the complex causes of natural selection in clinical infections.

    PubMed

    Brockhurst, Michael A

    2015-06-01

    It is increasingly clear that rapid evolutionary dynamics are an important process in microbial ecology. Experimental evolution, wherein microbial evolution is observed in real-time, has revealed many instances of appreciable evolutionary change occurring on very short timescales of a few days or weeks in response to a variety of biotic and abiotic selection pressures. From clinical infections, including the chronic bacterial lung infections associated with cystic fibrosis that form a focus of my research, there is now abundant evidence suggesting that rapid evolution by infecting microbes contributes to host adaptation, treatment failure and worsening patient prognosis. However, disentangling the drivers of natural selection in complex infection environments is extremely challenging and limits our understanding of the selective pressures acting upon microbes in infections. Controlled evolution experiments can make a vital contribution to this by determining the causal links between predicted drivers of natural selection and the evolutionary responses of microbes. Integration of experimental evolution into studies of clinical infections is a key next step towards a better understanding of the causes and consequences of rapid microbial evolution in infections, and discovering how these evolutionary processes might be influenced to improve patient health.A video of this Prize Lecture, presented at the Society for General Microbiology Annual Conference 2015, can be viewed via this link: Michael A. Brockhurst https://www.youtube.com/watch?v=N1bodVSl27E.

  6. Experimental evolution can unravel the complex causes of natural selection in clinical infections.

    PubMed

    Brockhurst, Michael A

    2015-06-01

    It is increasingly clear that rapid evolutionary dynamics are an important process in microbial ecology. Experimental evolution, wherein microbial evolution is observed in real-time, has revealed many instances of appreciable evolutionary change occurring on very short timescales of a few days or weeks in response to a variety of biotic and abiotic selection pressures. From clinical infections, including the chronic bacterial lung infections associated with cystic fibrosis that form a focus of my research, there is now abundant evidence suggesting that rapid evolution by infecting microbes contributes to host adaptation, treatment failure and worsening patient prognosis. However, disentangling the drivers of natural selection in complex infection environments is extremely challenging and limits our understanding of the selective pressures acting upon microbes in infections. Controlled evolution experiments can make a vital contribution to this by determining the causal links between predicted drivers of natural selection and the evolutionary responses of microbes. Integration of experimental evolution into studies of clinical infections is a key next step towards a better understanding of the causes and consequences of rapid microbial evolution in infections, and discovering how these evolutionary processes might be influenced to improve patient health.A video of this Prize Lecture, presented at the Society for General Microbiology Annual Conference 2015, can be viewed via this link: Michael A. Brockhurst https://www.youtube.com/watch?v=N1bodVSl27E. PMID:25957311

  7. Simian virus 40-permissive cell interactions: selection and characterization of spontaneously arising monkey cells that are resistant to simian virus 40 infection.

    PubMed Central

    Wilson, J H; DePamphilis, M; Berg, P

    1976-01-01

    A fraction of permissive cells survive simian virus 40 (SV40) infection. The frequency of such surviving cells depends only upon the concentration of infecting virus, both parental and progeny, to which the cells are exposed during the course of selection. Surviving clones, which can be freed of virus by cloning in the presence of SV40 antiserum, are indistinguishable from parental cells in their growth of characteristics and display no SV40 antigen; thus they are not transformed. Most surviving clones are less than 10% as susceptible as parental cells to SV40 infection; 5 to 10% are less than 1% as susceptible. None of these SV40-resistant clones is absolutely resistant to SV40 infection. Analysis of 16 independently arising resistant clones indicates that they all block SV40 infection at an early stage after adsorption and eclipse but before full uncoating. Viral mutants have been isolated that partially overcome the block to infection in these cells; these host range viruses plaque on resistant lines fivefold more efficiently than wild-type SV40 and have a characteristic plaque morphology. Fluctuation analysis indicates that resistant cells arise spontaneously during the growth of normally susceptible permissive cells. Thus, SV40-resistant cells are selected for, not induced by, SV40 infection. Images PMID:185424

  8. Selection of a chitosan gelatin-based edible coating for color preservation of beef in retail display.

    PubMed

    Cardoso, Giselle Pereira; Dutra, Monalisa Pereira; Fontes, Paulo Rogério; Ramos, Alcinéia de Lemos Souza; Gomide, Lúcio Alberto de Miranda; Ramos, Eduardo Mendes

    2016-04-01

    Chitosan gelatin-based coating films were applied to beef steaks, and their effects on color preservation and lipid oxidation during retail display were evaluated. Response surface methodology was used to model and describe the effects of different biopolymer concentrations (0 to 6% gelatin; 0.5 to 1.5% chitosan; and 0 to 12% glycerol based on dry gelatin+chitosan weight) in the coating film for optimizing the best combination for meat application. Film application reduced weight loss and lipid oxidation of the steaks after 5 days of storage, and films with higher gelatin concentrations were more effective. The percentage levels of different myoglobin-redox forms were not affected by coating, but myoglobin oxidation during retail display was reduced and the percentage of deoxymyoglobin increased with the gelatin content of the film. Steak color stability during retail display was promoted by film application; the steaks exhibited a darker, more intensely red color when coated in blends with higher gelatin and chitosan contents. Blends containing between 3% and 6% gelatin, between 0.5% and 1.0% chitosan and 6% glycerol exhibited the best results and provide a promising alternative to the preservation of beef in retail display.

  9. A novel Omp25-binding peptide screened by phage display can inhibit Brucella abortus 2308 infection in vitro and in vivo

    PubMed Central

    Zhang, Junbo; Guo, Fei; Huang, Xiaoqiang; Zhang, Hui; Wang, Yuanzhi; Yin, Shuanghong; Li, Zhiqiang

    2014-01-01

    Brucellosis is a globally distributed zoonotic disease affecting animals and humans, and current antibiotic and vaccine strategies are not optimal. The surface-exposed protein Omp25 is involved in Brucella virulence and plays an important role in Brucella pathogenesis during infection, suggesting that Omp25 could be a useful target for selecting potential therapeutic molecules to inhibit Brucella pathogenesis. In this study, we identified, we believe for the first time, peptides that bind specifically to the Omp25 protein of pathogens, using a phage panning technique, After four rounds of panning, 42 plaques of eluted phages were subjected to pyrosequencing. Four phage clones that bound better than the other clones were selected following confirmation by ELISA and affinity constant determination. The peptides selected could significantly inhibit Brucella abortus 2308 (S2308) internalization and intracellular growth in RAW264.7 macrophages, and significantly induce secretion of TNF-α and IL-12 in peptide- and S2308-treated cells. Any observed peptide (OP11, OP27, OP35 or OP40) could significantly inhibit S2308 infection in BALB/c mice. Moreover, the peptide OP11 was the best candidate peptide for inhibiting S2308 infection in vitro and in vivo. These results suggest that peptide OP11 has potential for exploitation as a peptide drug in resisting S2308 infection. PMID:24722798

  10. Lipophosphoglycans from Leishmania amazonensis Strains Display Immunomodulatory Properties via TLR4 and Do Not Affect Sand Fly Infection.

    PubMed

    Nogueira, Paula M; Assis, Rafael R; Torrecilhas, Ana C; Saraiva, Elvira M; Pessoa, Natália L; Campos, Marco A; Marialva, Eric F; Ríos-Velasquez, Cláudia M; Pessoa, Felipe A; Secundino, Nágila F; Rugani, Jerônimo N; Nieves, Elsa; Turco, Salvatore J; Melo, Maria N; Soares, Rodrigo P

    2016-08-01

    The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly.

  11. Lipophosphoglycans from Leishmania amazonensis Strains Display Immunomodulatory Properties via TLR4 and Do Not Affect Sand Fly Infection

    PubMed Central

    Nogueira, Paula M.; Assis, Rafael R.; Torrecilhas, Ana C.; Saraiva, Elvira M.; Pessoa, Natália L.; Campos, Marco A.; Marialva, Eric F.; Ríos-Velasquez, Cláudia M.; Pessoa, Felipe A.; Secundino, Nágila F.; Rugani, Jerônimo N.; Nieves, Elsa; Turco, Salvatore J.; Melo, Maria N.

    2016-01-01

    The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly. PMID:27508930

  12. Lipophosphoglycans from Leishmania amazonensis Strains Display Immunomodulatory Properties via TLR4 and Do Not Affect Sand Fly Infection.

    PubMed

    Nogueira, Paula M; Assis, Rafael R; Torrecilhas, Ana C; Saraiva, Elvira M; Pessoa, Natália L; Campos, Marco A; Marialva, Eric F; Ríos-Velasquez, Cláudia M; Pessoa, Felipe A; Secundino, Nágila F; Rugani, Jerônimo N; Nieves, Elsa; Turco, Salvatore J; Melo, Maria N; Soares, Rodrigo P

    2016-08-01

    The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly. PMID:27508930

  13. Effect of selected antiasthmatic plant constituents against micro organism causing upper respiratory tract infection.

    PubMed

    Nilani, P; Duraisamy, B; Dhamodaran, P; Ravichandran, S; Elango, K

    2010-01-01

    Most exacerbations of asthma can be proven to be associated with bacterial infections and there is scientific evidence that frequent respiratory infections particularly bacterial infections provoke asthma attack. Considering these facts different plant extracts and phytoconstituents with proven anti asthmatic property had been selected for screening anti microbial activity in in-vitro models. In the present study, Coleus forskohlii Willd. extract (10% Forskolin), Piper Longum L. Extract (20% Piperine), Adathoda vasica Nees. extract (30% Vasicinone), Curcuma longa L. extract (60% Curcumin) were screened for the antibacterial activity against human pathogens causing upper respiratory infection namely Haemophilus influenzae , Streptococcus pneumoniae , Streptococcus pyrogene and Staphylococcus aureus, by taking Gentamycin, Optochin, Bacitracin and Amoxicillin as reference standards. Except for Adathoda vasica Nees. extract, all the other selected plant extracts exhibited a moderate activity antibacterial activity against selected strains.

  14. Rapid selection against arbovirus-induced apoptosis during infection of a mosquito vector

    PubMed Central

    O’Neill, Katelyn; Olson, Bradley J. S. C.; Huang, Ning; Unis, Dave; Clem, Rollie J.

    2015-01-01

    Millions of people are infected each year by arboviruses (arthropod-borne viruses) such as chikungunya, dengue, and West Nile viruses, yet for reasons that are largely unknown, only a relatively small number of mosquito species are able to transmit arboviruses. Understanding the complex factors that determine vector competence could facilitate strategies for controlling arbovirus infections. Apoptosis is a potential antiviral defense response that has been shown to be important in other virus–host systems. However, apoptosis is rarely seen in arbovirus-infected mosquito cells, raising questions about its importance as an antiviral defense in mosquitoes. We tested the effect of stimulating apoptosis during arbovirus infection by infecting Aedes aegypti mosquitoes with a Sindbis virus (SINV) clone called MRE/Rpr, in which the MRE-16 strain of SINV was engineered to express the proapoptotic gene reaper from Drosophila. MRE/Rpr exhibited an impaired infection phenotype that included delayed midgut infection, delayed virus replication, and reduced virus accumulation in saliva. Nucleotide sequencing of the reaper insert in virus populations isolated from individual mosquitoes revealed evidence of rapid and strong selection against maintenance of Reaper expression in MRE/Rpr-infected mosquitoes. The impaired phenotype of MRE/Rpr, coupled with the observed negative selection against Reaper expression, indicates that apoptosis is a powerful defense against arbovirus infection in mosquitoes and suggests that arboviruses have evolved mechanisms to avoid stimulating apoptosis in mosquitoes that serve as vectors. PMID:25713358

  15. Rapid selection against arbovirus-induced apoptosis during infection of a mosquito vector.

    PubMed

    O'Neill, Katelyn; Olson, Bradley J S C; Huang, Ning; Unis, Dave; Clem, Rollie J

    2015-03-10

    Millions of people are infected each year by arboviruses (arthropod-borne viruses) such as chikungunya, dengue, and West Nile viruses, yet for reasons that are largely unknown, only a relatively small number of mosquito species are able to transmit arboviruses. Understanding the complex factors that determine vector competence could facilitate strategies for controlling arbovirus infections. Apoptosis is a potential antiviral defense response that has been shown to be important in other virus-host systems. However, apoptosis is rarely seen in arbovirus-infected mosquito cells, raising questions about its importance as an antiviral defense in mosquitoes. We tested the effect of stimulating apoptosis during arbovirus infection by infecting Aedes aegypti mosquitoes with a Sindbis virus (SINV) clone called MRE/Rpr, in which the MRE-16 strain of SINV was engineered to express the proapoptotic gene reaper from Drosophila. MRE/Rpr exhibited an impaired infection phenotype that included delayed midgut infection, delayed virus replication, and reduced virus accumulation in saliva. Nucleotide sequencing of the reaper insert in virus populations isolated from individual mosquitoes revealed evidence of rapid and strong selection against maintenance of Reaper expression in MRE/Rpr-infected mosquitoes. The impaired phenotype of MRE/Rpr, coupled with the observed negative selection against Reaper expression, indicates that apoptosis is a powerful defense against arbovirus infection in mosquitoes and suggests that arboviruses have evolved mechanisms to avoid stimulating apoptosis in mosquitoes that serve as vectors.

  16. Automated simulation and evaluation of autostereoscopic multiview 3D display designs by time-sequential and wavelength-selective filter barrier

    NASA Astrophysics Data System (ADS)

    Kuhlmey, Mathias; Jurk, Silvio; Duckstein, Bernd; de la Barré, René

    2015-09-01

    A novel simulation tool has been developed for spatial multiplexed 3D displays. Main purpose of our software is the 3D display design with optical image splitter in particular lenticular grids or wavelength-selective barriers. As a result of interaction of image splitter with ray emitting displays a spatial light-modulator generating the autostereoscopic image representation was modeled. Based on the simulation model the interaction of optoelectronic devices with the defined spatial planes is described. Time-sequential multiplexing enables increasing the resolution of such 3D displays. On that reason the program was extended with an intermediate data cumulating component. The simulation program represents a stepwise quasi-static functionality and control of the arrangement. It calculates and renders the whole display ray emission and luminance distribution on viewing distance. The degree of result complexity will increase by using wavelength-selective barriers. Visible images at the viewer's eye positon were determined by simulation after every switching operation of optical image splitter. The summation and evaluation of the resulting data is processed in correspondence to the equivalent time sequence. Hereby the simulation was expanded by a complex algorithm for automated search and validation of possible solutions in the multi-dimensional parameter space. For the multiview 3D display design a combination of ray-tracing and 3D rendering was used. Therefore the emitted light intensity distribution of each subpixel will be evaluated by researching in terms of color, luminance and visible area by using different content distribution on subpixel plane. The analysis of the accumulated data will deliver different solutions distinguished by standards of evaluation.

  17. Major histocompatibility complex selection dynamics in pathogen-infected túngara frog (Physalaemus pustulosus) populations.

    PubMed

    Kosch, Tiffany A; Bataille, Arnaud; Didinger, Chelsea; Eimes, John A; Rodríguez-Brenes, Sofia; Ryan, Michael J; Waldman, Bruce

    2016-08-01

    Pathogen-driven selection can favour major histocompatibility complex (MHC) alleles that confer immunological resistance to specific diseases. However, strong directional selection should deplete genetic variation necessary for robust immune function in the absence of balancing selection or challenges presented by other pathogens. We examined selection dynamics at one MHC class II (MHC-II) locus across Panamanian populations of the túngara frog, Physalaemus pustulosus, infected by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). We compared MHC-II diversity in highland túngara frog populations, where amphibian communities have experienced declines owing to Bd, with those in the lowland region that have shown no evidence of decline. Highland region frogs had MHC variants that confer resistance to Bd. Variant fixation appeared to occur by directional selection rather than inbreeding, as overall genetic variation persisted in populations. In Bd-infected lowland sites, however, selective advantage may accrue to individuals with only one Bd-resistance allele, which were more frequent. Environmental conditions in lowlands should be less favourable for Bd infection, which may reduce selection for specific Bd resistance in hosts. Our results suggest that MHC selection dynamics fluctuate in túngara frog populations as a function of the favourability of habitat to pathogen spread and the vulnerability of hosts to infection. PMID:27531158

  18. Ground squirrel tail-flag displays alter both predatory strike and ambush site selection behaviours of rattlesnakes.

    PubMed

    Barbour, Matthew A; Clark, Rulon W

    2012-09-22

    Many species approach, inspect and signal towards their predators. These behaviours are often interpreted as predator-deterrent signals--honest signals that indicate to a predator that continued hunting is likely to be futile. However, many of these putative predator-deterrent signals are given when no predator is present, and it remains unclear if and why such signals deter predators. We examined the effects of one such signal, the tail-flag display of California ground squirrels, which is frequently given both during and outside direct encounters with northern Pacific rattlesnakes. We video-recorded and quantified the ambush foraging responses of rattlesnakes to tail-flagging displays from ground squirrels. We found that tail-flagging deterred snakes from striking squirrels, most likely by advertising squirrel vigilance (i.e. readiness to dodge a snake strike). We also found that tail-flagging by adult squirrels increased the likelihood that snakes would leave their ambush site, apparently by elevating the vigilance of nearby squirrels which reduces the profitability of the ambush site. Our results provide some of the first empirical evidence of the mechanisms by which a prey display, although frequently given in the absence of a predator, may still deter predators during encounters. PMID:22787023

  19. Ground squirrel tail-flag displays alter both predatory strike and ambush site selection behaviours of rattlesnakes.

    PubMed

    Barbour, Matthew A; Clark, Rulon W

    2012-09-22

    Many species approach, inspect and signal towards their predators. These behaviours are often interpreted as predator-deterrent signals--honest signals that indicate to a predator that continued hunting is likely to be futile. However, many of these putative predator-deterrent signals are given when no predator is present, and it remains unclear if and why such signals deter predators. We examined the effects of one such signal, the tail-flag display of California ground squirrels, which is frequently given both during and outside direct encounters with northern Pacific rattlesnakes. We video-recorded and quantified the ambush foraging responses of rattlesnakes to tail-flagging displays from ground squirrels. We found that tail-flagging deterred snakes from striking squirrels, most likely by advertising squirrel vigilance (i.e. readiness to dodge a snake strike). We also found that tail-flagging by adult squirrels increased the likelihood that snakes would leave their ambush site, apparently by elevating the vigilance of nearby squirrels which reduces the profitability of the ambush site. Our results provide some of the first empirical evidence of the mechanisms by which a prey display, although frequently given in the absence of a predator, may still deter predators during encounters.

  20. Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation.

    PubMed

    Resino, Elena; San-Juan, Rafael; Aguado, Jose Maria

    2016-07-14

    Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gram-negative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination (SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients. PMID:27468189

  1. Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation

    PubMed Central

    Resino, Elena; San-Juan, Rafael; Aguado, Jose Maria

    2016-01-01

    Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gram-negative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination (SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients. PMID:27468189

  2. Viral Evolution and Cytotoxic T Cell Restricted Selection in Acute Infant HIV-1 Infection.

    PubMed

    Garcia-Knight, Miguel A; Slyker, Jennifer; Payne, Barbara Lohman; Pond, Sergei L Kosakovsky; de Silva, Thushan I; Chohan, Bhavna; Khasimwa, Brian; Mbori-Ngacha, Dorothy; John-Stewart, Grace; Rowland-Jones, Sarah L; Esbjörnsson, Joakim

    2016-01-01

    Antiretroviral therapy-naive HIV-1 infected infants experience poor viral containment and rapid disease progression compared to adults. Viral factors (e.g. transmitted cytotoxic T- lymphocyte (CTL) escape mutations) or infant factors (e.g. reduced CTL functional capacity) may explain this observation. We assessed CTL functionality by analysing selection in CTL-targeted HIV-1 epitopes following perinatal infection. HIV-1 gag, pol and nef sequences were generated from a historical repository of longitudinal specimens from 19 vertically infected infants. Evolutionary rate and selection were estimated for each gene and in CTL-restricted and non-restricted epitopes. Evolutionary rate was higher in nef and gag vs. pol, and lower in infants with non-severe immunosuppression vs. severe immunosuppression across gag and nef. Selection pressure was stronger in infants with non-severe immunosuppression vs. severe immunosuppression across gag. The analysis also showed that infants with non-severe immunosuppression had stronger selection in CTL-restricted vs. non-restricted epitopes in gag and nef. Evidence of stronger CTL selection was absent in infants with severe immunosuppression. These data indicate that infant CTLs can exert selection pressure on gag and nef epitopes in early infection and that stronger selection across CTL epitopes is associated with favourable clinical outcomes. These results have implications for the development of paediatric HIV-1 vaccines. PMID:27403940

  3. Viral Evolution and Cytotoxic T Cell Restricted Selection in Acute Infant HIV-1 Infection

    PubMed Central

    Garcia-Knight, Miguel A.; Slyker, Jennifer; Payne, Barbara Lohman; Pond, Sergei L. Kosakovsky; de Silva, Thushan I.; Chohan, Bhavna; Khasimwa, Brian; Mbori-Ngacha, Dorothy; John-Stewart, Grace; Rowland-Jones, Sarah L.; Esbjörnsson, Joakim

    2016-01-01

    Antiretroviral therapy-naive HIV-1 infected infants experience poor viral containment and rapid disease progression compared to adults. Viral factors (e.g. transmitted cytotoxic T- lymphocyte (CTL) escape mutations) or infant factors (e.g. reduced CTL functional capacity) may explain this observation. We assessed CTL functionality by analysing selection in CTL-targeted HIV-1 epitopes following perinatal infection. HIV-1 gag, pol and nef sequences were generated from a historical repository of longitudinal specimens from 19 vertically infected infants. Evolutionary rate and selection were estimated for each gene and in CTL-restricted and non-restricted epitopes. Evolutionary rate was higher in nef and gag vs. pol, and lower in infants with non-severe immunosuppression vs. severe immunosuppression across gag and nef. Selection pressure was stronger in infants with non-severe immunosuppression vs. severe immunosuppression across gag. The analysis also showed that infants with non-severe immunosuppression had stronger selection in CTL-restricted vs. non-restricted epitopes in gag and nef. Evidence of stronger CTL selection was absent in infants with severe immunosuppression. These data indicate that infant CTLs can exert selection pressure on gag and nef epitopes in early infection and that stronger selection across CTL epitopes is associated with favourable clinical outcomes. These results have implications for the development of paediatric HIV-1 vaccines. PMID:27403940

  4. Selection and refinement: the malaria parasite's infection and exploitation of host hepatocytes.

    PubMed

    Kaushansky, Alexis; Kappe, Stefan Hi

    2015-08-01

    Plasmodium parasites belong to the Apicomplexan phylum, which consists mostly of obligate intracellular pathogens that vary dramatically in host cell tropism. Plasmodium sporozoites are highly hepatophilic. The specific molecular mechanisms, which facilitate sporozoite selection and successful infection of hepatocytes, remain poorly defined. Here, we discuss the parasite and host factors which are critical to hepatocyte infection. We derive a model where sporozoites initially select host cells that constitute a permissive environment and then further refine the chosen hepatocyte during liver stage development, ensuring life cycle progression. While many unknowns of pre-erythrocytic infection remain, advancing models and technologies that enable analysis of human malaria parasites and of single infected cells will catalyze a comprehensive understanding of the interaction between the malaria parasite and its hepatocyte host. PMID:26102161

  5. Optical processing of color images with incoherent illumination: orientation-selective edge enhancement using a modified liquid-crystal display.

    PubMed

    Fernández, Ariel; Alonso, Julia R; Flores, Jorge L; Ayubi, Gastón A; Di Martino, J Matías; Ferrari, José A

    2011-10-10

    We present a novel optical method for edge enhancement in color images based on the polarization properties of liquid-crystal displays (LCD). In principle, a LCD generates simultaneously two color-complementary, orthogonally polarized replicas of the digital image used as input. The currently viewed image in standard LCD monitors and cell phone's screens -which we will refer as the "positive image or true-color image"- is the one obtained by placing an analyzer in front of the LCD, in cross configuration to the back polarizer of the display. The orthogonally polarized replica of this image -the "negative image or complementary-color image"- is absorbed by the front polarizer. In order to generate the positive and negative replica with a slight displacement between them, we used a LCD monitor whose analyzer (originally a linear polarizer) was replaced by a calcite crystal acting as beam displacer. When both images are superimposed laterally displaced across the image plane, one obtains an image with enhanced first-order derivatives along a specific direction. The proposed technique works under incoherent illumination and does not require precise alignment, and thus, it could be potentially useful for processing large color images in real-time applications. Validation experiments are presented.

  6. Novel β-lactamase-random peptide fusion libraries for phage display selection of cancer cell-targeting agents suitable for enzyme prodrug therapy

    PubMed Central

    Shukla, Girja S.; Krag, David N.

    2010-01-01

    Novel phage-displayed random linear dodecapeptide (X12) and cysteine-constrained decapeptide (CX10C) libraries constructed in fusion to the amino-terminus of P99 β-lactamase molecules were used for identifying β-lactamase-linked cancer cell-specific ligands. The size and quality of both libraries were comparable to the standards of other reported phage display systems. Using the single-round panning method based on phage DNA recovery, we identified severalβ-lactamase fusion peptides that specifically bind to live human breast cancer MDA-MB-361 cells. The β-lactamase fusion to the peptides helped in conducting the enzyme activity-based clone normalization and cell-binding screening in a very time- and cost-efficient manner. The methods were suitable for 96-well readout as well as microscopic imaging. The success of the biopanning was indicated by the presence of ~40% cancer cell-specific clones among recovered phages. One of the binding clones appeared multiple times. The cancer cell-binding fusion peptides also shared several significant motifs. This opens a new way of preparing and selecting phage display libraries. The cancer cell-specific β-lactamase-linked affinity reagents selected from these libraries can be used for any application that requires a reporter for tracking the ligand molecules. Furthermore, these affinity reagents have also a potential for their direct use in the targeted enzyme prodrug therapy of cancer. PMID:19751096

  7. Complementary DNA display selection of high-affinity peptides binding the vacuolating toxin (VacA) of Helicobacter pylori.

    PubMed

    Hayakawa, Yumiko; Matsuno, Mitsuhiro; Tanaka, Makoto; Wada, Akihiro; Kitamura, Koichiro; Takei, Osamu; Sasaki, Ryuzo; Mizukami, Tamio; Hasegawa, Makoto

    2015-09-01

    Artificial peptides designed for molecular recognition of a bacterial toxin have been developed. Vacuolating cytotoxin A protein (VacA) is a major virulence factor of Helicobacter pylori, a gram-negative microaerophilic bacterium inhabiting the upper gastrointestinal tract, particularly the stomach. This study attempted to identify specific peptide sequences with high affinity for VacA using systematic directed evolution in vitro, a cDNA display method. A surface plasmon resonance-based biosensor and fluorescence correlation spectroscopy to examine binding of peptides with VacA identified a peptide (GRVNQRL) with high affinity. Cyclization of the peptide by attaching cysteine residues to both termini improved its binding affinity to VacA, with a dissociation constant (Kd ) of 58 nm. This study describes a new strategy for the development of artificial functional peptides, which are promising materials in biochemical analyses and medical applications.

  8. Selection of novel peptide mimics of the GD2 ganglioside from a constrained phage-displayed peptide library.

    PubMed

    Horwacik, Irena; Czaplicki, Dominik; Talarek, Katarzyna; Kowalczyk, Aleksandra; Bolesta, Elzbieta; Kozbor, Danuta; Rokita, Hanna

    2007-05-01

    Aberrant glycosylation is a universal feature of cancer cells. There are quantitative and qualitative changes in expression of gangliosides observed in tumors of a neuroectodermal origin such as neuroblastoma, melanoma and astrocytoma. The presence of large amounts of GD2 ganglioside on neuroblastoma cells, as compared to normal cells, opens the possibilities to use the tumor-associated carbohydrate antigen in diagnosis and immunotherapeutic approaches. In the quest for immunogens potentially capable of eliciting anti-GD2 ganglioside immune responses, we performed affinity purification of phage-displayed peptides from the LX-8 library (12-mer containing disulphide bridge). The library was screened with the biotinylated anti-GD2 ganglioside 14G2a mAb monoclonal antibody. Our goal was to isolate and characterize peptide mimics of GD2 ganglioside. Numerous individual phage clones that bound 14G2a mAb were identified with the application of immunoblotting technique in the phage pools yielded from the pannings. The phage-borne peptides were tested for their anti-GD2 ganglioside antibody binding ability using ELISA. Among these clones five different phage-displayed peptide sequences were identified. Moreover, we showed that the secondary structure of the peptides, stabilized by the disulfide bridging between cysteine residues at positions 2 and 11, was crucial for the binding of the peptides to 14G2a mAb. In a separate set of experiments, we observed a competition of the peptides, expressed on phages as well as in their synthetic form, with the nominal antigen GD2 ganglioside expressed on IMR-32 neuroblastoma cells for binding to 14G2a mAb. Based on the obtained results we concluded that all of these 5 peptides were mimics of the GD2 ganglioside. PMID:17390090

  9. Displaying Images Of Planets

    NASA Technical Reports Server (NTRS)

    Martin, Michael D.; Evans, Frank; Nakamura, Daniel I.

    1991-01-01

    Interactive Image Display Program (IMDISP) is interactive image-displaying utility program for IBM personal computer (PC, XT, and AT models) and compatibles. Magnifications, contrasts, and/or subsampling selected for whole or partial images. IMDISP developed for use with CD-ROM (Compact Disk Read-Only Memory) storage system. Written in C language (94 percent) and Assembler (6 percent).

  10. Variation in infection length and superinfection enhance selection efficiency in the human malaria parasite.

    PubMed

    Chang, Hsiao-Han; Childs, Lauren M; Buckee, Caroline O

    2016-01-01

    The capacity for adaptation is central to the evolutionary success of the human malaria parasite Plasmodium falciparum. Malaria epidemiology is characterized by the circulation of multiple, genetically diverse parasite clones, frequent superinfection, and highly variable infection lengths, a large number of which are chronic and asymptomatic. The impact of these characteristics on the evolution of the parasite is largely unknown, however, hampering our understanding of the impact of interventions and the emergence of drug resistance. In particular, standard population genetic frameworks do not accommodate variation in infection length or superinfection. Here, we develop a population genetic model of malaria including these variations, and show that these aspects of malaria infection dynamics enhance both the probability and speed of fixation for beneficial alleles in complex and non-intuitive ways. We find that populations containing a mixture of short- and long-lived infections promote selection efficiency. Interestingly, this increase in selection efficiency occurs even when only a small fraction of the infections are chronic, suggesting that selection can occur efficiently in areas of low transmission intensity, providing a hypothesis for the repeated emergence of drug resistance in the low transmission setting of Southeast Asia. PMID:27193195

  11. Selection of a T7 promoter mutant with enhanced in vitro activity by a novel multi-copy bead display approach for in vitro evolution.

    PubMed

    Paul, Siddhartha; Stang, Alexander; Lennartz, Klaus; Tenbusch, Matthias; Überla, Klaus

    2013-01-01

    In vitro evolution of nucleic acids and proteins is a powerful strategy to optimize their biological and physical properties. To select proteins with the desired phenotype from large gene libraries, the proteins need to be linked to the gene they are encoded by. To facilitate selection of the desired phenotype and isolation of the encoding DNA, a novel bead display approach was developed, in which each member of a library of beads is first linked to multiple copies of a clonal gene variant by emulsion polymerase chain reaction. Beads are transferred to a second emulsion for an in vitro transcription-translation reaction, in which the protein encoded by each bead's amplicon covalently binds to the bead present in the same picoliter reactor. The beads then contain multiple copies of a clonal gene variant and multiple molecules of the protein encoded by the bead's gene variant and serve as the unit of selection. As a proof of concept, we screened a randomized library of the T7 promoter for high expression levels by flow cytometry and identified a T7 promoter variant with an ~10-fold higher in vitro transcriptional activity, confirming that the multi-copy bead display approach can be efficiently applied to in vitro evolution.

  12. Ligand binding analyses of the putative peptide transporter YjdL from E. coli display a significant selectivity towards dipeptides

    SciTech Connect

    Ernst, Heidi A.; Pham, Antony; Hald, Helle; Kastrup, Jette S.; Rahman, Moazur; Mirza, Osman

    2009-11-06

    Proton-dependent oligopeptide transporters (POTs) are secondary active transporters that couple the inwards translocation of di- and tripeptides to inwards proton translocation. Escherichia coli contains four genes encoding the putative POT proteins YhiP, YdgR, YjdL and YbgH. We have over-expressed the previously uncharacterized YjdL and investigated the peptide specificity by means of uptake inhibition. The IC{sub 50} value for the dipeptide Ala-Ala was measured to 22 mM while Ala-Ala-Ala was not able to inhibit uptake. In addition, IC{sub 50} values of 0.3 mM and 1.5 mM were observed for Ala-Lys and Tyr-Ala, respectively, while the alanyl-extended tripeptides Ala-Lys-Ala, Ala-Ala-Lys, Ala-Tyr-Ala and Tyr-Ala-Ala displayed values of 8, >50, 31 and 31 mM, respectively. These results clearly indicate that unlike most POT members characterized to date, including YdgR and YhiP, YjdL shows significantly higher specificity towards dipeptides.

  13. Manipulation of unfolding-induced protein aggregation by peptides selected for aggregate-binding ability through phage display library screening.

    PubMed

    Kundu, Bishwajit; Shukla, Anshuman; Guptasarma, Purnananda

    2002-03-01

    A phage-displayed library of peptides (12-mer) was screened for the ability to bind to thermally aggregated bovine carbonic anhydrase (BCA), with a view toward examining whether peptides possessing this ability might bind to partially structured intermediates on the protein's unfolding pathway and, therefore, constitute useful tools for manipulation of the kinetic partitioning of molecules between the unfolded and aggregated states. Two peptides [N-HPSTMGLRTMHP-C and N-TPSAWKTALVKA-C] were identified and tested. While neither showed thermal aggregation autonomously, both peptides individually elicited remarkable increases in the levels of thermal aggregation of BCA. A possible explanation is that both peptides bind to surfaces on molten BCA that are not directly involved in aggregation. Such binding could slow down interconversions between folded and unfolded states and stabilize aggregation-prone intermediate(s) to make them more prone to aggregation, while failing to achieve any steric prevention of aggregation. The approach has the potential of yielding useful aggregation-aiding/inhibiting agents, and may provide clues to whether amorphous aggregates are "immobilized" forms of folding intermediates. PMID:11866450

  14. Specific Selection of Essential Oil Compounds for Treatment of Children’s Infection Diseases

    PubMed Central

    Pauli, Alexander; Schilcher, Heinz

    2004-01-01

    Preparations with essential oils and their dosages applied in the therapy of children’s infectious diseases are well documented. In contrast, information is only sparingly available about uses of isolated pure essential oil compounds for the treatment of such infections. To find out safe antimicrobials from essential oils, microbiological inhibitory data of children pathogens were combined with oral and dermal acute toxicity data to calculate oral and dermal therapeutical indices (TI). The superiority of antibiotic drugs became obvious following calculating oral TIs of antimicrobials from higher plants, which suggests that oral administrations of essential oil compounds are not suitable to cure severe infections. A few selected compounds from higher plants show moderate effectiveness against gram-positive bacteria, yeast and fungi, but not gram-negative bacteria. Topical application or inhalation of selected compounds for the treatment or additional treatment of mild infections is reasonable.

  15. Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections.

    PubMed

    Jr, Christopher S Kovacs; Koval, Christine E; van Duin, David; de Morais, Amanda Guedes; Gonzalez, Blanca E; Avery, Robin K; Mawhorter, Steven D; Brizendine, Kyle D; Cober, Eric D; Miranda, Cyndee; Shrestha, Rabin K; Teixeira, Lucileia; Mossad, Sherif B

    2014-06-24

    Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor. PMID:25032095

  16. Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

    PubMed Central

    Jr, Christopher S Kovacs; Koval, Christine E; van Duin, David; de Morais, Amanda Guedes; Gonzalez, Blanca E; Avery, Robin K; Mawhorter, Steven D; Brizendine, Kyle D; Cober, Eric D; Miranda, Cyndee; Shrestha, Rabin K; Teixeira, Lucileia; Mossad, Sherif B

    2014-01-01

    Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor. PMID:25032095

  17. Migratory Recovery from Infection as a Selective Pressure for the Evolution of Migration.

    PubMed

    Shaw, Allison K; Binning, Sandra A

    2016-04-01

    Migration, a widespread animal behavior, can influence how individuals acquire and transmit pathogens. Past work has demonstrated that migration can reduce the costs of pathogen or parasite infection through two processes: migratory escape from infected areas or individuals and migratory culling of infected individuals. Here, we propose a third process: migratory recovery, where infected individuals lose their parasites and recover from infection during migration. Recovery can occur when parasites and/or their intermediate hosts cannot support changes in the migratory host's internal or external environment during migration. Thus, parasite mortality increases with migration. Although migratory recovery is likely widespread across species, it remains challenging to empirically test it as a selective force promoting migration. We develop a model and determine the conditions under which migratory recovery theoretically favors the evolution of migration. We show that incorporating migratory recovery into a model of migratory escape increases the range of biologically realistic conditions favoring migration and leads to scenarios where partial migration can evolve. Motivated by empirical estimates of infection costs, our model shows how recovery from infection could drive the evolution of migration. We suggest a number of future directions for both theoretical and empirical research in this area.

  18. Novel Human Cytomegalovirus Viral Chemokines, vCXCL-1s, Display Functional Selectivity for Neutrophil Signaling and Function.

    PubMed

    Heo, Jinho; Dogra, Pranay; Masi, Tom J; Pitt, Elisabeth A; de Kruijf, Petra; Smit, Martine J; Sparer, Tim E

    2015-07-01

    Human CMV (HCMV) uses members of the hematopoietic system including neutrophils for dissemination throughout the body. HCMV encodes a viral chemokine, vCXCL-1, that is postulated to attract neutrophils for dissemination within the host. The gene encoding vCXCL-1, UL146, is one of the most variable genes in the HCMV genome. Why HCMV has evolved this hypervariability and how this affects the virus' dissemination and pathogenesis is unknown. Because the vCXCL-1 hypervariability maps to important binding and activation domains, we hypothesized that vCXCL-1s differentially activate neutrophils, which could contribute to HCMV dissemination, pathogenesis, or both. To test whether these viral chemokines affect neutrophil function, we generated vCXCL-1 proteins from 11 different clades from clinical isolates from infants infected congenitally with HCMV. All vCXCL-1s were able to induce calcium flux at a concentration of 100 nM and integrin expression on human peripheral blood neutrophils, despite differences in affinity for the CXCR1 and CXCR2 receptors. In fact, their affinity for CXCR1 or CXCR2 did not correlate directly with chemotaxis, G protein-dependent and independent (β-arrestin-2) activation, or secondary chemokine (CCL22) expression. Our data suggest that vCXCL-1 polymorphisms affect the binding affinity, receptor usage, and differential peripheral blood neutrophil activation that could contribute to HCMV dissemination and pathogenesis.

  19. (125)I-spectramide: A novel benzamide displaying potent and selective effects at the D sub 2 dopamine receptor

    SciTech Connect

    Sanchez-Roa, P.M.; Grigoriadis, D.E.; Wilson, A.A.; Sharkey, J.; Dannals, R.F.; Villemagne, Victor, L.; Wong, D.F.; Wagner, H.N. Jr.; Kuhar, M.J. )

    1989-01-01

    The new substituted benzamide Spectramide, (N-(2-(4-iodobenzyl-N-methylamino)-2-methoxy-4-ethyl)-5-chloro-methylamine benzamide) labelled with {sup 125}I was used as a potent and highly selective dopamine-D{sub 2} receptor antagonist in rat striatal homogenates for in vitro receptor binding. Kinetic experiments demonstrated the reversibility of the binding and the estimated Kd from saturation analysis was 25 pM, with a Bmax of 20 pmol/g of tissue. Competition studies showed that spectramide did not interact potently with the D{sub 1} or dopamine-uptake site. Drugs known to interact with other receptor system were weak competitors of the binding, while binding was potently inhibited by other D{sub 2} antagonists, such as spiperone and eticlopride. These data indicate that Spectramide binds selectively and with high affinity to the dopamine D{sub 2} receptors, and may prove to be a useful tool for the study of these receptors in vivo using PET or SPECT.

  20. Naive CD8⁺ T-cell precursors display structured TCR repertoires and composite antigen-driven selection dynamics.

    PubMed

    Neller, Michelle A; Ladell, Kristin; McLaren, James E; Matthews, Katherine K; Gostick, Emma; Pentier, Johanne M; Dolton, Garry; Schauenburg, Andrea J A; Koning, Dan; Fontaine Costa, Ana Isabel C A; Watkins, Thomas S; Venturi, Vanessa; Smith, Corey; Khanna, Rajiv; Miners, Kelly; Clement, Mathew; Wooldridge, Linda; Cole, David K; van Baarle, Debbie; Sewell, Andrew K; Burrows, Scott R; Price, David A; Miles, John J

    2015-08-01

    Basic parameters of the naive antigen (Ag)-specific T-cell repertoire in humans remain poorly defined. Systematic characterization of this 'ground state' immunity in comparison with memory will allow a better understanding of clonal selection during immune challenge. Here, we used high-definition cell isolation from umbilical cord blood samples to establish the baseline frequency, phenotype and T-cell antigen receptor (TCR) repertoire of CD8(+) T-cell precursor populations specific for a range of viral and self-derived Ags. Across the board, these precursor populations were phenotypically naive and occurred with hierarchical frequencies clustered by Ag specificity. The corresponding patterns of TCR architecture were highly ordered and displayed partial overlap with adult memory, indicating biased structuring of the T-cell repertoire during Ag-driven selection. Collectively, these results provide new insights into the complex nature and dynamics of the naive T-cell compartment.

  1. FDA-approved selective estrogen receptor modulators inhibit Ebola virus infection.

    PubMed

    Johansen, Lisa M; Brannan, Jennifer M; Delos, Sue E; Shoemaker, Charles J; Stossel, Andrea; Lear, Calli; Hoffstrom, Benjamin G; Dewald, Lisa Evans; Schornberg, Kathryn L; Scully, Corinne; Lehár, Joseph; Hensley, Lisa E; White, Judith M; Olinger, Gene G

    2013-06-19

    Ebola viruses remain a substantial threat to both civilian and military populations as bioweapons, during sporadic outbreaks, and from the possibility of accidental importation from endemic regions by infected individuals. Currently, no approved therapeutics exist to treat or prevent infection by Ebola viruses. Therefore, we performed an in vitro screen of Food and Drug Administration (FDA)- and ex-US-approved drugs and selected molecular probes to identify drugs with antiviral activity against the type species Zaire ebolavirus (EBOV). From this screen, we identified a set of selective estrogen receptor modulators (SERMs), including clomiphene and toremifene, which act as potent inhibitors of EBOV infection. Anti-EBOV activity was confirmed for both of these SERMs in an in vivo mouse infection model. This anti-EBOV activity occurred even in the absence of detectable estrogen receptor expression, and both SERMs inhibited virus entry after internalization, suggesting that clomiphene and toremifene are not working through classical pathways associated with the estrogen receptor. Instead, the response appeared to be an off-target effect where the compounds interfere with a step late in viral entry and likely affect the triggering of fusion. These data support the screening of readily available approved drugs to identify therapeutics for the Ebola viruses and other infectious diseases. The SERM compounds described in this report are an immediately actionable class of approved drugs that can be repurposed for treatment of filovirus infections.

  2. Two-stage selection of sequences from a random phage display library delineates both core residues and permitted structural range within an epitope.

    PubMed

    Miceli, R M; DeGraaf, M E; Fischer, H D

    1994-01-01

    Libraries of random peptides can be screened to identify species which interact with antibodies or receptors. Similarly, maps of native molecular interactions can frequently be deduced by screening a limited set of peptide fragments derived from sequences within a native antigen or ligand. However, the existence of cross-reactive sequences that mimic original epitopes and the limited replaceability of amino acid residues suggest that the sequence space accessible by a receptor can be much broader. Definition of this space is of particular importance where structural information is required for peptidomimetic or drug design. We have used a two-stage selection scheme to expand the sequence space accessible by a phage display library and to define peptide epitopes of the anti-FLAG octapeptide monoclonal M2 antibody. Affinity selection of a primary library of 2 x 10(6) random decapeptides identified a non-contiguous core of three residues in the binding motif Tyr-Lys-Xaa-Xaa-Asp. A second stage library with 2 x 10(7) individual clones bearing the core motif but with the remaining flanking and internal residues re-randomized permitted access to a broader sequence space represented in a library equivalent to several orders of magnitude larger. Data here demonstrate that extended access to binding sequence space permitted by multi-stage screening of phage display libraries can reveal not only essential residues required for ligand binding, but also the ligand structural range permitted within the receptor binding pocket.

  3. PL-100, a novel HIV-1 protease inhibitor displaying a high genetic barrier to resistance: an in vitro selection study.

    PubMed

    Dandache, Serge; Coburn, Craig A; Oliveira, Maureen; Allison, Timothy J; Holloway, M Katharine; Wu, Jinzi J; Stranix, Brent R; Panchal, Chandra; Wainberg, Mark A; Vacca, Joseph P

    2008-12-01

    The development of new HIV inhibitors with distinct resistance profiles is essential in order to combat the development of multi-resistant viral strains. A drug discovery program based on the identification of compounds that are active against drug-resistant viruses has produced PL-100, a novel potent protease inhibitor (PI) that incorporates a lysine-based scaffold. A selection for resistance against PL-100 in cord blood mononuclear cells was performed, using the laboratory-adapted IIIb strain of HIV-1, and it was shown that resistance appears to develop slower against this compound than against amprenavir, which was studied as a control. Four mutations in protease (PR) were selected after 25 weeks: two flap mutations (K45R and M46I) and two novel active site mutations (T80I and P81S). Site-directed mutagenesis revealed that all four mutations were required to develop low-level resistance to PL-100, which is indicative of the high genetic barrier of the compound. Importantly, these mutations did not cause cross-resistance to currently marketed PIs. In contrast, the P81S mutation alone caused hypersensitivity to two other PIs, saquinavir (SQV) and nelfinavir (NFV). Analysis of p55Gag processing showed that a marked defect in protease activity caused by mutation P81S could only be compensated when K45R and M46I were present. These data correlated well with the replication capacity (RC) of the mutant viruses as measured by a standard viral growth assay, since only viruses containing all four mutations approached the RC of wild type virus. X-ray crystallography provided insight on the structural basis of the resistance conferred by the identified mutations. PMID:19040279

  4. Selective alterations of the host cell architecture upon infection with parvovirus minute virus of mice

    SciTech Connect

    Nueesch, Juerg P.F. . E-mail: jpf.nuesch@dkfz-heidelberg.de; Lachmann, Sylvie; Rommelaere, Jean

    2005-01-05

    During a productive infection, the prototype strain of parvovirus minute virus of mice (MVMp) induces dramatic morphological alterations to the fibroblast host cell A9, resulting in cell lysis and progeny virus release. In order to understand the mechanisms underlying these changes, we characterized the fate of various cytoskeletal filaments and investigated the nuclear/cytoplasmic compartmentalization of infected cells. While most pronounced effects could be seen on micro- and intermediate filaments, manifest in dramatic rearrangements and degradation of filamentous (F-)actin and vimentin structures, only little impact could be seen on microtubules or the nuclear envelope during the entire monitored time of infection. To further analyze the disruption of the cytoskeletal structures, we investigated the viral impact on selective regulatory pathways. Thereby, we found a correlation between microtubule stability and MVM-induced phosphorylation of {alpha}/{beta} tubulin. In contrast, disassembly of actin filaments late in infection could be traced back to the disregulation of two F-actin associated proteins gelsolin and Wiscott-Aldrich Syndrome Protein (WASP). Thereby, an increase in the amount of gelsolin, an F-actin severing protein was observed during infection, accounting for the disruption of stress fibers upon infection. Concomitantly, the actin polymerization activity also diminished due to a loss of WASP, the activator protein of the actin polymerization machinery the Arp2/3 complex. No effects could be seen in amount and distribution of other F-actin regulatory factors such as cortactin, cofilin, and profilin. In summary, the selective attack of MVM towards distinct host cell cytoskeletal structures argues for a regulatory feature during infection, rather than a collapse of the host cell as a mere side effect of virus production.

  5. Tangled bank of experimentally evolved Burkholderia biofilms reflects selection during chronic infections.

    PubMed

    Traverse, Charles C; Mayo-Smith, Leslie M; Poltak, Steffen R; Cooper, Vaughn S

    2013-01-15

    How diversity evolves and persists in biofilms is essential for understanding much of microbial life, including the uncertain dynamics of chronic infections. We developed a biofilm model enabling long-term selection for daily adherence to and dispersal from a plastic bead in a test tube. Focusing on a pathogen of the cystic fibrosis lung, Burkholderia cenocepacia, we sequenced clones and metagenomes to unravel the mutations and evolutionary forces responsible for adaptation and diversification of a single biofilm community during 1,050 generations of selection. The mutational patterns revealed recurrent evolution of biofilm specialists from generalist types and multiple adaptive alleles at relatively few loci. Fitness assays also demonstrated strong interference competition among contending mutants that preserved genetic diversity. Metagenomes from five other independently evolved biofilm lineages revealed extraordinary mutational parallelism that outlined common routes of adaptation, a subset of which was found, surprisingly, in a planktonic population. These mutations in turn were surprisingly well represented among mutations that evolved in cystic fibrosis isolates of both Burkholderia and Pseudomonas. These convergent pathways included altered metabolism of cyclic diguanosine monophosphate, polysaccharide production, tricarboxylic acid cycle enzymes, global transcription, and iron scavenging. Evolution in chronic infections therefore may be driven by mutations in relatively few pathways also favored during laboratory selection, creating hope that experimental evolution may illuminate the ecology and selective dynamics of chronic infections and improve treatment strategies.

  6. The atypical antipsychotics clozapine and olanzapine promote down-regulation and display functional selectivity at human 5-HT7 receptors

    PubMed Central

    Andressen, K W; Manfra, O; Brevik, C H; Ulsund, A H; Vanhoenacker, P; Levy, F O; Krobert, K A

    2015-01-01

    Background and Purpose Classically, ligands of GPCRs have been classified primarily upon their affinity and efficacy to activate a signal transduction pathway. Recent reports indicate that the efficacy of a particular ligand can vary depending on the receptor-mediated response measured (e.g. activating G proteins, other downstream responses, internalization). Previously, we reported that inverse agonists induce both homo- and heterologous desensitization, similar to agonist stimulation, at the Gs-coupled 5-HT7 receptor. The primary objective of this study was to determine whether different inverse agonists at the 5-HT7 receptor also induce internalization and/or degradation of 5-HT7 receptors. Experimental Approach HEK293 cells expressing 5-HT7(a, b or d) receptors were pre-incubated with 5-HT, clozapine, olanzapine, mesulergine or SB269970 and their effects upon receptor density, AC activity, internalization, recruitment of β-arrestins and lysosomal trafficking were measured. Key Results The agonist 5-HT and three out of four inverse agonists tested increased internalization independently of β-arrestin recruitment. Among these, only the atypical antipsychotics clozapine and olanzapine promoted lysosomal sorting and reduced 5-HT7 receptor density (∼60% reduction within 24 h). Inhibition of lysosomal degradation with chloroquine blocked the clozapine- and olanzapine-induced down-regulation of 5-HT7 receptors. Incubation with SB269970 decreased both 5-HT7(b) constitutive internalization and receptor density but increased 5-HT7(d) receptor density, indicating differential ligand regulation among the 5-HT7 splice variants. Conclusions and Implications Taken together, we found that various ligands differentially activate regulatory processes governing receptor internalization and degradation in addition to signal transduction. Thus, these data extend our understanding of functional selectivity at the 5-HT7 receptor. PMID:25884989

  7. Selective vulnerability of mouse CNS neurons to latent infection with a neuroattenuated herpes simplex virus-1.

    PubMed

    Kesari, S; Lee, V M; Brown, S M; Trojanowski, J Q; Fraser, N W

    1996-09-15

    Herpes simplex viruses that lack ICP34.5 are neuroattenuated and are presently being considered for cancer and gene therapy in the nervous system. Previously, we documented the focal presence of the latency-associated transcripts (LATs) in the hippocampi of immunocompromised mice after intracranial (IC) inoculation of an ICP34.5-deficient virus called strain 1716. To characterize further the biological properties of strain 1716 in the CNS of immunocompetent mice, we determined the extent of viral gene expression in different cell types and regions of the CNS after stereotactic IC inoculation of this virus. At survival times of > 30 d after inoculation, we found that (1) infectious virus was not detectable by titration and immunohistochemical studies; (2) neurons harbored virus as demonstrated by the detection of the LATs by in situ hybridization (ISH); (3) transcripts expressed during the lytic cycle of infection were not detected by ISH; and (4) subsets of neurons were selectively vulnerable to latent infection, depending on the site of inoculation. These results suggest that the absence of ICP34.5 does not abrogate latent infection of the CNS by strain 1716. Additional studies of strain 1716 in the model system described here will facilitate the elucidation of the mechanisms that regulate the selective vulnerability of CNS cells to latent viral infection and lead to the development of ICP34.5 mutant viruses as therapeutic vectors for CNS diseases.

  8. Gold nanoprobe functionalized with specific fusion protein selection from phage display and its application in rapid, selective and sensitive colorimetric biosensing of Staphylococcus aureus.

    PubMed

    Liu, Pei; Han, Lei; Wang, Fei; Petrenko, Valery A; Liu, Aihua

    2016-08-15

    Staphylococcus aureus (S. aureus) is one of the most ubiquitous pathogens in public healthcare worldwide. It holds great insterest in establishing robust analytical method for S. aureus. Herein, we report a S. aureus-specific recognition element, isolated from phage monoclone GQTTLTTS, which was selected from f8/8 landscape phage library against S. aureus in a high-throughput way. By functionalizing cysteamine (CS)-stabilized gold nanoparticles (CS-AuNPs) with S. aureus-specific pVIII fusion protein (fusion-pVIII), a bifunctional nanoprobe (CS-AuNPs@fusion-pVIII) for S. aureus was developed. In this strategy, the CS-AuNPs@fusion-pVIII could be induced to aggregate quickly in the presence of target S. aureus, resulting in a rapid colorimetric response of gold nanoparticles. More importantly, the as-designed probe exhibited excellent selectivity over other bacteria. Thus, the CS-AuNPs@fusion-pVIII could be used as the indicator of target S. aureus. This assay can detect as low as 19CFUmL(-1)S. aureus within 30min. Further, this approach can be applicable to detect S. aureus in real water samples. Due to its sensitivity, specificity and rapidness, this proposed method is promising for on-site testing of S. aureus without using any costly instruments.

  9. Selection of the vascular catheter: can it minimise the risk of infection?

    PubMed

    Bouza, E; Guembe, M; Muñoz, P

    2010-12-01

    Data regarding the prevention of catheter-related bloodstream infection (CRBSI) by making the correct decisions about when to place a central line, the appropriate selection of catheter composition and the size and number of lumens, a suitable choice of insertion site and the technique used are not well reported in recent medical literature. There is no clear evidence that the composition of the catheters presently on the market makes a significant difference to the risk of infection. Several prospective studies suggest that femoral vein location represents the highest risk of infection, followed by jugular vein and subclavian vein positioning, however, most articles do not correct for basic confounding variables. Several papers have reported that arterial catheters have a similar risk of infection as central venous catheters (CVCs). The slight increase in infection risk when using multi-lumen catheters is probably offset by their improved convenience. Current evidence does not support routine tunnelling of short-term catheters until its efficacy is evaluated at different placement sites, using specific catheters and situations and in relation to other preventive interventions. Cuffing is usually applied only to long-term tunnelled catheters. The available evidence suggests that chlorhexidine-silver sulfadiazine, minocycline-rifampicin CVCs and antifungal-coated catheters are useful in decreasing the incidence of CRBSI when other measures are not effective. PMID:21130605

  10. Transgenic banana plants expressing small interfering RNAs targeted against viral replication initiation gene display high-level resistance to banana bunchy top virus infection.

    PubMed

    Shekhawat, Upendra K S; Ganapathi, Thumballi R; Hadapad, Ashok B

    2012-08-01

    The banana aphid-transmitted Banana bunchy top virus (BBTV) is the most destructive viral pathogen of bananas and plantains worldwide. Lack of natural sources of resistance to BBTV has necessitated the exploitation of proven transgenic technologies for obtaining BBTV-resistant banana cultivars. In this study, we have explored the concept of using intron-hairpin-RNA (ihpRNA) transcripts corresponding to viral master replication initiation protein (Rep) to generate BBTV-resistant transgenic banana plants. Two ihpRNA constructs namely ihpRNA-Rep and ihpRNA-ProRep generated using Rep full coding sequence or Rep partial coding sequence together with its 5' upstream regulatory region, respectively, and castor bean catalase intron were successfully transformed into banana embryogenic cells. ihpRNA-Rep- and ihpRNA-ProRep-derived transgenic banana plants, selected based on preliminary screening for efficient reporter gene expression, were completely resistant to BBTV infection as indicated by the absence of disease symptoms after 6 months of viruliferous aphid inoculation. The resistance to BBTV infection was also evident by the inability to detect cDNAs coding for viral coat protein, movement protein and Rep protein by RT-PCR from inoculated transgenic leaf extracts. Southern analysis of the two groups of transgenics showed that ihpRNA transgene was stably integrated into the banana genome. The detection of small interfering RNAs (siRNAs) derived from the ihpRNA transgene sequence in transformed BBTV-resistant plants positively established RNA interference as the mechanism underlying the observed resistance to BBTV. Efficient screening of optimal transformants in this vegetatively propagated non-segregating fruit crop ensured that all the transgenic plants assayed were resistant to BBTV infection. PMID:22552945

  11. Selective predation on hantavirus-infected voles by owls and confounding effects from landscape properties.

    PubMed

    Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Hörnfeldt, Birger

    2016-06-01

    It has been suggested that predators may protect human health through reducing disease-host densities or selectively preying on infected individuals from the population. However, this has not been tested empirically. We hypothesized that Tengmalm's owl (Aegolius funereus) selectively preys on hantavirus-infected individuals of its staple prey, the bank vole (Myodes glareolus). Bank voles are hosts of Puumala hantavirus, which causes a form of hemorrhagic fever in humans. Selective predation by owls on infected voles may reduce human disease risk. We compared the prevalence of anti-Puumala hantavirus antibodies (seroprevalence), in bank voles cached by owls in nest boxes to seroprevalence in voles trapped in closed-canopy forest around each nest box. We found no general difference in seroprevalence. Forest landscape structure could partly account for the observed patterns in seroprevalence. Only in more connected forest patches was seroprevalence in bank voles cached in nest boxes higher than seroprevalence in trapped voles. This effect disappeared with increasing forest patch isolation, as seroprevalence in trapped voles increased with forest patch isolation, but did not in cached voles. Our results suggest a complex relationship between zoonotic disease prevalence in hosts, their predators, and landscape structure. Some mechanisms that may have caused the seroprevalence patterns in our results include higher bank vole density in isolated forest patches. This study offers future research potential to shed further light on the contribution of predators and landscape properties to human health. PMID:26873607

  12. Military display performance parameters

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Meyer, Frederick

    2012-06-01

    The military display market is analyzed in terms of four of its segments: avionics, vetronics, dismounted soldier, and command and control. Requirements are summarized for a number of technology-driving parameters, to include luminance, night vision imaging system compatibility, gray levels, resolution, dimming range, viewing angle, video capability, altitude, temperature, shock and vibration, etc., for direct-view and virtual-view displays in cockpits and crew stations. Technical specifications are discussed for selected programs.

  13. Specific probe selection from landscape phage display library and its application in enzyme-linked immunosorbent assay of free prostate-specific antigen.

    PubMed

    Lang, Qiaolin; Wang, Fei; Yin, Long; Liu, Mingjun; Petrenko, Valery A; Liu, Aihua

    2014-03-01

    Probes against targets can be selected from the landscape phage library f8/8, displaying random octapeptides on the pVIII coat protein of the phage fd-tet and demonstrating many excellent features including multivalency, stability, and high structural homogeneity. Prostate-specific antigen (PSA) is usually determined by immunoassay, by which antibodies are frequently used as the specific probes. Herein we found that more advanced probes against free prostate-specific antigen (f-PSA) can be screened from the landscape phage library. Four phage monoclones were selected and identified by the specificity array. One phage clone displaying the fusion peptide ERNSVSPS showed good specificity and affinity to f-PSA and was used as a PSA capture probe in a sandwich enzyme-linked immunosorbent assay (ELISA) array. An anti-human PSA monoclonal antibody (anti-PSA mAb) was used to recognize the captured antigen, followed by horseradish peroxidase-conjugated antibody (HRP-IgG) and o-phenylenediamine, which were successively added to develop plate color. The ELISA conditions such as effect of blocking agent, coating buffer pH, phage concentration, antigen incubation time, and anti-PSA mAb dilution for phage ELISA were optimized. On the basis of the optimal phage ELISA conditions, the absorbance taken at 492 nm on a microplate reader was linear with f-PSA concentration within 0.825-165 ng/mL with a low limit of detection of 0.16 ng/mL. Thus, the landscape phage is an attractive biomolecular probe in bioanalysis.

  14. Triclosan can select for an AdeIJK-overexpressing mutant of Acinetobacter baumannii ATCC 17978 that displays reduced susceptibility to multiple antibiotics.

    PubMed

    Fernando, Dinesh M; Xu, Wayne; Loewen, Peter C; Zhanel, George G; Kumar, Ayush

    2014-11-01

    In order to determine if triclosan can select for mutants of Acinetobacter baumannii ATCC 17978 that display reduced susceptibilities to antibiotics, we isolated a triclosan-resistant mutant, A. baumannii AB042, by serial passaging of A. baumannii ATCC 17978 in growth medium supplemented with triclosan. The antimicrobial susceptibility of AB042 was analyzed by the 2-fold serial dilution method. Expression of five different resistance-nodulation-division (RND) pump-encoding genes (adeB, adeG, adeJ, A1S_2818, and A1S_3217), two outer membrane porin-encoding genes (carO and oprD), and the MATE family pump-encoding gene abeM was analyzed using quantitative reverse transcriptase (qRT) PCR. A. baumannii AB042 exhibited elevated resistance to multiple antibiotics, including piperacillin-tazobactam, doxycycline, moxifloxacin, ceftriaxone, cefepime, meropenem, doripenem, ertapenem, ciprofloxacin, aztreonam, tigecycline, and trimethoprim-sulfamethoxazole, in addition to triclosan. Genome sequencing of A. baumannii AB042 revealed a (116)G→V mutation in fabI, the gene encoding the target enzyme for triclosan. Expression analysis of efflux pumps showed overexpression of the AdeIJK pump, and sequencing of adeN, the gene that encodes the repressor of the adeIJK operon, revealed a 73-bp deletion which would cause a premature termination of translation, resulting in an inactive truncated AdeN protein. This work shows that triclosan can select for mutants of A. baumannii that display reduced susceptibilities to multiple antibiotics from chemically distinct classes in addition to triclosan resistance. This multidrug resistance can be explained by the overexpression of the AdeIJK efflux pump.

  15. Retail display evaluation of steaks from select beef strip loins injected with a brine containing 1% ammonium hydroxide. Part 2: Cook yield, tenderness, and sensory attributes.

    PubMed

    Parsons, A N; VanOverbeke, D L; Goad, C L; Mireles DeWitt, C A

    2011-01-01

    The impact of 2 different brines on the palatability and tenderness of select beef strip loin steaks was evaluated. Brines were differentiated by the type of alkaline agent, 4.5% sodium-based phosphate (control brine; CON) or 1% ammonium hydroxide (ammonium hydroxide treatment; AHT), incorporated into the formula. Injected steaks were placed in high oxygen (80% O(2)/20% CO(2)) MAP, stored 4 d at 4 °C in dark storage to simulate transportation, and then placed in retail display. Steaks were selected randomly on day 0, 7, and 14 retail display to measure pH, cook loss, shear force, and sensory characteristics. The pH for AHT steaks (pH 5.96) was slightly higher than CON steaks (pH 5.86; P < 0.05). Cook loss was lower (21%) for CON than AHT steaks (23%). There was neither a treatment nor day effect on tenderness as measured by Warner-Braztler shear force (P > 0.05). Sensory evaluation indicated that on day 0, retail display the initial juiciness, sustained juiciness, tenderness 1st impression, tenderness overall impression, and connective tissue in AHT steaks was not different from CON steaks (P > 0.05). A day effect (decrease) for those sensory parameters was observed only for sustained juiciness (P < 0.05). AHT steaks were rated higher in cooked beef flavor while CON steaks were higher in peppery and salty flavor. There was no difference in soapy and ammonia intensity between treatments. Results indicated that despite lower performance in cook loss the replacement of 4.5% sodium-based phosphate in a meat injection brine with 1% ammonium hydroxide produced a beef loin steak with comparable tenderness and palatability. Practical Application: The research in this study compares steaks that have been injected with a commercial brine formulated with sodium phosphates to steaks that have been injected with a brine where the sodium phosphate in the formulation was replaced with 1% ammonium hydroxide. Ammonium hydroxide is an USDA-FSIS approved ingredient in brines

  16. Positive selection of cytotoxic T lymphocyte escape variants during acute hepatitis C virus infection.

    PubMed

    Guglietta, Silvia; Garbuglia, Anna Rosa; Pacciani, Valentina; Scottà, Cristiano; Perrone, Maria Paola; Laurenti, Luca; Spada, Enea; Mele, Alfonso; Capobianchi, Maria Rosaria; Taliani, Gloria; Folgori, Antonella; Vitelli, Alessandra; Ruggeri, Lionello; Nicosia, Alfredo; Piccolella, Enza; Del Porto, Paola

    2005-09-01

    Cellular immune responses are induced during hepatitis C virus (HCV) infection and acute-phase CD8+ T cells are supposed to play an important role in controlling viral replication. In chimpanzees, failure of CD8+ T cells to control HCV replication has been associated with acquisition of mutations in MHC class I-restricted epitopes. In humans, although selection of escape mutations in an immunodominant CTL epitope has been recently described, the overall impact of immune escape during acute HCV infection is unclear. Here, by performing an in depth analysis of the relationship between early cellular immune responses and viral evolution in a chronically evolving HCV acutely infected individual, we demonstrate: (i) the presence of a potent and focused CD8(+ T cell response against a novel epitope in the NS3 protein, (ii) the elimination of the quasi-species harboring the original amino acid sequence within this epitope, and (iii) the selection for a virus population bearing amino acid changes at a single residue within the cytotoxic T cell epitope that strongly diminished T cell recognition. These results support the view that acute-phase CD8+ T cell responses exert a biologically relevant pressure on HCV replication and that viruses escaping this host response could have a significant survival advantage. PMID:16114108

  17. In vitro selection of novel RNA ligands that bind human cytomegalovirus and block viral infection.

    PubMed Central

    Wang, J; Jiang, H; Liu, F

    2000-01-01

    Ribonuclease-resistant RNA molecules that bind to infectious human cytomegalovirus (HCMV) were isolated in vitro from a pool of randomized sequences after 16 cycles of selection and amplification. The two ligands (L13 and L19) characterized exhibited high HCMV-binding affinity in vitro and effectively inhibited viral infection in tissue culture. Their antiviral activity was also specific as they only reacted with two different strains of HCMV but not with the related herpes simplex virus 1 and human cells. These two ligands appeared to function as antivirals by blocking viral entry. Ultraviolet (UV) crosslinking studies suggested that L13 and L19 bind to HCMV essential glycoproteins B and H, respectively. Thus, RNA ligands that bind to different surface antigens of HCMV can be simultaneously isolated by the selection procedure. Our study demonstrates the feasibility of using these RNA ligands as a research tool to identify viral proteins required for infectivity and as an antiviral agent to block viral infection. PMID:10786848

  18. Phage display of human antibodies from a patient suffering from coeliac disease and selection of isotype-specific scFv against gliadin

    PubMed Central

    Rhyner, Claudio; Weichel, Michael; Hübner, Philipp; Achatz, Gernot; Blaser, Kurt; Crameri, Reto

    2003-01-01

    Coeliac disease (CD), a gastrointestinal illness characterized by intestinal malabsorption, results from gluten intolerance accompanied with immunological responses towards gliadin, an ethanol-soluble protein fraction of wheat and other cereals. The role of gliadin in eliciting immune responses in CD is still partly unclear; however, the occurrence of anti-gliadin in the sera of patients suffering from CD correlates well with clinical symptoms. In this work we report the construction of isotype-specific, phage-displayed scFv libraries from peripheral blood lymphocytes of a patient with CD and from a healthy control individual. VH and VL chains were amplified by reverse transcription–polymerase chain reaction (RT–PCR) using a set of oligonucleotides recognizing all human variable gene families. The three scFv libraries (IgA, IgG and IgM) were selectively enriched for gliadin-binding phage. After four rounds of affinity selection, polyclonal enrichment of gliadin-binding phage was observed in all libraries from the CD patient but in none from the healthy donor. Phagemid particles generated from single clones were demonstrated to be gliadin-specific, as shown by strongly positive enzyme-linked immunosorbent assay (ELISA) and BiaCore signals. The VH and VL chains from samples of these monoclonal isotype-specific phage were sequenced to identify the most common variable regions used by the immune system to elicit antibody responses against gliadin. PMID:14511241

  19. Well-Ordered Trimeric HIV-1 Subtype B and C Soluble Spike Mimetics Generated by Negative Selection Display Native-like Properties

    PubMed Central

    Guenaga, Javier; de Val, Natalia; Tran, Karen; Feng, Yu; Satchwell, Karen; Ward, Andrew B.; Wyatt, Richard T.

    2015-01-01

    The structure of BG505 gp140 SOSIP, a soluble mimic of the native HIV-1 envelope glycoprotein (Env), marks the beginning of new era in Env structure-based immunogen design. Displaying a well-ordered quaternary structure, these subtype A-derived trimers display an excellent antigenic profile, discriminating recognition by broadly neutralizing antibodies (bNAbs) from non-broadly neutralizing antibodies (non-bNAbs), and provide a solid Env-based immunogenic platform starting point. Even with this important advance, obtaining homogeneous well-ordered soluble SOSIP trimers derived from other subtypes remains challenging. Here, we report the “rescue” of homogeneous well-ordered subtype B and C SOSIP trimers from a heterogeneous Env mixture using CD4 binding site-directed (CD4bs) non-bNAbs in a negative-selection purification process. These non-bNAbs recognize the primary receptor CD4bs only on disordered trimers but not on the native Env spike or well-ordered soluble trimers due to steric hindrance. Following negative selection to remove disordered oligomers, we demonstrated recovery of well-ordered, homogeneous trimers by electron microscopy (EM). We obtained 3D EM reconstructions of unliganded trimers, as well as in complex with sCD4, a panel of CD4bs-directed bNAbs, and the cleavage-dependent, trimer-specific bNAb, PGT151. Using bio-layer light interferometry (BLI) we demonstrated that the well-ordered trimers were efficiently recognized by bNAbs and poorly recognized by non-bNAbs, representing soluble mimics of the native viral spike. Biophysical characterization was consistent with the thermostability of a homogeneous species that could be further stabilized by specific bNAbs. This study revealed that Env trimers generate different frequencies of well-ordered versus disordered aberrant trimers even when they are genetically identical. By negatively selecting the native-like well-ordered trimers, we establish a new means to obtain soluble Env mimetics derived

  20. Candidacidal Activity of Selected Ceragenins and Human Cathelicidin LL-37 in Experimental Settings Mimicking Infection Sites.

    PubMed

    Durnaś, Bonita; Wnorowska, Urszula; Pogoda, Katarzyna; Deptuła, Piotr; Wątek, Marzena; Piktel, Ewelina; Głuszek, Stanisław; Gu, Xiaobo; Savage, Paul B; Niemirowicz, Katarzyna; Bucki, Robert

    2016-01-01

    Fungal infections, especially those caused by antibiotic resistant pathogens, have become a serious public health problem due to the growing number of immunocompromised patients, including those subjected to anticancer treatment or suffering from HIV infection. In this study we assessed fungicidal activity of the ceragenins CSA-13, CSA-131 and CSA-192 against four fluconazole-resistant Candida strains. We found that ceragenins activity against planktonic Candida cells was higher than activity of human LL-37 peptide and synthetic cationic peptide omiganan. Compared to LL-37 peptide, ceragenins in the presence of DNase I demonstrated an increased ability to kill DNA-induced Candida biofilm. Microscopy studies show that treatment with LL-37 or ceragenins causes Candida cells to undergo extensive surface changes indicating surface membrane damage. This conclusion was substantiated by observation of rapid incorporation of FITC-labeled CSA-13, CSA-131 or LL-37 peptide into the more lipophilic environment of the Candida membrane. In addition to activity against Candida spp., ceragenins CSA-131 and CSA-192 display strong fungicidal activity against sixteen clinical isolates including Cryptococcus neoformans and Aspergillus fumigatus. These results indicate the potential of ceragenins for future development as new fungicidal agents. PMID:27315208

  1. Candidacidal Activity of Selected Ceragenins and Human Cathelicidin LL-37 in Experimental Settings Mimicking Infection Sites

    PubMed Central

    Durnaś, Bonita; Wnorowska, Urszula; Pogoda, Katarzyna; Deptuła, Piotr; Wątek, Marzena; Piktel, Ewelina; Głuszek, Stanisław; Gu, Xiaobo; Savage, Paul B.; Niemirowicz, Katarzyna; Bucki, Robert

    2016-01-01

    Fungal infections, especially those caused by antibiotic resistant pathogens, have become a serious public health problem due to the growing number of immunocompromised patients, including those subjected to anticancer treatment or suffering from HIV infection. In this study we assessed fungicidal activity of the ceragenins CSA-13, CSA-131 and CSA-192 against four fluconazole–resistant Candida strains. We found that ceragenins activity against planktonic Candida cells was higher than activity of human LL-37 peptide and synthetic cationic peptide omiganan. Compared to LL-37 peptide, ceragenins in the presence of DNase I demonstrated an increased ability to kill DNA-induced Candida biofilm. Microscopy studies show that treatment with LL-37 or ceragenins causes Candida cells to undergo extensive surface changes indicating surface membrane damage. This conclusion was substantiated by observation of rapid incorporation of FITC-labeled CSA-13, CSA-131 or LL-37 peptide into the more lipophilic environment of the Candida membrane. In addition to activity against Candida spp., ceragenins CSA-131 and CSA-192 display strong fungicidal activity against sixteen clinical isolates including Cryptococcus neoformans and Aspergillus fumigatus. These results indicate the potential of ceragenins for future development as new fungicidal agents. PMID:27315208

  2. Streptococcus agalactiae clones infecting humans were selected and fixed through the extensive use of tetracycline.

    PubMed

    Da Cunha, Violette; Davies, Mark R; Douarre, Pierre-Emmanuel; Rosinski-Chupin, Isabelle; Margarit, Immaculada; Spinali, Sebastien; Perkins, Tim; Lechat, Pierre; Dmytruk, Nicolas; Sauvage, Elisabeth; Ma, Laurence; Romi, Benedetta; Tichit, Magali; Lopez-Sanchez, Maria-José; Descorps-Declere, Stéphane; Souche, Erika; Buchrieser, Carmen; Trieu-Cuot, Patrick; Moszer, Ivan; Clermont, Dominique; Maione, Domenico; Bouchier, Christiane; McMillan, David J; Parkhill, Julian; Telford, John L; Dougan, Gordan; Walker, Mark J; Holden, Matthew T G; Poyart, Claire; Glaser, Philippe

    2014-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal of the digestive and genitourinary tracts of humans that emerged as the leading cause of bacterial neonatal infections in Europe and North America during the 1960s. Due to the lack of epidemiological and genomic data, the reasons for this emergence are unknown. Here we show by comparative genome analysis and phylogenetic reconstruction of 229 isolates that the rise of human GBS infections corresponds to the selection and worldwide dissemination of only a few clones. The parallel expansion of the clones is preceded by the insertion of integrative and conjugative elements conferring tetracycline resistance (TcR). Thus, we propose that the use of tetracycline from 1948 onwards led in humans to the complete replacement of a diverse GBS population by only few TcR clones particularly well adapted to their host, causing the observed emergence of GBS diseases in neonates. PMID:25088811

  3. Low Frequency of Drug-Resistant Variants Selected by Long-Acting Rilpivirine in Macaques Infected with Simian Immunodeficiency Virus Containing HIV-1 Reverse Transcriptase

    PubMed Central

    Melody, Kevin; McBeth, Sarah; Kline, Christopher; Kashuba, Angela D. M.; Mellors, John W.

    2015-01-01

    Preexposure prophylaxis (PrEP) using antiretroviral drugs is effective in reducing the risk of human immunodeficiency virus type 1 (HIV-1) infection, but adherence to the PrEP regimen is needed. To improve adherence, a long-acting injectable formulation of the nonnucleoside reverse transcriptase (RT) inhibitor rilpivirine (RPV LA) has been developed. However, there are concerns that PrEP may select for drug-resistant mutations during preexisting or breakthrough infections, which could promote the spread of drug resistance and limit options for antiretroviral therapy. To address this concern, we administered RPV LA to macaques infected with simian immunodeficiency virus containing HIV-1 RT (RT-SHIV). Peak plasma RPV levels were equivalent to those reported in human trials and waned over time after dosing. RPV LA resulted in a 2-log decrease in plasma viremia, and the therapeutic effect was maintained for 15 weeks, until plasma drug concentrations dropped below 25 ng/ml. RT mutations E138G and E138Q were detected in single clones from plasma virus in separate animals only at one time point, and no resistance mutations were detected in viral RNA isolated from tissues. Wild-type and E138Q RT-SHIV displayed similar RPV susceptibilities in vitro, whereas E138G conferred 2-fold resistance to RPV. Overall, selection of RPV-resistant variants was rare in an RT-SHIV macaque model despite prolonged exposure to slowly decreasing RPV concentrations following injection of RPV LA. PMID:26438501

  4. Low Frequency of Drug-Resistant Variants Selected by Long-Acting Rilpivirine in Macaques Infected with Simian Immunodeficiency Virus Containing HIV-1 Reverse Transcriptase.

    PubMed

    Melody, Kevin; McBeth, Sarah; Kline, Christopher; Kashuba, Angela D M; Mellors, John W; Ambrose, Zandrea

    2015-12-01

    Preexposure prophylaxis (PrEP) using antiretroviral drugs is effective in reducing the risk of human immunodeficiency virus type 1 (HIV-1) infection, but adherence to the PrEP regimen is needed. To improve adherence, a long-acting injectable formulation of the nonnucleoside reverse transcriptase (RT) inhibitor rilpivirine (RPV LA) has been developed. However, there are concerns that PrEP may select for drug-resistant mutations during preexisting or breakthrough infections, which could promote the spread of drug resistance and limit options for antiretroviral therapy. To address this concern, we administered RPV LA to macaques infected with simian immunodeficiency virus containing HIV-1 RT (RT-SHIV). Peak plasma RPV levels were equivalent to those reported in human trials and waned over time after dosing. RPV LA resulted in a 2-log decrease in plasma viremia, and the therapeutic effect was maintained for 15 weeks, until plasma drug concentrations dropped below 25 ng/ml. RT mutations E138G and E138Q were detected in single clones from plasma virus in separate animals only at one time point, and no resistance mutations were detected in viral RNA isolated from tissues. Wild-type and E138Q RT-SHIV displayed similar RPV susceptibilities in vitro, whereas E138G conferred 2-fold resistance to RPV. Overall, selection of RPV-resistant variants was rare in an RT-SHIV macaque model despite prolonged exposure to slowly decreasing RPV concentrations following injection of RPV LA. PMID:26438501

  5. Phage and Yeast Display.

    PubMed

    Sheehan, Jared; Marasco, Wayne A

    2015-02-01

    Despite the availability of antimicrobial drugs, the continued development of microbial resistance--established through escape mutations and the emergence of resistant strains--limits their clinical utility. The discovery of novel, therapeutic, monoclonal antibodies (mAbs) offers viable clinical alternatives in the treatment and prophylaxis of infectious diseases. Human mAb-based therapies are typically nontoxic in patients and demonstrate high specificity for the intended microbial target. This specificity prevents negative impacts on the patient microbiome and avoids driving the resistance of nontarget species. The in vitro selection of human antibody fragment libraries displayed on phage or yeast surfaces represents a group of well-established technologies capable of generating human mAbs. The advantage of these forms of microbial display is the large repertoire of human antibody fragments present during a single selection campaign. Furthermore, the in vitro selection environments of microbial surface display allow for the rapid isolation of antibodies--and their encoding genes--against infectious pathogens and their toxins that are impractical within in vivo systems, such as murine hybridomas. This article focuses on the technologies of phage display and yeast display, as these strategies relate to the discovery of human mAbs for the treatment and vaccine development of infectious diseases. PMID:26104550

  6. Selection of scFv Antibody Fragments Binding to Human Blood versus Lymphatic Endothelial Surface Antigens by Direct Cell Phage Display

    PubMed Central

    Keller, Thomas; Kalt, Romana; Raab, Ingrid; Schachner, Helga; Mayrhofer, Corina; Kerjaschki, Dontscho; Hantusch, Brigitte

    2015-01-01

    The identification of marker molecules specific for blood and lymphatic endothelium may provide new diagnostic tools and identify new targets for therapy of immune, microvascular and cancerous diseases. Here, we used a phage display library expressing human randomized single-chain Fv (scFv) antibodies for direct panning against live cultures of blood (BECs) and lymphatic (LECs) endothelial cells in solution. After six panning rounds, out of 944 sequenced antibody clones, we retrieved 166 unique/diverse scFv fragments, as indicated by the V-region sequences. Specificities of these phage clone antibodies for respective compartments were individually tested by direct cell ELISA, indicating that mainly pan-endothelial cell (EC) binders had been selected, but also revealing a subset of BEC-specific scFv antibodies. The specific staining pattern was recapitulated by twelve phage-independently expressed scFv antibodies. Binding capacity to BECs and LECs and differential staining of BEC versus LEC by a subset of eight scFv antibodies was confirmed by immunofluorescence staining. As one antigen, CD146 was identified by immunoprecipitation with phage-independent scFv fragment. This antibody, B6-11, specifically bound to recombinant CD146, and to native CD146 expressed by BECs, melanoma cells and blood vessels. Further, binding capacity of B6-11 to CD146 was fully retained after fusion to a mouse Fc portion, which enabled eukaryotic cell expression. Beyond visualization and diagnosis, this antibody might be used as a functional tool. Overall, our approach provided a method to select antibodies specific for endothelial surface determinants in their native configuration. We successfully selected antibodies that bind to antigens expressed on the human endothelial cell surfaces in situ, showing that BECs and LECs share a majority of surface antigens, which is complemented by cell-type specific, unique markers. PMID:25993332

  7. Selection of single chain variable fragment (scFv) antibodies from a hyperimmunized phage display library for the detection of the antibiotic monensin.

    PubMed

    Makvandi-Nejad, Shokouh; Sheedy, Claudia; Veldhuis, Linda; Richard, Gabrielle; Hall, J Christopher

    2010-08-31

    Concerns over the occurrence of the veterinary antibiotic monensin (MW 671Da) in animal food products and water have given rise to the need for a sensitive and rapid detection method. In this study, four monensin-specific single chain variable fragments (scFvs) were isolated from a hyperimmunized phage-displayed library originating from splenocytes of a mouse immunized with monensin conjugated to bovine serum albumin (BSA). The coding sequences of the scFvs were engineered in the order 5'-V(L)-linker-V(H)-3', where the linker encodes for Gly(10)Ser(7)Arg. Three rounds of selection were performed against monensin conjugated to chicken ovalbumin (OVA) and keyhole limpet hemocyanin (KLH), alternately. In the third round of selection, two different strategies, which differed in the number of washes and the concentration of the coating conjugates, were used to select for specific binders to monensin. A total of 376 clones from round two and three were screened for their specific binding to monensin conjugates and positive clones were sequenced. It was found that 80% of clones from round three contained a stop codon. After removing the stop codon by site-directed mutagenesis, ten binders with different amino acid sequences were subcloned into the vector pMED2 for soluble expression in Escherichia coli HB2151. Four of these scFvs bound to free monensin as determined using competitive fluorescence polarization assays (C-FPs). IC(50) values ranged from 0.031 and 231 microM. A cross-reactivity assay against salinomycin, lasalocid A, kanamycin and ampicillin revealed that the two best binders were highly specific to monensin.

  8. Molecular study on selected vector-borne infections in urban stray colony cats in northern Italy.

    PubMed

    Spada, Eva; Proverbio, Daniela; Galluzzo, Paola; Della Pepa, Alessandra; Perego, Roberta; Bagnagatti De Giorgi, Giada; Ferro, Elisabetta

    2014-08-01

    Feline vector-borne diseases can be caused by a range of pathogens transmitted by arthropods. Many of these infections have zoonotic implications, and stray cats are potential sentinels for human and pet health. This study investigated the prevalence of selected vector-borne infections in stray colony cats in Milan. Blood samples from 260 stray cats were evaluated, using conventional polymerase chain reaction tests (cPCRs), for the presence of DNA associated with Rickettsia species, Anaplasma phagocytophilum and Ehrlichia species. Positive cPCR results occurred in 127/260 subjects (48.9%; 95% confidence interval [CI] = 40.7-58.1), with a prevalence of 31.9% (83/260, 95% CI = 25.4-39.6) for Rickettsia species, 17.7% (46/260, 95% CI= 13.0-23.6) for A phagocytophilum, and 5.4% (14/260, 95% CI = 2.9-9.0) for Ehrlichia species. There was no statistical association between a positive PCR test for vector-borne infections surveyed and colony location, age, gender, body condition score or complete blood count abnormalities, nor feline immunodeficiency virus, feline leukaemia virus or Toxoplasma gondii status. The only variable linked to positive PCR results was detection of signs of ocular infection and PCR positivity for Rickettsia species (P = 0.04, odds ratio [OR] = 2.2, 95% CI = 1.1-4.4, P = 0.02). There is a significant prevalence of vector-borne infections with zoonotic potential in urban stray cats in Milan. Thus, dogs and pet cats with outdoor access should be monitored and treated for ectoparasites on a regular basis to minimise risks of disease and the potential transmission of zoonotic agents to people.

  9. Molecular study on selected vector-borne infections in urban stray colony cats in northern Italy.

    PubMed

    Spada, Eva; Proverbio, Daniela; Galluzzo, Paola; Della Pepa, Alessandra; Perego, Roberta; Bagnagatti De Giorgi, Giada; Ferro, Elisabetta

    2014-08-01

    Feline vector-borne diseases can be caused by a range of pathogens transmitted by arthropods. Many of these infections have zoonotic implications, and stray cats are potential sentinels for human and pet health. This study investigated the prevalence of selected vector-borne infections in stray colony cats in Milan. Blood samples from 260 stray cats were evaluated, using conventional polymerase chain reaction tests (cPCRs), for the presence of DNA associated with Rickettsia species, Anaplasma phagocytophilum and Ehrlichia species. Positive cPCR results occurred in 127/260 subjects (48.9%; 95% confidence interval [CI] = 40.7-58.1), with a prevalence of 31.9% (83/260, 95% CI = 25.4-39.6) for Rickettsia species, 17.7% (46/260, 95% CI= 13.0-23.6) for A phagocytophilum, and 5.4% (14/260, 95% CI = 2.9-9.0) for Ehrlichia species. There was no statistical association between a positive PCR test for vector-borne infections surveyed and colony location, age, gender, body condition score or complete blood count abnormalities, nor feline immunodeficiency virus, feline leukaemia virus or Toxoplasma gondii status. The only variable linked to positive PCR results was detection of signs of ocular infection and PCR positivity for Rickettsia species (P = 0.04, odds ratio [OR] = 2.2, 95% CI = 1.1-4.4, P = 0.02). There is a significant prevalence of vector-borne infections with zoonotic potential in urban stray cats in Milan. Thus, dogs and pet cats with outdoor access should be monitored and treated for ectoparasites on a regular basis to minimise risks of disease and the potential transmission of zoonotic agents to people. PMID:24319060

  10. An anti-infective peptide that selectively modulates the innate immune response.

    PubMed

    Scott, Monisha G; Dullaghan, Edie; Mookherjee, Neeloffer; Glavas, Natalie; Waldbrook, Matthew; Thompson, Annick; Wang, Aikun; Lee, Ken; Doria, Silvana; Hamill, Pam; Yu, Jie Jessie; Li, Yuexin; Donini, Oreola; Guarna, M Marta; Finlay, B Brett; North, John R; Hancock, Robert E W

    2007-04-01

    We show that an innate defense-regulator peptide (IDR-1) was protective in mouse models of infection with important Gram-positive and Gram-negative pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus and Salmonella enterica serovar Typhimurium. When given from 48 h before to 6 h after infection, the peptide was effective by both local and systemic administration. Because protection by IDR-1 was prevented by in vivo depletion of monocytes and macrophages, but not neutrophils or B- and T-lymphocytes, we conclude that monocytes and macrophages are key effector cells. IDR-1 was not directly antimicrobial: gene and protein expression analysis in human and mouse monocytes and macrophages indicated that IDR-1, acting through mitogen-activated protein kinase and other signaling pathways, enhanced the levels of monocyte chemokines while reducing pro-inflammatory cytokine responses. To our knowledge, an innate defense regulator that counters infection by selective modulation of innate immunity without obvious toxicities has not been reported previously.

  11. A novel in vivo method for isolating antibodies from a phage display library by neuronal retrograde transport selectively yields antibodies against p75(NTR.).

    PubMed

    Tani, Hiroaki; Osbourn, Jane K; Walker, Edward H; Rush, Robert A; Ferguson, Ian A

    2013-01-01

    The neurotrophin receptor p75(NTR) is utilized by a variety of pathogens to gain entry into the central nervous system (CNS). We tested if this entry portal might be exploited using a phage display library to isolate internalizing antibodies that target the CNS in vivo. By applying a phage library that expressed human single chain variable fragment (scFv) antibodies on their surface to a transected sciatic nerve, we showed that (1) phage conjugated to anti-p75(NTR) antibody or phage scFv library pre-panned against p75(NTR) are internalized by neurons expressing p75(NTR); (2) subsequent retrograde axonal transport separates internalized phage from the applied phage; and, (3) internalized phage can be recovered from a proximal ligature made on a nerve. This approach resulted in 13-fold increase in the number of phage isolated from the injured nerve compared with the starting population, and isolation of 18 unique internalizing p75(NTR) antibodies that were transported from the peripheral nerve into the spinal cord, through the blood-brain barrier. In addition, antibodies recognizing other potentially internalized antigens were identified through in vivo selection using a fully diverse library. Because p75(NTR) expression is upregulated in motor neurons in response to injury and in disease, the p75(NTR) antibodies may have substantial potential for cell-targeted drug/gene delivery. In addition, this novel selection method provides the potential to generate panels of antibodies that could be used to identify further internalization targets, which could aid drug delivery across the blood-brain barrier.

  12. Selection of recombinant antibodies by phage display technology and application for detection of allergenic Brazil nut (Bertholletia excelsa) in processed foods.

    PubMed

    de la Cruz, Silvia; López-Calleja, Inés María; Alcocer, Marcos; González, Isabel; Martín, Rosario; García, Teresa

    2013-10-30

    Current immunological methods for detection of Brazil nut allergens in foods are based on polyclonal antibodies raised in animals. Phage display technology allows the procurement of high-affinity antibodies avoiding animal immunization steps and therefore attaining the principle of replacement supported by animal welfare guidelines. In this study, we screened Tomlinson I and J libraries for specific binders against Brazil nut by employing a Brazil nut protein extract and a purified Brazil nut 2S globulin, and we successfully isolated a phage single chain variable fragment (named BE95) that specifically recognizes Brazil nut proteins. The selected phage scFv was further used as affinity probe to develop an indirect phage-ELISA for detection of Brazil nut in experimental binary mixtures and in commercial food products, with a limit of detection of 5 mg g(-1). This study describes for the first time the isolation of recombinant antibody fragments specific for an allergenic tree nut protein from a naïve library and paves the way to develop new immunoassays for food analysis based on probes that can be produced in vitro when required and do not rely on animal immunization.

  13. A phage display selected 7-mer peptide inhibitor of the Tannerella forsythia metalloprotease-like enzyme Karilysin can be truncated to Ser-Trp-Phe-Pro.

    PubMed

    Skottrup, Peter Durand; Sørensen, Grete; Ksiazek, Miroslaw; Potempa, Jan; Riise, Erik

    2012-01-01

    Tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. Karilysin is a newly identified metalloprotease-like enzyme, that is secreted from T. forsythia. Karilysin modulates the host immune response and is therefore considered a likely drug target. In this study peptides were selected towards the catalytic domain from Karilysin (Kly18) by phage display. The peptides were linear with low micromolar binding affinities. The two best binders (peptide14 and peptide15), shared the consensus sequence XWFPXXXGGG. A peptide15 fusion with Maltose Binding protein (MBP) was produced with peptide15 fused to the N-terminus of MBP. The peptide15-MBP was expressed in E. coli and the purified fusion-protein was used to verify Kly18 specific binding. Chemically synthesised peptide15 (SWFPLRSGGG) could inhibit the enzymatic activity of both Kly18 and intact Karilysin (Kly48). Furthermore, peptide15 could slow down the autoprocessing of intact Kly48 to Kly18. The WFP motif was important for inhibition and a truncation study further demonstrated that the N-terminal serine was also essential for Kly18 inhibition. The SWFP peptide had a Ki value in the low micromolar range, which was similar to the intact peptide15. In conclusion SWFP is the first reported inhibitor of Karilysin and can be used as a valuable tool in structure-function studies of Karilysin.

  14. Antimicrobial Peptides: Their Role as Infection-Selective Tracers for Molecular Imaging

    PubMed Central

    Ebenhan, Thomas; Gheysens, Olivier; Kruger, Hendrick Gert; Zeevaart, Jan Rijn; Sathekge, Mike Machaba

    2014-01-01

    Antimicrobial peptides (AMPs) are a heterogeneous class of compounds found in a variety of organisms including humans and, so far, hundreds of these structures have been isolated and characterised. They can be described as natural microbicide, selectively cytotoxic to bacteria, whilst showing minimal cytotoxicity towards the mammalian cells of the host organism. They act by their relatively strong electrostatic attraction to the negatively charged bacterial cells and a relatively weak interaction to the eukaryote host cells. The ability of these peptides to accumulate at sites of infection combined with the minimal host's cytotoxicity motivated for this review to highlight the role and the usefulness of AMPs for PET with emphasis on their mechanism of action and the different interactions with the bacterial cell. These details are key information for their selective properties. We also describe the strategy, design, and utilization of these peptides as potential radiopharmaceuticals as their combination with nuclear medicine modalities such as SPECT or PET would allow noninvasive whole-body examination for detection of occult infection causing, for example, fever of unknown origin. PMID:25243191

  15. Low multiplicity of infection in vivo results in purifying selection against baculovirus deletion mutants.

    PubMed

    Zwart, Mark P; Erro, Eloy; van Oers, Monique M; de Visser, J Arjan G M; Vlak, Just M

    2008-05-01

    The in vivo fate of Autographa californica multiple nucleopolyhedrovirus deletion mutants originating from serial passage in cell culture was investigated by passaging a population enriched in these mutants in insect larvae. The infectivity of polyhedra and occlusion-derived virion content per polyhedron were restored within two passages in vivo. The frequency of occurrence of deletion mutants was determined by real-time PCR. The frequency of the non-homologous region origin (non-HR ori) of DNA replication was reduced to wild-type levels within two passages. The frequency of the polyhedrin gene did not increase and remained below wild-type levels. A low m.o.i. during the initial infection in insect larvae, causing strong purifying selection for autonomously replicating viruses, could explain these observations. The same virus population used in vivo was also passaged once at a different m.o.i. in cell culture. A similar effect (i.e. lower non-HR ori frequency) was observed at low m.o.i. only, indicating that m.o.i. was the key selective condition.

  16. Natural Selection on Individual Variation in Tolerance of Gastrointestinal Nematode Infection

    PubMed Central

    Hayward, Adam D.; Nussey, Daniel H.; Wilson, Alastair J.; Berenos, Camillo; Pilkington, Jill G.; Watt, Kathryn A.; Pemberton, Josephine M.; Graham, Andrea L.

    2014-01-01

    Hosts may mitigate the impact of parasites by two broad strategies: resistance, which limits parasite burden, and tolerance, which limits the fitness or health cost of increasing parasite burden. The degree and causes of variation in both resistance and tolerance are expected to influence host–parasite evolutionary and epidemiological dynamics and inform disease management, yet very little empirical work has addressed tolerance in wild vertebrates. Here, we applied random regression models to longitudinal data from an unmanaged population of Soay sheep to estimate individual tolerance, defined as the rate of decline in body weight with increasing burden of highly prevalent gastrointestinal nematode parasites. On average, individuals lost weight as parasite burden increased, but whereas some lost weight slowly as burden increased (exhibiting high tolerance), other individuals lost weight significantly more rapidly (exhibiting low tolerance). We then investigated associations between tolerance and fitness using selection gradients that accounted for selection on correlated traits, including body weight. We found evidence for positive phenotypic selection on tolerance: on average, individuals who lost weight more slowly with increasing parasite burden had higher lifetime breeding success. This variation did not have an additive genetic basis. These results reveal that selection on tolerance operates under natural conditions. They also support theoretical predictions for the erosion of additive genetic variance of traits under strong directional selection and fixation of genes conferring tolerance. Our findings provide the first evidence of selection on individual tolerance of infection in animals and suggest practical applications in animal and human disease management in the face of highly prevalent parasites. PMID:25072883

  17. Immune response to a Trichinella spiralis infection in house mice from lines selectively bred for high voluntary wheel running.

    PubMed

    Dlugosz, Elizabeth M; Schutz, Heidi; Meek, Thomas H; Acosta, Wendy; Downs, Cynthia J; Platzer, Edward G; Chappell, Mark A; Garland, Theodore

    2013-11-15

    Four lines of mice bred for high voluntary wheel running (HR lines) have high baseline circulating corticosterone levels and increased daily energy expenditure as compared with four non-selected control (C) lines. High corticosterone may suppress immune function and competing energy demands may limit ability to mount an immune response. We hypothesized that HR mice have a reduced immune response and therefore a decreased ability to fight an infection by Trichinella spiralis, an ecologically relevant nematode common in mammals. Infections have an acute, intestinal phase while the nematode is migrating, reproducing and traveling throughout the bloodstream, followed by a chronic phase with larvae encysted in muscles. Adult males (generation 55 of the selection experiment) were sham-infected or infected by oral gavage with ~300 J1 T. spiralis larvae. During the chronic phase of infection, mice were given wheel access for 6 days, followed by 2 days of maximum aerobic performance trials. Two weeks post-infection, infected HR had significantly lower circulating immunoglobulin E levels compared with infected C mice. However, we found no statistical difference between infected HR and C mice in numbers of encysted larvae within the diaphragm. As expected, both voluntary running and maximum aerobic performance were significantly higher in HR mice and lower in infected mice, with no line type-by-infection interactions. Results complement those of previous studies suggesting decreased locomotor abilities during the chronic phase of T. spiralis infection. However, despite reduced antibody production, breeding for high voluntary wheel exercise does not appear to have a substantial negative impact on general humoral function.

  18. Infection.

    PubMed

    Miclau, Theodore; Schmidt, Andrew H; Wenke, Joseph C; Webb, Lawrence X; Harro, Janette M; Prabhakara, Ranjani; Shirtliff, Mark E

    2010-09-01

    Musculoskeletal infection is a clinical problem with significant direct healthcare costs. The prevalence of infection after closed, elective surgery is frequently estimated to be less than 2%, but in severe injuries, posttraumatic infection rates have been reported as 10% or greater. Although clinical infections are found outside the realm of medical devices, it is clear that the enormous increase of infections associated with the use of implants presents a major challenge worldwide. This review summarizes recent advances in the understanding, diagnosis, and treatment of musculoskeletal infections.

  19. Core–shell magnetic nanoparticles display synergistic antibacterial effects against Pseudomonas aeruginosa and Staphylococcus aureus when combined with cathelicidin LL-37 or selected ceragenins

    PubMed Central

    Niemirowicz, Katarzyna; Piktel, Ewelina; Wilczewska, Agnieszka Z; Markiewicz, Karolina H; Durnaś, Bonita; Wątek, Marzena; Puszkarz, Irena; Wróblewska, Marta; Niklińska, Wiesława; Savage, Paul B; Bucki, Robert

    2016-01-01

    Core–shell magnetic nanoparticles (MNPs) are promising candidates in the development of new treatment methods against infections, including those caused by antibiotic-resistant pathogens. In this study, the bactericidal activity of human antibacterial peptide cathelicidin LL-37, synthetic ceragenins CSA-13 and CSA-131, and classical antibiotics vancomycin and colistin, against methicillin-resistant Staphylococcus aureus Xen 30 and Pseudomonas aeruginosa Xen 5, was assessed alone and in combination with core–shell MNPs. Fractional inhibitory concentration index and fractional bactericidal concentration index were determined by microdilution methods. The potential of combined therapy using nanomaterials and selected antibiotics was confirmed using chemiluminescence measurements. Additionally, the ability of tested agents to prevent bacterial biofilm formation was evaluated using crystal violet staining. In most conditions, synergistic or additive effects were observed when combinations of core–shell MNPs with ceragenins or classical antibiotics were used. Our study revealed that a mixture of membrane-active agents such as LL-37 peptide or ceragenin CSA-13 with MNPs potentialized their antibacterial properties and might be considered as a method of delaying and overcoming bacterial drug resistance. PMID:27799768

  20. Matrine displayed antiviral activity in porcine alveolar macrophages co-infected by porcine reproductive and respiratory syndrome virus and porcine circovirus type 2.

    PubMed

    Sun, Na; Sun, Panpan; Lv, Haipeng; Sun, Yaogui; Guo, Jianhua; Wang, Zhirui; Luo, Tiantian; Wang, Shaoyu; Li, Hongquan

    2016-01-01

    The co-infection of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) is quite common in clinical settings and no effective treatment to the co-infection is available. In this study, we established the porcine alveolar macrophages (PAM) cells model co-infected with PRRSV/PCV2 with modification in vitro, and investigated the antiviral activity of Matrine on this cell model and further evaluated the effect of Matrine on virus-induced TLR3,4/NF-κB/TNF-α pathway. The results demonstrated PAM cells inoculated with PRRSV followed by PCV2 2 h later enhanced PRRSV and PCV2 replications. Matrine treatment suppressed both PRRSV and PCV2 infection at 12 h post infection. Furthermore, PRRSV/PCV2 co- infection induced IκBα degradation and phosphorylation as well as the translocation of NF-κB from the cytoplasm to the nucleus indicating that PRRSV/PCV2 co-infection induced NF-κB activation. Matrine treatment significantly down-regulated the expression of TLR3, TLR4 and TNF-α although it, to some extent, suppressed p-IκBα expression, suggesting that TLR3,4/NF-κB/TNF-α pathway play an important role of Matrine in combating PRRSV/PCV2 co-infection. It is concluded that Matrine possesses activity against PRRSV/PCV2 co-infection in vitro and suppression of the TLR3,4/NF-κB/TNF-α pathway as an important underlying molecular mechanism. These findings warrant Matrine to be further explored for its antiviral activity in clinical settings. PMID:27080155

  1. Matrine displayed antiviral activity in porcine alveolar macrophages co-infected by porcine reproductive and respiratory syndrome virus and porcine circovirus type 2.

    PubMed

    Sun, Na; Sun, Panpan; Lv, Haipeng; Sun, Yaogui; Guo, Jianhua; Wang, Zhirui; Luo, Tiantian; Wang, Shaoyu; Li, Hongquan

    2016-04-15

    The co-infection of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) is quite common in clinical settings and no effective treatment to the co-infection is available. In this study, we established the porcine alveolar macrophages (PAM) cells model co-infected with PRRSV/PCV2 with modification in vitro, and investigated the antiviral activity of Matrine on this cell model and further evaluated the effect of Matrine on virus-induced TLR3,4/NF-κB/TNF-α pathway. The results demonstrated PAM cells inoculated with PRRSV followed by PCV2 2 h later enhanced PRRSV and PCV2 replications. Matrine treatment suppressed both PRRSV and PCV2 infection at 12 h post infection. Furthermore, PRRSV/PCV2 co- infection induced IκBα degradation and phosphorylation as well as the translocation of NF-κB from the cytoplasm to the nucleus indicating that PRRSV/PCV2 co-infection induced NF-κB activation. Matrine treatment significantly down-regulated the expression of TLR3, TLR4 and TNF-α although it, to some extent, suppressed p-IκBα expression, suggesting that TLR3,4/NF-κB/TNF-α pathway play an important role of Matrine in combating PRRSV/PCV2 co-infection. It is concluded that Matrine possesses activity against PRRSV/PCV2 co-infection in vitro and suppression of the TLR3,4/NF-κB/TNF-α pathway as an important underlying molecular mechanism. These findings warrant Matrine to be further explored for its antiviral activity in clinical settings.

  2. Matrine displayed antiviral activity in porcine alveolar macrophages co-infected by porcine reproductive and respiratory syndrome virus and porcine circovirus type 2

    PubMed Central

    Sun, Na; Sun, Panpan; Lv, Haipeng; Sun, Yaogui; Guo, Jianhua; Wang, Zhirui; Luo, Tiantian; Wang, Shaoyu; Li, Hongquan

    2016-01-01

    The co-infection of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) is quite common in clinical settings and no effective treatment to the co-infection is available. In this study, we established the porcine alveolar macrophages (PAM) cells model co-infected with PRRSV/PCV2 with modification in vitro, and investigated the antiviral activity of Matrine on this cell model and further evaluated the effect of Matrine on virus-induced TLR3,4/NF-κB/TNF-α pathway. The results demonstrated PAM cells inoculated with PRRSV followed by PCV2 2 h later enhanced PRRSV and PCV2 replications. Matrine treatment suppressed both PRRSV and PCV2 infection at 12 h post infection. Furthermore, PRRSV/PCV2 co- infection induced IκBα degradation and phosphorylation as well as the translocation of NF-κB from the cytoplasm to the nucleus indicating that PRRSV/PCV2 co-infection induced NF-κB activation. Matrine treatment significantly down-regulated the expression of TLR3, TLR4 and TNF-α although it, to some extent, suppressed p-IκBα expression, suggesting that TLR3,4/NF-κB/TNF-α pathway play an important role of Matrine in combating PRRSV/PCV2 co-infection. It is concluded that Matrine possesses activity against PRRSV/PCV2 co-infection in vitro and suppression of the TLR3,4/NF-κB/TNF-α pathway as an important underlying molecular mechanism. These findings warrant Matrine to be further explored for its antiviral activity in clinical settings. PMID:27080155

  3. Variable selection in covariate dependent random partition models: an application to urinary tract infection.

    PubMed

    Barcella, William; Iorio, Maria De; Baio, Gianluca; Malone-Lee, James

    2016-04-15

    Lower urinary tract symptoms can indicate the presence of urinary tract infection (UTI), a condition that if it becomes chronic requires expensive and time consuming care as well as leading to reduced quality of life. Detecting the presence and gravity of an infection from the earliest symptoms is then highly valuable. Typically, white blood cell (WBC) count measured in a sample of urine is used to assess UTI. We consider clinical data from 1341 patients in their first visit in which UTI (i.e. WBC ≥ 1) is diagnosed. In addition, for each patient, a clinical profile of 34 symptoms was recorded. In this paper, we propose a Bayesian nonparametric regression model based on the Dirichlet process prior aimed at providing the clinicians with a meaningful clustering of the patients based on both the WBC (response variable) and possible patterns within the symptoms profiles (covariates). This is achieved by assuming a probability model for the symptoms as well as for the response variable. To identify the symptoms most associated to UTI, we specify a spike and slab base measure for the regression coefficients: this induces dependence of symptoms selection on cluster assignment. Posterior inference is performed through Markov Chain Monte Carlo methods. PMID:26536840

  4. Prevalence of Selected Bacterial Infections Associated with the Use of Animal Waste in Louisiana

    PubMed Central

    Hill, Dagne D.; Owens, William E.; Tchounwou, Paul B.

    2005-01-01

    Human health is a major concern when considering the disposal of large quantities of animal waste. Health concerns could arise from exposure to pathogens and excess nitrogen associated with this form of pollution. The objective was to collect and analyze health data related to selected bacterial infections associated with the use of animal waste in Louisiana. An analysis of adverse health effects has been conducted based on the incidence/prevalence rates of campylobacteriosis, E. coli O157:H7 infection, salmonellosis and shigellosis. The number of reported cases increased during the summer months. Analysis of health data showed that reported disease cases of E. coli O157:H7 were highest among Caucasian infants in the 0–4 year old age category and in Caucasian children in the 5–9 year old age category. Fatalities resulting from salmonellosis are low and increases sharply with age. The number of reported cases of shigellosis was found to be higher in African American males and females than in Caucasians. The high rate of identification in the younger population may result from the prompt seeking of medical care, as well as the frequent ordering of stool examination when symptoms become evident among this group of the population. The association with increasing age and fatality due to salmonellosis could be attributed to declining health and weaker immune systems often found in the older population. It is concluded that both animal waste and non-point source pollution may have a significant impact on human health. PMID:16705805

  5. Effect of Poor Access to Water and Sanitation As Risk Factors for Soil-Transmitted Helminth Infection: Selectiveness by the Infective Route

    PubMed Central

    Echazú, Adriana; Bonanno, Daniela; Juarez, Marisa; Cajal, Silvana P.; Heredia, Viviana; Caropresi, Silvia; Cimino, Ruben O.; Caro, Nicolas; Vargas, Paola A.; Paredes, Gladys; Krolewiecki, Alejandro J.

    2015-01-01

    Background Soil-transmitted helminth (STH) infections are a public health problem in resource-limited settings worldwide. Chronic STH infection impairs optimum learning and productivity, contributing to the perpetuation of the poverty-disease cycle. Regular massive drug administration (MDA) is the cardinal recommendation for its control; along with water, sanitation and hygiene (WASH) interventions. The impact of joint WASH interventions on STH infections has been reported; studies on the independent effect of WASH components are needed to contribute with the improvement of current recommendations for the control of STH. The aim of this study is to assess the association of lacking access to water and sanitation with STH infections, taking into account the differences in route of infection among species and the availability of adequate water and sanitation at home. Methods and Findings Cross-sectional study, conducted in Salta province, Argentina. During a deworming program that enrolled 6957 individuals; 771 were randomly selected for stool/serum sampling for parasitological and serological diagnosis of STH. Bivariate stratified analysis was performed to explore significant correlations between risk factors and STH infections grouped by mechanism of entry as skin-penetrators (hookworms and Strongyloides stercoralis) vs. orally-ingested (Ascaris lumbricoides and Trichuris trichiura). After controlling for potential confounders, unimproved sanitation was significantly associated with increased odds of infection of skin-penetrators (adjusted odds ratio [aOR] = 3.9; 95% CI: 2.6–5.9). Unimproved drinking water was significantly associated with increased odds of infection of orally-ingested (aOR = 2.2; 95% CI: 1.3–3.7). Conclusions Lack of safe water and proper sanitation pose a risk of STH infections that is distinct according to the route of entry to the human host used by each of the STH species. Interventions aimed to improve water and sanitation access should

  6. Risk factors and effect of selective removal on retroviral infections prevalence in Belgian stray cats.

    PubMed

    Garigliany, M; Jolly, S; Dive, M; Bayrou, C; Berthemin, S; Robin, P; Godenir, R; Petry, J; Dahout, S; Cassart, D; Thiry, E; Desmecht, D; Saegerman, C

    2016-01-01

    The aim of this study was to evaluate the effect of several risk/protective factors and predictors on the prevalence of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) infections in 302 stray cats captured during a trap-neuter-release programme in a mixed urban-rural area from Belgium, from 2010 to 2012. The impact of selective removal of FIV-positive cats on the apparent prevalence in the remaining population over this three-year period was also assessed. The seroprevalences over three years were 18.8 per cent for FIV and 0.7 per cent for FeLV. For FIV, the seroprevalence decreased significantly from the first year of the programme (2010; 30.5 per cent) to the last (2012; 13.1 per cent). Sex (male) and age (adult and old cats) were risk factors, while the year of sampling (years 2011 and 2012) was a protective factor. Age, sex and location were the most relevant predictors of FIV status. The data presented in this study revealed a very high FIV seroprevalence in Belgian stray cats, while FeLV was almost absent. The selective removal of positive cats had a drastic effect on the FIV seroprevalence in the remaining cat population.

  7. Baculovirus display of functional antibody Fab fragments.

    PubMed

    Takada, Shinya; Ogawa, Takafumi; Matsui, Kazusa; Suzuki, Tasuku; Katsuda, Tomohisa; Yamaji, Hideki

    2015-08-01

    The generation of a recombinant baculovirus that displays antibody Fab fragments on the surface was investigated. A recombinant baculovirus was engineered so that the heavy chain (Hc; Fd fragment) of a mouse Fab fragment was expressed as a fusion to the N-terminus of baculovirus gp64, while the light chain of the Fab fragment was simultaneously expressed as a secretory protein. Following infection of Sf9 insect cells with the recombinant baculovirus, the culture supernatant was analyzed by enzyme-linked immunosorbent assay using antigen-coated microplates and either an anti-mouse IgG or an anti-gp64 antibody. A relatively strong signal was obtained in each case, showing antigen-binding activity in the culture supernatant. In western blot analysis of the culture supernatant using the anti-gp64 antibody, specific protein bands were detected at an electrophoretic mobility that coincided with the molecular weight of the Hc-gp64 fusion protein as well as that of gp64. Flow cytometry using a fluorescein isothiocyanate-conjugated antibody specific to mouse IgG successfully detected the Fab fragments on the surface of the Sf9 cells. These results suggest that immunologically functional antibody Fab fragments can be displayed on the surface of baculovirus particles, and that a fluorescence-activated cell sorter with a fluorescence-labeled antigen can isolate baculoviruses displaying specific Fab fragments. This successful baculovirus display of antibody Fab fragments may offer a novel approach for the efficient selection of specific antibodies.

  8. Variants selected by treatment of human immunodeficiency virus-infected cells with an immunotoxin

    PubMed Central

    1990-01-01

    An immunotoxin has been made by coupling anti-human immunodeficiency virus (HIV) envelope antibody 907 to ricin A chain (907-RAC). 907 recognizes an epitope within the immunodominant PB-1 loop of gp120. Variant cells were selected by cloning persistently infected H9/human T lymphocyte virus IIIB cells in the presence of the immunotoxin. Clones resistant to 907-RAC arose at a frequency of 0.1-1.0%. Seven clones were selected for intensive analysis. When studied, these clones fell into two distinct groups, members of which appeared to be identical, suggesting that the variation arose before the selection process. In contrast to the parent cells, none of the cloned variants produced infectious HIV. The first set of clones, designated the "E" variants, expressed decreased levels of the HIV envelope on the cell surface. However, levels of intracellular HIV antigens and reverse transcriptase were equal to or greater than that of the parental cell line. Radioimmunoprecipitation demonstrated that the gp160 was truncated to 145 kD (gp120 was normal length), capable of binding to CD4, and, unlike normal gp160, was released in its unprocessed form into the cellular supernatant. Sequence analysis demonstrated that a deletion at codon 687 of the envelope gene resulted in the production of this truncated protein. Ultrastructural analysis of E variants demonstrated some budding forms of virus, but also large numbers of HIV within intracellular vesicles. The second set of variants, the "F" series, produced no HIV antigens, reverse transcriptase, nor was there ultrastructural evidence of virus. However, proviral DNA was present. Virus could not be induced with agents known to activate latent HIV. These cells also lacked cell surface CD4 and could not be infected with HIV. These studies demonstrate that variation in HIV can affect the phenotype of the cells carrying the altered virus, allowing for escape from immunologic destruction. The E variants may serve as prototypes for

  9. Toxoplasma gondii Oral Infection Induces Intestinal Inflammation and Retinochoroiditis in Mice Genetically Selected for Immune Oral Tolerance Resistance

    PubMed Central

    Dias, Raul Ramos Furtado; de Carvalho, Eulógio Carlos Queiroz; Leite, Carla Cristina da Silva; Tedesco, Roberto Carlos; Calabrese, Katia da Silva; Silva, Antonio Carlos; DaMatta, Renato Augusto; de Fatima Sarro-Silva, Maria

    2014-01-01

    Toxoplasmosis is a worldwide disease with most of the infections originating through the oral route and generates various pathological manifestations, ranging from meningoencephalitis to retinochoroiditis and inflammatory bowel disease. Animal models for these pathologies are scarce and have limitations. We evaluated the outcome of Toxoplasma gondii oral infection with 50 or 100 cysts of the ME-49 strain in two lines of mice with extreme phenotypes of susceptibility (TS) or resistance (TR) to immune oral tolerance. Therefore, the aim of this study was to evaluate the behaviour of TS and TR mice, orally infected by T. gondii, and determine its value as a model for inflammatory diseases study. Mortality during the acute stage of the infection for TR was 50% for both dosages, while 10 and 40% of the TS died after infection with these respective dosages. In the chronic stage, the remaining TS succumbed while TR survived for 90 days. The TS displayed higher parasite load with lower intestinal inflammation and cellular proliferation, notwithstanding myocarditis, pneumonitis and meningoencephalitis. TR presented massive necrosis of villi and crypt, comparable to inflammatory bowel disease, with infiltration of lymphoid cells in the lamina propria of the intestines. Also, TR mice infected with 100 cysts presented intense cellular infiltrate within the photoreceptor layer of the eyes, changes in disposition and morphology of the retina cell layers and retinochoroiditis. During the infection, high levels of IL-6 were detected in the serum of TS mice and TR mice presented high amounts of IFN-γ and TNF-α. Both mice lineages developed different disease outcomes, but it is emphasized that TR and TS mice presented acute and chronic stages of the infection, demonstrating that the two lineages offer an attractive model for studying toxoplasmosis. PMID:25437299

  10. Bgp, a secreted glycosaminoglycan-binding protein of Borrelia burgdorferi strain N40, displays nucleosidase activity and is not essential for infection of immunodeficient mice.

    PubMed

    Parveen, Nikhat; Cornell, Kenneth A; Bono, James L; Chamberland, Christen; Rosa, Patricia; Leong, John M

    2006-05-01

    Bgp, one of the surface-localized glycosaminoglycan-binding proteins of the Lyme disease spirochete, Borrelia burgdorferi, exhibited nucleosidase activity. Infection of SCID mice with B. burgdorferi strain N40 mutants harboring a targeted insertion in bgp and apparently retaining all endogenous plasmids revealed that Bgp is not essential for colonization of immunocompromised mice.

  11. Microgap flat panel display

    DOEpatents

    Wuest, Craig R.

    1998-01-01

    A microgap flat panel display which includes a thin gas-filled display tube that utilizes switched X-Y "pixel" strips to trigger electron avalanches and activate a phosphor at a given location on a display screen. The panel utilizes the principal of electron multiplication in a gas subjected to a high electric field to provide sufficient electron current to activate standard luminescent phosphors located on an anode. The X-Y conductive strips of a few micron widths may for example, be deposited on opposite sides of a thin insulating substrate, or on one side of the adjacent substrates and function as a cathode. The X-Y strips are separated from the anode by a gap filled with a suitable gas. Electrical bias is selectively switched onto X and Y strips to activate a "pixel" in the region where these strips overlap. A small amount of a long-lived radioisotope is used to initiate an electron avalanche in the overlap region when bias is applied. The avalanche travels through the gas filled gap and activates a luminescent phosphor of a selected color. The bias is adjusted to give a proportional electron multiplication to control brightness for given pixel.

  12. Microgap flat panel display

    DOEpatents

    Wuest, C.R.

    1998-12-08

    A microgap flat panel display is disclosed which includes a thin gas-filled display tube that utilizes switched X-Y ``pixel`` strips to trigger electron avalanches and activate a phosphor at a given location on a display screen. The panel utilizes the principal of electron multiplication in a gas subjected to a high electric field to provide sufficient electron current to activate standard luminescent phosphors located on an anode. The X-Y conductive strips of a few micron widths may for example, be deposited on opposite sides of a thin insulating substrate, or on one side of the adjacent substrates and function as a cathode. The X-Y strips are separated from the anode by a gap filled with a suitable gas. Electrical bias is selectively switched onto X and Y strips to activate a ``pixel`` in the region where these strips overlap. A small amount of a long-lived radioisotope is used to initiate an electron avalanche in the overlap region when bias is applied. The avalanche travels through the gas filled gap and activates a luminescent phosphor of a selected color. The bias is adjusted to give a proportional electron multiplication to control brightness for given pixel. 6 figs.

  13. Progress in the Development of Effective Vaccines to Prevent Selected Gram Positive Bacterial Infections

    PubMed Central

    Bronze, Michael S.; Dale, James B.

    2010-01-01

    Infections due to virulent gram positive bacteria, such as Staphylococcus aureus, group B streptococci and group A streptococci remain significant causes of morbidity and mortality despite progress in antimicrobial therapy. Despite significant advances in the understanding of the pathogenesis of infection due to these organisms, there are only limited strategies to prevent infection. In this paper, we review efforts to develop safe and effective vaccines that would prevent infections due to these 3 pathogens. PMID:20697258

  14. Methicillin-susceptible strains responsible for postoperative orthopedic infection are not selected by the use of cefazolin in prophylaxis.

    PubMed

    Trouillet-Assant, Sophie; Valour, Florent; Mouton, William; Martins-Simões, Patrícia; Lustig, Sébastien; Laurent, Frédéric; Ferry, Tristan

    2016-03-01

    Comparison of methicillin-susceptible Staphylococcus aureus (MSSA) isolates responsible for bone and joint infection (BJI, n=73) and nasal colonization (n=57) revealed similar prevalence of β-lactamase (blaZ) type A production, associated with cefazolin hydrolysis, suggesting that blaZ type A-carrying MSSA isolates implicated in postoperative BJI are not selected by cefazolin prophylaxis. PMID:26707070

  15. Association of KPC-producing Klebsiella pneumoniae colonization or infection with Candida isolation and selection of non-albicans species.

    PubMed

    Papadimitriou-Olivgeris, Matthaios; Spiliopoulou, Anastasia; Fligou, Fotini; Manolopoulou, Patroula; Spiliopoulou, Iris; Vrettos, Theofanis; Dodou, Vasiliki; Filos, Kriton S; Anastassiou, Evangelos D; Marangos, Markos; Christofidou, Myrto

    2014-11-01

    Clinical specimens from 565 patients hospitalized in 2 intensive care units (ICUs A and B) during a 28-month period were cultured on appropriate media for isolation of Candida. Forty-nine (9%) patients had at least a Candida spp.-positive sample. Candida albicans was the predominant species isolated from 26 (53%) patients. Seventeen patients (3%) developed candidemia. Multivariate analysis showed that obesity, female gender, hospitalization during summer months, admission at ICU B, parenteral nutrition, administration of metronidazole, transplantation, and KPC-producing Klebsiella pneumoniae (KPC-Kp) infection were independently associated with Candida spp. isolation. Candidemia was associated with cortisone administration, KPC-Kp infection, and presence of colostomy or abdominal catheter. Administration of fluconazole was a protective factor for both Candida spp. isolation and infection, leading to selection of Candida non-albicans species. Among several risk factors, KPC-Kp infection and colonization are identified as statistically significant factors associated with Candida isolation, especially of non-albicans species.

  16. In vivo selection of lymphocyte-tropic and macrophage-tropic variants of lymphocytic choriomeningitis virus during persistent infection.

    PubMed Central

    King, C C; de Fries, R; Kolhekar, S R; Ahmed, R

    1990-01-01

    This study demonstrates cell-specific selection of viral variants during persistent lymphocytic choriomeningitis virus infection in its natural host. We have analyzed viral isolates obtained from CD4+ T cells and macrophages of congenitally infected carrier mice and found that three types of variants are present in individual carrier mice: (i) macrophage-tropic, (ii) lymphotropic, and (iii) amphotropic. The majority of the isolates were amphotropic and exhibited enhanced growth in both lymphocytes and macrophages. However, some of the lymphocyte-derived isolates grew well in lymphocytes but poorly in macrophages, and a macrophage-derived isolate replicated well in macrophages but not in lymphocytes. In striking contrast, the original wild-type (wt) Armstrong strain of lymphocytic choriomeningitis virus that was used to initiate the chronic infection and from which the variants are derived grew poorly in both lymphocytes and macrophages. These three types of variants also differed from the parental virus in their ability to establish a chronic infection in immunocompetent hosts. Adult mice infected with the wt Armstrong strain cleared the infection within 2 weeks, whereas adult mice infected with the variants harbored virus for several months. These results suggest that the ability of the variants to persist in adult mice is due to enhanced replication in macrophages and/or lymphocytes. This conclusion is further strengthened by the finding that the variants and the parental wt virus grew equally well in mouse fibroblasts and that the observed growth differences were specific for cells of the immune system. Images PMID:1976825

  17. Pertactin negative Bordetella pertussis demonstrates higher fitness under vaccine selection pressure in a mixed infection model.

    PubMed

    Safarchi, Azadeh; Octavia, Sophie; Luu, Laurence Don Wai; Tay, Chin Yen; Sintchenko, Vitali; Wood, Nicholas; Marshall, Helen; McIntyre, Peter; Lan, Ruiting

    2015-11-17

    Whooping cough or pertussis is a highly infectious respiratory disease in humans caused by Bordetella pertussis. The use of acellular vaccines (ACV) has been associated with the recent resurgence of pertussis in developed countries including Australia despite high vaccination coverage where B. pertussis strains that do not express pertactin (Prn), a key antigenic component of the ACV, have emerged and become prevalent. In this study, we used an in vivo competition assay in mice immunised with ACV and in naïve (control) mice to compare the proportion of colonisation with recent clinical Prn positive and Prn negative B. pertussis strains from Australia. The Prn negative strain colonised the respiratory tract more effectively than the Prn positive strain in immunised mice, out-competing the Prn positive strain by day 3 of infection. However, in control mice, the Prn positive strain out-competed the Prn negative strain. Our findings of greater ability of Prn negative strains to colonise ACV-immunised mice are consistent with reports of selective advantage for these strains in ACV-immunised humans.

  18. Pertactin negative Bordetella pertussis demonstrates higher fitness under vaccine selection pressure in a mixed infection model.

    PubMed

    Safarchi, Azadeh; Octavia, Sophie; Luu, Laurence Don Wai; Tay, Chin Yen; Sintchenko, Vitali; Wood, Nicholas; Marshall, Helen; McIntyre, Peter; Lan, Ruiting

    2015-11-17

    Whooping cough or pertussis is a highly infectious respiratory disease in humans caused by Bordetella pertussis. The use of acellular vaccines (ACV) has been associated with the recent resurgence of pertussis in developed countries including Australia despite high vaccination coverage where B. pertussis strains that do not express pertactin (Prn), a key antigenic component of the ACV, have emerged and become prevalent. In this study, we used an in vivo competition assay in mice immunised with ACV and in naïve (control) mice to compare the proportion of colonisation with recent clinical Prn positive and Prn negative B. pertussis strains from Australia. The Prn negative strain colonised the respiratory tract more effectively than the Prn positive strain in immunised mice, out-competing the Prn positive strain by day 3 of infection. However, in control mice, the Prn positive strain out-competed the Prn negative strain. Our findings of greater ability of Prn negative strains to colonise ACV-immunised mice are consistent with reports of selective advantage for these strains in ACV-immunised humans. PMID:26432908

  19. Selective Inhibition of Hepatitis C Virus Infection by Hydroxyzine and Benztropine

    PubMed Central

    Mingorance, Lidia; Friesland, Martina; Coto-Llerena, Mairene; Pérez-del-Pulgar, Sofía; Boix, Loreto; López-Oliva, Juan Manuel; Bruix, Jordi; Forns, Xavier

    2014-01-01

    Hepatitis C virus (HCV) infection is a major biomedical problem worldwide as it causes severe liver disease in millions of humans around the world. Despite the recent approval of specific drugs targeting HCV replication to be used in combination with alpha interferon (IFN-α) and ribavirin, there is still an urgent need for pangenotypic, interferon-free therapies to fight this genetically diverse group of viruses. In this study, we used an unbiased screening cell culture assay to interrogate a chemical library of compounds approved for clinical use in humans. This system enables identifying nontoxic antiviral compounds targeting every aspect of the viral life cycle, be the target viral or cellular. The aim of this study was to identify drugs approved for other therapeutic applications in humans that could be effective components of combination therapies against HCV. As a result of this analysis, we identified 12 compounds with antiviral activity in cell culture, some of which had previously been identified as HCV inhibitors with antiviral activity in cell culture and had been shown to be effective in patients. We selected two novel HCV antivirals, hydroxyzine and benztropine, to characterize them by determining their specificity and genotype spectrum as well as by defining the step of the replication cycle targeted by these compounds. We found that both compounds effectively inhibited viral entry at a postbinding step of genotypes 1, 2, 3, and 4 without affecting entry of other viruses. PMID:24709263

  20. Neutrophils Select Hypervirulent CovRS Mutants of M1T1 Group A Streptococcus during Subcutaneous Infection of Mice

    PubMed Central

    Li, Jinquan; Liu, Guanghui; Feng, Wenchao; Zhou, Yang; Liu, Mengyao; Wiley, James A.

    2014-01-01

    Pathogen mutants arise during infections. Mechanisms of selection for pathogen variants are poorly understood. We tested whether neutrophils select mutations in the two-component regulatory system CovRS of group A Streptococcus (GAS) during infection using the lack of production of the protease SpeB (SpeB activity negative [SpeBA−]) as a marker. Depletion of neutrophils by antibodies RB6-8C5 and 1A8 reduced the percentage of SpeBA− variants (SpeBA−%) recovered from mice infected with GAS strain MGAS2221 by >76%. Neutrophil recruitment and SpeBA−% among recovered GAS were reduced by 95% and 92%, respectively, in subcutaneous MGAS2221 infection of CXCR2−/− mice compared with control mice. In air sac infection with MGAS2221, levels of neutrophils and macrophages in lavage fluid were reduced by 49% and increased by 287%, respectively, in CXCR2−/− mice compared with control mice, implying that macrophages play an insignificant role in the reduction of selection for SpeBA− variants in CXCR2−/− mice. One randomly chosen SpeBA− mutant outcompeted MGAS2221 in normal mice but was outcompeted by MGAS2221 in neutropenic mice and had enhancements in expression of virulence factors, innate immune evasion, skin invasion, and virulence. This and nine other SpeBA− variants from a mouse all had nonsynonymous covRS mutations that resulted in the SpeBA− phenotype and enhanced expression of the CovRS-controlled secreted streptococcal esterase (SsE). Our findings are consistent with a model that neutrophils select spontaneous covRS mutations that maximize the potential of GAS to evade neutrophil responses, resulting in variants with enhanced survival and virulence. To our knowledge, this is the first report of the critical contribution of neutrophils to the selection of pathogen variants. PMID:24452689

  1. Effects of Infection on Selected Clinical and Biochemical Parameters in Dogs

    PubMed Central

    Williams, Gail; Newberne, P. M.

    1970-01-01

    Five month old male beagles injected i.p. with a washed 18-hr culture of Salmonella typhimurium 1 × 109 organisms/kg. responded clinically with a marked depression, anorexia, and a febrile response 12 hr following infection. Animals allowed to live beyond 36 hr showed a decrease in febrile response. Although they still refused food 36 hr following infection, they appeared more alert by 60 hr post-infection. Changes at necropsy were minimal and histologic findings consistent with Salmonella infection were found in both liver and spleen. In animals infected 60 hr liver microabscesses and circumscribed foci of reticuloendothelial cell hyperplasia in the spleen indicated that the animals were responding favourably by mounting a defence against the infection. As a result of infection there was an outpouring of band neutrophils resulting in an increase in the absolute numbers of circulating white blood cells. Associated with the neutrophilia was an early lymphopenia and eosinopenia. The total free amino acids were depressed in serum and increased in the liver at all time periods observed, but the degree of change as well as the specific amino acids affected varied; however, alterations in concentration of amino acids in serum of animals infected with Salmonella were similar to those observed in dogs infected with the virus of canine distemper. In both viral and bacterial infected dogs serum phenylalanine was increased and tyrosine remained the same or decreased, resulting in a significant alteration in the phenylalanine/tyrosine (P/T) ratio. As with distemper infected dogs, an increase of the alpha-2 fraction of serum proteins was detected at 36 hr following infection. There was a decrease in the monosome peak and a corresponding increase in the polysome fraction of the liver post-mitochondrial supernatant preparation associated with infection. The significance of this change in the liver polysome profile following infection is not yet understood. PMID:4913856

  2. Evolution of oseltamivir resistance mutations in Influenza A(H1N1) and A(H3N2) viruses during selection in experimentally infected mice.

    PubMed

    Pizzorno, Andrés; Abed, Yacine; Plante, Pier-Luc; Carbonneau, Julie; Baz, Mariana; Hamelin, Marie-Ève; Corbeil, Jacques; Boivin, Guy

    2014-11-01

    The evolution of oseltamivir resistance mutations during selection through serial passages in animals is still poorly described. Herein, we assessed the evolution of neuraminidase (NA) and hemagglutinin (HA) genes of influenza A/WSN/33 (H1N1) and A/Victoria/3/75 (H3N2) viruses recovered from the lungs of experimentally infected BALB/c mice receiving suboptimal doses (0.05 and 1 mg/kg of body weight/day) of oseltamivir over two generations. The traditional phenotypic and genotypic methods as well as deep-sequencing analysis were used to characterize the potential selection of mutations and population dynamics of oseltamivir-resistant variants. No oseltamivir-resistant NA or HA changes were detected in the recovered A/WSN/33 viruses. However, we observed a positive selection of the I222T NA substitution in the recovered A/Victoria/3/75 viruses, with a frequency increasing over time and with an oseltamivir concentration from 4% in the initial pretherapy inoculum up to 28% after two lung passages. Although the presence of mixed I222T viral populations in mouse lungs only led to a minimal increase in oseltamivir 50% enzyme-inhibitory concentrations (IC50s) (by a mean of 5.7-fold) compared to that of the baseline virus, the expressed recombinant A/Victoria/3/75 I222T NA protein displayed a 16-fold increase in the oseltamivir IC50 level compared to that of the recombinant wild type (WT). In conclusion, the combination of serial in vivo passages under neuraminidase inhibitor (NAI) pressure and temporal deep-sequencing analysis enabled, for the first time, the identification and selection of the oseltamivir-resistant I222T NA mutation in an influenza H3N2 virus. Additional in vivo selection experiments with other antivirals and drug combinations might provide important information on the evolution of antiviral resistance in influenza viruses.

  3. Infection.

    PubMed

    Saigal, Gaurav; Nagornaya, Natalya; Post, M Judith D

    2016-01-01

    Imaging is useful in the diagnosis and management of infections of the central nervous system. Typically, imaging findings at the outset of the disease are subtle and nonspecific, but they often evolve to more definite imaging patterns in a few days, with less rapidity than for stroke but faster than for neoplastic lesions. This timing is similar to that of noninfectious inflammatory brain disease, such as multiple sclerosis. Fortunately, imaging patterns help to distinguish the two kinds of processes. Other than for sarcoidosis, the meninges are seldom involved in noninfectious inflammation; in contrast, many infectious processes involve the meninges, which then enhance with contrast on computed tomography (CT) or magnetic resonance imaging (MRI). However, brain infection causes a vast array of imaging patterns. Although CT is useful when hemorrhage or calcification is suspected or bony detail needs to be determined, MRI is the imaging modality of choice in the investigation of intracranial infections. Imaging sequences such as diffusion-weighted imaging help in accurately depicting the location and characterizing pyogenic infections and are particularly useful in differentiating bacterial infections from other etiologies. Susceptibility-weighted imaging is extremely useful for the detection of hemorrhage. Although MR spectroscopy findings can frequently be nonspecific, certain conditions such as bacterial abscesses show a relatively specific spectral pattern and are useful in diagnosing and constituting immediate therapy. In this chapter we review first the imaging patterns associated with involvement of various brain structures, such as the epidural and subdural spaces, the meninges, the brain parenchyma, and the ventricles. Involvement of these regions is illustrated with bacterial infections. Next we illustrate the patterns associated with viral and prion diseases, followed by mycobacterial and fungal infections, to conclude with a review of imaging findings

  4. The hitchhiker's guide to Europe: the infection dynamics of an ongoing Wolbachia invasion and mitochondrial selective sweep in Rhagoletis cerasi.

    PubMed

    Schuler, Hannes; Köppler, Kirsten; Daxböck-Horvath, Sabine; Rasool, Bilal; Krumböck, Susanne; Schwarz, Dietmar; Hoffmeister, Thomas S; Schlick-Steiner, Birgit C; Steiner, Florian M; Telschow, Arndt; Stauffer, Christian; Arthofer, Wolfgang; Riegler, Markus

    2016-04-01

    Wolbachia is a maternally inherited and ubiquitous endosymbiont of insects. It can hijack host reproduction by manipulations such as cytoplasmic incompatibility (CI) to enhance vertical transmission. Horizontal transmission of Wolbachia can also result in the colonization of new mitochondrial lineages. In this study, we present a 15-year-long survey of Wolbachia in the cherry fruit fly Rhagoletis cerasi across Europe and the spatiotemporal distribution of two prevalent strains, wCer1 and wCer2, and associated mitochondrial haplotypes in Germany. Across most of Europe, populations consisted of either 100% singly (wCer1) infected individuals with haplotype HT1, or 100% doubly (wCer1&2) infected individuals with haplotype HT2, differentiated only by a single nucleotide polymorphism. In central Germany, singly infected populations were surrounded by transitional populations, consisting of both singly and doubly infected individuals, sandwiched between populations fixed for wCer1&2. Populations with fixed infection status showed perfect association of infection and mitochondria, suggesting a recent CI-driven selective sweep of wCer2 linked with HT2. Spatial analysis revealed a range expansion for wCer2 and a large transition zone in which wCer2 splashes appeared to coalesce into doubly infected populations. Unexpectedly, the transition zone contained a large proportion (22%) of wCer1&2 individuals with HT1, suggesting frequent intraspecific horizontal transmission. However, this horizontal transmission did not break the strict association between infection types and haplotypes in populations outside the transition zone, suggesting that this horizontally acquired Wolbachia infection may be transient. Our study provides new insights into the rarely studied Wolbachia invasion dynamics in field populations. PMID:26846713

  5. Colorimetric evaluation of display performance

    NASA Astrophysics Data System (ADS)

    Kosmowski, Bogdan B.

    2001-08-01

    The development of information techniques, using new technologies, physical phenomena and coding schemes, enables new application areas to be benefited form the introduction of displays. The full utilization of the visual perception of a human operator, requires the color coding process to be implemented. The evolution of displays, from achromatic (B&W) and monochromatic, to multicolor and full-color, enhances the possibilities of information coding, creating however a need for the quantitative methods of display parameter assessment. Quantitative assessment of color displays, restricted to photometric measurements of their parameters, is an estimate leading to considerable errors. Therefore, the measurements of a display's color properties have to be based on spectral measurements of the display and its elements. The quantitative assessment of the display system parameters should be made using colorimetric systems like CIE1931, CIE1976 LAB or LUV. In the paper, the constraints on the measurement method selection for the color display evaluation are discussed and the relations between their qualitative assessment and the ergonomic conditions of their application are also presented. The paper presents the examples of using LUV colorimetric system and color difference (Delta) E in the optimization of color liquid crystal displays.

  6. Infections may select for filial cannibalism by impacting egg survival in interactions with water salinity and egg density.

    PubMed

    Lehtonen, Topi K; Kvarnemo, Charlotta

    2015-07-01

    In aquatic environments, externally developing eggs are in constant contact with the surrounding water, highlighting the significance of water parameters and pathogens for egg survival. In this study we tested the impact of water salinity, egg density and infection potential of the environment on egg viability in the sand goby (Pomatoschistus minutus), a small fish that exhibits paternal egg care and has a marine origin, but which in the Baltic Sea lives in brackish water. To manipulate the infection potential of the environment, we added either a Saprolegnia infection vector into UV-filtered water or a fungicide into natural Baltic Sea water. Saprolegnia are widely spread water moulds that are a key cause of egg mortality in aquatic organisms in fresh- and brackish water. We found that increased water salinity indeed decreased the egg infection rate and had a positive effect on egg viability, while high egg density tended to have the opposite effect. However, the different factors influenced egg viability interactively, with a higher egg density having negative effects at low, but not in high, salinity. Thus, the challenges facing marine organisms adapting to lower salinity levels can be amplified by Saprolegnia infections that reduce egg survival in interaction with other environmental factors. Our results support the hypothesis that suppressing egg infections is an important aspect of parental care that can select for filial cannibalism, a common but poorly understood behaviour, especially in fish with parental care.

  7. Human immunodeficiency virus type 1 long terminal repeat variants from 42 patients representing all stages of infection display a wide range of sequence polymorphism and transcription activity.

    PubMed Central

    Estable, M C; Bell, B; Merzouki, A; Montaner, J S; O'Shaughnessy, M V; Sadowski, I J

    1996-01-01

    Despite extensive in vitro studies identifying a myriad of cellular transcription factors that bind the human immunodeficiency virus type 1 5' long terminal repeat (LTR), the relative contribution of these factors to human immunodeficiency virus type 1 replication in infected individuals remains obscure. To address this question, we investigated 478 proviral quasispecies derived from uncultured peripheral blood mononuclear cells of 42 patients representing all stages of infection. In addition to highly conserved TATA box, SP-1, and NF-kappaB sites, the Ets core and an adjacent 5'-ACYGCTGA-3' motif were extremely conserved. Importantly, the most frequent naturally occurring length polymorphism (MFNLP) duplicated 5'-ACYGCTGA-3' motifs in LTRs in which this same motif was disrupted or in LTRs in which a single point mutation to the Ets core ablated binding of c-Ets 1 and another factor distinct from both c-Ets 1 and Elf 1. The MFNLP's location was precise (position -121) and surprisingly frequent (38% of patients) and demarcated LTR Nef-coding sequences from LTR noncoding sequences that appear to be evolving independently. Aside from these features, we found no definitive clinical or transcription phenotype common to all MFNLP LTRs. We also found previously described and novel point polymorphisms, including some conferring TAR-dependent and TAR- independent Tat unresponsiveness, and showed that differential binding of nuclear factor(s) to a TCTAA TATA box variant may be the mechanism for the latter. PMID:8648743

  8. Virus-Specific Read-Through Codon Preference Affects Infectivity of Chimeric Cucumber Green Mottle Mosaic Viruses Displaying a Dengue Virus Epitope

    PubMed Central

    Teoh, Pak-Guan; Ooi, Aik-Seng; AbuBakar, Sazaly; Othman, Rofina Yasmin

    2009-01-01

    A Cucumber green mottle mosaic virus (CGMMV) was used to present a truncated dengue virus type 2 envelope (E) protein binding region from amino acids 379 to 423 (EB4). The EB4 gene was inserted at the terminal end of the CGMMV coat protein (CP) open reading frame (ORF). Read-through sequences of TMV or CGMMV, CAA-UAG-CAA-UUA, or AAA-UAG-CAA-UUA were, respectively, inserted in between the CP and the EB4 genes. The chimeric clones, pRT, pRG, and pCG+FSRTRE, were transcribed into full-length capped recombinant CGMMV transcripts. Only constructs with the wild-type CGMMV read-through sequence yielded infectious viruses following infection of host plant, muskmelon (Cucumis melo) leaves. The ratio of modified to unmodified CP for the read-through expression clone developed was also found to be approximately 1:1, higher than what has been previously reported. It was also observed that infectivity was not affected by differences in pI between the chimera and its wild counterpart. Analysis of recombinant viruses after 21-days-postinculation (dpi) revealed that deletions occurred resulting in partial reversions of the viral population to near wild type and suggesting that this would be the limiting harvest period for obtaining true to type recombinants with this construct. PMID:19325913

  9. Comparison of Test Procedures and Energy Efficiency Criteria in Selected International Standards & Labeling Programs for Copy Machines, External Power Supplies, LED Displays, Residential Gas Cooktops and Televisions

    SciTech Connect

    Zheng, Nina; Zhou, Nan; Fridley, David

    2012-03-01

    This report presents a technical review of international minimum energy performance standards (MEPS), voluntary and mandatory energy efficiency labels and test procedures for five products being considered for new or revised MEPS in China: copy machines, external power supply, LED displays, residential gas cooktops and flat-screen televisions. For each product, an overview of the scope of existing international standards and labeling programs, energy values and energy performance metrics and description and detailed summary table of criteria and procedures in major test standards are presented.

  10. Selection for a CEACAM Receptor-Specific Binding Phenotype during Neisseria gonorrhoeae Infection of the Human Genital Tract

    PubMed Central

    Sintsova, Anna; Wong, Henry; MacDonald, Kelly S.; Kaul, Rupert; Virji, Mumtaz

    2015-01-01

    Infections by Neisseria gonorrhoeae are increasingly common, are often caused by antibiotic-resistant strains, and can result in serious and lasting sequelae, prompting the reemergence of gonococcal disease as a leading global health concern. N. gonorrhoeae is a human-restricted pathogen that primarily colonizes urogenital mucosal surfaces. Disease progression varies greatly between the sexes: men usually present with symptomatic infection characterized by a painful purulent urethral discharge, while in women, the infection is often asymptomatic, with the most severe pathology occurring when the bacteria ascend from the lower genital tract into the uterus and fallopian tubes. Classical clinical studies demonstrated that clinically infectious strains uniformly express Opa adhesins; however, their specificities were unknown at the time. While in vitro studies have since identified CEACAM proteins as the primary target of Opa proteins, the gonococcal specificity for this human family of receptors has not been addressed in the context of natural infection. In this study, we characterize a collection of low-passage-number clinical-specimen-derived N. gonorrhoeae isolates for Opa expression and assess their CEACAM-binding profiles. We report marked in vivo selection for expression of phase-variable Opa proteins that bind CEACAM1 and CEACAM5 but selection against expression of Opa variants that bind to the neutrophil-restricted decoy receptor CEACAM3. This is the first study showing phenotypic selection for distinct CEACAM-binding phenotypes in vivo, and it supports the opposing functions of CEACAMs that facilitate infection versus driving inflammation within the genital tract. PMID:25605771

  11. A Comprehensive Process for Display Systems Development.

    ERIC Educational Resources Information Center

    Simcox, William A.

    A comprehensive development process for display design, focusing on computer-generated cathode ray tube (CRT) displays is presented. A framework is created for breaking the display into its component parts, used to guide the design process. The objective is to design or select the most cost effective graphics solution (hardware and software) to…

  12. Rapid selection of escape mutants by the first CD8 T cell responses in acute HIV-1 infection

    SciTech Connect

    Korber, Bette Tina Marie

    2008-01-01

    The recent failure of a vaccine that primes T cell responses to control primary HIV-1 infection has raised doubts about the role of CD8+ T cells in early HIV-1 infection. We studied four patients who were identified shortly after HIV-1 infection and before seroconversion. In each patient there was very rapid selection of multiple HIV-1 escape mutants in the transmitted virus by CD8 T cells, including examples of complete fixation of non-synonymous substitutions within 2 weeks. Sequencing by single genome amplification suggested that the high rate of virus replication in acute infection gave a selective advantage to virus molecules that contained simultaneous and gained sequential T cell escape mutations. These observations show that whilst early HIV-1 specific CD8 T cells can act against virus, rapid escape means that these T cell responses are unlikely to benefit the patient and may in part explain why current HIV-1 T cell vaccines may not be protective.

  13. Discovery of raltegravir, a potent, selective orally bioavailable HIV-integrase inhibitor for the treatment of HIV-AIDS infection.

    PubMed

    Summa, Vincenzo; Petrocchi, Alessia; Bonelli, Fabio; Crescenzi, Benedetta; Donghi, Monica; Ferrara, Marco; Fiore, Fabrizio; Gardelli, Cristina; Gonzalez Paz, Odalys; Hazuda, Daria J; Jones, Philip; Kinzel, Olaf; Laufer, Ralph; Monteagudo, Edith; Muraglia, Ester; Nizi, Emanuela; Orvieto, Federica; Pace, Paola; Pescatore, Giovanna; Scarpelli, Rita; Stillmock, Kara; Witmer, Marc V; Rowley, Michael

    2008-09-25

    Human immunodeficiency virus type-1 (HIV-1) integrase is one of the three virally encoded enzymes required for replication and therefore a rational target for chemotherapeutic intervention in the treatment of HIV-1 infection. We report here the discovery of Raltegravir, the first HIV-integrase inhibitor approved by FDA for the treatment of HIV infection. It derives from the evolution of 5,6-dihydroxypyrimidine-4-carboxamides and N-methyl-4-hydroxypyrimidinone-carboxamides, which exhibited potent inhibition of the HIV-integrase catalyzed strand transfer process. Structural modifications on these molecules were made in order to maximize potency as HIV-integrase inhibitors against the wild type virus, a selection of mutants, and optimize the selectivity, pharmacokinetic, and metabolic profiles in preclinical species. The good profile of Raltegravir has enabled its progression toward the end of phase III clinical trials for the treatment of HIV-1 infection and culminated with the FDA approval as the first HIV-integrase inhibitor for the treatment of HIV-1 infection.

  14. Co-infection Weakens Selection Against Epistatic Mutations in RNA Viruses

    PubMed Central

    Froissart, Rémy; Wilke, Claus O.; Montville, Rebecca; Remold, Susanna K.; Chao, Lin; Turner, Paul E.

    2004-01-01

    Co-infection may be beneficial in large populations of viruses because it permits sexual exchange between viruses that is useful in combating the mutational load. This advantage of sex should be especially substantial when mutations interact through negative epistasis. In contrast, co-infection may be detrimental because it allows virus complementation, where inferior genotypes profit from superior virus products available within the cell. The RNA bacteriophage φ6 features a genome divided into three segments. Co-infection by multiple φ6 genotypes produces hybrids containing reassorted mixtures of the parental segments. We imposed a mutational load on φ6 populations by mixing the wild-type virus with three single mutants, each harboring a deleterious mutation on a different one of the three virus segments. We then contrasted the speed at which these epistatic mutations were removed from virus populations in the presence and absence of co-infection. If sex is a stronger force, we predicted that the load should be purged faster in the presence of co-infection. In contrast, if complementation is more important we hypothesized that mutations would be eliminated faster in the absence of co-infection. We found that the load was purged faster in the absence of co-infection, which suggests that the disadvantages of complementation can outweigh the benefits of sex, even in the presence of negative epistasis. We discuss our results in light of virus disease management and the evolutionary advantage of haploidy in biological populations. PMID:15454523

  15. Preliminary display comparison for dental diagnostic applications

    NASA Astrophysics Data System (ADS)

    Odlum, Nicholas; Spalla, Guillaume; van Assche, Nele; Vandenberghe, Bart; Jacobs, Reinhilde; Quirynen, Marc; Marchessoux, Cédric

    2012-02-01

    The aim of this study is to predict the clinical performance and image quality of a display system for viewing dental images. At present, the use of dedicated medical displays is not uniform among dentists - many still view images on ordinary consumer displays. This work investigated whether the use of a medical display improved the perception of dental images by a clinician, compared to a consumer display. Display systems were simulated using the MEdical Virtual Imaging Chain (MEVIC). Images derived from two carefully performed studies on periodontal bone lesion detection and endodontic file length determination, were used. Three displays were selected: a medical grade one and two consumer displays (Barco MDRC-2120, Dell 1907FP and Dell 2007FPb). Some typical characteristics of the displays are evaluated by measurements and simulations like the Modulation Function (MTF), the Noise Power Spectrum (NPS), backlight stability or calibration. For the MTF, the display with the largest pixel pitch has logically the worst MTF. Moreover, the medical grade display has a slightly better MTF and the displays have similar NPS. The study shows the instability effect for the emitted intensity of the consumer displays compared to the medical grade one. Finally the study on the calibration methodology of the display shows that the signal in the dental images will be always more perceivable on the DICOM GSDF display than a gamma 2,2 display.

  16. Intra-domain phage display (ID-PhD) of peptides and protein mini-domains censored from canonical pIII phage display

    PubMed Central

    Tjhung, Katrina F.; Deiss, Frédérique; Tran, Jessica; Chou, Ying; Derda, Ratmir

    2015-01-01

    In this paper, we describe multivalent display of peptide and protein sequences typically censored from traditional N-terminal display on protein pIII of filamentous bacteriophage M13. Using site-directed mutagenesis of commercially available M13KE phage cloning vector, we introduced sites that permit efficient cloning using restriction enzymes between domains N1 and N2 of the pIII protein. As infectivity of phage is directly linked to the integrity of the connection between N1 and N2 domains, intra-domain phage display (ID-PhD) allows for simple quality control of the display and the natural variations in the displayed sequences. Additionally, direct linkage to phage propagation allows efficient monitoring of sequence cleavage, providing a convenient system for selection and evolution of protease-susceptible or protease-resistant sequences. As an example of the benefits of such an ID-PhD system, we displayed a negatively charged FLAG sequence, which is known to be post-translationally excised from pIII when displayed on the N-terminus, as well as positively charged sequences which suppress production of phage when displayed on the N-terminus. ID-PhD of FLAG exhibited sub-nanomolar apparent Kd suggesting multivalent nature of the display. A TEV-protease recognition sequence (TEVrs) co-expressed in tandem with FLAG, allowed us to demonstrate that 99.9997% of the phage displayed the FLAG-TEVrs tandem and can be recognized and cleaved by TEV-protease. The residual 0.0003% consisted of phage clones that have excised the insert from their genome. ID-PhD is also amenable to display of protein mini-domains, such as the 33-residue minimized Z-domain of protein A. We show that it is thus possible to use ID-PhD for multivalent display and selection of mini-domain proteins (Affibodies, scFv, etc.). PMID:25972845

  17. Intra-domain phage display (ID-PhD) of peptides and protein mini-domains censored from canonical pIII phage display.

    PubMed

    Tjhung, Katrina F; Deiss, Frédérique; Tran, Jessica; Chou, Ying; Derda, Ratmir

    2015-01-01

    In this paper, we describe multivalent display of peptide and protein sequences typically censored from traditional N-terminal display on protein pIII of filamentous bacteriophage M13. Using site-directed mutagenesis of commercially available M13KE phage cloning vector, we introduced sites that permit efficient cloning using restriction enzymes between domains N1 and N2 of the pIII protein. As infectivity of phage is directly linked to the integrity of the connection between N1 and N2 domains, intra-domain phage display (ID-PhD) allows for simple quality control of the display and the natural variations in the displayed sequences. Additionally, direct linkage to phage propagation allows efficient monitoring of sequence cleavage, providing a convenient system for selection and evolution of protease-susceptible or protease-resistant sequences. As an example of the benefits of such an ID-PhD system, we displayed a negatively charged FLAG sequence, which is known to be post-translationally excised from pIII when displayed on the N-terminus, as well as positively charged sequences which suppress production of phage when displayed on the N-terminus. ID-PhD of FLAG exhibited sub-nanomolar apparent Kd suggesting multivalent nature of the display. A TEV-protease recognition sequence (TEVrs) co-expressed in tandem with FLAG, allowed us to demonstrate that 99.9997% of the phage displayed the FLAG-TEVrs tandem and can be recognized and cleaved by TEV-protease. The residual 0.0003% consisted of phage clones that have excised the insert from their genome. ID-PhD is also amenable to display of protein mini-domains, such as the 33-residue minimized Z-domain of protein A. We show that it is thus possible to use ID-PhD for multivalent display and selection of mini-domain proteins (Affibodies, scFv, etc.). PMID:25972845

  18. Display formats manual

    NASA Technical Reports Server (NTRS)

    Runnels, R. L.

    1973-01-01

    The standards and procedures for the generation of operational display formats to be used in the Mission Control Center (MCC) display control system are presented. The required effort, forms, and fundamentals for the design, specifications, and production of display formats are identified. The principles of display design and system constraints controlling the creation of optimum operational displays for mission control are explained. The basic two types of MCC display systems for presenting information are described.

  19. CD4+ T cells from elite controllers resist HIV-1 infection by selective upregulation of p21

    PubMed Central

    Chen, Huabiao; Li, Chun; Huang, Jinghe; Cung, Thai; Seiss, Katherine; Beamon, Jill; Carrington, Mary F.; Porter, Lindsay C.; Burke, Patrick S.; Yang, Yue; Ryan, Bethany J.; Liu, Ruiwu; Weiss, Robert H.; Pereyra, Florencia; Cress, William D.; Brass, Abraham L.; Rosenberg, Eric S.; Walker, Bruce D.; Yu, Xu G.; Lichterfeld, Mathias

    2011-01-01

    Elite controllers represent a unique group of HIV-1–infected persons with undetectable HIV-1 replication in the absence of antiretroviral therapy. However, the mechanisms contributing to effective viral immune defense in these patients remain unclear. Here, we show that compared with HIV-1 progressors and HIV-1–negative persons, CD4+ T cells from elite controllers are less susceptible to HIV-1 infection. This partial resistance to HIV-1 infection involved less effective reverse transcription and mRNA transcription from proviral DNA and was associated with strong and selective upregulation of the cyclin-dependent kinase inhibitor p21 (also known as cip-1 and waf-1). Experimental blockade of p21 in CD4+ T cells from elite controllers resulted in a marked increase of viral reverse transcripts and mRNA production and led to higher enzymatic activities of cyclin-dependent kinase 9 (CDK9), which serves as a transcriptional coactivator of HIV-1 gene expression. This suggests that p21 acts as a barrier against HIV-1 infection in CD4+ T cells from elite controllers by inhibiting a cyclin-dependent kinase required for effective HIV-1 replication. These data demonstrate a mechanism of host resistance to HIV-1 in elite controllers and may open novel perspectives for clinical strategies to prevent or treat HIV-1 infection. PMID:21403397

  20. Experimental infection of selected arthropods with spirurid nematodes Spirocerca lupi Railliet & Henry, 1911 and Gongylonema ingluvicola Molin, 1857.

    PubMed

    Mukaratirwa, S; Pillay, E; Munsammy, K

    2010-12-01

    Gongylonema ingluvicola and Spirocerca lupi are spirurid nematodes that require arthropod intermediate hosts in order to complete their life cycle. Beetles of the family Scarabaeidae are reported to serve as intermediate hosts for both these parasites. In this study selected species of beetles of the family Scarabaeidae as well as other groups of arthropods were screened for susceptibility to infection with S. lupi and G. ingluvicola. Arthropods were exposed to infective eggs of both parasites for a determined period of time and dissected/digested to determine the presence or absence of pre-infective and infective larvae. All the five species of dung beetles exposed to infection with S. lupi, namely, Pachylomerus femoralis, Scarabaeus rugosus, Gymnopleurus humanus, Kheper nigroaeneus and Anachalcos convexus were susceptible and, of the two species exposed to G. ingluvicola, only Gy. humanus was susceptible. Spirocerca lupi eggs developed in millipede species, Daratoagonus cristulatus, and remained as encysted larvae, while in Orthoporoides kyrhocephalus no development was observed. Spirocerca lupi larvae were not detected in the cricket species Gryllus assimilis, or the cockroach species Periplaneta americana, and, similarly, G. ingluvicola larvae were not detected in the millipede species O. kyrhocephalus. The difference in the susceptibility of the arthropods to the two parasite species may depend on their feeding biology.

  1. Selective Loss of Innate CD4+ Vα24 Natural Killer T Cells in Human Immunodeficiency Virus Infection

    PubMed Central

    Sandberg, Johan K.; Fast, Noam M.; Palacios, Emil H.; Fennelly, Glenn; Dobroszycki, Joanna; Palumbo, Paul; Wiznia, Andrew; Grant, Robert M.; Bhardwaj, Nina; Rosenberg, Michael G.; Nixon, Douglas F.

    2002-01-01

    Vα24 natural killer T (NKT) cells are innate immune cells involved in regulation of immune tolerance, autoimmunity, and tumor immunity. However, the effect of human immunodeficiency virus type 1 (HIV-1) infection on these cells is unknown. Here, we report that the Vα24 NKT cells can be subdivided into CD4+ or CD4− subsets that differ in their expression of the homing receptors CD62L and CD11a. Furthermore, both CD4+ and CD4− NKT cells frequently express both CXCR4 and CCR5 HIV coreceptors. We find that the numbers of NKT cells are reduced in HIV-infected subjects with uncontrolled viremia and marked CD4+ T-cell depletion. The number of CD4+ NKT cells is inversely correlated with HIV load, indicating depletion of this subset. In contrast, CD4− NKT-cell numbers are unaffected in subjects with high viral loads. HIV infection experiments in vitro show preferential depletion of CD4+ NKT cells relative to regular CD4+ T cells, in particular with virus that uses the CCR5 coreceptor. Thus, HIV infection causes a selective loss of CD4+ lymph node homing (CD62L+) NKT cells, with consequent skewing of the NKT-cell compartment to a predominantly CD4− CD62L− phenotype. These data indicate that the key immunoregulatory NKT-cell compartment is compromised in HIV-1-infected patients. PMID:12097565

  2. Cutaneous Manifestations of Selected Parasitic Infections in Western Pacific and Southeast Asian Regions.

    PubMed

    Belizario, Vicente; Delos Trinos, John Paul Caesar; Garcia, Nikko Benjamin; Reyes, Maureen

    2016-09-01

    Cutaneous manifestations of parasitic infections often result in discomfort, debilitation, and even stigmatization. Data on cutaneous manifestations of parasitic infections, however, are limited. This article provides updates on the cutaneous manifestations of parasitic infections which are known to occur in Western Pacific and Southeast Asian regions, such as scabies, pediculosis, cutaneous larva migrans, larva currens, cutaneous schistosomiasis, cutaneous enterobiasis, cutaneous cysticercosis, acute dermatolymphangioadenitis (lymphatic filariasis), and cutaneous amoebiasis. The lack of epidemiological data on these conditions suggests the need for improvements in recording and reporting of cases. Utilization of advance diagnostic modalities and capacity building of health workers are important for proper case management. Cutaneous manifestations of parasitic infections are a topic rarely studied and thus represent an opportunity for further research. PMID:27447892

  3. Raster graphic helmet-mounted display study

    NASA Technical Reports Server (NTRS)

    Beamon, William S.; Moran, Susanna I.

    1990-01-01

    A design of a helmet mounted display system is presented, including a design specification and development plan for the selected design approach. The requirements for the helmet mounted display system and a survey of applicable technologies are presented. Three helmet display concepts are then described which utilize lasers, liquid crystal display's (LCD's), and subminiature cathode ray tubes (CRT's), respectively. The laser approach is further developed in a design specification and a development plan.

  4. Role of GP82 in the selective binding to gastric mucin during oral infection with Trypanosoma cruzi.

    PubMed

    Staquicini, Daniela I; Martins, Rafael M; Macedo, Silene; Sasso, Gisela R S; Atayde, Vanessa D; Juliano, Maria A; Yoshida, Nobuko

    2010-03-02

    Oral infection by Trypanosoma cruzi has been the primary cause of recent outbreaks of acute Chagas' diseases. This route of infection may involve selective binding of the metacyclic trypomastigote surface molecule gp82 to gastric mucin as a first step towards invasion of the gastric mucosal epithelium and subsequent systemic infection. Here we addressed that question by performing in vitro and in vivo experiments. A recombinant protein containing the complete gp82 sequence (J18), a construct lacking the gp82 central domain (J18*), and 20-mer synthetic peptides based on the gp82 central domain, were used for gastric mucin binding and HeLa cell invasion assays, or for in vivo experiments. Metacyclic trypomastigotes and J18 bound to gastric mucin whereas J18* failed to bind. Parasite or J18 binding to submaxillary mucin was negligible. HeLa cell invasion by metacyclic forms was not affected by gastric mucin but was inhibited in the presence of submaxillary mucin. Of peptides tested for inhibition of J18 binding to gastric mucin, the inhibitory peptide p7 markedly reduced parasite invasion of HeLa cells in the presence of gastric mucin. Peptide p7*, with the same composition as p7 but with a scrambled sequence, had no effect. Mice fed with peptide p7 before oral infection with metacyclic forms developed lower parasitemias than mice fed with peptide p7*. Our results indicate that selective binding of gp82 to gastric mucin may direct T. cruzi metacyclic trypomastigotes to stomach mucosal epithelium in oral infection.

  5. Selective photoinactivation of Candida albicans in the non-vertebrate host infection model Galleria mellonella

    PubMed Central

    2013-01-01

    Background Candida spp. are recognized as a primary agent of severe fungal infection in immunocompromised patients, and are the fourth most common cause of bloodstream infections. Our study explores treatment with photodynamic therapy (PDT) as an innovative antimicrobial technology that employs a nontoxic dye, termed a photosensitizer (PS), followed by irradiation with harmless visible light. After photoactivation, the PS produces either singlet oxygen or other reactive oxygen species (ROS) that primarily react with the pathogen cell wall, promoting permeabilization of the membrane and cell death. The emergence of antifungal-resistant Candida strains has motivated the study of antimicrobial PDT (aPDT) as an alternative treatment of these infections. We employed the invertebrate wax moth Galleria mellonella as an in vivo model to study the effects of aPDT against C. albicans infection. The effects of aPDT combined with conventional antifungal drugs were also evaluated in G. mellonella. Results We verified that methylene blue-mediated aPDT prolonged the survival of C. albicans infected G. mellonella larvae. The fungal burden of G. mellonella hemolymph was reduced after aPDT in infected larvae. A fluconazole-resistant C. albicans strain was used to test the combination of aPDT and fluconazole. Administration of fluconazole either before or after exposing the larvae to aPDT significantly prolonged the survival of the larvae compared to either treatment alone. Conclusions G. mellonella is a useful in vivo model to evaluate aPDT as a treatment regimen for Candida infections. The data suggests that combined aPDT and antifungal therapy could be an alternative approach to antifungal-resistant Candida strains. PMID:24083556

  6. Reference gene selection for gene expression studies using RT-qPCR in virus-infected planthoppers

    PubMed Central

    2011-01-01

    Background Planthoppers not only severely affect crops by causing mechanical damage when feeding but are also vectors of several plant virus species. The analysis of gene expression in persistently infected planthoppers might unveil the molecular basis of viral transmission. Quantitative real-time RT-PCR (RT-qPCR) is currently the most accurate and sensitive method used for quantitative gene expression analysis. In order to normalize the resulting quantitative data, reference genes with constant expression during the experimental procedures are needed. Results Partial sequences of the commonly used reference genes actin (ACT), α1-tubulin (TUB), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), elongation factor 1 alpha (EF1A), ribosomal protein S18 (RPS18) and polyubiquitin C (UBI) from Delphacodes kuscheli, a planthopper capable of persistently transmitting the plant fijivirus Mal de Río Cuarto virus (MRCV), were isolated for the first time. Specific RT-qPCR primers were designed and the expression stability of these genes was assayed in MRCV-infective and naïve planthoppers using geNorm, Normfinder and BestKeeper tools. The overall analysis showed that UBI, followed by 18S and ACT, are the most suitable genes as internal controls for quantitative gene expression studies in MRCV-infective planthoppers, while TUB and EF1A are the most variable ones. Moreover, EF1A was upregulated by MRCV infection. Conclusions A RT-qPCR platform for gene expression analysis in the MRCV-infected planthopper vector Delphacodes kuscheli was developed. Our work is the first report on reference gene selection in virus-infected insects, and might serve as a precedent for future gene expression studies on MRCV and other virus-planthopper pathosystems. PMID:21679431

  7. Biopriming of Infected Carrot Seed with an Antagonist, Clonostachys rosea, Selected for Control of Seedborne Alternaria spp.

    PubMed

    Jensen, Birgit; Knudsen, Inge M B; Madsen, Mette; Jensen, Dan Funck

    2004-06-01

    ABSTRACT An ecological approach was used to select fungal antagonists effective against the seedborne pathogens Alternaria dauci and A. radicina on carrot. Twenty-five and 105 isolates originating from cereal and carrot habitats were screened against the pathogens in planta, respectively. Irrespective of isolate origin, fungal isolates belonging to Clonostachys rosea controlled pre- and postemergence death caused by A. dauci and A. radicina as effectively as the fungicide iprodione. Isolate IK726 of C. rosea was used in biopriming a seed lot with 29% A. radicina and 11% A. dauci (highly infected), and a seed lot with 4% A. radicina and 7% A. dauci (low infection). Seeds were primed with water alone (hydropriming) or with addition of C. rosea IK726 (biopriming). The occurrence of A. radicina and A. dauci increased twofold and fivefold, respectively, during 14 days hydropriming, irrespective of the initial infection level. On highly infected seed, biopriming reduced the incidence of A. radicina to <2.3% and that of A. dauci to <4.8% while the level of both pathogens was <0.5% on bioprimed seed with a low initial infection rate. In sand stand establishment tests, hydroprimed seeds had a lower healthy seedling stand than nonprimed seeds, mainly due to a high degree of postemergence seedling death. In contrast, biopriming resulted in a seedling stand that was better than that of both nonprimed and hydroprimed seeds. C. rosea IK726 multiplied fivefold to eightfold, and microscopic observations using C. rosea IK726 transformed with a green fluorescent protein (GFP) reporter gene showed that seeds were covered with a fine web of sporulating mycelium of C. rosea. The positive effect of biopriming on healthy seedling stand remained after 5 months of storage at 4 degrees C and IK726 survived at high numbers on these seed. In this study, we demonstrated that bio-priming with the biocontrol strain C. rosea IK726 facilitates priming of infected seeds without risking adverse

  8. B-1a, B-1b and B-2 B cells display unique VHDJH repertoires formed at different stages of ontogeny and under different selection pressures.

    PubMed Central

    Tornberg, U C; Holmberg, D

    1995-01-01

    Analyses of VHDJH rearrangements isolated from murine peritoneal B-1a cells (CD5+, IgMhi, B220lo), peritoneal B-1b cells (CD5-, IgMhi, B220lo), and conventional splenic B cells provide evidence that a unique repertoire of VH regions is displayed by each of these B-cell subsets. The B-1a subset is characterized by a low N-region diversity, by a high frequency of sequence homologies in the VH-D and D-JH junctions, and by a limited exonuclease nibbling of the terminals of the joining gene segments. Through expansion in ageing mice, B-1a clones with these properties are favoured. B-1b cells are similar to conventional B-2 cells with respect to N-region diversity, but are unique in terms of D gene expression. Thus, while most murine pre-B and B cells preferentially use DSP and DFL gene segments in a given reading frame (RF1), B-1b cells frequently express D genes in another reading frame (RF2). Together, these findings provide structural evidence for a model where B-1a, B-1b and B-2 cells are produced by separate progenitors that are active at different stages of ontogeny. Images PMID:7737121

  9. Electrochromic display device

    NASA Astrophysics Data System (ADS)

    Nicholson, M. M.

    1984-07-01

    This invention relates to electrochromic devices. In one aspect it relates to electrically controllable display devices. In another aspect it relates to electrically tunable optical or light filters. In yet another aspect it relates to a chemical sensor device which employs a color changing film. There are many uses for electrically controllable display devices. A number of such devices have been in commercial use for some time. These display devices include liquid crystal displays, light emitting diode displays, plasma displays, and the like. Light emitting diode displays and plasma display panels both suffer from the fact that they are active. Light emissive devices which require substantial power for their operation, In addition, it is difficult to fabricate light emitting diode displays in a manner which renders them easily distinguishable under bright ambient illumination. Liquid crystal displays suffer from the disadvantage that they are operative only over a limited temperature range and have substantially no memory within the liquid crystal material.

  10. High frequency of transmitted HIV-1 Gag HLA class I-driven immune escape variants but minimal immune selection over the first year of clade C infection.

    PubMed

    Gounder, Kamini; Padayachi, Nagavelli; Mann, Jaclyn K; Radebe, Mopo; Mokgoro, Mammekwa; van der Stok, Mary; Mkhize, Lungile; Mncube, Zenele; Jaggernath, Manjeetha; Reddy, Tarylee; Walker, Bruce D; Ndung'u, Thumbi

    2015-01-01

    In chronic HIV infection, CD8+ T cell responses to Gag are associated with lower viral loads, but longitudinal studies of HLA-restricted CD8+ T cell-driven selection pressure in Gag from the time of acute infection are limited. In this study we examined Gag sequence evolution over the first year of infection in 22 patients identified prior to seroconversion. A total of 310 and 337 full-length Gag sequences from the earliest available samples (median = 14 days after infection [Fiebig stage I/II]) and at one-year post infection respectively were generated. Six of 22 (27%) individuals were infected with multiple variants. There was a trend towards early intra-patient viral sequence diversity correlating with viral load set point (p = 0.07, r = 0.39). At 14 days post infection, 59.7% of Gag CTL epitopes contained non-consensus polymorphisms and over half of these (35.3%) comprised of previously described CTL escape variants. Consensus and variant CTL epitope proportions were equally distributed irrespective of the selecting host HLA allele and most epitopes remained unchanged over 12 months post infection. These data suggest that intrapatient diversity during acute infection is an indicator of disease outcome. In this setting, there is a high rate of transmitted CTL escape variants and limited immune selection in Gag during the first year of infection. These data have relevance for vaccine strategies designed to elicit effective CD8+ T cell immune responses. PMID:25781986

  11. High Frequency of Transmitted HIV-1 Gag HLA Class I-Driven Immune Escape Variants but Minimal Immune Selection over the First Year of Clade C Infection

    PubMed Central

    Gounder, Kamini; Padayachi, Nagavelli; Mann, Jaclyn K.; Radebe, Mopo; Mokgoro, Mammekwa; van der Stok, Mary; Mkhize, Lungile; Mncube, Zenele; Jaggernath, Manjeetha; Reddy, Tarylee; Walker, Bruce D.; Ndung’u, Thumbi

    2015-01-01

    In chronic HIV infection, CD8+ T cell responses to Gag are associated with lower viral loads, but longitudinal studies of HLA-restricted CD8+ T cell-driven selection pressure in Gag from the time of acute infection are limited. In this study we examined Gag sequence evolution over the first year of infection in 22 patients identified prior to seroconversion. A total of 310 and 337 full-length Gag sequences from the earliest available samples (median = 14 days after infection [Fiebig stage I/II]) and at one-year post infection respectively were generated. Six of 22 (27%) individuals were infected with multiple variants. There was a trend towards early intra-patient viral sequence diversity correlating with viral load set point (p = 0.07, r = 0.39). At 14 days post infection, 59.7% of Gag CTL epitopes contained non-consensus polymorphisms and over half of these (35.3%) comprised of previously described CTL escape variants. Consensus and variant CTL epitope proportions were equally distributed irrespective of the selecting host HLA allele and most epitopes remained unchanged over 12 months post infection. These data suggest that intrapatient diversity during acute infection is an indicator of disease outcome. In this setting, there is a high rate of transmitted CTL escape variants and limited immune selection in Gag during the first year of infection. These data have relevance for vaccine strategies designed to elicit effective CD8+ T cell immune responses. PMID:25781986

  12. HIV Evolution in Early Infection: Selection Pressures, Patterns of Insertion and Deletion, and the Impact of APOBEC

    PubMed Central

    Wood, Natasha; Bhattacharya, Tanmoy; Keele, Brandon F.; Giorgi, Elena; Liu, Michael; Gaschen, Brian; Daniels, Marcus; Ferrari, Guido; Haynes, Barton F.; McMichael, Andrew; Shaw, George M.; Hahn, Beatrice H.; Korber, Bette; Seoighe, Cathal

    2009-01-01

    The pattern of viral diversification in newly infected individuals provides information about the host environment and immune responses typically experienced by the newly transmitted virus. For example, sites that tend to evolve rapidly across multiple early-infection patients could be involved in enabling escape from common early immune responses, could represent adaptation for rapid growth in a newly infected host, or could represent reversion from less fit forms of the virus that were selected for immune escape in previous hosts. Here we investigated the diversification of HIV-1 env coding sequences in 81 very early B subtype infections previously shown to have resulted from transmission or expansion of single viruses (n = 78) or two closely related viruses (n = 3). In these cases, the sequence of the infecting virus can be estimated accurately, enabling inference of both the direction of substitutions as well as distinction between insertion and deletion events. By integrating information across multiple acutely infected hosts, we find evidence of adaptive evolution of HIV-1 env and identify a subset of codon sites that diversified more rapidly than can be explained by a model of neutral evolution. Of 24 such rapidly diversifying sites, 14 were either i) clustered and embedded in CTL epitopes that were verified experimentally or predicted based on the individual's HLA or ii) in a nucleotide context indicative of APOBEC-mediated G-to-A substitutions, despite having excluded heavily hypermutated sequences prior to the analysis. In several cases, a rapidly evolving site was embedded both in an APOBEC motif and in a CTL epitope, suggesting that APOBEC may facilitate early immune escape. Ten rapidly diversifying sites could not be explained by CTL escape or APOBEC hypermutation, including the most frequently mutated site, in the fusion peptide of gp41. We also examined the distribution, extent, and sequence context of insertions and deletions, and we provide

  13. Selected overview of nongynecologic surgical intra-abdominal infections. Prophylaxis and therapy.

    PubMed

    Levin, S; Goodman, L J

    1985-11-29

    True prophylaxis of intra-abdominal nongynecologic infections is limited to elective, nonemergency surgery and is best shown in three clean-contaminated surgical procedures. All of these have an infection rate of approximately 10 to 20 percent and include all colon resection surgery, most gastric surgery, and about one third of the cholecystectomies for chronic calculous cholecystitis. Each of these three surgical procedures has a somewhat different pattern of bacterial pathogens. The most useful comparative studies of early preoperative therapy have been performed in cases of suspected appendicitis (50 percent of which usually show perforation or gangrene at the time of surgery) and penetrating abdominal wounds (80 percent of which usually enter some part of the bowel and theoretically soil the peritoneum). These procedures are usually classified as contaminated, with a 20 to 30 percent infection rate, or dirty, with a more than 30 percent infection rate, depending upon several factors. Comparative investigations of intraoperative and postoperative antibiotic therapy of established intra-abdominal infections are more difficult to obtain because of the heterogeneity of the sites, organisms, and medical and surgical therapy. The initial pathogens causing secondary peritonitis and hepatic, perirectal, diverticular, and most other types of intraperitoneal abscesses are mixed coliforms and anaerobes, with emphasis on the anaerobes. Retroperitoneal abscesses, pancreatic abscesses, and biliary tract infections are predominantly caused by coliforms. The organisms responsible for these early infections are usually community-acquired rather than more antibiotic-resistant hospital-acquired bacteria. Considering the availability of a large number of effective broad-spectrum antibacterial agents and therapeutic combinations, it has become increasingly difficult to assess the rightful place of any new prospective antimicrobial regimen unless it has quite unique characteristics

  14. A translation-attenuating intraleader open reading frame is selected on coronavirus mRNAs during persistent infection.

    PubMed Central

    Hofmann, M A; Senanayake, S D; Brian, D A

    1993-01-01

    Short open reading frames within the 5' leader of some eukaryotic mRNAs are known to regulate the rate of translation initiation on the downstream open reading frame. By employing the polymerase chain reaction, we learned that the 5'-terminal 5 nt on the common leader sequence of bovine coronavirus subgenomic mRNAs were heterogeneous and hypervariable throughout early infection in cell culture and that as a persistent infection became established, termini giving rise to a common 33-nt intraleader open reading frame were selected. Since the common leader is derived from the genomic 5' end during transcription, a common focus of origin for the heterogeneity is expected. The intraleader open reading frame was shown by in vitro translation studies to attenuate translation of downstream open reading frames in a cloned bovine coronavirus mRNA molecule. Selection of an intraleader open reading frame resulting in a general attenuation of mRNA translation and a consequent attenuation of virus replication may, therefore, be a mechanism by which coronaviruses and possibly other RNA viruses with a similar transcriptional strategy maintain a persistent infection. Images Fig. 1 Fig. 3 PMID:8265618

  15. Effect of Cytomegalovirus Co-Infection on Normalization of Selected T-Cell Subsets in Children with Perinatally Acquired HIV Infection Treated with Combination Antiretroviral Therapy

    PubMed Central

    Kapetanovic, Suad; Aaron, Lisa; Montepiedra, Grace; Anthony, Patricia; Thuvamontolrat, Kasalyn; Pahwa, Savita; Burchett, Sandra; Weinberg, Adriana; Kovacs, Andrea

    2015-01-01

    Background We examined the effect of cytomegalovirus (CMV) co-infection and viremia on reconstitution of selected CD4+ and CD8+ T-cell subsets in perinatally HIV-infected (PHIV+) children ≥ 1-year old who participated in a partially randomized, open-label, 96-week combination antiretroviral therapy (cART)-algorithm study. Methods Participants were categorized as CMV-naïve, CMV-positive (CMV+) viremic, and CMV+ aviremic, based on blood, urine, or throat culture, CMV IgG and DNA polymerase chain reaction measured at baseline. At weeks 0, 12, 20 and 40, T-cell subsets including naïve (CD62L+CD45RA+; CD95-CD28+), activated (CD38+HLA-DR+) and terminally differentiated (CD62L-CD45RA+; CD95+CD28-) CD4+ and CD8+ T-cells were measured by flow cytometry. Results Of the 107 participants included in the analysis, 14% were CMV+ viremic; 49% CMV+ aviremic; 37% CMV-naïve. In longitudinal adjusted models, compared with CMV+ status, baseline CMV-naïve status was significantly associated with faster recovery of CD8+CD62L+CD45RA+% and CD8+CD95-CD28+% and faster decrease of CD8+CD95+CD28-%, independent of HIV VL response to treatment, cART regimen and baseline CD4%. Surprisingly, CMV status did not have a significant impact on longitudinal trends in CD8+CD38+HLA-DR+%. CMV status did not have a significant impact on any CD4+ T-cell subsets. Conclusions In this cohort of PHIV+ children, the normalization of naïve and terminally differentiated CD8+ T-cell subsets in response to cART was detrimentally affected by the presence of CMV co-infection. These findings may have implications for adjunctive treatment strategies targeting CMV co-infection in PHIV+ children, especially those that are now adults or reaching young adulthood and may have accelerated immunologic aging, increased opportunistic infections and aging diseases of the immune system. PMID:25794163

  16. Selective Susceptibility of Human Skin Antigen Presenting Cells to Productive Dengue Virus Infection

    PubMed Central

    Cerny, Daniela; Haniffa, Muzlifah; Shin, Amanda; Bigliardi, Paul; Tan, Bien Keem; Lee, Bernett; Poidinger, Michael; Tan, Ern Yu; Ginhoux, Florent; Fink, Katja

    2014-01-01

    Dengue is a growing global concern with 390 million people infected each year. Dengue virus (DENV) is transmitted by mosquitoes, thus host cells in the skin are the first point of contact with the virus. Human skin contains several populations of antigen-presenting cells which could drive the immune response to DENV in vivo: epidermal Langerhans cells (LCs), three populations of dermal dendritic cells (DCs), and macrophages. Using samples of normal human skin we detected productive infection of CD14+ and CD1c+ DCs, LCs and dermal macrophages, which was independent of DC-SIGN expression. LCs produced the highest viral titers and were less sensitive to IFN-β. Nanostring gene expression data showed significant up-regulation of IFN-β, STAT-1 and CCL5 upon viral exposure in susceptible DC populations. In mice infected intra-dermally with DENV we detected parallel populations of infected DCs originating from the dermis and migrating to the skin-draining lymph nodes. Therefore dermal DCs may simultaneously facilitate systemic spread of DENV and initiate the adaptive anti-viral immune response. PMID:25474532

  17. Towards the selection of chickens resistant to Salmonella and Campylobacter infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance to infection with enteric pathogens such as Salmonella and Campylobacter can be at many levels and include both non-immune and immune mechanisms. Immune resistance mechanisms can be specific, at the level of the adaptive immune response, or non-specific, at the level of the innate immune...

  18. Seamless tiled display system

    NASA Technical Reports Server (NTRS)

    Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor); Kolosowsky, Aleksandra (Inventor)

    2006-01-01

    A modular and scalable seamless tiled display apparatus includes multiple display devices, a screen, and multiple lens assemblies. Each display device is subdivided into multiple sections, and each section is configured to display a sectional image. One of the lens assemblies is optically coupled to each of the sections of each of the display devices to project the sectional image displayed on that section onto the screen. The multiple lens assemblies are configured to merge the projected sectional images to form a single tiled image. The projected sectional images may be merged on the screen by magnifying and shifting the images in an appropriate manner. The magnification and shifting of these images eliminates any visual effect on the tiled display that may result from dead-band regions defined between each pair of adjacent sections on each display device, and due to gaps between multiple display devices.

  19. Failure of combination therapy for Staphylococcus aureus bone infection: a case of in vivo selection with resistance to rifampicin and fusidic acid.

    PubMed

    Aubin, Guillaume G; Bémer, Pascale; Guillouzouic, Aurélie; Launay, Elise; Geffroy, Loïc; Touchais, Sophie; Corvec, Stéphane

    2016-09-01

    Staphylococcus aureus is one of the main etiologies of bone and device-related infections. Treatment of these orthopedic infections combines mostly rifampicin with other antibiotics. The recurrence or failure rate after fusidic acid/rifampicin treatment remains low (<10%). We discuss here a case of antibiotic treatment failure for Staphylococcus aureus bone infection with in vivo selection of rifampicin and fusidic acid resistance. We also report a new mutation in fusA gene involved in fusidic acid resistance.

  20. Failure of combination therapy for Staphylococcus aureus bone infection: a case of in vivo selection with resistance to rifampicin and fusidic acid.

    PubMed

    Aubin, Guillaume G; Bémer, Pascale; Guillouzouic, Aurélie; Launay, Elise; Geffroy, Loïc; Touchais, Sophie; Corvec, Stéphane

    2016-09-01

    Staphylococcus aureus is one of the main etiologies of bone and device-related infections. Treatment of these orthopedic infections combines mostly rifampicin with other antibiotics. The recurrence or failure rate after fusidic acid/rifampicin treatment remains low (<10%). We discuss here a case of antibiotic treatment failure for Staphylococcus aureus bone infection with in vivo selection of rifampicin and fusidic acid resistance. We also report a new mutation in fusA gene involved in fusidic acid resistance. PMID:27194514

  1. Selective Subnormal IgG1 in 54 Adult Index Patients with Frequent or Severe Bacterial Respiratory Tract Infections

    PubMed Central

    Barton, James C.; Bertoli, Luigi F.; Barton, J. Clayborn; Acton, Ronald T.

    2016-01-01

    We characterized 54 adult index patients with reports of frequent or severe bacterial respiratory tract infections at diagnosis of selective subnormal IgG1. Mean age was 50 ± 13 (SD) y; 87.0% were women. Associated disorders included the following: autoimmune conditions 50.0%; hypothyroidism 24.1%; atopy 38.9%; and other allergy 31.5%. In 35.5%, proportions of protective S. pneumoniae serotype-specific IgG levels did not increase after polyvalent pneumococcal polysaccharide vaccination (PPPV). Blood lymphocyte subset levels were within reference limits in most patients. Regressions on IgG1 and IgG3 revealed no significant association with age, sex, autoimmune conditions, hypothyroidism, atopy, other allergy, corticosteroid therapy, or lymphocyte subsets. Regression on IgG2 revealed significant associations with PPPV response (negative) and CD19+ lymphocytes (positive). Regression on IgG4 revealed significant positive associations with episodic corticosteroid use and IgA. Regression on IgA revealed positive associations with IgG2 and IgG4. Regression on IgM revealed negative associations with CD56+/CD16+ lymphocytes. Regressions on categories of infection revealed a negative association of urinary tract infections and IgG1. HLA-A⁎03, HLA-B⁎55 and HLA-A⁎24, HLA-B⁎35 haplotype frequencies were greater in 38 patients than 751 controls. We conclude that nonprotective S. pneumoniae IgG levels and atopy contribute to increased susceptibility to respiratory tract infections in patients with selective subnormal IgG1. PMID:27123464

  2. Targeting the active site of the placental isozyme of alkaline phosphatase by phage-displayed scFv antibodies selected by a specific uncompetitive inhibitor

    PubMed Central

    Saini, Deepti; Kala, Mrinalini; Jain, Vishal; Sinha, Subrata

    2005-01-01

    Background The isozymes of alkaline phosphatase, the tissue non-specific, intestinal and placental, have similar properties and a high degree of identity. The placental isozyme (PLAP) is an oncofetal antigen expressed in several malignancies including choriocarcinoma, seminoma and ovarian carcinoma. We had earlier attempted to isolate PLAP-specific scFv from a synthetic human immunoglobulin library but were unable to do so, presumably because of the similarity between the isozymes. In this work, we have employed a PLAP-specific uncompetitive inhibitor, L-Phe-Gly-Gly, to select isozyme specific scFvs. An uncompetitive inhibitor binds to the enzyme in the presence of substrate and stabilizes the enzyme-substrate complex. Several uncompetitive inhibitors have varying degrees of isozyme specificity for human alkaline phosphatase isozymes. A specific uncompetitive inhibitor would be able to unmask conformational differences between the otherwise very similar molecules. Also, such inhibitors would be directed to regions at/close to the active site of the enzyme. In this work, the library was first incubated with PLAP and the bound clones then eluted by incubation with L-Phe-Gly-Gly along with the substrate, para-nitro phenyl phosphate (pNPP). The scFvs were then studied with regard to the biochemical modulation of their binding, isozyme specificity and effect on enzyme activity. Results Of 13 clones studied initially, the binding of 9 was inhibited by L-Phe-Gly-Gly (with pNPP) and 2 clones were inhibited by pNPP alone. Two clones had absolute and 2 clones had partial specificity to PLAP. Two clones were cross-reactive with only one other isozyme. Three scFv clones, having an accessible His6-tag, were purified and studied for their modulation of enzyme activity. All the three scFvs inhibited PLAP activity with the kinetics of competitive inhibition. Cell ELISA could demonstrate binding of the specific scFvs to the cell surface expressed PLAP. Conclusion The results

  3. HIV evolution in early infection: selection pressures, patterns of insertion and deletion, and the impact of apobec

    SciTech Connect

    Korber, Bette; Bhattacharya, Tanmoy; Giorgi, Elena; Gaschen, B; Daniels, M

    2009-01-01

    The pattern of viral diversification in newly infected individuals provides information about the host environment and immune responses typically experienced by the newly transmitted virus. For example, sites that tend to evolve rapidly across multiple early-infection patients could be involved in enabling escape from common early immune responses, represent adaptation for rapid growth in a newly infected host, or reversion from less fit forms of the virus that were selected for immune escape in previous hosts. Here we investigated the diversification of HIV -I env coding sequences in 81 very early B SUbtype infections previously shown to have resulted from transmission or expansion of single viruses (n=78) or two closely related viruses (n=3). In these cases the sequence of the infecting virus can be estimated accurately, enabling inference of both the direction of substitutions as well as distinction between insertion and deletion events. By integrating information across multiple acutely infected hosts, we find evidence of adaptive evolution of HIV-1 envand identified a subset of codon sites that diversified more rapidly than can be explained by a model of neutral evolution. Of 24 such rapidly diversifying sites, 14 were either (i) clustered and embedded in CTL epitopes that were verified experimentally or predicted based on the individual's HLA or (ii) in a nucleotide context indicative of APOBEC mediated G-to-A substitutions, despite having excluded heavily hypermutated sequences prior to the analysis. In several cases, a rapidly evolving site was both embedded in an APOBEC motif and in a CTL epitope, suggesting that APOBEC may facilitate early immune escape. Ten rapidly diversifying sites could not be explained by CTL escape or APOBEC hypermutation, including the most frequently mutated site, in the fusion peptide of gp4l. We also examined the distribution, extent, and sequence context of insertions and deletions and provide evidence that the length variation

  4. Effects of consuming endophyte-infected tall fescue on growth, reproduction and lactation in mice selected for high fecundity.

    PubMed

    Godfrey, V B; Washburn, S P; Eisen, E J; Johnson, B H

    1994-01-01

    Effects of a diet containing endophyte-infected tall fescue seed (83% infected) were investigated using 2 lines of mice, one line selected for fecundity (L(+)) and the other a randomly selected control line (K). Treatments included a commercial stock diet (C), 50% stock plus 50% non-infected tall fescue seed (N), and 50% stock plus 50% infected tall fescue seed (I). The experiment was conducted using mice on respective treatments in 2 phases (successive generations), with 15 to 23 mated females per line and diet subgroups. Mated females of Phase 1 were assigned at random within line to experimental diets which were fed during gestation and through 21 d of lactation. Litters were standardized to 10 pups 1 d after birth. Stock diets were fed to all groups from Day 21 to weaning on Day 28. Weaned male and female pups were allotted to previous diets. Mated females in Phase 2 were managed as in Phase 1 through weaning at 28 d. Diets of males did not affect reproduction and data were pooled within female diets. Selected (L(+)) dams gave birth to more live pups than K dams (P<0.05) during both phases (+3.4 and +2.8 +/- 0.4 pups, respectively). Diet but not line affected littering rate of mated females in Phase 1 (71.3%, I; < 87.1%, C or 93.0%, N; P<0.05) and Phase 2 (82.1%, I < 93.8%, N or 97.1%, C; P<0.05). Diet had no effect on fecundity during Phase 1 but females on I diet had reduced (P<0.05) litter size by 1.9 and 3.2 +/- 0.5 pups compared with the females on N and C diets, respectively, in Phase 2. Feed consumption and weights of dams during lactation generally ranked C>N>I. Growth of pups during both phases also ranked C>N>I. Vaginal opening at 28 d differed by line (71.4%, K < 89.3%, L(+), P<0.05) and diet (56.8%, I < 92.0%, C or 92.2%, N, P<0.05). These results suggest both acute and chronic effects of consumption of endophyte-infected diets. Absence of line-by-diet interactions demonstrates that adverse effects were unrelated to genetic differences between lines.

  5. Comparative performance analysis of mobile displays

    NASA Astrophysics Data System (ADS)

    Safaee-Rad, Reza; Aleksic, Milivoje

    2012-01-01

    Cell-phone display performance (in terms of color quality and optical efficiency) has become a critical factor in creating a positive user experience. As a result, there is a significant amount of effort by cell-phone OEMs to provide a more competitive display solution. This effort is focused on using different display technologies (with significantly different color characteristics) and more sophisticated display processors. In this paper, the results of a mobile-display comparative performance analysis are presented. Three cell-phones from major OEMs are selected and their display performances are measured and quantified. Comparative performance analysis is done using display characteristics such as display color gamut size, RGB-channels crosstalk, RGB tone responses, gray tracking performance, color accuracy, and optical efficiency.

  6. Rapid and Selective Detection of Pathogenic Bacteria in Bloodstream Infections with Aptamer-Based Recognition.

    PubMed

    Shen, Haijing; Wang, Jie; Liu, Haoyang; Li, Zhihao; Jiang, Fenglei; Wang, Fu-Bing; Yuan, Quan

    2016-08-01

    Sepsis and bacteremia are life-threatening clinical syndromes associated with significant patient morbidity and mortality. Rapid and sensitive detection of pathogenic bacteria is the key to improve patient survival rates. Herein, we have rationally constructed a simple aptamer-based capture platform to shorten the time needed for confirmation of bacterial bloodstream infection in clinical blood samples. This capture platform is made of a mesoporous TiO2-coated magnetic nanoparticle and is modified with target aptamer. It features excellent bacterial enrichment efficiency of about 80% even at low bacterial concentrations (10-2000 CFU mL(-1)). More importantly, the bacteria can be enriched within 2 h, and the time for bacterial identification is effectively shortened in comparison to the "gold standard" in clinical diagnosis of bloodstream infection. The aptamer-based capture platform may pave a way for the detection of biomarkers and find potential applications in disease diagnosis. PMID:27411775

  7. Effect of Infection Duration on Habitat Selection and Morphology of Adult Echinostoma caproni (Digenea: Echinostomatidae) in ICR Mice.

    PubMed

    Platt, Thomas R; Zelmer, Derek A

    2016-02-01

    The course of infection of Echinostoma caproni was followed in female ICR mice, a permissive laboratory host, from infection to natural termination. Twenty-one mice were infected with 20 metacercariae via oral intubation and housed 3 per cage. Three mice from a randomly selected cage were necropsied at 1 mo intervals. A second group of 15 mice was infected approximately 1 yr later to replace mice negative at necropsy in the first group. Mice in the second group were examined weekly for the presence of eggs in the feces. Mice negative for eggs on consecutive days were killed and necropsied. The location of individual worms and worm clusters were located in 20 segments of the small intestine. Adult worms were killed and fixed in hot formalin, stained, and prepared as whole mounts. Standard measurements were taken using a compound microscope fitted with an ocular micrometer. The infection spontaneously resolved in 10 mice from 7 to 32 wk PI, indicating the host response is highly variable and extending the maximum recorded length of E. caproni infections in ICR mice to 31 wk. A moribund worm was found in the feces of an animal that continued to pass eggs for an additional 2 mo indicating individual variation in worm responses. Worms located preferentially in the ileum (segments 11-13) during the first 3 mo of the infection but shifted to the jejunum (segments 8-9) during weeks 4-6. Morphologically, worms of different ages clustered together in multivariate space, with substantial overlap between the 3- and 4-mo-old infrapopulations and between the 5- and 6-mo-old infrapopulations. Muscular structures increased in size throughout the experiment, while the gonads increased in size for the first 3 mo and then declined during the last 3 mo. The relationship between E. caproni and ICR mice is more nuanced than previously reported. The reduction in gonad size and the shift from the ileum to the jejunum in the last 3 mo likely are related. These changes might be attributable

  8. [Selected bacterial infections - unavoidable threats to the health and lives of the man].

    PubMed

    Sobieraj-Garbiak, Izabela Anna; Drozdzyńska, Marta

    2015-01-01

    In the present study we wanted to show that bacterial infections are an important factor threatening both the health and life of humans. This problem concerns the global population, both in developed and developing countries, and is often the cause of a significant proportion of deaths due to the negative impact of exo- and endotoxins on the host. Numerous infectious diseases caused by biological factors are undoubtedly associated with various risk factors. Despite the continuous development of medicine and countless actions spreading knowledge about bacterial gastrointestinal infections and sepsis, these conditions are still not marginal in the everyday hospital environment. Particular attention in this work was put on hospital infections because they are a major public health concern. Although a significant increase in awareness of the problem has been observed in Poland in recent years, this is still an important problem for medicine, and is also an economic issue. In addition, bacteria and their toxins can be used as a biological weapon for terrorist attacks.

  9. Protein and Antibody Engineering by Phage Display.

    PubMed

    Frei, J C; Lai, J R

    2016-01-01

    Phage display is an in vitro selection technique that allows for the rapid isolation of proteins with desired properties including increased affinity, specificity, stability, and new enzymatic activity. The power of phage display relies on the phenotype-to-genotype linkage of the protein of interest displayed on the phage surface with the encoding DNA packaged within the phage particle, which allows for selective enrichment of library pools and high-throughput screening of resulting clones. As an in vitro method, the conditions of the binding selection can be tightly controlled. Due to the high-throughput nature, rapidity, and ease of use, phage display is an excellent technological platform for engineering antibody or proteins with enhanced properties. Here, we describe methods for synthesis, selection, and screening of phage libraries with particular emphasis on designing humanizing antibody libraries and combinatorial scanning mutagenesis libraries. We conclude with a brief section on troubleshooting for all stages of the phage display process. PMID:27586328

  10. EMU helmet mounted display

    NASA Technical Reports Server (NTRS)

    Marmolejo, Jose (Inventor); Smith, Stephen (Inventor); Plough, Alan (Inventor); Clarke, Robert (Inventor); Mclean, William (Inventor); Fournier, Joseph (Inventor)

    1990-01-01

    A helmet mounted display device is disclosed for projecting a display on a flat combiner surface located above the line of sight where the display is produced by two independent optical channels with independent LCD image generators. The display has a fully overlapped field of view on the combiner surface and the focus can be adjusted from a near field of four feet to infinity.

  11. No evidence that presence of sexually transmitted infection selects for reduced mating rate in the two spot ladybird, Adalia bipunctata

    PubMed Central

    Jones, Sophie L.; Pastok, Daria

    2015-01-01

    Sexually transmitted infections (STIs) are common in animals and plants, and frequently impair individual fertility. Theory predicts that natural selection will favour behaviours that reduce the chance of acquiring a STI. We investigated whether an STI, Coccipolipus hippodamiae has selected for increased rejection of mating by female Adalia bipunctata as a mechanism to avoid exposure. We first demonstrated that rejection of mating by females did indeed reduce the chance of acquiring the mite. We then examined whether rejection rate and mating rate differed between ladybirds from mite-present and mite-absent populations when tested in a common environment. No differences in rejection intensity or remating propensity were observed between the two populations. We therefore conclude there is no evidence that STIs have driven the evolution of female mating behaviour in this species. PMID:26290801

  12. XVD Image Display Program

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Andres, Paul M.; Mortensen, Helen B.; Parizher, Vadim; McAuley, Myche; Bartholomew, Paul

    2009-01-01

    The XVD [X-Windows VICAR (video image communication and retrieval) Display] computer program offers an interactive display of VICAR and PDS (planetary data systems) images. It is designed to efficiently display multiple-GB images and runs on Solaris, Linux, or Mac OS X systems using X-Windows.

  13. Screens and Displays.

    ERIC Educational Resources Information Center

    Edstrom, Malin

    1987-01-01

    Discusses the characteristics of different computer screen technologies including the possible harmful effects on health of cathode ray tube (CRT) terminals. CRT's are compared to other technologies including liquid crystal displays, plasma displays, electroluminiscence displays, and light emitting diodes. A chart comparing the different…

  14. Digital video display system

    NASA Technical Reports Server (NTRS)

    Zygielbaum, A. I.; Martin, W. L.; Engle, A.

    1973-01-01

    System displays image data in real time on 120,000-element raster scan with 2, 4, or 8 shades of grey. Designed for displaying planetary range Doppler data, system can be used for X-Y plotting, displaying alphanumerics, and providing image animation.

  15. Selection of broilers with improved innate immune responsiveness to reduce on-farm infection by foodborne pathogens.

    PubMed

    Swaggerty, Christina L; Pevzner, Igal Y; He, Haiqi; Genovese, Kenneth J; Nisbet, David J; Kaiser, Pete; Kogut, Michael H

    2009-09-01

    Economic pressure on the modern poultry industry has directed the selection process towards fast-growing broilers that have a reduced feed conversion ratio. Selection based heavily on growth characteristics could adversely affect immune competence leaving chickens more susceptible to disease. Since the innate immune response directs the acquired immune response, efforts to select poultry with an efficient innate immune response would be beneficial. Our laboratories have been evaluating the innate immune system of two parental broiler lines to assess their capacity to protect against multiple infections. We have shown increased in vitro heterophil function corresponds with increased in vivo resistance to Gram-positive and Gram-negative bacterial infections. Additionally, there are increased mRNA expression levels of pro-inflammatory cytokines/chemokines in heterophils isolated from resistant lines compared to susceptible lines. Collectively, all data indicate there are measurable differences in innate responsiveness under genetic control. Recently, a small-scale selection trial was begun. We identified sires within a broiler population with higher and/or lower-than-average pro-inflammatory cytokine/chemokine mRNA expression levels and subsequently utilized small numbers of high-expressing and low-expressing sires to produce progeny with increased or decreased, respectively, pro-inflammatory cytokine/chemokine profiles. This novel approach should allow us to improve breeding stock by improving the overall immunological responsiveness. This will produce a line of chickens with an effective pro-inflammatory innate immune response that should improve resistance against diverse pathogens, improve responses to vaccines, and increase livability. Ongoing work from this project is providing fundamental information for the development of poultry lines that will be inherently resistant to colonization by pathogenic and food-poisoning microorganisms. Utilization of pathogen

  16. Syndrome of selective IgM deficiency with severe T cell deficiency associated with disseminated cutaneous mycobacterium avium intracellulaire infection

    PubMed Central

    Gharib, Asal; Louis, Ankmalika Gupta; Agrawal, Sudhanshu; Gupta, Sudhir

    2015-01-01

    Cutaneous non-disseminated, non-tuberculous mycobacterial infections have been reported in both immunocompetent and immunocompromised subjects. Systemic Mycobacterium avium intracellulaire (MAI) have been reported in non-HIV patients with Idiopathic CD4 lymphocytopenia. We report a comprehensive immunological analysis in syndrome of selective IgM deficiency and T lymphocytopenia (both CD4+ and CD8+) with disseminated cutaneous MAI infection. Naïve (TN) and Central memory (TCM) subsets of both CD4+ and CD8+ T cells were decreased, whereas terminally differentiated effector memory (TEMRA) subset of CD4+ and CD8+ T cells were markedly increased. IFN-γ producing T cells were markedly decreased. Although CD14highCD16- proinflammatory monocytes were modestly increased, IFN-γR+ monocytes were markedly decreased. The expression of TLR3, TLR5, TLR7, and TLR9 on monocytes was decreased. Germinal center B cells (CD19+IgD-CD38+CD27lo) and B1 cells (CD20+CD27+CD43+CD70-) were markedly decreased. A role of immune alterations, including B cells and antibodies in disseminated cutaneous MAI infection is discussed. PMID:26550546

  17. Experimental infection and serologic survey for selected paramyxoviruses in red-winged blackbirds (Agelaius phoeniceus).

    PubMed

    Vickers, M L; Hanson, R P

    1980-01-01

    Red-winged blackbirds (Agelaius phoeniceus) were experimentally exposed to three avian paramyxoviruses: turkey parainfluenza virus, Yucaipa virus, and two strains of Newcastle disease virus. Aerosol exposure resulted in infection but exposure in food or drinking water rarely or never did. Tracheal swabs contained virus for up to eight days post exposure, cloacal swabs were negative. Transmission to contact birds occurred infrequently. Antibody response was of low titer and short duration. No hemagglutination inhibition activity against these viruses was found in 387 sera collected from red-winged blackbirds and tricolored blackbirds (Agelaius tricolor) trapped in six states.

  18. Natural selection underlies apparent stress-induced mutagenesis in a bacteriophage infection model.

    PubMed

    Yosef, Ido; Edgar, Rotem; Levy, Asaf; Amitai, Gil; Sorek, Rotem; Munitz, Ariel; Qimron, Udi

    2016-01-01

    The emergence of mutations following growth-limiting conditions underlies bacterial drug resistance, viral escape from the immune system and fundamental evolution-driven events. Intriguingly, whether mutations are induced by growth limitation conditions or are randomly generated during growth and then selected by growth limitation conditions remains an open question(1). Here, we show that bacteriophage T7 undergoes apparent stress-induced mutagenesis when selected for improved recognition of its host's receptor. In our unique experimental set-up, the growth limitation condition is physically and temporally separated from mutagenesis: growth limitation occurs while phage DNA is outside the host, and spontaneous mutations occur during phage DNA replication inside the host. We show that the selected beneficial mutations are not pre-existing and that the initial slow phage growth is enabled by the phage particle's low-efficiency DNA injection into the host. Thus, the phage particle allows phage populations to initially extend their host range without mutagenesis by virtue of residual recognition of the host receptor. Mutations appear during non-selective intracellular replication, and the frequency of mutant phages increases by natural selection acting on free phages, which are not capable of mutagenesis. PMID:27572836

  19. Natural resistance to experimental feline infectious peritonitis virus infection is decreased rather than increased by positive genetic selection.

    PubMed

    Pedersen, Niels C; Liu, Hongwei; Durden, Monica; Lyons, Leslie A

    2016-03-01

    A previous study demonstrated the existence of a natural resistance to feline infectious peritonitis virus (FIPV) among 36% of randomly bred laboratory cats. A genome wide association study (GWAS) on this population suggested that resistance was polygenic but failed to identify any strong specific associations. In order to enhance the power of GWAS or whole genome sequencing to identify strong genetic associations, a decision was made to positively select for resistance over three generations. The inbreeding experiment began with a genetically related parental (P) population consisting of three toms and four queens identified from among the survivors of the earlier study and belonging to a closely related subgroup (B). The subsequent effects of inbreeding were measured using 42 genome-wide STR markers. P generation cats produced 57 first filial (F1) kittens, only five of which (9.0%) demonstrated a natural resistance to FIPV infection. One of these five F1 survivors was then used to produce six F1/P-backcrosses kittens, only one of which proved resistant to FIP. Six of eight of the F1 and F1/P survivors succumbed to a secondary exposure 4-12 months later. Therefore, survival after both primary and secondary infection was decreased rather than increased by positive selection for resistance. The common genetic factor associated with this diminished resistance was a loss of heterozygosity.

  20. Toxoplasma gondii, Neospora caninum and tick-transmitted bacterium Anaplasma phagocytophilum infections in one selected goat farm in Slovakia.

    PubMed

    Čobádiová, Andrea; Reiterová, Katarina; Derdáková, Markéta; Špilovská, Silvia; Turčeková, Ludmila; Hviščová, Ivana; Hisira, Vladimir

    2013-12-01

    Parasitic diseases of livestock together with poor welfare conditions can negatively affect the health status and production of small ruminants. Protozoan parasites and tick-borne infectious agents are common threat of livestock including small ruminants mostly during the pasture season. Therefore the priority of the study was to analyse the circulation and presence of two protozoan parasites Toxoplasma gondii and Neospora caninum as well as tick-transmitted bacterium Anaplasma phagocytophilum in one selected goat farm in Eastern Slovakia. Throughout a three-year study period we have repeatedly screened the sera and blood of goats and dogs from monitored farm. In total, 343 blood serum samples from 116 goats were examined by ELISA. The mean seropositivity for T. gondii was 56.9% (66/116, CI (95%) = 48-66.0) and 15.5% (18/116, CI (95%) = 9.3-22.7) for N. caninum. The permanent occurrence of anti-Toxoplasma and anti-Neospora antibodies was detected in repeatedly examined goats during the whole monitored period. The presence of both parasites in the flock was analysed by PCR. DNA of T. gondii was confirmed in 12 out of 25 Toxoplasma-seropositive goats and N. caninum in 14 samples out of 18 Neospora-seropositive animals; four goats were co-infected with both pathogens. The risk of endogenous transmission of both parasites was pursued by examination of 41 kid's sera, where seropositivity for toxoplasmosis was 31.7% and for neosporosis 14.6%. In dogs 61.1% seropositivity for T. gondii and 38.9% for N. caninum was found, however, their faeces were negative for coccidian oocysts. Eight out of 108 tested animals were infected with A. phagocytophilum, the causative agent of tick-borne fever. Seven of them were simultaneously infected with T. gondii and A. phagocytophilum, out of which four goats were concurrently infected with all three pathogens.

  1. Engineering antibodies by yeast display.

    PubMed

    Boder, Eric T; Raeeszadeh-Sarmazdeh, Maryam; Price, J Vincent

    2012-10-15

    Since its first application to antibody engineering 15 years ago, yeast display technology has been developed into a highly potent tool for both affinity maturing lead molecules and isolating novel antibodies and antibody-like species. Robust approaches to the creation of diversity, construction of yeast libraries, and library screening or selection have been elaborated, improving the quality of engineered molecules and certainty of success in an antibody engineering campaign and positioning yeast display as one of the premier antibody engineering technologies currently in use. Here, we summarize the history of antibody engineering by yeast surface display, approaches used in its application, and a number of examples highlighting the utility of this method for antibody engineering.

  2. Cytoplasmic bacteriophage display system

    DOEpatents

    Studier, F. William; Rosenberg, Alan H.

    1998-06-16

    Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest.

  3. Cytoplasmic bacteriophage display system

    DOEpatents

    Studier, F.W.; Rosenberg, A.H.

    1998-06-16

    Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest. 1 fig.

  4. Mouse ENU Mutagenesis to Understand Immunity to Infection: Methods, Selected Examples, and Perspectives.

    PubMed

    Caignard, Grégory; Eva, Megan M; van Bruggen, Rebekah; Eveleigh, Robert; Bourque, Guillaume; Malo, Danielle; Gros, Philippe; Vidal, Silvia M

    2014-01-01

    Infectious diseases are responsible for over 25% of deaths globally, but many more individuals are exposed to deadly pathogens. The outcome of infection results from a set of diverse factors including pathogen virulence factors, the environment, and the genetic make-up of the host. The completion of the human reference genome sequence in 2004 along with technological advances have tremendously accelerated and renovated the tools to study the genetic etiology of infectious diseases in humans and its best characterized mammalian model, the mouse. Advancements in mouse genomic resources have accelerated genome-wide functional approaches, such as gene-driven and phenotype-driven mutagenesis, bringing to the fore the use of mouse models that reproduce accurately many aspects of the pathogenesis of human infectious diseases. Treatment with the mutagen N-ethyl-N-nitrosourea (ENU) has become the most popular phenotype-driven approach. Our team and others have employed mouse ENU mutagenesis to identify host genes that directly impact susceptibility to pathogens of global significance. In this review, we first describe the strategies and tools used in mouse genetics to understand immunity to infection with special emphasis on chemical mutagenesis of the mouse germ-line together with current strategies to efficiently identify functional mutations using next generation sequencing. Then, we highlight illustrative examples of genes, proteins, and cellular signatures that have been revealed by ENU screens and have been shown to be involved in susceptibility or resistance to infectious diseases caused by parasites, bacteria, and viruses.

  5. Selective infection of maize roots by streptomycin-resistant Azospirillum lipoferum and other bacteria.

    PubMed

    Döbereiner, J; Baldani, V L

    1979-11-01

    The percentage of low-level streptomycin-resistant (20 microgram/mL) bacteria in surface-sterilized or washed maize roots was more than a thousand times higher than that in soil populations. There was also a higher incidence of resistant bacteria in rhizosphere as compared with non-rhizosphere soil and bacteria isolated from maize roots were relatively tolerant to several other antibiotics. Azospirillum lipoferum was predominant in surface-sterilized roots of field-grown maize and was low-level streptomycin-resistant while most soil isolates were sensitive. Inoculation with A. brasilense isolated from wheat roots was unsuccessful in terms of establishment even when streptomycin-resistant strains were used. Unidentified causes of specific plant-bacteria affinities therefore transcend the role of antibiotic resistance in maize root infection. PMID:540253

  6. Inhibitory effect of nicotinamide on enzymatic activity of selected fungal strains causing skin infection.

    PubMed

    Ciebiada-Adamiec, Anna; Małafiej, Eugeniusz; Ciebiada, Ireneusz

    2010-05-01

    Pathogenicity of fungi is connected with their ability to easily penetrate the host tissues, survive in the infected host organism and use the elements of the host tissues as nutrients. Hence, the co-occurrence of pathogenic properties with the high enzymatic activity, which is manifested through the production of various enzymes including extracellular enzymes, was observed. It can be expected that it is possible to decrease fungal pathogenicity by lowering their enzymatic activity. The aim of the study was to determine the effect of nicotinamide on enzymatic activity of the fungi, which are most frequently isolated in cases of skin infection. Enzymatic activity was analysed using 15 Candida albicans, 15 Trichophyton rubrum and 15 Trichophyton mentagrophytes strains. The strains used for the study were collected from the current diagnostic material. API ZYM tests were used in diagnostic analysis. MICs of nicotinamide were determined by the macrodilution method in liquid medium. In the case of Candida strains, the presence of nicotinamide in the broth had a significant effect on the decrease of enzymatic activity (P < 0.05) of esterase (C4), esterase lipase (C-8), valin-arylamidase, acid phosphatase and alpha-glycosydase. A considerably stronger effect of nicotinamide was observed in the case of dermatophytes (P < 0.005). Its action led to a decrease in the activity of all the enzymes under study except alpha-glucosidase produced by T. rubrum strains. Thus, nicotinamide exhibited biological activity towards C. albicans, T. rubrum and Trichophyton mentagrophytes, which resulted in a decrease in the activity of enzymes produced by the fungi.

  7. Resistance pattern of enterobacteriaceae isolates from urinary tract infections to selected quinolones in Yaoundé

    PubMed Central

    Lyonga, Emilia Enjema; Toukam, Michel; Nkenfou, Celine; Gonsu, Hortense Kamga; Assoumou, Marie-Claire Okomo; Mesembe, Martha Tongo; Eyoh, Agnes Bedie; Ikomey, George Mondinde; Ndze, Valantine Ngum; Koulla-Shiro, Sinata

    2015-01-01

    Introduction It is estimated that 150 million urinary tract infections (UTIs) occur yearly worldwide, resulting in more than 6 billion dollar in direct healthcare cost. The etiology of UTIs is predictable, with Escherichia coli, an Enterobacteriaceae being the principal pathogen. Quinolones are usually the drug of choice. In this study, we report the resistance pattern of Enterobacteriaceae isolates from UTIs to quinolones among in-patients and out-patients at the Yaoundé Reference Hospital in Cameroon. Methods A cross-sectional descriptive study was carried out for a ten-month period. Consecutive clean-catch mid-stream urine samples were collected from 207 in and out-patients. Identification was done using the Api 20E, and susceptibility testing using the Kirby Bauer's disc diffusion method and the MIC was done using the E-test. Results Out of the 207 isolates, 58(28.0%) were found to be resistant to all the quinolones used in the study. The resistances observed by species were in the order: Enterobacter 4(30.8%); Klebsiella 19(29.7%); Escherichia 25 (29.4%); Proteus 2(11.8%); Serratia 4(25.0%). Quinolone resistance for Escherichia was 42.9% for In-Patients (IP) and 16.3% for Out-Patient (OP) (P-value = 0.006); Klebsiella 35.9% for IP and 20% for OP; Proteus 11.1% for IP and 12.5% for OP; Serratia 18.2% for IP and 40% for OP; Enterobacter 22.2 for IP and 50% for OP. Conclusion High resistance rates to quinolones were observed not only for in-patients but also for out-patients with urinary tract enterobacterial infections. These findings demonstrate the importance of antibiotics susceptibility testing in improving quinolones prescription practices in Cameroon. PMID:26327943

  8. Reconfigurable Auditory-Visual Display

    NASA Technical Reports Server (NTRS)

    Begault, Durand R. (Inventor); Anderson, Mark R. (Inventor); McClain, Bryan (Inventor); Miller, Joel D. (Inventor)

    2008-01-01

    System and method for visual and audible communication between a central operator and N mobile communicators (N greater than or equal to 2), including an operator transceiver and interface, configured to receive and display, for the operator, visually perceptible and audibly perceptible signals from each of the mobile communicators. The interface (1) presents an audible signal from each communicator as if the audible signal is received from a different location relative to the operator and (2) allows the operator to select, to assign priority to, and to display, the visual signals and the audible signals received from a specified communicator. Each communicator has an associated signal transmitter that is configured to transmit at least one of the visual signals and the audio signal associated with the communicator, where at least one of the signal transmitters includes at least one sensor that senses and transmits a sensor value representing a selected environmental or physiological parameter associated with the communicator.

  9. Simplified night sky display system

    NASA Technical Reports Server (NTRS)

    Castellano, Timothy P. (Inventor)

    2008-01-01

    A portable structure, simply constructed with inexpensive and generally lightweight materials, for displaying a selected portion of the night sky and selected planets, satellites, comets and other astronomically observable objects that are visually perceptible within that portion of the night sky. The structure includes a computer having stored signals representing the observable objects, an image projector that converts and projects the stored signals as visually perceptible images, a first curvilinear light-reflecting surface to receive and reflect the visually perceptible images, and a second curvilinear surface to receive and display the visually perceptible images reflected from the first surface. The images may be motionless or may move with passage of time. In one embodiment, the structure includes an inflatable screen surface that receives gas in an enclosed volume, supports itself without further mechanical support, and optionally self-regulates pressure of the received gas within the enclosed volume.

  10. Virtual acoustics displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

    1991-01-01

    The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

  11. Polyplanar optic display

    SciTech Connect

    Veligdan, J.; Biscardi, C.; Brewster, C.; DeSanto, L.; Beiser, L.

    1997-07-01

    The Polyplanar Optical Display (POD) is a unique display screen which can be used with any projection source. This display screen is 2 inches thick and has a matte black face which allows for high contrast images. The prototype being developed is a form, fit and functional replacement display for the B-52 aircraft which uses a monochrome ten-inch display. The new display uses a 100 milliwatt green solid state laser (532 nm) as its optical source. In order to produce real-time video, the laser light is being modulated by a Digital Light Processing (DLP{trademark}) chip manufactured by Texas Instruments, Inc. A variable astigmatic focusing system is used to produce a stigmatic image on the viewing face of the POD. In addition to the optical design, the authors discuss the electronic interfacing to the DLP{trademark} chip, the opto-mechanical design and viewing angle characteristics.

  12. Monitor displays in radiology: Part 1

    PubMed Central

    Indrajit, IK; Verma, BS

    2009-01-01

    Monitor displays are an integral part of today's radiology work environment, attached to workstations, USG, CT/MRI consoles and PACS terminals. For each modality and method of use, the correct display monitor needs to be deployed. It helps to have a basic understanding of how monitors work and what are the issues involved in their selection. PMID:19774135

  13. A Guide to Making a Display.

    ERIC Educational Resources Information Center

    Gilmour, Frederick T., Comp.

    For media specialists, step-by-step instructions are given for design and construction of classroom and corridor displays. Included are sections on selecting the form, choosing construction materials, covering and mounting, lettering, and utilizing scrap materials. A bibliography lists other books on display building. An appendix lists…

  14. Display innovations through glass

    NASA Astrophysics Data System (ADS)

    Hamilton, Lori L.

    2016-03-01

    Prevailing trends in thin, lightweight, high-resolution, and added functionality, such as touch sensing, continue to drive innovation in the display market. While display volumes grow, so do consumers’ need for portability, enhanced optical performance, and mechanical reliability. Technical advancements in glass design and process have enabled display innovations in these areas while supporting industry growth. Opportunities for further innovation remain open for glass manufacturers to drive new applications, enhanced functionality, and increased demand.

  15. Global Footprints of Purifying Selection on Toll-Like Receptor Genes Primarily Associated with Response to Bacterial Infections in Humans

    PubMed Central

    Mukherjee, Souvik; Ganguli, Debdutta; Majumder, Partha P.

    2014-01-01

    Toll-like receptors (TLRs) are directly involved in host–pathogen interactions. Polymorphisms in these genes are associated with susceptibility to infectious diseases. To understand the influence of environment and pathogen diversity on the evolution of TLR genes, we have undertaken a large-scale population-genetic study. Our study included two hunter–gatherer tribal populations and one urbanized nontribal population from India with distinct ethnicities (n = 266) and 14 populations inhabiting four different continents (n = 1,092). From the data on DNA sequences of cell-surface TLR genes, we observed an excess of rare variants and a large number of low frequency haplotypes in each gene. Nonsynonymous changes were few in every population and the commonly used statistical tests for detecting natural selection provided evidence of purifying selection. The evidence of purifying selection acting on the cell-surface TLRs of the innate immune system is not consistent with Haldane’s theory of coevolution of immunity genes, at least of innate immunity genes, with pathogens. Our study provides evidence that genes of the cell-surface TLRs, that is, TLR2 and TLR4, have been so optimized to defend the host against microbial infections that new mutations in these genes are quickly eliminated. PMID:24554585

  16. Displaying Data As Movies

    NASA Technical Reports Server (NTRS)

    Moore, Judith G.

    1992-01-01

    NMSB Movie computer program displays large sets of data (more than million individual values). Presentation dynamic, rapidly displaying sequential image "frames" in main "movie" window. Any sequence of two-dimensional sets of data scaled between 0 and 255 (1-byte resolution) displayed as movie. Time- or slice-wise progression of data illustrated. Originally written to present data from three-dimensional ultrasonic scans of damaged aerospace composite materials, illustrates data acquired by thermal-analysis systems measuring rates of heating and cooling of various materials. Developed on Macintosh IIx computer with 8-bit color display adapter and 8 megabytes of memory using Symantec Corporation's Think C, version 4.0.

  17. Interactive holographic display

    NASA Astrophysics Data System (ADS)

    Son, Jung-Young; Lee, Beam-Ryeol; Kim, Jin-Woong; Chernyshov, Oleksii O.; Park, Min-Chul

    2014-06-01

    A holographic display which is capable of displaying floating holographic images is introduced. The display is for user interaction with the image on the display. It consists of two parts; multiplexed holographic image generation and a spherical mirror. The time multiplexed image from 2 X 10 DMD frames appeared on PDLC screen is imaged by the spherical mirror and becomes a floating image. This image is combined spatially with two layered TV images appearing behind. Since the floating holographic image has a real spatial position and depth, it allows a user to interact with the image.

  18. JAVA Stereo Display Toolkit

    NASA Technical Reports Server (NTRS)

    Edmonds, Karina

    2008-01-01

    This toolkit provides a common interface for displaying graphical user interface (GUI) components in stereo using either specialized stereo display hardware (e.g., liquid crystal shutter or polarized glasses) or anaglyph display (red/blue glasses) on standard workstation displays. An application using this toolkit will work without modification in either environment, allowing stereo software to reach a wider audience without sacrificing high-quality display on dedicated hardware. The toolkit is written in Java for use with the Swing GUI Toolkit and has cross-platform compatibility. It hooks into the graphics system, allowing any standard Swing component to be displayed in stereo. It uses the OpenGL graphics library to control the stereo hardware and to perform the rendering. It also supports anaglyph and special stereo hardware using the same API (application-program interface), and has the ability to simulate color stereo in anaglyph mode by combining the red band of the left image with the green/blue bands of the right image. This is a low-level toolkit that accomplishes simply the display of components (including the JadeDisplay image display component). It does not include higher-level functions such as disparity adjustment, 3D cursor, or overlays all of which can be built using this toolkit.

  19. Histochemical characterization of early response to Cochliobolus sativus infection in selected barley genotypes.

    PubMed

    Rodríguez-Decuadro, Susana; Silva, Paula; Bentancur, Oscar; Gamba, Fernanda; Pritsch, Clara

    2014-07-01

    Much effort is being made to breed barley with durable resistance to leaf spot blotch incited by Bipolaris sorokiniana (teleomorph: Cochliobolus sativus). We hypothesized that susceptibility and resistance traits in 11 diverse barley genotypes inoculated with a single C. sativus isolate might specify a range of distinct host cell responses. Quantitative descriptions of interaction microphenotypes exhibited by different barley genotype seedlings after infection with C. sativus are provided. Early oxidative responses occurring in epidermis and mesophyll leaf tissue were monitored by histochemical analysis of H2O2 accumulation at 8, 24, and 48 h after inoculation. Cell wall apposition (CWA) in epidermal cells and hypersensitive reaction (HR) of epidermal or mesophyll tissue were early defenses in both resistant and susceptible genotypes. There were differences in level, duration, and frequency of occurrence for CWA and HR for the different barley genotypes. Occurrence of HR in epidermal cells at post-penetration stages was indicative of compatibility. Patterns of cell responses were microphenotypically diverse between different resistant and susceptible genotypes. This suggests that timing and level of response are key features of microphenotypic diversity that distinguish different functional mechanisms of resistance and susceptibility present in barley.

  20. Selective neurocognitive deficits and poor life functioning are associated with significant depressive symptoms in alcoholism-HIV infection comorbidity.

    PubMed

    Sassoon, Stephanie A; Rosenbloom, Margaret J; Fama, Rosemary; Sullivan, Edith V; Pfefferbaum, Adolf

    2012-09-30

    Alcoholism, HIV, and depressive symptoms frequently co-occur and are associated with impairment in cognition and life function. We administered the Beck Depression Inventory-II (BDI-II), measures of life function, and neurocognitive tests to 67 alcoholics, 56 HIV+ patients, 63 HIV+ alcoholics, and 64 controls to examine whether current depressive symptom level (significant, BDI-II>14 vs. minimal, BDI-II<14) was associated with poorer cognitive or psychosocial function in alcoholism-HIV comorbidity. Participants with significant depressive symptoms demonstrated slower manual motor speed and poorer visuospatial memory than those with minimal depressive symptoms. HIV patients with depressive symptoms showed impaired manual motor speed. Alcoholics with depressive symptoms showed impaired visuospatial memory. HIV+ alcoholics with depressive symptoms reported the poorest quality of life; alcoholics with depressive symptoms, irrespective of HIV status, had poorest life functioning. Thus, significant depressive symptoms were associated with poorer selective cognitive and life functioning in alcoholism and in HIV infection, even though depressive symptoms had neither synergistic nor additive effects on cognition in alcoholism-HIV comorbidity. The results suggest the relevance of assessing and treating current depressive symptoms to reduce cognitive compromise and functional disability in HIV infection, alcoholism, and their comorbidity.

  1. HIV and selected blood-borne and sexually transmitted infections in a predominantly Roma (Gypsy) neighbourhood in Budapest, Hungary

    PubMed Central

    Gyarmathy, V. Anna; Ujhelyi, Eszter; Neaigus, Alan

    2008-01-01

    We assessed the prevalence of HIV and selected blood-borne and sexually transmitted infections among a convenience sample of 64 residents of Dzsumbuj, a predominantly Roma (Gypsy) neighbourhood in Budapest, Hungary. No cases of HIV were detected, while the prevalence of Hepatitis B infection (anti-HBc) was 27% and syphilis prevalence was 2%. Romas (n=50) were significantly more likely than non-Romas (n=14) to have HAV antibodies (80% vs. 43%) and less likely to be HBV immunized (anti-HBs only; 6% vs. 29%). Current drug injectors (n=13) were more likely than non-injectors (n=51) to have antibodies against HAV (85% vs. 69%) and HCV (85% vs. 8%). While HIV has not been introduced in this population, risk conditions for a potentially explosive HIV epidemic are present. Health care policies should focus on expanding coverage for HAV and HBV immunizations, and access to HIV preventive services needs to be extended to marginalized, mostly minority populations, such as the Roma in Europe. PMID:18935777

  2. Inhibitory effect of etodolac, a selective cyclooxygenase-2 inhibitor, on stomach carcinogenesis in Helicobacter pylori-infected Mongolian gerbils

    SciTech Connect

    Magari, Hirohito; Shimizu, Yasuhito; Inada, Ken-ichi; Enomoto, Shotaro; Tomeki, Tatsuji; Yanaoka, Kimihiko; Tamai, Hideyuki; Arii, Kenji; Nakata, Hiroya; Oka, Masashi; Utsunomiya, Hirotoshi; Tsutsumi, Yutaka; Tsukamoto, Tetsuya; Tatematsu, Masae; Ichinose, Masao E-mail: ichinose@wakayama-med.ac.jp

    2005-08-26

    The effect of the selective COX-2 inhibitor, etodolac, on Helicobacter pylori (Hp)-associated stomach carcinogenesis was investigated in Mongolian gerbils (MGs). Hp-infected MGs were fed for 23 weeks with drinking water containing 10 ppm N-methyl-N-nitrosourea. They were then switched to distilled water and placed on a diet containing 5-30 mg/kg/day etodolac for 30 weeks. We found that etodolac dose-dependently inhibited the development of gastric cancer, and no cancer was detected at a dose of 30 mg/kg/day. Etodolac did not affect the extent of inflammatory cell infiltration or oxidative DNA damage, but it significantly inhibited mucosal cell proliferation and dose-dependently repressed the development of intestinal metaplasia in the stomachs of Hp-infected MGs. These results suggest that COX-2 is a key molecule in inflammation-mediated stomach carcinogenesis and that chemoprevention of stomach cancer should be possible by controlling COX-2 expression or activity.

  3. Polyplanar optical display electronics

    SciTech Connect

    DeSanto, L.; Biscardi, C.

    1997-07-01

    The Polyplanar Optical Display (POD) is a unique display screen which can be used with any projection source. The prototype ten inch display is two inches thick and has a matte black face which allows for high contrast images. The prototype being developed is a form, fit and functional replacement display for the B-52 aircraft which uses a monochrome ten-inch display. In order to achieve a long lifetime, the new display uses a 100 milliwatt green solid-state laser (10,000 hr. life) at 532 nm as its light source. To produce real-time video, the laser light is being modulated by a Digital Light Processing (DLP{trademark}) chip manufactured by Texas Instruments. In order to use the solid-state laser as the light source and also fit within the constraints of the B-52 display, the Digital Micromirror Device (DMD{trademark}) circuit board is removed from the Texas Instruments DLP light engine assembly. Due to the compact architecture of the projection system within the display chassis, the DMD{trademark} chip is operated remotely from the Texas Instruments circuit board. The authors discuss the operation of the DMD{trademark} divorced from the light engine and the interfacing of the DMD{trademark} board with various video formats (CVBS, Y/C or S-video and RGB) including the format specific to the B-52 aircraft. A brief discussion of the electronics required to drive the laser is also presented.

  4. Display and Presentation Boards.

    ERIC Educational Resources Information Center

    Midgley, Thomas Keith

    The use of display and presentation boards as tools to help teachers/trainers convey messages more clearly is briefly discussed, and 24 different types of display and presentation boards are described and illustrated; i.e., chalk, paste-up, hook-n-loop, electric, flannel, scroll, communication planning, acetate pocket, slot, pin-tack, preview,…

  5. Split image optical display

    DOEpatents

    Veligdan, James T.

    2007-05-29

    A video image is displayed from an optical panel by splitting the image into a plurality of image components, and then projecting the image components through corresponding portions of the panel to collectively form the image. Depth of the display is correspondingly reduced.

  6. Split image optical display

    DOEpatents

    Veligdan, James T.

    2005-05-31

    A video image is displayed from an optical panel by splitting the image into a plurality of image components, and then projecting the image components through corresponding portions of the panel to collectively form the image. Depth of the display is correspondingly reduced.

  7. Effective Monitor Display Design.

    ERIC Educational Resources Information Center

    Harrell, William

    1999-01-01

    Describes some of the factors that affect computer monitor display design and provides suggestions and insights into how screen displays can be designed more effectively. Topics include color, font choices, organizational structure of text, space outline, and general principles. (Author/LRW)

  8. Displays enabling mobile multimedia

    NASA Astrophysics Data System (ADS)

    Kimmel, Jyrki

    2007-02-01

    With the rapid advances in telecommunications networks, mobile multimedia delivery to handsets is now a reality. While a truly immersive multimedia experience is still far ahead in the mobile world, significant advances have been made in the constituent audio-visual technologies to make this become possible. One of the critical components in multimedia delivery is the mobile handset display. While such alternatives as headset-style near-to-eye displays, autostereoscopic displays, mini-projectors, and roll-out flexible displays can deliver either a larger virtual screen size than the pocketable dimensions of the mobile device can offer, or an added degree of immersion by adding the illusion of the third dimension in the viewing experience, there are still challenges in the full deployment of such displays in real-life mobile communication terminals. Meanwhile, direct-view display technologies have developed steadily, and can provide a development platform for an even better viewing experience for multimedia in the near future. The paper presents an overview of the mobile display technology space with an emphasis on the advances and potential in developing direct-view displays further to meet the goal of enabling multimedia in the mobile domain.

  9. Mining gut microbiome oligopeptides by functional metaproteome display

    PubMed Central

    Zantow, Jonas; Just, Sarah; Lagkouvardos, Ilias; Kisling, Sigrid; Dübel, Stefan; Lepage, Patricia; Clavel, Thomas; Hust, Michael

    2016-01-01

    Pathogen infections, autoimmune diseases, and chronic inflammatory disorders are associated with systemic antibody responses from the host immune system. Disease-specific antibodies can be important serum biomarkers, but the identification of antigens associated with specific immune reactions is challenging, in particular if complex communities of microorganisms are involved in the disease progression. Despite promising new diagnostic opportunities, the discovery of these serological markers becomes more difficult with increasing complexity of microbial communities. In the present work, we used a metagenomic M13 phage display approach to select immunogenic oligopeptides from the gut microbiome of transgenic mice suffering from chronic ileitis. We constructed three individual metaproteome phage display libraries with a library size of approximately 107 clones each. Using serum antibodies, we selected and validated three oligopeptides that induced specific antibody responses in the mouse model. This proof-of-concept study provides the first successful application of functional metaproteome display for the study of protein-protein interactions and the discovery of potential disease biomarkers. PMID:27703179

  10. System status display evaluation

    NASA Technical Reports Server (NTRS)

    Summers, Leland G.

    1988-01-01

    The System Status Display is an electronic display system which provides the crew with an enhanced capability for monitoring and managing the aircraft systems. A flight simulation in a fixed base cockpit simulator was used to evaluate alternative design concepts for this display system. The alternative concepts included pictorial versus alphanumeric text formats, multifunction versus dedicated controls, and integration of the procedures with the system status information versus paper checklists. Twelve pilots manually flew approach patterns with the different concepts. System malfunctions occurred which required the pilots to respond to the alert by reconfiguring the system. The pictorial display, the multifunction control interfaces collocated with the system display, and the procedures integrated with the status information all had shorter event processing times and lower subjective workloads.

  11. Assessment of selected biochemical parameters and humoral immune response of Nile crocodiles (Crocodylus niloticus) experimentally infected with Trichinella zimbabwensis.

    PubMed

    La Grange, Louis J; Mukaratirwa, Samson

    2014-08-21

    Fifteen crocodiles were randomly divided into three groups of five animals. They represented high-infection, medium-infection and low-infection groups of 642 larvae/kg, 414 larvae/kg and 134 larvae/kg bodyweight, respectively. The parameters assessed were blood glucose, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), aspartate transaminase (AST) and alanine transaminase (ALT). The humoral immune response to Trichinella zimbabwensis infection was evaluated in all three groups by an indirect ELISA method. The results showed deviations from normal parameters of blood glucose, CPK, LDH, AST and ALT when compared with reported levels in uninfected reptiles. Contrary to studies involving mammals, hypoglycaemia was not observed in the infected groups in this study. Peak values of blood glucose were reached on post-infection (PI) Day 49, Day 42 and Day 35 in the high-infection, medium-infection and low-infection groups, respectively. Peak values of LDH and AST were observed on PI Day 56, Day 49 and Day 42 in the high-infection, medium-infection and low-infection groups, respectively. Peak values of CPK were observed on Day 35 PI in all three groups. Peak ALT values were reached on Day 56 in the high-infection group and on Day 28 PI in both the medium-infection and low-infection groups. No correlations between the biochemical parameters and infection intensity were observed. Peak antibody titres were reached on Day 49 PI in the medium-infection group, and on Day 42 PI in both the high-infection and low-infection groups. Infection intensity could not be correlated with the magnitude of the humoral immune response or time to sero-conversion. Results from this study were in agreement with results reported in mammals infected with other Trichinella species and showed that antibody titres could not be detected indefinitely.

  12. Defense display market assessment

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    1998-09-01

    This paper addresses the number, function and size of principal military displays and establishes a basis to determine the opportunities for technology insertion in the immediate future and into the next millennium. Principal military displays are defined as those occupying appreciable crewstation real-estate and/or those without which the platform could not carry out its intended mission. DoD 'office' applications are excluded from this study. The military displays market is specified by such parameters as active area and footprint size, and other characteristics such as luminance, gray scale, resolution, angle, color, video capability, and night vision imaging system (NVIS) compatibility. Funded, future acquisitions, planned and predicted crewstation modification kits, and form-fit upgrades are taken into account. This paper provides an overview of the DoD niche market, allowing both government and industry a necessary reference by which to meet DoD requirements for military displays in a timely and cost-effective manner. The aggregate DoD market for direct-view and large-area military displays is presently estimated to be in excess of 242,000. Miniature displays are those which must be magnified to be viewed, involve a significantly different manufacturing paradigm and are used in helmet mounted displays and thermal weapon sight applications. Some 114,000 miniature displays are presently included within Service weapon system acquisition plans. For vendor production planning purposes it is noted that foreign military sales could substantially increase these quantities. The vanishing vendor syndrome (VVS) for older display technologies continues to be a growing, pervasive problem throughout DoD, which consequently must leverage the more modern display technologies being developed for civil- commercial markets.

  13. Real-Time, Interactive Sonic Boom Display

    NASA Technical Reports Server (NTRS)

    Haering, Jr., Edward A. (Inventor); Plotkin, Kenneth J. (Inventor)

    2012-01-01

    The present invention is an improved real-time, interactive sonic boom display for aircraft. By using physical properties obtained via various sensors and databases, the invention determines, in real-time, sonic boom impacts locations and intensities for aircraft traveling at supersonic speeds. The information is provided to a pilot via a display that lists a selectable set of maneuvers available to the pilot to mitigate sonic boom issues. Upon selection of a maneuver, the information as to the result of the maneuver is displayed and the pilot may proceed with making the maneuver, or provide new data to the system in order to calculate a different maneuver.

  14. Takeoff Performance Monitoring System display options

    NASA Technical Reports Server (NTRS)

    Middleton, David B.; Srivatsan, Raghavachari; Person, Lee H., Jr.

    1992-01-01

    The development of displays for the Takeoff Performance Monitoring System (TPMS) is described with attention given to the three concepts prepared for commercial applications. The TPMS algorithm is described and related to the display requirements for pilots of two-engine airplanes. Head-up and -down displays are considered for displaying the simple advisory data which indicate whether the takeoff is a 'Go' or 'No-go' based on engine failure, acceleration error, and runway length. Six pilots are shown the three display options which include: (1) basic information; (2) basic data with 'Go/No-go' advisory flags; and (3) basic data, advisory flags, and an abort-warning symbol. The pilots tended to select the option with the most advisory data available, but the inconclusive preference study led to the concept of presenting all three configurations as possible display options for the TPMS.

  15. Vibratory tactile display for textures

    NASA Technical Reports Server (NTRS)

    Ikei, Yasushi; Ikeno, Akihisa; Fukuda, Shuichi

    1994-01-01

    We have developed a tactile display that produces vibratory stimulus to a fingertip in contact with a vibrating tactor matrix. The display depicts tactile surface textures while the user is exploring a virtual object surface. A piezoelectric actuator drives the individual tactor in accordance with both the finger movement and the surface texture being traced. Spatiotemporal display control schemes were examined for presenting the fundamental surface texture elements. The temporal duration of vibratory stimulus was experimentally optimized to simulate the adaptation process of cutaneous sensation. The selected duration time for presenting a single line edge agreed with the time threshold of tactile sensation. Then spatial stimulus disposition schemes were discussed for representation of other edge shapes. As an alternative means not relying on amplitude control, a method of augmented duration at the edge was investigated. Spatial resolution of the display was measured for the lines presented both in perpendicular and parallel to a finger axis. Discrimination of texture density was also measured on random dot textures.

  16. Selective contribution of IFN-/ signaling to the maturation of dendritic cells induced by double-stranded RNA or viral infection

    NASA Astrophysics Data System (ADS)

    Honda, Kenya; Sakaguchi, Shinya; Nakajima, Chigusa; Watanabe, Ai; Yanai, Hideyuki; Matsumoto, Misako; Ohteki, Toshiaki; Kaisho, Tsuneyasu; Takaoka, Akinori; Akira, Shizuo; Seya, Tsukasa; Taniguchi, Tadatsugu

    2003-09-01

    A complex mechanism may be operational for dendritic cell (DC) maturation, wherein Toll-like receptor and other signaling pathways may be coordinated differently depending on the nature of the pathogens, in order for DC maturation to be most effective to a given threat. Here, we show that IFN-/ signaling is selectively required for the maturation of DCs induced by double-stranded RNA or viral infection in vitro. Interestingly, the maturation is still observed in the absence of either of the two target genes of IFN-/, TLR3 and PKR (double-stranded-RNA-dependent protein kinase R), indicating the complexity of the IFN-/-induced transcriptional program in DCs. We also show that the DCs stimulated in vivo by these agents can migrate into the T cell zone of the spleen but fail to mature without the IFN signal. The immune system may have acquired the selective utilization of this cytokine system, which is essential for innate antiviral immunity, to effectively couple with the induction of adaptive immunity.

  17. Evolution of displays within the pair bond

    PubMed Central

    Servedio, Maria R.; Price, Trevor D.; Lande, Russell

    2013-01-01

    Although sexual selection is an important cause of display evolution, in socially monogamous species (e.g. many birds), displays continue after formation of the pair bond. Here, we consider that these displays evolve because they stimulate the partner to increase investment in offspring. Our study is motivated by elaborate mutual displays in species that are largely monomorphic and have long-term pair bonds (e.g. the great crested grebe, Podiceps cristatus) and by many empirical results evidencing that display manipulation affects parental investment. Using population genetic models, we show that a necessary condition for the permanent establishment of mutual displays in the pair bond is that the benefit of investment by the pair is more than twice that resulting from investment by a single individual. Pre-existing biases to respond to displays by increased investment are a necessary component of display evolution. We also consider examples where one sex (e.g. males) stimulates increased investment in offspring by the other sex. Here, display and additional investment cannot evolve permanently, but can increase and linger at high frequency for a long time before loss. We discuss how such transient effects may lead to the evolution of permanent displays as a result of evolution at additional loci. PMID:23427172

  18. Cathode-ray tube displays for medical imaging.

    PubMed

    Keller, P A

    1990-02-01

    This paper will discuss the principles of cathode-ray tube displays in medical imaging and the parameters essential to the selection of displays for specific requirements. A discussion of cathode-ray tube fundamentals and medical requirements is included.

  19. Gardens on Display.

    ERIC Educational Resources Information Center

    Steinheimer, Margaret

    1998-01-01

    Discusses display gardens and their development by students. Presents guidelines for construction and size consideration and describes details of an outdoor garden, volcanic garden, and shoe box dioramas. (DDR)

  20. Raster graphics display library

    NASA Technical Reports Server (NTRS)

    Grimsrud, Anders; Stephenson, Michael B.

    1987-01-01

    The Raster Graphics Display Library (RGDL) is a high level subroutine package that give the advanced raster graphics display capabilities needed. The RGDL uses FORTRAN source code routines to build subroutines modular enough to use as stand-alone routines in a black box type of environment. Six examples are presented which will teach the use of RGDL in the fastest, most complete way possible. Routines within the display library that are used to produce raster graphics are presented in alphabetical order, each on a separate page. Each user-callable routine is described by function and calling parameters. All common blocks that are used in the display library are listed and the use of each variable within each common block is discussed. A reference on the include files that are necessary to compile the display library is contained. Each include file and its purpose are listed. The link map for MOVIE.BYU version 6, a general purpose computer graphics display system that uses RGDL software, is also contained.

  1. Impact of a treatment including tenofovir plus didanosine on the selection of the 65R mutation in highly drug-experienced HIV-infected patients.

    PubMed

    Gianotti, Nicola; Seminari, Elena; Fusetti, Giuliana; Salpietro, Stefania; Boeri, Enzo; Galli, Andrea; Lazzarin, Adriano; Clementi, Massimo; Castagna, Antonella

    2004-11-01

    Data from 20 highly drug-experienced HIV-infected patients receiving tenofovir plus didanosine as part of a salvage regimen were analysed. At baseline, all but one patient harboured a virus bearing at least one nucleoside excision mutation (NEM); in 13 cases (65%) three or more NEM were detectable. After a median of 26 weeks of treatment, two patients (10%) selected the 65R mutation. These results support the hypothesis that NEM hinder the selection of this mutation.

  2. Fiber array based hyperspectral Raman imaging for chemical selective analysis of malaria-infected red blood cells.

    PubMed

    Brückner, Michael; Becker, Katja; Popp, Jürgen; Frosch, Torsten

    2015-09-24

    A new setup for Raman spectroscopic wide-field imaging is presented. It combines the advantages of a fiber array based spectral translator with a tailor-made laser illumination system for high-quality Raman chemical imaging of sensitive biological samples. The Gaussian-like intensity distribution of the illuminating laser beam is shaped by a square-core optical multimode fiber to a top-hat profile with very homogeneous intensity distribution to fulfill the conditions of Koehler. The 30 m long optical fiber and an additional vibrator efficiently destroy the polarization and coherence of the illuminating light. This homogeneous, incoherent illumination is an essential prerequisite for stable quantitative imaging of complex biological samples. The fiber array translates the two-dimensional lateral information of the Raman stray light into separated spectral channels with very high contrast. The Raman image can be correlated with a corresponding white light microscopic image of the sample. The new setup enables simultaneous quantification of all Raman spectra across the whole spatial area with very good spectral resolution and thus outperforms other Raman imaging approaches based on scanning and tunable filters. The unique capabilities of the setup for fast, gentle, sensitive, and selective chemical imaging of biological samples were applied for automated hemozoin analysis. A special algorithm was developed to generate Raman images based on the hemozoin distribution in red blood cells without any influence from other Raman scattering. The new imaging setup in combination with the robust algorithm provides a novel, elegant way for chemical selective analysis of the malaria pigment hemozoin in early ring stages of Plasmodium falciparum infected erythrocytes. PMID:26423630

  3. Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks.

    PubMed

    Feng, Junchang; Wang, Lihong; Zhou, Luoxiong; Yang, Xin; Zhao, Xin

    2016-01-01

    Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 1.0%) conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231) and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1) were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF), IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry. PMID:26799658

  4. Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks

    PubMed Central

    Feng, Junchang; Wang, Lihong; Zhou, Luoxiong; Yang, Xin; Zhao, Xin

    2016-01-01

    Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 1.0%) conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231) and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1) were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF), IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry. PMID:26799658

  5. Crystal Structures of Trypanosoma brucei Sterol 14[alpha]-Demethylase and Implications for Selective Treatment of Human Infections

    SciTech Connect

    Lepesheva, Galina I.; Park, Hee-Won; Hargrove, Tatiana Y.; Vanhollebeke, Benoit; Wawrzak, Zdzislaw; Harp, Joel M.; Sundaramoorthy, Munirathinam; Nes, W. David; Pays, Etienne; Chaudhuri, Minu; Villalta, Fernando; Waterman, Michael R.

    2010-01-25

    Sterol 14{alpha}-demethylase (14DM, the CYP51 family of cytochrome P450) is an essential enzyme in sterol biosynthesis in eukaryotes. It serves as a major drug target for fungal diseases and can potentially become a target for treatment of human infections with protozoa. Here we present 1.9 {angstrom} resolution crystal structures of 14DM from the protozoan pathogen Trypanosoma brucei, ligand-free and complexed with a strong chemically selected inhibitor N-1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethyl-4-(5-phenyl-1,3,4-oxadi-azol-2-yl)benzamide that we previously found to produce potent antiparasitic effects in Trypanosomatidae. This is the first structure of a eukaryotic microsomal 14DM that acts on sterol biosynthesis, and it differs profoundly from that of the water-soluble CYP51 family member from Mycobacterium tuberculosis, both in organization of the active site cavity and in the substrate access channel location. Inhibitor binding does not cause large scale conformational rearrangements, yet induces unanticipated local alterations in the active site, including formation of a hydrogen bond network that connects, via the inhibitor amide group fragment, two remote functionally essential protein segments and alters the heme environment. The inhibitor binding mode provides a possible explanation for both its functionally irreversible effect on the enzyme activity and its selectivity toward the 14DM from human pathogens versus the human 14DM ortholog. The structures shed new light on 14DM functional conservation and open an excellent opportunity for directed design of novel antiparasitic drugs.

  6. Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks.

    PubMed

    Feng, Junchang; Wang, Lihong; Zhou, Luoxiong; Yang, Xin; Zhao, Xin

    2016-01-01

    Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 1.0%) conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231) and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1) were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF), IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry.

  7. Dichroic Liquid Crystal Displays

    NASA Astrophysics Data System (ADS)

    Bahadur, Birendra

    The following sections are included: * INTRODUCTION * DICHROIC DYES * Chemical Structure * Chemical and Photochemical Stability * THEORETICAL MODELLING * DEFECTS CAUSED BY PROLONGED LIGHT IRRADIATION * CHEMICAL STRUCTURE AND PHOTOSTABILITY * OTHER PARAMETERS AFFECTING PHOTOSTABILITY * CELL PREPARATION * DICHROIC PARAMETERS AND THEIR MEASUREMENTS * Order Parameter and Dichroic Ratio Of Dyes * Absorbance, Order Parameter and Dichroic Ratio Measurements * IMPACT OF DYE STRUCTURE AND LIQUID CRYSTAL HOST ON PHYSICAL PROPERTIES OF A DICHROIC MIXTURE * Order Parameter and Dichroic Ratio * EFFECT OF LENGTH OF DICHROIC DYES ON THE ORDER PARAMETER * EFFECT OF THE BREADTH OF DYE ON THE ORDER PARAMETER * EFFECT OF THE HOST ON THE ORDER PARAMETER * TEMPERATURE VARIATION OF THE ORDER PARAMETER OF DYES IN A LIQUID CRYSTAL HOST * IMPACT OF DYE CONCENTRATION ON THE ORDER PARAMETER * Temperature Range * Viscosity * Dielectric Constant and Anisotropy * Refractive Indices and Birefringence * solubility43,153-156 * Absorption Wavelength and Auxochromic Groups * Molecular Engineering of Dichroic Dyes * OPTICAL, ELECTRO-OPTICAL AND LIFE PARAMETERS * Colour And CIE Colour space120,160-166 * CIE 1931 COLOUR SPACE * CIE 1976 CHROMATICITY DIAGRAM * CIE UNIFORM COLOUR SPACES & COLOUR DIFFERENCE FORMULAE120,160-166 * Electro-Optical Parameters120 * LUMINANCE * CONTRAST AND CONTRAST RATIO * SWITCHING SPEED * Life Parameters and Failure Modes * DICHROIC MIXTURE FORMULATION * Monochrome Mixture * Black Mixture * ACHROMATIC BLACK MIXTURE FOR HEILMEIER DISPLAYS * Effect of Illuminant on Display Colour * Colour of the Field-On State * Effect of Dye Linewidth * Optimum Centroid Wavelengths * Effect of Dye Concentration * Mixture Formulation Using More Than Three Dyes * ACHROMATIC MIXTURE FOR WHITE-TAYLOR TYPE DISPLAYS * HEILMEIER DISPLAYS * Theoretical Modelling * Threshold Characteristic * Effects of Dye Concentration on Electro-optical Parameters * Effect of Cholesteric Doping * Effect of Alignment

  8. Crewstation display interface standardization

    NASA Astrophysics Data System (ADS)

    Hardy, Gregory J.

    1999-08-01

    Military sensors and crewstation displays are all moving to digital-based technologies, an epochal shift from the previous world of analog interfaces throughout the video chain. It is no longer possible to specify a sensor and display to the same interface specification such as the venerable RS-170 and RS- 343 standards without paying an unacceptable resolution penalty. Consequently a new standard is required to allow sensor and display manufacturers to easily design system interfaces without relying on cumbersome, costly and unique interface control documents. This paper presents one possible hardware and protocol standard based on FibreChannel technology, and solicits inputs into the standards setting process which is now in progress.

  9. EKG and ultrasonoscope display

    NASA Technical Reports Server (NTRS)

    Lee, Robert D. (Inventor)

    1979-01-01

    A system is disclosed which permits simultaneous display of an EKG waveform in real time in conjunction with a two-dimensional cross-sectional image of the heart, so that the EKG waveform can be directly compared with dimensional changes in the heart. The apparatus of the invention includes an ultrasonoscope for producing a C-scan cross-sectional image of the heart. An EKG monitor circuit along with EKG logic circuitry is combined with the ultrasonoscope circuitry to produce on the same oscilloscope screen a continuous vertical trace showing the EKG waveform simultaneously with the heart image. The logic circuitry controls the oscilloscope display such that the display of both heart and EKG waveforms occurs on a real time basis.

  10. Displays, deja vu.

    PubMed

    Huntoon, R B

    1985-02-01

    Developments in electronic displays and computers have enabled avionics designers to present the pilot with ever-increasing amounts of information in greater detail and with more accuracy. However, technicological developments have not always brought about enhancement of the pilot's role as aircraft systems manager. In fact, there is evidence that the new technology may add to the pilot's workload to the extent that his performance decreases. Recent articles and reports of research indicate that application of human factor principles and procedures to: (1) develop appropriate display formats, (2) consider the total avionics suite as an integrated system, and (3) simplify or summarize related data will significantly improve total aircraft performance. Indeed, development of the "chip" and new display techniques create an imperative demand for human factor considerations early in system design, ensuring that user evaluation, information integration, and simplification are intrinsic qualities of the system.

  11. Thin display optical projector

    DOEpatents

    Veligdan, James T.

    1999-01-01

    An optical system (20) projects light into a planar optical display (10). The display includes laminated optical waveguides (12) defining an inlet face (14) at one end and an outlet screen (16) at an opposite end. A first mirror (26) collimates light from a light source (18) along a first axis, and distributes the light along a second axis. A second mirror (28) collimates the light from the first mirror along the second axis to illuminate the inlet face and produce an image on the screen.

  12. Integrated display scanner

    DOEpatents

    Veligdan, James T.

    2004-12-21

    A display scanner includes an optical panel having a plurality of stacked optical waveguides. The waveguides define an inlet face at one end and a screen at an opposite end, with each waveguide having a core laminated between cladding. A projector projects a scan beam of light into the panel inlet face for transmission from the screen as a scan line to scan a barcode. A light sensor at the inlet face detects a return beam reflected from the barcode into the screen. A decoder decodes the return beam detected by the sensor for reading the barcode. In an exemplary embodiment, the optical panel also displays a visual image thereon.

  13. Oral infection with enteropathogenic Escherichia coli triggers immune response and intestinal histological alterations in mice selected for their minimal acute inflammatory responses.

    PubMed

    Vulcano, Amanda Bardella; Tino-De-Franco, Milene; Amaral, José Araujo; Ribeiro, Orlando Garcia; Cabrera, Wafa Hanna Koury; Bordenalli, Marcela Aparecida; Carbonare, Cristiane Barros; Álvares, Eliana Parisi; Carbonare, Solange Barros

    2014-06-01

    Enteropathogenic Escherichia coli (EPEC), a leading cause of infant diarrhea, is an important public health problem in Brazil and other developing countries. In vitro assays of bacterial adhesion to cultured cells are important tools for studying bacterial pathogenicity but do not reproduce all the events that occur in natural infections. In this study, the effects of oral infection with EPEC on mice selected for their minimal acute inflammatory response (AIR min) were evaluated. Mice were orally infected with EPEC and variations in body weight, bacterial shedding and antibody production observed. The infected animals developed seric and secretory anti-EPEC antibodies; however, neither mortality nor diarrhea was observed. Light microscopy of their intestines demonstrated histological modifications that were not present in controls. However, electron microscopy did not show bacteria attached to the intestinal epithelia to form attaching and effacing lesions, characteristic of EPEC in humans. The bacteria were detected in Peyer's patches and intestinal contents up to 5 hr post-infection. When human anti-EPEC secretory immunoglobulin A or avian immunoglobulin Y antibodies were administered to infected animals, they developed minor histological alterations compared with non-treated animals. In summary, it was found that EPEC triggers immune responses and intestinal histological alterations but does not produce evidence of diarrheal disease in mice infected by the oral route. This study of EPEC experimental infection provides a better understanding of the effects of antibodies on bacterial infections and may provide a suitable model for the design and testing of immunobiological products for active or passive immunization. PMID:24750489

  14. Transparent displays enabled by resonant nanoparticle scattering

    NASA Astrophysics Data System (ADS)

    Hsu, Chia Wei; Zhen, Bo; Qiu, Wenjun; Shapira, Ofer; Delacy, Brendan G.; Joannopoulos, John D.; Soljačić, Marin

    2014-01-01

    The ability to display graphics and texts on a transparent screen can enable many useful applications. Here we create a transparent display by projecting monochromatic images onto a transparent medium embedded with nanoparticles that selectively scatter light at the projected wavelength. We describe the optimal design of such nanoparticles, and experimentally demonstrate this concept with a blue-color transparent display made of silver nanoparticles in a polymer matrix. This approach has attractive features including simplicity, wide viewing angle, scalability to large sizes and low cost.

  15. Deep sequencing and Circos analyses of antibody libraries reveal antigen-driven selection of Ig VH genes during HIV-1 infection.

    PubMed

    Xiao, Madelyne; Prabakaran, Ponraj; Chen, Weizao; Kessing, Bailey; Dimitrov, Dimiter S

    2013-12-01

    The vast diversity of antibody repertoires is largely attributed to heavy chain (V(H)) recombination of variable (V), diversity (D) and joining (J) gene segments. We used 454 sequencing information of the variable domains of the antibody heavy chain repertoires from neonates, normal adults and an HIV-1-infected individual, to analyze, with Circos software, the VDJ pairing patterns at birth, adulthood and a time-dependent response to HIV-1 infection. Our comparative analyses of the Ig VDJ repertoires from these libraries indicated that, from birth to adulthood, VDJ recombination patterns remain the same with some slight changes, whereas some V(H) families are selected and preferentially expressed after long-term infection with HIV-1. We also demonstrated that the immune system responds to HIV-1 chronic infection by selectively expanding certain HV families in an attempt to combat infection. Our findings may have implications for understanding immune responses in pathology as well as for development of new therapeutics and vaccines.

  16. Lack of Clinical Manifestations in Asymptomatic Dengue Infection Is Attributed to Broad Down-Regulation and Selective Up-Regulation of Host Defence Response Genes

    PubMed Central

    Yeo, Adeline S. L.; Azhar, Nur Atiqah; Yeow, Wanyi; Talbot, C. Conover; Khan, Mohammad Asif; Shankar, Esaki M.; Rathakrishnan, Anusyah; Azizan, Azliyati; Wang, Seok Mui; Lee, Siew Kim; Fong, Mun Yik; Manikam, Rishya; Sekaran, Shamala Devi

    2014-01-01

    Objectives Dengue represents one of the most serious life-threatening vector-borne infectious diseases that afflicts approximately 50 million people across the globe annually. Whilst symptomatic infections are frequently reported, asymptomatic dengue remains largely unnoticed. Therefore, we sought to investigate the immune correlates conferring protection to individuals that remain clinically asymptomatic. Methods We determined the levels of neutralizing antibodies (nAbs) and gene expression profiles of host immune factors in individuals with asymptomatic infections, and whose cognate household members showed symptoms consistent to clinical dengue infection. Results We observed broad down-regulation of host defense response (innate, adaptive and matrix metalloprotease) genes in asymptomatic individuals as against symptomatic patients, with selective up-regulation of distinct genes that have been associated with protection. Selected down-regulated genes include: TNF α (TNF), IL8, C1S, factor B (CFB), IL2, IL3, IL4, IL5, IL8, IL9, IL10 and IL13, CD80, CD28, and IL18, MMP8, MMP10, MMP12, MMP15, MMP16, and MMP24. Selected up-regulated genes include: RANTES (CCL5), MIP-1α (CCL3L1/CCL3L3), MIP-1β (CCL4L1), TGFβ (TGFB), and TIMP1. Conclusion Our findings highlight the potential association of certain host genes conferring protection against clinical dengue. These data are valuable to better explore the mysteries behind the hitherto poorly understood immunopathogenesis of subclinical dengue infection. PMID:24727912

  17. Drivers license display system

    NASA Astrophysics Data System (ADS)

    Prokoski, Francine J.

    1997-01-01

    Carjackings are only one of a growing class of law enforcement problems associated with increasingly violent crimes and accidents involving automobiles plays weapons, drugs and alcohol. Police traffic stops have become increasingly dangerous, with an officer having no information about a vehicle's potentially armed driver until approaching him. There are 15 million alcoholics in the US and 90 percent of them have drivers licenses. Many of them continue driving even after their licenses have ben revoked or suspended. There are thousands of unlicensed truck drivers in the country, and also thousands who routinely exceed safe operating periods without rest; often using drugs in an attempt to stay alert. MIKOS has developed the Drivers License Display Systems to reduce these and other related risks. Although every state requires the continuous display of vehicle registration information on every vehicle using public roads, no state yet requires the display of driver license information. The technology exists to provide that feature as an add-on to current vehicles for nominal cost. An initial voluntary market is expected to include: municipal, rental, and high value vehicles which are most likely to be mis-appropriated. It is anticipated that state regulations will eventually require such systems in the future, beginning with commercial vehicles, and then extending to high risk drivers and eventually all vehicles. The MIKOS system offers a dual-display approach which can be deployed now, and which will utilize all existing state licenses without requiring standardization.

  18. Refreshing Refreshable Braille Displays.

    PubMed

    Russomanno, Alexander; O'Modhrain, Sile; Gillespie, R Brent; Rodger, Matthew W M

    2015-01-01

    The increased access to books afforded to blind people via e-publishing has given them long-sought independence for both recreational and educational reading. In most cases, blind readers access materials using speech output. For some content such as highly technical texts, music, and graphics, speech is not an appropriate access modality as it does not promote deep understanding. Therefore blind braille readers often prefer electronic braille displays. But, these are prohibitively expensive. The search is on, therefore, for a low-cost refreshable display that would go beyond current technologies and deliver graphical content as well as text. And many solutions have been proposed, some of which reduce costs by restricting the number of characters that can be displayed, even down to a single braille cell. In this paper, we demonstrate that restricting tactile cues during braille reading leads to poorer performance in a letter recognition task. In particular, we show that lack of sliding contact between the fingertip and the braille reading surface results in more errors and that the number of errors increases as a function of presentation speed. These findings suggest that single cell displays which do not incorporate sliding contact are likely to be less effective for braille reading. PMID:25879973

  19. Christmas Light Display

    NASA Astrophysics Data System (ADS)

    Ross, Arthur; Renfro, Timothy

    2012-03-01

    The Digital Electronics class at McMurry University created a Christmas light display that toggles the power of different strands of lights, according to what frequencies are played in a song, as an example of an analog to digital circuit. This was accomplished using a BA3830S IC six-band audio filter and six solid-state relays.

  20. Refreshing Refreshable Braille Displays.

    PubMed

    Russomanno, Alexander; O'Modhrain, Sile; Gillespie, R Brent; Rodger, Matthew W M

    2015-01-01

    The increased access to books afforded to blind people via e-publishing has given them long-sought independence for both recreational and educational reading. In most cases, blind readers access materials using speech output. For some content such as highly technical texts, music, and graphics, speech is not an appropriate access modality as it does not promote deep understanding. Therefore blind braille readers often prefer electronic braille displays. But, these are prohibitively expensive. The search is on, therefore, for a low-cost refreshable display that would go beyond current technologies and deliver graphical content as well as text. And many solutions have been proposed, some of which reduce costs by restricting the number of characters that can be displayed, even down to a single braille cell. In this paper, we demonstrate that restricting tactile cues during braille reading leads to poorer performance in a letter recognition task. In particular, we show that lack of sliding contact between the fingertip and the braille reading surface results in more errors and that the number of errors increases as a function of presentation speed. These findings suggest that single cell displays which do not incorporate sliding contact are likely to be less effective for braille reading.

  1. Virtual acoustic displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.

    1991-01-01

    A 3D auditory display can potentially enhance information transfer by combining directional and iconic information in a quite naturalistic representation of dynamic objects in the interface. Another aspect of auditory spatial clues is that, in conjunction with other modalities, it can act as a potentiator of information in the display. For example, visual and auditory cues together can reinforce the information content of the display and provide a greater sense of presence or realism in a manner not readily achievable by either modality alone. This phenomenon will be particularly useful in telepresence applications, such as advanced teleconferencing environments, shared electronic workspaces, and monitoring telerobotic activities in remote or hazardous situations. Thus, the combination of direct spatial cues with good principles of iconic design could provide an extremely powerful and information-rich display which is also quite easy to use. An alternative approach, recently developed at ARC, generates externalized, 3D sound cues over headphones in realtime using digital signal processing. Here, the synthesis technique involves the digital generation of stimuli using Head-Related Transfer Functions (HRTF's) measured in the two ear-canals of individual subjects. Other similar approaches include an analog system developed by Loomis, et. al., (1990) and digital systems which make use of transforms derived from normative mannikins and simulations of room acoustics. Such an interface also requires the careful psychophysical evaluation of listener's ability to accurately localize the virtual or synthetic sound sources. From an applied standpoint, measurement of each potential listener's HRTF's may not be possible in practice. For experienced listeners, localization performance was only slightly degraded compared to a subject's inherent ability. Alternatively, even inexperienced listeners may be able to adapt to a particular set of HRTF's as long as they provide adequate

  2. Selection of genetic variants of lymphocytic choriomeningitis virus in spleens of persistently infected mice. Role in suppression of cytotoxic T lymphocyte response and viral persistence

    PubMed Central

    1984-01-01

    We studied the mechanism of lymphocytic choriomeningitis virus (LCMV) persistence and the suppression of cytotoxic T lymphocyte (CTL) responses in BALB/c WEHI mice infected at birth with LCMV Armstrong strain. Using adoptive transfer experiments we found that spleen cells from persistently infected (carrier) mice actively suppressed the expected LCMV-specific CTL response of spleen cells from normal adult mice. The suppression was specific for the CTL response and LCMV - specific antibody responses were not affected. Associated with the specific CTL suppression was the establishment of persistent LCMV infection. The transfer of spleen or lymph node cells containing LCMV - specific CTL resulted in virus clearance and prevented establishment of the carrier state. The suppression of LCMV -specific CTL responses by carrier spleen cells is not mediated by a suppressor cell, but is due to the presence of genetic variants of LCMV in spleens of carrier mice. Such virus variants selectively suppress LCMV-specific CTL responses and cause persistent infections in immunocompetent mice. In striking contrast, wild-type LCMV Armstrong, from which these variants were generated, induces a potent CTL response in immunocompetent mice and the LCMV infection is rapidly cleared. Our results show that LCMV variants that emerge during infection in vivo play a crucial role in the suppression of virus-specific CTL responses and in the maintenance of virus persistence. PMID:6332167

  3. Selective recruitment of mRNAs and miRNAs to polyribosomes in response to rhizobia infection in Medicago truncatula.

    PubMed

    Reynoso, Mauricio Alberto; Blanco, Flavio Antonio; Bailey-Serres, Julia; Crespi, Martín; Zanetti, María Eugenia

    2013-01-01

    Translation of mRNAs is a key regulatory step that contributes to the coordination and modulation of eukaryotic gene expression during development or adaptation to the environment. mRNA stability or translatability can be regulated by the action of small regulatory RNAs (sRNAs), which control diverse biological processes. Under low nitrogen conditions, leguminous plants associate with soil bacteria and develop a new organ specialized in nitrogen fixation: the nodule. To gain insight into the translational regulation of mRNAs during nodule formation, the association of mRNAs and sRNAs to polysomes was characterized in roots of the model legume Medicago truncatula during the symbiotic interaction with Sinorhizobium meliloti. Quantitative comparison of steady-state and polysomal mRNAs for 15 genes involved in nodulation identified a group of transcripts with slight or no change in total cellular abundance that were significantly upregulated at the level of association with polysomes in response to rhizobia. This group included mRNAs encoding receptors like kinases required either for nodule organogenesis, bacterial infection or both, and transcripts encoding GRAS and NF-Y transcription factors (TFs). Quantitative analysis of sRNAs in total and polysomal RNA samples revealed that mature microRNAs (miRNAs) were associated with the translational machinery, notably, miR169 and miR172, which target the NF-YA/HAP2 and AP2 TFs, respectively. Upon inoculation, levels of miR169 pronouncedly decreased in polysomal complexes, concomitant with the increased accumulation of the NF-YA/HAP2 protein. These results indicate that both mRNAs and miRNAs are subject to differential recruitment to polysomes, and expose the importance of selective mRNA translation during root nodule symbiosis.

  4. Biopanning of endotoxin-specific phage displayed peptides.

    PubMed

    Thomas, Celestine J; Sharma, Shilpi; Kumar, Gyanendra; Visweswariah, Sandhya S; Surolia, Avadhesha

    2003-07-18

    Systemic bacterial infections frequently lead to a plethora of symptoms termed "endotoxic shock" or "sepsis." Characterized by hypotension, coagulation abnormalities, and multiple organ failure, treatment of sepsis still remains mostly supportive. Of the various experimental therapeutic interventional strategies, neutralization of endotoxin by peptides or proteins is becoming popular recently. Hence, design of endotoxin binding peptides is gaining currency as their structural complexity and mode of recognition of endotoxin precludes mounting of resistance against them by the susceptible bacteria by genetic recombination, mutation, etc. Earlier work from our laboratory had shown that the amphiphilic cationic peptides are good ligands for endotoxin binding. In this study, we report the results of studies with the 12 selected lipid A binding phage displayed peptides by biopanning of a repertoire of a random pentadecapeptide library displayed on the filamentous M-13 phage. A comparison of the sequences revealed no consensus sequence between the 12 selected peptides suggesting that the lipid A binding motif is not sequence specific which is in accord with the sequence variation seen with the naturally occurring anti-microbial and/or endotoxin binding peptides. Thus, the flexibility of the peptides coupled with their plasticity in recognizing the lipid A moiety, explains their tight binding to endotoxin. At a structural level, asymmetric distribution of the charged polar residues on one face of the helix and non-polar residues on the opposite face appears to correlate with their activity.

  5. Selection and characterization of novel DNA aptamers specifically recognized by Singapore grouper iridovirus-infected fish cells.

    PubMed

    Li, Pengfei; Wei, Shina; Zhou, Lingli; Yang, Min; Yu, Yepin; Wei, Jingguang; Jiang, Guohua; Qin, Qiwei

    2015-11-01

    Singapore grouper iridovirus (SGIV) is a major viral pathogen of grouper aquaculture, and has caused heavy economic losses in China and South-east Asia. In this study, we generated four ssDNA aptamers against SGIV-infected grouper spleen (GS) cells using SELEX (systematic evolution of ligands by exponential enrichment) technology. Four aptamers exhibited high affinity to SGIV-infected GS cells, in particular the Q2 aptamer. Q2 had a binding affinity of 12.09 nM, the highest of the four aptamers. These aptamers also recognized SGIV-infected tissues with high levels of specificity. Protease treatment and flow cytometry analysis of SGIV-infected cells revealed that the target molecules of the Q3, Q4 and Q5 aptamers were trypsin-sensitive proteins, whilst the target molecules of Q2 might be membrane lipids or surface proteins that were not trypsin-sensitive. The generated aptamers appeared to inhibit SGIV infection in vitro. Aptamer Q2 conferred the highest levels of protection against SGIV and was able to inhibit SGIV infection in a dose-dependent manner. In addition, Q2 was efficiently internalized by SGIV-infected GS cells and localized at the viral assembly sites. Our results demonstrated that the four novel aptamers we generated were specific for SGIV-infected cells and could potentially be applied as rapid molecular diagnostic test reagents or therapeutic drugs targeting SGIV.

  6. Single layer multi-color luminescent display

    NASA Technical Reports Server (NTRS)

    Robertson, James B. (Inventor)

    1991-01-01

    The invention is a multi-color luminescent display comprising an insulator substrate and a single layer of host material which may be a phosphor deposited thereon that hosts one or more differential impurities, therein forming a pattern of selected and distinctly colored phosphors such as blue, green, and red phosphors in a single layer of host material. Transparent electrical conductor means may be provided for subjecting selected portions of the pattern of colored phosphors to an electric field thereby forming a multi-color, single layer electroluminescent display.

  7. Text File Display Program

    NASA Technical Reports Server (NTRS)

    Vavrus, J. L.

    1986-01-01

    LOOK program permits user to examine text file in pseudorandom access manner. Program provides user with way of rapidly examining contents of ASCII text file. LOOK opens text file for input only and accesses it in blockwise fashion. Handles text formatting and displays text lines on screen. User moves forward or backward in file by any number of lines or blocks. Provides ability to "scroll" text at various speeds in forward or backward directions.

  8. Attention-Seeking Displays

    PubMed Central

    Számadó, Szabolcs

    2015-01-01

    Animal communication abounds with extravagant displays. These signals are usually interpreted as costly signals of quality. However, there is another important function for these signals: to call the attention of the receiver to the signaller. While there is abundant empirical evidence to show the importance of this stage, it is not yet incorporated into standard signalling theory. Here I investigate a general model of signalling - based on a basic action-response game - that incorporates this searching stage. I show that giving attention-seeking displays and searching for them can be an ESS. This is a very general result and holds regardless whether only the high quality signallers or both high and low types give them. These signals need not be costly at the equilibrium and they need not be honest signals of any quality, as their function is not to signal quality but simply to call the attention of the potential receivers. These kind of displays are probably more common than their current weight in the literature would suggest. PMID:26287489

  9. Engine monitoring display study

    NASA Technical Reports Server (NTRS)

    Hornsby, Mary E.

    1992-01-01

    The current study is part of a larger NASA effort to develop displays for an engine-monitoring system to enable the crew to monitor engine parameter trends more effectively. The objective was to evaluate the operational utility of adding three types of information to the basic Boeing Engine Indicating and Crew Alerting System (EICAS) display formats: alphanumeric alerting messages for engine parameters whose values exceed caution or warning limits; alphanumeric messages to monitor engine parameters that deviate from expected values; and a graphic depiction of the range of expected values for current conditions. Ten training and line pilots each flew 15 simulated flight scenarios with five variants of the basic EICAS format; these variants included different combinations of the added information. The pilots detected engine problems more quickly when engine alerting messages were included in the display; adding a graphic depiction of the range of expected values did not affect detection speed. The pilots rated both types of alphanumeric messages (alert and monitor parameter) as more useful and easier to interpret than the graphic depiction. Integrating engine parameter messages into the EICAS alerting system appears to be both useful and preferred.

  10. Stage Cylindrical Immersive Display

    NASA Technical Reports Server (NTRS)

    Abramyan, Lucy; Norris, Jeffrey S.; Powell, Mark W.; Mittman, David S.; Shams, Khawaja S.

    2011-01-01

    Panoramic images with a wide field of view intend to provide a better understanding of an environment by placing objects of the environment on one seamless image. However, understanding the sizes and relative positions of the objects in a panorama is not intuitive and prone to errors because the field of view is unnatural to human perception. Scientists are often faced with the difficult task of interpreting the sizes and relative positions of objects in an environment when viewing an image of the environment on computer monitors or prints. A panorama can display an object that appears to be to the right of the viewer when it is, in fact, behind the viewer. This misinterpretation can be very costly, especially when the environment is remote and/or only accessible by unmanned vehicles. A 270 cylindrical display has been developed that surrounds the viewer with carefully calibrated panoramic imagery that correctly engages their natural kinesthetic senses and provides a more accurate awareness of the environment. The cylindrical immersive display offers a more natural window to the environment than a standard cubic CAVE (Cave Automatic Virtual Environment), and the geometry allows multiple collocated users to simultaneously view data and share important decision-making tasks. A CAVE is an immersive virtual reality environment that allows one or more users to absorb themselves in a virtual environment. A common CAVE setup is a room-sized cube where the cube sides act as projection planes. By nature, all cubic CAVEs face a problem with edge matching at edges and corners of the display. Modern immersive displays have found ways to minimize seams by creating very tight edges, and rely on the user to ignore the seam. One significant deficiency of flat-walled CAVEs is that the sense of orientation and perspective within the scene is broken across adjacent walls. On any single wall, parallel lines properly converge at their vanishing point as they should, and the sense of

  11. Successful selection of an infection-protective anti-Staphylococcus aureus monoclonal antibody and its protective activity in murine infection models.

    PubMed

    Ohsawa, Hiroyoshi; Baba, Tadashi; Enami, Jumpei; Hiramatsu, Keiichi

    2015-04-01

    Recent clinical trials to develop anti-methicillin-resistant Staphylococcus aureus (MRSA) therapeutic antibodies have met unsuccessful sequels. To develop more effective antibodies against MRSA infection, a panel of mAbs against S. aureus cell wall was generated and then screened for the most protective mAb in mouse infection models. Twenty-two anti-S. aureus IgG mAbs were obtained from mice that had been immunized with alkali-processed, deacetylated cell walls of S. aureus. One of these mAbs, ZBIA5H, exhibited life-saving effects in mouse models of sepsis caused by community-acquired MRSA strain MW2 and vancomycin-resistant S. aureus strain VRS1. It also had a curative effect in a MW2-caused pneumonia model. Curiously, the target of ZBIA5H was considered to be a conformational epitope of either the 1,4-β-linkage between N-acetylmuramic acid and N-acetyl-D-glucosamine or the peptidoglycan per se. Reactivity of ZBIA5H to S. aureus whole cells or purified peptidoglycan was weaker than that of most of the other mAbs generated in this study. However, the latter mAbs did not have the protective activities against S. aureus that ZBIA5H did. These data indicate that the epitopes that trigger production of high-yield and/or high-affinity antibodies may not be the most suitable epitopes for developing anti-infective antibodies. ZBIA5H or its humanized form may find a future clinical application, and its target epitope may be used for the production of vaccines against S. aureus infection.

  12. Relationship between Functional Profile of HIV-1 Specific CD8 T Cells and Epitope Variability with the Selection of Escape Mutants in Acute HIV-1 Infection

    PubMed Central

    Goonetilleke, Nilu; Liu, Michael K. P.; Turnbull, Emma L.; Salazar-Gonzalez, Jesus F.; Hawkins, Natalie; Self, Steve; Watson, Sydeaka; Betts, Michael R.; Gay, Cynthia; McGhee, Kara; Pellegrino, Pierre; Williams, Ian; Tomaras, Georgia D.; Haynes, Barton F.; Gray, Clive M.; Borrow, Persephone; Roederer, Mario; McMichael, Andrew J.; Weinhold, Kent J.

    2011-01-01

    In the present study, we analyzed the functional profile of CD8+ T-cell responses directed against autologous transmitted/founder HIV-1 isolates during acute and early infection, and examined whether multifunctionality is required for selection of virus escape mutations. Seven anti-retroviral therapy-naïve subjects were studied in detail between 1 and 87 weeks following onset of symptoms of acute HIV-1 infection. Synthetic peptides representing the autologous transmitted/founder HIV-1 sequences were used in multiparameter flow cytometry assays to determine the functionality of HIV-1-specific CD8+ T memory cells. In all seven patients, the earliest T cell responses were predominantly oligofunctional, although the relative contribution of multifunctional cell responses increased significantly with time from infection. Interestingly, only the magnitude of the total and not of the poly-functional T-cell responses was significantly associated with the selection of escape mutants. However, the high contribution of MIP-1β-producing CD8+ T-cells to the total response suggests that mechanisms not limited to cytotoxicity could be exerting immune pressure during acute infection. Lastly, we show that epitope entropy, reflecting the capacity of the epitope to tolerate mutational change and defined as the diversity of epitope sequences at the population level, was also correlated with rate of emergence of escape mutants. PMID:21347345

  13. Infection Rate by Trypanosoma cruzi and Biased Vertebrate Host Selection in the Triatoma dimidiata (Hemiptera: Reduvidae) Species Complex.

    PubMed

    Ramirez-Sierra, M J; Dumonteil, E

    2016-01-01

    Chagas disease is a vector-borne disease, caused by the protozoan parasite Trypanosoma cruzi and transmitted by hematophagous insects. Triatoma dimidiata (Hemiptera: Reduvidae (Latreille 1811)) is one of the main vectors, and recent molecular studies indicate that it is a species complex, with potentially different vectorial competences. We investigated the differences in natural T. cruzi infection rate within T. dimidiata complex in Yucatan, Mexico. ITS-2 hybrid bugs had a twofold higher infection rate than ITS-2 Groups 2 and 3 bugs, and this pattern was consistent over time and in several villages. To test if T. dimidiata ITS-2 hybrid bugs could feed more frequently on T. cruzi-infected hosts, we evaluated their host-seeking behavior in a dual-choice chamber. Group 2 and 3 bugs were equally attracted to T. cruzi-infected or uninfected mice. On the contrary, ITS-2 hybrid bugs reached three times more frequently the T. cruzi-infected mouse, compared to the uninfected one, indicating a significant bias toward an infected host. This behavior may explain in part their higher natural infection rate. Further studies should explore the complex and unique interactions among T. cruzi, triatomines vectors, and mammalian hosts, as this may led to new strategies to interfere with transmission cycles and improve Chagas disease control.

  14. No selection of CXCR4-using variants in cell reservoirs of dual-mixed HIV-infected patients on suppressive maraviroc therapy.

    PubMed

    Raymond, Stéphanie; Nicot, Florence; Carcenac, Romain; Jeanne, Nicolas; Cazabat, Michelle; Requena, Mary; Cuzin, Lise; Delobel, Pierre; Izopet, Jacques

    2016-03-27

    We used ultradeep sequencing to investigate the evolution of the frequency of CXCR4-using viruses in the peripheral blood mononuclear cells of 22 patients infected with both CCR5 and CXCR4-using viruses treated with the CCR5 antagonist maraviroc for 24 weeks and a stable antiviral therapy. The mean CXCR4-using virus frequency in peripheral blood mononuclear cells was 59% before maraviroc intensification and 52% after 24 weeks of effective treatment, indicating no selection by maraviroc. PMID:26752281

  15. Military market for flat panel displays

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    1997-07-01

    This paper addresses the number, function and size of primary military displays and establishes a basis to determine the opportunities for technology insertion in the immediate future and into the next millennium. The military displays market is specified by such parameters as active area and footprint size, and other characteristics such as luminance, gray scale, resolution, color capability and night vision imaging system capability. A select grouping of funded, future acquisitions, planned and predicted cockpit kits, and form-fit-function upgrades are taken into account. It is the intent of this paper to provide an overview of the DoD niche market, allowing both government and industry a timely reference to insure meeting DoD requirements for flat-panel displays on schedule and in a cost-effective manner. The aggregate DoD market for direct view displays is presently estimated to be in excess of 157,000. Helmet/head mounted displays will add substantially to this total. The vanishing vendor syndrome for older display technologies is becoming a growing, pervasive problem throughout DoD, which consequently just leverage the more modern display technologies being developed for civil-commercial markets.

  16. Phage display of engineered binding proteins.

    PubMed

    Levisson, Mark; Spruijt, Ruud B; Winkel, Ingrid Nolla; Kengen, Servé W M; van der Oost, John

    2014-01-01

    In current purification processes optimization of the capture step generally has a large impact on cost reduction. At present, valuable biomolecules are often produced in relatively low concentrations and, consequently, the eventual selective separation from complex mixtures can be rather inefficient. A separation technology based on a very selective high-affinity binding may overcome these problems. Proteins in their natural environment manifest functionality by interacting specifically and often with relatively high affinity with other molecules, such as substrates, inhibitors, activators, or other proteins. At present, antibodies are the most commonly used binding proteins in numerous applications. However, antibodies do have limitations, such as high production costs, low stability, and a complex patent landscape. A novel approach is therefore to use non-immunoglobulin engineered binding proteins in affinity purification. In order to obtain engineered binders with a desired specificity, a large mutant library of the new to-be-developed binding protein has to be created and screened for potential binders. A powerful technique to screen and select for proteins with desired properties from a large pool of variants is phage display. Here, we indicate several criteria for potential binding protein scaffolds and explain the principle of M13 phage display. In addition, we describe experimental protocols for the initial steps in setting up a M13 phage display system based on the pComb3X vector, including construction of the phagemid vector, production of phages displaying the protein of interest, and confirmation of display on the M13 phage.

  17. Can selection for resistance to OsHV-1 infection modify susceptibility to Vibrio aestuarianus infection in Crassostrea gigas? First insights from experimental challenges using primary and successive exposures.

    PubMed

    Azéma, Patrick; Travers, Marie-Agnès; De Lorgeril, Julien; Tourbiez, Delphine; Dégremont, Lionel

    2015-01-01

    Since 2008, the emergent virus OsHV-1µvar has provoked massive mortality events in Crassostrea gigas spat and juveniles in France. Since 2012, mortality driven by the pathogenic bacteria Vibrio aestuarianus has stricken market-sized adults. A hypothesis to explain the sudden increase in mortality observed in France since 2012 is that selective pressure due to recurrent viral infections could have led to a higher susceptibility of adults to Vibrio infection. In our study, two OsHV-1-resistant lines (AS and BS) and their respective controls (AC and BC) were experimentally challenged in the laboratory to determine their level of susceptibility to V. aestuarianus infection. At the juvenile stage, the selected lines exhibited lower mortality (14 and 33%) than the control lines (71 and 80%), suggesting dual-resistance to OsHV-1 and V. aestuarianus in C. gigas. Interestingly, this pattern was not observed at the adult stage, where higher mortality was detected for AS (68%) and BC (62%) than AC (39%) and BS (49%). These results were confirmed by the analysis of the expression of 31 immune-related genes in unchallenged oysters. Differential gene expression discriminated oysters according to their susceptibility to infection at both the juvenile and adult stages, suggesting that resistance to V. aestuarianus infection resulted in complex interactions between the genotype, stage of development and immunity status. Finally, survivors of the V. aestuarianus challenge at the juvenile stage still exhibited significant mortality at the adult stage during a second and third V. aestuarianus challenge, indicating that these survivors were not genetically resistant. PMID:26646058

  18. The Use of a Shelter Software (a) to Track Frequency and Selected Risk Factors for Feline Upper Respiratory Infection.

    PubMed

    Kommedal, Ann Therese; Wagner, Denae; Hurley, Kate

    2015-01-01

    Objective-Feline upper respiratory infection (URI) is a common, multi-factorial infectious disease syndrome endemic to many animal shelters. Although a significant cause of morbidity and mortality in shelter cats, URI is seldom formally monitored in shelter cat populations. Without monitoring, effective control and prevention of this often endemic disease is difficult. We looked at an integrated case management software system (a) for animal care organizations, widely used in shelters across the United States. Shelter staff routinely enter information regarding individual animals and disease status, but do not commonly use the software system to track frequency of disease. The purpose of this study was to determine if the software system (a) can be used to track URI frequency and selected risk factors in a population, and to evaluate the quality and completeness of the data as currently collected in a shelter. Design (type of study)-Descriptive Survey. Animals (or Sample)-317 cats in an animal shelter. Procedures-Reports from the software system (a) containing data regarding daily inventory, daily intake, animal identification, location, age, vaccination status, URI diagnosis and URI duration were evaluated. The reports were compared to data collected manually by an observer (Ann Therese Kommedal) to assess discrepancies, completeness, timeliness, availability and accuracy. Data were collected 6 days a week over a 4 week period. Results-Comparisons between the software system (a) reports and manually collected reports showed that 93% of inventory reports were complete and of these 99% were accurate. Fifty-two percent of the vaccination reports were complete, of which 97% were accurate. The accuracy of the software system's age reports was 76%. Two-hundred and twenty-three cats were assigned a positive or negative URI diagnosis by the observer. The predictive value of the URI status in the software system (a) was below 60% both for positive and negative URI

  19. Spatial, temporal, molecular, and intraspecific differences of haemoparasite infection and relevant selected physiological parameters of wild birds in Georgia, USA☆

    PubMed Central

    Astudillo, Viviana González; Hernández, Sonia M.; Kistler, Whitney M.; Boone, Shaun L.; Lipp, Erin K.; Shrestha, Sudip; Yabsley, Michael J.

    2013-01-01

    The prevalence of five avian haemoparasite groups was examined for effects on health and associations with extrinsic factors. Overall, 786 samples were examined from six sites in two Georgia (USA) watersheds, during breeding and non-breeding periods in 2010 and 2011. Among the four most commonly infected species, Haemoproteus prevalence was significantly higher in Northern Cardinals (Cardinalis cardinalis) compared to Indigo Buntings (Passerina cyanea) and Tufted Titmice (Baeolophus bicolor) while prevalence in White-throated Sparrows (Zonotrichia albicollis) was significantly higher than in Indigo Buntings. Higher prevalence of Plasmodium was noted in Tufted Titmice and Northern Cardinals. While Leucocytozoon prevalence was highest in White-throated Sparrows, Trypanosoma prevalence was highest in Tufted Titmice. Interesting differences in infection probabilities were noted between foraging guilds with Haemoproteus associated with low-middle level strata and birds in the middle-upper strata were more likely to be infected with Plasmodium and Trypanosoma. In contrast, ground-foraging birds were more likely to be infected with Leucocytozoon. Breeding season was correlated with higher polychromasia counts and higher prevalence of Haemoproteus, Plasmodium and Trypanosoma. In addition, prevalence of infection with certain haemoparasite genera and packed cell volume (PCV) were different among host species. Body mass index was inversely correlated with prevalence of microfilaria infection but positively related to Haemoproteus infection. However, we found no relationship between PCV or polychromasia levels with haemoparasite infection. Molecular characterization of 61 samples revealed 19 unique Haemoproteus (n = 7) and Plasmodium (n = 12) haplotypes with numerous new host records. No differences were noted in haplotype diversity among birds with different migratory behaviors or foraging heights, thus additional studies are needed that incorporate molecular analysis

  20. Acrobatic courtship display coevolves with brain size in manakins (Pipridae).

    PubMed

    Lindsay, Willow R; Houck, Justin T; Giuliano, Claire E; Day, Lainy B

    2015-01-01

    Acrobatic display behaviour is sexually selected in manakins (Pipridae) and can place high demands on many neural systems. Manakin displays vary across species in terms of behavioural complexity, differing in number of unique motor elements, production of mechanical sounds, cooperation between displaying males, and construction of the display site. Historically, research emphasis has been placed on neurological specializations for vocal aspects of courtship, and less is known about the control of physical, non-vocal displays. By examining brain evolution in relation to extreme acrobatic feats such as manakin displays, we can vastly expand our knowledge of how sexual selection acts on motor behaviour. We tested the hypothesis that sexual selection for complex motor displays has selected for larger brains across the Pipridae. We found that display complexity positively predicts relative brain weight (adjusted for body size) after controlling for phylogeny in 12 manakin species and a closely related flycatcher. This evidence suggests that brain size has evolved in response to sexual selection to facilitate aspects of display such as motor, sensorimotor, perceptual, and cognitive abilities. We show, for the first time, that sexual selection for acrobatic motor behaviour can drive brain size evolution in avian species and, in particular, a family of suboscine birds. PMID:25660714

  1. Landing Hazard Avoidance Display

    NASA Technical Reports Server (NTRS)

    Abernathy, Michael Franklin (Inventor); Hirsh, Robert L. (Inventor)

    2016-01-01

    Landing hazard avoidance displays can provide rapidly understood visual indications of where it is safe to land a vehicle and where it is unsafe to land a vehicle. Color coded maps can indicate zones in two dimensions relative to the vehicles position where it is safe to land. The map can be simply green (safe) and red (unsafe) areas with an indication of scale or can be a color coding of another map such as a surface map. The color coding can be determined in real time based on topological measurements and safety criteria to thereby adapt to dynamic, unknown, or partially known environments.

  2. Bucknell Automated Retrieval and Display System.

    ERIC Educational Resources Information Center

    Rivoire, Helena; Lozoski, Laurene

    This report describes the development and operation of BARDS, the Bucknell Automated Retrieval and Display System, an online bibliographic access system for a selected section of the collection at the Ellen Clarke Bertrand Library. This system was used by the Bucknell University community from June 1974 through January 1975; further development…

  3. Correlation between infectivity and disease associated prion protein in the nervous system and selected edible tissues of naturally affected scrapie sheep.

    PubMed

    Chianini, Francesca; Cosseddu, Gian Mario; Steele, Philip; Hamilton, Scott; Hawthorn, Jeremy; Síso, Sílvia; Pang, Yvonne; Finlayson, Jeanie; Eaton, Samantha L; Reid, Hugh W; Dagleish, Mark P; Di Bari, Michele Angelo; D'Agostino, Claudia; Agrimi, Umberto; Terry, Linda; Nonno, Romolo

    2015-01-01

    The transmissible spongiform encephalopathies (TSEs) or prion diseases are a group of fatal neurodegenerative disorders characterised by the accumulation of a pathological form of a host protein known as prion protein (PrP). The validation of abnormal PrP detection techniques is fundamental to allow the use of high-throughput laboratory based tests, avoiding the limitations of bioassays. We used scrapie, a prototype TSE, to examine the relationship between infectivity and laboratory based diagnostic tools. The data may help to optimise strategies to prevent exposure of humans to small ruminant TSE material via the food chain. Abnormal PrP distribution/accumulation was assessed by immunohistochemistry (IHC), Western blot (WB) and ELISA in samples from four animals. In addition, infectivity was detected using a sensitive bank vole bioassay with selected samples from two of the four sheep and protein misfolding cyclic amplification using bank vole brain as substrate (vPMCA) was also carried out in selected samples from one animal. Lymph nodes, oculomotor muscles, sciatic nerve and kidney were positive by IHC, WB and ELISA, although at levels 100-1000 fold lower than the brain, and contained detectable infectivity by bioassay. Tissues not infectious by bioassay were also negative by all laboratory tests including PMCA. Although discrepancies were observed in tissues with very low levels of abnormal PrP, there was an overall good correlation between IHC, WB, ELISA and bioassay results. Most importantly, there was a good correlation between the detection of abnormal PrP in tissues using laboratory tests and the levels of infectivity even when the titre was low. These findings provide useful information for risk modellers and represent a first step toward the validation of laboratory tests used to quantify prion infectivity, which would greatly aid TSE risk assessment policies.

  4. Latest development of display technologies

    NASA Astrophysics Data System (ADS)

    Gao, Hong-Yue; Yao, Qiu-Xiang; Liu, Pan; Zheng, Zhi-Qiang; Liu, Ji-Cheng; Zheng, Hua-Dong; Zeng, Chao; Yu, Ying-Jie; Sun, Tao; Zeng, Zhen-Xiang

    2016-09-01

    In this review we will focus on recent progress in the field of two-dimensional (2D) and three-dimensional (3D) display technologies. We present the current display materials and their applications, including organic light-emitting diodes (OLEDs), flexible OLEDs quantum dot light emitting diodes (QLEDs), active-matrix organic light emitting diodes (AMOLEDs), electronic paper (E-paper), curved displays, stereoscopic 3D displays, volumetric 3D displays, light field 3D displays, and holographic 3D displays. Conventional 2D display devices, such as liquid crystal devices (LCDs) often result in ambiguity in high-dimensional data images because of lacking true depth information. This review thus provides a detailed description of 3D display technologies.

  5. Multilineage polyclonal engraftment of Cal-1 gene-modified cells and in vivo selection after SHIV infection in a nonhuman primate model of AIDS

    PubMed Central

    Peterson, Christopher W.; Haworth, Kevin G.; Burke, Bryan P.; Polacino, Patricia; Norman, Krystin K.; Adair, Jennifer E.; Hu, Shiu-Lok; Bartlett, Jeffrey S.; Symonds, Geoff P.; Kiem, Hans-Peter

    2016-01-01

    We have focused on gene therapy approaches to induce functional cure/remission of HIV-1 infection. Here, we evaluated the safety and efficacy of the clinical grade anti-HIV lentiviral vector, Cal-1, in pigtailed macaques (Macaca nemestrina). Cal-1 animals exhibit robust levels of gene marking in myeloid and lymphoid lineages without measurable adverse events, suggesting that Cal-1 transduction and autologous transplantation of hematopoietic stem cells are safe, and lead to long-term, multilineage engraftment following myeloablative conditioning. Ex vivo, CD4+ cells from transplanted animals undergo positive selection in the presence of simian/human immunodeficiency virus (SHIV). In vivo, Cal-1 gene-marked cells are evident in the peripheral blood and in HIV-relevant tissue sites such as the gastrointestinal tract. Positive selection for gene-marked cells is observed in blood and tissues following SHIV challenge, leading to maintenance of peripheral blood CD4+ T-cell counts in a normal range. Analysis of Cal-1 lentivirus integration sites confirms polyclonal engraftment of gene-marked cells. Following infection, a polyclonal, SHIV-resistant clonal repertoire is established. These findings offer strong preclinical evidence for safety and efficacy of Cal-1, present a new method for tracking protected cells over the course of virus-mediated selective pressure in vivo, and reveal previously unobserved dynamics of virus-dependent T-cell selection. PMID:26958575

  6. Multilineage polyclonal engraftment of Cal-1 gene-modified cells and in vivo selection after SHIV infection in a nonhuman primate model of AIDS.

    PubMed

    Peterson, Christopher W; Haworth, Kevin G; Burke, Bryan P; Polacino, Patricia; Norman, Krystin K; Adair, Jennifer E; Hu, Shiu-Lok; Bartlett, Jeffrey S; Symonds, Geoff P; Kiem, Hans-Peter

    2016-01-01

    We have focused on gene therapy approaches to induce functional cure/remission of HIV-1 infection. Here, we evaluated the safety and efficacy of the clinical grade anti-HIV lentiviral vector, Cal-1, in pigtailed macaques (Macaca nemestrina). Cal-1 animals exhibit robust levels of gene marking in myeloid and lymphoid lineages without measurable adverse events, suggesting that Cal-1 transduction and autologous transplantation of hematopoietic stem cells are safe, and lead to long-term, multilineage engraftment following myeloablative conditioning. Ex vivo, CD4+ cells from transplanted animals undergo positive selection in the presence of simian/human immunodeficiency virus (SHIV). In vivo, Cal-1 gene-marked cells are evident in the peripheral blood and in HIV-relevant tissue sites such as the gastrointestinal tract. Positive selection for gene-marked cells is observed in blood and tissues following SHIV challenge, leading to maintenance of peripheral blood CD4+ T-cell counts in a normal range. Analysis of Cal-1 lentivirus integration sites confirms polyclonal engraftment of gene-marked cells. Following infection, a polyclonal, SHIV-resistant clonal repertoire is established. These findings offer strong preclinical evidence for safety and efficacy of Cal-1, present a new method for tracking protected cells over the course of virus-mediated selective pressure in vivo, and reveal previously unobserved dynamics of virus-dependent T-cell selection. PMID:26958575

  7. Reference gene selection for normalization of PCR analysis in chicken embryo fibroblast infected with H5N1 AIV.

    PubMed

    Yue, Hua; Lei, Xiao-wen; Yang, Fa-long; Li, Ming-yi; Tang, Cheng

    2010-12-01

    Chicken embryo fibroblasts (CEFs) are among the most commonly used cells for the study of interactions between chicken hosts and H5N1 avian influenza virus (AIV). In this study, the expression of eleven housekeeping genes typically used for the normalization of quantitative real-time PCR (QPCR) analysis in mammals were compared in CEFs infected with H5N1 AIV to determine the most reliable reference genes in this system. CEFs cultured from 10-day-old SPF chicken embryos were infected with 100 TCID(50) of H5N1 AIV and harvested at 3, 12, 24 and 30 hours post-infection. The expression levels of the eleven reference genes in infected and uninfected CEFs were determined by real-time PCR. Based on expression stability and expression levels, our data suggest that the ribosomal protein L4 (RPL4) and tyrosine 3-monooxygenase tryptophan 5-monooxygenase activation protein zeta polypeptide (YWHAZ) are the best reference genes to use in the study of host cell response to H5N1 AIV infection. However, for the study of replication levels of H5N1 AIV in CEFs, the β-actin gene (ACTB) and the ribosomal protein L4 (RPL4) gene are the best references.

  8. Chronic Periprosthetic Hip Joint Infection. A Retrospective, Observational Study on the Treatment Strategy and Prognosis in 130 Non-Selected Patients

    PubMed Central

    Troelsen, Anders; Søballe, Kjeld

    2016-01-01

    Introduction Limited information is available regarding the treatment strategy and prognosis of non-selected patients treated for chronic periprosthetic hip joint infection. Such information is important as no head-to-head studies on treatment strategies are available. The purpose of this study is to report on the treatment strategy and prognosis of a non-selected, consecutive patient population Methods We identified 130 patients in the National Patient Registry, consecutively treated for a chronic periprosthetic hip joint infection between 2003–2008 at 11 departments of orthopaedic surgery. We extracted information regarding patient demographics, treatment and outcome. 82 patients were re-implanted in a two-stage revision (national standard), the remaining 48 were not re-implanted in a two-stage revision. We were able to collect up-to-date information on all patients to date of death or medical chart review with a minimum of 5 years follow-up by the nationwide electronic patient record system Results After primary revision surgery, 53 patients (41%) had a spacer in situ, 64 (50%) had a resection arthroplasty and 13 (9%) did not have the infected implant removed. 63% were re-implanted in a two-stage revision. Re-implantation was performed after an interim period of 14 weeks (IQR 10–18). Patients re-implanted were younger (p-value 0.0006), had a lower CCS score (p-value 0.005), a lower ASA score (p-value 0.0001) and a 68% lower mortality risk in the follow-up period (p-value <0.00001). After adjusting for selected confounders, the mortality risk was no longer significantly different. The 5-year re-infection rate after re-implantation was 14.6% (95%CI 8.0–23.1). Re-infections occurred mainly within 3 years of follow-up. The overall 1-year survival rate was 92% (95%CI 86–96) and the overall 5-year survival rate was 68% (95%CI 59–75). The 5-year survival rate after a two-stage revision was 82% (95%CI 71–89) and in those not re-implanted 45% (95%CI 30–58

  9. Methods and apparatus for transparent display using scattering nanoparticles

    DOEpatents

    Hsu, Chia Wei; Qiu, Wenjun; Zhen, Bo; Shapira, Ofer; Soljacic, Marin

    2016-05-10

    Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

  10. Selected Pool of Peptides from ESAT-6 and CFP-10 Proteins for Detection of Mycobacterium tuberculosis Infection

    PubMed Central

    Scarpellini, Paolo; Tasca, Silvana; Galli, Laura; Beretta, Alberto; Lazzarin, Adriano; Fortis, Claudio

    2004-01-01

    We have validated a new test for detecting Mycobacterium tuberculosis infection. A pool of synthetic peptides derived from ESAT-6 and CFP-10 proteins was used to detect the number of specific gamma interferon-producing T cells by means of an enzyme-linked immunospot assay. Sixty-eight individuals positive for M. tuberculosis infection, either human immunodeficiency virus-seropositive or -seronegative, were studied. The test results were highly specific (87.5%) and sensitive (93.1%), more so than a classical lymphoproliferative assay (specificity and sensitivity of 77.27%), opening new possibilities for diagnosis and screening of tuberculosis. Moreover, the test allowed us to distinguish individuals infected with M. tuberculosis from those vaccinated with BCG. PMID:15297485

  11. Black optic display

    DOEpatents

    Veligdan, James T.

    1997-01-01

    An optical display includes a plurality of stacked optical waveguides having first and second opposite ends collectively defining an image input face and an image screen, respectively, with the screen being oblique to the input face. Each of the waveguides includes a transparent core bound by a cladding layer having a lower index of refraction for effecting internal reflection of image light transmitted into the input face to project an image on the screen, with each of the cladding layers including a cladding cap integrally joined thereto at the waveguide second ends. Each of the cores is beveled at the waveguide second end so that the cladding cap is viewable through the transparent core. Each of the cladding caps is black for absorbing external ambient light incident upon the screen for improving contrast of the image projected internally on the screen.

  12. Flat-panel display solutions for ground-environment military displays (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Thomas, J., II; Roach, R.

    2005-05-01

    Displays for military vehicles have very distinct operational and cost requirements that differ from other military applications. These requirements demand that display suppliers to Army and Marine ground-environments provide low cost equipment that is capable of operation across environmental extremes. Inevitably, COTS components form the foundation of these "affordable" display solutions. This paper will outline the major display requirements and review the options that satisfy conflicting and difficult operational demands, using newly developed equipment as an example. Recently, a new supplier was selected for the Drivers Vision Enhancer (DVE) equipment, including the Display Control Module (DCM). The paper will outline the DVE and describe development of a new DCM solution. The DVE programme, with several thousand units presently in service and operational in conflicts such as "Operation Iraqi Freedom", represents a critical balance between cost and performance. We shall describe design considerations that include selection of COTS sources, the need to minimise display modification; video interfaces, power interfaces, operator interfaces and new provisions to optimise displayed video content.

  13. An Investigation of Interval Management Displays

    NASA Technical Reports Server (NTRS)

    Swieringa, Kurt A.; Wilson, Sara R.; Shay, Rick

    2015-01-01

    NASA's first Air Traffic Management (ATM) Technology Demonstration (ATD-1) was created to transition the most mature ATM technologies from the laboratory to the National Airspace System. One selected technology is Interval Management (IM), which uses onboard aircraft automation to compute speeds that help the flight crew achieve and maintain precise spacing behind a preceding aircraft. Since ATD-1 focuses on a near-term environment, the ATD-1 flight demonstration prototype requires radio voice communication to issue an IM clearance. Retrofit IM displays will enable pilots to both enter information into the IM avionics and monitor IM operation. These displays could consist of an interface to enter data from an IM clearance and also an auxiliary display that presents critical information in the primary field-of-view. A human-in-the-loop experiment was conducted to examine usability and acceptability of retrofit IM displays, which flight crews found acceptable. Results also indicate the need for salient alerting when new speeds are generated and the desire to have a primary field of view display available that can display text and graphic trend indicators.

  14. Growth, nutrient absorption, and moisture status of selected woody species in coal mine spoil in response to an induced infection by the ectomycorrhizal fungus Pisolithus tinctorius

    SciTech Connect

    Walker, R.F.

    1982-01-01

    The growth, nutrient absorption, and internal moisture status of selected woody species in coal mine spoil in response to an induced infection by the ectomycorrhizal fungus Pisolithus tinctorius was studied. Nursery grown loblolly and Virginia pine seedlings infected with Pisolithus and control seedlings were outplanted on a coal mine spoil in Tennessee which had been previously hydroseeded with a mixture of herbaceous ground cover species. Granular fertilizer was applied by broadcasting to one-half of the seedlings of each ectomycorrhizal treatment at the rate of 112 kg/ha NPK. After three years, the survival and growth of loblolly pine infected with Pisolithus was superior to that of the control seedlings, and chemical analyses of foliar samples revealed that the seedlings with Pisolithus ectomycorrhizae had a higher foliar concentration of NO/sub 3/ and a lower concentration of Zn than the control seedlings. The survival, growth, and nutrient absorption of Virginia pine were not significantly affected by the infection with Pisolithus after two years, but both loblolly and Virginia pine seedlings with Pisolithus ectomycorrhizae exhibited an enhanced ability to absorb water during periods of high moisture stress, as determined by the pressure chamber technique. Fertilization substantially reduced the survival of the seedlings of both species.

  15. Design and use of an interactive simulation display generator

    SciTech Connect

    Patterson, D.R.; Rhodes, J.J.

    1983-03-31

    As part of a continuing applied research effort into interactive graphics utilization, we have developed an interactive Simulation Display Generator (SDG). This SDG operates in response to menu selections chosen via a graphics tablet and textual information entered using a keyboard. It has the capability to create, display, modify, store, and retrieve either a complete display or individual components of a display which can later be used by a variety of simulation models. This paper discusses the development of the requirement for the SDG as well as the decisions and tradeoffs that went into the design and implementation. Its use in creating displays for a typical simulation is illustrated.

  16. Simultaneous EKG and ultrasonoscope display

    NASA Technical Reports Server (NTRS)

    Lee, R. D.

    1977-01-01

    Display of two dimensional image of heart and EKG waveform concurrently on same cathode-ray, is achieved by device. Concurrent display allows continuous comparision of dimensional changes in heart and periodicity of EKG waveform.

  17. Human factors of visual displays

    NASA Technical Reports Server (NTRS)

    Snyder, H. L.

    1984-01-01

    Several human factors issues in visual displays are addressed in this report. They are as follows: (1) the importance of luminance range and contrast; (2) uniformity of visual displays; (3) image quality; (4) color contrast; and (5) dot matrix fonts.

  18. Human C4b-binding protein selectively interacts with Neisseria gonorrhoeae and results in species-specific infection.

    PubMed

    Ngampasutadol, Jutamas; Ram, Sanjay; Blom, Anna M; Jarva, Hanna; Jerse, Ann E; Lien, Egil; Goguen, Jon; Gulati, Sunita; Rice, Peter A

    2005-11-22

    Neisseria gonorrhoeae is the causative agent of gonorrhea, a disease that is restricted to humans. Complement forms a key arm of the innate immune system that combats gonococcal infections. N. gonorrhoeae uses its outer membrane porin (Por) molecules to bind the classical pathway of complement down-regulatory protein C4b-binding protein (C4bp) to evade killing by human complement. Strains of N. gonorrhoeae that resisted killing by human serum complement were killed by serum from rodent, lagomorph, and primate species, which cannot be readily infected experimentally with this organism and whose C4bp molecules did not bind to N. gonorrhoeae. In contrast, we found that Yersinia pestis, an organism that can infect virtually all mammals, bound species-specific C4bp and uniformly resisted serum complement-mediated killing by these species. Serum resistance of gonococci was restored in these sera by human C4bp. An exception was serotype Por1B-bearing gonococcal strains that previously had been used successfully in a chimpanzee model of gonorrhea that simulates human disease. Por1B gonococci bound chimpanzee C4bp and resisted killing by chimpanzee serum, providing insight into the host restriction of gonorrhea and addressing why Por1B strains, but not Por1A strains, have been successful in experimental chimpanzee infection. Our findings may lead to the development of better animal models for gonorrhea and may also have implications in the choice of complement sources to evaluate neisserial vaccine candidates.

  19. HIV-1--Infected T Cells Show a Selective Signaling Defect after Perturbation of CD3/Antigen Receptor

    NASA Astrophysics Data System (ADS)

    Linette, Gerald P.; Hartzman, Robert J.; Ledbetter, Jeffrey A.; June, Carl H.

    1988-07-01

    The binding of antigen or monoclonal antibody to the T cell receptor for antigen or the closely associated CD3 complex causes increases in the concentration of intracellular ionized calcium and subsequent cell proliferation. By measuring second messenger production in primary cultures of human immunodeficiency virus (HIV-1)--infected T cells stimulated with monoclonal antibodies specific for either CD3 or CD2, a specific impairment of membrane signaling was revealed. The HIV-1--infected T cells were unable to mobilize Ca2+ after stimulation with anti-CD3, whereas CD2-induced calcium mobilization remained intact. Furthermore, the HIV-1--infected cells proliferated poorly after CD3 stimulation, although the cells retained normal DNA synthesis in response to interleukin-2 stimulation. These results show that the signals initiated by CD2 and CD3 can be regulated independently within the same T cell; uncoupling of signal transduction after antigen-specific stimulation provides a biochemical mechanism to explain, in part, the profound immunodeficiency of patients with HIV-1 infection.

  20. Developing Intepretive Soil Education Displays.

    ERIC Educational Resources Information Center

    Hansmeyer, T. L.; Cooper, T. H.

    1993-01-01

    Describes several soil educational displays developed for park and nature center trails. Displays include full-scale soil monoliths displayed along the trails with explanations on why and how the soils are different, and micro-monoliths exhibiting the different soil types. (MDH)

  1. Selection of reference genes from two leafhopper species challenged by phytoplasma infection, for gene expression studies by RT-qPCR

    PubMed Central

    2013-01-01

    Background Phytoplasmas are phloem-limited phytopathogenic wall-less bacteria and represent a major threat to agriculture worldwide. They are transmitted in a persistent, propagative manner by phloem-sucking Hemipteran insects. For gene expression studies based on mRNA quantification by RT-qPCR, stability of housekeeping genes is crucial. The aim of this study was the identification of reference genes to study the effect of phytoplasma infection on gene expression of two leafhopper vector species. The identified reference genes will be useful tools to investigate differential gene expression of leafhopper vectors upon phytoplasma infection. Results The expression profiles of ribosomal 18S, actin, ATP synthase β, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and tropomyosin were determined in two leafhopper vector species (Hemiptera: Cicadellidae), both healthy and infected by “Candidatus Phytoplasma asteris” (chrysanthemum yellows phytoplasma strain, CYP). Insects were analyzed at three different times post acquisition, and expression stabilities of the selected genes were evaluated with BestKeeper, geNorm and Normfinder algorithms. In Euscelidius variegatus, all genes under all treatments were stable and could serve as reference genes. In Macrosteles quadripunctulatus, BestKeeper and Normfinder analysis indicated ATP synthase β, tropomyosin and GAPDH as the most stable, whereas geNorm identified reliable genes only for early stages of infection. Conclusions In this study a validation of five candidate reference genes was performed with three algorithms, and housekeeping genes were identified for over time transcript profiling of two leafhopper vector species infected by CYP. This work set up an experimental system to study the molecular basis of phytoplasma multiplication in the insect body, in order to elucidate mechanisms of vector specificity. Most of the sequences provided in this study are new for leafhoppers, which are vectors of economically

  2. Genetic analysis of in vivo-selected viral variants causing chronic infection: importance of mutation in the L RNA segment of lymphocytic choriomeningitis virus.

    PubMed Central

    Ahmed, R; Simon, R S; Matloubian, M; Kolhekar, S R; Southern, P J; Freedman, D M

    1988-01-01

    Viral variants with different biological properties are present in the central nervous systems (CNS) and lymphoid tissues of mice persistently infected with lymphocytic choriomeningitis virus (LCMV). Viral isolates from the CNS are similar to the original Armstrong LCMV strain and induce potent virus-specific T-cell responses in adult mice, and the infection is rapidly cleared. In contrast, LCMV isolates derived from spleens of carrier mice cause persistent infections in adult mice. This chronic infection is associated with low levels of antiviral T-cell responses. In this study, we genetically characterized two independently derived spleen variants by making recombinants (reassortants) between the spleen isolates and wild-type (wt) LCMV and showed that the ability to persist in adult mice and the associated suppression of T-cell responses segregates with the large (L) RNA segment. In addition, we analyzed a revertant (isolated from the CNS) derived from one of the spleen variants. By comparing the biological properties of three reassortants that contained the same S segment but had the L segment of either the original wt Armstrong LCMV, the spleen variant derived from it, or the CNS revertant derived from the spleen variant, we were able to show unequivocally that biologically relevant mutations occurred in the L segment not only during generation of the spleen variant from wt LCMV but also in reversion of the spleen variant to the wt phenotype. Thus, our results showed that (i) genetic alterations in the L genomic segment were involved in organ-specific selection of viral variants, and (ii) these mutations profoundly affected the ability of LCMV to cause chronic infections in adult mice. Images PMID:3261347

  3. Corruption of phage display libraries by target-unrelated clones: diagnosis and countermeasures.

    PubMed

    Thomas, William D; Golomb, Miriam; Smith, George P

    2010-12-15

    Phage display is used to discover peptides or proteins with a desired target property-most often, affinity for a target selector molecule. Libraries of phage clones displaying diverse surface peptides are subject to a selection process designed to enrich for the target behavior and subsequently propagated to restore phage numbers. A recurrent problem is enrichment of clones, called target-unrelated phages or peptides (TUPs), that lack the target behavior. Many TUPs are propagation related; they have mutations conferring a growth advantage and are enriched during the propagations accompanying selection. Unlike other filamentous phage libraries, fd-tet-based libraries are relatively resistant to propagation-related TUP corruption. Their minus-strand origin is disrupted by a large cassette that simultaneously confers resistance to tetracycline and imposes a rate-limiting growth defect that cannot be bypassed with simple mutations. Nonetheless, a new type of propagation-related TUP emerged in the output of in vivo selections from an fd-tet library. The founding clone had a complex rearrangement that restored the minus-strand origin while retaining tetracycline resistance. The rearrangement involved two recombination events, one with a contaminant having a wild-type minus-strand origin. The founder's infectivity advantage spread by simple recombination to clones displaying different peptides. We propose measures for minimizing TUP corruption.

  4. Respiratory syncytial virus a and b display different temporal patterns in a 4-year prospective cross-sectional study among children with acute respiratory infection in a tropical city

    PubMed Central

    Bouzas, Maiara L.; Oliveira, Juliana R.; Fukutani, Kiyoshi F.; Borges, Igor C.; Barral, Aldina; Van der Gucht, Winke; Wollants, Elke; Van Ranst, Marc; de Oliveira, Camila I.; Van Weyenbergh, Johan; Nascimento-Carvalho, Cristiana M.

    2016-01-01

    Abstract Respiratory syncytial virus (RSV) is one of the most common etiological agents of childhood respiratory infections globally. Information on seasonality of different antigenic groups is scarce. We aimed to describe the frequency, seasonality, and age of children infected by RSV antigenic groups A (RSVA) and B (RSVB) among children with ARI in a 4-year period. Children (6–23 months old) with respiratory infection for ≤7 days were enrolled in a prospective cross-sectional study, from September, 2009 to October, 2013, in Salvador, in a tropical region of Brazil. Upon recruitment, demographic, clinical data, and nasopharyngeal aspirates (NPA) were collected. A multiplex quantitative real-time polymerase chain reaction (RT-PCR) with a group-specific primer and probeset for RSVA and RSVB was used. Seasonal distribution of infection by RSV different antigenic groups was evaluated by Prais-Wisten regression. Of 560 cases, the mean age was 11.4 ± 4.5 months and there were 287 (51.3%) girls. Overall, RSV was detected in 139 (24.8%; 95% CI: 21.4%–28.5%) cases, RSVA in 74 (13.2%; 95% CI: 10.6%–16.2%) cases, and RSVB in 67 (12.0%; 95% CI: 9.5%–14.9%) cases. Two (0.4%; 95% CI: 0.06%–1.2%) cases had coinfection. RSVA frequency was 9.6%, 18.4%, 21.6%, and 3.1% in 2010, 2011, 2012, and 2013, respectively. RSVB frequency was 19.2%, 0.7%, 1.4%, and 35.4% in the same years. RSVA was more frequently found from August to January than February to July (18.2% vs. 6.4%, P < 0.001). RSVB was more frequently found (P < 0.001) between March and June (36.0%) than July to October (1.0%) or November to February (1.6%). RSVB infection showed seasonal distribution and positive association with humidity (P = 0.02) whereas RSVA did not. RSVA was more common among children ≥1-year-old (17.8% vs. 1.8%; P = 0.02), as opposed to RSVB (11.5% vs. 12.2%; P = 0.8). One quarter of patients had RSV infection. RSVA compromised more frequently children aged ≥1 year. RSVA

  5. [Selected immune response parameters in respiratory tract infections in mice--effect of combined treatment with tienamycin and coparvax].

    PubMed

    Korczak, E; Ciebiada, I; Denys, A

    1996-01-01

    The combined model of viral/bacterial infections has been used in the study. Tienamycin and Coparvax have been administered to infected mice. During the time of 3, 6, 9 and 14 days the hemagglutination inhibition reactions, migration inhibition of leukocytes, phagocytic activity and killing effect of the peritoneal exudate granulocytes have been made. The analysis of migration inhibition of leukocytes gave a statistically characteristic answer after using antigen of anatoxin compared to influenza antigen. In the group of animals which were treated with tienamycin and Coparvax a higher percentage of migration inhibition was observed than in the other group are substantial in the reaction of phagocytosis. Generally, a more beneficial influence of the combined treatment with tienamycin and coparvax has been observed. PMID:8924882

  6. LED instrument approach instruction display

    NASA Technical Reports Server (NTRS)

    Meredith, B. D.; Kelly, W. L., IV; Crouch, R. K.

    1979-01-01

    A display employing light emitting diodes (LED's) was developed to demonstrate the feasibility of such displays for presenting landing and navigation information to reduce the workload of general aviation pilots during IFR flight. The display consists of a paper tape reader, digital memory, control electronics, digital latches, and LED alphanumeric displays. A presentable digital countdown clock-timer is included as part of the system to provide a convenient means of monitoring time intervals for precise flight navigation. The system is a limited capability prototype assembled to test pilot reaction to such a device under simulated IFR operation. Pilot opinion indicates that the display is helpful in reducing the IFR pilots workload when used with a runway approach plate. However, the development of a compact, low power second generation display was recommended which could present several instructions simultaneously and provide information update capability. A microprocessor-based display could fulfill these requirements.

  7. Unique interactive projection display screen

    SciTech Connect

    Veligdan, J.T.

    1997-11-01

    Projection systems continue to be the best method to produce large (1 meter and larger) displays. However, in order to produce a large display, considerable volume is typically required. The Polyplanar Optic Display (POD) is a novel type of projection display screen, which for the first time, makes it possible to produce a large projection system that is self-contained and only inches thick. In addition, this display screen is matte black in appearance allowing it to be used in high ambient light conditions. This screen is also interactive and can be remotely controlled via an infrared optical pointer resulting in mouse-like control of the display. Furthermore, this display need not be flat since it can be made curved to wrap around a viewer as well as being flexible.

  8. Selective elimination of HIV-1-infected cells by Env-directed, HIV-1-based virus-like particles

    SciTech Connect

    Peretti, Silvia; Schiavoni, Ilaria; Pugliese, Katherina; Federico, Maurizio . E-mail: federico@iss.it

    2006-02-05

    We recently showed that both replicating and resting cells cultivated with ganciclovir (GCV) were killed when challenged with vesicular stomatitis virus G glycoprotein pseudotyped HIV-1-based virus-like particles (VLPs) carrying the Nef7 (i.e., an HIV-1 Nef mutant incorporating in virions at high levels)/herpes simplex virus-1 thymidine kinase (HSV-TK) fusion product. On this basis, a novel anti-HIV therapeutic approach based on Nef7/TK VLPs expressing X4 or R5 HIV cell receptor complexes has been attempted. We here report that (CD4-CXCR4) and (CD4-CCR5) Nef7-based VLPs efficiently enter cells infected by X4- or R5-tropic HIV-1 strains, respectively. Importantly, the delivery of the VLP-associated Nef7/TK led to cell death upon GCV treatment. Of interest, VLPs were effective also against non-replicating, HIV-1-infected primary human monocyte-derived macrophages. HIV-targeted VLPs represent a promising candidate for the treatment of persistently HIV-1-infected cells that are part of virus reservoirs resistant to HAART therapies.

  9. Pattern of Bacterial Pathogens and Their Susceptibility Isolated from Surgical Site Infections at Selected Referral Hospitals, Addis Ababa, Ethiopia

    PubMed Central

    Mulugeta, Gebru; Fentaw, Surafael; Mihret, Amete; Hassen, Mulu; Abebe, Engida

    2016-01-01

    Background. The emergence of multidrug resistant bacterial pathogens in hospitals is becoming a challenge for surgeons to treat hospital acquired infections. Objective. To determine bacterial pathogens and drug susceptibility isolated from surgical site infections at St. Paul Specialized Hospital Millennium Medical College and Yekatit 12 Referral Hospital Medical College, Addis Ababa, Ethiopia. Methods. A cross-sectional study was conducted between October 2013 and March 2014 on 107 surgical site infected patients. Wound specimens were collected using sterile cotton swab and processed as per standard operative procedures in appropriate culture media; and susceptibility testing was done using Kirby-Bauer disc diffusion technique. The data were analyzed by using SPSS version 20. Result. From a total of 107 swabs collected, 90 (84.1%) were culture positive and 104 organisms were isolated. E. coli (24 (23.1%)) was the most common organism isolated followed by multidrug resistant Acinetobacter species (23 (22.1%)). More than 58 (75%) of the Gram negative isolates showed multiple antibiotic resistance (resistance ≥ 5 drugs). Pan-antibiotic resistance was noted among 8 (34.8%) Acinetobacter species and 3 (12.5%) E. coli. This calls for abstinence from antibiotic abuse. Conclusion. Gram negative bacteria were the most important isolates accounting for 76 (73.1%). Ampicillin, amoxicillin, penicillin, cephazoline, and tetracycline showed resistance while gentamicin and ciprofloxacin were relatively effective antimicrobials. PMID:27446213

  10. Can Effective Synthetic Vision System Displays be Implemented on Limited Size Display Spaces?

    NASA Technical Reports Server (NTRS)

    Comstock, J. Raymond, Jr.; Glaab, Lou J.; Prinzel, Lance J.; Elliott, Dawn M.

    2004-01-01

    The Synthetic Vision Systems (SVS) element of the NASA Aviation Safety Program is striving to eliminate poor visibility as a causal factor in aircraft accidents, and to enhance operational capabilities of all types or aircraft. To accomplish these safety and situation awareness improvements, the SVS concepts are designed to provide a clear view of the world ahead through the display of computer generated imagery derived from an onboard database of terrain, obstacle and airport information. An important issue for the SVS concept is whether useful and effective Synthetic Vision System (SVS) displays can be implemented on limited size display spaces as would be required to implement this technology on older aircraft with physically smaller instrument spaces. In this study, prototype SVS displays were put on the following display sizes: (a) size "A' (e.g. 757 EADI), (b) form factor "D" (e.g. 777 PFD), and (c) new size "X" (Rectangular flat-panel, approximately 20 x 25 cm). Testing was conducted in a high-resolution graphics simulation facility at NASA Langley Research Center. Specific issues under test included the display size as noted above, the field-of-view (FOV) to be shown on the display and directly related to FOV is the degree of minification of the displayed image or picture. Using simulated approaches with display size and FOV conditions held constant no significant differences by these factors were found. Preferred FOV based on performance was determined by using approaches during which pilots could select FOV. Mean preference ratings for FOV were in the following order: (1) 30 deg., (2) Unity, (3) 60 deg., and (4) 90 deg., and held true for all display sizes tested. Limitations of the present study and future research directions are discussed.

  11. Signal Processing, Analysis, & Display

    1986-06-01

    SIG is a general-purpose signal processing, analysis, and display program. Its main purpose is to perform manipulations on time- and frequency-domain signals. However, it has been designed to ultimately accommodate other representations for data such as multiplexed signals and complex matrices. Two user interfaces are provided in SIG - a menu mode for the unfamiliar user and a command mode for more experienced users. In both modes errors are detected as early as possible andmore » are indicated by friendly, meaningful messages. An on-line HELP package is also included. A variety of operations can be performed on time- and frequency-domain signals including operations on the samples of a signal, operations on the entire signal, and operations on two or more signals. Signal processing operations that can be performed are digital filtering (median, Bessel, Butterworth, and Chebychev), ensemble average, resample, auto and cross spectral density, transfer function and impulse response, trend removal, convolution, Fourier transform and inverse window functions (Hamming, Kaiser-Bessel), simulation (ramp, sine, pulsetrain, random), and read/write signals. User definable signal processing algorithms are also featured. SIG has many options including multiple commands per line, command files with arguments,commenting lines, defining commands, and automatic execution for each item in a repeat sequence. Graphical operations on signals and spectra include: x-y plots of time signals; real, imaginary, magnitude, and phase plots of spectra; scaling of spectra for continuous or discrete domain; cursor zoom; families of curves; and multiple viewports.« less

  12. Multifocal planes head-mounted displays.

    PubMed

    Rolland, J P; Krueger, M W; Goon, A

    2000-07-01

    Stereoscopic head-mounted displays (HMD's) provide an effective capability to create dynamic virtual environments. For a user of such environments, virtual objects would be displayed ideally at the appropriate distances, and natural concordant accommodation and convergence would be provided. Under such image display conditions, the user perceives these objects as if they were objects in a real environment. Current HMD technology requires convergent eye movements. However, it is currently limited by fixed visual accommodation, which is inconsistent with real-world vision. A prototype multiplanar volumetric projection display based on a stack of laminated planes was built for medical visualization as discussed in a paper presented at a 1999 Advanced Research Projects Agency workshop (Sullivan, Advanced Research Projects Agency, Arlington, Va., 1999). We show how such technology can be engineered to create a set of virtual planes appropriately configured in visual space to suppress conflicts of convergence and accommodation in HMD's. Although some scanning mechanism could be employed to create a set of desirable planes from a two-dimensional conventional display, multiplanar technology accomplishes such function with no moving parts. Based on optical principles and human vision, we present a comprehensive investigation of the engineering specification of multiplanar technology for integration in HMD's. Using selected human visual acuity and stereoacuity criteria, we show that the display requires at most 27 equally spaced planes, which is within the capability of current research and development display devices, located within a maximal 26-mm-wide stack. We further show that the necessary in-plane resolution is of the order of 5 microm.

  13. Selection pressure in CD8⁺ T-cell epitopes in the pol gene of HIV-1 infected individuals in Colombia. A bioinformatic approach.

    PubMed

    Acevedo-Sáenz, Liliana; Ochoa, Rodrigo; Rugeles, Maria Teresa; Olaya-García, Patricia; Velilla-Hernández, Paula Andrea; Diaz, Francisco J

    2015-03-20

    One of the main characteristics of the human immunodeficiency virus is its genetic variability and rapid adaptation to changing environmental conditions. This variability, resulting from the lack of proofreading activity of the viral reverse transcriptase, generates mutations that could be fixed either by random genetic drift or by positive selection. Among the forces driving positive selection are antiretroviral therapy and CD8+ T-cells, the most important immune mechanism involved in viral control. Here, we describe mutations induced by these selective forces acting on the pol gene of HIV in a group of infected individuals. We used Maximum Likelihood analyses of the ratio of non-synonymous to synonymous mutations per site (dN/dS) to study the extent of positive selection in the protease and the reverse transcriptase, using 614 viral sequences from Colombian patients. We also performed computational approaches, docking and algorithmic analyses, to assess whether the positively selected mutations affected binding to the HLA molecules. We found 19 positively-selected codons in drug resistance-associated sites and 22 located within CD8+ T-cell epitopes. A high percentage of mutations in these epitopes has not been previously reported. According to the docking analyses only one of those mutations affected HLA binding. However, algorithmic methods predicted a decrease in the affinity for the HLA molecule in seven mutated peptides. The bioinformatics strategies described here are useful to identify putative positively selected mutations associated with immune escape but should be complemented with an experimental approach to define the impact of these mutations on the functional profile of the CD8+ T-cells.

  14. Selection Pressure in CD8+ T-cell Epitopes in the pol Gene of HIV-1 Infected Individuals in Colombia. A Bioinformatic Approach

    PubMed Central

    Acevedo-Sáenz, Liliana; Ochoa, Rodrigo; Rugeles, Maria Teresa; Olaya-García, Patricia; Velilla-Hernández, Paula Andrea; Diaz, Francisco J.

    2015-01-01

    One of the main characteristics of the human immunodeficiency virus is its genetic variability and rapid adaptation to changing environmental conditions. This variability, resulting from the lack of proofreading activity of the viral reverse transcriptase, generates mutations that could be fixed either by random genetic drift or by positive selection. Among the forces driving positive selection are antiretroviral therapy and CD8+ T-cells, the most important immune mechanism involved in viral control. Here, we describe mutations induced by these selective forces acting on the pol gene of HIV in a group of infected individuals. We used Maximum Likelihood analyses of the ratio of non-synonymous to synonymous mutations per site (dN/dS) to study the extent of positive selection in the protease and the reverse transcriptase, using 614 viral sequences from Colombian patients. We also performed computational approaches, docking and algorithmic analyses, to assess whether the positively selected mutations affected binding to the HLA molecules. We found 19 positively-selected codons in drug resistance-associated sites and 22 located within CD8+ T-cell epitopes. A high percentage of mutations in these epitopes has not been previously reported. According to the docking analyses only one of those mutations affected HLA binding. However, algorithmic methods predicted a decrease in the affinity for the HLA molecule in seven mutated peptides. The bioinformatics strategies described here are useful to identify putative positively selected mutations associated with immune escape but should be complemented with an experimental approach to define the impact of these mutations on the functional profile of the CD8+ T-cells. PMID:25803098

  15. Augmenting digital displays with computation

    NASA Astrophysics Data System (ADS)

    Liu, Jing

    As we inevitably step deeper and deeper into a world connected via the Internet, more and more information will be exchanged digitally. Displays are the interface between digital information and each individual. Naturally, one fundamental goal of displays is to reproduce information as realistically as possible since humans still care a lot about what happens in the real world. Human eyes are the receiving end of such information exchange; therefore it is impossible to study displays without studying the human visual system. In fact, the design of displays is rather closely coupled with what human eyes are capable of perceiving. For example, we are less interested in building displays that emit light in the invisible spectrum. This dissertation explores how we can augment displays with computation, which takes both display hardware and the human visual system into consideration. Four novel projects on display technologies are included in this dissertation: First, we propose a software-based approach to driving multiview autostereoscopic displays. Our display algorithm can dynamically assign views to hardware display zones based on multiple observers' current head positions, substantially reducing crosstalk and stereo inversion. Second, we present a dense projector array that creates a seamless 3D viewing experience for multiple viewers. We smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the arrays field of view, reducing image distortion, crosstalk, and artifacts from tracking errors. Third, we propose a method for high dynamic range display calibration that takes into account the variation of the chrominance error over luminance. We propose a data structure for enabling efficient representation and querying of the calibration function, which also allows user-guided balancing between memory consumption and the amount of computation. Fourth, we present user studies that demonstrate that the ˜ 60 Hz critical flicker fusion

  16. Antibody Phage Display Libraries: Contributions to Oncology

    PubMed Central

    Dantas-Barbosa, Carmela; de Macedo Brigido, Marcelo; Maranhao, Andrea Queiroz

    2012-01-01

    Since the advent of phage display technology, dating back to 1985, antibody libraries displayed on filamentous phage surfaces have been used to identify specific binders for many different purposes, including the recognition of tumors. Phage display represents a high-throughput technique for screening billions of random fusion antibodies against virtually any target on the surface or inside cancer cells, or even soluble markers found in patient serum. Many phage display derived binders targeting important tumor markers have been identified. Selection directed to tumoral cells’ surfaces lead to the identification of unknown tumoral markers. Also the improvement of methods that require smaller amounts of cells has opened the possibility to use this approach on patient samples. Robust techniques combining an antibody library displayed on the phage surface and protein microarray allowed the identification of auto antibodies recognized by patient sera. Many Ab molecules directly or indirectly targeting angiogenesis have been identified, and one of them, ramucirumab, has been tested in 27 phase I–III clinical trials in a broad array of cancers. Examples of such antibodies will be discussed here with emphasis on those used as probes for molecular imaging and other clinical trials. PMID:22754305

  17. MEMS tactile display: from fabrication to characterization

    NASA Astrophysics Data System (ADS)

    Miki, Norihisa; Kosemura, Yumi; Watanabe, Junpei; Ishikawa, Hiroaki

    2014-03-01

    We report fabrication and characterization of MEMS-based tactile display that can display users various tactile information, such as Braille codes and surface textures. The display consists of 9 micro-actuators that are equipped with hydraulic displacement amplification mechanism (HDAM) to achieve large enough displacement to stimulate the human tactile receptors. HDAM encapsulates incompressible liquids. We developed a liquid encapsulation process, which we termed as Bonding-in-Liquid Technique, where bonding with a UV-curable resin in glycerin is conducted in the liquid, which prevented interfusion of air bubbles and deformation of the membrane during the bonding. HDAM successfully amplified the displacement generated by piezoelectric actuators by a factor of 6. The display could virtually produce "rough" and "smooth" surfaces, by controlling the vibration frequency, displacement, and the actuation periods of an actuator until the adjacent actuator was driven. We introduced a sample comparison method to characterize the surfaces, which involves human tactile sensation. First, we prepared samples whose mechanical properties are known. We displayed a surface texture to the user by controlling the parameters and then, the user selects a sample that has the most similar surface texture. By doing so, we can correlate the parameters with the mechanical properties of the sample as well as find the sets of the parameters that can provide similar tactile information to many users. The preliminary results with respect to roughness and hardness is presented.

  18. Advanced poly-LED displays

    NASA Astrophysics Data System (ADS)

    Childs, Mark; Nisato, Giovanni; Fish, D.; Giraldo, Andrea; Jenkins, A. J.; Johnson, Mark T.

    2003-05-01

    Philips have been actively developing polymer OLED (poly-LED) displays as a future display technology. Their emissive nature leads to a very attractive visual appearance, with wide viewing angle, high brightness and fast response speed. Whilst the first generation of poly-LED displays are likely to be passive-matrix driven, power reduction and resolution increase will lead to the use of active-matrix poly-LED displays. Philips Research have designed, fabricated and characterized five different designs of active-matrix polymer-LED display. Each of the five displays makes use of a distinct pixel programming- or pixel drive-technique, including current programming, threshold voltage measurement and photodiode feedback. It will be shown that hte simplest voltage-programmed current-source pixel suffers from potentially unacceptable brightness non-uniformity, and that advanced pixel circuits can provide a solution to this. Optical-feedback pixel circuits will be discussed, showing that they can be used to improve uniformity and compensate for image burn-in due to polymer-LED material degradation, improving display lifetime. Philips research has also been active in developing technologies required to implement poly-LED displays on flexible substrates, including materials, processing and testing methods. The fabrication of flexible passive-matrix poly-LED displays will be presented, as well as the ongoing work to assess the suitability of processing flexible next-generation poly-LED displays.

  19. Rapid display of radiographic images

    NASA Astrophysics Data System (ADS)

    Cox, Jerome R., Jr.; Moore, Stephen M.; Whitman, Robert A.; Blaine, G. James; Jost, R. Gilbert; Karlsson, L. M.; Monsees, Thomas L.; Hassen, Gregory L.; David, Timothy C.

    1991-07-01

    The requirements for the rapid display of radiographic images exceed the capabilities of widely available display, computer, and communications technologies. Computed radiography captures data with a resolution of about four megapixels. Large-format displays are available that can present over four megapixels. One megapixel displays are practical for use in combination with large-format displays and in areas where the viewing task does not require primary diagnosis. This paper describes an electronic radiology system that approximates the highest quality systems, but through the use of several interesting techniques allows the possibility of its widespread installation throughout hospitals. The techniques used can be grouped under three major system concepts: a local, high-speed image server, one or more physician's workstations each with one or more high-performance auxiliary displays specialized to the radiology viewing task, and dedicated, high-speed communication links between the server and the displays. This approach is enhanced by the use of a progressive transmission scheme to decrease the latency for viewing four megapixel images. The system includes an image server with storage for over 600 4-megapixel images and a high-speed link. A subsampled megapixel image is fetched from disk and transmitted to the display in about one second followed by the full resolution 4-megapixel image in about 2.5 seconds. Other system components include a megapixel display with a 6-megapixel display memory space and frame-rate update of image roam, zoom, and contrast. Plans for clinical use are presented.

  20. Interactive Display of Scenes with Annotations

    NASA Technical Reports Server (NTRS)

    Vona, Marsette; Powell, Mark; Backes, Paul; Norris, Jeffrey; Steinke, Robert

    2005-01-01

    ThreeDView is a computer program that enables high-performance interactive display of real-world scenes with annotations. ThreeDView was developed primarily as a component of the Science Activity Planner (SAP) software, wherein it is to be used to display annotated images of terrain acquired by exploratory robots on Mars and possibly other remote planets. The images can be generated from sets of multiple-texture image data in the Visible Scalable Terrain (ViSTa) format, which was described in "Format for Interchange and Display of 3D Terrain Data" (NPO-30600) NASA Tech Briefs, Vol. 28, No. 12 (December 2004), page 25. In ThreeDView, terrain data can be loaded rapidly, the geometric level of detail and texture resolution can be selected, false colors can be used to represent scientific data mapped onto terrain, and the user can select among navigation modes. ThreeDView consists largely of modular Java software components that can easily be reused and extended to produce new high-performance, application-specific software systems for displaying images of three-dimensional real-world scenes.

  1. Reduced survival and reproductive success generates selection pressure for the dengue mosquito Aedes aegypti to evolve resistance against infection by the microsporidian parasite Vavraia culicis

    PubMed Central

    Sy, Victoria E; Agnew, Philip; Sidobre, Christine; Michalakis, Yannis

    2014-01-01

    The success and sustainability of control measures aimed at reducing the transmission of mosquito-borne diseases will depend on how they influence the fitness of mosquitoes in targeted populations. We investigated the effects of the microsporidian parasite Vavraia culicis on the survival, blood-feeding behaviour and reproductive success of female Aedes aegypti mosquitoes, the main vector of dengue. Infection reduced survival to adulthood and increased adult female mosquito age-dependent mortality relative to uninfected individuals; this additional mortality was closely correlated with the number of parasite spores they harboured when they died. In the first gonotrophic cycle, infected females were less likely to blood-feed, took smaller meals when they did so, and developed fewer eggs than uninfected females. Even though the conditions of this laboratory study favoured minimal developmental times, the costs of infection were already being experienced by the time females reached an age at which they could first reproduce. These results suggest there will be selection pressure for mosquitoes to evolve resistance against this pathogen if it is used as an agent in a control program to reduce the transmission of mosquito-borne human diseases. PMID:24822081

  2. Difference in skin immune responses to infection with salmon louse (Lepeophtheirus salmonis) in Atlantic salmon (Salmo salar L.) of families selected for resistance and susceptibility.

    PubMed

    Holm, Helle; Santi, Nina; Kjøglum, Sissel; Perisic, Nebojsa; Skugor, Stanko; Evensen, Øystein

    2015-02-01

    Atlantic salmon is susceptible to the salmon louse (Lepeophtheirus salmonis) and the variation in susceptibility within the species can be exploited in selective breeding programs for louse resistant fish. In this study, lice counts were completed on 3000 siblings from 150 families of Atlantic salmon identified as high resistant (HR) and low resistant (LR) families in two independent challenge trials. Skin samples behind the dorsal fin (nearby lice attachment) were collected from ten extreme families (HR or LR) and analyzed by qPCR for the expression of 32 selected genes, including a number of genes involved in T helper cell (Th) mediated immune responses, which have been previously implied to play important roles during salmon louse infections. Most genes showed lower expression patterns in the LR than in HR fish, suggesting an immunosuppressed state in LR families. The average number of lice (chalimi) was 9 in HR and 15 in LR fish. Large variation in lice counts was seen both within resistant and susceptible families, which enabled us to subdivide the groups into HR < 10 and HR > 10, and LR < 10 and LR > 10 to better understand the effect of lice burden per se. As expected, expression patterns were influenced both by genetic background and the number of attached parasites. Higher number of lice (>10) negatively affected gene expression in both HR and LR families. In general, strongest down-regulation was seen in LR > 10 and lesser down-regulation in HR < 10. HR in general and especially HR < 10 fish were better at resisting suppression of expression of both Th1 and Th2 genes. However, the best inverse correlation with infection level was seen for the prototypical Th1 genes, including several members from the interferon pathways. In addition, skin histomorphometry suggests that infected LR salmon had thicker epidermis in the area behind the dorsal fin and larger mucous cell size compared to infected HR fish, however marginally significant (p = 0.08). This

  3. Phage display creates innovative applications to combat hepatitis B virus

    PubMed Central

    Tan, Wen Siang; Ho, Kok Lian

    2014-01-01

    Hepatitis B virus (HBV) has killed countless lives in human history. The invention of HBV vaccines in the 20th century has reduced significantly the rate of the viral infection. However, currently there is no effective treatment for chronic HBV carriers. Newly emerging vaccine escape mutants and drug resistant strains have complicated the viral eradication program. The entire world is now facing a new threat of HBV and human immunodeficiency virus co-infection. Could phage display provide solutions to these life-threatening problems? This article reviews critically and comprehensively the innovative and potential applications of phage display in the development of vaccines, therapeutic agents, diagnostic reagents, as well as gene and drug delivery systems to combat HBV. The application of phage display in epitope mapping of HBV antigens is also discussed in detail. Although this review mainly focuses on HBV, the innovative applications of phage display could also be extended to other infectious diseases. PMID:25206271

  4. X-1 on display

    NASA Technical Reports Server (NTRS)

    1949-01-01

    A Bell Aircraft Corporation X-1 series aircraft on display at an Open House at NACA Muroc Flight Test Unit or High-Speed Flight Research Station hangar on South Base of Edwards Air Force Base, California. (The precise date of the photo is uncertain, but it is probably before 1948.) The instrumentation that was carried aboard the aircraft to gather data is on display. The aircraft data was recorded on oscillograph film that was read, calibrated, and converted into meaningful parameters for the engineers to evaluate from each research flight. In the background of the photo are several early U.S. jets. These include several Lockheed P-80 Shooting Stars, which were used as chase planes on X-1 flights; two Bell P-59 Airacomets, the first U.S. jet pursuit aircraft (fighter in later parlance); and a prototype Republic XP-84 Thunderjet. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for eXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant

  5. A baculoviral display system to assay viral entry.

    PubMed

    Iida, Manami; Yoshida, Takeshi; Watari, Akihiro; Yagi, Kiyohito; Hamakubo, Takao; Kondoh, Masuo

    2013-01-01

    In this study, we evaluated a baculoviral display system for analysis of viral entry by using a recombinant adenovirus (Ad) carrying a luciferase gene and budded baculovirus (BV) that displays the adenoviral receptor, coxsackievirus and adenovirus receptor (CAR). CAR-expressing B16 cells (B16-CAR cells) were infected with luciferase-expressing Ad vector in the presence of BV that expressed or lacked CAR (CAR-BV and mock-BV, respectively). Treatment with mock-BV even at doses as high as 5 µg/mL failed to attenuate the luciferase activity of B16-CAR cells. In contrast, treatment with CAR-BV with doses as low as 0.5 µg/mL significantly decreased the luciferase activity of infected cells, which reached 65% reduction at 5 µg/mL. These findings suggest that a receptor-displaying BV system could be used to evaluate viral infection. PMID:24189431

  6. Spectrally selective UV bactericidal effect for curative treatment of post-surgical intra-abdominal abscesses and other infections

    NASA Astrophysics Data System (ADS)

    Dudelzak, Alexander E.; Miller, Mark A.; Babichenko, Sergey M.

    2004-07-01

    Results of in-vitro studies of bactericidal effects of ultraviolet (UV) irradiation on strains causing drug-resistant endo-cavital infections (Enterococcus, Staphylococcus aureus, Pseudomonas aeruginosa, and others) are presented. An original technique to measure effects of UV-irradiation on bacterial growth at different wavelengths has been developed. Spectral dependences of the bactericidal effect have been observed, and spectral maxima of bactericidal efficiency have been found. Applications to curative treatments of wounds, post-surgical intra-abdominal abscesses and other diseases are discussed.

  7. Panoramic, large-screen, 3-D flight display system design

    NASA Technical Reports Server (NTRS)

    Franklin, Henry; Larson, Brent; Johnson, Michael; Droessler, Justin; Reinhart, William F.

    1995-01-01

    The report documents and summarizes the results of the required evaluations specified in the SOW and the design specifications for the selected display system hardware. Also included are the proposed development plan and schedule as well as the estimated rough order of magnitude (ROM) cost to design, fabricate, and demonstrate a flyable prototype research flight display system. The thrust of the effort was development of a complete understanding of the user/system requirements for a panoramic, collimated, 3-D flyable avionic display system and the translation of the requirements into an acceptable system design for fabrication and demonstration of a prototype display in the early 1997 time frame. Eleven display system design concepts were presented to NASA LaRC during the program, one of which was down-selected to a preferred display system concept. A set of preliminary display requirements was formulated. The state of the art in image source technology, 3-D methods, collimation methods, and interaction methods for a panoramic, 3-D flight display system were reviewed in depth and evaluated. Display technology improvements and risk reductions associated with maturity of the technologies for the preferred display system design concept were identified.

  8. Laser illuminated flat panel display

    SciTech Connect

    Veligdan, J.T.

    1995-12-31

    A 10 inch laser illuminated flat panel Planar Optic Display (POD) screen has been constructed and tested. This POD screen technology is an entirely new concept in display technology. Although the initial display is flat and made of glass, this technology lends itself to applications where a plastic display might be wrapped around the viewer. The display screen is comprised of hundreds of planar optical waveguides where each glass waveguide represents a vertical line of resolution. A black cladding layer, having a lower index of refraction, is placed between each waveguide layer. Since the cladding makes the screen surface black, the contrast is high. The prototype display is 9 inches wide by 5 inches high and approximately I inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  9. The Avian XPR1 Gammaretrovirus Receptor Is under Positive Selection and Is Disabled in Bird Species in Contact with Virus-Infected Wild Mice

    PubMed Central

    Martin, Carrie; Buckler-White, Alicia; Wollenberg, Kurt

    2013-01-01

    Xenotropic mouse leukemia viruses (X-MLVs) are broadly infectious for mammals except most of the classical strains of laboratory mice. These gammaretroviruses rely on the XPR1 receptor for entry, and the unique resistance of laboratory mice is due to two mutations in different putative XPR1 extracellular loops. Cells from avian species differ in susceptibility to X-MLVs, and 2 replacement mutations in the virus-resistant chicken XPR1 (K496Q and Q579E) distinguish it from the more permissive duck and quail receptors. These substitutions align with the two mutations that disable the laboratory mouse XPR1. Mutagenesis of the chicken and duck genes confirms that residues at both sites are critical for virus entry. Among 32 avian species, the 2 disabling XPR1 mutations are found together only in the chicken, an omnivorous, ground-dwelling fowl that was domesticated in India and/or Southeast Asia, which is also where X-MLV-infected house mice evolved. The receptor-disabling mutations are also present separately in 5 additional fowl and raptor species, all of which are native to areas of Asia populated by the virus-infected subspecies Mus musculus castaneus. Phylogenetic analysis showed that the avian XPR1 gene is under positive selection at sites implicated in receptor function, suggesting a defensive role for XPR1 in the avian lineage. Contact between bird species and virus-infected mice may thus have favored selection of mouse virus-resistant receptor orthologs in the birds, and our data suggest that similar receptor-disabling mutations were fixed in mammalian and avian species exposed to similar virus challenges. PMID:23843647

  10. Flat panel planar optic display

    SciTech Connect

    Veligdan, J.T.

    1994-11-01

    A prototype 10 inch flat panel Planar Optic Display, (POD), screen has been constructed and tested. This display screen is comprised of hundreds of planar optic class sheets bonded together with a cladding layer between each sheet where each glass sheet represents a vertical line of resolution. The display is 9 inches wide by 5 inches high and approximately 1 inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  11. Peripheral vision displays: The future

    NASA Technical Reports Server (NTRS)

    Assenhein, H. M.

    1984-01-01

    Several areas of research relating to peripheral vision displays used by aircraft pilots are outlined: fiber optics, display color, and holography. Various capacities and specifications of gas and solid state lasers are enumerated. These lasers are potential sources of green light for the peripheral vision displays. The relative radiance required for rod and cone vision at different wavelengths is presented graphically. Calculated and measured retinal sensitivities (foveal and peripheral) are given for wavelength produced by various lasers.

  12. Diminished representation of HIV-1 variants containing select drug resistance-conferring mutations in primary HIV-1 infection.

    PubMed

    Turner, Dan; Brenner, Bluma; Routy, Jean-Pierre; Moisi, Daniela; Rosberger, Zeev; Roger, Michel; Wainberg, Mark A

    2004-12-15

    This study compared the incidence of HIV-1 variants harboring mutations conferring resistance to thymidine analogues, ie, thymidine analogue mutations (TAMs), nonnucleoside reverse transcriptase (RT) inhibitors (NNMs), lamivudine (3TC) (ie, M184V), and protease inhibitors (PIs) acquired in primary HIV infection (PHI) (n = 59) to their observed prevalence in a corresponding potential transmitter (PT) population of persons harboring resistant infections (n = 380). Both of these populations in the context of this cohort analysis possessed similar demographics. Whereas the frequencies of observed TAMs, NNMs, M184V, and protease-associated mutations (PRAMs) were similar in the PT groups, the prevalence of M184V and major PI mutations were significantly lower in the PHI group (PHI/PT ratios of 0.14 and 0.39, respectively). There was a decreased prevalence in the PHI population of resistant viruses co-expressing NNMs or TAMs with M184V compared with viruses that harbored NNMs or TAMs in the absence of M184V (P < 0.0001). It was also observed that individuals in the PT subgroups who harbored RT mutations or PRAMs with M184V had lower levels of plasma viremia than individuals who lacked M184V (P < 0.05). These findings suggest that both decreased viremia and viral fitness in the case of M184V-containing HIV-1 variants may impact on viral transmissibility.

  13. Monoclonal antibody that inhibits infection of HeLa and rhabdomyosarcoma cells by selected enteroviruses through receptor blockade

    SciTech Connect

    Crowell, R.L.; Field, A.K.; Schleif, W.A.; Long, W.L.; Colonno, R.J.; Mapoles, J.E.; Emini, E. A.

    1986-02-01

    BALB/c mice were immunized with HeLa cells, and their spleen cells were fused with myeloma cells to produce hybridomas. Initial screening of culture fluids from 800 fusion products in a cell protection assay against coxsackievirus B3 (CB3) and the CB3-RD virus variant yielded five presumptive monoclonal antibodies with three specificities: (i) protection against CB3 on HeLa, (ii) protection against CB3-RD on rhabdomyosarcoma (RD) cells, and (iii) protection against both viruses on the respective cells. Only one of the monoclonal antibodies (with dual specificity) survived two subclonings and was studied in detail. The antibody was determined to have an immunoglobulin G2a isotype and protected cells by blockade of cellular receptors, since attachment of (/sup 35/S)methionine-labeled CB3 was inhibited by greater than 90%. The monoclonal antibody protected HeLa cells against infection by CB1, CB3, CB5, echovirus 6, and coxsackievirus A21 and RD cells against CB1-RD, CB3-RD, and CB5-Rd virus variants. The monoclonal antibody did not protect either cell type against 16 other immunotypes of picornaviruses. The monoclonal antibody produced only positive fluorescence on those cells which were protected against infection, and /sup 125/I-labeled antibody confirmed the specific binding to HeLa and RD cells. The results suggest that this monoclonal antibody possesses some of the receptor specificity of the group B coxsackieviruses.

  14. The display of tactile information

    NASA Technical Reports Server (NTRS)

    Sherrick, Carl E.

    1991-01-01

    There are a number of examples of natural tactile displays that can five us some insights about the solid geometry of touch, and recent experimental work on the subject has extended our thinking considerably. The concern of here is, however, more with synthetic or artificial displays for the production of a virtual environment. Features of synthetic displays that have enjoyed some success in one of the following two enterprises are discussed: the study of the spatio-temporal dimensions of stimuli that afford accurate and rapid processing of environmental information, or the use of displays in the design of sensory aids for disabled persons.

  15. Liquid crystal Fresnel lens display

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Qian; Abhishek Kumar, Srivastava; Alwin Tam, Ming-Wai; Zheng, Zhi-Gang; Shen, Dong; Vladimir, Chigrinov G.; Kwok, Hoi-Sing

    2016-09-01

    A novel see-through display with a liquid crystal lens array was proposed. A liquid crystal Fresnel lens display (LCFLD) with a holographic screen was demonstrated. The proposed display system has high efficiency, simple fabrication, and low manufacturing cost due to the absence of a polarizer and color filter. Project supported by Partner State Key Laboratory on Advanced Displays and Optoelectronics Technologies HKUST, China, the National Natural Science Foundation of China (Grant Nos. 61435008 and 61575063), and the Fundamental Research Funds for the Central Universities, China (Grant No. WM1514036).

  16. Liquid crystal Fresnel lens display

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Qian; Abhishek Kumar, Srivastava; Alwin Tam, Ming-Wai; Zheng, Zhi-Gang; Shen, Dong; Vladimir, Chigrinov G.; Kwok, Hoi-Sing

    2016-09-01

    A novel see-through display with a liquid crystal lens array was proposed. A liquid crystal Fresnel lens display (LCFLD) with a holographic screen was demonstrated. The proposed display system has high efficiency, simple fabrication, and low manufacturing cost due to the absence of a polarizer and color filter. Project supported by Partner State Key Laboratory on Advanced Displays and Optoelectronics Technologies HKUST, China, the National Natural Science Foundation of China (Grant Nos. 61435008 and 61575063), and the Fundamental Research Funds for the Central Universities, China (Grant No. WM1514036).

  17. Maintenance Procedure Display: Head Mounted Display (HMD) Evaluations

    NASA Technical Reports Server (NTRS)

    Whitmore, Milrian; Litaker, Harry L., Jr.; Solem, Jody A.; Holden, Kritina L.; Hoffman, Ronald R.

    2007-01-01

    A viewgraph presentation describing maintenance procedures for head mounted displays is shown. The topics include: 1) Study Goals; 2) Near Eye Displays (HMDs); 3) Design; 4) Phase I-Evaluation Methods; 5) Phase 1 Results; 6) Improved HMD Mounting; 7) Phase 2 -Evaluation Methods; 8) Phase 2 Preliminary Results; and 9) Next Steps.

  18. Effects of Darwinian Selection and Mutability on Rate of Broadly Neutralizing Antibody Evolution during HIV-1 Infection

    PubMed Central

    Sheng, Zizhang; Schramm, Chaim A.; Connors, Mark; Morris, Lynn; Mascola, John R.; Kwong, Peter D.; Shapiro, Lawrence

    2016-01-01

    Accumulation of somatic mutations in antibody variable regions is critical for antibody affinity maturation, with HIV-1 broadly neutralizing antibodies (bnAbs) generally requiring years to develop. We recently found that the rate at which mutations accumulate decreases over time, but the mechanism governing this slowing is unclear. In this study, we investigated whether natural selection and/or mutability of the antibody variable region contributed significantly to observed decrease in rate. We used longitudinally sampled sequences of immunoglobulin transcripts of single lineages from each of 3 donors, as determined by next generation sequencing. We estimated the evolutionary rates of the complementarity determining regions (CDRs), which are most significant for functional selection, and found they evolved about 1.5- to 2- fold faster than the framework regions. We also analyzed the presence of AID hotspots and coldspots at different points in lineage development and observed an average decrease in mutability of less than 10 percent over time. Altogether, the correlation between Darwinian selection strength and evolutionary rate trended toward significance, especially for CDRs, but cannot fully explain the observed changes in evolutionary rate. The mutability modulated by AID hotspots and coldspots changes correlated only weakly with evolutionary rates. The combined effects of Darwinian selection and mutability contribute substantially to, but do not fully explain, evolutionary rate change for HIV-1-targeting bnAb lineages. PMID:27191167

  19. Description, microhabitat selection and infection patterns of sealworm larvae (Pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from Patagonia, Argentina

    PubMed Central

    2013-01-01

    Background Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South American coast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. However, despite their economic and zoonotic importance, morphological and molecular characterization of species of Pseudoterranova in South America is still scarce. Methods A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined for sealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detect nematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecular identification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for 10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained. Results A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula, followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata. Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigula formed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranova cattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species of Pseudoterranova. A morphological description, including drawings and scanning electron microscopy photomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in their diagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests that specimens from P. nudigula were significantly larger than those from other fishes

  20. Genetic diversity at endoplasmic reticulum aminopeptidases is maintained by balancing selection and is associated with natural resistance to HIV-1 infection.

    PubMed

    Cagliani, Rachele; Riva, Stefania; Biasin, Mara; Fumagalli, Matteo; Pozzoli, Uberto; Lo Caputo, Sergio; Mazzotta, Francesco; Piacentini, Luca; Bresolin, Nereo; Clerici, Mario; Sironi, Manuela

    2010-12-01

    Human ERAP1 and ERAP2 encode two endoplasmic reticulum aminopeptidases. These enzymes trim peptides to optimal size for loading onto major histocompatibility complex class I molecules and shape the antigenic repertoire presented to CD8(+) T cells. Therefore, ERAP1 and ERAP2 may be considered potential selection targets and modulators of infection susceptibility. We resequenced two genic regions in ERAP1 and ERAP2 in three HapMap populations. In both cases, we observed high levels of nucleotide variation, an excess of intermediate-frequency alleles, and reduced population genetic differentiation. The genealogy of ERAP1 and ERAP2 haplotypes was split into two major branches with deep coalescence times. These features suggest that long-standing balancing selection has acted on these genes. Analysis of the Lys528Arg (rs30187 in ERAP1) and Asn392Lys (rs2549782 in ERAP2) variants in an Italian population of HIV-1-exposed seronegative (ESN) individuals and a larger number of Italian controls indicated that rs2549782 significantly deviates from Hardy-Weinberg equilibrium (HWE) in ESN but not in controls. Technical errors were excluded and a goodness-of-fit test indicated that a recessive model with only genetic effects adequately explains HWE deviation. The genotype distribution of rs2549782 is significantly different in the two cohorts (P = 0.004), mainly as the result of an over-representation of Lys/Lys genotypes in the ESN sample (P-value for a recessive model: 0.00097). Our data suggest that genetic diversity in ERAP1 and ERAP2 has been maintained by balancing selection and that variants in ERAP2 confer resistance to HIV-1 infection possibly via the presentation of a distinctive peptide repertoire to CD8(+) T cells.

  1. Updated defense display market assessment

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    1999-08-01

    This paper addresses the number, function and size of principal military displays and establishes a basis to determine the opportunities for technology insertion in the immediate future and into the next millennium. Principal military displays are defined as those occupying appreciable crewstation real-estate and/or those without which the platform could not carry out its intended mission. DoD 'office' applications are excluded from this study. The military displays market is specified by such parameters as active area and footprint size, and other characteristics such as luminance, gray scale, resolution, angle, color, video capability, and night vision imaging system compatibility. Funded, future acquisitions, planned and predicted crewstation modification kits, and form-fit upgrades are taken into account. This paper provides an overview of the DoD niche market, allowing both government and industry a necessary reference by which to meet DoD requirements for military displays in a timely and cost-effective manner. The aggregate DoD installed base for direct-view and large-area military displays is presently estimated to be in excess of 313,000. Miniature displays are those which must be magnified to be viewed, involve a significantly different manufacturing paradigm and are used in helmet mounted displays and thermal weapon sight applications. Some 114,000 miniature displays are presently included within future weapon system acquisition plans. For vendor production planning purposes it is noted that foreign military sales could substantially increase these quantities. The vanishing vendor syndrome (VVS) for older display technologies continues to be a growing, pervasive problem throughout DoD, which consequently must leverage the more modern, especially flat panel, display technologies being developed to replace older, especially cathode ray tube, technology for civil-commercial markets. Total DoD display needs (FPD, HMD) are some 427,000.

  2. Selection of a potential diagnostic biomarker for HIV infection from a random library of non-biological synthetic peptoid oligomers.

    PubMed

    Gearhart, Tricia L; Montelaro, Ronald C; Schurdak, Mark E; Pilcher, Chris D; Rinaldo, Charles R; Kodadek, Thomas; Park, Yongseok; Islam, Kazi; Yurko, Raymond; Marques, Ernesto T A; Burke, Donald S

    2016-08-01

    Non-biological synthetic oligomers can serve as ligands for antibodies. We hypothesized that a random combinatorial library of synthetic poly-N-substituted glycine oligomers, or peptoids, could represent a random "shape library" in antigen space, and that some of these peptoids would be recognized by the antigen-binding pocket of disease-specific antibodies. We synthesized and screened a one bead one compound combinatorial library of peptoids, in which each bead displayed an 8-mer peptoid with ten possible different amines at each position (10(8) theoretical variants). By screening one million peptoid/beads we found 112 (approximately 1 in 10,000) that preferentially bound immunoglobulins from human sera known to be positive for anti-HIV antibodies. Reactive peptoids were then re-synthesized and rigorously evaluated in plate-based ELISAs. Four peptoids showed very good, and one showed excellent, properties for establishing a sero-diagnosis of HIV. These results demonstrate the feasibility of constructing sero-diagnostic assays for infectious diseases from libraries of random molecular shapes. In this study we sought a proof-of-principle that we could identify a potential diagnostic antibody ligand biomarker for an infectious disease in a random combinatorial library of 100 million peptoids. We believe that this is the first evidence that it is possible to develop sero-diagnostic assays - for any infectious disease - based on screening random libraries of non-biological molecular shapes. PMID:27182050

  3. [Ticks Ixodes ricinus (Linnaeus, 1758) from selected municipal forests of the city Poznań and their infection with the spirochetes Borrelia burgdorferi senso lato].

    PubMed

    Nowosad, A; Jenek, J; Głazaczow, A; Wal, M

    1999-01-01

    The results of research (1997-1998) on the occurrence of the spirochetes Borrelia burgdorferi s.l. in ticks Ixodes ricinus (L.) in selected municipal forests of the city of Poznań (localities--districts of Poznań: 1 Debiec, 2 Marcelin, 3 Golecin and Wola, 4 Krzyzowniki and Smochowice, 5 Kiekrz and Strzeszynek, 6 Morasko, 7 Piatkowo, 8 Umultowo, 9 Naramowice and Rózany Młyn, 10 Malta and Antoninek) are presented. A total of 1432 ticks were collected from 10 localities (748 larvae, 590 nymphs, 47 males, and 47 females). Out of this number, 266 specimens were selected at random for further analysis (20 larvae, 160 nymphs, 44 males, and 42 females) which were then tested for the presence of the spirochetes using the PCR technique (tab. I-III, fig. 1). Spirochetes were found in 60 specimens (22.6%). Percentages of infected nymphs and males were similar: 25.6% and 27.3%, respectively. The level of infection of females was lower (14.3%) and of larvae lowest (5.0%). Infected ticks were found in all ten localities, but their proportions differed from site to site and varied from 9.5% (Piatkowo) to 34.6% (Krzyzowniki and Smochowice). Special attention was devoted to those municipal woods where ticks were abundant (Kiekrz and Strzeszynek, as well as Malta and Antoninek, and relatively numerous Debiec) and where their extensiveness of infestation was high (Krzyzowniki and Smochowice: 34.6%; Debiec: 29.6%; Naramowice and Rózany Młyn: 28.6%; Malta and Antoninek: 28.1%; and Golecin and Wola: 26.9%). After summing up all the data from the literature on Wielkopolska and the city of Poznań, the mean extensiveness of infestation in Wielkopolska turns out to be 21.8% and in Poznań slightly higher, 22.2% (tab. IV). The infection levels of the particular developmental stages are different, though: highly variable in nymphs (8.3-25.6%), and more stable in males (22.0-27.3%) and females (22.0-24.5%).

  4. Flexible Bistable Cholesteric Reflective Displays

    NASA Astrophysics Data System (ADS)

    Yang, Deng-Ke

    2006-03-01

    Cholesteric liquid crystals (ChLCs) exhibit two stable states at zero field condition-the reflecting planar state and the nonreflecting focal conic state. ChLCs are an excellent candidate for inexpensive and rugged electronic books and papers. This paper will review the display cell structure,materials and drive schemes for flexible bistable cholesteric (Ch) reflective displays.

  5. Displays: Entering a New Dimension

    ERIC Educational Resources Information Center

    Starkman, Neal

    2007-01-01

    As display technologies prepare to welcome 3-D, the 21st-century classroom will soon bear little resemblance to anything students and teachers have ever seen. In this article, the author presents the latest innovations in the world of digital display technology. These include: (1) Touchlight, an interactive touch screen program that takes a normal…

  6. Drugs derived from phage display

    PubMed Central

    Nixon, Andrew E; Sexton, Daniel J; Ladner, Robert C

    2014-01-01

    Phage display, one of today’s fundamental drug discovery technologies, allows identification of a broad range of biological drugs, including peptides, antibodies and other proteins, with the ability to tailor critical characteristics such as potency, specificity and cross-species binding. Further, unlike in vivo technologies, generating phage display-derived antibodies is not restricted by immunological tolerance. Although more than 20 phage display-derived antibody and peptides are currently in late-stage clinical trials or approved, there is little literature addressing the specific challenges and successes in the clinical development of phage-derived drugs. This review uses case studies, from candidate identification through clinical development, to illustrate the utility of phage display as a drug discovery tool, and offers a perspective for future developments of phage display technology. PMID:24262785

  7. INFORMATION DISPLAY: CONSIDERATIONS FOR DESIGNING COMPUTER-BASED DISPLAY SYSTEMS.

    SciTech Connect

    O'HARA,J.M.; PIRUS,D.; BELTRATCCHI,L.

    2004-09-19

    This paper discussed the presentation of information in computer-based control rooms. Issues associated with the typical displays currently in use are discussed. It is concluded that these displays should be augmented with new displays designed to better meet the information needs of plant personnel and to minimize the need for interface management tasks (the activities personnel have to do to access and organize the information they need). Several approaches to information design are discussed, specifically addressing: (1) monitoring, detection, and situation assessment; (2) routine task performance; and (3) teamwork, crew coordination, collaborative work.

  8. Selection and Counterselection of Hia Expression Reveals a Key Role for Phase-Variable Expression of Hia in Infection Caused by Nontypeable Haemophilus influenzae

    PubMed Central

    Atack, John M.; Winter, Linda E.; Jurcisek, Joseph A.; Bakaletz, Lauren O.; Barenkamp, Stephen J.; Jennings, Michael P.

    2015-01-01

    Hia is a major adhesin of nontypeable Haemophilus influenzae (NTHi) and has long been investigated as a vaccine candidate. Here we show that Hia phase variation is controlled by changes in the length of a polythymidine tract located in the hia promoter. Studies of an invasive clinical isolate (strain R2866) show that strains expressing high Hia levels are more efficiently killed by opsonophagocytosis. An opsonophagocytic assay was used to select for a subpopulation of variants that expressed a low level of Hia, which facilitated their escape from killing by anti-Hia antisera. Conversely, a subpopulation of variants expressing a high level of Hia was selected for during passaging through Chang cells. In both cases, phase variation of Hia expression corresponded directly with discrete modal changes in polythymidine tract length. In the chinchilla model of NTHi infection, we observed consistent selection for high Hia expression upon nasopharyngeal colonization, confirming the key role of phase-variable expression of Hia within a specific niche in vivo. PMID:25712964

  9. Hepatitis C virus quasispecies and pseudotype analysis from acute infection to chronicity in HIV-1 co-infected individuals.

    PubMed

    Ferns, R Bridget; Tarr, Alexander W; Hue, Stephane; Urbanowicz, Richard A; McClure, C Patrick; Gilson, Richard; Ball, Jonathan K; Nastouli, Eleni; Garson, Jeremy A; Pillay, Deenan

    2016-05-01

    HIV-1 infected patients who acquire HCV infection have higher rates of chronicity and liver disease progression than patients with HCV mono-infection. Understanding early events in this pathogenic process is important. We applied single genome sequencing of the E1 to NS3 regions and viral pseudotype neutralization assays to explore the consequences of viral quasispecies evolution from pre-seroconversion to chronicity in four co-infected individuals (mean follow up 566 days). We observed that one to three founder viruses were transmitted. Relatively low viral sequence diversity, possibly related to an impaired immune response, due to HIV infection was observed in three patients. However, the fourth patient, after an early purifying selection displayed increasing E2 sequence evolution, possibly related to being on suppressive antiretroviral therapy. Viral pseudotypes generated from HCV variants showed relative resistance to neutralization by autologous plasma but not to plasma collected from later time points, confirming ongoing virus escape from antibody neutralization. PMID:26971243

  10. Hepatitis C virus quasispecies and pseudotype analysis from acute infection to chronicity in HIV-1 co-infected individuals.

    PubMed

    Ferns, R Bridget; Tarr, Alexander W; Hue, Stephane; Urbanowicz, Richard A; McClure, C Patrick; Gilson, Richard; Ball, Jonathan K; Nastouli, Eleni; Garson, Jeremy A; Pillay, Deenan

    2016-05-01

    HIV-1 infected patients who acquire HCV infection have higher rates of chronicity and liver disease progression than patients with HCV mono-infection. Understanding early events in this pathogenic process is important. We applied single genome sequencing of the E1 to NS3 regions and viral pseudotype neutralization assays to explore the consequences of viral quasispecies evolution from pre-seroconversion to chronicity in four co-infected individuals (mean follow up 566 days). We observed that one to three founder viruses were transmitted. Relatively low viral sequence diversity, possibly related to an impaired immune response, due to HIV infection was observed in three patients. However, the fourth patient, after an early purifying selection displayed increasing E2 sequence evolution, possibly related to being on suppressive antiretroviral therapy. Viral pseudotypes generated from HCV variants showed relative resistance to neutralization by autologous plasma but not to plasma collected from later time points, confirming ongoing virus escape from antibody neutralization.

  11. Engineering RNA phage MS2 virus-like particles for peptide display

    NASA Astrophysics Data System (ADS)

    Jordan, Sheldon Keith

    Phage display is a powerful and versatile technology that enables the selection of novel binding functions from large populations of randomly generated peptide sequences. Random sequences are genetically fused to a viral structural protein to produce complex peptide libraries. From a sufficiently complex library, phage bearing peptides with practically any desired binding activity can be physically isolated by affinity selection, and, since each particle carries in its genome the genetic information for its own replication, the selectants can be amplified by infection of bacteria. For certain applications however, existing phage display platforms have limitations. One such area is in the field of vaccine development, where the goal is to identify relevant epitopes by affinity-selection against an antibody target, and then to utilize them as immunogens to elicit a desired antibody response. Today, affinity selection is usually conducted using display on filamentous phages like M13. This technology provides an efficient means for epitope identification, but, because filamentous phages do not display peptides in the high-density, multivalent arrays the immune system prefers to recognize, they generally make poor immunogens and are typically useless as vaccines. This makes it necessary to confer immunogenicity by conjugating synthetic versions of the peptides to more immunogenic carriers. Unfortunately, when introduced into these new structural environments, the epitopes often fail to elicit relevant antibody responses. Thus, it would be advantageous to combine the epitope selection and immunogen functions into a single platform where the structural constraints present during affinity selection can be preserved during immunization. This dissertation describes efforts to develop a peptide display system based on the virus-like particles (VLPs) of bacteriophage MS2. Phage display technologies rely on (1) the identification of a site in a viral structural protein that is

  12. Cockpit display requirements and specifications

    NASA Astrophysics Data System (ADS)

    Hopper, Darrel G.

    1993-12-01

    Flight instrument design has begun to include a new electronic technology for the display head: active matrix liquid crystal display (AMLCD). This is a significant design transition and applies across the board to complete cockpit modernization programs, individual instrument replacement projects, and new systems. AMLCD-based instruments are expected to have a substantially higher mean time between failure compared to both electromechanical and CRT- based instruments. Thus, the new technology will pay for itself. Furthermore, AMLCDs are truly sunlight-readable whereas CRT displays are not; it is mission critical that a pilot be able to see an instrument with the sun shining directly in the eye or onto the display. AMLCDs can also provide larger display areas enabling formats which increase situational awareness. As this is a new technology for the military, an industrial base for militarized AMLCDs must be created based on present research capabilities. The requirements for AMLCDs in DOD programs have been analyzed. Projects to build infrastructure and capacity are described. Applications include not only cockpits, but also digital map/GPS integrated displays for tank commanders and field laptop computers. We have the opportunity with this new technology to establish a common critical item product function specification for sunlight-readable, color and grayscale capable, flat panel displays for military applications. the Wright Laboratory is leading the development of such functional specification for U.S. military aircraft.

  13. Lizard threat display handicaps endurance.

    PubMed Central

    Brandt, Y

    2003-01-01

    Honest-signalling theory asserts that threat displays reliably advertise attributes that influence fighting success. Endurance, as measured by treadmill performance, predicts the outcome of agonistic interactions among lizards. If threat displays in lizards function to advertise endurance capacity then variation in threat displays should correlate with endurance. I tested this prediction for the duration of threat posturing in male side-blotched lizards (Uta stansburiana) and examined whether threat displays act as quality handicaps, reliable signals that expend the attribute that is advertised. Individual variation in the duration of threat posturing correlated with endurance, while an experimental reduction of endurance diminished the duration of threat posturing. As expected of a quality handicap, endurance fell below baseline after display production. A restriction of aerobic metabolism can account for this effect. In threat posturing, lateral compression of the thorax may interfere with respiration or with circulation, limiting aerobic metabolism and causing a compensatory increase in anaerobic metabolism, thereby generating lactate and diminishing locomotor capacity. Concentrations of lactate measured after display production were higher than baseline, consistent with the proposed mechanism. By restricting aerobic metabolism, the threat posture can act as a quality handicap, simultaneously advertising and expending the endurance capacity of displaying lizards. PMID:12803896

  14. Vaccines to combat river blindness: expression, selection and formulation of vaccines against infection with Onchocerca volvulus in a mouse model.

    PubMed

    Hess, Jessica A; Zhan, Bin; Bonne-Année, Sandra; Deckman, Jessica M; Bottazzi, Maria Elena; Hotez, Peter J; Klei, Thomas R; Lustigman, Sara; Abraham, David

    2014-08-01

    Human onchocerciasis is a neglected tropical disease caused by Onchocerca volvulus and an important cause of blindness and chronic disability in the developing world. Although mass drug administration of ivermectin has had a profound effect on control of the disease, additional tools are critically needed including the need for a vaccine against onchocerciasis. The objectives of the present study were to: (i) select antigens with known vaccine pedigrees as components of a vaccine; (ii) produce the selected vaccine antigens under controlled conditions, using two expression systems and in one laboratory and (iii) evaluate their vaccine efficacy using a single immunisation protocol in mice. In addition, we tested the hypothesis that joining protective antigens as a fusion protein or in combination, into a multivalent vaccine, would improve the ability of the vaccine to induce protective immunity. Out of eight vaccine candidates tested in this study, Ov-103, Ov-RAL-2 and Ov-CPI-2M were shown to reproducibly induce protective immunity when administered individually, as fusion proteins or in combination. Although there was no increase in the level of protective immunity induced by combining the antigens into one vaccine, these antigens remain strong candidates for inclusion in a vaccine to control onchocerciasis in humans. PMID:24907553

  15. Selective killing of Kaposi's sarcoma-associated herpesvirus lytically infected cells with a recombinant immunotoxin targeting the viral gpK8.1A envelope glycoprotein.

    PubMed

    Chatterjee, Deboeeta; Chandran, Bala; Berger, Edward A

    2012-01-01

    Kaposi sarcoma-associated herpesvirus (KSHV, human herpesvirus 8) is etiologically associated with three neoplastic syndromes: Kaposi sarcoma and the uncommon HIV-associated B-cell lymphoproliferative disorders primary effusion lymphoma and multicentric Castleman disease. The incidence of the latter B-cell pathology has been increasing in spite of antiretroviral therapy; its association with lytic virus replication has prompted interest in therapeutic strategies aimed at this phase of the virus life cycle. We designed and expressed a recombinant immunotoxin (2014-PE38) targeting the gpK8.1A viral glycoprotein expressed on the surface of the virion and infected cells. We show that this immunotoxin selectively kills KSHV-infected cells in dose-dependent fashion, resulting in major reductions of infectious virus release. The immunotoxin and ganciclovir, an inhibitor of viral DNA replication, showed marked reciprocal potentiation of antiviral activities. These results suggest that the immunotoxin, alone or in combination, may represent a new approach to treat diseases associated with KSHV lytic replication. PMID:22377676

  16. PRMT5 Is Upregulated in HTLV-1-Mediated T-Cell Transformation and Selective Inhibition Alters Viral Gene Expression and Infected Cell Survival.

    PubMed

    Panfil, Amanda R; Al-Saleem, Jacob; Howard, Cory M; Mates, Jessica M; Kwiek, Jesse J; Baiocchi, Robert A; Green, Patrick L

    2015-12-30

    Human T-cell leukemia virus type-1 (HTLV-1) is a tumorigenic retrovirus responsible for development of adult T-cell leukemia/lymphoma (ATLL). This disease manifests after a long clinical latency period of up to 2-3 decades. Two viral gene products, Tax and HBZ, have transforming properties and play a role in the pathogenic process. Genetic and epigenetic cellular changes also occur in HTLV-1-infected cells, which contribute to transformation and disease development. However, the role of cellular factors in transformation is not completely understood. Herein, we examined the role of protein arginine methyltransferase 5 (PRMT5) on HTLV-1-mediated cellular transformation and viral gene expression. We found PRMT5 expression was upregulated during HTLV-1-mediated T-cell transformation, as well as in established lymphocytic leukemia/lymphoma cell lines and ATLL patient PBMCs. shRNA-mediated reduction in PRMT5 protein levels or its inhibition by a small molecule inhibitor (PRMT5i) in HTLV-1-infected lymphocytes resulted in increased viral gene expression and decreased cellular proliferation. PRMT5i also had selective toxicity in HTLV-1-transformed T-cells. Finally, we demonstrated that PRMT5 and the HTLV-1 p30 protein had an additive inhibitory effect on HTLV-1 gene expression. Our study provides evidence for PRMT5 as a host cell factor important in HTLV-1-mediated T-cell transformation, and a potential target for ATLL treatment.

  17. Clinical and Serologic Response to the 23-valent Polysaccharide Pneumococcal Vaccine in Children and Teens with Recurrent Upper Respiratory Tract Infections and Selective Antibody Deficiency.

    PubMed

    Estrada, Jaime; Najera, Maria; Pounds, Natalie; Catano, Gabriel; Infante, Anthony J

    2016-02-01

    We report the clinical and serological response of 72 children and adolescents after immunization with the 23-valent polysaccharide pneumococcal vaccine (PPV23). All had been diagnosed with recurrent upper respiratory tract infections and low antipneumococcal immunity. Forty-five (62%) of these patients had received PCV7, the 7-serotype pneumococcal conjugated vaccine (Prevnar7). After immunization with the polysaccharide vaccine, 69 (96%) patients, including 42 of the 45 who had previously been immunized with the conjugate vaccine, had a positive clinical response including 12 patients (17%) whose serological response to the polysaccharide vaccine was inadequate. Clinical and serological response to PPV23 was assessed at approximately 1, 3 and 6 months after immunization. Our study also confirmed that a small group of patients with recurrent upper respiratory tract infections are unable to develop a normal response to pneumococcal and other bacterial polysaccharides despite vaccination with the newer conjugated vaccines. This immunodeficiency has been named selective antibody deficiency with normal immunoglobulins or impaired polysaccharide responsiveness. These patients did well after administration of intravenous IgG.

  18. Impact of clonal competition for peptide-MHC complexes on the CD8[superscript +] T-cell repertoire selection in a persistent viral infection

    SciTech Connect

    Wynn, Katherine K.; Fulton, Zara; Cooper, Leanne; Silins, Sharon L.; Gras, Stephanie; Archbold, Julia K.; Tynan, Fleur E.; Miles, John J.; McCluskey, James; Burrows, Scott R.; Rossjohn, Jamie; Khanna, Rajiv

    2008-04-29

    CD8{sup +} T-cell responses to persistent viral infections are characterized by the accumulation of an oligoclonal T-cell repertoire and a reduction in the naive T-cell pool. However, the precise mechanism for this phenomenon remains elusive. Here we show that human cytomegalovirus (HCMV)-specific CD8{sup +} T cells recognizing distinct epitopes from the pp65 protein and restricted through an identical HLA class I allele (HLA B*3508) exhibited either a highly conserved public T-cell repertoire or a private, diverse T-cell response, which was uniquely altered in each donor following in vitro antigen exposure. Selection of a public T-cell receptor (TCR) was coincident with an atypical major histocompatibility complex (MHC)-peptide structure, in that the epitope adopted a helical conformation that bulged from the peptide-binding groove, while a diverse TCR profile was observed in response to the epitope that formed a flatter, more 'featureless' landscape. Clonotypes with biased TCR usage demonstrated more efficient recognition of virus-infected cells, a greater CD8 dependency, and were more terminally differentiated in their phenotype when compared with the T cells expressing diverse TCR. These findings provide new insights into our understanding on how the biology of antigen presentation in addition to the structural features of the pMHC-I might shape the T-cell repertoire and its phenotype.

  19. Why do animals repeat displays?

    PubMed

    Payne; Pagel

    1997-07-01

    Both agonistic and sexual animal displays often involve more than one performance of some specific display action. Since repetition is energetically costly there must be good reasons why a signaller should carry out such repetitive actions, rather than simply displaying once. We briefly review three different 'reasons' which arise from three different receiver assessment rules: when assessment is based on the average magnitude of all display actions so far, the reason for the repetition is to improve the accuracy of the estimate (model A); when the assessment is based solely on the action of greatest magnitude so far, the repetition is to replace the signal with one of greater magnitude (model B); when the assessment is based on the cumulative sum of all display actions so far, the repetition is to augment that sum (model C). We discuss how to characterize each case from an understanding of its expected optimal behaviour as predicted by formal models. For model A the mean magnitude of display actions should stay constant and the contest duration should depend on relative qualities. In models B and C the encounter duration depends only on the weaker participant. In model B each display action is greater than the previous, but only a small number of steps are expected. In model C the magnitude of display actions can either escalate, stay constant, or even decrease. The displays of cichlid fish, the roaring contests of red deer, Cervus elaphusthe calling of Blanchard's cricket frogs, Acris crepitans blanchardiand the pheromonal exchanges of yeast gametes are used as illustrative examples.

  20. Vaccine-Induced Simian Immunodeficiency Virus-Specific CD8+ T-Cell Responses Focused on a Single Nef Epitope Select for Escape Variants Shortly after Infection

    PubMed Central

    Tully, Damien C.; Cruz, Michael A.; Power, Karen A.; Veloso de Santana, Marlon G.; Bean, David J.; Ogilvie, Colin B.; Gadgil, Rujuta; Lima, Noemia S.; Magnani, Diogo M.; Ejima, Keisuke; Allison, David B.; Piatak, Michael; Altman, John D.; Parks, Christopher L.; Rakasz, Eva G.; Capuano, Saverio; Galler, Ricardo; Bonaldo, Myrna C.; Lifson, Jeffrey D.; Allen, Todd M.; Watkins, David I.

    2015-01-01

    example of an effective immune response against HIV/SIV, elucidating the basis of this phenomenon may provide useful insights into how to elicit such responses by vaccination. We have previously established that vaccine-induced CD8+ T-cell responses against three immunodominant epitopes can increase the incidence of elite control in SIV-infected Mamu-B*08+ rhesus macaques—a model of HLA-B*27-mediated elite control. Here, we investigated whether a monotypic vaccine-induced CD8+ T-cell response targeting the conserved “late-escaping” Nef RL10 epitope can increase the incidence of elite control in Mamu-B*08+ monkeys. Surprisingly, vaccine-induced Nef RL10-specific CD8+ T cells selected for variants within days after infection and, ultimately, did not facilitate the development of elite control. Elite control is, therefore, likely to involve CD8+ T-cell responses against more than one epitope. Together, these results underscore the complexity and multidimensional nature of virologic control of lentivirus infection. PMID:26292326