1
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O’Rourke D, Gravato-Nobre MJ, Stroud D, Pritchett E, Barker E, Price RL, Robinson SA, Spiro S, Kuwabara P, Hodgkin J. Isolation and molecular identification of nematode surface mutants with resistance to bacterial pathogens. G3 (Bethesda) 2023; 13:jkad056. [PMID: 36911920 PMCID: PMC10151413 DOI: 10.1093/g3journal/jkad056] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/14/2023]
Abstract
Numerous mutants of the nematode Caenorhabditis elegans with surface abnormalities have been isolated by utilizing their resistance to a variety of bacterial pathogens (Microbacterium nematophilum, Yersinia pseudotuberculosis, and 2 Leucobacter strains), all of which are able to cause disease or death when worms are grown on bacterial lawns containing these pathogens. Previous work led to the identification of 9 srf or bus genes; here, we report molecular identification and characterization of a further 10 surface-affecting genes. Three of these were found to encode factors implicated in glycosylation (srf-2, bus-5, and bus-22), like several of those previously reported; srf-2 belongs to the GT92 family of putative galactosyltransferases, and bus-5 is homologous to human dTDP-D-glucose 4,6-dehydratase, which is implicated in Catel-Manzke syndrome. Other genes encoded proteins with sequence similarity to phosphatidylinositol phosphatases (bus-6), Patched-related receptors (ptr-15/bus-13), steroid dehydrogenases (dhs-5/bus-21), or glypiation factors (bus-24). Three genes appeared to be nematode-specific (srf-5, bus-10, and bus-28). Many mutants exhibited cuticle fragility as revealed by bleach and detergent sensitivity; this fragility was correlated with increased drug sensitivity, as well as with abnormal skiddy locomotion. Most of the genes examined were found to be expressed in epidermal seam cells, which appear to be important for synthesizing nematode surface coat. The results reveal the genetic and biochemical complexity of this critical surface layer, and provide new tools for its analysis.
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Affiliation(s)
- Delia O’Rourke
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | | | - Dave Stroud
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Emily Pritchett
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Emily Barker
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Rebecca L Price
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Sarah A Robinson
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Simon Spiro
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | | | - Jonathan Hodgkin
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
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2
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Mathews EA, Stroud D, Mullen GP, Gavriilidis G, Duerr JS, Rand JB, Hodgkin J. Allele-specific suppression in C. elegans reveals details of EMS mutagenesis and a possible moonlighting interaction between the vesicular acetylcholine transporter and ERD2 receptors. Genetics 2021; 218:6259149. [PMID: 33914877 PMCID: PMC8664489 DOI: 10.1093/genetics/iyab065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/17/2021] [Indexed: 11/12/2022] Open
Abstract
A missense mutant, unc-17(e245), which affects the Caenorhabditis elegans vesicular acetylcholine transporter UNC-17, has a severe uncoordinated phenotype, allowing efficient selection of dominant suppressors that revert this phenotype to wild-type. Such selections permitted isolation of numerous suppressors after EMS (ethyl methanesulfonate) mutagenesis, leading to demonstration of delays in mutation fixation after initial EMS treatment, as has been shown in T4 bacteriophage but not previously in eukaryotes. Three strong dominant extragenic suppressor loci have been defined, all of which act specifically on allele e245, which causes a G347R mutation in UNC-17. Two of the suppressors (sup-1 and sup-8/snb-1) have previously been shown to encode synaptic proteins able to interact directly with UNC-17. We found that the remaining suppressor, sup-2, corresponds to a mutation in erd-2.1, which encodes an endoplasmic reticulum retention protein; sup-2 causes a V186E missense mutation in transmembrane helix 7 of ERD-2.1. The same missense change introduced into the redundant paralogous gene erd-2.2 also suppressed unc-17(e245). Suppression presumably occurred by compensatory charge interactions between transmembrane helices of UNC-17 and ERD-2.1 or ERD-2.2, as previously proposed in work on suppression by SUP-1(G84E) or SUP-8(I97D)/synaptobrevin. erd-2.1(V186E) homozygotes were fully viable, but erd-2.1(V186E); erd-2.2(RNAi) exhibited synthetic lethality (like erd-2.1(RNAi); erd-2.2(RNAi)), indicating that the missense change in ERD-2.1 impairs its normal function in the secretory pathway but may allow it to adopt a novel moonlighting function as an unc-17 suppressor.
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Affiliation(s)
- Eleanor A Mathews
- Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Dave Stroud
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Gregory P Mullen
- Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | | | - Janet S Duerr
- Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.,Department of Biological Sciences, Ohio University, Athens, Ohio 45701, USA
| | - James B Rand
- Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.,Oklahoma Center for Neuroscience, Oklahoma City, Oklahoma 73104, USA
| | - Jonathan Hodgkin
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
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3
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Lambeta M, Chou PW, Tian S, Yang B, Maloon B, Most VR, Stroud D, Santos R, Byagowi A, Kammerer G, Jayaraman D, Calandra R. DIGIT: A Novel Design for a Low-Cost Compact High-Resolution Tactile Sensor With Application to In-Hand Manipulation. IEEE Robot Autom Lett 2020. [DOI: 10.1109/lra.2020.2977257] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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4
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GRANATA C, Thallas-Bonke V, Qin C, Laskowski A, Jap E, Ramm G, Cooper M, Stroud D, Ritchie R, Coughlan M. SAT-105 GLUCOSE-DEPENDENT MITOCHONDRIAL ALTERATIONS IN DIABETIC KIDNEY DISEASE. Kidney Int Rep 2019. [DOI: 10.1016/j.ekir.2019.05.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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5
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Stroud D. SU-E-T-619: Planning 131I Thyroid Treatments for Patients Requiring Hemodialysis. Med Phys 2015. [DOI: 10.1118/1.4924982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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6
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Loer CM, Calvo AC, Watschinger K, Werner-Felmayer G, O'Rourke D, Stroud D, Tong A, Gotenstein JR, Chisholm AD, Hodgkin J, Werner ER, Martinez A. Cuticle integrity and biogenic amine synthesis in Caenorhabditis elegans require the cofactor tetrahydrobiopterin (BH4). Genetics 2015; 200:237-53. [PMID: 25808955 PMCID: PMC4423366 DOI: 10.1534/genetics.114.174110] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 03/12/2015] [Indexed: 11/18/2022] Open
Abstract
Tetrahydrobiopterin (BH4) is the natural cofactor of several enzymes widely distributed among eukaryotes, including aromatic amino acid hydroxylases (AAAHs), nitric oxide synthases (NOSs), and alkylglycerol monooxygenase (AGMO). We show here that the nematode Caenorhabditis elegans, which has three AAAH genes and one AGMO gene, contains BH4 and has genes that function in BH4 synthesis and regeneration. Knockout mutants for putative BH4 synthetic enzyme genes lack the predicted enzymatic activities, synthesize no BH4, and have indistinguishable behavioral and neurotransmitter phenotypes, including serotonin and dopamine deficiency. The BH4 regeneration enzymes are not required for steady-state levels of biogenic amines, but become rate limiting in conditions of reduced BH4 synthesis. BH4-deficient mutants also have a fragile cuticle and are generally hypersensitive to exogenous agents, a phenotype that is not due to AAAH deficiency, but rather to dysfunction in the lipid metabolic enzyme AGMO, which is expressed in the epidermis. Loss of AGMO or BH4 synthesis also specifically alters the sensitivity of C. elegans to bacterial pathogens, revealing a cuticular function for AGMO-dependent lipid metabolism in host-pathogen interactions.
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Affiliation(s)
- Curtis M Loer
- Department of Biology, University of San Diego, San Diego, California, 92110
| | - Ana C Calvo
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
| | - Katrin Watschinger
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, A-6020 Innsbruck, Austria
| | - Gabriele Werner-Felmayer
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, A-6020 Innsbruck, Austria
| | - Delia O'Rourke
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Dave Stroud
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Amy Tong
- Division of Biological Sciences, University of California, San Diego, California 92093
| | - Jennifer R Gotenstein
- Division of Biological Sciences, University of California, San Diego, California 92093
| | - Andrew D Chisholm
- Division of Biological Sciences, University of California, San Diego, California 92093
| | - Jonathan Hodgkin
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Ernst R Werner
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, A-6020 Innsbruck, Austria
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
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7
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Parsons LM, Mizanur RM, Jankowska E, Hodgkin J, O′Rourke D, Stroud D, Ghosh S, Cipollo JF. Caenorhabditis elegans bacterial pathogen resistant bus-4 mutants produce altered mucins. PLoS One 2014; 9:e107250. [PMID: 25296196 PMCID: PMC4189790 DOI: 10.1371/journal.pone.0107250] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 08/13/2014] [Indexed: 11/25/2022] Open
Abstract
Caenorabditis elegans bus-4 glycosyltransferase mutants are resistant to infection by Microbacterium nematophilum, Yersinia pestis and Yersinia pseudotuberculosis and have altered susceptibility to two Leucobacter species Verde1 and Verde2. Our objective in this study was to define the glycosylation changes leading to this phenotype to better understand how these changes lead to pathogen resistance. We performed MALDI-TOF MS, tandem MS and GC/MS experiments to reveal fine structural detail for the bus-4 N- and O-glycan pools. We observed dramatic changes in O-glycans and moderate ones in N-glycan pools compared to the parent strain. Ce core-I glycans, the nematode's mucin glycan equivalent, were doubled in abundance, halved in charge and bore shifts in terminal substitutions. The fucosyl O-glycans, Ce core-II and neutral fucosyl forms, were also increased in abundance as were fucosyl N-glycans. Quantitative expression analysis revealed that two mucins, let-653 and osm-8, were upregulated nearly 40 fold and also revealed was a dramatic increase in GDP-Man 4,6 dehydratease expression. We performed detailed lectin binding studies that showed changes in glycoconjugates in the surface coat, cuticle surface and intestine. The combined changes in cell surface glycoconjugate distribution, increased abundance and altered properties of mucin provide an environment where likely the above pathogens are not exposed to normal glycoconjugate dependent cues leading to barriers to these bacterial infections.
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Affiliation(s)
- Lisa M. Parsons
- Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America
| | - Rahman M. Mizanur
- Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America
| | - Ewa Jankowska
- Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America
| | - Jonathan Hodgkin
- Genetics Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Delia O′Rourke
- Genetics Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Dave Stroud
- Genetics Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Salil Ghosh
- Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America
| | - John F. Cipollo
- Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America
- * E-mail:
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8
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Hodgkin J, Félix MA, Clark LC, Stroud D, Gravato-Nobre MJ. Two Leucobacter strains exert complementary virulence on Caenorhabditis including death by worm-star formation. Curr Biol 2013; 23:2157-61. [PMID: 24206844 PMCID: PMC3898767 DOI: 10.1016/j.cub.2013.08.060] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 08/09/2013] [Accepted: 08/30/2013] [Indexed: 01/26/2023]
Abstract
The nematode Caenorhabditis elegans has been much studied as a host for microbial infection. Some pathogens can infect its intestine, while others attack via its external surface. Cultures of Caenorhabditis isolated from natural environments have yielded new nematode pathogens, such as microsporidia and viruses. We report here a novel mechanism for bacterial attack on worms, discovered during investigation of a diseased and coinfected natural isolate of Caenorhabditis from Cape Verde. Two related coryneform pathogens (genus Leucobacter) were obtained from this isolate, which had complementary effects on C. elegans and related nematodes. One pathogen, Verde1, was able to cause swimming worms to stick together irreversibly by their tails, leading to the rapid formation of aggregated "worm-stars." Adult worms trapped in these aggregates were immobilized and subsequently died, with concomitant growth of bacteria. Trapped larval worms were sometimes able to escape from worm-stars by undergoing autotomy, separating their bodies into two parts. The other pathogen, Verde2, killed worms after rectal invasion, in a more virulent version of a previously studied infection. Resistance to killing by Verde2, by means of alterations in host surface glycosylation, resulted in hypersensitivity to Verde1, revealing a trade-off in bacterial susceptibility. Conversely, a sublethal surface infection of worms with Verde1 conferred partial protection against Verde2. The formation of worm-stars by Verde1 occurred only when worms were swimming in liquid but provides a striking example of asymmetric warfare as well as a bacterial equivalent to the trapping strategies used by nematophagous fungi.
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Affiliation(s)
- Jonathan Hodgkin
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
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9
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Bhallamudi VP, Wolfe CS, Amin VP, Labanowski DE, Berger AJ, Stroud D, Sinova J, Hammel PC. Experimental demonstration of scanned spin-precession microscopy. Phys Rev Lett 2013; 111:117201. [PMID: 24074116 DOI: 10.1103/physrevlett.111.117201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Indexed: 06/02/2023]
Abstract
We present a new tool for imaging spin properties. We show that a spatially averaged spin signal, measured as a function of a scanned magnetic probe's position, contains information about the local spin properties. In this first demonstration we map the injected spin density in GaAs by measuring spin photoluminescence with a resolution of 1.2 μm. The ultimate limit of the technique is set by the gradient of the probe's field, allowing for a resolution beyond the optical diffraction limit. Such probes can also be integrated with other detection methods. This generality allows the technique to be extended to buried interfaces and optically inactive materials.
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Affiliation(s)
- V P Bhallamudi
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
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10
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Kim K, Stroud D. Photonic band structures of periodic arrays of pores in a metallic host: tight-binding beyond the quasistatic approximation. Opt Express 2013; 21:19834-19849. [PMID: 24105532 DOI: 10.1364/oe.21.019834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have calculated the photonic band structures of metallic inverse opals and of periodic linear chains of spherical pores in a metallic host, below a plasma frequency ωp. In both cases, we use a tight-binding approximation, assuming a Drude dielectric function for the metallic component, but without making the quasistatic approximation. The tight-binding modes are linear combinations of the single-cavity transverse magnetic (TM) modes. For the inverse-opal structures, the lowest modes are analogous to those constructed from the three degenerate atomic p-states in fcc crystals. For the linear chains, in the limit of small spheres compared to a wavelength, the results bear some qualitative resemblance to the dispersion relation for metal spheres in an insulating host, as calculated by Brongersma et al. [Phys. Rev. B 62, R16356 (2000)]. Because the electromagnetic fields of these modes decay exponentially in the metal, there are no radiative losses, in contrast to the case of arrays of metallic spheres in air. We suggest that this tight-binding approach to photonic band structures of such metallic inverse materials may be a useful approach for studying photonic crystals containing metallic components, even beyond the quasistatic approximation.
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11
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Gravato-Nobre MJ, Stroud D, O'Rourke D, Darby C, Hodgkin J. Glycosylation genes expressed in seam cells determine complex surface properties and bacterial adhesion to the cuticle of Caenorhabditis elegans. Genetics 2011; 187:141-55. [PMID: 20980242 PMCID: PMC3018313 DOI: 10.1534/genetics.110.122002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 10/19/2010] [Indexed: 11/18/2022] Open
Abstract
The surface of the nematode Caenorhabditis elegans is poorly understood but critical for its interactions with the environment and with pathogens. We show here that six genes (bus-2, bus-4, and bus-12, together with the previously cloned srf-3, bus-8, and bus-17) encode proteins predicted to act in surface glycosylation, thereby affecting disease susceptibility, locomotory competence, and sexual recognition. Mutations in all six genes cause resistance to the bacterial pathogen Microbacterium nematophilum, and most of these mutations also affect bacterial adhesion and biofilm formation by Yersinia species, demonstrating that both infection and biofilm formation depend on interaction with complex surface carbohydrates. A new bacterial interaction, involving locomotory inhibition by a strain of Bacillus pumilus, reveals diversity in the surface properties of these mutants. Another biological property--contact recognition of hermaphrodites by males during mating--was also found to be impaired in mutants of all six genes. An important common feature is that all are expressed most strongly in seam cells, rather than in the main hypodermal syncytium, indicating that seam cells play the major role in secreting surface coat and consequently in determining environmental interactions. To test for possible redundancies in gene action, the 15 double mutants for this set of genes were constructed and examined, but no synthetic phenotypes were observed. Comparison of the six genes shows that each has distinctive properties, suggesting that they do not act in a linear pathway.
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Affiliation(s)
- Maria J. Gravato-Nobre
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom and Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
| | - Dave Stroud
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom and Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
| | - Delia O'Rourke
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom and Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
| | - Creg Darby
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom and Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
| | - Jonathan Hodgkin
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom and Department of Cell and Tissue Biology, University of California, San Francisco, California 94143
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12
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Palaima E, Leymarie N, Stroud D, Mizanur RM, Hodgkin J, Gravato-Nobre MJ, Costello CE, Cipollo JF. The Caenorhabditis elegans bus-2 mutant reveals a new class of O-glycans affecting bacterial resistance. J Biol Chem 2010; 285:17662-72. [PMID: 20385555 PMCID: PMC2878530 DOI: 10.1074/jbc.m109.065433] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 04/02/2010] [Indexed: 11/06/2022] Open
Abstract
Microbacterium nematophilum causes a deleterious infection of the C. elegans hindgut initiated by adhesion to rectal and anal cuticle. C. elegans bus-2 mutants, which are resistant to M. nematophilum and also to the formation of surface biofilms by Yersinia sp., carry genetic lesions in a putative glycosyltransferase containing conserved domains of core-1 beta1,3-galactosyltransferases. bus-2 is predicted to act in the synthesis of core-1 type O-glycans. This observation implies that the infection requires the presence of host core-1 O-glycoconjugates and is therefore carbohydrate-dependent. Chemical analysis reported here reveals that bus-2 is indeed deficient in core-1 O-glycans. These mutants also exhibit a new subclass of O-glycans whose structures were determined by high performance tandem mass spectrometry; these are highly fucosylated and have a novel core that contains internally linked GlcA. Lectin studies showed that core-1 glycans and this novel class of O-glycans are both expressed in the tissue that is infected in the wild type worms. In worms having the bus-2 genetic background, core-1 glycans are decreased, whereas the novel fucosyl O-glycans are increased in abundance in this region. Expression analysis using a red fluorescent protein marker showed that bus-2 is expressed in the posterior gut, cuticle seam cells, and spermatheca, the first two of which are likely to be involved in secreting the carbohydrate-rich surface coat of the cuticle. Therefore, in the bus-2 background of reduced core-1 O-glycans, the novel fucosyl glycans likely replace or mask remaining core-1 ligands, leading to the resistance phenotype. There are more than 35 Microbacterium species, some of which are pathogenic in man. This study is the first to analyze the biochemistry of adhesion to a host tissue by a Microbacterium species.
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Affiliation(s)
- Elizabeth Palaima
- From the Departments of Biochemistry and Molecular Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Nancy Leymarie
- From the Departments of Biochemistry and Molecular Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Dave Stroud
- the Genetics Unit, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom, and
| | - Rahman M. Mizanur
- the Center for Biologics Evaluation and Research, United States Food and Drug Administration, Bethesda, Maryland 20892
| | - Jonathan Hodgkin
- the Genetics Unit, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom, and
| | - Maria J. Gravato-Nobre
- the Genetics Unit, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom, and
| | - Catherine E. Costello
- From the Departments of Biochemistry and Molecular Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
| | - John F. Cipollo
- From the Departments of Biochemistry and Molecular Medicine, Boston University School of Medicine, Boston, Massachusetts 02118
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Abstract
We show that, when a gold nanoparticle is coated by a thin layer of nematic liquid crystal, the nanoparticle surface has a strong effect on the director orientation, but, surprisingly, this deformation can enhance the surface plasmon splitting. We consider three plausible liquid crystal director configurations in zero electric field: boojum pair (north-south pole configuration), baseball (tetrahedral), and homogeneous. From the discrete dipole approximation, we find that the surface plasmon splitting is largest for the boojum pair, and this result is in good agreement with experiment.
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Affiliation(s)
- Sung Yong Park
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
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14
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Trees BR, Saranathan V, Stroud D. Synchronization in disordered Josephson junction arrays: small-world connections and the Kuramoto model. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 71:016215. [PMID: 15697706 DOI: 10.1103/physreve.71.016215] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Indexed: 05/24/2023]
Abstract
We study synchronization in disordered arrays of Josephson junctions. In the first half of the paper, we consider the relation between the coupled resistively and capacitively shunted junction (RCSJ) equations for such arrays and effective phase models of the Winfree type. We describe a multiple-time-scale analysis of the RCSJ equations for a ladder array of junctions with non-negligible capacitance in which we arrive at a second order phase model that captures well the synchronization physics of the RCSJ equations for that geometry. In the second half of the paper, motivated by recent work on small-world networks, we study the effect on synchronization of random, long-range connections between pairs of junctions. We consider the effects of such shortcuts on ladder arrays, finding that the shortcuts make it easier for the array of junctions in the nonzero voltage state to synchronize. In two-dimensional (2D) arrays we find that the additional shortcut junctions are only marginally effective at inducing synchronization of the active junctions. The differences in the effects of shortcut junctions in 1D and 2D can be partly understood in terms of an effective phase model.
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Affiliation(s)
- B R Trees
- Department of Physics and Astronomy, Ohio Wesleyan University, Delaware, Ohio 43015, USA.
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15
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Almaas E, Kulkarni RV, Stroud D. Scaling properties of random walks on small-world networks. Phys Rev E Stat Nonlin Soft Matter Phys 2003; 68:056105. [PMID: 14682844 DOI: 10.1103/physreve.68.056105] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2003] [Indexed: 05/24/2023]
Abstract
Using both numerical simulations and scaling arguments, we study the behavior of a random walker on a one-dimensional small-world network. For the properties we study, we find that the random walk obeys a characteristic scaling form. These properties include the average number of distinct sites visited by the random walker, the mean-square displacement of the walker, and the distribution of first-return times. The scaling form has three characteristic time regimes. At short times, the walker does not see the small-world shortcuts and effectively probes an ordinary Euclidean network in d dimensions. At intermediate times, the properties of the walker shows scaling behavior characteristic of an infinite small-world network. Finally, at long times, the finite size of the network becomes important, and many of the properties of the walker saturate. We propose general analytical forms for the scaling properties in all three regimes, and show that these analytical forms are consistent with our numerical simulations.
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Affiliation(s)
- E Almaas
- Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA.
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Welch RA, Burland V, Plunkett G, Redford P, Roesch P, Rasko D, Buckles EL, Liou SR, Boutin A, Hackett J, Stroud D, Mayhew GF, Rose DJ, Zhou S, Schwartz DC, Perna NT, Mobley HLT, Donnenberg MS, Blattner FR. Extensive mosaic structure revealed by the complete genome sequence of uropathogenic Escherichia coli. Proc Natl Acad Sci U S A 2002; 99:17020-4. [PMID: 12471157 PMCID: PMC139262 DOI: 10.1073/pnas.252529799] [Citation(s) in RCA: 1026] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We present the complete genome sequence of uropathogenic Escherichia coli, strain CFT073. A three-way genome comparison of the CFT073, enterohemorrhagic E. coli EDL933, and laboratory strain MG1655 reveals that, amazingly, only 39.2% of their combined (nonredundant) set of proteins actually are common to all three strains. The pathogen genomes are as different from each other as each pathogen is from the benign strain. The difference in disease potential between O157:H7 and CFT073 is reflected in the absence of genes for type III secretion system or phage- and plasmid-encoded toxins found in some classes of diarrheagenic E. coli. The CFT073 genome is particularly rich in genes that encode potential fimbrial adhesins, autotransporters, iron-sequestration systems, and phase-switch recombinases. Striking differences exist between the large pathogenicity islands of CFT073 and two other well-studied uropathogenic E. coli strains, J96 and 536. Comparisons indicate that extraintestinal pathogenic E. coli arose independently from multiple clonal lineages. The different E. coli pathotypes have maintained a remarkable synteny of common, vertically evolved genes, whereas many islands interrupting this common backbone have been acquired by different horizontal transfer events in each strain.
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Affiliation(s)
- R A Welch
- Department of Medical Microbiology and Immunology, Laboratory of Genetics, Genome Center of Wisconsin, and Animal Health and Biological Sciences, University of Wisconsin, Madison, WI 53706, USA
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Abstract
We give exact relations for small-world networks (SWN's) which are independent of the "degree distribution," i.e., the distribution of nearest-neighbor connections. For the original SWN model, we illustrate how these exact relations can be used to obtain approximations for the corresponding basic probability distribution. In the limit of large system sizes and small disorder, we use numerical studies to obtain a functional fit for this distribution. Finally, we obtain the scaling properties for the mean-square displacement of a random walker, which are determined by the scaling behavior of the underlying SWN.
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Affiliation(s)
- E Almaas
- Department of Physics, The Ohio State University, Columbus, OH 43210, USA.
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19
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Tang CM, Stroud D, Mackinnon F, Makepeace K, Plested J, Moxon ER, Chalmers R. Genetic linkage analysis to identify a gene required for the addition of phosphoethanolamine to meningococcal lipopolysaccharide. Gene 2002; 284:133-40. [PMID: 11891054 DOI: 10.1016/s0378-1119(02)00383-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lipopolysaccharide (LPS) is important for the virulence of Neisseria meningitidis, and is the target of immune responses. We took advantage of a monoclonal antibody (Mab B5) that recognises phosphoethanolamine (PEtn) attached to the inner core of meningococcal LPS to identify genes required for the addition of PEtn to LPS. Insertional mutants that lost Mab B5 reactivity were isolated and characterised, but failed to yield genes directly responsible for PEtn substitution. Subsequent genetic linkage analysis was used to define a region of DNA containing a single intact open reading frame which is sufficient to confer B5 reactivity to a B5 negative meningococcal isolate. The results provide an initial characterisation of the genetic basis of a key, immunodominant epitope of meningococcal LPS.
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Affiliation(s)
- Christoph M Tang
- Department of Infectious Diseases, Centre for Molecular Microbiology and Infection, Imperial College of Science, Technology, and Medicine, Armstrong Road, London SW7 2AZ, UK.
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Abstract
Strains of Escherichia coli expressing the K1 polysaccharide capsule colonize the large intestine of newborn infants, and are the leading cause of Gram-negative septicaemia and meningitis in the neonatal period. We used signature-tagged mutagenesis (STM) to identify genes that E. coli K1 requires to colonize the gastrointestinal (GI) tract. A total of 2140 mTn5 mutants was screened for their capacity to colonize the GI tract of infant rats, and 16 colonization defective mutants were identified. The mutants have transposon insertions in genes affecting the synthesis of cell surface structures, membrane transporters, transcriptional regulators, enzymes in metabolic pathways, and in genes of unknown function, designated dgc (defective in GI colonization). Three dgcs are absent from the whole genome sequence of E. coli K-12, although related sequences are found in other pathogenic strains of E. coli and in Shigella flexneri. Additionally, immunohistochemistry was used to define the nature of the colonization defect in five mutants including all dgc mutants. STM was successfully applied to examine the factors involved in E. coli K1 colonization, and the findings are relevant to the pathogenesis of other enteric infections.
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Affiliation(s)
- J Martindale
- University Department of Paediatrics, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK
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21
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Ward LC, Heitmann BL, Craig P, Stroud D, Azinge EC, Jebb S, Cornish BH, Swinburn B, O'Dea K, Rowley K, McDermott R, Thomas BJ, Leonard D. Association between ethnicity, body mass index, and bioelectrical impedance. Implications for the population specificity of prediction equations. Ann N Y Acad Sci 2000; 904:199-202. [PMID: 10865738 DOI: 10.1111/j.1749-6632.2000.tb06449.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- L C Ward
- Department of Biochemistry, University of Queensland, Brisbane, Australia.
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22
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Kulkarni RV, Almaas E, Stroud D. Exact results and scaling properties of small-world networks. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 61:4268-4271. [PMID: 11088222 DOI: 10.1103/physreve.61.4268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/1999] [Indexed: 05/23/2023]
Abstract
We study the distribution function for minimal paths in small-world networks. We derive its general form, which we verify numerically, and also discuss its scaling properties. Using the general form of this distribution function, we derive exact expressions for the average minimal distance &lmacr; and its variance sigma(2). Finally, we study the limit of large system sizes and obtain some approximate results.
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Affiliation(s)
- RV Kulkarni
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
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23
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Arora P, Strauss BJ, Borovnicar D, Stroud D, Atkins RC, Kerr PG. Total body nitrogen predicts long-term mortality in haemodialysis patients--a single-centre experience. Nephrol Dial Transplant 1998; 13:1731-6. [PMID: 9681720 DOI: 10.1093/ndt/13.7.1731] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND It has been estimated that 30-50% of adult haemodialysis patients have moderate to severe malnutrition. We have previously shown that estimation of total body nitrogen, expressed as a nitrogen index (NI) by in vivo neutron activation analysis (IVNAA) is an accurate tool for estimating total body protein in dialysis patients. It is not clear whether the nitrogen index is predictive of mortality and morbidity in dialysis patients. METHODS We studied the long-term predictive value of nutritional assessment by IVNAA and serum albumin on mortality and morbidity (including infection episodes requiring hospital admission, ischaemic heart disease (IHD), cerebrovascular or peripheral vascular disease (PVD). Seventy-six chronic haemodialysis patients were initially studied between 1989 and 1991, with a minimum follow-up of 5 years. The mean age of the patients was 48.3 years (range 21-76). Patients were divided into two groups, group I, n = 22, had a NI < or = 0.8 (NI < or = 0.8 represents protein malnutrition) and group II, n = 54, had a NI > 0.8. RESULTS Fifteen patients in group II died in the follow-up period compared to nine from group I (P < 0.05), but NI < or = 0.8 did not predict vascular or infective morbidity. Serum albumins < or = 35 g/day did predict over all mortality (P < 0.05) as well as infection episodes (P < 0.001). When patients above the age of 50 years were analysed, NI did predict mortality (P < 0.05) but serum albumin did not, while the age of> 50 itself was a strong predictor of mortality (P < 0.001). CONCLUSION We conclude that NI < or = 0.8 is predictive of long-term mortality. This reinforces the view that low body protein stores are predictive of increased mortality in dialysis patients and that the serum albumin is predictive of mortality because of its reflection of protein stores.
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Affiliation(s)
- P Arora
- Nephrology Unit, Monash Medical Centre, Clayton, Victoria, Australia
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24
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Lambert JR, Tai E, Strauss B, Blackwell L, Manolitsas N, Marks S, Bainbridge R, Stroud D, Wahlqvist ML. Nutritional and pulmonary function assessment in chronic obstructive pulmonary disease: Effects of nutritional supplementation. Asia Pac J Clin Nutr 1998; 7:88-93. [PMID: 24394903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We found that with oral supplementation by a liquid soy-based protein hydrolysate in malnourished COPD patients (BMI <= 20), it possible to increase weight over a 6-week period, and body water and an index of muscle mass (MAMC), but not total body nitrogen (TBN judged by Nitrogen Index) which identifies a particular challenge for nutrition support in COPD patients. There was no associated improvement in pulmonary function but we found that better nourished COPD patients (BMI > 20) had some pulmonary function advantage; it is suggested that TBN may need to improve with nutrition support for pulmonary function to improve.
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Affiliation(s)
- J R Lambert
- Department of Medicine, Monash Medical Centre, Monash University, Melbourne, Victoria, Australia
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25
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Pulford K, Lamant L, Morris SW, Butler LH, Wood KM, Stroud D, Delsol G, Mason DY. Detection of anaplastic lymphoma kinase (ALK) and nucleolar protein nucleophosmin (NPM)-ALK proteins in normal and neoplastic cells with the monoclonal antibody ALK1. Blood 1997; 89:1394-404. [PMID: 9028963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The t(2;5)(p23;q35) translocation, associated with anaplastic large-cell lymphoma (ALCL), results in the production of the nucleolar protein nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) protein. This report describes an immunocytochemical study of the distribution of ALK and NPM-ALK proteins using a new monoclonal antibody, ALK1, that recognizes a formalin resistant epitope in both the 80-kD NPM-ALK chimeric and the 200-kD normal human ALK proteins. Cytoplasmic and nuclear labeling was seen in the t(2;5)+ SU-DHL-1 and Karpas 299 cell lines. Normal ALK protein expression was restricted to the central nervous system (in scattered neurons, glial cells, and endothelial cells). Two hundred and thirty-nine cases of lymphoma and 80 nonhematopoietic tumors were immunostained. Antibody ALK1 labeled 53.4% (39 of 73 cases) of CD30+ ALCL. A case of ALCL with a t(1;2) translocation was ALK1+. Three cases of CD30- ALCL with prominent nucleoli showed a unique pattern of coarse granular cytoplasmic labeling. All other tumors, including Hodgkin's disease and lymphomatoid papulosis, were ALK1-. These results indicate that reliable immunostaining of routine biopsy material for NPM-ALK and ALK proteins is feasible. Such analysis is of diagnostic importance, especially because t(2;5)+ ALCL cases have a good prognosis with appropriate treatment.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Anaplastic Lymphoma Kinase
- Animals
- Antibodies, Monoclonal/immunology
- Biomarkers, Tumor/analysis
- Child
- Child, Preschool
- Chromosomes, Human, Pair 2/genetics
- Chromosomes, Human, Pair 5/genetics
- Chromosomes, Human, Pair 5/ultrastructure
- DNA, Neoplasm/genetics
- Diagnosis, Differential
- Feasibility Studies
- Female
- Hodgkin Disease/diagnosis
- Hodgkin Disease/enzymology
- Humans
- Immunoenzyme Techniques
- Lymphoma/enzymology
- Lymphoma/ultrastructure
- Lymphoma, Large B-Cell, Diffuse/diagnosis
- Lymphoma, Large B-Cell, Diffuse/enzymology
- Male
- Mice
- Mice, Inbred BALB C
- Middle Aged
- Neoplasm Proteins/analysis
- Neoplasm Proteins/genetics
- Neoplasms/enzymology
- Neoplasms/ultrastructure
- Nerve Tissue Proteins/analysis
- Nerve Tissue Proteins/immunology
- Nuclear Proteins/analysis
- Nuclear Proteins/genetics
- Nucleophosmin
- Oncogene Proteins, Fusion/analysis
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/immunology
- Organ Specificity
- Polymerase Chain Reaction
- Protein-Tyrosine Kinases/analysis
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/immunology
- Receptor Protein-Tyrosine Kinases
- Transfection
- Translocation, Genetic
- Tumor Cells, Cultured/enzymology
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Affiliation(s)
- K Pulford
- University Department of Cellular Science, John Radcliffe Hospital, Oxford, UK
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26
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Ryu S, Hellerqvist M, Doniach S, Kapitulnik A, Stroud D. Dynamical Phase Transition in a Driven Disordered Vortex Lattice. Phys Rev Lett 1996; 77:5114-5117. [PMID: 10062717 DOI: 10.1103/physrevlett.77.5114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Yu W, Wang ZQ, Stroud D. Empirical molecular-dynamics study of diffusion in liquid semiconductors. Phys Rev B Condens Matter 1996; 54:13946-13954. [PMID: 9985313 DOI: 10.1103/physrevb.54.13946] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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29
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Hwang IJ, Sásik R, Stroud D. Flux-lattice melting in artificially layered superconductors. Phys Rev B Condens Matter 1996; 54:12010-12013. [PMID: 9985055 DOI: 10.1103/physrevb.54.12010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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30
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Rozhkov A, Stroud D. Quantum melting of a two-dimensional vortex lattice at zero temperature. Phys Rev B Condens Matter 1996; 54:R12697-R12700. [PMID: 9985222 DOI: 10.1103/physrevb.54.r12697] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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31
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Stroud D. Giant enhancement of cubic nonlinearity in a polycrystalline quasi-one-dimensional conductor. Phys Rev B Condens Matter 1996; 54:3295-3299. [PMID: 9986228 DOI: 10.1103/physrevb.54.3295] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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32
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Ryu S, Stroud D. First-order melting and dynamics of flux lines in a model for YBa2Cu3O7- delta. Phys Rev B Condens Matter 1996; 54:1320-1333. [PMID: 9985405 DOI: 10.1103/physrevb.54.1320] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Stroud D, Kazaryan A. Optical sum rules and effective-medium theories for a polycrystalline material: Application to a model for polypyrrole. Phys Rev B Condens Matter 1996; 53:7076-7084. [PMID: 9982153 DOI: 10.1103/physrevb.53.7076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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34
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Ryu S, Yu W, Stroud D. Dynamics of an underdamped Josephson-junction ladder. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1996; 53:2190-2195. [PMID: 9964498 DOI: 10.1103/physreve.53.2190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Sásik R, Stroud D. Three-dimensional to two-dimensional crossover in layered high-Tc superconductors. Phys Rev B Condens Matter 1995; 52:3696-3701. [PMID: 9981497 DOI: 10.1103/physrevb.52.3696] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Lee WM, Hui PM, Stroud D. Propagating photonic modes below the gap in a superconducting composite. Phys Rev B Condens Matter 1995; 51:8634-8637. [PMID: 9977486 DOI: 10.1103/physrevb.51.8634] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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40
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Roddick E, Stroud D. Supersolid phases in underdamped Josephson arrays: Quantum Monte Carlo simulations. Phys Rev B Condens Matter 1995; 51:8672-8675. [PMID: 9977498 DOI: 10.1103/physrevb.51.8672] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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41
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Puce A, Stroud D. NH & MRC support for physics projects. Australas Phys Eng Sci Med 1995; 18:58. [PMID: 7755498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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42
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Roddick E, Stroud D. Effect of phase fluctuations on the low-temperature penetration depth of high-Tc superconductors. Phys Rev Lett 1995; 74:1430-1433. [PMID: 10059018 DOI: 10.1103/physrevlett.74.1430] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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43
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Sásik R, Stroud D, Tesanovic Z. Phase coherence in two-dimensional type-II superconductors. Phys Rev B Condens Matter 1995; 51:3042-3046. [PMID: 9979086 DOI: 10.1103/physrevb.51.3042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Yu W, Stroud D. Kinetic inductance of Josephson-junction arrays: Dynamic and equilibrium calculations. Phys Rev B Condens Matter 1994; 50:13632-13637. [PMID: 9975559 DOI: 10.1103/physrevb.50.13632] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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46
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Wang ZQ, Stroud D, Dregia SA. Effective-medium theory for the optical properties of diamond and diamondlike films. Phys Rev B Condens Matter 1994; 50:12073-12077. [PMID: 9975349 DOI: 10.1103/physrevb.50.12073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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47
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Jardim RF, Ben-Dor L, Stroud D, Maple MB. Granular behavior in polycrystalline Sm2-xCexCuO4-y compounds. Phys Rev B Condens Matter 1994; 50:10080-10087. [PMID: 9975091 DOI: 10.1103/physrevb.50.10080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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48
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Sásik R, Stroud D. Wannier-function approach to phase transitions in superconducting films. Phys Rev B Condens Matter 1994; 50:3294-3301. [PMID: 9976581 DOI: 10.1103/physrevb.50.3294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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50
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