bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-Step Scheme for Rapid Identification and Differentiation of
Legionella pneumophila
and Non-
Legionella pneumophila
Species
Authors: Zhan Xiao-Yong , Li Lian-Qing , Hu Chao-Hui , Zhu Qing-Yi
Published: December 2009

A rapid two-step scheme based on PCR amplification and enzymatic digestion analysis of a 226-bp fragment of the 16S rRNA gene was developed to identify the
Legionella
genus by PCR amplification and to differentiate the
Legionella pneumophila
and non-
Legionella pneumophila
species by enzymatic digestion analysis. Among 42 ATCC strains (16 strains of
L. pneumophila
and 26 strains of non-
L. pneumophila
) and 200
Legionella
isolates from environmental water samples, including pools, rivers, lakes, and cooling towers in Guangdong province, 99.59% of
L. pneumophila
and non-
L. pneumophila
strains were correctly identified and differentiated by this scheme. The procedure of this two-step identification and differentiation scheme is simple and takes only about 4 h. These results suggest that this two-step scheme provides a simple and convenient method for the rapid identification and differentiation of
L. pneumophila
and non-
L. pneumophila
species.
Evaluation of Risk Factors for Coinfection or Cocolonization with Vancomycin-Resistant Enterococcus and Methicillin-Resistant
Staphylococcus aureus
Authors: Reyes Katherine , Malik Rushdah , Moore Carol , Donabedian Susan , Perri Mary , Johnson Laura , Zervos Marcus
Published: December 2009

We retrospectively evaluated 410 patients with coinfection or cocolonization due to vancomycin-resistant (VR) enterococcus (VRE) and methicillin-resistant
Staphylococcus aureus
(MRSA). The prevalence rate was 19.8%. Risk factors included isolation of VR
Enterococcus faecalis
and use of linezolid or clindamycin. Inc18-like
vanA
plasmids were found in 7% of VR
E. faecalis
isolates and none of the VR
E. faecium
isolates.
Nucleolin Associates with the Human Cytomegalovirus DNA Polymerase Accessory Subunit UL44 and Is Necessary for Efficient Viral Replication
Authors: Strang Blair L. , Boulant Steeve , Coen Donald M.
Published: December 2009

In the eukaryotic cell, DNA replication entails the interaction of multiple proteins with the DNA polymerase processivity factor PCNA. As the structure of the presumptive human cytomegalovirus (HCMV) DNA polymerase processivity factor UL44 is highly homologous to that of PCNA, we hypothesized that UL44 also interacts with numerous proteins. To investigate this possibility, recombinant HCMV expressing FLAG-tagged UL44 was generated and used to immunoprecipitate UL44 and associated proteins from infected cell lysates. Unexpectedly, nucleolin, a major protein component of the nucleolus, was identified among these proteins by mass spectrometry and Western blotting. The association of nucleolin and UL44 in infected cell lysate was confirmed by reciprocal coimmunoprecipitation in the presence and absence of nuclease. Western blotting and immunofluorescence assays demonstrated that the level of nucleolin increases during infection and that nucleolin becomes distributed throughout the nucleus. Furthermore, the colocalization of nucleolin and UL44 in infected cell nuclei was observed by immunofluorescence assays. Assays of HCMV-infected cells treated with small interfering RNA (siRNA) targeting
nucleolin
mRNA indicated that nucleolin was required for efficient virus production, viral DNA synthesis, and the expression of a late viral protein, with a correlation between the efficacy of knockdown and the effect on virus replication. In contrast, the level of neither global protein synthesis nor the replication of an unrelated virus (reovirus) was reduced in siRNA-treated cells. Taken together, our results indicate an association of nucleolin and UL44 in HCMV-infected cells and a role for nucleolin in viral DNA synthesis.
A Rotavirus Spike Protein Conformational Intermediate Binds Lipid Bilayers
Authors: Trask Shane D. , Kim Irene S. , Harrison Stephen C. , Dormitzer Philip R.
Published: December 2009

During rotavirus entry, a virion penetrates a host cell membrane, sheds its outer capsid proteins, and releases a transcriptionally active subviral particle into the cytoplasm. VP5*, the rotavirus protein believed to interact with the membrane bilayer, is a tryptic cleavage product of the outer capsid spike protein, VP4. When a rotavirus particle uncoats, VP5* folds back, in a rearrangement that resembles the fusogenic conformational changes in enveloped-virus fusion proteins. We present direct experimental evidence that this rearrangement leads to membrane binding. VP5* does not associate with liposomes when mounted as part of the trypsin-primed spikes on intact virions, nor does it do so after it has folded back into a stably trimeric, low-energy state. But it does bind liposomes when they are added to virions before uncoating, and VP5* rearrangement is then triggered by addition of EDTA. The presence of liposomes during the rearrangement enhances the otherwise inefficient VP5* conformational change. A VP5* fragment, VP5CT, produced from monomeric recombinant VP4 by successive treatments with chymotrypsin and trypsin, also binds liposomes only when the proteolysis proceeds in their presence. A monoclonal antibody that neutralizes infectivity by blocking a postattachment entry event also blocks VP5* liposome association. We propose that VP5* binds lipid bilayers in an intermediate conformational state, analogous to the extended intermediate conformation of enveloped-virus fusion proteins.
Dynamics of Coronavirus Replication-Transcription Complexes
Authors: Hagemeijer Marne C. , Verheije Monique H. , Ulasli Mustafa , Shaltiël Indra A. , de Vries Lisa A. , Reggiori Fulvio , Rottier Peter J. M. , de Haan Cornelis A. M.
Published: December 2009

Coronaviruses induce in infected cells the formation of double-membrane vesicles (DMVs) in which the replication-transcription complexes (RTCs) are anchored. To study the dynamics of these coronavirus replicative structures, we generated recombinant murine hepatitis coronaviruses that express tagged versions of the nonstructural protein nsp2. We demonstrated by using immunofluorescence assays and electron microscopy that this protein is recruited to the DMV-anchored RTCs, for which its C terminus is essential. Live-cell imaging of infected cells demonstrated that small nsp2-positive structures move through the cytoplasm in a microtubule-dependent manner. In contrast, large fluorescent structures are rather immobile. Microtubule-mediated transport of DMVs, however, is not required for efficient replication. Biochemical analyses indicated that the nsp2 protein is associated with the cytoplasmic side of the DMVs. Yet, no recovery of fluorescence was observed when (part of) the nsp2-positive foci were bleached. This result was confirmed by the observation that preexisting RTCs did not exchange fluorescence after fusion of cells expressing either a green or a red fluorescent nsp2. Apparently, nsp2, once recruited to the RTCs, is not exchanged with nsp2 present in the cytoplasm or at other DMVs. Our data show a remarkable resemblance to results obtained recently by others with hepatitis C virus. The observations point to intriguing and as yet unrecognized similarities between the RTC dynamics of different plus-strand RNA viruses.
The Prostate Cancer-Associated Human Retrovirus XMRV Lacks Direct Transforming Activity but Can Induce Low Rates of Transformation in Cultured Cells
Authors: Metzger Michael J. , Holguin Christiana J. , Mendoza Ramon , Miller A. Dusty
Published: December 2009

The human retrovirus XMRV (xenotropic murine leukemia virus-related virus) is associated with prostate cancer, but a causal relationship has not been established. Here, we have used cultured fibroblast and epithelial cell lines to test the hypothesis that XMRV might have direct transforming activity but found only rare transformation events, suggestive of indirect transformation, even when the target cells expressed the human Xpr1 cell entry receptor for XMRV. Characterization of cells from three transformed foci showed that all were infected with and produced XMRV, and one produced a highly active transforming virus, presumably generated by recombination between XMRV and host cell nucleic acids. Given the sequence similarity of XMRV to mink cell focus-forming (MCF) viruses and the enhanced leukemogenic activity of the latter, we tested XMRV for related MCF-like cytopathic activities in cultured mink cells but found none. These results indicate that XMRV has no direct transforming activity but can activate endogenous oncogenes, resulting in cell transformation. As part of these experiments, we show that XMRV can infect and be produced at a high titer from human HT-1080 fibrosarcoma cells that express TRIM5α (
Ref1
), showing that XMRV is resistant to TRIM5α restriction. In addition, XMRV poorly infects NIH 3T3 cells expressing human Xpr1 but relatively efficiently infects BALB 3T3 cells expressing human Xpr1, showing that XMRV is a B-tropic virus and that its infectivity is regulated by the
Fv1
mouse locus.
Effect of Dimerizing Domains and Basic Residues on
In Vitro
and
In Vivo
Assembly of Mason-Pfizer Monkey Virus and Human Immunodeficiency Virus
Authors: Bohmová Karolína , Hadravová Romana , Štokrová Jitka , Tůma Roman , Ruml Tomáš , Pichová Iva , Rumlová Michaela
Published: December 2009

Assembly of immature retroviral particles is a complex process involving interactions of several specific domains of the Gag polyprotein localized mainly within capsid protein (CA), spacer peptide (SP), and nucleocapsid protein (NC). In the present work we focus on the contribution of NC to the oligomerization of CA leading to assembly of Mason-Pfizer monkey virus (M-PMV) and HIV-1. Analyzing
in vitro
assembly of substitution and deletion mutants of ΔProCANC, we identified a “spacer-like” sequence (NC
15
) at the M-PMV NC N terminus. This NC
15
domain is indispensable for the assembly and cannot be replaced with oligomerization domains of GCN4 or CREB proteins. Although the M-PMV NC
15
occupies a position analogous to that of the HIV-1 spacer peptide, it could not be replaced by the latter one. To induce the assembly, both M-PMV NC
15
and HIV-1 SP1 must be followed by a short peptide that is rich in basic residues. This region either can be specific, i.e., derived from the downstream NC sequence, or can be a nonspecific positively charged peptide. However, it cannot be replaced by heterologous interaction domains either from GCN4 or from CREB. In summary, we report here a novel M-PMV spacer-like domain that is functionally similar to other retroviral spacer peptides and contributes to the assembly of immature-virus-like particles.
Multiple Diverse Circoviruses Infect Farm Animals and Are Commonly Found in Human and Chimpanzee Feces
Authors: Li Linlin , Kapoor Amit , Slikas Beth , Bamidele Oderinde Soji , Wang Chunlin , Shaukat Shahzad , Masroor Muhammad Alam , Wilson Michael L. , Ndjango Jean-Bosco N. , Peeters Martine , Gross-Camp Nicole D. , Muller Martin N. , Hahn Beatrice H. , Wolfe Nathan D. , Triki Hinda , Bartkus Joanne , Zaidi Sohail Zahoor , Delwart Eric
Published: December 2009

Circoviruses are known to infect birds and pigs and can cause a wide range of severe symptoms with significant economic impact. Using viral metagenomics, we identified circovirus-like DNA sequences and characterized 15 circular viral DNA genomes in stool samples from humans in Pakistan, Nigeria, Tunisia, and the United States and from wild chimpanzees. Distinct genomic features and phylogenetic analysis indicate that some viral genomes were part of a previously unrecognized genus in the
Circoviridae
family we tentatively named “
Cyclovirus
” whose genetic diversity is comparable to that of all the known species in the
Circovirus
genus.
Circoviridae
detection in the stools of U.S. adults was limited to porcine circoviruses which were also found in most U.S. pork products. To determine whether the divergent cycloviruses found in non-U.S. human stools were of dietary origin, we genetically compared them to the cycloviruses in muscle tissue samples of commonly eaten farm animals in Pakistan and Nigeria. Limited genetic overlap between cycloviruses in human stool samples and local cow, goat, sheep, camel, and chicken meat samples indicated that the majority of the 25
Cyclovirus
species identified might be human viruses. We show that the genetic diversity of small circular DNA viral genomes in various mammals, including humans, is significantly larger than previously recognized, and frequent exposure through meat consumption and contact with animal or human feces provides ample opportunities for cyclovirus transmission. Determining the role of cycloviruses, found in 7 to 17% of non-U.S. human stools and 3 to 55% of non-U.S. meat samples tested, in both human and animal diseases is now facilitated by knowledge of their genomes.
Heterotypic Humoral and Cellular Immune Responses following Norwalk Virus Infection
Authors: Lindesmith Lisa C. , Donaldson Eric , Leon Juan , Moe Christine L. , Frelinger Jeffrey A. , Johnston Robert E. , Weber David J. , Baric Ralph S.
Published: December 2009

Norovirus immunity is poorly understood as the limited data available on protection after infection are often contradictory. In contrast to the more prominent GII noroviruses, GI norovirus infections are less frequent in outbreaks. The GI noroviruses display very complex patterns of heterotypic immune responses following infection, and many individuals are highly susceptible to reinfection. To study the immune responses and mechanisms of GI.1 persistence, we built structural models and recombinant virus-like particles (VLPs) of five GI strains: GI.1-1968, GI.1-2001, GI.2-1999, GI.3-1999, and GI.4-2000. Structural models of four GI genotype capsid P domain dimers suggested that intragenotype structural variation is limited, that the GI binding pocket is mostly preserved between genotypes, and that a conserved, surface-exposed epitope may allow for highly cross-reactive immune responses. GI VLPs bound to histo-blood group antigens (HBGAs) including fucose, Lewis, and A antigens. Volunteers infected with GI.1-1968 (
n
= 10) had significant increases between prechallenge and convalescent reactive IgG for all five GI VLPs measured by enzyme immunoassay. Potential cross-neutralization of GI VLPs was demonstrated by convalescent-phase serum cross-blockade of GI VLP-HBGA interaction. Although group responses were significant for all GI VLPs, each individual volunteer demonstrated a unique VLP blockade pattern. Further, peripheral blood mononuclear cells (PBMCs) were stimulated with each of the VLPs, and secretion of gamma interferon (IFN-γ) was measured. As seen with blockade responses, IFN-γ secretion responses differed by individual. Sixty percent responded to at least one GI VLP, with only two volunteers responding to GI.1 VLP. Importantly, four of five individuals with sufficient PBMCs for cross-reactivity studies responded more robustly to other GI VLPs. These data suggest that preexposure history and deceptive imprinting may complicate PBMC and B-cell immune responses in some GI.1-1968-challenged individuals and highlight a potential complication in the design of efficacious norovirus vaccines.
A Single Tyrosine in the Severe Acute Respiratory Syndrome Coronavirus Membrane Protein Cytoplasmic Tail Is Important for Efficient Interaction with Spike Protein
Authors: McBride Corrin E. , Machamer Carolyn E.
Published: December 2009

Severe acute respiratory syndrome coronavirus (SARS-CoV) encodes 3 major envelope proteins: spike (S), membrane (M), and envelope (E). Previous work identified a dibasic endoplasmic reticulum retrieval signal in the cytoplasmic tail of SARS-CoV S that promotes efficient interaction with SARS-CoV M. The dibasic signal was shown to be important for concentrating S near the virus assembly site rather than for direct interaction with M. Here, we investigated the sequence requirements of the SARS-CoV M protein that are necessary for interaction with SARS-CoV S. The SARS-CoV M tail was shown to be necessary for S localization in the Golgi region when the proteins were exogenously coexpressed in cells. This was specific, since SARS-CoV M did not retain an unrelated glycoprotein in the Golgi. Importantly, we found that an essential tyrosine residue in the SARS-CoV M cytoplasmic tail, Y
195
, was important for S-M interaction. When Y
195
was mutated to alanine, M
Y195A
no longer retained S intracellularly at the Golgi. Unlike wild-type M, M
Y195A
did not reduce the amount of SARS-CoV S carbohydrate processing or surface levels when the two proteins were coexpressed. Mutating Y
195
also disrupted SARS-CoV S-M interaction
in vitro
. These results suggest that Y
195
is necessary for efficient SARS-CoV S-M interaction and, thus, has a significant involvement in assembly of infectious virus.
Electrochemical studies of ganciclovir as the adsorbed catalyst on mercury electrode
Authors: Skrzypek Sławomira , Nosal-Wiercińska Agnieszka , Ciesielski Witold
Published: December 2009

Although ganciclovir (gan) as a purine analogue is a compound of biological interest (antiviral drug), it has been rarely electrochemically studied. In this paper surface catalytic electrode mechanism based on the hydrogen evolution reaction is analyzed under conditions of square-wave voltammetry and differential capacity curves of double layer measurements. The electrode mechanism is assumed to involve a preceding chemical reaction in which the adsorbed catalyst (ganads) is protonated at the electrode surface, i.e., ganads + H+aq → ganH+ads. The protonated form of the catalyst (ganH+ads) is irreversibly reduced at potential about –1.35 V vs Ag|AgCl, yielding the initial form of the catalyst and atomic hydrogen, i.e., ganH+ads + e → ganads + Haq. Changes of zero charge potential and surface tension point to the adsorption of ganciclovir molecule directed with guanine group to the mercury surface and suggests that ganciclovir molecules are not placed flat on the mercury surface. The effect of adsorption on mercury electrode was studied in detail in respect to analytical usefulness of the obtained results. A new catalytic method for voltammetric determination of ganciclovir was developed. The detection and quantification limits were 1.3 × 10–7 and 4.3 × 10–7 mol l–1 for square-wave voltammetry, and 1.4 × 10–7 and 4.7 × 10–7 mol l–1 for linear-sweep voltammetry.
EURISOL DESIGN STUDY: TOWARDS AN ULTIMATE ISOL FACILITY FOR EUROPE
Authors: BLUMENFELD Y. , BUTLER P. , CORNELL J. , FORTUNA G. , LINDROOS M.
Published: December 2009

The European roadmap for nuclear physics advocates the construction of two next generation radioactive beam facilities: the projectile fragmentation facility FAIR at Darmstadt, Germany and the ISOL facility EURISOL. The EURISOL concept is being studied in the framework of a pan-european Design Study funded by the European Commission. The general design of EURISOL and the latest achievements in terms of modeling and prototyping are presented.
SHELL STRUCTURE EVOLUTION IN NUCLEI: NEW PARADIGM
Authors: AZAIEZ F.
Published: December 2009

Shell structure evolution in nuclei situated at the extremes of neutron and proton excess are investigated using in-beam gamma spectroscopy techniques with radioactive beams at GANIL. A selection of results obtained very recently is presented: i) The reduced transition probabilities [Formula: see text] of the neutron-rich 74 Zn and 70 Ni nuclei have been measured using Coulomb excitation at intermediate energy. An unexpected large proton core polarization has been found in 70 Ni and interpreted as being due to the monopole interaction between the neutron g 9/2 and protons f 7/2 and f 5/2 spin-orbit partner orbitals. ii) Two proton knock-out reactions has been performed in order to study the most neutron-rich nuclei at the N =28 shell closure. Gamma rays spectra and momentum distribution have been obtained for 42 Si and neighboring nuclei. Evidences has been found for a deformed structure for 42 Si and for the disappearance of the spherical N =28 shell effect. iii) The in-beam gamma spectroscopy of 36 Ca performed using neutron knock-out reactions revealed that N =16 is as large sub-shell closure as large as Z =16 in 36 S . The uniquely large excitation energy difference of the first 2+ state in these mirror nuclei turns out to be a consequence of the relatively pure neutron (in 36 Ca ) or proton (in 36 S ) 1 p ( d 3/2)-1 h ( s 1/2) nature.
EXOTIC ELECTROMAGNETIC TRANSITIONS IN NEUTRON-RICH CARBON ISOTOPES
Authors: SUZUKI TOSHIO , OTSUKA TAKAHARU
Published: December 2009

Structure and electromagnetic properties of exotic neutron-rich carbon isotopes are studied by shell model calculations. A p-sd shell model Hamiltonian is modified by enhancing the effects of the tensor force in the p-sd cross shell matrix elements as well as with corrections in the T=1 monopole terms. A considerable suppression of the magnetic dipole (M1) transition in 17 C from the [Formula: see text] state recently observed is found to be well explained by the modified Hamiltonian. The anomalous hindrance of the quadrupole (E2) transitions in 16 C and 18 C is also shown to be reproduced by our new Hamiltonian.
CONTINUUM COUPLING AND PAIR CORRELATION IN WEAKLY BOUND DEFORMED NUCLEI
Authors: OBA HIROSHI , MATSUO MASAYUKI
Published: December 2009

We formulate a new Hartree-Fock-Bogoliubov method applicable to weakly bound deformed nuclei using the coordinate-space Green's function technique. An emphasis is put on treatment of quasiparticle states in the continuum, on which we impose the correct boundary condition of the asymptotic out-going wave. We illustrate this method with numerical examples.
STUDY OF NEUTRON-RICH NUCLEI THROUGH STATIC ELECTROMAGNETIC MOMENTS
Authors: ASAHI K. , SHIMADA K. , KAMEDA K. , NAGAE D. , UCHIDA M. , SUZUKI K. , INOUE T. , HATAKEYAMA N. , KAGAMI S. , HASAMA Y. , UENO H. , YOSHIMI H. , NAGATOMO T. , SUGIMOTO T. , ISHIHARA M. , MURATA J. , KAWAMURA H. , NARITA K.
Published: December 2009

Nuclear moment studies on nuclei situated far from the β-stability line, performed by taking advantage of the projectile fragmentation reaction, are reviewed. A method to produce spin polarization/alignment in the projectile fragments was developed and utilized for the β-NMR/NQR measurements. Several new findings in nuclear structure physics were obtained from the nuclear moment experiments done with these techniques.
PAIRING CORRELATIONS IN UNSTABLE NUCLEI AND BCS-BEC CROSSOVER
Authors: SAGAWA H. , MARGUERON J. , HAGINO K.
Published: December 2009

We propose new types of density dependent contact pairing interaction which reproduce the pairing gaps in symmetric and neutron matters obtained by a microscopic treatment of the realistic nucleon-nucleon interaction. The BCS-BEC crossover of neutrons pairs in symmetric and asymmetric nuclear matters is studied by using these contact interactions. It is shown that the bare and screened pairing interactions lead to different features of the BCS-BEC crossover in symmetric nuclear matter. We perform Hartree-Fock-Bogoliubov (HFB) calculations for semi-magic Calcium, Nickel, Tin and Lead isotopes using these density-dependent pairing interactions. It is pointed out that the isospin dependent pairing interaction reproduces well the neutron number dependence of experimental data for the binding energy, two neutrons separation energy, and odd-even mass staggering of these isotopes.
TENSOR OPTIMIZED SHELL MODEL AND THE ROLE OF PION IN FINITE NUCLEI
Authors: TOKI HIROSHI , MYO TAKAYUKI , IKEDA KIYOMI
Published: December 2009

The pion plays an important role for the structure of nucleus and nuclear matter. We propose a new theoretical framework, named the tensor optimized shell model (TOSM) to calculate the tensor interaction together with the unitary correlation operator method (UCOM) for the short range repulsion. We are able to handle the pion exchange interaction directly in the proposed framework. We compare the calculated results for 4 He with the rigorous calculation to show the power of TOSM to treat the tensor interaction.
BREAKUP REACTIONS AND EXOTIC STRUCTURES OF HALO NUCLEI
Authors: NAKAMURA TAKASHI , SATOU YOSHITERU , SUGIMOTO TAKASHI , KONDO YOSUKE
Published: December 2009

We have performed breakup experiments of halo nuclei: 11 Li with a Pb target, 14 Be with 12 C and proton targets, and 19 C on a proton target at approximately 70 MeV/nucleon at RIKEN. These experiments aim at investigating the E1 response of 11 Li , and at searching for the low-lying discrete resonances of 14 Be and 19 C above the neutron decay threshold. The former results shows the strong E1 transitions at low excitation energies (soft E1 excitation), which suggests the spatial neutron-neutron correlation. The latter revealed the first 2+ state of 14 Be , and the second 5/2+ state of 19 C for the first time.
RESPONSE FUNCTIONS IN THE CONTINUUM OF DEFORMED NUCLEI STUDIED WITH THE TIME-DEPENDENT DENSITY-FUNCTIONAL CALCULATIONS
Authors: INAKURA TSUNENORI , NAKATSUKASA TAKASHI , YABANA KAZUHIRO
Published: December 2009

Electric dipole response functions of even-even nuclei are calculated with the time-dependent density-functional theory in perturbative regime. For an easy implementation of the fully self-consistent calculation, the finite amplitude method which we have proposed recently is employed. This is the first fully self-consistent RPA calculation in the three-dimensional mesh representation, including high-energy regions of giant resonances.
FUSION-FISSION DYNAMICS IN SUPERHEAVY MASS REGION
Authors: ARITOMO YOSHIHIRO
Published: December 2009

In heavy nucleus collision experiments, the fusion-fission cross section is derived from counting mass-symmetric fission events. However, a discrepancy exists between the experimental and theoretical estimations of the fusion cross section. We attempt to clarify the origin of the discrepancy and remove it by performing a dynamical calculation. The trajectory calculation has been performed in three-dimensional coordinate space with the Langevin equation.
SUPER SEPARATOR SPECTROMETER FOR THE LINAG HEAVY ION BEAMS
Authors: DROUART A. , NOLEN J. A. , SAVAJOLS H.
Published: December 2009

The Super Separator Spectrometer (S3) will receive the very high intensity heavy ion beams from the LINAG accelerator of SPIRAL2. Its privileged fields of physics are the delayed study of rare nuclei and secondary reactions with exotic nuclei. The project is presently in a phase of conceptual design. It includes a rotating target to sustain the high energy deposit, a two stages separator (momentum achromat) and spectrometer (mass spectrometer). Various detection set-ups are foreseen, especially a delayed α, γ, and electron spectroscopy array and a gas catcher coupled to a low energy branch. We present here the current status of the project and its main features.
NUCLEON STRUCTURE AT JEFFERSON LAB: FROM TWO DIMENSIONS TO THREE DIMENSIONS
Authors: GUIDAL MICHEL
Published: December 2009

We review very briefly a few recent highlight results from Jefferson Lab concerning nucleon Form Factors and Generalized Parton Distributions for which data with unprecedented precision and phase space coverage have be obtained these past few years. Along with new theoretical developements, these data allow to make some nucleon imaging in terms of partonic degrees of freedom in both momentum and space dimensions.
THE HYPHI PROJECT: HYPERNUCLEAR SPECTROSCOPY WITH STABLE HEAVY ION BEAMS AND RARE ISOTOPE BEAMS AT GSI AND FAIR
Authors: BIANCHIN S. , ACHENBACH P. , AJIMURA S. , BORODINA O. , FUKUDA T. , HOFFMANN J. , KAVATSYUK M. , KOCH K. , KOIKE T. , KURZ N. , MAAS F. , MINAMI S. , MIZOI Y. , NAGAE T. , NAKAJIMA D. , OKAMURA A. , OTT W. , ÖZEL B. , POCHODZALLA J. , RAPPOLD C. , SAITO T.R. , SAKAGUCHI A. , SAKO M. , SEKIMOTO M. , SUGIMURA H. , TAKAHASHI T. , TAMURA H. , TANIDA K. , TRAUTMANN W.
Published: December 2009

The HypHI collaboration aims to perform a precise hypernuclear spectroscopy with stable heavy ion beams and rare isotope beams at GSI and FAIR in order to study hypernuclei at extreme isospin, especially neutron rich hypernuclei to look insight hyperon-nucleon interactions in the neutron rich medium, and hypernuclear magnetic moments to investigate baryon properties in the nuclei1,2. We are currently preparing for the first experiment with 6 Li and 12 C beams at 2 A GeV to demonstrate the feasibility of a precise hypernuclear spectroscopy by identifying [Formula: see text], [Formula: see text] and [Formula: see text]. The first physics experiment on these hypernuclei is planned for 2009. In the present document, an overview of the HypHI project and the details of this first experiment will be discussed.
Iron supply determines apical/basolateral membrane distribution of intestinal iron transporters DMT1 and ferroportin 1
Authors: Núñez Marco T. , Tapia Victoria , Rojas Alejandro , Aguirre Pabla , Gómez Francisco , Nualart Francisco
Published: December 2009

Intestinal iron absorption comprises the coordinated activity of the influx transporter divalent metal transporter 1 (DMT1) and the efflux transporter ferroportin (FPN). In this work, we studied the movement of DMT1 and FPN between cellular compartments as a function of iron supply. In rat duodenum, iron gavage resulted in the relocation of DMT1 to basal domains and the internalization of basolateral FPN. Considerable FPN was also found in apical domains. In Caco-2 cells, the apical-to-basal movement of cyan fluorescent protein-tagged DMT1 was complete 90 min after the addition of iron. Steady-state membrane localization studies in Caco-2 cells revealed that iron status determined the apical/basolateral membrane distribution of DMT1 and FPN. In agreement with the membrane distribution of the transporters, 55Fe flux experiments revealed inward and outward iron fluxes at both membrane domains. Antisense oligonucleotides targeted to DMT1 or FPN inhibited basolateral iron uptake and apical iron efflux, respectively, indicating the participation of DMT1 and FPN in these fluxes. The fluxes were regulated by the iron supply; increased iron reduced apical uptake and basal efflux and increased basal uptake and apical efflux. These findings suggest a novel mechanism of regulation of intestinal iron absorption based on inward and outward fluxes at both membrane domains, and repositioning of DMT1 and FPN between membrane and intracellular compartments as a function of iron supply. This mechanism should be complementary to those based in the transcriptional or translational regulation of iron transport proteins.
5-HT1A, SST1, and SST2receptors mediate inhibitory postsynaptic potentials in the submucous plexus of the guinea pig ileum
Authors: Foong Jaime Pei Pei , Parry Laura J. , Gwynne Rachel M. , Bornstein Joel C.
Published: December 2009

Vasoactive intestinal peptide (VIP) immunoreactive neurons are important secretomotor neurons in the submucous plexus. They are the only submucosal neurons to receive inhibitory inputs and exhibit both noradrenergic and nonadrenergic inhibitory synaptic potentials (IPSPs). The former are mediated by α2-adrenoceptors, but the receptors mediating the latter have not been identified. We used standard intracellular recording, RT-PCR, and confocal microscopy to test whether 5-HT1A, SST1, and/or SST2receptors mediate nonadrenergic IPSPs in VIP submucosal neurons in guinea pig ileum in vitro. The specific 5-HT1Areceptor antagonist WAY 100135 (1 μM) reduced the amplitude of IPSPs, an effect that persisted in the presence of the α2-adrenoceptor antagonist idazoxan (2 μM), suggesting that 5-HT might mediate a component of the IPSPs. Confocal microscopy revealed that there were many 5-HT-immunoreactive varicosities in close contact with VIP neurons. The specific SSTR2antagonist CYN 154806 (100 nM) and a specific SSTR1antagonist SRA 880 (3 μM) each reduced the amplitude of nonadrenergic IPSPs and hyperpolarizations evoked by somatostatin. In contrast with the other antagonists, CYN 154806 also reduced the durations of nonadrenergic IPSPs. Effects of WAY 100135 and CYN 154806 were additive. RT-PCR revealed gene transcripts for 5-HT1A, SST1, and SST2receptors in stripped submucous plexus preparations consistent with the pharmacological data. Although the involvement of other neurotransmitters or receptors cannot be excluded, we conclude that 5-HT1A, SST1, and SST2receptors mediate nonadrenergic IPSPs in the noncholinergic (VIP) secretomotor neurons. This study thus provides the tools to identify functions of enteric neural pathways that inhibit secretomotor reflexes.
Gene expression profiling of dilated cardiomyopathy in older male EP4 knockout mice
Authors: Harding Pamela , Yang Xiao-Ping , Yang James , Shesely Ed , He Quan , LaPointe Margot C.
Published: December 2009

Using a line of mice with cardiac-specific knockout (KO) of the EP4 receptor gene, experiments were designed to determine whether a cardiac phenotype developed with age. Cardiac function was assessed by echocardiography in 23- to 33-wk-old male and female KO and littermate controls (WT) mice. After echocardiography, hearts were removed to assess weight, and then some were further processed for histology [myocyte cross-sectional area (MCSA), interstitial collagen fraction (ICF), and macrophage infiltration] and some for extraction of total RNA and protein. Older male KO mice had reduced ejection fraction (EF) coupled with left ventricular dilatation. MCSA and infiltrating macrophages were not different between groups, but ICF increased by 39% in KO mice. In contrast to male KO mice, 30- to 32-wk-old female KO mice had only a slight reduction in EF. To understand gene expression differences between male WT and KO mice, we performed whole genome gene expression profiling (Illumina BeadChips) on hearts of 30-to 32-wk-old mice. Data indicated that 156 genes were overexpressed in the KO hearts more than twofold, including genes involved in remodeling, inflammation, and oxidative stress. Overexpressed chemokines/cytokines were further examined in hearts of 10- to 12-wk-old male KO mice, and we found that growth differentiation factor-15 (GDF-15) expression was higher in KO than in WT hearts. In conclusion, EP4 knockdown in cardiac myocytes in aged male KO mice is in part associated with increased fibrosis, reduced EF, and dilated cardiomyopathy. Early overexpression of GDF-15 in hearts of male KO mice may contribute to or be a marker of the disease phenotype. The absence of serious cardiac dysfunction in aged female mice suggests a sexual dimorphism in the phenotype.
Impairment of maximal aerobic power with moderate hypoxia in endurance athletes: do skeletal muscle mitochondria play a role?
Authors: Ponsot Elodie , Dufour Stéphane P. , Doutreleau Stéphane , Lonsdorfer-Wolf Evelyne , Lampert Eliane , Piquard François , Geny Bernard , Mettauer Bertrand , Ventura-Clapier Renée , Richard Ruddy
Published: December 2009

This study investigates the role of central vs. peripheral factors in the limitation of maximal oxygen uptake (V̇o2max) with moderate hypoxia [inspired fraction (FiO2) =14.5%]. Fifteen endurance-trained athletes performed maximal cycle incremental tests to assess V̇o2max, maximal cardiac output (Q̇max), and maximal arteriovenous oxygen (a-vO2) difference in normoxia and hypoxia. Muscle biopsies of vastus lateralis were taken 1 wk before the cycling tests to evaluate maximal muscle oxidative capacity (V̇max) and sensitivity of mitochondrial respiration to ADP ( Km) on permeabilized muscle fibers in situ. Those athletes exhibiting the largest reduction of V̇o2max in moderate hypoxia (Severe Loss group: −18 ± 2%) suffered from significant reductions in Q̇max (−4 ± 1%) and maximal a-vO2 difference (−14 ± 2%). Athletes who well tolerated hypoxia, as attested by a significantly smaller drop of V̇o2max with hypoxia (Moderate Loss group: −7 ± 1%), also display a blunted Q̇max (−9 ± 2%) but, conversely, were able to maintain maximal a-vO2 difference (+1 ± 2%). Though V̇max was similar in the two experimental groups, the smallest reduction of V̇o2max with moderate hypoxia was observed in those athletes presenting the lowest apparent Km for ADP in the presence of creatine ( Km+Cr). In already-trained athletes with high muscular oxidative capacities, the qualitative, rather than quantitative, aspects of the mitochondrial function may constitute a limiting factor to aerobic ATP turnover when exercising at low FiO2, presumably through the functional coupling between the mitochondrial creatine kinase and ATP production. This study suggests a potential role for peripheral factors, including the alteration of cellular homeostasis in active muscles, in determining the tolerance to hypoxia in maximally exercising endurance-trained athletes.
A peripheral neuroimmune link: glutamate agonists upregulate NMDA NR1 receptor mRNA and protein, vimentin, TNF-α, and RANTES in cultured human synoviocytes
Authors: McNearney Terry A. , Ma Yinghong , Chen Yueping , Taglialatela Giulio , Yin Huaizhi , Zhang Wen-Ru , Westlund Karin N.
Published: December 2009

Human primary and clonal synovial cells were incubated with glutamate receptor agonists to assess their modulating influence on glutamate receptors N-methyl-d-aspartate (NMDA) NR1 and NR2 and inflammatory cytokines to determine potential for paracrine or autocrine (neurocrine) upregulation of glutamate receptors, as has been shown for bone and chondrocytes. Clonal SW982 synoviocytes constitutively express vimentin, smooth muscle actin (SMA), and NMDA NR1 and NR2. Coincubation (6 h) with glutamate agonists NMDA (5 μM), and the NMDA NR1 glycine site activator (±)1-aminocyclopentane- cis-1,3-dicarboxylic acid (5 μM), significantly increases cellular mRNA and protein levels of glutamate receptors, as well as increasing vimentin, SMA, tumor necrosis factor-α, and RANTES (regulated on activation, normal T-cell expressed and secreted), assessed qualitatively and quantitatively with nucleotide amplification, image analysis of immunocytochemical staining, fluorescein-activated cell sorting, Western blotting, and immunoassays. Human primary synovial cells harvested from patients with arthritic conditions also constitutively expressed NMDA NR1 with increases after agonist treatment. Glutamate receptor agonist-induced increases were blocked by the noncompetitive glutamate antagonist MK-801 (8 μg/ml) and NR1 blocking antibody. Coincubation with glutamate agonists and phorbol 12-myristate 13-acetate, a protein kinase C activator, significantly enhanced mean levels of TNF-α and RANTES in SW982 cell supernatants compared with incubation with either agent alone. Increases were diminished with protein kinase inhibitor and NR1 blocking antibody. The functional activation of glutamate receptors on human synoviocytes establishes a neurogenic cell signaling link between neurotransmitter glutamate released from nerve terminals and target cells in the joint capsule. The influence of glutamate on subsequent release of cellular proinflammatory mediators in non-neural tissue for activation of downstream immune events supports a peripheral neuroimmune link in arthritis.
Eccentric contraction induces inflammatory responses in rat skeletal muscle: role of tumor necrosis factor-α
Authors: Liao Peng , Zhou Jinping , Ji Li Li , Zhang Yong
Published: December 2009

Eccentric contraction (EC) is known to elicit inflammation and damage in skeletal muscle. Proinflammatory cytokine TNF-α plays an important role in this pathogenesis, but the time course of its response to EC and the regulatory mechanisms involved are not clear. The purpose of the study is twofold: 1) to investigate the gene expression of TNF-α in rat muscle during and after an acute bout of downhill running and the associated oxidoreductive (redox) changes; and 2) to examine whether EC activates muscle ubiquitin-proteolytic pathway resulting in necrosis and oxidative damage. Female Sprague-Dawley rats (age 3 mo) were randomly divided into five groups ( n = 6) that ran on treadmill at 25 m/min at −10% grade for 1 h ( group 1) or 2 h ( group 2) and were killed immediately; ran for 2 h and killed at 6 h after exercise ( group 3), ran for 2 h and killed at 24 h after exercise ( group 4); and killed at rest as controls ( group 5). TNF-α mRNA and protein content showed progressive increases in the deep portion of vastus lateralis (DVL) and gastrocnemius muscles during and after EC. These changes were accompanied by a progressive decrease of mitochondrial aconitase activity and NF-κB activation. After 2 h of exercise, elevated levels of serum TNF-α, endotoxin, creatine kinase, and lipid peroxidation marker were evident and persisted through 24 h postexercise. At 24 h, there were marked increases in H2O2concentration, myleoperoxidase activity, and endotoxin level, along with nuclear accumulation of p65, in both muscles. mRNA level of ubiquitin-conjugating enzymes (E2)-14k was progressively upregulated during exercise and recovery, whereas the expression of the Toll-like receptor 4 (TLR4) in DVL was downregulated in both muscles. We conclude that prolonged EC induces TNF-α expression possibly due to NF-κB activation stimulated by increased reactive oxygen species generation and endotoxin release. These inflammatory and prooxidative responses may underlie the processes of muscle proteolysis and oxidative damage.
Comparative effect of direct renin inhibition and AT1R blockade on glomerular filtration barrier injury in the transgenic Ren2 rat
Authors: Whaley-Connell Adam , Nistala Ravi , Habibi Javad , Hayden Melvin R. , Schneider Rebecca I. , Johnson Megan S. , Tilmon Roger , Rehmer Nathan , Ferrario Carlos M. , Sowers James R.
Published: December 2009

Renin-angiotensin system (RAS) activation contributes to kidney injury through oxidative stress. Renin is the rate-limiting step in angiotensin (ANG II) generation. Recent work suggests renin inhibition improves proteinuria comparable to ANG type 1 receptor (AT1R) blockade (ARB). Thereby, we investigated the relative impact of treatment with a renin inhibitor vs. an ARB on renal oxidative stress and associated glomerular structural and functional changes in the transgenic Ren2 rat, which manifests hypertension, albuminuria, and increased tissue RAS activity. Young Ren2 and age-matched Sprague-Dawley (SD) controls (age 6–9 wk) were treated with a renin inhibitor (aliskiren), an ARB (irbesartan), or vehicle for 21 days. Ren2 rats exhibited increases in systolic pressure (SBP), albuminuria, and renal 3-nitrotyrosine content as well as ultrastructural podocyte foot-process effacement and diminution of the podocyte-specific protein nephrin. Structural and functional alterations were accompanied by increased renal cortical ANG II, AT1R, as well as NADPH oxidase subunit (Nox2) expression compared with SD controls. Abnormalities were attenuated to a similar extent with both aliskiren and irbesartan treatment. Despite the fact the dose of irbesartan used caused a greater reduction in SBP than aliskerin treatment ( P < 0.05), the effects on proteinuria, nephrin, and oxidative stress were similar between the two treatments. Our results highlight both the importance of pressor-related reductions on podocyte integrity and albuminuria as well as RAS-mediated oxidant stress largely comparable between ARB and renin inhibition treatment.
Loss of clusterin expression worsens renal ischemia-reperfusion injury
Authors: Zhou Wenjun , Guan Qiunong , Kwan Chris C. H. , Chen Huifang , Gleave Martin E. , Nguan Christopher Y. C. , Du Caigan
Published: December 2009

Prevention of ischemia-reperfusion injury (IRI) is a challenge in clinical care of the patients with kidney transplants or acute kidney injury, and understanding of the intrinsic mechanisms of resistance to injury in the kidney will lead to a novel therapy. Clusterin, a secreted glycoprotein, is an antiapoptotic protein in cancer cells. Our study is to investigate the role of clusterin in renal IRI. Renal IRI in mice was induced by clamping renal vein and artery for 45 or 50 min at 32°C. Apoptosis of renal tubular epithelial cells (TECs) was determined by FACS analysis. Clusterin expression was examined by Western blot or immunohistochemistry. Here, we showed that clusterin protein was induced in TECs following IRI, and more tubules expressed clusterin in the kidneys following ischemia at higher temperatures. In human proximal TEC HKC-8 cultures, clusterin was upregulated by removal of serum and growth factors in medium and was downregulated by TNF-α-IFN-γ mixture. The levels of clusterin were positively correlated with cell survival in these conditions. Knockdown or knockout of clusterin expression enhanced the sensitivity of TECs to apoptosis. In experimental models of renal IRI, deficiency in clusterin expression worsened the injury, as indicated by a significant increase in renal tissue damage with higher levels of serum creatinine and blood urea nitrogen and by a poorer recovery from the injury in clusterin-deficient mice compared with wild-type mice. Our data indicate that the reduction of inducible expression of clusterin results in an increase in TEC apoptosis in the cultures and renders mice susceptibility to IRI, implying a protective role of clusterin in kidney injury.
Representation of Horizontal Head-on-Body Position in the Primate Superior Colliculus
Authors: Nagy Benjamin , Corneil Brian D.
Published: December 2009

Movement-related activity within the superior colliculus (SC) represents the desired displacement of an impending gaze shift. This representation must ultimately be transformed into position-based reference frames appropriate for coordinated eye–head gaze shifts. Parietal areas that project to the SC are modulated by the initial position of both the eye-re-head and head-re-body and SC activity is modulated by eye-re-head position. These considerations led us to investigate whether SC activity is modulated by the head-re-body position. We recorded activity from movement-related SC neurons while head-restrained monkeys performed a delayed-saccade task. Across blocks of trials, the horizontal position of the body was rotated under a space-fixed head to three to five different positions spanning ±25°. We observed a significant influence of body-under-head position on SC activity in 50/60 neurons. This influence was expressed predominantly as a linear gain field, scaling task-related SC activity without changing the location of the response field (linear gain fields explained ≥20% of the variance in neural activity in ∼50% of our sample). Smaller nonlinear modulations were also observed in roughly 30% of our sample. SC activity was equally likely to increase or decrease as the body was rotated to the side of neuronal recording and we found no systematic relationship between the directionality or magnitude of the linear gain field with recording location in the SC. We conclude that a signal conveying head-re-body position is present in the SC. Although the functional significance remains open, our findings are consistent with the SC contributing to a displacement-to-position transformation for oculomotor control.
Deformation of SS 304 LN during Scratch Test and Influence on Evolution of Coefficient of Friction
Authors: Kataria Satender , Kumar Niranjan , Dash Sitaram , Tyagi Ashok Kumar
Published: December 2009

An AISI 304 LN nuclear grade forged, metallographically polished specimen was subjected to progressive load scratch tests using a spheroconical indenter at three different scratch speeds 1, 3, and 27 mm/min. The present study attempts to address the evolution of coefficient of friction with scratch speed invoking its correlation with scratch induced deformation in the specimen. At higher scratch speeds, plastic deformation rates were higher which caused friction coefficient to be of higher magnitude. This was correlated with dynamically obtained high resolution optical images that revealed deformation driven microstructural alterations. These alterations significantly influenced the evolution of friction coefficient which was intimately related to plasticity of the surface.