bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular characterization of the novel rat NK receptor 1C7
Authors: Bäckman‐Petersson Eva , Miller J. Ross , Hollyoake Martine , Aguado Begoña , Butcher Geoffrey W. 
Published: February 2003

AbstractA novel receptor, named 1C7 or NKp30 and involved in natural cytotoxicity, was recently identified. This receptor is encoded by the 1C7 gene, which is located within the class III region of the human MHC, HLA. It is a member of the immunoglobulin gene superfamily (IgSF) and, remarkably, is expressed at the mRNA level as six different splice variants in human. Recent investigations have indicated that the 1c7 gene of the mouse is silenced by in‐frame stop codons. In this study, the molecular characterization of the rat 1c7 gene is described. cDNA derived from this gene encode a protein of 192 amino acid residues predicted to contain a single IgV‐set domain in the extracellular region and a positively charged residue in the transmembrane region. Expression of the gene was detected in freshly isolated rat Natural Killer (NK) and T splenocytes. Transfection of rat 1C7 into the NK cell line RNK‐16 induced cytolytic activity against glioma as well as lymphoma tumor cells. In addition, binding of a r1C7‐Fc fusion protein by a panel of target cells correlated with susceptibility to killing by RNK‐16–1C7 effector cells. These results indicate that the r1C7 molecule could function as an NK activating receptor as previously reported for the human NKp30 receptor molecule.
CD2+/CD14+ monocytes rapidly differentiate into CD83+ dendritic cells
Authors: Pucchio Tiziana Di , Lapenta Caterina , Santini Stefano Maria , Logozzi Mariantonia , Parlato Stefania , Belardelli Filippo 
Published: February 2003

AbstractSince denditric cells (DC) represent the main players linking innate and adaptive immunity, their prompt generation from blood cells would be instrumental for an efficient immune response to infections. Consistent with this, CD2+ monocytes were found to express the DC maturation marker CD83, along with acquisition of high antigen‐presenting activity, after a surprisingly short time in culture. This rapid process is associated with expression of IFN‐α/β genes and secretion of low levels of pro‐inflammatory cytokines. Exposure of monocytes to IFN‐α, but not to IL‐4, induced persistence of CD2+/CD83+ cells, which were fully competent in stimulating primary responses by naive T cells. These results unravel the natural pathway by which infection‐induced signals rapidly transform pre‐armed monocytes into active DC.
A novel ligand for the NKG2D receptor activates NK cells and macrophages and induces tumor immunity
Authors: Diefenbach Andreas , Hsia Jennifer K. , Hsiung Ming‐Yu B. , Raulet David H. 
Published: February 2003

AbstractNK cells are involved in the immune response against viral and microbial infections and tumors. In contrast to B and T cells, NK cells employ various modes of immune recognition. An important mode of immune recognition employed by NK cells is "induced self recognition" exemplified by the NKG2D receptor–ligand system. The NKG2D immunoreceptor, expressed by NK cells, and by activated CD8+ T cells and macrophages, recognizes one of several cell surface ligands that are distantly related to MHC class I molecules (i.e. H60 and Rae1 proteins in mice, and MHC class I chain‐related proteins and UL‐16‐binding proteins in humans). These ligands are not expressed abundantly by most normal cells but are up‐regulated on cells exposed to various forms of cellular insults.Here we report the cloning of another ligand for NKG2D; transcripts of this ligand are found in a wide variety of tissues and in various tumor cells. Cross‐linking of NKG2D with the novel ligand potently activated NK cells and macrophages. Tumor cells ectopically expressing the molecule were efficiently rejected by naive mice, and induced strong protective immunity to the parental, ligand‐negative tumor cells.
Costimulation of human CD28– T cells by 4‐1BB ligand
Authors: Bukczynski Jacob , Wen Tao , Watts Tania H. 
Published: February 2003

AbstractThe T cell surface protein CD28 provides a critical costimulatory signal for T cell activation. With age, humans accumulate increasing numbers of CD28– T cells, and this loss of CD28 expression is exacerbated certain disease states, such as HIV infection, autoimmune conditions or cancer. It is unclear whether CD28– T cells represent terminally differentiated effector cells or whether they remain sensitive to costimulation by CD28‐independent pathways. Here, we demonstrate that 4–1BB ligand can costimulate human CD28– T cells, resulting in cell division, inflammatory cytokine production, increased perforin levels, enhancement of cytolytic effector function, as well as the up‐regulation of the anti‐apoptotic protein Bcl‐XL. Thus, human CD28– T cells can respond to costimulatory signals and as such become attractive targets for therapeutic intervention, particularly in chronic infectious and inflammatory diseases where large numbers of these cells accumulate.
Biochemical and functional characterization of the interaction between pentraxin 3 and C1q
Authors: Nauta Alma J. , Bottazzi Barbara , Mantovani Alberto , Salvatori Giovanni , Kishore Uday , Schwaeble Wilhelm J. , Gingras Alexandre R. , Tzima Sotiria , Vivanco Fernando , Egido Jesús , Tijsma Odette , Hack Erik C. , Daha Mohamed R. , Roos Anja 
Published: February 2003

AbstractPentraxin 3 (PTX3) is a recently characterized member of the pentraxin family of acute‐phase proteins produced during inflammation. Classical short pentraxins, C‐reactive protein, and serum amyloid P component can bind to C1q and thereby activate the classical complement pathway. Since PTX3 can also bind C1q, the present study was designed to define the interaction between PTX3 and C1q and to examine the functional consequences of this interaction. A dose‐dependent binding of both C1q and the C1 complex to PTX3 was observed. Experiments with recombinant globular head domains of human C1q A, B, and C chains indicated that C1q interacts with PTX3 via its globular head region. Binding of C1q to immobilized PTX3 induced activation of the classical complement pathway as assessed by C4 deposition. Furthermore, PTX3 enhanced C1q binding and complement activation on apoptotic cells. However, in the fluid‐phase, pre‐incubation of PTX3 with C1q resulted in inhibition of complement activation by blocking the interaction of C1q with immunoglobulins. These results indicate that PTX3 can both inhibit and activate the classical complement pathway by binding C1q, depending on the way it is presented. PTX3 may therefore be involved in the regulation of the innate immune response.
Kinetics and expression patterns of chemokine receptors in human CD4+ T lymphocytes primed by myeloid or plasmacytoid dendritic cells
Authors: Langenkamp Anja , Nagata Kinya , Murphy Kristine , Wu Lijun , Lanzavecchia Antonio , Sallusto Federica 
Published: February 2003

AbstractWe investigated the kinetics of expression of 12 chemoattractant receptors as a function of cell division following priming of human naive CD4+ T cells by different populations of dendritic cells (DC) and under conditions favoring Th1 or Th2 differentiation. Two chemokine receptors, CXCR3 and CXCR5, were rapidly up‐regulated following T cell activation by either monocyte‐derivedDC, myeloid DC (mDC) or plasmacytoid DC (pDC). While CXCR5 expression was transient, expression of CXCR3 at advanced cell divisions was dependent on differentiation, being expressed at high levels on Th1 cells. Several other receptors (CCR2, CCR3, CCR4, CCR5, CXCR6 and CRTh2) were acquired progressively as a function of cell division and in a fashion that was influenced by polarizing cytokines. The Th2‐associated chemoattractant receptors CRTh2 and CCR3 were up‐regulated with slower kinetics compared to the Th1‐associated receptors CXCR3 and CXCR6, consistent with a different kinetics and efficiency of polarization. Moreover, CCR4 and CXCR6 were preferentially induced in T cells activated by mDC and pDC, respectively. Finally, CXCR5 and CCR7 were also rapidly and transiently up‐regulated in memory T cells following TCR stimulation. These results indicate a complex chemokine receptor regulation dependent on both T cell activation and differentiation state. In addition, they reveal the existence of DC‐specific cues for the regulation of T cell migratory capacity.
Antigen‐presenting cell exosomes are protected from complement‐mediated lysis by expression of CD55 and CD59
Authors: Clayton Aled , Harris Claire L. , Court Jacquelyn , Mason Malcolm D. , Morgan B. Paul 
Published: February 2003

AbstractExosomes are secreted nanometer‐sized vesicles derived from antigen‐presenting cells, which have attracted recent interest as they likely play important roles in immune regulation, and their use as cell‐free tools for immunotherapy has been proposed. Liposomes used clinically as transport vehicles can activate the complement system, leading to their rapid degradation and significant inflammatory toxicity. The use of isolated exosomes in therapy, therefore, may also elicit complement activation, reducing their potential efficacy. We have examined the expression and functional roles of the membrane regulators of complement (CD46, CD55 and CD59) on antigen‐presenting cell‐derived exosomes. Exosomes express the glycosylphosphatidylinositol (GPI)‐anchored regulators CD55 and CD59,but not the transmembrane protein CD46. Antibody blocking of CD55 in the presence of sensitizing antibody (w6/32) and human serum resulted in increased C3b deposition and significantly increased exosome lysis. Blockade of CD59 also resulted in significant lysis, while blocking both CD55 and CD59 increased lysis still further. We conclude that exosomes express GPI‐anchored complement regulators in order to permit their survival in the extracellular environment.
Deviation of islet autoreactivity to cryptic epitopes protects NOD mice from diabetes
Authors: Song Aihua , Winer Shawn , Tsui Hubert , Sampson Anastazia , Pasceri Peter , Ellis James , Elliott John F. , Dosch H.‐Michael 
Published: February 2003

AbstractTo better understand loss of self‐tolerance in diabetes‐prone NOD mice, we are generating ICA69 transgenes under control of the tetracycline‐regulated tet07 minimal promoter. In vitro pilot studies showed leaky transgene expression, but addition of β‐globin genomic insulator flanks prevented leakage and dramatically enhanced transgene expression even in transient transfection, with excellent suppression by Doxycycline. In vivo, the accidental loss of insulator flanks during transgene insertion in one transgenic NOD founder, tet1, re‐established leakiness with high level, exclusive ICA69‐transgene expression in stromal elements of thymus and spleen. This led to persistent deletion of T cells targeting the immunodominant ICA69 epitope, Tep69, but emergenceof T cell pools targeting cryptic ICA69 epitopes not normally generated in sufficient density to select and maintain ICA69‐autoreactive T cells. This subtle modification of T cell repertoires reduced insulitis, and protected from diabetes in transgenics and in wild‐type mice carrying irradiated tet1 thymus grafts. The low pathogenicity of T cells targeting cryptic epitopes likely reflects the fact that the major ICA69 determinant presented in the islet milieu remains Tep69, while cryptic epitopes are under‐represented. Deviation of T cell autoreactivity from major to cryptic target epitopes in tet1 mice provides a fortuitous model to explain previously observed diabetes protection by immunotherapy or autoantigen transgenes despite apparent failure to achieve tolerance to the full length islet antigens.
Attitudes and reactions to media coverage of terrorist acts
Authors: Keinan Giora , Sadeh Avi , Rosen Sefi 
Published: February 2003

AbstractThe present study examined attitudes and reactions of individuals towards media coverage of terrorist acts. Shortly after a series of severe terrorist attacks had taken place in Israel, 534 people were asked to fill out a questionnaire that assessed their attitudes and reactions to the media's coverage of these acts as well as a questionnaire that examined their information‐seeking style. The results suggested that although a considerable proportion of media consumers preferred detailed coverage of terrorist acts, when the coverage included horrifying details, the readiness for receiving detailed information declined. In addition, the results indicated that exposure to such coverage was associated with the development of symptoms similar to those of Post‐Traumatic Stress Disorder. Finally, individual differences in both attitudes and reactions towards media coverage were found as a function of participants' gender, political orientation, and information‐seeking style. The theoretical and empirical implications of these findings are discussed. © 2003 Wiley Periodicals, Inc.
Action research on leadership for community development in West Africa and North America: A joining of liberation theology and community psychology
Authors: Trout John , Dokecki Paul R. , Newbrough J. R. , O'Gorman Robert T. 
Published: February 2003

AbstractOur purpose is to enhance the field's understanding of the nature of community leadership, the psychological sense of community, and the spiritual dimensions of community life. We describe an action research community development project conducted in a low‐income Catholic parish in Lagos, Nigeria, in Western Africa. After describing the community development process that resulted in the establishment of 40 small/street basic communities (SBCs), we report an evaluation study in which 70 SBC leaders were surveyed regarding (1) SBC background characteristics (socioeconomic and environmental conditions and statistical information), (2) the state of community life in the SBCs (spirit/sense of community, participation in activities, benefits of community life), and (3) challenges for the future (what SBC members and leaders can do to improve the community, problems influencing community development). We then reflect on the Lagos findings in light of leadership‐for‐community and spirituality frameworks developed in an action research project conducted in a Catholic parish in the United States. © 2003 Wiley Periodicals, Inc.
Mass spectrometry of polyaromatic sulfur compounds in the presence of palladium(II)
Authors: Rudzinski Walter E. , Zhang Yi , Luo Xuemei 
Published: February 2003

AbstractElectrospray ionization mass spectrometry (ESI‐MS) and tandem MS in an ion trap were used to explore the reduction of a PdCl2 solution and the role of the metal in the formation of organosulfur radical cations. For tandem MS experiments, a 32 Da neutral loss (M − S), was observed for dibenzothiophene, thianthrene and benzonaphthothiophene, whereas both 32 and 33 Da neutral losses were observed for 2‐methyldibenzothiophene and 4,6‐dimethyldibenzothiophene. The effects of several variables on the formation of molecular ions or molecular fragments were studied to optimize radical cation formation, including the concentration ratio between PdCl2 and sulfur and the collision energy. Electrochemical and chromatographic data were used to provide an explanation for the relative sensitivity observed for a mixture of polyaromatic sulfur heterocycles. Copyright © 2003 John Wiley & Sons, Ltd.
Non‐linearity in the quadrupole detector system: implications for the determination of the 13C mass distribution of an ion fragment
Authors: Vogt Josef A. , Wachter Ulrich , Georgieff Michael 
Published: February 2003

AbstractSome biomedical 13C tracer applications to study glucose/lactate metabolism require the determination of up to 7 mass isotopomers of glucose, generated by the 13C‐labeling. Isotopomer ratios determined by GC‐Quadrupole‐MS can depend on the analyte amount being measured and may differ from expected theoretical values. A calibration is necessary to correct these effects. However, the large number of different isotopomers prevents an empirical calibration, that is based on known isotopomer mixtures. Neither insufficient mass separation in the quadrupole nor proton adducts or losses of the ionized fragment can account for the observed deviation from expected values and the dependency on the sample size. We explain the deviations with a nonlinear mapping of the isotopomer amount being analyzed to the area under the elution curve for the corresponding mass channel. The nonlinear relation allows to estimate potential errors in the determination of isotopomer ratios. It also allows to define a dynamic range as the range of signal areas, for which the systematic error in the isotopomer ratio determination is below 5% of the nominal value. It is 1 : 200 and 1 : 500 for two different fragments of glucose, measured under EI and CI and is smaller than the range imposed by the measurement precision. After correcting the nonlinearities the dynamic range improved by the factor 10 in both cases. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of the pigments on painted pottery figurines from the Han Dynasty's Yangling Tombs by Raman microscopy
Authors: Zuo Jian , Zhao Xichen , Wu Ruo , Du Guangfen , Xu Cunyi , Wang Changsui 
Published: February 2003

AbstractThe pigments on painted pottery figurines from the Han Dynasty's Yangling Tombs were analysed by Raman microscopy. It was found that BaCuSi2O6 is included in the purple pigment, which was first synthesized by ancient people 1845 years ago. The red pigments were identified as haematite and cinnabar, the yellow pigment as goethite, the white pigment as calcite, the blue pigment as azurite and the black pigment as soot. Copyright © 2003 John Wiley & Sons, Ltd.
Structural phase transition in (n‐C4H9NH3)2SiF6: DSC and Raman studies
Authors: Jeghnou H. , Ouasri A. , Rhandour A. , Dhamelincourt M.‐C. , Dhamelincourt P. , Mazzah A. 
Published: February 2003

AbstractButylammonium hexafluorosilicate, (n‐C4H9NH3)2SiF6, crystallizes at room temperature in the trigonal system with a probable space group P321. A new structural phase transition was detected at low temperatures for this compound by means of differential scanning calorimetry (DSC) and the basic thermodynamic data for this transition were determined. The internal vibrational modes of (n‐C4H9NH3)2SiF6 were studied at ambient temperature and as a function of the temperature, through the phase transition, by means of Raman spectroscopy. The observed phase transition is associated with the dynamics of the system and is of the order–disorder type. Copyright © 2003 John Wiley & Sons, Ltd.
Three‐layer substrates for surface‐enhanced Raman scattering: preparation and preliminary evaluation
Authors: Mulvaney Shawn P. , He Lin , Natan Michael J. , Keating Christine D. 
Published: February 2003

AbstractIn surface‐enhanced Raman scattering (SERS), the magnitude of enhancement is highly dependent on the nanometer‐scale morphological and optical properties of the substrate employed. This paper reports the development of an improved SERS‐active substrate that is based on a combination of nanoparticle assembly and evaporated thin films. Highly enhancing, three‐layer SERS‐active substrates were constructed by evaporation of an Ag film over an Ag‐clad colloidal Au submonolayer; the distinguishing feature of the three‐layer substrate is the formation of evaporated Ag islands between the surface‐bound colloidal particles. UV–visible absorption spectroscopy, atomic force microscopy and field emission scanning electron microscopy were used to characterize the substrate morphology. The thickness of the evaporated layer was varied in order to determine the optimal substrate architecture. The estimated enhancement factor for the optimized substrate architecture was 7 × 104. Furthermore, better than 15% reproducibility in the Raman spectra for adsorbed analytes was observed from spot to spot on a given substrate, and also from substrate to substrate. Finally, a sub‐picogram detection limit was demonstrated with the environmental pollutant 1,3,5‐triazine. Copyright © 2003 John Wiley & Sons, Ltd.
Capillary zone electrophoretic assay of biologically active thioacridine derivatives
Authors: Matalová Radka , Jelínek Ivan , Pumera Martin , Barbe Jacques 
Published: February 2003

AbstractA capillary zone electrophoretic method was developed for the analytical evaluation of newly synthesized biologically active thioacridine derivatives. Based on background electrolyte pH optimization, the experimental conditions ensuring satisfactory resolution of the studied set of thioacridine derivatives and their accompanying synthetic impurities were found. Optimum background electrolyte consists of 30 mM citric acid and 30 mM β‐alanine (pH 3.74). Calibration data confirmed linear response for all compounds of interest in the concentration range 1–500 μg/mL, sufficiently high sensitivity, and limits of detection not exceeding 0.16 μg/mL. The described assay proved to be suitable for rapid identification and purity evaluation of studied thioacridine derivatives. The qualitative and quantitative results have been compared with those obtained using conventional liquid chromatography. The differences were not generally significant.
Facile monitoring and evaluation of bacteria in a fermentation process using perfusion chromatography and polarimetry detection
Authors: Berthod Alain , Zhang Bo , Armstrong Daniel W. 
Published: February 2003

AbstractA 670 nm diode laser polarimeter was used as a detector for living cells in perfusion chromatography. It was found that all microorganisms examined, including vegetal organisms such as algae and fungi as well as several strains of different bacteria, gave a levorotatory signal, producing negative peaks in the chromatograms. Most naturally occurring chiral molecules, such as sugars and amino acids are dextrorotatory and give positive polarimetric peaks. A hydrophilic OH‐functionalized polystyrene divinylbenzene spherical porous particle packing was used as a sieving and size exclusion material and packed in 27×0.95 cm columns. The theory of the close‐packing of spheres is summarized to show that common bacteria should be able to perfuse in the interparticle voids of the 50 μm packing. It is shown that bacteria are eluted with the exclusion volume; a selective permeation of polymer with molecular weight ranging from 103 to 2×106 is obtained, and total permeation occurs for small molecules. The restricted access columns are used to follow the changes in cell concentration in bacteria cultures. The growth of three different bacteria was studied using calibrated polarimetric signals.
Quantitative sample injection for capillary electrophoresis
Authors: Yao Chuanyi , Gao Ruyu , Yan Chao 
Published: February 2003

AbstractAn apparatus including a rotary‐type injector was designed for quantitative sample injection in capillary electrophoresis (CE), in which both pressurized flow and electroosmotic flow were used to drive the background electrolyte solution. A relative standard deviation of peak area of lower than 1% was achieved by using this apparatus. The effects of back‐pressure regulator, restrictor, and applied voltage on separation efficiency and resolution were investigated. The utility of this apparatus in both micro‐HPLC and pressurized capillary electrochromatography (pCEC) was also demonstrated.