bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of Adaptive Vγ2Vδ2+T-Cell Responses during Active Mycobacterial Coinfection of Simian Immunodeficiency Virus SIVmac-Infected Monkeys
Authors: Zhou Dejiang , Lai Xiaomin , Shen Yun , Sehgal Prabhat , Shen Ling , Simon Meredith , Qiu Liyou , Huang Dan , Du George Z. , Wang Qifan , Letvin Norman L. , Chen Zheng W. 
Published: February 2003

ABSTRACTAdaptive immune responses of γδ T cells during active mycobacterial coinfection of human immunodeficiency virus-infected humans have not been studied. Macaques infected with the simian immunodeficiency virus (SIV) SIVmac were employed to determine the extent to which a coincident AIDS virus infection might compromise immune responses of mycobacterium-specific Vγ2Vδ2+T cells during active mycobacterial infection. Control SIVmac-negative macaques developed primary and recall expansions of phosphoantigen-specific Vγ2Vδ2+T cells afterMycobacterium bovisBCG infection and BCG reinfection, respectively. In contrast, SIVmac-infected macaques did not exhibit sound primary and recall expansions of Vγ2Vδ2+T cells in the blood and pulmonary alveoli following BCG infection and reinfection. The absence of adaptive Vγ2Vδ2+T-cell responses was associated with profound CD4+T-cell deficiency and subsequent development of SIVmac-related tuberculosis-like disease in the coinfected monkeys. Consistently, Vγ2Vδ2+T cells from coinfected monkeys displayed a reduced capacity to expand in vitro following stimulation with phosphoantigen. The reduced ability of Vγ2Vδ2+peripheral blood lymphocytes (PBL) to expand could be restored to some extent by coculture of these cells with CD4+T cells purified from PBL of SIV-negative monkeys. Furthermore, naïve monkeys inoculated simultaneously with SIVmac and BCG were unable to sustain expansion of Vγ2Vδ2+T cells at the time that the coinfected monkeys developed lymphoid depletion and a fatal tuberculosis-like disease. Nevertheless, no deletion in Vδ2 T-cell receptor repertoire was identified in SIVmac-BCG-coinfected macaques, implicating an SIVmac-induced down-regulation rather than a clonal exhaustion of these cells. Thus, an SIVmac-induced compromise of the adaptive Vγ2Vδ2+T-cell responses may contribute to the immunopathogenesis of the SIV-related tuberculosis-like disease in macaques.
Differential Impairment of Lytic and Cytokine Functions in Senescent Human Immunodeficiency Virus Type 1-Specific Cytotoxic T Lymphocytes
Authors: Dagarag Mirabelle , Ng Hwee , Lubong Rachel , Effros Rita B. , Yang Otto O. 
Published: February 2003

ABSTRACTTelomere length is abnormally short in the CD8+T-cell compartment of human immunodeficiency virus type 1 (HIV-1)-infected persons, likely because of chronic cell turnover. Although clonal exhaustion of CD8+cytotoxic T lymphocytes (CTL) has been proposed as a mechanism for loss of antigen-specific responses, the functional consequences of exhaustion are poorly understood. Here we used telomerase transduction to evaluate the impact of senescence on CTL effector functions. Constitutive expression of telomerase in an HIV-1-specific CTL clone results in enhanced proliferative capacity, in agreement with prior studies of other human cell types. Whereas the CTL remain phenotypically normal in terms of antigenic specificity and requirements for proliferation, their cytolytic and antiviral capabilities are superior to those of control CTL. In contrast, their ability to produce gamma interferon and RANTES is essentially unchanged. The selective enhancement of cytolytic function in memory CTL by ectopic telomerase expression implies that loss of this function (but not cytokine production) is a specific consequence of replicative senescence. These data suggest a unifying mechanism for the in vivo observations that telomere lengths are shortened in the CD8+cells of HIV-1-infected persons and that HIV-1-specific CTL are deficient in perforin. Telomerase transduction could therefore be a tool with which to explore a potential therapeutic approach to an important pathophysiologic process of immune dysfunction in chronic viral infection.
Effects of Point Mutations in the Major Capsid Protein of Beet Western Yellows Virus on Capsid Formation, Virus Accumulation, and Aphid Transmission
Authors: Brault V. , Bergdoll M. , Mutterer J. , Prasad V. , Pfeffer S. , Erdinger M. , Richards K. E. , Ziegler-Graff V. 
Published: February 2003

ABSTRACT

Point mutations were introduced into the major capsid protein (P3) of cloned infectious cDNA of the polerovirus beet western yellows virus (BWYV) by manipulation of cloned infectious cDNA. Seven mutations targeted sites on the S domain predicted to lie on the capsid surface. An eighth mutation eliminated two arginine residues in the R domain, which is thought to extend into the capsid interior. The effects of the mutations on virus capsid formation, virus accumulation in protoplasts and plants, and aphid transmission were tested. All of the mutants replicated in protoplasts. The S-domain mutant W166R failed to protect viral RNA from RNase attack, suggesting that this particular mutation interfered with stable capsid formation. The R-domain mutant R7A/R8A protected ∼90% of the viral RNA strand from RNase, suggesting that lower positive-charge density in the mutant capsid interior interfered with stable packaging of the complete strand into virions. Neither of these mutants systemically infected plants. The six remaining mutants properly packaged viral RNA and could invade
Nicotiana clevelandii
systemically following agroinfection. Mutant Q121E/N122D was poorly transmitted by aphids, implicating one or both targeted residues in virus-vector interactions. Successful transmission of mutant D172N was accompanied either by reversion to the wild type or by appearance of a second-site mutation, N137D. This finding indicates that D172 is also important for transmission but that the D172N transmission defect can be compensated for by a “reverse” substitution at another site. The results have been used to evaluate possible structural models for the BWYV capsid.
Reversible Oxidative Modification as a Mechanism for Regulating Retroviral Protease Dimerization and Activation
Authors: Davis David A. , Brown Cara A. , Newcomb Fonda M. , Boja Emily S. , Fales Henry M. , Kaufman Joshua , Stahl Stephen J. , Wingfield Paul , Yarchoan Robert 
Published: February 2003

ABSTRACT
Human immunodeficiency virus protease activity can be regulated by reversible oxidation of a sulfur-containing amino acid at the dimer interface. We show here that oxidation of this amino acid in human immunodeficiency virus type 1 protease prevents dimer formation. Moreover, we show that human T-cell leukemia virus type 1 protease can be similarly regulated through reversible glutathionylation of its two conserved cysteine residues. Based on the known three-dimensional structures and multiple sequence alignments of retroviral proteases, it is predicted that the majority of retroviral proteases have sulfur-containing amino acids at the dimer interface. The regulation of protease activity by the modification of a sulfur-containing amino acid at the dimer interface may be a conserved mechanism among the majority of retroviruses.
Defects in Virion Production Caused by Mutations Affecting the C-Terminal Portion of the Moloney Murine Leukemia Virus Capsid Protein
Authors: Wang Margaret Q. , Goff Stephen P. 
Published: February 2003

ABSTRACT
The capsid (CA) domain of the Moloney murine leukemia virus (Mo-MuLV) Gag protein has a unique carboxy terminus with a highly charged arginine-rich sequence. Mutant viruses harboring arginine-to-alanine mutations affecting this region of CA displayed significant defects in virion release, and the few viral particles produced were noninfectious. The interaction between the mutant Gag precursors was affected, as judged by the yeast two-hybrid assay. The results suggest that the unique carboxy terminus of CA in the Mo-MuLV plays an important role in Gag-Gag association during virion production.
Comparison of maintenance policies with monotone failure rate distributions
Authors: Frostig Esther 
Published: February 2003

AbstractWe compare different maintenance policies assuming that the system lifetime has either increasing failure rate (IFR), or decreasing failure rate (DFR) distribution. We show that these assumptions yield strongly stochastic comparisons between the process' intensities. This yields weaker stochastic comparison between the processes than the stochastic comparison that hold when the system lifetime is new better than used (NBU) or new worse than used (NWU). Copyright © 2002 John Wiley & Sons, Ltd.
Latent variable modelling of price‐change in 295 manufacturing industries
Authors: Georganta Zoe 
Published: February 2003

AbstractIn contrast to traditional regression analysis, latent variable modelling (LVM) can explicitly differentiate between measurement errors and other random disturbances in the specification and estimation of econometric models. This paper argues that LVM could be a promising approach to test economic theories because applied research in business and economics is based on statistical information, which is frequently inaccurately measured. Considering the theory of industry‐price determination, where the price variables involved are known to include a large measurement error, a latent variable, structural‐equations model is constructed and applied to data on 7381 product categories classified into 295 manufacturing industries of the USA economy. The obtained estimates, compared and evaluated against a traditional regression model fitted to the same data, show the advantages of the LVM analytical framework, which could lead a long drawn‐out conflict between empirical results and theory to a satisfactory reconciliation. Copyright © 2003 John Wiley & Sons, Ltd.
Altered expression of insulins I and II and their mRNAs in the islets of Langerhans in dexamethasone‐induced diabetic rats
Authors: Toriumi Chifuyu , Imai Kazuhiro 
Published: February 2003

AbstractRats have two isomeric insulins (insulins I and II). There have been no reports on the expression of the isomeric insulins in glucocorticoid‐induced diabetic rats. To clarify the relation of the expression of each insulin and its mRNAs in dexamethasone‐induced diabetic rats, the amounts of the isomeric insulins and mRNAs in the islets of Langerhans were determined in vivo and in vitro. A sensitive and selective HPLC‐fluorescence determination method for the isomeric insulins and a newly developed real‐time quantitative RT–PCR method for their mRNAs were used. There was a greater reduction of insulin II than insulin I in the islets of Langerhans in dexamethasone‐induced diabetic rats. This alteration may be caused by a disproportionate expression of the respective mRNA for the isomeric insulins that resulted from the direct effect of dexamethasone. In addition, continuous hyperglycemia may also suppress the expression of the insulin II mRNA. The overall effects of dexamethasone and hyperglycemia may cause a greater reduction of insulin II than insulin I in the dexamethasone‐induced diabetic rat. Conversely, an elevated ratio of insulin I to II in the islets could suggest a diabetic condition. Copyright © 2003 John Wiley & Sons, Ltd.
Evidence for the Intermediacy of Arylbenzylnitrenium Ions in the Thermal Rearrangement of Isoxazolidines Derived from C,N‐Diarylnitrones and 2‐Morpholin‐4‐yl‐acrylonitrile
Authors: Liard Annie , Nguyen Thi‐Huu , Djelloul Smir Abdel Illah , Vaultier Michel , Derdour Aïcha , Mortier Jacques 
Published: February 2003

AbstractIn contrast to the diaryl, dialkyl, alkylaryl, and parent series, nothing is known about the generation and chemical behavior of arylbenzylnitrenium ions. Herein, we report that these species can be generated by a process involving an unprecedented thermal rearrangement of isoxazolidines derived from C,N‐diarylnitrones and 2‐morpholin‐4‐yl‐acrylonitrile. The products from these reactions are dramatically dependent upon the nature of the nitrone. Most of the observed chemistry originates from the singlet state.
Towards a Universal Polymer Backbone: Design and Synthesis of Polymeric Scaffolds Containing Terminal Hydrogen‐Bonding Recognition Motifs at Each Repeating Unit
Authors: Stubbs Ludger P. , Weck Marcus 
Published: February 2003

AbstractPolymers containing terminal hydrogen‐bonding recognition motifs based on diaminotriazine and diaminopyridine groups in their side chains for the self‐assembly of appropriate receptors have been prepared by ring‐opening metathesis polymerization (ROMP) of norbornenes. A new synthetic method for the preparation of norbornene monomers based on pure alkyl spacers is introduced. These monomers show unprecedented high reactivity using ROMP. To suppress self‐association of diaminotriazine‐based polymers, polymerizations were run in presence of N‐butylthymine. The butylthymine acts as a protecting group via self‐assembly onto the hydrogen‐bonding sites of the polymeric scaffold, thereby solubilizing the polymer. Diaminopyridine monomers do not require the presence of a protecting group due to their low propensity to dimerize. In addition, they exhibit a high affinity for hydrogen‐bonded receptors on both monomeric and polymeric level. These polymers present our first building blocks towards the design and synthesis of a “universal polymer scaffold”.
Synthetic Scheme for the Preparation of 13C‐Labeled 3,4‐Didehydro‐Retinal, 3‐Hydroxyretinal, and 4‐Hydroxyretinal up to Uniform 13C‐Enrichment
Authors: van Wijk Arjan A. C. , van de Weerd Michiel B. , Lugtenburg Johan 
Published: February 2003

AbstractA modular synthetic scheme has been developed for the synthesis of 13C‐labeled naturally occurring visual pigment chromophores; 3,4‐didehydroretinal, 3‐hydroxyretinal, and 4‐hydroxyretinal. These compounds can now be made with > 99% 13C enrichment at any position or combination of positions. We used the common C10+C5+C5 scheme for the synthesis of retinals, and by making variations in the C10 part we can now prepare the desired retinal derivatives with selective or uniform 13C enrichment. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Experimental Assessment of the Effect of a Bicyclo[1.1.0]butane System in Strain‐Induced Localisation of Aromatic π‐Bonds
Authors: Cohrs Carsten , Reuchlein Horst , Musch Patrick W. , Selinka Carola , Walfort Bernhard , Stalke Dietmar , Christl Manfred 
Published: February 2003

AbstractThe geometrical parameters of the dimethyl pyridazine‐1,4‐dicarboxylates 13−16, in which a σ‐bond system is annulated at the C5−C6 bond, have been determined by X‐ray diffraction. As compared to the cyclopentene subunit in 16, which is believed to exert no significant influence on the bond lengths of the aromatic moiety, the norbornene, benzvalene, and bicyclo[2.1.1]hexene subunits of 13−15, respectively, cause alternating bond elongations and shortenings in the pyridazine moiety, with increasing magnitudes, in that order. These effects are in line with the heats of the isodesmic reactions that convert norbornene (8), benzvalene (6), and bicyclo[2.1.1]hex‐2‐ene (4) with buta‐1,3‐diene into ethene as well as 2,3‐bis(methylene)norbornane (9), 3,4‐bis(methylene)tricyclo[3.1.0.02,6]hexane (7), and 2,3‐bis(methylene)bicyclo[2.1.1]hexane (5), respectively. Calculated originally by W. L. Jorgensen and W. T. Borden in the 1970s, the reactions have now been reexamined by employing much higher levels of theory. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Spectroelectrochemical and Voltammetric Studies of L‐DOPA
Authors: Liu Xiaoqiang , Zhang Zheling , Cheng Guangjin , Dong Shaojun 
Published: February 2003

AbstractThe electrooxidation of L‐dopa at GC electrode was studied by in situ UV‐vis spectroelectrochemistry (SEC) and cyclic voltammetry. The mechanism of electrooxidation and some reaction parameters were obtained. The results showed that the whole electrooxidation reaction of L‐dopa at glassy carbon (GC) electrode was an irreversible electrochemical process followed by a chemical reaction in neutral solution (EC mechanism). The spectroelectrochemical data were treated by the double logarithm method together with nonlinear regression, from which the formal potential E0=228 mV, the apparent electron‐transfer number of the electrooxidation reaction αn=0.376 (R=0.99, SD=0.26), the standard electrochemical rate constant k0=(3.93±0.12)×10−4 cm s−1 (SD=1.02×10−2), and the formation equilibrium constant of the following chemical reaction kc=(5.38±0.34)×10−1 s−1 (SD=1.02×10−2) were also obtained.
Novel Liquid Membrane Electrode for Selective Determination of Monohydrogenphosphate
Authors: Ganjali Mohammad Reza , Mizani Farhang , Emami Mehdi , Niasari Masoud Salavati , Shamsipur Mojtaba , Yousefi Mohammad , Javanbakht Mehran 
Published: February 2003

AbstractA highly selective and sensitive membrane electrode based on vanadyl salen complex (VS), which responds to monohydrogenphosphate (MHP) ions is described. The response of the sensor is Nernstian over the wide concentration range (1.0×10−1 − 5.0×10−6 M) of MHP. The sensitivity of the electrode is high enough to permit the detection of as little as 0.6 μg/mL of MHP without any significant interference from high levels of other anions. The potentiometric selectivity coefficient data revealed negligible interference from 11 common anions. The electrode has a fast response time (<25 s), good slope stability at pH 8.2 for a period of at least eight weeks. It was successfully applied for the direct determination of monohydrogenphosphate in fertilizer and, as indicator electrode, in potentiometric titration of HPO42− ion with barium chloride.
Isoperimetric problems and roses of neighborhood for stationary flat processes
Authors: Spodarev Eugene 
Published: February 2003

AbstractThe paper yields necessary conditions for the directional distributions of stationary k–flat processes in ℝd that maximize their intersection density of order 2, that is, the mean (2k – d)–volume of their self–intersections in an observation window of unit d–volume. The conditions are given in terms of the rose of intersections (i.e., the intensity of intersections of the flat process with test flats). The notion of the rose of neighborhood is introduced which is an analogue of the rose of intersections for lower dimensional flat processes. Some properties of the rose of neighborhood are studied and an asymptotically unbiased estimator is given.
Cooperative R&D and the Canadian forest products industry
Authors: Nakamura Masao , Nelson Harry , Vertinsky Ilan 
Published: February 2003

AbstractIn the past decade the share of cooperative R&D has increased. In this paper, using a case study of the forest industry in Canada, the antecedents of cooperative R&D and the forms it take are investigated. We show how market failures are corrected in the industry largely through industry wide R&D consortia. The share of government funding to maintain the cooperation reflects the degree to which the consortia can appropriate the full value of their knowledge products (i.e. prevent spillover of innovations to non‐members in Canada and elsewhere). The case study indicates that the prime role of these nationwide consortia is the provision of potential access to R&D expertise, technological intelligence, and technology transfer services. The success and stability of these consortia depend on the degree to which their governance systems allow for better alignment of the costs and benefits that accrue to members from the consortia. Copyright © 2003 John Wiley & Sons, Ltd.
Interaction between public research organizations and industry in biotechnology
Authors: Dalpé Robert 
Published: February 2003

AbstractThis paper summarizes the most important findings of the literature on the close interaction between public research organizations and industry in biotechnology. The first question deals with why researchers in academic organizations were and are still important players in the biotechnology industry. Three arguments explain why biotechnology emerged as an organization network: its origins in academic research, the impact of participation in networks on competitiveness and the weight of these networks on R&D intensity and innovation. The second focuses on the factors that explain the regional concentration of such interactions and of biotechnology firms. The paper concludes with a discussion of policy implications. The dynamic of biotechnology is rather unique and can be attributed to the specific institutional arrangements characterizing the American scientific system. Its replication to other sectors or countries seems rather difficult. Copyright © 2003 John Wiley & Sons, Ltd.
Intergenerational value discrepancies in immigrant and host‐national families and their impact on psychological adaptation
Authors: Sam David Lackland , Virta Erkki 
Published: February 2003

ABSTRACTThis study investigated the relationship between intergenerational value discrepancies and psychological adaptation among adolescents with immigrant background (mean age=15.5 years) in Norway and Sweden. Results from two cohorts (parents and their children) of immigrant and host‐national families in the two countries (n=574) indicated that immigrant adolescents on the whole neither differed from their host peers with respect to psychological adaptation nor on value discrepancies. Value discrepancies were weakly related to psychological adaptation. Results are discussed as to whether the findings may reflect a general phenomenon for all adolescents or specific to those with immigrant background.
Wrapping up BLAST and other applications for use on Unix clusters
Authors: Hokamp Karsten , Shields Denis C. , Wolfe Kenneth H. , Caffrey Daniel R. 
Published: February 2003

Abstract
Summary: We have developed two programs that speed up common bioinformatic applications by spreading them across a UNIX cluster.(1) BLAST.pm, a new module for the ‘MOLLUSC’ package. (2) WRAPID, a simple tool for parallelizing large numbers of small instances of programs such as BLAST, FASTA and CLUSTALW.
Availability: The packages were developed in Perl on a 20-node Linux cluster and are provided together with a configuration script and documentation. They can be freely downloaded from http://wolfe.gen.tcd.ie/wrapper
Contact: daniel_r_caffrey@cambridge.pfizer.comkarsten@oscar.gen.tcd.ie
* These authors contributed equally to this work.
† Current Address: Pfizer Discovery Technology Center, 620 Memorial Drive, Cambridge, MA 02139, USA.