868 research outputs found

    CELL INTERACTIONS BETWEEN HISTOINCOMPATIBLE T AND B LYMPHOCYTES : IV. INVOLVEMENT OF THE IMMUNE RESPONSE (Ir) GENE IN THE CONTROL OF LYMPHOCYTE INTERACTIONS IN RESPONSES CONTROLLED BY THE GENE

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    In the present study we have asked the question of whether F1 carrier-primed T cells can serve as helper cells for either or both parental B cells when (a) the carrier molecule employed is under genetic control such that one parental strain is a responder and the other is a nonresponder, and (b) the determinant specificity of the parental B cells being assessed is not under genetic control and bears no relationship to the specificity of the carrier molecule. Utilizing the system of immune response gene control of responses to the terpolymer L-glutamic acid-L-lysine-L-tyrosine (GLT) to which A strain mice (H-2a) are nonresponders, whereas BALB/c (H-2d) and (BALB/c x A)F1 hybrids (CAF1) are responders, these studies demonstrate that GLT-primed T cells of CAF1 donors can provide for responder BALB/c, but not for nonresponder A/J, the required stimulus for the anti-DNP responses of DNP-specific B cells of these respective parental strains to the DNP conjugate of GLT. The implications of these findings for Ir gene function in physiologic T-B cell interactions are discussed in detail

    A Contributing Role for Anti-Neuraminidase Antibodies on Immunity to Pandemic H1N1 2009 Influenza A Virus

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    Exposure to contemporary seasonal influenza A viruses affords partial immunity to pandemic H1N1 2009 influenza A virus (pH1N1) infection. The impact of antibodies to the neuraminidase (NA) of seasonal influenza A viruses to cross-immunity against pH1N1 infection is unknown.Antibodies to the NA of different seasonal H1N1 influenza strains were tested for cross-reactivity against A/California/04/09 (pH1N1). A panel of reverse genetic (rg) recombinant viruses was generated containing 7 genes of the H1N1 influenza strain A/Puerto Rico/08/34 (PR8) and the NA gene of either the pandemic H1N1 2009 strain (pH1N1) or one of the following contemporary seasonal H1N1 strains: A/Solomon/03/06 (rg Solomon) or A/Brisbane/59/07 (rg Brisbane). Convalescent sera collected from mice infected with recombinant viruses were measured for cross-reactive antibodies to pH1N1 via Hemagglutinin Inhibition (HI) or Enzyme-Linked Immunosorbent Assay (ELISA). The ectodomain of a recombinant NA protein from the pH1N1 strain (pNA-ecto) was expressed, purified and used in ELISA to measure cross-reactive antibodies. Analysis of sera from elderly humans immunized with trivalent split-inactivated influenza (TIV) seasonal vaccines prior to 2009 revealed considerable cross-reactivity to pNA-ecto. High titers of cross-reactive antibodies were detected in mice inoculated with either rg Solomon or rg Brisbane. Convalescent sera from mice inoculated with recombinant viruses were used to immunize naïve recipient Balb/c mice by passive transfer prior to challenge with pH1N1. Mice receiving rg California sera were better protected than animals receiving rg Solomon or rg Brisbane sera.The NA of contemporary seasonal H1N1 influenza strains induces a cross-reactive antibody response to pH1N1 that correlates with reduced lethality from pH1N1 challenge, albeit less efficiently than anti-pH1N1 NA antibodies. These findings demonstrate that seasonal NA antibodies contribute to but are not sufficient for cross-reactive immunity to pH1N1

    Can care of elderly be measured? A method for estimating the individual care of recipients in community health care

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    <p>Abstract</p> <p>Background</p> <p>Almost every country in the Western world has great difficulties allocating enough financial resources to meet the needs in the care of the increasing elderly population. The main problem is common to all countries and concerns the efforts to meet elderly persons' needs on an individual level while still maintaining society's responsibility for distributing justice. The aim of this study is to elaborate an instrument for measuring the quality of individual care and staff's working time in order to allocate public resources fairly. The present study gives an account of a new classification system named TiC (Time in Care), indicating how it can be used most effectively and also investigating the validity and reliability of the system.</p> <p>Methods</p> <p>All recipients in 13 sheltered homes for elderly care (n = 505) in a Swedish municipality were surveyed regarding the care they needed, in dimensions of General Care, Medical Care, Cognitive Dysfunction and Rehabilitation, and the time required. Construct validity was assessed by means of factor analysis. The inter-rater agreement of two raters concerning 79 recipients was measured using weighted Kappa. The stability of the instrument and its sensitivity to change were investigated through test-retest reliability measurements, conducted once a month during a six-month period. The content validity of the instrument was also assessed.</p> <p>Results</p> <p>Factor analysis resulted in a reduction of the number of items from 25 to 16 in three dimensions: General Care, Medical Care and Cognitive Dysfunction. The Kappa analysis showed satisfactory to excellent inter-rater agreement. The care need scores were basically stable but showed sensitivity to change in health status.</p> <p>Conclusion</p> <p>The instrument was found to be useful and reliable for assessing individual needs in community health care.</p

    Muscle fiber conduction velocity is more affected after eccentric than concentric exercise

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    It has been shown that mean muscle fiber conduction velocity (CV) can be acutely impaired after eccentric exercise. However, it is not known whether this applies to other exercise modes. Therefore, the purpose of this experiment was to compare the effects of eccentric and concentric exercises on CV, and amplitude and frequency content of surface electromyography (sEMG) signals up to 24 h post-exercise. Multichannel sEMG signals were recorded from biceps brachii muscle of the exercised arm during isometric maximal voluntary contraction (MVC) and electrically evoked contractions induced by motor-point stimulation before, immediately after and 2 h after maximal eccentric (ECC group, N = 12) and concentric (CON group, N = 12) elbow flexor exercises. Isometric MVC decreased in CON by 21.7 ± 12.0% (± SD, p < 0.01) and by 30.0 ± 17.7% (p < 0.001) in ECC immediately post-exercise when compared to baseline. At 2 h post-exercise, ECC showed a reduction in isometric MVC by 24.7 ± 13.7% (p < 0.01) when compared to baseline, while no significant reduction (by 8.0 ± 17.0%, ns) was observed in CON. Similarly, reduction in CV was observed only in ECC both during the isometric MVC (from baseline of 4.16 ± 0.3 to 3.43 ± 0.4 m/s, p < 0.001) and the electrically evoked contractions (from baseline of 4.33 ± 0.4 to 3.82 ± 0.3 m/s, p < 0.001). In conclusion, eccentric exercise can induce a greater and more prolonged reduction in muscle force production capability and CV than concentric exercis

    Long term productivity and collaboration in information science

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    This is an accepted manuscript of an article published by Springer in Scientometrics on 02/07/2016, available online: https://doi.org/10.1007/s11192-016-2061-8 The accepted version of the publication may differ from the final published version.Funding bodies have tended to encourage collaborative research because it is generally more highly cited than sole author research. But higher mean citation for collaborative articles does not imply collaborative researchers are in general more research productive. This article assesses the extent to which research productivity varies with the number of collaborative partners for long term researchers within three Web of Science subject areas: Information Science & Library Science, Communication and Medical Informatics. When using the whole number counting system, researchers who worked in groups of 2 or 3 were generally the most productive, in terms of producing the most papers and citations. However, when using fractional counting, researchers who worked in groups of 1 or 2 were generally the most productive. The findings need to be interpreted cautiously, however, because authors that produce few academic articles within a field may publish in other fields or leave academia and contribute to society in other ways

    On becoming (un)committed: A taxonomy and test of newcomer on-boarding scenarios

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    How does the bond between the newcomer and the organization develop over time? Process research on temporal patterns of newcomer's early commitment formation has been very scarce because theory and appropriate longitudinal research designs in this area are lacking. From extant research we extract three process-theoretical accounts regarding how the newcomer adjustment process evolves over time: (1) Learning to Love; (2) Honeymoon Hangover; and (3) High Match, Moderate Match, or Low Match. From these scenarios we develop a taxonomy of newcomer adjustment scenarios. Further, we empirically verify these different scenarios by examining naturally occurring "trajectory classes," which are found to display strengthening, weakening, or stabilizing of the employee-organization linkage. For this, we use a sample of 72 Ph. D. graduates whose organizational commitment history was recorded in their first 25 consecutive weeks of new employment. In closing, we discuss the theoretical and practical implications of the scenario-based approach

    Election proximity and representation focus in party-constrained environments

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    Do elected representatives have a time-constant representation focus or do they adapt their focus depending on election proximity? In this article, we examine these overlooked theoretical and empirical puzzles by looking at how reelection-seeking actors adapt their legislative behavior according to the electoral cycle. In parliamentary democracies, representatives need to serve two competing principals: their party and their district. Our analysis hinges on how representatives make a strategic use of parliamentary written questions in a highly party-constrained institutional context to heighten their reselection and reelection prospects. Using an original data set of over 32,000 parliamentary questions tabled by Portuguese representatives from 2005 to 2015, we examine how time interacts with two key explanatory elements: electoral vulnerability and party size. Results show that representation focus is not static over time and, in addition, that electoral vulnerability and party size shape strategic use of parliamentary questions

    γ-H2AX Kinetics as a Novel Approach to High Content Screening for Small Molecule Radiosensitizers

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    Persistence of γ-H2AX after ionizing radiation (IR) or drug therapy is a robust reporter of unrepaired DNA double strand breaks in treated cells.DU-145 prostate cancer cells were treated with a chemical library ±IR and assayed for persistence of γ-H2AX using an automated 96-well immunocytochemistry assay at 4 hours after treatment. Hits that resulted in persistence of γ-H2AX foci were tested for effects on cell survival. The molecular targets of hits were validated by molecular, genetic and biochemical assays and in vivo activity was tested in a validated Drosophila cancer model.We identified 2 compounds, MS0019266 and MS0017509, which markedly increased persistence of γ-H2AX, apoptosis and radiosensitization in DU-145 cells. Chemical evaluation demonstrated that both compounds exhibited structurally similar and biochemical assays confirmed that these compounds inhibit ribonucleotide reductase. DNA microarray analysis and immunoblotting demonstrates that MS0019266 significantly decreased polo-like kinase 1 gene and protein expression. MS0019266 demonstrated in vivo antitumor activity without significant whole organism toxicity.MS0019266 and MS0017509 are promising compounds that may be candidates for further development as radiosensitizing compounds as inhibitors of ribonucleotide reductase
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