208 research outputs found

    Cytokine receptor expression in human lymphoid tissue: analysis by fluorescence microscopy

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    A highly-sensitive flourescence method, capable of detecting cytokine receptors present at low concentrations (around I DO molecules per cell) by flow cytometry, was adapted for use on tissue sections. This method was used to examine the expression of several cytokine receptors in lymphoid ti ss ues. lL-2 receptors were distributed broadly, with higher concentrations in T cell areas. lL-1 receptor Type I was detected in T cell areas and in the follicular mantle, and was strongly expressed on vasc ular endothelium. IL-6 receptor was found at very low concentration, both within and outside germinal centres. The gp 130 molecule, which is involved in the functional receptor complex for IL-6 and several other cytokines, was present at higher concentrations, particularly in the germinal centre. Analysis of receptor expression in secondary lymphoid tissue provides evidence bearing on the physiological roles of cytokines, as these tissues contain cells at various stages of physiological activation located in well-defined functional zones.Heddy Zola, Jodie Ridings, Helen Weedon, Michael Fusco, Roger W. Byard, Peter J. Macardl

    Effect of Multivitamin Supplementation on Measles Vaccine Response among HIV-exposed Uninfected Tanzanian Infants.

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    Immunization and nutritional interventions are mainstays of child health programs in sub-Saharan Africa, yet few published data exist on their interactions. HIV-exposed (but uninfected) infants enrolled in a randomized placebo-controlled trial of multivitamin supplements (vitamins B complex, C, and E) conducted in Tanzania were sampled for an assessment of measles IgG quantity and avidity at 15 to 18 months. Infants were vaccinated between 8.5 and 12 months of age, and all mothers received high-dose multivitamins as the standard of care. Of 201 HIV-exposed infants who were enrolled, 138 (68.7%) were seropositive for measles. There were no effects of infant multivitamin supplementation on measles seroconversion proportions, IgG concentrations, or IgG avidity (P > 0.05). The measles seroconversion proportion was greater for HIV-exposed infants vaccinated at 10 to 11 months of age than for those vaccinated at 8.5 to 10 months (P = 0.032) and greater for infants whose mothers had a CD4 T-cell count of <200 cells/ÎĽl than for infants whose mothers had a CD4 T-cell count of >350 cells/ÎĽl (P = 0.039). Stunted infants had a significantly decreased IgG quantity compared to nonstunted infants (P = 0.012). As for measles avidity, HIV-exposed infants vaccinated at 10 to 11 months had increased antibody avidity compared to those vaccinated at 8.5 to 10 months (P = 0.031). Maternal CD4 T-cell counts of <200 cells/ÎĽl were associated with decreased avidity compared to counts of >350 cells/ÎĽl (P = 0.047), as were lower infant height-for-age z-scores (P = 0.016). Supplementation with multivitamins containing B complex, C, and E does not appear to improve measles vaccine responses for HIV-exposed infants. Studies are needed to better characterize the impact of maternal HIV disease severity on the immune system development of HIV-exposed infants and the effect of malnutrition interventions on vaccine responses. (This study has been registered at ClinicalTrials.gov under registration no. NCT00197730.)

    “PMA Sounds Fun”: Negotiating Drug Discourses Online

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    In 2007, a young woman, Annabel Catt, died after consuming a capsule sold as “ecstasy” that contained para-methoxyamphetamine. In this paper, we describe how this death was depicted in online drug-user communities and illustrate how the meanings of drug use are negotiated in online settings. News articles, public online discussions, and online fieldwork formed the data. This paper demonstrates how dominant drug discourses may be resisted by drug users, drawing on theories of health resistance and Kane Race’s concept of counter public health. Online environments may offer ways of engaging people who use drugs that acknowledge both pleasure and safety. The study’s limitations are noted

    Liquid exfoliation of solvent-stabilized few-layer black phosphorus for applications beyond electronics

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    Few-layer black phosphorus (BP) is a new two-dimensional material which is of great interest for applications, mainly in electronics. However, its lack of environmental stability severely limits its synthesis and processing. Here we demonstrate that high-quality, few-layer BP nanosheets, with controllable size and observable photoluminescence, can be produced in large quantities by liquid phase exfoliation under ambient conditions in solvents such as N-cyclohexyl-2-pyrrolidone (CHP). Nanosheets are surprisingly stable in CHP, probably due to the solvation shell protecting the nanosheets from reacting with water or oxygen. Experiments, supported by simulations, show reactions to occur only at the nanosheet edge, with the rate and extent of the reaction dependent on the water/oxygen content. We demonstrate that liquid-exfoliated BP nanosheets are potentially useful in a range of applications from ultrafast saturable absorbers to gas sensors to fillers for composite reinforcement

    Keep them alive! Design and Evaluation of the “Community Fostering Reference Model”

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    Firms host online communities for commercial purposes, for example in order to integrate customers into ideation for new product development. The success of these firm-hosted online communities depends entirely on the cooperation of a high number of customers that constantly produce valuable knowledge for firms. However, in practice, the majority of successfully implemented communities suffers from stagnation and even a decrease of member activities over time. Literature provides numerous guidelines on how to build and launch these online communities. While these models describe the initial steps of acquiring and activating a community base from scratch very well and explicitly, they neglect continuous member activation and acquistion after a successful launch. Against this background, the authors propose the Community Fostering Reference Model (CoFoRM), which represents a set of general procedures and instruments to continuously foster member activity. In this paper, the authors present the theory-driven design as well as the evaluation of the CoFoRM in a practical use setting. The evaluation results reveal that the CoFoRM represents a valuable instrument in the daily working routine of community managers, since it efficiently helps activating community members especially in the late phases of a community’s LifeCycle

    Borderline Personality Disorder Symptoms in College Students: The Complex Interplay between Alexithymia, Emotional Dysregulation and Rumination.

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    Both Emotional Cascade Theory and Linehan's Biosocial Theory suggest dysregulated behaviors associated with Borderline Personality Disorder (BPD) emerge, in part, because of cycles of rumination, poor emotional recognition and poor emotion regulation. In this study we examined relationships between rumination, alexithymia, and emotion regulation in predicting dysregulated behaviors associated with BPD (e.g. self-harm, substance use, aggression), and explored both indirect and moderating effects among these variables. The sample comprised 2261 college students who completed self-report measures of the aforementioned constructs. BPD symptoms, stress, family psychological illness, and alexithymia exerted direct effects on behaviors. Symptoms had an indirect effect on behaviors through rumination, alexithymia and emotional dysregulation. In addition, the relationship between symptoms and dysregulated behaviors was conditional on level of rumination and alexithymia. Implications for early identification and treatment of BPD and related behaviors in college settings are discussed
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