129 research outputs found

    Determination of Cellular Lipids Bound to Human CD1d Molecules

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    CD1 molecules are glycoproteins that present lipid antigens at the cell surface for immunological recognition by specialized populations of T lymphocytes. Prior experimental data suggest a wide variety of lipid species can bind to CD1 molecules, but little is known about the characteristics of cellular ligands that are selected for presentation. Here we have molecularly characterized lipids bound to the human CD1d isoform. Ligands were eluted from secreted CD1d molecules and separated by normal phase HPLC, then characterized by mass spectroscopy. A total of 177 lipid species were molecularly identified, comprising glycerophospholipids and sphingolipids. The glycerophospholipids included common diacylglycerol species, reduced forms known as plasmalogens, lyso-phospholipids (monoacyl species), and cardiolipins (tetraacyl species). The sphingolipids included sphingomyelins and glycosylated forms, such as the ganglioside GM3. These results demonstrate that human CD1d molecules bind a surprising diversity of lipid structures within the secretory pathway, including compounds that have been reported to play roles in cancer, autoimmune diseases, lipid signaling, and cell death

    A Dominant Language Constellations case-study on language use and the affective domain

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    Globalisation, international mobility, and new technologies make current multilingualism qualitatively different to not only mono- and bi-lingualism but also to any of its historical incarnations. As a new linguistic dispensation (Aronin & Singleton, 2008, 2012; Aronin, 2015), current multilingualism is understood to be complex, suffusive, liminal, and super-diverse; four essential properties which necessitate alternative foci in multilingual research. From this view, multilinguals are the ‘glue’ that binds cultures and societies, it is therefore essential to focus on their socioculturally-situated multilingual practices if we are to better understand the protagonists of this considerable social responsibility. In this regard, two concepts of profound interest are multilinguality (Aronin & Ó Laoire, 2004) and, its expression/realisation in concrete time-frames and socio-cultural contexts, dominant language constellations (DLC - Aronin, 2006; 2016). With this in mind, the current study examines the individual DLC of a Moroccan immigrant living in the Valencian Community in Spain. In line with earlier research calling for more varied self-report data (Todeva & Cenoz, 2009; Canagarajah & Wurr, 2011; Gorter & Cenoz, 2011), the study uses semi-structured interviews to investigate relationships between the DLC and the affective domain; specifically, attitudes, emotion, and identity. The resulting qualitative data explores the following questions: How does a multilingual speaker use their DLC to navigate specific sociolinguistic contexts? What influence does the DLC have on the expression of identity and emotions in concrete daily situations? What role does the DLC play in the formation of language attitudes? Moreover, these issues are framed within an acculturation context to articulate what Canagarajah and Wurr (2011) call ‘voices from the periphery’. While accepting that a case-study limits any attempt at generalisation, it is hoped that this research focus may contribute by providing another small piece to the overall puzzle of multilingual practices realised in concrete social and cultural contexts

    The ROS Scavenger, NAC, Regulates Hepatic Vα14iNKT Cells Signaling during Fas mAb-Dependent Fulminant Liver Failure

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    Uncontrolled systemic activation of the immune system is an early initiating event that leads to development of acute fulminant liver failure (FLF) in mice after treatment with agonistic Fas mAb. In this study, we demonstrate that treatment of mice with N-acetylcysteine (NAC), an ROS scavenger and glutathione (GSH) precursor, almost completely abolished Fas mAb-induced FLF through suppression of Vα14iNKT cell activation, IFN-γ signaling, apoptosis and nitrotyrosine formation in liver. In addition, enrichment of the liver with GSH due to Vα14iNKT cells deficiency, induced an anti-inflammatory response in the liver of Jα18−/− mice that inhibited apoptosis, nitrotyrosine formation, IFN-γ signaling and effector functions. In summary, we propose a novel and previously unrecognized pro-inflammatory and pro-apoptotic role for endogenous ROS in stimulating Th1 signaling in Vα14iNKT cells to promote the development of FLF. Therefore, our study provides critical new insights into how NAC, a ROS scavenger, regulates Th1 signaling in intrahepatic Vα14iNKT cells to impact inflammatory and pathological responses

    Innate partnership of HLA-B and KIR3DL1 subtypes against HIV-1

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    Allotypes of the natural killer (NK) cell receptor KIR3DL1 vary in both NK cell expression patterns and inhibitory capacity upon binding to their ligands, HLA-B Bw4 molecules, present on target cells. Using a sample size of over 1,500 human immunodeficiency virus (HIV)+ individuals, we show that various distinct allelic combinations of the KIR3DL1 and HLA-B loci significantly and strongly influence both AIDS progression and plasma HIV RNA abundance in a consistent manner. These genetic data correlate very well with previously defined functional differences that distinguish KIR3DL1 allotypes. The various epistatic effects observed here for common, distinct KIR3DL1 and HLA-B Bw4 combinations are unprecedented with regard to any pair of genetic loci in human disease, and indicate that NK cells may have a critical role in the natural history of HIV infection

    The role of conversation in health care interventions: enabling sensemaking and learning

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    <p>Abstract</p> <p>Background</p> <p>Those attempting to implement changes in health care settings often find that intervention efforts do not progress as expected. Unexpected outcomes are often attributed to variation and/or error in implementation processes. We argue that some unanticipated variation in intervention outcomes arises because unexpected conversations emerge during intervention attempts. The purpose of this paper is to discuss the role of conversation in shaping interventions and to explain why conversation is important in intervention efforts in health care organizations. We draw on literature from sociolinguistics and complex adaptive systems theory to create an interpretive framework and develop our theory. We use insights from a fourteen-year program of research, including both descriptive and intervention studies undertaken to understand and assist primary care practices in making sustainable changes. We enfold these literatures and these insights to articulate a common failure of overlooking the role of conversation in intervention success, and to develop a theoretical argument for the importance of paying attention to the role of conversation in health care interventions.</p> <p>Discussion</p> <p>Conversation between organizational members plays an important role in the success of interventions aimed at improving health care delivery. Conversation can facilitate intervention success because interventions often rely on new sensemaking and learning, and these are accomplished through conversation. Conversely, conversation can block the success of an intervention by inhibiting sensemaking and learning. Furthermore, the existing relationship contexts of an organization can influence these conversational possibilities. We argue that the likelihood of intervention success will increase if the role of conversation is considered in the intervention process.</p> <p>Summary</p> <p>The generation of productive conversation should be considered as one of the foundations of intervention efforts. We suggest that intervention facilitators consider the following actions as strategies for reducing the barriers that conversation can present and for using conversation to leverage improvement change: evaluate existing conversation and relationship systems, look for and leverage unexpected conversation, create time and space where conversation can unfold, use conversation to help people manage uncertainty, use conversation to help reorganize relationships, and build social interaction competence.</p

    The impact of language barriers on trust formation in multinational teams

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    This study systematically investigates how language barriers influence trust formation in multinational teams (MNTs). Based on 90 interviews with team members, team leaders, and senior managers in 15 MNTs in three German automotive corporations, we show how MNT members’ cognitive and emotional reactions to language barriers influence their perceived trustworthiness and intention to trust, which in turn affect trust formation. We contribute to diversity research by distinguishing the exclusively negative language effects from the more ambivalent effects of other diversity dimensions. Our findings also illustrate how surface-level language diversity may create perceptions of deep-level diversity. Furthermore, our study advances MNT research by revealing the specific influences of language barriers on team trust, an important mediator between team inputs and performance outcomes. It thereby encourages the examination of other team processes through a language lens. Finally, our study suggests that multilingual settings necessitate a reexamination and modification of the seminal trust theories by Mayer, Davis and Schoorman (1995) and McAllister (1995). In terms of practical implications, we outline how MNT leaders can manage their subordinates’ problematic reactions to language barriers and how MNT members can enhance their perceived trustworthiness in multilingual settings
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