133 research outputs found

    Educating gratitude : Some conceptual and moral misgivings Educating gratitude : Some conceptual and moral misgivings

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    In a rapidly expanding academic literature on gratitude, psychologists, philosophers and educational theorists have argued that gratitude is not just of great psycho-social importance but also of moral significance. It would therefore seem to follow that the promotion of gratitude is also of moral educational significance. In this regard, recent attempts by psychologists to develop practical interventions designed to make people more grateful should be of some interest. However, while appreciating some benefits of such work, this article argues that much of it falls short of the educational task of developing an adequate pedagogy of gratitude focused on assisting learners’ acquaintance with the complex normative grammar (moral and conceptual) of gratitude discourse. With reference to ongoing work by the authors, the article proceeds to explore further this important dimension of educating gratitude

    Free Radical-Dependent Dysfunction of Small-for-Size Rat Liver Grafts: Prevention by Plant Polyphenols

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    BACKGROUND & AIMS: The mechanisms by which small-for-size liver grafts decrease survival remain unclear. This study investigated the role of free radicals in injury to small-for-size grafts. METHODS: Rat liver explants were reduced in size ex vivo and transplanted into recipients of the same or greater body weight, resulting in a graft weight and standard liver weight of approximately 50% and 25%, respectively. A polyphenol extract from Camellia sinenesis (20 microg/mL) or an equivalent concentration of epicatechin was added to the storage solution and the lactated Ringer poststorage rinse solution. RESULTS: Serum alanine aminotransferase release increased from approximately 60 U/L before implantation to 750, 1410, and 2520 U/L after full-size, half-size, and quarter-size transplantation, respectively. Total bilirubin increased slightly after transplantation of full-size and half-size grafts but increased 104-fold in quarter-size grafts. In quarter-size grafts, histological changes included necrosis, leukocyte infiltration, and eosinophilic inclusion body formation. Polyphenol treatment ameliorated these effects by > or =67%. Survival was 30% after transplantation of small-for-size grafts. After polyphenol treatment, survival increased to 70%. Free radicals in bile assessed by spin trapping and 4-hydroxynonenal adducts measured by immunohistochemistry were also greater in reduced-size grafts, an effect ameliorated by polyphenols. Epicatechin, a major polyphenol from Camellia sinenesis, also improved graft function and decreased enzyme release, histopathologic changes, and free radical formation. CONCLUSIONS: Increased formation of free radicals occurs after transplantation of reduced-size livers, which contributes to graft dysfunction and failure. Plant polyphenols decrease liver graft injury and increase survival of small-for-size liver grafts, most likely by scavenging free radicals

    Improved lung preservation relates to an increase in tubular myelin-associated surfactant protein A

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    BACKGROUND: Declining levels of surfactant protein A (SP-A) after lung transplantation are suggested to indicate progression of ischemia/reperfusion (IR) injury. We hypothesized that the previously described preservation-dependent improvement of alveolar surfactant integrity after IR was associated with alterations in intraalveolar SP-A levels. METHODS: Using immuno electron microscopy and design-based stereology, amount and distribution of SP-A, and of intracellular surfactant phospholipids (lamellar bodies) as well as infiltration by polymorphonuclear leukocytes (PMNs) and alveolar macrophages were evaluated in rat lungs after IR and preservation with EuroCollins or Celsior. RESULTS: After IR, labelling of tubular myelin for intraalveolar SP-A was significantly increased. In lungs preserved with EuroCollins, the total amount of intracellular surfactant phospholipid was reduced, and infiltration by PMNs and alveolar macrophages was significantly increased. With Celsior no changes in infiltration or intracellular surfactant phospholipid amount occurred. Here, an increase in the number of lamellar bodies per cell was associated with a shift towards smaller lamellar bodies. This accounts for preservation-dependent changes in the balance between surfactant phospholipid secretion and synthesis as well as in inflammatory cell infiltration. CONCLUSION: We suggest that enhanced release of surfactant phospholipids and SP-A represents an early protective response that compensates in part for the inactivation of intraalveolar surfactant in the early phase of IR injury. This beneficial effect can be supported by adequate lung preservation, as e.g. with Celsior, maintaining surfactant integrity and reducing inflammation, either directly (via antioxidants) or indirectly (via improved surfactant integrity)
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