2,118 research outputs found

    Myoblasts and macrophages share molecular components that contribute to cell–cell fusion

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    Cell–cell fusion is critical to the normal development of certain tissues, yet the nature and degree of conservation of the underlying molecular components remains largely unknown. Here we show that the two guanine-nucleotide exchange factors Brag2 and Dock180 have evolutionarily conserved functions in the fusion of mammalian myoblasts. Their effects on muscle cell formation are distinct and are a result of the activation of the GTPases ARF6 and Rac, respectively. Inhibition of ARF6 activity results in a lack of physical association between paxillin and β1-integrin, and disruption of paxillin transport to sites of focal adhesion. We show that fusion machinery is conserved among distinct cell types because Dock180 deficiency prevented fusion of macrophages and the formation of multinucleated giant cells. Our results are the first to demonstrate a role for a single protein in the fusion of two different cell types, and provide novel mechanistic insight into the function of GEFs in the morphological maturation of multinucleated cells

    Updates in Hospital Palliative Care

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    Background: This review critiques recent palliative care (PC) literature with likelihood of impacting general hospital practice in order to help address the PC needs of patients. Methods: Articles published between January and December 2018 were identified through hand-search of leading PC journals and MEDLINE search. The final ten selected articles were determined by consensus based on scientific rigor, relevance to general hospital medicine, and impact to practice. Results: Key findings include: Early PC interventions reduced healthcare costs; Prognostic awareness of surrogates of patients with advanced dementia was associated with reduced burdensome interventions; Care transitions, especially in the last 3 days of life, can be detrimental to caregivers' well-being and perceptions of care; Haloperidol was effective for treatment of nausea and vomiting without untoward effects; Antipsychotics did not improve delirium symptoms in hospitalized patients; A fan directed to the face improved dyspnea; Disparities in advance directive completion disappeared when equal opportunities were given; Improving communication with families of critically ill patients improved perceptions of patient-centered care; Communication-priming tools improved the quality and documentation of goals of care conversations; Discussing prognosis did not harm the patient-provider relationship. Conclusion: Recent PC research affirmed the importance of PC delivery to patients with life-limiting illness and provided important guidance to hospitalists on symptom management, advance care planning, and communication.Rachel D. Havyer (1*), Nauzley Abedini (2), Robert L. Jayes (3), Brenda Matti-Orozco (4), Daniel H. Pomerantz (5), Aziz A. Ansari (6); 1. Division of Community Internal Medicine, Mayo Clinic. 2. Division of Palliative Medicine, University of California San Francisco. 3. Division of Geriatrics and Palliative Medicine, George Washington University Medical Faculty Associates. 4. Division of General Internal Medicine and Palliative Medicine, Morristown Medical Center, Atlantic Health System. 5. Department of Medicine, Montefiore New Rochelle Hospital. 6. Division of Hospital Medicine, Loyola University Medical CenterIncludes bibliographical reference

    Developmental, cellular, and biochemical basis of transparency in the glasswing butterfly Greta oto

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    Numerous species of Lepidoptera have transparent wings, which often possess scales of altered morphology and reduced size, and the presence of membrane surface nanostructures that dramatically reduce reflection. Optical properties and anti-reflective nanostructures have been characterized for several ‘clearwing’ Lepidoptera, but the developmental basis of wing transparency is unknown. We apply confocal and electron microscopy to create a developmental time-series in the glasswing butterfly, Greta oto, comparing transparent and non-transparent wing regions. We find that scale precursor cell density is reduced in transparent regions, and cytoskeletal organization differs between flat scales in opaque regions, and thin, bristle-like scales in transparent regions. We also reveal that sub-wavelength nanopillars on the wing membrane are wax-based, derive from wing epithelial cells and their associated microvillar projections, and demonstrate their role in enhancing-anti-reflective properties. These findings provide insight into morphogenesis of naturally organized micro- and nanostructures and may provide bioinspiration for new anti-reflective materials

    Interactional positioning and narrative self-construction in the first session of psychodynamic-interpersonal psychotherapy

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    The purpose of this study is to identify possible session one indicators of end of treatment psychotherapy outcome using the framework of three types of interactional positioning; client’s self-positioning, client’s positioning between narrated self and different partners, and the positioning between client and therapist. Three successful cases of 8-session psychodynamic-interpersonal (PI) therapy were selected on the basis of client Beck Depression Inventory scores. One unsuccessful case was also selected against which identified patterns could be tested. The successful clients were more descriptive about their problems and demonstrated active rapport-building, while the therapist used positionings expressed by the client in order to explore the positionings developed between them during therapy. The unsuccessful case was characterized by lack of positive self-comment, minimization of agentic self-capacity, and empathy-disrupting narrative confusions. We conclude that the theory of interactional positioning has been useful in identifying patterns worth exploring as early indicators of success in PI therapy

    Achieving consensus through professionalized head nods: The role of nodding in service encounters in Japan

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    While the interactional functions of head nodding in everyday Japanese conversation have been frequently studied, a discourse on head nodding as a professional communicative practice has yet to be explored. With the method of multimodal conversation analysis, the current study examines the role of nodding in a particular professional-client setting, namely, hair salon interactions. My interest specifically lies in the frequent occurrence of synchronized head nods during the “service-assessment sequence,” where both service provider and customer inspect and determine whether the completed work is adequate. I pursue mechanisms of synchronized head nods by revealing exactly how participants collaborate in producing a nod, and how their verbal actions may at times be designed accordingly. In doing so, the study provides insight into what consensus may look like at service encounters in Japan, and discusses how such nodding practices may contribute to a satisfactory closure of a business negotiation
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