1,420 research outputs found

    SUPPORT FOR COLLABORATIVE AUTHORING VIA EMAIL - THE MESSIE ENVIRONMENT

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    MESSIE is a collaborative authoring environment to support the production of large-scale documents by teams of geographically distributed groups of authors working with hetereogenous systems. The environment allows authors to submit text at various stages of gestation (e.g. list of topics, first draft) to a shared filestore via email. All authors collaborating on a document can read each others’ contributions, and add suggestions, comments and additional material directly to the document. The system integrates automatically answered electronic mail, shared file store administration, and a version control tool in a UNIX environment. The paper describes design and implementation strategy, and reports observations and a number of changes which were made during a 4-month trial period with three collaborative authoring teams

    Triad3a induces the degradation of early necrosome to limit RipK1-dependent cytokine production and necroptosis.

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    Understanding the molecular signaling in programmed cell death is vital to a practical understanding of inflammation and immune cell function. Here we identify a previously unrecognized mechanism that functions to downregulate the necrosome, a central signaling complex involved in inflammation and necroptosis. We show that RipK1 associates with RipK3 in an early necrosome, independent of RipK3 phosphorylation and MLKL-induced necroptotic death. We find that formation of the early necrosome activates K48-ubiquitin-dependent proteasomal degradation of RipK1, Caspase-8, and other necrosomal proteins. Our results reveal that the E3-ubiquitin ligase Triad3a promotes this negative feedback loop independently of typical RipK1 ubiquitin editing enzymes, cIAPs, A20, or CYLD. Finally, we show that Triad3a-dependent necrosomal degradation limits necroptosis and production of inflammatory cytokines. These results reveal a new mechanism of shutting off necrosome signaling and may pave the way to new strategies for therapeutic manipulation of inflammatory responses

    Matched sizes of activating and inhibitory receptor/ligand pairs are required for optimal signal integration by human Natural Killer cells

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    It has been suggested that receptor-ligand complexes segregate or co-localise within immune synapses according to their size, and this is important for receptor signaling. Here, we set out to test the importance of receptor-ligand complex dimensions for immune surveillance of target cells by human Natural Killer (NK) cells. NK cell activation is regulated by integrating signals from activating receptors, such as NKG2D, and inhibitory receptors, such as KIR2DL1. Elongating the NKG2D ligand MICA reduced its ability to trigger NK cell activation. Conversely, elongation of KIR2DL1 ligand HLA-C reduced its ability to inhibit NK cells. Whereas normal-sized HLA-C was most effective at inhibiting activation by normal-length MICA, only elongated HLA-C could inhibit activation by elongated MICA. Moreover, HLA-C and MICA that were matched in size co-localised, whereas HLA-C and MICA that were different in size were segregated. These results demonstrate that receptor-ligand dimensions are important in NK cell recognition, and suggest that optimal integration of activating and inhibitory receptor signals requires the receptor-ligand complexes to have similar dimensions

    The Hot (Invisible?) Hand: Can Time Sequence Patterns of Success/Failure in Sports Be Modeled as Repeated Random Independent Trials?

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    The long lasting debate initiated by Gilovich, Vallone and Tversky in is revisited: does a “hot hand” phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons () of the National Basketball Association (NBA). Evidence supporting the existence of the “hot hand” phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of “success breeds success” and “failure breeds failure” mechanisms or simply “better” and “worse” periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the “hot hand” phenomenon in the data

    Local and systemic immunomodulatory mechanisms triggered by Human Papillomavirus transformed cells: a potential role for G-CSF and neutrophils

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    Cervical cancer is the last stage of a series of molecular and cellular alterations initiated with Human Papillomavirus (HPV) infection. The process involves immune responses and evasion mechanisms, which culminates with tolerance toward tumor antigens. Our objective was to understand local and systemic changes in the interactions between HPV associated cervical lesions and the immune system as lesions progress to cancer. Locally, we observed higher cervical leukocyte infiltrate, reflected by the increase in the frequency of T lymphocytes, neutrophils and M2 macrophages, in cancer patients. We observed a strong negative correlation between the frequency of neutrophils and T cells in precursor and cancer samples, but not cervicitis. In 3D tumor cell cultures, neutrophils inhibited T cell activity, displayed longer viability and longer CD16 expression half-life than neat neutrophil cultures. Systemically, we observed higher plasma G-CSF concentration, higher frequency of immature low density neutrophils, and tolerogenic monocyte derived dendritic cells, MoDCs, also in cancer patients. Interestingly, there was a negative correlation between T cell activation by MoDCs and G-CSF concentration in the plasma. Our results indicate that neutrophils and G-CSF may be part of the immune escape mechanisms triggered by cervical cancer cells, locally and systemically, respectively.Tis study was supported by Sao Paulo Research foundation: grants 2008/57889-1, 2010/20010-4, 2014/19326-6, by the Brazilian National Counsel of Technological and Scientifc Development: grant 573799/2008-3. KLFA and RAMR had PhD fellowships by Sao Paulo Research Foundation, CRSF has a Coordination for the Improvement of Higher Education Personnel PhD fellowship. We thank the Pathology Department of the School of Medicine, coordinated by Prof. Venâncio Avancini Ferreira Alves, Universidade de São Paulo for the slides containing histological samples from the biopsies used in this study. We thank Sandra Alexandre Alves for her technical support.info:eu-repo/semantics/publishedVersio

    Chemical Modification of Graphene Oxide by Nitrogenation: An X-ray Absorption and EmissionSpectroscopy Study

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    Nitrogen-doped graphene oxides (GO:Nx) were synthesized by a partial reduction of graphene oxide (GO) using urea [CO(NH2)2]. Their electronic/bonding structures were investigated using X-ray absorption near-edge structure (XANES), valence-band photoemission spectroscopy (VB-PES), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS). During GO:Nx synthesis, different nitrogen-bonding species, such as pyrrolic/graphitic-nitrogen, were formed by replacing of oxygen-containing functional groups. At lower N-content (2.7 at%), pyrrolic-N, owing to surface and subsurface diffusion of C, N and NH is deduced from various X-ray spectroscopies. In contrast, at higher N-content (5.0 at%) graphitic nitrogen was formed in which each N-atom trigonally bonds to three distinct sp2-hybridized carbons with substitution of the N-atoms for C atoms in the graphite layer. Upon nitrogen substitution, the total density of state close to Fermi level is increased to raise the valence-band maximum, as revealed by VB-PES spectra, indicating an electron donation from nitrogen, molecular bonding C/N/O coordination or/and lattice structure reorganization in GO:Nx. The well-ordered chemical environments induced by nitrogen dopant are revealed by XANES and RIXS measurements

    Lichen planus and Hepatitis C: a case-control study

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    BACKGROUND: The association of lichen planus with hepatitis C (HCV) has been widely reported in the literature. However, there are wide geographical variations in the reported prevalence of HCV infection in patients with lichen planus. This study was conducted to determine the frequency of hepatitis C in Iranian patients with lichen planus at Razi hospital, Tehran. METHODS: During the years 1997 and 1998, 146 cases of lichen planus, 78 (53.1%) women and 69 (46.9%) men were diagnosed. They were diagnosed on the basis of the usual clinical features and, if necessary, typical histological findings. The patients were screened for the presence of anti-HCV antibodies by third generation ELISA and liver function tests. We used the results from screening of blood donors for anti HCV (carried out by Iranian Blood Transfusion Organization) for comparison as the control group. RESULTS: Anti-HCV antibodies were detected in seven cases (4.8%). This was significantly higher than that of the blood donors' antibodies (p < 0.001). The odds ratio was 50.37(21.45–112.24). A statistically significant association was demonstrated between erosive lichen planus and HCV infection. Liver function tests were not significantly different between HCV infected and non-infected patients. CONCLUSION: HCV apears to have an etiologic role for lichen planus in Iranian patients. On the other hand, liver function tests are not good screening means for HCV infection

    Macrophage Migration Inhibitory Factor Induces Autophagy via Reactive Oxygen Species Generation

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    Autophagy is an evolutionarily conserved catabolic process that maintains cellular homeostasis under stress conditions such as starvation and pathogen infection. Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine that plays important roles in inflammation and tumorigenesis. Cytokines such as IL-1β and TNF-α that are induced by MIF have been shown to be involved in the induction of autophagy. However, the actual role of MIF in autophagy remains unclear. Here, we have demonstrated that incubation of human hepatoma cell line HuH-7 cells with recombinant MIF (rMIF) induced reactive oxygen species (ROS) production and autophagy formation, including LC3-II expression, LC3 punctae formation, autophagic flux, and mitochondria membrane potential loss. The autophagy induced by rMIF was inhibited in the presence of MIF inhibitor, ISO-1 as well as ROS scavenger N-acetyl-L-cysteine (NAC). In addition, serum starvation-induced MIF release and autophagy of HuH-7 cells were partly blocked in the presence of NAC. Moreover, diminished MIF expression by shRNA transfection or inhibition of MIF by ISO-1 decreased serum starvation-induced autophagy of HuH-7 cells. Taken together, these data suggest that cell autophagy was induced by MIF under stress conditions such as inflammation and starvation through ROS generation

    Macrophage CD74 contributes to MIF-induced pulmonary inflammation

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    <p>Abstract</p> <p>Background</p> <p>MIF is a critical mediator of the host defense, and is involved in both acute and chronic responses in the lung. Neutralization of MIF reduces neutrophil accumulation into the lung in animal models. We hypothesized that MIF, in the alveolar space, promotes neutrophil accumulation via activation of the CD74 receptor on macrophages.</p> <p>Methods</p> <p>To determine whether macrophage CD74 surface expression contributes MIF-induced neutrophil accumulation, we instilled recombinant MIF (r-MIF) into the trachea of mice in the presence or absence of anti-CD74 antibody or the MIF specific inhibitor, ISO-1. Using macrophage culture, we examined the downstream pathways of MIF-induced activation that lead to neutrophil accumulation.</p> <p>Results</p> <p>Intratracheal instillation of r-MIF increased the number of neutrophils as well as the concentration of macrophage inflammatory protein 2 (MIP-2) and keratinocyte-derived chemokine (KC) in BAL fluids. CD74 was found to be expressed on the surface of alveolar macrophages, and MIF-induced MIP-2 accumulation was dependent on p44/p42 MAPK in macrophages. Anti-CD74 antibody inhibited MIF-induced p44/p42 MAPK phosphorylation and MIP-2 release by macrophages. Furthermore, we show that anti-CD74 antibody inhibits MIF-induced alveolar accumulation of MIP-2 (control IgG vs. CD74 Ab; 477.1 ± 136.7 vs. 242.2 ± 102.2 pg/ml, p < 0.05), KC (1796.2 ± 436.1 vs. 1138.2 ± 310.2 pg/ml, p < 0.05) and neutrophils (total number of neutrophils, 3.33 ± 0.93 × 10<sup>4 </sup>vs. 1.90 ± 0.61 × 10<sup>4</sup>, p < 0.05) in our mouse model.</p> <p>Conclusion</p> <p>MIF-induced neutrophil accumulation in the alveolar space results from interaction with CD74 expressed on the surface of alveolar macrophage cells. This interaction induces p44/p42 MAPK activation and chemokine release. The data suggest that MIF and its receptor, CD74, may be useful targets to reduce neutrophilic lung inflammation, and acute lung injury.</p
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