1,177 research outputs found

    MAP kinase phosphatase 2 deficient mice develop attenuated experimental autoimmune encephalomyelitis through regulating dendritic cells and T cells

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    Mitogen-activated protein kinase phosphatases (MKPs) play key roles in inflammation and immune mediated diseases. Here we investigated the mechanisms by which MKP-2 modulates central nervous system (CNS) inflammation in experimental autoimmune encephalomyelitis (EAE). Our results show that MKP-2 mRNA levels in the spinal cord and lymphoid organs of EAE mice were increased compared with naive controls, indicating an important role for MKP-2 in EAE development. Indeed, MKP-2-/- mice developed reduced EAE severity, associated with diminished CNS immune cell infiltration, decreased proinflammatory cytokine production and reduced frequency of CD4+ and CD8+ T cells in spleens and lymph nodes. In addition, MKP-2-/- CD11c+ dendritic cells (DCs) had reduced expression of MHC-II and CD40 compared with MKP-2+/+ mice. Subsequent experiments revealed that CD4+ T cells from naĂŻve MKP-2-/- mice had decreased cell proliferation and IL-2 and IL-17 production relative to wild type controls. Furthermore, co-culture experiments showed that bone marrow derived DCs of MKP-2-/-mice had impaired capability in antigen presentation and T cell activation. While MKP-2 also modulates macrophage activation, our study suggests that MKP-2 is essential to the pathogenic response of EAE, and it acts mainly via regulating the important antigen presenting DC function and T cell activation

    Is Chimpanzee (Pan troglodytes) Wounding Frequency Affected by the Presence Versus Absence of Visitors? A Multi-Institutional Study

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    Visitor effect studies have had inconsistent results, due in part to the inability to control for all confounding variables such as time of day, seasonal weather patterns, and so forth. This study represents the first instance where chimpanzee (Pan troglodytes) wounding frequencies were investigated across extensive time periods in the presence and complete absence of visitors, thus eliminating many visitor-related variables. Additional variables were eliminated through the zoo selection process, based on institutional responses to a 29-question survey, providing a novel approach to the question of visitor effects. The aim of this study was to determine if visitors were associated with a change in chimpanzee wound event frequencies across four 51-day time conditions, three of which occurred prior to the COVID-19 pandemic, and one during the first wave of pandemic-related zoo closures. We analyzed the archival records of 21 chimpanzees housed at three U.S. zoos. Due to the small number of wound events across all study windows, frequencies of “no wound” events were analyzed. A chi-square goodness of fit test was performed to determine whether the frequency of “no wound” events was equal between the “open” and “closed” trials. Results indicate that the frequencies did not differ, suggesting that chimpanzee welfare, as it relates to wounding, may not be adversely affected by zoo visitors

    Conflicting evidence for the role of JNK as a target in breast cancer cell proliferation: comparisons between pharmacological inhibition and selective shRNA knockdown approaches

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    As a target, the JNK pathway has been implicated in roles including cell death, proliferation, and inflammation in variety of contexts which span cardiovascular disease, neurodegenerative pathologies, and cancer. JNK1 and JNK2 have recently been demonstrated to function independently, highlighting a new parameter in the study of the JNK pathway. In order for JNK1 and JNK2-specific roles to be defined, better tools need to be employed. Previous studies have relied upon the broad spectrum JNK inhibitor, SP600125, to characterize the role of JNK signaling in a number of cell lines, including the breast cancer cell line MCF-7. In line with previous literature, our study has demonstrated that SP600125 treatment inhibited c-Jun and JNK phosphorylation and MCF-7 proliferation. However, in addition to targeting JNK1, JNK2, and JNK3, SP600125 has been previously demonstrated to suppress the activity of a number of other serine/threonine kinases, making SP600125 an inadequate tool for JNK isoform-specific roles to be determined. In this study, lentiviral shRNA was employed to selectively knockdown JNK1, JNK2, and JNK1/2 in MCF-7 cells. Using this approach, JNK phosphorylation was fully inhibited following stable knockdown of respective JNK isoforms. Interestingly, despite suppression of JNK phosphorylation, MCF-7 cell proliferation, cell cycle progression, or cell death remained unaffected. These findings raise the question of whether JNK phosphorylation really is pivotal in MCF-7 cell growth and death or if suppression of these events is a result of one of the many off-targets cited for SP600125

    String Matching and 1d Lattice Gases

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    We calculate the probability distributions for the number of occurrences nn of a given ll letter word in a random string of kk letters. Analytical expressions for the distribution are known for the asymptotic regimes (i) k≫rl≫1k \gg r^l \gg 1 (Gaussian) and k,l→∞k,l \to \infty such that k/rlk/r^l is finite (Compound Poisson). However, it is known that these distributions do now work well in the intermediate regime k≳rl≳1k \gtrsim r^l \gtrsim 1. We show that the problem of calculating the string matching probability can be cast into a determining the configurational partition function of a 1d lattice gas with interacting particles so that the matching probability becomes the grand-partition sum of the lattice gas, with the number of particles corresponding to the number of matches. We perform a virial expansion of the effective equation of state and obtain the probability distribution. Our result reproduces the behavior of the distribution in all regimes. We are also able to show analytically how the limiting distributions arise. Our analysis builds on the fact that the effective interactions between the particles consist of a relatively strong core of size ll, the word length, followed by a weak, exponentially decaying tail. We find that the asymptotic regimes correspond to the case where the tail of the interactions can be neglected, while in the intermediate regime they need to be kept in the analysis. Our results are readily generalized to the case where the random strings are generated by more complicated stochastic processes such as a non-uniform letter probability distribution or Markov chains. We show that in these cases the tails of the effective interactions can be made even more dominant rendering thus the asymptotic approximations less accurate in such a regime.Comment: 44 pages and 8 figures. Major revision of previous version. The lattice gas analogy has been worked out in full, including virial expansion and equation of state. This constitutes the main part of the paper now. Connections with existing work is made and references should be up to date now. To be submitted for publicatio

    Generation and Characterization of Anti-AA Amyloid-Specific Monoclonal Antibodies

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    AA amyloidosis results from the pathologic deposition in the kidneys and other organs of fibrils composed of N-terminal fragments of serum amyloid A protein (SAA). Given that there are only limited means to visualize these deposits, we have developed a series of mAbs, 2A4, 7D8, and 8G9, that bind specifically with nanomolar affinity to a carboxy-terminal epitope generated following proteolysis of SAA that yields the predominant component of AA amyloid deposits. Notably, these antibodies do not recognize native SAA, they retain their immunoreactivity when radiolabeled with I-125 and, after injection into AA amyloidotic mice, localize, as evidenced by autoradiography and micro-single photon emission computed tomography imaging, to histologically confirmed areas of amyloid deposition; namely, spleen, liver, and pancreas. The results of our in vitro and in vivo studies demonstrate the AA fibril-selectivity of mAbs 2A4, 7D8, and 8G9 and warrant further investigation into their role as novel diagnostic agents for patients with AA amyloidosis

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

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    A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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