859 research outputs found

    FK506 and Cyclosporin A Enhance IL-6 Production in Monocytes: A single-Cell Assay

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    The effect of FK506 and cyclosporin A (CsA) on the production of interleukin 6 (IL-6) in adherent monocytes was studied at a single-cell level by the avidinbiotin- peroxidase complex methods. The percentage of IL-6-producing monocytes increased when stimulated with lipopolysaccharide (LPS) at concentrations between 10 ng/ml and 10 μg/ml, in a dose dependent manner. Both FK506 and CsA enhanced the percentage of IL-6- producing monocytes stimulated with 100 pg/ml-1 μg/ml of LPS up to values near those obtained with 10 μg/ml of LPS. The enhancement by FK506 and CsA was not seen when monocytes were stimulated with a high concentration of LPS (10 μg/ml). When monocytes were stimulated with a low concentration of LPS (10 ng/ml), FK506 and CsA enhanced IL-6 production in a dose dependent manner, at a drug concentration of 0.12 nM–1.2 μM (0.1–1 000 ng/ml) for FK506 and 0.83 nM–8.3 μM (1–10 000 ng/ml) for CsA. The optimal effect of FK506 was achieved at a concentration 7-fold lower than that of CsA. In contrast, production of turnout necrosis factor-α (TNFα and interleukin 1β (IL-1β) was slightly suppressed by FK506 and CsA at the concentrations tested. Moreover, pretreatment of monocytes with FK506 and CsA had a significant enhancing effect on LPS-induced IL-6 production, while treatment with FK506 or CsA after LPS stimulation had no effects on IL-6 production, suggesting that the enhancing effect of each drug is exerted before LPS stimulation or at an early stage of the post-receptor pathway after LPS stimulation. These experiments demonstrate that FK506 and CsA can selectively enhance IL-6 production in monocytes under certain conditions in vitro and, possibly, also in vivo

    Autoimmune rheumatic diseases : An update on the role of atherogenic electronegative ldl and potential therapeutic strategies

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    Altres ajuts: Vascular and Medicinal Research Fund, Texas Heart Institute (#765-64050), Houston, TX, USA; Ministry of Science and Technology (Taiwana grant MOST 107-2314-B-039-053-MY3); Ministerio de Sanidad, Spain (co-financed by Fondo Europeo de Desarrollo Regional (FEDER)).Atherosclerosis has been linked with an increased risk of atherosclerotic cardiovascular disease (ASCVD). Autoimmune rheumatic diseases (AIRDs) are associated with accelerated atherosclerosis and ASCVD. However, the mechanisms underlying the high ASCVD burden in patients with AIRDs cannot be explained only by conventional risk factors despite disease-specific factors and chronic inflammation. Nevertheless, the normal levels of plasma low-density lipoprotein (LDL) cholesterol observed in most patients with AIRDs do not exclude the possibility of increased LDL atherogenicity. By using anion-exchange chromatography, human LDL can be divided into five increasingly electronegative subfractions, L1 to L5, or into electropositive and electronegative counterparts, LDL (+) and LDL (−). Electronegative L5 and LDL (−) have similar chemical composi-tions and can induce adverse inflammatory reactions in vascular cells. Notably, the percentage of L5 or LDL (−) in total LDL is increased in normolipidemic patients with AIRDs. Electronegative L5 and LDL (−) are not recognized by the normal LDL receptor but instead signal through the lectin-like oxidized LDL receptor 1 (LOX-1) to activate inflammasomes involving interleukin 1β (IL-1β). Here, we describe the detailed mechanisms of AIRD-related ASCVD mediated by L5 or LDL (−) and discuss the potential targeting of LOX-1 or IL-1β signaling as new therapeutic modalities for these diseases

    A comparison study of regional atmospheric simulations with an elastic backscattering Lidar and sunphotometry in an urban area

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    We describe a comparison study of Aerosol Optical Thickness (AOT) from numerical simulations using a regional atmospheric model with an elastic backscattering lidar operating at 532 nm and a sunphotometer belonging to the AERONET network at São Paulo (23° S 46° W) city, Brazil, a very populated urban area. The atmospheric model includes an aerosol emission, transport and deposition module coupled to a radiative transfer parameterization, which takes the interaction between aerosol particles and short and long wave radiation into account. A period of one week was taken as case study during the dry season (late August) when intense biomass burning activities occur at remote areas in South America, and meteorological conditions disfavor the pollution dispersion in the city of São Paulo. The situation presented here showed how smoke from biomass burning in remote areas is transported to the south-east part of Brazil and affects the optical atmospheric conditions in São Paulo. The numerical simulations are corroborated by in situ measurements of AOT obtained by lidar and sun photometry

    Tunable terahertz emission from the intrinsic Josephson junctions in acute isosceles triangular Bi2Sr2CaCu2O8+delta mesas

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    In order to determine if the mesa geometry might affect the properties of the coherent terahertz (THz) radiation emitted from the intrinsic Josephson junctions in mesas constructed from single crystals of the high-temperature superconductor, Bi2Sr2CaCu2O8+delta, we studied triangular mesas. For equilateral triangular mesas, the observed emission was found to be limited to the single mesa TM(1,0) mode. However, tunable radiation over the range from 0.495 to 0.934 THz was found to arise from an acute isosceles triangular mesa. This 47% tunability is the widest yet observed from the outer current-voltage characteristic branch of such mesas of any geometry. Although the radiation at a few of the frequencies in the tunable range appear to have been enhanced by cavity resonances, most frequencies are far from such resonance frequencies, and can only be attributed to the ac-Josephson effect

    Beam-Breakup Instability Theory for Energy Recovery Linacs

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    Here we will derive the general theory of the beam-breakup instability in recirculating linear accelerators, in which the bunches do not have to be at the same RF phase during each recirculation turn. This is important for the description of energy recovery linacs (ERLs) where bunches are recirculated at a decelerating phase of the RF wave and for other recirculator arrangements where different RF phases are of an advantage. Furthermore it can be used for the analysis of phase errors of recirculated bunches. It is shown how the threshold current for a given linac can be computed and a remarkable agreement with tracking data is demonstrated. The general formulas are then analyzed for several analytically solvable cases, which show: (a) Why different higher order modes (HOM) in one cavity do not couple so that the most dangerous modes can be considered individually. (b) How different HOM frequencies have to be in order to consider them separately. (c) That no optics can cause the HOMs of two cavities to cancel. (d) How an optics can avoid the addition of the instabilities of two cavities. (e) How a HOM in a multiple-turn recirculator interferes with itself. Furthermore, a simple method to compute the orbit deviations produced by cavity misalignments has also been introduced. It is shown that the BBU instability always occurs before the orbit excursion becomes very large.Comment: 12 pages, 6 figure

    Bosonic t-J Model in a stacked triangular lattice and its phase diagram

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    In this paper, we study phase diagram of a system of two-component hard-core bosons with nearest-neighbor (NN) pseudo-spin antiferromagnetic (AF) interactions in a stacked triangular lattice. Hamiltonian of the system contains three parameters one of which is the hopping amplitude tt between NN sites, and the other two are the NN pseudo-spin exchange interaction JJ and the one that measures anisotropy of pseudo-spin interactions. We investigate the system by means of the Monte-Carlo simulations and clarify the low-temperature phase diagram. In particular, we are interested in how the competing orders, i.e., AF order and superfluidity, are realized, and also whether supersolid forms as a result of hole doping into the state of the 3×3\sqrt{3}\times \sqrt{3} pseudo-spin pattern with the 120o120^o structure.Comment: 18 pages, 17 figures, Version to appear in J.Phys.Soc.Jp

    A habituation account of change detection in same/different judgments

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    We investigated the basis of change detection in a short-term priming task. In two experiments, participants were asked to indicate whether or not a target word was the same as a previously presented cue. Data from an experiment measuring magnetoencephalography failed to find different patterns for “same” and “different” responses, consistent with the claim that both arise from a common neural source, with response magnitude defining the difference between immediate novelty versus familiarity. In a behavioral experiment, we tested and confirmed the predictions of a habituation account of these judgments by comparing conditions in which the target, the cue, or neither was primed by its presentation in the previous trial. As predicted, cue-primed trials had faster response times, and target-primed trials had slower response times relative to the neither-primed baseline. These results were obtained irrespective of response repetition and stimulus–response contingencies. The behavioral and brain activity data support the view that detection of change drives performance in these tasks and that the underlying mechanism is neuronal habituation

    Identification of a Simple Sequence Repeat molecular-marker set for large-scale analyses of pear germplasm

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    Simple Sequence Repeats (SSR) are molecular markers suitable to assess the genetic variation of germplasm resources; however, large-scale SSR use requires protocol optimization. The present work aimed to identify SSR markers, developed for pear and other fruit species that are effective in characterizing pear germplasm collections and in demonstrating their use in providing support for genetic breeding programs. From a total of 62 SSR markers investigated, 23 yielding reproducible and polymorphic patterns were used to genotype a sample of 42 pear accessions of the Brazilian Pear Germplasm Bank (PGB). When compared to these 23 SSR markers, a subset of eleven markers, selected based on He, PIC and PId, was used to distinguish individual accessions and perform cluster analysis with similar efficacy. Genetic diversity analysis clustered the European, Japanese and Chinese accessions in distinct groups. This markers subset constitutes a valuable tool for several applications related to pear genetic resources management and breeding
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