206 research outputs found

    A Novel Fluid Resuscitation Strategy Modulates Pulmonary Transcription Factor Activation in a Murine Model of Hemorrhagic Shock

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    INTRODUCTION: Combining the hemodynamic and immune benefits of hypertonic saline with the anti-inflammatory effects of the phosphodiesterase inhibitor pentoxifylline (HSPTX) as a hemorrhagic shock resuscitation strategy reduces lung injury when compared with the effects of Ringer's lactate (RL). We hypothesized that HSPTX exerts its anti-inflammatory effects by interfering with nuclear factor kappa B/cAMP response element-binding protein (NF-κB-CREB) competition for the coactivator CREB-binding protein (CBP) in lung tissue, thus affecting pro-inflammatory mediator production. METHODS: Male Sprague-Dawley rats underwent 60 minutes of hemorrhagic shock to reach a mean arterial blood pressure of 35 mmHg followed by resuscitation with either RL or HSPTX (7.5% HS + 25 mg/kg PTX). After four hours, lung samples were collected. NF-κB activation was assessed by measuring the levels of phosphorylated cytoplasmic inhibitor of kappa B (I-κB) and nuclear NF-κB p65 by western blot. NF-κB and CREB DNA-binding activity were measured by electrophoretic mobility shift assay (EMSA). Competition between NF-κB and CREB for the coactivator CBP was determined by immunoprecipitation. Interleukin-8 (IL-8) levels in the lung were measured by ELISA. RESULTS: RL resuscitation produced significantly higher levels of lung IL-8 levels, I-κB phosphorylation, p65 phosphorylation, and NF-κB DNA binding compared with HSPTX. NF-κB-CBP-binding activity was similar in both groups, whereas CREB-CBP-binding activity was significantly increased with HSPTX. CREB-DNA binding-activity increased to a greater level with HSPTX compared with RL. DISCUSSION: HSPTX decreases lung inflammation following hemorrhagic shock compared with conventional resuscitation using RL through attenuation of NF-κB signaling and increased CREB-DNA binding activity. HSPTX may have therapeutic potential in the attenuation of ischemia-reperfusion injury observed after severe hemorrhagic shock

    O Conflito Político. Alguns Aspectos da sua Modelação

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    Objective: Sports practice alters the homeostasis of athletes. To achieve homeostatic equilibrium, the integrated action of the neuroendocrine and immune systems is necessary. Here we studied the relation between cytokines, hormones and mood states in marathon runners. Methods: A total of 20 male recreational marathon runners (mean age = 35.7 ± 9 years) and 20 male sedentary individuals (mean age = 35.5 ± 7 years) were recruited. We compared the serum levels of growth hormone (GH), cortisol and interleukins 8 and 10 and the amounts of these two cytokines spontaneously produced by peripheral blood mononuclear cells. Blood samples of the sedentary group were collected at rest. Blood from the marathon runners was collected at rest (baseline: 24 h before the race), immediately after a marathon and 72 h after a marathon. Mood state analysis in both groups was performed using the 24-item Brunel Mood Scale (BRUMS). Results: Our results showed that, at rest, levels of interleukins 8 and 10 in the supernatant of culture cells, the serum concentration of GH, and tension and vigour (evaluated using the BRUMS), were significantly higher in athletes compared to sedentary people. Immediately after the race all serum parameters analysed were statistically higher than baseline values. At 72 h after the marathon, serum levels of hormones and interleukins returned to values at rest, but the concentrations of interleukins in the supernatant of culture cells showed a significant reduction compared to values at rest. Conclusion: The higher serum levels of GH in athletes at rest and the higher production of cytokines in culture without previous stimulus suggest that marathon runners present mechanisms that may be associated with preparing the body to perform prolonged strenuous exercise, such as a marathon

    Open charm and charmonium production at relativistic energies

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    We calculate open charm and charmonium production in Au+AuAu+Au reactions at s\sqrt{s} = 200 GeV within the hadron-string dynamics (HSD) transport approach employing open charm cross sections from pNpN and πN\pi N reactions that are fitted to results from PYTHIA and scaled in magnitude to the available experimental data. Charmonium dissociation with nucleons and formed mesons to open charm (D+DˉD+\bar{D} pairs) is included dynamically. The 'comover' dissociation cross sections are described by a simple phase-space model including a single free parameter, i.e. an interaction strength M02M_0^2, that is fitted to the J/ΨJ/\Psi suppression data for Pb+PbPb+Pb collisions at SPS energies. As a novel feature we implement the backward channels for charmonium reproduction by DDˉD \bar{D} channels employing detailed balance. From our dynamical calculations we find that the charmonium recreation is comparable to the dissociation by 'comoving' mesons. This leads to the final result that the total J/ΨJ/\Psi suppression at s\sqrt{s} = 200 GeV as a function of centrality is slightly less than the suppression seen at SPS energies by the NA50 Collaboration, where the 'comover' dissociation is substantial and the backward channels play no role. Furthermore, even in case that all directly produced J/ΨJ/\Psi mesons dissociate immediately (or are not formed as a mesonic state), a sizeable amount of charmonia is found asymptotically due to the D+DˉJ/ΨD+\bar{D} \to J/\Psi + meson channels in central collisions of Au+AuAu+Au at s\sqrt{s} = 200 GeV which, however, is lower than the J/ΨJ/\Psi yield expected from binary scaling of pppp collisions.Comment: 42 pages, including 14 eps figures, discussions extended and references added, to be published in Phys. Rev.

    Langstroth hive construction with cement-vermiculite

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    Exfoliated vermiculite is a light-weight and cheap product that, because of its thermal resistance, has become a valuable insulating material. With regard to its use in beekeeping, this research tested whether the box for honey bees constructed with cement-vermiculite mortar (CVM) presents physical characteristics similar to those of wood. The experiment was carried out at Seropédica, RJ, Brazil, for eight months. The cement-vermiculite mortar was compared with a control material (pinewood), in the construction of Langstroth boxes and boards, in a completely randomized design, with respect to thermal control, thermal conductivity and its capacity to absorb and lose water. The production cost for a CVM box was estimated. There were no internal temperature differences between CVM and wooden boxes. Thermal conductivity values for CVM and pinewood were similar. CVM absorbed more water and lost water faster than pinewood. Since CVM boxes can be easily constructed, at a low cost and with similar characteristics as traditional boxes, made of wood, the material can be recommended for use in non-migratory beekeeping
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