99 research outputs found

    Temperature and pressure-induced spin-state transitions in LaCoO3

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    We report the continuous variation of the spin moment of cobalt in LaCoO3 across its temperature and pressure-induced spin transitions evidenced with K\beta emission spectra. The first thermal transition is best described by a transition to an orbitally nondegenerate intermediate spin (S=1) state. In parallel, continuous redistribution of the 3d electrons is also indicated by partial fluorescence yield X-ray absorption spectra. At high pressure, our study confirms that the material becomes low spin between 40 and 70 kbar at room temperature

    Adenosine Metabolized From Extracellular ATP Ameliorates Organ Injury by Triggering A2BR Signaling

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    BACKGROUND: Trauma and a subsequent hemorrhagic shock (T/HS) result in insufficient oxygen delivery to tissues and multiple organ failure. Extracellular adenosine, which is a product of the extracellular degradation of adenosine 5\u27 triphosphate (ATP) by the membrane-embedded enzymes CD39 and CD73, is organ protective, as it participates in signaling pathways, which promote cell survival and suppress inflammation through adenosine receptors including the A METHODS: T/HS shock was induced by blood withdrawal from the femoral artery in wild-type, global knockout (CD39, CD73, A RESULTS: T/HS upregulated the expression of CD39, CD73, and the A CONCLUSION: In conclusion, the CD39-CD73-

    Adenosine metabolized from extracellular ATP ameliorates organ injury by triggering A2BR signaling

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    BACKGROUND: Trauma and a subsequent hemorrhagic shock (T/HS) result in insufficient oxygen delivery to tissues and multiple organ failure. Extracellular adenosine, which is a product of the extracellular degradation of adenosine 5' triphosphate (ATP) by the membrane-embedded enzymes CD39 and CD73, is organ protective, as it participates in signaling pathways, which promote cell survival and suppress inflammation through adenosine receptors including the A2BR. The aim of this study was to evaluate the role of CD39 and CD73 delivering adenosine to A2BRs in regulating the host's response to T/HS. METHODS: T/HS shock was induced by blood withdrawal from the femoral artery in wild-type, global knockout (CD39, CD73, A2BR) and conditional knockout (intestinal epithelial cell-specific deficient VillinCre-A2BRfl/fl) mice. At 3 three hours after resuscitation, blood and tissue samples were collected to analyze organ injury. RESULTS: T/HS upregulated the expression of CD39, CD73, and the A2BR in organs. ATP and adenosine levels increased after T/HS in bronchoalveolar lavage fluid. CD39, CD73, and A2BR mimics/agonists alleviated lung and liver injury. Antagonists or the CD39, CD73, and A2BR knockout (KO) exacerbated lung injury, inflammatory cytokines, and chemokines as well as macrophage and neutrophil infiltration and accumulation in the lung. Agonists reduced the levels of the liver enzymes aspartate transferase and alanine transaminase in the blood, whereas antagonist administration or CD39, CD73, and A2BR KO enhanced enzyme levels. In addition, intestinal epithelial cell-specific deficient VillinCre-A2BRfl/fl mice showed increased intestinal injury compared to their wild-type VillinCre controls. CONCLUSION: In conclusion, the CD39-CD73-A2BR axis protects against T/HS-induced multiple organ failure

    Role of A2A adenosine receptors in regulation of opsonized E. coli-induced macrophage function

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    Adenosine is a biologically active molecule that is formed at sites of metabolic stress associated with trauma and inflammation, and its systemic level reaches high concentrations in sepsis. We have recently shown that inactivation of A2A adenosine receptors decreases bacterial burden as well as IL-10, IL-6, and MIP-2 production in mice that were made septic by cecal ligation and puncture (CLP). Macrophages are important in both elimination of pathogens and cytokine production in sepsis. Therefore, in the present study, we questioned whether macrophages are responsible for the decreased bacterial load and cytokine production in A2A receptor-inactivated septic mice. We showed that A2A KO and WT peritoneal macrophages obtained from septic animals were equally effective in phagocytosing opsonized E. coli. IL-10 production induced by opsonized E. coli was decreased in macrophages obtained from septic A2A KO mice as compared to WT counterparts. In contrast, the release of IL-6 and MIP-2 induced by opsonized E. coli was higher in septic A2A KO macrophages than WT macrophages. These results suggest that peritoneal macrophages are not responsible for the decreased bacterial load and diminished MIP-2 and IL-6 production that are observed in septic A2A KO mice. In contrast, peritoneal macrophages may contribute to the suppressive effect of A2A receptor inactivation on IL-10 production during sepsis

    Estimating the solar wind pressure at comet 67P from Rosetta magnetic field measurements

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    The solar wind pressure is an important parameter of planetary space weather, which plays a crucial role in the interaction of the solar wind with the planetary plasma environment. Unfortunately, it is not always possible to measure its value at every locations where it would be useful or needed. Spacecraft observing the internal dynamics of a planetary magnetosphere, for example, would benefit greatly from solar wind pressure data, but as the solar wind does not penetrate to their locations, direct measurements are impossible. It is well known that the maximum of the magnetic field in the pile-up region of a magnetosphere is proportional to the square root of the solar wind pressure. Recent investigation of Rosetta data revealed that the maximum of the magnetic field in the pile-up region can be approximated by magnetic field measurements performed in the inner regions of the cometary magnetosphere close to the boundary of the diamagnetic cavity. This relationship holds for several months spanning from June 2015 to January 2016. Here we investigate the possibility to use this relationship to determine a solar wind pressure proxy for this time interval using magnetic field data measured by the Rosetta Magnetometer. This pressure proxy would be useful not only for other Rosetta related studies, but could also serve as a new independent input database for space weather propagation to other locations in the Solar System

    The flavonoid compound apigenin prevents colonic inflammation and motor dysfunctions associated with high fat diet-induced obesity

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    When compared to SD mice, HFD animals displayed increased body weight, epididymal fat weight and metabolic indexes. HFD mice showed increments in colonic MDA, IL-1 beta and IL-6 levels, as well as a decrease in let-7f expression in both colonic and epididymal tissues. HFD mice displayed an increase in colonic eosinophil infiltration. Immunohistochemistry revealed an increase in SP and iNOS expression in myenteric ganglia of HFD mice. In preparations from HFD mice, electrically evoked contractions upon NOS blockade or mediated by tachykininergic stimulation were enhanced. In HFD mice, Apigenin counteracted the increase in body and epididymal fat weight, as well as the alterations of metabolic indexes. Apigenin reduced also MDA, IL-1 beta and IL-6 colonic levels as well as eosinophil infiltration, SP and iNOS expression, along with a normalization of electrically evoked tachykininergic and nitrergic contractions. In addition, apigenin normalized let-7f expression in epididymal fat tissues, but not in colonic specimens

    Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy

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    Background Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence.Methods ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362.Findings Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow- up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2. 5% in each group for fatal or disabling stroke, and 5.3% with CAS versus 4.5% with CEA for any stroke (rate ratio [RR] 1.16, 95% CI 0.86-1.57; p=0 .33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1.11, 95% CI 0.91-1.32; p=0.21).Interpretation Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable
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