156 research outputs found

    Serial measurements of circulating tissue plastninogen activator and fibrin(ogen) degradation products predict outcome in gestational proteinuric hypertension

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    Gestational proteinuric hypertension (GPH), a major cause of maternal death, may be characterised by hypertension and proteinuria alone or may progress to disturbed coagulation and multiorgan failure. Since the condition can only be reversed by termination of pregnancy, there is a need for reliable indicators of severity. We found circulating levels of tissue plasminogen activator (tPA)(27,98 ± 2,12 v. 7,17 ± 0,81 ng/ml, mean ± SEM), fibrin(ogen) degradation products (FDP) (7,55 ± 1,99 v. 1,92 ± 0,47 μg/ml) and fibronectin (221 ± 15,2 v. 120 ± 15,2 μg/ml) to be significantly increased in 21 patients with severe GPH when compared with 21 normotensive, age- and gestational age-matched pregnant controls. More importantly, patients who developed severe GPH showed a progressive increase in tPA and FDP levels with time. This was in contrast to patients who had hypertension and proteinuria alone, in whom tPA and FDP concentrations did not increase. Parallel measurements did not reveal a fall in platelet count or an increase in urinary protein excretion in patients who subsequently progressed to severe disease. Our findings may be of assistance to clinicians faced with the need to prolong pregnancy in patients with GPH in order to ensure fetal viability

    Targeting inflammation after myocardial infarction: A therapeutic opportunity for extracellular vesicles?

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    After myocardial infarction (MI), a strong inflammatory response takes place in the heart to remove the dead tissue resulting from ischemic injury. A growing body of evidence suggests that timely resolution of this inflammatory process may aid in the prevention of adverse cardiac remodeling and heart failure post-MI. The present challenge is to find a way to stimulate this process without interfering with the reparative role of the immune system. Extracellular vesicles (EVs) are natural membrane particles that are released by cells and carry different macromolecules, including proteins and non-coding RNAs. In recent years, EVs derived from various stem and progenitor cells have been demonstrated to possess regenerative properties. They can provide cardioprotection via several mechanisms of action, including immunomodulation. In this review, we summarize the role of the innate immune system in post-MI healing. We then discuss the mechanisms by which EVs modulate cardiac inflammation in preclinical models of myocardial injury through regulation of monocyte influx and macrophage function. Finally, we provide suggestions for further optimization of EV-based therapy to improve its potential for the treatment of MI

    Two- and Three-photon Fusion in Relativistic Heavy ion Collisions

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    The production of mesons in ultra-peripheral collisions of relativistic heavy ions is re-analyzed using a projection technique to calculate the amplitudes for the appropriate Feynman diagrams. The virtuality of the exchanged photons is fully accounted for in this approach. In the case of two-photon fusion, it is explicitly shown that the inclusion of nuclear form factors validates the equivalent photon approximation. However, this does not apply to three-photon fusion cross sections. The cross section of J/\psi production in ultra-peripheral collisions at RHIC and LHC are shown to be much smaller than the cross sections for the production of C=even mesons of similar masses.Comment: Version to be published in Nuclear Physics

    Requirements for Proper Immunosuppressive Regimens to Limit Translational Failure of Cardiac Cell Therapy in Preclinical Large Animal Models

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    Various cell-based therapies are currently investigated in an attempt to tackle the high morbidity and mortality associated with heart failure. The need for these therapies to move towards the clinic is pressing. Therefore, preclinical large animal studies that use non-autologous cells are needed to evaluate their potential. However, non-autologous cells are highly immunogenic and trigger immune rejection responses resulting in potential loss of efficacy. To overcome this issue, adequate immunosuppressive regimens are of imminent importance but clear guidelines are currently lacking. In this review, we assess the immunological barriers regarding non-autologous cell transplantation and immune modulation with immunosuppressive drugs. In addition, we provide recommendations with respect to immunosuppressive regimens in preclinical cardiac cell-replacement studies

    Immunomodulation in Heart Failure with Preserved Ejection Fraction: Current State and Future Perspectives

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    The heart failure (HF) epidemic is growing and approximately half of the HF patients have heart failure with preserved ejection fraction (HFpEF). HFpEF is a heterogeneous syndrome, characterized by a preserved left ventricular ejection fraction (LVEF ≥ 50%) with diastolic dysfunction, and is associated with high morbidity and mortality. Underlying comorbidities of HFpEF, i.e., hypertension, type 2 diabetes mellitus, obesity, and renal failure, lead to a systemic pro-inflammatory state, thereby affecting normal cardiac function. Increased inflammatory biomarkers predict incident HFpEF and are higher in patients with HFpEF as compared with heart failure with reduced ejection fraction (HFrEF). Randomized trials in HFpEF patients using traditional HF medication failed to demonstrate a clear benefit on hard endpoints (mortality and/or HF hospitalization). Therefore, therapies targeting underlying comorbidities and systemic inflammation in early HFpEF may provide better opportunities. Here, we provide an overview of the current state and future perspectives of immunomodulatory therapies for HFpEF

    A geometrical estimation of saturation of partonic densities

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    We propose a new criterium for saturation of the density of partons both in nucleons and nuclei. It is applicable to any multiple scattering model which would be used to compute the number of strings exchanged in epep and eAeA collisions. The criterium is based on percolation of strings, and the onset of percolation is estimated from expectations coming from the study of heavy ion collisions at high energies. We interpret this onset as an indication of saturation of the density of partons in the wave function of the hadron. In order to produce quantitative results, a particular model fitted to describe present HERA data and generalized to the nuclear case is used. Nevertheless, with the number of scatterings controlled by the relation between inclusive and diffractive processes, conclusions are weakly model-dependent as long as different models are tuned to describe the experimental data. This constitutes a new approach, based on the eikonal description of soft hadronic collisions, and different from others which employ either perturbative QCD ideas or semiclassical methods. It offers an alternative picture for saturation in the small Q2Q^2 region.Comment: LaTeX, 15 pages, 2 eps figures included using epsfig; final version, abstract and discussions enlarged, references added and updated, results unchanged; more references adde

    x_F-dependence of J/Psi suppression in pA collisions

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    Coherence effects are important in the description of collisions with extended objects as nuclei. At fixed target energies and small x_F, the coherence length of the fluctuation containing the ccˉc\bar c is small and the usual nuclear absorption model is valid. However, at higher energies and/or x_F the nucleus is seen as a whole by the fluctuation. In this case, the total, not the absorptive, ccˉNc\bar c-N cross section controls the suppression and also shadowing of gluons appears. We propose that the growth of the coherence length can explain the x_F-dependence of present experimental data. For this, we need a ratio of absorptive over total ccˉNc\bar c-N cross section of 0.2.Comment: 15 pages, 3 postscript figure

    Extracellular vesicle-mediated delivery of CRISPR/Cas9 ribonucleoprotein complex targeting proprotein convertase subtilisin-kexin type 9 (Pcsk9) in primary mouse hepatocytes

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    The loss-of-function of the proprotein convertase subtilisin–kexin type 9 (Pcsk9) gene has been associated with significant reductions in plasma serum low-density lipoprotein cholesterol (LDL-C) levels. Both CRISPR/Cas9 and CRISPR-based editor-mediated Pcsk9 inactivation have successfully lowered plasma LDL-C and PCSK9 levels in preclinical models. Despite the promising preclinical results, these studies did not report how vehicle-mediated CRISPR delivery inactivating Pcsk9 affected low-density lipoprotein receptor recycling in vitro or ex vivo. Extracellular vesicles (EVs) have shown promise as a biocompatible delivery vehicle, and CRISPR/Cas9 ribonucleoprotein (RNP) has been demonstrated to mediate safe genome editing. Therefore, we investigated EV-mediated RNP targeting of the Pcsk9 gene ex vivo in primary mouse hepatocytes. We engineered EVs with the rapamycin-interacting heterodimer FK506-binding protein (FKBP12) to contain its binding partner, the T82L mutant FKBP12-rapamycin binding (FRB) domain, fused to the Cas9 protein. By integrating the vesicular stomatitis virus glycoprotein on the EV membrane, the engineered Cas9 EVs were used for intracellular CRISPR/Cas9 RNP delivery, achieving genome editing with an efficacy of ±28.1% in Cas9 stoplight reporter cells. Administration of Cas9 EVs in mouse hepatocytes successfully inactivated the Pcsk9 gene, leading to a reduction in Pcsk9 mRNA and increased uptake of the low-density lipoprotein receptor and LDL-C. These readouts can be used in future experiments to assess the efficacy of vehicle-mediated delivery of genome editing technologies targeting Pcsk9. The ex vivo data could be a step towards reducing animal testing and serve as a precursor to future in vivo studies for EV-mediated CRISPR/Cas9 RNP delivery targeting Pcsk9

    NLRP3-Inflammasome Inhibition with IZD334 Does Not Reduce Cardiac Damage in a Pig Model of Myocardial Infarction

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    NLRP3-inflammasome-mediated signaling is thought to significantly contribute to the extent of myocardial damage after myocardial infarction (MI). The purpose of this study was to investigate the effects of the NLRP3-inflammasome inhibitor IZD334 on cardiac damage in a pig model of myocardial infarction. Prior to in vivo testing, in vitro, porcine peripheral blood mononuclear cells and whole blood were treated with increasing dosages of IZD334, a novel NLRP3-inflammasome inhibitor, and were stimulated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP). After determination of the pharmacological profile in healthy pigs, thirty female Landrace pigs were subjected to 75 min of transluminal balloon occlusion of the LAD coronary artery and treated with placebo or IZD334 (1 mg/kg, 3 mg/kg, or 10 mg/kg once daily) in a blinded randomized fashion. In vitro, NLRP3-inflammasome stimulation showed the pronounced release of interleukin (IL)-1β that was attenuated by IZD334 (p < 0.001). In vivo, no differences were observed between groups in serological markers of inflammation nor myocardial IL-1β expression. After 7 days, the ejection fraction did not differ between groups, as assessed with MRI (placebo: 45.1 ± 8.7%, 1 mg/kg: 49.9 ± 6.1%, 3 mg/kg: 42.7 ± 3.8%, 10 mg/kg: 44.9 ± 6.4%, p = 0.26). Infarct size as a percentage of the area at risk was not reduced (placebo: 73.1 ± 3.0%, 1 mg/kg: 75.5 ± 7.3%, 3 mg/kg: 80.3 ± 3.9%, 10 mg/kg: 78.2 ± 8.0%, p = 0.21). In this pig MI model, we did not observe attenuation of the inflammatory response after NLRP3-inflammasome inhibition in vivo. Consecutively, no difference was observed in IS and cardiac function, while in vitro inhibition successfully reduced IL-1β release from stimulated porcine blood cells

    Cold exposure increases circulating fibroblast growth factor 21 in the eveninin males and females

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    Objectives: Cold exposure is linked to cardiometabolic benefits. Cold activates brown adipose tissue (BAT), increases energy expenditure, and induces secretion of the hormones fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15). The cold-induced increase in energy expenditure exhibits a diurnal rhythm in men. Therefore, we aimed to investigate the effect of cold exposure on serum FGF21 and GDF15 levels in humans and whether cold-induced changes in FGF21 and GDF15 levels differ between morning and evening in males and female Method: In this randomized cross-over study, serum FGF21 and GDF15 levels were measured in healthy lean males (n = 12) and females (n = 12) before, during, and after 90 min of stable cold exposure in the morning (07:45 h) and evening (19:45 h) with a 1-day washout period in between. Results: Cold exposure increased FGF21 levels in the evening compared to the morning both in males (+61% vs −13%; P < 0.001) and in females (+58% vs +8%; P < 0.001). In contrast, cold exposure did not significantly modify serum GDF15 levels, and no diurnal variation was found. Changes in FGF21 and GDF15 levels did not correlate with changes in cold-induced energy expenditure in the morning and evening. Conclusion: Cold exposure increased serum FGF21 levels in the evening, but not in the morning, in both males and females. GDF15 levels were not affected by cold exposure. Thus, this study suggests that the timing of cold exposure may influence cold-induced changes in FGF21 levels but not GDF15 levels and seems to be independent of changes ienergy expenditure
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