4,599 research outputs found

    Blood immunoglobulins, complement and TNF receptor following minimally invasive surgery in patients undergoing pulmonary lobectomy

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    The reasons for improved survival following minimally invasive surgery remain elusive. Circulating mediators link surgical trauma, vascular and tissue homeostasis. Acute phase reactants, leukocytes and leukocyte Reactive Oxygen Species (ROS) are affected differentially by minimally invasive video-assisted thoracic surgery (VATS). Also, immunoglobulins, complement, TNF receptor and P-selectin changes have been observed, but the influence of minimally invasive surgery on these opsonins is less well defined. In this prospective randomised trial, 41 patients were randomly assigned to minimally invasive or open thoracic surgery, and immunoglobulins and vascular endothelial damage biomarkers were analysed. Humoral mediators (blood IgG, IgM, IgA; complement fragments C3, C4, and complement haemolytic index of activation CH50; TNF receptors I, II and P-selectin) were analysed before and 2, 5 and 7 days after surgery. Post-surgical changes in individual patients were determined. Substantial immunoglobulin decreases followed minimally invasive and open surgery. Decreased IgG, IgM and IgE were detected 2 days after surgery, and IgG and IgM after 7 days. These changes were greater than haemodilution, reaching greater significance in open surgery patients. Immunoglobulin decreases followed lymphocyte decreases. In contrast, increased complement and inflammatory endothelial cell signals (C3 and C4, soluble TNFR-II) were detected 7 days after surgery. In both groups, increased C3 and TNFR-II followed early acute phase reactants CRP, IL-6 and ROS. Acute phase reactants and CD4/CD8 lymphocytes were factors most attenuated in patients undergoing minimally invasive thoracic surgery (VATS). This study suggests local trauma mediators are better biomarkers than circulating opsonins in defining the response to minimally invasive surgery, and a systems approach, comparing individual metabolic responses, is effective in small patient groups

    Cellular and humoral responses following minimally invasive surgery : role of reactive oxygen species

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    Surgery is associated with release of local and systemic mediators which influence vascular and tissue homeostasis. The post-surgical release of acute phase reactants, particularly IL-6 and CRP, is reduced in minimally invasive surgery, compared with conventional surgery. Additionally, there is emerging evidence that leukocytes and Reactive Oxygen Species (ROS) are affected differentially by minimally invasive surgery. ROS and mediators of oxidative stress influence vascular endothelium, organ perfusion and angiogenesis, and may be critical determinants of survival and outcome. ROS also influence cell proliferation and cell death and have been implicated in neoplastic signalling. Advances in ROS detection and oxidative stress signalling have shown cellular changes affected by minimally invasive surgery. It has been observed that the invasiveness of surgery is proportional to changes in phagocyte and lymphocyte ROS. A potential role for ROS signalling in the immune system is suggested by evidence of closer ROS/leukocyte correlation in patients undergoing minimally invasive surgery. At lower ROS levels, phagocyte and lymphocyte ROS following minimally invasive surgery implicate a homeostatic response with closer leukocyte/ROS correlations, whereas higher ROS in open surgery and greater leukocyte depletion indicate more cytotoxic signalling. Interactions between humoral and cellular elements suggest that an integrated systems approach, using individual patient responses, should be used to analyse the response to surgical trauma and oxidative stress. These studies are being used to investigate ROS as biomarkers of the effects of surgery on vascular and pulmonary reactivity. ROS signalling may provide insights into post surgical trauma and its underlying pathology

    Detectability of Strange Matter in Heavy Ion Experiments

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    We discuss the properties of two distinct forms of hypothetical strange matter, small lumps of strange quark matter (strangelets) and of hyperon matter (metastable exotic multihypernuclear objects: MEMOs), with special emphasis on their relevance for present and future heavy ion experiments. The masses of small strangelets up to A = 40 are calculated using the MIT bag model with shell mode filling for various bag parameters. The strangelets are checked for possible strong and weak hadronic decays, also taking into account multiple hadron decays. It is found that strangelets which are stable against strong decay are most likely highly negative charged, contrary to previous findings. Strangelets can be stable against weak hadronic decay but their masses and charges are still rather high. This has serious impact on the present high sensitivity searches in heavy ion experiments at the AGS and CERN facilities. On the other hand, highly charged MEMOs are predicted on the basis of an extended relativistic mean-field model. Those objects could be detected in future experiments searching for short-lived, rare composites. It is demonstrated that future experiments can be sensitive to a much wider variety of strangelets.Comment: 26 pages, 5 figures, uses RevTeX and epsf.st

    Antideuteron yield at the AGS and coalescence implications

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    We present Experiment 864's measurement of invariant antideuteron yields in 11.5A GeV/c Au + Pt collisions. The analysis includes 250 million triggers representing 14 billion 10% central interactions sampled for events with high mass candidates. We find (1/2 pi pt) d^(2)N/dydpt = 3.5 +/- 1.5 (stat.) +0.9,-0.5 (sys.) x 10^(-8) GeV^(-2)c^(2) for 1.8=0.35 GeV/c (y(cm)=1.6) and 3.7 +/- 2.7 (stat.) +1.4,-1.5 (sys.) x 10^(-8) GeV^(-2)c^(2) for 1.4=0.26 GeV/c, and a coalescence parameter B2-bar of 4.1 +/- 2.9 (stat.) +2.3,-2.4 (sys.) x 10^(-3) GeV^(2)c^(-3). Implications for the coalescence model and antimatter annihilation are discussed.Comment: 8 pages, 4 figures, Latex, submitted to Phys. Rev. Let

    Search for the Weak Decay of an H Dibaryon

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    We have searched for a neutral HH dibaryon decaying via HΛnH\to\Lambda n and HΣ0nH\to\Sigma^0 n. Our search has yielded two candidate events from which we set an upper limit on the HH production cross section. Normalizing to the inclusive Λ\Lambda production cross section, we find (dσH/dΩ)/(dσΛ/dΩ)<6.3×106(d\sigma_H/d\Omega) / (d\sigma_\Lambda/d\Omega) < 6.3\times 10^{-6} at 90% C.L., for an HH of mass \approx 2.15 GeV/c2c^2.Comment: 11 pages, 6 postscript figures, epsfig, aps, preprint, revte

    Averages of bb-hadron, cc-hadron, and τ\tau-lepton properties as of summer 2014

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    This article reports world averages of measurements of bb-hadron, cc-hadron, and τ\tau-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG) using results available through summer 2014. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CPCP violation parameters, parameters of semileptonic decays and CKM matrix elements.Comment: 436 pages, many figures and tables. Online updates available at http://www.slac.stanford.edu/xorg/hfag

    Measurement of Pion Enhancement at Low Transverse Momentum and of the Delta-Resonance Abundance in Si-Nucleus Collisions at AGS Energy

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    We present measurements of the pion transverse momentum (p_t) spectra in central Si-nucleus collisions in the rapidity range 2.0<y<5.0 for p_t down to and including p_t=0. The data exhibit an enhanced pion yield at low p_t compared to what is expected for a purely thermal spectral shape. This enhancement is used to determine the Delta-resonance abundance at freeze-out. The results are consistent with a direct measurement of the Delta-resonance yield by reconstruction of proton-pion pairs and imply a temperature of the system at freeze-out close to 140 MeV.Comment: 12 pages + 4 figures (uuencoded at end-of-file

    Evidence for the role of EPHX2 gene variants in anorexia nervosa.

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    Anorexia nervosa (AN) and related eating disorders are complex, multifactorial neuropsychiatric conditions with likely rare and common genetic and environmental determinants. To identify genetic variants associated with AN, we pursued a series of sequencing and genotyping studies focusing on the coding regions and upstream sequence of 152 candidate genes in a total of 1205 AN cases and 1948 controls. We identified individual variant associations in the Estrogen Receptor-ß (ESR2) gene, as well as a set of rare and common variants in the Epoxide Hydrolase 2 (EPHX2) gene, in an initial sequencing study of 261 early-onset severe AN cases and 73 controls (P=0.0004). The association of EPHX2 variants was further delineated in: (1) a pooling-based replication study involving an additional 500 AN patients and 500 controls (replication set P=0.00000016); (2) single-locus studies in a cohort of 386 previously genotyped broadly defined AN cases and 295 female population controls from the Bogalusa Heart Study (BHS) and a cohort of 58 individuals with self-reported eating disturbances and 851 controls (combined smallest single locus P&lt;0.01). As EPHX2 is known to influence cholesterol metabolism, and AN is often associated with elevated cholesterol levels, we also investigated the association of EPHX2 variants and longitudinal body mass index (BMI) and cholesterol in BHS female and male subjects (N=229) and found evidence for a modifying effect of a subset of variants on the relationship between cholesterol and BMI (P&lt;0.01). These findings suggest a novel association of gene variants within EPHX2 to susceptibility to AN and provide a foundation for future study of this important yet poorly understood condition
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