138 research outputs found

    Bloodstream-To-Eye Infections Are Facilitated by Outer Blood-Retinal Barrier Dysfunction

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    This work was funded by National Institutes of Health (NIH; http://www.nih.gov) Grants R01EY024140 and R21EY022466 (to M.C.C.) and R01EY019494 (to M.H.E.). Our research is also funded in part by NIH Core Grant P30EY021725 (to Robert E. Anderson, OUHSC) and an unrestricted grant from Research to Prevent Blindness Inc. (http://www.rpbusa.org) to the Dean A. McGee Eye Institute. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.We thank Bolanle Adebayo (Cameron University, Lawton OK), Craig Land (Oklahoma State University, Stillwater OK), Nathan Jia (Oklahoma Christian University, Edmond OK), Kobbe Wiafe (Oklahoma School of Science and Mathematics, Oklahoma City OK), and Amanda Roehrkasse and Madhu Parkunan (OUHSC) for intellectual discussions and technical assistance. The authors also acknowledge thank Nanette Wheatley, Dr. Feng Li, and Mark Dittmar (OUHSC Live Animal Imaging Core, P30EY021725) for their invaluable technical assistance.This work was presented in part at the 2014 Association for Research in Vision and Ophthalmology Annual Conference in Orlando FL.The blood-retinal barrier (BRB) functions to maintain the immune privilege of the eye, which is necessary for normal vision. The outer BRB is formed by tightly-associated retinal pigment epithelial (RPE) cells which limit transport within the retinal environment, maintaining retinal function and viability. Retinal microvascular complications and RPE dysfunction resulting from diabetes and diabetic retinopathy cause permeability changes in the BRB that compromise barrier function. Diabetes is the major predisposing condition underlying endogenous bacterial endophthalmitis (EBE), a blinding intraocular infection resulting from bacterial invasion of the eye from the bloodstream. However, significant numbers of EBE cases occur in non-diabetics. In this work, we hypothesized that dysfunction of the outer BRB may be associated with EBE development. To disrupt the RPE component of the outer BRB in vivo, sodium iodate (NaIO3) was administered to C57BL/6J mice. NaIO3-treated and untreated mice were intravenously injected with 108 colony forming units (cfu) of Staphylococcus aureus or Klebsiella pneumoniae. At 4 and 6 days postinfection, EBE was observed in NaIO3-treated mice after infection with K. pneumoniae and S. aureus, although the incidence was higher following S. aureus infection. Invasion of the eye was observed in control mice following S. aureus infection, but not in control mice following K. pneumoniae infection. Immunohistochemistry and FITC-dextran conjugate transmigration assays of human RPE barriers after infection with an exoprotein-deficient agr/sar mutant of S. aureus suggested that S. aureus exoproteins may be required for the loss of the tight junction protein, ZO-1, and for permeability of this in vitro barrier. Our results support the clinical findings that for both pathogens, complications which result in BRB permeability increase the likelihood of bacterial transmigration from the bloodstream into the eye. For S. aureus, however, BRB permeability is not required for the development of EBE, but toxin production may facilitate EBE pathogenesis.Yeshttp://www.plosone.org/static/editorial#pee

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Multi-messenger Observations of a Binary Neutron Star Merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

    Impact of Donor Characteristics and HLA Matching on Survival of Chinese Patients with Hematologic Malignancies Undergoing Unrelated Hematopoietic Stem Cell Transplantation

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    We retrospectively analyzed the impact of donor characteristics and HLA matching on outcomes in Chinese patients undergoing unrelated hematopoietic stem cell transplantation (HSCT). A total of 693 patients with hematologic malignancies who underwent HSCT between 2005 and 2010 had available survival data at 100 days or 1 year posttransplantation in the Buddhist Tzu-Chi Stem Cell Center database. The overall survival rates at 100 days and 1 year were 83.3% and 65.2%, respectively. Mismatches of HLA-A, -B, and -DRB1 at the antigen or allele level, along with inadequate cell dose, were associated with a significant risk of mortality (hazard ratio [HR] = 2.36, P &lt; .001; HR = 1.44, P = .005; and HR = 2.20, P = .009, respectively). In 107 donors with matched HLA-A, -B and -DRB1 and known HLA-C match status, 22.4% had an HLA-C antigen mismatch, resulting in an HR of 2.87 for mortality relative to complete 8/8 matches (P = .005). Recipients with unknown HLA-C match status also had a significantly worse outcome (HR = 1.73; P = .039). Multivariate analysis revealed that cell dose and HLA-A, -B, -C, and -DRB1 antigen match status significantly affected the final outcome of survival (P = .012 and &lt;.001, respectively). Our data indicate that HLA-C match status should be confirmed before HSCT from an unrelated donor. Inadequate cell dose remains an important determinant of poor transplantation survival. Further studies to elucidate the importance of matching of specific HLA loci are needed to better understand the risk of HSCT and improve patient outcomes

    Hematologic Markers as Prognostic Factors in Nonmetastatic Esophageal Cancer Patients under Concurrent Chemoradiotherapy

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    Nonmetastatic esophageal cancer can demonstrate a high local recurrence rate even under the standard treatment. We evaluated platelet counts before and after concurrent chemoradiotherapy (CCRT), neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio for predicting esophageal cancer prognosis under CCRT. Newly diagnosed patients with esophageal cancer (stages IA–IIIC) who underwent CCRT during January 2013–December 2017 were enrolled. The data were collected retrospectively. Overall survival (OS), time to progressive disease (TPD), and time to metastasis (TM) were recorded for indicating prognosis. Kaplan–Meier curves were plotted and univariate and multivariate analyses were performed. In total, 105 patients were enrolled. The stages of esophageal cancer and surgery were associated with prognosis (i.e., OS, TPD, and TM). Based on TPD and TM, women had better prognosis than men. In the univariate analysis, high pre- and post-CCRT platelet counts (>300,000/μL), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) as well as low lymphocyte percentage were significantly associated with poor prognosis. However, in the multivariate analysis, only post-CCRT high platelet count (>300,000/μL) remained significantly associated with poor prognosis (P = .041, .045, and .023 for OS, TPD, and TM, respectively). Poor prognosis was observed in patients with high platelet counts, PLR, NLR, and low lymphocyte percentage. Surgery was an independent factor predicting better prognosis. Our findings may have clinical significance with regard to therapeutic decision-making

    Janus kinase 2 V617F mutation in an unrelated peripheral blood stem cell donor

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    Polycythemia vera (PV) is relatively uncommon in early adulthood, and evidence about the prevalence of the Janus kinase 2 (JAK2) V617F mutation in the general population is limited. Here, we report a previously healthy volunteer peripheral blood stem cell (PBSC) donor who developed symptomatic PV with the JAK2 V617F mutation 2 years after PBSC mobilization and harvest. The characteristic mutation was identified retrospectively in the blood sample of the donor at the confirmation typing stage, which was before granulocyte colony-stimulating factor injection. This report presents a safety issue for both donor and recipient of hematopoietic stem cell transplantation. Clinicians should be aware of this during health workup and postdonation follow-up of unrelated PBSC donors. Any abnormal and/or equivocal laboratory data, especially during the donor workup stage, should not be overlooked

    Platelet Activation and Cytokine Release of Interleukin-8 and Interferon-Gamma-Induced Protein 10 after ChAdOx1 nCoV-19 Coronavirus Vaccine Injection

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    Coronavirus disease 2019 (COVID-19) vaccines are associated with serious thromboembolic or thrombocytopenic events including vaccine-induced immune thrombocytopenia and thrombosis and immune thrombocytopenia, particularly AZD1222/ChAdOx1. According to the proposed mechanism, COVID-19 vaccines stimulate inflammation and platelet activation. In this study, we analyzed the role of AZD1222/ChAdOx1 vaccines in the activation of platelets and the release of anti-PF4 antibodies and inflammatory cytokines in a cohort of healthy donors without vaccine-induced immune thrombotic thrombocytopenia (VITT). Forty-eight healthy volunteers were enrolled in this study. Blood samples were collected from peripheral blood at three time points: before vaccination and 1 and 7 days after vaccination. Compared with the prevaccination data, a decrease in the leukocyte and platelet counts was observed 1 day after vaccination, which recovered 7 days after injection. The percentage of activated GPIIb/IIIa complex (PAC-1) under high ADP or thrombin receptor-activating peptide stimulation increased 1 day after vaccination. Furthermore, interluekin-8 (IL-8) and interferon-gamma-induced protein 10 (IP-10) increased significantly. Additionally, platelet activation and inflammation, with the release of cytokines, were observed; however, none of the individuals developed VITT. Mild thrombocytopenia with platelet activation and inflammation with an elevation of IL-8 and IP-10 were observed after AZ vaccination
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