98 research outputs found

    The neuropathogenesis of highly pathogenic avian influenza H5Nx viruses in mammalian species including humans

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    Circulation of highly pathogenic avian influenza (HPAI) H5Nx viruses of the A/Goose/Guangdong/1/96 lineage in birds regularly causes infections of mammals, including humans. In many mammalian species, infections are associated with severe neurological disease, a unique feature of HPAI H5Nx viruses compared with other influenza A viruses. Here, we provide an overview of the neuropathogenesis of HPAI H5Nx virus infection in mammals, centered on three aspects: neuroinvasion, neurotropism, and neurovirulence. We focus on in vitro studies, as well as studies on naturally or experimentally infected mammals. Additionally, we discuss the contribution of viral factors to the neuropathogenesis of HPAI H5Nx virus infections and the efficacy of intervention strategies to prevent neuroinvasion or the development of neurological disease.</p

    Pyridazinediones and amino acid receptors: theoretical studies, design, synthesis, and evaluation of novel analogues

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    http://www.pharmacol.usyd.edu.au/thesis This thesis is primarily concerned with a class of chemical compounds known as pyridazinediones, being 6-membered aromatic rings containing two adjacent nitrogen atoms (pyridazine), doubly substituted with oxygen. In particular, the work focuses on pyridazine-3,6-diones, derivatives of maleic hydrazide (1). Understanding of the chemistry of these compounds is extended, using theoretical and synthetic techniques. This thesis is also concerned with two very important classes of receptors which bind amino acids in the brain: firstly, the inhibitory GABA receptor, which binds g-aminobutyric acid (GABA) (2) in vivo, and for which muscimol (3) is an agonist of the GABAA subclass; secondly, Excitatory Amino Acid (EAA) receptors, which bind glutamate (4) in vivo, and in particular the AMPA subclass, for which (S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) (5) is an agonist. The connection between pyridazinediones and amino acid receptors is the design, synthesis, and evaluation of structures based on pyridazinediones as potential GABA and EAA receptor ligands. Techniques of theoretical chemistry, molecular modelling, synthetic chemistry, and in vitro pharmacology are used to explore pyridazine-3,6-dione derivatives as ligands

    No Treatment versus 24 or 60 Weeks of Antiretroviral Treatment during Primary HIV Infection: The Randomized Primo-SHM Trial

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    Background: The objective of this study was to assess the benefit of temporary combination antiretroviral therapy (cART) during primary HIV infection (PHI). Methods and Findings: Adult patients with laboratory evidence of PHI were recruited in 13 HIV treatment centers in the Netherlands and randomly assigned to receive no treatment or 24 or 60 wk of cART (allocation in a 1:1:1 ratio); if therapy was clinically indicated, participants were randomized over the two treatment arms (allocation in a 1:1 ratio). Primary end points were (1) viral set point, defined as the plasma viral load 36 wk after randomization in the no treatment arm and 36 wk after tr Conclusions: In this trial, temporary cART during PHI was found to transiently lower the viral set point and defer the restart of cART during chronic HIV infection

    Teleparallel Gravity and Dimensional Reductions of Noncommutative Gauge Theory

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    We study dimensional reductions of noncommutative electrodynamics on flat space which lead to gauge theories of gravitation. For a general class of such reductions, we show that the noncommutative gauge fields naturally yield a Weitzenbock geometry on spacetime and that the induced diffeomorphism invariant field theory can be made equivalent to a teleparallel formulation of gravity which macroscopically describes general relativity. The Planck length is determined in this setting by the Yang-Mills coupling constant and the noncommutativity scale. The effective field theory can also contain higher-curvature and non-local terms which are characteristic of string theory. Some applications to D-brane dynamics and generalizations to include the coupling of ordinary Yang-Mills theory to gravity are also described.Comment: 31 pages LaTeX; References adde

    The impact of regionalized trauma care on the distribution of severely injured patients in the Netherlands

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    Background Twenty years ago, an inclusive trauma system was implemented in the Netherlands. The goal of this study was to evaluate the impact of structured trauma care on the concentration of severely injured patients over time. Methods All severely injured patients (Injury Severity Score [ISS] >= 16) documented in the Dutch Trauma Registry (DTR) in the calendar period 2008-2018 were included for analysis. We compared severely injured patients, with and without severe neurotrauma, directly brought to trauma centers (TC) and non-trauma centers (NTC). The proportion of patients being directly transported to a trauma center was determined, as was the total Abbreviated Injury Score (AIS), and ISS. Results The documented number of severely injured patients increased from 2350 in 2008 to 4694 in 2018. During this period, on average, 70% of these patients were directly admitted to a TC (range 63-74%). Patients without severe neurotrauma had a lower chance of being brought to a TC compared to those with severe neurotrauma. Patients directly presented to a TC were more severely injured, reflected by a higher total AIS and ISS, than those directly transported to a NTC. Conclusion Since the introduction of a well-organized trauma system in the Netherlands, trauma care has become progressively centralized, with more severely injured patients being directly presented to a TC. However, still 30% of these patients is initially brought to a NTC. Future research should focus on improving pre-hospital triage to facilitate swift transfer of the right patient to the right hospital.Trauma Surger

    Dutch trauma system performance: are injured patients treated at the right place?

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    Background: The goal of trauma systems is to match patient care needs to the capabilities of the receiving centre. Severely injured patients have shown better outcomes if treated in a major trauma centre (MTC). We aimed to evaluate patient distribution in the Dutch trauma system. Furthermore, we sought to identify factors associated with the undertriage and transport of severely injured patients (Injury Severity Score (ISS) >15) to the MTC by emergency medical services (EMS).Methods: Data on all acute trauma admissions in the Netherlands (2015-2016) were extracted from the Dutch national trauma registry. An ambulance driving time model was applied to calculate MTC transport times and transport times of ISS >15 patients to the closest MTC and non-MTC. A multivariable logistic regression analysis was performed to identify factors associated with ISS >15 patients' EMS undertriage to an MTC.Results: Of the annual average of 78,123 acute trauma admissions, 4.9% had an ISS >15. The nonseverely injured patients were predominantly treated at non-MTCs (79.2%), and 65.4% of patients with an ISS >15 received primary MTC care. This rate varied across the eleven Dutch trauma networks (36.8%-88.4%) and was correlated with the transport times to an MTC (Pearson correlation -0.753, p=0.007). The trauma networks also differed in the rates of secondary transfers of ISS >15 patients to MTC hospitals (7.8% 59.3%) and definitive MTC care (43.6% - 93.2%). Factors associated with EMS undertriage of ISS >15 patients to the MTC were female sex, older age, severe thoracic and abdominal injury, and longer additional EMS transport times.Conclusions: Approximately one-third of all severely injured patients in the Netherlands are not initially treated at an MTC. Special attention needs to be directed to identifying patient groups with a high risk of undertriage. Furthermore, resources to overcome longer transport times to an MTC, including the availability of ambulance and helicopter services, may improve direct MTC care and result in a decrease in the variation of the undertriage of severely injured patients to MTCs among the Dutch trauma networks. Furthermore, attention needs to be directed to improving primary triage guidelines and instituting uniform interfacility transfer agreements. (C) 2021 Elsevier Ltd. All rights reserved.Trauma Surger

    The Dutch nationwide trauma registry: The value of capturing all acute trauma admissions

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    Introduction: Twenty years ago the Dutch trauma care system was reformed by the designating 11 level one Regional trauma centres (RTCs) to organise trauma care. The RTCs set up the Dutch National Trauma Registry (DNTR) to evaluate epidemiology, patient distribution, resource use and quality of care. In this study we describe the DNTR, the incidence and main characteristics of Dutch acutely admitted trauma patients, and evaluate the value of including all acute trauma admissions compared to more stringent criteria applied by the national trauma registries of the United Kingdom and Germany. Methods: The DNTR includes all injured patients treated at the ED within 48 hours after trauma and consecutively followed by direct admission, transfers to another hospital or death at the ED. DNTR data on admission years 2007-2018 were extracted to describe the maturation of the registry. Data from 2018 was used to describe the incidence rate and patient characteristics. Inclusion criteria of the Trauma Audit and Research (TARN) and the Deutsche Gesellschaft für Unfallchirurgie (DGU) were applied on 2018 DNTR data. Results: Since its start in 2007 a total of 865,460 trauma cases have been registered in the DNTR. Hospital participation increased from 64% to 98%. In 2018, a total of 77,529 patients were included, the median age was 64 years, 50% males. Severely injured patients with an ISS≥16, accounted for 6% of all admissions, of which 70% was treated at designated RTCs. Patients with an ISS≤ 15were treated at non-RTCs in 80% of cases. Application of DGU or TARN inclusion criteria, resulted in inclusion of respectively 5% and 32% of the DNTR patients. Particularly children, elderly and patients admitted at non-RTCs are left out. Moreover, 50% of ISS≥16 and 68% of the fatal cases did not meet DGU inclusion criteria Conclusion: The DNTR has evolved into a comprehensive well-structured nationwide population-based trauma register. With 80,000 inclusions annually, the DNTR has become one of the largest trauma databases in Europe The registries strength lies in the broad inclusion criteria which enables studies on the burden of injury and the quality and efficiency of the entire trauma care system, encompassing all trauma‐receiving hospitals

    Candidate CSPG4 mutations and induced pluripotent stem cell modeling implicate oligodendrocyte progenitor cell dysfunction in familial schizophrenia

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    Schizophrenia is highly heritable, yet its underlying pathophysiology remains largely unknown. Among the most well-replicated findings in neurobiological studies of schizophrenia are deficits in myelination and white matter integrity; however, direct etiological genetic and cellular evidence has thus far been lacking. Here, we implement a family-based approach for genetic discovery in schizophrenia combined with functional analysis using induced pluripotent stem cells (iPSCs). We observed familial segregation of two rare missense mutations in Chondroitin Sulfate Proteoglycan 4 (CSPG4) (c.391G > A [p.A131T], MAF 7.79 × 10−5 and c.2702T > G [p.V901G], MAF 2.51 × 10−3). The CSPG4A131T mutation was absent from the Swedish Schizophrenia Exome Sequencing Study (2536 cases, 2543 controls), while the CSPG4V901G mutation was nominally enriched in cases (11 cases vs. 3 controls, P = 0.026, OR 3.77, 95% CI 1.05–13.52). CSPG4/NG2 is a hallmark protein of oligodendrocyte progenitor cells (OPCs). iPSC-derived OPCs from CSPG4A131T mutation carriers exhibited abnormal post-translational processing (P = 0.029), subcellular localization of mutant NG2 (P = 0.007), as well as aberrant cellular morphology (P = 3.0 × 10−8), viability (P = 8.9 × 10−7), and myelination potential (P = 0.038). Moreover, transfection of healthy non-carrier sibling OPCs confirmed a pathogenic effect on cell survival of both the CSPG4A131T (P = 0.006) and CSPG4V901G (P = 3.4 × 10−4) mutations. Finally, in vivo diffusion tensor imaging of CSPG4A131T mutation carriers demonstrated a reduction of brain white matter integrity compared to unaffected sibling and matched general population controls (P = 2.2 × 10−5). Together, our findings provide a convergence of genetic and functional evidence to implicate OPC dysfunction as a candidate pathophysiological mechanism of familial schizophrenia

    Gender differences in respiratory symptoms in 19-year-old adults born preterm

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    Objective: To study the prevalence of respiratory and atopic symptoms in (young) adults born prematurely, differences between those who did and did not develop Bronchopulmonary Disease (BPD) at neonatal age and differences in respiratory health between males and females. Methods: Design: Prospective cohort study. Setting: Nation wide follow-up study, the Netherlands. Participants: 690 adults (19 year old) born with a gestational age below 32 completed weeks and/or with a birth weight less than 1500g. Controls were Dutch participants of the European Community Respiratory Health Survey (ECRHS). Main outcome measures: Presence of wheeze, shortness of breath, asthma, hay fever and eczema using the ECRHS-questionnaire
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