Management and outcomes following emergency surgery for traumatic brain injury - A multi-centre, international, prospective cohort study (the Global Neurotrauma Outcomes Study).

Introduction:Traumatic brain injury (TBI) accounts for a significant amount of death and disability worldwide and the majority of this burden affects individuals in low-and-middle income countries. Despite this, considerable geographical differences have been reported in the care of TBI patients. On this background, we aim to provide a comprehensive international picture of the epidemiological characteristics, management and outcomes of patients undergoing emergency surgery for traumatic brain injury (TBI) worldwide. Methods and analysis:The Global Neurotrauma Outcomes Study (GNOS) is a multi-centre, international, prospective observational cohort study. Any unit performing emergency surgery for TBI worldwide will be eligible to participate. All TBI patients who receive emergency surgery in any given consecutive 30-day period beginning between 1st of November 2018 and 31st of December 2019 in a given participating unit will be included. Data will be collected via a secure online platform in anonymised form. The primary outcome measures for the study will be 14-day mortality (or survival to hospital discharge, whichever comes first). Final day of data collection for the primary outcome measure is February 13th. Secondary outcome measures include return to theatre and surgical site infection. Ethics and dissemination:This project will not affect clinical practice and has been classified as clinical audit following research ethics review. Access to source data will be made available to collaborators through national or international anonymised datasets on request and after review of the scientific validity of the proposed analysis by the central study team

Reaction hijacking inhibition of Plasmodium falciparum asparagine tRNA synthetase

Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl-tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure-activity relationship and the selectivity mechanism.</p

Reaction hijacking inhibition of Plasmodium falciparum asparagine tRNA synthetase

Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl-tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure-activity relationship and the selectivity mechanism

Reaction hijacking inhibition of Plasmodium falciparum asparagine tRNA synthetase

Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl-tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure-activity relationship and the selectivity mechanism

Para-Fluoro Postpolymerization Chemistry of Poly(pentafluorobenzyl methacrylate): Modification with Amines, Thiols, and Carbonylthiolates

A methacrylic polymer undergoing highly efficient para-fluoro substitution reactions is presented. A series of well-defined poly(2,3,4,5,6-pentafluorobenzyl methacrylate) (pPFBMA) homopolymers with degrees of polymerization from 28 to 132 and Ð ≤ 1.29 was prepared by the RAFT process. pPFBMA samples were atactic (with triad tacticity apparent in 1H and 19F NMR spectra) and soluble in most organic solvents. pPFBMA reacted quantitatively through parafluoro substitution with a range of thiols (typically 1.1 equiv thiol, base, RT, < 1h) in the absence of any observed side reactions. Para-fluoro substitution with different (thio)carbonylthio reagents was possible and allowed for subsequent one-pot cleavage of dithioester pendent groups with concurrent thia-Michael side group modification. Reactions with aliphatic amines (typically 2.5 equiv amine, 50–60 °C, overnight) resulted in complete substitution of the para-fluorides without any observed ester cleavage reactions. However, for primary amines, H2NR, double substitution reactions yielding tertiary (–C6F4)2NR amine bridges were observed, which were absent with secondary amine reagents. No reactions were found for attempted modifications of pPFBMA with bromide, iodide, methanethiosulfonate, or thiourea, indicating a highly selective reactivity toward nucleophiles. The versatility of this reactive platform is demonstrated through the synthesis of a pH-responsive polymer and novel thermoresponsive polymers: an oligo(ethylene glycol)-functional species with an LCST in water and two zwitterionic polymers with UCSTs in water and aqueous salt solution (NaCl concentration up to 178 mM)

Denomi/Nation: Envisioning Possibilities of Reconstructing an Alternative Zimbabwe in Muzorewa’s Rise Up and Walk

Political developments in Zimbabwe in the new millennium have per force called for a re-look at the very concepts that inform the bedrock of nationhood and belonging to the nation state. They call for questions that interrogate the ways in which certain memories and processes have been privileged as constitutive of the elements that gave birth to the Zimbabwean nation. The political whirlwind that became acutely defined between 1997 and 2009 demands that several modes of remembering Zimbabwean nationhood be allowed to contest and be interpreted in different ways in an effort to envisiona better Zimbabwe. The point of departure in such a project is to view nations as products of collective memory that come into being through narrative

<i>Para</i>-Fluoro Postpolymerization Chemistry of Poly(pentafluorobenzyl methacrylate): Modification with Amines, Thiols, and Carbonylthiolates

A methacrylic polymer undergoing highly efficient <i>para</i>-fluoro substitution reactions is presented. A series of well-defined poly­(2,3,4,5,6-penta­fluorobenzyl methacrylate) (pPFBMA) homopolymers with degrees of polymerization from 28 to 132 and <i>Đ</i> ≤ 1.29 was prepared by the RAFT process. pPFBMA samples were atactic (with triad tacticity apparent in ¹H and ¹⁹F NMR spectra) and soluble in most organic solvents. pPFBMA reacted quantitatively through <i>para</i>-fluoro substitution with a range of thiols (typically 1.1 equiv of thiol, base, RT, <1 h) in the absence of any observed side reactions. <i>Para</i>-fluoro substitution with different (thio)­carbonylthio reagents was possible and allowed for subsequent one-pot cleavage of dithioester pendent groups with concurrent thia-Michael side group modification. Reactions with aliphatic amines (typically 2.5 equiv of amine, 50–60 °C, overnight) resulted in complete substitution of the <i>para</i>-fluorides without any observed ester cleavage reactions. However, for primary amines, H₂NR, double substitution reactions yielding tertiary (−C₆F₄)₂NR amine bridges were observed, which were absent with secondary amine reagents. No reactions were found for attempted modifications of pPFBMA with bromide, iodide, methane­thiosulfonate, or thiourea, indicating a highly selective reactivity toward nucleophiles. The versatility of this reactive platform is demonstrated through the synthesis of a pH-responsive polymer and novel thermoresponsive polymers: an oligo­(ethylene glycol)-functional species with an LCST in water and two zwitterionic polymers with UCSTs in water and aqueous salt solution (NaCl concentration up to 178 mM)