101
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Katz FS, Pecic S, Tran TH, Trakht I, Schneider L, Zhu Z, Ton-That L, Luzac M, Zlatanic V, Damera S, Macdonald J, Landry DW, Tong L, Stojanovic MN. Discovery of New Classes of Compounds that Reactivate Acetylcholinesterase Inhibited by Organophosphates. Chembiochem 2015; 16:2205-2215. [PMID: 26350723 DOI: 10.1002/cbic.201500348] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Indexed: 11/11/2022]
Abstract
Acetylcholinesterase (AChE) that has been covalently inhibited by organophosphate compounds (OPCs), such as nerve agents and pesticides, has traditionally been reactivated by using nucleophilic oximes. There is, however, a clearly recognized need for new classes of compounds with the ability to reactivate inhibited AChE with improved in vivo efficacy. Here we describe our discovery of new functional groups--Mannich phenols and general bases--that are capable of reactivating OPC--inhibited AChE more efficiently than standard oximes and we describe the cooperative mechanism by which these functionalities are delivered to the active site. These discoveries, supported by preliminary in vivo results and crystallographic data, significantly broaden the available approaches for reactivation of AChE.
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Affiliation(s)
- Francine S Katz
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Stevan Pecic
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Timothy H Tran
- Department of Biological Sciences, Columbia University, 1212 Amsterdam Avenue, New York, NY 10027 (USA)
| | - Ilya Trakht
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Laura Schneider
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Zhengxiang Zhu
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Long Ton-That
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Michal Luzac
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Viktor Zlatanic
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Shivani Damera
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Joanne Macdonald
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA).,Genecology Research Centre, Inflammation and Healing Research Cluster, School of Science and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD 4556 (Australia)
| | - Donald W Landry
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA)
| | - Liang Tong
- Department of Biological Sciences, Columbia University, 1212 Amsterdam Avenue, New York, NY 10027 (USA)
| | - Milan N Stojanovic
- Department of Medicine/Division of Experimental Therapeutics, Columbia University Medical Center, 630 W. 168th Street, New York, NY 10032 (USA).,Departments of Biomedical Engineering and Systems Biology, Columbia University, 630 W. 168th street, New York, NY 10032 (USA)
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102
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Winter M, Wille T, Musilek K, Kuca K, Thiermann H, Worek F. Investigation of the reactivation kinetics of a large series of bispyridinium oximes with organophosphate-inhibited human acetylcholinesterase. Toxicol Lett 2015. [PMID: 26210933 DOI: 10.1016/j.toxlet.2015.07.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The limited effectiveness of the established oximes obidoxime and pralidoxime resulted in ongoing research on novel oximes for the reactivation of acetylcholinesterase (AChE) inhibited by organophosphorus compounds (OP). In order to get more insight into the ability of bispyridinium oximes to reactivate human AChE inhibited by structurally different OP the reactivation kinetics of 31 compounds was determined with tabun-, cyclosarin- and paraoxon-inhibited AChE under identical experimental conditions. The determined affinity (KD), reactivity (kr) and hybrid reactivation rate constants (kr2) enabled theoretical calculations and gave insight into distinct structural features which are important for the reactivation of AChE inhibited by different OP. Several oximes with superior reactivating potency towards selective OP-AChE conjugates were identified but none of the tested oximes can be considered as a broad spectrum reactivator. In the end, the data of this and previous studies gives rise to the question whether further modifications of the bispyridinium structure could ever result in a universal reactivator or whether future research should be directed to different templates.
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Affiliation(s)
- Michael Winter
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Timo Wille
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Kamil Musilek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Hradec Králové, Czech Republic
| | - Kamil Kuca
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Hradec Králové, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Center, Hradec Králové, Czech Republic
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany.
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103
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Hua G, Du J, Surgenor BA, Slawin AMZ, Woollins JD. Novel Fluorinated Phosphorus-Sulfur Heteroatom Compounds: Synthesis and Characterization of Ferrocenyl- and Aryl-Phosphonofluorodithioic Salts, Adducts, and Esters. Molecules 2015; 20:12175-97. [PMID: 26151115 PMCID: PMC6332468 DOI: 10.3390/molecules200712175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 06/27/2015] [Accepted: 06/30/2015] [Indexed: 11/16/2022] Open
Abstract
A series of novel ferrocenyl- and aryl-phosphonofluorodithioic salts, adducts, and esters has been prepared. The reaction of 2,4-diferrocenyl-1,3,2,4-diathiadiphosphetane 2,4-disulfide {[FcP(μ-S)S]2, FcLR} with dry KF or tetrabutylammonium fluoride (TBAF) led to the corresponding potassium and tetrabutylammonium salts of ferrocenyldithiofluorophosphinic acids. Treating potassium ferrocenyldithiofluorophosphinic acid with an equimolar amount of tetraphenylphosphonium chloride readily yielded the corresponding organic adducts, and with mono- and di-halogenated alkanes generated a series of the corresponding esters of ferrocenylphosphonofluoridodithioates. Similarly, using 1,3-epithionaphtho[1,8-cd][1,2,6] oxadiphosphinine 1,3-disulfide or Belleau's Reagent in place of FcLR resulted in the corresponding novel salts, adducts, and ester derivatives. All new compounds have been characterized by means of multi-NMR (1H, 13C, 31P, 19F) spectroscopy and accurate mass measurement in conjunction with single crystal X-ray crystallography of four structures.
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Affiliation(s)
- Guoxiong Hua
- EaStCHEM School of Chemistry, University of St. Andrews, St Andrews, Fife KY16 9ST, UK.
| | - Junyi Du
- EaStCHEM School of Chemistry, University of St. Andrews, St Andrews, Fife KY16 9ST, UK.
| | - Brian A Surgenor
- EaStCHEM School of Chemistry, University of St. Andrews, St Andrews, Fife KY16 9ST, UK.
| | - Alexandra M Z Slawin
- EaStCHEM School of Chemistry, University of St. Andrews, St Andrews, Fife KY16 9ST, UK.
| | - J Derek Woollins
- EaStCHEM School of Chemistry, University of St. Andrews, St Andrews, Fife KY16 9ST, UK.
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104
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105
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John H, Mikler J, Worek F, Thiermann H. Reversed-phase ion-pair chromatography-diode array detection of the bispyridinium compound MB327: plasma analysis of a potential novel antidote for the treatment of organophosphorus poisoning. Drug Test Anal 2015; 8:154-63. [PMID: 26041012 DOI: 10.1002/dta.1821] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Revised: 05/12/2015] [Accepted: 05/12/2015] [Indexed: 11/08/2022]
Abstract
In the case of poisoning by organophosphorus nerve agents or pesticides, there is still a lack of pharmacological treatment of the cholinergic crisis selectively targeting the nicotinic acetylcholine receptor. Recently, the compound MB327 was identified as a potential novel lead structure to close this gap, thus demanding a quantitative assay for initial pharmacokinetic (PK) studies. MB327 is a salt consisting of the dicationic bispyridinium compound (BPC) 1,1´-(propane-1,3-diyl)bis(4-tert-butylpyridinium) and two iodide counter ions. Due to the permanent positive charge of the BPC, an isocratic reversed-phase ion-pair chromatographic separation (RPIPC) was developed using heptanesulfonic acid as ion-pairing reagent and 45% v/v methanol as organic modifier (1 mL/min). Selective UV-detection (230 nm) was done by a diode array detector (DAD) for reliable, rugged, precise (RSD < 7%) and accurate (96-104%) quantitative analysis of 50 μL swine plasma (linear range 1-1000 µg BPC/mL plasma, lower limit of quantification 2 µg/mL). During method validation, diverse parameters essential for the chromatographic process were investigated to generate van´t Hoff, van Deemter and width plots allowing calculation of thermodynamic data like the distribution constant K (5.7 ± 0.3), change in enthalpy, ΔH(0) : -23.66 kJ/mol, and entropy, ΔS(0) : -65 J/(mol*K). In addition, RPIPC-DAD analysis enabled calculation of molar absorptivities of the BPC, ε230 : 17 400 ± 1100 L/(mol*cm), and iodide, ε230 : 9900 ± 400 L/(mol*cm), which determination was hampered by interference with each other in conventional cuvette UV-spectrophotometric measurements. Finally, the RPIPC-DAD procedure was applied to samples from an in vivo study of swine.
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Affiliation(s)
- Harald John
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - John Mikler
- Defence Research and Development Canada-Suffield Research Station, Medicine Hat, Alberta, Canada
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
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106
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Chow CF, Ho KYF, Gong CB. Synthesis of a New Bimetallic Re(I)–NCS–Pt(II) Complex as Chemodosimetric Ensemble for the Selective Detection of Mercapto-Containing Pesticides. Anal Chem 2015; 87:6112-8. [DOI: 10.1021/acs.analchem.5b00684] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
| | | | - Cheng-Bin Gong
- College
of Chemistry and Chemical Engineering, Southwest University, Chong Qing, China
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107
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108
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Scheffel C, Thiermann H, Worek F. Effect of reversible ligands on oxime-induced reactivation of sarin- and cyclosarin-inhibited human acetylcholinesterase. Toxicol Lett 2015; 232:557-65. [DOI: 10.1016/j.toxlet.2014.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 10/24/2022]
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109
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Iyer R, Iken B, Leon A. Developments in alternative treatments for organophosphate poisoning. Toxicol Lett 2015; 233:200-6. [PMID: 25595305 DOI: 10.1016/j.toxlet.2015.01.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 01/10/2015] [Accepted: 01/12/2015] [Indexed: 12/25/2022]
Abstract
Organophosphosphates (OPs) are highly effective acetylcholinesterase (AChE) inhibitors that are used worldwide as cheap, multi-purpose insecticides. OPs are also used as chemical weapons forming the active core of G-series and V-series chemical agents including tabun, sarin, soman, cyclosarin, VX, and their chemical analogs. Human exposure to any of these compounds leads to neurotoxic accumulation of the neurotransmitter acetylcholine, resulting in abnormal nerve function and multiple secondary health complications. Suicide from deliberate exposure to OPs is particularly prevalent in developing countries across the world and constitutes a major global health crisis. The prevalence and accessible nature of OP compounds within modern agricultural spheres and concern over their potential use in biochemical weapon attacks have incentivized both government agencies and medical researchers to enact stricter regulatory policies over their usage and to begin developing more proactive medical treatments in cases of OP poisoning. This review will discuss the research undertaken in recent years that has investigated new supplementary drug options for OP treatment and support therapy, including progress in the development of enzymatic prophylaxis.
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Affiliation(s)
- Rupa Iyer
- Center for Life Sciences Technology, Engineering Technology, University of Houston, 300 Technology Building, Houston, TX 77204, USA.
| | - Brian Iken
- Center for Life Sciences Technology, Engineering Technology, University of Houston, 300 Technology Building, Houston, TX 77204, USA
| | - Alex Leon
- Center for Life Sciences Technology, Engineering Technology, University of Houston, 300 Technology Building, Houston, TX 77204, USA
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110
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Lucchini RG, Hashim D. Tremor secondary to neurotoxic exposure: mercury, lead, solvents, pesticides. HANDBOOK OF CLINICAL NEUROLOGY 2015; 131:241-249. [PMID: 26563793 DOI: 10.1016/b978-0-444-62627-1.00014-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Lead, mercury, solvents, and pesticide exposures are common in certain occupations and may cause nervous system dysfunction. Tremors may be the herald manifestation among a constellation of acute toxicity signs and symptoms. However, since tremors may also be the only sign on clinical presentation and since tremors also occur in other diseases, relating tremors to a specific occupational exposure can be challenging. Diagnosis of tremor etiology must be based on other findings on physical exam, laboratory results, and/or imaging. Discerning whether the tremor resulted from the occupational environment versus other etiologies requires knowledge of potential exposure sources, additional detail in history taking, and support of other health and industrial professionals. Reduction or removal from the exposure source remains the key first step in treating patients suffering from tremor that had resulted from occupational exposure toxicity.
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Affiliation(s)
- Roberto G Lucchini
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Unit of Occupational Medicine, Department of Medical Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy.
| | - Dana Hashim
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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111
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Evaluation of Cardiac Function Using Transthoracic Echocardiography in Patients with Myocardial Injury Secondary to Methomyl Poisoning. Cardiovasc Toxicol 2014; 15:269-75. [DOI: 10.1007/s12012-014-9295-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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112
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Voicu V, Rădulescu FŞ, Medvedovici A. Relationships between the antidotal efficacy and structure, PK/PD parameters and bio-relevant molecular descriptors of AChE reactivating oximes: inclusion and integration to biopharmaceutical classification systems. Expert Opin Drug Metab Toxicol 2014; 11:95-109. [DOI: 10.1517/17425255.2015.980813] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Victor Voicu
- 1Romanian Academy, Medical Sciences Section, Calea Victoriei no. 125, Bucharest – 010071, Romania
- 2University of Medicine and Pharmacy “Carol Davila”, Faculty of Medicine, Department of Clinical Pharmacology, Toxicology and Psychopharmacology, Şcoala Floreasca Street no. 8, Bucharest - 011643, Romania
| | - Flavian Ştefan Rădulescu
- 3University of Medicine and Pharmacy “Carol Davila”, Faculty of Pharmacy, Department of Drug Industry and Pharmaceutical Biotechnology, Traian Vuia Street no. 6, Bucharest-020956, Romania
| | - Andrei Medvedovici
- 4University of Bucharest, Faculty of Chemistry, Department of Analytical Chemistry, Panduri Ave., no. 90, Bucharest- 050663, Romania
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113
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Zghab I, Trimeche B, Besbes M, Touboul D, Martin MT, Jannet HB. Synthesis and spectral studies of biologically active organophosphorus derivatives of substituted 4-(2-hydroxyphenylamino)-2H-chromen-2-one. Med Chem Res 2014. [DOI: 10.1007/s00044-014-1291-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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114
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Kaur S, Singh S, Chahal KS, Prakash A. Potential pharmacological strategies for the improved treatment of organophosphate-induced neurotoxicity. Can J Physiol Pharmacol 2014; 92:893-911. [DOI: 10.1139/cjpp-2014-0113] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Organophosphates (OP) are highly toxic compounds that cause cholinergic neuronal excitotoxicity and dysfunction by irreversible inhibition of acetylcholinesterase, resulting in delayed brain damage. This delayed secondary neuronal destruction, which arises primarily in the cholinergic areas of the brain that contain dense accumulations of cholinergic neurons and the majority of cholinergic projection, could be largely responsible for persistent profound neuropsychiatric and neurological impairments such as memory, cognitive, mental, emotional, motor, and sensory deficits in the victims of OP poisoning. The therapeutic strategies for reducing neuronal brain damage must adopt a multifunctional approach to the various steps of brain deterioration: (i) standard treatment with atropine and related anticholinergic compounds; (ii) anti-excitotoxic therapies to prevent cerebral edema, blockage of calcium influx, inhibition of apoptosis, and allow for the control of seizure; (iii) neuroprotection by aid of antioxidants and N-methyl-d-aspartate (NMDA) antagonists (multifunctional drug therapy), to inhibit/limit the secondary neuronal damage; and (iv) therapies targeting chronic neuropsychiatric and neurological symptoms. These neuroprotective strategies may prevent secondary neuronal damage in both early and late stages of OP poisoning, and thus may be a beneficial approach to treating the neuropsychological and neuronal impairments resulting from OP toxicity.
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Affiliation(s)
- Shamsherjit Kaur
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
- Punjab Technical University, Kapurthala 144601, Punjab, India
| | - Satinderpal Singh
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
| | - Karan Singh Chahal
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
| | - Atish Prakash
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
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115
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Zunec S, Kopjar N, Zeljezić D, Kuca K, Musilek K, Lucić Vrdoljak A. In vivo evaluation of cholinesterase activity, oxidative stress markers, cyto- and genotoxicity of K048 oxime–a promising antidote against organophosphate poisoning. Basic Clin Pharmacol Toxicol 2014; 114:344-51. [PMID: 24741714 DOI: 10.1111/bcpt.12158] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
K048 is a member of K-oximes, a new oxime class that has recently been confirmed effective against poisoning by the nerve agent tabun and several pesticides. The toxicity profile of the K048 oxime has not been fully characterized and its optimal therapeutic dose has not yet been established. Earlier studies report excellent results with K048 in reactivating tabun-phosphorylated AChE and in the therapy of tabun-poisoned mice. It possesses a low acute toxicity and exerts an acceptable toxicity profile on isolated human peripheral blood lymphocytes in vitro. Intraperitoneal administration of K048 in rats resulted in an LD50 of 238.3 mg/kg. In this in vivo study, we investigated cholinesterase (ChE) activity and oxidative stress marker levels (lipid peroxidation and superoxide dismutase activity) in the plasma of exposed rats after administering the compound at 25% of its LD50. Lymphocyte viability was evaluated using an acridine orange/ethidium bromide in situ fluorescent assay. The levels of primary DNA damage in rat white blood cells were measured using the alkaline comet assay. The compound applied at 25% of its LD50 did not significantly affect ChE activity and lipid peroxidation and did not cause significant changes in the SOD activity in plasma. The cytotoxicity profile of K048 in the tested dose was also acceptable, and it did not possess significant DNA-damaging potential. The obtained results are promising for further evaluations of the K048 oxime, which should include tests on a broader concentration range and longer incubation times.
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116
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López MD, Pascual-Villalobos MJ. Are monoterpenoids and phenylpropanoids efficient inhibitors of acetylcholinesterase from stored product insect strains? FLAVOUR FRAG J 2014. [DOI: 10.1002/ffj.3220] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- María Dolores López
- Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA); C/Mayor, s/n, 30150, La Alberca Murcia Spain
| | - María Jesús Pascual-Villalobos
- Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA); C/Mayor, s/n, 30150, La Alberca Murcia Spain
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117
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Liu N, Mao LL, Yang B, Yang SD. Copper-promoted oxidative-fluorination of arylphosphine under mild conditions. Chem Commun (Camb) 2014; 50:10879-82. [PMID: 25090483 DOI: 10.1039/c4cc04830j] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient method for the synthesis of phosphoric fluoride via oxidative coupling between hydrophosphine oxide and NaF is reported. DDQ serves as the oxidizing reagent as well as the hydrogen acceptor. The process involves a Cu(II) catalysis and exhibits great functional group tolerance under mild reaction conditions.
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Affiliation(s)
- Na Liu
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China.
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118
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Rajapakse BN, Neeman T, Buckley NA. Effect of acetylcholinesterase (AChE) point-of-care testing in OP poisoning on knowledge, attitudes and practices of treating physicians in Sri Lanka. BMC Health Serv Res 2014; 14:104. [PMID: 24589276 PMCID: PMC4015291 DOI: 10.1186/1472-6963-14-104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 01/21/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Toxicology and Emergency medicine textbooks recommend measurement of acetylcholinesterase (AChE) in all symptomatic cases of organophosphorus (OP) poisoning but laboratory facilities are limited in rural Asia. The accuracy of point-of-care (POC) acetylcholinesterase testing has been demonstrated but it remains to be shown whether results would be valued by clinicians. This study aims to assess the effect of seeing AChE POC test results on the knowledge, attitudes and practices of doctors who frequently manage OP poisoning. METHODS We surveyed 23 clinicians, who had different levels of exposure to seeing AChE levels in OP poisoned patients, on a) knowledge of OP poisoning and biomarker interpretation, b) attitudes towards AChE in guiding poison management, oxime therapy and discharge decisions, and c) practices of ordering AChE in poisoning scenarios. RESULTS An overall high proportion of doctors valued the test (68-89%). However, we paradoxically found that doctors who were more experienced in seeing AChE results valued the test less. Lower proportions valued the test in guidance of acute poisoning management (50%, p = 0.015) and guidance of oxime therapy (25%, p = 0.008), and it was apparent it would not generally be used to facilitate early discharge. The highest proportion of respondents valued it on admission (p < 0.001). A lack of correlation of test results with the clinical picture, and a perception that the test was a waste of money when compared to clinical observation alone were also comments raised by some of the respondents.Greater experience with seeing AChE test results was associated with increased knowledge (p = 0.034). However, a disproportionate lack of knowledge on interpretation of biomarkers and the pharmacology of oxime therapy (12-50%) was noted, when compared with knowledge on the mechanism of OP poisoning and management (78-90%). CONCLUSIONS Our findings suggest an AChE POC test may not be valued by rural doctors. The practical use of AChE in OP poisoning management is complex, and a poor understanding of how to interpret test results may have affected its perceived utility. Future research should evaluate the impact of providing both AChE and training in interpretation on clinicians' attitudes and practice.
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Affiliation(s)
- Bishan N Rajapakse
- College of Medicine, Biology and Environment, Australian National University, Canberra, Australia.
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119
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Wang W, Chen QF, Li QB, Wu YB, Chen K, Chen B, Wen JM. Efficiency of anisodamine for organophosphorus-poisoned patients when atropinization cannot be achieved with high doses of atropine. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:477-481. [PMID: 24561530 DOI: 10.1016/j.etap.2013.12.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/14/2013] [Accepted: 12/19/2013] [Indexed: 06/03/2023]
Abstract
Poisoning by organophosphorus insecticides is a major global public health problem. Although atropine has been widely used to treat organophosphate (OP) poisoning, sometimes atropinization cannot be achieved, even with high doses of atropine. Hence, we aimed to assess the effect of anisodamine for organophosphorus poisoned patients for whom atropinization could not be achieved through high doses of atropine. In this study, sixty-four OP-poisoning patients, all of whom accepted routine treatments but who did not attain atropinization after high doses of atropine for 12 h, were enrolled. The result showed that the time to atropinization was 24.3±4.3 h in the anisodamine group, significantly shorter than in the atropine group (29.2±7.0 h, p<0.05); the hospital stay in the anisodamine group was 5.3±2.5 days, significantly shorter than the 6.9±2.3 days needed by the atropine group (p<0.05). We draw a conclusion that anisodamine can shorten the process of atropinization and hospital stay in organophosphorus poisoned patients for whom atropinization cannot be achieved with high doses of atropine.
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Affiliation(s)
- Wei Wang
- Department of Emergency, The First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Quan-Fang Chen
- Department of Respiratory, The First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Qi-Bin Li
- Department of Emergency, The First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Yan-Bin Wu
- Department of Respiratory, The First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China.
| | - Kun Chen
- Department of Emergency, The Second Affiliated Hospital, Guangxi Liuzhou Technical College of Medicine, 17 Jianpanshan Road, Liuzhou 545006, Guangxi, China.
| | - Bo Chen
- Department of Medicine, The Second Affiliated Hospital, Guangxi Liuzhou Technical College of Medicine, 17 Jianpanshan Road, Liuzhou 545006, Guangxi, China.
| | - Jian-Mei Wen
- Department of Medicine, The Second Affiliated Hospital, Guangxi Liuzhou Technical College of Medicine, 17 Jianpanshan Road, Liuzhou 545006, Guangxi, China.
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Kassa J, Sepsova V, Tumova M, Musilek K, Horova A. The evaluation of the reactivating and therapeutic efficacy of two novel oximes (K361 and K378) in comparison with the oxime K203 and trimedoxime in tabun-poisoned rats and mice. Toxicol Mech Methods 2013; 24:173-8. [DOI: 10.3109/15376516.2013.871766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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121
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Konickx LA, Worek F, Jayamanne S, Thiermann H, Buckley NA, Eddleston M. Reactivation of plasma butyrylcholinesterase by pralidoxime chloride in patients poisoned by WHO class II toxicity organophosphorus insecticides. Toxicol Sci 2013; 136:274-83. [PMID: 24052565 PMCID: PMC3858199 DOI: 10.1093/toxsci/kft217] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Some clinicians assess the efficacy of pralidoxime in organophosphorus (OP) poisoned patients by measuring reactivation of butyrylcholinesterase (BuChE). However, the degree of BuChE inhibition varies by OP insecticide, and it is unclear how well oximes reactivate BuChE in vivo. We aimed to assess the usefulness of BuChE activity to monitor pralidoxime treatment by studying its reactivation after pralidoxime administration to patients with laboratory-proven World Health Organization (WHO) class II OP insecticide poisoning. Patient data were derived from 2 studies, a cohort study (using a bolus treatment of 1g pralidoxime chloride) and a randomized controlled trial (RCT) (comparing 2g pralidoxime over 20min, followed by an infusion of 0.5g/h, with placebo). Two grams of pralidoxime variably reactivated BuChE in patients poisoned by 2 diethyl OP insecticides, chlorpyrifos and quinalphos; however, unlike acetylcholinesterase reactivation, this reactivation was not sustained. It did not reactivate BuChE inhibited by the dimethyl OPs dimethoate or fenthion. The 1-g dose produced no reactivation. Pralidoxime produced variable reactivation of BuChE in WHO class II OP-poisoned patients according to the pralidoxime dose administered, OP ingested, and individual patient. The use of BuChE assays for monitoring the effect of pralidoxime treatment is unlikely to be clinically useful.
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Affiliation(s)
- Lisa A Konickx
- * Department of Pharmacology, Toxicology, and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, EH16 4TJ, UK
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122
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Hong SP, Gibbs ST, Kobs DJ, Hawk MA, Croutch CR, Osheroff MR, Johnson JD, Burback BL. Comparative Toxicokinetics of MMB4 DMS in Rats, Rabbits, Dogs, and Monkeys Following Single and Repeated Intramuscular Administration. Int J Toxicol 2013; 32:38S-48S. [DOI: 10.1177/1091581813488631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
1,1′-Methylenebis[4-[(hydroxyimino)methyl]-pyridinium] (MMB4) dimethanesulfonate (DMS) is a bisquaternary pyridinium aldoxime that reactivates acetylcholinesterase inhibited by organophosphorus nerve agent. Time courses of MMB4 concentrations in plasma were characterized following 7-day repeated intramuscular (IM) administrations of MMB4 DMS to male and female Sprague-Dawley rats, New Zealand White rabbits, beagle dogs (single dose only), and rhesus monkeys at drug dose levels used in earlier toxicology studies. In general, there were no significant differences in MMB4 toxicokinetic (TK) parameters between males and females for all the species tested in these studies. After a single IM administration to rats, rabbits, dogs, and monkeys, MMB4 DMS was rapidly absorbed, resulting in average Tmax values ranging from 5 to 30 minutes. Although Cmax values did not increase dose proportionally, the overall exposure to MMB4 in these preclinical species, as indicated by area under the curve (AUC) extrapolated to the infinity (AUC∞) values, increased in an approximately dose-proportional manner. The MMB4 DMS was extensively absorbed into the systemic circulation after IM administration as demonstrated by greater than 80% absolute bioavailability values for rats, rabbits, and dogs. Repeated administrations of MMB4 DMS for 7 days did not overtly alter TK parameters for MMB4 in rats, rabbits, and monkeys (150 and 300 mg/kg/d dose groups only). However, Cmax and AUC values decreased in monkeys given 450 and 600 mg/kg IM doses of MMB4 DMS following repeated administrations for 7 days. Based on the TK results obtained from the current study and published investigations, it was found that the apparent volume of distribution and clearance values were similar among various preclinical species, except for the rat.
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123
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The value of novel oximes for treatment of poisoning by organophosphorus compounds. Pharmacol Ther 2013; 139:249-59. [DOI: 10.1016/j.pharmthera.2013.04.009] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 04/08/2013] [Indexed: 11/23/2022]
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124
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Cortés-Eslava J, Gómez-Arroyo S, Arenas-Huertero F, Flores-Maya S, Díaz-Hernández ME, Calderón-Segura ME, Valencia-Quintana R, Espinosa-Aguirre JJ, Villalobos-Pietrini R. The role of plant metabolism in the mutagenic and cytotoxic effects of four organophosphorus insecticides in Salmonella typhimurium and in human cell lines. CHEMOSPHERE 2013; 92:1117-1125. [PMID: 23434078 DOI: 10.1016/j.chemosphere.2013.01.058] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 01/09/2013] [Accepted: 01/14/2013] [Indexed: 06/01/2023]
Abstract
This study used a cell/microbe co-incubation assay to evaluate the effect of four organophosphorus insecticides (parathion-methyl, azinphos-methyl, omethoate, and methamidophos) metabolized by coriander (Coriandrum sativum). The reverse mutation of Salmonella typhimurium strains TA98 and TA100 was used as an indicator of genetic damage. Treatments with these insecticides inhibited peroxidase activity in plant cells by between 17% (omethoate) and 98% (azinphos-methyl) and decreased plant protein content by between 36% (omethoate) and 99.6% (azinphos-methyl). Azinphos-methyl was the most toxic when applied directly. In the Ames test, treatments applied directly to strain TA100 killed the bacteria; however, the presence of plant metabolism detoxified the system and permitted the growth of bacteria. In strain TA98, plant metabolites of insecticides were mutagenic. This result suggests that the tested pesticides produce mutations through frameshifting. The same pesticides were applied to human skin (HaCaT) and lung (NL-20) cell lines to evaluate their effects on cell viability. Pesticides applied directly were more cytotoxic than the combination of pesticide plus coriander metabolic fraction. Omethoate and methamidophos did not affect the viability of HaCaT cells, but azinphos-methyl and parathion-methyl at 100 and 1000μgmL(-1) significantly decreased viability (p<0.05). The NL-20 cell line was remarkably sensitive to the direct application of insecticides. All of the treatment conditions caused decreases in NL-20 cell viability (e.g., viability decreased to 12.0% after parathion-methyl treatment, to 14.7% after azinphos-methyl treatment, and to 6.9% after omethoate treatment). Similar to the Ames test, all of the insecticides showed decreased toxicity in human cells when they were cultured in the presence of plant metabolism. In conclusion, when the studied organophosphorus insecticides were plant-metabolized, they induced mutations in the bacterial strain TA98. In human cell lines, plant metabolism reduced the cytotoxic properties of the insecticides, and human keratinocytes were more resistant to mortality than bronchial cells.
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Affiliation(s)
- Josefina Cortés-Eslava
- Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, 04510 México, D.F., Mexico
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125
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Hua G, Du J, Slawin AMZ, Woollins JD. Fluorinated phosphorus-selenium heteroatom compounds: phenylphosphonofluorodiselenoic salts, adducts, and esters. Inorg Chem 2013; 52:8214-7. [PMID: 23815129 DOI: 10.1021/ic400612w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
2,4-Bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide, [PhP(Se)(μ-Se)]2, Woollins' reagent (WR), reacts with dry KF or tetrabutylammonium fluoride (TBAF) at room temperature generating the corresponding potassium and tetrabutylammonium phenyldiselenofluorophosphinates 1 and 2 in almost quantitative yields. Treating 1 with equimolar amounts of tetraphenylphosphonium chloride or 1,3-dimesityl-1H-imidazol-3-ium chloride in THF at room temperature afforded the corresponding organic adducts 3 and 4 in 90% and 87% yields. Reaction of 1 with mono- and dihalogenated alkanes gave a series of esters of phenylphosphonofluoridodiselenoates 5-8 and 9 in 79-93% yields. Two representative crystal structures are reported.
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Affiliation(s)
- Guoxiong Hua
- EaStCHEM School of Chemistry, University of St Andrews, Fife KY16 9ST, United Kingdom
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126
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Dhananjayan V, Ravichandran B, Anitha N, Rajmohan HR. Assessment of acetylcholinesterase and butyrylcholinesterase activities in blood plasma of agriculture workers. Indian J Occup Environ Med 2013; 16:127-30. [PMID: 23776322 PMCID: PMC3683181 DOI: 10.4103/0019-5278.111755] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background: Cholinesterase determination indicates whether the person has been under pesticide exposure is not. It is recommended that the worker′s cholinesterase level should be assessed for workers at a pesticide applied region. Hence, cholinesterase activities in blood samples of agricultural workers exposed to vegetables and grape cultivation with age matched, unexposed workers, who never had any exposure to pesticides, were estimated. Methods: The detailed occupational history and lifestyle characters were obtained by questionnaire. Cholinesterase activity was determined by the method of Ellman as modified by Chambers and Chambers. Results: AChE was ranging from 1.65 to 3.54μmoles/min/ml in exposed subjects where as it was ranged from 2.22 to 3.51μmoles/min/ml in control subjects. BChE activity was ranging from 0.16 to 5.2μmoles/min/ml among exposed subjects, where as it was ranged from 2.19 to 5.06μmoles/min/ml in control subjects. The results showed statistically significant reduction in enzyme activities (AChE 14%; BChE 56%) among exposed subjects. Conclusion: It was concluded that the reduction in cholinesterase activity may lead to varieties of effects. Hence it is compulsory to use protective gadgets during pesticide spray. Further a continuous biomonitoring study is recommended to assess pesticide exposure.
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Affiliation(s)
- V Dhananjayan
- Industrial Hygiene and Toxicology Division, Regional Occupational Health Centre (Southern), ICMR, Kannanmangala PO, Devenahalli TK, Bangalore, India
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127
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Jafarzadeh M, Nasri Nasrabadi Z, Sheikhazadi A, Abbaspour A, Vasigh S, Yousefinejad V, Marashi SM. Is there a role for progesterone in the management of acute organophosphate poisoning during pregnancy? Med Hypotheses 2013; 80:804-5. [DOI: 10.1016/j.mehy.2013.03.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 03/09/2013] [Indexed: 11/27/2022]
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128
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Hrabetz H, Thiermann H, Felgenhauer N, Zilker T, Haller B, Nährig J, Saugel B, Eyer F. Organophosphate poisoning in the developed world - a single centre experience from here to the millennium. Chem Biol Interact 2013; 206:561-8. [PMID: 23685200 DOI: 10.1016/j.cbi.2013.05.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/06/2013] [Accepted: 05/08/2013] [Indexed: 12/20/2022]
Abstract
Organophosphate (OP) poisoning is still associated with high morbidity and mortality rates, both in resource-poor settings and in well-developed countries. Despite numerous publications dealing with this particular poison, detailed clinical data on more severe overdoses with these agents are relatively sparsely reported. A retrospective study was consequently conducted on 33 patients with OP poisoning admitted to our intensive care unit (ICU) to provide additional data on clinical features. We included moderate to severe poisonings between 2000 and 2012 who required admission to ICU. Patients ingested dimethyl-OPs in 19 cases, diethyl-OPs in 8 cases and otherwise classified OPs in 6 cases. Death (5/33) occurred rather late and only one of these fatalities died during on-going cholinergic crisis. Of the survivors (28/33), 71% recovered fully while 29% showed predominantly neurological disabilities before being transferred to neurologic rehabilitation. Aspiration pneumonia predominated in 27/33 patients and one patient died in refractory acute respiratory distress syndrome (ARDS). The intermediate syndrome occurred twice and cardiopulmonary resuscitation had to be performed in 6/33 patients. Fatalities showed a higher Poison-severity-score, APACHE-II-score and SOFA-score on admission compared with survivors and they showed significantly longer QTc-time in the ECG, lower systolic blood pressure and heart rate, a lower pH and a lower base excess on admission. Patients with diethyl-OPs required intubation significantly earlier and showed lower and more sustained inhibited activity of the plasma-cholinesterase on admission compared with patients ingesting dimethyl-OPs. Treatment with atropine and obidoxime was comparable between these groups and severity of poisoning, outcome, hemodynamics on admission, duration of mechanical ventilation and length of stay in the ICU did not significantly differ between the involved group of dimethyl- and diethyl-OPs. We conclude that the fatality rate in our patient cohort treated in a well-staffed and equipped ICU of a developed country is quite similarly high compared with the rate observed in developing countries. Patients died rather late when severe cholinergic crisis had mostly been overcome and death was therefore related to non-poison specific complications.
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Affiliation(s)
- Heidi Hrabetz
- Department of Clinical Toxicology, II. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 Munich, Germany
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129
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Tang X, Wang R, Xie H, Hu J, Zhao W. Repeated pulse intramuscular injection of pralidoxime chloride in severe acute organophosphorus pesticide poisoning. Am J Emerg Med 2013; 31:946-9. [PMID: 23680326 DOI: 10.1016/j.ajem.2013.03.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 03/05/2013] [Accepted: 03/06/2013] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE This study aimed to clarify the efficacy of 2 therapies for patients with severe acute organophosphorus pesticide poisoning, including atropine adverse effects, the length of intensive care unit (ICU) stay, complications, and mortality. METHODS A retrospective cohort study of 152 cases collected from May 2008 to November 2012 at 2 urban university hospitals was conducted. Patients admitted to the hospital for organophosphate poisoning were divided into 2 groups with different therapeutic regimens: group A was administered a repeated pulse intramuscular injection of pralidoxime chloride, and group B received the same initial dosage of atropine and pralidoxime chloride, but pralidoxime chloride intravenous therapy was administered for only 3 days, regardless of the length of atropine therapy. Subsequently, atropine adverse effects, length of ICU stay, complications, and mortality were statistically analyzed and compared between the 2 groups. RESULTS The total dose of atropine was 57.40 ± 15.14 mg in group A and 308.26 ± 139.16 mg in group B; group A received less atropine than did group B (P = .001). The length of ICU stay in group A was reduced (P = .025), and group A had fewer atropine adverse effects (P = .002). However, there was no significant difference in the mortality or complication rate between the 2 groups (P > .05). CONCLUSION In patients with severe poisoning, group A used less atropine, had fewer atropine adverse effects, and had a shorter ICU stay. We suggest that therapy should be started as early as possible using a sufficient amount of pralidoxime chloride started intramuscularly in combination with atropine and that the drugs should not be prematurely discontinued.
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Affiliation(s)
- Xue Tang
- Intensive Care Unit, First People's Hospital Affiliated Shanghai Jiao Tong University, Shanghai, China
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130
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Abney CW, Knaack JLS, Ali AAI, Johnson RC. Novel Dual-Mode Immunomagnetic Method for Studying Reactivation of Nerve Agent-Inhibited Butyrylcholinesterase. Chem Res Toxicol 2013; 26:775-82. [DOI: 10.1021/tx4000717] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Carter W. Abney
- Oak Ridge Institute for Science
and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Jennifer L. S. Knaack
- Division of Laboratory Sciences,
National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Ahmed A. I. Ali
- Oak Ridge Institute for Science
and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Rudolph C. Johnson
- Division of Laboratory Sciences,
National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
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131
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Čolović MB, Krstić DZ, Lazarević-Pašti TD, Bondžić AM, Vasić VM. Acetylcholinesterase inhibitors: pharmacology and toxicology. Curr Neuropharmacol 2013; 11:315-35. [PMID: 24179466 PMCID: PMC3648782 DOI: 10.2174/1570159x11311030006] [Citation(s) in RCA: 1367] [Impact Index Per Article: 124.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 01/04/2013] [Accepted: 02/02/2013] [Indexed: 12/12/2022] Open
Abstract
Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer's disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases.
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Affiliation(s)
- Mirjana B Čolović
- Department of Physical Chemistry, Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
| | - Danijela Z Krstić
- University School of Medicine, Institute of Medical Chemistry, University of Belgrade, Belgrade, Serbia
| | - Tamara D Lazarević-Pašti
- Department of Physical Chemistry, Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
| | - Aleksandra M Bondžić
- Department of Physical Chemistry, Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
| | - Vesna M Vasić
- Department of Physical Chemistry, Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
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132
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Structural requirements for effective oximes – Evaluation of kinetic in vitro data with phosphylated human AChE and structurally different oximes. Chem Biol Interact 2013; 203:125-8. [DOI: 10.1016/j.cbi.2012.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 07/13/2012] [Indexed: 11/18/2022]
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133
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Gao X, Lin H, Ray R, Ray P. Toxicogenomic studies of human neural cells following exposure to organophosphorus chemical warfare nerve agent VX. Neurochem Res 2013; 38:916-34. [PMID: 23440544 DOI: 10.1007/s11064-013-0996-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/25/2013] [Accepted: 01/31/2013] [Indexed: 02/01/2023]
Abstract
Organophosphorus (OP) compounds represent an important group of chemical warfare nerve agents that remains a significant and constant military and civilian threat. OP compounds are considered acting primarily via cholinergic pathways by binding irreversibly to acetylcholinesterase, an important regulator of the neurotransmitter acetylcholine. Many studies over the past years have suggested that other mechanisms of OP toxicity exist, which need to be unraveled by a comprehensive and systematic approach such as genome-wide gene expression analysis. Here we performed a microarray study in which cultured human neural cells were exposed to 0.1 or 10 μM of VX for 1 h. Global gene expression changes were analyzed 6, 24, and 72 h post exposure. Functional annotation and pathway analysis of the differentially expressed genes has revealed many genes, networks and canonical pathways that are related to nervous system development and function, or to neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, and Parkinson's disease. In particular, the neuregulin pathway impacted by VX exposure has important implications in many nervous system diseases including schizophrenia. These results provide useful information valuable in developing suitable antidotes for more effective prevention and treatment of, as well as in developing biomarkers for, VX-induced chronic neurotoxicity.
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Affiliation(s)
- Xiugong Gao
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA.
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134
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Employment of pyridyl oximes and dioximes in zinc(II) chemistry: Synthesis, structural and spectroscopic characterization, and biological evaluation. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2012.09.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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135
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Verma AK, Srivastava AK, Singh B, Shah D, Shrivastava S, Shinde CKP. Alumina-supported oxime for the degradation of sarin and diethylchlorophosphate. CHEMOSPHERE 2013. [PMID: 23206531 DOI: 10.1016/j.chemosphere.2012.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
1-(4-Chlorophenyl))-N-hydroxymethanimine and cyclohexyl-N-hydroxymethanimine were synthesized and a well-established oxime, i.e., 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride was purchased. Thereafter; all were loaded over Al(2)O(3) using incipient wetness technique. The prepared systems were characterized using surface area analyzer, scanning electron microscope, energy dispersive X-ray spectrophotometer, Fourier transform infrared spectrophotometer and thermogravimetric analyzer. Kinetics of the degradation of sarin (GB) and simulant, i.e. diethylchlorophosphate (DEClP) was studied over synthesized oxime impregnated Al(2)O(3) and results were compared with well reported oxime impregnated Al(2)O(3). Kinetics of reaction was found to be following the pseudo first order reaction kinetics. The order of reactivity of the prepared systems was found to be cyclohexyl-N-hydroxymethanimine/Al(2)O(3)>1-(4-chlorophenyl)-N-hydroxymethanimine/Al(2)O(3)>2-[(hydroxyimino)methyl]-1-methylpyridinium chloride/Al(2)O(3)>Al(2)O(3). From the reaction kinetics it was observed that the reaction with DEClP was faster than with GB. Cyclohexyl-N-hydroxymethanimine/Al(2)O(3) was found to be the most reactive system with half-life of 0.94 and 15 h for DEClP and GB respectively.
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Affiliation(s)
- Aniza K Verma
- Defence Research and Development Establishment, Jhansi Road, Gwalior 474 002, MP, India
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136
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Bae AR, Lee J, Um IH. Decomposition of Paraoxon and Parathion by Amines, HOO-and OH-Ions: Reaction Mechanism and Origin of the α-Effect. B KOREAN CHEM SOC 2013. [DOI: 10.5012/bkcs.2013.34.1.201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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137
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Sterner TR, Ruark CD, Covington TR, Yu KO, Gearhart JM. A physiologically based pharmacokinetic model for the oxime TMB-4: simulation of rodent and human data. Arch Toxicol 2013; 87:661-80. [PMID: 23314320 DOI: 10.1007/s00204-012-0987-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 11/21/2012] [Indexed: 11/29/2022]
Abstract
Multiple oximes have been synthesized and evaluated for use as countermeasures against chemical warfare nerve agents. The current U.S. military and civilian oxime countermeasure, 2-[(hydroxyimino)methyl]-1-methylpyridin-1-ium chloride (2-PAM), is under consideration for replacement with a more effective acetylcholinesterase reactivator, 1,1'-methylenebis{4-hydroxyiminomethyl}pyridinium dimethanesulfonate (MMB-4). Kinetic data in the scientific literature for MMB-4 are limited; therefore, a physiologically based pharmacokinetic (PBPK) model was developed for a structurally related oxime, 1,1'-trimethylenebis{4-hydroximinomethyl}pyridinium dibromide. Based on a previous model structure for the organophosphate diisopropylfluorophosphate, the model includes key sites of acetylcholinesterase inhibition (brain and diaphragm), as well as fat, kidney, liver, rapidly perfused tissues and slowly perfused tissues. All tissue compartments are diffusion limited. Model parameters were collected from the literature, predicted using quantitative structure-property relationships or, when necessary, fit to available pharmacokinetic data from the literature. The model was parameterized using rat plasma, tissue and urine time course data from intramuscular administration, as well as human blood and urine data from intravenous and intramuscular administration; sensitivity analyses were performed. The PBPK model successfully simulates rat and human data sets and has been evaluated by predicting intravenous mouse and intramuscular human data not used in the development of the model. Monte Carlo analyses were performed to quantify human population kinetic variability in the human evaluation data set. The model identifies potential pharmacokinetic differences between rodents and humans, indicated by differences in model parameters between species. The PBPK model can be used to optimize the dosing regimen to improve oxime therapeutic efficacy in a human population.
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Affiliation(s)
- Teresa R Sterner
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 2729 R Street, Bldg 837, Wright-Patterson AFB, OH 45433-5707, USA.
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138
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Chung SP, Roh HK. Antidote for organophosphate insecticide poisoning: atropine and pralidoxime. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2013. [DOI: 10.5124/jkma.2013.56.12.1057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Sung Phil Chung
- Department of Emergency Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Hyung-Keun Roh
- Division of Clinical Pharmacology, Department of Internal Medicine, Gachon University Graduate School of Medicine, Incheon, Korea
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139
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Protein adducts as biomarkers of exposure to organophosphorus compounds. Toxicology 2012; 307:46-54. [PMID: 23261756 DOI: 10.1016/j.tox.2012.12.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 12/11/2012] [Accepted: 12/13/2012] [Indexed: 01/11/2023]
Abstract
Exposure to organophosphorus (OP) compounds can lead to serious neurological damage or death. Following bioactivation by the liver cytochromes P450, the OP metabolites produced are potent inhibitors of serine active-site enzymes including esterases, proteases and lipases. OPs may form adducts on other cellular proteins. Blood cholinesterases (ChEs) have long served as biomarkers of OP exposure in humans. However, the enzymatic assays used for biomonitoring OP exposures have several drawbacks. A more useful approach will focus on multiple biomarkers and avoid problems with the enzymatic activity assays. OP inhibitory effects result from a covalent bond with the active-site serine of the target enzymes. The serine OP adducts become irreversible following a process referred to as aging where one alkyl group dissociates over variable lengths of time depending on the OP adduct. The OP-adducted enzyme then remains in circulation until it is degraded, allowing for a longer window of detection compared with direct analysis of OPs or their metabolites. Mass spectrometry (MS) provides a very sensitive method for identification of post-translational protein modifications. MS analyses of the percentage adduction of the active-site serine of biomarker proteins such as ChEs will eliminate the need for basal activity levels of the individual and will provide for a more accurate determination of OP exposure. MS analysis of biomarker proteins also provides information about the OP that has caused inhibition. Other useful biomarker proteins include other serine hydrolases, albumin, tubulin and transferrin.
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140
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Brandhuber F, Zengerle M, Porwol L, Tenberken O, Thiermann H, Worek F, Kubik S, Reiter G. Detoxification of tabun at physiological pH mediated by substituted β-cyclodextrin and glucose derivatives containing oxime groups. Toxicology 2012; 302:163-71. [DOI: 10.1016/j.tox.2012.08.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 01/10/2023]
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141
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Moshiri M, Darchini-Maragheh E, Balali-Mood M. Advances in toxicology and medical treatment of chemical warfare nerve agents. ACTA ACUST UNITED AC 2012; 20:81. [PMID: 23351280 PMCID: PMC3556041 DOI: 10.1186/2008-2231-20-81] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 11/17/2012] [Indexed: 11/10/2022]
Abstract
Organophosphorous (OP) Nerve agents (NAs) are known as the deadliest chemical warfare agents. They are divided into two classes of G and V agents. Most of them are liquid at room temperature. NAs chemical structures and mechanisms of actions are similar to OP pesticides, but their toxicities are higher than these compounds. The main mechanism of action is irreversible inhibition of Acetyl Choline Esterase (AChE) resulting in accumulation of toxic levels of acetylcholine (ACh) at the synaptic junctions and thus induces muscarinic and nicotinic receptors stimulation. However, other mechanisms have recently been described. Central nervous system (CNS) depression particularly on respiratory and vasomotor centers may induce respiratory failure and cardiac arrest. Intermediate syndrome after NAs exposure is less common than OP pesticides poisoning. There are four approaches to detect exposure to NAs in biological samples: (I) AChE activity measurement, (II) Determination of hydrolysis products in plasma and urine, (III) Fluoride reactivation of phosphylated binding sites and (IV) Mass spectrometric determination of cholinesterase adducts. The clinical manifestations are similar to OP pesticides poisoning, but with more severity and fatalities. The management should be started as soon as possible. The victims should immediately be removed from the field and treatment is commenced with auto-injector antidotes (atropine and oximes) such as MARK I kit. A 0.5% hypochlorite solution as well as novel products like M291 Resin kit, G117H and Phosphotriesterase isolated from soil bacterias, are now available for decontamination of NAs. Atropine and oximes are the well known antidotes that should be infused as clinically indicated. However, some new adjuvant and additional treatment such as magnesium sulfate, sodium bicarbonate, gacyclidine, benactyzine, tezampanel, hemoperfusion, antioxidants and bioscavengers have recently been used for OP NAs poisoning.
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Affiliation(s)
- Mohammd Moshiri
- Medical Toxicology Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
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142
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Voicu V, Rădulescu FŞ, Medvedovici A. Toxicological considerations of acetylcholinesterase reactivators. Expert Opin Drug Metab Toxicol 2012; 9:31-50. [DOI: 10.1517/17425255.2013.736489] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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143
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Shahraki M, Habibi-Khorassani SM, Ebrahimi A, Maghsoodlou M, Ghalandarzehi Y. Intramolecular hydrogen bonding in chemoselective synthesized 2-substituted pyrrole stable phosphorus ylide: GIAO, AIM, and NBO approaches. Struct Chem 2012. [DOI: 10.1007/s11224-012-0114-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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144
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Lugokenski TH, Gubert P, Bueno DC, Nogara PA, de Aquino Saraiva R, Barcelos RP, Carratu VS, Bresolin L, de Vargas Barbosa NB, Pereira ME, da Rocha JBT, Soares FAA. Effect of different oximes on rat and human cholinesterases inhibited by methamidophos: a comparative in vitro and in silico study. Basic Clin Pharmacol Toxicol 2012; 111:362-70. [PMID: 22703537 DOI: 10.1111/j.1742-7843.2012.00912.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Accepted: 05/25/2012] [Indexed: 11/29/2022]
Abstract
Methamidophos is one of the most toxic organophosphorus (OP) compounds. It acts via phosphorylation of a serine residue in the active site of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), leading to enzyme inactivation. Different oximes have been developed to reverse this inhibition. Thus, our work aimed to test the protective or reactivation capability of pralidoxime and obidoxime, as well as two new oximes synthesised in our laboratory, on human and rat cholinesterases inhibited by methamidophos. In addition, we performed molecular docking studies in non-aged methamidophos-inhibited AChE to understand the mechanisms involved. Our results suggested that pralidoxime protected and reactivated methamidophos-inhibited rat brain AChE. Regarding human erythrocyte AChE, all oximes tested protected and reactivated the enzyme, with the best reactivation index observed at the concentration of 50 μM. Concerning BChE, butane-2,3-dionethiosemicarbazone oxime (oxime 1) was able to protect and reactivate the methamidophos-inhibited BChE by 45% at 50 μM, whereas 2(3-(phenylhydrazono)butan-2-one oxime (oxime 2) reactivated 28% of BChE activity at 100 μM. The two classical oximes failed to reactivate BChE. The molecular docking study demonstrated that pralidoxime appears to be better positioned in the active site to attack the O-P moiety of the inhibited enzyme, being near the oxyanion hole, whereas our new oximes were stably positioned in the active site in a manner similar to that of obidoxime. In conclusion, our work demonstrated that the newly synthesised oximes were able to reactivate not only human erythrocyte AChE but also human plasma BChE, which could represent an advantage in the treatment of OP compounds poisoning.
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145
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Koumousi ES, Zampakou M, Raptopoulou CP, Psycharis V, Beavers CM, Teat SJ, Psomas G, Stamatatos TC. First Palladium(II) and Platinum(II) Complexes from Employment of 2,6-Diacetylpyridine Dioxime: Synthesis, Structural and Spectroscopic Characterization, and Biological Evaluation. Inorg Chem 2012; 51:7699-710. [DOI: 10.1021/ic300739x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
| | - Marianthi Zampakou
- Department of General and Inorganic
Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki,
Greece
| | | | - Vassilis Psycharis
- Institute
of Materials Science, NCSR “Demokritos”, GR-153 10 Aghia Paraskevi
Attikis, Greece
| | - Christine M. Beavers
- Advanced
Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron
Road, Mail Stop 2-400, Berkeley, California 94720, United States
| | - Simon J. Teat
- Advanced
Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron
Road, Mail Stop 2-400, Berkeley, California 94720, United States
| | - George Psomas
- Department of General and Inorganic
Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki,
Greece
| | - Theocharis C. Stamatatos
- Department
of Chemistry, University of Patras, GR-265
04 Patras, Greece
- Department of General and Inorganic
Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki,
Greece
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146
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Acharya J, Rana H, Aditya Kapil V, Kaushik MP. In vitro reactivation of organophosphorus (OP)-inhibited electric eel acetylcholinesterase by novel monoquaternary pyridinium oximes. Med Chem Res 2012. [DOI: 10.1007/s00044-012-0128-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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147
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Vlček V, Pohanka M. CARBAMATE INSECTICIDES IN THE CZECH REPUBLIC: HEALTH AND ENVIRONMENTAL IMPACTS. ACTA ACUST UNITED AC 2012. [DOI: 10.31482/mmsl.2012.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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148
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Substitution of the Catalytic Metal and Protein PEGylation Enhances Activity and Stability of Bacterial Phosphotriesterase. Appl Biochem Biotechnol 2012; 166:1236-47. [DOI: 10.1007/s12010-011-9510-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 12/14/2011] [Indexed: 10/14/2022]
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149
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Herkert NM, Freude G, Kunz U, Thiermann H, Worek F. Comparative kinetics of organophosphates and oximes with erythrocyte, muscle and brain acetylcholinesterase. Toxicol Lett 2012; 209:173-8. [PMID: 22230262 DOI: 10.1016/j.toxlet.2011.12.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 12/20/2011] [Accepted: 12/23/2011] [Indexed: 11/27/2022]
Abstract
There is an ongoing debate whether oximes can effectively counteract the effects of organophosphorus compounds (OP) on brain acetylcholinesterase (AChE) activity and whether there are differences in the kinetic properties of brain and erythrocyte AChE. In order to investigate the kinetics of AChE from different tissues and species the well established dynamically working in vitro model with real-time determination of membrane-bound AChE activity was adapted for use with brain AChE. The enzyme reactor, that was loaded with brain, erythrocyte or muscle AChE, was continuously perfused with substrate and chromogen while AChE activity was on-line analyzed in a flow-through detector. It was possible to determine the Michaelis-Menten constants of human erythrocyte, muscle and brain AChE which were almost identical. In addition, the inhibition kinetics of sarin and paraoxon as well as the reactivation kinetics of obidoxime and HI 6 were determined with human, swine and guinea pig brain and erythrocyte AChE. It was found that the inhibition and reactivation kinetics of brain and erythrocyte AChE were highly comparable in all tested species. These data support the view that AChE from different tissue has similar kinetic properties and that brain AChE is comparably susceptible toward reactivation by oximes.
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Affiliation(s)
- Nadja M Herkert
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
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150
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Jokanović M, Škrbić R. Neurotoxic disorders and medical management of patients poisoned with organophosphorus pesticides. SCRIPTA MEDICA 2012. [DOI: 10.5937/scriptamed1202091j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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