RESUMEN
In life's constant battle for survival, it takes one to kill but two to conquer. Toxin-antitoxin or toxin-antidote (TA) elements are genetic dyads that cheat the laws of inheritance to guarantee their transmission to the next generation. This seemingly simple genetic arrangement-a toxin linked to its antidote-is capable of quickly spreading and persisting in natural populations. TA elements were first discovered in bacterial plasmids in the 1980s and have recently been characterized in fungi, plants, and animals, where they underlie genetic incompatibilities and sterility in crosses between wild isolates. In this review, we provide a unified view of TA elements in both prokaryotic and eukaryotic organisms and highlight their similarities and differences at the evolutionary, genetic, and molecular levels. Finally, we propose several scenarios that could explain the paradox of the evolutionary origin of TA elements and argue that these elements may be key evolutionary players and that the full scope of their roles is only beginning to be uncovered.
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Antitoxinas/genética , Toxinas Biológicas/genética , Animales , Antídotos , Bacterias/crecimiento & desarrollo , Proteínas Bacterianas/genética , Evolución Molecular , Humanos , Plásmidos/genéticaRESUMEN
Ferroptosis, a non-apoptotic form of cell death marked by iron-dependent lipid peroxidation1, has a key role in organ injury, degenerative disease and vulnerability of therapy-resistant cancers2. Although substantial progress has been made in understanding the molecular processes relevant to ferroptosis, additional cell-extrinsic and cell-intrinsic processes that determine cell sensitivity toward ferroptosis remain unknown. Here we show that the fully reduced forms of vitamin K-a group of naphthoquinones that includes menaquinone and phylloquinone3-confer a strong anti-ferroptotic function, in addition to the conventional function linked to blood clotting by acting as a cofactor for γ-glutamyl carboxylase. Ferroptosis suppressor protein 1 (FSP1), a NAD(P)H-ubiquinone reductase and the second mainstay of ferroptosis control after glutathione peroxidase-44,5, was found to efficiently reduce vitamin K to its hydroquinone, a potent radical-trapping antioxidant and inhibitor of (phospho)lipid peroxidation. The FSP1-mediated reduction of vitamin K was also responsible for the antidotal effect of vitamin K against warfarin poisoning. It follows that FSP1 is the enzyme mediating warfarin-resistant vitamin K reduction in the canonical vitamin K cycle6. The FSP1-dependent non-canonical vitamin K cycle can act to protect cells against detrimental lipid peroxidation and ferroptosis.
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Ferroptosis , Vitamina K , Antídotos/farmacología , Antioxidantes/metabolismo , Antioxidantes/farmacología , Ligasas de Carbono-Carbono/metabolismo , Coenzimas/metabolismo , Ferroptosis/efectos de los fármacos , Hidroquinonas/metabolismo , Hidroquinonas/farmacología , Peroxidación de Lípido/efectos de los fármacos , Oxidación-Reducción , Proteína de Unión al Calcio S100A4/metabolismo , Vitamina K/metabolismo , Vitamina K/farmacología , Warfarina/efectos adversosRESUMEN
Prokaryotic toxin-antitoxin (TA) systems are composed of a toxin capable of interfering with key cellular processes and its neutralizing antidote, the antitoxin. Here, we focus on the HEPN-MNT TA system encoded in the vicinity of a subtype I-D CRISPR-Cas system in the cyanobacterium Aphanizomenon flos-aquae. We show that HEPN acts as a toxic RNase, which cleaves off 4 nt from the 3' end in a subset of tRNAs, thereby interfering with translation. Surprisingly, we find that the MNT (minimal nucleotidyltransferase) antitoxin inhibits HEPN RNase through covalent di-AMPylation (diadenylylation) of a conserved tyrosine residue, Y109, in the active site loop. Furthermore, we present crystallographic snapshots of the di-AMPylation reaction at different stages that explain the mechanism of HEPN RNase inactivation. Finally, we propose that the HEPN-MNT system functions as a cellular ATP sensor that monitors ATP homeostasis and, at low ATP levels, releases active HEPN toxin.
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Antitoxinas/genética , Toxinas Bacterianas/genética , Ribonucleasas/genética , Sistemas Toxina-Antitoxina/genética , Adenosina Monofosfato/genética , Antídotos/química , Antitoxinas/metabolismo , Aphanizomenon/química , Aphanizomenon/genética , Sistemas CRISPR-Cas/genética , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismo , Ribonucleasas/metabolismo , Tirosina/genéticaRESUMEN
In this commentary, Sonne-Hansen and colleagues argue that research leaders and organizations should encourage more "theory-guessing" by budding young scientists, rather than incentivizing safe mainstream research.
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Antídotos , CreatividadRESUMEN
Mosquitoes of the Culex pipiens complex are worldwide vectors of arbovirus, filarial nematodes, and avian malaria agents. In these hosts, the endosymbiotic bacteria Wolbachia induce cytoplasmic incompatibility (CI), i.e., reduced embryo viability in so-called incompatible crosses. Wolbachia infecting Culex pipiens (wPip) cause CI patterns of unparalleled complexity, associated with the amplification and diversification of cidA and cidB genes, with up to 6 different gene copies described in a single wPip genome. In wPip, CI is thought to function as a toxin-antidote (TA) system where compatibility relies on having the right antidotes (CidA) in the female to bind and neutralize the male's toxins (CidB). By repeating crosses between Culex isofemale lines over a 17 years period, we documented the emergence of a new compatibility type in real time and linked it to a change in cid genes genotype. We showed that loss of specific cidA gene copies in some wPip genomes results in a loss of compatibility. More precisely, we found that this lost antidote had an original sequence at its binding interface, corresponding to the original sequence at the toxin's binding interface. We showed that these original cid variants are recombinant, supporting a role for recombination rather than point mutations in rapid CI evolution. These results strongly support the TA model in natura, adding to all previous data acquired with transgenes expression.
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Culex , Wolbachia , Animales , Femenino , Masculino , Wolbachia/genética , Antídotos/metabolismo , Mosquitos Vectores/genética , CitoplasmaRESUMEN
Simultaneous poisoning by carbon monoxide (CO) and hydrogen cyanide is the major cause of mortality in fire gas accidents. Here, we report on the invention of an injectable antidote against CO and cyanide (CN-) mixed poisoning. The solution contains four compounds: iron(III)porphyrin (FeIIITPPS, F), two methyl-ß-cyclodextrin (CD) dimers linked by pyridine (Py3CD, P) and imidazole (Im3CD, I), and a reducing agent (Na2S2O4, S). When these compounds are dissolved in saline, the solution contains two synthetic heme models including a complex of F with P (hemoCD-P) and another one of F with I (hemoCD-I), both in their iron(II) state. hemoCD-P is stable in its iron(II) state and captures CO more strongly than native hemoproteins, while hemoCD-I is readily autoxidized to its iron(III) state to scavenge CN- once injected into blood circulation. The mixed solution (hemoCD-Twins) exhibited remarkable protective effects against acute CO and CN- mixed poisoning in mice (~85% survival vs. 0% controls). In a model using rats, exposure to CO and CN- resulted in a significant decrease in heart rate and blood pressure, which were restored by hemoCD-Twins in association with decreased CO and CN- levels in blood. Pharmacokinetic data revealed a fast urinary excretion of hemoCD-Twins with an elimination half-life of 47 min. Finally, to simulate a fire accident and translate our findings to a real-life scenario, we confirmed that combustion gas from acrylic cloth caused severe toxicity to mice and that injection of hemoCD-Twins significantly improved the survival rate, leading to a rapid recovery from the physical incapacitation.
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Monóxido de Carbono , Porfirinas , Ratas , Ratones , Animales , Antídotos/farmacología , Oxígeno , Compuestos Férricos , Cianuros/toxicidad , Hierro , Compuestos FerrososRESUMEN
In this short Perspective, we discuss the history of, and recent progress toward, the development of aptamers that can serve as rapid onset anticoagulants during cardiopulmonary bypass (CPB), extracorporeal membrane oxygenation (ECMO), and catheter-based diagnostic and interventional procedures, several million of which are performed each year worldwide. Aptamer anticoagulants provide potent and antidote-controllable anticoagulation and have low immunogenicity. New methods of aptamer isolation and engineering have not only improved the quality of aptamers, but also accelerated their development. Unfortunately, no aptamer identified to date can produce an anticoagulant effect as potent as that produced by unfractionated heparin (UFH), the standard anticoagulant for CPB. We have suggested several possible strategies to amplify the anticoagulant potency of existing aptamer anticoagulants.
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Aptámeros de Nucleótidos , Heparina , Heparina/farmacología , Aptámeros de Nucleótidos/farmacología , Aptámeros de Nucleótidos/uso terapéutico , Coagulación Sanguínea , Anticoagulantes/farmacología , Anticoagulantes/uso terapéutico , Antídotos/farmacologíaRESUMEN
Injectable anticoagulants are widely used in medical procedures to prevent unwanted blood clotting. However, many lack safe, effective reversal agents. Here, we present new data on a previously described RNA origami-based, direct thrombin inhibitor (HEX01). We describe a new, fast-acting, specific, single-molecule reversal agent (antidote) and present in vivo data for the first time, including efficacy, reversibility, preliminary safety, and initial biodistribution studies. HEX01 contains multiple thrombin-binding aptamers appended on an RNA origami. It exhibits excellent anticoagulation activity in vitro and in vivo. The new single-molecule, DNA antidote (HEX02) reverses anticoagulation activity of HEX01 in human plasma within 30 s in vitro and functions effectively in a murine liver laceration model. Biodistribution studies of HEX01 in whole mice using ex vivo imaging show accumulation mainly in the liver over 24 h and with 10-fold lower concentrations in the kidneys. Additionally, we show that the HEX01/HEX02 system is non-cytotoxic to epithelial cell lines and non-hemolytic in vitro. Furthermore, we found no serum cytokine response to HEX01/HEX02 in a murine model. HEX01 and HEX02 represent a safe and effective coagulation control system with a fast-acting, specific reversal agent showing promise for potential drug development.
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Aptámeros de Nucleótidos , Trombina , Animales , Ratones , Humanos , Aptámeros de Nucleótidos/farmacología , Aptámeros de Nucleótidos/química , Trombina/metabolismo , Coagulación Sanguínea/efectos de los fármacos , Distribución Tisular , ARN , Modelos Animales de Enfermedad , Hígado/metabolismo , Hígado/efectos de los fármacos , Anticoagulantes/farmacología , Anticoagulantes/química , Antitrombinas/farmacología , Antídotos/farmacología , Antídotos/químicaRESUMEN
There do not appear to be any established therapeutics for treating azide poisoning at this time, and presently available antidotes to cyanide poisoning are far from ideal, being particularly impractical for use if multiple victims present. The cobalt (II/III) complex of the Schiff-base ligand trans-[14]-diene (5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (CoN4[14]) is shown to act as an effective antidote to both azide and cyanide toxicity in mice. Groups of animals challenged with an LD40 dose of NaCN (100 µmol/kg i.p.) exhibited significantly faster recovery from knockdown and fewer (zero) deaths if given CoN4[14] (50 µmol/kg i.p.) 2 minutes after the toxicant. Groups of animals challenged with an essentially lethal dose of NaCN (1.5 x LD50 = 150 µmol/kg i.p.) all survived if given the CoN4[14] (75 µmol/kg i.p.) 5 minutes before the toxicant dose. These data represent improved antidotal capability over the Food and Drug Administration-approved cobalt-based cyanide antidote hydroxocobalamin. Recovery of animals challenged sublethally with NaN3 (415 µmol/kg i.p.) was assessed employing a modified pole-climbing test. Mice given the CoN4[14] antidote (70 µg/kg i.p.) 5 minutes after the toxicant dose recovered twice as fast as the controls given no antidote. The interactions of cyanide and azide with CoN4[14] in vitro (buffered aqueous solutions) have been further investigated by a combination of spectroscopic approaches. The Co(II) form of the complex is able to bind two CN- anions while only binding a single N3 -, providing a reasonable explanation for the difference between their therapeutic abilities. SIGNIFICANCE STATEMENT: The Schiff-base complex CoN4[14] is shown to be an effective antidote to cyanide in mice, with improved therapeutic capabilities compared to the Food and Drug Administration-approved cobalt-containing hydroxocobalamin. CoN4[14] is also antidotal in mice toward azide poisoning, for which there is seemingly no approved therapy currently available. The activity toward cyanide involves a "redox-switching" mechanism that could be a common, but largely unrecognized, feature of all cobalt-based cyanide antidotes in use and under development.
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Antídotos , Hidroxocobalamina , Estados Unidos , Animales , Ratones , Antídotos/farmacología , Antídotos/uso terapéutico , Hidroxocobalamina/farmacología , Hidroxocobalamina/uso terapéutico , Azidas , Cobalto/química , Cianuros/química , Bases de Schiff/químicaRESUMEN
Inhalation of high levels of sulfur mustard (SM), a potent vesicating and alkylating agent used in chemical warfare, results in acutely lethal pulmonary damage. Sodium 2-mercaptoethane sulfonate (mesna) is an organosulfur compound that is currently Food and Drug Administration (FDA)-approved for decreasing the toxicity of mustard-derived chemotherapeutic alkylating agents like ifosfamide and cyclophosphamide. The nucleophilic thiol of mesna is a suitable reactant for the neutralization of the electrophilic group of toxic mustard intermediates. In a rat model of SM inhalation, treatment with mesna (three doses: 300 mg/kg intraperitoneally 20 minutes, 4 hours, and 8 hours postexposure) afforded 74% survival at 48 hours, compared with 0% survival at less than 17 hours in the untreated and vehicle-treated control groups. Protection from cardiopulmonary failure by mesna was demonstrated by improved peripheral oxygen saturation and increased heart rate through 48 hours. Additionally, mesna normalized arterial pH and pACO2 Airway fibrin cast formation was decreased by more than 66% in the mesna-treated group at 9 hour after exposure compared with the vehicle group. Finally, analysis of mixtures of a mustard agent and mesna by a 5,5'-dithiobis(2-nitrobenzoic acid) assay and high performance liquid chromatography tandem mass spectrometry demonstrate a direct reaction between the compounds. This study provides evidence that mesna is an efficacious, inexpensive, FDA-approved candidate antidote for SM exposure. SIGNIFICANCE STATEMENT: Despite the use of sulfur mustard (SM) as a chemical weapon for over 100 years, an ideal drug candidate for treatment after real-world exposure situations has not yet been identified. Utilizing a uniformly lethal animal model, the results of the present study demonstrate that sodium 2-mercaptoethane sulfonate is a promising candidate for repurposing as an antidote, decreasing airway obstruction and improving pulmonary gas exchange, tissue oxygen delivery, and survival following high level SM inhalation exposure, and warrants further consideration.
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Sustancias para la Guerra Química , Gas Mostaza , Ratas , Animales , Gas Mostaza/toxicidad , Mesna/farmacología , Mesna/uso terapéutico , Antídotos/farmacología , Antídotos/uso terapéutico , Pulmón , Sodio , Sustancias para la Guerra Química/toxicidadRESUMEN
PURPOSE OF REVIEW: Unintentional intoxication comprises a major chunk of all intoxications. Most patients are in the pediatric age group with another set of patients being the elderly. Substances found to cause accidental intoxication vary from country to country and even within different regions of a country. Frequent reviews of current literature are needed to be abreast of trends. RECENT FINDINGS: Prescription drugs and household chemicals are major culprits when it comes to accidental intoxication. Acetaminophen, digoxin and metformin are some of the prominent prescription drugs frequently associated with unintentional intoxications. Increasingly alcohol based hand sanitizers are becoming an important etiology of these events, following their increased usage during the COVID-19 pandemic. Pattern recognition to identify class of intoxicant and supportive care including prevention of further absorption and increased excretion are cornerstones of therapy. Antidote when available should be used promptly. SUMMARY: Knowledge about current epidemiology of accidental intoxications, toxidrome pattern recognition and appropriate antidote usage beside adequate and timely supportive care help in successful management of the unfortunate victim of accidental intoxication.
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Antídotos , Metformina , Humanos , Niño , Anciano , Pandemias , EtanolRESUMEN
Paraquat is a highly toxic quaternary ammonium herbicide. It can damage the functions of multiple organs and cause irreversible pulmonary fibrosis in the human body. However, the toxicological mechanism of paraquat is not yet fully understood, and due to the lack of specific antidotes, the clinical treatment of paraquat intoxication is still a great medical challenge. In-depth research on its toxicity mechanism, toxicokinetics, and effective antidotes is urgently demanded. A new molecular imaging technique, matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), can simultaneously achieve quantitative and spatial analysis and offer an alternative, distinct, and useful technique for paraquat intoxication and consequent detoxication. Here, we visualized the spatial-temporal distribution and conducted toxicokinetic research on paraquat in zebrafish by using stable isotope-labeled internal-standard-aided MALDI-MSI for the first time. The results indicated that paraquat had a fast absorption rate and was widely distributed in different organs, such as the brain, gills, kidneys, and liver in zebrafish. Its half-life was long, and the elimination rate was slow. Paraquat reached its peak at 30 min and was mainly distributed in kidneys and intestines and then showed a tendency of declining first but mildly rising later at 6 h, accompanied by a wide distribution in kidneys and intestines again. It suggested that entero-systemic recirculation might lead to the observed secondary peaks, and perhaps it extended the residence time of paraquat in the body. In addition, we validated the potential detoxification effect of sodium salicylate as a potential antidote for paraquat from both the dimensions of distribution and quantification. In conclusion, MALDI-MSI conveniently provided the distinct and quantitative spatial-temporal distribution information on paraquat in the whole body of zebrafish; it will promote the understanding of its toxicokinetic characteristics and provide more valuable information for clinical treatment.
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Paraquat , Pez Cebra , Animales , Humanos , Paraquat/toxicidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Antídotos , Toxicocinética , Rayos LáserRESUMEN
Paracetamol (acetaminophen) was marketed in the 1950s as a nonprescription analgesic/antipyretic without any preclinical toxicity studies. It became used increasingly for self-poisoning, particularly in the UK and was belatedly found to cause acute liver damage, which could be fatal. Management of poisoned patients was difficult as maximum abnormalities of liver function were delayed for 3 days or more after an overdose. There was no treatment and the mechanism of hepatotoxicity was not known. The paracetamol half-life was prolonged with liver damage occurring when it exceeded 4 h and the Rumack-Matthew nomogram was an important advance that allowed stratification of patients into separate zones of risk. It is used to guide prognosis and treatment and its predictive value could be increased by combining it with the paracetamol half-life. The problems of a sheep farmer in Australia in the early 1970s led to the discovery of the mechanism of paracetamol hepatotoxicity, and the first effective treatment of overdosage with intravenous (IV) cysteamine. This had unpleasant side effects and administration was difficult. N-acetylcysteine soon became the treatment of choice for paracetamol overdose and given early it was very effective when administered either IV or orally. N-acetylcysteine could cause anaphylactoid reactions, particularly early during IV administration when the concentrations were highest. Simpler and shorter regimes with slower initial rates of infusion have now been introduced with a reduced incidence of these adverse effects. In addition, there has been a move to use larger doses of N-acetylcysteine given over longer periods for patients who are more severely poisoned and those with risk factors. There has been much interest recently in the search for novel biomarkers such as microRNAs, procalcitonin and cyclophilin that promise to have greater specificity and sensitivity than transaminases. Paracetamol-protein adducts predict hepatotoxicity and are specific biomarkers of toxic paracetamol metabolite exposure. Another approach would be measurement of the plasma levels of cysteine and inorganic sulfate. It is 50 years since the first effective treatment for paracetamol poisoning and, apart from liver transplantation, there is still no effective treatment for patients who present late.
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Analgésicos no Narcóticos , Enfermedad Hepática Inducida por Sustancias y Drogas , Sobredosis de Droga , Hepatopatías , Humanos , Animales , Ovinos , Acetaminofén , Acetilcisteína/uso terapéutico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Sobredosis de Droga/tratamiento farmacológico , Hepatopatías/tratamiento farmacológico , Biomarcadores , Antídotos/uso terapéuticoRESUMEN
This study in vitro comprehensively assessed reversal of the anticoagulant effects of rivaroxaban, an oral factor Xa inhibitor, using andexanet alfa and various prothrombin complex concentrate (PCC) products in a battery of tests. In static coagulation assays, andexanet alpha outperformed PCCs except for activated PCC being more effective in standard coagulation times. However, in a flow chamber model mimicking arterial shear, both andexanet alpha and high-concentration PCC restored fibrin formation, but not platelet adhesion. In the Russell's viper venom test and anti-Xa assay, only andexanet alpha could be tested for efficacy. The antidote effects of andexanet alpha and PCCs in restoring coagulation can be qualitatively or selectively demonstrated using in vitro coagulation tests.
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Antídotos , Inhibidores del Factor Xa , Factor Xa , Humanos , Inhibidores del Factor Xa/farmacología , Antídotos/farmacología , Antídotos/uso terapéutico , Factores de Coagulación Sanguínea/farmacología , Factores de Coagulación Sanguínea/uso terapéutico , Rivaroxabán/farmacología , Factor IX , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Anticoagulantes/efectos adversosRESUMEN
Thrombosis leads to elevated mortality rates and substantial medical expenses worldwide. Human factor IXa (HFIXa) protease is pivotal in tissue factor (TF)-mediated thrombin generation, and represents a promising target for anticoagulant therapy. We herein isolated novel DNA aptamers that specifically bind to HFIXa through systematic evolution of ligands by exponential enrichment (SELEX) method. We identified two distinct aptamers, seq 5 and seq 11, which demonstrated high binding affinity to HFIXa (Kd = 74.07 ± 2.53 nM, and 4.93 ± 0.15 nM, respectively). Computer software was used for conformational simulation and kinetic analysis of DNA aptamers and HFIXa binding. These aptamers dose-dependently prolonged activated partial thromboplastin time (aPTT) in plasma. We further rationally optimized the aptamers by truncation and site-directed mutation, and generated the truncated forms (Seq 5-1t, Seq 11-1t) and truncated-mutated forms (Seq 5-2tm, Seq 11-2tm). They also showed good anticoagulant effects. The rationally and structurally designed antidotes (seq 5-2b and seq 11-2b) were competitively bound to the DNA aptamers and effectively reversed the anticoagulant effect. This strategy provides DNA aptamer drug-antidote pair with effective anticoagulation and rapid reversal, developing advanced therapies by safe, regulatable aptamer drug-antidote pair.
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Antídotos , Aptámeros de Nucleótidos , Factor IXa , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/farmacología , Humanos , Factor IXa/antagonistas & inhibidores , Factor IXa/metabolismo , Antídotos/farmacología , Antídotos/química , Antídotos/síntesis química , Relación Dosis-Respuesta a Droga , Anticoagulantes/farmacología , Anticoagulantes/química , Relación Estructura-Actividad , Estructura Molecular , Técnica SELEX de Producción de AptámerosRESUMEN
A-series agent A-234 belongs to a new generation of nerve agents. The poisoning of a former Russian spy Sergei Skripal and his daughter in Salisbury, England, in March 2018 led to the inclusion of A-234 and other A-series agents into the Chemical Weapons Convention. Even though five years have already passed, there is still very little information on its chemical properties, biological activities, and treatment options with established antidotes. In this article, we first assessed A-234 stability in neutral pH for subsequent experiments. Then, we determined its inhibitory potential towards human recombinant acetylcholinesterase (HssAChE; EC 3.1.1.7) and butyrylcholinesterase (HssBChE; EC 3.1.1.8), the ability of HI-6, obidoxime, pralidoxime, methoxime, and trimedoxime to reactivate inhibited cholinesterases (ChEs), its toxicity in rats and therapeutic effects of different antidotal approaches. Finally, we utilized molecular dynamics to explain our findings. The results of spontaneous A-234 hydrolysis showed a slow process with a reaction rate displaying a triphasic course during the first 72 h (the residual concentration 86.2%). A-234 was found to be a potent inhibitor of both human ChEs (HssAChE IC50 = 0.101 ± 0.003 µM and HssBChE IC50 = 0.036 ± 0.002 µM), whereas the five marketed oximes have negligible reactivation ability toward A-234-inhibited HssAChE and HssBChE. The acute toxicity of A-234 is comparable to that of VX and in the context of therapy, atropine and diazepam effectively mitigate A-234 lethality. Even though oxime administration may induce minor improvements, selected oximes (HI-6 and methoxime) do not reactivate ChEs in vivo. Molecular dynamics implies that all marketed oximes are weak nucleophiles, which may explain the failure to reactivate the A-234 phosphorus-serine oxygen bond characterized by low partial charge, in particular, HI-6 and trimedoxime oxime oxygen may not be able to effectively approach the A-234 phosphorus, while pralidoxime displayed low interaction energy. This study is the first to provide essential experimental preclinical data on the A-234 compound.
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Reactivadores de la Colinesterasa , Compuestos de Pralidoxima , Taurina/análogos & derivados , Ratas , Humanos , Animales , Reactivadores de la Colinesterasa/farmacología , Trimedoxima/farmacología , Butirilcolinesterasa , Acetilcolinesterasa , Oximas/farmacología , Compuestos de Piridinio/farmacología , Antídotos/farmacología , Inhibidores de la Colinesterasa/toxicidad , Fósforo , OxígenoRESUMEN
A 53-year-old male patient presented to a regional hospital Emergency Department approximately 2 h post an intentional ingestion of Coopers Instant Wetting Powder Sheep Dip (66% arsenic trioxide, 23% sulphur and 0.42% rotenone), mixed in 600 mL water, as a suicide attempt. On arrival to the Emergency Department, the patient had nausea, vomiting and diarrhoea. Seven hours post ingestion, hypotension developed (BP 90/60 mmHg) and intravenous fluids were commenced. He later developed QTc prolongation. He was treated with 2,3-Dimercapto-1-propanesulfonic acid (DMPS) and N-acetylcysteine and improved without development of neurology. Further investigation of NAC efficacy in humans in the setting of acute arsenic poisoning is required and the optimal duration of treatment and dosing needs to be established. This case highlights an uncommon poisoning which presented to the Emergency Department, the acute symptoms of arsenic toxicity and considerations for management.
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Acetilcisteína , Intoxicación por Arsénico , Arsenicales , Intento de Suicidio , Masculino , Humanos , Persona de Mediana Edad , Acetilcisteína/uso terapéutico , Trióxido de Arsénico/envenenamiento , Óxidos/envenenamiento , Antídotos/uso terapéutico , Unitiol/uso terapéuticoRESUMEN
INTRODUCTION: Extravasation is a potentially severe complication of intravenous administration of antineoplastic drugs. The limited data makes it difficult to develop an optimal management scheme. The objective of this study is to describe the clinical practice in the extravasation management of antineoplastic agents in Spanish centers. METHODS: An online survey was distributed to oncology pharmacists using the email distribution list of the Spanish Society of Hospital Pharmacists. Respondents were surveyed on the standard operational protocol (SOP) of extravasation, tissue damage risk classification, and specific measures of extravasation management. RESULTS: A total of 68 surveys were completed. A specific extravasation SOP was available in 82.4% centers. The pharmacist participates in the authorship (100%) and actively collaborates in extravasation management (76.5%). A tissue damage risk classification based on the three categories was mostly adopted (48.2%) and 73.2% applied specific criteria based on concentration and/or extravasated volume. Extravasation management was mainly performed with the application of physical measures and/or antidotes (91.2%). High variability in the choices of pharmacological and/or physical measures recommended is outstanding. CONCLUSION: The results of this study highlight the involvement of Spanish pharmacists in extravasation management, the application of physical measures and/or pharmacological measures as the method of choice in extravasation management, as well as the existing discrepancies in tissue damage risk classification and management recommendations.
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Antídotos , Antineoplásicos , Extravasación de Materiales Terapéuticos y Diagnósticos , Humanos , Antídotos/uso terapéutico , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Infusiones IntravenosasRESUMEN
METHODS: This study was designed as a cross-sectional, observational, retrospective study. The variables of the study were paracetamol overdose, demographic information, poisoning mechanisms, clinical, laboratory findings, and clinical progression of the cases. The cases compared in whom treatment was initiated within the first 8 hours after poisoning and those in whom it was not. χ 2 , t test, and logistic regression analyses were conducted at appropriate facilities. RESULTS: Three hundred forty-eight cases were included in the study. N-AC treatment was initiated within the first 8 hours after poisoning in 322 cases (92.5%), and 26 cases received N-AC treatment after 8 hours after poisoning. Liver toxicity developed in 6 cases (1.7%), and indications for liver transplantation were met in 36 cases (10.3%). Among the 26 cases for which treatment was not initiated within the first 8 hours, 18 cases (69.2%) had indications for liver transplantation ( P < 0.01). It was found that N-AC within the first 8 hours reduced the risk by 43 times ( P = 0.02) and being older than 6 years, being admitted to the intensive care unit, and having alanine aminotransferase values above 1000 U/L increased the risk significantly ( P = 0.009, P = 0.005, P < 0.001). When a receiver operating characteristic curve was plotted for the 4th-hour blood acetaminophen level to predict liver transplantation, a value of 684.5 µg/mL emerged with 89% sensitivity and 93% specificity (area under the curve, 0.951). CONCLUSIONS: As a result, this study demonstrates the protective effect of early-initiated N-AC therapy on liver toxicity in pediatric acetaminophen poisoning cases. It also highlights a significant impact of gastrointestinal decontamination methods.
Asunto(s)
Acetaminofén , Acetilcisteína , Enfermedad Hepática Inducida por Sustancias y Drogas , Humanos , Acetaminofén/envenenamiento , Estudios Retrospectivos , Femenino , Masculino , Estudios Transversales , Niño , Preescolar , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/epidemiología , Acetilcisteína/uso terapéutico , Lactante , Analgésicos no Narcóticos/envenenamiento , Sobredosis de Droga , Antídotos/uso terapéutico , Trasplante de Hígado , Adolescente , HígadoRESUMEN
PURPOSE OF REVIEW: The advent of direct oral anticoagulants (DOACs) marks a significant milestone in anticoagulant treatment. However, DOACs can exacerbate bleeding, which is challenging for the treating clinician, especially when combined with traumatic injury. RECENT FINDINGS: In major bleeding associated with DOACs, rapid reversal of the anticoagulant effects is crucial. Recent observational and nonrandomized interventional trials have demonstrated the effectiveness of the specific antidotes andexanet alfa and idarucizumab as well as the unspecific prothrombin complex concentrates (PCCs) to counteract the anticoagulant effects of DOACs. The European Society of Anaesthesiology and Intensive Care guideline for severe perioperative bleeding and the European trauma guideline propose divergent recommendations for the use of andexanet alfa and PCC to obtain hemostasis in Factor Xa inhibitor-related bleeding. The conflicting recommendations are due to limited evidence from clinical studies and the potential increased risk of thromboembolic complications after the administration of andexanet. Regarding dabigatran-associated major bleeding, both guidelines recommend the specific reversal agent idarucizumab as first-line therapy. SUMMARY: Current guidelines recommend specific antidots and PCCs in DOAC-related major bleeding. Prospective randomized trials comparing specific vs. nonspecific hemostatic agents in the perioperative setting are needed to evaluate the effectiveness and safety of the hemostatic agents.