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Zinenko O, Durkin DM, Carter RW, Ritter B, Lewin MR. Cold Finger: Raynaud Phenomenon Following Snakebite Envenoming by Nikolsky's Viper ( Vipera berus nikolskii). Toxins (Basel) 2023; 15:598. [PMID: 37888629 PMCID: PMC10610580 DOI: 10.3390/toxins15100598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 10/28/2023] Open
Abstract
A field biologist was bitten by a female Nikolsky's viper (Vipera berus nikolskii) in Kharkiv Oblast, Ukraine. Two months later, the patient began to experience cold-induced vasospasm of the affected digit diagnosed as acquired Raynaud phenomenon. The patient had more than 30 occurrences during the single winter following the bite, but the signs and symptoms of Raynaud phenomenon disappeared with the end of winter. This report describes the case and puts it into context with the literature on the topic of toxin-induced peripheral vasospastic disorders and their potential importance in snakebite envenoming.
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Affiliation(s)
- Oleksandr Zinenko
- V. N. Karazin Kharkiv University, 61058 Kharkiv, Ukraine;
- California Academy of Sciences, San Francisco, CA 94118, USA;
| | | | | | - Brandi Ritter
- Ophirex, Inc., Corte Madera, CA 94925, USA; (R.W.C.); (B.R.)
| | - Matthew R. Lewin
- California Academy of Sciences, San Francisco, CA 94118, USA;
- Ophirex, Inc., Corte Madera, CA 94925, USA; (R.W.C.); (B.R.)
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Salim A, Williams J, Abdel Wahab S, Adeshokan T, Almeida JR, Williams HF, Vaiyapuri R, Senthilkumaran S, Thirumalaikolundusubramanian P, Patel K, Baksh MF, Lewin MR, Vaiyapuri S. Identifying key factors contributing to treatment costs for snakebite envenoming in private tertiary healthcare settings in Tamil Nadu, India. PLoS Negl Trop Dis 2023; 17:e0011699. [PMID: 37844081 PMCID: PMC10602377 DOI: 10.1371/journal.pntd.0011699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/26/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND India suffers ~58,000 annual deaths due to snakebites. The 'Big Four' snakes (Russell's viper, Indian cobra, common krait, and saw-scaled viper) that are responsible for most bites cause diverse clinical effects. Delayed treatment increases the risk of serious complications and treatment costs. Although government hospitals offer free treatment for snakebites in India, most patients opt for private healthcare, which is an out-of-pocket expense as they often lack health insurance coverage. This study aims to analyse snakebite treatment costs in private tertiary care hospitals in Tamil Nadu, India and identifies the key factors contributing to treatment costs. METHODOLOGY/PRINCIPAL FINDINGS The treatment cost details for 913 snakebite victims were collected from 10 private tertiary care hospitals across Tamil Nadu. The data were classified into hospital, pharmacy, investigation, and laboratory costs, and analysed to determine various factors that contribute to the costs. The results demonstrate that the average treatment costs vary widely for different snakes. The hospital and pharmacy costs are higher than investigation and laboratory costs for all snakebites. Notably, Russell's viper bites cost significantly more than the bites from other snakes. Overall, the type of snake, nature of complications, specialist treatments required, and arrival time to hospitals were identified as some of the key factors for higher treatment costs. CONCLUSIONS/SIGNIFICANCE These data demonstrate that ~80% of snakebite patients can be treated with INR 100,000 (~GBP 1000 or USD 1200) or less. This study emphasises the urgent need to improve rural medical care by providing appropriate training for healthcare professionals and essential resources to facilitate early assessment of patients, administer the initial dose of antivenom and refer the patients to tertiary care only when needed. Moreover, the outcome of this study forms a basis for developing appropriate policies to regulate snakebite treatment costs and provide affordable medical insurance for vulnerable communities.
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Affiliation(s)
- Anika Salim
- School of Pharmacy, University of Reading, Reading, United Kingdom
| | - Jarred Williams
- School of Pharmacy, University of Reading, Reading, United Kingdom
| | | | - Tade Adeshokan
- School of Pharmacy, University of Reading, Reading, United Kingdom
| | - José R. Almeida
- School of Pharmacy, University of Reading, Reading, United Kingdom
| | | | | | | | | | - Ketan Patel
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - M. Fazil Baksh
- Department of Mathematics and Statistics, University of Reading, Reading, United Kingdom
| | - Matthew R. Lewin
- California Academy of Sciences, San Francisco, California, United States of America
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Gilliam LL, Gilliam J, Samuel SP, Carter RW, Ritchey J, Bulfone T, Gutiérrez JM, Williams DJ, Durkin DM, Stephens SI, Lewin MR. Oral and IV Varespladib Rescue Experiments in Juvenile Pigs with Weakness Induced by Australian and Papuan Oxyuranus scutellatus Venoms. Toxins (Basel) 2023; 15:557. [PMID: 37755983 PMCID: PMC10537020 DOI: 10.3390/toxins15090557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/02/2023] [Accepted: 08/17/2023] [Indexed: 09/28/2023] Open
Abstract
Antivenom is currently the standard-of-care treatment for snakebite envenoming, but its efficacy is limited by treatment delays, availability, and in many cases, species specificity. Many of the rapidly lethal effects of envenoming are caused by venom-derived toxins, such as phospholipase A2 (sPLA2); therefore, small molecule direct toxin inhibitors targeting these toxins may have utility as initial and adjunct therapies after envenoming. Varespladib (intravenous, IV) and varespladib-methyl (oral) have been shown to potently inhibit sPLA2s from snake venoms in murine and porcine models, thus supporting their further study as potential treatments for snakebite envenoming. In this pilot study, we tested the ability of these compounds to reverse neurotoxic effects of venom from the Australian and Papuan taipan (Oxyuranus scutellatus) subspecies in juvenile pigs (Sus domesticus). The mean survival time for control animals receiving Australian taipan venom (0.03 mg/kg, n = 3) was 331 min ± 15 min; for those receiving Papuan taipan venom (0.15 mg/kg, n = 3) it was 178 ± 31 min. Thirteen pigs received Australian taipan venom and treatment with either IV or oral varespladib (or with IV to oral transition) and all 13 survived the duration of the study (≥96 h). Eight pigs received Papuan taipan venom followed by treatment: Briefly: Two animals received antivenom immediately and survived to the end of the study. Two animals received antivenom treatment delayed 45 min from envenoming and died within 4 h. Two animals received similarly delayed antivenom treatment and were rescued by varespladib. Two animals were treated with varespladib alone after a 45-min delay. Treatment with varespladib only was effective but required repeat dosing over the course of the study. Findings highlight both the importance of early treatment and, as well, a half-life for the investigational inhibitors now in Phase II clinical trials for snakebite. Varespladib rapidly reversed weakness even when administered many hours post-envenoming and, overall, our results suggest that varespladib and varespladib-methyl could be efficacious tools in the treatment of sPLA2-induced weakness from Oxyuranus envenoming. Further clinical study as initial therapy and as potential method of rescue from some types of antivenom-resistant envenomings are supported by these data.
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Affiliation(s)
- Lyndi L. Gilliam
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA; (L.L.G.); (J.G.); (J.R.)
| | - John Gilliam
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA; (L.L.G.); (J.G.); (J.R.)
| | - Stephen P. Samuel
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
| | - Rebecca W. Carter
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
| | - Jerry Ritchey
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA; (L.L.G.); (J.G.); (J.R.)
| | - Tommaso Bulfone
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA; (T.B.)
- School of Medicine, University of California, San Francisco, CA 94143, USA
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica;
| | - David J. Williams
- Regulation and Prequalification Department (RPQ) at the World Health Organization (WHO), 1211 Geneva, Switzerland;
| | - Daniela M. Durkin
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA; (T.B.)
| | - Sally I. Stephens
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
| | - Matthew R. Lewin
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA; (T.B.)
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Salvador GHM, Pinto ÊKR, Ortolani PL, Fortes-Dias CL, Cavalcante WLG, Soares AM, Lomonte B, Lewin MR, Fontes MRM. Structural basis of the myotoxic inhibition of the Bothrops pirajai PrTX-I by the synthetic varespladib. Biochimie 2023; 207:1-10. [PMID: 36403756 DOI: 10.1016/j.biochi.2022.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
Varespladib (LY315920) is a potent inhibitor of human group IIA phospholipase A2 (PLA2) originally developed to control inflammatory cascades of diseases associated with high or dysregulated levels of endogenous PLA2. Recently, varespladib was also found to inhibit snake venom PLA2 and PLA2-like toxins. Herein, ex vivo neuromuscular blocking activity assays were used to test the inhibitory activity of varespladib. The binding affinity between varespladib and a PLA2-like toxin was quantified and compared with other potential inhibitors for this class of proteins. Crystallographic and bioinformatic studies showed that varespladib binds to PrTX-I and BthTX-I into their hydrophobic channels, similarly to other previously characterized PLA2-like myotoxins. However, a new finding is that an additional varespladib binds to the MDiS region, a particular site that is related to muscle cell disruption by these toxins. The present results further advance the characterization of the molecular interactions of varespladib with PLA2-like myotoxins and provide additional evidence for this compound as a promising inhibitor candidate for different PLA2 and PLA2-like toxins.
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Affiliation(s)
- Guilherme H M Salvador
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Êmylle K R Pinto
- Departmento de Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais (UFMG), Brazil
| | - Paula L Ortolani
- Centro de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias (FUNED), Brazil
| | | | - Walter L G Cavalcante
- Departmento de Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais (UFMG), Brazil
| | - Andreimar M Soares
- Laboratório de Biotecnologia de Proteínas e Compostos Bioativos Aplicados à Saúde, LABIOPROT, Fundação Oswaldo Cruz, FIOCRUZ, unidade Rondônia e Instituto Nacional de Ciência e Tecnologia de Epidemiologia da Amazônia Ocidental, INCT EPIAMO, Porto Velho, RO, Brazil
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Matthew R Lewin
- Ophirex, Inc. Corte Madera, CA, 94925, USA; Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA, 94118, USA
| | - Marcos R M Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil.
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Bickler PE, Abouyannis M, Bhalla A, Lewin MR. Neuromuscular Weakness and Paralysis Produced by Snakebite Envenoming: Mechanisms and Proposed Standards for Clinical Assessment. Toxins (Basel) 2023; 15:49. [PMID: 36668869 PMCID: PMC9861841 DOI: 10.3390/toxins15010049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/23/2022] [Accepted: 12/10/2022] [Indexed: 01/11/2023] Open
Abstract
Respiratory and airway-protective muscle weakness caused by the blockade of neuromuscular transmission is a major cause of early mortality from snakebite envenoming (SBE). Once weakness is manifest, antivenom appears to be of limited effectiveness in improving neuromuscular function. Herein, we review the topic of venom-induced neuromuscular blockade and consider the utility of adopting clinical management methods originally developed for the safe use of neuromuscular blocking agents by anesthesiologists in operating rooms and critical care units. Failure to quantify neuromuscular weakness in SBE is predicted to cause the same significant morbidity that is associated with failure to do so in the context of using a clinical neuromuscular block in surgery and critical care. The quantitative monitoring of a neuromuscular block, and an understanding of its neurophysiological characteristics, enables an objective measurement of weakness that may otherwise be overlooked by traditional clinical examination at the bedside. This is important for the initial assessment and the monitoring of recovery from neurotoxic envenoming. Adopting these methods will also be critical to the conduct of future clinical trials of toxin-inhibiting drugs and antivenoms being tested for the reversal of venom-induced neuromuscular block.
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Affiliation(s)
- Philip E. Bickler
- Center for Exploration and Travel Health, California Academy of Science, San Francisco, CA 94118, USA
- Anesthesia and Perioperative Care, University of California at San Francisco, 513 Parnassus Ave, Medical Science Room S-257, San Francisco, CA 94143-0542, USA
| | - Michael Abouyannis
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Ashish Bhalla
- Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Matthew R. Lewin
- Center for Exploration and Travel Health, California Academy of Science, San Francisco, CA 94118, USA
- Ophirex, Inc., Corte Madera, CA 94925, USA
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Carter RW, Gerardo CJ, Samuel SP, Kumar S, Kotehal SD, Mukherjee PP, Shirazi FM, Akpunonu PD, Bammigatti C, Bhalla A, Manikath N, Platts-Mills TF, Lewin MR. The BRAVO Clinical Study Protocol: Oral Varespladib for Inhibition of Secretory Phospholipase A2 in the Treatment of Snakebite Envenoming. Toxins (Basel) 2022; 15:22. [PMID: 36668842 PMCID: PMC9862656 DOI: 10.3390/toxins15010022] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/19/2022] [Accepted: 12/24/2022] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Snakebite is an urgent, unmet global medical need causing significant morbidity and mortality worldwide. Varespladib is a potent inhibitor of venom secretory phospholipase A2 (sPLA2) that can be administered orally via its prodrug, varespladib-methyl. Extensive preclinical data support clinical evaluation of varespladib as a treatment for snakebite envenoming (SBE). The protocol reported here was designed to evaluate varespladib-methyl for SBE from any snake species in multiple geographies. METHODS AND ANALYSIS BRAVO (Broad-spectrum Rapid Antidote: Varespladib Oral for snakebite) is a multicenter, randomized, double-blind, placebo-controlled, phase 2 study to evaluate the safety, tolerability, and efficacy of oral varespladib-methyl plus standard of care (SoC) vs. SoC plus placebo in patients presenting with acute SBE by any venomous snake species. Male and female patients 5 years of age and older who meet eligibility criteria will be randomly assigned 1:1 to varespladib-methyl or placebo. The primary outcome is the Snakebite Severity Score (SSS) that has been modified for international use. This composite outcome is based on the sum of the pulmonary, cardiovascular, nervous, hematologic, and renal systems components of the updated SSS. ETHICS AND DISSEMINATION This protocol was submitted to regulatory authorities in India and the US. A Clinical Trial No Objection Certificate from the India Central Drugs Standard Control Organisation, Drug Controller General-India, and a Notice to Proceed from the US Food and Drug Administration have been obtained. The study protocol was approved by properly constituted, valid institutional review boards or ethics committees at each study site. This study is being conducted in compliance with the April 1996 ICH Guidance for Industry GCP E6, the Integrated Addendum to ICH E6 (R2) of November 2016, and the applicable regulations of the country in which the study is conducted. The trial is registered on Clinical trials.gov, NCT#04996264 and Clinical Trials Registry-India, 2021/07/045079 000062.
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Affiliation(s)
| | - Charles J. Gerardo
- Department of Emergency Medicine, Duke University, Durham, NC 27708, USA
| | | | - Surendra Kumar
- Department of Medicine, Sardar Patel Medical College, PBM Hospital, Bikaner 334001, India
| | - Suneetha D. Kotehal
- Department of Medicine, Mysore Medical College and Research Institute, Mysore 570001, India
| | - Partha P. Mukherjee
- Department of General Medicine, Calcutta National Medical College, Kolkata 700014, India
| | - Farshad M. Shirazi
- Arizona Poison & Drug Information Center, College of Pharmacy and University of Arizona College of Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Peter D. Akpunonu
- Department of Emergency Medicine and Medical Toxicology, University of Kentucky College of Medicine, Lexington, KY 40506, USA
| | - Chanaveerappa Bammigatti
- Department of Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605006, India
| | - Ashish Bhalla
- Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Neeraj Manikath
- Department of Emergency Medicine, Government Medical College, Kozhikode 673008, India
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Chowdhury A, Lewin MR, Carter RW, Casewell NR, Fry BG. Keel venom: Rhabdophis subminiatus (red-necked keelback) venom pathophysiologically affects diverse blood clotting pathways. Toxicon 2022; 218:19-24. [PMID: 36057394 DOI: 10.1016/j.toxicon.2022.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/02/2022] [Accepted: 08/24/2022] [Indexed: 10/14/2022]
Abstract
Venoms are evolutionary novelties that have real-world implications due to their impact upon human health. However, relative to the abundant studies of elapid and viperid snake venoms, fewer investigations have been undertaken on those of rear-fanged snakes as they are more problematic for obtaining venom. While most rear-fanged venomous snakes are not considered to be of great medical importance, several species are capable of producing fatalities. Most notable among these are snakes from the genus Rhabdophis, the Asian "keelback" snakes. Prior work have described potent procoagulant toxicity suggesting Factor X and prothrombin activation, but did not investigate the ability to activate other clotting factors. Here we show that in addition to activating both Factor X and prothrombin (with prothrombin twice that of FX), the venom of Rhabdophis subminiatus is able to more potently activate Factor VII (ten times that of prothrombin), while also activating FXII and FIX equipotently to prothrombin, and with FXI also activated but at a much lower level. The ability to activate FVII represents a third convergent evolution of this trait. The Australian elapid clade of [Oxyuranus (taipans) + Pseudonaja (brown snakes)] was the first identified to have evolved this trait. and only recently was it shown to be independently present in another lineage (the Central American viperid species Porthidium volcanicum). In addition, the abilities to activate FXI and FXII are also convergent between R. subminiatus and P. volcanicum, but with R. subminiatus being much more potent. By testing across amphibian, avian, and mammalian plasmas we demonstrate that the venom is potently procoagulant across diverse plasma types. However, consistent with dietary preference, R. subminiatus venom was most potent upon amphibian plasma. While a Rhabdophis antivenom is produced in Japan to treat R. tigrinus envenomings, it is scarce even within Japan and is not exported. As this genus is very wide-ranging in Asia, alternate treatment options are in need of development. Hence we tested the ability of candidate, broad-spectrum enzyme inhibitors to neutralize R. subminiatus venom: marimastat was more effective than prinomastat but both marimastat and prinomastat were significantly more effective than DMPS (2,3-Dimercapto-1-propanesulfonic acid). The findings of this study shed light on the evolution of these fascinating rear-fanged snakes as well as explored their systemic effects upon blood coagulation and point to potential treatment options for the rare, but potentially lethal encounters.
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Affiliation(s)
- Abhinandan Chowdhury
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia; Department of Biochemistry & Microbiology, North South University, Dhaka, Bangladesh.
| | - Matthew R Lewin
- Ophirex Inc., Corte Madera, CA, 94925, USA; California Academy of Sciences, San Francisco, CA, 94118, USA
| | | | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Bryan G Fry
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia.
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Jones L, Youngman NJ, Neri-Castro E, Guadarrama-Martínez A, Lewin MR, Carter R, Frank N, Fry BG. Differential Antivenom and Small-Molecule Inhibition of Novel Coagulotoxic Variations in Atropoides, Cerrophidion, Metlapilcoatlus, and Porthidium American Viperid Snake Venoms. Toxins (Basel) 2022; 14:toxins14080511. [PMID: 35893753 PMCID: PMC9332056 DOI: 10.3390/toxins14080511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 02/04/2023] Open
Abstract
Within Neotropical pit-vipers, the Mexican/Central-American clade consisting of Atropoides, Cerrophidion, Metlapilcoatlus, and Porthidium is a wide-ranging, morphologically and ecologically diverse group of snakes. Despite their prevalence, little is known of the functional aspects of their venoms. This study aimed to fill the knowledge gap regarding coagulotoxic effects and to examine the potential of different therapeutic approaches. As a general trait, the venoms were shown to be anticoagulant but were underpinned by diverse biochemical actions. Pseudo-procoagulant activity (i.e., thrombin-like), characterized by the direct cleavage of fibrinogen to form weak fibrin clots, was evident for Atropoides picadoi, Cerrophidiontzotzilorum, Metlapilcoatlus mexicanus, M. nummifer, M. occiduus, M. olmec, and Porthidium porrasi. In contrast, other venoms cleaved fibrinogen in a destructive (non-clotting) manner, with C. godmani and C. wilsoni being the most potent. In addition to actions on fibrinogen, clotting enzymes were also inhibited. FXa was only weakly inhibited by most species, but Cerrophidion godmani and C. wilsoni were extremely strong in their inhibitory action. Other clotting enzymes were more widely inhibited by diverse species spanning the full taxonomical range, but in each case, there were species that had these traits notably amplified relatively to the others. C. godmani and C. wilsoni were the most potent amongst those that inhibited the formation of the prothrombinase complex and were also amongst the most potent inhibitors of Factor XIa. While most species displayed only low levels of thrombin inhibition, Porthidium dunni potently inhibited this clotting factor. The regional polyvalent antivenom produced by Instituto Picado Clodomiro was tested and was shown to be effective against the diverse anticoagulant pathophysiological effects. In contrast to the anticoagulant activities of the other species, Porthidium volcanicum was uniquely procoagulant through the activation of Factor VII and Factor XII. This viperid species is the first snake outside of the Oxyuranus/Pseudonaja elapid snake clade to be shown to activate FVII and the first snake venom of any kind to activate FXII. Interestingly, while small-molecule metalloprotease inhibitors prinomastat and marimastat demonstrated the ability to prevent the procoagulant toxicity of P. volcanicum, neither ICP antivenom nor inhibitor DMPS showed this effect. The extreme variation among the snakes here studied underscores how venom is a dynamic trait and how this can shape clinical outcomes and influence evolving treatment strategies.
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Affiliation(s)
- Lee Jones
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia;
- Correspondence: (L.J.); (B.G.F.)
| | - Nicholas J. Youngman
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia;
| | - Edgar Neri-Castro
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Mexico; (E.N.-C.); (A.G.-M.)
| | - Alid Guadarrama-Martínez
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Mexico; (E.N.-C.); (A.G.-M.)
| | | | - Rebecca Carter
- Ophirex Inc., Corte Madera, CA 94925, USA; (M.R.L.); (R.C.)
| | | | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia;
- Correspondence: (L.J.); (B.G.F.)
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Chowdhury A, Youngman NJ, Liu J, Lewin MR, Carter RW, Fry BG. The relative efficacy of chemically diverse small-molecule enzyme-inhibitors against anticoagulant activities of Black Snake (Pseudechis spp.) venoms. Toxicol Lett 2022; 366:26-32. [PMID: 35788045 DOI: 10.1016/j.toxlet.2022.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/31/2022] [Accepted: 06/28/2022] [Indexed: 11/28/2022]
Abstract
Snakebite remains a worldwide public health burden and a severely neglected tropical disease. Recent research has begun to focus on the potential use of repurposed small-molecule enzyme-inhibitors as early treatments to neutralise the effects of snake venoms. Black snakes (Pseudechis spp.) are a widespread and dangerously venomous group found throughout Australia and New Guinea. Utilising validated coagulation assays, our study assessed the efficacy of two chemically different small molecule inhibitors, a phospholipase A2 inhibitor (varespladib) and a metalloproteinase inhibitor (prinomastat), in vitro neutralisation of the anticoagulant prothrombinase-inhibiting activity of venom from seven species within the Pseudechis genus (P. australis, P. butleri, P. coletti, P. guttatus, P. papuanus, P.rossignolii, P. sp (NT).). Varespladib was shown to be highly effective at neutralising this anticoagulant activity for all seven species, but with P. coletti notably less so than the others. In contrast, prinomastat showed strong neutralisation for five out of the seven species, but was ineffective at neutralising the activity of P. coletti or P. rossignolii venoms. This suggests that varespladib binds to a highly conserved site but that prinomastat binds to a more variable site. These results build upon recent literature indicating that metalloproteinase inhibitors have cross-neutralising potential towards snake venom phospholipase A2 toxins, but with higher degrees of variability that PLA2-specific inhibitors. An important caveat is that these are in vitro tests and while suggestive of potential clinical utility, in vivo animal testing and clinical trials are required as future work.
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Affiliation(s)
- Abhinandan Chowdhury
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia QLD, 4072 Australia; Department of Biochemistry & Microbiology, North South University, Dhaka 1229, Bangladesh.
| | - Nicholas J Youngman
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia QLD, 4072 Australia
| | - Jiaojiao Liu
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia QLD, 4072 Australia
| | - Matthew R Lewin
- California Academy of Sciences, San Francisco, CA, 94118, USA; Ophirex, Inc., Corte Madera, CA, 94925, USA
| | | | - Bryan G Fry
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia QLD, 4072 Australia.
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10
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Platts-Mills TF, Lewin MR. Acute Kidney Injury as a Complication of Venomous Snakebite in the United States. Am Surg 2022; 88:1377-1378. [PMID: 35333624 DOI: 10.1177/00031348221080430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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House LM, Lewin MR, Naidu RK, Beqaj H. Complex regional pain syndrome following southern pacific rattlesnake ( C. oreganus helleri) envenoming. Clin Case Rep 2021; 9:e05019. [PMID: 34804529 PMCID: PMC8587178 DOI: 10.1002/ccr3.5019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 09/16/2021] [Accepted: 10/04/2021] [Indexed: 12/22/2022] Open
Abstract
Complex regional pain syndrome (CRPS) has rarely been reported in the setting of snakebite but might be more common than previously reported. We present the third case of CRPS reported in North America and the first resulting from a pit-viper's bite.
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Affiliation(s)
- Lawrence McLean House
- University of California San Francisco, Pain Management, Anesthesia & Perioperative CareSan FranciscoCaliforniaUSA
| | - Matthew R Lewin
- Center for Exploration and Travel Health & Ophirex, Inc.California Academy of SciencesSan FranciscoCaliforniaUSA
| | - Ramana K. Naidu
- Marin Health, Medical Director of Pain Management for Marin Health Medical CenterGreenbraeCaliforniaUSA
| | - Halil Beqaj
- Columbia Presbyterian Medical CenterNew YorkNew YorkUSA
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12
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Chowdhury A, Lewin MR, Zdenek CN, Carter R, Fry BG. The Relative Efficacy of Chemically Diverse Small-Molecule Enzyme-Inhibitors Against Anticoagulant Activities of African Spitting Cobra ( Naja Species) Venoms. Front Immunol 2021; 12:752442. [PMID: 34691069 PMCID: PMC8529177 DOI: 10.3389/fimmu.2021.752442] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/22/2021] [Indexed: 11/23/2022] Open
Abstract
African spitting cobras are unique among cobras for their potent anticoagulant venom activity arising from strong inhibition of Factor Xa. This anticoagulant effect is exerted by venom phospholipase A2 (Group I PLA2) toxins whose activity contributes to the lethality of these species. This anticoagulant toxicity is particularly problematic as it is not neutralized by current antivenoms. Previous work demonstrated this trait for Naja mossambica, N. nigricincta, N. nigricollis, and N. pallida. The present work builds upon previous research by testing across the full taxonomical range of African spitting cobras, demonstrating that N. ashei, N. katiensis, and N. nubiae are also potently anticoagulant through the inhibition of Factor Xa, and therefore the amplification of potent anticoagulant activity occurred at the base of the African spitting cobra radiation. Previous work demonstrated that the enzyme-inhibitor varespladib was able to neutralize this toxic action for N. mossambica, N. nigricincta, N. nigricollis, and N. pallida venoms. The current work demonstrates that varespladib was also able to neutralize N. ashei, N. katiensis, and N. nubiae. Thus varespladib is shown to have broad utility across the full range of African spitting cobras. In addition, we examined the cross-reactivity of the metalloprotease inhibitor prinomastat, which had been previously intriguingly indicated as being capable of neutralizing viperid venom PLA2 (Group II PLA2). In this study prinomastat inhibited the FXa-inhibiting PLA2 toxins of all the African spitting cobras at the same concentration at which it has been shown to inhibit metalloproteases, and thus was comparably effective in its cross-reactivity. In addition we showed that the metalloprotease-inhibitor marimastat was also able to cross-neutralize PLA2 but less effectively than prinomastat. Due to logistical (cold-chain requirement) and efficacy (cross-reactivity across snake species) limitations of traditional antivenoms, particularly in developing countries where snakebite is most common, these small molecule inhibitors (SMIs) might hold great promise as initial, field-based, treatments for snakebite envenoming as well as addressing fundamental limitations of antivenom in the clinical setting where certain toxin effects are unneutralized.
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Affiliation(s)
- Abhinandan Chowdhury
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia.,Department of Biochemistry & Microbiology, North South University, Dhaka, Bangladesh
| | - Matthew R Lewin
- California Academy of Sciences, San Francisco, CA, United States.,Ophirex, Inc., Corte Madera, CA, United States
| | - Christina N Zdenek
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia
| | | | - Bryan G Fry
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia
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13
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Hamza M, Knudsen C, Gnanathasan CA, Monteiro W, Lewin MR, Laustsen AH, Habib AG. Clinical management of snakebite envenoming: Future perspectives. Toxicon X 2021; 11:100079. [PMID: 34430847 PMCID: PMC8374517 DOI: 10.1016/j.toxcx.2021.100079] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/29/2021] [Accepted: 07/30/2021] [Indexed: 11/18/2022] Open
Abstract
Snakebite envenoming is a major cause of morbidity and mortality in rural communities throughout the tropics. Generally, the main clinical features of snakebites are local swelling, tissue necrosis, shock, spontaneous systemic hemorrhage, incoagulable blood, paralysis, rhabdomyolysis, and acute kidney injury. These clinical manifestations result from complex biochemical venom constituents comprising of cytotoxins, hemotoxins, neurotoxins, myotoxins, and other substances. Timely diagnosis of envenoming and identification of the responsible snake species is clinically challenging in many parts of the world and necessitates prompt and thorough clinical assessment, which could be supported by the development of reliable, affordable, widely-accessible, point-of-care tests. Conventional antivenoms based on polyclonal antibodies derived from animals remain the mainstay of therapy along with supportive medical and surgical care. However, while antivenoms save countless lives, they are associated with adverse reactions, limited potency, and are relatively inefficacious against presynaptic neurotoxicity and in preventing necrosis. Nevertheless, major scientific and technological advances are facilitating the development of new molecular and immunologic diagnostic tests, as well as a new generation of antivenoms comprising human monoclonal antibodies with broader and more potent neutralization capacity and less immunogenicity. Repurposed pharmaceuticals based on small molecule inhibitors (e.g., marimastat and varespladib) used alone and in combination against enzymatic toxins, such as metalloproteases and phospholipase A2s, have shown promise in animal studies. These orally bioavailable molecules could serve as early interventions in the out-of-hospital setting if confirmed to be safe and efficacious in clinical studies. Antivenom access can be improved by the usage of drones and ensuring constant antivenom supply in remote endemic rural areas. Overall, the improvement of clinical management of snakebite envenoming requires sustained, coordinated, and multifaceted efforts involving basic and applied sciences, new technology, product development, effective clinical training, implementation of existing guidelines and therapeutic approaches, supported by improved supply of existing antivenoms.
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Affiliation(s)
- Muhammad Hamza
- Infectious and Tropical Diseases Unit, Bayero University Kano, Nigeria
| | - Cecilie Knudsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Wuelton Monteiro
- Department of Research, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
- School of Health Sciences, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Matthew R. Lewin
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, USA
| | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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14
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Chowdhury A, Zdenek CN, Lewin MR, Carter R, Jagar T, Ostanek E, Harjen H, Aldridge M, Soria R, Haw G, Fry BG. Venom-Induced Blood Disturbances by Palearctic Viperid Snakes, and Their Relative Neutralization by Antivenoms and Enzyme-Inhibitors. Front Immunol 2021; 12:688802. [PMID: 34177943 PMCID: PMC8222980 DOI: 10.3389/fimmu.2021.688802] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/25/2021] [Indexed: 12/19/2022] Open
Abstract
Palearctic vipers are medically significant snakes in the genera Daboia, Macrovipera, Montivipera, and Vipera which occur throughout Europe, Central Asia, Near and Middle East. While the ancestral condition is that of a small-bodied, lowland species, extensive diversification has occurred in body size, and niche specialization. Using 27 venom samples and a panel of in vitro coagulation assays, we evaluated the relative coagulotoxic potency of Palearctic viper venoms and compared their neutralization by three antivenoms (Insoserp Europe, VIPERFAV and ViperaTAb) and two metalloprotease inhibitors (prinomastat and DMPS). We show that variation in morphology parallels variation in the Factor X activating procoagulant toxicity, with the three convergent evolutions of larger body sizes (Daboia genus, Macrovipera genus, and Vipera ammodytes uniquely within the Vipera genus) were each accompanied by a significant increase in procoagulant potency. In contrast, the two convergent evolutions of high altitude specialization (the Montivipera genus and Vipera latastei uniquely within the Vipera genus) were each accompanied by a shift away from procoagulant action, with the Montivipera species being particularly potently anticoagulant. Inoserp Europe and VIPERFAV antivenoms were both effective against a broad range of Vipera species, with Inoserp able to neutralize additional species relative to VIPERFAV, reflective of its more complex antivenom immunization mixture. In contrast, ViperaTAb was extremely potent in neutralizing V. berus but, reflective of this being a monovalent antivenom, it was not effective against other Vipera species. The enzyme inhibitor prinomastat efficiently neutralized the metalloprotease-driven Factor X activation of the procoagulant venoms. In contrast, DMPS (2,3-dimercapto-1-propanesulfonic acid), which as been suggested as another potential treatment option in the absence of antivenom, DMPS failed against all venoms tested. Overall, our results highlight the evolutionary variations within Palearctic vipers and help to inform clinical management of viper envenomation.
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Affiliation(s)
- Abhinandan Chowdhury
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia
- Department of Biochemistry & Microbiology, North South University, Dhaka, Bangladesh
| | - Christina N. Zdenek
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia
| | - Matthew R. Lewin
- California Academy of Sciences, San Francisco, CA, United States
- Ophirex, Inc., Corte Madera, CA, United States
| | | | | | | | - Hannah Harjen
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | | | | | - Grace Haw
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, Australia
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15
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Salvador GHM, Borges RJ, Lomonte B, Lewin MR, Fontes MRM. The synthetic varespladib molecule is a multi-functional inhibitor for PLA 2 and PLA 2-like ophidic toxins. Biochim Biophys Acta Gen Subj 2021; 1865:129913. [PMID: 33865953 DOI: 10.1016/j.bbagen.2021.129913] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND The treatment for snakebites is early administration of antivenom, which can be highly effective in inhibiting the systemic effects of snake venoms, but is less effective in the treatment of extra-circulatory and local effects. To complement standard-of-care treatments such as antibody-based antivenoms, natural and synthetic small molecules have been proposed for the inhibition of key venom components such as phospholipase A2 (PLA2) and PLA2-like toxins. Varespladib (compound LY315920) is a synthetic molecule developed and clinically tested aiming to block inflammatory cascades of several diseases associated with high PLA2s. Recent studies have demonstrated this molecule is able to potently inhibit snake venom catalytic PLA2 and PLA2-like toxins. METHODS In vivo and in vitro techniques were used to evaluate the inhibitory effect of varespladib against MjTX-I. X-ray crystallography was used to reveal details of the interaction between these molecules. A new methodology that combines crystallography, mass spectroscopy and phylogenetic data was used to review its primary sequence. RESULTS Varespladib was able to inhibit the myotoxic and cytotoxic effects of MjTX-I. Structural analysis revealed a particular inhibitory mechanism of MjTX-I when compared to other PLA2-like myotoxin, presenting an oligomeric-independent function. CONCLUSION Results suggest the effectiveness of varespladib for the inhibition of MjTX-I, in similarity with other PLA2 and PLA2-like toxins. GENERAL SIGNIFICANCE Varespladib appears to be a promissory molecule in the treatment of local effects led by PLA2 and PLA2-like toxins (oligomeric dependent and independent), indicating that this is a multifunctional or broadly specific inhibitor for different toxins within this superfamily.
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Affiliation(s)
- Guilherme H M Salvador
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Rafael J Borges
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Matthew R Lewin
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
| | - Marcos R M Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil.
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16
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Fontana Oliveira IC, Gutiérrez JM, Lewin MR, Oshima-Franco Y. Varespladib (LY315920) inhibits neuromuscular blockade induced by Oxyuranus scutellatus venom in a nerve-muscle preparation. Toxicon 2020; 187:101-104. [PMID: 32889027 DOI: 10.1016/j.toxicon.2020.08.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/08/2020] [Accepted: 08/30/2020] [Indexed: 11/28/2022]
Abstract
The phospholipase A2 (PLA2) inhibitors varespladib (LY315920) and its orally available derivative methyl-varespladib (LY333013) have been proposed as potential therapies for the treatment of snakebite envenomings in which toxicity depends on the action of PLA2s. In this study, the ability of LY315920 to abrogate the effect of the potent neurotoxic venom of Oxyuranus scutellatus (taipan) was assessed using the mouse phrenic nerve-diaphragm preparation. LY315920 inhibited the venom when (a) incubated with venom before addition to the medium; (b) added to the medium before addition of venom, and; (c) added to the medium within 30 min after addition of venom, and even after the onset of decline in twitch response. This contrasts with previous results with antivenom using the same experimental model, in which the window of time when antibodies are effective is shorter than 10 min. It is proposed that such differences may depend either on the higher affinity of the inhibitor for PLA2s or on the possibility that LY315920 reaches the cytosol of the nerve terminals, inhibiting neurotoxins that have been internalized. Our findings bear implications on the therapeutic potential of varespladib in neurotoxic snakebite envenomings mediated by presynaptically-acting PLA2s.
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Affiliation(s)
- Isadora Caruso Fontana Oliveira
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares Km 92.5, 18023-000, Sorocaba, SP, Brazil
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Matthew R Lewin
- California Academy of Sciences, San Francisco, CA, 94118, USA; Ophirex, Inc., Corte Madera, CA, 94925, USA
| | - Yoko Oshima-Franco
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares Km 92.5, 18023-000, Sorocaba, SP, Brazil.
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Lewin MR, Bulfone T. Varespladib (LY315920) rescues mice from rapidly lethal doses of venoms from five vipers, suggesting direct and indirect mechanisms for its therapeutic effect in a mouse model of snakebite envenomation. Toxicon 2019. [DOI: 10.1016/j.toxicon.2018.10.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lewin MR, Gilliam LL, Gilliam J, Samuel SP, Bulfone TC, Bickler PE, Gutiérrez JM. Delayed LY333013 (Oral) and LY315920 (Intravenous) Reverse Severe Neurotoxicity and Rescue Juvenile Pigs from Lethal Doses of Micrurus fulvius (Eastern Coral Snake) Venom. Toxins (Basel) 2018; 10:E479. [PMID: 30453607 PMCID: PMC6265968 DOI: 10.3390/toxins10110479] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/14/2018] [Accepted: 11/14/2018] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE There is a clear, unmet need for effective, lightweight, shelf-stable and economical snakebite envenoming therapies that can be given rapidly after the time of a snake's bite and as adjuncts to antivenom therapies in the hospital setting. The sPLA2 inhibitor, LY315920, and its orally bioavailable prodrug, LY333013, demonstrate surprising efficacy and have the characteristics of an antidote with potential for both field and hospital use. METHODS The efficacy of the active pharmaceutical ingredient (LY315920) and its prodrug (LY333013) to treat experimental, lethal envenoming by Micrurus fulvius (Eastern coral snake) venom was tested using a porcine model. Inhibitors were administered by either intravenous or oral routes at different time intervals after venom injection. In some experiments, antivenom was also administered alone or in conjunction with LY333013. RESULTS 14 of 14 animals (100%) receiving either LY315920 (intravenous) and/or LY333013 (oral) survived to the 120 h endpoint despite, in some protocols, the presence of severe neurotoxic signs. The study drugs demonstrated the ability to treat, rescue, and re-rescue animals with advanced manifestations of envenoming. CONCLUSIONS Low molecular mass sPLA2 inhibitors were highly effective in preventing lethality following experimental envenoming by M. fulvius. These findings suggest the plausibility of a new therapeutic approach to snakebite envenoming, in this example, for the treatment of a coral snake species for which there are limitations in the availability of effective antivenom.
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Affiliation(s)
- Matthew R Lewin
- Ophirex, Inc., Corte Madera, CA 94925, USA.
- California Academy of Sciences, San Francisco, CA 94118, USA.
| | - Lyndi L Gilliam
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
| | - John Gilliam
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Stephen P Samuel
- California Academy of Sciences, San Francisco, CA 94118, USA.
- Queen Elizabeth Hospital, Kings Lynn, Norfolk PE30 4ET, UK.
| | - Tommaso C Bulfone
- Ophirex, Inc., Corte Madera, CA 94925, USA.
- California Academy of Sciences, San Francisco, CA 94118, USA.
| | - Philip E Bickler
- Anesthesia and Perioperative Care, University of California, San Francisco, CA 94143, USA.
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica.
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Lewin MR, Gutiérrez JM, Samuel SP, Herrera M, Bryan-Quirós W, Lomonte B, Bickler PE, Bulfone TC, Williams DJ. Delayed Oral LY333013 Rescues Mice from Highly Neurotoxic, Lethal Doses of Papuan Taipan (Oxyuranus scutellatus) Venom. Toxins (Basel) 2018; 10:E380. [PMID: 30241297 PMCID: PMC6215158 DOI: 10.3390/toxins10100380] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 09/17/2018] [Accepted: 09/17/2018] [Indexed: 11/25/2022] Open
Abstract
There is an unmet need for economical snakebite therapies with long shelf lives that are effective even with delays in treatment. The orally bioavailable, heat-stable, secretory phospholipase A₂ (sPLA₂) inhibitor, LY333013, demonstrates antidotal characteristics for severe snakebite envenoming in both field and hospital use. A murine model of lethal envenoming by a Papuan taipan (Oxyuranus scutellatus) demonstrates that LY333013, even with delayed oral administration, improves the chances of survival. Furthermore, LY333013 improves the performance of antivenom even after it no longer reverses neurotoxic signs. Our study is the first demonstration that neurotoxicity from presynaptic venom sPLA2S can be treated successfully, even after the window of therapeutic antivenom has closed. These results suggest that sPLA₂ inhibitors have the potential to reduce death and disability and should be considered for the initial and adjunct treatment of snakebite envenoming. The scope and capacity of the sPLA2 inhibitors ability to achieve these endpoints requires further investigation and development efforts.
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Affiliation(s)
- Matthew R Lewin
- Ophirex, Inc., Corte Madera, CA 94925, USA.
- California Academy of Sciences, San Francisco, CA 94118, USA.
| | - José María Gutiérrez
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, an José 11501-2060, Costa Rica.
| | - Stephen P Samuel
- California Academy of Sciences, San Francisco, CA 94118, USA.
- Queen Elizabeth Hospital, Kings Lynn, Norfolk PE30 4ET, UK.
| | - María Herrera
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, an José 11501-2060, Costa Rica.
| | - Wendy Bryan-Quirós
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, an José 11501-2060, Costa Rica.
| | - Bruno Lomonte
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, an José 11501-2060, Costa Rica.
| | - Philip E Bickler
- Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Tommaso C Bulfone
- Ophirex, Inc., Corte Madera, CA 94925, USA.
- California Academy of Sciences, San Francisco, CA 94118, USA.
| | - David J Williams
- Department of Pharmacology and Therapeutics, Australian Venom Research Unit, University of Melbourne, Parkville, VIC 3010, Australia.
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20
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Bulfone TC, Samuel SP, Bickler PE, Lewin MR. Developing Small Molecule Therapeutics for the Initial and Adjunctive Treatment of Snakebite. J Trop Med 2018; 2018:4320175. [PMID: 30154870 PMCID: PMC6091453 DOI: 10.1155/2018/4320175] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/03/2018] [Indexed: 01/19/2023] Open
Abstract
The World Health Organization (WHO) recently added snakebite envenoming to the priority list of Neglected Tropical Diseases (NTD). It is thought that ~75% of mortality following snakebite occurs outside the hospital setting, making the temporal gap between a bite and antivenom administration a major therapeutic challenge. Small molecule therapeutics (SMTs) have been proposed as potential prereferral treatments for snakebite to help address this gap. Herein, we discuss the characteristics, potential uses, and development of SMTs as potential treatments for snakebite envenomation. We focus on SMTs that are secretory phospholipase A2 (sPLA2) inhibitors with brief exploration of other potential drug targets on venom molecules.
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Affiliation(s)
- Tommaso C. Bulfone
- California Academy of Sciences, San Francisco, 94118 CA, USA
- Ophirex, Inc., Corte Madera, 94925 CA, USA
- University of California, San Francisco, 94118 CA, USA
| | - Stephen P. Samuel
- California Academy of Sciences, San Francisco, 94118 CA, USA
- General Medicine, Queen Elizabeth Hospital, King's Lynn, PE30 4ET, Norfolk, UK
| | | | - Matthew R. Lewin
- California Academy of Sciences, San Francisco, 94118 CA, USA
- Ophirex, Inc., Corte Madera, 94925 CA, USA
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Sasidaran MN, Samuel SP, ChinnaRaju S, Antonysamy M, Bulfone TC, Lewin MR. Parotid swelling after Russell's viper envenomation: an unusual and poor prognostic sign. Clin Case Rep 2018; 6:262-266. [PMID: 29445459 PMCID: PMC5799621 DOI: 10.1002/ccr3.1105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/10/2017] [Accepted: 03/29/2017] [Indexed: 11/11/2022] Open
Abstract
Parotid swelling, an unusual and poorly understood sign, is associated with poor prognosis in the setting of Russell's viper envenomation. The large, aggressive Russell's viper is one of the most deadly snakes causing severe hematological and neurological manifestations. Research into this sign should be initiated and understanding could lead to improved outcomes.
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Affiliation(s)
- Maanoj N Sasidaran
- TCR Multispeciality Hospital and Snakebite Research Centre Krishnagiri Tamilnadu India.,Department of Microbiology PSG College of Arts and Science Coimbatore Tamilnadu India
| | - Stephen P Samuel
- TCR Multispeciality Hospital and Snakebite Research Centre Krishnagiri Tamilnadu India.,General Medicine Queen Elizabeth Hospital King's Lynn Norfolk UK
| | | | - Michael Antonysamy
- Department of Microbiology PSG College of Arts and Science Coimbatore Tamilnadu India
| | | | - Matthew R Lewin
- Center for Exploration and Travel Health California Academy of Sciences San Francisco California USA
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McMackin MZ, Lewin MR, Tabuena DR, Arreola FE, Moffatt C, Fuse M. Use of von Frey filaments to assess nociceptive sensitization in the hornworm, Manduca sexta. J Neurosci Methods 2015; 257:139-46. [PMID: 26432932 DOI: 10.1016/j.jneumeth.2015.09.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 09/16/2015] [Accepted: 09/19/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND The hornworm Manduca sexta exhibits a defensive strike to noxious assaults, a response that is robust and is easily observed by experimenters. Von Frey filaments and methods typical for studying nociception in other animals were used to assess the strike response in M. sexta. NEW METHODS A series of von Frey filaments was applied to the body wall in ascending order and the data generated were used to determine the strike threshold by (i) the up-and-down method, (ii) the first response method, and (iii) the simplified up-and-down order method (SUDO). The effect of a noxious pinch on strike threshold was assessed. COMPARISON WITH EXISTING METHODS To our knowledge none of these methods has been used on M. sexta previously, making the use of the up-and-down and SUDO methods the first in an invertebrate. The use of the first response method has been used in other invertebrates, and the method appears equally suited to M. sexta. RESULTS All three methods were successful in monitoring the threshold sensitivity to touch, which was lowered (sensitized) by tissue damage induced with a pinch. Sensitization lasted 19h. CONCLUSIONS All three methods of assessing nociception were successfully applied to quantify the defensive strike response in M. sexta, although the SUDO method required empirical assessment of which filament to start the test sequence with. The results revealed both short- and long-term sensitization. These methods should prove to be useful for quantifying sensitization in M. sexta.
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Affiliation(s)
- Marissa Zubia McMackin
- Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132, USA.
| | - Matthew R Lewin
- Institute for Biodiversity Science and Sustainability Director Center for Exploration and Travel Health, California Academy of Sciences, 55 Music Concourse Dr., Golden Gate Park, San Francisco, CA 94118, USA.
| | - Dennis R Tabuena
- Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132, USA.
| | - F Eric Arreola
- Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132, USA.
| | - Christopher Moffatt
- Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132, USA.
| | - Megumi Fuse
- Department of Biology, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132, USA.
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Lewin MR, Bickler P, Heier T, Feiner J, Montauk L, Mensh B. Reversal of experimental paralysis in a human by intranasal neostigmine aerosol suggests a novel approach to the early treatment of neurotoxic envenomation. Clin Case Rep 2013; 1:7-15. [PMID: 25356201 PMCID: PMC4184533 DOI: 10.1002/ccr3.3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 06/03/2013] [Accepted: 06/25/2013] [Indexed: 12/19/2022] Open
Abstract
Key Clinical Message Neurotoxic snake envenomation can result in respiratory failure and death. Early treatment is considered important to survival. Inexpensive, heat-stable, needle-free, antiparalytics could facilitate early treatment of snakebite and save lives, but none have been developed. An experiment using aerosolized neostigmine to reverse paralysis suggests how early interventions could be developed.
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Affiliation(s)
- Matthew R Lewin
- Center for Exploration and Travel Health, California Academy of Sciences San Francisco, California, USA
| | - Philip Bickler
- Department of Anesthesia, University of California San Francisco, California, USA
| | - Tom Heier
- Department of Anesthesia, University of California San Francisco, California, USA
| | - John Feiner
- Department of Anesthesia, University of California San Francisco, California, USA
| | - Lance Montauk
- U.S. State Department (Ret) Berkeley, California, USA
| | - Brett Mensh
- Janelia Farm Research Campus Ashburn, Virginia, USA
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Affiliation(s)
- Joseph E. Tonna
- Stanford/Kaiser Emergency Medicine Residency, Stanford University, Stanford, California, United States of America
| | - Matthew R. Lewin
- Institute for Exploration and Travel Health, California Academy of Sciences, San Francisco, California, United States of America
- * E-mail:
| | - Brett Mensh
- Institute for Exploration and Travel Health, California Academy of Sciences, San Francisco, California, United States of America
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Du T, Zhang Y, Wu JS, Wang H, Ji X, Xu T, Li Y, Xu L, Lewin MR. Domicile-related carbon monoxide poisoning in cold months and its relation with climatic factors. Am J Emerg Med 2010; 28:928-32. [DOI: 10.1016/j.ajem.2009.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2009] [Revised: 06/17/2009] [Accepted: 06/18/2009] [Indexed: 10/19/2022] Open
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Du T, Lewin MR, Wang H, Ji X, Bohn HH, Xu T, Xu L, Zhang Y, Li Y. Circadian and seasonal rhythms of acute upper gastrointestinal bleeding in Beijing. Emerg Med J 2010; 27:504-7. [PMID: 20515908 DOI: 10.1136/emj.2009.075820] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To investigate the circadian and seasonal patterns in the presentation of acute upper gastrointestinal bleeding (AUGIB) in Beijing, China. METHODS Medical records of the Beijing Emergency Medical Service System (EMSS) for 1 August 2005 to 31 July 2007 were reviewed; all patients diagnosed with AUGIB were included in the study. RESULTS 2580 patients were recorded in the EMSS system with a diagnosis of AUGIB during the study period. 1888 (73%) were male and 692 (27%) were female. Mean age was 53+/-20 years for male patients and 63+/-21 years for female patients. Significant differences in the presentation of AUGIB were noticed between seasons (p<0.001) and months (p<0.001). The number of cases in cold months (from December to April) was significantly higher than that in warm months (June to September). There was a significant circadian rhythm; there were fewer cases during daytime hours compared with night-time hours (p<0.001). CONCLUSIONS The presentation of AUGIB in Beijing has a clear seasonal and circadian rhythm. Circadian and seasonal rhythms associated with AUGIB may aid in identifying modifiable risk factors in individuals and populations.
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Affiliation(s)
- Tiekuan Du
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuai-Fu-Yuan No 1, Dong-Cheng District, Beijing 100730, China
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Furtado AD, Adraktas DD, Brasic N, Cheng SC, Ordovas K, Smith WS, Lewin MR, Chun K, Chien JD, Schaeffer S, Wintermark M. The triple rule-out for acute ischemic stroke: imaging the brain, carotid arteries, aorta, and heart. AJNR Am J Neuroradiol 2010; 31:1290-6. [PMID: 20360341 DOI: 10.3174/ajnr.a2075] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Ischemic stroke is commonly embolic, either from carotid atherosclerosis or from cardiac origin. These potential sources of emboli need to be investigated to accurately prescribe secondary stroke prevention. Moreover, the mortality in ischemic stroke patients due to ischemic heart disease is greater than that of age-matched controls, thus making evaluation for coronary artery disease important in this patient population. The purpose of this study was to evaluate the image quality of a comprehensive CTA protocol in patients with acute stroke that expands the standard CTA coverage to include all 4 chambers of the heart and the coronary arteries. MATERIALS AND METHODS One hundred twenty patients consecutively admitted to the emergency department with suspected cerebrovascular ischemia undergoing standard-of-care CTA were prospectively enrolled in our study. We used an original tailored acquisition protocol using a 64-section CT scanner, consisting of a dual-phase intravenous injection of iodinated contrast and saline flush, in conjunction with a dual-phase CT acquisition, ascending from the top of the aortic arch to the vertex of the head, then descending from the top of the aortic arch to the diaphragm. No beta blockers were administered. The image quality, attenuation, and CNRs of the carotid, aortic, vertebral, and coronary arteries were assessed. RESULTS Carotid, aorta, and vertebral artery image quality was 100% diagnostic (rated good or excellent) in all patients. Coronary artery image quality was diagnostic in 58% of RCA segments, 73% of LAD segments, and 63% of LCX segments. When we considered proximal segments only, the diagnostic quality rose to 71% in the RCA, 83% in the LAD, and 74% in the LCX. CONCLUSIONS Our stroke protocol achieved excellent opacification of the left heart chambers, the cervical arteries, and each coronary artery, in addition to adequate carotid and coronary artery image quality.
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Affiliation(s)
- A D Furtado
- Department of Radiology, University of California, San Francisco, San Francisco, California, USA
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Li Y, Du T, Lewin MR, Wang H, Ji X, Zhang Y, Xu T, Xu L. Circadian, day-of-week, and age patterns of the occurrence of acute coronary syndrome in Beijing's emergency medical services system. Am J Emerg Med 2010; 28:663-7. [PMID: 20637380 PMCID: PMC7126581 DOI: 10.1016/j.ajem.2009.02.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2009] [Revised: 02/19/2009] [Accepted: 02/27/2009] [Indexed: 11/18/2022] Open
Abstract
Background Previous in-hospital studies suggest that there are significant circadian rhythms associated with the incidence of acute coronary syndromes (ACSs). No study to date has examined the presentation of ACS in the prehospital setting. Our goal was to examine circadian, day-of-week, and age patterns of occurrence in ACS in a large, urban emergency medical services (EMS) system. Methods We retrospectively reviewed the electronic prehospital medical records from the Beijing's EMS system spanning August 1, 2005, to July 31, 2007. Data were analyzed by hour of the day and day of the week. χ2 tests were performed to compare the difference. Results Seven thousand thirty-two cases of ACS were identified by the EMS system physicians during the 2-year study period, including 536 cases of acute myocardial infarction. A significant variation of circadian distribution of ACS was observed in both 24-hour (P < .001) and 2-hour (P < .001) interval time course. Two peaks were observed in the morning from 0800 to 1000 and approaching midnight from 2200 to 2400. Increases of 50% and 60.8% in the morning and evening peaks were found, respectively, when compared with the early morning baseline (nadir). No significant difference was found among the accumulated cases in 2 years on each day in a week (P = .203). Conclusions Our study shows that, in the Beijing metropolitan area, the presentation of ACS has significant circadian rhythm characterized by 2 peaks within 24 hours, the morning peak is 0800 to 1000, and the late evening peak is 2200 to 2400. No significant weekly rhythm was observed in the present study.
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Affiliation(s)
- Yi Li
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, PR China
| | - Tiekuan Du
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, PR China
| | - Matthew R. Lewin
- Department of Emergency Medicine, University of California, San Francisco, CA 94143, USA
| | - Houli Wang
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, PR China
- Corresponding author. Tel.: +86 10 65295326; fax: 86 10 65295327.
| | - Xu Ji
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, PR China
| | - Yanping Zhang
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, PR China
| | - Tengda Xu
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, PR China
| | - Lingjie Xu
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, PR China
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Tonna JE, Lewin MR, Hahn IH, Platts-Mills TF, Norell MA. A Prospective, Multi-Year Analysis of Illness and Injury During Summer Travel to Arid Environments. Wilderness Environ Med 2009; 20:107-12. [DOI: 10.1580/08-weme-or-193r3.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Wang H, Xu T, Lewin MR. Future possibilities for the treatment of septic shock with herbal components. Am J Emerg Med 2009; 27:107-112. [PMID: 19041541 DOI: 10.1016/j.ajem.2008.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Revised: 07/28/2008] [Accepted: 08/01/2008] [Indexed: 12/11/2022] Open
Abstract
The treatment of septic shock remains challenging even with the armamentarium of modern antibiotics and intensive care technologies. Reliance on antibiotics and other methods targeting modulation of the systemic inflammatory response such as steroids, hemofiltration, and cytokine antagonists has not led to reliable successful treatment for inflammation and infection-related shock. In part, this is attributable to the continuous evolution of antibacterial drug resistance. Herbal medicine has been used in treating infections and shock, worldwide, for thousands of years. The active components contained in these naturally occurring products usually have one or more of the following properties: (1) direct attack or suppression on bacterial pathogens, (2) modulation of the host's immune system resulting in suppression of inflammation and overproduction of inflammatory mediators, and (3) neutralization of toxic free-radicals. In vitro and in vivo animal and human clinical studies of herbal medicines' effectiveness in the treatment of septic shock are needed. Their pharmacological mechanisms need to be elucidated at molecular level to investigate and improve targeted therapy using heretofore unexplored uses for traditional herbal remedies. Herein, we discuss historical examples of herbal remedies used to fight infection. In addition, we discuss the use of herbal and traditional medicines as potential adjuncts in the ongoing battle against septic shock and systemic infections.
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Affiliation(s)
- Houli Wang
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Tsinghua University, Beijing 100730, PR China.
| | - Tengda Xu
- Department of Emergency Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Tsinghua University, Beijing 100730, PR China
| | - Matthew R Lewin
- Department of Emergency Medicine, University of California, San Francisco, CA 94143, USA
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Affiliation(s)
- Matthew R Lewin
- Assistant professor of emergency medicine in the Department of Emergency Medicine at the University of California, San Francisco
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Balanoff AM, Norell MA, Grellet-Tinner G, Lewin MR. Digital preparation of a probable neoceratopsian preserved within an egg, with comments on microstructural anatomy of ornithischian eggshells. Naturwissenschaften 2008; 95:493-500. [PMID: 18347769 DOI: 10.1007/s00114-008-0347-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 12/17/2007] [Accepted: 01/12/2008] [Indexed: 11/25/2022]
Abstract
We describe the first known embryo of a neoceratopsian dinosaur, perhaps the most ubiquitous Laurasian group of Cretaceous dinosaurs, which is preserved completely enclosed within an egg. This specimen was collected from Late Cretaceous beds of southern Mongolia, which commonly preserve fossils of the neoceratopsian, Yamaceratops dorngobiensis. The small egg was scanned using high-resolution X-ray computed tomography and digitally prepared from the matrix. The preserved and imaged elements support a diagnosis of the embryo to Neoceratopsia and allow preliminary observations of ontogenetic transformations within this group. The addition of an embryo also adds another important data point to the already impressive postnatal ontogenetic series that are available for this clade.
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Affiliation(s)
- Amy M Balanoff
- Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA.
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Platts-Mills TF, Stendell E, Shalit M, Stroh G, Lewin MR. Reply to Intravenous Fluid Warming with Body Contact in a Wilderness Setting. Wilderness Environ Med 2008. [DOI: 10.1580/07-weme-le-169.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Platts-Mills TF, Stendell E, Lewin MR, Moya MN, Dhah K, Stroh G, Shalit M. An Experimental Study of Warming Intravenous Fluid in a Cold Environment☆. Wilderness Environ Med 2007; 18:177-85. [PMID: 17896849 DOI: 10.1580/06-weme-or-051r1.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Numerous studies support the use of warmed intravenous fluids in hypothermic patients. The most effective method to accomplish this goal in a cold prehospital, wilderness, or combat setting is unknown. We evaluated various methods of warming intravenous fluids for a bolus infusion in a cold remote environment. METHODS One liter and 500 mL bags of intravenous fluid at 5 degrees C were heated using various methods in a 5 degrees C cold room. Methods included attachment of 3 types of chemical heat packs and heating the fluid in a pot on a camping stove. For all methods, fluids were run at a wide-open rate through an intravenous line with an 18-gauge catheter attached to the end to simulate a bolus infusion. The temperature of the fluid at the end of the intravenous line was measured. Each method was tested twice. Equipment weight and setup times are reported. Mean infusion temperatures for the various methods are compared. RESULTS Equipment weights ranged from 19 to 665 gm. Setup times ranged from 5 to 11 minutes. The 2 methods which achieved the desired mean infusion temperature of 35 to 42 degrees C without excessive maximum temperatures were 1) 2 Meal Ready to Eat hot packs attached to a 500 mL bag of fluid for 10 minutes prior to infusion, and 2) a camping stove heating the surface of a 500 mL bag of fluid to 75 degrees C prior to infusion. Other methods, including the use of commonly available heat packs and a commercially available IV fluid warmer were ineffective, with mean infusion temperatures ranging from 7 to 12 degrees C. CONCLUSIONS Heating of cold intravenous fluids in a cold environment is possible using either Meal Ready to Eat heat packs or a camping stove. Further study is needed to evaluate the ability of either method to consistently produce an appropriate fluid temperature given various ambient and initial fluid temperatures.
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Affiliation(s)
- Timothy F Platts-Mills
- Department of Emergency Medicine, University of California, San Francisco, University Medical Center, Fresno, California 93702, USA.
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Lewin MR, Stein J, Wang R, Lee MM, Kernberg M, Boukhman M, Hahn IH, Lewiss RE. Humming Is as Effective as Valsalva’s Maneuver and Trendelenburg’s Position for Ultrasonographic Visualization of the Jugular Venous System and Common Femoral Veins. Ann Emerg Med 2007; 50:73-7. [PMID: 17433497 DOI: 10.1016/j.annemergmed.2007.01.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 01/08/2007] [Accepted: 01/23/2007] [Indexed: 01/10/2023]
Abstract
STUDY OBJECTIVE The purpose of this study is to compare ultrasonographic visualization of the jugular and common femoral veins by using a novel technique (humming) and 2 conventional techniques (Valsalva's maneuver and Trendelenburg's position). The Valsalva's maneuver and Trendelenburg's position are common methods for producing venous distention, aiding ultrasonographically guided identification and cannulation of the jugular and common femoral veins. We hypothesize that humming is as effective as either Valsalva's maneuver or Trendelenburg's position for distention and ultrasonographic visualization of these procedurally important blood vessels. Herein, we investigate a new method of venous distension that may aid in the placement of central venous catheters by ultrasonographic guidance. METHODS Healthy, normal volunteers aged 28 to 67 years were enrolled. Each subject's internal jugular, external jugular, and common femoral veins were measured in cross-section by ultrasonograph during rest (baseline), humming, Valsalva's maneuver, and Trendelenburg's position. Three measurements were recorded per observation in each position. Subjects were used as their own controls, and measurements were normalized to percentage increase in diameter during each maneuver or position for later comparison. RESULTS The study population consisted of 7 subjects, with a mean age of 47 years. Cross-sectional area was calculated for each vessel in 3 groups: baseline/control, Valsalva, Trendelenburg, and humming. The mean percentage change (+/-SD) relative to baseline cross-sectional area of the jugular vessels for each subject were external jugular vein: humming 134%+/-25% (95% confidence interval [CI] 124.9% to 146.9%), Valsalva 136%+/-23% (95% CI 121.3% to 147.5%), Trendelenburg 137%+/-32% (95% CI 120.7% to 156.9%); internal jugular vein: humming 137%+/-27% (95% CI 119.4% to 148.2%), Valsalva 139%+/-24% (95% CI 122.4% to 148.7%), Trendelenburg 141%+/-35% (95% CI 116.5% to 156.5%); common femoral vein: humming 131%+/-15% (95% CI 120.4% to 139.1%), Valsalva 139%+/-18% (95% CI 127.9% to 150.4%), Trendelenburg 132%+/-24% (95% CI 113.3% to 142.9%). CONCLUSION All 3 maneuvers distended the external jugular, internal jugular, and common femoral veins compared to baseline. There was no important difference in magnitude of cross-sectional area between any of the 3 maneuvers when compared with one another. Humming shares many physiologic similarities to Valsalva's maneuver and may be more familiar and easier to perform during procedures such as ultrasonographically guided central venous catheter placement and insertion of external jugular intravenous catheters.
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Affiliation(s)
- Matthew R Lewin
- Division of Emergency Medicine, University of California, San Francisco, CA 94143, USA.
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Platts-Mills TF, Lewin MR. Reply to Improvised Airway Management Devices. Wilderness Environ Med 2007. [DOI: 10.1580/06-weme-le-090.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Platts-Mills TF, Lewin MR, Wells J, Bickler P. Improvised Cricothyrotomy Provides Reliable Airway Access in an Unembalmed Human Cadaver Model. Wilderness Environ Med 2006; 17:81-6. [PMID: 16805143 DOI: 10.1580/pr20-05.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Patients with injuries requiring surgical airway management occurring far from medical care might benefit from the availability of a simple, reliable, improvisational method of cricothyrotomy with materials available in a wilderness or prehospital setting. We evaluated an improvised cricothyrotomy device in an experimental, unembalmed human cadaver model. METHODS A high-flow intravenous spike and drip chamber was cut through the drip chamber and used as the sole apparatus for performing cricothyrotomy on unembalmed cadavers whose anterior neck surfaces and deep tissues were warmed to or near body temperature. Correct placement in the trachea and damage to the posterior wall of the trachea were assessed by either fiberoptic bronchoscopy or neck dissection. Video recordings were used to time each procedure. Each operator was responsible for both device insertion and bag valve mask attachment and ventilation, modeling as the sole care provider for the patient. RESULTS One physician and 3 emergency medicine residents, all without previous, specific instruction, performed 10 procedures on 5 female and 5 male unembalmed cadavers weighing a mean of 65 kg (range 45-110 kg). All 10 attempts at placement of the intravenous tubing spike through the cricothyroid membrane were successful. On 2 attempts, the initial placement of the device was incorrect, but the error was immediately identified on attempt to ventilate the patient. Repositioning of the device resulted in appropriate cannulation of the trachea in both attempts. The median time span from manual identification of the cricothyroid membrane to percutaneous access and connection of the bag valve mask with successful ventilation was 27.3 seconds. Violation of the posterior tracheal wall was not seen on any of the 5 procedures in which fiberoptic visualization was available or in the 5 procedures evaluated by neck dissection. CONCLUSIONS Cricothyrotomy is the quickest and most effective method for obtaining airway access when nonsurgical methods of securing the airway are contraindicated or fail. Although frequently described, no improvised airway devices of this type have been tested in a systematic manner. We tested the reliability and utility of cricothyrotomy with a high-flow intravenous spike and drip chamber. Our results suggest that the spike and drip chamber is a plausible means of temporarily establishing airway access in patients with acute airway obstruction in a wilderness or prehospital environment.
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Affiliation(s)
- Timothy F Platts-Mills
- Department of Emergency Medicine, University of California, San Francisco, Fresno, Fresno, CA 94143, USA
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Affiliation(s)
- Timothy F Platts-Mills
- Department of Emergency Medicine, University Medical Center, Fresno, CA 93702-2907, USA.
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Lewin MR, Montauk L, Shalit M, Nobay F. An Unusual Case of Subterfuge in the Emergency Department: Covert Administration of Antipsychotic and Anxiolytic Medications to Control an Agitated Patient. Ann Emerg Med 2006; 47:75-8. [PMID: 16387221 DOI: 10.1016/j.annemergmed.2005.11.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 11/15/2005] [Accepted: 11/18/2005] [Indexed: 11/19/2022]
Abstract
Pediatric, nursing home, and institutionalized psychiatric patients frequently receive medications covertly or against their will. Surreptitious medicating of emergency department (ED) psychiatric patients may occur but has not been reported. We discuss competing ethical, therapeutic, and legal issues in potential conflict during the treatment of an acutely psychotic patient who had homicidal and suicidal ideation and presented to a busy, urban ED. The practice of covertly medicating may not be uncommon in EDs, but fear of professional censure probably inhibits open discussion and documentation of such events. No specific statutory, ethical, or case law in the United States seems to control this type of situation.
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Lewin MR, Hori S, Aikawa N. Emergency medical services in Japan: An opportunity for the rational development of pre-hospital care and research. J Emerg Med 2005; 28:237-41. [PMID: 15707828 DOI: 10.1016/j.jemermed.2004.09.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 07/28/2004] [Accepted: 09/16/2004] [Indexed: 11/18/2022]
Abstract
Japan is at a crossroads in the development of its Emergency Medical Services (EMS). At present, Japan has an essentially pure scoop-and-run, defibrillation system. However, there is a strong movement toward expanding the scope of paramedic practice to include more complex, Advanced Life Support (ALS) and trauma protocols to its nationally standardized pre-hospital protocols. The implications of introducing complex pre-hospital protocols guided by the use of existing scientific evidence to support such action is discussed in the context of Japan's unique opportunity to test many fundamental questions in pre-hospital medical care and the public's understanding and acceptance of these practices. Japan, a technologically advanced country that is not encumbered by entrenched "standards of care," has the opportunity to develop an efficient and rational EMS system.
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Affiliation(s)
- Matthew R Lewin
- Division of Emergency Medicine, University of California, San Francisco (Fresno), CA, USA
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Affiliation(s)
- Marc Shalit
- Division of Emergency Medicine, UCSF-Fresno, 445 South Cedar Avenue, Room 275, Fresno, CA 94702, USA.
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Hasham SN, Lewin MR, Tran VT, Pannu H, Muilenburg A, Willing M, Milewicz DM. Nonsyndromic genetic predisposition to aortic dissection: a newly recognized, diagnosable, and preventable occurrence in families. Ann Emerg Med 2004; 43:79-82. [PMID: 14707946 DOI: 10.1016/s0196-0644(03)00818-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The major diseases affecting the aorta are aortic aneurysms and dissections, with patients with acute dissections often presenting in the emergency department (ED). Recent studies demonstrate a strong genetic predisposition to thoracic aortic aneurysms and dissections, independent of syndromes traditionally considered to predispose to aortic disease (such as Marfan syndrome). Nonsyndromic familial thoracic aortic aneurysms and dissections are inherited in families as an autosomal dominant disorder and a variable age of onset of the aortic disease. The case reported here illustrates the critical importance of obtaining a family history of thoracic aortic aneurysms and dissections, along with unexplained sudden death, when assessing an individual with chest pain in the ED, regardless of age and in the absence of a known genetic syndrome.
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Affiliation(s)
- Sumera N Hasham
- Division of Medical Genetics, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, TX, USA
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Affiliation(s)
- Matthew R Lewin
- Division of Emergency Medicine, School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
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Affiliation(s)
- Ann Burelbach
- Department of Emergency Medicine, University of California, San Francisco-Fresno, Fresno, CA 93702, USA
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Abstract
The risk of acquiring North Asian tick typhus (infection by Rickettsia sibirica) during travel to regions of Asia where this disease is endemic is unknown. We investigated prospectively 13 paleontologists on expedition to Mongolia. Four paleontologists had acute illness characterised by fever, rash, headache, and lymphadenopathy. All had IgM and IgG antibodies to R sibirica. Paleontologists with no illness and people who went on expeditions in other parts of the world did not have antibodies to R sibirica. Only two of the four infected persons were aware of tick bites. Travellers to regions endemic for R sibirica are at risk of contracting North Asian tick typhus even in the absence of recognised tick-bites.
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Affiliation(s)
- Joseph A Pollard
- College of Osteopathic Medicine, Oklahoma State University, Tulsa, OK, USA
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