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A Mosquera - One of the best experts on this subject based on the ideXlab platform.
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stroke following Bothrops spp snakebite
Neurology, 2003Co-Authors: A Mosquera, Luis Idrovo, Alfonso Tafur, Oscar H Del BruttoAbstract:Objective: To determine the prevalence and subtypes of cerebrovascular complications of Bothrops spp. snakebites. Methods: The authors studied 309 consecutive patients bitten by Bothrops spp. who attended a large general hospital. Special emphasis was placed on the time elapsed between the bite and admission to the hospital, clinical manifestations, laboratory findings, severity of envenomation, CT findings, and outcome. Results: Eight of 309 patients (2.6%) developed a cerebrovascular event. Six presented >8 hours after being bitten, and all had clinical and laboratory evidence of severe envenoming. CT revealed intracranial bleeding in seven patients and multiple brain infarcts in one. Hemorrhages were located in the subcortical white matter of the cerebral hemispheres in five patients, in the cerebellum in one, and in the subarachnoid space in one. All patients with intracranial hemorrhage had a bleeding disorder, and the patient with cerebral infarcts may have had angiitis. Five of the eight patients died despite therapy, and the remaining three had irreversible sequelae. Conclusions: The prevalence of cerebrovascular complications related to Bothrops spp. bites is 2.6%. Intracranial hemorrhages are more frequent than cerebral infarcts. The prognosis of these patients is poor.
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stroke following Bothrops spp snakebite
Neurology, 2003Co-Authors: A Mosquera, Luis Idrovo, Alfonso Tafur, Oscar H Del BruttoAbstract:Objective: To determine the prevalence and subtypes of cerebrovascular complications of Bothrops spp. snakebites. Methods: The authors studied 309 consecutive patients bitten by Bothrops spp. who attended a large general hospital. Special emphasis was placed on the time elapsed between the bite and admission to the hospital, clinical manifestations, laboratory findings, severity of envenomation, CT findings, and outcome. Results: Eight of 309 patients (2.6%) developed a cerebrovascular event. Six presented >8 hours after being bitten, and all had clinical and laboratory evidence of severe envenoming. CT revealed intracranial bleeding in seven patients and multiple brain infarcts in one. Hemorrhages were located in the subcortical white matter of the cerebral hemispheres in five patients, in the cerebellum in one, and in the subarachnoid space in one. All patients with intracranial hemorrhage had a bleeding disorder, and the patient with cerebral infarcts may have had angiitis. Five of the eight patients died despite therapy, and the remaining three had irreversible sequelae. Conclusions: The prevalence of cerebrovascular complications related to Bothrops spp. bites is 2.6%. Intracranial hemorrhages are more frequent than cerebral infarcts. The prognosis of these patients is poor.
Jose Maria Gutierrez - One of the best experts on this subject based on the ideXlab platform.
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Third-generation antivenomics analysis of the preclinical efficacy of Bothrofav® antivenom towards Bothrops lanceolatus venom
Elsevier, 2019Co-Authors: Davinia Pla, Jose Maria Gutierrez, Yania Rodríguez, Dabor Resiere, Hossein Mehdaoui, Juan J. CalveteAbstract:Bothrops lanceolatus inflicts severe envenomings in the Lesser Caribbean island of Martinique. Bothrofav®, a monospecific antivenom against B. lanceolatus venom, has proven highly effective at the preclinical and clinical levels. Here, we report a detailed third-generation antivenomics quantitative analysis of Bothrofav®. With the exception of poorly-immunogenic peptides, Bothrofav® immunocaptured all the major protein components. These results, along with previous preclinical and clinical observations, underscore the high neutralizing efficacy of the antivenom against B. lanceolatus venom. Keywords: Bothrops lanceolatus, Antivenom, Snake venom, Bothrofav®, Third-generation antivenomics, Martiniqu
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neutralization of four peruvian Bothrops sp snake venoms by polyvalent antivenoms produced in peru and costa rica preclinical assessment
Acta Tropica, 2005Co-Authors: Ermila Rojas, Bruno Lomonte, Gustavo Rojas, Lil Quesada, Viviana Arce, Jose Maria GutierrezAbstract:Envenomations after bites inflicted by snakes of the genus Bothrops constitute a public health hazard in Peru, and the intravenous administration of equine-derived antivenoms represents the only scientifically validated treatment. This study presents a preclinical assessment of the efficacy of two whole IgG antivenoms, prepared in Peru and Costa Rica, to neutralize the most relevant toxic effects induced by the venoms of Bothrops atrox, B. brazili, B. barnetti and B. pictus from Peru. Peruvian antivenom is produced by immunizing horses with Bothrops sp. venoms from this country, whereas the production of Costa Rican antivenom involves immunization with venoms from Central American snakes. The neutralization of lethal, hemorrhagic, edema-forming, myotoxic, coagulant and defibrinating activities was evaluated in assays involving incubation of venom and antivenom prior to testing. Both antivenoms were effective in the neutralization of these effects, with quantitative variations in the values of effective dose 50% depending on the effects being studied. Peruvian antivenom was more effective in the neutralization of lethality induced by B. atrox and B. barnetti venoms. However, Peruvian antivenom failed to neutralize coagulant activity of B. barnetti venom and edema-forming activity of B. brazili venom, whereas neutralization was achieved by Costa Rican antivenom. It is concluded that an extensive immunological cross-reactivity exists between Bothrops sp. venoms from Peru and Costa Rica, and that both antivenoms are effective in the neutralization of these four venoms in a rodent model of envenoming.
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Bothrops asper and Bothrops jararaca snake venoms trigger microbicidal functions of peritoneal leukocytes in vivo
Toxicon, 2001Co-Authors: Stella Regina Zamuner, Jose Maria Gutierrez, Marcelo Nicolas Muscara, Simone A Teixeira, Catarina De Fatima TeixeiraAbstract:Abstract Venoms from snakes of the genus Bothrops cause pronounced local effects in the victims. These alterations result not only from the direct toxic action of venom components, but also from the prominent inflammatory reaction associated with these envenomations. In this study we investigated the ability of Bothrops asper (BaV) and Bothrops jararaca (BjV) venoms to induce cellular influx and microbicidal functions in leukocytes. BaV and BjV (5 μg/animal) caused a long lasting infiltration of leukocytes (3–48 h) when injected into mouse peritoneal cavity. Both venoms increased phagocytosis and production of hydrogen peroxide (H 2 O 2 ) by polymorphonuclear (PMN) and mononuclear (MN) peritoneal leukocytes. In addition, nitric oxide (NO) production by macrophages was also enhanced after the venom injections. This effect was inhibited by treating animals with L-NAME and aminoguanidine, thus suggesting the induction of iNOS synthesis by the venoms. Western blot analysis confirmed the expression of iNOS in macrophages. BaV and BjV injection led to increased levels of IFN-γ at the site of inflammation. Since IFN-γ is an effective inducer of iNOS expression, an indirect action of the venoms on iNOS expression can be proposed. A marked formation of nitrotyrosine-containing proteins was also observed in macrophage homogenates. Based on these results, we suggest that reactive oxygen and nitrogen-derived species are involved in the pathogenesis of the local tissue damage characteristic of Bothrops sp envenomations.
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phospholipase a2 myotoxins from Bothrops snake venoms
Toxicon, 1995Co-Authors: Jose Maria Gutierrez, Bruno LomonteAbstract:Several myotoxins have been isolated from Bothrops snake venoms during the last 10 years. All of them are group II basic phospholipases A2, although some lack enzymatic activity (i.e. Lys-49 variants). These myotoxins appear as an antigenically related family of proteins occurring in many, but not all, Bothrops venoms, bearing a close structural and antigenic relationship to toxins found in other crotalid venoms of the genera Agkistrodon and Trimeresurus. Myotoxins are quantitatively important venom components in some Bothrops species. Intramuscular injection of Bothrops myotoxins leads to a rapid series of drastic degenerative events, probably initiated at the plasma membrane level, which culminate in a selective skeletal muscle necrosis. This in vivo specificity contrasts with the ability of myotoxins to lyse many types of cells in culture. Muscle damage, as well as cytolysis and liposome disruption, occur in conditions where phospholipase A2 activity is inhibited, although enzymatic activity might enhance myotoxin actions. A membrane receptor for Bothrops myotoxins has not been identified yet. A working hypothesis on the mechanism of action is proposed. Current evidence suggests that these toxins interact with biological membranes via a molecular region distinct from their known catalytic site. The active region is likely to be formed by a combination of basic and hydrophobic amino acid residues near the C-terminus of the protein, which allow electrostatic interaction and bilayer penetration. These events may lead to membrane destabilization and loss of selective permeability to ions such as calcium, both of which appear to be important mediators in the process of muscle necrosis.
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A potent antihemorrhagin in the serum of the non-poisonous water snake Natrix tessellata: isolation, characterization and mechanism of neutralization
Biochimica et Biophysica Acta, 1994Co-Authors: Gadi Borkow, Jose Maria Gutierrez, Michael OvadiaAbstract:Abstract The main natural antihemorrhagic factor (NtAH), which inhibits the hemorrhagic activity of Bothrops asper snake venom, was isolated from the serum of the non-poisonous water snake Natrix tessellata by ammonium sulfate precipitation at 35–55%, Sephadex G-75 gel filtration, ion exchange chromatography on DEAE-Sepharose and CM-Sepharose and hydrophobic Phenyl-Sepharose chromatography. The purified protein showed one band with an isoelectric point of 4.5 and a molecular mass of about 880 kDa. The antihemorrhagic activity was stable between pH 5.5–11.7 and up to 50°C, but lost activity after 20 min at 60°C. It did not form a precipitin line with the main hemorrhagin of Bothrops asper snake venom (BaH1), nor with the whole venom, which suggests that the antihemorrhagic factor is not an immunoglobulin. The mechanism of neutralization by the isolated antihemorrhagic factor NtAH did not include digestion of the hemorrhagic toxin BaH1. Chromatography of NtAH with active 125I-labeled BaH1 toxin as well as ELISA experiments demonstrated that the mechanism of neutralization involves formation of an inactive soluble complex between the natural NtAH of the non-poisonous water snake and the main hemorrhagin of Bothrops asper venom.
Allyson M Fenwick - One of the best experts on this subject based on the ideXlab platform.
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morphological and molecular evidence for phylogeny and classification of south american pitvipers genera Bothrops bothriopsis and bothrocophias serpentes viperidae
Zoological Journal of the Linnean Society, 2009Co-Authors: Allyson M Fenwick, Ronald L Gutberlet, Jennafer A Evans, Christopher L ParkinsonAbstract:Species in the genus Bothrops s. l. are extraordinarily variable in ecology and geography, compared with other genera in the subfamily Crotalinae. In contrast to the trend of splitting large and variable groups into smaller, more ecologically and phenotypically cohesive genera, the genus Bothrops has remained speciose. In addition, previous phylogenetic analyses have found Bothrops to be paraphyletic with respect to the genus Bothriopsis. Taxonomic arguments exist for synonymizing Bothriopsis with Bothrops, and for splitting Bothrops into smaller genera, but the greatest hindrance to taxonomic revision has been incomplete phylogenetic information. We present a phylogeny of Bothrops, Bothriopsis, and Bothrocophias based on 85 characters of morphology and 2343 bp of four mitochondrial gene regions, and with significantly greater taxonomic coverage than previous studies. The combined data provide improved support over independent datasets, and support the existence of discrete species groups within Bothrops. The monophyly and distinctness of these groups warrant recognition at the generic level, and we propose a new taxonomic arrangement to reflect these findings. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156, 617–640.
Oscar H Del Brutto - One of the best experts on this subject based on the ideXlab platform.
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stroke following Bothrops spp snakebite
Neurology, 2003Co-Authors: A Mosquera, Luis Idrovo, Alfonso Tafur, Oscar H Del BruttoAbstract:Objective: To determine the prevalence and subtypes of cerebrovascular complications of Bothrops spp. snakebites. Methods: The authors studied 309 consecutive patients bitten by Bothrops spp. who attended a large general hospital. Special emphasis was placed on the time elapsed between the bite and admission to the hospital, clinical manifestations, laboratory findings, severity of envenomation, CT findings, and outcome. Results: Eight of 309 patients (2.6%) developed a cerebrovascular event. Six presented >8 hours after being bitten, and all had clinical and laboratory evidence of severe envenoming. CT revealed intracranial bleeding in seven patients and multiple brain infarcts in one. Hemorrhages were located in the subcortical white matter of the cerebral hemispheres in five patients, in the cerebellum in one, and in the subarachnoid space in one. All patients with intracranial hemorrhage had a bleeding disorder, and the patient with cerebral infarcts may have had angiitis. Five of the eight patients died despite therapy, and the remaining three had irreversible sequelae. Conclusions: The prevalence of cerebrovascular complications related to Bothrops spp. bites is 2.6%. Intracranial hemorrhages are more frequent than cerebral infarcts. The prognosis of these patients is poor.
Oscar H Del Brutto - One of the best experts on this subject based on the ideXlab platform.
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stroke following Bothrops spp snakebite
Neurology, 2003Co-Authors: A Mosquera, Luis Idrovo, Alfonso Tafur, Oscar H Del BruttoAbstract:Objective: To determine the prevalence and subtypes of cerebrovascular complications of Bothrops spp. snakebites. Methods: The authors studied 309 consecutive patients bitten by Bothrops spp. who attended a large general hospital. Special emphasis was placed on the time elapsed between the bite and admission to the hospital, clinical manifestations, laboratory findings, severity of envenomation, CT findings, and outcome. Results: Eight of 309 patients (2.6%) developed a cerebrovascular event. Six presented >8 hours after being bitten, and all had clinical and laboratory evidence of severe envenoming. CT revealed intracranial bleeding in seven patients and multiple brain infarcts in one. Hemorrhages were located in the subcortical white matter of the cerebral hemispheres in five patients, in the cerebellum in one, and in the subarachnoid space in one. All patients with intracranial hemorrhage had a bleeding disorder, and the patient with cerebral infarcts may have had angiitis. Five of the eight patients died despite therapy, and the remaining three had irreversible sequelae. Conclusions: The prevalence of cerebrovascular complications related to Bothrops spp. bites is 2.6%. Intracranial hemorrhages are more frequent than cerebral infarcts. The prognosis of these patients is poor.