Compositional and toxicological investigation of pooled venom from farm-raised Naja atra

Background: Naja atra is a venomous snake species medically relevant in China. In the current study, we evaluated the composition and toxicological profile of venom collected from farm-raised N. atra. Methods: Venom was collected from third-generation captive bred N. atra on a snake farm in Hunan Province, China. The venom was analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis and nano-liquid chromatography with electrospray ionization tandem mass spectrometry. In addition, hemolytic activity, median lethal dose, serum biochemical and histopathological parameters were accessed. Results: N. atra venom proteome was dominated by phospholipase A2 (46.5%) and three-finger toxins (41.4 %), and a set of common low relative abundance proteins, including cysteine-rich secretory proteins (4.7%), NGF-beta (2.4%), snake venom metalloproteinase (1.5%), glutathione peroxidase (0.6%), vespryn (0.3%), and 5ʹ-nucleotidases (0.2%) were also found. Furthermore, the venom exhibited direct hemolytic activity, neurotoxicity, myotoxicity, and high lethal potency in mice, with a subcutaneous median lethal dose of 1.02 mg/kg. Histopathological analysis and serum biochemical tests revealed that venom caused acute hepatic, pulmonary and renal injury in mice. Conclusion: This study revealed the composition and toxicity of venom collected from farm-raised N. atra, thereby providing a reference for the analysis of venom samples collected from captive-born venomous snakes in the future.(AU)

Mordedura de Phalotris lemniscatus (Duméril, Bibron & Duméril, 1854) (Squamata, Dipsadidae) en Uruguay / Phalotris lemniscatus (Duméril, Bibron & Duméril, 1854) (Squamata, Dipsadidae) bites in Uruguay

Phalotris lemniscatus es la única especie representante del género Phalotris en Uruguay. Esta especie tiene una amplia distribución que incluye Uruguay, Rio Grande do Sul en Brasil y el norte de Argentina que se extiende a las áreas fronterizas con Bolivia y Paraguay. Aunque este ofidio no es agresivo, se registraron dos accidentes en Uruguay en los que se observó acción local y sistémica del veneno. Los mismos ocurrieron en las manos después de manipulación excesiva y prolongada de los ejemplares. Localmente presentaron edema leve, pero en términos sistémicos el veneno de Phalotris causó alteraciones en la coagulación. Los pacientes se recuperaron totalmente después de 3 días. Serán necesarios más estudios para establecer una terapia adecuada para los envenenamientos graves provocados por esta especie.

Phalotris lemniscatus is the only species representative of Phalotris genus in Uruguay. This species has a wide distribution that includes Uruguay, Rio Grande do Sul in Brazil and northern Argentina extending to the areas bordering Bolivia and Paraguay. Although this snake is not aggressive, there were two snakebite accidents in Uruguay. They occurred on the hands after excessive and prolonged handling of the specimens. Locally they showed mild edema, but in systemically Phalotris venom caused alterations in blood coagulation. The patients recovered completely after 3 days. More studies will be required to establish an adequate therapy for Phalotris severe envenomations.

l-Amino acid oxidase isolated from calloselasma rhodostoma snake venom induces cytotoxicity and apoptosis in JAK2V617F-positive cell lines

BACKGROUND: Myeloproliferative neoplasms are Philadelphia chromosome-negative diseases characterized by hyperproliferation of mature myeloid cells, associated or not with the Janus kinase 2 tyrosine kinase mutation, JAK2V617F. As there is no curative therapy, researchers have been investigating new drugs to treat myeloproliferative neoplasms, including l-amino acid oxidase from Calloselasma rhodostoma snake venom (CR-LAAO), which is a toxin capable of eliciting apoptosis in several tumor cell lines. OBJECTIVE: To evaluate the effects of l-amino acid oxidase from C. rhodostoma snake venom in the apoptotic machinery of JAK2-mutated cell lines. METHODS: The HEL 92.1.7 and SET-2 cell lines were cultured with l-amino acid oxidase and catalase for 12 h at 37 °C in 5% carbon dioxide. The cell viability was assessed by the multi-table tournament method, the level of apoptosis was measured by flow cytometry, and the expression of cysteine-dependent aspartate-specific proteases and cleaved Poly(ADP-ribose) polymerase were analyzed by Western blotting. RESULTS: l-Amino acid oxidase from C. rhodostoma snake venom was cytotoxic to HEL 92.1.7 and SET-2 cells (50% inhibitory concentration = 0.15 µg/mL and 1.5 µg/mL, respectively) and induced apoptosis in a concentration-dependent manner. Cell treatment with catalase mitigated the l-amino acid oxidase toxicity, indicating that hydrogen peroxide is a key component of its cytotoxic effect.The activated caspases 3 and 8 expression and cleaved PARP in HEL 92.1.7 and SET-2 cells confirmed the apoptosis activation by CR-LAAO. CONCLUSIONS: l-Amino acid oxidase from C. rhodostoma snake venom is a potential antineoplastic agent against HEL 92.1.7 and SET-2 JAK2V617F-positive cells as it activates the extrinsic apoptosis pathway.

Fatal neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal: a case report

Neurotoxic envenomation following bites by kraits (Bungarus species) is a leading cause of snakebite mortality in South Asia. Over a long time, this had been attributed only to one species, the common krait (Bungarus caeruleus). However, recent research has provided increasing evidence of the involvement of several krait species. Here, we report a fatal case of neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal. Case presentation A 33-year-old man was bitten in the outdoor corridor of his home in the eastern hills of Ilam district while handling a snake he thought to be non-venomous. He subsequently developed severe abdominal pain, frequent vomiting, and signs of neurotoxic envenomation leading to respiratory paralysis. The patient did not respond to Indian polyvalent antivenom given 4 h after the bite and died under treatment 8 h after the bite. This is the second time that a B. niger was observed in Nepal, the first documented case of envenomation by this species in the country and the sixth reported case worldwide. Conclusions Previous distribution records from eastern India and western Nepal, from western hills in Nepal, and from lowland localities in India and Bangladesh indicate risk of envenomation by B. niger throughout the low and intermediate elevations of Nepal up to at least 1,500 m above sea level. As very few people in Nepal bring killed snakes to healthcare centers and because there is a general belief among local people that there are no kraits in the hills, bites by B. niger are likely to be misdiagnosed and underreported.

Transcritoma da glândula venenífera da serpente Bothrops neuwiedi: montagem, anotação e identificação de proteínas de interesse farmacológico

Os componentes de venenos de serpentes são importantes ferramentas para a pesquisa científica, desenvolvimento de drogas, e para o diagnóstico de várias doenças. Descrevemos a montagem de novo e análise do transcritoma da glândula de veneno de uma serpente amplamente distribuída no Brasil a Bothrops neuwiedi. Com base em 9.500.000 sequências identificamos várias sequências inteiras codificantes de toxinas. A mais abundante expressão foi de transcritos de metaloproteinases de veneno de serpentes (SVMPs), que apresentou o maio rpercentual de sequências mapeadas em um transcriptoma de referência (34,40 %),seguido por lectinas tipo C (25,20 %), fosfolipases A2 (14,20%) e serino-proteinases(7,51 %). Devido à importância fisiopatológica no envenenamento e seu potencial uso como um modelo para o desenvolvimento biotecnológico de fármacos, as SVMPs tornaram-se o principal alvo deste estudo, para o qual realizamos análises filogenéticas com o objetivo de contribuir para uma melhor compreensão da biodiversidade e dos mecanismos moleculares subjacentes a evolução destas proteínas, e também contribuir para a descoberta de novos compostos com potencial ação terapêutica.

Transcritoma da glândula venenífera da serpente Bothrops neuwiedi: montagem, anotação e identificação de proteínas de interesse farmacológico / Transcriptome of vinifera gland of Bothrops neuwiedi: assembly, annotation and identification of proteins of pharmacological interest

Os componentes de venenos de serpentes são importantes ferramentas para a pesquisa científica, desenvolvimento de drogas, e para o diagnóstico de várias doenças. Descrevemos a montagem de novo e análise do transcritoma da glândula de veneno de uma serpente amplamente distribuída no Brasil a Bothrops neuwiedi. Com base em 9.500.000 sequências identificamos várias sequências inteiras codificantes de toxinas. A mais abundante expressão foi de transcritos de metaloproteinases de veneno de serpentes (SVMPs), que apresentou o maio rpercentual de sequências mapeadas em um transcriptoma de referência (34,40 %),seguido por lectinas tipo C (25,20 %), fosfolipases A2 (14,20%) e serino-proteinases(7,51 %). Devido à importância fisiopatológica no envenenamento e seu potencial uso como um modelo para o desenvolvimento biotecnológico de fármacos, as SVMPs tornaram-se o principal alvo deste estudo, para o qual realizamos análises filogenéticas com o objetivo de contribuir para uma melhor compreensão da biodiversidade e dos mecanismos moleculares subjacentes a evolução destas proteínas, e também contribuir para a descoberta de novos compostos com potencial ação terapêutica...

Isolated biomolecules of pharmacological interest in hemostasis from Cerastes cerastes venom

Biomolecules from Cerastes cerastes venom have been purified and characterized. Two phospholipases isolated from Cerastes cerastes venom share 51% of homology. CC2-PLA2 exhibits antiplatelet activity that blocks coagulation. CCSV-MPase, a non-hemorrhagic Zn2+-metalloproteinase, significantly reduced the plasmatic fibrinogen level and hydrolyzes only its Bβ chain. Serine proteinases such as RP34, afaâcytin and CC3-SPase hydrolyze the fibrinogen and are respectively α, αβ and αβ fibrinogenases. In deficient human plasma, afaâcytin replaces the missing factors VIII and IX, and activates purified human factor X into factor Xa. It releases serotonin from platelets and directly aggregates human (but not rabbit) blood platelets. RP34 proteinase also had no effect on both human and rabbit blood platelet aggregation. CC3-SPase revealed a pro-coagulant activity. However, the insolubility of the obtained clot indicates that CC3-SPase does not activate factor XIII. In addition, CC3-SPase clotting activity was carried out with human plasmas from volunteer patients deficient in clotting factors. Results showed that CC3-SPase shortens clotting time of plasma deficient in factors II and VII but with weaker clotting than normal plasma. The clotting time of plasma deficient in factor II is similar to that obtained with normal plasma; suggesting that CC3-SPase is able to replace both factors IIa and VII in the coagulation cascade and thus could be involved in the blood clotting process via an extrinsic pathway. These results imply that CC3-SPase and afaâcytin could repair hemostatic abnormalities and may replace some factors missing in pathological deficiency. Afaâcytin also exhibits α fibrinase property similar to a plasmin-like proteinase. Despite its thrombin-like characteristics, afaâcytin is not inhibited by plasmatic thrombin inhibitors. The procoagulant properties of afaâcytin might have potential clinical applications.

Neutralización heteróloga e interacción de amanitinas con venenos de Bothropsy Crotalus y de abeja / Heterologous neutralization and interaction of toxic amanitins with Bothrops and Crotalus venoms, and honey bee venom / Neutralização heteróloga e interação das amanitinas tóxicas com veneno de Bothrops e Crotalus e veneno de abelha

En el presente trabajo se examinó la interacción de las amanitinas de Amanita phalloides (Basidiomycetes) con los venenos de las serpientes Bothrops neuwiedi diporus ("yarará pequeña"), B. alternatus ("yarará grande"), Crotalus durissus terrificus ("serpiente de cascabel") y de la abeja mielera Apis mellifera. Se aplicaron las técnicas de Ouchterlony, inmunotransferencia, electroforesis rocket y electroforesis en gel de poliacrilamida a los anti-venenos y anti-toxinas obtenidos por inmunización en caballos y/o en conejos. Los anti­sueros de serpientes y las amanitinas reaccionaron en forma cruzada, así como el veneno de abeja y las amanitinas. Cuando los venenos de Bothrops neuwiedii diporus y Crotalus durissus terrificus se preincubaron con las amanitinas y se analizaron por electroforesis en gel de poliacrilamida-dodecilsulfato de sodio (dodecylsulfate-polyacrylamide gel electrophoresis: SDS-PAGE), algunas bandas de proteínas desaparecieron y otras se redujeron notablemente. Estos resultados revelan por primera vez la interacción y la degradación de las proteínas de los venenos de serpientes por las amanitinas. Por otra parte, la modificación del tiempo de coagulación de la sangre humana, debida a los venenos, se corrigió con los ciclopéptidos de Amanita. Estos resultados también se informan por primera vez en este trabajo. La presencia de polipéptidos tóxicos en los venenos de serpientes y abejas, así como en A. phalloides y la reactividad cruzada demostradas en este trabajo, sugieren la existencia de epítopos comunes a todos ellos. Teniendo en cuenta estas reacciones, el uso de anti-venenos heterólogos parece ser de utilidad en el tratamiento del envenenamiento.

In the present work, the interaction of the amanitins of Amanita phalloides (Basidiomycetes) with the venoms of Bothrops neuwiedi diporus ("small yarará snake"), B. alternatus ("big yarará"), Crotalus durissus terrificus ("rattlesnake"), and honey bee Apis mellifera was examined. Ouchterlony, immunotransfer, rocket-electrophoresis, and polyacrylamide gel electrophoresis techniques were applied to anti-venoms and anti-toxins obtained by immunization in horses and/or in rabbits. Snake antisera and amanitins cross-reacted as well as bee venom and amanitins. When venoms of Bothrops neuwiedii diporus and Crotalus durissus terrificus were preincubated with amanitins and analysed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), some protein bands disappeared and others were significantly reduced. These results reveal for the first time the interaction and degradation of proteins in snake venoms by amanitins. Moreover, the modification of the human blood clotting time due to snake venoms was corrected by the Amanita cyclopeptides. These results are also reported for the first time in this work. The occurrence of toxic polypeptides in the snake and bee venoms as well as in A. phalloides, and the cross-reactivity demostrated herein, suggest the occurrence of epitopes common to all of them. Taking into account these reactions,the use of heterologous anti-venoms seems to be of value in envenomation treatment.

No presente trabalho foi examinada a interação das amanitinas de Amanita phalloides (Basidiomy­cetes) com os venenos das serpentes Bothrops neuwiedi diporus ("jararaca-cruzeira"), B. alternatus ("urutu"), Crotalus durissus terrificus ("serpente cascavel") e da abelha-europeia Apis mellifera. Foram aplicadas as técnicas de Ouchterlony, imunotransferência, eletroforese rocket e eletroforese em gel de poliacrilamida aos anti-venenos e anti-toxinas obtidos por imunização em cavalos e/ou em coelhos. Os anti-soros de serpentes e as amanitinas reagiram em forma cruzada, bem como o veneno de abelha e as amanitinas. Quando os venenos de Bothrops neuwiedii diporus e Crotalus durissus terrificus foram incubados previamente com as amanitinas e foram analisados por eletroforese em gel de poliacrilamida-dodecilsulfato de sódio (dodecylsulfate-polyacrylamide gel electrophoresis: SDS-PAGE), algumas faixas de proteínas desapareceram e outras se reduziram notavelmente. Estes resultados revelam por primeira vez a interação e a degradação das proteínas dos venenos de serpentes pelas amanitinas. Por outra parte, a modificação do tempo de coagulação do sangue humano, devido aos venenos, se corrigiu com os ciclopeptídeos de Amanita. Estes resultados também se informam por primeira vez neste trabalho. A presença de polipeptídeos tóxicos nos venenos de serpentes e abelhas, bem como em A. phalloides e a reatividade cruzada demonstradas neste trabalho, sugerem a existência de epítopos comuns a todos eles. Levando em consideração estas reações, o uso de anti-venenos heterólogos parece ser de utilidade no tratamento do envenenamento.

Perfil eco-epidemiológico de los accidentes por ofidios en Monagas, Venezuela (2002-2006) / Eco-epidemiological profile of snakebite accidents in Monagas state, Venezuela (2002-2006)

El accidente causado por animales venenosos representa un problema global, especialmente en las áreas subtropicales y tropicales del mundo. En Venezuela, es endémico para varias regiones incluyendo la zona nororiental. Con el objetivo de ampliar y actualizar el perfil eco-epidemiológico del ofidismo en el estado Monagas, se evaluó su comportamiento, en cada municipio, durante 5 años de registro (2002 - 2006). Se contabilizaron 339 accidentes ofídicos (con promedio de 68 anuales). El incidente ocurrió con mayor frecuencia en agricultores, adultos jóvenes y de género masculino, durante sus labores en el campo y en el periodo diurno. La incidencia siguió un patrón estacional bimodal con predominio en épocas de alta y baja pluviosidad. Los envenenamientos botrópicos (28,6%) fueron más frecuentes que los crotálicos (14,5%), con proporción 2:1. El 87,9% recibió sueroterapia específica. La incidencia promedio anual en la entidad se ubicó en 11,30 casos por 100.000 habitantes, siendo Punceres (46,29), Acosta (20,91) y Bolívar (19,52) los municipios con mayor impacto. El estado Monagas presentó un mapa de endemicidad distribuido en municipios de (1) muy alta endemicidad, (2) alta endemicidad, (3) mediana endemicidad, (4) baja endemicidad y (5) muy baja endemicidad. Durante el período analizado no se registró muerte por esta causa en el estado. Los hallazgos sugieren la importancia del accidente por serpientes en Monagas, con especial importancia en la mitad norte de la entidad.

The accidents caused by venomous animals are a global problem, especially in subtropical and tropical regions of the world. In Venezuela, they are endemic in several regions including the northeast. In order to expand and update the ecoepidemiological profile of snake bites in Monagas state, their behavior was assessed in each municipality for 5 years (2002 -2006). There were 339 ophidian accidents (on average 68 per year). The bites occurred more frequently in young adult male farmers, while working in the field and during daytime. The incidence followed a bimodal seasonal pattern with predominance in high and low rainfall periods. Bothropic envenoming (28.6%) were the most frequent followed by Crotalic ones (14.5%), with a 2:1 ratio. 87.9% received specific serum therapy. The annual average incidence in the state was 11.30 cases per 100,000 inhabitants. Punceres (46.29), Acosta (20.91) and Bolivar (19.52) were the municipalities with the highest impact. Monagas state showed an endemicity map with municipalities having (1) very high endemicity, (2) high endemicity, (3) medium endemicity, (4) low endemicity and (5) very low endemicity. In the studied period there were no deaths from this cause in the state. The findings suggest the importance of snake accidents in Monagas, especially in the northern half of the state.

Development of a sensitive enzyme immunoassay (ELISA) for specific identification of Lachesis acrochorda venom

The snake genus Lachesis provokes 2 to 3% of snakebites in Colombia every year. Two Lachesis species, L. acrochorda and L. muta, share habitats with snakes from another genus, namely Bothrops asper and B. atrox. Lachesis venom causes systemic and local effects such as swelling, hemorrhaging, myonecrosis, hemostatic disorders and nephrotoxic symptoms similar to those induced by Bothrops, Portidium and Bothriechis bites. Bothrops antivenoms neutralize a variety of Lachesis venom toxins. However, these products are unable to avoid coagulation problems provoked by Lachesis snakebites. Thus, it is important to ascertain whether the envenomation was caused by a Bothrops or Lachesis snake. The present study found enzyme linked immunosorbent assay (ELISA) efficient for detecting Lachesis acrochorda venom in a concentration range of 3.9 to 1000 ng/mL, which did not show a cross-reaction with Bothrops, Portidium, Botriechis and Crotalus venoms. Furthermore, one fraction of L. acrochorda venom that did not show crossreactivity with B. asper venom was isolated using the same ELISA antibodies; some of its proteins were identified including one Gal-specific lectin and one metalloproteinase. This test may be useful to physicians, since it could be applicable for tracking the kinetic distribution of antigens in patients or experimentally envenomed animals.(AU)

Caracterização estrutural e funcional de uma proteína isolada do plasma de serpentes Bothrops jararaca, relacionada ao cininogênio de alta massa molecular de mamíferos / Structural and functional characterization of a protein isolated from Bothrops jararaca snake plasma, related to the mammalian high molecular weight kininogen

O plasma da serpente Bothrops jararaca é rico em inibidores de proteases, alguns dos quais com atividade inibitória sobre toxinas presentes no veneno de serpentes da mesma espécie. Um desses inibidores apresenta massa molecular de 110 kDa, é um potente inibidor de cisteíno-peptidase e libera um peptídeo que induz contração de musculatura lisa homóloga. Por estas características, essa proteína, denominada BjHK (Bothrops jararaca High Molecular Weight Kininogen), foi correlacionada ao cininogênio de alta massa molecular de mamíferos. Além dessas propriedades, verificou-se que essa proteína inibe metaloproteases presentes no veneno de B. jararaca. Esse efeito também foi observado no cininogênio de alta massa molecular humano e correlacionado a porções do domínio 5 dessa proteína. O objetivo do presente projeto é procurar possíveis homologias entre a BjHK e o cininogênio humano, além de possíveis atividades inibitórias sobre agregação plaquetária e adesão celular, atividades estas também descritas no cininogênio de alta massa molecular humano...

The Bothrops jararaca snake plasma is rich in protease inhibitors, some of which have inhibitory activity on toxins from its own venom. One of these, which has a molecular mass of 110 kDa, is a potent inhibitor of cysteine-peptidase and releases a peptide that induces contraction of homologous smooth musculature. For these characteristics this protein, named BjHK (Bothrops jararaca High Molecular Weight Kininogen) was correlated to mammalian high molecular weight kininogens. Moreover, it was found that this protein inhibits metalloproteases present in the B. jararaca venom. This effect was also observed in human high molecular weight kininogen and correlated to portions of the domain 5 of this protein. The aim of this project is to search for homologies between BjHK and the human kininogen, as well as a possible inhibitory activity of this protein on platelet aggregation and cells adhesion. These activities were also described in human high molecular weight kininogen...

Comparação da toxidade entre peçonhas de serpentes do gênero Bothrops* presentes nas regiões sul e sudeste do Brasil (*Serpentes, Viperidae) / Comparison of toxicity among pitvipers poison of the genus Bothrops* present in the south and southeast regions of Brazil (*Serpentes: Viperidae)

Were analyzed poison samples as a pool extracted from B. alternatus and B. jararaca. The regional pool from different areas of Rio Grande do Sul. The national pool, poisons specially from São Paulo, Espírito Santo, Minas Gerais and Paraná states. Were analyzed: acute intraperitoneal median lethal doses (LD50), proteolytic activity on casein, coagulant effect on human plasma. The phospholipasic enzyme activities; the measurement of protein bands and the electrophoretic patterns were analyzed too. The analyses between the samples were made by comparison of biochemical actions and protein composition into the species, and inter-regionally between the pools. The comparison by electrophoresis, regional samples showed particularities in their venom protein composition sharing phospholipasic miotoxins, with 14 KDa, that were poorly observed in the national pool. However, we can observe other proteins with compatible size with phospholipases with miotoxic activities, with different molecular weigh (16 KDa), present in all of the samples. The major phospholipasic activity and protein quantity were verified in regional samples. The regional pool has differences in proteolytic and coagulant activities, when compared with the national pool.

Analisaram-se amostras de peçonha em forma de "pool", extraídas de B. alternatus, B. jararaca. O "pool"regional foi composto de peçonhas exclusivamente do Rio Grande do Sul, coletados de diversas regiões do estado. No "pool" nacional, peçonhas provenientes principalmente, de São Paulo, Espírito Santo, Minas Gerais e Paraná. O objetivo deste trabalho foi determinar a DL50 IP aguda, ação proteolítica da caseína, ação enzimática fosfolipásica, efeito coagulatório sobre o plasma humano, mensuração das bandas protéicas e perfil eletroforético, em camundongos. Quando comparadas pela eletroforese, as amostras regionais apresentaram particularidades, como a composição protéica da peçonha compartilhando miotoxinas fosfolipásicas com 14 KDa, que são pouco observadas nas amostras do "pool" nacional, sugerindo ser esta maior concentração a responsável pela maior ação do "pool" regional para estas peçonhas. Entretanto, observam-se outras proteínas com tamanhos compatíveis com as fosfolipases com atividade miotóxicas com peso molecular diferente (16KDa) presentes em todas as amostras. Também verificou- se maior atividade fosfolipásica e teor protéico nas amostras regionais. O "pool" regional teve diferenças nas atividades proteolítica e coagulante no plasma quando comparado com o "pool" nacional.

Neural network-based species identification in venom-interacted cases in India

India is home to a number of venomous species. Every year in harvesting season, a large number of productive citizens are envenomed by such species. For efficient medical management of the victims, identification of the aggressor species as well as assessment of the envenomation degree is necessary. Species identification is generally based on the visual description by the victim or a witness and is therefore quite likely to be erroneous. Symptomatic identification remains the only available method. In a previous published work, the authors proposed a classification table for snake species based on manifested symptoms applicable in Indian subcontinent. The classification table serves the purpose to a great deal but as a manual method it demands human expertise. The current paper presents a neural network-based symptomatic species identification system. A symptom vector is fed as input to the neural network and the system yields the most probable species as well as the envenomation severity as the output. The severity status can be very helpful in calculating the antivenom dosage and in deciding the species-specific prognostic measures for efficient medical management.(AU)

Experimental ophitoxemia produced by the opisthoglyphous lora snake (Philodryas olfersii) venom

Várias serpentes da família Colubridae produzem secrecões orais venenosas. Neste trabalho, foi estudado o veneno coletado da presa posterior da serpente opistóglifa venezuelana Philodryas olfersii. Deferentes proteínas estavam presentes no veneno, sendo caracterizadas pela eletroforese de proteínas (SDS-PAGE) a 20%. A secrecão mostrou atividade proteolítica (gelatinase) a qual foi parcialmente purificada em uma coluna de intercâmbio iônico (mono Q2). Adicionalmente, a atividade hemorrágica do veneno de Philodryas olfersii foi demonstrada em embriões de galinha, pele e peritônio de rato. Os sintomas neurológicos foram demonstrados em camundongos inoculados com veneno de Philodryas olfersii. Em conclusão, o veneno da Philodryas olfersii mostrou atividade proteolítica, hemorrágica, e neurotóxica, assim aumentando o interesse na elevada acão tóxica do veneno da Philodryas olfersii.

Acute renal failure in viperidae snake bite victims

This study included 10 cases of viperidae snake bite that developed acute renal failure out of 73 cases admitted to various wards of Liaquat Medical College hospital during the last two years. All these patients reported to the hospital 3-5 days after the bite. All had signs of severe envenomation with incoagulable blood and prolonged PT and APTT. All has bleeding manifestations. Blood urea and serum creatinine were increased in all patients and four were anuric. Leucocytosis and thrombocytopenia were found in 7 cases, serum bilirubin was increased in 4 cases, 4 patients required dialysis and 4 out of 10 cases expired. Bad prognostic features included severe envenomation, leucocytosis, thrombocytopenia, and necessity for dialysis. We conclude that acute renal failure is a serious complication of viperidae snake bite with high mortality rate and it necessitates early and effective treatment

Effects of prolonged poisoning by cobra venom on blood coagulation, platelets and fibrinolysis

The effects of Cobra Venom [CV] on blood coagulation, platelets and fibrinolytic system were studied in rabbits after injecting repeated doses of 0.05 MLD of the Venom. Thrombocytopenia was the earliest change to appear. It was followed by rise in serum fibrinogen degradation products and prolongation of prothrombin time, [PT] activated partial thromboplastin time [APTT] and thrombin time [TT] indicating a progressive consumption coagulapathy and activation of fibrinolysis. Red blood cell morphology was unchanged during first three weeks; whereas fragmentation appeared after fourth week and it increased in severity with further envenomations i.e., when chronic disseminated intravascular clotting was established

Toxicidad de venenos de serpientes de importancia médica en México / Toxicity of venoms from snakes of medical importance in Mexico

La caracterización de las actividades tóxicas de los venenos de serpientes es necesaria para el cabal entendimiento de los procesos fisiopatológicos que se producen ante su mordedura, como también para evaluar la potencia neutralizante de los antivenenos utilizados para tratar estos envenenamientos. A causa de los pocos datos disponibles sobre la toxicidad del veneno de serpientes con importancia sanitaria en México, estudiamos las actividades tóxicas de los venenos de Bothrops asper, Athropoides nummifer, Agkistrodon billineatus> Crotalus durissus durissus, Crotalus basiliscus, Crotalus scutulatus, Crotalus atrox y Micrurus nigrocinctus. A los venenos se les realizaron los siguientes estudios: SDS-PAUE, determinación de la potencia letal, y de las actividades hemorrágica, necrotizante, coagulante en plasma y fibrinógeno, fosfolipásica y fibrinogenolítica. Se estudió además la capacidad neutralizante de un antiveneno de uso corriente para la terapéutica de las mordeduras de serpientes venenosas en México, sobre varias de estas actividades. Los venenos de vipéridos mostraron actividades hemorrágicas, necrotizante, coagulante sobre plasma, protrombínica, fibrinogenolítica y fosfolipásica importantes. Los venenos de mayor potencia letal fueron los de Micrurus nigrocinctus y Crotalus scutulatus, sin embargo el veneno que presentó en general potencias tóxicas mayores fue el de Bothrops asper. Las diferentes potencias tóxicas halladas se encontraron dentro de los márgenes descritos para especies de vipéridos y elápidos de Sudamérica. La actividad sobre el plasma y el fibrinógeno fue muy diferente en los diferentes venenos viperinos, sin embargo todos mostraron ser capaces de afectar componentes del sistema de la coagulación. El antiveneno probado no sólo neutralizó la letalidad del veneno sino también sus actividades tóxicas.

The characterization of the toxic activities of snake venoms is necessary to understand the physiopathology of the envenomation and to test the potency of the antivenoms used to treat this pathology. Because of the lack of data on the toxic activities of venoms from Mexican snakes of medical importance, we studied the venoms from Bothrops asper, Athropoides nummifer, Agkistrodon billineatus, Crotalus durissus durissus, Crotalus basiliscus, Crotalus scutulatus, Crotalus atrox and Micrurus nigrocinctus. The studies performed were : SDS-PAOE, determination of lethal potency, hemorrhagic, necrotizing, coagulation on plasma and fibrinogen, phospholipasic and fibrinogenolytic activities. In addition we studied the neutralizing capacity of the toxic activities of an antivenom currently used for the treatment of snakebites in Mexico. The venom from viperids showed important hemorrhagic, necrotizing, coagulative on plasma, prothrombinic, fibrinogenolytic and phospholipase activities. The venoms with the highest lethal potency were those of Micrurus nigrocinctus and Crotalus scutulatus; however, the viperine venom that globally displayed the most potent toxic activities was from Bothrops asper. All the venoms showed toxic activities of similar range to those described for other American venomous snakes. The activity on plasma or fibrinogen varied widely among the different venoms but all displayed capacity to act on the coagulation system. The antivenom tested not only neutralized the lethalityB. asper venom but also its other toxic activities.

Bilateral angle closure glaucoma following snake bite.

Snake venoms are complex heterogenous poisons with multiple effects. Ocular complications with snake bite are rare. This report describes two cases which developed bilateral acute angle closure glaucoma following snake bite. There was complete recovery in the two patients following timely diagnosis and treatment.

Histopathological features in a horse on repeated injections of polyvalent snake venom

A 7-year-old stallion was bought for production of polyvalent snake antiserum. The animal died in less than two months from the beginning, of weakly injection with an increasing concentration of polyvalent snake venom. In histopathological examination, severe necrosis of renal tubules [nephrosis] and portal sclerosis with necrosis of hepatocytes were observed. In the myocardium, thrombosis in small arteries, concurrent necrosis and fibrosis, as well as arteriosclerotic changes inside a coronary artery were observed. In the lung, there were severe congestion and hemorrhage. Moreover, destruction of alveolar walls caused marked emphysema