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This case report presents an exotic envenomation by a Chinese snake, Protobothrops mangshanensis. Its venom exhibited potent activity against plasma and fibrinogen, among other enzymatic activities. The patient initially presented with edema of the right upper limb, without tissue necrosis. There were no signs of bleeding; however, severe hypofibrinogenemia was observed (nadir value at 0.4 g/L), with a marked increase in fibrinogen degradation products and D-dimers, without any other coagulation disturbances. In the absence of a specific antivenom available against Asian Crotalinae venoms, the patient was treated at the 29th hour after bite with six vials of Antivipmyn™ TRI (Instituto Bioclon, Mexico, Mexico), a Mexican antivenom initially intended for American Crotalinae venoms, i.e., Bothrops asper, Lachesis muta and Crotalus durissus. Fibrinogen began to rise 6 hours after the antivenom infusion and was within the normal range 38 hours later. The report also underscores the utility of ClotPro® (Haemonetics ®USA), a viscoelastic test, for real-time monitoring of the snakebite-related coagulopathy. The clotting time was extended to 188 seconds on the EX-test while the MCF was decreased to 31 mm on the EX-test and the AP-test and was not measurable on the FIB-test, confirming severe hypofibrinogenemia. In order to confirm the paraspecificity of antivenom on the venom of P. mangshanensis, we studied the experimental neutralization of the venom procoagulant effect by Antivipmyn TRI and Green Pit Viper antivenom, which has been used in previous published clinical cases of P. mangshanensis envenomation. Both Antivipmyn™ TRI and Green Pit Viper antivenom corrected the procoagulant effect induced by P. mangshanensis venom. These findings suggest that Antivipmyn™ TRI cross-reacts with Protobothrops mangshanensis venom. In the absence of antivenom covering Asian Crotalinae, Antivipmyn TRI should be considered to treat an envenomation by Protobothrops spp.

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Despite a recent surge in high-throughput venom research that has enabled many species to be studied, some snake venoms remain understudied. The long-tailed rattlesnakes (Crotalus ericsmithi, C. lannomi, and C. stejnegeri) are one group where such research lags, largely owing to the rarity of these snakes and the hazardous areas, ripe with drug (marijuana and opium) production, they inhabit in Mexico. To fill this knowledge gap, we used multiple functional assays to examine the coagulotoxic (including across different plasma types), neurotoxic, and myotoxic activity of the venom of the long-tailed rattlesnakes. All crude venoms were shown to be potently anticoagulant on human plasma, which we discovered was not due to the destruction of fibrinogen, except for C. stejnegeri displaying minor fibrinogen destruction activity. All venoms exhibited anticoagulant activity on rat, avian, and amphibian plasmas, with C. ericsmithi being the most potent. We determined the mechanism of anticoagulant activity by C. ericsmithi and C. lannomi venoms to be phospholipid destruction and inhibition of multiple coagulation factors, leading to a net disruption of the clotting cascade. In the chick biventer assay, C. ericsmithi and C. lannomi did not exhibit neurotoxic activity but displayed potential weak myotoxic activity. BIRMEX® (Faboterápico Polivalente Antiviperino) antivenom was not effective in neutralising this venom effect. Overall, this study provides an in-depth investigation of venom function of understudied long-tailed rattlesnakes and provides a springboard for future venom and ecology research on the group.

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Background: Snake envenomation is a medical condition with high morbidity and mortality in southwestern Colombia. Objectives: To describe the characteristics of the envenomation caused by Viperidae snakes view in a highly complex hospital in Southwestern Colombia. Methods: A cross-sectional study was carried out. Patients treated for Viperidae snake envenomation from 2001 to 2020 in a Hospital Fundación Valle del Lili, Cali, Colombia, were studied. Results: Twenty-eight patients were included. Envenomation was caused by the genera Bothrops, Bothriechis, Porthidium, and Bothrocophias. The median age was 37.7 (±20.6), and they were predominantly male (19, 68%). Bites occurred on the upper extremities in 16 (57%) patients. Pain (23, 81%) and edema (22, 78%) were the most common clinical symptoms. Thirteen (46%) patients presented coagulopathy. Prolonged prothrombin and activated partial thromboplastin times were common: (22, 78% and 15, 53%, respectively). Twenty (71%) patients were treated with polyvalent antivenom (median dose of 6 (2-15) vials). The median time between the accident and antivenom administration was 9 h (5.5-17). Door-to-needle time was 37.5 (0-62) min. Eighteen (64%) patients were admitted to the intensive care unit. Three (11%) patients had serum sickness. Seven (25%) developed infectious complications, four (14%) had surgery, one (3%) had compartment syndrome, one (3%) underwent amputation of the affected limb, and one (3%) patient died. Conclusions: Local manifestations and coagulopathy were common clinical features. Polyvalent antivenom was an effective treatment for disease control. Significant complications were associated with delays in seeking medical care.

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INTRODUCTION: Bothriechis schlegelii is a Crotaline viperid species of Central America and Northern South America. The characteristics of its envenomation have not been well established. We present clinical characteristics of human cases evaluated and treated in a hospital in southwestern Colombia. METHODS: We evaluated data from patients who suffered Bothriechis schlegelii envenomation and were seen at Fundación Valle del Lili Hospital, Cali, Colombia between 2011 and 2022. RESULTS: Eight patients were included, with a median age of 24 years. Snakebites occurred in rural areas. Six (75%) patients were bitten on the upper extremities in relation to the arboreal habits of this animal. The most common symptoms were pain and edema (N = 8, 100%), ecchymoses (N = 2, 25%), and paresthesia (N = 2, 25%). The most common systemic findings were hypofibrinogenemia (N = 8, 100%) and prolonged prothrombin time in five patients (N = 5, 62.5%). All were treated with polyvalent antivenom for Colombian snakes, with a good response and outcome. CONCLUSIONS: Most bite sites from B. schlegelii were on the upper limbs. All patients had both local manifestations, including edema, pain, and systemic effects with hypofibrinogenemia, but none had systemic bleeding. Every patient received antivenom and had favorable outcomes.

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In snakes that are known to be ambush predators, tail luring, in which the movement of a snake’s tail resembles that of a worm or insect larva and is used to attract prey, has emerged as a complementary hunting strategy. In certain species, some individuals may present a conspicuously bright colour at the tail tip, which eventually disappears with age. Some authors argue that the bright colour enhances the resemblance of the snake’s tail with a potential food item, increasing the success of capture. Here, we tested the influence of geographic variation, sex, and environmental factors on the probability that Common Lanceheads Bothrops jararaca (Wied-Neuwied, 1824) from southeastern Brazil were born with this contrasting tail tip and whether snakes retain this trait throughout adulthood. None of the predictors affected the probability of births with a contrasting tail tip. However, a higher proportion of individuals from the coastal populations retained this trait into adulthood. The absence of difference in the probability of being born with this trait indicates that there are other factors influencing tail tip colour, such as phylogenetic correlates, rather than intrinsic or environmental factors. A higher proportion of ectothermic prey in the diet of coastal populations may explain why this population retains tail luring throughout adulthood.

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Thoroughly documenting prey items and diet composition is crucial for understanding a predator's role in the ecosystem. In gape restricted predators, such as snakes, documenting and analyzing the type and size of the prey is important to interpret their ecological role. We describe the diet patterns of a species of venomous snake, the Terciopelo pit viper (Bothrops asper), from its Ecuadorian populations. Examining the gastrointestinal contents of museum specimens collected over an extensive area of the Pacific lowlands of Ecuador, we encountered 69 identifiable prey items from four major taxonomic groups (amphibians, centipedes, mammals, and reptiles). We evaluated the observed composition of prey to check for differences between sexes and size-classes. To complement our observations of the Terciopelo species complex throughout their distribution, we carried out a systematic literature review. Our data show an ontogenetic shift in diet, with a transition from more diverse diet in juveniles towards a mammal-specialized diet in adults, and distinct proportion of prey taxa between the sexes in the juvenile size class.

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The internet is one of the world’s main communication channels these days. Unfortunately, because of its accessibility, this digital media also enables the circulation of biased and unreliable information, like fake news. Snakes, for example, are, to this day, target of the sensationalist media, which pictures them as scary and violent animals and makes people kill them because they think they’re evil beings. This may cause many snake species to be endangered, including the golden lancehead pit viper (Bothrops insularis). This species is endemic to Ilha da Queimada Grande and is object of misinformation on the part of many national and international communication channels. In this sense, this study aimed to identify false information about the biology and ecology of B. insularis disseminated by digital media in the last ten years, and, later, clarify them based on reliable sources to demystify the species in question. Incorrect data about the venom, habits, population size, diet, morphology, and reproduction of B. insularis were collected from internet sources and stored in tables and graphics, and then the frequency with which the data about each considered topic were found was calculated. A bibliographic survey was conducted to identify and clarify the wrong information that were found. A total of 174 false information about B. insularis was collected, given that 113 were about its venom (64,9%), 32 about its population size (18,4%), 12 about its habits (6,9%), eight about its diet (4,6%), seven about its body size (4%) and two about its reproduction (1,1%). These results highlight the necessity to invest even more in scientific divulgation and environmental education projects to bring people closer to these animals and make them understand their ecological roles and the importance of conserving all species of snakes, especially the endangered island species.

A internet é considerada atualmente um dos principais meios de comunicação do mundo. Paradigmaticamente, entretanto, decorrente de sua acessibilidade, essa mídia digital também permite a circulação de informações tendenciosas, pouco confiáveis ou inverídicas, como é o caso das fake news. As serpentes, por exemplo, são até hoje alvo da mídia sensacionalista, que as retrata como animais assustadores e violentos, fazendo com que as pessoas as matem por acharem que são seres maldosos. Isso acaba colocando em risco inúmeras espécies de serpentes, venenosas ou não, incluindo a jararaca-ilhoa (Bothrops insularis), endêmica da Ilha da Queimada Grande, a qual é objeto de desinformação por parte dos diversos veículos de comunicação digitais nacionais e internacionais. Desse modo, este estudo teve como objetivo identificar informações falsas referentes à biologia e ecologia de B. insularis veiculadas em meios digitais nos últimos dez anos e, posteriormente, esclarecê-las com base em fontes bibliográficas confiáveis para desmistificar a espécie estudada. Foi realizado um levantamento de fontes da internet que contivessem informações incorretas sobre o veneno, hábito, tamanho populacional, alimentação, morfologia e reprodução de B. insularis. Os resultados foram organizados em tabelas e gráficos, e foi calculada a frequência com que os dados sobre cada tópico analisado foram encontrados. Para a identificação e posterior esclarecimento dessas informações, foi realizado um levantamento bibliográfico em fontes científicas. Foram coletadas 174 informações falsas sobre B. insularis, sendo 113 sobre o veneno (64,9%), 32 sobre o tamanho populacional (18,4%), 12 sobre o hábito (6,9%), oito sobre a alimentação (4,6%), sete sobre o comprimento do corpo (4%) e duas sobre a reprodução (1,1%). Estes resultados evidenciam a necessidade de investir ainda mais em projetos de divulgação científica e educação ambiental, a fim de aproximar as pessoas desses animais e fazê-las entender sua função ecológica e a importância de conservar as diversas espécies ofídicas, em especial as insulares ameaçadas de extinção.

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Snakebite is a globally neglected tropical disease, with coagulation disturbances being the primary pathology of many deadly snake venoms. Age-related differences in human plasma have been abundantly reported, yet the effect that these differences pose regarding snakebite is largely unknown. We tested for differences in coagulotoxic effects (via clotting time) of multiple snake venoms upon healthy human adult (18+) and paediatric (median 3.3 years old) plasma in vivo and compared these effects to the time it takes the plasmas to clot without the addition of venom (the spontaneous clotting time). We tested venoms from 15 medically significant snake species (from 13 genera) from around the world with various mechanisms of coagulotoxic actions, across the three broad categories of procoagulant, pseudo-procoagulant, and anticoagulant, to identify any differences between the two plasmas in their relative pathophysiological vulnerability to snakebite. One procoagulant venom (Daboia russelii, Russell’s Viper) produced significantly greater potency on paediatric plasma compared with adult plasma. In contrast, the two anticoagulant venoms (Pseudechis australis, Mulga Snake; and Bitis cornuta, Many-horned Adder) were significantly more potent on adult plasma. All other procoagulant venoms and all pseudo-procoagulant venoms displayed similar potency across both plasmas. Our preliminary results may inform future studies on the effect of snake venoms upon plasmas from different age demographics and hope to reduce the burden of snakebite upon society.

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RATIONALE: The endocannabinoid modulation of fear and anxiety due to the on-demand synthesis and degradation is supported by a large body of research. Although it has been proposed that anandamide (AEA) in the substantia nigra pars reticulata (SNpr) seems to be important for the organisation of innate fear-related behaviours, a role for endogenous AEA has yet to be clarified. METHODS: Mice were treated with the fatty acid amide hydrolase (FAAH) selective inhibitor URB597 at different concentrations (0.01, 0.1, 1 nmol/0.1 µL) in the SNpr and confronted by rattlesnakes (Crotalus durissus terrificus). The most effective dose of URB597 (1 nmol) was also preceded by microinjections of the CB1 receptor antagonist AM251 (0.1 nmol) into the SNpr, and mice were then confronted by the venomous snake. RESULTS: URB597 (0.1 and 1 nmol) in the SNpr decreased the expression of defensive behaviours such as defensive attention, escape, and time spent inside the burrow of mice confronted by rattlesnakes. Moreover, pretreatment of SNpr with AM251 suppressed these antiaversive effects of URB597 in this midbrain structure. CONCLUSION: Overall, these data clearly indicate that the panicolytic consequences of endogenous AEA enhancement in the SNpr are mediated by CB1 receptor signalling.

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Crotoxin complex CA/CB and crotamine are the main toxins associated with Crotalus envenomation besides the enzymatic activities of phospholipases (PLA2) and proteases. The neutralization at least of the crotoxin complex by neutralizing the subunit B could be a key in the production process of antivenoms against crotalids. Therefore, in this work, a Crotoxin B was recombinantly expressed to evaluate its capacity as an immunogen and its ability to produce neutralizing antibodies against crotalid venoms. A Crotoxin B transcript from Crotalus tzabcan was cloned into a pCR®2.1-TOPO vector (Invitrogen, Waltham, MA, USA) and subsequently expressed heterologously in bacteria. HisrCrotoxin B was extracted from inclusion bodies and refolded in vitro. The secondary structure of HisrCrotoxin B was comparable to the secondary structure of the native Crotoxin B, and it has PLA2 activity as the native Crotoxin B. HisrCrotoxin B was used to immunize rabbits, and the obtained antibodies partially inhibited the activity of PLA2 from C. tzabcan. The anti-HisrCrotoxin B antibodies neutralized the native Crotoxin B and the whole venoms from C. tzabcan, C. s. salvini, and C. mictlantecuhtli. Additionally, anti-HisrCrotoxin B antibodies recognized native Crotoxin B from different Crotalus species, and they could discriminate venom in species with high or low levels of or absence of Crotoxin B.

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