Abstract in English:Envenomation by insects, snakes, scorpions, and spiders involves the activation of the inflammatory system with the release and activation of pro-inflammatory cytokines, chemotactic mediators, cellular infiltration, and other vasoactive mediators. Activation of the inflammatory system and its cascade of events play a major role in the pathogenesis of envenomation, its clinical picture, and outcome. Additional clinical and laboratory studies are required to characterize the exact mechanisms by which the inflammatory system affects the pathophysiology, clinical course, and complications following envenomations. A better understanding of the involvement of the inflammatory cascade in different envenoming syndromes may have future therapeutic benefits.
Abstract in English:Labelling of scorpion (Mesobuthus tamulus concanesis Pocock) venom was successfully achieved with Tc 99m using direct tin reduction procedure. Biodistribution studies were carried out in Wistar rats at different time intervals after i.v. administration of the labelled venom. Scintiimages were obtained after scorpion envenoming using a large field of view gamma camera to ascertain the pharmacological action of venom in the body. Within 5 min of administration, labelled venom was found in the blood (27.7%), muscle (30.11%), bone (13.3%), kidneys (11.5%), liver (10.4%), and other organs. The level of venom in the kidneys was higher than in the liver. The labelled venom was excreted through renal and hepatobiliary pathways. An immunoreactivity study was carried out in rabbits after i.v. injection of labelled scorpion venom followed by the injection of the species specific antivenom. A threefold increase in uptake by the kidneys was observed compared with that seen with scorpion venom alone. The neutralisation of the venom in the kidneys was higher than in the liver.
Abstract in English:Severe envenoming was induced in two groups of experimental dogs after subcutaneous (SQ) injection of venom of the scorpion (Mesobuthus tamulus concanesis, Pocock) (3.0 and 3.5 mg/kg body weight). The circulating levels of blood sugar, insulin, glucagon, and cortisol were assayed at 0, and 30, 60, 90 and 120 min after venom injection. There was an increase in the circulating levels of blood sugar, insulin, glucagon, and cortisol following envenoming. Scorpion envenoming causes an autonomic storm resulting in a massive release of catecholamines, angiotensin II, glucagon, and cortisol accompanied by changes in insulin secretion. The rise in the counter-regulatory hormones (glucagon, cortisol, and catecholamines) oppose the anabolic actions of insulin resulting in a variety of clinical manifestations. These changes may lead to a syndrome of fuel-energy deficits and to an inability of the vital organs to utilise the existing metabolic substrates, ultimately resulting in multisystem organ failure (MSOF) and death.
Abstract in English:Currently, the use of antivenoms is the only available treatment for envenomation caused by venomous animals namely, snake, scorpion, spider, tick and jelly fish. Antivenoms are generally produced in large animals, mostly in horses. A large percentage of the population is allergic to horse proteins. Several animals are known to be resistant to snakebites and the antihemorrhagic and anti-lethal components have been isolated from sera of opossum, mongoose, meerkat and hedgehog, as well as from venomous and non-venomous snakes. Anti-lethal factor named Lethal Toxin Neutralizing Factor (LTNF) has been isolated in purity from opossum (Didelphis virginiana) serum by high pressure liquid chromatography (HPLC). The molecular weight of LTNF is 63 kDa, and it does not form precipitation with venoms or toxins by immunodiffusion. Death due to intraperitoneal (IP) injection of a predetermined lethal dose of venom from major families of snakes, for instance Crotalidae, Elapidae, Viperidae and Hydrophiidae, is prevented in mice by subsequent IP inoculation of LTNF. Furthermore, LTNF neutralizes the lethality of scorpion and bee venoms and toxins from various animals, plants and bacteria. Thus, natural LTNF from opossum serum has potential as a universal therapy for envenomation caused by animals, plants and bacteria.
Abstract in English:The immunochemical reactivity and neutralizing capacity of polyvalent Vipera antivenom (Vipera ammodytes, Vipera aspis, Vipera berus, Vipera lebetina, and Vipera xanthina) were tested on the enzymatic and biological activities of Crotalus durissus terrificus and the following Bothrops venoms from Argentina (Bothrops alternatus, Bothrops ammodytoides, Bothrops neuwiedii, Bothrops jararaca, Bothrops jararacussu, and Bothrops moojeni). The Vipera antivenom reacted weakly when tested by double immunoprecipitation (DIP) and reacted with all the venoms when tested by ELISA. Several components in all the venoms studied were recognized in Western blots. Vipera antivenom deactivated to different degrees in vitro procoagulant, (indirect) hemolytic, and proteolytic activities in all the venoms studied. Preincubation of Bothrops alternatus venom with Vipera antivenom neutralized a lethal potency of 4.5 LD50 in mice with an ED50 of 1.25 <FONT FACE="Symbol">±</FONT> 0.25 <FONT FACE="Symbol">m</FONT>l per <FONT FACE="Symbol">m</FONT>g of venom, and with 1.0 <FONT FACE="Symbol">m</FONT>l/<FONT FACE="Symbol">m</FONT>g inhibited 54% of the hemorragic activity and 48% of necrotic activity. Vipera antivenom (2.0 <FONT FACE="Symbol">m</FONT>l per <FONT FACE="Symbol">m</FONT>g toxin) inhibited the phospholipase A2 activity of purified crotoxin and decreased its lethal potency by 60%, while the neutralizing capacity on the lethal potency of crude Crotalus durissus terrificus venom was poor even at a level of 5.0 <FONT FACE="Symbol">m</FONT>l/<FONT FACE="Symbol">m</FONT>g of venom.
Abstract in English:Two hundred and fifty-two specimens of Ochetosoma heterocoelium (Travassos, 1921) (Trematoda: Digenea: Ochetosomatidae) were detected in the mouth and esophagus of the snake Chironius exoletus (Linnaeus, 1758) (Ophidia: Colubridae) at the serpentarium of the Center for the Study of Venoms and Venomous Animals (CEVAP) of São Paulo State University (UNESP) in Botucatu, State of São Paulo, Brazil.
Abstract in English:This report documents a case of a melanic specimen of Crotalus durissus terrificus (Laurenti, 1768) found in Bofete, São Paulo State, Brazil. The authors describe this melanic snake, determine the electrophoretic pattern of its venom, and compare the venom of this specimen against that of normal Crotalus durissus terrificus. This report is very important because melanism is a rare chromatic anomaly