Crotoxin in humans: analysis of the effects on extraocular and facial muscles.

Purpose: Crotoxin is the main neurotoxin of South American rattlesnake Crotalus durissus terrificus. The neurotoxic action is characterized by a presynaptic blockade. The purpose of this research is to assess the ability of crotoxin to induce temporary paralysis of extraocular and facial muscles in humans.

Study of crotoxin on the induction of paralysis in extraocular muscle in animal model.

Purpose: Crotoxin is the major toxin of the venom of the South American rattlesnake Crotalus durissus terrificus, capable of causing a blockade of the neurotransmitters at the neuromuscular junction. The objective of this study was to appraise the action and effectiveness of the crotoxin induced paralysis of the extraocular muscle and to compare its effects with the botulinum toxin type A (BT-A).

Methods: The crotoxin, with LD50 of 1.

Clinical trial of two antivenoms for the treatment of Bothrops and Lachesis bites in the north eastern Amazon region of Brazil.

The efficacies of specific Bothrops atrox-Lachesis and standard Bothrops-Lachesis antivenoms were compared in the north eastern Amazon region of Brazil. The main aim was to investigate whether a specific antivenom raised against the venom of B. atrox, the most important Amazon snake species from a medical point of view, was necessary for the treatment of patients in this region.

Kallikrein-like proteinase from bushmaster snake venom.

A kallikrein-like proteinase of Lachesis muta muta (bushmaster) venom, designated LV-Ka, was purified by gel filtration and anion exchange chromatographies. Physicochemical studies indicated that the purified enzyme is a 33 kDa monomeric glycoprotein, the Mr of which fell to 28 kDa after deglycosylation with PNGase F. Approximately 77% of the protein sequence was determined by sequencing the various fragments derived from digestions with endoproteases.

Pharmacological characterization and neutralization of the venoms used in the production of Bothropic antivenom in Brazil.

Some pharmacological effects of the venoms of five different Brazilian Bothrops species and a pool of these venoms (AgB) were quantified. The ability of polyspecific Bothropic antivenom produced at Fundação Ezequiel Dias (FUNED, Brazil) to neutralize the principal toxic and enzymatic activities was studied using in vivo and in vitro assays. The lethality, hemorrhagic, necrotizing, proteolytic, phospholipase, coagulant and fibrinolytic activities were measured for each of these venoms.