Toxicon : official journal of the International Society on Toxinology
-
Venom toxicity assessments are often based upon non-native surrogate prey species that are not consumed in the wild by the venomous predator. This raises questions about the relevance of toxicity results on these "model" prey in addressing ecological or evolutionary questions about venom effects on native prey. We explore this issue by comparing the toxicity of venom from pygmy rattlesnakes (Sistrurus miliarius) on taxonomically-diverse sets of model (non-native) and native prey. ⋯ Second, native prey generally showed higher LD50 values than their non-native counterparts, suggesting greater resistance to venom from a predator with which they interact in nature. Our results suggest that researchers should use native prey to generate measures of venom toxicity that are ecologically and evolutionarily relevant. If this is not possible using "model" prey species that are close taxonomic relatives to natural prey may be a reasonable alternative.
-
Snakebite in dogs from Pseudechis porphyriacus (red-bellied black snake; RBBS) is a common envenomation treated by veterinarians in Australia where this snake occurs. This case report describes the successful treatment of a clinically severe RBBS envenomation in a dog with an experimental bivalent equine whole IgG antivenom and mechanical ventilation, following its presentation in a cyanotic state. The cause of the cyanosis and respiratory distress was considered due to paralysis from neurotoxins in RBBS venom. ⋯ Free RBBS venom antigen was not detected post-antivenom treatment. Human cases of RBBS requiring ventilatory support are rare. This unusual case of RBBS envenomation in a dog highlights its potential clinical severity in dogs, and the need for early, aggressive, MV to achieve a successful outcome in cyanosed and clinically severe cases.
-
In Guadeloupe (French West Indies), many marine envenomation cases by jellyfish are observed. Some of them might induce an Irukandji syndrome (IS). The aim of this study was to analyse the clinical features of IS from the envenomation cases in the two public hospitals in Guadeloupe, and to compare them to non-IS stings. ⋯ Jellyfish envenomation is frequently associated with IS in Guadeloupean emergency wards. The IS cases were probably due to the species Alatina alata, and their periodicity can be determined according to the cycle of the moon. If patients showed symptoms slightly less severe than those in Australian studies, a case of cardiac decompensation, the first out of the Pacific, was observed. Based on our results, new definition of IS and severe IS are proposed.
-
Currently the Australian Resuscitation Council (ARC) recommends dousing with vinegar followed by ice as first aid for jellyfish stings in tropical Australia, with limited evidence to support this recommendation (Li et al., 2013). We report our successful experience in using hot water immersion as first aid in treating two people stung by venomous tropical Australian jellyfish, one by Chironex fleckeri and one by Carukia barnesi.
-
Disintegrins are small peptides produced in viper venom that act as integrin antagonists. When bound to integrins, disintegrins induce altered cellular behaviors, such as apoptotic induction. Disintegrins with RGDDL or RGDDM motifs induce apoptosis of normal and cancer cells. ⋯ Cell proliferation inhibition by r-Moj-D_ peptides was significantly reduced in SK-Mel-28 cells with a stable αv integrin knockdown. All six r-Moj-D_ peptides inhibited SK-Mel-28 cell migration at high levels (69%-100%). As a consequence, rac-1 mRNA expression levels were significantly reduced as early as 1 h after treatment, suggesting that rac-1 is involved in the cell migration activity of SK-Mel-28.