RESUMO
Envenomation by Loxosceles spiders can result in severe systemic and local reactions, which are mainly triggered by Sphingomyelinase D (SMase D), a toxic component of Loxosceles venom. SMase D induces a systemic inflammatory condition similar to the reaction observed during an endotoxic shock. Considering the potent pro inflammatory potential of Loxosceles venom and the SMase D, in this study we have used the whole human blood model to study the endotoxic-like shock triggered by SMase D. Recombinant purified SMase D from L. intermedia venom, similarly to LPS, induced activation of blood leukocytes, as observed by the increase in the expression of CD11b and TLR4, production of reactive oxygen and nitrogen species (superoxide anion and peroxynitrite) and release of TNF-alpha. Complement consumption in the plasma was also detected, and complement inhibition by compstatin decreased the SMase D and LPS-induced leukocyte activation, as demonstrated by a reduction in the expression of CD11b and TLR4 and superoxide anion production. Similar results were found for the L. intermedia venom, except for the production of TNF-alpha. These findings indicate that SMase D present in Loxosceles venom is able to activate leukocytes in a partially complement-dependent manner, which can contribute to the systemic inflammation that follows envenomation by this spider. Thus, future therapeutic management of systemic Loxosceles envenomation could include the use of complement inhibitors as adjunct therapy.
RESUMO
Envenomation by Loxosceles spiders can result in severe systemic and local reactions, which are mainly triggered by Sphingomyelinase D (SMase D), a toxic component of Loxosceles venom. SMase D induces a systemic inflammatory condition similar to the reaction observed during an endotoxic shock. Considering the potent pro inflammatory potential of Loxosceles venom and the SMase D, in this study we have used the whole human blood model to study the endotoxic-like shock triggered by SMase D. Recombinant purified SMase D from L. intermedia venom, similarly to LPS, induced activation of blood leukocytes, as observed by the increase in the expression of CD11b and TLR4, production of reactive oxygen and nitrogen species (superoxide anion and peroxynitrite) and release of TNF-alpha. Complement consumption in the plasma was also detected, and complement inhibition by compstatin decreased the SMase D and LPS-induced leukocyte activation, as demonstrated by a reduction in the expression of CD11b and TLR4 and superoxide anion production. Similar results were found for the L. intermedia venom, except for the production of TNF-alpha. These findings indicate that SMase D present in Loxosceles venom is able to activate leukocytes in a partially complement-dependent manner, which can contribute to the systemic inflammation that follows envenomation by this spider. Thus, future therapeutic management of systemic Loxosceles envenomation could include the use of complement inhibitors as adjunct therapy.
RESUMO
Dentre as principais questões endereçadas à psicanálise contemporânea, uma boa parte dos temas diz respeito ao papel da psicanálise frente às neurociências, e à presença cada vez mais frequente de conceitos psicodinâmicos em modelos neurobiológicos sobre a mente e o cérebro. Há diversos artigos científicos recentes que se apoiam em recursos de neuroimagem para propor aproximações entre alguns conceitos freudianos clássicos e determinados resultados empíricos. Alguns estudos até propõem uma junção entre as duas áreas, o que tem gerado polêmicas. Este artigo discute o surgimento da Neuropsicanálisee o que ela representa nesse debate. Para traçar uma reflexão inicial sobre a proposta neuropsicanalítica, relatamos alguns de seus procedimentos clínicos em associação com o método psicanalítico de investigação do inconsciente e as concepções freudianas de melancolia e narcisismo
Assuntos
Neurociências , Procedimentos Clínicos , Empirismo , Métodos , NeuroimagemRESUMO
Dentre as principais questões endereçadas à psicanálise contemporânea, uma boa parte dos temas diz respeito ao papel da psicanálise frente às neurociências, e à presença cada vez mais frequente de conceitos psicodinâmicos em modelos neurobiológicos sobre a mente e o cérebro. Há diversos artigos científicos recentes que se apoiam em recursos de neuroimagem para propor aproximações entre alguns conceitos freudianos clássicos e determinados resultados empíricos. Alguns estudos até propõem uma junção entre as duas áreas, o que tem gerado polêmicas. Este artigo discute o surgimento da Neuropsicanálisee o que ela representa nesse debate. Para traçar uma reflexão inicial sobre a proposta neuropsicanalítica, relatamos alguns de seus procedimentos clínicos em associação com o método psicanalítico de investigação do inconsciente e as concepções freudianas de melancolia e narcisismo
Assuntos
Neurociências , Procedimentos Clínicos , Empirismo , NeuroimagemRESUMO
Ctenus medius Keyserling, 1891 (Araneae: Ctenidae) co-occurs in various microhabitats of the Brazilian Atlantic Forest and can be easily misidentified as the medically important spider Phoneutria nigriventer Keyserling, 1981 (Ctenidae). Despite being phylogenetically close to Phoneutria, no data are available about the toxic potential of Ctenus medius venom. Here we show that, although presenting different profile of protein composition, C. medius venom displays some of the toxic properties exhibited by P. nigriventer venom, including proteolytic, hyaluronidasic and phospholipasic activities, as well as the ability of causing hyperalgesia and edema. Moreover, C. medius venom interferes in the activation of the complement system in concentrations that P. nigriventer venom is inactive. Thus, these data show that venoms of spiders from Ctenidae family share important proinflammatory properties and suggest that the C. medius bite may have an important noxious effect in human accidents.
