Antivenoms for the treatment of snakebite envenomings: The road ahead

The parenteral administration of antivenoms is the cornerstone of snakebite envenoming therapy. Efforts are made to ensure that antivenoms of adequate efficacy and safety are available world-wide. We address the main issues to be considered for the development and manufacture of improved antivenoms. Those include: (a) A knowledge-based composition design of venom mixtures used for immunization, based on biochemical, immunological, toxicological, taxonomic, clinical and epidemiological data; (b) a careful selection and adequate management of animals used for immunization; (c) well-designed immunization protocols; (d) sound innovations in plasma fractionation protocols to improve recovery, tolerability and stability of antivenoms; (e) the use of recombinant toxins as immunogens to generate antivenoms and the synthesis of engineered antibodies to substitute for animal-derived antivenoms; (f) scientific studies of the contribution of existing manufacturing steps to the inactivation or removal of viruses and other zoonotic pathogens; (g) the introduction of novel quality control tests; (h) the development of in vitro assays in substitution of in vivo tests to assess antivenom potency; and (i) scientifically-sound pre-clinical and clinical assessments of antivenoms. These tasks demand cooperative efforts at all main stages of antivenom development and production, and need concerted international partnerships between key stakeholders.Universidad de Costa Rica//UCR/Costa RicaInternational Foundation for Science//IFS/SueciaCiencia y Tecnología para el Desarrollo//CYTED/EspañaConsejo Superior de Investigaciones Científicas//CRUSA-CSIC/EspañaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

Experimental pathology of local tissue damage induced by Bothrops asper snake venom

Envenomations by Bothrops asper are often associated with complex and severe local pathological manifestations, including edema, blistering, dermonecrosis, myonecrosis and hemorrhage. The pathogenesis of these alterations has been investigated at the experimental level. These effects are mostly the consequence of the direct action of zinc-dependent metalloproteinases (SVMPs) and myotoxic phospholipases A2 (PLA2s). SVMPs induce hemorrhage, blistering, dermonecrosis and general extracellular matrix degradation, whereas PLA2s induce myonecrosis and also affect lymphatic vessels. In addition, the prominent vascular alterations leading to hemorrhage and edema may contribute to ischemia and further tissue necrosis. The mechanisms of action of SVMPs and PLA2s are discussed in detail in this review. Venom-induced tissue damage plays also a role in promoting bacterial infection. A prominent inflammatory reaction develops as a consequence of these local pathological alterations, with the synthesis and release of abundant mediators, resulting in edema and pain. However, whether inflammatory cells and mediators contribute to further tissue damage is not clear at present. Muscle tissue regeneration after venom-induced pathological effects is often impaired, thus resulting in permanent tissue loss and dysfunction. SVMP-induced microvessel damage is likely to be responsible of this poor regenerative outcome. Antivenoms are only partially effective in the neutralization of B. asper-induced local effects, and the search for novel toxin inhibitors represents a potential avenue for improving the treatment of this serious aspect of snakebite envenomation.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

Prospecção dos inibidores de fosfolipases A2 das classes alfa e gama (PLI e PLI) endógenos no plasma de serpentes Crotalidae brasileiras: caracterização molecular e propriedades biológicas

Exportado OPUSMade available in DSpace on 2019-08-12T11:49:57Z (GMT). No. of bitstreams: 1 17.04.2012_tese_completa.pdf: 4500978 bytes, checksum: 40917f6e99bc14d30f8e6abbd7652823 (MD5) Previous issue date: 8A presença de inibidores plasmáticos de fosfolipase A2 (PLA2) no plasma de serpentes tem sido relatada por vários pesquisadores. Estes inibidores atualmente são classificados em três classes: alfa, beta e gama, de acordo com sua estrutura (Ohkura e cols., 1997). Inibidores alfa apresentam domínios semelhantes ao domínio de reconhecimento de carboidratos (CRD) das lectinas tipo-C, enquanto inibidores da classe gama apresentam em sua estrutura, repetições ricas em leucina (LRR), como a 2-macroglobulna humana. Já a classe gama mostram um padrão de resíduos cisteína similar ao do receptor do ativador de plasminogênio tipo uroquinase (u-PAR). Neste trabalho investigamos a presença de cDNAs codificadores de inibidores de PLA2 (PLIs) das classes alfa e gama no fígado de seis espécies de serpentes do gênero Bothrops (B. alternatus, B. erythromelas, B. jararaca, B. jararacussu, B. moojeni e B. neuwiedi), além de Lachesis muta muta e Crotalus durissus terrificus. Os cDNAs foram obtidos por RT-PCR a partir do RNA total do fígado de cada espécime. A amplificação do DNA foi realizada por PCR na presença de oligonucleotídeos desenhados com base na sequência de nucleotídeos publicados na literatura (inibidor alfa de Agkistrodon blomhoffii siniticus e no inibidor gama de C. d. terrificus). Os produtos de amplificação foram clonados em vetores do tipo TA e colônias recombinantes positivas foram confirmadas por PCR. Os DNAs de pelo menos quatro clones positivos para cada inibidor alfa e dois clones para cada inibidor gama foram completamente sequenciados. As sequências nucleotídicas, assim como as estruturas primárias deduzidas foram alinhados com sequências de inibidores conhecidos para pesquisa de homologia. Utilizando ferramentas de bioinformática foram realizadas análises detalhadas para cada proteína. Foram derivadas árvores filogenéticas para cada classe de PLIs brasileiros descritos, assim como a sugestão de modelos tridimensionais. A expressão de uma proteína recombinante da classe alfa foi realizada com sucesso em sistema de expressão procariota.The presence of phospholipase A2 (PLA2) inhibitors in the blood plasma of snakes has been reported by several authors. These inhibitors are, presently, classified in three structural classes named alfa, beta and gamma. Alfa-inhibitors contain a domain similar to the carbohydrate recognition domain (CRD) of C-type lectins, whereas beta-inhibitors display leucine-rich repeats (LRR) such as those present in the human alpha2- macroglobulin. In the gamma-class members, in turn, the cystein pattern resembles that found in the uroquinase-type plasminogen activator receptor (u-PAR). In the present study we investigated the presence of mRNA codifying for alfa- and gamma-PLA2 inhibitors (PLIs) in the liver tissue of of six Brazilian snake species in the genus Bothrops (B. alternatus, B. erythromelas, B. jararaca, B. jararacussu, B. moojeni and B. neuwiedi) besides Lachesis muta and Crotalus durissus terrificus, by RT-PCR. DNA amplification was performed in the presence of primers designed based on PLIs already published in the literature (an alpha-PLI from Agkistrodon blomhoffii siniticus and a gamma-PLI from C. d. terrificus). The amplification products were cloned in TA-kind plasmid vector and a number of putative positive clones was confirmed by PCR. The DNAs of a minimum of four and two positive clones for alfa- and gamma- PLIs, respectively, were completely sequenced. The nucleotide sequences as well as the deduced primary sequences obtained were aligned with known PLIs looking for homology. A detailed analysis of each novel PLI-homologous protein was performed using bioinformatics tools. Phylogenetic trees were derived for the alpha- and gamma-PLIs from Brazilian snakes described, so far, and the tridimensional structure of an alpha-PLI (from L. muta) was modelled by homology. The obtention of a representative recombinant protein alpha-PLI (in procariote) are described

Fado do caroto dos Jor. / Estavao Amarante, BAR baryton. Fado cançāo : largarto / Savador Costa, chant ; e coro

[Traditions. Europe. Portugal]Comprend : Fado do caroto dos Jor. ; Fado cançā

La basura como instrumento de mejora del barrio (Maputo, Mozambique)

La basura como instrumento de mejora del barrio (Maputo, Mozambique

Úlcera gástrica em suínos naturalmente infectados por circovírus suíno tipo 2 (PCV2)

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Weed control strip influences the initial growth of Eucalyptus grandis

Reforestation in Brazil is conventionally carried out with a 50-cm weed control strip, using mechanical or manual hoeing or herbicides. The aim of this study was to determine effects of varying the width of the herbicide-treated strip on the establishment of Eucalyptus grandis. Eucalyptus plants were transplanted in Araraquara and Altinopolis counties, São Paulo State, Brazil. In Araraquara, the following treatments were evaluated: 0, 25, 50, 75, 100 and 150-cm wide strips, treated with herbicide, on either side of the eucalyptus row; in Altinopolis, the width of the strip on either side of the eucalyptus row was 0, 25, 50, 75, 100, 125 or 150 cm. Were evaluated dry matter of leaves, branches and stem and leaf area at 270 days after planting (270 DAP), chlorophyll content (400 DAP), stem diameter and eucalyptus plants height (410 DAP). In Araraquara, the main weed was Panicum maximum, and in Altinopolis, it was Rhynchelytrum repens. For both areas, a minimum of 75 cm of treated strip was required to minimise weed interference with eucalyptus plants' development.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq