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1.
J Proteomics ; 105: 285-94, 2014 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-24434587

RESUMO

For over a century, venom samples from wild snakes have been collected and stored around the world. However, the quality of storage conditions for "vintage" venoms has rarely been assessed. The goal of this study was to determine whether such historical venom samples are still biochemically and pharmacologically viable for research purposes, or if new sample efforts are needed. In total, 52 samples spanning 5 genera and 13 species with regional variants of some species (e.g., 14 different populations of Notechis scutatus) were analysed by a combined proteomic and pharmacological approach to determine protein structural stability and bioactivity. When venoms were not exposed to air during storage, the proteomic results were virtually indistinguishable from that of fresh venom and bioactivity was equivalent or only slightly reduced. By contrast, a sample of Acanthophis antarcticus venom that was exposed to air (due to a loss of integrity of the rubber stopper) suffered significant degradation as evidenced by the proteomics profile. Interestingly, the neurotoxicity of this sample was nearly the same as fresh venom, indicating that degradation may have occurred in the free N- or C-terminus chains of the proteins, rather than at the tips of loops where the functional residues are located. These results suggest that these and other vintage venom collections may be of continuing value in toxin research. This is particularly important as many snake species worldwide are declining due to habitat destruction or modification. For some venoms (such as N. scutatus from Babel Island, Flinders Island, King Island and St. Francis Island) these were the first analyses ever conducted and these vintage samples may represent the only venom ever collected from these unique island forms of tiger snakes. Such vintage venoms may therefore represent the last remaining stocks of some local populations and thus are precious resources. These venoms also have significant historical value as the Oxyuranus venoms analysed include samples from the first coastal taipan (Oxyuranus scutellatus) collected for antivenom production (the snake that killed the collector Kevin Budden), as well as samples from the first Oxyuranus microlepidotus specimen collected after the species' rediscovery in 1976. These results demonstrate that with proper storage techniques, venom samples can retain structural and pharmacological stability. This article is part of a Special Issue entitled: Proteomics of non-model organisms.


Assuntos
Venenos Elapídicos/química , Preservação Biológica , Proteômica/métodos , Estabilidade Proteica , Fatores de Tempo
2.
Rejuvenation Res ; 14(1): 57-66, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21329452

RESUMO

If controllable, stem cell activation following injury has the therapeutic potential for supporting regeneration in acute or chronic wounds. Human dermally-derived stem cells (FmSCs) were exposed to the cytokines interleukin-6 (IL-6), IL-1ß, and tumor necrosis factor-α (TNF-α) in the presence of erythropoietin (EPO). Cells were cultured under ischemic conditions and phenotypically characterized using flow cytometry. Topical EPO application was performed in three independent clinical wound healing attempts. The FmSCs expressed the receptor for EPO. EPO had a strong inhibitory effect on FmSC growth in the absence of IL-6 and TNF-α. With IL-6, the EPO effects were reversed to that of growth stimulation. TNF-α had the strongest stimulatory effect. In contrast, IL-1ß had an inhibitory effect. Topically applied EPO considerably enhanced wound healing and improved wound conditions of acute and chronic wounds. Site specificity of stem cell activation is mediated by IL-6 and TNF-α. In trauma, EPO ceases its inhibitory role and reverts to a clinically relevant boosting function. EPO may be an important therapeutic tool for the topical treatment of acute and chronic wounds.


Assuntos
Citocinas/uso terapêutico , Eritropoetina/uso terapêutico , Ferimentos e Lesões/tratamento farmacológico , Doença Aguda , Adulto , Idoso , Biomarcadores/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Pré-Escolar , Doença Crônica , Citocinas/farmacologia , Derme/citologia , Sinergismo Farmacológico , Eritropoetina/farmacologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Receptores da Eritropoetina/química , Análise de Sequência de Proteína , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Ferimentos e Lesões/patologia
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