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BackgroundSnake venoms are a complex mixture of proteins, organic and inorganic compounds. Some of these proteins, enzymatic or non-enzymatic ones, are able to interact with platelet receptors, causing hemostatic disorders. The possible therapeutic potential of toxins with antiplatelet properties may arouse interest in the pharmacological areas. The present study aimed to purify and characterize an antiplatelet DC protein from Bothrops alternatus snake venom.MethodsThe protein, called BaltDC (DC protein from B. alternatus snake venom), was purified by a combination of ion-exchange chromatography on DEAE-Sephacel column and gel filtration on Sephadex G-75. The molecular mass was estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The amino acid sequence of the N-terminal region was carried out by Edman degradation method. Platelet aggregation assays were performed in human platelet-rich plasma (PRP). Infrared (IR) spectroscopy was used in order to elucidate the interactions between BaltDC and platelet membrane.ResultsBaltDC ran as a single protein band on SDS-PAGE and showed apparent molecular mass of 32 kDa under reducing or non-reducing conditions. The N-terminal region of the purified protein revealed the amino acid sequence IISPPVCGNELLEVGEECDCGTPENCQNECCDA, which showed identity with other snake venom metalloproteinases (SVMPs). BaltDC was devoid of proteolytic, hemorrhagic, defibrinating or coagulant activities, but it showed a specific inhibitory effect on platelet aggregation induced by ristocetin and epinephrine in PRP. IR analysis spectra strongly suggests that PO3 2− groups, present in BaltDC, form hydrogen bonds with the PO2 − groups present in the non-lipid portion of the membrane platelets.ConclusionsBaltDC may be of medical interest since it was able to inhibit platelet aggregation.

This work reports the purification and functional characterization of BmooPAi, a platelet-aggregation-inhibiting factor from Bothrops moojeni snake venom. The toxin was purified by a combination of three chromatographic steps (ion-exchange on DEAE-Sephacel, molecular exclusion on Sephadex G-75, and affinity chromatography on HiTrap™ Heparin HP). BmooPAi was found to be a single-chain protein with an apparent molecular mass of 32 kDa on 14% SDS-PAGE, under reducing conditions. Sequencing of BmooPAi by Edman degradation revealed the amino acid sequence LGPDIVPPNELLEVM. The toxin was devoid of proteolytic, haemorrhagic, defibrinating, or coagulant activities and induced no significant oedema or hyperalgesia. BmooPAi showed a rather specific inhibitory effect on ristocetin-induced platelet aggregation in human platelet-rich plasma, whereas it had little or no effect on platelet aggregation induced by collagen and adenosine diphosphate. The results presented in this work suggest that BmooPAi is a toxin comprised of disintegrin-like and cysteine-rich domains, originating from autolysis/proteolysis of PIII SVMPs from B. moojeni snake venom. This toxin may be of medical interest because it is a platelet aggregation inhibitor, which could potentially be developed as a novel therapeutic agent to prevent and/or treat patients with thrombotic disorders.

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v (CAPES) e ao Ministério de Ciências e Tecnologia (MCT), pelo suporte financeiro, sem o qual seria impossível o desenvolvimento deste trabalho.

A Tomografia por Emissão de Pósitrons/Tomografia Computadorizada representa um grande salto tecnológico para a Medicina Nuclear e particularmente, para a Oncologia, visto que é capaz de distinguir alterações benignas e malignas com base em dados semiquantitativos da metabolização de radiofármacos pelos tecidos corporais. Este trabalho teve como objetivo realizar uma revisão narrativa dos principais levantamentos bibliográficos contemporâneos acerca dos princípios físicos da PET-CT/18F-FDG, suas aplicações na Oncologia e os avanços tecnológicos desta metodologia. Este trabalho foi elaborado com base em artigos obtidos de bancos de dados como PubMed, SciELO e Microsoft Academic Search, com descritores relacionados a PET-CT/18F-FDG e a Oncologia. A partir dos artigos analisados, observa-se que a PET-CT/18F-FDG é uma importante técnica para a obtenção de imagens morfofuncionais do corpo do paciente com sensibilidade e especificidade, muitas vezes, superiores aos métodos convencionais de diagnóstico por imagem. Dessa forma, a PET-CT/18F-FDG é recomendada nos casos de identificação e acompanhamento do estadiamento tumoral, monitoramento da taxa de resposta das terapias oncológicas e planejamento do alvo em tratamentos radioterápicos. Ainda, o desenvolvimento de algoritmos matemáticos e de sistemas de detecção de radiação mais eficientes na PET-CT/18F-FDG melhoram a qualidade da imagem e reduzem o tempo de exame.

This book chapter will comment on fluorescent reporter proteins and nanocrystals’ applicability as fluorescent markers. Fluorescent reporter proteins in the Drosophila model system offer a degree of specificity that allows monitoring cellular and biochemical phenomena in vivo, such as autophagy, mitophagy, and changes in the redox state of cells. Titanium dioxide (TiO2) nanocrystals (NCs) have several biological applications and emit in the ultraviolet, with doping of europium ions can be visualized in the red luminescence. Therefore, it is possible to monitor nanocrystals in biological systems using different emission channels. CdSe/CdS magic-sized quantum dots (MSQDs) show high luminescence stability in biological systems and can be bioconjugated with biological molecules. Therefore, this chapter will show exciting results of the group using fluorescent proteins and nanocrystals in biological systems.

Summary Ophidic accidents are among the problems of public health in Brazil. The components from bothropic venom are responsible for many systemic clinical complications resulting from envenomation. The present work aimed to analyse the systemic changes induced in mice after intraperitoneal administration of BmooTX‐I, a myotoxic acidic phospholipase A2 isolated from Bothrops moojeni venom. Urinalysis was performed and the following plasma biochemical markers were documented: urea, creatinine and uric acid (renal function); glucose and amylase (pancreatic function); alanine aminotransferase, alkaline phosphatase and gamma‐GT (intra‐ and extrahepatic function); creatine kinase and enzymatic lactate (muscle function). Our results showed that after the intraperitoneal injection of BmooTX‐I the urine of these animals showed glycosuria, proteinuria, haematuria, bacteriuria, bilirubinuria, polyuria and nitrite. The plasma biochemical analysis showed alterations in levels of urea, creatinine and uric acid. Amylase concentration was not altered significantly, but the plasma glucose increased significantly compared to controls. The plasma levels of alanine aminotransferase and alkaline phosphatase decreased and increased, respectively, in these same animals. On the other hand, the plasma γGT concentration did not undergo significant modification compared to the control group. The plasma concentration of CK increased, while the enzymatic lactate concentration decreased after the injection of the BmooTX‐I. Therefore, in mice BmooTX‐I is capable of causing systemic alterations which manifest as renal, muscular, hepatic and pancreatic impairment.