Evaluation of extracts from Coccoloba mollis using the Salmonella/microsome system and in vivo tests

The common everyday use of medicinal plants is an ancient, and still very widespread practice, whereby the need for studies on their possible toxicity and mutagenic properties. The species Coccoloba mollis has been much used in phytotherapy, mainly in cases involving loss of memory and stress. In order to investigate its genotoxic and mutagenic potential, ethanolic extracts from the leaves and roots underwent Salmonella/microsome assaying (TA98 and TA100 strains, with and without exogenous metabolism – S9), besides comet and micronucleus tests in vivo.There was no significant increase in the number of revertants/plate of Salmonella strains in any of the analyzed root-extract concentrations, although the extract itself was extremely toxic to the Salmonella TA98 strain in the tests carried out with S9 (doses varying from 0.005 to 0.5 μg/plate). On the other hand, the leaf-extract induced mutations in the TA98 strain in the absence of S9 in the highest concentration evaluated, although at very low mutagenic potency (0.004 rev/ μg). Furthermore, there was no statistically significant increase in the number of comets and micronuclei, in treatments involving Swiss mice. It was obvious that extracts of Coccoloba mollis, under the described experimental conditions, are not mutagenic

Medium Chain Fatty Acids Are Selective Peroxisome Proliferator Activated Receptor (PPAR) γ Activators and Pan-PPAR Partial Agonists

Thiazolidinediones (TZDs) act through peroxisome proliferator activated receptor (PPAR) γ to increase insulin sensitivity in type 2 diabetes (T2DM), but deleterious effects of these ligands mean that selective modulators with improved clinical profiles are needed. We obtained a crystal structure of PPARγ ligand binding domain (LBD) and found that the ligand binding pocket (LBP) is occupied by bacterial medium chain fatty acids (MCFAs). We verified that MCFAs (C8–C10) bind the PPARγ LBD in vitro and showed that they are low-potency partial agonists that display assay-specific actions relative to TZDs; they act as very weak partial agonists in transfections with PPARγ LBD, stronger partial agonists with full length PPARγ and exhibit full blockade of PPARγ phosphorylation by cyclin-dependent kinase 5 (cdk5), linked to reversal of adipose tissue insulin resistance. MCFAs that bind PPARγ also antagonize TZD-dependent adipogenesis in vitro. X-ray structure B-factor analysis and molecular dynamics (MD) simulations suggest that MCFAs weakly stabilize C-terminal activation helix (H) 12 relative to TZDs and this effect is highly dependent on chain length. By contrast, MCFAs preferentially stabilize the H2-H3/β-sheet region and the helix (H) 11-H12 loop relative to TZDs and we propose that MCFA assay-specific actions are linked to their unique binding mode and suggest that it may be possible to identify selective PPARγ modulators with useful clinical profiles among natural products

The Mycobacterium tuberculosis Rv2540c DNA sequence encodes a bifunctional chorismate synthase

Background: The emergence of multi- and extensively-drug resistant Mycobacterium tuberculosis strains has created an urgent need for new agents to treat tuberculosis (TB). The enzymes of shikimate pathway are attractive targets to the development of antitubercular agents because it is essential for M. tuberculosis and is absent from humans. Chorismate synthase (CS) is the seventh enzyme of this route and catalyzes the NADH- and FMN-dependent synthesis of chorismate, a precursor of aromatic amino acids, naphthoquinones, menaquinones, and mycobactins. Although the M. tuberculosis Rv2540c (aroF) sequence has been annotated to encode a chorismate synthase, there has been no report on its correct assignment and functional characterization of its protein product. Results: In the present work, we describe DNA amplification of aroF-encoded CS from M. tuberculosis (MtCS), molecular cloning, protein expression, and purification to homogeneity. N-terminal amino acid sequencing, mass spectrometry and gel filtration chromatography were employed to determine identity, subunit molecular weight and oligomeric state in solution of homogeneous recombinant MtCS. The bifunctionality of MtCS was determined by measurements of both chorismate synthase and NADH:FMN oxidoreductase activities. The flavin reductase activity was characterized, showing the existence of a complex between FMNox and MtCS. FMNox and NADH equilibrium binding was measured. Primary deuterium, solvent and multiple kinetic isotope effects are described and suggest distinct steps for hydride and proton transfers, with the former being more rate-limiting. Conclusion: This is the first report showing that a bacterial CS is bifunctional. Primary deuterium kinetic isotope effects show that C4-proS hydrogen is being transferred during the reduction of FMNox by NADH and that hydride transfer contributes significantly to the rate-limiting step of FMN reduction reaction. Solvent kinetic isotope effects and proton inventory results indicate that proton transfer from solvent partially limits the rate of FMN reduction and that a single proton transfer gives rise to the observed solvent isotope effect. Multiple isotope effects suggest a stepwise mechanism for the reduction of FMNox. The results on enzyme kinetics described here provide evidence for the mode of action of MtCS and should thus pave the way for the rational design of antitubercular agents

Proposta de melhorias e de indicadores na gestão sustentável de resíduos provenientes de navios no Porto de Lisboa

Trabalho final de mestrado para obtenção do grau de Mestre em Engenharia da Qualidade e AmbienteO transporte marítimo é essencial para a economia mundial, uma vez que mais do 90% do comércio mundial é efetuado por via marítima (IMO, 2019). O transporte marítimo de matérias-primas e mercadorias é considerado o mais económico, o mais eficiente e com menos impactes ambientais, no entanto não é isento de impactes ambientais negativos. Os mesmos resultam dos resíduos gerados pelos navios (RGN) e resíduos da carga (RC), da emissão de quantidades significativas de gases com efeito estufa (GEE) e de outros gases poluentes. Para evitar a poluição ambiental marinha causada pela descarga ilegal de substâncias e resíduos nocivos para o mar, em 1973, foi adotada uma Convenção Internacional: o protocolo MARPOL 73/78. Da mesma forma, a União Europeia (UE) adotou a diretiva 2000/59/CE, sobre meios portuários de receção de resíduos (MPRR), cujos principais objetivos são impedir a descarga de RGN e RC e da carga no mar, e a proteção do meio marinho. O Porto de Lisboa (PL) é o responsável pela gestão de RGN e RC, garantindo a sua gestão até ao destino final adequado. De acordo com os requisitos exigidos pela Diretiva 2000/59/CE, o PL implementou um sistema de gestão de RGN, cujos objetivos são os seguintes: reduzir as descargas de RGN e da carga no mar; fornecer MPRR adequados a todos e novos tipos de resíduos, em condições de segurança; melhorar o sistema de receção de resíduos; incentivar a descarga de resíduos nos MPRR e a proteção do meio marinho. O objetivo deste estudo é quantificar os RGN e RC descarregados no PL e analisar o sistema de gestão de resíduos (SGR) do porto, a fim de estabelecer indicadores e propostas de melhoria. O tratamento dos dados dos resíduos em conjunto com os das inspeções realizadas aos navios e aos MPRR forneceu informação relevante para a criação de indicadores sobre produção de resíduos a bordo dos navios e do sistema de gestão dos mesmos. Aplicou-se uma análise SWOT, para identificar possíveis barreiras na gestão e contribuir para um processo de melhoria contínua. As principais oportunidades de melhoria identificadas são: implementação das normas ISO 9001:2015 e 14001:2015, integração navio-porto; incentivar as descargas nos MPRR; o aumento das inspeções aos navios e a fiscalização nos terminais; sensibilizar e formar a todas as partes integrantes; incrementar o número de MPRR por tipologia e o controlo dos abastecimentos aos navios. Concluiu-se que, apesar dos avanços na redução da poluição causada pelo transporte marítimo, ainda há um grande desafio pela frente no PL.The protection of the environment has become a major issue since global pollution has reached such alarming levels. This pollution comes mainly from the industrialization of the world trade and also from means of transport. Maritime transport is essential for the global economy as more than 90% of the world trade is by ship. Even though maritime transport is considered the most economical, efficient and environmentally friendly means of transport, it has introduced negative environmental impacts due to the ship generated waste (SGW), the significant amount of greenhouse gas emissions, the fossil fuel consumption and the transport of animal products from third countries. In order to prevent ocean pollution caused by the illegal disposal of hazardous substances and waste, an International Convention was adopted in 1973, the Protocol of MARPOL 73/78. Additionally, the European Union (EU) adopted the Directive 2000/59/CE on Port Reception Facilities (PRF) whose main objectives are to avoid the disposal of SGW into the ocean and to protect the marine environment. The Port of Lisbon (PL) is responsible for the ship generated waste management (SGWM) of the ships which call at PL securing its delivery to the adequate final destination. The PL complies with the regulations required by the EU Directive 2000/59/CE on PRF and it has implemented a SGWM system whose objectives are as follows: to reduce SGW and cargo waste disposal into the sea; to provide adequate PRF to both all the waste and new residues in safe conditions, to improve the waste collection service; to encourage waste disposal to PRFs and to protect the marine environment. The purpose of this study is to quantify the waste coming from ships and cargo discharged at PL and to analyse the waste management system of the Port so as to improve it. To do this a SWOT analysis was carried out in order to identify possible management barriers and also to contribute to a continuous improvement process. The waste data processing together with ship inspections provided us with relevant information for the development of indicators of both waste generation on board and the management system of such waste. Some of the main opportunities for improvement identified are: implementation of the ISO 9001:2015 and 14001:2015 standards, port-ship integration, the improvement of management in the parties involved, to encourage waste disposal in PRF, the increase of ship inspections and audits in terminals, to raise awareness and train all the parties involved, to increase the number of waste reception facilities according to the different waste types and the supervision of ship supplies. It was concluded that in spite of the progress towards the reduction in pollution caused by maritime transport, there is still a great challenge before us.N/

Changes in amounts of total salivary gland proteins of Lutzomyia longipallpis (Diptera: Psychodidae) according to age and diet

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2014-03-13T16:57:01Z No. of bitstreams: 1 Prates DB Changes in amounts....pdf: 207901 bytes, checksum: d38c782c49e631a15a95ecc58be75e12 (MD5)Made available in DSpace on 2014-03-13T16:57:01Z (GMT). No. of bitstreams: 1 Prates DB Changes in amounts....pdf: 207901 bytes, checksum: d38c782c49e631a15a95ecc58be75e12 (MD5) Previous issue date: 2008Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, BrasilUniversidade Estadual Paulista de Rio Claro. Instituto de Biociências de Rio Claro. Departamento de Biologia. Laboratório de Biologia Estrutural e Zooquímica. Rio Claro, SP, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, BrasilInstituto de Investigação em Imunologia iii. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / Instituto de Investigação em Imunologia iii. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / Instituto de Investigação em Imunologia iii. Salvador, BA, BrasilSaliva plays important roles in facilitation of a bloodmeal, lubrication of mouthparts, and parasite transmission for some vector insects. Salivary composition changes during the lifetime of an insect, and differences in the salivary proÞle may inßuence its functions. In this report, the amount and proÞle of salivary gland protein of the American visceral leishmaniasis vector Lutzomyia longipalpis (Lutz & Neiva, 1912) were analyzed at different times of insect development and diet. Protein content from unfed female sand ßies increased signiÞcantly with age, and a signiÞcant difference was observed in sugar-fed females during the Þrst 10 d of adult life. Salivary protein content sharply decreased 1 d after blood feeding, with gradual increase in concentration the following days. SDSpolyacrylamide gel electrophoresis analysis revealed that most polypeptides present in the saliva of sugar-fed also were present in the saliva of blood-fed females. Understanding changes in sand ßyÕs saliva contents at distinct days after emergence and the inßuence of a bloodmeal in this aspect may reveal the role played by saliva during leishmaniasis transmission

A toxina JSTX-3 inibe a atividade epileptiforme espontânea e induzida pelo ringer sem magnésio

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A toxina JSTX-3 inibe a atividade epileptiforme espontânea e induzida pelo ringer sem magnésio

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Thermodynamics parameters of formation of binary complexes between <i>Mt</i>SK and substrate(s) or product(s).

<p>K_D represents the equilibrium dissociation constant, ΔH is the binding enthalpy, ΔS is the binding entropy, ΔG is the Free Gibbs energy, and –TΔS is the negative term for temperature (in Kelvin) times binding entropy.</p