Paulo Pereira

Bio: Paulo Pereira is an academic researcher from Universidade Federal de Goiás. The author has contributed to research in topics: Microcystis aeruginosa & Tabernaemontana catharinensis. The author has an hindex of 32, co-authored 133 publications receiving 3209 citations. Previous affiliations of Paulo Pereira include Instituto Nacional de Saúde Dr. Ricardo Jorge & Universidade de Ribeirão Preto.

Medicinal Plants with Inhibitory Properties Against Snake Venoms

Abstract: Envenomations due to snake bites are commonly treated by parenteral administration of horse or sheep-derived polyclonal antivenoms aimed at the neutralization of toxins. However, despite the widespread success of this therapy, it is still important to search for different venom inhibitors, either synthetic or natural, that could complement or substitute for the action of antivenoms. Several plants have been utilized in folk medicine as antiophidian. However, only a few species have been scientifically investigated and still less had their active components isolated and characterized both structurally and functionally. This article presents a review of plants showing neutralizing properties against snake venoms which were assayed in research laboratories, correlating them with ethnopharmacological studies, as (i) the part of the plant used as antidote, (ii) its respective genus and family and (iii) inhibition of the main pharmacological, toxic and enzymatic activities of snake venoms and isolated toxins. Protective activity of many of these plants against the lethal action of snake venoms has been confirmed by biological assays. Compounds in all of them belong to chemical classes capable of interacting with macromolecular targets (enzymes or receptors). Popular culture can often help to guide scientific studies. In addition, biotechnological application of these inhibitors, as helpful alternative or supplemental treatments to serum therapy, and also as important models for synthesis of new drugs of medical interest, needs to be better oriented and scientifically explored.

Climate change: A catalyst for global expansion of harmful cyanobacterial blooms

Abstract: Cyanobacteria are the Earth's oldest known oxygen-evolving photosynthetic microorganisms, and they have had major impacts on shaping our current atmosphere and biosphere. Their long evolutionary history has enabled cyanobacteria to develop survival strategies and persist as important primary producers during numerous geochemical and climatic changes that have taken place on Earth during the past 3.5 billion years. Today, some cyanobacterial species form massive surface growths or 'blooms' that produce toxins, cause oxygen depletion and alter food webs, posing a major threat to drinking and irrigation water supplies, fishing and recreational use of surface waters worldwide. These harmful cyanobacteria can take advantage of anthropogenically induced nutrient over-enrichment (eutrophication), and hydrologic modifications (water withdrawal, reservoir construction). Here, we review recent studies revealing that regional and global climatic change may benefit various species of harmful cyanobacteria by increasing their growth rates, dominance, persistence, geographic distributions and activity. Future climatic change scenarios predict rising temperatures, enhanced vertical stratification of aquatic ecosystems, and alterations in seasonal and interannual weather patterns (including droughts, storms, floods); these changes all favour harmful cyanobacterial blooms in eutrophic waters. Therefore, current mitigation and water management strategies, which are largely based on nutrient input and hydrologic controls, must also accommodate the environmental effects of global warming.

Metodologia da pesquisa científica

Abstract: A Metodologia Cientifica, mais do que uma disciplina, que em principio desperta a ideia de uma linha puramente teorica, deve ser encarada como um conjunto de procedimentos sistematicos e racionais, base da formacao tanto do estudioso quanto do profissional. Ambos atuam, alem da pratica, no mundo das ideias, ou seja, suas linhas basicas caminham pelo campo teorico, porem, o acumulo do conhecimento cientifico teorico, permite a sua aplicacao pratica no desenvolvimento tecnologico, alem de sua utilizacao nas atividades profissionais. Pode-se afirmar que a pratica nasce da concepcao sobre o que deve ser realizado e qualquer tomada de decisao fundamenta-se naquilo que se afigura como o mais logico, racional, eficiente e eficaz. Desta forma, deve-se encarar a Pesquisa Cientifica e o Metodo Cientifico, que fornece os subsidios para a sua realizacao, como fundamentais para o modelo de sociedade que estamos inseridos. Os alunos devem compreender a Metodologia da Pesquisa Cientifica como um instrumento que deve auxilia a humanidade a encontrar as respostas para os problemas que surgem em nossa vida cotidiana, alem da sua importância para a elaboracao do Trabalho Cientifico, que deve ser apresentado ao final do curso de Pos-Graduacao. Para atingir este objetivo, os alunos deverao produzir um resumo cientifico.

Metabolites from algae with economical impact

Abstract: In order to survive in a highly competitive environment, freshwater or marine algae have to develop defense strategies that result in a tremendous diversity of compounds from different metabolic pathways. Recent trends in drug research from natural sources have shown that algae are promising organisms to furnish novel biochemically active compounds. The current review describes the main substances biosynthesized by algae with potential economic impact in food science, pharmaceutical industry and public health. Emphasis is given to fatty acids, steroids, carotenoids, polysaccharides, lectins, mycosporine-like amino acids, halogenated compounds, polyketides and toxins.

Plant Cell, Tissue and Organ Culture

Abstract: The origin of plant cell and tissue culture can be found in a treatise published during the mid-18th century, entitled La Physique des Arbes, that describes the formation of callus tissue following the for mation of a ring of cortex from elm trees. Over the next two centuries, the discovery of plant growth hormones, in particular auxins and cytokinins, and detailed analyses on the nutritional requirements of plants, led to the formulation of media that could maintain actively dividing cultures derived from gymnosperms, and both dicotyledon ous and monocotyledonous angiosperms. However, much of the prog ress and technological development in the in vitro propagation of plant cells, tissues, and organs has occurred during the last 25 years. Recently, plant tissue culture techniques have been used as basic tools in the rapidly expanding field of plant biotechnology for the development and clonal propagation of new and/or improved plant varieties. Plant tissue culture is used for the micropropagation of commercially valuable cultivars that include ornamentals, oil palm, Glycyrrhiza, Pyrethrum, pine, Eucalyptus, sugar cane, and potatoes. Cultured plant tissue is also used for the selection of cells and, ul timately, the regeneration of plants that are tolerant to physical stresses such as pathogens, drought, and temperature extremes, and to chemical stress agents such as salinity, herbicides, proteins, and pyrethrins. In addition, new plants have been produced by the fusion of protoplasts prepared from cultured cells of different species in cluding sunflower and french bean, tomato and potato, and various cultivars of Datura. Finally, bacterial vectors and various mechanical methods have been used to introduce foreign genes into cultured plant tissues. Genetic transformation can result in profound changes in the phenotype and/or biochemical profile of the regenerated trans genic plants that are not characteristic of the wild type. An impressive variety of technologies in tissue culture, genetic manipulation, and molecular biology have been developed for nu merous plant species. Many of these techniques, sometimes referred to as plant biotechnology, have been extensively summarized and compiled in a well-balanced collection of easy-to-follow protocols presented in three separate, but complimentary, volumes. Plant Cell, Tissue and Organ Culture consists of 22 chapters (with 86 figures) and 5 appendices. The chapters cover critical aspects of (a) the es sential requirements for the operation of a plant tissue culture lab oratory; (b) the basic procedures of micropropagation, regeneration, and somatic embryogenesis; (c) some specific applications of organ culture systems such as embryo rescue and culture, and anther and microspore culture for haploid and double haploid production; (d) elementary transformation technology; and (e) useful microtechnique and analytical protocols specifically adapted to cultured tissues and cells. The appendices provide a convenient summary of media for mulations and commercial suppliers for the materials described in the text.