Comparison of Yarrowia lipolytica and Pichia pastoris cellular response to different agents of oxidative stress

Yeast cells exposed to adverse conditions employ a number of defense mechanisms in order to respond effectively to the stress effects of reactive oxygen species. In this work, the cellular response of Yarrowia lipolytica and Pichia pastoris to the exposure to the ROSinducing agents’ paraquat, hydrogen peroxide, and increased air pressure was analyzed. Yeast cells at exponential phase were exposed for 3 h to 1 mM paraquat, to 50 mM H2O2, or to increased air pressure of 3 or 5 bar. For both strains, the cellular viability loss and lipid peroxidation was lower for the cells exposed to increased air pressure than for those exposed to chemical oxidants. The glutathione induction occurred only in Y. lipolytica strain and reached the highest level as a response to PQ exposure. In general, antioxidant enzymes were more expressed in Y. lipolytica than in P. pastoris. The enzyme superoxide dismutase was induced in both strains under all the oxidant conditions but was dependent on the cellular growth phase, being undetectable in non-growing cells, whereas glutathione reductase was more induced in those conditions. Hydrogen peroxide was the most efficient inducer of catalase. Both yeast cultures underwent no cellular growth inhibition with increased air pressure, indicating that these yeast species were able to adapt to the oxidative stressful environment.The authors acknowledge the financial support provided by "Fundacao para a Ciencia e Tecnologia" (Grant SFRH/BD/47371/2008)

Problemas relacionados aos medicamentos em idosos fragilizados da Zona da Mata Mineira, Brasil

OBJETIVO: Identificar os principais problemas de saúde, o perfil de utilização de medicamentos e os problemas relacionados aos medicamentos (PRMs) envolvidos no tratamento de idosos fragilizados da Zona da Mata Mineira. MÉTODOS: Foram avaliados prontuários de 260 idosos atendidos pelo Centro Mais Vida, Juiz de Fora-MG, entre agosto e setembro de 2010. As doenças foram agrupadas de acordo com a Classificação Internacional de Doenças - 10ª revisão, os medicamentos de acordo com o Anatomical Therapeutic Chemical Classification System e os PRMs de acordo com o Método Dáder. RESULTADOS: Observou-se que 73,8% dos idosos eram do sexo feminino e 42,7% possuíam entre 60 e 69 anos. Foram constatadas 1.300 doenças, sendo 31,07% do aparelho circulatório, 19,85% endócrinas, nutricionais e metabólicas e 13,46% do sistema osteomuscular e tecido conjuntivo. Dos 1.737 medicamentos, os mais prevalentes foram os do sistema cardiovascular (42,8%), seguidos pelos do trato alimentar e metabolismo (23,7%) e pelos do sistema nervoso (18,2%). Do total de medicamentos, 53,9% apresentaram algum PRM, sendo o PRM 1 (não utilização da medicação necessária) o mais frequente (37,4%). CONCLUSÃO: Os resultados evidenciam a necessidade da revisão dos esquemas terapêuticos dos idosos, visando o uso racional e efetivo dos medicamentos. Os dados apontam, ainda, a necessidade de aprofundar estudos de avaliação de riscos de PRM nessa população

Production of fatty acids and protein by nannochloropsis in flat-plate photobioreactors

Nannochloropsis is an industrially-promising microalga that may be cultivated for alternative sources of nutrition due to its high productivity, protein content and lipid composition. We studied the growth and biochemical profile of Nannochloropsis 211/78 (CCAP) in optimized flat-plate photobioreactors. Eighteen cultivations were performed at two nutrient concentrations. The fatty acid, protein content and calorific values were analyzed after 8,12 and 16 days. Neutral lipids were separated and the changes in fatty acids in triglycerides (TAGs) during nutrient depletion were recorded. The maximum cell density reached 4.7 g·L-1 and the maximum productivity was 0.51 g·L-1·d-1. During nutrient-replete conditions, eicosapentaneoic acid (EPA) and total protein concentrations measured 4.2-4.9% and 50-55% of the dry mass, respectively. Nutrient starvation induced the accumulation of fatty acids up to 28.3% of the cell dry weight, largely due to the incorporation of C16:0 and C16:1 n-7 fatty acyl chains into neutral lipids. During nutrient starvation the total EPA content did not detectibly change, but up to 37% was transferred from polar membrane lipids to the neutral lipid fraction