2,3-Diphosphoglycerate and the Protective Effect of Pyruvate Kinase Deficiency against Malaria Infection—Exploring the Role of the Red Blood Cell Membrane

Malaria remains a major world public health problem, contributing to poverty and inequality. It is urgent to find new efficacious tools with few adverse effects. Malaria has selected red blood cell (RBC) alterations linked to resistance against infection, and understanding the protective mechanisms involved may be useful for developing host-directed tools to control Plasmodium infection. Pyruvate kinase deficiency has been associated with resistance to malaria. Pyruvate kinase-deficient RBCs display an increased concentration of 2,3-diphosphoglycerate (2,3-DPG).We recently showed that 2,3-DPG impacts in vitro intraerythrocytic parasite growth, induces a shift of the metabolic profile of infected cells (iRBCs), making it closer to that of noninfected ones (niRBCs), and decreases the number of parasite progenies that invade new RBCs. As an increase of 2,3-DPG content may also have an adverse effect on RBC membrane and, consequently, on the parasite invasion, in this study, we explored modifications of the RBC morphology, biomechanical properties, and RBC membrane on Plasmodium falciparum in vitro cultures treated with 2,3-DPG, using atomic force microscopy (AFM)-based force spectroscopy and other experimental approaches. The presence of infection by P. falciparum significantly increased the rigidity of parasitized cells and influenced the morphology of RBCs, as parasitized cells showed a decrease of the area-to-volume ratio. The extracellular addition of 2,3-DPG also slightly affected the stiffness of niRBCs, making it more similar to that of infected cells. It also changed the niRBC height, making the cells appear more elongated. Moreover, 2,3-DPG treatment influenced the cell surface charge, becoming more negative in treated RBCs than in untreated ones. The results indicate that treatment with 2,3-DPG has only a mild effect on RBCs in comparison with the effect of the presence of the parasite on the host cell. 2,3-DPG is an endogenous host metabolite, which may, in the future, originate a new antimalarial tool with few adverse effects on noninfected cells.publishersversionpublishe

Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods

Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations

A importância relativa da densidade da madeira e do teor de carboidratos no rendimento de polpa e na qualidade do produto.

The purpose of this study was to evaluate basic density, chemical composition and fiber dimensions of ten Eucalyptus sp wood samples and to verify the impact of this set of parameters and their combination on the Kraft pulping process yield and on bleached pulp quality. Ten eucalypt woods of different species, with basic densities varying from 365 to 544 kg/m³ and total wood carbohydrate contents varying from 70.0 to 74.5%, were transformed into kraft pulp of kappa number 15,5-16,7 and bleached to 90% ISO brightness by the sequence OD(PO)D. Wood basic density showed stronger correlations with fiber dimensions and pulp quality than did chemical composition. However, pulping yield was strongly affected by chemical composition. Lighter woods resulted in higher pulping yields. However, wood specific consumption was lower for denser woods, even though these demanded more drastic pulping conditions to achieve a given kappa number. The pulp quality results suggest that lower density woods should be directed towards fabrication of refined paper (printing and writing grades) while the denser woods should be directed to the sanitary papers segment (tissue grades).O objetivo deste estudo foi avaliar a densidade básica, a composição química e as dimensões de fibras de dez amostras de madeira de Eucalyptus spp. e, verificar o impacto desse conjunto de parâmetros e sua combinação no rendimento do processo de polpação kraft e na qualidade da polpa branqueada. A madeira de dez espécies de eucalipto, com densidade básica variando entre 365 a 544 kg/m3 e teores de carboidratos totais variando entre 70,0 a 74,5% foi transformada em polpa Kraft, com número kappa 15,5-16,7 e branqueada a 90% ISO por uma seqüência de quatro estágios (OD(PO)D) composta de deslignificação com oxigênio (O), deslignificação com dióxido de cloro (D),  extração alcalina com peróxido pressurizado (PO) e branqueamento com dióxido de cloro (D). A densidade básica da madeira mostrou melhor correlação com as dimensões da fibra e qualidade da polpa que a sua composição química. Porém o rendimento depurado foi mais influenciado pela composição química da madeira do que pela densidade básica. Madeiras de menor densidade apresentaram maiores rendimentos de polpação, mas o consumo específico de madeira foi mais baixo para as madeiras mais densas. Os resultados de qualidade de polpa sugerem que madeiras com densidade mais baixa devam ser direcionadas à fabricação de papel refinado (impressão e de escrita), enquanto que as mais densas sejam destinadas ao segmento de papéis sanitários (tissue)

Purification of antileukemic drugs through silica-based supported ionic liquids

L-asparaginase (LA) is an enzyme used as a biopharmaceutical for the treatment of acute lymphoblastic leukemia. LA can be produced via fermentation and its purification usually comprises several steps including precipitation, liquid-liquid extraction and chromatography techniques. Among these, ion exchange chromatography, which is often preceded by precipitation with salts as a first pre-chromatographic step, is the most used. However, theses common strategies for protein purification result in low yields and purity, requiring long processing times, while leading to a consequent increase of the process costs. Therefore, the demand for new cost-effective production/purification processes play now a priority role. This work aims the development of cost-effective technologies to purify LA from the complex fermentation medium from Bacillus Subtillis. Silica-based supported ionic liquids (SILs) are investigated as cost-effective purification materials for the target enzyme. The concentration of the extract from the fermentation, material/ extract from fermentation ratio and contact time effects in the purity and yield of LA were optimized. With this strategy, process costs, energy consumed, and waste generated, may be significantly decreased, which may lead to this biopharmaceutical price decrease and wider application.publishe

Purification of antileukemic drugs through silica-based supported ionic liquids

L-asparaginase (LA) is an enzyme used as a biopharmaceutical for the treatment of acute lymphoblastic leukemia. LA can be produced via fermentation and its purification usually comprises ion exchange chromatography, which is often preceded by precipitation with salts as a first pre-chromatographic step. However, this purification strategy result in low yields and purity, requires long processing times, while leading to a consequent increase of the process costs. Therefore, the demand for new cost-effective purification processes play now a priority role. In this work silica-based supported ionic liquids (SILs) are investigated as an alternative technology to purify LA from the complex fermentation medium from Bacillus subtillis. The concentration of the extract from the fermentation, material/ extract from fermentation ratio and contact time effects in the purity and yield of LA were optimized. With this strategy, process costs, energy consumed, and waste generated, may be significantly decreased, which may lead to this biopharmaceutical price decrease and wider application.publishe

The Proterozoic Vazante hypogene zinc silicate district, Minas Gerais, Brazil: a review of the ore system applied to mineral exploration

The Proterozoic Vazante zinc silicate district in Minas Gerais, Brazil, hosts world-class hypogene willemite deposits in dolomitic rocks interbedded with siliciclastic rocks deposited in subtidal to supratidal environments. Willemite ore bodies are structurally controlled along regional NE-trending structures which are interpreted as being active during the Neoproterozoic Brasiliano orogeny. The hydrothermal alteration is characterized by an early stage of Fe-dolomite, which replaced the host dolomitic rocks, followed by precipitation of minor sphalerite and then hematite and willemite. Elements commonly enriched in the zinc ore include As, Ba, Be, Bi, Cd, Co, Fe, Ge, In, Mo, Ni, Sb, Se, U, V and W. Mineralogical, fluid inclusion and isotopic data indicates that mixing of S-poor metalliferous saline fluids with meteoric water favored the formation of willemite ore. Carbonaceous phyllites from the underlying thick siliciclastic sequence show evidence of early enrichment in zinc (and ore-related metals) and remobilization, respectively, prior to and during the Brasiliano orogenic event. This unit is interpreted as a possible source of ore-related elements. It is proposed that during the Brasiliano orogeny, hot (T > 170 degrees C) saline fluids (>15 wt % eq. NaCl) leached metals from siliciclastic source rocks and precipitated willemite ore in the overlying dolomitic sequence along structures that favored mixing with oxidizing meteoric water

Feelings of nurses who work with cancer patients in terminal phase Sentimentos de enfermeiros que atuam junto a pacientes com câncer em fase terminal

Objetivo: identificar os sentimentos de enfermeiros que atuam junto a pacientes com câncer em fase terminal. Métodos: pesquisa qualitativa, realizada com 10 enfermeiros do setor de oncologia de um Hospital de Teresina, Piauí, Brasil. Coleta de dados realizada por meio de entrevista semiestruturada, submetida à análise temática. Obtenção de parecer favorável pelo Comitê de Ética em Pesquisa da Faculdade Santo Agostinho, conforme parecer N°350/10. Resultados: para os enfermeiros, uma das maiores ansiedades enfrentadas é o lidar com a morte, vista como fenômeno doloroso e de difícil aceitação. A maioria dos profissionais admitiu o despreparo no manejo e enfrentamento desta condição, experienciando de forma conflituosa, amarga e cruel tal vivência. Conclusão: mediante a fragilidade dos sentimentos dos enfermeiros, urge apoio ao profissional da área oncológica com formações de grupos de apoio ao profissional, a fim de compartilhar experiências e minimizar o sofrimento emocional. Descritores: Enfermagem; Oncologia; Saúde Mental