Metabolic fate of glutamine in lymphocytes, macrophages and neutrophils

Eric Newsholmes laboratory was the first to show glutamine utilization by lymphocytes and macrophages. Recently, we have found that neutrophils also utilize glutamine. This amino acid has been shown to play a role in lymphocyte proliferation, cytokine production by lymphocytes and macrophages and phagocytosis and superoxide production by macrophages and neutrophils. Knowledge of the metabolic fate of glutamine in these cells is important for the understanding of the role and function of this amino acid in the maintenance of the proliferative, phagocytic and secretory capacities of these cells. Glutamine and glucose are poorly oxidized by these cells and might produce important precursors for DNA, RNA, protein and lipid synthesis. The high rate of glutamine utilization and its importance in such cells have raised the question as to the source of this glutamine, which, according to current evidence, appears to be muscle

The chaperone balance hypothesis: The importance of the extracellular to intracellular HSP70 ratio to inflammation-driven type 2 diabetes, the effect of exercise, and the implications for clinical management

Recent evidence shows divergence between the concentrations of extracellular 70 kDa heat shock protein [eHSP70] and its intracellular concentrations [iHSP70] in people with type 2 diabetes (T2DM). A vital aspect regarding HSP70 physiology is its versatility to induce antagonistic actions, depending on the location of the protein. For example, iHSP70 exerts a powerful anti-inflammatory effect, while eHSP70 activates proinflammatory pathways. Increased eHSP70 is associated with inflammatory and oxidative stress conditions, whereas decreased iHSP70 levels are related to insulin resistance in skeletal muscle. Serum eHSP70 concentrations are positively correlated with markers of inflammation, such as C-reactive protein, monocyte count, and TNF-a, while strategies to enhance iHSP70 (e.g., heat treatment, chemical HSP70 inducers or coinducers, and physical exercise) are capable of reducing the inflammatory profile and the insulin resistance state. Here, we present recent findings suggesting that imbalances in the HSP70 status, described by the [eHSP70]/[iHSP70] ratio, may be determinant to trigger a chronic proinflammatory state that leads to insulin resistance and T2DM development. This led us to hypothesize that changes in this ratio value could be used as a biomarker for the management of the inflammatory response in insulin resistance and diabetes

Índices de erosividade da chuva, perdas de solo e fator erodibilidade para dois solos da região dos cerrados: primeira aproximação.

Os objetivos deste trabalho foram: testar a adequacao de diferentes indices de erosividade das chuvas, comparar duas equacoes propostas para calculo da energia cinetica das chuvas e estimar o fator K (erodibilidade) da equacao universal de perdas de solo (EUPS) para um latossolo vermelho-escuro (LE) alico muito argiloso e um podzolico vermelho-amarelo (PV) alico muito argiloso da regiao de Sete Lagoas (MG). Nao houve diferenca significativa entre as duas equacoes testadas para calculo da energia cinetica das chuvas. O indice EI30 mostrou ser um bom estimador da erosividade da chuva e pode continuar sendo utilizado como fator R (erosividade) da EUPS para a regiao estudada. Os valores do fator K, para o LE e o PV da regiao de Sete Lagoas, foram, respectivamente, 0,002 e 0,033 t h (MJ mm)-1

Involvement of formyl peptide receptors in the stimulatory effect of crotoxin on macrophages co-cultivated with tumour cells

Crotoxin (CTX) is the main neurotoxic component of Crotalus durissus terrificus snake venom. It inhibits tumour growth and modulates the function of macrophages, which are essential cells in the tumour microenvironment. the present study investigated the effect of CTX on the secretory activity of monocultured macrophages and macrophages co-cultivated with LLC-WRC 256 cells. the effect of the macrophage secretory activities on tumour cell proliferation was also evaluated. Macrophages pre-treated with CTX (0.3 mu g/mL) for 2 h were co-cultivated with LLC-WRC 256 cells, and the secretory activity of the macrophages was determined after 12, 24 and 48 h. the co-cultivation of CTX-treated macrophages with the tumour cells caused a 20% reduction in tumour cell proliferation. the production of both H2O2 and NO was increased by 41% and 29% after 24 or 48 h of co-cultivation, respectively, compared to the values for the co-cultures of macrophages of control. the level of secreted IL-1 beta increased by 3.7- and 3.2-fold after 12 h and 24 h of co-cultivation, respectively. Moreover, an increased level of LXA(4) (25%) was observed after 24 h of co-cultivation, and a 2.3- and 2.1-fold increased level of 15-epi-LXA(4) was observed after 24 h and 48 h, respectively. Boc-2, a selective antagonist of formyl peptide receptors, blocked both the stimulatory effect of CTX on the macrophage secretory activity and the inhibitory effect of these cells on tumour cell proliferation. Taken together, these results indicate that CTX enhanced the secretory activity of macrophages, which may contribute to the antitumour activity of these cells, and that activation of formyl peptide receptors appears to play a major role in this effect. (C) 2013 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)PAPInstituto Nacional de Ciencia e Tecnologia em ToxinasButantan Inst, Lab Pathophysiol, BR-05503900 São Paulo, BrazilUniversidade Federal de São Paulo, Lab Inflammat & Vasc Pharmacol, BR-09913030 Diadema, SP, BrazilUniv São Paulo, Fac Med, BR-01246000 São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, Dept Anat, BR-05508900 São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508900 São Paulo, BrazilButantan Inst, Special Lab Pain & Signaling, BR-05503900 São Paulo, BrazilUniversidade Federal de São Paulo, Lab Inflammat & Vasc Pharmacol, BR-09913030 Diadema, SP, BrazilFAPESP: 09/52330-9Instituto Nacional de Ciencia e Tecnologia em Toxinas: INCTTOX 2008/57898-0Web of Scienc

Atrativos alimentares na flutuação populacional de moscas-das-frutas e abelha irapuá

Fruit flies are important pests for most fruit species due to the damage they cause, precluding the marketing of fruit. This study aimed to test different fruit juices as food attractants in the monitoring of population fluctuation of fruit flies and Irapuá stingless bees, in an orchard in the south of Minas Gerais (Brazil) consisting of different fruit species: citrus, passion fruit, peach and acerola (west Indian cherry). The monitoring was conducted for a year, in a randomized block design with five treatments: fresh orange juice (50%), prepared with fresh fruit, and juices prepared from Brasfrut® frozen pulp and 10% granulated sugar in the flavors of mango (30%), guava (30%) and passion fruit (30%), in addition to granulated sugar solution (10%). Four replications were made, with split plots in time, related to the different evaluation times. Each block was represented by a different fruit species, namely citrus, passion fruit, peach and acerola. Traps with 200 mL of each attractant were distributed among the fruit plants, with a trap installed in the middle third of each plant, totaling 20 traps in the experiment. The juices of orange, mango, guava and passion fruit showed good attractiveness for the monitoring of fruit flies. For population monitoring of the stingless bee, the juices of orange, mango and guava were more efficient.As moscas-das-frutas são pragas importantes para a maioria das frutíferas em função dos danos que causam, inviabilizando a comercialização das frutas. Objetivou-se nesse trabalho testar diferentes sucos de frutas como atrativos alimentares no  monitoramento da flutuação populacional de moscas-das-frutas e abelha irapuá em um pomar localizado na região Sul de Minas Gerais, formado por diferentes frutíferas: citros, maracujazeiro, pessegueiro e aceroleira. O monitoramento foi realizado por um ano, em delineamento em blocos casualizados,  com cinco tratamentos, isto é, suco fresco de laranja (50%), preparado com fruta in natura, e sucos preparados com polpa congelada Brasfrut® e 10% de açúcar cristal nos sabores manga (30%), goiaba (30%) e maracujá (30%), além de solução de açúcar  cristal (10%). Foram feitas quatro repetições, com parcelas subdividas no tempo, referentes às diferentes épocas de avaliação. Cada bloco foi representado por uma frutífera, isto é, citros, maracujazeiro, pessegueiro e aceroleira, em cujas plantas foram distribuídas as armadilhas com 200 mL de solução atrativa cada, sendo uma armadilha instalada no  terço mediano  de cada planta,  totalizando 20 armadilhas no experimento. Os sucos de laranja, manga, goiaba e maracujá apresentaram boa atratividade para o monitoramento de moscas-das-frutas. Para o monitoramento populacional da abelha irapuá, os sucos de laranja, manga e goiaba foram mais eficientes

Cinética de sorção de fósforo em alguns solos de Minas Gerais.

Os processos cineticos e termodinamicos envolvidos nos mecanismos de troca de fosforo no sistema fase solida-solucao do solo sao ainda pouco conhecidos. O proposito do presente trabalho foi investigar o comportamento dinamico do fosforo em sistemas multifasicos. Como fase solida, foram utilizadas as fracoes argila de onze amostras de duas pedossequencias do Estado de Minas Gerais: uma com litologia variando em proporcoes de rochas peliticas e de tufito; outra de arenito e de basalto. E proposto um modelo cinetico para descrever a dinamica de sorcao do fosforo. Estimaram-se as constantes de taxa de reacao (ki, i = + ou - 1, + ou - 2) de primeira ordem, para as duas primeiras etapas consecutivas do mecanismo multiplo de reacao. Na maior parte das amostras, metade do fosforo adicionado (2 g de P kg -1 de solo) foi adsorvida entre 30 e 90 minutos de reacao. Como tendencia geral, a constante de equilibrio da primeira etapa do processo foi menor do que 1, indicando que a reacao reversa (dessorcao e termodinamicamente favorecida no equilibrio (variacao da energia livre padrao de Gibbs, delta G1 > 0), exceto para uma amostra. Nao houve correlacao significativa entre k e magnetizacao, o que reflete a influencia de rocha mafica no material de origem