Anti-infective properties of proton pump inhibitors: perspectives

International Microbiology - Infectious diseases are among the main causes of morbidity and mortality today. In facing this crisis, the development of new drug options and combat strategies is...     

Disentangling spatial,environmental and historical effects on tropical forest tree species turnover

空间、环境和历史因素对热带森林树种周转的影响 本文通过回答以下问题来分析空间距离、当前和过去的环境差异及这几个因素对树木群落分类和系统发育转换的影响：(i)树木群落分类和系统发育转换是否与空间距离通过环境差异产生的间接影响相关？(ii)树木群落分类和系统发育转换是否随古气候(末次盛冰期和中全新世)的变化而变化？本文对巴西的14个大西洋雨林样点(采样面积20.4 ha) 83个科615个种进行了研究，获得了当前、中全新世和末次盛冰 期的地块地理坐标、土壤变量和样点生物气候变量。我们使用基于距离的结构方程模型(SEM)来(i)检测空间距离和环境差异的直接影响，以及(ii)检测空间距离通过环境差异对分类(Bray-Curtis距离)和系统发育转换(Comdist和Comdistnt距离)的间接影响。研究结果表明，空间距离通过环境差异对分类和系统发育转换的间接影响较弱。基于生态位中性的历史过程带来的直接影响驱动了树木群落的转换。因此，我们推断古气候(历史过程)促进了产生当前植物区系分支的选择，而空间距离(中性的过程)限制了物种从区域种库向外扩散的范围，环境条件(基于生态位的过程)则在本地选择能够持续生存的分类群。     

Grape seed proanthocyanidins improves mitochondrial function and reduces oxidative stress through an increase in sirtuin 3 expression in EA.hy926 cells in high glucose condition

Proanthocyanidins are phenolic compounds abundant in the diet, commonly found in grapes and derivatives, foods known for their health-promoting benefits. There is previous evidence showing the antidiabetic activity of proanthocyanidins, however, their mechanisms of action have not been fully elucidated. This study evaluated the capacity of grape seed proanthocyanidins extract (GSPE) to modulate oxidative stress, nitric oxide levels, mitochondrial dysfunction, apoptosis, and sirtuin expression in endothelial cells EA.hy926 under high glucose condition. In addition, the possible toxic effects of GSPE was evaluated in a zebrafish embryos model. The results showed that GSPE was able to enhance cell viability and avoid the disturbance in redox metabolism induced by high glucose. Moreover, GSPE was able to avoid mitochondria dysfunction and the increased in p53 and poly-(ADP-ribose) polymerase expression induced by high glucose exposition. These effects were attributed to the increase in expression of sirtuin 3, a protein able to regulate mitochondrial function. GSPE in an effective concentration did not show toxic effects in zebrafish embryos model. Taken together, these data elucidate the key molecular target of GSPE for future pharmacological interventions in diabetic patients.

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L‐NAME co‐treatment prevent oxidative damage in the lung of adult Wistar rats treated with vitamin A supplementation

Based on the fact that vitamin A in clinical doses is a potent pro‐oxidant agent to the lungs, we investigated here the role of nitric oxide (NO^?) in the disturbances affecting the lung redox environment in vitamin A‐treated rats (retinol palmitate, doses of 1000–9000 IU·kg^?1·day^?1) for 28 days. Lung mitochondrial function and redox parameters, such as lipid peroxidation, protein carbonylation and the level of 3‐nytrotyrosine, were quantified. We observed, for the first time, that vitamin A supplementation increases the levels of 3‐nytrotyrosine in rat lung mitochondria. To determine whether nitric oxide (NO ?) or its derivatives such as peroxynitrite (ONOO‐) was involved in this damage, animals were co‐treated with the nitric oxide synthase inhibitor L‐NAME (30 mg·kg^?1, four times a week), and we analysed if this treatment prevented (or minimized) the biochemical disturbances resulting from vitamin A supplementation. We observed that L‐NAME inhibited some effects caused by vitamin A supplementation. Nonetheless, L‐NAME was not able to reverse completely the negative effects triggered by vitamin A supplementation, indicating that other factors rather than only NO? or ONOO‐ exert a prominent role in mediating the redox effects in the lung of rats that received vitamin A supplementation. Copyright © 2011 John Wiley & Sons, Ltd.     

Temporal fluctuations of cytokine concentrations in human milk

Circadian rhythms affect the circulating levels of proteins that can modulate immune responses. Cytokines represent a group of proteins present in breast milk that modulate the immune system, but the effects of fluctuations of these proteins have not yet been elucidated. In this work, the cytokines present in human milk were quantified, taking into account the phases of the day and the maturation stages of human milk. Samples were collected at different stages of milk maturation and in two phases, day and night. The levels of cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, INF-γ and IL-17 were evaluated by flow cytometry. All quantified cytokines showed chronobiological variations with regard to the phase of day and/or stage of breast milk maturation. These data indicate that cytokines are subjected to fluctuations, and this knowledge is important for the use of human breast milk as an intervention strategy.     

Microalgal secondary metabolites: effect of climatic variables,seasons, and photocycles on the biogeneration of volatile organic compounds (VOCs)

Journal of Applied Phycology - Microalgae produce many metabolites with diversified structures that play important roles in their development. This work evaluated the effects of different climatic...