1,008 research outputs found

    Peroxidases have more functions than a Swiss army knife

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    Plant peroxidases (class III peroxidases) are present in all land plants. They are members of a large multigenic family. Probably due to this high number of isoforms, and to a very heterogeneous regulation of their expression, plant peroxidases are involved in a broad range of physiological processes all along the plant life cycle. Due to two possible catalytic cycles, peroxidative and hydroxylic, peroxidases can generate reactive oxygen species (ROS) (•OH, HOO•), polymerise cell wall compounds, and regulate H2O2 levels. By modulating their activity and expression following internal and external stimuli, peroxidases are prevalent at every stage of plant growth, including the demands that the plant meets in stressful conditions. These multifunctional enzymes can build a rigid wall or produce ROS to make it more flexible; they can prevent biological and chemical attacks by raising physical barriers or by counterattacking with a large production of ROS; they can be involved in a more peaceful symbiosis. They are finally present from the first hours of a plant's life until its last moments. Although some functions look paradoxical, the whole process is probably regulated by a fine-tuning that has yet to be elucidated. This review will discuss the factors that can influence this delicate balanc

    Fluvial carbon export from a lowland Amazonian rainforest in relation to atmospheric fluxes

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    We constructed a whole carbon budget for a catchment in the Western Amazon Basin, combining drainage water analyses with eddy covariance measured terrestrial CO2 fluxes. As fluvial C export can represent permanent C export it must be included in assessments of whole site C balance, but is rarely done. The footprint area of the flux tower is drained by two small streams (~5-7 km2) from which we measured the dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), particulate organic carbon (POC) export and CO2 efflux. The EC measurements showed the site C balance to be +0.7 ± 9.7 Mg C ha-1 yr-1 (a source to the atmosphere) and fluvial export was 0.3 ± 0.04 Mg C ha-1 yr-1. Of the total fluvial loss 34% was DIC, 37% DOC and 29% POC. The wet season was most important for fluvial C export. There was a large uncertainty associated with the EC results and with previous biomass plot studies (-0.5 ± 4.1 Mg C ha-1 yr-1), hence it cannot be concluded with certainty whether the site is C sink or source. The fluvial export corresponds to only 3-7 % of the uncertainty related to the site C balance, thus other factors need to be considered to reduce the uncertainty and refine the estimated C balance. However, stream C export is significant, especially for almost neutral sites where fluvial loss may determine the direction of the site C balance. The fate of C downstream then dictates the overall climate impact of fluvial export

    Foliar lead uptake by lettuce exposed to atmospheric fallouts

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    Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

    The Cardiology Audit and Registration Data Standards (CARDS), European data standards for clinical cardiology practice

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    AIMS: Systematic registration of data from clinical practice is important for clinical care, local, national and international registries, and audit. Data to be collected for these different purposes should be harmonized. Therefore, during Ireland's Presidency of the European Union (EU) (January to June 2004), the Department of Health and Children worked with the European Society of Cardiology, the Irish Cardiac Society, and the European Commission to develop data standards for clinical cardiology. The Cardiology Audit and Registration Data Standards (CARDS) Project aimed to agree standards for three modules of cardiovascular health information systems: acute coronary syndromes (ACS), percutaneous coronary interventions (PCI), and clinical electrophysiology (pacemakers, implantable cardioverter defibrillators, and ablation procedures). METHODS AND RESULTS: Data items from existing registries and surveys were reviewed to derive draft data standards (variables, coding, and definitions). Variables common to the three modules include demographics, risk factors, medication, and discharge and follow-up data. Modules about a procedure contain variables on the l

    Evaluation of extra-virgin olive oils shelf life using an electronic tongue-chemometric approach

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    Physicochemical quality parameters, olfactory and gustatoryretronasal positive sensations of extra-virgin olive oils vary during storage leading to a decrease in the overall quality. Olive oil quality decline may prevent the compliance of olive oil quality with labeling and significantly reduce shelf life, resulting in important economic losses and negatively condition the consumer confidence. The feasibility of applying an electronic tongue to assess olive oils usual commercial light storage conditions and storage time was evaluated and compared with the discrimination potential of physicochemical or positive olfactory/gustatory sensorial parameters. Linear discriminant models, based on subsets of 58 electronic tongue sensor signals, selected by the meta-heuristic simulated annealing variable selection algorithm, allowed the correct classification of olive oils according to the light exposition conditions and/or storage time (sensitivities and specificities for leave-one-out cross-validation: 8296 %). The predictive performance of the E-tongue approach was further evaluated using an external independent dataset selected using the KennardStone algorithm and, in general, better classification rates (sensitivities and specificities for external dataset: 67100 %) were obtained compared to those achieved using physicochemical or sensorial data. So, the work carried out is a proof-of-principle that the proposed electrochemical device could be a practical and versatile tool for, in a single and fast electrochemical assay, successfully discriminate olive oils with different storage times and/or exposed to different light conditions.The authors acknowledge the financial support from the strategic funding of UID/BIO/04469/2013 unit, from Project POCI-01-0145-FEDER-006984—Associate Laboratory LSRELCM funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI)—and by national funds through FCT—Fundação para a Ciência e a Tecnologia and under the strategic funding of UID/BIO/04469/2013 unit. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).info:eu-repo/semantics/publishedVersio

    Beta defensin-2 is reduced in central but not in distal airways of smoker COPD patients

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    Background: Altered pulmonary defenses in chronic obstructive pulmonary disease (COPD) may promote distal airways bacterial colonization. The expression/activation of Toll Like receptors (TLR) and beta 2 defensin (HBD2) release by epithelial cells crucially affect pulmonary defence mechanisms. Methods: The epithelial expression of TLR4 and of HBD2 was assessed in surgical specimens from current smokers COPD (s-COPD; n = 17), ex-smokers COPD (ex-s-COPD; n = 8), smokers without COPD (S; n = 12), and from non-smoker non-COPD subjects (C; n = 13). Results: In distal airways, s-COPD highly expressed TLR4 and HBD2. In central airways, S and s-COPD showed increased TLR4 expression. Lower HBD2 expression was observed in central airways of s-COPD when compared to S and to ex-s-COPD. s-COPD had a reduced HBD2 gene expression as demonstrated by real-time PCR on micro-dissected bronchial epithelial cells. Furthermore, HBD2 expression positively correlated with FEV1/FVC ratio and inversely correlated with the cigarette smoke exposure. In a bronchial epithelial cell line (16 HBE) IL-1β significantly induced the HBD2 mRNA expression and cigarette smoke extracts significantly counteracted this IL-1 mediated effect reducing both the activation of NFkB pathway and the interaction between NFkB and HBD2 promoter. Conclusions: This study provides new insights on the possible mechanisms involved in the alteration of innate immunity mechanisms in COPD. © 2012 Pace et al

    Malassezia furfur bloodstream infection: still a diagnostic challenge in clinical practice

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    The opportunistic fungus Malassezia furfur (M. furfur) can cause either cutaneous or systemic infections. We report a case of M. furfur fungemia in a 22-year-old male with T-cell Acute Lymphoblastic Leukemia (T-ALL) who developed concomitant Bacillus cereus (B. cereus) septicemia. The fungal infection was diagnosed by microscopic examination and culture-based methods, while automated blood culture systems and molecular approaches failed in identifying the fungus. Despite appropriate therapy, the patient died 18 days after the hospitalization

    Renal transplantation for lupus nephritis: non-adherence and graft survival

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    Objectives: Poor adherence to immunosuppressive treatment is common in patients with systemic lupus erythematosus and may identify those with lupus nephritis (LN) who have a poorer prognosis. Non-adherence has also been reported to be a potential adverse outcome predictor in renal transplantation (rTp). We investigated whether non-adherence is associated with increased rTp graft rejection and/or failure in patients with LN. Methods: Patients with LN undergoing rTp in two major London hospitals were retrospectively included. Medical and electronic records were reviewed for documented concerns of non-adherence as well as laboratory biochemical drug levels. The role of non-adherence and other potential predictors of graft rejection/failure including demographics, comorbidities, age at systemic lupus erythematosus and LN diagnosis, type of LN, time on dialysis prior to rTp and medication use were investigated using logistic regression. Results: Out of 361 patients with LN, 40 had rTp. During a median follow-up of 8.7 years, 17/40 (42.5%) of these patients had evidence of non-adherence. A total of 12 (30.0%) patients experienced graft rejection or failure or both. In the adherent group 2/23 (8.7%) had graft rejection, whilst in the non-adherent this rose to 5/17 (29.4%, p = 0.11). Graft failure was seen in 5/23 (21.7%) patients from the adherent group and 4/17 (23.5%) in the non-adherent group (p = 0.89). Non-adherent patients had a trend towards increased graft rejection, hazard ratio 4.38, 95% confidence interval = 0.73–26.12, p = 0.11. Patients who spent more time on dialysis prior to rTp were more likely to be adherent to medication, p = 0.01. Conclusion: Poor adherence to immunosuppressive therapy is common and has been shown to associate with a trend towards increased graft failure in patients with LN requiring rTp. This is the first paper to report that shorter periods on dialysis prior to transplantation might lead to increased non-adherence in lupus patients
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