Mapping atmospheric pollutants emissions in European countries

In this paper we present a methodology which enables the graphical representation, in a bi-dimensional Euclidean space, of atmospheric pollutants emissions in European countries. This approach relies on the use of Multidimensional Unfolding (MDU), an exploratory multivariate data analysis technique. This technique illustrates both the relationships between the emitted gases and the gases and their geographical origins. The main contribution of this work concerns the evaluation of MDU solutions. We use simulated data to define thresholds for the model fitting measures, allowing the MDU output quality evaluation. The quality assessment of the model adjustment is thus carried out as a step before interpretation of the gas types and geographical origins results. The MDU maps analysis generates useful insights, with an immediate substantive result and enables the formulation of hypotheses for further analysis and modeling

Can Biofluids Metabolic Profiling Help to Improve Healthcare during Pregnancy?

This paper describes a metabonomics study of 2nd trimester biofluids (amniotic fluid, maternal urine, and blood plasma), in an attempt to correlate biofluid metabolic changes with suspected/diagnosed fetal malformations (FM) and chromosomal disorders as well as with later occurring gestational diabetes mellitus (GDM), preterm delivery (PTD), and premature rupture of membranes (PROM). The global biochemical picture given by the threesome of biofluids should enable the definition of potential disease signatures and unveil potential metabolite markers for clinical use in predictive prenatal diagnostics. Results show that relatively strong metabolic disturbances accompany FM, reflected in all three biofluids and thus suggesting the involvement of both fetal and maternal metabolisms. Regarding GDM, amniotic fluid and maternal urine seem potential good media to detect early metabolic changes, and PTD subjects show small metabolite changes in the same biofluids, undergoing work being focused on plasma composition. Chromosomal disorders show an interestingly marked effect on maternal urine, whereas no statistically relevant early changes have been observed for PROM subjects. Interestingly, in the case of FM and chromosomal disorders, maternal biofluids show some sensitivity to disorder type, for example, for central nervous system malformations and trisomy 21, respectively. These results show the usefulness of biofluid metabonomics to probe overall metabolic disturbances in relation to prenatal disorders

Metabolic Biomarkers of Prenatal Disorders: An Exploratory NMR Metabonomics Study of Second Trimester Maternal Urine and Blood Plasma

This work describes an exploratory NMR metabonomic study of second trimester maternal urine and plasma, in an attempt to characterize the metabolic changes underlying prenatal disorders and identify possible early biomarkers. Fetal malformations have the strongest metabolic impact in both biofluids, suggesting effects due to hypoxia (leading to hypoxanthine increased excretion) and a need for enhanced gluconeogenesis, with higher ketone bodies (acetone and 3-hydroxy-butyric acid) production and TCA cycle demand (suggested by glucogenic amino acids and cis-aconitate overproduction). Choline and nucleotide metabolisms also seem affected and a distinct plasma lipids profile is observed for mothers with fetuses affected by central nervous system malformations. Urine from women who subsequently develop gestational diabetes mellitus exhibits higher 3-hydroxyisovalerate and 2-hydroxyisobutyrate levels, probably due to altered biotin status and amino acid and/or gut metabolisms (the latter possibly related to higher BMI values). Other urinary changes suggest choline and nucleotide metabolic alterations, whereas lower plasma betaine and TMAO levels are found. Chromosomal disorders and pre-preterm delivery groups show urinary changes in choline and, in the latter case, in 2-hydroxyisobutyrate. These results show that NMR metabonomics of maternal biofluids enables the noninvasive detection of metabolic changes associated to prenatal disorders, thus unveiling potential disorder biomarkers.FCTPTDC/ QUI/66523/2006SFRH/BD/41869/2007SFRH/ BD/64159/2009SFRH/BD/73343/2010Portuguese National NMR Network - RNRM

NMR Metabolomics Reveals Metabolism-Mediated Protective Effects in Liver (HepG2) Cells Exposed to Subtoxic Levels of Silver Nanoparticles

The expansion of biomedical and therapeutic applications of silver nanoparticles (AgNPs) raises the need to further understand their biological effects on human cells. In this work, NMR metabolomics has been applied to reveal the metabolic effects of AgNPs toward human hepatoma (HepG2) cells, which are relevant with respect to nanoparticle accumulation and detoxification. Cellular responses to widely disseminated citrate-coated AgNPs (Cit30) and to emergent biogenic AgNPs prepared using an aqueous plant extract as reducing and stabilizing agent (GS30) have been compared with a view to assess the influence of nanoparticle coating on the metabolic effects produced. Subtoxic concentrations (IC₅ and IC₂₀) of both nanoparticle types caused profound changes in the cellular metabolome, suggesting adaptations in energy production processes (glucose metabolism and the phosphocreatine system), antioxidant defenses, protein degradation and lipid metabolism. These signatures were proposed to reflect mainly metabolism-mediated protective mechanisms and were found to be largely common to Cit30 and GS30 AgNPs, although differences in the magnitude of response, not captured by conventional cytotoxicity assessment, were detected. Overall, this study highlights the value of NMR metabolomics for revealing subtoxic biological effects and helping to understand cell–nanomaterial interactions