965 resultados para Halogenated Polycyclic Aromatic Hydrocarbons
Resumo:
Resveratrol has been shown to have beneficial effects on diseases related to oxidant and/or inflammatory processes and extends the lifespan of simple organisms including rodents. The objective of the present study was to estimate the dietary intake of resveratrol and piceid (R&P) present in foods, and to identify the principal dietary sources of these compounds in the Spanish adult population. For this purpose, a food composition database (FCDB) of R&P in Spanish foods was compiled. The study included 40 685 subjects aged 35–64 years from northern and southern regions of Spain who were included in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain cohort. Usual food intake was assessed by personal interviews using a computerised version of a validated diet history method. An FCDB with 160 items was compiled. The estimated median and mean of R&P intake were 100 and 933 μg/d respectively. Approximately, 32 % of the population did not consume R&P. The most abundant of the four stilbenes studied was trans-piceid (53·6 %), followed by trans-resveratrol (20·9 %), cis-piceid (19·3 %) and cis-resveratrol (6·2 %). The most important source of R&P was wines (98·4 %) and grape and grape juices (1·6 %), whereas peanuts, pistachios and berries contributed to less than 0·01 %. For this reason the pattern of intake of R&P was similar to the wine pattern. This is the first time that R&P intake has been estimated in a Mediterranean country.
The biological in vitro effect and selectivity of aromatic dicationic compounds on Trypanosoma cruzi
Resumo:
Trypanosoma cruzi is a parasite that causes Chagas disease, which affects millions of individuals in endemic areas of Latin America. One hundred years after the discovery of Chagas disease, it is still considered a neglected illness because the available drugs are unsatisfactory. Aromatic compounds represent an important class of DNA minor groove-binding ligands that exhibit potent antimicrobial activity. This study focused on the in vitro activity of 10 aromatic dicationic compounds against bloodstream trypomastigotes and intracellular forms of T. cruzi. Our data demonstrated that these compounds display trypanocidal effects against both forms of the parasite and that seven out of the 10 compounds presented higher anti-parasitic activity against intracellular parasites compared with the bloodstream forms. Additional assays to determine the potential toxicity to mammalian cells showed that the majority of the dicationic compounds did not considerably decrease cellular viability. Fluorescent microscopy analysis demonstrated that although all compounds were localised to a greater extent within the kinetoplast than the nucleus, no correlation could be found between compound activity and kDNA accumulation. The present results stimulate further investigations of this class of compounds for the rational design of new chemotherapeutic agents for Chagas disease.
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BACKGROUND Evidence associating exposure to water disinfection by-products with reduced birth weight and altered duration of gestation remains inconclusive. OBJECTIVE We assessed exposure to trihalomethanes (THMs) during pregnancy through different water uses and evaluated the association with birth weight, small for gestational age (SGA), low birth weight (LBW), and preterm delivery. METHODS Mother-child cohorts set up in five Spanish areas during the years 2000-2008 contributed data on water ingestion, showering, bathing, and swimming in pools. We ascertained residential THM levels during pregnancy periods through ad hoc sampling campaigns (828 measurements) and regulatory data (264 measurements), which were modeled and combined with personal water use and uptake factors to estimate personal uptake. We defined outcomes following standard definitions and included 2,158 newborns in the analysis. RESULTS Median residential THM ranged from 5.9 μg/L (Valencia) to 114.7 μg/L (Sabadell), and speciation differed across areas. We estimated that 89% of residential chloroform and 96% of brominated THM uptakes were from showering/bathing. The estimated change of birth weight for a 10% increase in residential uptake was -0.45 g (95% confidence interval: -1.36, 0.45 g) for chloroform and 0.16 g (-1.38, 1.70 g) for brominated THMs. Overall, THMs were not associated with SGA, LBW, or preterm delivery. CONCLUSIONS Despite the high THM levels in some areas and the extensive exposure assessment, results suggest that residential THM exposure during pregnancy driven by inhalation and dermal contact routes is not associated with birth weight, SGA, LBW, or preterm delivery in Spain.
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BACKGROUND. Exposure to xenoestrogens during pregnancy may disturb the development and function of male sexual organs. OBJECTIVE. In this study we aimed to determine whether the combined effect of environmental estrogens measured as total effective xenoestrogen burden (TEXB) is a risk factor for male urogenital malformations. METHODS. In a case-control study, nested in a mother-child cohort (n = 702) established at Granada University Hospital, we compared 50 newborns with diagnosis of cryptorchidism and/or hypospadias with 114 boys without malformations matched by gestational age, date of birth, and parity. Controls did not differ from the total cohort in confounding variables. TEXB and levels of 16 organochlorine pesticides were measured in placenta tissues. Characteristics of parents, pregnancy, and birth were gathered by questionnaire. We used conditional and unconditional regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS. TEXB from organohalogenated compounds was detectable in 72% and 54% of case and control placentas, respectively. Compared with controls, cases had an OR for detectable versus non-detectable TEXB of 2.82 (95% CI, 1.10-7.24). More pesticides were detected in cases than in controls (9.34 +/- 3.19 vs. 6.97 +/- 3.93). ORs for cases with detectable levels of pesticides, after adjusting for potential confounders in the conditional regression analysis, were o,p'-DDT (OR = 2.25; 95% CI, 1.03-4.89), p,p'-DDT (OR = 2.63; 95% CI, 1.21-5.72), lindane (OR = 3.38; 95% CI, 1.36-8.38), mirex (OR = 2.85; 95% CI, 1.22-6.66), and endosulfan alpha (OR = 2.19; 95% CI, 0.99-4.82). Engagement of mothers in agriculture (OR = 3.47; 95% CI, 1.33-9.03), fathers' occupational exposure to xenoestrogens (OR = 2.98; 95% CI, 1.11-8.01), and history of previous stillbirths (OR = 4.20; 95% CI, 1.11-16.66) were also associated with risk of malformations. CONCLUSIONS We found an increased risk for male urogenital malformations related to the combined effect of environmental estrogens in placenta.
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BACKGROUND. A growing body of research suggests that prenatal exposure to air pollution may be harmful to fetal development. We assessed the association between exposure to air pollution during pregnancy and anthropometric measures at birth in four areas within the Spanish Children's Health and Environment (INMA) mother and child cohort study. METHODS. Exposure to ambient nitrogen dioxide (NO2) and benzene was estimated for the residence of each woman (n = 2,337) for each trimester and for the entire pregnancy. Outcomes included birth weight, length, and head circumference. The association between residential outdoor air pollution exposure and birth outcomes was assessed with linear regression models controlled for potential confounders. We also performed sensitivity analyses for the subset of women who spent more time at home during pregnancy. Finally, we performed a combined analysis with meta-analysis techniques. RESULTS. In the combined analysis, an increase of 10 µg/m3 in NO2 exposure during pregnancy was associated with a decrease in birth length of -0.9 mm [95% confidence interval (CI), -1.8 to -0.1 mm]. For the subset of women who spent ≥ 15 hr/day at home, the association was stronger (-0.16 mm; 95% CI, -0.27 to -0.04). For this same subset of women, a reduction of 22 g in birth weight was associated with each 10-µg/m3 increase in NO2 exposure in the second trimester (95% CI, -45.3 to 1.9). We observed no significant relationship between benzene levels and birth outcomes. CONCLUSIONS. NO2 exposure was associated with reductions in both length and weight at birth. This association was clearer for the subset of women who spent more time at home.
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The management of patients scheduled for surgery with a coronary stent, and receiving 1 or more antiplatelet drugs, has many controversies. The premature discontinuation of antiplatelet drugs substantially increases the risk of stent thrombosis (ST), myocardial infarction, and cardiac death, and surgery under an altered platelet function could also lead to an increased risk of bleeding in the perioperative period. Because of the conflict in the recommendations, this article reviews the current antiplatelet protocols after positioning a coronary stent, the evidence of increased risk of ST associated with the withdrawal of antiplatelet drugs and increased bleeding risk associated with its maintenance, the different perioperative antiplatelet protocols when patients are scheduled for surgery or need an urgent operation, and the therapeutic options if excessive bleeding occurs.
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Assigning causality in drug-induced liver injury is challenging particularly when more than one drug could be responsible. We report a woman on long-term therapy with raloxifen who developed acute cholestasis shortly after starting fenofibrate. The picture evolved into chronic cholestasis. We hypothesized that an interaction at the metabolic level could have triggered the presentation of hepatotoxicity after a very short time of exposure to fenofibrate in this patient. The findings of an overexpression of vascular endothelial growth factor in the liver biopsy suggest that angiogenesis might play a role in the persistence of toxic cholestasis.
Resumo:
BACKGROUND A catheter-based approach after fibrinolysis is recommended if fibrinolysis is likely to be successful in patients with acute ST-elevation myocardial infarction. We designed a 2x2 randomized, open-label, multicenter trial to evaluate the efficacy and safety of the paclitaxel-eluting stent and tirofiban administered after fibrinolysis but before catheterization to optimize the results of this reperfusion strategy. METHODS AND RESULTS We randomly assigned 436 patients with acute ST-elevation myocardial infarction to (1) bare-metal stent without tirofiban, (2) bare-metal stent with tirofiban, (3) paclitaxel-eluting stent without tirofiban, and (4) paclitaxel-eluting stent with tirofiban. All patients were initially treated with tenecteplase and enoxaparin. Tirofiban was started 120 minutes after tenecteplase in those patients randomly assigned to tirofiban. Cardiac catheterization was performed within the first 3 to 12 hours after inclusion, and stenting (randomized paclitaxel or bare stent) was applied to the culprit artery. The primary objectives were the rate of in-segment binary restenosis of paclitaxel-eluting stent compared with that of bare-metal stent and the effect of tirofiban on epicardial and myocardial flow before and after mechanical revascularization. At 12 months, in-segment binary restenosis was similar between paclitaxel-eluting stent and bare-metal stent (10.1% versus 11.3%; relative risk, 1.06; 95% confidence interval, 0.74 to 1.52; P=0.89). However, late lumen loss (0.04+/-0.055 mm versus 0.27+/-0.057 mm, P=0.003) was reduced in the paclitaxel-eluting stent group. No evidence was found of any association between the use of tirofiban and any improvement in the epicardial and myocardial perfusion. Major bleeding was observed in 6.1% of patients receiving tirofiban and in 2.7% of patients not receiving it (relative risk, 2.22; 95% confidence interval, 0.86 to 5.73; P=0.14). CONCLUSIONS This trial does not provide evidence to support the use of tirofiban after fibrinolysis to improve epicardial and myocardial perfusion. Compared with bare-metal stent, paclitaxel-eluting stent significantly reduced late loss but appeared not to reduce in-segment binary restenosis. CLINICAL TRIAL REGISTRATION URL: http://clinicaltrials.gov. Unique identifier: NCT00306228.
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Plant-based whole foods provide thousands of bioactive metabolites to the human diet that reduce the risk of developing chronic diseases. β-Caryophyllene (CAR) is a common constituent of the essential oil of numerous plants, vegetables, fruits and medicinal herbs, and has been used as a flavouring agent since the 1930 s. Here, we report the antioxidant activity of CAR, its protective effect on liver fibrosis and its inhibitory capacity on hepatic stellate cell (HSC) activation. CAR was tested for the inhibition of lipid peroxidation and as a free radical scavenger. CAR had higher inhibitory capacity on lipid peroxidation than probucol, α-humulene and α-tocopherol. Also, CAR showed high scavenging activities against hydroxyl radical and superoxide anion. The activity of 5-lipoxygenase, an enzyme that actively participates in fibrogenesis, was significantly inhibited by CAR. Carbon tetrachloride-treated rats received CAR at 2, 20 and 200 mg/kg. CAR significantly improved liver structure, and reduced fibrosis and the expression of Col1a1, Tgfb1 and Timp1 genes. Oxidative stress was used to establish a model of HSC activation with overproduction of extracellular matrix proteins. CAR (1 and 10 μm) increased cell viability and significantly reduced the expression of fibrotic marker genes. CAR, a sesquiterpene present in numerous plants and foods, is as a natural antioxidant that reduces carbon tetrachloride-mediated liver fibrosis and inhibits hepatic cell activation.
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The cuticular hydrocarbons of the Triatoma sordida subcomplex (Hemiptera: Reduviidae: Triatominae) were ana-lysed by gas chromatography and their structures identified by mass spectrometry. They comprised mostly n-alkanes and methyl-branched alkanes with one-four methyl substitutions. n-alkanes consisted of a homologous series from C21-C33 and represented 33-45% of the hydrocarbon fraction; n-C29 was the major component. Methyl-branched alkanes showed alkyl chains from C24-C43. High molecular weight dimethyl and trimethylalkanes (from C35-C39) represented most of the methyl-branched fraction. A few tetramethylalkanes were also detected, comprising mostly even-numbered chains. Several components such as odd-numbered 3-methylalkanes, dimethylalkanes and trimethylalkanes of C37 and C39 showed patterns of variation that allowed the differentiation of the species and populations studied. Triatoma guasayana and Triatoma patagonica showed the most distinct hydrocarbon patterns within the subcomplex. The T. sordida populations from Brazil and Argentina showed significantly different hydrocarbon profiles that posed concerns regarding the homogeneity of the species. Triatoma garciabesi had a more complex hydrocarbon pattern, but it shared some similarity with T. sordida. The quantitative and qualitative variations in the cuticular hydrocarbons may help to elucidate the relationships between species and populations of this insect group.
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Growing awareness of cerebellar involvement in addiction is based on the cerebellum's intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] and the gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-arachidonylglycerol (2-AG) production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and glutamate systems. Repeated cocaine results in normalization of glutamate receptor expression, although sustained changes in eCB is observed. We suggest that cocaine-induced alterations to cerebellar eCB should be considered when analyzing the adaptations imposed by psychostimulants that lead to addiction.
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Recently, the surprising result that ab initio calculations on benzene and other planar arenes at correlated MP2, MP3, configuration interaction with singles and doubles (CISD), and coupled cluster with singles and doubles levels of theory using standard Pople’s basis sets yield nonplanar minima has been reported. The planar optimized structures turn out to be transition states presenting one or more large imaginary frequencies, whereas single-determinant-based methods lead to the expected planar minima and no imaginary frequencies. It has been suggested that such anomalous behavior can be originated by two-electron basis set incompleteness error. In this work, we show that the reported pitfalls can be interpreted in terms of intramolecular basis set superposition error (BSSE) effects, mostly between the C–H moieties constituting the arenes. We have carried out counterpoise-corrected optimizations and frequency calculations at the Hartree–Fock, B3LYP, MP2, and CISD levels of theory with several basis sets for a number of arenes. In all cases, correcting for intramolecular BSSE fixes the anomalous behavior of the correlated methods, whereas no significant differences are observed in the single-determinant case. Consequently, all systems studied are planar at all levels of theory. The effect of different intramolecular fragment definitions and the particular case of charged species, namely, cyclopentadienyl and indenyl anions, respectively, are also discussed
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During the first hours after release of petroleum at sea, crude oil hydrocarbons partition rapidly into air and water. However, limited information is available about very early evaporation and dissolution processes. We report on the composition of the oil slick during the first day after a permitted, unrestrained 4.3 m(3) oil release conducted on the North Sea. Rapid mass transfers of volatile and soluble hydrocarbons were observed, with >50% of ≤C17 hydrocarbons disappearing within 25 h from this oil slick of <10 km(2) area and <10 μm thickness. For oil sheen, >50% losses of ≤C16 hydrocarbons were observed after 1 h. We developed a mass transfer model to describe the evolution of oil slick chemical composition and water column hydrocarbon concentrations. The model was parametrized based on environmental conditions and hydrocarbon partitioning properties estimated from comprehensive two-dimensional gas chromatography (GC×GC) retention data. The model correctly predicted the observed fractionation of petroleum hydrocarbons in the oil slick resulting from evaporation and dissolution. This is the first report on the broad-spectrum compositional changes in oil during the first day of a spill at the sea surface. Expected outcomes under other environmental conditions are discussed, as well as comparisons to other models.