Pesticides and PPCPs in aquatic ecosystems of the andean central region: Occurrence and ecological risk assessment in the Uco valley

Uco valley (Mendoza, Argentina) suffers the concomitant effect of climate change, anthropic pressure and water scarcity. Moreover chemical pollution to aquatic ecosystems could be another pressuring factor, but it was not studied enough to the present. In this sense, the aim of this study was to assess the occurrence of pesticides, pharmaceuticals and personal care products (PPCPs) in aquatic ecosystems of the Uco Valley and to perform an ecological risk assessment (ERA). The presence of several insecticides (mainly neonicotinoids), herbicides (atrazine, diuron, metolachlor, terbutryn) and fungicides (strobilurins, triazolic and benzimidazolic compounds) in water samples in two seasons, related to crops like vineyards, garlic or fruit trees was associated to medium and high-risk probabilities for aquatic biota. Moreover, PPCPs of the group of non-steroidal anti-inflammatory drugs, parabens and bisphenol A were detected in all the samples and their calculated risk quotients also indicated a high risk. This is the first record of pesticides and PPCPs with an ERA in this growing agricultural oasis. Despite the importance of these findings in Uco Valley for decision makers in the region, this multilevel approach could bring a wide variety of tools for similar regions in with similar productive and environmental conditions, in order to afford actions to reach Sustainable Development Goals. SYNOPSIS: Aquatic ecosystems in arid mountain regions are threatened worldwide. This study reports relevant data about chemical pollution in Central Andes, which could be a useful tool to enhance SDGs' accomplishment.

Calibration and Application of PUF Disk Passive Air Samplers To Assess Chlorinated Paraffins in Ambient Air in Australia, China, and Vietnam

Ambient air samples were collected in Brisbane (Australia), Dalian (China), and Hanoi (Vietnam) during Mar 2013-Feb 2018 using polyurethane foam based passive air samplers. A sampling rate calibration experiment was conducted for chlorinated paraffins (CPs, i.e., short-chain, medium-chain, and long-chain CPs), where the sampling rates were 4.5 ± 0.7, 4.8 ± 0.3, and 4.8 ± 2.1 m3 day-1 for SCCPs, MCCPs, and LCCPs, respectively. The atmospheric concentration of CPs was then calculated and the medians of ∑CPs were 0.079, 1.0, and 0.89 ng m-3 in Brisbane, Dalian, and Hanoi, respectively. The concentration of CPs in Brisbane's air remained at low levels, with no significant differences observed between the city background site and the city center site, indicating limited usage and production of CPs in this city. The highest concentration of MCCPs was detected in Dalian, while the highest concentration of SCCPs was detected in Hanoi. A decrease of SCCP concentration and an increase of MCCPs' were found in Brisbane's air from 2016 to 2018, while increasing trends for both SCCPs and MCCPs were observed in Dalian. These results indicated impacts from different sources of CPs in the investigated cities.

Building a nonclinical pathology laboratory of the future for pharmaceutical research excellence

We describe a roadmap for a fully digital artificial intelligence (AI)-augmented nonclinical pathology laboratory across three continents. Underpinning the design are Good Laboratory Practice (GLP)-validated laboratory information management systems (LIMS), whole slide-scanners (WSS), image management systems (IMS), and a digital microscope intended for use by the nonclinical pathologist. Digital diagnostics are supported by tools that include AI-based virtual staining and deep learning-based decision support. Implemented during the COVID-19 pandemic, the initial digitized workflow largely mitigated disruption of pivotal nonclinical studies required to support pharmaceutical clinical testing. We believe that this digital transformation of our nonclinical pathology laboratories will promote efficiency and innovation in the future and enhance the quality and speed of drug development decision making.

Risk evaluation and prioritization of contaminants of emerging concern and other organic micropollutants in two river basins of central Argentina

A research gap exists in baseline concentrations of organic micropollutants in South American rivers. Identification of areas with different degrees of contamination and risk to the inhabitant biota is needed to improve management of freshwater resources. Here we inform the incidence and ecological risk assessment (ERA) of current used pesticides (CUPs), pharmaceutical and personal care products (PPCPs) and cyanotoxins (CTX) measured in two river basins from central Argentina (South America). Risk Quotients approach was used for ERA differentiating wet and dry seasons. High risk was associated to CUPs in both basins (45 % and 30 % of sites from Suquía and Ctalamochita rivers, respectively), mostly in the basins extremes. Main contributors to risk in water were insecticides and herbicides in Suquía river and insecticides and fungicides in Ctalamochita river. In Suquía river sediments, a very high risk was observed in the lower basin, mainly from AMPA contribution. Additionally, 36 % of the sites showed very high risk of PCPPs in Suquía river water, with the highest risk downstream the wastewater treatment plant of Córdoba city. Main contribution was from a psychiatric drug and analgesics. In sediments medium risk was observed at the same places with antibiotics and psychiatrics as main contributors. Few data of PPCPs are available in the Ctalamochita river. The risk in water was low, with one site (downstream Santa Rosa de Calamuchita town) presenting moderated risk caused by an antibiotic. CTX represented in general medium risk in San Roque reservoir, with San Antonio river mouth and the dam exit showing high risk during the wet season. The main contributor was microcystin-LR. Priority chemicals for monitoring or further management include two CUPs, two PPCPs, and one CTX, demonstrating a significant input of pollutants to water ecosystems from different sources and the need to include organic micropollutants in current and future monitoring.

Pesticides bioassays using neotropical aquatic species: Trends during the last twenty years and future challenges in Argentina

The presence of pesticides in aquatic ecosystems is one of the most relevant stressors which biota usually face. Laboratory tests using model organisms for pesticides toxicity assessment are employed worldwide. The use of these species has been encouraged in the scientific community due to their advantageous features and their acceptation by regulatory and standardization organizations. However, non-model species as well as those belonging particular ecosystems could contribute in the laboratory-field toxicity extrapolation. In this context, this work aims on exploring the state of the ecotoxicological studies of pesticides in neotropical aquatic species, focusing on bioassays performed in Argentina over the last 20 years as a case of study. Furthermore, we analyzed the possible advantages and disadvantages of these studies, possible differential sensitivities among native and model species, and future challenges to be faced. The analysis of more than 150 publications allowed identify the chemical identity of tested compounds, organisms used for the bioassays, characteristics of the experimental designs, and the toxicity endpoints. Particularly, the studied cases showed that the tested chemicals are related to those most used in the agricultural activity in Argentina, the predilection for particular species in some taxonomic groups (e.g. amphibians), and the wide election of biochemical biomarkers in the studies. Regarding the sensitivity comparison between native and non-native species, the amount of data available indicates that there is not a clear difference beyond some particular cases. However, deeper understanding of toxic effects of pesticides on non-model species could help in a more comprehensive ecological risk assessment in different ecosystems.

Clinical use of mean platelet volume and neutrophil-to-lymphocyte ratio to predict prognosis in heart failure with preserved ejection fraction patients

Background

Over the last decade, a new paradigm for heart failure with preserved ejection (HFpEF) development has been proposed. High burden of comorbidities would lead to a systemic inflammatory state and enhanced platelet activation. High platelet reactivity could be associated with higher mean platelet volume (MPV) due increased circulating immature platelets. Moreover, neutrophil-to-lymphocyte (NLR) reflects systemic inflammation. Both parameters have been associated with morbidity and mortality in heart failure (HF). However, data in HFpEF are limited.

Purpose

We aim to investigate the use of MPV and NLR to predict clinical outcome in HFpEF patients.

Methods

We prospectively enrolled 228 patients with HFpEF (79±9 years, 66% female patients) and 38 controls of similar age and gender (78±5, 63% female patients). All subjects underwent a complete two-dimensional echocardiography. Mean platelet volume and NLR were measured at baseline. Patients were followed over time for a primary end point of all-cause mortality or first HF hospitalization. The prognosis impact of MPV and NLR were determined with Cox proportional hazard models.

Results

Mean MPV and median NLR were significantly higher in HFpEF patients compared to controls (MPV: 11.7±1.1 fL vs 10.0±1.1 fL, p=0.005; NLR: 3.3 [2.2; 5.0] vs 2.2 [1.9; 2.9], p<0.001). HFpEF patients with MPV >75th percentile (n=56) had more frequently a history of ischemic cardiomyopathy (46%, p=0.04). HFpEF patients with NLR >75th percentile (n=57) were more frequently in New York Heart Association functional (NYHA) III or IV class (58%, p=0.02) and had higher levels of NT-proBNP (2152 [1336; 6397] pg/mL vs 1690 [705; 3304] pg/mL, p=0.02). Over a median follow-up of 26 months [11.5–56.7 months], 136 HFpEF patients (60%) reached the composite end point (87 deaths and 107 hospitalizations for HF). In univariate Cox regression analysis for the primary end point, MPV >75th percentile (HR: 1.45 [0.99; 2.13], p=0.05) and NLR >75th percentile (HR: 1.59 [1.11; 2.28], p=0.01) were predictors of the primary composite endpoint. In multivariate Cox regression analysis, mean platelet volume >75th percentile (χ2=8.11, P=0.004), continuous MPV (χ2=4.64, P=0.03) provided significant additional prognostic value over a baseline model created using independent predictors of the primary composite end point: body mass index (BMI), NYHA class III or IV, chronic obstructive pulmonary disease (COPD), loop diuretics, estimated glomerular filtration rate (eGFR) and NT-proBNP. By contrast, NLR did not provide any additional information (Figure 1 and 2).

Conclusion

MPV level and NLR were significantly higher in HFpEF patients compared with controls of similar age and gender. Elevated MPV offers an additional prognostic indication for clinicians and more interestingly it supports the hypothesis that of platelet activation could be involved in disease pathophysiology in HFpEF.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Fondation Saint-Luc

Acetyl-CoA carboxylase inhibition alters tubulin acetylation and aggregation in thrombin-stimulated platelets

Introduction

Acetyl-CoA carboxylase (ACC), the first enzyme regulating lipid synthesis, promotes thrombus formation by increasing platelet phospholipid content. Inhibition of its activity decreases lipogenesis and increases the content in acetyl-CoA which can serve as a substrate for protein acetylation. This posttranslational modification plays a key role in the regulation of platelet aggregation, via tubulin acetylation.

Purpose

To demonstrate that ACC inhibition may affect platelet functions via an alteration of lipid content and/or tubulin acetylation.

Methods

Platelets were treated 2 hours with CP640.186, a pharmacological ACC inhibitor, prior to thrombin stimulation. Platelet functions were assessed by aggregometry and flow cytometry. Lipogenesis was measured via 14C-acetate incorporation into lipids. Lipidomics analysis was carried out on the commercial Lipidyzer platform. Protein phosphorylation and acetylation were evaluated by western blot.

Results

Treatment with CP640.186 drastically decreased platelet lipogenesis. However, the quantitative lipidomics analyses showed that preincubation with the compound did not affect global platelet lipid content. Interestingly, this short-term ACC inhibition was sufficient to increase tubulin acetylation level, at basal state and after thrombin stimulation. It was associated with an impaired platelet aggregation, in response to low thrombin concentration, while granules secretion was not affected. Mechanistically, we highlighted a decrease in Rac1 activity, associated with a reduced phosphorylation of its downstream effector PAK2. Surprisingly, actin cytoskeleton was not impacted but we evidenced a significant decrease in ROS production which could result from a decreased NOX2 activity.

Conclusion

Pharmacological ACC inhibition decreases platelet aggregation upon thrombin stimulation. The mechanism depends on increased tubulin acetylation, with subsequent alteration of the Rac1/PAK2/NOX2 signaling pathway

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Fonds pour la formation à la Recherche dans l'Industrie et l'Agriculture (FRIA)

Role of platelet GARP in TGFB activation

Introduction

Transforming growth factor (TGF)β is known to be a central player in the control of cardiac fibroblast properties and fibrosis. However, cellular and molecular mechanisms that trigger its activation remain poorly understood. Platelets are considered as a major source of TGFβ and recent evidence suggest that they are involved in TGFβ activation via Glycoprotein A Repetitions Predominant (GARP) present on their surface.

Purpose

The present study sought to evaluate the role of platelet GARP in TGFβ activation using platelet specific GARP knockout mice.

Methods

We generated a new Cre transgenic mouse strain that allowed Megakaryocyte/platelet specific invalidation of GARP (GpIba-Cre x GARPfl/fl). The impact of GARP deficiency on platelet function was measured in vitro by flow cytometry using thrombin and CRP. Serum production of total and active TGFβ was assessed by ELISA.

Results

Platelet count and other hematological parameters were normal in platelet specific GARP knockout mice, except platelet volume, which was increased by 10.3%, as compared to wild-type platelets. Stimulation by thrombin and CRP increased GARP exposure at platelet surface. However, platelets without GARP displayed normal agonist induced activation, as reflected by CD62P and αIIbβ3 exposure. Interestingly, the generation of active TGFβ was drastically impaired in the serum of platelet specific GARP knockout mice, while the amount of total TGFβ was not affected.

Conclusion

We provided evidence that platelet GARP is a crucial contributor to the systemic activation of TGFβ. Future work will aim to determine its role in cardiac fibroblast myodifferentiation and fibrosis.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): FRIA

Platelet-specific deletion of acetyl-CoA carboxylase 1 decreases phospholipid content and impairs platelet functions

Background

Acetyl-CoA carboxylase (ACC), the first enzyme regulating lipid synthesis, promotes thrombus formation by increasing platelet phospholipid content and thromboxane A2 generation.

Purpose

Our study sought to evaluate whether ACC1 platelet-specific deletion may affect platelet functions by decreasing phospholipid content.

Methods

We generated a new Cre transgenic mouse strain that allows megakaryocyte/platelet specific ACC1 deletion (GpIbCre+/− x ACC1 flx/flx mouse). In vitro, platelet functions were assessed by aggregometry and flow cytometry. In vivo, hemostasis was assessed via the measurement of bleeding time. Lipidomics analysis was carried out on the commercial Lipidyzer platform. Thromboxane A2 secretion was evaluated by ELISA.

Results

As expected, ACC1 deletion was restricted to the megakaryocytic lineage. Hematological parameters in platelet-specific ACC1 knockout mice showed a decrease in platelet count by 30% and an increase in platelet volume by 31%, compared to ACC1 flx/flx platelets. In vitro, platelets from platelet-specific ACC1 knockout mice displayed a decrease in thrombin and CRP-induced platelet aggregation, associated with impaired dense granules secretion. In contrast, ADP-induced platelet aggregation was higher in the absence of ACC1. In vivo, platelet-specific ACC1 knockout mice showed a normal bleeding time. In agreement with our hypothesis, lipidomics analyses showed that ACC1 deletion in platelets was associated with a significant decrease in arachidonic acid-contaning phosphatidylethanolamine plasmalogen, and subsequently with a reduced production of thromboxane A2 upon thrombin or CRP stimulation.

Conclusion

Platelet-specific ACC1 deletion led to a decrease in phospholipid content which, in turn, decreased platelet thromboxane A2 generation, dense granules secretion and aggregation upon thrombin and CRP, but not ADP stimulation. Further studies are needed to elucidate the impact of ADP on platelet functions

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Fonds pour la formation à la Recherche dans l'Industrie et l'Agriculture (FRIA)

Nanoscale 3D quantitative imaging of 1.88 Ga Gunflint microfossils reveals novel insights into taphonomic and biogenic characters

Precambrian cellular remains frequently have simple morphologies, micrometric dimensions and are poorly preserved, imposing severe analytical and interpretational challenges, especially for irrefutable attestations of biogenicity. The 1.88 Ga Gunflint biota is a Precambrian microfossil assemblage with different types and qualities of preservation across its numerous geological localities and provides important insights into the Proterozoic biosphere and taphonomic processes. Here we use synchrotron-based ptychographic X-ray computed tomography to investigate well-preserved carbonaceous microfossils from the Schreiber Beach locality as well as poorly-preserved, iron-replaced fossil filaments from the Mink Mountain locality, Gunflint Formation. 3D nanoscale imaging with contrast based on electron density allowed us to assess the morphology and carbonaceous composition of different specimens and identify the minerals associated with their preservation based on retrieved mass densities. In the Mink Mountain filaments, the identification of mature kerogen and maghemite rather than the ubiquitously described hematite indicates an influence from biogenic organics on the local maturation of iron oxides through diagenesis. This non-destructive 3D approach to microfossil composition at the nanoscale within their geological context represents a powerful approach to assess the taphonomy and biogenicity of challenging or poorly preserved traces of early microbial life, and may be applied effectively to extraterrestrial samples returned from upcoming space missions.

Assessment of phytotoxic effects, uptake and translocation of diclofenac in chicory (Cichorium intybus)

Pharmaceuticals in the environment have been an increasing research topic over the past decade, since they can be found in both natural and drinking water, including irrigation of crops and edible plants with contaminated water. Our main goal was to evaluate the phytotoxic effect of diclofenac (DCF), a widely used pharmaceutical, on chicory (Cichorium intybus) seedlings. Additionally, we verified the uptake, bioconcentration and translocation of DCF from soil to chicory tissues. Results show that DCF induces different physiological changes in chicory seedlings. On the other hand, the soil-chicory experiment showed the activation of the detoxification system in plants treated with DCF (1 mg L-1). Finally, we found the migration of DCF from the irrigation water to the soil, followed by its uptake through the root, and its translocation to the aerial part of the chicory. However, DCF does not bioaccumulate in chicory leaves, being scarcely translocated from roots to aerial parts. This last result, along with the estimation of a daily intake of chicory, show that irrigation with water containing DCF (≤1 mg L-1) does not represent a threat to human health. To our knowledge, this is the first report on the effect of DCF on chicory seedlings, including the evaluation of its uptake and translocation.

A multilevel response approach reveals the Asian clam Corbicula largillierti as a mirror of aquatic pollution

The endobenthic bivalves are widely used as a bioindicators since they inhabit the sediment-water interface and are able to accumulate a different kind of contaminants. In the present work, we evaluated wild Corbicula largillierti (Phillippi, 1844) as a bioindicator of water quality in the central region of Argentina. The responses at different levels of the biological organization were used. We measured organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) levels in water and clams tissues. The biomarkers selected were enzymatic activities (Glutathione S-Transferase, Catalase, Acetyl-, Butyryl-cholinesterase, and Carboxylesterase) morphometry of the digestive gland, condition index and morphology of valves. In order to integrate all the responses a multivariate analysis and integrated stress index were applied. Our results showed the presence of contaminants along the studied river and the ability of C. largillierti to bioaccumulate them. All the biomarkers selected varied according to the water quality gradient, although there was no specific correlation with OCPs and PCBs levels. At the most polluted sites, the detoxification and oxidative stress enzymes, the morphometric analysis of the digestive gland and the variation in the morphology of the valves indicated the water quality degradation. The multivariate analyses allowed to discriminate the sites according to the different biomarker responses. The IBR index also showed a variation pattern according to the environmental quality gradient along the basin. According to the responses shown by C. largillierti we suggest this species as an useful bioindicator of aquatic pollution.

Native crustacean species as a bioindicator of freshwater ecosystem pollution: A multivariate and integrative study of multi-biomarker response in active river monitoring

The aim of this study was to evaluate the ability of Palaemonetes argentinus to evidence the environmental degradation due to pollutants mixture in a freshwater aquatic ecosystem. For this purpose, an active monitoring (96 h exposure) was carried out in seven sites along the Ctalamochita River basin (Córdoba, Argentina), as a case of study. Our results evidenced sewage discharges impact in the water quality index, as well as metal pollution in water (Ag, Al, B, Pb, Hg) and sediments (Hg) with a potential effect on aquatic biota. The accumulation of total metals measured in exposed P. argentinus showed significant correlation with metals in water. Also, metallothioneins in cephalothorax showed significant changes along the basin, correlating with soluble concentrations of Cr, Zn, Cd, Hg, and V measured in shrimp tissues, which would be reflecting their bioavailability in the environment. In addition, the increase in antioxidant and detoxifying enzymes suggests the occurrence of oxidative stress in exposed shrimps. The integrative biomarker response index (IBR) pointed out the effect of metals on P. argentinus but also the occurrence of others pollutants. Finally, a high consensus was observed for water, sediments, and shrimps through the multivariate analysis (90%), indicating that P. argentinus can reflect changes in the abiotic matrixes. Moreover, studied sites were grouped according to their environmental quality. The use of active biomonitoring and the integration of biological responses through an IBR confirm that native biota could be a useful monitoring tool for bioavailable pollutants in aquatic ecosystems constituting a highly valuable approach.

Tissue-specific bioconcentration and biotransformation of cypermethrin and chlorpyrifos in a native fish (Jenynsia multidentata) exposed to these insecticides singly and in mixtures

The aim of the present study was to evaluate the accumulation of cypermethrin and chlorpyrifos when the fish Jenynsia multidentata was exposed to these pesticides singly and in technical and commercial mixtures. Adult female fish were exposed over 96 h to 0.04 μg/L of cypermethrin; 0.4 μg/L of chlorpyrifos; 0.04 μg/L of cypermethrin + 0.4 μg/L of chlorpyrifos in a technical mixture; and 0.04 μg/L of cypermethrin + 0.4 μg/L of chlorpyrifos in a mixture of commercial products. Fish exposed to cypermethrin accumulated this compound only in muscle, probably because of the low biotransformation capacity of this organ and the induction of cytochrome P4501A1 (CYP1A1) expression in the liver. The accumulation of chlorpyrifos occurred in fish exposed to the insecticide (intestine > liver > gills) even when these fish had higher gluthatione-S-transferase (GST) activity in gills and P-glycoprotein (P-gp) expression in the liver, compared with the control. Fish exposed to the technical mixture showed cypermethrin accumulation (liver > intestine > gills) with higher levels than those measured in fish after only cypermethrin exposure. Higher expression levels of CYP1A1 in the liver were also observed compared with the Control. Fish exposed to the commercial mixture accumulated both insecticides (cypermethrin: intestine > gills and chlorpyrifos: liver > intestine > gills > muscle). In the organs where accumulation occurred, biotransformation enzymes were inhibited. Consequently, the commercial formulation exposure provoked the highest accumulation of cypermethrin and chlorpyrifos in J. multidentata, possibly associated with the biotransformation system inhibition. Environ Toxicol Chem 2017;36:1764-1774. © 2016 SETAC.

High spatial dynamics-photoluminescence imaging reveals the metallurgy of the earliest lost-wax cast object

Photoluminescence spectroscopy is a key method to monitor defects in semiconductors from nanophotonics to solar cell systems. Paradoxically, its great sensitivity to small variations of local environment becomes a handicap for heterogeneous systems, such as are encountered in environmental, medical, ancient materials sciences and engineering. Here we demonstrate that a novel full-field photoluminescence imaging approach allows accessing the spatial distribution of crystal defect fluctuations at the crystallite level across centimetre-wide fields of view. This capacity is illustrated in archaeology and material sciences. The coexistence of two hitherto indistinguishable non-stoichiometric cuprous oxide phases is revealed in a 6,000-year-old amulet from Mehrgarh (Baluchistan, Pakistan), identified as the oldest known artefact made by lost-wax casting and providing a better understanding of this fundamental invention. Low-concentration crystal defect fluctuations are readily mapped within ZnO nanowires. High spatial dynamics-photoluminescence imaging holds great promise for the characterization of bulk heterogeneous systems across multiple disciplines.

Photoluminescence is a powerful probe of chemical composition and structure, but it is challenging to image heterogeneous materials over large scale. Thoury et al. develop a full-field imaging approach to map two cuprous oxide phases in the earliest known lost-wax cast artefact manufactured 6,000 years ago.

Sensitive biomarker responses of the shrimp Palaemonetes argentinus exposed to chlorpyrifos at environmental concentrations: Roles of alpha-tocopherol and metallothioneins

The aim of this study was to evaluate the toxic effects of chlorpyrifos (CPF) at environmental concentrations on the shrimp Palaemonetes argentinus, a South American native species. Organisms were exposed to environmentally relevant concentrations of CPF (from 3.5 to 94.5ngCPFL(-1)) at laboratory conditions for 96h. A wide battery of biochemical responses including bioaccumulation, damage and defense biomarkers were measured in cephalothorax and abdomen of shrimp. The concentration of CPF was below the detection limit of the method in both body sectors (8ngCPFg(-1)ww), probably indicating fast biotransformation of the parental compound. Our results showed that CPF exposure inhibits acetylcholinesterase activity from 3.5ngCPFL(-1), a concentration below the suggested Argentinean guidelines for the protection of aquatic biota. Moreover, oxidative stress was evidenced by increased H2O2 content and increased levels of TBARs and carbonyl groups in proteins. The induction of antioxidant enzymes like catalase, glutathione S-transferase and glutathione peroxidase seems not be sufficient to prevent oxidative damages. In addition, the mobilization of α-tocopherol from abdomen to cephalothorax was observed and reported for the first time in non-reproductive condition. Likewise, a strong diminution of metallothioneins occurred in cephalothorax from the lowest CPF concentration while induction occurred from the same treatment in abdomen as an oxidative stress response. Finally, significant correlation between Integrated Biomarker Response values and exposure concentrations suggest the usefulness of P. argentinus as bioindicator of CPF exposure at concentrations as low as environmental ones.

Involvement of mTOR and Regulation by AMPK in Early Iodine Deficiency-Induced Thyroid Microvascular Activation

Iodine deficiency (ID) induces TSH-independent microvascular activation in the thyroid via the reactive oxygen species/nitric oxide-hypoxia-inducible factor-1α/vascular endothelial growth factor (VEGF) pathway. We hypothesized the additional involvement of mammalian target of rapamycin (mTOR) as a positive regulator of this pathway and AMP-activated protein kinase (AMPK) as a negative feedback regulator to explain the transient nature of ID-induced microvascular changes under nonmalignant conditions. mTOR and AMPK involvement was investigated using an in vitro model (human thyrocytes in primary cultures) and 2 murine models of goitrogenesis (normal NMRI and RET-PTC mice [a papillary thyroid cancer model]). In NMRI mice, ID had no effect on the phosphorylation of ribosomal S6 kinase (p70S6K), a downstream target of mTOR. However, rapamycin inhibited ID-induced thyroid blood flow and VEGF protein expression. In the RET-PTC model, ID strongly increased the phosphorylation of p70S6K, whereas rapamycin completely inhibited the ID-induced increase in p70S6K phosphorylation, thyroid blood flow, and VEGF-A expression. In vitro, although ID increased p70S6K phosphorylation, the ID-stimulated hypoxia-inducible factor/VEGF pathway was inhibited by rapamycin. Activation of AMPK by metformin inhibited ID effects both in vivo and in vitro. In AMPK-α1 knockout mice, the ID-induced increase in thyroid blood flow and VEGF-A protein expression persisted throughout the treatment, whereas both parameters returned to control values in wild-type mice after 4 days of ID. In conclusion, mTOR is required for early ID-induced thyroid microvascular activation. AMPK negatively regulates this pathway, which may account for the transient nature of ID-induced TSH-independent vascular effects under benign conditions.

Matching in Vitro Bioaccessibility of Polyphenols and Antioxidant Capacity of Soluble Coffee by Boosted Regression Trees

The aim of this study was to evaluate changes in polyphenol profile and antioxidant capacity of five soluble coffees throughout a simulated gastro-intestinal digestion, including absorption through a dialysis membrane. Our results demonstrate that both polyphenol content and antioxidant capacity were characteristic for each type of studied coffee, showing a drop after dialysis. Twenty-seven compounds were identified in coffee by HPLC-MS, while only 14 of them were found after dialysis. Green+roasted coffee blend and chicory+coffee blend showed the highest and lowest content of polyphenols and antioxidant capacity before in vitro digestion and after dialysis, respectively. Canonical correlation analysis showed significant correlation between the antioxidant capacity and the polyphenol profile before digestion and after dialysis. Furthermore, boosted regression trees analysis (BRT) showed that only four polyphenol compounds (5-p-coumaroylquinic acid, quinic acid, coumaroyl tryptophan conjugated, and 5-O-caffeoylquinic acid) appear to be the most relevant to explain the antioxidant capacity after dialysis, these compounds being the most bioaccessible after dialysis. To our knowledge, this is the first report matching the antioxidant capacity of foods with the polyphenol profile by BRT, which opens an interesting method of analysis for future reports on the antioxidant capacity of foods.

Oxidative stress response induced by atrazine in Palaemonetes argentinus: the protective effect of vitamin E

The widespread contamination and persistence of the herbicide atrazine residues in the environment resulted in the exposure of non-target organisms. The present study was undertaken to investigate the effect of atrazine in the response of oxidative stress biomarkers in the freshwater shrimp Palaemonetes argentinus and the protective effect of vitamin-E against atrazine-induced toxicity. Therefore, two batches of P. argentinus were fed for 21 days with a commercial food enriched in proteins (D1) or with D2, composed of D1 enriched with vitamin-E (6.8 and 16.0mg% of vitamin-E, respectively). Subsequently, half of the individuals of each group were exposed to atrazine (0.4mgL(-1)) for 24h and the others remained as controls. Atrazine promoted oxidative stress response in P. argentinus fed with D1 as indicated by enhanced H2O2 content and induction of superoxide dismutase, glutathione-S-transferases and glutathione reductase. This antioxidant activity would prevent the increment of thiobarbituric acid reactive substances in the shrimp tissues. P. argentinus fed with D2 reversed the response of the biomarkers measured. However, the activation of antioxidants response had an energetic cost, which was revealed by a decrease in lipids storage in shrimps. These results show the modulatory effect of vit-E on oxidative stress and its potential use as an effective antioxidant to be applied in chemoprotection strategies during aquaculture.