Cytotoxicity and enzymatic biomarkers as early indicators of benthic responses to the soluble-fraction of diesel oil.

Xenobiotics from oil tanker leaks and industrial discharges are amongst the main human impacts to confined coastal areas. We assessed the genotoxic responses to the water-soluble fraction of diesel oil in the polychaete Laeonereis culveri and the bivalve Anomalocardia flexuosa, two widespread benthic species in subtropical estuaries from the Southwestern Atlantic. We hypothesized that the highest responsiveness would be expressed by significantly different biomarkers responses between control and oil-impacted treatments. Responsiveness to diesel oil was investigated using an experimental design with two fixed factors (contaminant percentages and times of exposure). After exposure, we monitored the responses of the oxidative stress enzymes and performed micronuclei tests. Results were congruent for both species. Antioxidant defense of glutathione S-transferase and the induction of micronuclei and nuclear buds, the latter just for the bivalve, were significantly affected by polycyclic aromatic hydrocarbons, with significant increases on the seventh day of exposure and in the higher concentrations, compared to controls groups. We assessed the benefits and drawbacks of using each biomarker in laboratory experiments. Both species are indicators of early, and rapid responses to genotoxic contaminants in subtropical estuarine habitats. We suggest that the micronuclei frequency in A. flexuosa is a simple, fast and cheap test for genotoxicity in oil-impacted areas. Such early biomarkers are needed to develop better protocols for impact assessment and monitoring under real field conditions.

Toxicity assessment of 2,4-D and MCPA herbicides in primary culture of fish hepatic cells.

In this study, we used primary cultures of fish hepatic cells as a tool for evaluating the effects of environmental contamination. Primary hepatic cell cultures derived from the subtropical fish Metynnis roosevelti were exposed to different concentrations (0.275, 2.75 and 27.5 µg L(-1)) of the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA). Cellular respiratory activity was evaluated by polarography using three substrates: 0.5 M glucose, 0.5 M succinate and 0.5 M α-ketoglutarate. Significant changes were observed in cellular oxygen consumption with 0.5 M α-ketoglutarate. Even at low concentrations, 2,4-D and MCPA were potent uncouplers of oxidative phosphorylation. Primary cultures of M. roosevelti liver cells may provide a useful tool for the evaluation of environmental contaminant effects. A review of regulations regarding permitted concentrations of these herbicides is needed.

Effects of anti-inflammatory drugs in primary kidney cell culture of a freshwater fish.

The non-steroidal anti-inflammatory drugs are emerging contaminants in aquatic ecosystems. This study aimed to evaluate toxic effects of some representative drugs of this pharmaceutical group on primary culture of monocytic lineage of Hoplias malabaricus anterior kidney. The effects of diclofenac, acetaminophen and ibuprofen in cell viability, lipopolysaccharide (LPS)-induced NO production and genotoxicity were evaluated. Cytometry analysis CD11b(+) cells showed 71.5% of stem cells, 19.5% of macrophages and 9% of monocytes. Cell viability was lower in the ficoll compared to percoll separation. LPS-induced NO production by these cells was blocked after treatment with dexamethasone and NG-Methyl-L-Arginine (L-NMMA). Exposure of the cells to diclofenac (0.2-200 ng/mL), acetaminophen (0.025-250 ng/mL) ibuprofen (10-1000 ng/mL) reduced basal NO production and inhibited LPS-induced NO production at all concentrations after 24 h of exposure. Genotoxicity occurred at the highest concentration of diclofenac and at the intermediary concentration of acetaminophen. Genotoxicity was also observed by ibuprofen. In summary, the pharmaceuticals influenced NO production and caused DNA damage in monocytic cells suggesting that these drugs can induce immunosuppression and genotoxicity in fish.

Antioxidant defense responses in Mytella guyanensis (Lamarck, 1819) exposed to an experimental diesel oil spill in Paranaguá Bay (Paraná, Brazil).

We evaluated the effects of diesel oil on the bivalve Mytella guyanensis using biomarkers of oxidative stress (glutathione S-transferase, glutathione peroxidase, and reduced glutathione) after an experimental in situ spill in a mangrove area in southern Brazil. A linear model was developed for the Multiple Before-After Control-Impact (MBACI) experimental design to assess the significance of biological responses. Control and impacted sites were sampled seven and two days before as well as two and seven days after the spill. With the exception of a late response of reduced glutathione (GSH) levels on day seven, none of the biomarkers were significantly altered by the impact. This result was attributed to the high environmental variability of the experimental sites combined with a low sensitivity of Mytella guyanensis to diesel oil at short time-scales. The high resistance of M. guyanensis suggests that its antioxidant response is triggered only after a medium- to long-term exposure to contaminants.

Incorporating a weight-of-evidence approach into a tiered assessment for chemicals management, with emphasis on program development and applications in developing countries and emerging economies.

A flexible approach is described for incorporating a weight-of-evidence (WoE) methodology into a tiered ecological risk assessment (ERA)/management framework for chemicals. The approach is oriented toward informing decisions about chemicals. Communication is regarded as a critical component of the risk assessment process. The paper resulted from insights gained from seven ERA workshops held by SETAC (Society of Environmental Toxicology and Chemistry, www.setac.org) in the Asia-Pacific, African, and Latin American regions. Formal ERA methods are not fully developed or applied in many of these countries and assessments often begin with tables of risk values and test methods from countries where ERA is already implemented. While appropriate and sometimes necessary, workshop participants had questions about the reliability and relevance of using this information for regionally specific ecosystems with different receptors, fate processes, and exposure characteristics. The idea that an assessment of reliability and relevance of available information and the need for additional information was necessary at an early stage of the assessment process was considered. The judgment of reliability and relevance is central to WoE approaches along with the identification of information needs and the integration of such information. The need to engage in WoE considerations early and throughout the assessment process indicates that a tiered approach is appropriate for unifying the evaluation process in a consistent way from early screening-level steps to later more involved evaluations. The approach outlined in this article is complementary to WoE guidance developed by the Organization for Economic Co-operation and Development and many national guidance documents. To link assessments of risk to management decisions, emphasis is given to communications at each tier between the risk assessor (technical side) and the decision-makers (policy and regulatory side). Tools and information sources are suggested for each tier and suggestions are meant to be illustrative and not prescriptive. Integr Environ Assess Manag 2024;00:1-15. © 2024 SETAC.

Evaluation of Different Techniques and Materials for Filling in 3-dimensional Printed Teeth Replicas with Perforating Internal Resorption by Means of Micro-Computed Tomography.

INTRODUCTION: The aim of this study was to evaluate the filling ability of 2 obturation techniques in 3-dimensional (3D) printed teeth with perforating internal resorption (PIR). METHODS: A maxillary central incisor was instrumented and scanned by micro-computed tomographic (micro-CT) imaging. The 3D model was exported in the stereolithographic format and, with the aid of OrtogOnBlender software (Cícero Moraes, Sinop, SP, Brazil), a PIR in the middle third of the root canal was designed. Thirty-two replicas were printed in surgical resin and distributed into 4 groups (n = 8) according to the obturation technique and the material used: 2 groups used the hybrid technique, 1 with Bio-C Sealer (BCS; Angelus, Londrina, PR, Brazil)/gutta-percha (GP; VDW GmbH, Munich, Germany) + Bio-C Repair (BCR; Angelus, Londrina, PR, Brazil) and the other with BioRoot (BR; Septodont, Saint Maur des Fosses, France)/gutta-percha (GP) + Biodentine (BD; Septodont, Saint Maur des Fosses, France), and 2 groups used the incremental technique, 1 with BCR and the other with BD. Postobturation micro-CT imaging was performed to measure the percentage volume of voids and laser confocal microscopy to measure the surface roughness (µm) of the repair cements. Data were compared using analysis of variance and Kruskal-Wallis tests. RESULTS: Regarding the filling volume in the apical third, the BCS/GP + BCR (89.70 ± 5.15), BR/GP + BD (87.70 ± 8.43), and BCR (84.20 ± 9.00) groups showed the highest percentages compared with the BD group (69.70 ± 6.88) (P < .05). In the area of internal resorption, the BCS/GP + BCR (96.00 ± 2.64) and BCR (95.30 ± 2.93) groups showed the highest percentages compared with the BR/GP + BD group (91.50 ± 1.35) (P < .05). The BD group showed intermediate values that were sometimes similar to the BCS/GP + BCR and BCR groups and similar to the BR/GP + BD group (P > .05). Regarding the quality of the filling in the perforation area, the BCR group showed better results compared with the BD group (P < .001). Regarding roughness, the BCR group (1.66 ± 0.65) showed lower surface roughness compared with the BD group (2.51 ± 0.89) (P < .05). CONCLUSIONS: The capacity and quality of the filling in teeth with PIR were superior with the incremental technique with BCR and the hybrid technique with BCS/GP + BCR.

Temperature rise and its influence on the toxic effects caused by cyanotoxins in a neotropical catfish.

Potentially toxic cyanobacterial blooms (cyanoHABs) have become a problem in public water supply reservoirs. Temperature rise caused by climate change can increase the frequency and intensity of blooms, which may influence the cyanotoxins concentration in the environment. This study aimed to evaluate the effect of the temperature on the responses of a Neotropical catfish exposed to a neurotoxin-rich cyanobacterial crude extract (Raphidiopsis raciborskii T3). Juveniles of Rhamdia quelen were exposed to four treatments, based on study data: control at 25 °C (C25), control at 30 °C (C30), crude extract equivalent to 105 cells.mL-l of R. raciborskii at 25 °C (CE25) and 30 °C (CE30). After 96 h of exposure, the fish were anesthetized and blood was taken. After euthanasia, the gill, posterior kidney, brain, muscle, liver and gonad were sampled for hematological, biochemical, genotoxic and histopathological biomarker analysis. Liver was sampled for proteomic analysis for identification of proteins related to energy production. Water samples were collected at the beginning and the end of the experiment for neurotoxins quantification. Different parameters in both males and females were altered at CE25, evidencing the effects of neurotoxins in freshwater fish. At CE30, a water warming scenario, more effects were observed in females than at 25 °C, such as activation of saxitoxin metabolism pathway and genotoxicity. More damage to macromolecules was observed in females at the higher temperature, demonstrating that the increase in temperature can aggravate the toxicity of neurotoxins produced by R. raciborskii T3.

Estrogen-like effects in male goldfish co-exposed to fluoxetine and 17 alpha-ethinylestradiol.

The antidepressant fluoxetine (FLX) and the synthetic estrogen, 17 alpha-ethinylestradiol (EE2), are present in municipal sewage discharges. To better understand possible interactions between them, male goldfish were exposed to an ethanol control or to nominal concentrations of FLX (0.54 µg/L) and EE2 (5 ng/L) alone and in combination for 14 days. Real-time reverse-transcription polymerase chain reaction was used to assess effects on hepatic gene expression and liquid chromatography tandem mass spectrometry to analyze the plasma proteome. The results showed an increase in estrogen receptor alpha (esr1) and vitellogenin (vtg) gene expression by 1.9-2.4-fold in the FLX and EE2 groups, but this did not reach statistical significance. In contrast, co-exposure up regulated esr1 and vtg gene expression by 5.5- and 5.3-fold, respectively. Fluoxetine and EE2 alone did not affect estrogen receptor beta (esr2), but the co-exposure down regulated esr2 expression by 50%. There was a significant increase in the number of plasma proteins that were related to endocrine system disorders in the FLX and FLX plus EE2 groups. The level of VTG protein was increased in the plasma from goldfish exposed to EE2, FLX, and FLX plus EE2. Our study demonstrates that low concentrations of FLX and EE2 in a simple mixture produce strong estrogen-like effects in the male goldfish.

Can Carbodiimide (EDC) and Chitosan Cross-linking Agents Effect the Longevity of Fiberglass Posts Luted with Different Types of Composite Cements to Root Dentin?

PURPOSE: To evaluate the effect of carbodiimide (EDC) and chitosan (CHI) on the enzymatic activity (EA) and bond strength (BS) of different composite cements to root dentin. MATERIALS AND METHODS: Ninety (90) maxillary canines were sectioned, standardizing the length of the roots. The roots were endodontically treated, prepared, divided into 3 groups according to dentin treatment (distilled water [DW], CHI 0.2 wt%, or EDC 0.5M), and further subdivided into 3 subgroups according to composite cement (RelyX ARC [3M Oral Care], Panavia F 2.0 [Kuraray Noritaki], or RelyX U200 [3M Oral Care]). Of the slices obtained by sectioning, the most cervical of each third were subjected to a push-out test and the most apical were subjected to in-situ zymography. Half of the slices were analyzed immediately, and the other half after 6 months. The results were analyzed with ANOVA or the chi-squared test. RESULTS: RelyX ARC showed higher BS associated with CHI, while RelyX U200 showed higher BS associated with EDC (p = 0.044). For Panavia F 2.0, the treatment did not influence BS (p > 0.05). For the cervical and middle thirds, no differences were observed between the cements, while the apical third revealed higher BS for RelyX U200 (p < 0.001). The highest percentage of adhesive-to-dentin failures was observed for Panavia F 2.0. EDC showed the lowest percentage of adhesive-to-dentin failures. According to zymographic analysis, DW and CHI showed greater fluorescence for RelyX ARC, while EDC exhibited the lowest fluorescence of all cements (p > 0.05). CONCLUSION: The different mechanisms of action of solutions for pre-treatment of intraradicular dentin yielded different results depending on the adhesive used. EDC resulted in higher bond strength and higher enzyme inhibition for RelyX U200, while the treatment with chitosan resulted in higher bond strength and lower enzymatic activity for RelyX ARC. Although EDC and chitosan treatments did not influence the bond strength for Panavia F 2.0, both resulted in higher enzyme inhibition for this composite cement.

Co-exposure effects of lead and TiO2 nanoparticles in primary kidney cell culture from the freshwater fish Hoplias malabaricus.

This study evaluated the effects of Lead (Pb) and titanium dioxide nanoparticles (TiO2 NPs) alone or in combination in anterior kidney macrophages of the freshwater fish Hoplias malabaricus, naïve or stimulated with 1 ng.mL-1 lipopolysaccharide (LPS). Pb (1 ×10-5 to 1 ×10-1 mg.mL-1) or TiO2 NPs (1.5 ×10-6 to 1.5 ×10-2 mg.mL-1) reduced cell viability despite LPS stimulation, especially Pb 10-1 mg.mL-1. In combination, lower concentrations of NPs intensified Pb-induced cell viability reduction while higher concentrations restored the cell viability independently of LPS stimulation. Basal and LPS- induced NO production was reduced by both TiO2 NPs and Pb isolated. The combination of both xenobiotics avoided this reduction of NO production by the isolated compounds at lower concentrations but the protective effect was lost as the concentrations increased. None xenobiotic increase DNA fragmentation. Therefore, at specific conditions, TiO2 NPs may have a protective effect over Pb toxicity, may also provide additional toxicity at higher concentrations.

Assessment of the sublethal toxicity of organochlorine pesticide endosulfan in juvenile common carp (Cyprinus carpio).

This study is aimed at evaluating the sublethal effects of endosulfan (EDS) in juvenile common carp (Cyprinus carpio). For this purpose, fish were exposed for 15 days to the technical EDS (95% pure) diluted in dimethyl sulfoxide (DMSO) 0.1% of the total volume in water solution in a semi-static system at sublethal concentration (1 µg/L). Subsequently, the liver somatic index (LSI) and factor condition (K) were determined. The total cytocrome P450 (CYP), CYP1A isoform, and the ethoxyresorufin-O-deethylase (EROD) activity were determined from the hepatic microsomal fraction as well as the activity of the oxidative stress enzyme system such as superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GP(X)), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH). Among the parameters assessed, EDS at the sublethal concentration in subchronic exposure caused significant changes in liver somatic indices as well as induction of the phase I biotransformation system and oxidative stress in juvenile common carp (Cyprinus carpio). Thus, it is seen that the use of biochemical biomarkers of environmental contamination in this study proved to be an extremely important tool for detecting the adverse effects of xenobiotics in the aquatic environment, even at low concentration.

Chronic genetic damages in Geophagus brasiliensis exposed to anthropic impact in estuarine lakes at Santa Catarina coast--southern of Brazil.

Biological monitoring through animals exposed to pollutants using biomarkers provides a promising tool for the identification of pollutants that may cause damage to human health and/or to sustainability of ecosystems. The effects of pollutants in fish tissues are important tools to understand the impact of human activities in natural ecosystems. The aim of this work was to study the water quality of two estuarine lakes in Santa Catarina, Brazil (Camacho Lake and Santa Marta Lake). Geophagus brasiliensis is a species widely distributed in Brazil and was used in this work. Comet assays in peripheral red blood and kidney cells, micronucleus tests in peripheral red blood cells, measurements of acetylcholinesterase activity in axial muscle and histopathological analysis of liver were used as biomarkers. Three sampling campaigns were undertaken in November 2004, June 2005 and November 2005. Thirty adult animals were sampled from each of three different sites (P1--Santa Marta Lake, P2 and P3--Camacho Lake). A negative control was sampled in a non-polluted site at Costa Ecological Park, Paraná. The positive control for genotoxicity was obtained by treating animals with copper sulphate. The results showed that both studied lakes are impacted by potential genotoxic substances. Severe lesions in liver of G. brasiliensis were also observed. The inhibition of acetylcholinesterase activity suggests the presence of pesticides or metals in the studied sites. This work shows that the water quality of Santa Marta and Camacho Lakes have been compromised and further control source of pollutants into these ecosystems is required.

Embryotoxicity and biotransformation responses in zebrafish exposed to water-soluble fraction of crude oil.

The toxic effects of water-soluble fraction (WSF) of crude oil (API27, Petrobras Campos Basin, Brazil) were evaluated during the early life stages of zebrafish, as well as its biotransformation in juvenile fish. Embryonic development was studied during 96 h. Reduced heartbeat rate, weak pigmentation, tail defects, and embryo mortality were observed for all of the tested concentrations of the WSF. Activities of the biotransformation enzymes were induced at the highest concentrations, showing that these enzymes played a role in its elimination. As shown in this study the crude oil WSF altered the normal embryonic development of fish.

Evaluation of Resistance Management for the Oriental Fruit Moth (Lepidoptera: Tortricidae) to Insecticides in Brazilian Apple Orchards.

The oriental fruit moth, Grapholita molesta (Busk, 1916), is one of the most important pests in apple orchards in southern Brazil. Chemical control is still the most commonly used strategy for pest control. The aim of this study was to determine the resistance evolution of seven South Brazilian populations to four insecticides (chlorantraniliprole, lufenuron, chlorpyrifos, and fenitrothion). Bioassays were paired with metabolic analyses of glutathione-S-transferase (GST), carboxylesterases (α-NA and ß-NA), and acetylcholinesterase (AChE) to understand the possible role with phytosanitary strategies in the insects' susceptibility. Insect populations were collected in the municipalities of Campo do Tenente, Lapa and Porto Amazonas, Fraiburgo, São Joaquim, and Vacaria and multiplied in the laboratory. Two susceptible and two resistant populations were used as references. The bioassays showed that five populations were considered more resistant to organophosphates, six to lufenuron and two to chlorantraniliprole when compared with the sensitive population. None of the field populations had greater resistance than the resistant laboratory population. The enzymatic activity of AChE and GST was elevated in most of the populations that were less susceptible to organophosphates and lufenuron. The populations originating from orchards that used sexual confusion techniques had the greatest susceptibility based on toxicological and biochemical bioassays. Populations under pressure from various compounds had high GST, α and ß-NA activity. There is evidence that a diversity of control strategies can provide better resistance management.

Synthesis, Characterization, and Low-Toxicity Study of a Magnesium(II) Complex Containing an Isovanillate Group.

The beneficial effect of polyphenols and magnesium(II) against oxidative stress motivated our research group to explore the antioxidant activity of phenMgIso, an aqueous soluble magnesium(II) complex containing 1,10-phenanthroline (phen) and isovanillic acid (Iso) as ligands. Combined electrospray ionization-mass spectrometry and DOSY-NMR techniques identified two complexes in methanolic solution: hexacoordinated [Mg(phen)2(Iso)]+ and tetracoordinated [Mg(phen)(Iso)]+. The cyclic voltammogram of phenMgIso in the anodic region showed a cyclic process that interrupts the isovanillic acid degradation, probably by stabilization of the corresponding phenoxyl radical via complexation with Mg(II), which is interesting for antioxidant applications. phenMgIso competes with 2,2,6,6-tetramethylpiperidine by 1O2 with IC50(1O2) = 15 µg m-1 and with nitrotetrazolium blue chloride by superoxide ions (IC50(O2 •-) = 3.6 µg mL-1). Exposure of both zebrafish (2 mg L-1) and wistar male rats (3 mg kg-1 day-1 dose for 21 days) to phenMgIso does not cause mortality or visual changes compared with the respective control groups, thus phenMgIso could be considered safe under the conditions of this study. Moreover, no significant changes in comparison to both control groups were observed in the biochemical parameters on the brain-acetylcholinesterase activity, digestive tract enzyme catalase, and glutathione-S-transferase. Conversely, the performance of superoxide dismutase activity in wistar male rats increased in the presence of a complex, resulting in enhanced capacity of rats for superoxide radical enzymatic scavenging. The synergistic action of phenMgIso may be explained by the strong electrostatic interaction between Mg(II) and the O,O(phenolate) group, which makes the Iso ligand easier to oxidize and deprotonate, generating a cyclic stable species under oxidative conditions.

Visible-light reduced silver nanoparticles' toxicity in Allium cepa test system.

Silver nanoparticles (AgNPs) are widely used in consumer products due to their antibacterial property; however, their potential toxicity and release into the environment raises concern. Based on the limited understanding of AgNPs aggregation behavior, this study aimed to investigate the toxicity of uncoated (uc-AgNP) and coated with polyvinylpyrrolidone (PVP-AgNP), at low concentrations (0.5-100 ng/mL), under dark and visible-light exposure, using a plant test system. We exposed Allium cepa seeds to both types of AgNPs for 4-5 days to evaluate several toxicity endpoints. AgNPs did not cause acute toxicity (i.e., inhibition of seed germination and root development), but caused genotoxicity and biochemical alterations in oxidative stress parameters (lipid peroxidation) and activities of antioxidant enzymes (superoxide dismutase and catalase) in light and dark conditions. However, the light exposure decreased the rate of chromosomal aberration and micronuclei up to 5.60x in uc-AgNP and 2.01x in PVP-AgNP, and 2.69x in uc-AgNP and 3.70x in PVP-AgNP, respectively. Thus, light exposure reduced the overall genotoxicity of these AgNPs. In addition, mitotic index alterations and morphoanatomical changes in meristematic cells were observed only in the dark condition at the highest concentrations, demonstrating that light also reduces AgNPs cytotoxicity. The light-dependent aggregation of AgNPs may have reduced toxicity by reducing the uptake of these NPs by the cells. Our findings demonstrate that AgNPs can be genotoxic, cytotoxic and induce morphoanatomical and biochemical changes in A. cepa roots even at low concentrations, and that visible-light alters their aggregation state, and decreases their toxicity. We suggest that visible light can be an alternative treatment to remediate AgNP residues, minimizing their toxicity and environmental risks.

Cloning, partial sequencing and expression analysis of the neural form of P450 aromatase (cyp19a1b) in the South America catfish Rhamdia quelen.

Brain aromatase is a key enzyme exclusively expressed in fish radial glial cells that convert androgens into estrogens, thus controlling neuroendocrine functions and neurogenesis. As an important step in characterizing the neuroendocrine systems of Rhamdia quelen (jundiá), a partial cDNA sequence (1045 bp) of brain aromatase (cyp19a1b) was cloned and sequenced. At the nucleotide level the cDNA sequence was found to be 88% identical to cyp19a1b of two species of catfish, Ictalurus punctatus and Silurus meridionalis. The predicted amino acid sequence was between 80 and 91% similar to other teleosts. Real-time RT-qPCR analysis revealed that cyp19a1b was detected in pituitary, hypothalamus, telencephalon, head and posterior kidneys, liver and gonads (testis and ovary) of both males and females. The effects of E2 on cyp19a1b expression are sexually dimorphic in R. quelen. The injection of 17ß-estradiol (E2) decreased head kidney mRNA levels of cyp19a1b in males and increased cyp19a1b mRNA levels in the pituitary and head kidney of females. This study demonstrated that the R. quelen cyp19a1b gene is expressed in brain, pituitary and peripheral tissues in both males and females.

Toward sustainable environmental quality: Identifying priority research questions for Latin America.

The Global Horizon Scanning Project (GHSP) is an innovative initiative that aims to identify important global environmental quality research needs. Here we report 20 key research questions from Latin America (LA). Members of the Society of Environmental Toxicology and Chemistry (SETAC) LA and other scientists from LA were asked to submit research questions that would represent priority needs to address in the region. One hundred questions were received, then partitioned among categories, examined, and some rearranged during a workshop in Buenos Aires, Argentina. Twenty priority research questions were subsequently identified. These research questions included developing, improving, and harmonizing across LA countries methods for 1) identifying contaminants and degradation products in complex matrices (including biota); 2) advancing prediction of contaminant risks and effects in ecosystems, addressing lab-to-field extrapolation challenges, and understanding complexities of multiple stressors (including chemicals and climate change); and 3) improving management and regulatory tools toward achieving sustainable development. Whereas environmental contaminants frequently identified in these key questions were pesticides, pharmaceuticals, endocrine disruptors or modulators, plastics, and nanomaterials, commonly identified environmental challenges were related to agriculture, urban effluents, solid wastes, pulp and paper mills, and natural extraction activities. Several interesting research topics included assessing and preventing pollution impacts on conservation protected areas, integrating environment and health assessments, and developing strategies for identification, substitution, and design of less hazardous chemicals (e.g., green chemistry). Finally, a recurrent research need included developing an understanding of differential sensitivity of regional species and ecosystems to environmental contaminants and other stressors. Addressing these critical questions will support development of long-term strategic research efforts to advance more sustainable environmental quality and protect public health and the environment in LA. Integr Environ Assess Manag 2018;14:344-357. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Inhibition of immune responses and related proteins in Rhamdia quelen exposed to diclofenac.

Nonsteroidal anti-inflammatory drugs are among the most widely detected pharmaceuticals in surface water worldwide. The nonsteroidal anti-inflammatory drug diclofenac is used to treat many types of pain and inflammation. Diclofenac's potential to cause adverse effects in exposed wildlife is a growing concern. To evaluate the effects of waterborne diclofenac on the immune response in Rhamdia quelen (South American catfish), fish were exposed to 3 concentrations of diclofenac (0.2, 2.0, and 20.0 µg/L) for 14 d. Some of the exposed fish were also given an intraperitoneal injection on day 14 of 1 mg/kg of carrageenan to evaluate cell migration to the peritoneum. Total blood leukocyte count and carrageenan-induced leukocyte migration to the peritoneal cavity, particularly of polymorphonuclear cells, were significantly affected for all diclofenac exposure groups. Nitric oxide production was significantly reduced in the diclofenac-treated fish. Plasma and kidney proteins were analyzed by means of liquid chromatography-tandem mass spectrometry in a shotgun proteomic approach. In both plasma and kidney of diclofenac-exposed R. quelen, the expression of 20 proteins related to the inflammatory process, nitric oxide production, leukocyte migration, and the complement cascade was significantly altered. In addition, class I major histocompatibility complex was significantly decreased in plasma of diclofenac-treated fish. Thus, waterborne exposure to diclofenac could lead to suppression of the innate immune system in R. quelen. Environ Toxicol Chem 2017;36:2092-2107. © 2017 SETAC.

Multivariate and integrative approach to analyze multiple biomarkers in ecotoxicology: A field study in Neotropical region.

Aquatic pollution has dramatically worsened in developing countries, due to the discharge of a mixture of pollutants into water bodies, to the lack of stringent laws, and the inadequate treatment of effluents. In this study, the Neotropical fish Astyanax aff. paranae was sampled from three sites with different pollution levels: 1) a Biological Reserve (Rebio), protected by the Brazilian government; 2) an agricultural area in one of the most productive regions of Brazil, upstream of an urban zone; and 3) a site downstream from urban zone, characterized by the influx of different effluents, including wastes from industry, a sewer treatment plant, and agricultural areas. We assess biomarkers at multiple levels, such as the comet assay, hepatic histopathological analysis, brain and muscle acetylcholinesterase (AChE) and the hepatic enzymes glutathione-S-transferase (GST), catalase (CAT), and lipoperoxidation (LPO), during winter and summer. The interpretation of field results is always a very complex operation, since many factors can influence the variables analyzed in uncontrollable conditions. For this reason, we apply an integrative multivariate analysis. The results showed that the environmental risk of the three sites was significantly different. We can see a gradient in data distribution in discriminant analysis: separating, from one side, the fish of Rebio; in the middle are the fish from agricultural area and, in the other side are the animals from downstream site. Overall, the biomarkers responses were more greatly altered in the downstream site, whereas fish from the agricultural area showed an intermediate level of damage. The greatest changes were likely caused by agriculture, industrial chemical effluents and ineffective sewage treatments, in a synergic interaction in downstream site. In conclusion, the use of multiple biomarkers at different response levels to assess the toxic effects of mixed pollutants in a natural aquatic environment is an important tool for monitoring polluted regions.