Amvm Soares | University of Aveiro (original) (raw)

Papers by Amvm Soares

Research paper thumbnail of Changes of chemical chronic toxicity to Daphnia magna under different food regimes

Ecotoxicology and Environmental Safety, 2014

Research paper thumbnail of Energy Basal Levels and Allocation among Lipids, Proteins, and Carbohydrates in Enchytraeus albidus: Changes Related to Exposure to Cu Salt and Cu Nanoparticles

Water, Air, & Soil Pollution, 2011

Research paper thumbnail of In vitro and in vivo inhibition of Daphnia magna acetylcholinesterase by surfactant agents: possible implications for contamination biomonitoring

Science of The Total Environment, 2000

Research paper thumbnail of Transcriptomic response of zebrafish embryos to polyaminoamine (PAMAM) dendrimers

Nanotoxicology, 2013

The progressive practical applications of engineered nanoparticles results in their ever-increasi... more The progressive practical applications of engineered nanoparticles results in their ever-increasing release into the environment. Accurate assessment of their environmental and health risks requires the development of methods allowing their monitoring in different environmental compartments and the evaluation of their potential toxicity at different levels of organization. Toxic effects of third-generation (G3) and fourth-generation (G4) poly(amidoamine) dendrimers (ethylenediamine cored, imine-terminated) were assessed on zebrafish embryos during the first two days post-fertilization. Particle characterization by dynamic light scattering showed no tendency to form aggregates in the assay conditions. G3 particles showed somewhat a higher acute toxicity than G4 particles, with LC50 values of 1.8 and 2.3 mg/L, respectively. At sublethal concentrations, both particles affected the zebrafish transcriptome following similar patterns, suggesting a similar mode of action. About 700 transcripts were affected by at least one of the treatments, following a pattern with significant correlations to the effects of bacterial infection in zebrafish embryos. We concluded that the response to G3 and G4 dendrimers was consistent with the activation of the innate immune response, a still unreported potential effect of these particles. These data may contribute to the characterization of hazards of these nanomaterials for both human health and the environment.

Research paper thumbnail of Characterization of cholinesterases in plasma of three portuguese native bird species: application to biomonitoring

PloS one, 2012

Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used... more Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used as a biomarker to diagnose organophosphate and carbamate exposure. Plasma ChE activity is a useful and non-invasive method to monitor bird exposure to anticholinesterase compounds; nonetheless several studies had shown that the ChE form(s) present in avian plasma may vary greatly among species. In order to support further biomonitoring studies and provide reference data for wildlife risk-assessment, plasma cholinesterase of the northern gannet (Morus bassanus), the white stork (Ciconia ciconia) and the grey heron (Ardea cinerea) were characterized using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51, and iso-OMPA). Additionally, the range of ChE activity that may be considered as basal levels for non-exposed individuals was determined. The results suggest that in the plasma of...

Research paper thumbnail of The Daphnia bioassay: a critique

Research paper thumbnail of Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

Environmental Pollution, 2004

Research paper thumbnail of Optimization of Culture Conditions of Porcellio dilatatus (Crustacea: Isopoda) for Laboratory Test Development

Ecotoxicology and Environmental Safety, 2000

Research paper thumbnail of Effect of Endosulfan and Parathion on Energy Reserves and Physiological Parameters of the Terrestrial Isopod Porcellio dilatatus

Ecotoxicology and Environmental Safety, 2001

Research paper thumbnail of Evaluation of the joint effect of glyphosate and dimethoate using a small-scale terrestrial ecosystem

Ecotoxicology and Environmental Safety, 2011

Research paper thumbnail of Effect of Cu-nanoparticles versus Cu-salt in Enchytraeus albidus (Oligochaeta): Differential gene expression through microarray analysis

Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 2012

Research paper thumbnail of The influence of metal speciation on the bioavailability and sub-cellular distribution of cadmium to the terrestrial isopod, Porcellio dilatatus

Chemosphere, 2011

Cadmium is a non-essential toxic metal that is able to bioaccumulate in both flora fauna and has ... more Cadmium is a non-essential toxic metal that is able to bioaccumulate in both flora fauna and has the potential to biomagnify in some food chains. However, the form in which cadmium is presented to consumers can alter the bioavailability and possibly the internal distribution of assimilated Cd. Previous studies in our laboratory highlighted differences in Cd assimilation among isopods when they were provided with a plant-based food with either Cd biologically incorporated into plant tissue or superficially amended with ionic Cd(2+). Cd is known for its high affinity for sulphur ligands in cysteine residues which form the basis for metal-binding proteins such as metallothionein. This study compares Cd assimilation efficiency (AE) in Porcellio dilatatus fed with food amended with either cadmium cysteinate or cadmium nitrate in an examination of the influence of Cd speciation on metal bioavailability followed by an examination of the sub-cellular distribution using a centrifugal fractionation protocol. As hypothesized the AE of Cd among isopods fed with Cd(NO(3))(2) (64%, SE=5%) was higher than AE for isopods fed with Cd(Cys)(2) (20%, SE=3%). The sub-cellular distribution also depended on the Cd species provided. Those isopods fed Cd(Cys)(2) allocated significantly more Cd to the cell debris and organelles fractions at the expense of allocation to metal-rich granules (MRG). The significance of the difference in sub-cellular distribution with regard to toxicity is discussed. This paper demonstrates that the assimilation and internal detoxification of Cd is dependent on the chemical form of Cd presented to the isopod.

Research paper thumbnail of Assessment of the pesticides atrazine, endosulfan sulphate and chlorpyrifos for juvenoid-related endocrine activity using Daphnia magna

Chemosphere, 2009

The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce b... more The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce by either parthenogenesis or sexual reproduction. Recent studies have reported the involvement of the methylfarnesoate hormone, in male sex determination of D. magna. The aim of this study was to evaluate the juvenoid and anti-juvenoid activity of atrazine, endosulfan sulphate, and chlorpyrifos. To assess the juvenoid activity we exposed maternal daphnids to several concentrations of the respective pesticides, using the percentage of male production as endpoint. Fenoxycarb (1microgL(-1)) was used as a positive control. The anti-juvenoid activity was assessed using a similar bioassay after the addition of fenoxycarb (1microgL(-1)) to all test solutions. Fenoxycarb is an insect growth regulator that mimics the action of methylfarnesoate, and promoted the production of 95% of male offspring at the given concentration. Weak juvenoid-agonist activity was detected for endosulfan sulphate, with a significant increase of the percentage of male daphnids detected through logistic regression. In addition, atrazine and endosulfan sulphate antagonized the juvenoid activity of fenoxycarb. These results also corroborate the hypothesis that weak juvenoid agonists can simultaneously act as juvenoid antagonists as it has been observed in other hormonal systems.

Research paper thumbnail of Activity of pyruvate kinase and malate dehydrogenase in Daphnia magna under 3,4-dichloroaniline stress

Archives of Environmental Contamination and Toxicology, 1995

Research paper thumbnail of Is ultraviolet radiation a synergistic stressor in combined exposures? The case study of Daphnia magna exposure to UV and carbendazim

Research paper thumbnail of Ring-Testing and Field-Validation of a Terrestrial Model Ecosystem (TME) – An Instrument for Testing Potentially Harmful Substances: Conceptual Approach and Study Design

Research paper thumbnail of Determining the ecotoxicological mode of action of toxic chemicals in meiobenthic marine organisms: stage-specific short tests with Tisbe battagliai

Research paper thumbnail of In situ and laboratory microalgal assays in the tropics: a microcosm simulation of edge-of-field pesticide runoff

Research paper thumbnail of Assessment of the pesticides atrazine, endosulfan sulphate and chlorpyrifos for juvenoid-related endocrine activity using Daphnia magna

The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce b... more The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce by either parthenogenesis or sexual reproduction. Recent studies have reported the involvement of the methylfarnesoate hormone, in male sex determination of D. magna. The aim of this study was to evaluate the juvenoid and anti-juvenoid activity of atrazine, endosulfan sulphate, and chlorpyrifos. To assess the juvenoid activity we exposed maternal daphnids to several concentrations of the respective pesticides, using the percentage of male production as endpoint. Fenoxycarb (1microgL(-1)) was used as a positive control. The anti-juvenoid activity was assessed using a similar bioassay after the addition of fenoxycarb (1microgL(-1)) to all test solutions. Fenoxycarb is an insect growth regulator that mimics the action of methylfarnesoate, and promoted the production of 95% of male offspring at the given concentration. Weak juvenoid-agonist activity was detected for endosulfan sulphate, with a significant increase of the percentage of male daphnids detected through logistic regression. In addition, atrazine and endosulfan sulphate antagonized the juvenoid activity of fenoxycarb. These results also corroborate the hypothesis that weak juvenoid agonists can simultaneously act as juvenoid antagonists as it has been observed in other hormonal systems.

Research paper thumbnail of Reducing variability in Daphnia toxicity tests—A case for further standardization

… in standardization of …, 1993

CHAPTER 4 Reducing Variability in Daphnia Toxicity Tests— A Case for Further Standardization Mair... more CHAPTER 4 Reducing Variability in Daphnia Toxicity Tests— A Case for Further Standardization Mairead C. Bradley, Caroline Naylor, Peter Calow, Donald J. Baird, Ian Barber, and Amadeu MVM Scares ABSTRACT Problems associated with reproducibility of Daphnia toxicity ...

Research paper thumbnail of Changes of chemical chronic toxicity to Daphnia magna under different food regimes

Ecotoxicology and Environmental Safety, 2014

Research paper thumbnail of Energy Basal Levels and Allocation among Lipids, Proteins, and Carbohydrates in Enchytraeus albidus: Changes Related to Exposure to Cu Salt and Cu Nanoparticles

Water, Air, & Soil Pollution, 2011

Research paper thumbnail of In vitro and in vivo inhibition of Daphnia magna acetylcholinesterase by surfactant agents: possible implications for contamination biomonitoring

Science of The Total Environment, 2000

Research paper thumbnail of Transcriptomic response of zebrafish embryos to polyaminoamine (PAMAM) dendrimers

Nanotoxicology, 2013

The progressive practical applications of engineered nanoparticles results in their ever-increasi... more The progressive practical applications of engineered nanoparticles results in their ever-increasing release into the environment. Accurate assessment of their environmental and health risks requires the development of methods allowing their monitoring in different environmental compartments and the evaluation of their potential toxicity at different levels of organization. Toxic effects of third-generation (G3) and fourth-generation (G4) poly(amidoamine) dendrimers (ethylenediamine cored, imine-terminated) were assessed on zebrafish embryos during the first two days post-fertilization. Particle characterization by dynamic light scattering showed no tendency to form aggregates in the assay conditions. G3 particles showed somewhat a higher acute toxicity than G4 particles, with LC50 values of 1.8 and 2.3 mg/L, respectively. At sublethal concentrations, both particles affected the zebrafish transcriptome following similar patterns, suggesting a similar mode of action. About 700 transcripts were affected by at least one of the treatments, following a pattern with significant correlations to the effects of bacterial infection in zebrafish embryos. We concluded that the response to G3 and G4 dendrimers was consistent with the activation of the innate immune response, a still unreported potential effect of these particles. These data may contribute to the characterization of hazards of these nanomaterials for both human health and the environment.

Research paper thumbnail of Characterization of cholinesterases in plasma of three portuguese native bird species: application to biomonitoring

PloS one, 2012

Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used... more Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used as a biomarker to diagnose organophosphate and carbamate exposure. Plasma ChE activity is a useful and non-invasive method to monitor bird exposure to anticholinesterase compounds; nonetheless several studies had shown that the ChE form(s) present in avian plasma may vary greatly among species. In order to support further biomonitoring studies and provide reference data for wildlife risk-assessment, plasma cholinesterase of the northern gannet (Morus bassanus), the white stork (Ciconia ciconia) and the grey heron (Ardea cinerea) were characterized using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51, and iso-OMPA). Additionally, the range of ChE activity that may be considered as basal levels for non-exposed individuals was determined. The results suggest that in the plasma of...

Research paper thumbnail of The Daphnia bioassay: a critique

Research paper thumbnail of Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

Environmental Pollution, 2004

Research paper thumbnail of Optimization of Culture Conditions of Porcellio dilatatus (Crustacea: Isopoda) for Laboratory Test Development

Ecotoxicology and Environmental Safety, 2000

Research paper thumbnail of Effect of Endosulfan and Parathion on Energy Reserves and Physiological Parameters of the Terrestrial Isopod Porcellio dilatatus

Ecotoxicology and Environmental Safety, 2001

Research paper thumbnail of Evaluation of the joint effect of glyphosate and dimethoate using a small-scale terrestrial ecosystem

Ecotoxicology and Environmental Safety, 2011

Research paper thumbnail of Effect of Cu-nanoparticles versus Cu-salt in Enchytraeus albidus (Oligochaeta): Differential gene expression through microarray analysis

Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 2012

Research paper thumbnail of The influence of metal speciation on the bioavailability and sub-cellular distribution of cadmium to the terrestrial isopod, Porcellio dilatatus

Chemosphere, 2011

Cadmium is a non-essential toxic metal that is able to bioaccumulate in both flora fauna and has ... more Cadmium is a non-essential toxic metal that is able to bioaccumulate in both flora fauna and has the potential to biomagnify in some food chains. However, the form in which cadmium is presented to consumers can alter the bioavailability and possibly the internal distribution of assimilated Cd. Previous studies in our laboratory highlighted differences in Cd assimilation among isopods when they were provided with a plant-based food with either Cd biologically incorporated into plant tissue or superficially amended with ionic Cd(2+). Cd is known for its high affinity for sulphur ligands in cysteine residues which form the basis for metal-binding proteins such as metallothionein. This study compares Cd assimilation efficiency (AE) in Porcellio dilatatus fed with food amended with either cadmium cysteinate or cadmium nitrate in an examination of the influence of Cd speciation on metal bioavailability followed by an examination of the sub-cellular distribution using a centrifugal fractionation protocol. As hypothesized the AE of Cd among isopods fed with Cd(NO(3))(2) (64%, SE=5%) was higher than AE for isopods fed with Cd(Cys)(2) (20%, SE=3%). The sub-cellular distribution also depended on the Cd species provided. Those isopods fed Cd(Cys)(2) allocated significantly more Cd to the cell debris and organelles fractions at the expense of allocation to metal-rich granules (MRG). The significance of the difference in sub-cellular distribution with regard to toxicity is discussed. This paper demonstrates that the assimilation and internal detoxification of Cd is dependent on the chemical form of Cd presented to the isopod.

Research paper thumbnail of Assessment of the pesticides atrazine, endosulfan sulphate and chlorpyrifos for juvenoid-related endocrine activity using Daphnia magna

Chemosphere, 2009

The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce b... more The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce by either parthenogenesis or sexual reproduction. Recent studies have reported the involvement of the methylfarnesoate hormone, in male sex determination of D. magna. The aim of this study was to evaluate the juvenoid and anti-juvenoid activity of atrazine, endosulfan sulphate, and chlorpyrifos. To assess the juvenoid activity we exposed maternal daphnids to several concentrations of the respective pesticides, using the percentage of male production as endpoint. Fenoxycarb (1microgL(-1)) was used as a positive control. The anti-juvenoid activity was assessed using a similar bioassay after the addition of fenoxycarb (1microgL(-1)) to all test solutions. Fenoxycarb is an insect growth regulator that mimics the action of methylfarnesoate, and promoted the production of 95% of male offspring at the given concentration. Weak juvenoid-agonist activity was detected for endosulfan sulphate, with a significant increase of the percentage of male daphnids detected through logistic regression. In addition, atrazine and endosulfan sulphate antagonized the juvenoid activity of fenoxycarb. These results also corroborate the hypothesis that weak juvenoid agonists can simultaneously act as juvenoid antagonists as it has been observed in other hormonal systems.

Research paper thumbnail of Activity of pyruvate kinase and malate dehydrogenase in Daphnia magna under 3,4-dichloroaniline stress

Archives of Environmental Contamination and Toxicology, 1995

Research paper thumbnail of Is ultraviolet radiation a synergistic stressor in combined exposures? The case study of Daphnia magna exposure to UV and carbendazim

Research paper thumbnail of Ring-Testing and Field-Validation of a Terrestrial Model Ecosystem (TME) – An Instrument for Testing Potentially Harmful Substances: Conceptual Approach and Study Design

Research paper thumbnail of Determining the ecotoxicological mode of action of toxic chemicals in meiobenthic marine organisms: stage-specific short tests with Tisbe battagliai

Research paper thumbnail of In situ and laboratory microalgal assays in the tropics: a microcosm simulation of edge-of-field pesticide runoff

Research paper thumbnail of Assessment of the pesticides atrazine, endosulfan sulphate and chlorpyrifos for juvenoid-related endocrine activity using Daphnia magna

The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce b... more The water flea Daphnia magna belongs to the cyclical parthenogenic species, which can reproduce by either parthenogenesis or sexual reproduction. Recent studies have reported the involvement of the methylfarnesoate hormone, in male sex determination of D. magna. The aim of this study was to evaluate the juvenoid and anti-juvenoid activity of atrazine, endosulfan sulphate, and chlorpyrifos. To assess the juvenoid activity we exposed maternal daphnids to several concentrations of the respective pesticides, using the percentage of male production as endpoint. Fenoxycarb (1microgL(-1)) was used as a positive control. The anti-juvenoid activity was assessed using a similar bioassay after the addition of fenoxycarb (1microgL(-1)) to all test solutions. Fenoxycarb is an insect growth regulator that mimics the action of methylfarnesoate, and promoted the production of 95% of male offspring at the given concentration. Weak juvenoid-agonist activity was detected for endosulfan sulphate, with a significant increase of the percentage of male daphnids detected through logistic regression. In addition, atrazine and endosulfan sulphate antagonized the juvenoid activity of fenoxycarb. These results also corroborate the hypothesis that weak juvenoid agonists can simultaneously act as juvenoid antagonists as it has been observed in other hormonal systems.

Research paper thumbnail of Reducing variability in Daphnia toxicity tests—A case for further standardization

… in standardization of …, 1993

CHAPTER 4 Reducing Variability in Daphnia Toxicity Tests— A Case for Further Standardization Mair... more CHAPTER 4 Reducing Variability in Daphnia Toxicity Tests— A Case for Further Standardization Mairead C. Bradley, Caroline Naylor, Peter Calow, Donald J. Baird, Ian Barber, and Amadeu MVM Scares ABSTRACT Problems associated with reproducibility of Daphnia toxicity ...