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1.
Ecotoxicology ; 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38776006

RESUMEN

The excessive use of pesticides in agriculture and the widespread use of metals in industrial activities and or technological applications has significantly increased the concentrations of these pollutants in both aquatic and terrestrial ecosystems worldwide, making aquatic biota increasingly vulnerable and putting many species at risk of extinction. Most aquatic habitats receive pollutants from various anthropogenic actions, leading to interactions between compounds that make them even more toxic. The aim of this study was to assess the effects of the compounds Chlorpyrifos (insecticide) and Cadmium (metal), both individually and in mixtures, on the cladocerans Ceriodaphnia rigaudi and Ceriodaphnia silvestrii. Acute toxicity tests were conducted for the compounds individually and in mixture, and an ecological risk assessment (ERA) was performed for both compounds. Acute toxicity tests with Cadmium resulted in EC50-48 h of 0.020 mg L-1 for C. rigaudi and 0.026 mg L-1 for C. silvestrii, while tests with Chlorpyrifos resulted in EC50-48 h of 0.047 µg L-1 and 0.062 µg L-1, respectively. The mixture test for C. rigaudi showed the occurrence of additive effects, while for C. silvestrii, antagonistic effects occurred depending on the dose level. The species sensitivity distribution curve for crustaceans, rotifers, amphibians, and fishes resulted in an HC5 of 3.13 and an HC50 of 124.7 mg L-1 for Cadmium; an HC5 of 9.96 and an HC50 of 5.71 µg L-1 for Chlorpyrifos. Regarding the ERA values, Cadmium represented a high risk, while Chlorpyrifos represented an insignificant to a high risk.

3.
Artículo en Inglés | MEDLINE | ID: mdl-38656040

RESUMEN

Inactivated COVID-19 vaccines data in immunocompromised individuals are scarce. This trial assessed the immunogenicity of two CoronaVac doses and additional BNT162b2 mRNA vaccine doses in immunocompromised (IC) and immunocompetent (H) individuals. Adults with solid organ transplant (SOT), hematopoietic stem cell transplant, cancer, inborn immunity errors or rheumatic diseases were included in the IC group. Immunocompetent adults were used as control group for comparison. Participants received two CoronaVac doses within a 28-day interval. IC received two additional BNT162b2 doses and H received a third BNT162b2 dose (booster). Blood samples were collected at baseline, 28 days after each dose, pre-booster and at the trial end. We used three serological tests to detect antibodies to SARS-CoV-2 nucleocapsid (N), trimeric spike (S), and receptor binding domain (RBD). Outcomes included seroconversion rates (SCR), geometric mean titers (GMT) and GMT ratio (GMTR). A total of 241 IC and 100 H adults participated in the study. After two CoronaVac doses, IC had lower SCR than H: anti-N, 33.3% vs 79%; anti-S, 33.8% vs 86%, and anti-RBD, 48.5% vs 85%, respectively. IC also showed lower GMT than H: anti-N, 2.3 vs 15.1; anti-S, 58.8 vs 213.2 BAU/mL; and anti-RBD, 22.4 vs 168.0 U/mL, respectively. After the 3rd and 4th BNT162b2 doses, IC had significant anti-S and anti-RBD seroconversion, but still lower than H after the 3rd dose. After boosting, GMT increased in IC, but remained lower than in the H group. CoronaVac two-dose schedule immunogenicity was lower in IC than in H. BNT162b2 heterologous booster enhanced immune response in both groups.


Asunto(s)
Anticuerpos Antivirales , Vacuna BNT162 , Vacunas contra la COVID-19 , COVID-19 , Huésped Inmunocomprometido , Inmunogenicidad Vacunal , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Anticuerpos Antivirales/sangre , Vacuna BNT162/inmunología , Vacuna BNT162/administración & dosificación , COVID-19/prevención & control , COVID-19/inmunología , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/administración & dosificación , Inmunización Secundaria , Inmunocompetencia/inmunología , Huésped Inmunocomprometido/inmunología , Vacunas de Productos Inactivados/inmunología , Vacunas de Productos Inactivados/administración & dosificación
4.
Sci Total Environ ; 926: 171480, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38492607

RESUMEN

The ability of aquatic organisms to sense the surrounding environment chemically and interpret these signals correctly is crucial to their survival and ecological niche. This study applied the Heterogenous Multi-Habitat Assay System - HeMHAS to evaluate the avoidance potential of Daphnia magna to detect fipronil-contaminated habitats in a connected landscape after a short (48 h), previous, forced exposure to an environmentally relevant concentration of the same insecticide. The swimming of daphnids was also analyzed by recording the total distance covered. D. magna preferred areas with less contamination, although the effect of fipronil on their swimming ability (a decrease) was observed for all the concentrations tested. The application of non-forced multi-compartment exposure methodologies is a recent trend and is ecologically relevant as it is based on how contamination can really produce changes in an organism's habitat selection. Finally, we consider the importance of more non-forced exposure approaches where Stress Ecology can be aggregated to improve systemic understanding of the risk that contaminants pose to aquatic ecosystems from a broader landscape perspective.


Asunto(s)
Insecticidas , Contaminantes Químicos del Agua , Animales , Ecosistema , Contaminantes Químicos del Agua/análisis , Insecticidas/toxicidad , Pirazoles/toxicidad , Daphnia
5.
Arch Environ Contam Toxicol ; 86(2): 112-124, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38265449

RESUMEN

Predation presents specific behavioral characteristics for each species, and the interaction between prey and predator influences the structuring of the food web. Concerning insects, predation can be affected in different ways, such as exposure to chemical stressors, e.g., pesticides. Therefore, analyses were carried out of the effects of exposure to insecticide fipronil and the herbicide 2,4-D on predation, parameters of food selectivity, and the swimming behavior of two neotropical predatory aquatic insects of the families Belostomatidae (giant water bugs) and larvae of Libellulidae (dragonfly). These predatory insects were exposed for 24 h to a commercial formulation of the chlorophenoxy herbicide, 2,4-D at nominal concentrations of 200, 300, 700, and 1400 µg L-1, and to a commercial formulation of the phenylpyrazole insecticide, fipronil at nominal concentrations of 10, 70, 140, and 250 µg L-1. In a control treatment, the insects were placed in clean, unspiked water. At the end of the exposure, the maximum swimming speed of the predators was evaluated. Afterward, the predators were placed in clean water in a shared environment for 24 h with several prey species, including the cladoceran Ceriodaphnia silvestrii, larvae of the insect Chironomus sancticaroli, the amphipod Hyalella meinerti, the ostracod Strandesia trispinosa, and the oligochaete Allonais inaequalis for 24 h. After this period, the consumed prey was counted. The results reveal that predators from both families changed prey consumption compared with organisms from the control treatment, marked by a decrease after exposure to fipronil and an increase in consumption caused by 2,4-D. In addition, there were changes in the food preferences of both predators, especially when exposed to the insecticide. Exposure to fipronil decreased the swimming speed of Belostomatidae individuals, possibly due to its neurotoxic effect. Exposure to the insecticide and the herbicide altered prey intake by predators, which could negatively influence the complex prey-predator relationship and the functioning of aquatic ecosystems in contaminated areas.


Asunto(s)
Herbicidas , Insecticidas , Odonata , Plaguicidas , Humanos , Animales , Insecticidas/toxicidad , Cadena Alimentaria , Ecosistema , Invertebrados , Insectos , Larva , Herbicidas/toxicidad , Ácido 2,4-Diclorofenoxiacético/toxicidad , Conducta Predatoria
6.
Chemosphere ; 346: 140569, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37918533

RESUMEN

2,4-D and fipronil are among Brazil's most used pesticides. The presence of these substances in surface waters is a concern for the aquatic ecosystem health. Thus, understanding the behavior of these substances under environmentally relevant conditions is essential for an effective risk assessment. This study aimed to determine the degradation profiles of 2,4-D and fipronil after controlled application in aquatic mesocosm systems under influencing factors such as environmental aspects and vinasse application, evaluate pesticide dissipation at the water-sediment interface, and perform an environmental risk assessment in water and sediment compartments. Mesocosm systems were divided into six different treatments, namely: control (C), vinasse application (V), 2,4-D application (D), fipronil application (F), mixture of 2,4-D and fipronil application (M), and mixture of 2,4-D and fipronil with vinasse application (MV). Pesticide application was performed according to typical Brazilian sugarcane management procedures, and the experimental systems were monitored for 150 days. Pesticide dissipation kinetics was modeled using first-order reaction models. The estimated half-life times of 2,4-D were 18.2 days for individual application, 50.2 days for combined application, and 9.6 days for combined application with vinasse. For fipronil, the respective half-life times were 11.7, 13.8, and 24.5 days. The dynamics of pesticides in surface waters resulted in the deposition of these compounds in the sediment. Also, fipronil transformation products fipronil-sulfide and fipronil-sulfone were quantified in water 21 days after pesticide application. Finally, performed risk assessments showed significant potential risk to environmental health, with RQ values for 2,4-D up to 1359 in freshwater and 98 in sediment, and RQ values for fipronil up to 22,078 in freshwater and 2582 in sediment.


Asunto(s)
Plaguicidas , Contaminantes Químicos del Agua , Ecosistema , Contaminantes Químicos del Agua/análisis , Plaguicidas/toxicidad , Plaguicidas/análisis , Agua , Ácido 2,4-Diclorofenoxiacético/toxicidad
7.
PLoS One ; 18(11): e0294654, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38033128

RESUMEN

Cotton crop yields are largely affected by infestations of Anthonomus grandis, which is its main pest. Although Bacillus thuringiensis (Bt) derived proteins can limit insect pest infestations, the diverse use of control methods becomes a viable alternative in order to prolong the use of technology in the field. One of the alternative methods to Bt technology has been the utilization of certain Pseudomonas species highly efficient in controlling coleopteran insects have been used to produce highly toxic insecticidal proteins. This study aimed to evaluate the toxicity of IPD072Aa and PIP-47Aa proteins, isolated from Pseudomonas spp., in interaction with Cry1Ia10, Cry3Aa, and Cry8B proteins isolated from B. thuringiensis, to control A. grandis in cotton crops. The genes IPD072Aa and PIP-47Aa were synthesized and cloned into a pET-SUMO expression vector. Moreover, Cry1Ia10, Cry3Aa, and Cry8B proteins were obtained by inducing recombinant E. coli clones, which were previously acquired by our research group from the Laboratory of Bacteria Genetics and Applied Biotechnology (LGBBA). These proteins were visualized in SDS-PAGE, quantified, and incorporated into an artificial diet to estimate their lethal concentrations (LC) through individual or combined bioassays. The results of individual toxicity revealed that IPD072Aa, PIP-47Aa, Cry1Ia10, Cry3Aa, and Cry8B were efficient in controlling A. grandis, with the latter being the most toxic. Regarding interaction assays, a high synergistic interaction was observed between Cry1Ia10 and Cry3Aa. All interactions involving Cry3Aa and PIP-47Aa, when combined with other proteins, showed a clear synergistic effect. Our findings highlighted that the tested proteins in combination, for the most part, increase toxicity against A. grandis neonate larvae, suggesting possible constructions for pyramiding cotton plants to the manage and the control boll weevils.


Asunto(s)
Bacillus thuringiensis , Escarabajos , Insecticidas , Gorgojos , Animales , Humanos , Recién Nacido , Gorgojos/genética , Gorgojos/metabolismo , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Insecticidas/farmacología , Insecticidas/metabolismo , Escherichia coli/metabolismo , Larva/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Endotoxinas/genética , Endotoxinas/metabolismo , Escarabajos/metabolismo
8.
Bull Environ Contam Toxicol ; 112(1): 3, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38017221

RESUMEN

Parabens, a group of preservatives with a wide industrial range, threaten human and aquatic biota health due to their toxicity and endocrine disruption potential. As conventional wastewater treatment may not be enough to keep natural environments safe, toxicity studies are useful tools for supporting ecological risk assessments. Here, we focused on assessing ethylparaben's, one of the most common kinds of paraben, toxicity in the cladocerans Daphnia similis and Ceriodaphnia silvestrii. The EC50 sensitivity for D. similis and C. silvestrii was 24 (21-28) mg L- 1 and 25 (19-33) mg L- 1, respectively. Inhibition of reproduction and late development of females were observed in C. silvestrii exposed to 8 mg L- 1. Furthermore, species sensitivity distribution was used to assess ecological risk, and ethylparaben demonstrated low potential risk for aquatic biota.


Asunto(s)
Cladóceros , Contaminantes Químicos del Agua , Animales , Femenino , Humanos , Daphnia , Parabenos/toxicidad , Reproducción , Contaminantes Químicos del Agua/toxicidad
9.
Chemosphere ; 345: 140413, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37844699

RESUMEN

Pollution by metals is a matter of concern around the world. In recent decades, the high population growth in urban centers has significantly magnified the entry of these pollutants into aquatic ecosystems. The Amazon region, intense migratory flow, gold mining, and industrialization have been considered the main driving forces for increasing metal pollution. Thus, the main aim of this study is to conduct, for the first time, an Ecological Risk Assessment (ERA) based on metal concentrations measured in the sediment and water of several aquatic environments from the Amazon basin, based on the risk quotient values (RQ = measured environmental concentration - MEC/predicted no effect concentration - PNEC). In addition, the metal contamination factor (CF) was estimated. Although metal concentrations in water were generally low, these values were far above the limits established by current national legislation in many areas, showing higher concentrations for the metals Co, Pb, Cr, Cu, and Ni. Concentrations of Mn, Cu, Ba, Pb, Co, Ni, Cr, Zn, Cd, and As were especially high in the sediment for several evaluated environments. The ERA for the water compartment revealed that 56% of the studied areas presented high risk (RQ > 1) for aquatic biota. In the sediment, 66% of the sites presented a high risk and 40% medium risk (RQ = 0.1-1). The CF indicated that 49% of the sampling points had high contamination and only 24%, had low contamination. These results reveal that monitoring studies in the Amazon region, provides important information so that public policies for the preservation of water resources can be strengthened in the Amazon.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Metales Pesados/análisis , Ecosistema , Brasil , Plomo , Sedimentos Geológicos , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Medición de Riesgo , Agua
10.
Reprod Domest Anim ; 58(9): 1279-1288, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37469236

RESUMEN

Vaginal cytology (VC) is an essential technique for monitoring the bitch's estrus cycle. Currently, animal-free teaching methodologies have not been investigated for VC. Hence, this study aimed to evaluate an immersive simulation with a VC model and augmented reality tools. Students (n = 219) from four universities were enrolled, having learning stations with models for practising VC that provided immediate feedback on the technique. Augmented reality tools comprised QR codes that endorsed students to short videos of owners' avatars reporting the clinical reproductive story of the simulated animals and slides with QR codes leading to microscopy slide navigation videos. Proestrus, estrus, diestrus, anestrus and vaginitis were identified in the learning stations. The students' perceptions were evaluated through questionnaires assessing satisfaction, motivation, confidence, impact on learning and diagnostic accuracy. Before the immersive simulation, students had no experience with VC, being afraid of doing a VC with a live dog. Almost all the students considered practicing VC as essential and 94% reported that repeating the procedure (>2 times) was the most important parameter for learning. The simulation activity lasted ≈3 h and significantly improved the confidence of students, being less afraid of doing a VC in a live animal. Slide navigation videos improved the diagnostic accuracy of the estrus cycle stage, and students diagnosed the estrus and vaginitis cases more accurately. The immersive simulation strategy allowed repeated practice in a safe, motivated and standardized environment, being appraised by students as an essential strategy for learning VC.


Asunto(s)
Citodiagnóstico , Aprendizaje , Femenino , Perros , Animales , Técnicas Citológicas/veterinaria , Citodiagnóstico/veterinaria , Simulación por Computador , Vagina
11.
Bull Environ Contam Toxicol ; 110(6): 106, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37284985

RESUMEN

In this study we evaluated the acute (immobility/mortality) and chronic (survival and reproduction) effects of the drugs caffeine, diclofenac sodium salt, ketoprofen, paracetamol and salicylic acid on the cladoceran Ceriodaphnia silvestrii. The environmental risks of these substances for tropical freshwaters were estimated from the risk quotient MEC/PNEC. Sensitivity in acute exposures varied up on the drug as follows: salicylic acid (EC50 = 69.15 mg L- 1) < caffeine (EC50 = 45.94 mg L- 1) < paracetamol (EC50 = 34.49 mg L- 1) < ketoprofen (EC50 = 24.84 mg L- 1) < diclofenac sodium salt (EC50 = 14.59 mg L- 1). Chronic toxicity data showed negative effects of the drugs on reproduction. Paracetamol and salicylic acid caused reduction in fecundity in concentrations starting from 10 mg L- 1 and 35 mg L- 1, respectively. Ketoprofen caused total inhibition at 5 mg L- 1. MEC/PNEC values were relatively low for all drugs. The risk was estimated as low or insignificant, except for caffeine, whose MEC/PNEC value was greater than 1 (moderate risk).


Asunto(s)
Cladóceros , Cetoprofeno , Contaminantes Químicos del Agua , Animales , Acetaminofén , Diclofenaco , Cafeína , Cetoprofeno/farmacología , Agua Dulce , Medición de Riesgo , Ácido Salicílico/farmacología , Contaminantes Químicos del Agua/toxicidad
12.
Sci Total Environ ; 888: 164259, 2023 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-37201850

RESUMEN

Sugarcane is one of the main monocultures in Brazil and widely uses herbicide 2,4-D and fipronil insecticide. In addition, vinasse can be mentioned as it is widely used in this plantation. These compounds occurring simultaneously in the aquatic environment can potentiate the deleterious effects on organisms. Thus, this study aimed to evaluate the composition, abundance and ecological indices of the benthic macroinvertebrate community, as well as its ability to reestablish itself considering environmental contamination by the pesticides Regent® 800WG (active ingredient - a.i. fipronil) (F) and DMA® 806BR (a.i. 2,4-D) (D) and vinasse (V), alone and in mixtures: pesticides - M and the three contaminants - MV. The study was conducted using open-air mesocosms. The macroinvertebrate community was monitored by colonization structures, the physical-chemical parameters, metals and pesticides were determined and the effects of contaminants were evaluated over the exposure time in 1, 7, 14, 28, 75 to 150 days. A multiple regression was performed between the water parameters and significant relationships were found between parameters associated with vinasse contamination (pH, total nitrogen, turbidity, and dissolved oxygen) and concentration of fipronil and the ecological variables studied. Over time, changes were observed in the composition of the community. The dominance and richness increased in treatments V and MV. The family Chironomidae and subclass Oligochaeta were more sensitive to the treatment V and MV, while individuals from the families Phoridae, Ephydridae and Sciomyzidae were occasionally found (depending on the experimental time) in these treatments. The insects were sensitive to treatments F and M, disappearing in these mesocosms after contamination, reappearing only after 75 days. The results reveal that sugarcane management practices associated with the use of pesticides and vinasse as fertilizer pose risks to the macroinvertebrate community with consequences for the trophic chains, given its importance in freshwater ecosystems and adjacent terrestrial environments.


Asunto(s)
Herbicidas , Plaguicidas , Contaminantes Químicos del Agua , Humanos , Ecosistema , Plaguicidas/análisis , Ácido 2,4-Diclorofenoxiacético
13.
J Vet Med Educ ; : e20220141, 2023 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-37040445

RESUMEN

Vaginal cytology is a widely used cytological technique mostly taught by observation, either through direct tutoring or videos. To the best of our knowledge, vaginal cytology simulators have never been assessed in veterinary medicine. Twenty-five undergraduate students with no prior experience in canine vaginal sampling were randomly assigned to two groups that either practiced the procedure in a simulator or a live animal. An inverted classroom design was followed. After observing a video tutorial, students practiced with the simulator/live animal for two classes. Three weeks later, they performed a vaginal cytology on a live animal being recorded. The videos were evaluated through an objective structured clinical examination (OSCE) by an observer blinded to the student's groups. The learning outcome was compared through OSCE pass rates and questionnaires. The simulation model was made by 3D printing and soft silicone for the vulvar labia, having pink and blue colored vaseline in the correct and incorrect locations for sampling. The model was economic and accurately replicated the female reproductive tract. It provided immediate feedback to students, by obtaining pink or blue swabs from the correct and incorrect locations, respectively. Students reported that three to five or more attempts were needed to properly learn the procedure, thus justifying the need for a simulator. No differences in the OSCE pass rates were observed between the groups. The simulation model was effective for learning the vaginal cytology procedure, replacing the use of live animals. This low-cost model should be incorporated in the tool-kit of reproduction classes.

14.
Environ Sci Pollut Res Int ; 30(23): 63479-63490, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37052836

RESUMEN

In Brazil, among the pesticides widely applied simultaneously in sugarcane monocultures are the Regent® 800 WG insecticide (active ingredient (a.i.) fipronil) and the DMA® 806 BR herbicide (a.i. 2,4-D). Thus, this study aimed to investigate, through different endpoints, the effects of the fipronil and 2,4-D pesticides, isolated and as mixtures, on the cladoceran Daphnia similis. To do this, acute toxicity tests were carried out with the compounds acting in isolation and in mixture, where the survival of the organisms was evaluated, and chronic toxicity tests with the isolated compounds, where reproduction and maternal and neonatal body length were evaluated. In this study, the physiological endpoints of D. similis were also analyzed, through the analysis of feeding rates (filtration and ingestion) in exposure and post-exposure scenarios, in order to verify the cladoceran food recovery capacity. In addition, D. similis data were compared with other species when exposed to the studied pesticides, using species sensitivity distribution curves. Acute toxicity tests of the fipronil and 2,4-D showed an average EC50-48 h of 66.68 µg a.i./L and 327.07 mg a.i./L, respectively. In both cases, D. similis showed lower sensitivity compared to other species. For the mixture test, the evaluation by the IA model (independent action) and deviation DR (dose ratio dependent) indicated the occurrence of mostly antagonistic effects. The chronic test with fipronil showed a decrease in the fecundity of the organism at a concentration of 16 µg a.i./L, a concentration already found in aquatic environments. For 2,4-D, no significant differences were observed for reproduction at the concentrations tested. Regarding the maternal body length, there were no significant changes when D. similis were exposed to both fipronil and 2,4-D, but these differences were observed in the body length of the neonates only for 2,4-D. There were no significant changes in the feeding rates of the organisms when exposed to both pesticides.


Asunto(s)
Herbicidas , Plaguicidas , Contaminantes Químicos del Agua , Animales , Plaguicidas/toxicidad , Daphnia , Herbicidas/toxicidad , Ácido 2,4-Diclorofenoxiacético/toxicidad , Contaminantes Químicos del Agua/toxicidad
15.
Bull Environ Contam Toxicol ; 110(3): 64, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36920531

RESUMEN

The ecotoxicity of metals is generally assessed individually, in part because current knowledge does not allow for the accurate prediction of the toxicity of metal mixtures to aquatic organisms. The objective of this study was to investigate the toxic effects of binary combinations of metal salts (copper sulphate-CuSO4, cadmium chloride-CdCl2, mercury chloride-HgCl2 and manganese sulphate-MnSO4) on the tropical ostracod Strandesia trispinosa through acute toxicity tests. To this end, ostracods were exposed to each individual metal salt as well as to their combinations by applying a full factorial design. The model that best explained the effects of the mixtures CuSO4 x CdCl2, CuSO4 x HgCl2 and CuSO4 x MnSO4 on the survival of S. trispinosa was Concentration Addition, whereas this was Independent Action for the CdCl2 x HgCl2 mixture. The observed synergistic interactions are likely to result in unacceptable risks to aquatic ecosystems under real field conditions. This is especially the case if CuSO4 predominates the metal mixture, as observed for its combination with mercury and manganese.


Asunto(s)
Cadmio , Mercurio , Animales , Ecosistema , Metales , Crustáceos , Cobre
16.
Sci Total Environ ; 857(Pt 3): 159643, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36306835

RESUMEN

Sugarcane management practices include the application of pesticides, including the herbicide 2,4-D and the insecticide fipronil. In addition, a by-product from the ethanol industry, called vinasse, is commonly applied to fertilize sugarcane areas. The potential risks of these practices to the edge-of-field aquatic ecosystems were assessed in the present study. This was done by contaminating mesocosms with (single and mixtures of) both pesticides and vinasse and evaluating the effects on the midge Chironomus sancticaroli through in-situ and laboratory bioassays. To this end, outdoor mesocosms were treated with fipronil (F), 2,4-D (D), and vinasse (V) alone and with the mixture of fipronil and 2,4-D (M), as well as with both pesticides and vinasse (MV). C. sancticaroli was deployed in mesocosms before contamination in cages, which were taken out 4- and 8-days-post-contamination. Water and sediment samples were also taken for laboratory bioassays on the first day of contamination, as well as 7-, 14-, 21-, 30-, 45-, and 75-days post-contamination. The responses assessed in subchronic assays (8-day) were survival, growth, head capsule width, development, and mentum deformities. Low survival occurred in the in-situ experiments of all treatments due to the low oxygen levels. In the laboratory tests, effects on survival occurred for F, V, and M over time after exposure to both water and sediment. All organisms died post-exposure to water samples from the MV treatment, even 75-days-post-contamination. Impairments in body length and head capsule width occurred for F, V, and M for water and F, V, M, and MV for sediment samples over time. All treatments increased mentum deformities in exposed larvae for any of the sampling periods. The negative effects observed were more significant in the mixture mesocosms (M and MV), thus indicating increased risks from management practices applying these compounds together or with a short time interval in crops.


Asunto(s)
Chironomidae , Plaguicidas , Saccharum , Contaminantes Químicos del Agua , Animales , Ecosistema , Agua , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Ácido 2,4-Diclorofenoxiacético/toxicidad
17.
Chemosphere ; 310: 136719, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36206917

RESUMEN

The high levels of contamination in aquatic ecosystems caused by pesticides and the organisms' consequent continuous exposure to it has made them vulnerable to damage. However, mobile organisms can avoid this continued exposure to contaminants by moving to less disturbed habitats. Therefore, through the use of the Heterogenous Multi-Habitat Assay System (HeMHAS), our objective was to evaluate the ability of Daphnia magna to detect and avoid habitats contaminated by fipronil and 2,4-D, in a spatially connected landscape. Further, the role of contamination by these pesticides, isolated and in mixtures, concerning the colonization of habitats by daphnids was also evaluated. Given that not all organisms successfully escape contamination, the chronic toxicity of the same pesticides using different parameters for D. magna (maternal survival, fecundity and maternal body length) was also evaluated. When evaluating the avoidance response by D. magna exposed to pesticides, there was no preference for the less contaminated areas for both compounds. However, organisms did not move to contaminated zones in the colonization experiments, with no immigration of daphnids to the zones with intermediate and the highest levels of fipronil, nor to the highest concentration of 2,4-D. Finally, the colonization by daphnids was significantly prevented when exposed to a mixture of the pesticides, in which the areas with the highest combinations of pesticide concentrations were not colonized by D. magna. Regarding the long-term chronic effects, negative consequences were observed, particularly for maternal body length, fecundity and maternal survival, due to the exposure to fipronil. Considering that pesticides can limit the areas colonized by organisms by making them unattractive, the risk of local population extinction may be underestimated if only standard endpoints involving forced exposure are studied.


Asunto(s)
Plaguicidas , Contaminantes Químicos del Agua , Animales , Daphnia/fisiología , Plaguicidas/toxicidad , Ecosistema , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Ácido 2,4-Diclorofenoxiacético/toxicidad
18.
Sci Total Environ ; 847: 157525, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-35872193

RESUMEN

Temperature variations and thermal extremes events caused by climate change can have profound implications for the toxicity of pesticides in aquatic organisms. Using an innovative system (Heterogeneous Multi-Habitat Test System - HeMHAS) that allows the simulation of different scenarios within a spatially heterogeneous landscape, the effects on the habitat selection of Danio rerio fish caused by the pesticides fipronil and 2,4-D were studied as single compounds and in mixture and integrated with air temperature variation (20, 24 and 28 °C). As a result, D. rerio detected and avoided both pesticides at air temperatures of 20 and 24 °C; however, at 28 °C no significant difference was observed in habitat choice by fish. Additionally, when pesticides were mixed in a heterogeneously contaminated landscape, it was observed that D. rerio detected contamination and preferred the clean zone at 20 and 24 °C; however, at 28 °C the potential to escape from the most contaminated areas was impaired. Thus, contamination by both pesticides made the habitat selection behavior of fish at 20 and 24 °C more noticeable. In addition, the association between pesticides and temperature showed negative effects on the response of fish to detect and escape from contaminated environments, suggesting the influence of temperature in altering the ability of the organism to provide an efficient response to stress.


Asunto(s)
Plaguicidas , Contaminantes Químicos del Agua , Ácido 2,4-Diclorofenoxiacético , Animales , Cambio Climático , Ecosistema , Plaguicidas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Pez Cebra/fisiología
19.
Vet Res Commun ; 46(3): 641-654, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35717511

RESUMEN

Veterinary cytology faced a remarkable evolution in the last 15 years, in part due to increase recognition of the advantages of the cytology by veterinary clinicians. Simultaneously, there has been a growing awareness by the owners about the importance of a complete diagnostic workup aimed at defining a proper treatment protocol. With the extended use of cytology, challenging diagnostic cases are more frequent, and more clinically useful answers are requested. In this scenario, the use of cytology specimens to perform ancillary techniques is a valid approach. Rather than being simply archived, cytology slides can be a valuable source and a good platform to carry out cytochemistry, immunocytochemistry, and molecular techniques. Therefore, several diagnostic techniques can be applied in tiny samples, thus following the "doing more with less" principle. The aim of this approach is to refine the cytologic diagnosis and provide additional prognostic and therapeutic information. Herein, we detailed this principle in veterinary cytology and reviewed the use of cytology specimens for ancillary techniques as a single procedure, i.e., using the whole slide, or multiple procedures, i.e., multiple procedures applied in the same slide.


Asunto(s)
Técnicas Citológicas , Medicina Veterinaria , Animales , Técnicas Citológicas/veterinaria
20.
Arch Environ Contam Toxicol ; 82(3): 330-340, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35138446

RESUMEN

Sugarcane crops are dependent on chemicals for maintaining plantations. Therefore, environmental consequences concern adjacent areas that can be affected by contaminants in common use, including pesticides and vinasse (i.e., a by-product from the ethanol industry). This study aimed to evaluate phytotoxicity through two plant bioassays with water from mesocosms contaminated with the herbicide 2,4-D (447.0 µg L-1), the insecticide fipronil (63.5 µg L-1), and sugarcane vinasse (1.3%). First, the germination test (4 d) with Eruca sativa L. assessed water samples collected three times after the contamination (2 h, 14 d, and 30 d), considering germination, shoot, and root growth. The results from this bioassay indicated higher phytotoxicity for 2,4-D as it fully inhibited the shoot and root growth even in low concentrations (0.2 µg L-1). However, no significant effect was reported for fipronil and vinasse. Also, the 2,4-D effects drastically decreased due to an expressive concentration reduction (99.4% after 30 d in mixture with vinasse). Second, the irrigation test with Phaseolus vulgaris L. and Zea mays L. considered shoot and root growth and biomass under 21 days after plants emergence. The herbicide 2,4-D inhibited the initial growth of tested species, especially the roots (up to 45% inhibition). Furthermore, sugarcane vinasse caused harmful effects on plant growth (up to 31% inhibition). Therefore, our data showed that these contaminants could inhibit plant germination and initial growth under our tested conditions. These evaluations can endorse risk assessments and water management in sugarcane crops surrounding areas.


Asunto(s)
Plaguicidas , Saccharum , Destilación , Etanol , Germinación/efectos de los fármacos , Plaguicidas/toxicidad , Semillas , Agua , Contaminantes Químicos del Agua/efectos adversos , Contaminación Química del Agua/efectos adversos
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