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1.
Actas Esp Psiquiatr ; 50(5): 246-248, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36273385

RESUMO

Existential obsessions (EO) are an uncommon type of obsessive thought, also described as philosophical or ruminative obsessions. In Obsessive Compulsive Disorder (OCD) with postpartum onset, the clinical picture frequently counts with intrusive thoughts about infant harm and compulsions of verification.


Assuntos
Comportamento Obsessivo , Transtorno Obsessivo-Compulsivo , Lactente , Feminino , Humanos , Transtorno Obsessivo-Compulsivo/diagnóstico , Período Pós-Parto , Comportamento Compulsivo , Cognição
2.
Rev Port Cir Cardiotorac Vasc ; 27(1): 43-45, 2020.
Artigo em Português | MEDLINE | ID: mdl-32239825

RESUMO

The authors present the case of a previously healthy, 22-year-old male nonsmoker who sought emergency room treatment complaining of retrosternal pain. He reported a history of odynophagia two days before, followed by produc- tive cough, fever and dyspnea. On chest radiography, a line could be observed surrounding the heart and the continuous diaphragm sign. The chest computed tomography scan confirmed the presence of pneumomediastinum and soft tissue emphysema. The case was discussed in a multidisciplinary team, and the possibility of surgical intervention was rejected. Conservative treatment was decided with complete resolution of the pneumomediastinum.


Assuntos
Enfisema Mediastínico , Enfisema Subcutâneo , Adulto , Dor no Peito , Dispneia , Humanos , Masculino , Enfisema Mediastínico/diagnóstico , Enfisema Subcutâneo/diagnóstico , Síndrome , Adulto Jovem
3.
Ecotoxicol Environ Saf ; 172: 246-254, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30711859

RESUMO

Free-ranging animals are often used as bioindicators of both short- and long-term changes in ecosystem health, mainly to detect the presence and effects of contaminants. Birds, and gulls in particular, have been used as bioindicators over a broad range of marine and terrestrial ecosystems. In this study, we standardise the conditions for the use of a suite of biochemical markers in non-destructive matrices of Lesser Black-backed Gull (Larus fuscus) to facilitate future biomonitoring of marine and terrestrial contaminants. We characterized cholinesterase (ChE) in plasma and optimized assay conditions for ChE activity as a marker of neurotoxic damage. Moreover, we quantified variation in activity of ChE, lactate dehydrogenase (LDH), glutathione-S-transferase (GST) and catalase (CAT) as well as variation ranges of lipid peroxidation (LPO), in free-ranging adults and captive chicks. The main ChE form present in plasma of both adults and chicks was butyrylcholinesterase (BChE) followed by acetylcholinesterase (AChE), whose relative proportion in plasma tended to decrease with increased chick age. LPO levels and GST activity in blood cells (BCs) decreased significantly with increasing chick age, while BChE and LDH activity in plasma were not age-dependent. CAT in BCs tended to decline non-significantly in older chicks. Results of this study underscore the importance of standardising assay conditions and assessing intrinsic baseline variation in biochemical markers, before biochemical quantification. Data presented here provide a foundation for future use of BChE and LDH activity in plasma, as well as oxidative stress markers (LPO, CAT and GST) in BCs, to monitor environmental stress effects in Lesser Black-backed gulls.


Assuntos
Charadriiformes/metabolismo , Monitoramento Ambiental/métodos , Acetilcolinesterase/sangue , Fatores Etários , Animais , Bioensaio , Biomarcadores/metabolismo , Butirilcolinesterase/sangue , Catalase/metabolismo , Feminino , Glutationa Transferase/metabolismo , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos , Masculino
4.
Biomed Microdevices ; 20(3): 78, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30182296

RESUMO

Dengue is an infectious viral disease transmitted by the Aedes aegypti mosquito, the control of which is complex. In addition, the clinical diagnosis is difficult to perform since it resembles other febrile infections; thus, the development of more effective methods to detect dengue virus (DV) has drawn increasing attention. The present study aimed to develop an impedimetric immunosensor for dengue diagnosis using a screen-printed electrode (SPE) functionalized with polymer films derived from 4-aminophenylacetic acid (4-APA). Data obtained from scanning electron microscopy (SEM) showed the deposition of a uniformly distributed material over the electrode surface. The immunosensor was based on the specific interaction between dengue antigen, NS1 protein, and anti-NS1 antibodies, IgG and IgM. In a characterization study using cyclic voltammetry (CV), the polymer film showed two oxidation peaks at +0.17 and + 0.35 V in 0.50 M sulfuric acid solution, indicating its adsorption and electroactivity at the SPE surface. Electrochemical impedance spectroscopy (EIS) measurements showed a higher charge transfer resistance (Rct) to the polymer film-modified SPE as compared with the bare SPE, corroborating a previous study. The best rNS1 concentration for immobilization was 1.00 ng/mL, and the immunoreaction time between the antigen (Ag) and the antibody (Ab) was 20 min. Dilutions of positive and negative clinical serum samples were evaluated by EIE, from which it was possible to elucidate, for the positive serum, that the more diluted the serum the greater the Rct. Negative serum also showed an analytical signal, probably due to the presence of non-specific antibodies; however, the generated signal presented values closer to the rNS1 signal, indicating good selectivity of the proposed platform. The experiments were repeated using bare SPE to verify the importance of the polymer film in biosensor construction. No significant difference was observed between these results. Graphical abstract Proposed schematic for the genosensor development.


Assuntos
Compostos de Anilina/química , Técnicas Biossensoriais , Materiais Revestidos Biocompatíveis/química , Vírus da Dengue/isolamento & purificação , Dengue/diagnóstico , Grafite/química , Fenilacetatos/química , Anticorpos Antivirais/sangue , Antígenos Virais/sangue , Dengue/sangue , Dengue/imunologia , Vírus da Dengue/imunologia , Espectroscopia Dielétrica , Eletrodos , Humanos , Limite de Detecção , Polímeros/química , Propriedades de Superfície , Proteínas não Estruturais Virais/metabolismo
5.
Ecotoxicol Environ Saf ; 136: 104-110, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27833047

RESUMO

Over the past decades, the presence of micronucleated blood cells has been used to detect genotoxic effects of xenobiotics in fish, amphibians and birds. This study assessed the frequency of micronuclei (MN) and other nuclear abnormalities in erythrocytes of individuals of Ardea cinerea and Ciconia ciconia retrieved for rehabilitation in order to evaluate the influence of age, temporal and spatial factors on the occurrence of DNA damage in Portuguese wild birds. Blood smears from 65 birds with different life-history backgrounds (e.g. geographic origin, age) were collected between 2007 and 2011 and the frequency of erythrocyte nuclear abnormalities (ENAs) was analysed. Differences in DNA damage between ages were observed to occur in C. ciconia, with chicks displaying significantly higher frequencies of ENAs (both when looking at total ENAs or only MN frequency) than juveniles and adults. Additionally, significant differences in ENAs frequencies were observed between different years and geographic origins, whereas MN frequency alone did not show significant alterations concerning spatial and temporal variations. These results suggest that the assessment of ENAs rather than MN frequency alone may be a useful and valuable tool to complement the evaluation of DNA damage in populations of birds, as prompted by individual life-history traits and environmental factors.


Assuntos
Aves/metabolismo , Dano ao DNA , Exposição Ambiental , Eritrócitos/efeitos dos fármacos , Fatores Etários , Animais , Feminino , Geografia , Masculino , Testes para Micronúcleos , Portugal , Estações do Ano
9.
Ecotoxicol Environ Saf ; 132: 270-8, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27344015

RESUMO

Many methods in freshwater biomonitoring tend to be restricted to a few levels of biological organization, limiting the potential spectrum of measurable of cause-effect responses to different anthropogenic impacts. We combined distinct organisational levels, covering biological biomarkers (histopathological and biochemical reactions in liver and fish gills), community based bioindicators (fish guilds, invertebrate metrics/traits and chironomid pupal exuviae) and ecosystem functional indicators (decomposition rates) to assess ecological status at designated Water Framework Directive monitoring sites, covering a gradient of human impact across several rivers in northern Portugal. We used Random Forest to rank the variables that contributed more significantly to successfully predict the different classes of ecological status and also to provide specific cut levels to discriminate each WFD class based on reference condition. A total of 59 Biological Quality Elements and functional indicators were determined using this procedure and subsequently applied to develop the integrated Multiple Ecological Level Index (MELI Index), a potentially powerful bioassessment tool.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Monitoramento Ambiental/métodos , Rios/química , Animais , Biomarcadores/metabolismo , Ecologia , Peixes/metabolismo , Brânquias/metabolismo , Invertebrados/metabolismo , Portugal
10.
Environ Monit Assess ; 187(4): 208, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25805370

RESUMO

In recent years, the use of biochemical markers, especially in the assessment of toxic effects and modes of action, under controlled laboratory conditions has increased. However, transposing their use to in situ monitoring or risk assessment evaluations has encountered barriers, mainly related to the difficulty in interpreting the meaning of biochemical variation. In this work, we aimed at understanding if biochemical marker activities (cholinesterase, glutathione S-transferase and lactate dehydrogenase) can be used to monitor the health status of natural populations of fish (Gambusia affinis) and daphnids (Daphnia magna). For that, two ponds with different water properties were chosen as study sites, and organisms collected at four sampling periods along the year. The pattern of biochemical marker responses was not the same in the two species, showing higher integrated biochemical marker response values in the winter for G. affinis and in the autumn for D. magna, suggesting specificities that must be taken into account in biomonitoring programmes by including representative species of several trophic levels. In the case of G. affinis, the differences in key physicochemical parameters between the two ponds (especially dissolved oxygen levels) did not seem to affect biochemical marker levels as if organisms were already perfectly adapted to their environment. In general, seasonal variation of water quality seems to have an important role on biochemical marker responses. Several parameters above Environmental Quality Standards were identified such as dissolved oxygen (DO), ammonia, nitrites, sulphides and metals, but eventual responses to these stressors could not be discriminated from natural variation except for particular cases.


Assuntos
Biomarcadores/metabolismo , Monitoramento Ambiental/métodos , Animais , Colinesterases/metabolismo , Ciprinodontiformes/fisiologia , Daphnia/fisiologia , Glutationa Transferase/metabolismo , Lagoas , Estações do Ano , Qualidade da Água
12.
Nurs Rep ; 14(3): 1769-1780, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39051367

RESUMO

A stroke is a time-sensitive emergency, so diagnosing and treating the victim promptly is extremely important. Therefore, the purpose of this study was to identify the influence of the Stroke Code Protocol's activation on the door-to-computed-tomography (door-to-CT) time and determine whether factors such as previous Modified Rankin Scale (mRS), age, and gender influence its activation. A retrospective study was conducted in a Medical-Surgical Emergency Department in the centre of Portugal from 1 January 2021 to 31 December 2022. The sample was selected according to the diagnosis assigned at the time of clinical discharge from the Emergency Department and the Stroke Code Protocol activation criteria. It was observed that 113 (50%) suspected stroke victims who met the activation criteria for the Stroke Code Protocol did not have the protocol activated, which had a highly significant influence (p < 0.001) on door-to-CT time. It was determined that activation at triage has an average door-to-CT time of 35 ± 18 min, post-triage activation has an average door-to-CT time of 38 ± 26 min, and non-activation has an average door-to-CT time of 1 h 04 ± 45 min. The need to implement an institutional protocol for activating the Stroke Code Protocol and provide specialised training for the multidisciplinary team is reiterated.

13.
Nurs Rep ; 14(3): 1792-1806, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39051369

RESUMO

BACKGROUND: A robust safety culture is essential for ensuring high-quality healthcare delivery. From a nursing perspective, especially among critical patients, it fosters ongoing improvement by highlighting areas that need attention. AIMS: This study aimed to evaluate the perception of patient safety culture among nurses within the critical care environment. METHODOLOGY: An observational study was conducted at a central hospital in Portugal employing the Hospital Survey on Patient Safety Culture (HSPSC) questionnaire. RESULTS: The study encompassed 57, nurses predominantly female (73.7%), aged 25-64. Most participants were general nurses (77.2%), with a significant proportion (61.4%) working in the emergency department and possessing an average tenure of 13 years at the facility. The perception of critical patient safety culture (CPSC) was predominantly positive (40.6%), varying by department, with intensive care nurses reporting the highest positivity rates. Teamwork was identified as a strong point, receiving 80.7% positivity, highlighting it as a well-established domain in the CPSC, whereas other domains were recognised as requiring enhancements. CONCLUSIONS: The study pinpointed both strengths and weaknesses within the CPSC, offering a foundation for developing targeted strategies to bolster patient safety culture in critical care settings.

14.
Healthcare (Basel) ; 12(2)2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38255076

RESUMO

The COVID-19 pandemic imposed changes upon the capacity of healthcare systems, with significant repercussions on healthcare provision, particularly at end-of-life. This study aims to analyze the concept map of death unpreparedness due to the COVID-19 pandemic, capturing the relationships among the attributes, antecedents, consequences, and empirical indicators. Walker and Avant's method was used to guide an analysis of this concept. A literature search was performed systematically, between May 2022 and August 2023, using the following electronic databases on the Elton Bryson Stephens Company (EBSCO) host platform: Medical Literature Analysis and Retrieval System Online (Medline), Psychological Information Database (PsycINFO), Cumulative Index to Nursing and Allied Health Literature (CINAHL) Complete, Cochrane Library, and Nursing and Allied Health Collection. Thirty-four articles were retrieved. The unexpected and unpredictable impositions associated with inexperience and unskillfulness in dealing with COVID-19 configured challenges for healthcare professionals, family/caregivers, and even the dying person. Nine key attributes emerged in three main domains: (1) Individual: (a) disease-related conditions, (b) separation distress, and (c) scarcity of death and grief literacy; (2) Relational: (a) Dying alone, (b) poor communication, and (c) existential issues; and (3) Contextual: (a) disrupted collective mourning and grieving, (b) disrupted compassionate care and, (c) pandemic social stigma. This study contributed a full definition of death unpreparedness in a global pandemic scenario such as COVID-19. In this sense, feeling unprepared or unready for death brought new challenges to the bioecological resources of those affected. It is essential to embrace strategies capable of providing emotional and spiritual support in the dying process and to respect patient wishes. The lessons learned from COVID-19 should be applied to events with a comparable impact to minimize their consequences.

15.
Nurs Rep ; 14(3): 1553-1569, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-39051353

RESUMO

Medication errors have serious consequences and high costs for the patient and the system. The treatment process and the care required for critically ill patients are complex, and these patients are more vulnerable to errors and potential consequences. A scoping review using the JBI methodology was conducted across PubMed, CINAHL, and MEDLINE databases and reported by the PRISMA-ScR guidelines to explore strategies that can mitigate medication errors by nurses. The search strategy focused on references published between January 2012 and April 2023. Sixteen studies were included, and the results were organized into thematic areas. Medication errors by nurses are in the areas of preparation, administration, and documentation; organizational, system-related, procedural, personal, and knowledge and training factors are predisposing factors for errors; educational intervention, verification and safety methods, organizational changes, and error reporting are the strategic areas to mitigate medication error. The organization of the data could be different, as it depends on the reviewers' experience. Knowledge of the factors that cause medication errors and interventions to mitigate them make it possible to outline strategies to minimize their occurrence and achieve health gains. The protocol preceding this review has been registered in the Open Science Framework and published.

16.
Healthcare (Basel) ; 12(11)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38891178

RESUMO

BACKGROUND: The incidence and mortality of pleural mesothelioma (PM) reflect the production and consumption of asbestos over time. However, despite the current global concern, these data remain to be known. OBJECTIVE: Our aim was to carry out a descriptive analysis of PM cases and mortality from some Portuguese databases between 2014 and 2020. METHODS: A retrospective observational study was carried out between 2014 and 2020. Data on the number of PM cases were provided by the Portuguese Cancer Registry, and data on mortality were from the Portuguese Death Certificate Information System. RESULTS: Between 2014 and 2020, 315 cases of PM were reported, with 222 (70.5%) men. The average age of patients was 72.1, with the highest number of cases in patients aged >70 years (n = 198; 62.9%). The highest number of cases was reported in 2018 (n = 62; 19.7%). Regarding mortality, 169 deaths were reported, with 126 (74.6%) men and mostly in individuals aged >70 years (n = 109; 64.5%). It is estimated that around 520 years of potential life were lost. The highest number of deaths occurred in 2015 (n = 33; 19.5%). CONCLUSION: It is mandatory to reinforce the need for surveillance programs that allow us to gather real and reliable data and eliminate asbestos-related diseases.

17.
Healthcare (Basel) ; 12(2)2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38255132

RESUMO

This scoping review, conducted within the Joanna Briggs Institute (JBI) framework, analysed the recent literature (January 2018 to March 2023) addressing factors inherent to professional practice environments and organisational contexts influencing nurses' adoption of evidence-based practice (EBP). This review included studies involving nurses regardless of sector, practice setting, and scope of practice. A systematic search was undertaken across the PubMed, Web of Science, CINAHL, and MEDLINE databases, as well as the EThOS, OATD, and RCAAP platforms. The extracted textual elements underwent a content analysis, resulting in a coding structure established through an inductive approach that categorised information into main categories and subcategories linked by similarity and thematic affinity. Forty-one studies were included, revealing four main categories of factors impacting EBP adoption by nurses: (1) organisational dynamics, (2) management and leadership, (3) teamwork and communication, and (4) resources and infrastructure. The study's limitations acknowledge the subjective nature of categorisation, recognising potential variations based on individual perspectives despite adopting procedures to minimise the risk of bias. The results provide a substantial foundation for developing interventions to cultivate environments conducive to EBP adoption by nurses, thereby enhancing the integration of evidence into nurses' professional practice contexts. This review was prospectively registered on the Open Science Framework (registration no. osf.io/e86qz).

18.
NanoImpact ; 34: 100506, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38626862

RESUMO

The foreseen increasing application of copper-based nanomaterials (Cu-NMs), replacing or complementing existing Cu-agrochemicals, may negatively impact the soil microbiome. Thus, we studied the effects on soil microbiome function and composition of nano copper oxide (nCuO) or copper hydroxide NMs in a commercial (Kocide®3000) or a lab-synthetized formulation (nCu(OH)2) or bulk copper hydroxide (Cu(OH)2-B), at the commonly recommended Cu dose of 50 mg(Cu)kg-1 soil. Microbial responses were studied over 28 days in a designed indoor mesocosm. On day-28, in comparison to non-treated soil (CT), all Cu-treatments led to a reduction in dehydrogenase (95% to 68%), arylsulfatase (41% to 27%), and urease (40% to 20%) activity. There was a 32% increase in the utilization of carbon substrates in the nCuO-treatment and an increased abundance of viable bacteria in the nCu(OH)2-treatment (75% of heterotrophic and 69% of P-solubilizing bacteria). The relative abundance of Acidobacteria [Kocide®3000, nCuO, and Cu(OH)2-B treatments] and Flavobacteriia [nCu(OH)2-treatment] was negatively affected by Cu exposure. The abundance of Cu-tolerant bacteria increased in soils treated with Kocide®3000 (Clostridia) and nCu(OH)2 (Gemmatimonadetes). All Cu-treated soils exhibited a reduced abundance of denitrification-related genes (0.05% of nosZ gene). The DTPA-extractable pool of ionic Cu(II) varied among treatments: Cu(OH)2-B > Kocide®3000 âˆ¼ nCuO>nCu(OH)2, which may explain changes on the soil microbiome composition, at the genera and OTU levels. Thus, our study revealed that Cu-materials (nano and bulk) influence the soil microbiome with implications on its ecological role. It highlights the importance of assessing the impact of Cu-materials under dynamic and complex exposure scenarios and emphasizes the need for specific regulatory frameworks for NMs.


Assuntos
Agricultura , Cobre , Microbiota , Microbiologia do Solo , Cobre/farmacologia , Microbiota/efeitos dos fármacos , Solo/química , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/metabolismo , Hidróxidos/química , Hidróxidos/farmacologia , Nanopartículas Metálicas/química , Nanoestruturas/química
19.
J Bacteriol ; 195(20): 4753-60, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23974026

RESUMO

Sulfate-reducing bacteria are characterized by a high number of hydrogenases, which have been proposed to contribute to the overall energy metabolism of the cell, but exactly in what role is not clear. Desulfovibrio spp. can produce or consume H2 when growing on organic or inorganic substrates in the presence or absence of sulfate. Because of the presence of only two hydrogenases encoded in its genome, the periplasmic HynAB and cytoplasmic Ech hydrogenases, Desulfovibrio gigas is an excellent model organism for investigation of the specific function of each of these enzymes during growth. In this study, we analyzed the physiological response to the deletion of the genes that encode the two hydrogenases in D. gigas, through the generation of ΔechBC and ΔhynAB single mutant strains. These strains were analyzed for the ability to grow on different substrates, such as lactate, pyruvate, and hydrogen, under respiratory and fermentative conditions. Furthermore, the expression of both hydrogenase genes in the three strains studied was assessed through quantitative reverse transcription-PCR. The results demonstrate that neither hydrogenase is essential for growth on lactate-sulfate, indicating that hydrogen cycling is not indispensable. In addition, the periplasmic HynAB enzyme has a bifunctional activity and is required for growth on H2 or by fermentation of pyruvate. Therefore, this enzyme seems to play a dominant role in D. gigas hydrogen metabolism.


Assuntos
Proteínas de Bactérias/metabolismo , Desulfovibrio gigas/enzimologia , Regulação Bacteriana da Expressão Gênica/fisiologia , Hidrogenase/classificação , Hidrogenase/metabolismo , Proteínas de Bactérias/genética , Desulfovibrio gigas/genética , Desulfovibrio gigas/metabolismo , Fermentação , Deleção de Genes , Regulação Enzimológica da Expressão Gênica/fisiologia , Hidrogênio/metabolismo , Hidrogenase/genética , Ácido Láctico/metabolismo , Dados de Sequência Molecular , Ácido Pirúvico/metabolismo , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcriptoma
20.
Neurotoxicol Teratol ; 100: 107302, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37739188

RESUMO

Mercury (Hg) is a global contaminant affecting aquatic ecosystems' health. Chronic exposure to Hg has shown that the normal development of zebrafish embryo-larvae is affected. However, the molecular mechanisms behind the toxicity of Hg on fish embryonic development are still poorly understood. This work aimed to investigate the effects of Hg exposure on zebrafish embryo-larvae using a combined approach at individual (mortality, embryo development and locomotor behavior) and biochemical (neurotoxicity and oxidative stress enzymatic activities and protein phosphatase expression) levels. The Fish Embryo Toxicity assay followed the Organization for Economic Cooperation and Development Guideline 236 and used a concentration range between 13 and 401 µg Hg/L. Lethal and developmental endpoints were examined at 24, 48, 72 and 96 hpf. Biochemical markers, including Acetylcholinesterase (AChE), Catalase (CAT), Glutathione Reductase (GR), and Glutathione-S-Transferase (GST) activities and, for the first time, the expression of the protein phosphatase 1 gamma (PP1γ) was assessed after 24, 48, 72 and 96 h of exposure to 10 and 100 µg Hg/L. The behavioral effects of a sublethal range of Hg (from 0.8 to 13 µg Hg/L) were assessed using an automated video tracking system at 120 hpf. Several developmental abnormalities on zebrafish embryos and larvae, including pericardial edema, spin and tail deformities and reduced rate of consumption of the yolk sac, were found after exposure to Hg (LC50 at 96 hpf of 139 µg Hg/L) with EC50 values for total malformations ranging from 22 to 264 µg Hg/L. After 96 hpf, no significant effects were observed in the CAT and GR activities. However, an increase in the GST activity in a concentration and time-dependent manner was found, denoting possible stress-related adaptation of zebrafish embryos to deleterious effects of Hg exposure. The AchE activity showed a response pattern in line with the behavioral responses. At the lowest concentration tested, no significant effects were found for the AChE activity, whereas a decrease in AChE activity was observed at 100 µg Hg/L, suggesting that exposure to Hg induced neurotoxic effects in zebrafish embryos which in turn may explain the lack of equilibrium found in this study (EC50 at 96 hpf of 83 µg Hg/L). Moreover, a decrease in the PP1γ expression was found after 96 h of exposure to 10 and 100 µg Hg/L. Thus, we suggest that Hg may be an inhibitor of PP1γ in zebrafish embryos-larvae and thus, along with the alterations in the enzymatic activity of GST, explain some of the developmental malformations observed, as well as the lack of equilibrium. Hence, in this study, we propose the use of PP1 expression, in combination with apical and biochemical endpoints, as a precursor for assessing Hg's toxic mechanism on embryonic development.


Assuntos
Mercúrio , Poluentes Químicos da Água , Animais , Peixe-Zebra , Acetilcolinesterase/metabolismo , Larva , Ecossistema , Estresse Oxidativo , Embrião não Mamífero , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/metabolismo
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