Regulation and distribution of European sea bass perforins point to their role in the adaptive cytotoxic response against NNV.

Cell-mediated cytotoxicity is a complex immune mechanism that involves the release of several killing molecules, being perforin (PRF) one of the most important effector players. Perforin is synthesized by T lymphocytes and natural killer cells in mammals and responsible for the formation of pores on the target cell membrane during the killing process. Although perforin has been extensively studied in higher vertebrates, this knowledge is very limited in fish. Therefore, in this study we have identified four prf genes in European sea bass (Dicentrarchus labrax) and evaluated their mRNA levels. All sea bass prf genes showed the typical and conserved domains of its human orthologue and were closely clustered by the phylogenetic analysis. In addition, all genes showed constitutive and ubiquitous tissular expression, being prf1.9 gene the most highly expressed in immune tissues. Subsequently, in vitro stimulation of head-kidney (HK) cells with phytohemagglutinin, a T-cell activator, showed an increase of all prf gene levels, except for prf1.3 gene. European sea bass HK cells increased the transcription of prf1.2 and prf1.9 during the innate cell-mediated cytotoxic activity against xenogeneic target cells. In addition, sea bass infected with nodavirus (NNV) showed a similar expression pattern of all prf in HK and brain at 15 days post-infection, except for prf1.3 gene and in the gonad. Finally, the use of a polyclonal antibody against PRF1.9 showed an increase of positive cells in HK, brain and gonad from NNV-infected fish. Taken together, the data seem to indicate that all prf genes, except prf1.3, appear to be involved in the European sea bass immunity, and probably in the cell-mediated cytotoxic response, with PRF1.9 playing the most important role against nodavirus. The involvement of the PRFs and the CMC activity in the vertical transmission success of the virus is also discussed.

Molecular characterization of the cytotoxic and regulatory T cell coreceptor (CRTAM), and its ligand CADM1, in the European seabass and gilthead seabream.

T cell activation is a multifaceted process that depends on the activation of the T cell receptor (TCR). However, other coreceptors are also strictly necessary to provide co-signals and modulate the immune response. However, to date, most of these coreceptors are unknown in fish or their information is very limited. Therefore, in this work, we have identified the cytotoxic and regulatory T cell molecule, CRTAM, and its ligand, the cell adhesion molecule 1, CADM1, in European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata); and evaluated their transcriptional levels. Both putative proteins showed the canonical architecture observed in mammals, where CRTAM exhibited two immunoglobulin domains and CADM1, both the a and b forms, exhibited three of these domains. In addition, phylogeny and synteny analyses showed their conservation throughout vertebrate evolution. We found constitutive expression of all three genes, with crtam and cadm1a being predominant in immune tissues such as spleen, thymus and head-kidney (HK), while cadm1b expression was more limited to the brain. In vitro, only the T cell mitogen phytohemagglutinin (PHA) up-regulated the transcription of crtam and cadm1a in HK leucocytes. Nodavirus (NNV) infection elicited an up-regulation of crtam and cadm1a in brain and HK, appearing earlier in seabream than in seabass, which could explain the resistance of seabream to the development of nodavirus disease. In addition, they are up-regulated during the innate cell-mediated cytotoxic response in seabream but not in seabass. Altogether, our data seem to indicate that CRTAM is more related to the innate cytotoxicity in seabream and more in the specific and T cell-mediated cytotoxicity in seabass. Our results highlight the importance of CRTAM and CADM1 as important molecules in the activation of T lymphocytes in seabass and seabream, but further studies are needed.

Immunity elicited by AMP-encoding plasmids fails to increase the protection of European sea bass against nodavirus.

Antimicrobial peptides (AMPs) are a potent arm of the innate immune system that can directly kill pathogens and induce immunomodulation. In the marine aquaculture, European sea bass (Dicentrarchus labrax L.) is one of the most prosperous species but is highly susceptible to nodavirus (NNV), which produces high rates of mortality in larvae and juvenile stages. Thus, we aimed to evaluate whether AMPs exert immunomodulatory and/or NNV-preventive actions in sea bass. To do this, plasmids encoding the sea bass AMPs dicentracin (pDIC), beta-defensin (pDB1), hepcidin (pHAMP2) or NK-lysin (pNKL) were generated and intramuscularly injected into sea bass juveniles to evaluate their immunomodulatory and anti-NNV roles. Sea bass muscle transcribes the AMPs and produces an increase in their circulating levels, along with an increase of the antibacterial activity. Immune-related gene analysis revealed a great activation of the inflammatory response and the recruitment of neutrophilic granulocytes at the site of injection. However, AMP-encoding plasmids, namely pHAMP2, negatively affected to NNV disease by increasing fish mortality. In conclusion, plasmids encoding AMPs show immunostimulatory effects on European sea bass but do not improve the resistance to NNV.

Immunotoxicological effects of perfluorooctanesulfonic acid on European seabass are reduced by polyethylene microplastics.

Marine environments receive plastic waste, where it suffers a transformation process into smaller particles. Among them, microplastics (MPs; <5 mm) are ingested by aquatic organisms leading to negative effects on animal welfare. The interactions between MPs, contaminants and organisms are poorly understood. To clarify this issue, European seabass (Dicentrarchus labrax L.) were fed with diets supplemented with 0 (control), polyethylene (PE) MPs (100 mg/kg diet), perfluorooctanesulfonic acid (PFOS, 4.83 µg/kg diet) or PFOS adsorbed to MPs (MPs-PFOS; final concentrations of 4.83 µg and 100 mg of PFOS and MP per kg of feed, respectively). Samples of skin mucus, serum, head-kidney (HK), liver, muscle, brain and intestine were obtained. PFOS levels were high in the liver of fish fed with the PFOS-diet, and markedly reduced when adsorbed to MPs. Compared to the control groups, liver EROD activity did not show any significant changes, whereas brain and muscle cholinesterase activities were decreased in all the groups. The histological and morphometrical study on liver and intestine showed significant alterations in fish fed with the experimental diets. At functional level, all the experimental diets affected the humoral (peroxidase, IgM, protease and bactericidal activities) as well as cellular (phagocytosis, respiratory burst and peroxidase) activities of HK leukocytes, being more marked those effects caused by the PFOS diet. Besides, treatments produced inflammation and oxidative stress as evidenced at gene level. Principal component analysis demonstrated that seabass fed with MPs-PFOS showed more similar effects to MPs alone than to PFOS. Overall, seabass fed with MPs-PFOS diet showed similar or lower toxicological alterations than those fed with MPs or PFOS alone demonstrating the lack of additive effects or even protection against PFOS toxicity.

Nanoplastics Increase Fish Susceptibility to Nodavirus Infection and Reduce Antiviral Immune Responses.

Nanoplastics (NPs) might cause different negative effects on aquatic organisms at different biological levels, ranging from single cells to whole organisms, including cytotoxicity, reproduction, behavior or oxidative stress. However, the impact of NPs on disease resistance is almost unknown. The objective of this study was to assess whether exposure to 50 nm functionalized polystyrene NPs impacts fish susceptibility to viral diseases both in vitro and in vivo. In particular, we focused on the nervous necrosis virus (NNV), which affects many fish species, producing viral encephalopathy and retinopathy (VER), and causes great economic losses in marine aquaculture. In vitro and in vivo approaches were used. A brain cell line (SaB-1) was exposed to 1 µg mL-1 of functionalized polystyrene NPs (PS-NH2, PS-COOH) and then infected with NNV. Viral titers were increased in NP-exposed cells whilst the transcription of inflammatory and antiviral markers was lowered when compared to those cells only infected with NNV. In addition, European sea bass (Dicentrarchus labrax) juveniles were intraperitoneally injected with the same NPs and then challenged with NNV. Our results indicated that NPs increased the viral replication and clinical signs under which the fish died although the cumulate mortality was unaltered. Again, exposure to NPs produced a lowered inflammatory and antiviral response. Our results highlight that the presence of NPs might impact the infection process of NNV and fish resistance to the disease, posing an additional risk to marine organisms.

Severe Natural Outbreak of Cryptocaryon irritans in Gilthead Seabream Produces Leukocyte Mobilization and Innate Immunity at the Gill Tissue.

The protozoan parasite Cryptocaryon irritans causes marine white spot disease in a wide range of fish hosts, including gilthead seabream, a very sensitive species with great economic importance in the Mediterranean area. Thus, we aimed to evaluate the immunity of gilthead seabream after a severe natural outbreak of C. irritans. Morphological alterations and immune cell appearance in the gills were studied by light microscopy and immunohistochemical staining. The expression of several immune-related genes in the gills and head kidney were studied by qPCR, including inflammatory and immune cell markers, antimicrobial peptides (AMP), and cell-mediated cytotoxicity (CMC) molecules. Serum humoral innate immune activities were also assayed. Fish mortality reached 100% 8 days after the appearance of the C. irritans episode. Gill filaments were engrossed and packed without any space between filaments and included parasites and large numbers of undifferentiated and immune cells, namely acidophilic granulocytes. Our data suggest leukocyte mobilization from the head kidney, while the gills show the up-regulated transcription of inflammatory, AMPs, and CMC-related molecules. Meanwhile, only serum bactericidal activity was increased upon infection. A potent local innate immune response in the gills, probably orchestrated by AMPs and CMC, is triggered by a severe natural outbreak of C. irritans.

Molecular characterization of the T cell costimulatory receptors CD28 and CTLA4 in the European sea bass.

For the activation of T cells, it is necessary the specific recognition of the peptide by the T cell receptors (TCR) in the surface of antigen-presenting cells (APCs) and additional signals delivered by costimulatory receptors. In fish, knowledge about the presence of these costimulatory signals is limited and functional evidence almost absent. Thus, in this study, we have identified the stimulatory CD28 and the inhibitory cytotoxic T-lymphocyte-associated protein 4 (CTLA4) coreceptors in the European sea bass (Dicentrarchus labrax), and evaluated their transcription. In parallel, the transcription encoding for the T cell markers CD8α and CD4 was also evaluated. Both coreceptors showed the canonical architecture including a signal peptide, an immunoglobulin domain, a transmembrane region and a cytosolic tail. Protein predictions and phylogenetic tree identify them as true mammalian orthologues of CD28 and CTLA4. We found these genes constitutively expressed in all studied organs of European sea bass with high expression in lymphoid organs (thymus, spleen and head-kidney) and liver. The molecular expression pattern of these genes was up-regulated in head-kidney leucocytes stimulated with T mitogens as concanavalin A and phytohemagglutinin (PHA), but not with the B cell mitogen lipopolysaccharide (LPS). Fish challenged with nodavirus (NNV) evidenced a differential and opposing regulation of the cd28 and ctla4 transcription levels in the brain, the target organ for viral replication, and head-kidney. While cd28 transcription tends to decrease over the infection time in both organs the expression of the ctla4 gene tends to increase. Interestingly, the coreceptor expression is highly and significantly correlated to the transcription of the T cell markers. Our results highlight the important role of CD28 and CTLA4 as costimulatory receptors of T cells in European sea bass but further studies are deserved.

Functionalized Nanoplastics (NPs) Increase the Toxicity of Metals in Fish Cell Lines.

Nanoplastics (NPs) are one of the most abundant environment-threatening nanomaterials on the market. The objective of this study was to determine in vitro if functionalized NPs are cytotoxic by themselves or increase the toxicity of metals. For that, we used 50 nm polystyrene nanoparticles with distinct surface functionalization (pristine, PS-Plain; carboxylic, PS-COOH; and amino PS-NH2) alone or combined with the metals arsenic (As) and methylmercury (MeHg), which possess an environmental risk to marine life. As test model, we chose a brain-derived cell line (SaB-1) from gilthead seabream (Sparus aurata), one of the most commercial fish species in the Mediterranean. First, only the PS-NH2 NPs were toxic to SaB-1 cells. NPs seem to be internalized into the cells but they showed little alteration in the transcription of genes related to oxidative stress (nrf2, cat, gr, gsta), cellular protection against metals (mta) or apoptosis (bcl2, bax). However, NPs, mainly PS-COOH and PS-NH2, significantly increased the toxicity of both metals. Since the coexistence of NPs and other pollutants in the aquatic environment is inevitable, our results reveal that the combined effect of NPs with the rest of pollutants deserves more attention.

Identification and Regulation of Interleukin-17 (IL-17) Family Ligands in the Teleost Fish European Sea Bass.

Interleukin-17 (IL-17) cytokine comprises a family of six ligands in mammals with proinflammatory functions, having an important role in autoimmune disorders and against bacterial, viral, and fungal pathogens. While IL-17A and IL-17F ligands are mainly produced by Th cells (Th17 cells), the rest of the ligands are expressed by other immune and non-immune cells and have different functions. The identification of IL-17 ligands in fish has revealed the presence of six members, counterparts to mammalian ones, and a teleost-specific form, the fish IL-17N. However, tissue distribution, the regulation of gene expression, and scarce bioactivity assays point to similar functions compared to mammalian ones, though this yet to be investigated and confirmed. Thus, we have identified seven IL-17 ligands in the teleost European sea bass (Dicentrarchus labrax), for the first time, corresponding to IL-17A/F1, IL-17A/F2, IL-17A/F3, IL-17C1, IL-17C2, IL-17D, and IL-17N, according to the predicted protein sequences and phylogenetic analysis. They are constitutively and widely transcribed in sea bass tissues, with some of them being mainly expressed in the thymus, brain or intestine. Upon in vitro stimulation of head-kidney leucocytes, the mRNA levels of all sea bass IL-17 ligands were up-regulated by phytohemagglutinin treatment, a well-known T cell mitogen, suggesting a major expression in T lymphocytes. By contrast, the infection of sea bass juveniles with nodavirus (NNV), a very pathogenic virus for this fish species, resulted in the up-regulation of the transcription of IL-17C1 in the head-kidney and of IL-17C1 and IL-17D in the brain, the target tissue for NNV replication. By contrast, NNV infection led to a down-regulated transcription of IL-17A/F1, IL-17A/F2, IL-17C1, IL-17C2, and IL-17D in the head-kidney and of IL-17A/F1 and IL-17A/F3 in the brain. The data are discussed accordingly with the IL-17 ligand expression and the immune response under the different situations tested.

Early Discharge Programme on Hospital-at-Home Evaluation for Patients with Immediate Postoperative Course after Laparoscopic Colorectal Surgery.

BACKGROUND: To audit the safety of the early hospital discharge care model offered by a Hospital-at-home (HAH) unit during early postoperative follow-up of these patients, and to determine whether this care model is more efficient compared to the traditional care model. METHODS: A prospective study of 50 patients included consecutively for 1 year in an early discharge programme after laparoscopic colorectal surgery was performed. As of day 3 after surgery, if the patient met the relevant inclusion criteria they were transferred to the HAH unit. The domiciliary protocol consists of daily clinical follow-up and a series of analytical controls with the purpose of early detection of postoperative complications. If the clinical course was favourable on day 7 after the postoperative period the patient was discharged. RESULTS: A total of 66% were males, and the mean age was 60.6 years. The surgical procedure most commonly performed was sigmoidectomy. The mean stay was 5.5 days. There were no deaths during follow-up. The average estimated cost per day of stay in a HAH system was EUR 174.29 whilst the same average cost on a surgery ward stood at EUR 1,032.42. CONCLUSIONS: For patients undergoing major colorectal surgery with minimally invasive surgical technique, an early hospital discharge care programme by means of referral to a HAH unit is a safe and efficient care model which entails a significant cost saving for the public healthcare system.

Influence of mussel biological variability on pollution biomarkers.

This study deals with the identification and characterization of biological variables that may affect some of the biological responses used as pollution biomarkers. With this aim, during the 2012 mussel survey of the Spanish Marine Pollution monitoring program (SMP), at the North-Atlantic coast, several quantitative and qualitative biological variables were measured (corporal and shell indices, gonadal development and reserves composition). Studied biomarkers were antioxidant enzymatic activities (CAT, GST, GR), lipid peroxidation (LPO) and the physiological rates integrated in the SFG biomarker (CR, AE, RR). Site pollution was considered as the chemical concentration in the whole tissues of mussels. A great geographical variability was observed for the biological variables, which was mainly linked to the differences in food availability along the studied region. An inverse relationship between antioxidant enzymes and the nutritional status of the organism was evidenced, whereas LPO was positively related to nutritional status and, therefore, with higher metabolic costs, with their associated ROS generation. Mussel condition was also inversely related to CR, and therefore to SFG, suggesting that mussels keep an "ecological memory" from the habitat where they have been collected. No overall relationship was observed between pollution and biomarkers, but a significant overall effect of biological variables on both biochemical and physiological biomarkers was evidenced. It was concluded that when a wide range of certain environmental factors, as food availability, coexist in the same monitoring program, it determines a great variability in mussel populations which mask the effect of contaminants on biomarkers.

Identification and functional characterization of fish IL-17 receptors suggest important roles in the response to nodavirus infection.

Th17 is a lymphocyte T helper (Th) subpopulation relevant in the control and regulation of the immune response characterized by the production of interleukin (IL)-17. This crucial cytokine family acts through their binding to the IL-17 receptors (IL-17R), having up to six members. Although the biology of fish Th17 is well-recognized, the molecular and functional characterization of IL-17 and IL-17R has been limited. Thus, our aim was to identify and characterize the IL-17R repertory and regulation in the two main Mediterranean cultured fish species, the gilthead seabream (Sparus aurata) and the European sea bass (Dicentrarchus labrax). Our in silico results showed the clear identification of six members in each fish species, from IL-17RA to IL-17RE-like, with well-conserved gene structure and protein domains with their human orthologues. All of them showed wide and constitutive transcription in naïve tissues but with highest levels in mucosal tissues, namely skin, gill or intestine. In leucocytes, T mitogens showed the strongest up-regulation in most of the il17 receptors though il17ra resulted in inhibition by most stimulants. Interestingly, in vivo nodavirus infection resulted in alterations on the transcription of il17 receptors. While nodavirus infection led to some increments in the il17ra, il17rb, il17rc and il17rd transcripts in the susceptible European sea bass, many down-regulations were observed in the resistant gilthead seabream. Our data identify the presence and conservation of six coding IL-17R in gilthead seabream and European sea bass as well as their differential regulation in vitro and upon nodavirus infection. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-024-00225-1.

Evaluation of the Differential Postbiotic Potential of Shewanella putrefaciens Pdp11 Cultured in Several Growing Conditions.

The increased knowledge of functional foods has led to the development of a new generation of health products, including those containing probiotics and products derived from them. Shewanella putrefaciens Pdp11 (SpPdp11) is a strain described as a probiotic that exerts important beneficial effects on several farmed fish. However, the use of live probiotic cells in aquaculture has limitations such as uncertain survival and shelf life, which can limit their efficacy. In addition, its efficacy can vary across species and hosts. When probiotics are administered orally, their activity can be affected by the environment present in the host and by interactions with the intestinal microbiota. Furthermore, live cells can also produce undesired substances that may negatively impact the host as well as the risk of potential virulence reversion acquired such as antibiotic resistance. Therefore, new alternatives emerged such as postbiotics. Currently, there is no knowledge about the postbiotic potential of SpPdp11 in the aquaculture industry. Postbiotic refers to the use of bacterial metabolites, including extracellular products (ECPs), to improve host physiology. However, the production of postbiotic metabolites can be affected by various factors such as cultivation conditions, which can affect bacterial metabolism. Thus, the objective of this study was to evaluate the postbiotic potential of ECPs from SpPdp11 under different cultivation conditions, including culture media, temperature, growth phase, and salinity. We analyzed their hydrolytic, antibacterial, antiviral, and cytotoxic capacity on several fish cell lines. The results obtained have demonstrated how each ECP condition can exert a different hydrolytic profile, reduce the biofilm formation by bacterial pathogens relevant to fish, lower the titer of nervous necrosis virus (NNV), and exert a cytotoxic effect on different fish cell lines. In conclusion, the ECPs obtained from SpPdp11 have different capacities depending on the cultivation conditions used. These conditions must be considered in order to recover the maximum number of beneficial capacities or to choose the appropriate conditions for specific activities.

Application of transcriptomic profiling to investigate the toxicity mechanisms caused by dietary exposure of nanoplastics in fish.

Nowadays, nanoplastics (NPs) are one of the main concerns regarding plastic pollution. The increasing presence of plastic particles, fibers and fragments in the marine environment pose an additional risk to both, wild and cultured fish. Ingestion is the main mechanism by which particles are internalized. Thus, this study evaluated the impact of a diet containing NPs in one of the most cultivated species across the Mediterranean Sea, the European sea bass (Dicentrarchus labrax). Polystyrene NPs (50 nm) were supplied in the food for a period of 21 days and the transcriptomic changes were measured in the intestine through RNA-seq. Additionally, enzymatic and bactericidal activities were measured in the liver or serum, respectively of the same fish to evaluate the organism stress. No significant changes in the enzymatic activities were observed in the liver, whilst the seric bactericidal activity decreased by NPs dietary treatments. This suggests that ingestion of NPs at low dosages might have an impact on fish health. In addition, our data suggested that NPs impact some important biological pathways related to fish morphogenesis, organ development, membrane receptors, and fish immunity. These routes are extremely important for fish development and growth and can have long-term impact, since the early stages of fish are the most sensitive to this kind of pollution. This study provides information on the impact of the ingestion of NPs in sea bass and can serve as a basis for future investigations on the prevention and treatment of such pollutants in aquaculture.

Systemic lupus erythematosus and systemic autoimmune connective tissue disorders behind recurrent diastolic heart failure.

Diastolic heart failure (DHF) remains unexplained in some patients with recurrent admissions after full investigation. A study was directed for screening SLE and systemic autoimmune connective tissue disorders in recurrent unexplained DHF patients admitted at a short-stay and intermediate care unit. It was found that systemic autoimmune conditions explained 11% from all of cases. Therapy also prevented new readmissions. Autoimmunity should be investigated in DHF.

Allelochemicals of Alexandrium minutum: Kinetics of membrane disruption and photosynthesis inhibition in a co-occurring diatom.

Allelopathy is an efficient strategy by which some microalgae can outcompete other species. Allelochemicals from the toxic dinoflagellate Alexandrium minutum have deleterious effects on diatoms, inhibiting metabolism and photosynthesis and therefore give a competitive advantage to the dinoflagellate. The precise mechanisms of allelochemical interactions and the molecular target of allelochemicals remain however unknown. To understand the mechanisms, the short-term effects of A. minutum allelochemicals on the physiology of the diatom Chaetoceros muelleri were investigated. The effects of a culture filtrate were measured on the diatom cytoplasmic membrane integrity (polarity and permeability) using flow-cytometry and on the photosynthetic performance using fluorescence and absorption spectroscopy. Within 10 min, the unknown allelochemicals induced a depolarization of the cytoplasmic membranes and an impairment of photosynthesis through the inhibition of the plastoquinone-mediated electron transfer between photosystem II and cytochrome b6f. At longer time of exposure, the cytoplasmic membranes were permeable and the integrity of photosystems I, II and cytochrome b6f was compromised. Our demonstration of the essential role of membranes in this allelochemical interaction provides new insights for the elucidation of the nature of the allelochemicals. The relationship between cytoplasmic membranes and the inhibition of the photosynthetic electron transfer remains however unclear and warrants further investigation.

NK-lysin peptides ameliorate viral encephalopathy and retinopathy disease signs and provide partial protection against nodavirus infection in European sea bass.

Antimicrobial peptides (AMP) comprise a wide range of small molecules with direct antibacterial activity and immunostimulatory role and are proposed as promising substitutes of the antibiotics. Additionally, they also exert a role against other pathogens such as viruses and fungi less evaluated. NK-lysin, a human granulysin orthologue, possess a double function, taking part in the innate immunity as AMP and also as direct effector in the cell-mediated cytotoxic (CMC) response. This molecule is suggested as a pivotal molecule involved in the defence upon nervous necrosis virus (NNV), an epizootic virus provoking serious problems in welfare and health status in Asian and Mediterranean fish destined to human consumption. Having proved that NK-lysin derived peptides (NKLPs) have a direct antiviral activity against NNV in vitro, we aimed to evaluate their potential use as a prophylactic treatment for European sea bass (Dicentrarchus labrax), one of the most susceptible cultured-fish species. Thus, intramuscular injection of synthetic NKLPs resulted in a very low transcriptional response of some innate and adaptive immune markers. However, the injection of NKLPs ameliorated disease signs and increased fish survival upon challenge with pathogenic NNV. Although NKLPs showed promising results in treatments against NNV, more efforts are needed to understand their mechanisms of action and their applicability to the aquaculture industry.

Burnout Syndrome in Paediatric Nurses: A Multi-Centre Study.

BACKGROUND: Burnout syndrome is an increasingly prevalent problem, characterised by emotional exhaustion (EE), depersonalization (D), and low personal accomplishment (PA), feelings that appear with prolonged exposure to stress-inducing situations. The syndrome alters physical well-being and endangers the quality of services provided. Among nurses working in the paediatric area, the association between burnout and the corresponding risk profile has received little research attention, despite the highly stressful nature of this work. MATERIALS AND METHODS: The study population was composed of 95 nurses working in four hospitals in the province of Granada. Data were collected using the Maslach Burnout Inventory, the NEO Personality Inventory, and the Educational-Clinical Questionnaire: Anxiety and Depression. RESULTS: According to the results obtained, 22.0% of the nurses working in the paediatric area present high levels of EE, 18.5% present high levels of D, and 39.6% had feelings of low PA. These burnout levels do not depend on sociodemographic or labour variables, but the three domains of the syndrome are related to the psychological factors analysed. CONCLUSIONS: Among the nurses who participated in this study, 38.6% presented high levels of burnout, especially regarding feelings of low personal accomplishment. Personality factors play an important role in the development of this syndrome. This study shows the impact of burnout in paediatric nurses as well as the risk factors, providing information for the development of strategies to prevent it.

Nanoplastics exposure modulate lipid and pigment compositions in diatoms.

The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS-NH2) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 µg mL-1) and a high (5 µg mL-1) concentrations for 96 h. Results evidenced an impact on pigment composition associated to the light-harvesting function and photoprotection mainly at exponential phase. NP also impacted lipid composition of diatoms with a re-adjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol's at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly, exponential cultures exposed to high NP concentration showed an impairment of long chain fatty acids synthesis. Changes in pigment and lipid content of diatom' cells revealed that algae physiology is determinant in the way cells adjust their thylakoid membrane composition to cope with NP contamination stress. Compositions of reserve and membrane lipids are proposed as sensitive markers to assess the impact of NP exposure, including at potential predicted environmental doses, on marine organisms.