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Celery is a food allergen that must be included in the ingredient list of commercial food products in the European Union. This is a challenge for the food industry because of potential cross-contamination and undeclared ingredients because of their low concentrations. So, the food industry requires expedited high-performance analytical methods. The development, validation and application of a magnetic nanomaterial-based voltammetric immunosensor is reported to quantify a major celery allergen (Api g 1), achieving a low limit of detection (32 pg·mL-1, in a 40-µL sample). The applicability of the biosensor was evaluated by analysing twenty food products and the lowest Api g 1 content (1.1 ± 0.9 mg·kg-1) was quantified in a cooked sample. The selectivity of the method and the interference of similar fresh products (e.g., parsley, basil) were evaluated. This portable and easy-to-use biosensor can be a fit-for-purpose solution to tackle a major problem for the food industry.
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Ischemic heart disease represents a significant global burden of morbidity and mortality. While revascularization strategies are well defined in acute settings, there are uncertainties regarding chronic coronary artery disease treatment. Recent trials have raised doubts about the necessity of revascularization for "stable", chronic coronary syndromes or disease, leading to a shift towards a more conservative approach. However, the issue remains far from settled. In this narrative review, we offer a summary of the most pertinent evidence regarding revascularization for chronic coronary disease, while reflecting on less-often-discussed details of major clinical trials. The cumulative evidence available indicates that there can be a prognostic benefit from revascularization in chronic coronary syndrome patients, provided there is significant ischemia, as demonstrated by either imaging or coronary physiology. Trials that have effectively met this criterion consistently demonstrate a reduction in rates of spontaneous myocardial infarction, which holds both prognostic and clinical significance. The prognostic benefit of revascularization in patients with heart failure with reduced ejection fraction remains especially problematic, with a single contemporary trial favouring surgical revascularization. The very recent publication of a trial focused on revascularizing non-flow-limiting "vulnerable" plaques adds further complexity to the field. The ongoing debates surrounding revascularization in chronic coronary syndromes emphasize the importance of personalized strategies. Revascularization, added to the foundational pillar of medical therapy, should be considered, taking into account symptoms, patient preferences, coronary anatomy and physiology, ischemia tests and intra-coronary imaging.
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Observations of transiting gas giant exoplanets have revealed a pervasive depletion of methane1-4, which has only recently been identified atmospherically5,6. The depletion is thought to be maintained by disequilibrium processes such as photochemistry or mixing from a hotter interior7-9. However, the interiors are largely unconstrained along with the vertical mixing strength and only upper limits on the CH4 depletion have been available. The warm Neptune WASP-107b stands out among exoplanets with an unusually low density, reported low core mass10, and temperatures amenable to CH4, though previous observations have yet to find the molecule2,4. Here we present a JWST-NIRSpec transmission spectrum of WASP-107b that shows features from both SO2 and CH4 along with H2O, CO2, and CO. We detect methane with 4.2σ significance at an abundance of 1.0 ± 0.5 ppm, which is depleted by 3 orders of magnitude relative to equilibrium expectations. Our results are highly constraining for the atmosphere and interior, which indicate the envelope has a super-solar metallicity of 43 ± 8 × solar, a hot interior with an intrinsic temperature of Tint = 460 ± 40 K, and vigorous vertical mixing which depletes CH4 with a diffusion coefficient of Kzz = 1011.6±0.1 cm2 s-1. Photochemistry has a negligible effect on the CH4 abundance but is needed to account for the SO2. We infer a core mass of 11.5 - 3.6 + 3.0 M â , which is much higher than previous upper limits10, releasing a tension with core-accretion models11.
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(1) Background: The present scoping review aims to scrutinize all existing patient-reported outcomes and assess the perspectives of obstructive sleep apnea patients after maxillomandibular surgery. (2) Methods: The review was carried out according to the extensions for scoping reviews using the PRISMA-ScR guidelines. Several databases were used to carry out the initial search. This study included randomized controlled trials, cohort studies, cross-sectional and case-control studies. The included studies considered patients with obstructive sleep apnea who were submitted to orthognathic surgery as the main subjects, and the patient's perception of quality of life, satisfaction, treatment experience and side effects were assessed. (3) Results: From 1407 examined articles, a total of 16 were included. Most of the included studies used more than one questionnaire to assess quality of life, except for five articles. The most commonly referred instruments were the Epworth Sleepiness Scale, SF-36, the Functional Outcomes of Sleep and Ottawa Sleep Apnea. The most commonly assessed outcomes were sleep quality, daytime function, facial aesthetics, dental function and emotional health. (4) Conclusions: The number of variables that can be evaluated from a patient's perspective are endless, as are the tools available to assess them. Not all of these tools, which are generally questionnaires, assess all the various outcomes, and some do not compare the pre- and post-surgical situations. Most of them are generic and lack specificity for obstructive sleep apnea.
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May-Thurner syndrome (MTS) is caused by compression of the left common iliac vein by the right common iliac artery against the spinal column. It can range from asymptomatic or present with subtle and unspecific signs and symptoms and rarely exhibit severe complications such as pulmonary embolism (PE). The diagnosis is confirmed by typical imaging findings. Treatment may include conservative measures, anticoagulation, endovascular or even surgical options. We report the case of a 20-year-old female who presented with cardiac arrest caused by an acute massive PE. Further study showed partial thrombosis of the internal iliac veins resulting from MTS. She continued anticoagulation therapy with low-molecular-weight heparin and then switched to edoxaban with a good clinical outcome. She was also referred to Vascular Surgery to discuss the possibility of iliac vein stenting. Abdominopelvic vascular compression syndromes include a large spectrum of conditions, and they are rarely considered as an etiology for venous thromboembolism. The clinical presentation of PE varies with several triggering factors and atypical presentation is more common in nonmalignant causes. The combination of noninvasive and invasive imaging modalities might be beneficial to establish a definitive diagnosis. Nevertheless, invasive procedures are often restricted to doubtful cases or to guide endovascular procedures which is the current treatment of choice. There is little evidence using nonvitamin K oral anticoagulants, but there are some case reports detailing their successful use. This case aims to point out the need for a profound understanding of different causes of deep vein and pulmonary thromboembolism; common entities in our practice but with a variety of clinical presentations and potentially caused by rare underlying conditions. MTS can be the origin of serious and deadly complications, hence the importance of early recognition and treatment.
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Background: Coronary artery calcification is a predictor of adverse outcomes after percutaneous coronary intervention (PCI). Intravascular lithotripsy (IVL) is a promising tool for the treatment of calcified lesions. The aim of this study was to assess the effectiveness and safety of IVL. Methods: A single-center observational study of PCI procedure, with assessment of the outcomes of patients undergoing PCI using IVL, was performed. Angiographic procedural success was used as the primary effectiveness endpoint. The primary safety endpoint was defined as a composite of cardiac death, myocardial infarction and target vessel revascularization within 30 days. Results: A total of 111 patients were included. Indications for PCI spanned the spectrum of chronic (53.2%) and acute coronary syndromes (43%). Lesion preparation before IVL was performed with non-compliant (42%), cutting or OPN (14.4%) balloons and with atherectomy techniques in 11% of procedures. Intravascular imaging was used in 21.6% of procedures. The primary effectiveness endpoint was achieved in 100% and the primary safety endpoint in 3.6% of procedures. Peri-procedural complications were minimal and successfully resolved. Conclusions: IVL was an effective and safe technique for the treatment of calcified coronary lesions. These findings contribute to the growing body of evidence supporting the use of IVL in the management of these challenging scenarios.
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The Epstein-Barr virus (EBV) is a DNA virus that has been infecting humans since ancient times, capable of causing a wide range of pathologies and affecting approximately 90% of the population. A 61-year-old male with no significant medical history presented with a 5-day history of imbalance and difficulty walking. Neurological examination revealed specific findings, including absent reflexes, bilateral asynergy, and gait abnormalities. Contrasting with Guillain-Barré Syndrome, lumbar puncture suggested a central nervous system infection. Serological testing confirmed Epstein-Barr virus (EBV) positivity, and intravenous immunoglobulin led to significant improvement. Electromyogram results suggested inflammatory/ipnfectious polyradiculopathy. Repeat EBV serology, showing strongly positive IgG and negative IgM, confirmed the diagnosis of Polyradiculoneuropathy secondary to EBV. This case underscores the rare neurological complications of EBV and the importance of considering viral infections in such presentations.
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Objective To report the outcomes with high-dose-rate (HDR) brachytherapy (BT) treatment in patients with lower eyelid basal cell carcinoma (BCC) and to evaluate the relationship between dosimetric parameters and acute and late toxicities. Material and methods A retrospective unicentric study with patients diagnosed with lower eyelid biopsy-proven BCC treated with HDR BT between January 2012 and December 2019. The prescribed dose was 36 Gy to 40 Gy in 9 to 10 fractions, twice daily, over five days. The primary endpoint was local control, and the secondary endpoints were acute and late toxicities, registered according to CTCAE v4.0. The cosmetic result was evaluated on a qualitative scale (the CAIB scale). Local control was calculated according to the Kaplan-Meier test. Two sample T-tests and a Wilcoxon signed-rank test were used to determine the association between dosimetric parameters and side effects. Results Fifty-eight patients with a median age of 76 years were included. Among these patients, 55.2% received adjuvant HDR BT and 44.8% received radical HDR BT. At a median follow-up of 44 months, there were four local relapses, achieving a probability of local control at four years of 95% and 100% in the adjuvant and radical groups, respectively. Acute toxicity occurred in 76% of patients with only one grade 3 event (radiation dermatitis). Late toxicity was present in 56%. Eight patients underwent treatment for grade 3 cataracts during follow-up. Cosmetic results were excellent or very good in 93% of patients. Acute conjunctival hyperemia is strongly associated with the dose received by the ocular globe (volumes of 0.1cc, 1cc, and 2 cc) (p<0.05). Conclusion Lower eyelid BCC treatment with interstitial HDR BT is associated with excellent local control, acceptable long-term side effects, and good cosmetic results.
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BACKGROUND: Acute kidney injury (AKI) is a multifactorial condition often induced by drugs commonly used in hospitals. Identifying and staging AKI necessitates frequent monitoring of renal function. AIM: To assess the impact of real-world hospital practices regarding serum creatinine (SCr) testing on the identification and staging of AKI, and its implications for adjusting drug doses. METHOD: A historical cohort study utilizing hospital records from all adult patients admitted between 01/06/2018 and 31/12/2020 was conducted. Patients with no SCr assessment during their stay or those with an SCr at admission ≥ 2 mg/dL were excluded. AKI was determined using two criteria, namely AKIN and KDIGO, considering the time intervals between two SCr tests as outlined in the criteria. Additionally, patients with SCr increases exceeding AKI limits, regardless the time interval, were also identified. The estimated glomerular filtration rate (eGFR) and kinetic eGFR (KeGFR) were calculated. RESULTS: During the study period, 17,269 hospitalizations and 62,255 SCr tests were recorded. Among the 17,032 hospitalizations with a length of stay > 48 h, 46.8% experienced periods with no SCr tests performed for more than 48 h. Any stage of AKI was identified in 7.0% of patients and in 9.1% using AKI and KDIGO criteria, respectively. Ignoring time limits in both criteria revealed potential AKI in 1942 patients (11.2%), indicating a potential underdiagnosis of AKI by 37.5% or 19.1%, depending on the criteria used. A total of 76 drugs requiring dose adjustment in patients with eGFR ≤ 50 ml/min were prescribed in 78.5% admissions. These drugs were prescribed in 87.9% of patients potentially underdiagnosed with AKIN and in 88.9% with KDIGO. CONCLUSION: There is a need for changes in the established hospital procedures to ensure more frequent testing of SCr levels. Implementing an advanced scope of practice for clinical pharmacists could support these changes.
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Lesión Renal Aguda , Creatinina , Tasa de Filtración Glomerular , Humanos , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/sangre , Masculino , Femenino , Creatinina/sangre , Persona de Mediana Edad , Anciano , Estudios de Cohortes , Pacientes Internos , Hospitalización , Adulto , Anciano de 80 o más Años , Estudios RetrospectivosRESUMEN
Introduction: Empowerment lifestyle programs are needed to reduce the risk of hypertension. Our study compared the effectiveness of two empowerment-based approaches toward blood pressure (BP) reduction: salt reduction-specific program vs. healthy lifestyle general program. Methods: Three hundred and eleven adults (median age of 44 years, IQR 34-54 years) were randomly assigned to a salt reduction (n = 147) or a healthy lifestyle program (n = 164). The outcome measures were urinary sodium (Na+) and potassium (K+) excretion, systolic (SBP) and diastolic (DBP) blood pressure, weight, and waist circumference. Results: There were no significant differences in primary and secondary outcomes between the two program groups. When comparing each program to baseline, the program focused on salt reduction was effective in lowering BP following a 12-week intervention with a mean change of -2.5 mm Hg in SBP (95% CI, -4.1 to -0.8) and - 2.7 mm Hg in DBP (95% CI, -3.8 to -1.5) in the intention-to-treat (ITT) analysis. In the complete-case (CC) analysis, the mean change was -2.1 mm Hg in SBP (95% CI, -3.7 to -0.5) and - 2.3 mm Hg in DBP (95% CI, -3.4 to -1.1). This effect increases in subjects with high-normal BP or hypertension [SBP - 7.9 mm Hg (95% CI, -12.5 to -3.3); DBP - 7.3 mm Hg (95% CI, -10.2 to -4.4)]. The healthy lifestyle group also exhibited BP improvements after 12 weeks; however, the changes were less pronounced compared to the salt reduction group and were observed only for DBP [mean change of -1.5 mm Hg (95% CI, -2.6 to -0.4) in ITT analysis and - 1.4 mm Hg (95% CI, -2.4 to -0.3) in CC analysis, relative to baseline]. Overall, improvements in Na+/K+ ratio, weight, and Mediterranean diet adherence resulted in clinically significant SBP decreases. Importantly, BP reduction is attributed to improved dietary quality, rather than being solely linked to changes in the Na+/K+ ratio. Conclusion: Salt-focused programs are effective public health tools mainly in managing individuals at high risk of hypertension. Nevertheless, in general, empowerment-based approaches are important strategies for lowering BP, by promoting health literacy that culminates in adherence to the Mediterranean diet and weight reduction.
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Hipertensión , Adulto , Humanos , Persona de Mediana Edad , Presión Sanguínea , Hipertensión/prevención & control , Cloruro de Sodio Dietético , Evaluación de Resultado en la Atención de SaludRESUMEN
BACKGROUND: Coronary artery calcium (CAC) evaluated on dedicated cardiac computed tomography (CT) is an independent predictor of cardiovascular events. This study aimed to evaluate the correlation between CAC detected on non-gated standard chest CT and coronary lesions on coronary angiography (CAG) and determine its impact on prognosis. METHODS: Consecutive patients who underwent CAG due to acute coronary syndrome and had prior non-contrasted non-gated chest CT were included and retrospectively evaluated. Coronary artery calcium was evaluated by quantitative (Agatston score) and qualitative (visual assessment) assessment. RESULTS: A total of 114 patients were included in this study. The mean time difference between chest CT and CAG was 23 months. Coronary artery calcium was visually classified as mild, moderate, and severe in 31%, 33%, and 16% of patients, respectively. Moderate or severe CAC was an independent predictor of significant lesions on CAG (OR 22; 95% CI 8-61; p<0.001) and all-cause mortality (OR 4; 95% CI 2-9; p=0.001). Quantitative CAC evaluation accurately predicted significant lesions on CAG (AUC 0.81; p<0.001). While significant CAC was identified in 80% of chest CTs, formal reporting was 25%. CONCLUSION: Coronary artery calcium evaluation with chest CT was feasible and strongly associated with severity of coronary disease on CAG and mortality. Although the identification of CAC on chest CT represents a unique opportunity for cardiovascular risk stratification for preventive care, CAC underreporting is frequent.
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Enfermedad de la Arteria Coronaria , Calcificación Vascular , Humanos , Calcio , Vasos Coronarios/diagnóstico por imagen , Estudios Retrospectivos , Factores de Riesgo , Calcificación Vascular/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/complicaciones , Tomografía Computarizada por Rayos X , Angiografía Coronaria/métodos , Valor Predictivo de las PruebasRESUMEN
Axolotl limb regeneration is accompanied by the transient induction of cellular senescence within the blastema, the structure that nucleates regeneration. The precise role of this blastemal senescent cell (bSC) population, however, remains unknown. Here, through a combination of gain- and loss-of-function assays, we elucidate the functions and molecular features of cellular senescence in vivo. We demonstrate that cellular senescence plays a positive role during axolotl regeneration by creating a pro-proliferative niche that supports progenitor cell expansion and blastema outgrowth. Senescent cells impact their microenvironment via Wnt pathway modulation. Further, we identify a link between Wnt signaling and senescence induction and propose that bSC-derived Wnt signals facilitate the proliferation of neighboring cells in part by preventing their induction into senescence. This work defines the roles of cellular senescence in the regeneration of complex structures.
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Ambystoma mexicanum , Senescencia Celular , Animales , Ambystoma mexicanum/metabolismo , Vía de Señalización Wnt , Células Madre , Proliferación Celular , ExtremidadesRESUMEN
Introduction and objectives: Dietary supplements are part of the nutritional strategies frequently applied in sports performance support. With growing research on this subject and high demand from athletes, nutritionists need to keep up to date with the latest evidence and utility of dietary supplements, particularly in real-world contexts. As information about the use of dietary supplements among elite soccer players is still scarce, this work aimed to know how nutritionists working with elite soccer teams perceive and use these substances in their daily practice. Methods: A questionnaire previously used to describe nutritionists' beliefs and attitudes regarding the use of dietary supplements in a clinical context was adapted for this study. The online questionnaire was addressed to nutritionists working with elite soccer teams from six European Leagues and Brazil, between November 2022 and February 2023. Results: Overall, the participants considered themselves well-trained (76.9%), knowledgeable (95.4%), and interested in dietary supplements (95.4%). The majority (70.8%) of the participants agreed or strongly agreed to recommend dietary supplements to soccer players. Personal usage of dietary supplements was associated with recommending supplements (p < 0.001), but no relationships were found with years of experience and academic level. Discussion: Nutritionists working with elite soccer players consider the use of dietary supplements for performance-enhancement purposes and not only to compensate for nutritional deficits, which might contribute to their higher interest, training and perceived knowledge about this topic. Participants recognize players' interest in dietary supplements, and are mindful of the safety and efficacy of these products. The present study suggests that nutritionists working with elite soccer teams are among the highest prescribers of dietary supplements, although personal usage is lower than that of nutritionists working in a clinical context.
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Salmonella is present in the poultry production chain and is a major challenge in terms of food safety and animal health. The early Salmonella detection is one of the main tools to control and prevent the transmission of this pathogen. Microbiological isolation and serotyping to identify and differentiate Salmonella serovars are laborious processes, time-consuming, and expensive. Therefore, molecular diagnostic methods can be rapid and efficient alternatives to the detection of this pathogen. Thus, the aim herein was to standardize and evaluate the use of loop-mediated isothermal amplification (LAMP) in comparison with real-time PCR (qPCR) for detection of Salmonella associated with a multiplex qPCR for simultaneous identification and differentiation of S. Enteritidis, S. Typhimurium, S. Pullorum, and S. Gallinarum. The LAMP, qPCR, and multiplex qPCR assays were comparable in specificity. The three techniques were evaluated for specificity for 16 different serovars of Salmonella and for 37 strains of the serovars of interest. The limit of detection and the efficiency of the LAMP, qPCR, and multiplex qPCR reactions were determined. The techniques were applied to 33 samples of chicken carcasses and compared to the results of conventional microbiology for validation. As results, LAMP was specific in the detection of different Salmonella serovars but presented lower limit of detection ranging from 101 to 104 CFU/reaction. In comparison, qPCR could detect less cells (100 to 102 CFU/reaction), reaching equal specificity and better repeatability in the assays. The qPCR multiplexing for identification of the different serovars also showed good specificity, with the detection threshold between entre 101 and 102 CFU/reaction. The results obtained in the analyses on poultry carcasses suggested a correspondence between the results obtained in molecular methods and in conventional microbiology. Thus, the proposed assays are promising for the diagnosis of Salmonella in poultry carcasses, already proved to be faster and more efficient than conventional diagnostics techniques, being of great interest for poultry production, animal, and public health.
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Aves de Corral , Salmonella , Animales , Aves de Corral/microbiología , Serogrupo , Inocuidad de los Alimentos/métodos , Pollos/microbiología , Sensibilidad y EspecificidadRESUMEN
INTRODUCTION: Obesity is a chronic and multifactorial disease, and the COVID-19 pandemic and lockdown have led to changes in the lifestyle habits of those patients. This study aimed to compare compliance with dietary and lifestyle measures, physical activity, mental health status, and motivation to lose weight during the pandemic in these patients. METHODS: An observational study was conducted, which included 63 patients over 18 years old who were followed in the outpatient setting through obesity medical appointments and who agreed to answer a questionnaire. RESULTS: We found that the majority of patients lost weight during the pandemic (61.7%), associating it with a 68% change in dietary habits. Regarding physical activity, there was a 34.9% reduction in its practice among those who used to exercise before the pandemic. Moreover, 52.4% felt more anxious and 44.4% felt sadder during the lockdown. DISCUSSION: The weight loss reported in our study seems to be related to a decrease in the consumption of carbohydrates and snacks and a lower percentage of those who relied on takeaways. Additionally, we hypothesize a greater number of home-cooked meals. Regarding exercise, the closure of gyms and the limitations imposed on daily life appear to have contributed unfavorably to this matter. Home confinement, loneliness, and a lack of social activities had harmful effects on the mental health of our sample. CONCLUSION: Overall, the hostile influence of the pandemic on mental well-being and exercise habits was evident. Nevertheless, contrary to our expectations, we observed weight loss during the lockdown.
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Dietary supplements are widely used among athletes, and soccer players are no exception. Nevertheless, evidence supporting the use of dietary supplements aiming to enhance performance in soccer is somewhat contradictory, scarce, or even nonexistent. Thus, the present study aimed to systematically review and synthesize the effects of dietary supplements on athletic performance (e.g. distance covered, sprinting, jump performance) in elite soccer players. Studies enrolling highly trained, elite, and world-class soccer players using dietary supplements were searched in MEDLINE/PubMed, Web of Science, Scopus, and EBSCO databases in June 2022. In total, 1043 studies were identified, and 18 met the eligibility criteria. The studies evaluated the impacts on athletic performance of several dietary supplements, including caffeine, creatine, protein, beverages with carbohydrates and electrolytes, tart cherry juice, nitrate-rich beetroot juice, sodium bicarbonate with minerals, yohimbine, and a proprietary nutraceutical blend. Caffeine supplementation in doses between 3 and 6 mg/kg of body mass may improve jump height and sprint ability, particularly in female players, but individual response to caffeine must be considered. Creatine may improve sprint, agility, and in female players, jump performance. Protein supplementation can improve sprint and jump performance between matches, especially if protein ingested from food is not up to recommendations. Beverages containing carbohydrates and electrolytes can be used as part of the strategies to achieve carbohydrate intake during training and match-days but used alone do not benefit athletic performance. Tart cherry juice might be useful for maintaining athletic performance after matches that produce higher force loss and exercise-induced muscle damage, although polyphenols from the diet might attenuate the effects of tart cherry supplementation. Nitrate-rich beetroot concentrate can attenuate performance decrease in the days following matches. Further investigation with sodium bicarbonate alone is necessary, as supplementation protocols with elite players included other substances. Finally, the available data does not support yohimbine supplementation or the use of Resurgex Plus® to improve athletic performance in elite soccer players. Still, more well-designed research with elite soccer players is needed to improve support and advice regarding the use of dietary supplements for athletic performance enhancement.
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Rendimiento Atlético , Fútbol , Humanos , Femenino , Fútbol/fisiología , Cafeína/farmacología , Bicarbonato de Sodio , Creatina/farmacología , Nitratos , Rendimiento Atlético/fisiología , Suplementos Dietéticos , Electrólitos , CarbohidratosRESUMEN
Marine pollution by nanoparticles (NPs) can be reprotoxic for fish and disturb successful reproduction of wild populations. In gilthead seabream (Sparus aurata), a mild effect on sperm motility was observed after exposure to high concentrations of silver NPs. Considering the great heterogeneity traits within a sperm sample, it is possible that NPs affect spermatozoa accordingly, modulating subpopulation profile. Thus, this work aimed to analyse NP effects in sperm motility in general and considering spermatozoa population structure, using a subpopulation approach. Seabream sperm samples from mature males were exposed for 1 h to increasing concentrations of titanium dioxide (1, 10, 100, 1000 and 10,000 µg L-1) and silver (0.25, 25 and 250 µg L-1) NPs, including Ag NP and Ag+, dissolved in a non-activating medium (0.9 % NaCl). Concentrations chosen include realistic (10-100 and 0.25 µg L-1, respectively, for TiO2 and Ag) and supra-environmental values. The mean particle diameter was determined as 19.34 ± 6.72 and 21.50 ± 8.27 nm in the stock suspension, respectively, for titanium dioxide and silver. After the ex vivo exposure, sperm motility parameters were determined using computer-assisted sperm analysis, and sperm subpopulations were later identified using a two-step cluster analysis. Results revealed a significant reduction in total motility after exposure to the 2 highest concentrations of titanium dioxide NPs, while curvilinear and straight-line velocities were not altered. Exposure to silver NPs (Ag NP and Ag+) lowered significantly total and progressive motilities at all concentrations, while curvilinear and straight-line velocities were significantly lower only at the highest concentration. Sperm subpopulations were also affected by the exposure to both titanium dioxide and silver NPs. In both cases, the highest levels of NPs triggered a decrease in the percentage of fast sperm subpopulations (38.2% in TiO2 1000 µg L-1, 34.8.% in Ag NP 250 µg L-1, and 45.0% in Ag+ 250 µg L-1 vs 53.4% in the control), while an increase on slow sperm subpopulations. A reprotoxic effect was proven for both NPs, but only at supra-environmental concentrations.
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The present study aimed to evaluate the reprotoxicity of environmental (0.25 µg.L-1) and supra-environmental (25 µg.L-1 and 250 µg.L-1) levels of silver nanoparticles (Ag NP) on the Pacific oyster (Magallana gigas), by determining sperm quality. For that, we evaluated sperm motility, mitochondrial function and oxidative stress. To determine whether the Ag toxicity was related to the NP or its dissociation into Ag ions (Ag+), we tested the same concentrations of Ag+. We observed no dose-dependent responses for Ag NP and Ag+, and both impaired sperm motility indistinctly without affecting mitochondrial function or inducing membrane damage. We hypothesize that the toxicity of Ag NP is mainly due to adhesion to the sperm membrane. Blockade of membrane ion channels may also be a mechanism by which Ag NP and Ag+ induce toxicity. The presence of Ag in the marine ecosystem is of environmental concern as it may affect reproduction in oysters.