Early-onset neonatal sepsis: Effectiveness of classification based on ante- and intrapartum risk factors and clinical monitoring.

INTRODUCTION: In 2017, the French public health authority HAS published new guidelines for the management of newborns at risk of early bacterial neonatal infection. These guidelines were based on ante- and intrapartum risk factors and clinical monitoring. In January 2021, we implemented a new protocol based on these guidelines in our tertiary maternity unit. OBJECTIVES: To assess the impact of the protocol implemented on neonates' antibiotic prescriptions. METHOD: An "old protocol" group comprising newborns hospitalized between July 1, 2020 and December 31, 2020, was compared to a "new protocol" group formed between January 14, 2021 and July 13, 2021. Data were collected on infectious risk factors, antibiotic prescriptions, and emergency room visits within 2 weeks for an infection or suspected infection. RESULTS: The "old protocol" population comprised 1565 children and the "new protocol" population 1513. Antibiotic therapy was prescribed for 29 newborns (1.85 %) in the old protocol group versus 15 (0.99 %) in the new one (p = 0.05). The median duration was 5 days and 2 days respectively (p = 0.08). With the new protocol, newborns in category B were about 20 times more likely (p = 0.01), and those in category C about 54 times more likely (p = 0.005) to have an infection than those classified in categories N or A. CONCLUSION: This study demonstrates that clinical monitoring criteria enable reduced use and duration of antibiotic therapy and are reliable.

Reossification of Bone Defects After Surgical Correction of Nonsyndromic Craniosynostosis: A Review and An Original Study.

BACKGROUND AND OBJECTIVES: Surgical correction of nonsyndromic craniosynostosis (NSC) aims to restore cranial shape. Reossification of bone defects is paramount for the best aesthetic prognosis. However, the literature on the quantitative evaluation of bone defects after NSC surgery is scarce. This study aimed to quantify and analyze the surface area of bone defects after NSC surgery and establish a threshold value for predicting persistent defects. METHODS: We conducted a systematic review and a prospective study of 28 children undergoing surgical treatment for NSC. We analyzed 426 defects on the first computed tomography scan (1 year postoperative) and 132 defects on the second computed tomography scan (4.6 years postoperative). Statistical analysis was performed using Spearman's rank correlation coefficient, Mann-Whitney-Wilcoxon rank-sum test, and Youden's J statistic. RESULTS: Our systematic review identified three studies reporting on bone defects' surface area and reossification rate. In our study, we found no statistically significant differences in the number or size of defects between sex or type of NSC. The threshold value for the surface area of bone defects above which there was a higher probability of persistent defects was 0.19 cm2 (Youden point), with an 89.47 % probability of persistence. Defects with a surface area below 0.19 cm2 had a considerably lower probability, only 15.07%, of persistence over time. CONCLUSION: Our study provides valuable quantitative data for managing bone defects after NSC surgery. Defects with a surface area above 0.19 cm2 should be monitored with radiological imaging because of the risk of persistence. Our findings highlight the importance of developing robust and reproducible methods for the quantitative analysis of bone defects after NSC surgery.

The use of a complex tetra-culture alveolar model to study the biological effects induced by gold nanoparticles with different physicochemical properties.

A substantial increase in engineered nanoparticles in consumer products has been observed, heightening human and environmental exposure. Inhalation represents the primary route of human exposure, necessitating a focus on lung toxicity studies. However, to avoid ethical concerns the use of in vitro models is an efficient alternative to in vivo models. This study utilized an in vitro human alveolar barrier model at air-liquid-interface with four cell lines, for evaluating the biological effects of different gold nanoparticles. Exposure to PEGylated gold nanospheres, nanorods, and nanostars did not significantly impact viability after 24 h, yet all AuNPs induced cytotoxicity in the form of membrane integrity impairment. Gold quantification revealed cellular uptake and transport. Transcriptomic analysis identified gene expression changes, particularly related to the enhancement of immune cells. Despite limited impact, distinct effects were observed, emphasizing the influence of nanoparticles physicochemical parameters while demonstrating the model's efficacy in investigating particle biological effects.

A broad-taxa approach as an important concept in ecotoxicological studies and pollution monitoring.

Aquatic invertebrates play a pivotal role in (eco)toxicological assessments because they offer ethical, cost-effective and repeatable testing options. Additionally, their significance in the food chain and their ability to represent diverse aquatic ecosystems make them valuable subjects for (eco)toxicological studies. To ensure consistency and comparability across studies, international (eco)toxicology guidelines have been used to establish standardised methods and protocols for data collection, analysis and interpretation. However, the current standardised protocols primarily focus on a limited number of aquatic invertebrate species, mainly from Arthropoda, Mollusca and Annelida. These protocols are suitable for basic toxicity screening, effectively assessing the immediate and severe effects of toxic substances on organisms. For more comprehensive and ecologically relevant assessments, particularly those addressing long-term effects and ecosystem-wide impacts, we recommended the use of a broader diversity of species, since the present choice of taxa exacerbates the limited scope of basic ecotoxicological studies. This review provides a comprehensive overview of (eco)toxicological studies, focusing on major aquatic invertebrate taxa and how they are used to assess the impact of chemicals in diverse aquatic environments. The present work supports the use of a broad-taxa approach in basic environmental assessments, as it better represents the natural populations inhabiting various ecosystems. Advances in omics and other biochemical and computational techniques make the broad-taxa approach more feasible, enabling mechanistic studies on non-model organisms. By combining these approaches with in vitro techniques together with the broad-taxa approach, researchers can gain insights into less-explored impacts of pollution, such as changes in population diversity, the development of tolerance and transgenerational inheritance of pollution responses, the impact on organism phenotypic plasticity, biological invasion outcomes, social behaviour changes, metabolome changes, regeneration phenomena, disease susceptibility and tissue pathologies. This review also emphasises the need for harmonised data-reporting standards and minimum annotation checklists to ensure that research results are findable, accessible, interoperable and reusable (FAIR), maximising the use and reusability of data. The ultimate goal is to encourage integrated and holistic problem-focused collaboration between diverse scientific disciplines, international standardisation organisations and decision-making bodies, with a focus on transdisciplinary knowledge co-production for the One-Health approach.

Transfemoral versus trans-subclavian access in transcatheter aortic valve implantation using self-expandable valve: A propensity-matched comparison.

BACKGROUND: Transcatheter aortic valve implantation is unfeasible for 10-15% of patients using the conventional transfemoral approach. Other alternative approaches, such as the subclavian approach, have emerged, with no clear recommendation indicating the superiority of one technique over another. AIM: To compare the 1-month mortality and postprocedural outcomes of patients undergoing transcatheter aortic valve implantation using a self-expandable valve via transfemoral and subclavian access. METHODS: This was a retrospective single-centre study including 1496 patients who underwent transcatheter aortic valve implantation between January 2016 and December 2020 at Clermont-Ferrand University Hospital, France. Propensity score matching was used to compare transfemoral and subclavian access. RESULTS: After building two propensity score-matched groups of 221 patients each with either access route (total n=442), baseline characteristics were similar. The procedure duration was significantly longer in the subclavian access group (53 [45-64] versus 60 [51-72] minutes; P<0.001), but with a lower amount of contrast agent (138 [118-165] versus 123 [105-150] mL; P<0.001), fluoroscopy time (11.2 [9-14] versus 9.9 [7-12] minutes; P<0.001) and radiation dose (397 [264-620] versus 321 [217-485] mGy; P<0.001). No significant difference was observed concerning 1-month mortality (odds ratio 1.62, 95% confidence interval 0.52-5.03; P=0.39) or periprocedural complications. Follow-up at 1 year confirmed no difference in longer-term mortality (hazard ratio 0.78, 95% confidence interval 0.52-5.03; P=0.43). CONCLUSIONS: The subclavian approach provides similar results to the transfemoral approach in terms of mortality, efficacy and safety; it is a reasonable and effective alternative when the reference transfemoral approach is impossible or seems complex.

Prescription-free consultation: A cross-sectional study in general practice.

PURPOSE: In 2005, 10% of consultations in France ended without a prescription. In 2019, a review of the literature found 30 to 70% of prescription-free consultations in Northern Europe and 10 to 22% in Southern Europe and underlined the scarcity of quantitative data. Different factors contribute to this heterogeneity, such as product availability and status, modes of management, distribution channels, clinical practice recommendations, public policies targeting certain classes, etc. The main objective of our study was to quantify the rate of prescription-free consultations in general practice in France in 2021. The secondary objective was to characterize prescription-free consultations and analyze their determinants. METHODS: This was a quantitative observational study conducted using self-questionnaires among patients in medical practices in Auvergne. RESULTS: Out of 540 questionnaires, the rate of prescription-free consultations was 24% (95% CI [20.11-27.41]). Prescription-free consultations were for prevention, administrative problems, and gestures. The limiting factors are "feeling a need for a medication" (OR=0,006), "not knowing if a medication is needed" (OR=0.11) and "consultations for acute reasons" (OR=0.33). CONCLUSION: Acute consultations limit prescription-free consultations. General practitioners (GPs) probably overestimate patients' expectation of drug prescription. The French GP must be supported in their decision to not prescribe drugs. This is a long-term investment of time, to educate patients and avoid new consultations for acute reasons. A tool to help doctors manage non-prescription during acute consultations will be created in a future study in France.

Assessing the effects of silver nanoparticles on the ecophysiology of Gammarus roeseli.

Being part of the macrobenthic fauna, gammarids are efficient indicators of contamination of aquatic ecosystems by nanoparticles that are likely to sediment on the bottom. The present study investigates the effects of silver nanoparticles (nAg) on ecophysiological functions in Gammarus roeseli by using a realistic scenario of contamination. Indeed, an experiment was conducted during 72 h, assessing the effects of 5 silver nAg from 10 to 100 nm diluted at concentrations of maximum 5 µg L-1 in a natural water retrieved from a stream and supplemented with food. The measured endpoints in gammarids were survival, silver concentrations in tissues, consumption of oxygen and ventilation of gills. Additionally, a set of biomarkers of the energetic metabolism was measured. After a 72-h exposure, results showed a concentration-dependent increase of silver levels in G. roeseli that was significant for the smallest nAg size (10 nm). Ecophysiological responses in G. roeseli were affected and the most striking effect was a concentration-dependent increase in oxygen consumption especially for the smallest nAg (10 to 40 nm), whereas ventilation of gills by gammarids was not changed. The potential mechanisms underlying these findings are discussed. Thus, we demonstrated the very low exposure concentration of 0.5 µg L-1 for the small nAg size led to significant ecophysiological effects reinforcing the need to further investigate subtle effects on nanoparticles on aquatic organisms.

Maximizing the relevance and reproducibility of A549 cell culture using FBS-free media.

Scientists are using in vitro methods to answer important research questions and implementing strategies to maximize the reliability and human relevance of these methods. One strategy is to replace the use of fetal bovine serum (FBS)-an undefined and variable mixture of biomolecules-in cell culture media with chemically defined or xeno-free medium. In this study, A549 cells, a human lung alveolar-like cell line commonly used in respiratory research, were transitioned from a culture medium containing FBS to media without FBS. A successful transition was determined based on analysis of cell morphology and functionality. Following transition to commercially available CnT-Prime Airway (CELLnTEC) or X-VIVO™ 10 (Lonza) medium, the cells were characterized by microscopic evaluation and calculation of doubling time. Their genotype, morphology, and functionality were assessed by monitoring the expression of gene markers for lung cell types, surfactant production, cytokine release, the presence of multilamellar bodies, and cell viability following sodium dodecyl sulphate exposure. Our results showed that A549 cells successfully transitioned to FBS-free media under submerged and air-liquid-interface conditions. Cells grown in X-VIVO™ 10 medium mimicked cellular characteristics of FBS-supplemented media while those grown in CnT-Prime Airway medium demonstrated characteristics possibly more reflective of normal human alveolar epithelial cells.

Methodological Issues in Analyzing Real-World Longitudinal Occupational Health Data: A Useful Guide to Approaching the Topic.

Ever greater technological advances and democratization of digital tools such as computers and smartphones offer researchers new possibilities to collect large amounts of health data in order to conduct clinical research. Such data, called real-world data, appears to be a perfect complement to traditional randomized clinical trials and has become more important in health decisions. Due to its longitudinal nature, real-world data is subject to specific and well-known methodological issues, namely issues with the analysis of cluster-correlated data, missing data and longitudinal data itself. These concepts have been widely discussed in the literature and many methods and solutions have been proposed to cope with these issues. As examples, mixed and trajectory models have been developed to explore longitudinal data sets, imputation methods can resolve missing data issues, and multilevel models facilitate the treatment of cluster-correlated data. Nevertheless, the analysis of real-world longitudinal occupational health data remains difficult, especially when the methodological challenges overlap. The purpose of this article is to present various solutions developed in the literature to deal with cluster-correlated data, missing data and longitudinal data, sometimes overlapped, in an occupational health context. The novelty and usefulness of our approach is supported by a step-by-step search strategy and an example from the Wittyfit database, which is an epidemiological database of occupational health data. Therefore, we hope that this article will facilitate the work of researchers in the field and improve the accuracy of future studies.

Does metaphyseal modularity in femoral revision stems have a role in treating bone defects less severe than IIIB? Clinical and radiological results of a series of 163 modular femoral stems.

INTRODUCTION: Revision for loosening of femoral stems requires an extensive analysis of bone defects to determine the most appropriate course of action. The drawbacks of using modular stems are that they can break or corrode at their junction. They have rarely been evaluated based on the extent of bone loss and particularly in patients with less severe bone loss. This led us to carry out a retrospective study to analyze modular femoral stems as a function of the initial bone defect (stage IIIB versus less severe in the Paprosky classification): 1) implant survivorship, 2) osteointegration and subsidence of the stem, and 3) breakage of implant. HYPOTHESIS: Modular femoral stems can be used for all types of bone defects (not only IIIB) as the complication rate is identical. PATIENTS AND METHODS: Between January 1, 1996, and December 31, 2016, 163 patients were included who had received a modular femoral revision stem. The minimum follow-up was 4 years; the mean was 6.7 years±3.3 [4-21]. One patient was lost to follow-up, 88 had died before the analysis date and 74 were still alive; however, 10 of them had the stem removed less than 4 years after implantation. Thus 64 patients were available for the clinical evaluation. There were 44% (72 patients) with Paprosky stage IIIB femoral bone loss and 56% (91 patients) with stage I, II or IIIA bone loss. The stem's bone integration was evaluated using the Engh and Massin score. All complications were documented. RESULTS: The survivorship of the femoral stem was 93.75% (95% CI: 83.33-96.70) at 5 years with removal for any reason as the end point. There was no significant difference (p=0.0877) in survivorship relative to the severity of the initial bone loss: 89.84% (95% CI: 78.73-95.31) for stage IIIB; 95.23% (95% CI: 82.24-98.79) for stage IIIA; 97.06% (95% CI: 80.90-99.58) for stage II. Bone integration was considered as being achieved in 76% of stems based on available radiographs (119 of 156 patients) with the severity of bone loss having no effect. We found 18 instances of stem subsidence out of 156 stems with available data (11.5%). The mean subsidence was 14.7 mm ± 12.3 [5-40]. Among the 18 stems with postoperative subsidence, 13 had been implanted for stage IIIB defects, while 5 were for less severe defects (p=0.751). Two stem fractures occurred in patients with stage IIIB bone loss, thus 2/66 for stage IIIB and 0/86 in the less severe bone loss cases (p=0.188). CONCLUSION: Modularity provides similar results no matter the severity of initial bone loss, without the risk of additional complications. LEVEL OF EVIDENCE: IV, Retrospective study.

Exploration of the co-structuring and stabilising role of flaxseed gum in whey protein isolate based cryo-hydrogels.

In the present work, the structuring and stabilising potential of flaxseed gum (FG) in whey protein isolate (WPI) cryo-hydrogels was investigated. The FG presence (0.1-1% wt.) in the heat-treated WPI dispersions (10% wt.) induced strong segregative phase separation phenomena, which were associated with a depletion flocculation mechanism. The cryotropic processing of the WPI-FG solutions led to the formation of diverse macroporous protein gel networks depending on the colloidal state of their biopolymeric precursors. Cryogel formation was primarily mediated via covalent (thiol-disulphide bond) bridging, whilst to a lesser extent, non-covalent interactions contributed to the overall stabilisation of the protein gel network. Although FG had a rather minor contribution to the formation of elastically active crosslinks (FG was partitioning mainly into the serum phase located in the macropores), its presence (at concentrations ≥0.75% wt.) improved the homogeneity and interconnectivity of the stranded protein network, whilst it reduced its colloidal instability and macroporosity.

eDOL mHealth App and Web Platform for Self-monitoring and Medical Follow-up of Patients With Chronic Pain: Observational Feasibility Study.

BACKGROUND: Chronic pain affects approximately 30% of the general population, severely degrades quality of life (especially in older adults) and professional life (inability or reduction in the ability to work and loss of employment), and leads to billions in additional health care costs. Moreover, available painkillers are old, with limited efficacy and can cause significant adverse effects. Thus, there is a need for innovation in the management of chronic pain. Better characterization of patients could help to identify the predictors of successful treatments, and thus, guide physicians in the initial choice of treatment and in the follow-up of their patients. Nevertheless, current assessments of patients with chronic pain provide only fragmentary data on painful daily experiences. Real-life monitoring of subjective and objective markers of chronic pain using mobile health (mHealth) programs can address this issue. OBJECTIVE: We hypothesized that regular patient self-monitoring using an mHealth app would lead physicians to obtain deeper understanding and new insight into patients with chronic pain and that, for patients, regular self-monitoring using an mHealth app would play a positive therapeutic role and improve adherence to treatment. We aimed to evaluate the feasibility and acceptability of a new mHealth app called eDOL. METHODS: We conducted an observational study to assess the feasibility and acceptability of the eDOL tool. Patients completed several questionnaires using the tool over a period of 2 weeks and repeated assessments weekly over a period of 3 months. Physicians saw their patients at a follow-up visit that took place at least 3 months after the inclusion visit. A composite criterion of the acceptability and feasibility of the eDOL tool was calculated after the completion of study using satisfaction surveys from both patients and physicians. RESULTS: Data from 105 patients (of 133 who were included) were analyzed. The rate of adherence was 61.9% (65/105) after 3 months. The median acceptability score was 7 (out of 10) for both patients and physicians. There was a high rate of completion of the baseline questionnaires and assessments (mean 89.3%), and a low rate of completion of the follow-up questionnaires and assessments (63.8% (67/105) and 61.9% (65/105) respectively). We were also able to characterize subgroups of patients and determine a profile of those who adhered to eDOL. We obtained 4 clusters that differ from each other in their biopsychosocial characteristics. Cluster 4 corresponds to patients with more disabling chronic pain (daily impact and comorbidities) and vice versa for cluster 1. CONCLUSIONS: This work demonstrates that eDOL is highly feasible and acceptable for both patients with chronic pain and their physicians. It also shows that such a tool can integrate many parameters to ensure the detailed characterization of patients for future research works and pain management. TRIAL REGISTRATION: ClinicalTrial.gov NCT03931694; http://clinicaltrials.gov/ct2/show/NCT03931694.

The Negative Impact of Night Shifts on Diet in Emergency Healthcare Workers.

Despite the consequences of night-shift work, the diet of night-shift workers has not been widely studied. To date, there are no studies related to food intake among emergency healthcare workers (HCWs). We performed a prospective observational study to assess the influence of night work on the diet of emergency HCWs. We monitored 24-h food intake during a day shift and the consecutive night, and during night work and the daytime beforehand. We analyzed 184 emergency HCWs' food intakes. Emergency HCWs had 14.7% lower (-206 kcal) of their 24-h energy intake during night shifts compared to their day-shift colleagues (1606.7 ± 748.2 vs. 1400.4 ± 708.3 kcal, p = 0.049) and a 16.7% decrease in water consumption (1451.4 ± 496.8 vs. 1208.3 ± 513.9 mL/day, p = 0.010). Compared to day shifts, night-shift had 8.7% lower carbohydrates, 17.6% proteins, and 18.7% lipids. During the night shift the proportion of emergency HCWs who did not drink for 4 h, 8 h and 12 h increased by 20.5%, 17.5%, and 9.1%, respectively. For those who did not eat for 4 h, 8 h and 12 h increased by 46.8%, 27.7%, and 17.7%, respectively. A night shift has a huge negative impact on both the amount and quality of nutrients consumed by emergency healthcare workers.

Physiological and histopathological alterations in male Swiss mice after exposure to titanium dioxide (anatase) and zinc oxide nanoparticles and their binary mixture.

Existing studies have shown the systemic damage of titanium dioxide (TiO2) or zinc oxide (ZnO) nanoparticles (NPs), but there is little or no existing knowledge on the potential adverse toxic effects of the mixture of the two. In order to investigate the in vivo toxic effect of the mixture of TiO2 NPs and ZnO NPs, the acute toxicities of TiO2 NPs, ZnO NPs by themselves, and their mixture (1:1) were determined. The systemic toxicities of the individual NPs and mixture were evaluated in mice using hematological indices, hepatic, renal, and lipid profile parameters, and histopathology as endpoints. NPs were intraperitoneally administered at doses of 9.38, 18.75, 37.50, 75.00, and 150.00 mg/kg bw each. Individual NPs and their mixture were administered daily for 5 and 10 d, respectively. The LD50 of ZnO NPs was 299.9 mg/kg while TiO2 NPs by themselves or TiO2 NPs + ZnO NPs were indeterminate due to the absence of mortality of the male mice treated. TiO2 NPs, ZnO NPs by themselves and TiO2 NPs + ZnO NPs induced significant alterations in the hematological and biochemical parameters, with higher toxicity at 10 d. Histopathological lesions were observed in the liver, kidneys, spleen, heart, and brain of mice treated with the individual NPs and their mixture. TiO2 NPs + ZnO NPs were able to induce a higher systemic toxicity than TiO2 NPs or ZnO NPs individually. Our data suggest that more comprehensive risk assessments should be carried out on the mixture of NPs before utilization in consumer products.

npSCOPE: A New Multimodal Instrument for In Situ Correlative Analysis of Nanoparticles.

Over the last few decades, nanoparticles have become a key element in a number of scientific and technological fields, spanning from materials science to life sciences. The characterization of nanoparticles or samples containing nanoparticles, in terms of morphology, chemical composition, and other parameters, typically involves investigations with various analytical tools, requiring complex workflows and extending the duration of such studies to several days or even weeks. Here, we report on the development of a new unique in situ correlative instrument, allowing us to answer questions about the shape, size, size distribution, and chemical composition of the nanoparticles using a single probe. Combining various microscopic and analytical capabilities in one single instrument allows a considerable increase in flexibility and a reduction in the duration of such complex investigations. The new instrument is based on focused ion beam microscopy technology using a gas field ion source as a key enabler and combining it with specifically developed secondary ion mass spectrometry and scanning transmission ion microscopy technology. We will present the underlying concept, the instrument and its main components, and proof-of-concept studies performed on this novel instrument. For this purpose, different pure titanium dioxide nanoparticle samples were investigated. Furthermore, the distribution and localization of the nanoparticles in biological model systems were studied. Our results demonstrate the performance and usefulness of the instrument for nanoparticle investigations, paving the way for a number of future applications, in particular, nanotoxicological research.

Physico-chemical properties and toxicological effects on plant and algal models of carbon nanosheets from a nettle fibre clone.

Carbon nanosheets are two-dimensional nanostructured materials that have applications as energy storage devices, electrochemical sensors, sample supports, filtration membranes, thanks to their high porosity and surface area. Here, for the first time, carbon nanosheets have been prepared from the stems and leaves of a nettle fibre clone, by using a cheap and straight-forward procedure that can be easily scaled up. The nanomaterial shows interesting physical parameters, namely interconnectivity of pores, graphitization, surface area and pore width. These characteristics are similar to those described for the nanomaterials obtained from other fibre crops. However, the advantage of nettle over other plants is its fast growth and easy propagation of homogeneous material using stem cuttings. This last aspect guarantees homogeneity of the starting raw material, a feature that is sought-after to get a nanomaterial with homogeneous and reproducible properties. To evaluate the potential toxic effects if released in the environment, an assessment of the impact on plant reproduction performance and microalgal growth has been carried out by using tobacco pollen cells and the green microalga Pseudokirchneriella subcapitata. No inhibitory effects on pollen germination are recorded, while algal growth inhibition is observed at higher concentrations of leaf carbon nanosheets with lower graphitization degree.

Stem cells of aquatic invertebrates as an advanced tool for assessing ecotoxicological impacts.

Environmental stressors are assessed through methods that quantify their impacts on a wide range of metrics including species density, growth rates, reproduction, behaviour and physiology, as on host-pathogen interactions and immunocompetence. Environmental stress may induce additional sublethal effects, like mutations and epigenetic signatures affecting offspring via germline mediated transgenerational inheritance, shaping phenotypic plasticity, increasing disease susceptibility, tissue pathologies, changes in social behaviour and biological invasions. The growing diversity of pollutants released into aquatic environments requires the development of a reliable, standardised and 3R (replacement, reduction and refinement of animals in research) compliant in vitro toolbox. The tools have to be in line with REACH regulation 1907/2006/EC, aiming to improve strategies for potential ecotoxicological risks assessment and monitoring of chemicals threatening human health and aquatic environments. Aquatic invertebrates' adult stem cells (ASCs) are numerous and can be pluripotent, as illustrated by high regeneration ability documented in many of these taxa. This is of further importance as in many aquatic invertebrate taxa, ASCs are able to differentiate into germ cells. Here we propose that ASCs from key aquatic invertebrates may be harnessed for applicable and standardised new tests in ecotoxicology. As part of this approach, a battery of modern techniques and endpoints are proposed to be tested for their ability to correctly identify environmental stresses posed by emerging contaminants in aquatic environments. Consequently, we briefly describe the current status of the available toxicity testing and biota-based monitoring strategies in aquatic environmental ecotoxicology and highlight some of the associated open issues such as replicability, consistency and reliability in the outcomes, for understanding and assessing the impacts of various chemicals on organisms and on the entire aquatic environment. Following this, we describe the benefits of aquatic invertebrate ASC-based tools for better addressing ecotoxicological questions, along with the current obstacles and possible overhaul approaches.

Sub-chronic effects of AgNPs and AuNPs on Gammarus fossarum (Crustacea Amphipoda): From molecular to behavioural responses.

The aim of the present study was the assessment of the sub-chronic effects of silver (AgNPs) and gold nanoparticles (AuNPs) of 40 nm primary size either stabilised with citrate (CIT) or coated with polyethylene glycol (PEG) on the freshwater invertebrate Gammarus fossarum. Silver nitrate (AgNO3) was used as a positive control in order to study the contribution of silver ions potentially released from AgNPs on the observed effects. A multibiomarker approach was used to assess the long-term effects of AgNPs and AuNPs 40 nm on molecular, cellular, physiological and behavioural responses of G. fossarum. Specimen of G. fossarum were exposed for 15 days to 0.5 and 5 µgL-1 of CIT and PEG AgNPs and AuNPs 40 nm in the presence of food. A significant uptake of both Ag and Au was observed in exposed animals but was under the toxic threshold leading to mortality of G. fossarum. Silver nanoparticles (CIT-AgNPs and PEG-AgNPs 40 nm) led to an up-regulation of Na+K+ATPase gene expression. An up-regulation of Catalse and Chitinase gene expressions due to exposure to PEG-AgNPs 40 nm was also observed. Gold nanoparticles (CIT and PEG-AuNPs 40 nm) led to an increase of CuZnSOD gene expression. Furthermore, both AgNPs and AuNPs led to a more developed digestive lysosomal system indicating a general stress response in G. fossarum. Both AgNPs and AuNPs 40 nm significantly affected locomotor activity of G. fossarum while no effects were observed on haemolymphatic ions and ventilation.

Repeated exposure of Caco-2 versus Caco-2/HT29-MTX intestinal cell models to (nano)silver in vitro: Comparison of two commercially available colloidal silver products.

Colloidal silver products are sold for a wide range of disinfectant and health applications. This has increased the potential for human exposure to silver nanoparticles (AgNPs) and ions (Ag+), for which oral ingestion is considered to be a major route of exposure. Our objective was to evaluate and compare the toxicity of two commercially available colloidal silver products on two human intestinal epithelial models under realistic exposure conditions. Mesosilver™ and AgC were characterized and a concentration range between 0.1 and 12 µg/mL chosen. Caco-2 cells vs. co-culture of Caco-2 and mucus-secreting HT29-MTX cells (90/10) were used. Repeated exposure was carried out to determine cell viability over 18 days of cell differentiation in 24-well plates. Selected concentrations (0.1, 1, and 3 µg/mL) were tested on cells cultured in E-plates and Transwells with the same repeated exposure regimen, to determine cell impedance, and cell viability and trans-epithelial electrical resistance (TEER), respectively. Silver uptake, intracellular localisation, and translocation were determined by CytoViva™, HIM-SIMS, and ICP-MS. Genotoxicity was determined on acutely-exposed proliferating Caco-2 cells by γH2AX immunofluorescence staining. Repeated exposure of a given concentration of AgC, which is composed solely of ionic silver, generally exerted more toxic effects on Caco-2 cells than Mesosilver™, which contains a mix of AgNPs and ionic silver. Due to its patchy structure, the presence of mucus in the Caco-2/HT29-MTX co-culture only slightly mitigated the deleterious effects on cell viability. Increased genotoxicity was observed for AgC on proliferating Caco-2 cells. Silver uptake, intracellular localisation, and translocation were similar. In conclusion, Mesosilver™ and AgC colloidal silver products show different levels of gut toxicity due to the forms of distinct silver (AgNPs and/or Ag+) contained within. This study highlights the applicability of high-resolution (chemical) imaging to detect and localize silver and provides insights into its uptake mechanisms, intracellular fate and cellular effects.

Alteration of sperm parameters and reproductive hormones in Swiss mice via oxidative stress after co-exposure to titanium dioxide and zinc oxide nanoparticles.

In this study, Swiss male mice were intraperitoneally administered with titanium dioxide (TiO2 ) and zinc oxide (ZnO) nanoparticles (NPs) and their mixture (1:1) at doses between 9.38 and 75 mg/kg for 5 weeks to evaluate reproductive toxicity. Both NPs and their mixture significantly (p < .001) altered sperm motility, reduced sperm numbers and increased abnormalities, while their mixture induced more sperm abnormalities than either TiO2 NPs or ZnO NPs. Both NPs and their mixture significantly (p < .05) reduced the LH level, while ZnO NPs alone and their mixture (p < .001) increased the testosterone levels at tested doses. The testes of exposed mice showed pathological changes and altered histomorphometrics. TiO2 NPs and ZnO NPs individually induced a significant (p < .01) reduction in SOD and CAT activities, while the mixture significantly (p < .001) decreased CAT activity and increased SOD activity. TiO2 NPs alone at 9.38 mg/kg induced a significant (p < .001) reduction in the GSH level, while both NPs and their mixture increased the MDA level significantly (p < .05). The data showed that the mixture had a synergistic interaction to induce testicular damage. Overall, oxidative stress may be involved in the NP-mediated testicular damage observed.