bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrences and rechallenges of suspected drugs in patients with epidermal necrolysis
Authors: Bettuzzi Thomas , Lebrun-Vignes Bénédicte , Assier Haudrey , Pina Vegas Laura , Ingen-Housz-Oro Saskia , Sbidian Emilie
Published: January 2025

Background

Epidermal necrolysis (EN) is a rare and severe condition characterized by diffuse skin and mucosal detachment and mainly induced by drugs. The literature is scarce regarding the rate of recurrences and culprit drug re-exposure.

Objectives

To assess the rate of EN recurrences and to examine re-exposure to high-notoriety drugs in patients with EN.

Methods

We used the French health system database and included all patients with EN. Suspected drugs were assessed at the onset of EN. The primary outcome was the rate of EN recurrence. Secondary outcomes were re-exposure or cross-exposure to high-notoriety drugs (exposure to a drug of the same family) after the acute stage of EN.

Results

In total, 1203 of 1440 patients (83.5%) survived the acute stage, with 27 patients (2.2%, 95% confidence interval 1.5–3.2) meeting the recurrence criteria. In patients with allopurinol as the suspected drug, 10 of 77 (13%) were cross-exposed to febuxostat, without recurrence. Similarly, in patients with carbamazepine or oxcarbazepine as the suspected drug, 2 of 26 (8%) were cross-exposed to lamotrigine, without recurrence. Conversely, 12 of 38 (32%) and 16 of 37 (43%) patients were respectively re-exposed to pantoprazole and esomeprazole when initially suspected, and 12 of 42 (29%) were re-exposed to amoxicillin. Only one recurrence was noted in a patient re-exposed to pantoprazole.

Conclusions

Among patients with EN, the rate of recurrence seems low, contrasting with several re-exposures to beta-lactam antibiotics and proton pump inhibitors when initially suspected. Although we cannot exclude that the suspected drugs were not the responsible ones for several patients, future studies should assess the possible existence of transient risk factors inducing EN.
The potential of autologous patient-derived circulating extracellular vesicles to improve drug delivery in rheumatoid arthritis
Authors: Moskovitch Ori , Anaki Adi , Caller Tal , Gilburd Boris , Segal Ori , Gendelman Omer , Watad Abdulla , Mehrian-Shai Ruty , Mintz Yael , Segev Shlomo , Shoenfeld Yehuda , Popovtzer Rachela , Amital Howard , Halpert Gilad
Published: January 2025

Recognizing the need for innovative therapeutic approaches in the management of autoimmune diseases, our current investigation explores the potential of autologous extracellular vesicles (EVs), derived from the blood of rheumatoid arthritis patients, to serve as therapeutic vectors to improve drug delivery. We found that circulating EVs derived from arthritic mice (collagen-induced arthritis model) express the joint/synovia homing receptor, αVβ3 integrin. Importantly, both autologous labeled EVs, derived from the blood of arthritic mice (collagen antibody-induced arthritis model) and healthy mice-derived EVs, exhibit targeted migration toward inflamed synovia without infiltrating healthy joints, as demonstrated by an in vivo imaging system. Furthermore, EVs derived from plasma of rheumatoid arthritis patients show an overexpression of αV integrin and are effectively taken up by lipopolysaccharides/tumor necrosis factor alpha (TNFα)-induced activated human synovial cell line in vitro, although interestingly the uptake of healthy EVs was found to be significantly increased. Notably, arthritic mice-derived circulating EVs, strongly express murine glucose transporter 1, which in turn can facilitate their binding to glucose-coated gold nanoparticles (previously shown to be conjugated with drugs for improved drug delivery). The significance of our results, lies in the identification of autologous tissue homing EVs as promising vectors, offering a novel avenue to enhance targeted delivery of anti-inflammatory/rheumatic drugs in rheumatoid arthritis treatment.
Aging-related losses in dopamine D2/3 receptor availability are linked to working-memory decline across five years
Authors: Papenberg Goran , Karalija Nina , Salami Alireza , Johansson Jarkko , Wåhlin Anders , Andersson Micael , Axelsson Jan , Garrett Douglas D , Riklund Katrine , Lindenberger Ulman , Nyberg Lars , Bäckman Lars
Published: January 2025

Although age differences in the dopamine system have been suggested to contribute to age-related cognitive decline based on cross-sectional data, recent large-scale cross-sectional studies reported only weak evidence for a correlation among aging, dopamine receptor availability, and cognition. Regardless, longitudinal data remain essential to make robust statements about dopamine losses as a basis for cognitive aging. We present correlations between changes in D2/3 dopamine receptor availability and changes in working memory measured over 5 yr in healthy, older adults (n = 128, ages 64 to 68 yr at baseline). Greater decline in D2/3 dopamine receptor availability in working memory-relevant regions (caudate, middle frontal cortex, hippocampus) was related to greater decline in working memory performance in individuals who exhibited working memory reductions across time (n = 43; caudate: rs = 0.494; middle frontal cortex: rs = 0.506; hippocampus; rs = 0.423), but not in individuals who maintained performance (n = 41; caudate: rs = 0.052; middle frontal cortex: rs = 0.198; hippocampus; rs = 0.076). The dopamine–working memory link in decliners was not observed in the orbitofrontal cortex, which does not belong to the core working memory network. Our longitudinal analyses support the notion that aging-related changes in the dopamine system contribute to working memory decline in aging.
Differential neurogenic patterns underlie the formation of primary and secondary areas in the developing somatosensory cortex
Authors: Ohte Naoto , Kimura Takayuki , Sekine Rintaro , Yoshizawa Shoko , Furusho Yuta , Sato Daisuke , Nishiyama Chihiro , Hanashima Carina
Published: January 2025

The cerebral cortex consists of hierarchically organized areas interconnected by reciprocal axonal projections. However, the coordination of neurogenesis to optimize neuronal production and wiring between distinct cortical areas remains largely unexplored. The somatosensory cortex plays a crucial role in processing tactile information, with inputs from peripheral sensory receptors relayed through the thalamus to the primary and secondary somatosensory areas. To investigate the dynamics of neurogenesis in cortical circuit formation, we employed temporal genetic fate mapping of glutamatergic neuron cohorts across the somatosensory cortices. Our analysis revealed that neuronal production in the secondary somatosensory cortex (S2) precedes that of the primary somatosensory cortex (S1) from the deep-layer neuron production period and terminates earlier. We further revealed a progressive decline in upper-layer neuron output in S2, attributed to the attenuation of the apical ventricular surface, resulting in a reduced number of upper-layer neurons within S2. These findings support the existence of a protomap mechanism governing the area-specific assembly of primary and secondary areas in the developing neocortex.
Identifying causal neural oscillations underlying working memory
Authors: Mirjalili Mina , Zomorrodi Reza , Daskalakis Zafiris J , Blumberger Daniel M , Hill Sean L , Rajji Tarek K
Published: January 2025

Electroencephalography is instrumental in understanding neurophysiological mechanisms underlying working memory. While numerous studies have associated electroencephalography features to working memory, understanding causal relationships leads to better characterization of the neurophysiological mechanisms that are directly linked to working memory. Personalized causal modeling is a tool to discover these direct links between brain features and working memory performance. Therefore, we applied this approach to electroencephalography data from 66 adult healthy participants collected while performing a 3-back working memory task. Using graphical causal modeling, we discovered causal neural oscillations of working memory performance and compared the causal features between two groups: high and low performers. Total number of causal features in high performers was higher than low performers. Among the causal features, right temporal gamma oscillation was ~5 times (z-score = 3.87, P = 0.0001) more frequently a causal feature among high performers than low performers. However, the power of causal temporal gamma oscillation was not different between the two groups. Our findings suggest that one potential approach to improve working memory performance is to induce more causal gamma oscillations. This can be achieved by generating more local gamma entrainment over the right temporal cortex, rather than simply increasing gamma power.
The microgravity environment affects sensorimotor adaptation and its neural correlates
Authors: Tays G D , Hupfeld K E , McGregor H R , Banker L A , De Dios Y E , Bloomberg J J , Reuter-Lorenz P A , Mulavara A P , Wood S J , Seidler R D
Published: January 2025

The microgravity environment results in transient changes in sensorimotor behavior upon astronauts’ return to Earth; the effects on behavior inflight are less understood. We examined whether adaptation to sensory conflict is disrupted in microgravity, suggesting competition for adaptive resources. We evaluated sensorimotor adaptation pre-, in-, and post-flight, as well as functional brain changes at pre- and post-flight, in astronauts participating in International Space Station missions. Astronauts (n = 13) performed this task pre- and four times post-flight within an MRI scanner and performed the task three times in microgravity during a 6-mo mission. We collected behavioral data from Earth-bound controls (n = 13) along the same timeline. Astronauts displayed no change in adaptation from pre- to inflight or following their return to Earth. They showed greater aftereffects of adaptation inflight; controls did not. Astronauts also displayed increased brain activity from pre- to post-flight. These increases did not return to baseline levels until 90 d post-flight. This pattern of brain activity may reflect compensation, allowing astronauts to maintain pre-flight performance levels. These findings indicate that microgravity does not alter short-term visuomotor adaptation; however, it does affect de-adaptation, and post-flight sensorimotor neural activation can take up to 90 d to return to pre-flight levels.
Technical progress, organisational innovations and labour intensity
Authors: Brondino Gabriel , Gaddi Matteo , Garbellini Nadia
Published: January 2025

The purpose of this article is to discuss the combined effects of Industry 4.0 and lean production in the context of global supply chains on working conditions. Our thesis is that the changes of technique based on integrating Industry 4.0 technologies with lean production incur a substantial cost to labour, manifesting as increased work intensity. In Marxian terminology, they have increased the extraction rate of relative surplus value. Our contribution is closely related to the critical global value chain literature and proposes to contribute to this literature by emphasising the relevance of Industry 4.0 technologies in implementing lean production methods and reinforcing control by head companies over the entire chain. Additionally, it discusses how these dynamics manifest in companies and impact the world of work through surveys conducted with workers. These surveys were carried out in a set of Italian metal-mechanical companies involved in various global chains.
Utilizing thermal imaging drones to investigate sleeping site selection in an arboreal primate
Authors: Gazagne Eva , Goldblatt Chiara , Nguyễn Vỹ Trần , Brotcorne Fany , Hambuckers Alain
Published: January 2025

Sleeping site selection is essential for understanding primate behavioral ecology and survival. Identifying where species sleep helps determine priority areas and critical resources for targeted conservation efforts. However, observing sleeping sites at night is challenging, especially for species sensitive to human disturbance. Thermal infrared imaging (TIR) with drones is increasingly used for detecting and counting primates, yet it has not been utilized to investigate ecological strategies. This study investigates the sleeping site selection of the Critically Endangered black-shanked douc langur (Pygathrix nigripes) in Cát Tiên National Park, Vietnam. Our aim is to assess the feasibility of using a TIR drone to test sleeping site selection strategies in non-nesting primates, specifically examining hypotheses related to predation avoidance and food proximity. Between January and April 2023, we conducted 120 drone flights along 22 transects (~1-km long) and identified 114 sleeping sites via thermal imaging. We established 116 forest structure plots along 29 transects in non-selected sites and 65 plots within douc langur sleeping sites. Our observations reveal that douc langurs selected tall and large trees that may provide protection against predators. Additionally, they selected sleeping sites with increased access to food, such as Afzelia xylocarpa, which serves as a preferred food source during the dry season. These results highlight the effective use of TIR drones for studying douc langur sleeping site selection with minimal disturbance. Besides offering valuable insights into habitat selection and behavioral ecology for conservation, TIR drones hold great promise for the noninvasive and long-term monitoring of large-bodied arboreal species.
Genome-resolved analysis of Serratia marcescens strain SMTT infers niche specialization as a hydrocarbon-degrader
Authors: Ramdass Amanda C , Rampersad Sephra N
Published: January 2025

Bacteria that are chronically exposed to high levels of pollutants demonstrate genomic and corresponding metabolic diversity that complement their strategies for adaptation to hydrocarbon-rich environments. Whole genome sequencing was carried out to infer functional traits of Serratia marcescens strain SMTT recovered from soil contaminated with crude oil. The genome size (Mb) was 5,013,981 with a total gene count of 4,842. Comparative analyses with carefully selected S. marcescens strains, 2 of which are associated with contaminated soil, show conservation of central metabolic pathways in addition to intra-specific genetic diversity and metabolic flexibility. Genome comparisons also indicated an enrichment of genes associated with multidrug resistance and efflux pumps for SMTT. The SMTT genome contained genes that enable the catabolism of aromatic compounds via the protocatechuate para-degradation pathway, in addition to meta-cleavage of catechol (meta-cleavage pathway II); gene enrichment for aromatic compound degradation was markedly higher for SMTT compared to the other S. marcescens strains analysed. Our data presents a valuable genetic inventory for future studies on strains of S. marcescens and provides insights into those genomic features of SMTT with industrial potential.
A new protocolized treatment strategy optimizing medical and surgical care leads to improved healing of Crohn’s perianal fistulas
Authors: De Gregorio Michael , Winata Leon S , Hartley Imogen , Behrenbruch Corina C , Connor Susan J , D‘Souza Basil , Basnayake Chamara , Guerra Glen R , Johnston Michael J , Kamm Michael A , Keck James O , Lust Mark , Niewiadomski Ola , Ong Eugene J S , Schulberg Julien D , Srinivasan Ashish , Sutherland Tom , Woods Rodney J , Wright Emily K , Connell William R , Thompson Alexander J , Ding Nik S
Published: January 2025

Background and Aims

Crohn’s perianal fistula healing rates remain low. We evaluated the efficacy of a protocolized multidisciplinary treatment strategy optimizing care in adults with Crohn’s perianal fistulas.

Methods

A new treatment strategy was established at a single tertiary center. The strategy comprised 3 dynamic stages of care directed toward achieving and maintaining fistula healing. Stage A, active disease, focused on early commencement and proactive escalation of biologic therapies and structured surgical reviews ensuring adequate fistula drainage and conditioning. Stage B, optimized disease with a seton in situ, focused on consideration for seton removal and appropriateness of definitive surgical closure and/or ablative techniques. Stage C, healed disease, focused on proactive care maintenance. Sixty patients were sequentially enrolled and prospectively followed for ≥12 months. Endpoints included clinical healing and radiologic remission in those with clinically active fistulas, and relapse in those with healed fistulas.

Results

At baseline, 52% (n = 31) and 48% (n = 29) had clinically active and healed fistulas, respectively. For patients with clinically active fistulas, 71% achieved clinical healing after 22 months, with estimated healing rates of 39% and 84% at 1 and 2 years, respectively. Radiologic remission was achieved in 25%, significantly higher than baseline inclusion rates of 6%. For patients with healed fistulas, 7% experienced clinical relapse after 23 months, with no significant change in radiologic remission, 80% versus 86% at baseline.

Conclusions

A protocolized treatment strategy proactively optimizing care resulted in high rates of clinical healing and improved radiologic remission of Crohn’s perianal fistulas. Controlled-matched studies are needed.
Modeling time scale of integration in equilibrium passive sampling
Authors: Ghosh Oindrila , Yan Songjing , Bokare Mandar , Ghosh Upal
Published: January 2025

Passive samplers (PSs) deployed in the field for several months provide a time-averaged measurement of the freely dissolved concentration of pollutants, which is important for assessing ecological exposure and estimating pollutant loads. A comprehensive theoretical modeling assessment of the sampling time scale of integration (TSI) of an equilibrium PS is required to correctly interpret the results. We address this knowledge gap by modeling exchange kinetics of polychlorinated biphenyl congeners in low-density polyethylene (PE) PS based on diffusive transport and first-order kinetics. We evaluate the sampling TSI by analyzing the response of the PS to simulated pulsed concentration increases in the water column that lasted for 1 day in a total sampling period of 90 days. More hydrophobic compounds experience slower transfer into the sampler and show a longer TSI compared with less hydrophobic compounds. Similarly, a thick sampler shows longer TSI than a thinner sampler. The sampling TSI for a typical 25.4 μm PE sheet ranged widely from 14–15 days for a dichlorobiphenyl to 43–45 days for a hexachlorobiphenyl. We show that strategic deployment of a thick and thin passive sampler can be used to narrow the range of TSIs for all congeners and used to simultaneously capture episodic events along with long-term averages.
Heavy metal concentrations in feathers and metabolomic profiles in Pacific black ducks (Anas superciliosa) from Southeastern Australia
Authors: Nzabanita Damien , Shen Hao , Grist Stephen , Hampton Jordan O , Hufschmid Jasmin , Nugegoda Dayanthi
Published: January 2025

Heavy metals are cumulative toxicants that frequently create negative health effects for waterbirds inhibiting contaminated freshwater systems. Although levels of exposure to heavy metals have been well documented for many waterbird species, the adverse effects of exposure remain relatively poorly understood. One emerging field that allows the exploration of such effects is metabolomics. The aim of this study was to characterize metabolomic profiles in relation to long-term heavy metal exposure in a waterbird species. In 2021, wings from 44 Pacific black ducks (Anas superciliosa) were collected by recreational hunters at three sites in Victoria, southeastern Australia. The concentrations of seven heavy metals were measured in feathers and these data were quantified via inductive coupled plasma mass spectrometry and compared with a semiquantitative assessment of 21 metabolites identified in muscle tissues from the same birds via gas chromatography-mass spectrometry. Principal component analysis was conducted to test associations between metabolites, heavy metals, and sites. Mean heavy metal concentrations detected were copper (9.97 µg/g), chromium (0.73 µg/g), iron (123.24 µg/g), manganese (13.01 µg/g), mercury (0.58 µg/g), lead (0.86 µg/g), and zinc (183.95 µg/g; dry wt). No association was found between heavy metals and 17 metabolites, whereas four metabolites were negatively associated with some heavy metals: α-linolenic acid with iron, glucose with lead and manganese, lactic acid with mercury, and propanoic acid with mercury. There were few differences in the studied metabolites in ducks between the three sites. This study provides a novel approach to combining toxicological and metabolomic data for an ecologically important species from a relatively poorly studied global region.
Oxidative stress and filtration responses in Atlantic ribbed mussels (Geukensia demissa) exposed to radium-226
Authors: Donaher Sarah E , Van den Hurk Peter , Martinez Nicole E
Published: January 2025

Bivalves have been extensively utilized as sentinel biomonitoring species, organisms used to predict the extent and severity of environmental contamination. However, significant knowledge gaps remain regarding the operationalization and application of indicator species for radioactive contaminants in the marine environment. Dose-dependent organism responses with validated and practical measurement protocols need to be identified for use within biomonitoring frameworks. Our study explored tissue-specific oxidative stress and filtration responses in Geukensia demissa (Atlantic ribbed mussel) following static renewal exposure to a range of aqueous radium-226 (226Ra) concentrations and exposure durations. We investigated a two-tier antioxidant response system, with radical scavenging activity as the primary response and glutathione S-transferase and lipid peroxidation activities as secondary, downstream responses. A first-stage response of 226Ra exposure was observed, indicated by increased radical scavenging activity in the mantle tissues of mussels exposed to the highest treatment concentration (200 nCi/L = 200 ng/L, 73%) compared with the tissues of control and lower concentration (1, 10, and 100 nCi/L = 1, 10, and 100 ng/L) mussels (18%–44%). However, there was no clear impact for the second-stage responses. A reduction in filtration, quantified via algal removal, was also observed for mussels exposed to the highest 226Ra treatment concentration. This work represents the first investigation on the effects of a marine bivalve exposed to aqueous 226Ra. The responses of bivalves to radiological marine pollution, and the potential for cascading impacts to populations and ecosystems, is still relatively unknown but has important implications for ecological and human well-being.
Hazard assessment of oil spill response chemical herding agents to commercially valuable North Atlantic species
Authors: Asnicar Davide , Boloori Tahereh , Durante Jason , Lassen Pia , Fritt-Rasmussen Janne , de Jourdan Benjamin , Lee Kenneth
Published: January 2025

Herders are surface-collecting agents that can effectively reduce the surface area of oil slicks during a spill. Currently, two herding agents, Siltech OP-40 (OP-40) and ThickSlick 6535 (TS6535), are approved for use in oil spill response operations by the United States Environmental Protection Agency National Contingency Plan. These products may be deployed when there is evidence that environmental conditions are appropriate for their application and that their use will result in a net environmental benefit. Because the toxicity of these compounds is still poorly understood, toxicity of OP-40 and TS6535 was tested on four commercially relevant North Atlantic marine species: early life stages of green sea urchin (Strongylocentrotus droebachiensis), American lobster (Homarus americanus), Atlantic cod (Gadus morhua) and lumpfish (Cyclopterus lumpus). Lethal and sublethal toxicity data (LC50 and EC50) were determined at different time points. Siltech OP-40 was found to be between 4 and 78 times more toxic than TS6535. Toxicity values ranged from 1.0 (20-min EC50 in sea urchin fertilization) to 13.4 mg/L (3-hr LC50 in lumpfish) for OP-40, and from 7.6 (72-hr LC50 in 24-hour-old embryo cod) to 476.6 mg/L (24-hr EC50 in 20-day-old cod embryo) for TS6536. In terms of decision-making for oil spill response, data from this study supports their operational use, as the measured toxicity values exceeded the theoretical concentrations expected in the environment following the deployment of herding agents.
Selenium induces mercury isotope fractionation and detoxification in marine fish
Authors: Cho Moonkyoung , Lee Seunghan , Kim Kang Woong , Besnard Lucien , Jung Saebom , Lim Seung Hyeon , Li Mi-Ling , Kwon Sae Yun
Published: January 2025

Prey fish are vital in transferring nutrients and contaminants from lower to higher trophic levels. Although the role of selenium (Se) on mercury (Hg) detoxification has been identified in marine mammals and seabirds, the metabolic pathways of Hg-Se interaction in fish remain unknown. We used Hg stable isotopes (δ202Hg, Δ199Hg) to characterize the internal dynamics of methylmercury (MeHg) and inorganic Hg (IHg) in the presence and absence of Se in juvenile olive flounders (Paralichthys olivaceus). The fish were exposed to MeHg- (1,223 ng/g, n = 31) and IHg-amended (1,515 ng/g, n = 31) food pellets for 4 weeks (bioaccumulation phase) and switched to control or Se-amended food pellets for 10 weeks (excretion phase). During the bioaccumulation phase, the Hg isotopic composition of all fish tissues shifted toward their respective food pellets. During the excretion phase, significant negative δ202Hg shifts (0.27–0.59 ‰) were recorded in the liver of fish initially fed MeHg food pellets and then switched to Se food pellets, which is indicative of Se-induced hepatic MeHg demethylation. Fish fed IHg food pellets and then switched to control or Se food pellets exhibited similar isotopic behavior, suggesting that Se plays a minor role in IHg excretion. Both δ202Hg and Δ199Hg of the liver shifted toward IHg food pellets even during the excretion phase, which we attribute to slow intestinal IHg mobilization and redistribution to the liver. We found that the liver is the major site for MeHg demethylation in the presence of Se and that Se plays a relatively minor role in IHg excretion. Tissue-specific Hg isotope dynamics and interaction with Se should be considered in future Hg ecotoxicological assessments in fish.
Emissions of water-soluble polymers from household products to the environment: a prioritization study
Authors: Brunning Hattie , Sallach J Brett , Boxall Alistair
Published: January 2025

Water-soluble polymers (WSPs) are widely used in household products, including cleaning and personal care products. However, unlike insoluble plastic polymers, the environmental risks of WSPs are poorly understood. This study was performed to identify polymers in household use and characterize their emissions to the environment and key data gaps for prioritization. An inventory of polymers was developed and these were broadly grouped based on structure. Information from patents was combined with literature data to estimate down-the-drain emissions for each polymer. For the polymers with the highest emissions, predicted environmental concentrations for surface water and soil were estimated. A total of 339 individual polymers were identified and categorized into 26 groups. The polymers with the highest down-the-drain emissions were sodium laureth sulfate (1.6–3.4 g capita−1 day−1), styrene/acrylates copolymer (0.1–0.8 g capita−1 day−1), and monoethanolamine-laureth sulfate (0.4–0.8 g capita−1 day−1). An analysis of available fate and ecotoxicity data for 30 key high-emission polymers indicated that several are lacking in data. In particular, no data were found for styrene/acrylates copolymer and copolymer of polyethylene glycol/vinyl acetate, and the environmental fate of polyquaterniums and polyol ethoxylate esters has been understudied, particularly in light of their hazard potential. However, a lack of reporting of key polymer properties hinders analysis. We recommend increased transparency in reporting of polymer identities moving forward as well as experimental work determining fate, removal, and hazard of the prioritized high-emission polymers that are lacking in data.
Impact of developmental methylmercury exposure on avian embryonic development, hatchling growth, and survival
Authors: Leaphart James C , Chinn Sarah M , Beasley James C
Published: January 2025

Methylmercury (MeHg) is a globally ubiquitous and persistent environmental toxicant that negatively affects animal behavior, health, and reproduction. In birds, MeHg is transferred from female to egg, contaminating embryos during sensitive stages of early embryonic development and growth. This toxic exposure in the prenatal environment not only induces mortality but also possible lasting impacts on physiology, health, and survival, even once hatched. The purpose of our study was to further elucidate the negative effects of MeHg exposure during avian embryonic development and explore how such exposure can impact offspring development, growth, and survival, both in ovo and posthatch. To assess this, we experimentally dosed fertile mallard and wood duck eggs with MeHg II chloride and reared developing embryos and ducklings to various endpoints. We found that embryos not only readily accumulated MeHg throughout incubation, but they also displayed varying dose-dependent disparities in body mass and morphometrics, with control individuals being larger during early and late embryonic stages of development (p < 0.05). Furthermore, hatched offspring exposed to MeHg exhibited increasingly slower growth rates between 7 to 10 and 10 to 15 days posthatch (p < 0.05), and were found to have lower survival probabilities both under controlled laboratory conditions (p < 0.005), and in the natural environment (p < 0.05). Our findings on the detrimental effects of MeHg on avian embryos and hatchlings emphasize the need for more proactive means of environmental protection and remediation to protect vulnerable avian populations and the ecosystems they inhabit.
Development of a bioaccumulation model for selenium oxyanions and organoselenium in stream biota
Authors: de Bruyn Adrian M H , Heddle Cybele B , Ings Jennifer , Gürleyük Hakan , Brix Kevin V , Luoma Samuel N , Arnold Mariah C
Published: January 2025

Selenium (Se) occurs in natural surface waters as a variety of inorganic and organic chemical species, typically dominated by the oxyanions selenate and selenite. Organoselenium species, although hypothesized to be more bioavailable than oxyanions, have rarely been identified or quantified in natural waters and little is known about their fate or bioaccumulative potential. We studied spatial patterns of bioaccumulation in relation to aqueous Se speciation over 5 years at more than 100 locations near coal mine operations in southeast British Columbia, Canada. We used a sequential approach to fitting bioaccumulation model coefficients, first using sites with no detectable organic Se species (< 0.01 µg L−1) to describe the bioaccumulation of selenate and selenite, then applying those relationships to the remaining sites to infer the bioavailability of detectable organoselenium species. Our analysis indicated that the methylated species methylseleninic acid was the most bioaccumulative form, followed by dimethylselenoxide. Organoselenium species were associated primarily with mine sedimentation ponds and are presumed to be products of Se metabolism by algae and bacteria. Highly bioavailable organoselenium species exported from the ponds appear to be responsible for enhanced Se bioaccumulation in biota in downstream lotic reaches, with this influence diminishing with distance from ponds as concentrations decline. Our findings indicate that managing biological productivity in mine sedimentation ponds could help manage Se risk in the receiving environment.
The effect of pH on chronic copper toxicity to Ceriodaphnia dubia within its natural pH niche
Authors: De Schamphelaere Karel A C , Baken Stijn , Cardwell Allison , Du Laing Gijs , Nys Charlotte , Stubblefield William , Viaene Karel , Weighman Kristi
Published: January 2025

The pH of freshwater ecosystems affects bioavailability of various metals to various organisms, including daphnids. Although it is well known that daphnid species show interclonal variation of metal sensitivity, knowledge about interclonal variation of bioavailability effects, such as the pH effect, is scarce. Here, we compared the effect of pH on chronic copper toxicity between two clones of Ceriodaphnia dubia, within its natural pH niche, which we determined to be approximately pH 6.5–8.5 based on existing experimental and biological monitoring data. Using a Bayesian modeling approach, we found that the effect of pH was not statistically significantly different between the two clones (with a credibility > 95%). Overall, we found an approximately threefold decrease in chronic Cu toxicity with increasing pH between pH 6.5 and 8.5, with 7-day 20% effect concentration (EC20) values ranging between 11.0 and 30.9 µg/L dissolved Cu. We then calibrated a preliminary generalized bioavailability model (gBAM) using these data and found a pH-effect slope parameter SpH = −0.247, which is within the range of previously reported values for Daphnia magna (–0.056 to –0.361) and similar to the SpH value of −0.220 used in the “invertebrate gBAM” for bioavailability-based Cu risk assessment under the Registration, Evaluation, Authorisation and Restriction of Chemicals. The preliminary C. dubia gBAM captured the magnitude of the observed pH effect well (mean of 1.3-fold EC20 prediction error, n = 9). It was also able to accurately predict chronic Cu toxicity in natural waters reported in an independent dataset (mean of 1.4-fold prediction error, n = 6). Also, two D. magna gBAMs (for two clones) and the invertebrate gBAM showed comparable predictive capabilities. Collectively, our work highlights the importance of studying relations between pH and metal bioavailability within the species’ natural niche. It also confirms earlier findings that biological variation of pH-bioavailability relations typically does not have a large impact on predictive capacity of bioavailability models, which is important for regulatory applications.
Spatial patterns of microplastics in freshwater bivalves (Bivalvia: Unionidae and Sphaeriidae) relative to municipal wastewater effluent discharges
Authors: Robson Emily L , Kidd Karen A , Sun Evlyn K , Gillis Patricia L , Prosser Ryan S
Published: January 2025

Microplastics are discharged by municipal wastewater treatment plants (WWTPs); however, their uptake by filter-feeding freshwater bivalves is poorly understood. This study examined the abundance and characteristics of microplastics in wild bivalves from five locations along a 155 km stretch of the Grand River (Ontario, Canada) in 2021–2022, including upstream and downstream of three municipal WWTPs. At each site, fingernail clams (Sphaeriidae spp., n = 5 composites), freshwater mussels (Lasmigona costata, n = 10; gill, digestive gland, and hemolymph), and surface water (n = 3) were sampled at a single timepoint. Microplastics (particles >38 μm to 5 mm) were isolated and visualized via stereomicroscopy, and a subset chemically analyzed using Fourier transform infrared spectroscopy. Fingernail clams contained the highest total blank corrected microparticle counts (35.5 ± 29.4 g−1 [mean ± SD]), mussel tissues ranged from 4.3 ± 4.2 mL−1 in hemolymph to 6.5 ± 8.1 g−1 in digestive gland, and water contained 5.5 ± 2.8 L−1. Fibers were the dominant morphology across all samples, most particles were between 80 μm and 2 mm in length and, of those analyzed chemically, 30.0% were a plastic polymer. At sites downstream of WWTP outfalls, elevated counts were only seen in mussel gills and not in other bivalve tissues or water compared with upstream samples. Although microplastics were found across all sites in both biotic and abiotic compartments, results suggest little impact of WWTP discharges on their uptake in downstream bivalves.
The influence of soil organic matter content on the toxicity of pesticides to the springtail Folsomia candida
Authors: van Hall Bart G , Sweeney Christopher J , Bottoms Melanie , van Gestel Cornelis A M
Published: January 2025

The European environmental risk assessment (ERA) of pesticides to soil invertebrates applies a correction factor (CF) of 2 to endpoints derived from toxicity tests with lipophilic pesticides (log Kow > 2) to correct for differences in organic matter (OM) content between artificial soil (AS) and natural soils. Because the applicability of this CF to springtails has never been assessed, this study investigated the influence of soil OM content on the toxicity of five pesticide active substances differing in lipophilicity to the springtail Folsomia candida. Toxicity tests following Organisation for Economic Cooperation and Development guideline 232 were conducted in AS containing 10%, 5%, and 2.5% peat and a natural soil (LUFA 2.2) with 4.5% OM. For all pesticides, toxicity (median lethal and median effect concentrations [LC50s, EC50s]) differed significantly between soils and strongly negatively correlated with soil OM content in AS (r2 > 0.88). Utilizing the regression equations derived from the data, LC50s and EC50s were calculated for soils with 10% and 5% OM. For EC50s, the differences in model-estimated toxicity between these soils ranged from 1.85 to 3.23, sometimes exceeding the CF of 2. To identify differences between species, data from a sister paper on the earthworm Eisenia andrei was used. Although ratios between model-estimated EC50s in soils containing 10% and 5% OM were similar between species (2.08–3.24 for earthworms), pesticide-specific toxicity–OM relationships differed in some cases. Non-lipophilic pesticides were influenced by soil OM content in a similar manner as the lipophilic pesticides, showing that the influence of soil properties on non-lipophilic pesticides may currently be overlooked. Overall, this study shows that the CF of 2 suffers from erroneous assumptions concerning lipophilicity, OM content, and toxicity. Further research is required to improve our mechanistic understanding of the relationship between toxicity and soil OM content, ultimately increasing the ecological relevance of CFs used in ERAs.
Toxicogenomic signatures of estrogen-related modes of action in the zebrafish embryo
Authors: Frelih Milena , Ayobahan Steve U , Marghany Fatma , Essfeld Fabian , Eilebrecht Sebastian
Published: January 2025

Endocrine disruptors represent a diverse array of chemicals known to interfere with the endocrine systems of both human and environmental organisms, adversely affecting reproduction, development, and behavior, thus raising significant health and ecological concerns. Traditional regulatory tests for endocrine activity typically involve juvenile or adult fish, which is both time-consuming and resource-intensive and necessitates substantial animal use. This study adopts a transcriptomic approach to identify toxicogenomic signatures associated with the disruption of estrogen signaling in zebrafish (Danio rerio) embryos. Utilizing a modified zebrafish embryo toxicity test based on Organisation for Economic Co-operation and Development test guideline 236, the embryos were exposed to two sublethal concentrations of estradiol, bisphenol A, and fulvestrant. Despite no significant effects on survival or hatching rate observed in treated groups compared with the controls, our study effectively pinpointed several genes, including vtg1, cyp19a1b, fam20cl, sult1st2, pck1, agxtb, hsd17b12a, ptgs2a, and ccn1, as linked to a disruption of estrogen signaling. These genes emerge as promising biomarker candidates for identifying and distinguishing estrogen-related modes of action. Additionally, this approach not only supports the detection of potential endocrine disruptors but also opens up possibilities for prioritizing substances for higher tier endocrine testing, which could substantially reduce animal testing in the future.
Microplastic accumulation in various bird species in Turkey
Authors: Tatlı Hatice Hale , Parmaksız Arif , Uztemur Adil , Altunışık Abdullah
Published: January 2025

Plastic pollution constitutes one of the major environmental problems of our time, and in recent years, it has emerged as a significant threat to the environment and to various organisms, including bird species. In this context, this study, which provides the first data in Türkiye, aimed to determine the level of microplastic (MP) pollution in 12 bird species (Eurasian buzzard; short-toed snake-eagle; white stork; northern long-eared owl; common barn-owl; ruddy shelduck; Eurasian eagle-owl; scarlet macaw; common pheasant; Indian peafowl; common kestrel; and gray parrot). The results indicate that MPs were detected in 50% of the specimens (n = 20), with an average of one MP/item per individual. With an average of three MPs per individual, the short-toed snake-eagle was found to be the species with the highest MP accumulation. Fibers (range: 51–534 µm) were the most common type of plastic found in the gastrointestinal tract of birds, with ethylene vinyl acetate and navy blue being the most common polymer type and color, respectively. It was also found that the abundance of MPs increased with the weight of specimens, contributing to the hypothesis that there is a correlation between the size/weight of animals and increased levels of MP accumulation. These findings highlight the impact of plastic pollution on birdlife and the need for further monitoring to assess the ecological impact of pollution.
The effect of calcium on acute sodium chloride toxicity in Daphnia species
Authors: Buren Shakira , Arnott Shelley E
Published: January 2025

Chloride concentrations in freshwater are rising, with toxic effects on aquatic life. In temperate regions with cold winters, road salt used for deicing paved surfaces is a primary cause. There is evidence that water hardness can modify salt toxicity, but data are insufficient to inform policy. Because calcium is a primary ion influencing water hardness and there is widespread calcium decline in lakes, we examined the effects of varying calcium concentrations on acute salt toxicity in three Daphnia species to gain a greater understanding of the water hardness–salt toxicity relationship. We conducted 48-hr acute sodium chloride (NaCl) toxicity tests, using chloride concentrations as our metric, on neonates less than 24 hrs old in six calcium treatments: 1.5 to 128 mg/L (hardness ∼7 to 323 mgCaCO3/L). We determined the effective concentration of chloride that was lethal to 10%, 25%, and 50% of the sample populations from each iso-female line in each calcium treatment. Acute NaCl toxicity decreased as calcium concentrations increased. The relationship between NaCl toxicity and calcium concentration differed among Daphnia, such that Daphnia catawba and Daphnia pulex were more sensitive to NaCl in lower calcium treatments and less sensitive in higher calcium treatments compared to Daphnia pulicaria. Our results provide evidence that water quality guidelines are not protective enough for aquatic life in very soft water (≤3 mg Ca2+/L, 11.3 mg CaCO3/L) because most ECxx values we found for Daphnia were significantly lower than Canada’s national guidelines for short-term chloride exposure. There are already many lakes with calcium concentrations below 3 mg/L, and global widespread calcium decline may put more aquatic ecosystems at risk of experiencing NaCl toxicity.
Visualization of labeled micro- and nanoplastics in interaction with algae, using super-resolution stimulated emission depletion microscopy and fluorescence lifetime imaging
Authors: Sioen Marie , De Keersmaecker Herlinde , Vercauteren Maaike , Janssen Colin , Asselman Jana
Published: January 2025

In contrast to microplastics, studying the interactions of nanoplastics (NPs) with primary producers such as marine microalgae remains challenging. This is attributed to the lack of adequate visualization methods that can distinguish NPs from autofluorescent biological material such as marine algae. The aim of this study was to develop a method for labeling and visualizing nonfluorescent micro- and nanoplastics (MNPs) of various polymer types, shapes, and sizes, in interaction with marine primary producers, which are autofluorescent. A labeling technique for plastics was refined, using a swell incorporation method with the commercial dye “IDye.” Comprehensive quality control measures, including toxicity, leaching, and dye longevity tests, were applied to ensure the robustness of the method. Although stimulated emission depletion (STED) microscopy successfully enabled the visualization of the diverse labeled NPs smaller than 200 nm, it could not distinguish NPs from autofluorescent organic material such as marine microalgae, due to overlapping excitation and emission spectra with the photosynthetically active molecule chlorophyll-a. This study is the first to advance the field by coupling STED with fluorescence lifetime imaging microscopy (FLIM). The FLIM technique, based on the differing lifetimes of fluorescent signals, allowed us to overcome the challenge of overlapping spectra. Our work not only refines and expands existing plastic labeling protocols to accommodate a wide range of polymer types, but also introduces a more precise method for studying interactions between MNPs and autofluorescent organisms. This combined STED-FLIM approach provides a reproducible and reliable framework for examining MNP impacts in complex, ecologically relevant environments, particularly highlighting its potential for investigating MNP–microalgae interactions.
Spatial occurrence of emerging contaminants in rivers and wastewater. Analysis of environmental and human risks
Authors: Teglia Carla Mariela , Gutierrez Fabiana Andrea , Machado Selva , Hadad Hérnan Ricardo , Maine María Alejandra , Goicoechea Héctor Casimiro
Published: January 2025

This study assesses the occurrence of emerging contaminants (ECs) from agricultural and livestock production activities along the Salado River (Santa Fe province, Argentina). Of the 23 ECs studied, 8 were detected and quantified in river and wastewater samples, including ciprofloxacin, enrofloxacin, chlorpyrifos-methyl, albendazole, fenbendazole, levamisole, diazepam, and thiamethoxam. In river samples, the highest concentrations corresponded to ciprofloxacin, chlorpyrifos-methyl, and enrofloxacin. In wastewater samples, albendazole, fenbendazole, ciprofloxacin, enrofloxacin, and thiamethoxam were found. The detection frequency ranged from 4.2% to 54.2% in river samples and from 11.1% to 22.2% in wastewater samples. The spatial distribution of contaminants showed different concentrations, with higher levels often found near urban and agricultural areas, suggesting anthropogenic sources. Ecological risk assessments for different organisms were conducted. Ciprofloxacin posed the highest risk, especially affecting bacteria, cyanobacteria, and algae. Diazepam also was found to pose significant risks to algae, crustaceans, and fishes. Chlorpyrifos-methyl was identified as highly hazardous to multiple living organisms, which is in agreement with the fish mortality that occurred at the sampling sites. The risk assessment in humans showed differences among children, adolescents, and adults, with infants (6 months to 1 year) being at a higher risk than adults. Children may be at a higher daily intake of contaminants than adults, raising concerns about the long-term effects of exposure. This work underscores the critical need for monitoring and regulating ECs in aquatic environments. Further studies are necessary to fully understand their impact and to develop effective strategies for mitigating their presence in water systems.