Search

The aim of the present work is to demonstrate the expediency of using information technologies on the study of Brownian motion. The importance of using such software as VirtualDub, Tracker and Google Sheets for the study of Brownian motion has been substantiated. This made it possible to determine the values that cannot be measured directly (the displacement of the Brownian particle, the size of the Brownian particle and the Avogadro number). The advantage of this method is that all software are free.

In light of the growing plastic waste problem worldwide, including in agriculture, this study focuses on the usefulness of both conventional, non-degradable plastics and environmentally friendly bioplastics in the agricultural sector. Although conventional plastic products are still essential in modern, even ecological agriculture, the increasing contamination by these materials, especially in a fragmented form, highlights the urgent need to search for alternative, easily biodegradable materials that could replace the non-degradable ones. According to the literature, polymers are widely used in agriculture for the preparation of agrochemicals (mostly fertilizers) with prolonged release. They also play a role as functional polymers against pests, serve as very useful super absorbents of water to improve crop health under drought conditions, and are commonly used as mulching films, membranes, mats, non-woven fabrics, protective nets, seed coatings, agrochemical packaging, or greenhouse coverings. This widespread application leads to the uncontrolled contamination of soil with disintegrated polymeric materials. Therefore, this study highlights the possible applications of bio-based materials as alternatives to conventional polyolefins or other environmentally persistent polymers. Bio-based polymers align with the strategy of innovative agricultural advancements, leading to more productive farming by reducing plastic contamination and adverse ecotoxicological impacts on aquatic and terrestrial organisms. On the other hand, advanced polymer membranes act as catching agents for agrochemicals, protecting against environmental intoxication. The global versatility of polymer applications in agriculture will not permit the elimination of already existing technologies involving polymers in the near future. However, in line with ecological trends in modern agriculture, more "green" polymers should be employed in this sector. Moreover, we highlight that more comprehensive legislative work on these aspects should be undertaken at the European Union level to guarantee environmental and climate protection. From the EU legislation point of view, the implementation of a unified, legally binding system on applications of bio-based, biodegradable, and compostable plastics should be a priority to be addressed. In this respect, the EU already demonstrates an initial action plan. Unfortunately, these are still projected directions for future EU policy, which require in-depth analysis. [ABSTRACT FROM AUTHOR]

The European Union's Green Deal concept prioritizes the installation of photovoltaic and wind turbine systems, with the aim of significantly reducing greenhouse gas emissions and expanding the use of renewable energy. The inclusion of metals/metaloids such as Cd, Pb, Ni, and As to PV panels may be a matter of concern because they may provoke numerous negative environmental effects, especially after decommissioning. Although the release of Pb and Cd from solar panels is generally low, these releases may increase, posing long-term harm. Cd and Pb, if only released from solar panels, can enter the environment, including soil and water, posing a significant risk to human health and ecosystems. Cd, in particular, can have profound and lasting negative impacts on animals and humans, affecting cellular responses, enzyme operations, and immune system functionality. Pb exposure, in turn, can induce oxidative stress and neurotoxicity, disrupt ion regulatory pathways, and impair immune function. Despite efforts to reduce the release of toxic metals from PV panels, controlling their disposal and avoiding environmental contamination remains challenging. Discovering substitute materials for PV panel manufacture, implementing enhanced recycling procedures, performing bioremediation, and enforcing stronger restrictions are among the strategies to mitigate environmental concerns. [ABSTRACT FROM AUTHOR]

The United Nations World Drug Report published in 2022 alarmed that the global market of illicit drugs is steadily expanding in space and scale. Substances of abuse are usually perceived in the light of threats to human health and public security, while the environmental aspects of their use and subsequent emissions usually remain less explored. However, as with other human activities, drug production, trade, and consumption of drugs may leave their environmental mark. Therefore, this paper aims to review the occurrence of illicit drugs in surface waters and their bioaccumulation and toxicity in fish. Illicit drugs of different groups, i.e., psychostimulants (methamphetamines/amphetamines, cocaine, and its metabolite benzoylecgonine) and depressants (opioids: morphine, heroin, methadone, fentanyl), can reach the aquatic environment through wastewater discharge as they are often not entirely removed during wastewater treatment processes, resulting in their subsequent circulation in nanomolar concentrations, potentially affecting aquatic biota, including fish. Exposure to such xenobiotics can induce oxidative stress and dysfunction to mitochondrial and lysosomal function, distort locomotion activity by regulating the dopaminergic and glutamatergic systems, increase the predation risk, instigate neurological disorders, disbalance neurotransmission, and produce histopathological alterations in the brain and liver tissues, similar to those described in mammals. Hence, this drugs-related multidimensional harm to fish should be thoroughly investigated in line with environmental protection policies before it is too late. At the same time, selected fish species (e.g., Danio rerio, zebrafish) can be employed as models to study toxic and binge-like effects of psychoactive, illicit compounds. [ABSTRACT FROM AUTHOR]

Flow cytometry (FCM) is routinely used in medical and veterinary diagnostics although it is also widely applied in environmental studies, including phytoplankton investigations. Cyanobacteria are wide-spread photosynthetic microorganisms that attract attention due to their ecology and potential toxicity. Therefore, novel research tools are being applied in their investigation. This paper characterizes FCM as a technique that enables photopigments (chlorophylls and phycocyanin) expressed by cyanobacteria to be excited and their emission to be subsequently detected. This feature not only allows cells to be counted in a rapid manner but also enables a wide range of potential applications in ecological and biochemical studies. The main advantages of FCM, such as rapid, automatic and precise measurements requiring small sample volumes, are also discussed in this paper along with challenges including analyses of filamentous cyanobacteria and signal overlapping. It is expected that FCM will continue to be used in some fields of cyanobacterial studies.

The aim of the present work was to investigate the response of zebrafish to the effects of widely-used organophosphates roundup and chlorpyrifos and putative effectiveness of chlorella in terms of decreasing pesticides toxicity. Studied organophosphate pesticide roundup and chlorpyrifos in ecologically relevant concentrations, both individually and in a mixture, evoked the prominent suppression of catalase and total antioxidant capacity in the liver of Danio rerio which were consistent with higher levels of lipid peroxidation, protein carbonylation, and DNA strand break. Also, both roundup and chlorpyrifos provoked endocrine disorders registered as induction of vitellogenin and depletion of triiodothyronine as well as neurotoxicity appeared as inhibition of acetylcholinesterase after individual action or activation after combined action. The rate of apoptosis observed by caspase 3 activity was decreased, but in different manner depends on the exposure. The potency of toxicity followed the order: roundup > chlorpyrifos > roundup + chlorpyrifos (due to some kind of antagonistic action between chlorpyrifos and roundup in the binary mixture). Based on the results of CART analysis triiodothyronine, TBARS and caspase 3 were determined as the most significant indices for discrimination of the studied groups. The introduction of Chlorella vulgaris in the amount of about 100 thousand cells L-1 into the environment did not show a significant bioremediation effect on the harmful effect of studied pesticides for Danio rerio, which does not exclude the positive impact of algae on the functioning of the ecosystem as a whole and requires further comprehensive research.

Simple Summary: Due to the global increase in pesticide applications, aquatic animals are constantly subjected to their action in natural reservoirs. Terbuthylazine and malathion, two commonly detected pesticides in water and soil samples elsewhere, have been shown to have a significant negative impact on zebrafish, even at environmentally realistic concentrations. They can induce oxidative stress, mitochondrial and lysosomal destabilization, leading to immune toxicity, cytotoxicity, and DNA damage. All of these adverse outcomes might severely impact the health status of fish before being translated into an effect on the population. The present study should emphasize the importance of paying attention to pesticide traces in the environment, which can have devastating effects on biota even at low concentrations. Our research sought to determine the molecular and biochemical effects of environmentally relevant exposure to commonly used chloro-s-triazine herbicide terbuthylazine and organophosphate insecticide malathion on zebrafish. To this aim, mature zebrafish were exposed to 2 and 30 µg L−1 terbuthylazine and 5 and 50 µg L−1 malathion alone and in combination for 14 days. Aside from the accumulation of TBARS and protein carbonyls, a decrease in antioxidants and succinate dehydrogenase activity, an increase in oxidized glutathione, and enhanced apoptosis via Caspase-3 and BAX overexpression were observed. Furthermore, terbuthylazine and malathion induced mitochondrial swelling (up to 210% after single exposure and up to 470% after co-exposure) and lactate dehydrogenase leakage (up to 268% after single exposure and up to 570% after co-exposure) in a concentration-dependent manner. Significant upregulation of ubiquitin expression and increased cathepsin D activity were characteristics that appeared only upon terbuthylazine exposure, whereas the induction of IgM was identified as the specific characteristic of malathion toxicity. Meanwhile, no alterations in the zebrafish hypothalamic-pituitary-thyroid axis was observed. Co-exposure increased the adverse effects of individual pesticides on zebrafish. This study should improve the understanding of the mechanisms of pesticide toxicity that lead to fish impairment and biodiversity decline. [ABSTRACT FROM AUTHOR]

Global warming and human-induced eutrophication drive the occurrence of various cyanotoxins in aquatic environments. These metabolites reveal diversified mechanisms of action, encompassing cyto-, neuro-, hepato-, nephro-, and neurotoxicity, and pose a threat to aquatic biota and human health. In the present paper, we review data on the occurrence of the most studied cyanotoxins, microcystins, nodularins, cylindrospermopsin, anatoxins, and saxitoxins, in the aquatic environment, as well as their potential bioaccumulation and toxicity in fish. Microcystins are the most studied among all known cyanotoxins, although other toxic cyanobacterial metabolites are also commonly identified in aquatic environments and can reveal high toxicity in fish. Except for primary toxicity signs, cyanotoxins adversely affect the antioxidant system and anti-/pro-oxidant balance. Cyanotoxins also negatively impact the mitochondrial and endoplasmic reticulum by increasing intracellular reactive oxygen species. Furthermore, fish exposed to microcystins and cylindrospermopsin exhibit various immunomodulatory, inflammatory, and endocrine responses. Even though cyanotoxins exert a complex pressure on fish, numerous aspects are yet to be the subject of in-depth investigation. Metabolites other than microcystins should be studied more thoroughly to understand the long-term effects in fish and provide a robust background for monitoring and management actions. [ABSTRACT FROM AUTHOR]

The unprovoked aggression of Russian military forces on Ukraine in February 2022 has caused a high influx of refugees, including children, to neighboring countries, particularly Poland. This caused additional pressures on the healthcare system and the need to meet challenges for public health, such as those related to infectious diseases. Here, we discuss the potential epidemiological risks associated with the war-induced influx of refugees (coronavirus disease 2019, measles, pertussis, tetanus, and poliomyelitis) and highlight the need for their swift management through institutional support, educational campaigns, counteracting antiscience misinformation, and pursuing vaccinations of refugees but also improving or maintaining good levels of immunization in populations of countries welcoming them. These are necessary actions to avoid overlapping of war and infectious diseases and associated public health challenges. [ABSTRACT FROM AUTHOR]

Pesticides are well known for their high levels of persistence and ubiquity in the environment, and because of their capacity to bioaccumulate and disrupt the food chain, they pose a risk to animals and humans. With a focus on organophosphate and triazine pesticides, the present review aims to describe the current state of knowledge regarding spatial distribution, bioaccumulation, and mode of action of frequently used pesticides. We discuss the processes by which pesticides and their active residues are accumulated and bioconcentrated in fish, as well as the toxic mechanisms involved, including biological redox activity, immunotoxicity, neuroendocrine disorders, and cytotoxicity, which is manifested in oxidative stress, lysosomal and mitochondrial damage, inflammation, and apoptosis/autophagy. We also explore potential research strategies to close the gaps in our understanding of the toxicity and environmental risk assessment of organophosphate and triazine pesticides. [ABSTRACT FROM AUTHOR]

This study aimed to compare the occurrence and nuisance of adverse events following administration of each COVID-19 vaccine dose between two groups: individuals given three doses of mRNA vaccine (homologous group, 3 × mRNA, n = 252) and those given two doses of adenoviral vector vaccine further boosted with mRNA vaccine (heterologous group, 2 × AZ + 1 × mRNA, n = 205). Although the studied groups differed significantly in the frequency and number of side effects after the first and second vaccine dose, no relevant differences were seen following the booster administration. Arm pain and fatigue were the most common effects, regardless of the vaccination group and vaccine dose. In the homologous group, female sex, lower BMI, and no history of regular influenza vaccination were associated with a higher frequency of side effects of a booster dose. In the heterologous group, the history of COVID-19 was associated with an increased number of side effects seen after a booster. In both groups, the number of side effects related to the first and second dose correlated with the number observed after administration of a booster dose. Individuals receiving a homologous booster reported a higher nuisance of side effects than the heterologous group. It was similar to the level reported after the second dose in both groups. The use of pharmaceuticals to counteract the side effects was more frequent after a first dose in the 2 × AZ + 1 × mRNA group, but higher after second dose in individuals receiving the 3 × mRNA vaccination scheme. The frequency of pharmaceutical use after a booster dose was similar in both groups (approx. 60%). Paracetamol was most frequently chosen, regardless of the group and vaccine dose. In addition, the vast majority of participants (93%) declared to accept future doses of the COVID-19 vaccine if their administration would be recommended. This study provides an overview of the response to homologous and heterologous mRNA vaccine booster dose that may be valuable in shaping accurate and honest communication with vaccinated individuals, especially in those regions which are yet to pursue booster strategies. [ABSTRACT FROM AUTHOR]

The use of glyphosate-based Roundup and triazine herbicide Atrazine has increased markedly in last decades. Thus, it is important to evaluate toxic effects of these herbicides to non-targeted organisms such as zooplankton to understand their safety toward aquatic ecosystems. In the current study, we performed Daphnia toxicity tests based on lethality to identify LC50 that provides acute aquatic toxicity classification criteria. LC50 for Roundup exposure for 24 hours was found to be 0.022 mg/L and 48 hours - 0.0008 mg/L. Atrazine showed LC50 at concentrations of 40 mg/L and 7 mg/L for 24 and 48 hours, respectively. We demonstrated that exposure to ecologically relevant concentrations of Roundup or Atrazine decreases lipid peroxidation and protein thiol levels, however caused increase in carbonyl protein and low-molecular-weight thiols content. Moreover, the herbicide treatments caused increase of superoxide dismutase activity. Our data suggest that at very low concentrations Roundup and Atrazine disturb free radical processes in D. magna. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with a very poor prognosis and constantly growing incidence. Among other primary risks of HCC, metabolic disorders and obesity have been extensively investigated over recent decades. The latter can promote nonalcoholic fatty liver disease (NAFLD) leading to the inflammatory form of nonalcoholic steatohepatitis (NASH), that, in turn, promotes HCC. Molecular determinants of this pathogenic progression, however, remain largely undefined. In this study, we have focussed on the investigation of α-dicarbonyl compounds (α-dC), highly reactive and tightly associated with overweight-induced metabolic disorders, and studied their potential role in NAFLD and progression toward HCC using murine models. NAFLD was induced using high-fat diet (HFD). Autochthonous HCC was induced using transposon-based stable intrahepatic overexpression of oncogenic NRASG12V in mice lacking p19Arf tumor suppressor. Our study demonstrates that the HFD regimen and HCC resulted in strong upregulation of α-dC in the liver, heart, and muscles. In addition, an increase in α-dC was confirmed in sera of NAFLD and NASH patients. Furthermore, higher expression of the receptor for advanced glycation products (RAGE) was detected exclusively on immune cells and not on stroma cells in livers of mice with liver cancer progression. Our work confirms astable interplay of liver inflammation, carbonyl stress mediated by α-dC, and upregulated RAGE expression on CD8+ Tand natural killer (NK) cells in situ in NAFLD and HCC, as key factors/determinants in liver disease progression. The obtained findings underline the role of α-dC and RAGE+CD8+ Tand RAGE+ NK cells as biomarkers and candidates for a local therapeutic intervention in NAFLD and malignant liver disease. [ABSTRACT FROM AUTHOR]

Gastropod mollusks have achieved an eminent importance as biological indicators of environmental quality. In the present study, we applied a multibiomarker approach to evaluate its applicability for the pond snail Lymnaea stagnalis, exposed to common industrial and agricultural pollutants at environmentally relevant concentrations. The snails were exposed to copper (Cu2+, 10 µg L−1), zinc (Zn2+, 130 µg L−1), cadmium (Cd2+, 15 µg L−1), or the thiocarbamate fungicide "Tattoo" (91 µg L−1) during 14 days. Metal treatment and exposure to "Tattoo" caused variable patterns of increase or decrease of metal levels in the digestive gland, with a clear accumulation of only Cd and Zn after respective metal exposure. Treatment with Cu and "Tattoo" caused an increase of cytochrome P450-related EROD activity. Glutathione S-transferase was inhibited by exposure to Cu, Zn, and "Tattoo." Treatment with the "Tattoo" led to an inhibition of cholinesterase activity, whereas Cu and Cd increased its activity. Caspase-3 activity was enhanced by up to 3.3 times in all treatments. A nearly uniform inhibitory effect for oxidative stress response parameters was observed in all kinds of exposure, revealing an inhibition of superoxide dismutase (Mn-SOD) activity, a depression of glutathione (GSH and GSSG) and of protein carbonyl levels. Pollutant-specific effects were observed for the catalase activity, superoxide anion production, and lipid peroxidation levels. Due to the high response sensitivity of Lymnaea stagnalis to chemical impacts, we suggest our study as a contribution for biomarker studies with this species under field conditions. [ABSTRACT FROM AUTHOR]

Highlights • A hypolepidemic drug atorvastatin (ATO) is taken up and metabolized by mussels. • ATO exposure leads to elevated basal metabolic rate and depletion of energy reserves in mussels. • Lipid content and mRNA expression of key fatty acid metabolism enzymes are suppressed by ATO. • Xenobiotic efflux through P-glycoprotein and membrane diffusion is suppressed by ATO. • ATO can act as metabolic disruptor and chemosensitizer in mussels. Abstract Biologically active compounds from pharmaceuticals cause concern due to their common occurrence in water and sediments of urbanized coasts and potential threat to marine organisms. Atorvastatin (ATO), a globally prescribed drug, is environmentally stable and bioavailable to marine organisms; however, the physiological and toxic effects of this drug on ecologically important coastal species are yet to be elucidated. We studied the effect of ATO (˜1.2 μg L−1) on bioenergetics (including whole-organism and mitochondrial respiration, as well as tissue energy reserves and mRNA expression of genes involved in mitochondrial biogenesis and fatty acid metabolism in the gills and the digestive gland) of a keystone bivalve Mytulis edulis (the blue mussel) from the Baltic Sea. Xenobiotic detoxification systems including activity and mRNA expression of P-glycoprotein, and Phase I and II biotransformation enzymes (cytochrome P450 monooxygenase CYP1A and glutathione transferase, GST) were also assessed in the gill and digestive gland of the mussels. Exposure to ATO caused rapid uptake and biotransformation of the drug by the mussels. Standard metabolic rate of ATO-exposed mussels increased by 56% indicating higher maintenance costs, yet no changes were detected in the respiratory capacity of isolated mitochondria. ATO exposure led to ˜60% decrease in the lysosomal membrane stability of hemocytes and ˜3-fold decrease in the whole-organism P-glycoprotein-driven and diffusional efflux of xenobiotics indicating altered membrane properties. The digestive gland was a major target of ATO toxicity in the mussels. Exposure of mussels to ATO led to depletion of lipid, carbohydrate and protein pools, and suppressed transcription of key enzymes involved in mitochondrial biogenesis (peroxisome proliferator-activated receptor gamma coactivator 1-alpha PGC-1α) and fatty acid metabolism (acetyl-CoA carboxylase and CYP4Y1) in the digestive gland. No bioenergetic disturbances were observed in the gills of ATO-exposed mussels, and elevated GST activity indicated enhanced ATO detoxification in this tissue. These data demonstrate that ATO can act as a metabolic disruptor and chemosensitizer in keystone marine bivalves and warrant further investigations of statins as emerging pollutants of concern in coastal marine ecosystems. [ABSTRACT FROM AUTHOR]

Abstract Global decline of amphibian populations causes particular concern about their vulnerability to novel environmental pollutants, including engineering nanomaterials and pharmaceutical products. We evaluated the bioavailability of nanoform of zinc oxide (n-ZnO) in frog Pelophylax ridibundus and determined whether co-exposure to a common pharmaceutical, a calcium-channel blocker nifedipine (Nfd) can affect this bioavailability. Male frogs were exposed for 14 days to the tap water (Control) and n-ZnO (3.1 μM), Zn2+ (3.1 μM, as a positive control for n-ZnO exposures), Nfd (10 μM), and combination of n-ZnO and Nfd (n-ZnO + Nfd) in environmentally-relevant concentration. Exposure to Zn2+ or n-ZnO led to up-regulation of metal-binding proteins, metallothioneins (MTs) in the liver and Zn-carrying vitellogenin-like proteins in the blood plasma. Notably, upregulation of MTs by Zn2+ or n-ZnO exposures combined with increased binding of Zn and Cu to MTs. This was associated with the more reducing conditions in the liver tissue indicated by elevated lactate to pyruvate ratio. Nfd suppressed the binding of Zn and Cu to MTs and led to a decrease in Lactate/Pyruvate ratio and elevated protein carbonylation indicating pro-oxidant conditions. Redox status parameters were not directly related to DNA fragmentation, nuclear abnormalities or suppression of cholinesterase activity indicating that factors other than oxidative stress are involved in cytotoxicity of different pollutants and their combinations. Furthermore, activity of Phase I biotransformation enzyme (CYP450 oxidase measured as EROD) was elevated in Nfd-containing exposures and in Zn2+ exposed frogs. Tyrosinase-like activity in the frog liver was strongly stimulated by Zn2+ but suppressed by n-ZnO, Nfd and n-ZnO + Nfd. These findings show that Nfd modulates homeostasis of essential metals in amphibians and emphasize that physiological consequences of combined n-ZnO and Nfd exposures are difficult to predict based on the mechanisms of single stressors. [ABSTRACT FROM AUTHOR]

Abstract Bivalves from the cooling reservoirs of electrical power plants (PP) are exposed to the chronic heating and chemical pollution making them a suitable model to study the combined effects of these stressors. We investigated the effect of in situ exposures to chemical and thermal pollution in the PP cooling ponds on the metabolic responses of unionid bivalves (Unio tumidus) to a novel widespread pollutant, ZnO nanoparticles (nZnO). Male U. tumidus from the reservoirs of Dobrotvir and Burshtyn PPs (DPP and BPP) were maintained in clean water at 18 °C, or exposed for 14 days to one of the following conditions: nZnO (3.1 μM) or Zn2+ (3.1 μM, a positive control for Zn impacts) at 18 °C, elevated temperature (T, 25 °C), or nZnO at 25 °C (nZnO + T). Baseline levels of glycogen, lipids and ATP were similar in the two studied populations, whereas the levels of proteins, lactate/pyruvate ratio (L/P) and extralysosomal cathepsin D level were higher in the tissues of BPP mussels. The levels of glycogen and glucose declined in most experimental exposures indicating elevated energy demand except for a slight increase in the digestive gland of warming-exposed BPP mussels and in the gills of the nZnO + T-exposed DPP-mussels. Experimental exposures stimulated cathepsin D activity likely reflecting onset of autophagic processes to compensate for stress-induced energy demand. No depletion of ATP in Zn-containing exposures was observed indicating that the cellular metabolic adjustments were sufficient for such compensation. Unexpectedly, experimental warming mitigated most metabolic responses to nZnO in co-exposures. Our data thus indicate that metabolic effects of nZnO strongly depend on the environmental context of the mussels (such as temperature and acclimation history) which must be taken into account for the molecular and cellular biomarker-based assessment of the nanoparticle effects in the field. Graphical abstract Unlabelled Image Highlights • Bivalves from two cooling ponds were subjected to Zn2+, nZnO and warming. • The stress-induced depletion of energy reserves and pyruvate was population-dependent. • Cathepsin D activity and/or efflux were up-regulated. • Exposure to nZnO did not cause ATP decrease and anaerobic shift. • Warming diminished the effect of nZnO in co-exposures. [ABSTRACT FROM AUTHOR]

Highlights • Polish and Ukraine strains of R. raciborskii differ in in vitro toxicity. • Extracts of all strains increased oxidative stress indices in carp hepatocytes. • Extracts of Polish strains increased acetylcholinesterase activity in carp brain. • Further studies are required to determine metabolites implicated in toxicity. Abstract As yet European strains of Raphidiopsis raciborskii (previously Cylindrospermopsis raciborskii) have not been found to produce known cyanotoxins although their extracts have caused adverse effects in mammals, as shown using in vitro and in vivo experimental models. The present study investigated whether R. raciborskii isolated from Western Poland and Ukraine can affect fish cells using in vitro exposures of hepatocytes and red blood cells (RBC), and brain homogenates obtained from common carp (Cyprinus carpio) to 1.0% and 0.1% extracts of 7 strains. The studied extracts evoked different responses of catalase activity in hepatocytes with both increase and decrease observed under low and high concentrations. The cellular thiol pool was also altered with most extracts inducing a decrease in the activity of glutathione-S-transferase, and Ukrainian strains leading to an increase in glutathione level and a decrease in metallothionein content. All the studied extracts induced comparable reactive oxygen species formation, lipid peroxidation, protein carbonylation and DNA fragmentation in hepatocytes, and all but one increased the activity of caspase-3. Only one extract caused lysosomal membrane destabilization as measured by neutral red retention in RBC. In contrast to extracts of Ukrainian isolates, exposure of brain homogenates to extracts of Polish strains induced an increase in acetylcholinesterase activity suggesting the neurotoxic action of their exudates. The results indicate that both Polish and Ukrainian strains of R. raciborskii may pose a toxicological risk to freshwater fish, and further, that Polish strains may produce compound(s) evoking neurotoxic effects. [ABSTRACT FROM AUTHOR]

Bivalve mollusks from the cooling reservoirs of fuel power plants (PP) are acclimated to the chronic heating and chemical pollution. We investigated stress responses of the mussels from these ponds to determine their tolerance to novel environmental pollutant, zinc oxide nanoparticles (nZnO). Male Unio tumidus from the reservoirs of Dobrotvir and Burschtyn PPs (DPP and BPP), Ukraine were exposed for 14 days to nZnO (3.1 μM), Zn 2+ (3.1 μM) at 18 °C, elevated temperature (T, 25 °C), or nZnO at 25 °C (nZnO + T). Control groups were held at 18 °C. Zn-containing exposures resulted in the elevated concentrations of total and Zn-bound metallothionein (MT and Zn-MT) in the digestive gland, an increase in the levels of non-metalated MT (up to 5 times) and alkali-labile phosphates and lysosomal membrane destabilization in hemocytes. A common signature of nZnO exposures was modulation of the multixenobiotic-resistance protein activity (a decrease in the digestive gland and increase in the gills). The origin of population strongly affected the cellular stress responses of mussels. DPP-mussels showed depletion of caspase-3 in the digestive gland and up-regulation of HSP70, HSP72 and HSP60 levels in the gill during most exposures, whereas in the BPP-mussels caspase-3 was up-regulated and HSPs either downregulated or maintained stable. BPP-mussels were less adapted to heating shown by a glutathione depletion at elevated temperature (25 °C). Comparison with the earlier studies on mussels from pristine habitats show that an integrative ‘eco-exposome’-based approach is useful for the forecast of the biological responses to novel adverse effects on aquatic organisms. [ABSTRACT FROM AUTHOR]

The molluscan exoskeleton (shell) plays multiple important roles including structural support, protection from predators and stressors, and physiological homeostasis. Shell formation is a tightly regulated biological process that allows molluscs to build their shells even in environments unfavorable for mineral precipitation. Outer mantle edge epithelial cells (OME) and hemocytes were implicated in this process; however, the exact functions of these cell types in biomineralization are not clear. Pacific oysters (Crassostrea gigas) were used to study differences in the expression profiles of selected biomineralization-related genes in hemocytes and mantle cells, and the functional characteristics of hemocytes such as adhesion, motility and phagocytosis. The specialized role of OME in shell formation was supported by high expression levels of the extracellular matrix (ECM) related and cell-cell interaction genes. Density gradient separation of hemocytes revealed distinct phenotypes based on the cell morphology, gene expression patterns, motility and adhesion characteristics. These hemocyte fractions can be categorized into two functional groups, i.e. biomineralization and immune response cells. Gene expression profiles of the putative biomineralizing hemocytes indicate that in addition to their proposed role in mineral transport, hemocytes also contribute to the formation of the ECM, thus challenging the current paradigm of the mantle as the sole source of the ECM for shell formation. Our findings corroborate the specialized roles of hemocytes and the OME in biomineralization and emphasize complexity of the biological controls over shell formation in bivalves. [ABSTRACT FROM AUTHOR]

Freshwater organisms including amphibians experience increasing exposures to emerging pollutants such as nanoparticles and pharmaceuticals, which can affect their fitness and performance. We studied the effects of two common pollutants extensively used in industry, pharmaceutical and personal care products, nano-zinc oxide (nZnO) and a Ca-channel blocker nifedipine (Nfd), on endocrine status and cellular stress markers of the marsh frog Pelophylax ridibundus . Males were exposed for 14 days to nZnO (3.1 μM), Zn 2+ (3.1 μM, as a positive control for nZnO exposures), Nfd (10 μM), and combination of nZnO and Nfd (nZnO + Nfd). Exposure to nZnO and Zn 2+ led to an increase in Zn burdens, elevated concentrations of the metal-bound metallothioneins (MT-Me) in the liver and increased vitellogenin in the serum, whereas exposures to Nfd and nZnO + Nfd resulted in the metal release from MTs and a significant increase in the ratio of total to metal-bound MTs. This likely reflects oxidative stress caused by Nfd exposures as manifested in the elevated levels of oxyradical production, upregulation of superoxide dismutase activity (SOD) and increase in the total and oxidized glutathione concentrations in Nfd-exposed frogs. Zn-containing exposures upregulated activity of deiodinase (in nZnO and nZnO + Nfd exposures) and serum thyrotropin level (in the case of Zn 2+ ). All exposures caused an increase in DNA fragmentation, lipofuscin accumulation as well as upregulation of caspase-3 and CYP450 levels reflecting cytotoxicity of the studied compounds in the liver. Across all experimental treatments, nZnO exposures in the absence of Nfd had the least impact on the cellular stress traits or redox status in frogs. This indicates that at the low environmentally relevant levels of pollution, pharmaceuticals such as Nfd and free metals (such as Zn 2+ ) may represent a stronger threat to the health of the frogs than nZnO particles. [ABSTRACT FROM AUTHOR]

Estuarine organisms including mollusks are exposed to periodic oxygen deficiency (hypoxia) that leads to a decrease in intracellular pH and accumulation of bicarbonate (HCO 3 − ). These changes can affect cellular bioenergetics; however, their effects on mitochondria of estuarine mollusks are not well understood. We determined the interactive effects of bicarbonate (0–10 mM) and pH (7.2 and 6.5) on mitochondrial oxygen consumption (Ṁ O2 ), membrane potential (Δψ) and production of reactive oxygen species (ROS) in two common estuarine bivalves — hard clams Mercenaria mercenaria , and bay scallops Argopecten irradians . In both species, elevated HCO 3 − levels suppressed ADP-stimulated (state 3) Ṁ O2 but had little effect on the resting (state 4) respiration. These effects were not mediated by the soluble adenylyl cyclase or cyclic AMP. Effects of the low pH (6.5) on mitochondrial traits were species-specific and depended on the substrate oxidized by the mitochondria. Mild acidosis (pH 6.5) had minimal effects on Ṁ O2 and Δψ of the bivalve mitochondria oxidizing pyruvate but led to increased rates of ROS production in clams (ROS production could not be measured in scallops). In succinate-respiring mitochondria of clams, mild acidosis suppressed Ṁ O2 and increased mitochondrial coupling, while in scallop mitochondria the effects of low pH were opposite. Suppression of mitochondrial oxidative phosphorylation by bicarbonate and/or acidosis may contribute to the metabolic rate depression during shell closure or environmental hypoxia/hypercapnia. These findings have implications for understanding the physiological mechanisms involved in regulation of mitochondrial bioenergetics during hypoxia exposure in estuarine bivalves. [ABSTRACT FROM AUTHOR]

Metal-containing materials are extensively used in industry, personal care products and medicine, and their release in the environment causes concern for the potential impacts on aquatic organisms. We assessed endocrine disrupting potential of N -vinyl-2-pyrrolidone-based nanoparticles (Me-PSs) containing cobalt (Co 2+ ) or zinc (Zn 2+ ), using the marsh frog Pelophylax ridibundus as a model. Adult males were exposed for 14 days to waterborne Co 2+ (50 μg/L), Zn 2+ (100 μg/L) or corresponding concentrations of Co-PS, Zn-PS, or parental polymeric compound (PS). The indices of thyroid activity, vitellogenesis, cytochrome P450-dependent monooxygenases activity (EROD) and cytotoxicity markers were evaluated. Exposure to Co 2+ led to the elevation of serum thyrotropin (TSH) and hepatic deiodinase activities accompanied by the up-regulation of EROD activity. In contrast, the action of the polymer-containing substances (Co-PS, Zn-PS and PS) as well as free Zn 2+ caused a prominent decrease of EROD activity and a decrease in serum cortisol and TSH concentrations. Exposures to Zn 2+ , Zn-PS and PS upregulated vitellogenesis in males. All exposures except Co 2+ caused neurotoxicity as indicated by the depletion of cholinesterase. These results demonstrate toxicity of Co- and Zn-containing Me-PSs and their parental compounds (Zn 2+ and PS) in frogs and indicate distinct mechanisms of Co 2+ action. Broad disruption of the hormonal pathways and reduced capacity for organic xenobiotic detoxification may have deleterious impacts on amphibian populations from habitats exposed to metallorganic pollution. [ABSTRACT FROM AUTHOR]

Nanoparticle toxicity is a growing concern in freshwater habitats. However, understanding of the nanoparticle effects on aquatic organisms is impeded by the lack of the studies of the nanoparticles effects in the environmentally relevant context of multiple stress exposures. Zinc oxide nanoparticles (n-ZnO) are widely used metal-based nanoparticles in electronics and personal care products that accumulate in aquatic environments from multiple non-point sources. In this study, we evaluated the effects of n-ZnO in a model organism, a mussel Unio tumidus , and the potential modulation of these effects by common co-occurring environmental stressors. Male U. tumidus were exposed for 14 days to n-ZnO (3.1 μM), Zn 2+ (3.1 μM), Ca-channel blocker nifedipine (Nfd 10 μM), combinations of n-ZnO and Nfd or n-ZnO and thiocarbamate fungicide Tattoo (Ta, 91 μg L −1 ) at 18 °C, and n-ZnO at 25 °C (n-ZnO + t °). Total and metallothionein-bound Zn levels as well as levels of metallothioneins (MT), cellular stress responses and cytotoxicity biomarkers were assessed in the mussels. The key biomarkers that showed differential responses to different single and combined stressors in this study were activities of caspase-3 and lysosomal cathepsin D, as well as protein carbonyl content. At 18 °C, exposures to n-ZnO, organic pollutants and their combinations led to a prominent up-regulation of MT levels (by ∼30%) and oxidative stress response including up-regulation of superoxide dismutase activity, an increase in oxyradical production, and a 2–3-fold decrease in the levels of protein carbonyls in all exposures except nZnO + Ta. Expos ure to n-ZnO in the absence of other stressors also led to a strong (∼7-fold) elevation of cathepsin D activity. Cellular responses to Zn 2+ and n-ZnO were different indicating that n-ZnO was not due exclusively to Zn release. Ca-channel blocker Nfd affected intracellular Zn distribution (reflected in the prominent elevation of Zn-MT levels) and caused reductive stress indicated by elevated levels of reduced glutathione levels and an increase in lactate/pyruvate ratio (reflecting higher NADH/NAD ratio). Elevated temperature (25 °C) abolished most of the typical responses to n-ZnO and induced oxidative injury, DNA fragmentation and caspase-3 mediated apoptosis in n-ZnO-exposed mussels. DNA fragmentation was also induced by exposure to organic toxins (alone and in combination with n-ZnO) but not by n-ZnO alone. These data indicate that n-ZnO toxicity to freshwater organisms is modulated by organic pollutants and enhanced by elevated temperatures. [ABSTRACT FROM AUTHOR]

The goal of the study was to assess the adequacy of molecular responses in mollusks in relation to their in situ exposure history. Freshwater male bivalve mollusks Anadonta anatina (Unionidae) from polluted (A) and unpolluted (F) sites were subjected to 14 days of exposure to copper (Cu2+, 10μgL−1), zinc (Zn2+, 130μgL−1) or cadmium (Cd2+, 15μgL−1). The comparison of two control groups showed that the specimens from site A had higher levels of Cu, Zn and Cd and metallothionein (measured both through metal (MT-Me), and protein (MT-SH) levels) in the tissues. Cytotoxicity (low lysosomal membrane stability), low glutathione level, high antioxidant and apoptotic enzymes activities, lipid and protein oxidative injury, depletion of ethoxyresorufin-O-deethylase (EROD) in digestive gland, high vitellogenin-like protein (Vtg-LP) concentration in gonads confirmed the effect of toxic environment on this group. Exposures provoked increased number of hemocytes with micronuclei (by 100–500%) and nuclear abnormalities (by 50–400%) (genotoxicity), elevation of caspase-3 (in 1.5–10 times) and/or Vtg-LP (by 70–310%) levels in all groups. However, the responses were strongly dependent on the origin of mussels. Exposed mussels from site F demonstrated typical for the effect of toxic metals elevation of MT-SH (by 100–380%) and MT-Me (up to seven times) levels and accumulation of metals (with a few exceptions) in the tissues. Conversely, in the mussels inhabiting site A, exposures caused the decrease of metal (by 37% for Cu, by 62% for Zn, by 50% for Cd), MT-SH (by 68% in ZnA group) and MT-Me (by 50–68%) levels. That was accompanied with increase of cytotoxicity and EROD activity (by 144–240%). High level of protein carbonyls was the distinguished feature of all groups from site A. Hence, despite high efficiency of metal detoxification and oxidative stress responses in the mussels, in the specimens from spontaneously polluted site they were impaired. [Copyright &y& Elsevier]

Abstract: Cobalt (Co2+) is present in many nanoscaled materials created for various applications. The key goal of our study was to develop sensitive approaches for assessing the bio-risks associated with using novel Co2+-containing nanoscaled polymeric complex (Co-NC). Freshwater bivalve mollusk Anodonta cygnea (Unionidae) was subjected to 14d action of the developed Co-NC, as well as of Co2+ applied in the corresponding concentration (50μgL−1) or polymeric substance (PS). All experimental groups under study have demonstrated signs of toxic targeting, notably changes in DNA characteristics, oxidative stress (with particularities in each exposed group) and activation of anaerobiosis (Co2+ and Co-NC). However, the group exposed to Co-NC showed some advantages that can be related to the activation of metallothionein (MT) function (increase in the level of MT-related SH-groups (MT-SH)): low level of oxyradical formation, no increase in protein carbonylation and vitellogenin-like proteins concentration unlike in Co2+ and PS exposed groups. On the other hand, Co2+ increased metal (Co, Cu, Zn and Cd) binding to MT (MT-Me) without changes in MT-SH level jointly with activation of oxyradical formation and apoptosis and decreasing of lysosomal membrane stability. PS per se initiated unbalanced changes in activities of the biotransformation enzymes ethoxyresorufin-O-deethylase and glutathione-S-transferase. Thus, Co2+ complexing with the developed PS prevented bio-toxic effects of free Co2+ ions and PS per se, at least in the studied hydrobiont. The MT-SH was the main distinguishing index of Co-NC group selected by classification and regression tree analysis. [Copyright &y& Elsevier]

The aim of this study was to appreciate the consequences of spontaneous human activity for freshwater mollusks in the generally ecologically sustainable area in Western Ukraine. For this, bivalve mollusk, Anodonta cygnea, at three sites, with mixed agricultural and municipal activities (A), close to a municipal water inlet (F) and the cooling pond of a nuclear power plant (N), were studied in spring, summer, and autumn. The set of parameters included the characteristics of oxidative stress (activity of catalase (CAT), levels of protein carbonyls (PC)), levels of reduced and oxidized glutathione (GSH, GSSG, respectively), activities of lactate dehydrogenase (LD), cholinesterase (ChE), ethoxyresorufin- O-deethylase (EROD), glutathione S-transferase (GST) in the digestive gland, and concentrations of vitellogenin-like proteins (Vtg-LP) in gonads and also morphological indices. Although the discriminant functional analysis confirmed the general seasonal regularities for studied groups, it allowed to discriminate between sites ( P < 0.05). At site A, oxidative stress; high levels of LD, EROD, and GST; and low levels of ChE and condition factor were reflected. This demonstrated the sensitivity of mussels to constant effect of mixed pollution. At site N, oxidative injury was shown that might be explained by the constantly high temperature. At site F, abrupt elevations of Vtg-LP and EROD levels in autumn were probably related to an emergency situation on the nearby dump. So, both chronic and temporal environmental effects were reflected by a set of markers in mollusk. The classification and regression tree (CART) algorithm selected GSH and PC in the digestive gland and Vtg-LP as partitioning criteria for the characterization of mussel health status. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to estimate the sensitivity of biomarkers of stress and exposure in the bivalve mollusk Anodonta cygnea to spontaneous anthropogenic activities typical for the Western Ukraine. Three sites were examined during spring, summer and autumn: an agricultural site (A); the cooling pond of nuclear power plant (N) and a forestry close to the municipal water inlet (F). Common temporal changes of a battery of biochemical markers in the gills and hemolymph and morphological characteristics were shown by discriminant functional analysis. Classification trees built on the basis of the screened biomarkers demonstrated persistent peculiarities at each site: genotoxicity (nuclear abnormalities) at site A and endocrine disruption (high levels of vitellogenin-like proteins (Vtg-LP) in hemolymph) at site F. Interim local effects were best characterized by metallothionein (MT) concentrations, lipid peroxidation (LPO), activities of glutathione S-transferase and lactate dehydrogenase, and the conditional index of the gills. In autumn, the mollusks from the three sites revealed the highest differences in pollution status: the activation of antioxidant defense and cholinesterase were typical for site A, highest levels of MT related to high levels of Cu and Cd in the water at site B, and a steep increase in the level of Vtg-LP and the decrease of lysosomal membrane stability were recorded at the site selected as reference (F). The biomarker alterations recorded at site F were later related to an emergency event at the municipal dump located nearby. Thus, our case study demonstrated the reliability of using biomarkers of exposure to assess both long-term and accidental environmental pollution loads. [Copyright &y& Elsevier]

The aim of this study was to evaluate the health status of the comparatively tolerant fish Carassius carassius over three seasons in an area characterized by spontaneous human activities. Sites near the springs of a river (site Z) and downstream of a river (site B) in Western Ukraine were selected. According to the centroid grouping analysis, the biochemical and morphological indices allowed the fish to be distinguished according to season more than to site. The level of nuclear abnormalities was low in fish from both sites. However C. carassius inhabiting site B showed a lower metal-binding capacity of MTs in relation to fish from site Z. This was combined with high levels of MT protein (particularly in the liver), and reduced glutathione (GSH) and redox state of GSH (particularly in the gills), which might confer some advantages to fish inhabiting this site. The levels of ethoxyresorufin-O-deethylase, glutathione-S-transferase, cholinesterase and vitellogenin-like proteins indicated significant but intermittent inter-site differences. In summer, oxidative damage due to a high level of lipid peroxidation, and low superoxide dismutase and catalase activities was observed in fish from site B, and in autumn, it was observed in the gills of fish from site Z. The relationship between MT protein levels and antioxidant defense and the lack of a positive relationship between MT levels and their metal-binding capacity was confirmed by principal component analysis. [Copyright &y& Elsevier]

The aim of the present study was to elucidate the seasonal and spatial regularity of the properties of metallothioneins (MT) from the liver and gills of carp Cyprinus carpio L. in rural (R) and industrial (I) sites in Western Ukraine. The MT is represented by two chromatographic forms, the features of which exhibit seasonal rather than spatial dependence. The pronounced differences between the sites were due to the lower levels of Zn in the liver and the higher levels of Zn in MT of carp from site I, providing evidence of the higher overall anthropogenic impact here that leads to the distortion of this essential metal accumulation and to the activation of metal-binding function of MT. In spring, higher levels of Cu and Cd in MT and in the tissues were reflected at site R probably as the result of the permitting pollution here. The principal component analysis demonstrated the correlation of MT-bound metal levels to their levels in water and the absence of such relation for general tissue metal levels for Zn. [Copyright &y& Elsevier]

The aim of this study was to compare environmental quality in two sites of the river in Western Ukraine, rural (R) and industrial (I) during three seasons via a set of biochemical markers in carp Cyprinus carpio L. Upon comparing the values of the I-site with those of the R-site, we found that Mn- and Cu, Zn-superoxide dismutase (SOD) activities decreased and O· production increased; metallothionein (MT) and glutathione levels increased in most cases, and acetylcholinesterase (AChE) activity decreased in summer. This confirms our hypothesis about continuous environmental press at the I-site. The higher activity of catalase and lipid peroxidation (TBARS), as well as the increased levels of vitellogenin-like proteins at the R-site, compare to the I-site in spring reflects the permitting effect of agricultural discharges. According to the results of PCA, the most sensitive biomarkers of pollution are MT, TBARS, and AChE in liver. [Copyright &y& Elsevier]

Toxicity of cyanobacteria is the subject of ongoing research, and a number of toxic metabolites have been described, their biosynthesis pathways have been elucidated, and the mechanism of their action has been established. However, several knowledge gaps still exist, e.g., some strains produce hitherto unknown toxic compounds, while the exact dynamics of exerted toxicity during cyanobacterial growth still requires further exploration. Therefore, the present study investigated the toxicity of extracts of nine freshwater strains of Aphanizomenon gracile, an Aphanizomenon sp. strain isolated from the Baltic Sea, a freshwater strain of Planktothrix agardhii, and two strains of Raphidiopsis raciborskii obtained from 25- and 70-day-old cultures. An in vitro experimental model based on Cyprinus carpio hepatocytes (oxidative stress markers, DNA fragmentation, and serine/threonine protein activity) and brain homogenate (cholinesterase activity) was employed. The studied extracts demonstrated toxicity to fish cells, and in general, all examined extracts altered at least one or more of considered parameters, indicating that they possess, to some degree, toxic potency. Although the time from which the extracts were obtained had a significant importance for the response of fish cells, we observed strong variability between the different strains and species. In some strains, extracts that originated from 25-day-old cultures triggered more harmful effects on fish cells compared to those obtained from 70-day-old cultures, whereas in other strains, we observed the opposite effect or a lack of a significant change. Our study revealed that there was no clear or common pattern regarding the degree of cyanobacterial bloom toxicity at a given stage of development. This means that young cyanobacterial blooms that are just forming can pose an equally toxic threat to aquatic vertebrates and ecosystem functioning as those that are stable or old with a tendency to collapse. This might be largely due to a high variability of strains in the bloom. [ABSTRACT FROM AUTHOR]