Indirect Toxic Effects Research Articles

Spatiotemporal Distribution, Bioaccumulation, and Ecological and Human Health Risks of Polycyclic Aromatic Hydrocarbons in Surface Water: A Comprehensive Review

The release of polycyclic aromatic hydrocarbons (PAHs) by human energy exploitation and excessive environmental use has caused substantial environmental contamination. These compounds bioaccumulate in aquatic environments and translocate through the food chain, posing risks to health and environmental safety. To better understand the risks of PAHs in surface water and food chains, this review summarizes their distribution, concentration levels, sources, and toxicity in various surface water environments. It also examines how PAH bioaccumulation affects aquatic organisms and human health. Globally, PAHs have been detected in both aquatic environments and organisms with an increasing trend. Human activity is the main cause of PAH contamination. The results revealed a distinct geographical distribution of PAH risk influenced by population density, industrial development, climate, and seasonal variations. PAHs are found in remote areas, indicating their medium- and long-range transport by atmospheric dispersion. PAHs bioaccumulate in aquatic organisms and cause direct and indirect toxic effects via biomagnification. PAH bioaccumulation is directly correlated with aquatic pollution. This study also emphasizes the carcinogenicity of compounds such as benzo[a]pyrene, identifying occupational and environmental exposure frequencies as key risk factors. This study enhances our understanding of the dynamics of multiple PAHs in aquatic ecosystems and their health effects, thereby contributing to environmental sustainability.

Infectious complications among CD19 CAR-T cell therapy recipients: A single-center experience.

CD19 chimeric antigen receptor (CAR)-T cell therapy has emerged as an effective treatment in those with refractory or relapsed lymphoma. CD19 CAR-T cell therapy can cause direct and indirect toxic adverse effects and increased risk for infection. Infectious complications and optimal antimicrobial prophylaxis strategies are an ongoing area of investigation. A single-center retrospective cohort study was conducted to review recipients of CD19 CAR-T cell therapy between April 2018 and December 2020. Patient characteristics and clinical outcomes were extracted from the electronic health records. Infectious complications were identified in 18/50 (36%) recipients with 31 episodes of infection. The median time to infection was 225 days (range 0-614). Bacterial infections were most common with bloodstream infection followed by sinusitis and skin and soft tissue infection. Eight viral infections were identified, most being respiratory viral illnesses. Two fungal infections were identified: Pneumocystis jirovecii pneumonia (PJP) and disseminated fusariosis. Seventeen infections (54.8%) were classified as severe: leading to death, requiring hospitalization, need for empiric intravenous antibiotics, or significant alteration in hospital course. No characteristics were found to be statistically significant risks for infection, although a trend toward significance was seen in prior autologous stem cell transplant recipients (p = .12) and those with recurrent neutropenia (p = .14). Three patients (6%) died from infection. Infections were common after CD19 CAR-T cell therapy and occurred beyond the first year. Further multicenter studies are needed to define infectious risks and optimize antimicrobial prophylaxis recommendations in recipients of CD19 CAR-T cell therapy.

“Structural responses of non-targeted bacterial and hppd communities to the herbicide tembotrione in soil”

Tembotrione (TBT) is a β-triketone herbicide targeting the 4-Hydroxyphenylpyruvate dioxygenase enzyme (4-HPPD) of weeds. This molecule can also affect soil microorganisms, either through both direct and indirect toxic effects for microorganisms expressing 4-HPPD, or by promoting tolerant and/or degrading microbial populations. Our study aimed to characterize the impacts of TBT on the diversity of total- and hppd (coding for 4-HPPD) -soil bacterial communities. Soil microcosms were treated with the active ingredient TBT at the recommended field dose (100 g a.i/ha; D1) or the tenfold dose (D10). Soil samples were collected from 0 to 55 days post-treatment to study: (i) total- and hppd-bacterial diversities using 16SrRNA and hppd amplicons sequencing, respectively; (ii) TBT dissipation in soil. Both total- and hppd-bacterial community composition was not affected by TBT treatments (D1 and D10). However, D10 treatment slightly increased richness and phylogenetic diversity of the total bacterial community while decreasing hppd richness. Overall, the highest dose of TBT seemed to promote TBT-tolerant or TBT-degrading bacterial populations and to deplete TBT-sensitive ones. These effects were transient as TBT was rapidly dissipated with a DT50 of 7 days and 15 days for D1 and D10, respectively. Differential abundance analysis with a Generalized Linear Model allowed the identification of Sphingomonas, Steroidobacter and Lysobacter as genus that were influenced by TBT, and which could be used as a new class of exposure biomarkers.

Tephrosia toxicaria (Sw.) Pers. extracts: Screening by examining aedicidal action under laboratory and field conditions along with its antioxidant, antileishmanial, and antimicrobial activities.

An increase in the incidence of arboviral, microbial and parasitic infections, and to disorders related to oxidative stress has encouraged the development of adjuvant therapies based on natural formulations, such as those involving plant extracts. Thus, to expand the repertoire of the available therapeutic options, this study aimed to describe the versatility of Tephrosia toxicaria (Sw.) (Pers., 1807) extracts for the control of arbovirus vectors, as well as their antioxidant, antileishmanial, and antimicrobial potential. Among the aqueous and hydroethanolic extracts obtained, the hydroethanolic extract from roots (RHA) was identified as the most active larvicide extract demonstrating, respectively, the lowest lethal concentration (mg/mL) for 50%, 90% and 99% of Aedes aegypti (L., 1762) and Aedes albopictus (S., 1894) larvae, observed at 24 h (0.33, 0.84 and 1.80; 0.32, 0.70 and 1.32) and 48 h (0.17, 0.51 and 1.22; 0.26, 0.47 and 0.78) post-exposure. Field assays revealed that RHA (0.84 mg/mL) is a potential oviposition deterrent, reducing egg-laying by approximately 90%. RHA (0.1 mg/mL) also exhibited antioxidant activity for the following tests: total antioxidant capacity (286.86 mg AAE/g), iron (87.16%) and copper (25.64%) chelation, and superoxide scavenging (10%). In the cell culture assays, RHA (0.1 mg/mL) promoted regeneration of metabolic activity (92% cell viability) in cells exposed to oxidative stress. Furthermore, RHA displayed weak antileishmanial activity (IC50 = 3.53 mg/mL) against Leishmania amazonensis and not exhibit antimicrobial activity. The extraction favored the concentration of carbohydrates in RHA, in addition to lectins and protease inhibitors, with molecular masses estimated between 10 and 24 kDa. Cytotoxicity and phytotoxicity analyses of RHA suggested its biosecurity. Thus, RHA is a multivalent extract with insecticide and antioxidant properties at low and safe concentrations. However, others studies on its indirect toxic effects are ongoing to ensure the complete safety of RHA.

Enhanced coagulation process for removing dissolved organic matter, microplastics, and silver nanoparticles

Dissolved organic carbon (DOC), microplastics (MPs), and silver nanoparticles (AgNPs) in water are of major concern because of their direct and indirect toxic effects on aquatic organisms and human exposure via water. This work investigated the effect of poly aluminum chloride (PACl) coagulation for reducing DOC, MPs, and AgNPs. This work used water from a canal in Thailand with a DOC of 5.2 mg/L in the experiment. AgNPs of 5–20 mg/L were added to canal water to create synthetic water for the PACl coagulation. Polyethylene and polypropylene (PP) type MPs were identified in the raw water with Fourier transform infrared spectroscopy. Coagulation with 15 mg/L of PACl performed better in the PP removal. The PACl coagulation at dosages of 15, 40, and 70 mg/L removed DOC by 16–20%, 44–52%, and 46–63% and AgNPs by 34–90%, 53–93%, and 81–95%, respectively. The presence of AgNPs at high levels could inhibit the efficiency of DOC reduction by the PACl coagulation. The FESEM identified the adsorption of silver-containing nanoparticles onto the flocs with increased dosages of PACl. So, PACl is a coagulant in the removal of AgNPs that can reduce health hazards and eco-toxicological risks in water sources due to the release of silver.

HISTOPATHOLOGY IS A BIOMONITORING TOOL TO ASSESS PESTICIDE POLLUTION IN THE ENVIRONMENT

Histological alterations are sensitive biomarkers for xenobiotic effects and it is a tool for thediagnosis of direct and indirect toxic effects that affect the animal tissues. Fish gills aremultifunctional organs involved in ion transport, gas exchange, acid– base regulation and wasteexcretion. Furthermore, the gills are the main route of toxicants penetration into the fish organism,thus they are the first organ, which comes in contact with environmental pollutants and aresensitive subjects for identifying the effects of water toxicants on the fish tissues. Therefore, it isconsidered as an excellent method for assessing environmental quality. Histopathologicalanalysis of gills of Anabas testudineus exposed to sublethal concentrations of monocrotophos wasstudied. Estimation of the maximum allowable toxicant concentration of monocrotophos (MATC) andits application factor (AF) for the Anabas testudineus, was derived based on no observable effectconcentration (NOEC) and the least observable effect concentration (LOEC). MATC and AFcalculated for the pesticide was 13.4164ppm and 0.1308 respectively. The Application Factor, whichis worked out for one species can be used for other related species also, provided their 48hr LC50is known. From this the MATC for latter species can be conveniently found out. This will be animportant tool for the farmers in deciding the concentrations of pesticides before its applicationinto the paddy fields.

EFFICIENT REMOVAL OF TURBIDITY IN TURBID WATER BY NATURAL COAGULANTS

Access to clean water is the significant need in all nations on the planet in which many people and living live forms pass on because of tainted water related ailments consistently. Health problems caused by alum have been recently reported. Various reports have mentioned the direct and indirect toxic effects of alum in the form of tumours, cancers and allergies. No investigations have been done to discover whether seeds of Trigonella Foenum-graecum and Cuminum cyminum can be used as water coagulants. In order to partially replace alum as coagulant, the combination of Fenugreek seed powder and Cumin seed powder is used as coagulant in water treatment via coagulation-flocculation process. pH and coagulant dosage were identified for the combinations of Alum, Fenugreek and Cumin seed powder. The overall best efficient turbidity removal proportion is studied for both the synthesized turbid water and river water.

Tobacco Smoking and Liver Cancer Risk: Potential Avenues for Carcinogenesis.

Smoking a cigarette generates over 4000 chemicals that have a deleterious impact on each part of the human body. It produces three main severe effects on the liver organ: oncogenic, immunological, and indirect or direct toxic effects. It results in the production of cytotoxic substances, which raises fibrosis and necro-inflammation. Additionally, it also directs the production of pro-inflammatory cytokines tumour necrosis factor alfa (TNF-α) and interleukins (IL-1β, IL-6) that will be responsible for the chronic liver injury. Furthermore, it gives rise to secondary polycythemia and successively raises the turnover and mass of red cells, which might be a common factor responsible for the development of oxidative stress in the liver due to iron overload. It also produces chemicals that are having oncogenic properties and raises the risk of liver cancer especially in sufferers of chronic hepatitis C. Smoking modulates both humoral and cell-mediated responses by restricting the proliferation of lymphocytes and inducing their apoptosis and ultimately decreasing the surveillance of cancer cells. Moreover, it has been determined that heavy smoking impacts the response of hepatitis C patients to interferon (IFN) therapy through different mechanisms, which can be improved by phlebotomy. Efforts are being made in different nations in decreasing the prevalence of smoking to improve premature death and ill effects of their nation's individuals.

Toxicity risks of occupational exposure in 3D printing and bioprinting industries: A systematic review.

3-Dimensional (3D) printing and bioprinting are the new technologies. In 3D printing, synthetic polymers such as acrylonitrile, butadiene, and styrene, polylactic acid, nylon, and some metals are used as feedstocks. During 3D printing, volatile organic compounds (VOCs) and nanoparticles can be released. In the bioprinting process, natural polymers are most commonly used. All of these materials have direct and indirect toxic effects in exposed people. Therefore, the aim of this study was to provide a comprehensive review of toxicity risks due to occupational exposure to pollutants in the 3D printing and bioprinting industries. The Cochrane review method was used as a guideline for systematic review. Articles were searched in the databases including PubMed, Scopus, Web of Science, and Google Scholar. This systematic review showed that VOCs and ultra-fine particles are often released in fused deposition modeling and selective laser sintering, respectively. Asthma, chronic obstructive pulmonary disease, allergic rhinitis, and DNA damage were observed in occupational exposure to synthetic polymers. Metal nanoparticles can induce adverse health effects on the respiratory and nervous systems. This study emphasized the need to further study the toxicity of 3D printing and bioprinting-induced air pollutants. Also, consideration of safety and health principles is necessary in 3D printing and bioprinting workplaces.

A COMPARATIVE STUDY ASSESSING THE DIFFERENT PATTERNS OF RADIATION REACTIONS IN HEAD AND NECKCANCER PATIENTS UNDERGOING RADIATION THERAPY AT DIFFERENT TIMES OF THE DAY-IN THE MORNING VERSUS EVENING

Background: Human oral mucosa, is a prime target for radiation induced toxicity in patients undergoing radiotherapy for head and neck cancer. The oral cavity is highly susceptible to direct and indirect toxic effects of cancer chemotherapy and ionizing radiation. In our study we investigated the role of chronotherapy with respect to radiation induced mucositis occurring in the normal oral mucosa and treatment response in tumor tissue in cancer patients undergoing radiation therapy to head and neck region. Materials and Methods: This non-randomized clinical study was done to compare the two different timing schedules in the management of head and neck cancer by external beam radiation therapy by cobalt-60 (Theratron780C). In morning arm (arm A), Patients received external beam radiotherapy (EBRT) by cobalt-60 with SSD of 80cm with daily fractions, five days a week, between 8AM–10 AM whereas in evening arm (arm B), patients received EBRT by cobalt-60 with daily fractions, five days a week, between 3PM–5 PM. Both the arms received same radiation regimen. Results: The study concluded that in the morning arm the onset of oral mucositis was observed to be significantly delayed and the duration of mucositis was also significantly shorter as compared to the evening arm. Statistically significant difference in severity of mucositis was found between the two arms. Conclusion: Since there is no active measure to minimize normal tissue toxicity, chronomodulated radiotherapy would be a feasible and cost effective treatment strategy that can be put into clinical practice.

Benzalkonium chloride-induced direct and indirect toxicity on corneal epithelial and trigeminal neuronal cells: proinflammatory and apoptotic responses in vitro

Benzalkonium chloride (BAK), a quaternary ammonium compound widely used as disinfecting agent as well as preservative in eye drops is known to induce toxic effects on the ocular surface with inflammation and corneal nerve damage leading to dry eye disease (DED) in the medium-to-long term. The aim of this study was to evaluate in vitro the toxicity of a conditioned medium produced by corneal epithelial cells previously exposed to BAK (BAK-CM) on trigeminal neuronal cells. A human corneal epithelial (HCE) cell line was exposed to 5.10−3% BAK (i.e. 0.005% BAK) for 15 min and let recover for 5 h to prepare a BAK-CM. This BAK concentration is the lowest one found in eye drops. After this recovery period, BAK effect on HCE cells displayed cytotoxicity, morphological alteration, apoptosis, oxidative stress, ATP release, CCL2 and IL6 gene induction, as well as an increase in CCL2, IL-6 and MIF release. Next, a mouse trigeminal ganglion primary culture was exposed to the BAK-CM for 2 h, 4 h or 24 h. Whereas BAK-CM did not alter neuronal cell morphology, or induced neuronal cytotoxicity or oxidative stress, BAK-CM induced gene expression of Fos (neuronal activation marker), Atf3 (neuronal injury marker), Ccl2 and Il6 (inflammatory markers). Two and 4 h BAK-CM exposure promoted a neuronal damage (ATF-3, phospho-p38 increases; phospho-Stat3 decreases) while 24 h-BAK-CM exposure initiated a prosurvival pathway activation (phospho-p44/42, phospho-Akt increases; ATF-3, GADD153, active Caspase-3 decreases). In conclusion, this in vitro model, simulating paracrine mechanisms, represents an interesting tool to highlight the indirect toxic effects of BAK or any other xenobiotic on corneal trigeminal neurons and may help to better understand the cellular mechanisms that occur during DED pathophysiology.

Enhancement effects of process optimization technique while elucidating the degradation pathways of drugs present in pharmaceutical industry wastewater using Micrococcus yunnanensis

Pharmaceutical effluents released from industries are accountable to deteriorate the aquatic and soil environment through indirect toxic effects. Microbes are adequately been used to biodegrade pharmaceutical industry wastewater and present study was envisaged to determine biodegradation of pharmaceutical effluent by Micrococcus yunnanensis. The strain showed 42.82% COD (Chemical oxygen demand) reduction before optimization. After applying Taguchi's L8 array as an optimization technique, the biodegradation rate was enhanced by 82.95% at optimum conditions (dextrose- 0.15%, peptone 0.1%, inoculum size 4% (wv−1), rpm 200, pH 8 at 25 °C) within 6 h. The confirmation of pharmaceuticals degradation was done by 1H NMR (Nuclear magnetic resonance) studies followed by elucidation of transformation pathways of probable drugs in the effluent through Q-Tof-MS (Quadrupole Time of Flight- Mass Spectrometry). The cytotoxicity evaluation of treated and untreated wastewater was analyzed on Human Embryonic Kidney (HEK 293) cells using Alamar Blue assay, which showed significant variance.

Direct and indirect effects of toxins on competition dynamics of species in an aquatic environment.

When two competing species are simultaneously exposed in a polluted environment, one species may be more vulnerable to toxins than the other. To study the impact of environmental toxins on competition dynamics of two species, we develop a toxin-dependent competition model that incorporates both direct and indirect toxic effects on the species. The direct effects of toxins typically reduce population abundance by increasing mortality and reducing reproduction. However, the indirect effects, which are mediated through competitive interactions, may lead to counterintuitive effects. We investigate the toxin-dependent competition model and explore the impact of the interplay between environmental toxins and distinct toxic tolerance of two species on the competition outcomes. The results of theoretical analysis and numerical studies reveal that while high level of toxins is harmful to both species, possibly leading to extirpation of both species, intermediate level of toxins, plus different vulnerabilities of two species to toxins, affect competition outcomes in many counterintuitive ways. It turns out that sublethal toxins may boost coexistence of two species (hence keep species diversity in ecosystems) by reducing the abundance of the predominant species; sublethal toxins may overturn and exchange roles of winner and loser in competition; sublethal toxins may also induce different types of bistability of the competition dynamics, where the competition outcome is doomed to exclusion or coexistence, depending on initial population densities. The theory developed here provides a sound foundation for understanding competitive interactions between two species in a polluted aquatic environment.

Wheat germ and vitamin E decrease BAX/BCL-2 ratio in rat kidney treated with gentamicin

The intracellular accumulation of gentamicin acts on mitochondria directly (by increasing oxidative stress) and indirectly (by increasing the proapoptotic BAX gene expression levels) and thus activates intrinsic pathway of apoptosis. This study intended to investigate the probable prophylactic effect of wheat germ as a nephro-protective agent in relation to vitamin E as a well-known natural antioxidant on a nephrotoxic model induced by gentamicin. Forty male Sprague Dawley rats were divided randomly into four groups; of 10 rats each: control group, gentamicin group (120 mg/kg/day i.p. for 15 days), vitamin E group (200 mg/kg orally for 45 days) and wheat germ group (20% of the diet for 45 days). Gentamicin injection was started on the 30th day for both groups (3) and (4). It was noticed that wheat germ significantly decreased BAX/BCL-2 ratio. The significant decrement in MDA level and the significant increment in total antioxidant capacity (TAC) level and catalase (CAT) activity of wheat germ treated rats reflecting its antioxidant activity. Additionally, the wheat germ succeeded in improvement of the kidney function of rats of this group which was manifested by amelioration of deteriorated serum creatinine, urea, sodium and potassium levels. In conclusion, the efficacy of wheat germ as anti-apoptotic and antioxidant was higher than that of vitamin E and it effectively protected against the direct and indirect toxic effects of gentamicin on kidney through regulation of BAX-BCL-2 gene expressions and further inhibition of mitochondrial cytochrome c translocation into cytosol.

Modeling the effects of thiamethoxam on Midwestern farm ponds and emergent wetlands.

Potential toxic effects of thiamethoxam on nontarget organisms and the community structure of a generic Midwestern farm pond and emergent wetland were assessed using 2 versions of the comprehensive aquatic system model: CASMGFP , a generic farm pond model, and CASMGWL , a generic wetland model. The CASMGFP and CASMGWL are integrated bioenergetics-based and habitat quality models that describe the daily biomass values of selected producer and consumer populations representative of generalized Midwestern farm ponds and emergent wetlands. The CASMGFP demonstrated the ability to reproduce values of population biomass reported for Midwestern (and other) pond ecosystems; the CASMGWL provided a similar modeling capability for Midwestern emergent wetlands. Lethal and sublethal effects of thiamethoxam were modeled as extrapolations of laboratory toxicity assays using the CASMGFP and the CASMGWL . Time series of daily environmental concentrations of thiamethoxam constructed for 6 regional pesticide applications across the United States failed to produce any calculated impacts on modeled population biomass or changes in community structure of modeled trophic guilds in the CASMGFP or the CASMGWL . However, evaluation of systematically increased daily concentrations demonstrated the ability of both models to simulate direct and indirect toxic effects of this pesticide. The present model study suggests that process-based food web/ecosystem models can be used to characterize the potential ecological effects of thiamethoxam on generalized farm pond and emergent wetland ecosystems. Environ Toxicol Chem 2018;37:738-754. © 2017 SETAC.

Dimanche : PC.01 – PC.18

Alcoholic cardiomyopathy is a severe consequence of chronic alcohol abuse and is a form of dilated cardiomyopathy. Current research into the pathogenesis of this condition has refined our understanding of the direct and indirect toxic effects of alcohol on the heart. Epidemiological studies attribute a significant role to alcohol abuse as a cardiovascular risk factor while clinical reports have established that alcoholic cardiomyopathy results in increased morbidity and mortality. Initially a clinically silent condition that can be detected by echocardiographic and electrocardiographic abnormalities, alcoholic cardiomyopathy slowly progresses to overt low-output heart failure. Abstinence is beneficial and can determine the reversal of cardiac impairment with a positive impact on prognosis. Specific diagnostic criteria are not yet available and differentiating alcoholic cardiomyopathy from other forms of cardiovascular dysfunction such as cirrhotic cardiomyopathy is challenging.

Augmentation of antioxidant and iron(III) chelation properties of tertiary mixture of bioactive ligands

The excess of iron in plasma and cellular compartment pose direct and indirect toxic effects. In the present investigation, we proposed additive function of nutritional bioactive ligands in combination which has shown enhanced antioxidant and iron(III) chelation property. The optimal interaction and in vitro antioxidant activity of tertiary mixture comprising of curcumin+quercetin+gallic acid was validated by central composite design (CCD) based on ferric reducing antioxidant power assay (FRAP). The additive denticity of nutritional bioactive ligands was investigated by UV–vis, FTIR & MALDI-TOF-MS analysis, which has given substantial evidence for the formation of tris-bidentate [curcumin-quercetin-gallic acid-Fe(III)] co-ordination complex. The in vivo proof of concept of the hypothesis was tested in iron intoxicated male wistar rats intoxicated with iron dextran. Co-administration curcumin+quercetin+gallic acid (CQG) exhibit dose dependent response & found effective in subsiding acute iron intoxication both at plasma and cellular level, evaluated by studies including serum ferritin, ICP-OES, lipid peroxidation and histopathology studies among others. Thus, we conclude that in vitro and in vivo studies supported our hypothesis to deduce additive function nutritional ligands to counteract direct and indirect effects of iron(III).

Quantitative investigation of the mechanisms of microplastics and nanoplastics toward zebrafish larvae locomotor activity.

This study investigated the direct and indirect toxic effects of microplastics and nanoplastics toward zebrafish (Danio rerio) larvae locomotor activity. Results showed that microplastics alone exhibited no significant effects except for the upregulated zfrho visual gene expression; whereas nanoplastics inhibited the larval locomotion by 22% during the last darkness period, and significantly reduced larvae body length by 6%, inhibited the acetylcholinesterase activity by 40%, and upregulated gfap, α1-tubulin, zfrho and zfblue gene expression significantly. When co-exposed with 2μg/L 17 α-ethynylestradiol (EE2), microplastics led to alleviation on EE2's inhibition effect on locomotion, which was probably due to the decreased freely dissolved EE2 concentration. However, though nanoplastics showed stronger adsorption ability for EE2, the hypoactivity phenomenon still existed in the nanoplastics co-exposure group. Moreover, when co-exposed with a higher concentration of EE2 (20μg/L), both plastics showed an enhanced effect on the hypoactivity. Principal component analysis was performed to reduce data dimensions and four principal components were reconstituted in terms of oxidative stress, body length, nervous and visual system related genes explaining 84% of total variance. Furthermore, oxidative damage and body length reduction were evaluated to be main reasons for the hypoactivity. Therefore, nanoplastics alone suppressed zebrafish larvae locomotor activity and both plastic particles can change the larvae swimming behavior when co-exposed with EE2. This study provides new insights into plastic particles' effects on zebrafish larvae, improving the understanding of their environmental risks to the aquatic environment.

Acute and chronic toxicity of diuron and carbofuran to the neotropical cladoceran Ceriodaphnia silvestrii.

In order to contribute to the increase of the body of knowledge on the sensitivity of tropical indigenous species to pesticides, acute and chronic toxicity tests were conducted with the neotropical cladoceran Ceriodaphnia silvestrii. Tests were carried out with the active ingredients diuron and carbofuran and one of their commercial formulations, the Diuron Nortox® 500 SC and the Furadan® 350 SC, respectively. For carbofuran, the active ingredient was more toxic than the commercial product, whereas for diuron, the commercial product appeared more toxic. In addition, hormetic effects on fertility were recorded for intermediate diuron concentrations. Acute and chronic toxicity data indicated that C. silvestrii was among the most sensitive invertebrate species for both test compounds. Based on concentrations measured in Brazilian water bodies, these compounds represent ecological risks for causing direct and indirect toxic effects on C. silvestrii and other aquatic organisms. Our results support previous claims on the advantages of using native species to better tune ecological risk assessment of chemicals in tropical ecosystems.

Decoupling the Direct and Indirect Biological Effects of ZnO Nanoparticles Using a Communicative Dual Cell-Type Tissue Construct.

While matter at the nanoscale can be manipulated, the knowledge of the interactions between these nanoproducts and the biological systems remained relatively laggard. Current nanobiology study is rooted on in vitro study using conventional 2D cell culture model. A typical study employs monolayer cell culture that simplifies the real context of which to measure any nanomaterial effect; unfortunately, this simplification also demonstrated the limitations of 2D cell culture in predicting the actual biological response of some tissues. In fact, some of the characteristics of tissue such as spatial arrangement of cells and cell-cell interaction, which are simplified in 2D cell culture model, play important roles in how cells respond to a stimulus. To more accurately recapitulate the features and microenvironment of tissue for nanotoxicity assessments, an improved organotypic-like in vitro multicell culture system to mimic the kidney endoepithelial bilayer is introduced. Results showed that important nano-related parameters such as the diffusion, direct and indirect toxic effects of ZnO nanoparticles can be studied by combining this endoepithelial bilayer tissue model and traditional monolayer culture setting.