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Sample records for embryo toxicity test

  1. Use of blue crab (Callinectes sapidus) embryos for toxicity testing

    SciTech Connect

    Lee, R.; O`Malley, K.

    1995-12-31

    After fertilization, blue crab embryos develop in egg sacs attached to the female pleopods, often referred to as the sponge. Lipovitellin and lipid droplets in the egg sacs provide energy and nutrition for the developing embryos. Embryos were removed from the sponge and transferred to 24 well culture plates containing sea water with or without toxicants, Each well contained 10 embryos. After 7 to 10 days, embryos hatched to swimming zoea. The effects of toxicants at various concentrations on hatching were determined and the EC{sub 50} calculated. For example, the EC{sub 50} for tributyltin, fenvalerate and mercuric chloride were 50, 30 and 90 ng/liter, respectively. The hatching success of control embryos ranged from 95 to 98%. Formation of the heart, eyespot formation, appendage formation and utilization rate of lipovitellin were also effected by exposure to toxicants. At a low concentration of mercuric ion (30ng/liter) the heart formed, but there was no heart beat. Eyespot formation was abnormal in the presence of high concentrations of cadmium (2 {micro}g/liter) and zinc (5 {micro}g/liter), Crab embryos offer many advantages for toxicity testing of pure compounds or mixtures in water, including toxicity testing of sediment pore water. The crab embryos may also serve as models to understand the effect of specific toxicants on the heart and eye spots of crustaceans.

  2. Toxicity test of xanthone from mangosteen on zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Noordin, Muhammad Akram Mohd; Noor, Mahanem Mat; Kamaruddin, Wan Mohd Aizat Wan; Lazim, Azwan Mat; Fazry, Shazrul

    2016-11-01

    Xanthone is a chemical compound identified in mangosteen pericarp. A previous study showed that xanthone has anti-proliferating effect on cancer cells. In this study we investigate the toxicity level of xanthone in zebrafish embryo to for future reference on other animal model. We employed Fish Embryo Toxicity (FET) assay to determine the toxicity level of different concentrations of xanthone. Embryos were observed at 24, 48 and 72 hours post fertilization (hpf) under microscope at 4× magnification. The extract showed toxicity effect on embryo at concentrations of 250, 125 and 62.5 µg/mL. Concentrations at 15.63, 7.81 and 3.91 µg / mL of xanthone did not harm the embryos and showed 100% of survival.

  3. Draft Test Guideline: Bivalve Acute Toxicity Test (Embryo Larval)

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  4. Development of a general baseline toxicity QSAR model for the fish embryo acute toxicity test.

    PubMed

    Klüver, Nils; Vogs, Carolina; Altenburger, Rolf; Escher, Beate I; Scholz, Stefan

    2016-12-01

    Fish embryos have become a popular model in ecotoxicology and toxicology. The fish embryo acute toxicity test (FET) with the zebrafish embryo was recently adopted by the OECD as technical guideline TG 236 and a large database of concentrations causing 50% lethality (LC50) is available in the literature. Quantitative Structure-Activity Relationships (QSARs) of baseline toxicity (also called narcosis) are helpful to estimate the minimum toxicity of chemicals to be tested and to identify excess toxicity in existing data sets. Here, we analyzed an existing fish embryo toxicity database and established a QSAR for fish embryo LC50 using chemicals that were independently classified to act according to the non-specific mode of action of baseline toxicity. The octanol-water partition coefficient Kow is commonly applied to discriminate between non-polar and polar narcotics. Replacing the Kow by the liposome-water partition coefficient Klipw yielded a common QSAR for polar and non-polar baseline toxicants. This developed baseline toxicity QSAR was applied to compare the final mode of action (MOA) assignment of 132 chemicals. Further, we included the analysis of internal lethal concentration (ILC50) and chemical activity (La50) as complementary approaches to evaluate the robustness of the FET baseline toxicity. The analysis of the FET dataset revealed that specifically acting and reactive chemicals converged towards the baseline toxicity QSAR with increasing hydrophobicity. The developed FET baseline toxicity QSAR can be used to identify specifically acting or reactive compounds by determination of the toxic ratio and in combination with appropriate endpoints to infer the MOA for chemicals.

  5. Fish embryo toxicity test: identification of compounds with weak toxicity and analysis of behavioral effects to improve prediction of acute toxicity for neurotoxic compounds.

    PubMed

    Klüver, Nils; König, Maria; Ortmann, Julia; Massei, Riccardo; Paschke, Albrecht; Kühne, Ralph; Scholz, Stefan

    2015-06-02

    The fish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, but concerns have been raised for its predictivity given that a few compounds have been shown to exhibit a weak acute toxicity in the fish embryo. In order to better define the applicability domain and improve the predictive capacity of the fish embryo test, we performed a systematic analysis of existing fish embryo and acute fish toxicity data. A correlation analysis of a total of 153 compounds identified 28 compounds with a weaker or no toxicity in the fish embryo test. Eleven of these compounds exhibited a neurotoxic mode of action. We selected a subset of eight compounds with weaker or no embryo toxicity (cyanazine, picloram, aldicarb, azinphos-methyl, dieldrin, diquat dibromide, endosulfan, and esfenvalerate) to study toxicokinetics and a neurotoxic mode of action as potential reasons for the deviating fish embryo toxicity. Published fish embryo LC50 values were confirmed by experimental analysis of zebrafish embryo LC50 according to OECD guideline 236. Except for diquat dibromide, internal concentration analysis did not indicate a potential relation of the low sensitivity of fish embryos to a limited uptake of the compounds. Analysis of locomotor activity of diquat dibromide and the neurotoxic compounds in 98 hpf embryos (exposed for 96 h) indicated a specific effect on behavior (embryonic movement) for the neurotoxic compounds. The EC50s of behavior for neurotoxic compounds were close to the acute fish toxicity LC50. Our data provided the first evidence that the applicability domain of the fish embryo test (LC50s determination) may exclude neurotoxic compounds. However, neurotoxic compounds could be identified by changes in embryonic locomotion. Although a quantitative prediction of acute fish toxicity LC50 using behavioral assays in fish embryos may not yet be possible, the identification of neurotoxicity could trigger the conduction of a conventional fish

  6. Optimization of high-throughput nanomaterial developmental toxicity testing in zebrafish embryos

    EPA Science Inventory

    Nanomaterial (NM) developmental toxicities are largely unknown. With an extensive variety of NMs available, high-throughput screening methods may be of value for initial characterization of potential hazard. We optimized a zebrafish embryo test as an in vivo high-throughput assay...

  7. Progress Towards the Development of a Fathead Minnow Embryo Test and Comparison to the Zebrafish Embryo Test for Assessing Acute Fish Toxicity

    EPA Science Inventory

    The Zebrafish Embryo Test (ZFET) for acute fish toxicity is a well developed method nearing adoption as an OECD Test Guideline. Early drafts of the test guideline (TG) envisioned a suite of potential test species to be covered including zebrafish, fathead minnow, Japanese Medaka...

  8. PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.

    PubMed

    Seiler, Thomas-Benjamin; Best, Nina; Fernqvist, Margit Møller; Hercht, Hendrik; Smith, Kilian E C; Braunbeck, Thomas; Mayer, Philipp; Hollert, Henner

    2014-10-01

    As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates.

  9. A test for evaluating the toxicity of oils, dispersants, and oil biodegradation products to embryos of grass shrimp (Palaemonetes pugio)

    SciTech Connect

    Foss, S.S.; Fisher, W.S.; Chapman, P.J.; Shelton, M.

    1994-12-31

    A test has been developed to determine the toxicity of oil, commercial oil dispersants, and oil biodegradation products to embryos of the grass shrimp, Palaemonetes pugio. The system has several advantages over traditional toxicity tests: Embryos are exposed separately in glass tubes eliminating interaction between individuals, they do not require feeding, are easily examined, and require low volumes of test toxicant. Additionally, tests can be performed using artificial sea salts and adult P. pugio can be maintained and cultured year round in the laboratory. Toxicity tests demonstrated that oil dispersants increased the toxicity of the water-soluble fraction of No. 2 Fuel Oil with estimated LC50 values approximating those obtained with the 7d chronic tests using Mysidopsis bahia. Embryos exposed to neutral fractions derived by microbial degradation of weathered Prudhoe Bay crude oil showed toxicity of metabolic products at relatively low concentrations and cause virtually 100% mortality within a narrow time interval. P. pugio embryos were especially responsive to oil metabolites, exhibiting high sensitivity and low variability. All tests showed a consistently high survival (90--100%) of control embryos to hatch under a variety of temperatures and salinities; embryos at any given test condition usually hatched within 24h of one another.

  10. Comparison of toxicity test methods using embryos of the grass shrimp, Palaemonetes pugio

    SciTech Connect

    Rayburn, J.R.; Fisher, W.S.; Foss, S.S.; Glas, P.S.

    1995-12-31

    The embryos of the grass shrimp (Palaemonetes pugio) have shown sensitivity to the water soluble fraction of number 2 fuel oil (WSF{sub oil}). To determine the repeatability and versatility of the grass shrimp in bioassays, detailed concentration-response curves were performed using altered test methods. These alterations were to make the test system easier to use, require less volume of toxic material and to shorten the time of the assay. LC50 values for each method were obtained. The methods evaluated the differences between altering time of exposure from 12 to 4 days. The 4-day assay in 24-well plastic plates included the time of hatch, a critical life stage of these embryos. The average 12-day LC50 in the glass Leighton tubes was 11.8% VN WSF{sub oil}. The coefficient of variation of the individual test methods were approximately 25%, showing that the repeatability was reasonable for bioassays. These results show that a 4-day assay is practical for screening for the detection of number 2 fuel oil contamination. However, the 12-day assay may be necessary for detection of developmental abnormalities.

  11. Automated Lab-on-a-Chip Technology for Fish Embryo Toxicity Tests Performed under Continuous Microperfusion (μFET).

    PubMed

    Zhu, Feng; Wigh, Adriana; Friedrich, Timo; Devaux, Alain; Bony, Sylvie; Nugegoda, Dayanthi; Kaslin, Jan; Wlodkowic, Donald

    2015-12-15

    The fish embryo toxicity (FET) biotest has gained popularity as one of the alternative approaches to acute fish toxicity tests in chemical hazard and risk assessment. Despite the importance and common acceptance of FET, it is still performed in multiwell plates and requires laborious and time-consuming manual manipulation of specimens and solutions. This work describes the design and validation of a microfluidic Lab-on-a-Chip technology for automation of the zebrafish embryo toxicity test common in aquatic ecotoxicology. The innovative device supports rapid loading and immobilization of large numbers of zebrafish embryos suspended in a continuous microfluidic perfusion as a means of toxicant delivery. Furthermore, we also present development of a customized mechatronic automation interface that includes a high-resolution USB microscope, LED cold light illumination, and miniaturized 3D printed pumping manifolds that were integrated to enable time-resolved in situ analysis of developing fish embryos. To investigate the applicability of the microfluidic FET (μFET) in toxicity testing, copper sulfate, phenol, ethanol, caffeine, nicotine, and dimethyl sulfoxide were tested as model chemical stressors. Results obtained on a chip-based system were compared with static protocols performed in microtiter plates. This work provides evidence that FET analysis performed under microperfusion opens a brand new alternative for inexpensive automation in aquatic ecotoxicology.

  12. Simple test for toxicity of number 2 fuel oil and oil dispersants to embryos of grass shrimp, palaemonetes pugio

    SciTech Connect

    Fisher, W.S.; Foss, S.S.

    1993-01-01

    A simple test, using embryos of the grass shrimp Palaemonetes pugio, was employed to determine the toxicity of two commercial oil dispersants (Corexit 7664 and Corexit 9527) and toxicity of the water soluble fraction of Number 2 fuel oil (WSF oil) prepared with and without the addition of the dispersants. Tests revealed P. pugio embryos were similar to previously measured life stages in their sensitivity to WSF oil prepared without dispersants. They were approximately ten times more sensitive to water soluble fractions of dispersed oil, which may have been due to the approximately ten-fold increases in total hydrocarbons measured analytically. Both temperatures and salinity of the sea water affected toxicity of WSF prepared with dispersants, the most obvious effect being earlier onset of mortalities at higher temperatures. (Copyright (c) 1993 Pergamon Press Ltd.)

  13. Screening of Toxic Effects of Bisphenol A and Products of Its Degradation: Zebrafish (Danio rerio) Embryo Test and Molecular Docking.

    PubMed

    Makarova, Katerina; Siudem, Pawel; Zawada, Katarzyna; Kurkowiak, Justyna

    2016-10-01

    Bisphenol A (BPA) acts as an endocrine-disrupting compound even at a low concentration. Degradation of BPA could lead to the formation of toxic products. In this study, we compare the toxicity of BPA and seven intermediate products of its degradation. The accuracy of three molecular docking programs (Surflex, Autodock, and Autodock Vina) in predicting the binding affinities of selected compounds to human (ERα, ERβ, and ERRγ) and zebrafish (ERα, ERRγA, and ERRγB) estrogen and estrogen-related receptors was evaluated. The docking experiments showed that 4-isopropylphenol could have similar toxicity to that of BPA due to its high affinity to ERRγ and ERRγB and high octanol-water partitioning coefficient. The least toxic compounds were hydroquinone and phenol. Those compounds as well as BPA were screened in the zebrafish (Danio rerio) embryo test. 4-isopropylphenol had the strongest toxic effect on zebrafish embryos and caused 100% lethality shortly after exposure. BPA caused the delay in development, multiple deformations, and low heartbeats (30 bps), whereas hydroquinone had no impact on the development of the zebrafish embryo. Thus, the results of zebrafish screening are in good agreement with our docking experiment. The molecular docking could be used to screen the toxicity of other xenoestrogens and their products of degradation.

  14. Steroidal alkaloid toxicity to fish embryos.

    PubMed

    Crawford, L; Kocan, R M

    1993-02-01

    Embryos of two species of fish were evaluated for their suitability as model systems for steroidal alkaloid toxicity, the Japanese rice fish, medaka (Oryzius latipes) and the rainbow trout (Oncorhynchus mykiss). Additionally, the equine neurotoxic sesquiterpene lactone repin, was also tested. A PROBIT program was used to evaluate the EC1, EC50 and EC99 as well as the associated confidence limits. The steroidal alkaloids tested were the Solanum potato glycoalkaloids alpha-chaconine, alpha-solanine, the aglyclones solanidine and solasodine and the Veratrum alkaloid, jervine. Embryo mortality, likely due to structural or functional abnormalities in the early development stages of the embryo, were the only response observed in both species. The rainbow trout exhibited a toxic response to chaconine, solasidine, repin and solanine but the medaka embryos were only affected by the compounds, chaconine and solanine. Rainbow trout may indeed serve as a good lower vertebrate model for studying the toxicity of steroidal alkaloids.

  15. Synthesis of low and high chlorinated toxaphene and comparison of their toxicity by zebrafish (Danio rerio) embryo test.

    PubMed

    Kapp, Thomas; Kammann, Ulrike; Vobach, Michael; Vetter, Walter

    2006-11-01

    Toxaphene, also known as camphechlor, is a persistent organochlorine pesticide of complex composition. It is technically produced by photochlorination of camphene with elemental chlorine gas under ultraviolet irradiation. In the present work, a novel, laboratory-scale synthesis using sulfuryl chloride as a chlorinating reagent is described. This approach allowed the degree of chlorination of the resulting mixtures to be arbitrarily adjusted by varying the reaction conditions. Both the compositions and the chlorine contents of the low- and high-chlorinated mixtures acquired using this method were similar to those of environmentally altered toxaphene and technical toxaphene, respectively. For comparison of these mixtures regarding toxicity, they were subjected to the zebrafish (Danio rerio) embryo test. Median effective concentrations (EC50s) were calculated based on the presence of lethal and nonlethal embryonic malformations. Surprisingly, low-chlorinated toxaphene, comprising compounds that also are present in environmentally transformed toxaphene, exhibited a twofold-higher toxicity (according to the EC50 for nonlethal effects) toward the test organisms compared with high-chlorinated toxaphene, the composition of which resembled that of the technical product. Although the effective concentrations in the embryo test were much higher than those in aquatic ecosystems burdened with toxaphene, the present results lead to the assumption that toxaphene is becoming more toxic during transformation in the environment. A decrease in the total amount of toxaphene during environmental breakdown would then be compensated for, at least in part, by the higher toxicity of weathered toxaphene in sediments, soils, and biota of contaminated ecosystems.

  16. ADAPTING THE MEDAKA EMBRYO ASSAY TO A HIGH-THROUGHPUT APPROACH FOR DEVELOPMENTAL TOXICITY TESTING.

    EPA Science Inventory

    Chemical exposure during embryonic development may cause persistent effects, yet developmental toxicity data exist for very few chemicals. Current testing procedures are time consuming and costly, underlining the need for rapid and low cost screening strategies. While in vitro ...

  17. A novel system for embryo-larval toxicity testing of pelagic fish: Applications for impact assessment of Deepwater Horizon crude oil.

    PubMed

    Stieglitz, John D; Mager, Edward M; Hoenig, Ronald H; Alloy, Matthew; Esbaugh, Andrew J; Bodinier, Charlotte; Benetti, Daniel D; Roberts, Aaron P; Grosell, Martin

    2016-11-01

    Key differences in the developmental process of pelagic fish embryos, in comparison to embryos of standard test fish species, present challenges to obtaining sufficient control survival needed to successfully perform traditional toxicity testing bioassays. Many of these challenges relate to the change in buoyancy, from positive to negative, of pelagic fish embryos that occurs just prior to hatch. A novel exposure system, the pelagic embryo-larval exposure chamber (PELEC), has been developed to conduct successful bioassays on the early life stages (ELSs; embryos/larvae) of pelagic fish. Using this unique recirculating upwelling system, it was possible to significantly improve control survival in pelagic fish ELS bioassays compared to commonly used static exposure methods. Results demonstrate that control performance of mahi-mahi (Coryphaena hippurus) embryos in the PELEC system, measured as percent survival after 96-hrs, significantly outperformed agitated static exposure and static exposure systems. Similar significant improvements in 72-hr control survival were obtained with yellowfin tuna (Thunnus albacares). The PELEC system was subsequently used to test the effects of photo-induced toxicity of crude oil to mahi-mahi ELSs over the course of 96-hrs. Results indicate a greater than 9-fold increase in toxicity of Deepwater Horizon (DWH) crude oil during co-exposure to ambient sunlight compared to filtered ambient sunlight, revealing the importance of including natural sunlight in 96-hr DWH crude oil bioassays as well as the PELEC system's potential application in ecotoxicological assessments.

  18. Developmental arrest in grass shrimp embryos exposed to selected toxicants

    SciTech Connect

    Wilson, J.E.H.

    1998-12-31

    Excised embryos of the grass shrimp (Palaemonetes pugio) were exposed to single pulse concentrations of selected pollutants for 4 days. The following toxicity endpoints were monitored: rate of embryonic development, embryo mortality, and types of embryo malformation. Each endpoint exhibited concentration--response relationships which were modified by the embryonic age at which exposure commenced. Developmental retardation of up to 3 days was effected by phenol at 0.01% (V/V) and complete developmental arrest occurred at 0.05% and 0.1% (V/V). Similarly for methylene chloride, developmental retardation of 1003 days were observed at 0.1% (V/V) depending on the age of the embryos at the start of the tests. The morphological abnormalities of the embryos are described. The ecological significance of these findings and implications for the development of short-term toxicity tests using grass shrimp embryos are discussed.

  19. Toxicity of chlorine to zebrafish embryos.

    PubMed

    Kent, Michael L; Buchner, Cari; Barton, Carrie; Tanguay, Robert L

    2014-01-16

    Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce extraovum pathogens that may be released from brood fish during spawning, and this is routinely used in zebrafish Danio rerio research laboratories. Most laboratories use approximately 25 to 50 ppm unbuffered chlorine solution for 5 to 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, but is less effective against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbuffered and buffered chlorine solutions to embryos exposed at 6 or 24 h post-fertilization (hpf) to determine whether higher concentrations can be used for treating zebrafish embryos. Most of our experiments entailed using an outbred line (5D), with both mortality and malformations as endpoints. We found that 6 hpf embryos consistently were more resistant than 24 hpf embryos to the toxic effects of chlorine. Chlorine is more toxic and germicidal at lower pH, and chlorine causes elevated pH. Consistent with this, we found that unbuffered chlorine solutions (pH ca. 8-9) were less toxic at corresponding concentrations than solutions buffered to pH 7. Based on our findings here, we recommend treating 6 hpf embryos for 10 min and 24 hpf embryos for 5 min with unbuffered chlorine solution at 100 ppm.

  20. Ecotoxicological studies of environmental samples from Buenos Aires area using a standardized amphibian embryo toxicity test (AMPHITOX).

    PubMed

    Herkovits, Jorge; Perez-Coll, Cristina; Herkovits, Francisco D

    2002-01-01

    The toxicity of 34 environmental samples from potentially polluted and reference stations were evaluated by means of the AMPHITOX test from acute to chronic exposure according to the toxicity found in each sample. The samples were obtained from surface and ground water, leaches, industrial effluents and soils. The data, expressed in acute, short-term chronic and chronic Toxicity Units (TUa, TUstc and TUc) resulted in a maximal value of 1000 TUc, found in a leach, while the lower toxicity value was 1.4 TUa corresponding to two surface water samples. In five samples (four providing from reference places) no toxicity was detected. The results point out the possibility of evaluating the toxicity of a wide diversity of samples by means of AMPHITOX as a customized toxicity test. The fact that almost all samples with suspected toxicity in rivers and streams from the Metropolitan area of Buenos Aires city resulted toxic, indicates the need of enhanced stewardship of chemical substances for environmental and human health protection purposes.

  1. Extensive review of fish embryo acute toxicities for the prediction of GHS acute systemic toxicity categories.

    PubMed

    Scholz, Stefan; Ortmann, Julia; Klüver, Nils; Léonard, Marc

    2014-08-01

    Distribution and marketing of chemicals require appropriate labelling of health, physical and environmental hazards according to the United Nations global harmonisation system (GHS). Labelling for (human) acute toxicity categories is based on experimental findings usually obtained by oral, dermal or inhalative exposure of rodents. There is a strong societal demand for replacing animal experiments conducted for safety assessment of chemicals. Fish embryos are considered as alternative to animal testing and are proposed as predictive model both for environmental and human health effects. Therefore, we tested whether LC50s of the fish embryo acute toxicity test would allow effectively predicting of acute mammalian toxicity categories. A database of published fish embryo LC50 containing 641 compounds was established. For these compounds corresponding rat oral LD50 were identified resulting in 364 compounds for which both fish embryo LC50 and rat LD50 was available. Only a weak correlation of fish embryo LC50 and rat oral LD50 was obtained. Fish embryos were also not able to effectively predict GHS oral acute toxicity categories. We concluded that due to fundamental exposure protocol differences (single oral dose versus water-borne exposure) a reverse dosimetry approach is needed to explore the predictive capacity of fish embryos.

  2. Toxicity screening of diclofenac, propranolol, sertraline and simvastatin using Danio rerio and Paracentrotus lividus embryo bioassays.

    PubMed

    Ribeiro, Sílvia; Torres, Tiago; Martins, Rosário; Santos, Miguel M

    2015-04-01

    Early life-stage bioassays have been used as an alternative to short-term adult toxicity tests since they are cost-effective. A single couple can produce hundreds or thousands of embryos and hence can be used as a simple high-throughput approach in toxicity studies. In the present study, zebrafish and sea urchin embryo bioassays were used to test the toxicity of four pharmaceuticals belonging to different therapeutic classes: diclofenac, propranolol, simvastatin and sertraline. Simvastatin was the most toxic tested compound for zebrafish embryo, followed by diclofenac. Sertraline was the most toxic drug to sea urchin embryos, inducing development abnormalities at the ng/L range. Overall, our results highlight the potential of sea urchin embryo bioassay as a promising and sensitive approach for the high-throughput methods to test the toxicity of new chemicals, including pharmaceuticals, and identify several drugs that should go through more detailed toxicity assays.

  3. Testing strategies for embryo-fetal toxicity of human pharmaceuticals. Animal models vs. in vitro approaches: a workshop report.

    PubMed

    van der Laan, Jan Willem; Chapin, Robert E; Haenen, Bert; Jacobs, Abigail C; Piersma, Aldert

    2012-06-01

    Reproductive toxicity testing is characterized by high animal use. For registration of pharmaceutical compounds, developmental toxicity studies are usually conducted in both rat and rabbits. Efforts have been underway for a long time to design alternatives to animal use. Implementation has lagged, partly because of uncertainties about the applicability domain of the alternatives. The reproductive cycle is complex and not all mechanisms of development can be mimicked in vitro. Therefore, efforts are underway to characterize the available alternative tests with regard to the mechanism of action they include. One alternative test is the mouse embryonic stem cell test (EST), which has been studied since the late 1990s. It is a genuine 3R "alternative" assay as it is essentially animal-free. A meeting was held to review the state-of-the-art of various in vitro models for prediction of developmental toxicity. Although the predictivity of individual assays is improving, a battery of several assays is likely to have even higher predictivity, which is necessary for regulatory acceptance. The workshop concluded that an important first step is a thorough survey of the existing rat and rabbit studies, to fully characterize the frequency of responses and the types of effects seen. At the same time, it is important to continue the optimization of in vitro assays. As more experience accumulates, the optimal conditions, assay structure, and applicability of the alternative assays are expected to emerge.

  4. Comparison of the mouse Embryonic Stem cell Test, the rat Whole Embryo Culture and the Zebrafish Embryotoxicity Test as alternative methods for developmental toxicity testing of six 1,2,4-triazoles

    SciTech Connect

    Jong, Esther de; Barenys, Marta; Hermsen, Sanne A.B.; Verhoef, Aart; Ossendorp, Bernadette C.; Bessems, Jos G.M.; Piersma, Aldert H.

    2011-06-01

    The relatively high experimental animal use in developmental toxicity testing has stimulated the search for alternatives that are less animal intensive. Three widely studied alternative assays are the mouse Embryonic Stem cell Test (EST), the Zebrafish Embryotoxicity Test (ZET) and the rat postimplantation Whole Embryo Culture (WEC). The goal of this study was to determine their efficacy in assessing the relative developmental toxicity of six 1,2,4-triazole compounds, flusilazole, hexaconazole, cyproconazole, triadimefon, myclobutanil and triticonazole. For this purpose, we analyzed effects and relative potencies of the compounds in and among the alternative assays and compared the findings to their known in vivo developmental toxicity. Triazoles are antifungal agents used in agriculture and medicine, some of which are known to induce craniofacial and limb abnormalities in rodents. The WEC showed a general pattern of teratogenic effects, typical of exposure to triazoles, mainly consisting of reduction and fusion of the first and second branchial arches, which are in accordance with the craniofacial malformations reported after in vivo exposure. In the EST all triazole compounds inhibited cardiomyocyte differentiation concentration-dependently. Overall, the ZET gave the best correlation with the relative in vivo developmental toxicities of the tested compounds, closely followed by the EST. The relative potencies observed in the WEC showed the lowest correlation with the in vivo developmental toxicity data. These differences in the efficacy between the test systems might be due to differences in compound kinetics, in developmental stages represented and in the relative complexity of the alternative assays.

  5. Comparison of the mouse Embryonic Stem cell Test, the rat Whole Embryo Culture and the Zebrafish Embryotoxicity Test as alternative methods for developmental toxicity testing of six 1,2,4-triazoles.

    PubMed

    de Jong, Esther; Barenys, Marta; Hermsen, Sanne A B; Verhoef, Aart; Ossendorp, Bernadette C; Bessems, Jos G M; Piersma, Aldert H

    2011-06-01

    The relatively high experimental animal use in developmental toxicity testing has stimulated the search for alternatives that are less animal intensive. Three widely studied alternative assays are the mouse Embryonic Stem cell Test (EST), the Zebrafish Embryotoxicity Test (ZET) and the rat postimplantation Whole Embryo Culture (WEC). The goal of this study was to determine their efficacy in assessing the relative developmental toxicity of six 1,2,4-triazole compounds,(1) flusilazole, hexaconazole, cyproconazole, triadimefon, myclobutanil and triticonazole. For this purpose, we analyzed effects and relative potencies of the compounds in and among the alternative assays and compared the findings to their known in vivo developmental toxicity. Triazoles are antifungal agents used in agriculture and medicine, some of which are known to induce craniofacial and limb abnormalities in rodents. The WEC showed a general pattern of teratogenic effects, typical of exposure to triazoles, mainly consisting of reduction and fusion of the first and second branchial arches, which are in accordance with the craniofacial malformations reported after in vivo exposure. In the EST all triazole compounds inhibited cardiomyocyte differentiation concentration-dependently. Overall, the ZET gave the best correlation with the relative in vivo developmental toxicities of the tested compounds, closely followed by the EST. The relative potencies observed in the WEC showed the lowest correlation with the in vivo developmental toxicity data. These differences in the efficacy between the test systems might be due to differences in compound kinetics, in developmental stages represented and in the relative complexity of the alternative assays.

  6. The fish embryo toxicity test as a replacement for the larval growth and survival test: A comparison of test sensitivity and identification of alternative endpoints in zebrafish and fathead minnows.

    PubMed

    Jeffries, Marlo K Sellin; Stultz, Amy E; Smith, Austin W; Stephens, Dane A; Rawlings, Jane M; Belanger, Scott E; Oris, James T

    2015-06-01

    The fish embryo toxicity (FET) test has been proposed as an alternative to the larval growth and survival (LGS) test. The objectives of the present study were to evaluate the sensitivity of the FET and LGS tests in fathead minnows (Pimephales promelas) and zebrafish (Danio rerio) and to determine if the inclusion of sublethal metrics as test endpoints could enhance test utility. In both species, LGS and FET tests were conducted using 2 simulated effluents. A comparison of median lethal concentrations determined via each test revealed significant differences between test types; however, it could not be determined which test was the least and/or most sensitive. At the conclusion of each test, developmental abnormalities and the expression of genes related to growth and toxicity were evaluated. Fathead minnows and zebrafish exposed to mock municipal wastewater-treatment plant effluent in a FET test experienced an increased incidence of pericardial edema and significant alterations in the expression of genes including insulin-like growth factors 1 and 2, heat shock protein 70, and cytochrome P4501A, suggesting that the inclusion of these endpoints could enhance test utility. The results not only show the utility of the fathead minnow FET test as a replacement for the LGS test but also provide evidence that inclusion of additional endpoints could improve the predictive power of the FET test.

  7. Toxic effects of colloidal nanosilver in zebrafish embryos.

    PubMed

    Olasagasti, Maider; Gatti, Antonietta M; Capitani, Federico; Barranco, Alejandro; Pardo, Miguel Angel; Escuredo, Kepa; Rainieri, Sandra

    2014-05-01

    A variety of consumer products containing silver nanoparticles (Ag NPs) are currently marketed. However, their safety for humans and for the environment has not yet been established and no standard method to assess their toxicity is currently available. The objective of this work was to develop an effective method to test Ag NP toxicity and to evaluate the effects of ion release and Ag NP size on a vertebrate model. To this aim, the zebrafish animal model was exposed to a solution of commercial nanosilver. While the exposure of embryos still surrounded by the chorion did not allow a definite estimation of the toxic effects exerted by the compound, the exposure for 48 h of 3-day-old zebrafish hatched embryos afforded a reliable evaluation of the effects of Ag NPs. The effects of the exposure were detected especially at molecular level; in fact, some selected genes expressed differentially after the exposure. The Ag NP toxic performance was due to the combined effect of Ag(+) ion release and Ag NP size. However, the effect of NP size was particularly detectable at the lowest concentration of nanosilver tested (0.01 mg l(-1)) and depended on the solubilization media. The results obtained indicate that in vivo toxicity studies of nanosilver should be performed with ad hoc methods (in this case using hatched embryos) that might be different depending on the type of nanosilver. Moreover, the addition of this compound to commercial products should take into consideration the Ag NP solubilization media.

  8. The classification of motor neuron defects in the zebrafish embryo toxicity test (ZFET) as an animal alternative approach to assess developmental neurotoxicity.

    PubMed

    Muth-Köhne, Elke; Wichmann, Arne; Delov, Vera; Fenske, Martina

    2012-07-01

    Rodents are widely used to test the developmental neurotoxicity potential of chemical substances. The regulatory test procedures are elaborate and the requirement of numerous animals is ethically disputable. Therefore, non-animal alternatives are highly desirable, but appropriate test systems that meet regulatory demands are not yet available. Hence, we have developed a new developmental neurotoxicity assay based on specific whole-mount immunostainings of primary and secondary motor neurons (using the monoclonal antibodies znp1 and zn8) in zebrafish embryos. By classifying the motor neuron defects, we evaluated the severity of the neurotoxic damage to individual primary and secondary motor neurons caused by chemical exposure and determined the corresponding effect concentration values (EC₅₀). In a proof-of-principle study, we investigated the effects of three model compounds thiocyclam, cartap and disulfiram, which show some neurotoxicity-indicating effects in vertebrates, and the positive controls ethanol and nicotine and the negative controls 3,4-dichloroaniline (3,4-DCA) and triclosan. As a quantitative measure of the neurotoxic potential of the test compounds, we calculated the ratios of the EC₅₀ values for motor neuron defects and the cumulative malformations, as determined in a zebrafish embryo toxicity test (zFET). Based on this index, disulfiram was classified as the most potent and thiocyclam as the least potent developmental neurotoxin. The index also confirmed the control compounds as positive and negative neurotoxicants. Our findings demonstrate that this index can be used to reliably distinguish between neurotoxic and non-neurotoxic chemicals and provide a sound estimate for the neurodevelopmental hazard potential of a chemical. The demonstrated method can be a feasible approach to reduce the number of animals used in developmental neurotoxicity evaluation procedures.

  9. Developmental toxicity of cartap on zebrafish embryos.

    PubMed

    Zhou, Shengli; Dong, Qiaoxiang; Li, Shaonan; Guo, Jiangfeng; Wang, Xingxing; Zhu, Guonian

    2009-12-13

    Cartap is a widely used insecticide which belongs to a member of nereistoxin derivatives and acts on nicotinic acetylcholine receptor site. Its effects on aquatic species are of grave concern. To explore the potential developmental toxicity of cartap, zebrafish embryos were continually exposed, from 0.5 to 144h post-fertilization, to a range of concentrations of 25-1000microg/l. Results of the experiment indicated that cartap concentrations of 100microg/l and above negatively affected embryo survival and hatching success. Morphological analysis uncovered a large suite of abnormalities such as less melanin pigmentation, wavy notochord, crooked trunk, fuzzy somites, neurogenesis defects and vasculature defects. The most sensitive organ was proved to be the notochord which displayed defects at concentrations as low as 25microg/l. Both sensitivity towards exposure and localization of the defect were stage specific. To elucidate mechanisms concerning notochord, pigmentation, and hatching defects, enzyme assay, RT Q-PCR, and different exposure strategies were performed. For embryos with hatching failure, chorion was verified not to be digested, while removing cartap from exposure at early pre-hatching stage could significantly increase the hatching success. However, cartap was proved, via vitro assay, to have no effect on proteolytic activity of hatching enzyme. These findings implied that the secretion of hatching enzyme might be blocked. We also revealed that cartap inhibited the activity of melanogenic enzyme tyrosinase and matrix enzyme lysyl oxidase and induced expression of their genes. These suggested that cartap could impaired melanin pigmentation of zebrafish embryos through inhibiting tyrosinase activity, while inhibition of lysyl oxidase activity was responsible for notochord undulation, which subsequently caused somite defect, and at least partially responsible for defects in vasculature and neurogenesis.

  10. Evaluation of MWNT toxic effects on daphnia and zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Olasagasti, Maider; Alvarez, Noelia; Vera, Carolina; Rainieri, Sandra

    2009-05-01

    Organisms of daphnia (Daphnia magna) and zebrafish (Danio rerio) embryos were exposed to a range of different concentrations of COOH-functionalized MWCNT suspended in an aqueous solution of Tween 20. Immobilization of daphnia and growth retardation, inhibition and malformation of zebrafish embryos were the endpoints tested after 24 and 48 hours. Immobilization of daphnia could be observed from 3 to 16 ppm and an increasing mortality of zebrafish embryo was detected at all the concentration tested. To identify more subtle toxic effects, we took advantage of the extensive information available on the zebrafish genome and monitored by RT-PCR the expression patterns of different zebrafish genes that could act as toxicity bio-markers. At some of the concentrations tested, changes in the expression profiles of the genes examined were detected. Our results suggest that MWCNT could potentially represent a risk to human health and environment, therefore a wider range of concentrations and further testing of this molecules should be carried out to define possible limitations in their use.

  11. Developmental Toxicity of Drinking Water Disinfection By-Products to Embryos of the African Clawed Frog (Xenopus laevis)

    DTIC Science & Technology

    2005-06-10

    developmental toxicity tests with embryos of the South African clawed frog Xenopus laevis used to evaluate four individual DWDB; bromodichloromethane...SUBJECT TERMS Developmental toxicity; FETAX; water disinfection by-products; frogs ; Xenopus laevis; embryo malformations; embryo mortality...Disinfection By-Products to Embryos of the African Clawed Frog (Xenopus laevis) L. M. Brennan,1 M. W. Toussaint,1 D. M. Kumsher,1 W. E. Dennis,’ A. B

  12. Toxic Effects of Silica Nanoparticles on Zebrafish Embryos and Larvae

    PubMed Central

    Shi, Huiqin; Tian, Linwei; Guo, Caixia; Huang, Peili; Zhou, Xianqing; Peng, Shuangqing; Sun, Zhiwei

    2013-01-01

    Silica nanoparticles (SiNPs) have been widely used in biomedical and biotechnological applications. Environmental exposure to nanomaterials is inevitable as they become part of our daily life. Therefore, it is necessary to investigate the possible toxic effects of SiNPs exposure. In this study, zebrafish embryos were treated with SiNPs (25, 50, 100, 200 µg/mL) during 4–96 hours post fertilization (hpf). Mortality, hatching rate, malformation and whole-embryo cellular death were detected. We also measured the larval behavior to analyze whether SiNPs had adverse effects on larvae locomotor activity. The results showed that as the exposure dosages increasing, the hatching rate of zebrafish embryos was decreased while the mortality and cell death were increased. Exposure to SiNPs caused embryonic malformations, including pericardial edema, yolk sac edema, tail and head malformation. The larval behavior testing showed that the total swimming distance was decreased in a dose-dependent manner. The lower dose (25 and 50 µg/mL SiNPs) produced substantial hyperactivity while the higher doses (100 and 200 µg/mL SiNPs) elicited remarkably hypoactivity in dark periods. In summary, our data indicated that SiNPs caused embryonic developmental toxicity, resulted in persistent effects on larval behavior. PMID:24058598

  13. Chiral PCB 91 and 149 Toxicity Testing in Embryo and Larvae (Danio rerio): Application of Targeted Metabolomics via UPLC-MS/MS

    PubMed Central

    Chai, Tingting; Cui, Feng; Yin, Zhiqiang; Yang, Yang; Qiu, Jing; Wang, Chengju

    2016-01-01

    In this study, we aimed to investigate the dysfunction of zebrafish embryos and larvae induced by rac-/(+)-/(−)- PCB91 and rac-/(−)-/(+)- PCB149. UPLC-MS/MS (Ultra-performance liquid chromatography coupled with mass spectrometry) was employed to perform targeted metabolomics analysis, including the quantification of 22 amino acids and the semi-quantitation of 22 other metabolites. Stereoselective changes in target metabolites were observed in embryos and larvae after exposure to chiral PCB91 and PCB149, respectively. In addition, statistical analyses, including PCA and PLS-DA, combined with targeted metabolomics were conducted to identify the characteristic metabolites and the affected pathways. Most of the unique metabolites in embryos and larvae after PCB91/149 exposure were amino acids, and the affected pathways for zebrafish in the developmental stage were metabolic pathways. The stereoselective effects of PCB91/149 on the metabolic pathways of zebrafish embryos and larvae suggest that chiral PCB91/149 exposure has stereoselective toxicity on the developmental stages of zebrafish. PMID:27629264

  14. Chiral PCB 91 and 149 Toxicity Testing in Embryo and Larvae (Danio rerio): Application of Targeted Metabolomics via UPLC-MS/MS

    NASA Astrophysics Data System (ADS)

    Chai, Tingting; Cui, Feng; Yin, Zhiqiang; Yang, Yang; Qiu, Jing; Wang, Chengju

    2016-09-01

    In this study, we aimed to investigate the dysfunction of zebrafish embryos and larvae induced by rac-/(+)-/(‑)- PCB91 and rac-/(‑)-/(+)- PCB149. UPLC-MS/MS (Ultra-performance liquid chromatography coupled with mass spectrometry) was employed to perform targeted metabolomics analysis, including the quantification of 22 amino acids and the semi-quantitation of 22 other metabolites. Stereoselective changes in target metabolites were observed in embryos and larvae after exposure to chiral PCB91 and PCB149, respectively. In addition, statistical analyses, including PCA and PLS-DA, combined with targeted metabolomics were conducted to identify the characteristic metabolites and the affected pathways. Most of the unique metabolites in embryos and larvae after PCB91/149 exposure were amino acids, and the affected pathways for zebrafish in the developmental stage were metabolic pathways. The stereoselective effects of PCB91/149 on the metabolic pathways of zebrafish embryos and larvae suggest that chiral PCB91/149 exposure has stereoselective toxicity on the developmental stages of zebrafish.

  15. Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta

    NASA Astrophysics Data System (ADS)

    Yang, Zhihui; Zhang, Xiangjing; Cai, Zhonghua

    2009-05-01

    As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP, DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.

  16. Sediment Toxicity Testing

    EPA Science Inventory

    Sediment toxicity testing has become a fundamental component of regulatory frameworks for assessing the risks posed by contaminated sediments and for development of chemical sediment quality guidelines. Over the past two decades, sediment toxicity testing methods have advanced co...

  17. Rapid aquatic toxicity assay utilizing labeled thymidine incorporation in sea urchin embryos

    SciTech Connect

    Jackim, E.; Nacci, D.

    1984-01-01

    Aquatic toxicity was evaluated in the sea urchin embryo (Arbacea punctulata) by the inhibition of tritiated thymidine incorporation after a brief exposure to toxic chemicals. Arbacia is a useful surrogate species for assay: well-studied, easily cultured and fertile virtually year round. The simplicity and speed of this test system lends itself to screening large numbers of compounds, mixtures or water samples.

  18. Copper toxicity and copper-zinc interactions in amphibian embryos.

    PubMed

    Herkovits, J; Helguero, L A

    1998-09-29

    The copper hazard was evaluated by means of a 7-day toxicity test with Bufo arenarum embryos. The LC50 and LC10 values from 24 to 168 h of exposure were approx. 0.085 and 0.05 mg Cu2+/1, respectively, while the LC90 resulted in 0.155 mg Cu2+/1 but in this case from 96 h onwards the LC90 diminished up to approx. 0.105 mg Cu2+/1. These data plotted as Toxicity Profiles (TOP) provide a better understanding of concentration and time-dependent thresholds. For instance, exposure threshold occurs within the first 24 h of treatment while for concentration thresholds LC10 and LC90 seem to be more meaningful than LC50 because the S.D. of this last value is overlapping those of LC10 and LC90 for most of the exposure period evaluated. Toxicity data corresponds to a pH of 6.8 which is normal for the maintaining media. Combined treatments of copper and zinc point out a beneficial effect of zinc proportional to the zinc concentration in the maintaining media, e.g. 100% of protection was achieved with 30 mg Zn2+/1 for a copper concentration exerting 90% of mortality. The presence of Cu2+ did not enhance Zn2+ toxicity. The results are discussed in terms of water quality criteria for wildlife and human health protection purposes.

  19. Oil and oil dispersant do not cause synergistic toxicity to fish embryos.

    PubMed

    Adams, Julie; Sweezey, Michael; Hodson, Peter V

    2014-01-01

    Atlantic herring (Clupea harengus) embryos were exposed to water accommodated fractions (WAFs; oil dissolved in water) and chemically enhanced water accommodated fractions (CEWAFs; oil dispersed in water with Corexit 9500A) of Medium South American (MESA) crude oil. The CEWAF was approximately 100-fold more toxic than WAF based on nominal loadings of test solutions (% v/v). In contrast, the ratio of WAF and CEWAF toxicity expressed as measured oil concentrations approximated 1.0, indicating that the higher toxicity of CEWAFs was caused by an increase in exposure to hydrocarbons with chemical dispersion. In a second experiment, the chronic toxicity of Corexit 9500A and chemically dispersed heavy fuel oil 7102 (HFO 7102) to rainbow trout (Oncorhynchus mykiss) embryos was compared to chemically dispersed Nujol, a nontoxic mineral oil. Dispersant alone was toxic, but caused different signs of toxicity than HFO 7102. Nujol at a dispersant-to-oil ratio of 1:20 was nontoxic, suggesting that dispersant was sequestered by oil and not present at toxic concentrations. In contrast, the same nominal loadings of dispersed HFO 7102 caused concentration-dependent increases in toxicity. Both experiments suggest that chemically dispersed oil was more toxic to fish embryos than solutions created by mechanical mixing due to the increased exposure of fish to petroleum hydrocarbons and not to changes in hydrocarbon toxicity. The Nujol control discriminated between the toxicity of oil and chemical dispersant and would be a practical addition to programs of dispersant testing.

  20. Toxicity of selenium to developing Xenopus laevis embryos.

    PubMed

    Browne, C L; Dumont, J N

    1979-07-01

    Se in the form of sodium selenite is toxic to Xenopus laevis embryos and tadpoles continuously exposed to concentrations above 1 ppm. Concentrations of 2 ppm and above result in severe developmental abnormalities and increased mortality. Uptake and loss of radioactive Se from water are rapid, but depuration is not complete indicating that some Se can remain bound by the organism. The facts that Se is toxic at low levels to Xenopus embryos and tadpoles, can cause developmental abnormalities, and accumulates in tissues suggest that increased release of Se compounds into the environment poses a potential threat to aquatic organisms.

  1. DEVELOPMENTAL TOXICITY OF COPPER SULFATE AND METHYLENE CHLORIDE TO SHRIMP EMBRYOS

    EPA Science Inventory

    The embryos of the grass shrimp (Palaemonetes pugio) have shown sensitivity to the water-soluble fraction of Number 2 fuel oil which indicates they may be a useful test species in estuarine developmental toxicity tests. Detailed concentration-response curves for copper sulfate an...

  2. Chronic toxicity of copper on embryo development in Chinese toad, Bufo gargarizans.

    PubMed

    Xia, Kun; Zhao, Hongfeng; Wu, Minyao; Wang, Hongyuan

    2012-06-01

    This study examined the effects of copper exposure on embryonic development of Chinese toad, Bufo gargarizans. Firstly, the LC(50) values from 24 to 96 h of exposure were 3.61×10(-6) M, by means of a 4 d toxicity test with B. gargarizans embryos. Secondly, Chinese toad embryos were exposed to 10(-9)-10(-6) M copper from mid gastrula stage to operculum completion stage. Measurements included mortality, tadpole weight, tadpole total length, growth retardation, duration of different embryo stages and malformation. Embryonic survival was not affected by copper. Relative to control tadpoles, significantly decreased weight and total length were found at 10(-9)-10(-6) M reduced percentage of the embryos in right operculum stage after 10 d exposure to copper and reduced percentage of embryos in operculum completion stage after 12 d exposure to copper were also observed. Moreover, the duration of embryonic development increased at neural, circulation and operculum development stage in copper-treated groups. For the scanning microscope and histological observation, the abnormalities were malformation of wavy dorsal fin, flexural tail, curvature body axis, yolk sac oedema and reduced pigmentation in the yolk sac. Histopathological changes in olfactory, retinal epithelium and skin were also observed. DNA strand breaks exposed to the copper were analyzed by DNA ladder. In conclusion, copper induced toxic effects on B. gargarizans embryos. The present study indicated chronic toxicity tests may provide more accurate way in formulating the "safe levels" of heavy metals to amphibian.

  3. Developmental toxicity of albendazole and its three main metabolites in zebrafish embryos.

    PubMed

    Carlsson, Gunnar; Patring, Johan; Ullerås, Erik; Oskarsson, Agneta

    2011-07-01

    Albendazole (ABZ) is used as an anthelmintic drug in humans and animals. ABZ has been shown to cause developmental toxicity in experimental animals, however it is not clear if this is caused by the parent compound or a metabolite. Zebrafish embryos were exposed from 1 to 144hpf (hours post fertilization) to investigate the developmental toxicity of ABZ, the first metabolite albendazole sulphoxide and the subsequent metabolites albendazole sulphone (ABZSO(2)) and albendazole-2-aminosulphone (ABZSO(2)NH(2)). The results showed that ABZ caused malformations of head and tail and embryonic lethality from 0.3μM. In contrast, the metabolites did not display developmental toxicity at any tested concentration. Dechorionation did not influence the developmental toxic potential of ABZ and ABZSO, indicating that bioavailability was not a limiting factor. Chemical analysis showed that at sublethal concentrations, most of ABZ was metabolized to ABZSO. The results demonstrate that in zebrafish embryos ABZ rather than ABZSO displays developmental toxicity.

  4. Estradiol uptake, toxicity, metabolism, and adverse effects on cadmium-treated amphibian embryos.

    PubMed Central

    Fridman, Osvaldo; Corró, Lucrecia; Herkovits, Jorge

    2004-01-01

    The exposure of Bufo arenarum embryos to 25 micromol/L 17beta-estradiol (E2) resulted in 100% lethality within 48 hr, whereas 10 micromol//L E2 was the no observed effect concentration value for short-term chronic (7 days) exposure. The toxicity profile curves show that lethal effects were proportional to the E2 concentration and the time of exposure. The E2 uptake resulted in 20.1 ng E2/mg embryo at 8 hr posttreatment, but 67.3% of this value was achieved during the first 30 min of incubation with this estrogen. Regarding metabolism, the embryos synthesize estrone (E1) from E2 by means of 17beta-hydroxysteroid dehydrogenase. Simultaneous treatments of Bufo arenarum embryos with 1 mg/L Cd2+ and 0.1, 1, or 10 micromol/L E2 enhanced the lethality exerted by cadmium in 76.7, 80, and 83.3% of embryos, respectively. The results indicate that estrogenic endocrine disruptors could have an adverse effect on amphibian embryos and enhance the toxic effect of Cd on amphibian embryos. This study points to the possibility of using the AMPHITOX test as a screening method for potential endocrine disruption as well as the combined effects of chemical mixtures. PMID:15175173

  5. Virtual Embryo: Systems Modeling in Developmental Toxicity

    EPA Science Inventory

    High-throughput and high-content screening (HTS-HCS) studies are providing a rich source of data that can be applied to in vitro profiling of chemical compounds for biological activity and potential toxicity. EPA’s ToxCast™ project, and the broader Tox21 consortium, in addition t...

  6. Nanomaterial Toxicity Screening in Developing Zebrafish Embryos

    EPA Science Inventory

    To assess nanomaterial vertebrate toxicity, a high-content screening assay was created using developing zebrafish, Danio rerio. This included a diverse group of nanomaterials (n=42 total) ranging from metallic (Ag, Au) and metal oxide (CeO2, CuO, TiO2, ZnO) nanoparticles, to non...

  7. Use of Medaka in Toxicity Testing

    PubMed Central

    Cowden, John; Hinton, David E.; Johnson, Rodney; Flynn, Kevin; Hardman, Ronald C.; Yuen, Bonny; Law, Sheran; Kullman, Seth W.; Au, Doris W.T.

    2015-01-01

    Small aquarium fishes are increasingly used as animal models, and one of these, Japanese Medaka (Oryzias latipes), is frequently utilized for toxicity testing. While these vertebrates have many similarities with their terrestrial counterparts, there are differences that must be considered if these organisms are to be used to their highest potential. Testing commonly may employ either the developing embryo or adults; both are easy to use and to work with. We present here three main protocols to illustrate the utility and breadth of toxicity testing possible using medaka fish. The first protocol assesses neurotoxicity in developing embryos. The second protocol describes the sexual genotyping of medaka to evaluate toxicant effects on sexual phenotype after treatment with endocrine disrupting chemicals. The third protocol assesses hepatotoxicity in adult fish after treatment with a model hepatotoxicant. The methods run the gamut from immunohistology through PCR to basic histological techniques. PMID:20922755

  8. Tissue-specific direct microtransfer of nanomaterials into Drosophila embryos as a versatile in vivo test bed for nanomaterial toxicity assessment

    PubMed Central

    Vega-Alvarez, Sasha; Herrera, Adriana; Rinaldi, Carlos; Carrero-Martínez, Franklin A

    2014-01-01

    Nanomaterials are the subject of intense research, focused on their synthesis, modification, and biomedical applications. Increased nanomaterial production and their wide range of applications imply a higher risk of human and environmental exposure. Unfortunately, neither environmental effects nor toxicity of nanomaterials to organisms are fully understood. Cost-effective, rapid toxicity assays requiring minimal amounts of materials are needed to establish both their biomedical potential and environmental safety standards. Drosophila exemplifies an efficient and cost-effective model organism with a vast repertoire of in vivo tools and techniques, all with high-throughput scalability and screening feasibility throughout its life cycle. Here we report tissue specific nanomaterial assessment through direct microtransfer into target tissues. We tested several nanomaterials with potential biomedical applications such as single-wall carbon nanotubes, multiwall carbon nanotubes, silver, gold, titanium dioxide, and iron oxide nanoparticles. Assessment of nanomaterial toxicity was conducted by evaluating progression through developmental morphological milestones in Drosophila. This cost-effective assessment method is amenable to high-throughput screening. PMID:24790441

  9. ENGINEERING BULLETIN: BIOLOGICAL TOXICITY TESTING

    EPA Science Inventory

    This Engineering Bulletin is intended to provide site managers with information on ecological assessment and biological toxicity testing, applicability of biological toxicity testing, planning effective biological toxicity assessments, descriptions of test methods, limitations, c...

  10. Combined endosulfan and cypermethrin-induced toxicity to embryo-larval development of Rhinella arenarum.

    PubMed

    Svartz, Gabriela V; Aronzon, Carolina M; Pérez Coll, Cristina S

    2016-01-01

    The combined effects of two widely used pesticides, endosulfan and cypermethrin, on survival of embryo-larval development of the South American toad (Rhinella arenarum) were examined. The toxicity bioassays were performed according to the AMPHITOX test. Embryos and larvae were exposed to mixtures of these pesticides at equitoxic ratios from acute or chronic exposure to evaluate interaction effects. The results were analyzed using both Marking's additive index and combination index (CI)-isobologram methods. Acute (96-h) and intermediate (168-h) toxicity of endosulfan-cypermethrin mixtures remained almost constant for larvae and embryos, but when exposure duration was increased, there was a significant elevation in toxicity, obtaining chronic (240-h) no-observed-effect concentrations (NOEC) values of 0.045 and 0.16 mg/L for embryos and larvae, respectively. These are environmentally relevant concentrations that reflect a realistic risk of this pesticide mixture to this native amphibian species. The toxicity increment with the exposure duration was coincident with the central nervous system development on embryos reaching the larval period, the main target organ of these pesticides. The interactions of the pesticide mixtures at acute and chronic exposure were antagonistic for embryo development (CI > 1), and additive (CI = 1) for larvae, while chronic exposure interactions were synergistic (CI < 1) for both developmental periods. Data indicated that endosulfan-cypermethrin mixtures resulted in different interaction types depending on duration and developmental stage exposed. As a general pattern and considering conditions of overall developmental period and chronic exposure, this pesticide mixture usually applied in Argentine crop fields is synergistic with respect to toxicity for this native amphibian species.

  11. Virtual Embryo: Systems Modeling in Developmental Toxicity

    EPA Science Inventory

    High-throughput screening (HTS) studies are providing a rich source of data that can be applied to chemical profiling to address sensitivity and specificity of molecular targets, biological pathways, cellular and developmental processes. EPA’s ToxCast project is testing 960 uniq...

  12. Ultraviolet Radiation Enhances the Toxicity of Deepwater Horizon Oil to Mahi-mahi (Coryphaena hippurus) Embryos.

    PubMed

    Alloy, Matthew; Baxter, David; Stieglitz, John; Mager, Edward; Hoenig, Ronald; Benetti, Daniel; Grosell, Martin; Oris, James; Roberts, Aaron

    2016-02-16

    The 2010 Deepwater Horizon oil spill resulted in the accidental release of millions barrels of crude oil into the Gulf of Mexico. Photoinduced toxicity following coexposure to ultraviolet (UV) radiation is one mechanism by which polycyclic aromatic hydrocarbons (PAHs) from oil spills may exert toxicity. Mahi-mahi (Coryphaena hippurus), an important fishery resource, have positively buoyant, transparent eggs. These characteristics may result in mahi-mahi embryos being at particular risk from photoinduced toxicity. The goal of this study was to determine whether exposure to ultraviolet radiation as natural sunlight enhances the toxicity of crude oil to embryonic mahi-mahi. Mahi-mahi embryos were exposed to several dilutions of water accommodated fractions (WAF) from slick oil collected during the 2010 spill and gradations of natural sunlight in a fully factorial design. Here, we report that coexposure to natural sunlight and WAF significantly reduced percent hatch in mahi-mahi embryos. Effect concentrations of PAH in WAF were within the range of surface PAH concentrations reported in the Gulf of Mexico during the Deepwater Horizon spill. These data suggest that laboratory toxicity tests that do not include UV may underestimate the toxicity of oil spills to early lifestage fish species.

  13. Rapid aquatic toxicity assay using incorporation of tritiated-thymidine into sea urchin, Arbacia punctulata, embryo: evaluation of toxicant exposure procedures

    SciTech Connect

    Nacci, D.E.; Jackim, E.

    1985-01-01

    Toxicity of substances in seawater was measured using growth inhibition of embryonic sea urchins during a short period after fertilization. Growth of Arbacia punctulata embryos was monitored by incorporation of tritium-labeled thymidine. The paper presents a comparison of toxicant exposure procedures using the Arbacia embryo thymidine incorporation test. Toxicant exposure began before, at the time of, or after fertilization and continued for 4 h following fertilization. In addition to the eight organic chemicals tested for comparison to acute toxicity values for other species, several chemicals with embryotoxic potentials (tumor promoters and teratogens) were tested to determine differential sensitivities of exposed life-stages: unfertilized egg, fertilization, and early embryo. EC50 values for any one substance were not significantly changed by exposure modification. Toxicity values for exposures that included fertilization as well as early embryo growth were at least as sensitive as post-fertilization exposure values for all compounds tested except one. Because of technical ease and potential sensitivity, toxicant exposure that includes fertilization as well as early embryo growth (but not unfertilized egg exposure) is recommended for future testing.

  14. Molecular mechanisms of toxicity of silver nanoparticles in zebrafish embryos.

    PubMed

    van Aerle, Ronny; Lange, Anke; Moorhouse, Alex; Paszkiewicz, Konrad; Ball, Katie; Johnston, Blair D; de-Bastos, Eliane; Booth, Timothy; Tyler, Charles R; Santos, Eduarda M

    2013-07-16

    Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk-, and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24 h of exposure, but with a recovery at 48 h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24 h, but not at 48 h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms.

  15. Molecular Mechanisms of Toxicity of Silver Nanoparticles in Zebrafish Embryos

    PubMed Central

    2013-01-01

    Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk-, and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24 h of exposure, but with a recovery at 48 h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24 h, but not at 48 h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms. PMID:23758687

  16. Status and applications of echinoid (phylum echinodermata) toxicity test methods

    SciTech Connect

    Bay, S.; Burgess, R.; Nacci, D.

    1993-01-01

    The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). The status and relative sensitivity of various test methods are described. The most frequently used test methods consist of short-term exposures of sea urchin sperm or embryos; these tests can be easily conducted at all times of the year by using species with complementary spawning cycles or laboratory conditioned populations of a single species. Data from reference toxicant and effluent toxicity tests are summarized. Information on the precision and sensitivity of echinoid test methods are limited and preclude rigorous comparisons with other test methods. The available data indicate that the sensitivity and precision of these methods are comparable to short-term chronic methods for other marine invertebrates and fish. Recent application of the sperm test in toxicity identification evaluations (TIEs) and studies of effluent toxicity decay and sediment toxicity illustrate the versatility of this rapid (10 to 60 min exposure) test method. Embryo tests typically use a 48 to 96 h exposure period and measure the occurrence of embryo malformations. Most recent applications of the embryo test have been for the assessment of sediment elutriate toxicity. Adult echinoderms are not frequently used to assess effluent or receiving water toxicity. Recent studies have had success in using the adult life stage of urchins and sand dollars to assess the effects of contaminated sediment on growth, behavior, and bioaccumulation.

  17. [Interaction between calcium and lead affects the toxicity to embryo of zebrafish (Danio rerio)].

    PubMed

    Chen, Zhong-Zhi; Zhu, Lin; Yao, Kun; Wang, Xiu-Juan; Ding, Jun-Nan

    2009-04-15

    This study tested the hypothesis that increased Ca2+ content increases the sensitivity of the developing embryos and larvae of zebrafish (Danio rerio) to Pb. And the aim of the study was to investigate the extent to which calcium can individually mitigate lead ion toxicity based on the concept of biotic ligand model (BLM). Embryos of the zebrafish were exposed to various Pb concentrations. Chemical characteristics of water and representative toxicological endpoints of zebrafish embryo were recorded. And general growth retardation as a major toxicological endpoint was used for analysis at 72 h due to its sensitivity and facility. The BLM software of Visual MINTEQ (Version 2.5.2) was employed to calculate the chemical speciation in the solution. The results showed that when Ca2+ concentration increased from 0.25 mmol/L to 2.00 mmol/L, the toxicity of lead on embryos of zebrafish (Danio rerio) decreased markedly after 72 h. And a large part of these decrease can be explained by the positive linear relations between EC50{Pb2+}/EC50[Pb]T (expressed as lead ion activity/dissolved total concentration) and activity/total concentration of Ca2+, through which the influence of Ca2+ on toxicity could be predicted. The results support the assumptions of the BLM and associated with competition between lead and calcium for binding on transport and toxic action sites on biological surfaces. However, when Ca2+ concentration increased from 2.00 mmol/L to 4.00 mmol/L, the toxicity of lead on embryos of zebrafish (Danio rerio) seemed to be constant at 72 h.

  18. Assessing the toxicity of TBBPA and HBCD by zebrafish embryo toxicity assay and biomarker analysis.

    PubMed

    Hu, Jun; Liang, Yong; Chen, Minjie; Wang, Xiaorong

    2009-08-01

    Tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are two of the most widely used brominated flame retardants (BFRs). The biological toxicity effect of TBBPA and HBCD was studied by means of zebrafish embryo toxicity assays in combination with three biomarkers, including superoxide dismutase (SOD), lipid peroxidation, (LPO), and heat shock protein (Hsp70). The standard zebrafish embryo assay showed that high concentrations of TBBPA (> or =0.75 mg/L) can cause lethality or malformation. For HBCD within the concentration range (0.002-10 mg/L), no endpoint was observed. Furthermore, SOD activities of zebrafish embryos exposed to TBBPA were increased with the increasing concentrations. SOD activities in the group treated by HBCD showed an increase followed by a decline. Regardless of TBBPA or HBCD, LPO were increased along with the increase of the concentration. The change pattern of Hsp70 levels was the same with LPO. All these results showed that TBBPA and HBCD could cause oxidative stress and Hsp70 overexpression, inducing acute toxicity to zebrafish embryo in a short-term exposure. The study also indicates that the zebrafish embryo assay in combination with the biomarkers is effective in aquatic environmental toxicology and risk assessment.

  19. Copper toxicity to sperm, embryos and larvae of topsmelt 'Atherinops affinis', with notes on induced spawning

    SciTech Connect

    Anderson, B.S.; Middaugh, D.P.; Hunt, J.W.; Turpen, S.L.

    1991-01-01

    Topsmelt, Atherinops affinis, were induced to spawn repeatedly in the laboratory using a combination of environmental cues. Temperature spikes appeared to be the most important factor to induce spawning. Egg production peaked four days after a 2C increase in water temperature, and declined thereafter. A series of static toxicity tests compared the relative sensitivity of topsmelt sperm, embryos, and larvae to copper chloride. Of the three developmental stages compared, sperm were more sensitive than embryos, and embryos were more sensitive than larvae. The mean EC50 from four separate 48-h fertilization experiments was 109 micrograms copper/liter. The mean EC50 from three, 12-day embryo development development tests was 142-147 micrograms copper/liter, depending on the endpoint used. The mean LC50 from three, 96-h larval mortality tests was 238 micrograms copper/liter. Topsmelt are amenable to laboratory culture and are a promising eastern Pacific toxicity test species. (Copyright (c) 1991 Elsevier Science Publishers Ltd, England.)

  20. Toxicity Estimation Software Tool (TEST)

    EPA Science Inventory

    The Toxicity Estimation Software Tool (TEST) was developed to allow users to easily estimate the toxicity of chemicals using Quantitative Structure Activity Relationships (QSARs) methodologies. QSARs are mathematical models used to predict measures of toxicity from the physical c...

  1. Developmental toxicity and alteration of gene expression in zebrafish embryos exposed to PFOS

    SciTech Connect

    Shi Xiongjie; Du Yongbing; Lam, Paul K.S.; Wu, Rudolf S.S.; Zhou Bingsheng

    2008-07-01

    Perfluorooctanesulfonate (PFOS) is a persistent organic pollutant, the potential toxicity of which is causing great concern. In the present study, we employed zebrafish embryos to investigate the developmental toxicity of this compound. Four-hour post-fertilization (hpf) zebrafish embryos were exposed to 0.1, 0.5, 1, 3 and 5 mg/L PFOS. Hatching was delayed and hatching rates as well as larval survivorship were significantly reduced after the embryos were exposed to 1, 3 and 5 mg/L PFOS until 132 hpf. The fry displayed gross developmental malformations, including epiboly deformities, hypopigmentation, yolk sac edema, tail and heart malformations and spinal curvature upon exposure to PFOS concentrations of 1 mg/L or greater. Growth (body length) was significantly reduced in the 3 and 5 mg/L PFOS-treated groups. To test whether developmental malformation was mediated via apoptosis, flow cytometry analysis of DNA content, acridine orange staining and TUNEL assay was used. These techniques indicated that more apoptotic cells were present in the PFOS-treated embryos than in the control embryos. Certain genes related to cell apoptosis, p53 and Bax, were both significantly up-regulated upon exposure to all the concentrations tested. In addition, we investigated the effects of PFOS on marker genes related to early thyroid development (hhex and pax8) and genes regulating the balance of androgens and estrogens (cyp19a and cyp19b). For thyroid development, the expression of hhex was significantly up-regulated at all concentrations tested, whereas pax8 expression was significantly up-regulated only upon exposure to lower concentrations of PFOS (0.1, 0.5, 1 mg/L). The expression of cyp19a and of cyp19b was significantly down-regulated at all exposure concentrations. The overall results indicated that zebrafish embryos constitute a reliable model for testing the developmental toxicity of PFOS, and the gene expression patterns in the embryos were able to reveal some potential

  2. The sea urchin, Paracentrotus lividus, embryo as a "bioethical" model for neurodevelopmental toxicity testing: effects of diazinon on the intracellular distribution of OTX2-like proteins.

    PubMed

    Aluigi, M G; Angelini, C; Corte, G; Falugi, C

    2008-12-01

    Presently, a large effort is being made worldwide to increase the sustainability of industrial development, while preserving not only the quality of the environment but also that of animal and human life. In this work, sea urchin early developmental stages were used as a model to test the effects of the organophosphate pesticide (diazinon) on the regulation of gene expression by immunohistochemical localization of the human regulatory protein against the human OTX2. Egg exposure to diazinon did not affect fertilization; however, at concentrations 10(-5)-10(-6) M, it did cause developmental anomalies, among which was the dose-dependent alteration of the intracellular distribution of a regulatory protein that is immunologically related to the human OTX2. The severe anomalies and developmental delay observed after treatment at 10(-5) M concentration are indicators of systemic toxicity, while the results after treatment at 10(-6) M suggest a specific action of the neurotoxic compound. In this second case, exposure to diazinon caused partial delivery of the protein into the nuclei, a defective translocation that particularly affected the blastula and gastrula stages. Therefore, the possibility that neurotoxic agents such as organophosphates may damage embryonic development is taken into account. Specifically, the compounds are known to alter cytoplasmic dynamics, which play a crucial role in regulating the distribution of intracellular structures and molecules, as well as transcription factors. Speculatively, basing our assumptions on Fura2 experiments, we submit the hypothesis that this effect may be due to altered calcium dynamics, which in turn alter cytoskeleton dynamics: the asters, in fact, appear strongly positive to the OTX2 immunoreaction, in both control and exposed samples. Coimmunoprecipitation experiments seem to supply evidence to the hypothesis.

  3. The developmental toxicity of three carrier solvents using embryos of the grass shrimp, Palaemonetes pugio

    SciTech Connect

    Rayburn, J.R.; Fisher, W.S.

    1995-12-31

    The embryos of the grass shrimp (Palaemonetes pugio) have shown sensitivity to the water-soluble fraction of Number 2 fuel oil which indicates this test may be ideal for use as an estuarine developmental toxicity test. Many chemicals that require testing of this nature are insoluble in water. To determine the possible use of carrier solvents in the grass shrimp bioassays, detailed concentration-response curves for each solvent were performed using two test methods. LC50 values for each method were obtained. The first test was a 4-day assay that included the time of hatch, a critical life stage of these embryos. The second test was a 12-d assay which included development from tissue cap stage embryos through 2 days post hatch. The average 4-day LC50s for ETOH, DMSO and acetone were 12.07, 22.57, and 6.80 g/L, respectively. The average 12-day LC50s for ETOH, DMSO and Acetone were 3.63, 12.33 and 6.94 g/L, respectively. The coefficients of variation of each test were always less than 25.2%. Eye malformations were observed with embryos exposed to ETOH, while embryos exposed to DMSO and acetone showed very little embryo malformation. One experiment showed abnormal development of the last abdominal segment. Based on the concentration-response curves, the maximum allowable limit of ETOH, DMSO and acetone to be used as a carrier should be 1, 6, and 4 g/L, respectively.

  4. Effects-driven chemical fractionation of heavy fuel oil to isolate compounds toxic to trout embryos.

    PubMed

    Bornstein, Jason M; Adams, Julie; Hollebone, Bruce; King, Thomas; Hodson, Peter V; Brown, R Stephen

    2014-04-01

    Heavy fuel oil (HFO) spills account for approximately 60% of ship-source oil spills and are up to 50 times more toxic than medium and light crude oils. Heavy fuel oils contain elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and alkyl-PAHs, known to be toxic to fish; however, little direct characterization of HFO toxicity has been reported. An effects-driven chemical fractionation was conducted on HFO 7102 to separate compounds with similar chemical and physical properties, including toxicity, to isolate the groups of compounds most toxic to trout embryos. After each separation, toxicity tests directed the next phase of fractionation, and gas chromatography-mass spectrometry analysis correlated composition with toxicity, with a focus on PAHs. Low-temperature vacuum distillation permitted the separation of HFO into 3 fractions based on boiling point ranges. The most toxic of these fractions underwent wax precipitation to remove long-chain n-alkanes. The remaining PAH-rich extract was further separated using open column chromatography, which provided distinct fractions that were grouped according to increasing aromatic ring count. The most toxic of these fractions was richest in PAHs and alkyl-PAHs. The results of the present study were consistent with previous crude oil studies that identified PAH-rich fractions as the most toxic.

  5. Nickel and Copper Toxicity to Embryos of the Long-Spined Sea Urchin, Diadema savignyi.

    PubMed

    Rosen, G; Rivera-Duarte, I; Colvin, M A; Dolecal, R E; Raymundo, L J; Earley, P J

    2015-07-01

    The sensitivity of long-spined sea urchins (Diadema savignyi) collected from Guam (Northern Marianas Islands), USA, to nickel and copper in seawater was explored using 48-h embryo-larval development toxicity tests. The median effective concentrations (EC50) averaged 94 µg L(-1) for nickel, and 19 µg L(-1) from a single exposure to copper, and suggest relatively high sensitivity of this species to nickel compared with other sea urchin genera, but similar sensitivity to copper. Ambient nickel and copper concentrations concurrently sampled from 16 near-shore locations around Guam were one to two orders of magnitude lower than those that would be expected to result in adverse effects to D. savignyi embryos. Although nationally recommended chronic ambient water quality criteria, currently 8.2 and 3.1 µg L(-1) for nickel and copper, respectively, were not exceeded, recently derived qualifying toxicity data should be considered for updating these criteria to ensure protectiveness of sensitive tropical species.

  6. Screening the Toxicity of Selected Personal Care Products Using Embryo Bioassays: 4-MBC, Propylparaben and Triclocarban.

    PubMed

    Torres, Tiago; Cunha, Isabel; Martins, Rosário; Santos, Miguel M

    2016-10-21

    Recently, several emerging pollutants, including Personal Care Products (PCPs), have been detected in aquatic ecosystems, in the ng/L or µg/L range. Available toxicological data is limited, and, for certain PCPs, evidence indicates a potential risk for the environment. Hence, there is an urgent need to gather ecotoxicological data on PCPs as a proxy to improve risk assessment. Here, the toxicity of three different PCPs (4-Methylbenzylidene Camphor (4-MBC), propylparaben and triclocarban) was tested using embryo bioassays with Danio rerio (zebrafish) and Paracentrotus lividus (sea urchin). The No Observed Effect Concentration (NOEC) for triclocarban was 0.256 µg/L for sea urchin and 100 µg/L for zebrafish, whereas NOEC for 4-MBC was 0.32 µg/L for sea urchin and 50 µg/L for zebrafish. Both PCPs impacted embryo development at environmentally relevant concentrations. In comparison with triclocarban and 4-MBC, propylparaben was less toxic for both sea urchin (NOEC = 160 µg/L) and zebrafish (NOEC = 1000 µg/L). Overall, this study further demonstrates the sensitivity of embryo bioassays as a high-throughput approach for testing the toxicity of emerging pollutants.

  7. Screening the Toxicity of Selected Personal Care Products Using Embryo Bioassays: 4-MBC, Propylparaben and Triclocarban

    PubMed Central

    Torres, Tiago; Cunha, Isabel; Martins, Rosário; Santos, Miguel M.

    2016-01-01

    Recently, several emerging pollutants, including Personal Care Products (PCPs), have been detected in aquatic ecosystems, in the ng/L or µg/L range. Available toxicological data is limited, and, for certain PCPs, evidence indicates a potential risk for the environment. Hence, there is an urgent need to gather ecotoxicological data on PCPs as a proxy to improve risk assessment. Here, the toxicity of three different PCPs (4-Methylbenzylidene Camphor (4-MBC), propylparaben and triclocarban) was tested using embryo bioassays with Danio rerio (zebrafish) and Paracentrotus lividus (sea urchin). The No Observed Effect Concentration (NOEC) for triclocarban was 0.256 µg/L for sea urchin and 100 µg/L for zebrafish, whereas NOEC for 4-MBC was 0.32 µg/L for sea urchin and 50 µg/L for zebrafish. Both PCPs impacted embryo development at environmentally relevant concentrations. In comparison with triclocarban and 4-MBC, propylparaben was less toxic for both sea urchin (NOEC = 160 µg/L) and zebrafish (NOEC = 1000 µg/L). Overall, this study further demonstrates the sensitivity of embryo bioassays as a high-throughput approach for testing the toxicity of emerging pollutants. PMID:27775672

  8. Acute embryo toxicity and teratogenicity of three potential biofuels also used as flavor or solvent.

    PubMed

    Bluhm, Kerstin; Seiler, Thomas-Benjamin; Anders, Nico; Klankermayer, Jürgen; Schaeffer, Andreas; Hollert, Henner

    2016-10-01

    The demand for biofuels increases due to concerns regarding greenhouse gas emissions and depletion of fossil oil reserves. Many substances identified as potential biofuels are solvents or already used as flavors or fragrances. Although humans and the environment may be readily exposed little is known regarding their (eco)toxicological effects. In this study, the three potential biofuels ethyl levulinate (EL), 2-methyltetrahydrofuran (2-MTHF) and 2-methylfuran (2-MF) were investigated for their acute embryo toxicity and teratogenicity using the fish embryo toxicity (FET) test to identify unknown hazard potentials and to allow focusing further research on substances with low toxic potentials. In addition, two fossil fuels (diesel and gasoline) and an established biofuel (rapeseed oil methyl ester) were investigated as references. The FET test is widely accepted and used in (eco)toxicology. It was performed using the zebrafish Danio rerio, a model organism useful for the prediction of human teratogenicity. Testing revealed a higher acute toxicity for EL (LC50: 83mg/L) compared to 2-MTHF (LC50: 2980mg/L), 2-MF (LC50: 405mg/L) and water accommodated fractions of the reference fuels including gasoline (LC50: 244mg DOC/L). In addition, EL caused a statistically significant effect on head development resulting in elevated head lengths in zebrafish embryos. Results for EL reduce its likelihood of use as a biofuel since other substances with a lower toxic potential are available. The FET test applied at an early stage of development might be a useful tool to avoid further time and money requiring steps regarding research on unfavorable biofuels.

  9. Unexpected Interaction with Dispersed Crude Oil Droplets Drives Severe Toxicity in Atlantic Haddock Embryos

    PubMed Central

    Sørhus, Elin; Edvardsen, Rolf B.; Karlsen, Ørjan; Nordtug, Trond; van der Meeren, Terje; Thorsen, Anders; Harman, Christopher; Jentoft, Sissel; Meier, Sonnich

    2015-01-01

    The toxicity resulting from exposure to oil droplets in marine fish embryos and larvae is still subject for debate. The most detailed studies have investigated the effects of water-dissolved components of crude oil in water accommodated fractions (WAFs) that lack bulk oil droplets. Although exposure to dissolved petroleum compounds alone is sufficient to cause the characteristic developmental toxicity of crude oil, few studies have addressed whether physical interaction with oil micro-droplets are a relevant exposure pathway for open water marine speices. Here we used controlled delivery of mechanically dispersed crude oil to expose pelagic embryos and larvae of a marine teleost, the Atlantic haddock (Melanogrammus aeglefinus). Haddock embryos were exposed continuously to two different concentrations of dispersed crude oil, high and low, or in pulses. By 24 hours of exposure, micro-droplets of oil were observed adhering and accumulating on the chorion, accompanied by highly elevated levels of cyp1a, a biomarker for exposure to aromatic hydrocarbons. Embryos from all treatment groups showed abnormalities representative of crude oil cardiotoxicity at hatch (5 days of exposure), such as pericardial and yolk sac edema. Compared to other species, the frequency and severity of toxic effects was higher than expected for the waterborne PAH concentrations (e.g., 100% of larvae had edema at the low treatment). These findings suggest an enhanced tissue uptake of PAHs and/or other petroleum compounds from attached oil droplets. These studies highlight a novel property of haddock embryos that leads to greater than expected impact from dispersed crude oil. Given the very limited number of marine species tested in similar exposures, the likelihood of other species with similar properties could be high. This unanticipated result therefore has implications for assessing the ecological impacts of oil spills and the use of methods for dispersing oil in the open sea. PMID:25923774

  10. Unexpected interaction with dispersed crude oil droplets drives severe toxicity in Atlantic haddock embryos.

    PubMed

    Sørhus, Elin; Edvardsen, Rolf B; Karlsen, Ørjan; Nordtug, Trond; van der Meeren, Terje; Thorsen, Anders; Harman, Christopher; Jentoft, Sissel; Meier, Sonnich

    2015-01-01

    The toxicity resulting from exposure to oil droplets in marine fish embryos and larvae is still subject for debate. The most detailed studies have investigated the effects of water-dissolved components of crude oil in water accommodated fractions (WAFs) that lack bulk oil droplets. Although exposure to dissolved petroleum compounds alone is sufficient to cause the characteristic developmental toxicity of crude oil, few studies have addressed whether physical interaction with oil micro-droplets are a relevant exposure pathway for open water marine speices. Here we used controlled delivery of mechanically dispersed crude oil to expose pelagic embryos and larvae of a marine teleost, the Atlantic haddock (Melanogrammus aeglefinus). Haddock embryos were exposed continuously to two different concentrations of dispersed crude oil, high and low, or in pulses. By 24 hours of exposure, micro-droplets of oil were observed adhering and accumulating on the chorion, accompanied by highly elevated levels of cyp1a, a biomarker for exposure to aromatic hydrocarbons. Embryos from all treatment groups showed abnormalities representative of crude oil cardiotoxicity at hatch (5 days of exposure), such as pericardial and yolk sac edema. Compared to other species, the frequency and severity of toxic effects was higher than expected for the waterborne PAH concentrations (e.g., 100% of larvae had edema at the low treatment). These findings suggest an enhanced tissue uptake of PAHs and/or other petroleum compounds from attached oil droplets. These studies highlight a novel property of haddock embryos that leads to greater than expected impact from dispersed crude oil. Given the very limited number of marine species tested in similar exposures, the likelihood of other species with similar properties could be high. This unanticipated result therefore has implications for assessing the ecological impacts of oil spills and the use of methods for dispersing oil in the open sea.

  11. Toxicity of crude oil chemically dispersed in a wave tank to embryos of Atlantic herring (Clupea harengus).

    PubMed

    Greer, Colleen D; Hodson, Peter V; Li, Zhengkai; King, Thomas; Lee, Kenneth

    2012-06-01

    Tests of crude oil toxicity to fish are often chronic, exposing embryos from fertilization to hatch to oil solutions prepared using standard mixing procedures. However, during oil spills, fish are not often exposed for long periods and the dynamic nature of the ocean is not easily replicated in the lab. Our objective was to determine if brief exposures of Atlantic herring (Clupea harengus) embryos to dispersed oil prepared by standard mixing procedures was as toxic as oil dispersed in a more realistic model system. Embryos were first exposed to chemically dispersed Alaska North Slope crude and Arabian light crude oil for 2.4 h to 14 d from fertilization to determine if exposure time affected toxicity. Toxicity increased with exposure time, but 2.4-h exposures at realistic concentrations of oil induced blue-sac disease and reduced the percentage of normal embryos at hatch; there was little difference in toxicity between the two oils. Secondly, oil was chemically dispersed in a wave tank to determine if the resultant oil solutions were as toxic to herring embryos as laboratory-derived dispersed oil using a single exposure period of 24 h. Samples taken 15 min postdispersion were more toxic than laboratory-prepared solutions, but samples taken at 5, 30, and 60 min postdispersion were less toxic. Overall, the laboratory- and wave tank-derived solutions of dispersed oil provided similar estimates of toxicity despite differences in the methods for preparing test solutions, suggesting that laboratory and wave tank data are a reliable basis for ecological risk assessments of spilled oil.

  12. Marine toxicity tests development with a New Zealand echinoid

    SciTech Connect

    Nipper, M.G.; Roper, D.S.; Martin, M.L.; Williams, E.K.

    1995-12-31

    The generally low levels of contamination around New Zealand lead to the search for a sensitive toxicity test, which could be used to screen effluent and to detect contaminant effects in coastal waters and sediments. Echinoid early life stage tests were considered ideal candidates. However, the adaptation of international toxicity test methods to indigenous species has not been straightforward or troublefree! The echinoid Fellaster zelandiae was selected because it is abundant around New Zealand and is fertile year round. Fertilization tests showed that gamete density, rather than sperm/egg ratio, was a crucial factor for successful control fertilization rates. This method, however, presented several problems related to (1) temporal variability in the quality of sperm batches, (2) rapid reduction of egg quality and viability after spawning, and (3) highly variable sensitivity in reference toxicant tests. Embryo tests were more reliable, with good control results (> 80% normal embryos) and consistent sensitivity to a reference toxicant, zinc sulfate. EC{sub 50} values averaged 0.06 mg Zn/L, comparable to the sensitivity of echinoid species used elsewhere. Brine prepared by freezing seawater was suitable for adjusting the salinity of effluents, with more than 90% normal embryos developing in brine diluted with UV-treated deionized water as a test-control. The assessment of the embryo development test as a tool for screening sediment toxicity (using sediment pore water), is presently underway, concurrently with growth and behavioral endpoint tests using indigenous amphipods and bivalves.

  13. Ultrasound covers and sonographic gels are embryo-toxic and could be replaced by non-toxic polyethylene bags and paraffin oil.

    PubMed

    Van der Auwera, I; D'Hooghe, T M

    1998-08-01

    The objective of this study was to test the hypothesis that ultrasound covers and sonographic gels, used during vaginal ultrasound, are toxic for mouse embryonic development in vitro. A prospective randomized design was used on pronucleate ova of F1 hybrid CBA x C57Bl female mice. The mice were superovulated with pregnant mare's serum gonadotrophin and human chorionic gonadotrophin and mated with CBA x C57Bl males. The pronucleate ova were randomly divided between culture media with the addition of commercially available ultrasound covers and sonographic gels in different concentrations. As controls and potential alternatives, plastic polyethylene bags and paraffin oil were tested simultaneously. Embryo-toxicity was assessed by documenting cleavage capacity, blastocyst formation and embryo degeneration in vitro. Exposure of culture medium to the ultrasound covers and sonographic gels tested resulted in a severely reduced cleavage capacity, a high incidence of embryo degeneration and absent or impaired blastocyst formation. This toxic effect could be reduced by high dilutions in vitro. In contrast, plastic polyethylene bags and paraffin oil had no influence on in-vitro development of mouse ova. We conclude that commercially available ultrasound latex covers and sonographic gels are toxic for mouse embryos and can potentially influence embryonic development during infertility treatment. It is safer to perform vaginal ultrasonic measurements using non-toxic paraffin oil (as contact fluid) and plastic polyethylene bags (as ultrasonic cover).

  14. Toxicity of seabird guano to sea urchin embryos and interaction with Cu and Pb.

    PubMed

    Rial, Diego; Santos-Echeandía, Juan; Álvarez-Salgado, Xosé Antón; Jordi, Antoni; Tovar-Sánchez, Antonio; Bellas, Juan

    2016-02-01

    Guano is an important source of marine-derived nutrients to seabird nesting areas. Seabirds usually present high levels of metals and other contaminants because the bioaccumulation processes and biotic depositions can increase the concentration of pollutants in the receiving environments. The objectives of this study were to investigate: the toxicity of seabird guano and the joint toxicity of guano, Cu and Pb by using the sea urchin embryo-larval bioassay. In a first experiment, aqueous extracts of guano were prepared at two loading rates (0.462 and 1.952 g L(-1)) and toxicity to sea-urchin embryos was tested. Toxicity was low and not dependent of the load of guano used (EC50 0.42 ± 0.03 g L(-1)). Trace metal concentrations were also low either in guano or in aqueous extracts of guano and the toxicity of extracts were apparently related to dissolved organic matter. In a second experiment, the toxicity of Cu-Pb mixtures in artificial seawater and in extracts of guano (at two loadings: 0.015 and 0.073 g L(-1)), was tested. According to individual fittings, Cu added to extracts of guano showed less toxicity than when dissolved in artificial seawater. The response surfaces obtained for mixtures of Cu and Pb in artificial seawater, and in 0.015 g L(-1) and 0.073 g L(-1) of guano, were better described by Independent Action model adapted to describe antagonism, than by the other proposed models. This implied accepting that EC50 for Cu and Pb increased with the load of guano and with a greater interaction for Cu than for Pb.

  15. Toxicity of single-wall carbon nanotubes functionalized with polyethylene glycol in zebrafish (Danio rerio) embryos.

    PubMed

    Girardi, Felipe A; Bruch, Gisele E; Peixoto, Carolina S; Dal Bosco, Lidiane; Sahoo, Sangram K; Gonçalves, Carla O F; Santos, Adelina P; Furtado, Clascídia A; Fantini, Cristiano; Barros, Daniela M

    2017-02-01

    Single-wall carbon nanotubes functionalized with polyethylene glycol (SWCNT-PEG) are promising materials for biomedical applications such as diagnostic devices and controlled drug-release systems. However, several questions about their toxicological profile remain unanswered. Thus, the aim of this study was to investigate the action of SWCNT-PEG in Danio rerio zebrafish embryos at the molecular, physiological and morphological levels. The SWCNT used in this study were synthesized by the high-pressure carbon monoxide process, purified and then functionalized with distearoyl phosphatidylethanolamine block copolymer-PEG (molecular weight 2 kDa). The characterization process was carried out with low-resolution transmission electron microscopy, thermogravimetric analysis and Raman spectroscopy. Individual zebrafish embryos were exposed to the SWCNT-PEG. Toxic effects occurred only at the highest concentration tested (1 ppm) and included high mortality rates, delayed hatching and decreased total larval length. For all the concentrations tested, the alkaline comet assay revealed no genotoxicity, and Raman spectroscopy measurements on the histological slices revealed no intracellular nanotubes. The results shown here demonstrate that SWCNT-PEG has low toxicity in zebrafish embryos, but more studies are needed to understand what mechanisms are involved. However, the presence of residual metals is possibly among the primary mechanisms responsible for the toxic effects observed, because the purification process was not able to remove all metal contamination, as demonstrated by the thermogravimetric analysis. More attention must be given to the toxicity of these nanomaterials before they are used in biomedical applications. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Toxicity of different-sized copper nano- and submicron particles and their shed copper ions to zebrafish embryos.

    PubMed

    Hua, Jing; Vijver, Martina G; Ahmad, Farooq; Richardson, Michael K; Peijnenburg, Willie J G M

    2014-08-01

    Three sizes of copper nanoparticles (Cu NPs; 25 nm, 50 nm, and 100 nm), 1 submicron-sized particle, and Cu(NO3 )2 were added to the culture buffer of zebrafish embryos from 24 h postfertilization to 120 h postfertilization. In suspensions of Cu NPs and the Cu submicron-sized particle, the main contribution to the toxicity to zebrafish embryos was from the particle form of Cu particles (Cu NPparticle , >71%) rather than from dissolved Cu from the Cu particles (Cu NPion ). All particles tested as well as copper nitrate inhibited hatching, altered behavioral responses, and increased the incidence of malformations. Different kinds of abnormalities were observed in the morphology and behavior of the zebrafish embryos, depending on the particle size of the Cu suspensions tested. The median lethal concentrations of Cu NPparticle (25 nm, 50 nm, and 100 nm), the submicron-sized particle, and copper nitrate were 0.58 mg/L, 1.65 mg/L, 1.90 mg/L, 0.35 mg/L, and 0.70 mg/L, respectively. Submicron-sized particles and copper nitrate were more toxic than Cu NPs, and smaller Cu NPs were more toxic than larger Cu NPs. Dissolution of Cu NPs and the subsequent ion toxicity was not the primary mechanism of Cu NP toxicity in zebrafish embryos.

  17. Zebrafish Embryo Toxicity Microscale Model for Ichthyotoxicity Evaluation of Marine Natural Products.

    PubMed

    Bai, Hong; Kong, Wen-Wen; Shao, Chang-Lun; Li, Yun; Liu, Yun-Zhang; Liu, Min; Guan, Fei-Fei; Wang, Chang-Yun

    2016-04-01

    Marine organisms often protect themselves against their predators by chemical defensive strategy. The second metabolites isolated from marine organisms and their symbiotic microbes have been proven to play a vital role in marine chemical ecology, such as ichthyotoxicity, allelopathy, and antifouling. It is well known that the microscale models for marine chemoecology assessment are urgently needed for trace quantity of marine natural products. Zebrafish model has been widely used as a microscale model in the fields of environment ecological evaluation and drug safety evaluation, but seldom reported for marine chemoecology assessment. In this work, zebrafish embryo toxicity microscale model was established for ichthyotoxicity evaluation of marine natural products by using 24-well microplate based on zebrafish embryo. Ichthyotoxicity was evaluated by observation of multiple toxicological endpoints, including coagulation egg, death, abnormal heartbeat, no spontaneous movement, delayed hatch, and malformation of the different organs during zebrafish embryogenesis periods at 24, 48, and 72 h post-fertilization (hpf). 3,4-Dichloroaniline was used as the positive control for method validation. Subsequently, the established model was applied to test the ichthyotoxic activity of the compounds isolated from corals and their symbiotic microbes and to isolate the bioactive secondary metabolites from the gorgonian Subergorgia mollis under bioassay guidance. It was suggested that zebrafish embryo toxicity microscale model is suitable for bioassay-guided isolation and preliminary bioactivity screening of marine natural products.

  18. Drosophila embryos as model to assess cellular and developmental toxicity of multi-walled carbon nanotubes (MWCNT) in living organisms.

    PubMed

    Liu, Boyin; Campo, Eva M; Bossing, Torsten

    2014-01-01

    Different toxicity tests for carbon nanotubes (CNT) have been developed to assess their impact on human health and on aquatic and terrestrial animal and plant life. We present a new model, the fruit fly Drosophila embryo offering the opportunity for rapid, inexpensive and detailed analysis of CNTs toxicity during embryonic development. We show that injected DiI labelled multi-walled carbon nanotubes (MWCNTs) become incorporated into cells in early Drosophila embryos, allowing the study of the consequences of cellular uptake of CNTs on cell communication, tissue and organ formation in living embryos. Fluorescently labelled subcellular structures showed that MWCNTs remained cytoplasmic and were excluded from the nucleus. Analysis of developing ectodermal and neural stem cells in MWCNTs injected embryos revealed normal division patterns and differentiation capacity. However, an increase in cell death of ectodermal but not of neural stem cells was observed, indicating stem cell-specific vulnerability to MWCNT exposure. The ease of CNT embryo injections, the possibility of detailed morphological and genomic analysis and the low costs make Drosophila embryos a system of choice to assess potential developmental and cellular effects of CNTs and test their use in future CNT based new therapies including drug delivery.

  19. VIRTUAL EMBRYO: SYSTEMS MODELING IN DEVELOPMENTAL TOXICITY - Symposium: SOT 2012

    EPA Science Inventory

    High-throughput screening (HTS) studies are providing a rich source of data that can be applied to in vitro profiling of chemical compounds for biological activity and potential toxicity. Chemical profiling in ToxCast covered 965 drugs-chemicals in over 500 diverse assays testing...

  20. Toxicity test method development in southeast Asia

    SciTech Connect

    McPherson, C.A.

    1995-12-31

    Use of aquatic toxicity tests is relatively new in southeast Asia. As part of the ASEAN-Canada Cooperative Programme on Marine Science -- Phase 2, which includes development of marine environmental criteria, a need for tropical toxicity data was identified. A step-wise approach was used for test method development (simple, acute tests and easily measured endpoints first, then more complex short-term chronic methods), for test specific selection (using species found throughout the region first, and then considering species with narrower geographic distribution), and for integration of quality assurance/quality control (QA/QC) practices into all laboratory activities. Development of test protocols specifically for tropical species included acute and chronic toxicity tests with marine fish, invertebrates and algae. Criteria for test species selection will be reviewed. Method development was based on procedures and endpoints already widely used in North America and Europe (e.g., 96-h LC50 with fish), but adapted for use with tropical species. For example, a bivalve larval development test can use the same endpoints but the duration is only 24 hours. Test method development included research on culture and holding procedures, determination of test conditions (e.g., duration, test containers), and identification of appropriate endpoints. Acute tests with fish and invertebrates were developed first. The next step was development of short-term chronic tests to measure phytoplankton growth, bivalve and echinoderm embryo or larval development, and larval fish growth. The number of species and types of tests was increased in a staged approach, as laboratories became better equipped and personnel gained practical experience. In most cases, method development coincided with training workshops to introduce the principles of toxicity testing.

  1. Synergistic interaction of glycoalkaloids alpha-chaconine and alpha-solanine on developmental toxicity in Xenopus embryos.

    PubMed

    Rayburn, J R; Friedman, M; Bantle, J A

    1995-12-01

    The embryo toxicities of two major potato glycoalkaloids, alpha-chaconine and alpha-solanine, were examined individually and in mixtures using the frog embryo teratogenesis assay-Xenopus. Calculations of toxic units (TUs) were used to assess possible antagonism, synergism or response addition of several mixtures ranging from approximately 3:1 to 1:20 TUs of alpha-chaconine to alpha-solanine. Some combinations exhibited strong synergism in the following measures of developmental toxicity: (a) 96-hr LC50, defined as the median concentration causing 50% embryo lethality; (b) 96-hr EC50 (malformation), defined as the concentration causing 50% malformation of the surviving embryos; and (c) teratogenic index which is equal to LC50/EC50 (malformation). The results indicated that each of the mixtures caused synergistic mortality or malformation. Furthermore, these studies suggested that the synergism observed for a specific mixture cannot be used to predict possible synergism of other mixtures with different ratios of the two glycoalkaloids; toxicities observed for individual glycoalkaloids may not be able to predict toxicities of mixtures; and specific combinations found in different potato varieties need to be tested to assess the safety of a particular cultivar.

  2. Toxicity of binary mixtures of oil fractions to sea urchin embryos.

    PubMed

    Rial, Diego; Vázquez, José A; Menduiña, Araceli; García, Ana M; González, M Pilar; Mirón, Jesús; Murado, Miguel A

    2013-12-15

    The assumption of additive toxicity for oil compounds is related to a narcotic mode of action. However, the joint toxicity of oil fractions has not been fully investigated. A fractionation of Maya crude oil into aliphatics, aromatics and polars was performed, fractions were dissolved in dimethyl sulfoxide (DMSO) and subsequently toxicity of single fractions and binary mixtures was assessed using the sea urchin embryo test. The descriptive ability of Concentration Addition (CA), Independent Action (IA) and modifications of both models for describing the joint toxicity of mixtures has also been evaluated. The hydrocarbon content extractable with dichloromethane of the fractions dissolved in DMSO was: 12.0 ± 1.8 mg mL(-1), 39.0 ± 0.5 mg mL(-1) and 20.5 ± 2.5 mg mL(-1) for aliphatics, aromatics and polars, respectively. The toxicity of the extracts in DMSO of the fractions as EC50 (μLL(-1)) was: aliphatics (165.8-242.3)toxicity of oil fractions. In addition, synergistic or antagonistic effects were not observed.

  3. Effects of photoinduced toxicity of fluoranthene on amphibian embryos and larvae

    SciTech Connect

    Hatch, A.C.; Burton, G.A. Jr.

    1998-09-01

    Embryos and newly hatched larvae of three amphibian species, the spotted salamander (Ambystoma maculatum), the northern leopard frog (Rana pipiens), and the African clawed frog (Xenopus laevis), were exposed to fluoranthene and ultraviolet (UV) light in two scenarios. Embryos were exposed in a laboratory setting from an early developmental stage through hatching under artificial UV light, and newly hatched larvae were exposed outdoors in varying sunlight intensity levels. Outdoor exposures indicated greater sensitivity in the toxic response than did laboratory exposures. In the laboratory, mortality and malformation of X. laevis were the most sensitive indicators of exposure. Xenopus laevis was also the most sensitive species tested to the effects of UV light alone. Hatching success of R. pipiens was monitored outdoors and was not a useful predictive endpoint in the determination of photoinduced toxicity; however, newly hatched larvae were sensitive to the effects of photoinduced toxicity. Amybstoma maculatum and X. laevis larvae were affected by low ({micro}g/L) concentrations of fluoranthene in sunlight. These findings suggest that low levels of polycyclic aromatic hydrocarbons could be acting synergistically with environmental factors such as UV light to place young amphibians at risk.

  4. Transient overexpression of adh8a increases allyl alcohol toxicity in zebrafish embryos.

    PubMed

    Klüver, Nils; Ortmann, Julia; Paschke, Heidrun; Renner, Patrick; Ritter, Axel P; Scholz, Stefan

    2014-01-01

    Fish embryos are widely used as an alternative model to study toxicity in vertebrates. Due to their complexity, embryos are believed to more resemble an adult organism than in vitro cellular models. However, concerns have been raised with respect to the embryo's metabolic capacity. We recently identified allyl alcohol, an industrial chemical, to be several orders of magnitude less toxic to zebrafish embryo than to adult zebrafish (embryo LC50 = 478 mg/L vs. fish LC50 = 0.28 mg/L). Reports on mammals have indicated that allyl alcohol requires activation by alcohol dehydrogenases (Adh) to form the highly reactive and toxic metabolite acrolein, which shows similar toxicity in zebrafish embryos and adults. To identify if a limited metabolic capacity of embryos indeed can explain the low allyl alcohol sensitivity of zebrafish embryos, we compared the mRNA expression levels of Adh isoenzymes (adh5, adh8a, adh8b and adhfe1) during embryo development to that in adult fish. The greatest difference between embryo and adult fish was found for adh8a and adh8b expression. Therefore, we hypothesized that these genes might be required for allyl alcohol activation. Microinjection of adh8a, but not adh8b mRNA led to a significant increase of allyl alcohol toxicity in embryos similar to levels reported for adults (LC50 = 0.42 mg/L in adh8a mRNA-injected embryos). Furthermore, GC/MS analysis of adh8a-injected embryos indicated a significant decline of internal allyl alcohol concentrations from 0.23-58 ng/embryo to levels below the limit of detection (< 4.6 µg/L). Injection of neither adh8b nor gfp mRNA had an impact on internal allyl alcohol levels supporting that the increased allyl alcohol toxicity was mediated by an increase in its metabolization. These results underline the necessity to critically consider metabolic activation in the zebrafish embryo. As demonstrated here, mRNA injection is one useful approach to study the role of candidate enzymes involved in

  5. DEVELOPMENTAL TOXICITY OF DI- AND TETRACHLOROETHANE AND DICHLOROPROPANE IN EMBRYO CULTURE

    EPA Science Inventory

    DEVELOPMENTAL TOXICITY OF DI- AND TETRACHLOROETHANE AND DICHLOROPROPANE IN EMBRYO CULTURE. JE Andrews, H Nichols, and ES Hunter. Reproductive Toxicology Division, NHEERL, USEPA, RTP, NC.

    Disinfection of drinking water with chlorine results in numerous chlorinated byprodu...

  6. Toxicity of buprofezin on the survival of embryo and larvae of African catfish, Clarias gariepinus (Bloch).

    PubMed

    Marimuthu, Kasi; Muthu, Narmataa; Xavier, Rathinam; Arockiaraj, Jesu; Rahman, M Aminur; Subramaniam, Sreeramanan

    2013-01-01

    Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (p< 0.05). However, the mortality was not significantly different (p<0.05) among the following concentrations: 0 (control), 0.05, 0.5 and 5 mg/L. Data obtained from the buprofezin acute toxicity tests were evaluated using probit analysis. The 24 h LC50 value (with 95% confidence limits) of buprofezin for embryos was estimated to be 6.725 (3.167-15.017) mg/L. The hatching of fish embryos was recorded as 68.8, 68.9, 66.9, 66.4, 26.9, 25.1 and 0.12% in response to 7 different concentrations of buprofezin, respectively. The mortality rate of larvae significantly (p<0.05) increased with increasing buprofezin concentrations exposed to 24-48 h. The 24 and 48 h LC50 values (with 95% confidence limits) of buprofezin for the larvae was estimated to be 5.702 (3.198-8.898) and 4.642 (3.264-6.287) mg/L respectively. There were no significant differences (p>0.05) in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L) of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish.

  7. Toxicity of Buprofezin on the Survival of Embryo and Larvae of African Catfish, Clarias gariepinus (Bloch)

    PubMed Central

    Marimuthu, Kasi; Muthu, Narmataa; Xavier, Rathinam; Arockiaraj, Jesu; Rahman, M. Aminur; Subramaniam, Sreeramanan

    2013-01-01

    Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (p< 0.05). However, the mortality was not significantly different (p<0.05) among the following concentrations: 0 (control), 0.05, 0.5 and 5 mg/L. Data obtained from the buprofezin acute toxicity tests were evaluated using probit analysis. The 24 h LC50 value (with 95% confidence limits) of buprofezin for embryos was estimated to be 6.725 (3.167-15.017) mg/L. The hatching of fish embryos was recorded as 68.8, 68.9, 66.9, 66.4, 26.9, 25.1 and 0.12% in response to 7 different concentrations of buprofezin, respectively. The mortality rate of larvae significantly (p<0.05) increased with increasing buprofezin concentrations exposed to 24-48 h. The 24 and 48 h LC50 values (with 95% confidence limits) of buprofezin for the larvae was estimated to be 5.702 (3.198-8.898) and 4.642 (3.264-6.287) mg/L respectively. There were no significant differences (p>0.05) in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L) of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish. PMID:24098390

  8. Developmental toxic effects of monocrotophos, an organophosphorous pesticide, on zebrafish (Danio rerio) embryos.

    PubMed

    Pamanji, Rajesh; Bethu, M S; Yashwanth, B; Leelavathi, S; Venkateswara Rao, J

    2015-05-01

    The present study examined the response of zebrafish embryos exposed to different concentrations (10, 20, 30, 40, 50, and 60 mg/L) of monocrotophos under static conditions for 96 h. We found that mortality had occurred within 48 h at all test concentrations, later insignificant mortality was observed. Monocrotophos (MCP) can be rated as moderately toxic to the Zebrafish embryos with a 96-h median lethal concentration (LC50) of 37.44 ± 3.32 mg/L. In contrast, it greatly affected the development of zebrafish embryos by inducing several developmental abnormalities like pericardial edema, altered heart development, spinal and vertebral anomalies in a concentration-dependent manner. A significant percent reduction in length by 9-48% and heart beats by 18-51% was observed in hatchlings exposed to LC10 and LC50 concentrations at 96 h when compared to controls. The process of looping formation of heart at embryonic stage was greatly affected by the LC50 concentration of MCP. The neurotoxic potentiality of MCP was assessed by using a marker enzyme, acetylcholinesterase in both in vitro and in vivo experiments. MCP was found to be the most potent inhibitor of AChE in vitro with an IC50 value of 4.3 × 10(-4) M. The whole-body AChE enzyme activity in vivo was significantly inhibited during the exposure tenure with the maximum inhibition of 62% at 24 h.

  9. Differential toxicity of three PCB congeners in developing sea urchin embryos and implication of TEQ approach

    SciTech Connect

    Schweitzer, L.; Suffet, I.; Hose, J.; Bay, S.

    1995-12-31

    The relationship between body burden and toxicity of three individual PCB congeners in developing sea urchin embryos was investigated to evaluate the validity of current predictive models of PCB toxicity in an invertebrate system. The uptake and accumulation of radiolabeled PCB congeners from sea water was measured in the sea urchin embryo tissues and the relative toxicity determined. According to the toxic equivalents (TEQ) approach of assessing risk to mammals, congener 77, a nonortho-substituted congener, is predicted to be more toxic than the diortho-substituted congeners 47 and 153. Using a 72 hour embryo development assay, congener 47 was found to be at least four times as toxic as congener 77, with EC50s of 15.7 and > 72.5 mmol/kg, respectively. Congener 153, a hexachlorobiphenyl, was virtually nontoxic even at the highest dose used. Cytologic and cytogenetic anomalies were studied to find a possibly more sensitive endpoint and to suggest a mechanism of toxicity. The cytogenetic analysis revealed that the PCBs inhibited mitosis. At the highest doses, complete mitotic arrest was observed. Congener 77 was found to be at least two times more toxic than congener 153 but not as toxic as congener 47 using mitotic activity as the endpoint. Thus, the two endpoints of toxicity did not change the order in which the congeners are toxic, but established different EC50s. The relative toxicities of these congeners in this study contradict the structure-activity prediction of the mammalian-based TEQ approach.

  10. Three-dimensional printed millifluidic devices for zebrafish embryo tests

    PubMed Central

    Zhu, Feng; Skommer, Joanna; Macdonald, Niall P.; Friedrich, Timo; Kaslin, Jan; Wlodkowic, Donald

    2015-01-01

    Implementations of Lab-on-a-Chip technologies for in-situ analysis of small model organisms and embryos (both invertebrate and vertebrate) are attracting an increasing interest. A significant hurdle to widespread applications of microfluidic and millifluidic devices for in-situ analysis of small model organisms is the access to expensive clean room facilities and complex microfabrication technologies. Furthermore, these resources require significant investments and engineering know-how. For example, poly(dimethylsiloxane) soft lithography is still largely unattainable to the gross majority of biomedical laboratories willing to pursue development of chip-based platforms. They often turn instead to readily available but inferior classical solutions. We refer to this phenomenon as workshop-to-bench gap of bioengineering science. To tackle the above issues, we examined the capabilities of commercially available Multi-Jet Modelling (MJM) and Stereolithography (SLA) systems for low volume fabrication of optical-grade millifluidic devices designed for culture and biotests performed on millimetre-sized specimens such as zebrafish embryos. The selected 3D printing technologies spanned a range from affordable personal desktop systems to high-end professional printers. The main motivation of our work was to pave the way for off-the-shelf and user-friendly 3D printing methods in order to rapidly and inexpensively build optical-grade millifluidic devices for customized studies on small model organisms. Compared with other rapid prototyping technologies such as soft lithography and infrared laser micromachining in poly(methyl methacrylate), we demonstrate that selected SLA technologies can achieve user-friendly and rapid production of prototypes, superior feature reproduction quality, and comparable levels of optical transparency. A caution need to be, however, exercised as majority of tested SLA and MJM resins were found toxic and caused significant developmental abnormalities

  11. Toxic Substances; Biphenyl; Test Rule

    EPA Pesticide Factsheets

    This rule promulgates EPA’s decision to require manufacturers and processors to test biphenyl (CAS No: 92—52—4) for environmental effects and chemical fate under section 4(a) of the Toxic Substances Control Act (TSCA).

  12. Effects of storage temperature and duration on toxicity of sediments assessed by Crassostrea gigas oyster embryo bioassay

    SciTech Connect

    Beiras, R.; His, E.; Seaman, M.N.L.

    1998-10-01

    The effects of temperature and duration of storage on the toxicity of estuarine sediments were investigated with the Crassostrea gigas oyster embryo bioassay. Sediments ranging from unpolluted (controls) to extremely polluted with heavy metals (>100 ppm Hg, Cu, Zn, and Pb) and total hydrocarbons (>1,000 ppm) were collected from sites in southwest France and northern Spain, Control sediments were toxic only at the highest concentrations tested and after freezing in liquid nitrogen ({minus}196 C). Polluted sediments significantly reduced the success of oyster embryogenesis. Analysis of variance showed that the effect of storage temperature on toxicity increased with the prolongation of storage. Prolonged storage of fresh (4 C) sediments resulted in a loss of toxicity, which was more rapid in the less-polluted sediments. Deep-frozen sediments ({minus}196 C) were highly toxic regardless of origin and storage time, and because deep-freezing causes spurious toxicity in the control samples, it cannot be recommended for toxicological studies. In the context of the assessment of sediment toxicity by embryo-larval bioassays, fresh (4 C) storage is recommended when sediments need to be stored for no longer than a few days. The advisable duration of fresh storage to avoid false-negative results is directly related to the degree of toxicity. Should the sediments require prolonged storage, freezing at {minus}20 C appears to be the best choice.

  13. Draft Test Guideline: Gammarid Acute Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  14. Draft Test Guideline: Penaeid Acute Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  15. Draft Test Guideline: Daphnid Chronic Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  16. Draft Test Guideline: Chironomid Sediment Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  17. Draft Test Guideline: Mysid Chronic Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  18. Draft Test Guideline: Mysid Acute Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  19. Developmental toxicity of CdTe QDs in zebrafish embryos and larvae

    NASA Astrophysics Data System (ADS)

    Duan, Junchao; Yu, Yongbo; Li, Yang; Yu, Yang; Li, Yanbo; Huang, Peili; Zhou, Xianqing; Peng, Shuangqing; Sun, Zhiwei

    2013-07-01

    Quantum dots (QDs) have widely been used in biomedical and biotechnological applications. However, few studies focus on the assessing toxicity of QDs exposure in vivo. In this study, zebrafish embryos were treated with CdTe QDs (4 nm) during 4-96 h post-fertilization (hpf). Mortality, hatching rate, malformation, heart rate, and QDs uptake were detected. We also measured the larval behavior to analyze whether QDs had persistent effects on larvae locomotor activity at 144 hpf. The results showed that as the exposure dosages increased, the hatching rate and heart rate of zebrafish embryos were decreased, while the mortality increased. Exposure to QDs caused embryonic malformations, including head malformation, pericardial edema, yolk sac edema, bent spine, and yolk not depleted. QDs fluorescence was mainly localized in the intestines region. The larval behavior testing showed that the total swimming distance was decreased in a dose-dependent manner. The lowest dose (2.5 nM QDs) produced substantial hyperactivity while the higher doses groups (5, 10, and 20 nM QDs) elicited remarkably hypoactivity in dark periods. In summary, the data of this article indicated that QDs caused embryonic developmental toxicity, resulted in persistent effects on larval behavior.

  20. vEmbryo In Silico Models: Predicting Vascular Developmental Toxicity

    EPA Science Inventory

    The cardiovascular system is the first to function in the vertebrate embryo, reflecting the critical need for nutrient delivery and waste removal during organogenesis. Blood vessel development occurs by complex interacting signaling networks, including extra-cellular matrix remod...

  1. Salinity-dependent toxicity of water-dispersible, single-walled carbon nanotubes to Japanese medaka embryos.

    PubMed

    Kataoka, Chisato; Nakahara, Kousuke; Shimizu, Kaori; Kowase, Shinsuke; Nagasaka, Seiji; Ifuku, Shinsuke; Kashiwada, Shosaku

    2017-04-01

    To investigate the effects of salinity on the behavior and toxicity of functionalized single-walled carbon nanotubes (SWCNTs), which are chemical modified nanotube to increase dispersibility, medaka embryos were exposed to non-functionalized single-walled carbon nanotubes (N-SWCNTs), water-dispersible, cationic, plastic-polymer-coated, single-walled carbon nanotubes (W-SWCNTs), or hydrophobic polyethylene glycol-functionalized, single-walled carbon nanotubes (PEG-SWCNTs) at different salinities, from freshwater to seawater. As reference nanomaterials, we tested dispersible chitin nanofiber (CNF), chitosan-chitin nanofiber (CCNF) and chitin nanocrystal (CNC, i.e. shortened CNF). Under freshwater conditions, with exposure to 10 mg l(-1)  W-SWCNTs, the yolk sacks of 57.8% of embryos shrank, and the remaining embryos had a reduced heart rate, eye diameter and hatching rate. Larvae had severe defects of the spinal cord, membranous fin and tail formation. These toxic effects increased with increasing salinity. Survival rates declined with increasing salinity and reached 0.0% in seawater. In scanning electron microscope images, W-SWCNTs, CNF, CCNF and CNC were adsorbed densely over the egg chorion surface; however, because of chitin's biologically harmless properties, only W-SWCNTs had toxic effects on the medaka eggs. No toxicity was observed from N-SWCNT and PEG-SWCNT exposure. We demonstrated that water dispersibility, surface chemistry, biomedical properties and salinity were important factors in assessing the aquatic toxicity of nanomaterials. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Comparative toxicity of lead (Pb(2+)), copper (Cu(2+)), and mixtures of lead and copper to zebrafish embryos on a microfluidic chip.

    PubMed

    Li, Yinbao; Yang, Xiujuan; Chen, Zuanguang; Zhang, Beibei; Pan, Jianbin; Li, Xinchun; Yang, Fan; Sun, Duanping

    2015-03-01

    Investigations were conducted to determine acute effects of Pb(2+) and Cu(2+) presented individually and collectively on zebrafish embryos. Aquatic safety testing requires a cheap, fast, and highly efficient platform for real-time evaluation of single and mixture of metal toxicity. In this study, we have developed a microfluidic system for phenotype-based evaluation of toxic effects of Pb(2+) and Cu(2+) using zebrafish (Danio rerio) embryos. The microfluidic chip is composed of a disc-shaped concentration gradient generator and 24 culture chambers, which can generate one blank solution, seven mixture concentrations, and eight single concentrations for each metal solution, thus enabling the assessment of zebrafish embryos. To test the accuracy of this new chip platform, we have examined the toxicity and teratogenicity of Pb(2+) and Cu(2+) on embryos. The individual and combined impact of Pb(2+) and Cu(2+) on zebrafish embryonic development was quantitatively assessed by recording a series of physiological indicators, such as spontaneous motion at 22 hours post fertilization (hpf), mortality at 24 hpf, heartbeat and body length at 96 hpf, etc. It was found that Pb(2+) or Cu(2+) could induce deformity and cardiovascular toxicity in zebrafish embryos and the mixture could induce more severe toxicity. This chip is a multiplexed testing apparatus that allows for the examination of toxicity and teratogenicity for substances and it also can be used as a potentially cost-effective and rapid aquatic safety assessment tool.

  3. Developmental toxicity in flounder embryos exposed to crude oils derived from different geographical regions.

    PubMed

    Jung, Jee-Hyun; Lee, Eun-Hee; Choi, Kwang-Min; Yim, Un Hyuk; Ha, Sung Yong; An, Joon Geon; Kim, Moonkoo

    2017-03-06

    Crude oils from distinct geographical regions have distinct chemical compositions, and, as a result, their toxicity may be different. However, developmental toxicity of crude oils derived from different geographical regions has not been extensively characterized. In this study, flounder embryos were separately exposed to effluents contaminated by three crude oils including: Basrah Light (BLO), Pyrenees (PCO), and Sakhalin Vityaz (SVO), in addition to a processed fuel oil (MFO-380), to measure developmental toxicity and for gene expressions. Each oil possessed a distinct chemical composition. Edema defect was highest in embryos exposed to PCO and MFO-380 that both have a greater fraction of three-ring PAHs (33% and 22%, respectively) compared to BLO and SVO. Observed caudal fin defects were higher in embryos exposed to SVO and MFO-380, which are both dominated by naphthalenes (81% and 52%, respectively). CYP1A gene expressions were also highest in embryos exposed to SVO and MFO-380. Higher incidence of cardiotoxicity and lower nkx 2.5 expression were detected in embryos exposed to PCO. Unique gene expression profiles were observed in embryos exposed to crude oils with distinct compositions. This study demonstrates that crude oils of different geographical origins with different compositional characteristics induce developmental toxicity to different degrees.

  4. Comparison of the toxicity of silver, gold and platinum nanoparticles in developing zebrafish embryos.

    PubMed

    Asharani, P V; Lianwu, Yi; Gong, Zhiyuan; Valiyaveettil, Suresh

    2011-03-01

    Nanoparticles have diverse applications in electronics, medical devices, therapeutic agents and cosmetics. While the commercialization of nanoparticles is rapidly expanding, their health and environmental impact is not well understood. Toxicity assays of silver, gold, and platinum nanoparticles, using zebrafish embryos to study their developmental effects were carried out. Gold (Au-NP, 15-35 nm), silver (Ag-NP, 5-35 nm) and platinum nanoparticles (Pt-NP, 3-10 nm) were synthesized using polyvinyl alcohol (PVA) as a capping agent. Toxicity was recorded in terms of mortality, hatching delay, phenotypic defects and metal accumulation. The addition of Ag-NP resulted in a concentration-dependant increase in mortality rate. Both Ag-NP and Pt-NP induced hatching delays, as well as a concentration dependant drop in heart rate, touch response and axis curvatures. Ag-NP also induced other significant phenotypic changes including pericardial effusion, abnormal cardiac morphology, circulatory defects and absence or malformation of the eyes. In contrast, Au-NP did not show any indication of toxicity. Uptake and accumulation of nanoparticles in embryos was confirmed by inductively coupled plasma optical emission spectroscopy (ICP-OES), which revealed detectable levels in embryos within 72 hpf. Ag-NP and Au-NP were taken up by the embryos in relatively equal amounts whereas lower Pt concentrations were observed in embryos exposed to Pt-NP. This was probably due to the small size of the Pt nanoparticles compared to Ag-NP and Au-NP, thus resulting in fewer metal atoms being retained in the embryos. Among the nanoparticles studied, Ag-NPs were found to be the most toxic and Au-NPs the non-toxic. The toxic effects exhibited by the zebrafish embryos as a consequence of nanoparticle exposure, accompanied by the accumulation of metals inside the body calls for urgent further investigations in this field.

  5. Comparative performances of eggs and embryos of sea urchin (Paracentrotus lividus) in toxicity bioassays used for assessment of marine sediment quality.

    PubMed

    Khosrovyan, A; Rodríguez-Romero, A; Salamanca, M J; Del Valls, T A; Riba, I; Serrano, F

    2013-05-15

    The potential toxicity of sediments from various ports was assessed by means of two different liquid-phase toxicity bioassays (acute and chronic) with embryos and eggs of sea urchin Paracentrotus lividus. Performances of embryos and eggs of P. lividus in these bioassays were compared for their interchangeable applicability in integrated sediment quality assessment. The obtained endpoints (percentages of normally developed plutei and fertilized eggs) were linked to physical and chemical properties of sediments and demonstrated dependence on sediment contamination. The endpoints in the two bioassays were strongly correlated and generally exhibited similar tendency throughout the samples. Therein, embryos demonstrated higher sensitivity to elutriate exposure, compared to eggs. It was concluded that these tests could be used interchangeably for testing toxicity of marine sediments. Preferential use of any of the bioassays can be determined by the discriminatory capacity of the test or vulnerability consideration of the test subject to the surrounding conditions.

  6. Sediment spiking for toxicity testing

    SciTech Connect

    Murdoch, M.H.; Norman, D.M.; Chapman, P.M.; Norman, D.M.; Quintino, V.M.

    1994-12-31

    Sediment toxicity testing integrates responses to sediment variables and hence does not directly indicate cause-and-effect. One tool for determining cause-and-effect is sediment spiking in which relatively uncontaminated sediment is amended with known amounts of contaminants, then tested for toxicity. Based on the concentration-response relationship(s), the relative toxicity of the spiked contaminants and their significance in sediment mixtures can be assessed. However, sediment spiking methods vary considerably. The present study details an appropriate methodology for amending sediments with a range of organic contaminant concentrations including different solvent schemes and an equilibration period. This methodology is described as appropriate because predicted and actual concentrations were similar, and responses in an acute 10-d amphipod test matched predictions and other data.

  7. USING THE MEDAKA EMBRYO ASSAY TO INVESTIGATE DEVELOPMENTAL ETHANOL TOXICITY.

    EPA Science Inventory

    Ethanol (EtOH) is a well-known developmental toxicant that produces a range of abnormal phenotypes. While the toxic potential of developmental EtOH exposure is well characterized, the effect of the timing of exposure on the extent of toxicity remains unknown. Fish models such as ...

  8. Chronic toxicity of azo and anthracenedione dyes to embryo-larval fathead minnow.

    PubMed

    Parrott, Joanne L; Bartlett, Adrienne J; Balakrishnan, Vimal K

    2016-03-01

    The toxicity of selected azo and anthracenedione dyes was studied using chronic exposures of embryo-larval fathead minnows (Pimephales promelas). Newly fertilized fathead minnow embryos were exposed through the egg stage, past hatching, through the larval stage (until 14 days post-hatch), with dye solutions renewed daily. The anthracenedione dyes Acid Blue 80 (AB80) and Acid Blue 129 (AB129) caused no effects in larval fish at the highest measured concentrations tested of 7700 and 6700 μg/L, respectively. Both azo dyes Disperse Yellow 7 (DY7) and Sudan Red G (SRG) decreased survival of larval fish, with LC50s (based on measured concentrations of dyes in fish exposure water) of 25.4 μg/L for DY7 and 16.7 μg/L for SRG. Exposure to both azo dyes caused a delayed response, with larval fish succumbing 4-10 days after hatch. If the exposures were ended at the embryo stage or just after hatch, the potency of these two dyes would be greatly underestimated. Concentrations of dyes that we measured entering the Canadian environment were much lower than those that affected larval fish survival in the current tests. In a total of 162 samples of different municipal wastewater effluents from across Canada assessed for these dyes, all were below detection limits. The similarities of the structures and larval fish responses for the two azo and two anthracenedione dyes in this study support the use of read-across data for risk assessment of these classes of compounds.

  9. The VIRTUAL EMBRYO. A Computational Framework for Developmental Toxicity

    EPA Science Inventory

    EPA’s ‘Virtual Embryo Project’ (v-Embryo™) is focused on the predictive toxicology of children’s health and developmental defects following prenatal exposure to environmental chemicals. The research is motivated by scientific principles in systems biology as a framework for the g...

  10. Developmental Toxicity of Carbon Quantum Dots to the Embryos/Larvae of Rare Minnow (Gobiocypris rarus)

    PubMed Central

    Chen, Yao; Zeng, Yu-Lian

    2016-01-01

    The toxic effects of CDs on rare minnow (Gobiocypris rarus) embryos at different developmental stages were investigated. The results showed that rare minnow embryos had decreased spontaneous movements, body length, increased heart rate, pericardial edema, yolk sac edema, tail/spinal curvature, various morphological malformations, and decreased hatching rate. Biochemical analysis showed the CDs exposure significantly inhibited the activity of Na+/K+-ATPase and Ca2+-ATPase and increased the MDA contents and the activity of SOD, CAT, and GPX. Further examination suggested that the CDs exposure induced serious embryonic cellular DNA damage. Moreover, the CDs exposure induced upregulation of development related genes (Wnt8a and Mstn) along with the downregulation of Vezf1. Overall, the present study revealed that the CDs exposure has significant development toxicity on rare minnow embryos/larvae. Mechanistically, this toxicity might result from the pressure of induced oxidative stress coordinate with the dysregulated development related gene expression mediated by the CDs exposure. PMID:27872851

  11. Comparison of diazinon toxicity to embryos of Xenopus laevis and Danio rerio; degradation of diazinon in water.

    PubMed

    Modra, Helena; Vrskova, Dagmar; Macova, Stanislava; Kohoutkova, Jana; Hajslova, Jana; Haluzova, Ivana; Svobodova, Zdenka

    2011-06-01

    The aim of this study was to determine the toxic effect of diazinon (organophosphate insecticide) to embryos of Xenopus laevis and Danio rerio. The 96-h LC₅₀ values showed higher toxicity of diazinon for X. leavis in standard solution (9.84 mg/L) compared to the pond water (12.64 mg/L). Teratogenic index for diazinon was 1.3 and 1.6, respectively. The 96-h LC₅₀ diazinon values demonstrated similar sensitivity of embryos D. rerio (8.21-9.34 mg/L) and X. laevis in standard test solutions. Our results reflect that direct application of diazinon into the water can be associated with significant risks to aquatic organisms.

  12. Primary screening of the bioactivity of brackishwater cyanobacteria: toxicity of crude extracts to Artemia salina larvae and Paracentrotus lividus embryos.

    PubMed

    Lopes, Viviana R; Fernández, Nuria; Martins, Rosário F; Vasconcelos, Vitor

    2010-03-05

    Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. The aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuarine environments, towards the nauplii of the brine shrimp Artemia salina and embryos of the sea urchin Paracentrotus lividus. The A. salina lethality test was used as a frontline screen and then complemented by the more specific sea urchin embryo-larval assay. Eighteen cyanobacterial isolates, belonging to the genera Cyanobium, Leptolyngbya, Microcoleus, Phormidium, Nodularia, Nostoc and Synechocystis, were tested. Aqueous extracts of cyanobacteria strains showed potent toxicity against A. salina, whereas in P. lividus, methanolic and aqueous extracts showed embryo toxicity, with clear effects on development during early stages. The results suggest that the brackishwater cyanobacteria are producers of bioactive compounds with toxicological effects that may interfere with the dynamics of invertebrate populations.

  13. Primary Screening of the Bioactivity of Brackishwater Cyanobacteria: Toxicity of Crude Extracts to Artemia salina Larvae and Paracentrotus lividus Embryos

    PubMed Central

    Lopes, Viviana R.; Fernández, Nuria; Martins, Rosário F.; Vasconcelos, Vitor

    2010-01-01

    Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. The aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuarine environments, towards the nauplii of the brine shrimp Artemia salina and embryos of the sea urchin Paracentrotus lividus. The A. salina lethality test was used as a frontline screen and then complemented by the more specific sea urchin embryo-larval assay. Eighteen cyanobacterial isolates, belonging to the genera Cyanobium, Leptolyngbya, Microcoleus, Phormidium, Nodularia, Nostoc and Synechocystis, were tested. Aqueous extracts of cyanobacteria strains showed potent toxicity against A. salina, whereas in P. lividus, methanolic and aqueous extracts showed embryo toxicity, with clear effects on development during early stages. The results suggest that the brackishwater cyanobacteria are producers of bioactive compounds with toxicological effects that may interfere with the dynamics of invertebrate populations. PMID:20411110

  14. Effects of simulated weathering on the toxicity of selected crude oils and their components to sea urchin embryos.

    PubMed

    Rial, Diego; Radović, Jagoš R; Bayona, Josep M; Macrae, Kenneth; Thomas, Kevin V; Beiras, Ricardo

    2013-09-15

    Artificial weathering of Angolan crude and a Heavy Fuel Oil (HFO) was performed by evaporation and photooxidation. The aliphatic, aromatic, polar and asphaltene fractions of the fresh and weathered oils were isolated. The toxicity of the water accommodated fraction or an oil/fraction dissolved in DMSO was assessed using the sea urchin embryo test. Photooxidation was observed to decrease the aromatics content and increase polar compounds. A slight reduction in the toxicity of Angolan crude was observed following weathering for the water-accommodated fraction and the extract in DMSO, but no effect was seen for the Heavy Fuel Oil. For aliphatic compounds, the toxicity decreased in the order fresh>evaporated>photooxidated for both Angolan crude and HFO. Weathering slightly increased the toxicity of the aromatic and polar fractions of the oil. The aromatic fractions were responsible for most of the toxicity and the polar compounds were the second most important toxic components, despite having less or similar abundance than the aliphatic fraction. The toxic contribution of the aromatic compounds was higher for the HFO than for the Angolan crude. A decrease in the toxicity of Angolan crude following weathering correlated with a reduction in the toxicity of the aliphatic fraction.

  15. Early life stage and genetic toxicity of stannous chloride on zebrafish embryos and adults: toxic effects of tin on zebrafish.

    PubMed

    Şişman, Turgay

    2011-06-01

    Humans are exposed to stannous chloride (SnCl(2)), known as tin chloride, present in packaged food, soft drinks, biocides, dentifrices, etc. Health effects in children exposed to tin and tin compounds have not been investigated yet. Therefore, we evaluated the possible teratogenic effects and genotoxic of SnCl(2) in zebrafish (Danio rerio) adults and their embryos. In the embryo-larval study, SnCl(2) showed embryo toxicity and developmental delay after exposure to the various concentrations of 10-250 μM for 120 h. Teratogenic effects including morphological malformations of the embryos and larvae were observed. The embryos exposed to 100 μM displayed tail deformation at 28 hpf and the larvae exposed to 50 μM showed reduced body growth, smaller head and eyes, bent trunk, mild pericardial edema, and smaller caudal fin at 96 hpf. The results of the teratological study show that SnCl(2) induced a significant decrease in the number of living embryos and larvae. Regarding the chromosome analysis, SnCl(2) induced a dose-dependent increase in the micronucleus (MN) frequency in peripheral erythrocytes of adult zebrafish. In blood cells, the 25 μM dose of SnCl(2) caused a nonsignificant increase in the total chromosomal aberrations, but the high doses significantly increased the total number of chromosomal aberrations compared with the control groups. Overall, the results clearly indicate that SnCl(2) is teratogenic and genotoxic to zebrafish.

  16. Comparison of rat and rabbit embryo-fetal developmental toxicity data for 379 pharmaceuticals: on the nature and severity of developmental effects (Critical Reviews in Toxicology)

    EPA Science Inventory

    Regulatory non-clinical safety testing of human pharmaceutical compounds typically requires embryo fetal developmental toxicity (EFDT) testing in two species, (one rodent and one non-rodent, usually the rat and the rabbit). The question has been raised whether under some conditio...

  17. Aquatic toxicity assessment of single-walled carbon nanotubes using zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Pan, Huichin; Lin, Yu-Jun; Li, Meng-Wei; Chuang, Han-Ni; Chou, Cheng-Chung

    2011-07-01

    Zebrafish embryos selected at the 64-cell stage were exposed to various concentrations of amide functionalized single-walled carbon nanotubes (SWCNTs) ranging from 1 to 10 μg/ml dissolved in 1% Pluronic F-68 (a cell culture grade surfactant), and the development of embryos was examined from 24 to 120 hours post fertilization (hpf). Incubation of embryos in 1% F-68 did not induce overt abnormal phenotype as compared to the wild-type; neither did it cause significant mortality during the exposure period. Generally, there was a slight developmental delay in larvae treated with SWCNTs of 5 μg/ml or above. Only larvae exposed to >= 5 μg/ml SWCNTs showed significantly reduced survival rates. About 50% of the embryos exposed to 5 μg/ml showed abnormal phenotypes at 24 hpf as compared to the control group. As development proceeds to 120 hpf, more embryos displayed defective morphology. A slight hatching delay was observed in embryos exposed to concentrations above 5 μg/ml. There was a general reduction of body axes, including narrowed somite and shortened yolk stalk. In addition, pigmentation in the ventral trunk area was less than that observed in control group. The body lengths of the exposed embryos were decreased significantly at 48 hpf (3.11 mm in control vs. 3.00 mm in SWCNTs-exposed embryos). However, exposure to SWCNTs did not affect the number of somites. Other features that were noticed in the SWCNTs-exposed embryos included edema and shrinkage and blebbling of the epidermal lining. Most of these observed phenotypes persisted from 48 hpf through 120 hpf. Overall, the aforementioned results indicate that soluble amide-functionalized SWCNTs are toxic to zebrafish embryos at a minimum concentration of 5 μg/ml.

  18. Phytochemicals reduce aflatoxin-induced toxicity in chicken embryos

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins (AF) are toxic metabolites produced by molds, Aspergillus flavus and Aspergillus parasicitus, which frequently contaminate chicken feed ingredients. Ingestion of AF-contaminated feed by chickens leads to deleterious effects, including decreased chicken performance and reduced egg producti...

  19. GLUCOCORTICOID RECEPTOR REGULATION IN THE RAT EMBRYO: A POTENTIAL SITE FOR DEVELOPMENTAL TOXICITY?

    EPA Science Inventory

    Glucocorticoid receptor regulation in the rat embryo: a potential site for developmental toxicity?

    Ghosh B, Wood CR, Held GA, Abbott BD, Lau C.

    National Research Council, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.

  20. Toxicity of weathered Exxon Valdez crude oil to pink salmon embryos.

    PubMed

    Brannon, Ernest L; Collins, Keya M; Brown, John S; Neff, Jerry M; Parker, Keith R; Stubblefield, William A

    2006-04-01

    Research was conducted at the University of Idaho (Moscow, ID, USA) on the toxicity of weathered Exxon Valdez crude oil to embryos of pink salmon from 2001 to 2003 for the purpose of comparing these data with those from the National Oceanic and Atmospheric Administration Fisheries Laboratory at Auke Bay (AK, USA). Mortality reported at Auke Bay for embryos chronically exposed to very low concentrations of aqueous solutions of weathered oil, measured as dissolved polycyclic aromatic hydrocarbons (PAHs), was inconsistent with that in other published research. Using the Auke Bay experimental design, we found that toxicity is not evident in pink salmon embryos until chronic exposure to laboratory weathered and naturally weathered oil concentrations exceeding 1,500 and 2,250 ppm, respectively, representing a total PAH tissue burden in excess of 7,100 ppb. Effluent hydrocarbons also drop well below concentrations sufficient to cause harm over the time frame of a few weeks, regardless of oiling level. Resolution of differences with Auke Bay involved the source of contributing hydrocarbons. The experimental design did not exclude dispersed oil droplets from the aqueous solution; thus, toxicity was not limited to the dissolved hydrocarbon fraction. The implications of the present results are discussed regarding the toxic risk of weathered oil to pink salmon embryos in streams of Prince William Sound (AK, USA).

  1. Developmental toxicity testing of vaccines.

    PubMed

    Barrow, Paul C; Allais, Linda

    2013-01-01

    Preventative and therapeutic vaccines are increasingly used during pregnancy and present special considerations for developmental toxicity testing. The various components of the vaccine formulation (i.e., protein or polysaccharide antigen, adjuvants, and excipients) need to be assessed for direct effects on the developing conceptus. In addition, possible adverse influences of the induced antibodies on fetal and/or postnatal development need to be evaluated. A guidance document on the preclinical testing of preventative and therapeutic vaccines for developmental toxicity was issued by the FDA in 2006. Preclinical studies are designed to assess possible influences of vaccines on pre- and postnatal development. The choice of model animal for these experiments is influenced by species differences in the timing and extent of the transfer of the induced maternal antibodies to the fetus. The cross-placental transport of maternal immunoglobulins generally only occurs in late gestation and tends to be greater in humans and monkeys than in non-primate species. For many vaccines, the rabbit shows a greater rate of prenatal transfer of the induced antibodies than rodents. For biotechnology-derived vaccines that are not immunogenic in lower species, nonhuman primates may be the only appropriate models. It may be advisable to test new adjuvants using the ICH study designs for conventional pharmaceuticals in addition to the developmental toxicity study with the final vaccine formulation.

  2. Zebrafish (Danio rerio) embryos as a model for testing proteratogens.

    PubMed

    Weigt, Stefan; Huebler, Nicole; Strecker, Ruben; Braunbeck, Thomas; Broschard, Thomas H

    2011-03-15

    Zebrafish embryos have been shown to be a useful model for the detection of direct acting teratogens. This communication presents a protocol for a 3-day in vitro zebrafish embryo teratogenicity assay and describes results obtained for 10 proteratogens: 2-acetylaminofluorene, benzo[a]pyrene, aflatoxin B(1), carbamazepine, phenytoin, trimethadione, cyclophosphamide, ifosfamide, tegafur and thio-TEPA. The selection of the test substances accounts for differences in structure, origin, metabolism and water solubility. Apart from 2-acetylaminofluorene, which mainly produces lethal effects, all proteratogens tested were teratogenic in zebrafish embryos exposed for 3 days. The test substances and/or the substance class produced characteristic patterns of fingerprint endpoints. Several substances produced effects that could be identified already at 1 dpf (days post fertilization), whereas the effects of others could only be identified unambiguously after hatching at ≥ 3 dpf. The LC₅₀ and EC₅₀ values were used to calculate the teratogenicity index (TI) for the different substances, and the EC₂₀ values were related to human plasma concentrations. Results lead to the conclusion that zebrafish embryos are able to activate proteratogenic substances without addition of an exogenous metabolic activation system. Moreover, the teratogenic effects were observed at concentrations relevant to human exposure data. Along with other findings, our results indicate that zebrafish embryos are a useful alternative method for traditional teratogenicity testing with mammalian species.

  3. Toxicity and modulations of biomarkers in Xenopus laevis embryos exposed to polycyclic aromatic hydrocarbons and their N-heterocyclic derivatives.

    PubMed

    Burýsková, Blanka; Hilscherová, Klára; Bláha, Ludek; Marsálek, Blahoslav; Holoubek, Ivan

    2006-12-01

    Effects of a newly identified group of organic environmental pollutants of concern (N-heterocyclic derivatives of polycyclic aromatic hydrocarbons, NPAHs) were investigated using the 96 h FETAX (Frog Embryo Teratogenesis Assay - Xenopus). Beside standard FETAX parameters (mortality, malformations), changes in several biochemical markers were studied as early signs of intoxication. Biomarkers included determination of glutathione (GSH) levels and lipid peroxidation as well as activities of important detoxification and antioxidant enzymes (glutathione-S-transferase, glutathione peroxidase, glutathione reductase). 1,10-Phenathroline was the most toxic of all tested compounds (96 h LC(50) = 4 microM). All tested NPAHs induced malformations in the frog embryos. The data suggest that the exposure to NPAHs can induce oxidative stress in amphibians; most biochemical markers were modulated at concentrations lower than those resulting in significant mortality. Results document mortality and teratogenicity of all studied NPAHs to amphibian embryos while no significant mortality, teratogenicity or modulations in biochemical markers could be observed with unsubstituted polycyclic aromatic hydrocarbons (PAHs) at concentrations up to their water solubility. This information along with the significantly greater solubility and thus bioavailability compared to their nonsubstituted parent compounds suggests that NPAHs could contribute significantly to the overall aquatic toxicity of mixtures of PAHs and their derivatives.

  4. Differential toxicity of three polychlorinated biphenyl congeners in developing sea urchin embryos

    SciTech Connect

    Schweitzer, L.E.; Suffet, I.H.; Hose, J.E.; Bay, S.M.

    1997-07-01

    The relationship between body burden and toxicity of three individual polychlorinated biphenyl (PCB) congeners in developing sea urchin embryos was investigated to evaluate the validity of current predictive models of PCB toxicity in an invertebrate system. Body burdens of radiolabeled PCB congeners (IUPAC-47, 77, and 153) accumulated from a seawater were used to determine median effective concentrations (EC50s) for developmental and cytogenetic effects following a 72-h exposure. Congener 47, a di-ortho-substituted tetrachlorobiphenyl, was found to be at least four times more toxic than congener 77, a non-ortho-substituted (coplanar) tetrachlorobiphenyl, with EC50s of 47 and >218 mmol/kg, respectively, using an embryo development assay. This result contradicts the structure-activity prediction of the mammalian-based toxic equivalents (TEQs) approach, demonstrating the need for an ecotoxicologic model. Congener 153, a di-ortho-substituted hexachlorobiphenyl, was virtually nontoxic in terms of developmental effects at the highest dose achievable at its limit of water solubility. Cytogenetic analysis was a more sensitive method for assessing toxicity than the embryo development assay. Dose-response relationships were established with mitotic activity being the most sensitive endpoint because the PCBs appeared to inhibit mitosis. At the highest doses, complete mitotic arrest was observed. Congener 77 was found to be at least two times more toxic than congener 153 but not as toxic as congener 47 using mitotic activity as the endpoint for toxicity. Thus, the developmental and cytogenetic endpoints ranked the toxicity of the congeners similarly, but established different EC50s.

  5. Evaluation of developmental toxicity and teratogenicity of diclofenac using Xenopus embryos.

    PubMed

    Chae, Jeong-Pil; Park, Mi Seon; Hwang, Yoo-Seok; Min, Byung-Hwa; Kim, Sang-Hyun; Lee, Hyun-Shik; Park, Mae-Ja

    2015-02-01

    Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) with analgesic and anti-pyretic properties. This compound is therefore used to treat pain, inflammatory disorders, and dysmenorrhea. Due to its multimodal mechanism of action and ability to penetrate placenta, diclofenac is known to have undesirable side effects including teratogenicity. However, limited data exist on its teratogenicity, and a detailed investigation regarding harmful effects of this drug during embryogenesis is warranted. Here, we analyzed the developmental toxic effects of diclofenac using Xenopus embryos according to the Frog Embryo Teratogenesis Assay-Xenopus (FETAX) protocol. Diclofenac treatment exerted a teratogenic effect on Xenopus embryos with a teratogenic index (TI) value of 2.64 TI; if this value is higher than 1.2, the cut-off value indicative of toxicity. In particular, mortality of embryos treated with diclofenac increased in a concentration-dependent manner and a broad spectrum of malformations such as shortening and kinking of the axis, abdominal bulging, and prominent blister formation, was observed. The shape and length of internal organs also differed compared to the control group embryos and show developmental retardation on histological label. However, the expression of major tissue-specific markers did not change when analyzed by reverse transcription-polymerase chain reaction (RT-PCR). In conclusion, diclofenac treatment can promote teratogenicity that results in morphological anomalies, but not disrupt the developmental tissue arrangement during Xenopus embryogenesis.

  6. Toxicity potential of residual ethylene oxide on fresh or frozen embryos maintained in plastic straws.

    PubMed

    Schiewe, M C; Schmidt, P M; Pontbriand, D; Wildt, D E

    1988-01-01

    The toxic effects of residual ethylene oxide (EtO), a frequently used gas-sterilant, on embryos either frozen for long-term purposes or stored acutely for 30 min to 9 hr in a fresh condition in 0.25-ml straw containers were evaluated. In Experiment 1, fresh embryos were frozen (using conventional technology) in straws previously aerated for 0 hr to 8 mo after EtO sterilization. With the exception of the 8-mo group in which survival and quality ratings were depressed, embryo viability was not affected significantly by short-term prefreeze and post-thaw exposure to EtO residues. Experiment 2 was conducted to analyze the influence of prefreeze exposure to EtO residues on embryo development in vitro for embryos temporarily stored in previously sterilized straws aerated for different intervals. Compared to non-EtO-sterilized control straws, the development, quality, and viability of embryos exposed to EtO-treated straws were compromised (p less than 0.05) as the aeration interval decreased and the exposure interval increased. The combined results of both experiments indicate that EtO-treated straws can be used to cryopreserve gametes efficiently, but only if the aeration interval is greater than or equal to 72 hr and the prefreeze duration of exposure is less than or equal to 3 hr.

  7. Developmental and reproductive toxicity testing of vaccines.

    PubMed

    Barrow, Paul

    2012-03-01

    The majority of new preventative and therapeutic vaccines are now assessed for developmental toxicity according to guidelines issued by the FDA in 2006. Despite the absence of confirmed effects in humans, vaccines are frequently suspected of having adverse side-effects on the development of children. Such suspicions are perhaps unavoidable considering the extremely widespread use of vaccines. The preclinical developmental toxicology studies are designed to assess possible influences of each component of the vaccine formulation-and the induced antibodies-on the development of the conceptus, neonate and suckling organism. Immune modulation by a vaccine or an adjuvant could, for instance, affect the outcome of pregnancy by interfering with the natural shift in immune balance of the mother during gestation. Maternal immunoglobulins are transferred from the mother to the offspring in order to confer passive immunity during early life. This maternal antibody transport is prenatal in humans and monkeys, but tends to be delayed until after birth in other species. Therefore, a suitable model species needs to be chosen for preclinical studies in order to ensure exposure of the foetus to the induced maternal antibodies following vaccination. Rabbits are the best laboratory model for prenatal immunoglobulin transfer, but rodents are more practical for the necessary postnatal investigations. Non-human primates are the only appropriate models for the testing of vaccines that are not immunogenic in lower species. It is advisable to test new adjuvants separately according to the ICH S5(R2) guidelines. Preclinical paediatric investigations are not currently required for vaccines, even though most vaccines are given to children. Other areas of regulatory concern include developmental immunotoxicity and effects on the preimplantation embryo. Because of the limitations of the available animal models for developmental toxicity testing, pharmacovigilance is essential.

  8. Developmental toxicity of copper chloride, methylene chloride, and 6-aminonicotinamide to embryos of the grass shrimp Palaemonetes pugio

    SciTech Connect

    Rayburn, J.R.; Fisher, W.S.

    1999-05-01

    Embryos of estuarine grass shrimp Palaemonetes pugio have demonstrated sensitivity to various solvents and petroleum products, indicating utility for evaluating estuarine contamination. Testing was performed to establish concentration-response curves for methylene chloride, copper chloride, and 6-aminonicotinamide, three known teratogenic chemicals. Two exposure periods were used, 4 d and 12 d, and both periods extended through hatching. The average 4-d LC50 values for methylene chloride, copper chloride, and 6-aminonicotinamide were 0.071% v/v, 1.82 mg/L, and 0.21 mg/ml, respectively. The average 12-d LC50 values for methylene chloride, copper chloride, and 6-aminonicotinamide were 0.031% v/v, 1.44 mg/L, and 0.057 mg/ml, respectively. Eye malformations were observed with embryos exposed to concentrations greater than 3 mg/L copper chloride or greater than 0.07% v/v methylene chloride. Very few abnormalities were observed in embryos exposed to 6-aminonicotinamide. Abnormal larval development was found with exposure to copper chloride at concentrations greater than 1 mg/L. The sensitivity and low variability found here further supports the development of these relatively simple methods using grass shrimp embryos. Establishment of sublethal developmental endpoints warrants further investigation because of their potential correspondence to mechanisms of toxic action.

  9. Silver nanoparticles: in vivo toxicity in zebrafish embryos and a comparison to silver nitrate

    NASA Astrophysics Data System (ADS)

    Mosselhy, Dina A.; He, Wei; Li, Dan; Meng, Yaping; Feng, Qingling

    2016-08-01

    The wide antimicrobial administration of silver nanoparticles (AgNPs) has raised the risks associated with their exposure. However, there is lack of robust toxicological data for the applied AgNPs to be in line with their wide antimicrobial applications. This study therefore set out to assess the in vivo toxicity of two different sizes of AgNPs using zebrafish embryos ( Danio rerio) as a brilliant in vivo model. The pivotal role of size of AgNPs in the toxicity was highlighted, wherein the smaller AgNPs (Ag-9 nm) exhibited more embryo toxicities than the larger particles (Ag-30 nm). Much uncertainty still exists about whether the cause of in vivo toxicity of AgNPs is the physicochemical properties of AgNPs or the released silver ions (Ag+). Therefore, another purpose of this study is to compare the toxicity of AgNPs with silver nitrate (AgNO3) in terms of mortality, hatchability and cardiac rates, and a series of phenotypic endpoints of zebrafish embryos. Collectively, the present results point towards the remarkable size-dependent toxicity of AgNPs. Wherein, the smaller AgNPs (9 ± 2 nm) induce increased mortality rates and decreased hatchability rates than the larger particles (30 ± 5 nm) in a dose-dependent manner. Besides, AgNPs and AgNO3 induce holistic different toxic mortality and hatchability rates. We have also found striking discrepancies in the phenotypic defects that were induced by AgNPs and AgNO3. The significant phenotypic defect induced by AgNPs is the axial deformity, while it is the deposition of Ag+ on the embryonic chorion for AgNO3. Therefore, it is proposed that AgNPs and AgNO3 induce different in vivo toxicities.

  10. Multifaceted toxicity assessment of catalyst composites in transgenic zebrafish embryos.

    PubMed

    Jang, Gun Hyuk; Lee, Keon Yong; Choi, Jaewon; Kim, Sang Hoon; Lee, Kwan Hyi

    2016-09-01

    Recent development in the field of nanomaterials has given rise into the inquiries regarding the toxicological characteristics of the nanomaterials. While many individual nanomaterials have been screened for their toxicological effects, composites that accompany nanomaterials are not common subjects to such screening through toxicological assessment. One of the widely used composites that accompany nanomaterials is catalyst composite used to reduce air pollution, which was selected as a target composite with nanomaterials for the multifaceted toxicological assessment. As existing studies did not possess any significant data regarding such catalyst composites, this study focuses on investigating toxicological characteristics of catalyst composites from various angles in both in-vitro and in-vivo settings. Initial toxicological assessment on catalyst composites was conducted using HUVECs for cell viability assays, and subsequent in-vivo assay regarding their direct influence on living organisms was done. The zebrafish embryo and its transgenic lines were used in the in-vivo assays to obtain multifaceted analytic results. Data obtained from the in-vivo assays include blood vessel formation, mutated heart morphology, and heart functionality change. Our multifaceted toxicological assessment pointed out that chemical composites augmented with nanomaterials can too have toxicological threat as much as individual nanomaterials do and alarms us with their danger. This manuscript provides a multifaceted assessment for composites augmented with nanomaterials, of which their toxicological threats have been overlooked.

  11. Identification of compounds in heavy fuel oil that are chronically toxic to rainbow trout embryos by effects-driven chemical fractionation.

    PubMed

    Adams, Julie; Bornstein, Jason M; Munno, Keenan; Hollebone, Bruce; King, Thomas; Brown, R Stephen; Hodson, Peter V

    2014-04-01

    The present study isolated and identified compounds in heavy fuel oil 7102 (HFO 7102) that are bioavailable and chronically toxic to rainbow trout embryos (Oncorhynchus mykiss). An effects-driven chemical fractionation combined the chemical separation of oil with toxicity testing and chemical analyses of each fraction to identify the major classes of compounds associated with embryo toxicity. Toxicity was assessed with 2 exposure methods, a high-energy chemical dispersion of oil in water, which included oil droplets in test solutions, and water accommodated fractions which were produced by oiled gravel desorption columns, and which did not contain visible oil droplets. Fractions of HFO with high concentrations of naphthalenes, alkanes, asphaltenes, and resins were nontoxic to embryos over the range of concentrations tested. In contrast, fractions enriched with 3- to 4-ringed alkyl polycyclic aromatic hydrocarbons (PAHs) were embryotoxic, consistent with published studies of crude oils and individual alkyl PAHs. The rank order of fraction toxicity did not vary between the exposure methods and was consistent with their PAH content; fractions with higher-molecular weight alkyl PAHs were the most toxic. Exposure of juvenile trout to most fractions of HFO induced higher activities of cytochrome P450 enzymes, with a rank order of potency that varied with exposure method and differed somewhat from that of embryotoxicity. Induction reflected the bioavailability of PAHs but did not accurately predict embryotoxicity.

  12. Assessment of the toxic effect exerted by fluorescent pseudomonads on embryos and larvae of the sea urchin Strongylocentrotus nudus.

    PubMed

    Beleneva, I A; Shamshurina, E V; Eliseikina, M G

    2015-05-01

    Strains of bacteria capable of growing on artificial culture media were isolated from the fouling of brass plates submerged in Nha Trang Bay, South China Sea, and from tissues of the seastar Distolasterias nipon, caught in Peter the Great Bay, Sea of Japan. According to the complex of data of genetic and physiological/biochemical analyzes, two strains of cultivated bacteria were identified by us as the species Pseudomonas aeruginosa, two strains as Pseudomonas fluorescens, and one strain as Ruegeria sp. It was shown that the cultivated strains of P. aeruginosa released exotoxins, particularly phenazine pigments, into the environment. Production of the toxins did not depend on presence of a target organism in the system and was aimed at regulation of interactions in the microbial community. The toxicity of the studied natural isolates of fluorescent pseudomonads was analyzed by using embryos and larvae of the sea urchin Strongylocentrotus nudus, which are the sensitive and dynamic toxicological sea-urchin embryo test (SET) system. As was established, exotoxins produced by the strains of P. aeruginosa inhibit activity of cilia in sea urchin larvae, as well as disturb processes of cell differentiation in embryos and larvae. Their toxic influence is accompanied by disturbances of protein synthesis and the disruptions of cytoskeleton in the course of zygote cleavage and larval development. Unlike P. aeruginosa, the strains of P. fluorescens and Ruegeria sp. did not exert the toxic effect on SET. The obtained data allow considering objects of the environment as the natural reservoir of opportunistic microorganisms posing a potential threat to human, whereas the use of SET for determination of toxicity of isolated bacteria provides an opportunity to study the mechanisms of their interactions with organisms in marine ecosystems.

  13. Developmental toxicity from exposure to various forms of mercury compounds in medaka fish (Oryzias latipes) embryos

    PubMed Central

    Liu, Jie; Wei, Lixin; Jingfeng, Yang; Chernick, Melissa; Hinton, David E.

    2016-01-01

    This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001–10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6–7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity. PMID:27635309

  14. Developmental toxicity from exposure to various forms of mercury compounds in medaka fish (Oryzias latipes) embryos.

    PubMed

    Dong, Wu; Liu, Jie; Wei, Lixin; Jingfeng, Yang; Chernick, Melissa; Hinton, David E

    2016-01-01

    This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001-10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6-7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity.

  15. Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to embryos of the fathead minnow (Pimephales promelas, Rafinesque)

    SciTech Connect

    Olivieri, C.; Cooper, K.

    1995-12-31

    This study correlates the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) residue and its toxicity to the fathead minnow embryo exposed to levels lower than the TCDD solubility range. The TCDD tissue doses in the embryo/larvae were related to gross lesions, delayed hatching, and death. A 7-day bioconcentration factor on a lipid basis (BCF{sub L}) was calculated. Embryos at the blatsula stage were exposed to [{sup 3}H] TCDD water concentrations (0.37, 0.59, 1.2, 2.83, and 10.1 6 ng/L), a nontreatment control and a solvent carrier control. Lesions were qualified as mild and severe based on their onset and their pathogenesis. Thus, mild lesions developed just prior to hatching or post-hatching at the fifth day of development. The severe lesions appeared at the third day of development. Embryos with tissue doses {le}2.46 {+-} 1.34 ng/g consistently developed mild lesions, while embryos with tissue doses {ge} 12.07 {+-} 4.91 ng/g developed severe lesions. The lowest observable adverse effect level was 0.04 {+-} 0.02 ng/g. The calculated 7-day ED{sub 50} was 0.14 ng/g. There was no delayed hatching at any of the concentrations tested. Embryo death occurred at a tissue concentration {ge}2.46 ng/g. The calculated 7-day LD{sub 50} was 25.71 ng/g. The relationship between the concentration of TCDD in the water (x = ng/L) and in the tissue dose (y = ng/g) fitted a linear curve y = {minus}1,143 + 3,792.5x, r{sup 2} = 0.98. The calculated BCF{sub L} (wet weight) was dose dependent. Embryos with tissue doses of 0.04 and 0.16 ng/g had BCF{sub L} of 2,700 and 3,325, respectively. Embryos with tissue doses of 2.46, 12.07, and 37.07 ng/g, had a BCF{sub L} of 104,225, 106,625 and 91,075, respectively.

  16. Embryo-fetal development toxicity of honokiol microemulsion intravenously administered to pregnant rats.

    PubMed

    Zhang, Qianqian; Ye, Xiangfeng; Wang, Lingzhi; Peng, Bangjie; Zhang, Yingxue; Bao, Jie; Li, Wanfang; Wei, Jinfeng; Wang, Aiping; Jin, Hongtao; Chen, Shizhong

    2016-02-01

    The aim of this study was to evaluate the embryo-fetal development toxicity of honokiol microemulsion. The drug was intravenously injected to pregnant SD rats at dose levels of 0, 200, 600 and 2000 μg/kg/day from day 6-15 of gestation. All the pregnant animals were observed for body weights and any abnormal changes and subjected to caesarean-section on gestation day (GD) 20; all fetuses obtained from caesarean-section were assessed by external inspection, visceral and skeletal examinations. No treatment-related external alterations as well as visceral and skeletal malformations were observed in honokiol microemulsion groups. There was no significant difference in the body weight gain of the pregnant rats, average number of corpora lutea, and the gravid uterus weight in the honokiol microemulsion groups compared with the vehicle control group. However, at a dose level of 2000 μg/kg/day, there was embryo-fetal developmental toxicity observed, including a decrease in the body length and tail length of fetuses. In conclusion, the no-observed-adverse-effect level (NOAEL) of honokiol microemulsion is 600 μg/kg/day, 75 times above the therapeutic dosage and it has embryo-fetal toxicity at a dose level of 2000 μg/kg/day, which is approximately 250 times above the therapeutic dosage.

  17. Is UV radiation changing the toxicity of compounds to zebrafish embryos?

    PubMed

    Almeida, Ana Rita; Andrade, Thayres S; Burkina, Viktoriia; Fedorova, Ganna; Loureiro, Susana; Soares, Amadeu M V M; Domingues, Inês

    2015-12-01

    At ecosystems level, environmental parameters such as temperature, pH, dissolved oxygen concentration and intensity of UV radiation (UVR) have an important role on the efficiency of organisms' physiological and behavioral performances and consequently on the capacity of response to contaminants. Insignificant alterations of these parameters may compromise this response. In addition, these parameters can additionally alter chemical compounds by inducing their degradation, producing thereafter other metabolites. Understanding the combined effects of chemicals and environmental parameters is absolutely necessary for an adequate prediction of risk in aquatic environments. According to this scenario, this work aims at studying the combined toxicity of UVR and three xenobiotics: the biocide triclosan (TCS), the metal chromium (as potassium dichromate, PD) and the fungicide prochloraz (PCZ). To achieve this goal zebrafish (Danio rerio) embryos (3h post fertilization (hpf)) were exposed to several concentrations of each chemical combined with different UV intensities; mortality and eggs were recorded every 24h for the all test duration (96 h). Results showed different response patterns depending on the toxicant, stress levels and duration of exposure. The combination of UVR and TCS indicated a dose ratio deviation where synergism was observed when UVR was the dominant stressor (day 2). The combination of UVR and PD presented a dose level dependency at day 3 indicating antagonism at low stress levels, changing with time where at day 4, a dose ratio deviation showed statistically that synergism occurred at higher PD concentrations. Finally, UVR combined with PCZ indicated a dose ratio at day 3 and dose level deviation at day 4 of exposure, suggesting a synergistic response when PCZ is the dominant stressor in the combination. The obtained results in this study highlighted the importance of taking into account the possible interaction of stressors and time of exposure to

  18. AHR2 morpholino knockdown reduces the toxicity of total particulate matter to zebrafish embryos.

    PubMed

    Massarsky, Andrey; Bone, Audrey J; Dong, Wu; Hinton, David E; Prasad, G L; Di Giulio, Richard T

    2016-10-15

    The zebrafish embryo has been proposed as a 'bridge model' to study the effects of cigarette smoke on early development. Previous studies showed that exposure to total particulate matter (TPM) led to adverse effects in developing zebrafish, and suggested that the antioxidant and aryl hydrocarbon receptor (AHR) pathways play important roles. This study investigated the roles of these two pathways in mediating TPM toxicity. The study consisted of four experiments. In experiment I, zebrafish embryos were exposed from 6h post fertilization (hpf) until 96hpf to TPM0.5 and TPM1.0 (corresponding to 0.5 and 1.0μg/mL equi-nicotine units) in the presence or absence of an antioxidant (N-acetyl cysteine/NAC) or a pro-oxidant (buthionine sulfoximine/BSO). In experiment II, TPM exposures were performed in embryos that were microinjected with nuclear factor erythroid 2-related factor 2 (Nrf2), AHR2, cytochrome P450 1A (CYP1A), or CYP1B1 morpholinos, and deformities were assessed. In experiment III, embryos were exposed to TPM, and embryos/larvae were collected at 24, 48, 72, and 96hpf to assess several genes associated with the antioxidant and AHR pathways. Lastly, experiment IV assessed the activity and protein levels of CYP1A and CYP1B1 after exposure to TPM. We demonstrate that the incidence of TPM-induced deformities was generally not affected by NAC/BSO treatments or Nrf2 knockdown. In contrast, AHR2 knockdown reduced, while CYP1A or CYP1B1 knockdowns elevated the incidence of some deformities. Moreover, as shown by gene expression the AHR pathway, but not the antioxidant pathway, was induced in response to TPM exposure, providing further evidence for its importance in mediating TPM toxicity.

  19. Comparative toxicity of Euphorbia milii latex and synthetic molluscicides to Biomphalaria glabrata embryos.

    PubMed

    Oliveira-Filho, Eduardo C; Geraldino, Barbara R; Coelho, Deise R; De-Carvalho, Rosângela R; Paumgartten, Francisco J R

    2010-09-01

    Plant molluscicides have been regarded as possible alternatives to the costly and environmentally hazardous molluscicides currently available. This study was undertaken to compare the developmental toxicity of a plant molluscicide (Euphorbia milii latex, LAT) with that of three synthetic molluscicidal compounds. Biomphalaria glabrata egg masses (0-15 h after spawning) were exposed to molluscicides for 96 h and thereafter examined up to the 14th day after spawning. Embryo deaths, abnormal embryo development (malformations) and the day of hatching were recorded. Although exhibiting a weak ovicidal effect, LAT markedly impaired the development of snail embryos at concentrations 1000 microg L(-1) and produced anomalies (EC(50)=2040 microg L(-1)) such as abnormal shells, hydropic embryos, cephalic and non-specific malformations. Embryolethal potencies of molluscicides were as follows: triphenyltin hydroxide (TPTH; LC(50)=0.30 microg L(-1))>niclosamide (NCL; LC(50)=70 microg L(-1))>copper sulphate (CuSO(4); LC(50)=2190 microg L(-1)) > LAT (LC(50)=34030 microg L(-1)). A few malformations were recorded in embryos exposed to concentrations of TPTH within the range of lethal concentrations, while almost no anomalies were noted among those treated with NCL or CuSO(4). A hatching delay (hatching on day 10 after spawning or later) was observed among LAT-exposed embryos. The effects of NCL, TPTH and CuSO4 on hatching were to some extent masked by their marked embryolethality. The no-observed effect concentrations (NOEC) for embryotoxicity were as follows: TPTH, 0.1 microg L(-1); NCL, 25.0 microg L(-1); CuSO(4), 500.0 microg L(-1) and LAT, 500.0 microg L(-1). Results from this study suggest that, although LAT was not acutely embryolethal after a short-term exposure, it markedly disrupted snail development. The marked embryotoxicity of E. milii possibly contributes to its effectiveness as a molluscicide.

  20. Developmental toxicity and oxidative stress induced by gamma irradiation in zebrafish embryos.

    PubMed

    Hu, Miao; Hu, Nan; Ding, Dexin; Zhao, Weichao; Feng, Yongfu; Zhang, Hui; Li, Guangyue; Wang, Yongdong

    2016-11-01

    This study aimed to evaluate the biological effects of gamma irradiation on zebrafish embryos. Different doses of gamma rays (0.01, 0.05, 0.1, 0.5 and 1 Gy) were used to irradiate zebrafish embryos at three developmental stages (stage 1, 6 h post-fertilization (hpf); stage 2, 12 hpf; stage three, 24 hpf), respectively. The survival, malformation and hatching rates of the zebrafish embryos were measured at the morphological endpoint of 96 hpf. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed. Morphology analysis showed that gamma irradiation inhibited hatching and induced developmental toxicity in a dose-dependent manner. Interestingly, after irradiation the malformation rate changed not only in a dose-dependent manner but also in a developmental stage-dependent manner, indicating that the zebrafish embryos at stage 1 were more sensitive to gamma rays than those at other stages. Biochemical analysis showed that gamma irradiation modulated the activities of antioxidant enzymes in a dose-dependent manner. A linear relationship was found between GPx activity and irradiation dose in 0.1-1 Gy group, and GPx was a suitable biomarker for gamma irradiation in the dose range from 0.1 to 1 Gy. Furthermore, the activities of SOD, CAT, GR and GPx of the zebrafish embryos at stage 3 were found to be much higher than those at other stages, indicating that the zebrafish embryos at stage 3 had a greater ability to protect against gamma rays than those at other stages, and thus the activities of antioxidant enzymes changed in a developmental stage-dependent manner.

  1. Protective effects of glucose-6-phosphate and NADP against alpha-chaconine-induced developmental toxicity in Xenopus embryos.

    PubMed

    Rayburn, J R; Bantle, J A; Qualls, C W; Friedman, M

    1995-12-01

    In previous studies a metabolic activation system (MAS) composed of Aroclor 1254-induced rat liver microsomes led to an apparent reduction of potato glycoalkaloid developmental toxicity in the frog embryo teratogenesis assay-Xenopus (FETAX). The reasons for this reduction were investigated in this study. The effect of the exogenous MAS on glycoalkaloid developmental toxicity was examined in two experiments in which a concentration series of alpha-chaconine was tested with a MAS with and without a reduced nicotinamide adenine dinucleotide (NADPH) generator system consisting of NADPH, oxidized nicotinamide adenine dinucleotide (NADP), glucose-6-phosphate (G6P) and glucose-6-phosphate dehydrogenase. The NADPH generator system and each of its individual components were tested at a single high concentration of alpha-chaconine to evaluate their potential effects on toxicity. The findings indicated that the protective effect of the MAS was not the result of detoxification by microsomal enzyme systems, but was caused by two components of the NADPH generator system, namely NADP and G6P. G6P was more protective of alpha-chaconine-induced toxicity than NADP at the concentrations tested. Thus, FETAX with a MAS must be performed with appropriate controls that take into account the possible interactions with individual components of the system.

  2. Amphibian embryos as a biological test for environmental pollutants in leachates, industrial effluents, surface and ground water

    SciTech Connect

    Herkovits, J.; Perez-Coll, C.S.; Herkovits, F.D.; Tarlato, M.

    1995-12-31

    Test of early life stages are very sensitive to toxic effects and moreover a good predictive correlation between embryo-larval survival and independent ecological parameters such as species richness and diversity have been established. The main purpose of this preliminary study is to report that Bufo arenarum embryos are very sensitive to contaminants from a variety of sources such as leachates, industrial effluents, surface and ground water. The toxicity of 30 samples (five from each category plus controls of surface and ground water from reference places) was evaluated during a 14 day renewal toxicity test at 20 C, conducted with 10 embryos (by triplicate) from stage 23--25 onwards using six concentrations (V/V) of each sample of Holtfreter`s solution. For industrial effluents and leachates the results range from a concentration of 0.6% resulting in 24hs LC100 up to a sample which exert 20% of lethality after 14 days of treatment. The survival of controls and in samples from reference places was over 90% for 7 days and over 80% for 14 days. The results with Bufo arenarum embryos confirm that a 7 day Short-term Chronic Toxicity Test is appropriate for toxicity screening of industrial effluents (as it was established by EPA for whole effluent toxicity test for aquatic life protection performed with other species) as well as for leachates. On the other hand, for freshwater (surface and ground), it is convenient to extend the exposure period until 14 days in order to record situations of low, but significant levels of toxicity, which could be of particular value for surface as well as ground water quality criteria.

  3. 7 day chronic ceriodaphnia toxicity test -- reproductive

    SciTech Connect

    Not Available

    1989-01-01

    This toxicity test was conducted to determine if the effluent causes death (acute toxicity) or reduction in the reproduction of the test organisms (chronic toxicity) during a seven day period. A series of dilutions of the effluent are set to determine how much the effluent must be diluted before toxic effects are no longer noted. Acute toxicity is checked by statistically analyzing whether significantly more organisms die in the effluent dilutions than in the control treatment, and, if significantly more die, how much the effluent must be diluted so as to kill only 50% of the test organisms (the LC50). Chronic toxicity is checked by statistically analyzing whether significantly fewer young are produced by test organisms exposed to the effluent dilutions. Results indicate the lowest effluent concentration which shows a toxic effect (the LOEC) and the highest effluent concentration which does not demonstrate an effect (NOEC).

  4. Chronic toxicity of heavy fuel oils to fish embryos using multiple exposure scenarios.

    PubMed

    Martin, Jonathan D; Adams, Julie; Hollebone, Bruce; King, Thomas; Brown, R Stephen; Hodson, Peter V

    2014-03-01

    The chronic toxicity to rainbow trout (Oncorhynchus mykiss) embryos of heavy fuel oil (HFO) 6303, weathered HFO 6303, HFO 7102, and medium South American (MESA) crude oil was assessed by different exposure regimes. These included water accommodated fractions (WAF; water in contact with floating oil), chemically enhanced WAF (CEWAF; oil dispersed with Corexit 9500), and effluent from columns of gravel coated with stranded oil. Heavy fuel oil WAF was nontoxic and did not contain detectable concentrations of hydrocarbons, likely because the high density and viscosity of HFO prevented droplet formation. In contrast, chemically dispersed HFO and effluent from columns of stranded HFO contained measurable concentrations of alkyl polycyclic aromatic hydrocarbons (PAH), coincident with embryo toxicity. These exposure regimes enhanced the surface area of oil in contact with water, facilitating oil-water partitioning of hydrocarbons. Heavy fuel oil was consistently more toxic to fish than crude oil and the rank order of alkyl PAH concentrations in whole oil were sufficient to explain the rank order of toxicity, regardless of exposure method. Thus, the propensity of HFO to sink and strand in spawning shoals creates a long-term risk to developing fish because of the sustained release of PAHs from HFO to interstitial waters. Further, PAH monitoring is key to accurate risk assessment.

  5. Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa)

    USGS Publications Warehouse

    Augspurger, T.P.; Tillitt, D.E.; Bursian, S.J.; Fitzgerald, S.D.; Hinton, D.E.; Di Giulio, R.T.

    2008-01-01

    We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection. ?? 2008 US Government.

  6. Stage-dependent toxicity of bisphenol a on Rhinella arenarum (anura, bufonidae) embryos and larvae.

    PubMed

    Wolkowicz, Ianina R Hutler; Herkovits, Jorge; Pérez Coll, Cristina S

    2014-02-01

    The acute and chronic toxicity of bisphenol A (BPA) was evaluated on the common South American toad Rhinella arenarum embryos and larvae by means of continuous and pulse exposure treatments. Embryos were treated continuously from early blastula (S.4) up to complete operculum (S.25), during early larval stages and by means of 24 h pulse exposures of BPA in concentrations ranging between 1.25 and 40 mg L(-1) , in order to evaluate the susceptibility to this compound in different developmental stages. For lethal effects, S.25 was the most sensitive and gastrula was the most resistant to BPA. The Teratogenic Index for neurula, the most sensitive embryonic stage for sublethal effects was 4.7. The main morphological alterations during early stages were: delayed or arrested development, reduced body size, persistent yolk plug, microcephaly, axial/tail flexures, edemas, blisters, waving fin, underdeveloped gills, mouth malformations, and cellular dissociation. BPA caused a remarkable narcotic effect from gill circulation stage (S.20) onwards in all the organisms exposed after 3 h of treatment with 10 mg L(-1) BPA. After recovering, the embryos exhibited scarce response to stimuli, erratic or circular swimming, and spasmodic contractions from 5 mg L(-1) onwards. Our results highlight the lethal and sublethal effectsof BPA on R. arenarum embryos and larvae, in the last case both at structural and functional levels.

  7. Toxicity of different forms of graphene in a chicken embryo model.

    PubMed

    Szmidt, Maciej; Sawosz, Ewa; Urbańska, Kaja; Jaworski, Sławomir; Kutwin, Marta; Hotowy, Anna; Wierzbicki, Mateusz; Grodzik, Marta; Lipińska, Ludwika; Chwalibog, André

    2016-10-01

    In the present work, the toxicity of three forms of graphene: pristine graphene (pG), graphene oxide (GO), and reduced graphene oxide (rGO) was investigated using a chicken embryo model. Fertilized chicken eggs were divided into the control group and groups administered with pG, GO, and rGO, in concentrations of 50, 500, and 5000 μg/ml. The experimental solutions were injected in ovo into the eggs, and at day 18 of incubation, the embryo survival, body and organ weights, the ultrastructure of liver samples, and the concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the livers were measured. Survival of embryos decreased significantly after treatment with all types of graphene, but not in a dose-dependent manner. The body weights were only slightly affected by the highest doses of graphene, while the organ weights were not different among treatment groups. In all experimental groups, atypical hepatocyte ultrastructure and mitochondrial damage were observed. The concentration of the marker of DNA damage 8-OHdG in the liver significantly decreased after pG and rGO treatments. Further in vivo studies with different animal models are necessary to clarify the level of toxicity of different types of graphene and to estimate the concentrations appropriate to evaluate their biomedical applications and environmental hazard.

  8. POREWATER TOXICITY TESTING: AN OVERVIEW

    EPA Science Inventory

    Sediments act as sinks for contaminants, where they may build up to toxic levels. Sediments containing toxic levels of contaminants pose a risk to aquatic life, human health, and wildlife. There is an overwhelming amount of evidence that demonstrates chemicals in sediments are re...

  9. BIOEQUIVALENCE APPROACH FOR WHOLE EFFLUENT TOXICITY TESTING

    EPA Science Inventory

    Increased use of whole effluent toxicity (WET) tests in the regulatory arena has brought increased concern over the statistical analysis of WET test data and the determination of toxicity. One concern is the issue of statistical power. A number of WET tests may pass the current...

  10. Spiking sediment with organochlorines for toxicity testing

    SciTech Connect

    Murdoch, M.H.; Chapman, P.M.; Norman, D.M.; Quintino, V.M.

    1997-07-01

    Sediment toxicity testing integrates responses to sediment variables and hence does not directly indicate cause and effect. One tool for determining cause and effect is sediment spiking, in which relatively uncontaminated sediment is amended with known amounts of contaminants, then tested for toxicity. However, sediment spiking methods vary considerably. The present study details appropriate methodologies (dry and wet spiking) for amending sediments with a range of organic contaminant concentrations, i.e., polychlorinated biphenyl (PCB). Target and actual concentrations were similar. A dose-response was determined, but PCB was not toxic in an acute sediment toxicity test. Chronic testing of these same sediments is reported in a companion article in this issue.

  11. Nanosilver-coated socks and their toxicity to zebrafish (Danio rerio) embryos.

    PubMed

    Gao, Jiejun; Sepúlveda, Maria S; Klinkhamer, Christopher; Wei, Alexander; Gao, Yu; Mahapatra, Cecon T

    2015-01-01

    Silver nanoparticles (AgNPs) are being incorporated and are known to be released from various consumer products such as textiles. However, no data are available on the toxicity of AgNPs released from any of these commercial products. In this study, we quantified total silver released from socks into wash water by inductively coupled plasma mass spectrometry (ICP-MS) and determined the presence of AgNPs using transmission electron microscopy (TEM). We then exposed zebrafish (Danio rerio) embryos for 72 h to either this leachate ("sock-AgNP") or to the centrifugate ("spun-AgNP") free of AgNPs and compared their toxicity to that of ionic silver (Ag(+)). Our data suggest that AgNPs do get released into the wash water, and centrifugation eliminated AgNPs but did not decrease total silver concentrations, indicating that most of the silver in the sock-AgNP solution was in the ionic form. All embryos died during the first 24 h when exposed to undiluted sock-AgNP and spun-AgNP solutions resulting in significantly lower LC50 values (0.14 and 0.26 mg L(-1)) compared to AgNO3 (0.80 mg L(-1)). Similarly, at 72 hpf, both sock-derived solutions were more potent at affecting hatching and inducing abnormal development. These results suggest that both sock-AgNP and spun-AgNP solutions were more toxic than AgNO3. Previous studies have consistently shown the opposite, i.e., AgNPs are about 10 times less toxic that Ag(+). All together our results show that the high toxicity induced by the leachate of these socks is likely not caused by AgNPs or Ag(+). More studies are needed to evaluate the toxicity of the myriad of AgNP-coated commercial products that are now estimated to be close to 500.

  12. The status of toxicity tests with sediment in Brazil

    SciTech Connect

    Araujo, R.P.A.

    1995-12-31

    The earliest studies in Brazil aiming to evaluate sediment quality through toxicity tests started in the beginning of the 80`s. These were developed by the Environmental Sanitation Agency of Sao Paulo State (CETESB) in Cubatao River and Billings Reservoir, which are located in industrialized and populous regions. Elutriate phase sediment toxicity tests were run with Daphnia similis. In the Cubatao River Basin the combination of toxicity, chemistry data and benthic community structure provided clear indications of sites with different levels of pollution. At this time there was a consensus that the study of a complex compartment such as sediment needed improvements in sampling and analysis procedures. Only in the 90`s the investigations involving sediment toxicity assessment were resumed by CETESB, and it was clear that integrative studies were needed in order to make environmental quality assessment. This kind of studies were conducted by CETESB in some highly polluted areas of Sao Paulo State, Ceriodaphnia dubia and Photobacterium phosphoreum interstitial water tests and Hyalella sp whole sediment tests were run, and the results correlated with several sediment organic and inorganic contaminants. The Sediment Quality Triad proposed by Chapman was applied in one of these studies. This approach was extremely useful in interpreting the data. At the same time marine sediment toxicity tests were developed by CETESB in collaboration with Sao Paulo University, and tests were run with the amphipods Tiburonella viscana, Battyporeiapus bisetosus; tanaidacean Kalliapseudes shubarti and the echinoderm Lytechinus variegatus. The embryo test with L. variegatus was the most adequate in these studies. Nowadays there are other groups in some universities developing sediment toxicity tests with Hyalella and Chironomus in response to a growing concern in Brazil to establish adequate sediment quality assessment guidelines.

  13. TGF-β1 monoclonal antibody: Assessment of embryo-fetal toxicity in rats and rabbits.

    PubMed

    Hilbish, Kim G; Martin, Jennifer A; Stauber, Anja J; Edwards, Tammye L; Breslin, William J

    2016-08-01

    A humanized monoclonal antibody targeting transforming growth factor β1 (TGF-β1 mab) has been used in development for the treatment of chronic kidney disease. Embryo-fetal development studies were conducted in rats and rabbits using 30 and 25 animals per group, respectively. The TGF-β1 mab was administered subcutaneously to rats at 0, 2, or 50 mg/kg/dose on gestation days (GDs) 6, 10, and 14 and intravenously to rabbits at 0 or 3 mg/kg/dose on GDs 7, 12 to 19, and at 30 mg/kg/dose on GDs 7, 12, 14, 16, and 18. Maternal reproductive endpoints and fetal viability, weight, and morphology were evaluated. There was no indication of maternal or embryo-fetal toxicity in the rat. Effects in the rabbit were limited to the fetus where the 30 mg/kg TGF-β1 mab dose produced a slight decrease in fetal weight and an increase in the incidence of retrocaval ureter and an absent and/or malpositioned kidney/ureter in two fetuses. In conclusion, TGF-β1 mab produced no adverse maternal or embryo-fetal findings in rats when administered ≤50 mg/kg on GDs 6, 10, and 14. TGF-β1 mab did not demonstrate maternal toxicity or embryo-fetal lethality at doses as high as 30 mg/kg when administered on GDs 7, 12, 14, 16, and 18 in rabbits. Fetal growth and morphology were affected only at 30 mg/kg; thus, the no observed adverse effect level was 3 mg/kg in rabbits. The margin of safety for both rats and rabbits was ≥37-fold the clinical exposure level.

  14. Development of toxicant identification procedures for whole sediment toxicity tests

    SciTech Connect

    Mount, D.R.; Henke, C.E.; Ingersoll, C.G.; Besser, J.M.; Ankley, G.T.; Norberg-King, T.J.; West, C.W.

    1995-12-31

    To effectively assess and manage contaminated sediments, identifying the specific contaminants responsible for sediment toxicity is highly desirable. Though effective toxicity identification evaluation (TIE) methods are well established for water column toxicity, new TIE methodologies are needed that address the special characteristics of whole sediment toxicity tests. Much of the effort to date has focused on the assessment of ammonia toxicity. Whereas pH manipulation is a key tool used to characterize ammonia toxicity in water column TIE, control of pH in interstitial water is much more challenging. Direct addition of hard acid has shown undesirable side effects (e.g., liberation and oxidation of iron), while CO{sub 2}-enrichment is limited in penetration of fine-grained sediments. Biological buffers (MES and POPSO) incorporated into the sediment are effective at altering interstitial pH without causing direct toxicity to Chironomus tentans, Lumbriculus variegatus, and to a lesser extent Hyalella azteca, but the range of pH control achieved has been small ({+-} 0.5 units). Introduction of aquatic plants reduces ammonia concentrations in the water column, but may not provide sufficient control of interstitial water. To date, the most promising results have been achieved using zeolite; adding zeolite to sediment produces moderate reductions in interstitial ammonia concentrations and is non-toxic to the organisms referenced above. Attempts to induce microbial removal of ammonia have been unsuccessful thus far. This presentation will review these and other sediment TIE methods currently under development in laboratories.

  15. Toxicity of spill-treating agents and oil to sea urchin embryos.

    PubMed

    Rial, Diego; Vázquez, José A; Murado, Miguel A

    2014-02-15

    The aim of this study was to assess the joint toxicity of a Maya crude oil and four spill-treating agents (STAs) (CytoSol, Finasol OSR51, Agma OSD569 and OD4000). The acute toxicity of the binary mixtures of the water accommodated fractions (WAFs) obtained independently for the oil and each STA was assessed. The toxicity of the chemically enhanced WAF (CEWAF) of oil and Finasol OSR51 at several dispersant to oil ratios (1:2, 1:10 and 1:100) was also evaluated. The toxicity (EC50) obtained for the WAFs of the STAs was: CytoSol (15.1 mL/L)toxicity of binary mixtures was obtained by the following models: Concentration Addition (Agma OSD569 and CytoSol), Independent Action (Finasol OSR51) and extended Concentration Addition model to describe antagonistic effects (OD4000). The CEWAFs showed an intermediate position between the more moderate effects of the WAF of oil and the higher toxicity of the WAFs of Finasol OSR51, which suggested the high sensitivity of the sea urchin embryo toward the dispersant.

  16. Toxicity assessment and bioaccumulation in zebrafish embryos exposed to carbon nanotubes suspended in Pluronic® F-108

    PubMed Central

    Wang, Ruhung; Meredith, Alicea N.; Lee, Michael; Deutsch, Dakota; Miadzvedskaya, Lizaveta; Braun, Elizabeth; Pantano, Paul; Harper, Stacey; Draper, Rockford

    2015-01-01

    Carbon nanotubes (CNTs) are often suspended in Pluronic® surfactants by sonication, which may confound toxicity studies because sonication of surfactants can create degradation products that are toxic to mammalian cells. Here, we present a toxicity assessment of Pluronic® F-108 with and without suspended CNTs using embryonic zebrafish as an in vivo model. Pluronic® sonolytic degradation products were toxic to zebrafish embryos just as they were to mammalian cells. When the toxic Pluronic® fragments were removed, there was little effect of pristine multi-walled CNTs (pMWNTs), carboxylated MWNTs (cMWNTs) or pristine single-walled carbon nanotubes (pSWNTs) on embryo viability and development, even at high concentrations. A gel electrophoretic method coupled with Raman imaging was developed to measure the bioaccumulation of CNTs by zebrafish embryos, and dose-dependent uptake of CNTs was observed. These data indicate that embryos accumulate pMWNTs, cMWNTs and pSWNTs yet there is very little embryo toxicity. PMID:26559437

  17. Effects of ionization on the toxicity of silver nanoparticles to Japanese medaka (Oryzias latipes) embryos.

    PubMed

    Lee, Byoung-Cheun; Kim, Jungkon; Cho, Jae-Gu; Lee, Jae-Woo; Duong, Cuong N; Bae, Eunjoo; Yi, Jongheop; Eom, Ig-Chun; Choi, Kyunghee; Kim, Pilje; Yoon, Junheon

    2014-01-01

    Increase in the use of manufactured nanomaterials (NMs) has led to concerns about the environmental impacts. Especially, hazard of metal-based NMs is more severe due to ions released from surface by water quality parameters and physicochemical properties after entering into the water environment. However, little is known about the effects of ionization on the toxicity of metal-based NMs in the water environment. To address this question, we prepared the suspensions of silver nanoparticles (AgNP) at 25 μg L(-1) containing different concentrations of Ag(+) (5, 10, 20, 45, and 75% Ag(+) to total Ag), and evaluated their toxicity to Japanese medaka (Oryzias latipes) embryos. Higher Ag(+) ratios in the AgNP suspension, suggesting the lower number of particles, led to the higher adverse effects on embryos and sac-fries. In addition, histopathology analysis revealed that AgNPs penetrated through chorion of eggs and skin membrane, and were distributed into the tissues. The results imply that the ionization could decrease the toxicity of metal-based NMs in the water environment.

  18. Potential protective effect of L-cysteine against the toxicity of acrylamide and furan in exposed Xenopus laevis embryos: an interaction study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The embryo toxicities of two food-processing-induced toxic compounds, acrylamide and furan, with and without added L-cysteine were examined individually and in mixtures using the frog embryo teratogenesis assay-Xenopus (FETAX). The following measures of developmental toxicity were used (a) 96-h LC5...

  19. Toxic Substances; Mesityl Oxide; Final Test Rule

    EPA Pesticide Factsheets

    EPA is issuing a final test rule establishing testing requirements under section 4(a) of the Toxic Substances Control Act (TSCA) for manufacturers and processors of mesityl oxide (MO; CAS No. 141-97-7).

  20. Using Toxicity Tests in Ecological Risk Assessment

    EPA Pesticide Factsheets

    Toxicity tests are used to expose test organisms to a medium-water, sediment, or soil-and evaluate the effects of contamination on the survival, growth, reproduction, behavior and or other attributes of these organisms.

  1. Low-dose agrochemicals and lawn-care pesticides induce developmental toxicity in murine preimplantation embryos.

    PubMed Central

    Greenlee, Anne R; Ellis, Tammy M; Berg, Richard L

    2004-01-01

    Occupational exposures to pesticides may increase parental risk of infertility and adverse pregnancy outcomes such as spontaneous abortion, preterm delivery, and congenital anomalies. Less is known about residential use of pesticides and the risks they pose to reproduction and development. In the present study we evaluate environmentally relevant, low-dose exposures to agrochemicals and lawn-care pesticides for their direct effects on mouse preimplantation embryo development, a period corresponding to the first 5-7 days after human conception. Agents tested were those commonly used in the upper midwestern United States, including six herbicides [atrazine, dicamba, metolachlor, 2,4-dichlorophenoxyacetic acid (2,4-D)], pendimethalin, and mecoprop), three insecticides (chlorpyrifos, terbufos, and permethrin), two fungicides (chlorothalonil and mancozeb), a desiccant (diquat), and a fertilizer (ammonium nitrate). Groups of 20-25 embryos were incubated 96 hr in vitro with either individual chemicals or mixtures of chemicals simulating exposures encountered by handling pesticides, inhaling drift, or ingesting contaminated groundwater. Incubating embryos with individual pesticides increased the percentage of apoptosis (cell death) for 11 of 13 chemicals (p embryo for 3 of 13 agents (p embryos (p embryo (p

  2. Evaluation of the detoxication efficiencies for acrylonitrile wastewater treated by a combined anaerobic oxic-aerobic biological fluidized tank (A/O-ABFT) process: Acute toxicity and zebrafish embryo toxicity.

    PubMed

    Na, Chunhong; Zhang, Ying; Deng, Minjie; Quan, Xie; Chen, Shuo; Zhang, Yaobin

    2016-07-01

    Acrylonitrile (ACN) wastewater generated during ACN production has been reported to be toxic to many aquatic organisms. However, few studies have evaluated toxicity removal of ACN wastewater during and after the treatment process. In this study, the detoxication ability of an ACN wastewater treatment plant (WWTP) was evaluated using Daphnia magna, Danio rerio and zebrafish embryo. This ACN WWTP has a combined anaerobic oxic-aerobic biological fluidized tank (A/O-ABFT) process upgraded from the traditional anaerobic oxic (A/O) process. Moreover, the potential toxicants of the ACN wastewaters were identified by gas chromatography-mass spectrometry (GC-MS). The raw ACN wastewater showed high acute and embryo toxicity. 3-Cyanopyridine, succinonitrile and a series of nitriles were detected as the toxic contributors of ACN wastewater. The A/O process was effective for the acute and embryo toxicity removal, as well as the organic toxicants. However, the A/O effluent still showed acute and embryo toxicity which was attributed by the undegraded and the newly generated toxicants during the A/O process. The residual acute and embryo toxicity as well as the organic toxicants in the A/O effluent were further reduced after going through the downstream ABFT process system. The final effluent displayed no significant acute and embryo toxicity, and less organic toxicants were detected in the final effluent. The upgrade of this ACN WWTP results in the improved removal efficiencies for acute and embryo toxicity, as well as the organic toxicants.

  3. 9 CFR 113.37 - Detection of pathogens by the chicken embryo inoculation test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... embryo inoculation test. 113.37 Section 113.37 Animals and Animal Products ANIMAL AND PLANT HEALTH... VECTORS STANDARD REQUIREMENTS Standard Procedures § 113.37 Detection of pathogens by the chicken embryo...-serum mixture shall be inoculated into each of at least 20 fully susceptible chicken embryos. (1)...

  4. 9 CFR 113.37 - Detection of pathogens by the chicken embryo inoculation test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... embryo inoculation test. 113.37 Section 113.37 Animals and Animal Products ANIMAL AND PLANT HEALTH... VECTORS STANDARD REQUIREMENTS Standard Procedures § 113.37 Detection of pathogens by the chicken embryo...-serum mixture shall be inoculated into each of at least 20 fully susceptible chicken embryos. (1)...

  5. 9 CFR 113.37 - Detection of pathogens by the chicken embryo inoculation test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... embryo inoculation test. 113.37 Section 113.37 Animals and Animal Products ANIMAL AND PLANT HEALTH... VECTORS STANDARD REQUIREMENTS Standard Procedures § 113.37 Detection of pathogens by the chicken embryo...-serum mixture shall be inoculated into each of at least 20 fully susceptible chicken embryos. (1)...

  6. 9 CFR 113.37 - Detection of pathogens by the chicken embryo inoculation test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... embryo inoculation test. 113.37 Section 113.37 Animals and Animal Products ANIMAL AND PLANT HEALTH... VECTORS STANDARD REQUIREMENTS Standard Procedures § 113.37 Detection of pathogens by the chicken embryo...-serum mixture shall be inoculated into each of at least 20 fully susceptible chicken embryos. (1)...

  7. 9 CFR 113.37 - Detection of pathogens by the chicken embryo inoculation test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... embryo inoculation test. 113.37 Section 113.37 Animals and Animal Products ANIMAL AND PLANT HEALTH... VECTORS STANDARD REQUIREMENTS Standard Procedures § 113.37 Detection of pathogens by the chicken embryo...-serum mixture shall be inoculated into each of at least 20 fully susceptible chicken embryos. (1)...

  8. Living organisms influence on environmental conditions: pH modulation by amphibian embryos versus aluminum toxicity.

    PubMed

    Herkovits, Jorge; Castañaga, Luis Alberto; D'Eramo, José Luis; Jourani, Victoria Platonova

    2015-11-01

    The LC10, 50 and 90/24h of aluminum for Rhinella arenarum embryos at complete operculum stage were 0.55, 0.75 and 1mgAl(3+)/L respectively. Those values did not change significantly by expanding the exposure period till 168h. The aluminum toxicity was evaluated in different pH conditions by means of a citrate buffer resulting for instance, 1mgAl(3+)/L at pH 4, 4.1, 5 and 6 in 100%, 70%, 35% and 0% of lethality respectively. As an outstanding feature, the embryos changed the pH of the maintaining media both in the case of Al(3+) or citrate buffer treatments toward neutral. 10 embryos in 40mL of AMPHITOX solution were able to increase the pH from 4.2 to 7.05, a fact related with a metabolic shift resulting in an increase in nitrogen loss as ammonia. Our study point out the natural selection of the most resistant amphibian embryos both for pH or aluminum as well as the capacity of living organisms (as a population) to alter their chemical environment toward optimal conditions for their survival. As these facts occur at early life stages, it expand the concept that living organisms at ontogenic stages are biomarker of environmental signatures of the evolutionary process (Herkovits, 2006) to a global Onto-Evo concept which imply also the feedback mechanisms from living organisms to shape environmental conditions in a way that benefits them.

  9. Behavioural and developmental toxicity of chlorpyrifos and nickel chloride to zebrafish (Danio rerio) embryos and larvae.

    PubMed

    Kienle, Cornelia; Köhler, Heinz-R; Gerhardt, Almut

    2009-09-01

    In order to assess the combined toxicity of environmental chemicals with different modes of action in acute (2 h) and subchronic (11 d) exposures, embryos and larvae of Danio rerio were exposed to a heavy metal salt, nickel chloride (NiCl2), the insecticide chlorpyrifos (CHP) and their binary mixtures. Chlorpyrifos is an acetylcholine esterase inhibitor, which is likely to affect behaviour of the organism. NiCl2 targets the active sites of enzymes and is regarded as an unspecific toxicant for aquatic organisms. Several endpoints, such as locomotor activity, morphological abnormalities, and mortality of D. rerio embryos and larvae were studied. During acute exposures to > or =0.25 mg/L of chlorpyrifos, locomotor activity tended to increase. However, this activity decreased significantly at > or =7.5 mg Ni/L. Subchronic exposures to CHP resulted in behavioural changes at much lower concentrations (> or =0.01 mg/L) and considerably earlier than the observed increase in morphological abnormalities and mortality (LC(50) (10 d): 0.43 mg/L). Combined CHP and NiCl2 mixtures led to an antagonistic deviation from the concept of independent action, in the case of locomotor activity. Compared to developmental or survival parameters, behaviour was the most sensitive endpoint for CHP exposure in this study; therefore we recommend this parameter to complement already established endpoints.

  10. Toxicity and cardiac effects of carbaryl in early developing zebrafish (Danio rerio) embryos

    SciTech Connect

    Lin, C.C.; Hui, Michelle N.Y.; Cheng, S.H. E-mail: bhcheng@cityu.edu.hk

    2007-07-15

    Carbaryl, an acetylcholinesterase inhibitor, is known to be moderately toxic to adult zebrafish and has been reported to cause heart malformations and irregular heartbeat in medaka. We performed experiments to study the toxicity of carbaryl, specifically its effects on the heart, in early developing zebrafish embryos. LC50 and EC50 values for carbaryl at 28 h post-fertilization were 44.66 {mu}g/ml and 7.52 {mu}g/ml, respectively, and 10 {mu}g/ml carbaryl was used in subsequent experiments. After confirming acetylcholinesterase inhibition by carbaryl using an enzymatic method, we observed red blood cell accumulation, delayed hatching and pericardial edema, but not heart malformation as described in some previous reports. Our chronic exposure data also demonstrated carbaryl-induced bradycardia, which is a common effect of acetylcholinesterase inhibitors due to the accumulation of acetylcholine, in embryos from 1 day post-fertilization (dpf) to 5 dpf. The distance between the sinus venosus, the point where blood enters the atrium, and the bulbus arteriosus, the point where blood leaves the ventricle, indicated normal looping of the heart tube. Immunostaining of myosin heavy chains with the ventricle-specific antibody MF20 and the atrium-specific antibody S46 showed normal development of heart chambers. At the same time, acute exposure resulted in carbaryl-induced bradycardia. Heart rate dropped significantly after a 10-min exposure to 100 {mu}g/ml carbaryl but recovered when carbaryl was removed. The novel observation of carbaryl-induced bradycardia in 1- and 2-dpf embryos suggested that carbaryl affected cardiac function possibly through an alternative mechanism other than acetylcholinesterase inhibition such as inhibition of calcium ion channels, since acetylcholine receptors in zebrafish are not functional until 3 dpf. However, the exact nature of this mechanism is currently unknown, and thus further studies are required.

  11. Acute toxicity of chlorpyrifos to embryo and larvae of banded gourami Trichogaster fasciata.

    PubMed

    Sumon, Kizar Ahmed; Saha, Sampa; van den Brink, Paul J; Peeters, Edwin T H M; Bosma, Roel H; Rashid, Harunur

    2017-02-01

    This study elucidated the acute toxicity of chlorpyrifos on the early life stages of banded gourami (Trichogaster fasciata). To determine the acute effects of chlorpyrifos on their survival and development, we exposedthe embryos and two-day-old larvae to six concentrations (0, 0.01, 0.10, 1.0, 10 and 100 µg L(-1)) of chlorpyrifos in plastic bowls. Log-logistic regression was used to calculate LC10 and LC50 values. Results showed that embryo mortality significantly increased with increasing chlorpyrifos concentrations. The 24-h LC10 and LC50 values (with 95% confidence limits) of chlorpyrifos for embryos were 0.89 (0.50-1.58) and 11.8 (9.12-15.4) µg L(-1), respectively. Hatching success decreased and mortality of larvae significantly increased with increasing concentrations of chlorpyrifos. The 24-h LC10 and LC50 values (with 95% confidence limits) of chlorpyrifos for larvae were 0.53 (0.27-1.06) and 21.7 (15.9-29.4) µg L(-1), respectively; the 48-h LC10 and LC50 for larvae were 0.04 (0.02-0.09) and 5.47 (3.77-7.94) µg L(-1), respectively. The results of this study suggest that 1 µg L(-1) of chlorpyrifos in the aquatic environment may adversely affect the development and the reproduction of banded gourami. Our study also suggests that banded gourami fish can serve as an ideal model species for evaluating developmental toxicity of environmental contaminants.

  12. Developing a list of reference chemicals for testing alternatives to whole fish toxicity tests.

    PubMed

    Schirmer, Kristin; Tanneberger, Katrin; Kramer, Nynke I; Völker, Doris; Scholz, Stefan; Hafner, Christoph; Lee, Lucy E J; Bols, Niels C; Hermens, Joop L M

    2008-11-11

    This paper details the derivation of a list of 60 reference chemicals for the development of alternatives to animal testing in ecotoxicology with a particular focus on fish. The chemicals were selected as a prerequisite to gather mechanistic information on the performance of alternative testing systems, namely vertebrate cell lines and fish embryos, in comparison to the fish acute lethality test. To avoid the need for additional experiments with fish, the U.S. EPA fathead minnow database was consulted as reference for whole organism responses. This database was compared to the Halle Registry of Cytotoxicity and a collation of data by the German EPA (UBA) on acute toxicity data derived from zebrafish embryos. Chemicals that were present in the fathead minnow database and in at least one of the other two databases were subject to selection. Criteria included the coverage of a wide range of toxicity and physico-chemical parameters as well as the determination of outliers of the in vivo/in vitro correlations. While the reference list of chemicals now guides our research for improving cell line and fish embryo assays to make them widely applicable, the list could be of benefit to search for alternatives in ecotoxicology in general. One example would be the use of this list to validate structure-activity prediction models, which in turn would benefit from a continuous extension of this list with regard to physico-chemical and toxicological data.

  13. Toxic effects of pentachlorophenol, azinphos-methyl and chlorpyrifos on the development of Paracentrotus lividus embryos.

    PubMed

    Buono, Silvia; Manzo, Sonia; Maria, Giovanna; Sansone, Giovanni

    2012-04-01

    The application of many current-use pesticides has increased after the disuse of persistent, bioaccumulative or toxic ones as DDT or chlordane. Many of the used pesticides are considered less dangerous towards the environment for their physico-chemical properties. This study investigated the toxic effects of three current-use pesticides, pentachlorophenol (PCP), azinphos-methyl (AZM), and chlorpyrifos, on Mediterranean sea urchin Paracentrotus lividus early development and offspring quality. The experimental results showed that the most toxic pesticides were PCP and AZM at EC50 level. Nevertheless at low concentration PCP resulted the less toxic compound and showed EC1 value more protective than NOEC. PCP at high concentration seemed to modify cytoskeleton assembly, while at low concentrations, it could alter the deposition of the larval skeleton. OPs at low concentrations until 300 μg/l showed a similar toxicological behaviour with a trend corresponding to the pesticide concentrations. At high concentration (500 μg/l) the effect mainly observed was the embryos pre-larval arrest. This investigation highlighted the relevance to evaluate, in coastal seawaters, the levels of the used pesticides to understand the real impact on benthic populations mainly in sites characterized by intensive agriculture or floriculture activities, such as the coastal areas of the Mediterranean Sea.

  14. Draft Test Guideline: Fish Life Cycle Toxicity

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  15. Comparison of standard acute toxicity tests with rapid-screening toxicity tests

    SciTech Connect

    Toussaint, M.W.; Shedd, T.R.; VanDerSchal, W.H.; Leather, G.R.

    1995-10-01

    This study compared the relative sensitivity of five inexpensive, rapid toxicity tests to the sensitivity of five standard aquatic acute toxicity tests through literature review and testing. The rapid toxicity tests utilized organisms that require little culturing or handling prior to testing: a freshwater rotifer (Branchionus ccalyciflorus); brine shrimp (Artemia salina); lettuce (Lactuca sativa); and two microbial tests (Photo bacterium phosphoreum - Microtox test, and a mixture of bacterial species - the polytox test). Standard acute toxicity test species included water fleas (Daphnia magna and Ceriadaphnta dubia), green algae (Setenastrum capricarnutum), fathead minnows (Pimephalespromelas), and mysid shrimp (Mysidopsis bahia). Sensitivity comparisons between rapid and standard acute toxicity tests were based on LC5O/EC50 data from 11 test chemicals. Individually, the lettuce and rotifer tests ranked most similar in sensitivity to the standard tests, while Microtox fell just outside the range of sensitivities represented by the group of standard acute toxicity tests. The brine shrimp and Polytox tests were one or more orders of magnitude different from the standard acute toxicity tests for most compounds. The lettuce, rotifer, and Microtox tests could be used as a battery for preliminary toxicity screening of chemicals. Further evaluation of complex real-world environmental samples is recommended.

  16. A comparison of standard acute toxicity tests with rapid-screening toxicity tests

    SciTech Connect

    Toussaint, M.W.; Shedd, T.R.; Schalie, W.H. van der; Leather, G.R.

    1995-05-01

    This study compared the relative sensitivity of five inexpensive, rapid toxicity tests to the sensitivity of five standard aquatic acute toxicity tests through literature review and testing. The rapid toxicity tests utilized organisms that require little culturing or handling prior to testing: a freshwater rotifer (Branchionus calyciflorus); brine shrimp (Artemia salina); lettuce (Lactuca sativa); and two microbial tests (Photobacterium phosphoreum--Microtox{reg_sign} test, and a mixture of bacterial species--the Polytox{reg_sign} test). Standard acute toxicity test species included water fleas (Daphnia magna and Ceriodaphnia dubia), green algae (Selenastrum capricornutum), fathead minnows (Pimephales promelas), and mysid shrimp (Mysidopsis bahia). Sensitivity comparisons between rapid and standard acute toxicity tests were based on LC50/EC50 data from 11 test chemicals. Individually, the lettuce and rotifer tests ranked most similar in sensitivity to the standard tests, while Microtox fell just outside the range of sensitivities represented by the group of standard acute toxicity tests. The brine shrimp and Polytox tests were one or more orders of magnitude different from the standard acute toxicity tests for most compounds. The lettuce, rotifer, and Microtox tests could be used as a battery for preliminary toxicity screening of chemicals. Further evaluation of complex real-world environmental samples is recommended.

  17. REGULATORY APPLICATIONS OF POREWATER TOXICITY TESTING

    EPA Science Inventory

    The purpose of this chapter is to evaluate the use of porewater toxicity tests in regulatory applications, including their potential use in the development of sediment quality guideline (SQG) values. Specifically, the following discussion focuses on the appropriateness and readin...

  18. Automated Test Systems for Toxic Vapor Detectors

    NASA Technical Reports Server (NTRS)

    Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

    1997-01-01

    The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/temperature/humidity (FIFH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy

  19. Synthesis, physicochemical studies, embryos toxicity and DNA interaction of some new Iron(II) Schiff base amino acid complexes

    NASA Astrophysics Data System (ADS)

    Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.

    2013-05-01

    New Fe(II) Schiff base amino acid complexes derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized by elemental analysis, IR, electronic spectra, and conductance measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. The investigated Schiff bases exhibited tridentate coordination mode with the general formulae [Fe(HL)2]·nH2O for all amino acids except L-histidine. But in case of L-histidine, the ligand acts as tetradentate ([FeL(H2O)2]·2H2O), where HL = mono anion and L = dianion of the ligand. The structure of the prepared complexes is suggested to be octahedral. The prepared complexes were tested for their toxicity on chick embryos and found to be safe until a concentration of 100 μg/egg with full embryos formation. The interaction between CT-DNA and the investigated complexes were followed by spectrophotometry and viscosity measurements. It was found that, the prepared complexes bind to DNA via classical intercalative mode and showed a different DNA cleavage activity with the sequence: nhi > nari > nali > nasi > nphali. The thermodynamic Profile of the binding of nphali complex and CT-DNA was constructed by analyzing the experimental data of absorption titration and UV melting studies with the McGhee equation, van't Hoff's equation, and the Gibbs-Helmholtz equation.

  20. Off-season spawning and factors influencing toxicity test development with topsmelt Atherinops affinis

    SciTech Connect

    Anderson, B.S.; Hunt, J.W.; McNulty, H.R.; Turpen, S.L. . Inst. of Marine Sciences); Martin, M. . California Dept. of Fish and Game)

    1994-03-01

    Three separate groups of adult topsmelt (Atherinops affinis) were spawned in rotation in laboratory culture over a two-year period to provide larvae for toxicity tests. Size and viability of embryos and larvae produced during the normal summer spawning period (May-August) were compared to those produced during the off season (October-April). Mean embryo viability was relatively high throughout the study, whereas size of larvae varied. Larval size was significantly larger during the summer spawning period than in winter. A 7-d growth and survival toxicity test protocol was developed for topsmelt larvae. Variability of the protocol was assessed over a 12-month period using copper chloride as a reference toxicant. Precision of 12 toxicity tests using copper was high; the intralaboratory C.V. for copper LC50s was 19%. The 7-d larval protocol also gave comparable results in two interlaboratory toxicity tests using copper and complex effluent. This study demonstrates that topsmelt may be spawned throughout the year to provide larvae for toxicity tests and that topsmelt larvae have comparable sensitivity to other larval fishes commonly used in toxicity testing.

  1. Critical influence of chloride ions on silver ion-mediated acute toxicity of silver nanoparticles to zebrafish embryos.

    PubMed

    Groh, Ksenia J; Dalkvist, Trine; Piccapietra, Flavio; Behra, Renata; Suter, Marc J-F; Schirmer, Kristin

    2015-02-01

    The toxicity of silver nanoparticles (AgNP) to aquatic organisms, including zebrafish (Danio rerio), has been demonstrated, but differing opinions exist on the contribution of the physical properties of the particles themselves and the free dissolved silver ions (Ag(+)) to the observed effects. High concentrations of chloride ions (Cl(-)) in the routinely used exposure media can cause precipitation of Ag(+) as AgCl, as well as complexation of silver in diverse soluble chlorocomplexes, thus masking the contribution of dissolved silver to AgNP toxicity. In the present study, we formulated a zebrafish exposure medium with a low chloride content and exposed zebrafish embryos to AgNO3 or carbonate-coated AgNP. The severity of toxicity caused by both silver forms depended on the time of exposure start, with younger embryos being most sensitive. Toxicity caused by both AgNO3 and AgNP was of the same order of magnitude when compared based on the total dissolved silver concentration and could be prevented by addition of the Ag(+) chelator cysteine. Further, we have analyzed the data from several previous studies to evaluate the influence of interactions between Ag(+) and Cl(-) on silver toxicity to zebrafish embryos. Our analysis demonstrates that the acute toxicity of AgNP to zebrafish embryos is largely mediated by Ag(+). The influence of particle size and coating can at least partially be explained by the differences in Ag(+) dissolution. High Cl(-) levels in the exposure medium indeed have a pivotal influence on the resulting toxicity of AgNP, appearing to significantly attenuate toxicity in several studies. This consideration should influence the choice of exposure medium to be used when evaluating and comparing AgNP toxicity.

  2. In Vivo Quantitative Study of Sized-Dependent Transport and Toxicity of Single Silver Nanoparticles Using Zebrafish Embryos

    PubMed Central

    Lee, Kerry J.; Browning, Lauren M.; Nallathamby, Prakash D.; Desai, Tanvi; Cherukui, Pavan K.; Xu, Xiao-Hong Nancy

    2012-01-01

    Nanomaterials possess distinctive physicochemical properties (e.g., small sizes, high surface area-to-volume ratios) and promise a wide variety of applications, ranging from design of high quality consumer products to effective disease diagnosis and therapy. These properties can lead to toxic effects, potentially hindering advance in nanotechnology. In this study, we have synthesized and characterized purified and stable (non-aggregation) silver nanoparticles (Ag NPs, 41.6±9.1 nm in average diameters), and utilized early-developing (cleavage-stage) zebrafish embryos (critical aquatic and eco- species) as in vivo model organisms to probe diffusion and toxicity of Ag NPs. We found that single Ag NPs (30–72 nm diameters) passively diffused into the embryos through chorionic pores via random Brownian motion and stayed inside the embryos throughout their entire development (120 hours-post-fertilization, hpf). Dose and size dependent toxic effects of the NPs on embryonic development were observed, showing the possibility of tuning biocompatibility and toxicity of the NPs. At lower concentrations of the NPs (≤ 0.02 nM), 75–91% of embryos developed to normal zebrafish. At the higher concentrations of NPs (≥ 0.20 nM), 100% of embryos became dead. At the concentrations in between (0.02–0.2 nM), embryos developed to various deformed zebrafish. Number and sizes of individual Ag NPs embedded in tissues of normal and deformed zebrafish at 120 hpf were quantitatively analyzed, showing deformed zebrafish with higher number of larger NPs than normal zebrafish, and size-dependent nanotoxicity. By comparing with our previous studies of smaller Ag NPs (11.6±3.5 nm), the results further demonstrate striking size-dependent nanotoxicity that, at the same molar concentration, the larger Ag NPs (41.6±9.1 nm) are more toxic than the smaller Ag NPs (11.6±3.5 nm). PMID:22486336

  3. Toxicity of endosulfan on embryo-larval development of the South American toad Rhinella arenarum.

    PubMed

    Svartz, Gabriela V; Wolkowicz, Ianina R Hutler; Coll, Cristina S Pérez

    2014-04-01

    Endosulfan is a widely used pesticide despite its extreme toxicity to a variety of taxa and its worldwide ban. The aim of the present study was to evaluate the acute and chronic toxicity of endosulfan on the embryonic-larval development of the common South American toad Rhinella arenarum. The results showed that lethal and sublethal effects increased with concentration and exposure time. The sensitivity to endosulfan increased during the larval period, the complete operculum stage (S.25) being the most sensitive (504-h median lethal concentration [LC50] = 0.01 mg endosulfan/L; 10% lethal concentration [LC10] = 0.004 mg endosulfan/L). Endosulfan exposure caused morphological abnormalities such as general underdevelopment, edema, gill malformations, and cellular dissociation as well as neurotoxicity. Our results also showed that larvae exposed to concentrations of 0.005 mg endosulfan/L and 0.01 mg endosulfan/L completed metamorphosis earlier than controls, but with underdevelopment. The 240-h teratogenic index was 6.13, implying a high risk for embryos to be malformed in the absence of significant embryonic lethality. Because the hazard quotients for chronic exposure were over 1, the level of concern value and toxicity endpoints obtained in the present study for R. arenarum occurred at concentrations lower than the levels of endosulfan reported in the environment, this pesticide should be considered a potential risk for this species.

  4. Differential toxicity and uptake of Diazinon on embryo-larval development of Rhinella arenarum.

    PubMed

    Aronzon, Carolina Mariel; Marino, Damián J G; Ronco, Alicia E; Pérez Coll, Cristina Silvia

    2014-04-01

    Diazinon, an anti-cholinesterase organophosphate, is an extensively used pesticide. The main objective of this work was to assess the lethal and sublethal effects of Diazinon and its comparison with the uptake by embryos and larvae of the common South American toad Rhinella arenarum by means of standardized bioassays during acute (96 h), short-term chronic (168 h) and chronic (504 h) exposures. Toxicity resulted time- and stage-dependent, thus the lethal concentration 50 for 96 h, 168 h and 504 h were 27.2; 20.1 and 6.8 mg Diazinon L(-1) for embryos and 8, 6.7 and 1.9 mg Diazinon L(-1) for larvae. It is noteworthy the remarkable differences found in the concentration which caused lethality with those causing adverse effects on development such as malformations (teratogenic effects). Therefore, the teratogenic index from 144 h was greater than two; the main adverse effects were axial flexures, irregular borders, wavy tail, microcephaly, malformed mouth and adhesive structures, gut miscoiling, underdeveloped gills, cloacal edema, desquamation and severe hydropsy. Moreover, the characteristic sublethal effect of Diazinon on larvae was abnormal behavior related to neurotoxicity with a NOEC-168 h of 4.5 mg Diazinon L(-1). Diazinon contents in R. arenarum were time-dependent and significantly related to exposure concentration for both embryos and larvae. Diazinon contents were also stage-dependent, as it was up to 27 times higher for organisms exposed from blastula stage onwards than early larvae. These facts and the Hazard Quotients, a numerical expression of ecological risk, of 2.73, which is above USEPA's Level of Concern, showed the threat that Diazinon represents for R. arenarum populations.

  5. Searching for biomarkers of developmental toxicity with microarrays: normal eye morphogenesis in rodent embryos

    SciTech Connect

    Nemeth, Kimberly A.; Singh, Amar V.; Knudsen, Thomas B. . E-mail: thomas.knudsen@louisville.edu

    2005-08-07

    Gene expression arrays reveal the potential linkage of altered gene expression with specific adverse effects leading to disease phenotypes. But how closely do microarray data reflect early physiological or pharmacological measures that predict toxic event(s)? To explore this issue, we have undertaken experiments in early mouse embryos exposed to various teratogens during neurulation stages with the aim of correlating large-scale changes in gene expression across the critical period during exposure. This study reports some of the large-scale changes in gene expression that can be detected in the optic rudiment of the developing mouse and rat embryo across the window of development during which the eye is exceedingly sensitive to teratogen-induced micro-/anophthalmia. Microarray analysis was performed on RNA from the headfold or ocular region at the optic vesicle and optic cup stages when the ocular primordium is enriched for Pax-6, a master control gene for eye morphogenesis. Statistical selection of differentially regulated genes and various clustering techniques identified groups of genes in upward or downward trajectories in the normal optic primordium during early eye development in mouse and rat species. We identified 165 genes with significant differential expression during eye development, and a smaller subset of 58 genes that showed a tight correlation between mouse-rat development. Significantly over-represented functional categories included fatty acid metabolism (up-regulated) and glycolysis (down-regulated). From studies such as these that benchmark large-scale gene expression during normal embryonic development, we may be able to identify the panel of biomarkers that best correlate with species differences and the risks for developmental toxicity.

  6. THE FUTURE OF TOXICITY TESTING AND ASSESSMENT ...

    EPA Pesticide Factsheets

    The National Research Council's Board on Environmental Studies and Toxicology is conducting a two-part study to assess and advance current approaches to toxicity testing and assessment to meet regulatory data needs. The first part of the study was completed January 2006, in which the committee prepared a report reviewing selected aspects of several relevant reports by EPA and others on this topic. In the second part of the study currently underway, the committee will prepare a final report presenting a long-range vision and strategic plan for advancing the practices of toxicity testing and human health assessment for environmental contaminants. In developing the vision and strategic plan, the committee will consider evolving regulatory data needs; current toxicity testing guidelines and standards used by EPA and other federal agencies; the use of emerging science and tools (e.g., genomics, proteomics, transgenics, bioinformatics, computational toxicology, in vitro testing, and other alternatives to animal testing); and the challenges of incorporating more complex understanding of toxicity (e.g., toxicokinetics, mechanisms of action, systems biology) into human health risk assessment. The final report is expected to be released as early as the end of January, 2007. To develop a long-range vision and strategic plan for advancing the practices of toxicity testing and human health assessment for environmental contaminants.

  7. Comparison of rat and rabbit embryo-fetal developmental toxicity data for 379 pharmaceuticals: on the nature and severity of developmental effects.

    PubMed

    Theunissen, Peter T; Beken, Sonja; Beyer, Bruce K; Breslin, William J; Cappon, Gregg D; Chen, Connie L; Chmielewski, Gary; De Schaepdrijver, Luc; Enright, Brian; Foreman, Jennifer E; Harrouk, Wafa; Hew, Kok-Wah; Hoberman, Alan M; Hui, Julia Y; Knudsen, Thomas B; Laffan, Susan B; Makris, Susan L; Martin, Matt; McNerney, Mary Ellen; Siezen, Christine L; Stanislaus, Dinesh J; Stewart, Jane; Thompson, Kary E; Tornesi, Belen; Van der Laan, Jan Willem; Weinbauer, Gerhard F; Wood, Sandra; Piersma, Aldert H

    2016-11-01

    Regulatory non-clinical safety testing of human pharmaceuticals typically requires embryo-fetal developmental toxicity (EFDT) testing in two species (one rodent and one non-rodent). The question has been raised whether under some conditions EFDT testing could be limited to one species, or whether the testing in a second species could be decided on a case-by-case basis. As part of a consortium initiative, we built and queried a database of 379 compounds with EFDT studies (in both rat and rabbit animal models) conducted for marketed and non-marketed pharmaceuticals for their potential for adverse developmental and maternal outcomes, including EFDT incidence and the nature and severity of adverse findings. Manifestation of EFDT in either one or both species was demonstrated for 282 compounds (74%). EFDT was detected in only one species (rat or rabbit) in almost a third (31%, 118 compounds), with 58% (68 compounds) of rat studies and 42% (50 compounds) of rabbit studies identifying an EFDT signal. For 24 compounds (6%), fetal malformations were observed in one species (rat or rabbit) in the absence of any EFDT in the second species. In general, growth retardation, fetal variations, and malformations were more prominent in the rat, whereas embryo-fetal death was observed more often in the rabbit. Discordance across species may be attributed to factors such as maternal toxicity, study design differences, pharmacokinetic differences, and pharmacologic relevance of species. The current analysis suggests that in general both species are equally sensitive on the basis of an overall EFDT LOAEL comparison, but selective EFDT toxicity in one species is not uncommon. Also, there appear to be species differences in the prevalence of various EFDT manifestations (i.e. embryo-fetal death, growth retardation, and dysmorphogenesis) between rat and rabbit, suggesting that the use of both species has a higher probability of detecting developmental toxicants than either one alone.

  8. Avian models for toxicity testing

    USGS Publications Warehouse

    Hill, E.F.; Hoffman, D.J.

    1984-01-01

    The use of birds as test models in experimental and environmental toxicology as related to health effects is reviewed, and an overview of descriptive tests routinely used in wildlife toxicology is provided. Toxicologic research on birds may be applicable to human health both directly by their use as models for mechanistic and descriptive studies and indirectly as monitors of environmental quality. Topics include the use of birds as models for study of teratogenesis and embryotoxicity, neurotoxicity, behavior, trends of environmental pollution, and for use in predictive wildlife toxicology. Uses of domestic and wild-captured birds are discussed.

  9. The C. elegans model in toxicity testing

    PubMed Central

    2016-01-01

    Abstract Caenorhabditis elegans is a small nematode that can be maintained at low cost and handled using standard in vitro techniques. Unlike toxicity testing using cell cultures, C. elegans toxicity assays provide data from a whole animal with intact and metabolically active digestive, reproductive, endocrine, sensory and neuromuscular systems. Toxicity ranking screens in C. elegans have repeatedly been shown to be as predictive of rat LD50 ranking as mouse LD50 ranking. Additionally, many instances of conservation of mode of toxic action have been noted between C. elegans and mammals. These consistent correlations make the case for inclusion of C. elegans assays in early safety testing and as one component in tiered or integrated toxicity testing strategies, but do not indicate that nematodes alone can replace data from mammals for hazard evaluation. As with cell cultures, good C. elegans culture practice (GCeCP) is essential for reliable results. This article reviews C. elegans use in various toxicity assays, the C. elegans model's strengths and limitations for use in predictive toxicology, and GCeCP. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Journal of Applied Toxicology published by John Wiley & Sons Ltd. PMID:27443595

  10. Comparison of the in vitro and in vivo toxic effects of three sizes of zinc oxide (ZnO) particles using flounder gill (FG) cells and zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Han, Li; Zhai, Yanan; Liu, Yang; Hao, Linhua; Guo, Huarong

    2017-02-01

    Nano-sized zinc oxide (nZnO) particles are one kind of the most commonly used metal oxide nanoparticles (NPs). This study compared the cytotoxic and embryotoxic effects of three increasing sized ZnO particles (ϕ 30 nm, 80-150 nm and 2 μm) in the flounder gill (FG) cells and zebrafish embryos, and analyzed the contribution of size, agglomeration and released Zn2+ to the toxic effects. All the tested ZnO particles were found to be highly toxic to both FG cells and zebrafish embryos. They induced growth inhibition, LDH release, morphological changes and apoptosis in FG cells in a concentration-, size- and time-dependent manner. Moreover, the release of LDH from the exposed FG cells into the medium occurred before the observable morphological changes happened. The ultrasonication treatment and addition of serum favored the dispersion of ZnO particles and alleviated the agglomeration, thus significantly increased the corresponding cytotoxicity. The released Zn2+ ions from ZnO particles into the extracellular medium only partially contributed to the cytotoxicity. All the three sizes of ZnO particles tested induced developmental malformations, decrease of hatching rates and lethality in zebrafish embryos, but size- and concentration- dependent toxic effects were not so obvious as in FG cells possibly due to the easy aggregation of ZnO particles in freshwater. In conclusion, both FG cells and zebrafish embryos are sensitive bioassay systems for safety assessment of ZnO particles and the environmental release of ZnO particles should be closely monitored as far as the safety of aquatic organisms is concerned.

  11. Numeric Estimates of Teratogenic Severity from Embryo-Fetal Developmental Toxicity Studies.

    PubMed

    Wise, L David

    2016-02-01

    A developing organism exposed to a toxicant will have a response that ranges from none to severe (i.e., death or malformation). The response at a given dosage may be termed teratogenic (or developmental toxic) severity and is dependent on exposure conditions. Prenatal/embryo-fetal developmental (EFD) toxicity studies in rodents and rabbits are the most consistent and definitive assessments of teratogenic severity, and teratogenesis screening assays are best validated against their results. A formula is presented that estimates teratogenic severity for each group, including control, within an EFD study. The developmental components include embryonic/fetal death, malformations, variations, and mean fetal weight. The contribution of maternal toxicity is included with multiplication factors to adjust for the extent of mortality, maternal body weight change, and other parameters deemed important. The derivation of the formula to calculate teratogenic severity is described. Various EFD data sets from the literature are presented to highlight considerations to the calculation of the various components of the formula. Each score is compared to the concurrent control group to obtain a relative teratogenic severity. The limited studies presented suggest relative scores of two- to

  12. Developmental toxicity, acute toxicity and mutagenicity testing in freshwater snails Biomphalaria glabrata (Mollusca: Gastropoda) exposed to chromium and water samples.

    PubMed

    Tallarico, Lenita de Freitas; Borrely, Sueli Ivone; Hamada, Natália; Grazeffe, Vanessa Siqueira; Ohlweiler, Fernanda Pires; Okazaki, Kayo; Granatelli, Amanda Tosatte; Pereira, Ivana Wuo; Pereira, Carlos Alberto de Bragança; Nakano, Eliana

    2014-12-01

    A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies.

  13. New Zealand sediment toxicity testing methodologies

    SciTech Connect

    Hickey, C.W.; Roper, D.S.; Nipper, M.; Martin, M.L.

    1995-12-31

    Sediment toxicity testing in New Zealand is developing against a background of an increasing public desire for environmental protection and strict legislative requirements that contaminant discharges should not have any significant adverse effects on aquatic life. The importance of sediment contamination and its potential immediate and long term adverse effects on aquatic biota in general is becoming widely recognized, This has lead to an effort to develop acute and chronic sediment toxicity tests with organisms representative of the New Zealand indigenous biota. An amphipod species occurring in both freshwater and estuarine environments, Chaetocorophium cf lucasi, and the marine bivalve Macomona liliana, a common inhabitant of intertidal sandflats, have been evaluated for their sensitivity to natural sediment characteristics. The amphipod and bivalve are presently being used for testing sediment acute (10d) and chronic toxicity (20--30d), with survival and growth as test endpoints, and the bivalve has shown to be a useful organism for behavioral tests with burial and sediment avoidance by movement and drifting as endpoints. The estuarine bivalve Arthritica bifurca, abundant in muddy sediments, is a self-fertilizing hermaphroditic species and its suitability for sediment tests with a reproductive endpoint is underway. Freshwater sphaeriid bivalves, Sphaerium novazelandiae, are also being used for survival, growth, reproduction and behavioral endpoints. Sensitivity to reference toxicants and results for contaminated sediments will be presented and discussed in relation to sediment quality criteria developed elsewhere.

  14. DEVELOPMENTAL TOXICITY OF COPPER CHLORIDE, METHYLENE CHLORIDE,AND 6-AMINONICOTINAMIDE TO EMBRYOS OF THE GRASS SHRIMPPALAEMONETES PUGIO

    EPA Science Inventory

    Embryos of estuarine grass shrimp Palaemonetes pugio have demonstrated sensitivity to various solvents and petroleum products, indicating utility for evaluating estuarine contamination. Testing was performed to establish concentration-response curves for methylene chloride, cop...

  15. Draft Test Guideline: Tadpole/Sediment Subchronic Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  16. Draft Test Guideline: Oyster Acute Toxicity Test (Shell Deposition)

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  17. Draft Test Guideline: Fish Acute Toxicity Test, Freshwater And Marine

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  18. Draft Test Guideline: Aquatic Invetebrate Acute Toxicity, Test, Freshwater Daphnids

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  19. Draft Test Guideline: Fish Early-Life Stage Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  20. A high-throughput lab-on-a-chip interface for zebrafish embryo tests in drug discovery and ecotoxicology

    NASA Astrophysics Data System (ADS)

    Zhu, Feng; Akagi, Jin; Hall, Chris J.; Crosier, Kathryn E.; Crosier, Philip S.; Delaage, Pierre; Wlodkowic, Donald

    2013-12-01

    Drug discovery screenings performed on zebrafish embryos mirror with a high level of accuracy. The tests usually performed on mammalian animal models, and the fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, conventional methods utilising 96-well microtiter plates and manual dispensing of fish embryos are very time-consuming. They rely on laborious and iterative manual pipetting that is a main source of analytical errors and low throughput. In this work, we present development of a miniaturised and high-throughput Lab-on-a-Chip (LOC) platform for automation of FET assays. The 3D high-density LOC array was fabricated in poly-methyl methacrylate (PMMA) transparent thermoplastic using infrared laser micromachining while the off-chip interfaces were fabricated using additive manufacturing processes (FDM and SLA). The system's design facilitates rapid loading and immobilization of a large number of embryos in predefined clusters of traps during continuous microperfusion of drugs/toxins. It has been conceptually designed to seamlessly interface with both upright and inverted fluorescent imaging systems and also to directly interface with conventional microtiter plate readers that accept 96-well plates. We also present proof-of-concept interfacing with a high-speed imaging cytometer Plate RUNNER HD® capable of multispectral image acquisition with resolution of up to 8192 x 8192 pixels and depth of field of about 40 μm. Furthermore, we developed a miniaturized and self-contained analytical device interfaced with a miniaturized USB microscope. This system modification is capable of performing rapid imaging of multiple embryos at a low resolution for drug toxicity analysis.

  1. Prenatal toxicity test of Morinda citrifolia (noni) fruit.

    PubMed

    West, Brett J; Su, Chen X; Jensen, C Jarakae

    2008-12-01

    Morinda citrifolia (noni) fruit juice use has increased greatly within the past decade, with more than 80,000,000 liters being consumed world wide. With increasing widespread use and the potential use among pregnant women, a prenatal developmental toxicity test was conducted to further evaluate the safety of noni juice. Freeze-dried noni fruit puree from French Polynesia was administered daily by gastric intubation to separate dose groups (n = 12) of pregnant Sprague Dawley rats at 1.72, 3.43, and 6.86 g/kg body weight, with a control group receiving water in place of noni. The dose schedule was followed from the first day of gestation until one day prior to expected delivery, 21 days. There were no symptoms of toxicity in the pregnant dams. There was no difference between the control and any noni group in the number of live fetuses, resorptions, fetal weight and length, or skeletal abnormalities. No dead fetuses, gross external malformations, or internal organ defects were observed in any group. These findings do not indicate that toxicity from noni juice to developing embryos and fetuses is expected.

  2. The beneficial effect of small toxic molecules on dormancy alleviation and germination of apple embryos is due to NO formation.

    PubMed

    Gniazdowska, Agnieszka; Krasuska, Urszula; Debska, Karolina; Andryka, Paulina; Bogatek, Renata

    2010-09-01

    Deep dormancy of apple (Malus domestica Borkh.) seeds is terminated by a 3-month-long cold stratification. It is expressed by rapid germination of seeds and undisturbed growth of seedlings. However, stimulation of germination of isolated apple embryos is also observed after applying inhibitors of cytochrome c oxidase: nitric oxide (NO) or hydrogen cyanide (HCN) during the first 3-6 h of imbibition of dormant embryos. The aim of this work was to compare the effect of yet another toxic gaseous molecule carbon monoxide (CO) with the effects of HCN and NO on germination of apple embryos and growth and development of young seedlings. We demonstrated that stimulation of germination after short-term pre-treatment with HCN, NO or CO was accompanied by enhanced NO emission from the embryo axes during their elongation. Moreover, similarly high NO production from non-dormant embryos, after cold stratification, was detected. Therefore, we propose that NO may act as signaling molecule in apple embryo dormancy break.

  3. Automated Zebrafish Chorion Removal and Single Embryo Placement: Optimizing Throughput of Zebrafish Developmental Toxicity Screens

    PubMed Central

    Mandrell, David; Truong, Lisa; Jephson, Caleb; Sarker, Mushfiqur R.; Moore, Aaron; Lang, Christopher; Simonich, Michael T.; Tanguay, Robert L.

    2012-01-01

    The potential of the developing zebrafish model for toxicology and drug discovery is limited by inefficient approaches to manipulating and chemically exposing zebrafish embryos—namely, manual placement of embryos into 96- or 384-well plates and exposure of embryos while still in the chorion, a barrier of poorly characterized permeability enclosing the developing embryo. We report the automated dechorionation of 1600 embryos at once at 4 h postfertilization (hpf) and placement of the dechorionated embryos into 96-well plates for exposure by 6 hpf. The process removed ≥95% of the embryos from their chorions with 2% embryo mortality by 24 hpf, and 2% of the embryos malformed at 120 hpf. The robotic embryo placement allocated 6-hpf embryos to 94.7% ± 4.2% of the wells in multiple 96-well trials. The rate of embryo mortality was 2.8% (43 of 1536) from robotic handling, the rate of missed wells was 1.2% (18 of 1536), and the frequency of multipicks was <0.1%. Embryo malformations observed at 24 hpf occurred nearly twice as frequently from robotic handling (16 of 864; 1.9%) as from manual pipetting (9 of 864; 1%). There was no statistical difference between the success of performing the embryo placement robotically or manually. PMID:22357610

  4. Animal alternatives for whole effluent toxicity testing ...

    EPA Pesticide Factsheets

    Since the 1940s, effluent toxicity testing has been utilized to varying degrees in many countries to assess potential ecological impacts and assist in determining necessary treatment options for environmental protection. However, it was only in the early 1980’s that toxicity based effluent assessments and subsequent discharge controls became globally important, when it was recognized that physical and chemical measurements alone did not protect the environment from potential impacts. Consequently, various strategies using different toxicity tests, whole effluent assessment techniques (incorporating bioaccumulation potential and persistence) plus supporting analytical tools have been developed over 30 years of practice. Numerous workshops and meetings have focused on effluent risk assessment through ASTM, SETAC, OSPAR, UK competent authorities, and EU specific country rules. Concurrent with this drive to improve effluent quality using toxicity tests, interest in reducing animal use has risen. The Health and Environmental Sciences Institute (HESI) organized and facilitated an international workshop in March 2016 to evaluate strategies for concepts, tools, and effluent assessments and update the toolbox of for effluent testing methods. The workshop objectives were to identify opportunities to use a suite of strategies for effluents, and to identify opportunities to reduce the reliance on animal tests and to determine barriers to implementation of new methodologie

  5. Estimating the gasoline components and formulations toxicity to microalgae (Tetraselmis chuii) and oyster (Crassostrea rhizophorae) embryos: An approach to minimize environmental pollution risk

    SciTech Connect

    Paixao, J.F.; Nascimento, I.A. . E-mail: iracema@ftc.br; Pereira, S.A.; Leite, M.B.L.; Carvalho, G.C.; Silveira, J.S.C.; Reboucas, M.; Matias, G.R.A.; Rodrigues, I.L.P.

    2007-03-15

    Even though petrochemical contamination frequently occurs in the form of oil spills, it is thought that a greater danger to coastal habitats is posed by chronic petrochemical toxicity associated with urban run-off, in which gasoline water-soluble-fraction (WSF) plays an important role. The hypothesis of the entrepreneurs, who were associated to the scientists uncharged of this research, was that recycled petrochemical waste may provide different gasoline formulations, having different toxic properties; the correlation between the gasoline formulations and their components' toxicological effects might contribute to the reformulation of the products, in such a way that the gasoline generated could be less toxic and less harmful to the environment. The aim of this research was to determine the toxic effects of 14 different types of gasoline (formulated, in accordance with National Petroleum Agency standards, from petrochemical waste), on Tetraselmis chuii (microalgae culture) and Crassostrea rhizophorae (embryos). Microalgae and oyster embryos were exposed to different gasoline formulations water-soluble fractions (WSF) at a range of concentrations (0%, 4.6%, 10.0%, 22.0%, 46.0%, and 100%), for 96 and 24 h, respectively. The tests were carried out under controlled conditions. End-points have been CI50-96h (concentration causing 50% growth inhibition in microalgae cultures) and EC50-24h (concentration causing abnormalities on 50% of the exposed embryos). Through these procedures, gasoline formulations, which represent the lowest environmental risk, were selected. Bioassays carried out on the 8 different gasoline components aimed to correlate gasoline toxicity with the toxic potential of its components. The analysis of principal components showed that the C9DI, a mixture of aromatic hydrocarbons of 9 carbon atoms, had the highest level of toxic potential, followed by C9S (a mixture of aromatics with 9-11 carbon atoms) and heavy naphtha. The results showed gasoline

  6. Toxicity test of a dental commercial composite

    PubMed Central

    Ponce-Bravo, Santa; Martínez-Rivera, José-Luis; Garcés-Ortíz, Maricela

    2015-01-01

    Background International rules must be followed for testing biosecurity in dental materials. A new brand of restorative material appeared in the market and regulations indicated that it should be tested for toxicity. Objectives The aim of this study was to determine the 90-day sub chronic toxicity of one triethylene glycol dimethacrylate containing composite (MEDENTAL Light-Cure Composite™) orally administered to rats according to Organization for Economic Co-Operation and Development no. 48 guidelines and the requirements specified in the ISO 10993-11. Material and Methods Wistar rats ate the polymerized composite during 90 days and were observed to determine changes in their behavior, eye and skin signs and other attitudes such as aggressiveness, posture, walking and response to handling. After 90 days were sacrificed to ascertain blood alterations, we did special hematological tests and assessed microscopic slides from 33 different organs. Results We recorded no significant changes in clinical behavior of the animals. Microscopic review of the H&E stained slides obtained from the analyzed organs showed no abnormal inflammatory or cytological changes and all hematological special tests were within normal limits. Conclusions Results of this study show that under our experimental conditions the MEDENTAL Light-Cure Composite™ does not produce inflammatory or cytological changes suggestive of toxicity. Key words:Dental materials, composite resin, toxicity, inflammation, TEGDMA. PMID:26155348

  7. Evaluation of effectiveness of EDTA and sodium thiosulfate in removing metal toxicity toward sea urchin embryo-larval applying the TIE.

    PubMed

    Resgalla, C; Poleza, F; Souza, R C; Máximo, M V; Radetski, C M

    2012-09-01

    Since the development of the TIE (Toxicity Identification and Evaluation) in 1988 it has been assumed that the capacity of EDTA and sodium thiosulfate to complex some metals, and thus remove their toxicity, can be applied to both freshwater and seawater ecotoxicological tests and the results subsequently interpreted. However, it is now known that there is a wide variability in the extent of this complexation. In this context, the removal of toxicity caused by the presence of Hg(2+), Cd(2+), Cu(2+), Cr(6+), Zn(2+), Ni(2+), Pb(2+), Ag(1+) and Se(2+), through metal complexation by EDTA and sodium thiosulfate, in relation to the performance of embryo-larval tests with the sea urchin Arbacia lixula was investigated. It was observed that EDTA was capable of removing the toxicity of Pb(2+), Zn(2+) and Cu(2+) while sodium thiosulfate only reduced the toxicity of Ag(1+). Compared to the complexation observed in freshwater ecotoxicological tests, the complexing agents used in this study (EDTA and sodium thiosulfate) have a lower capacity to complex metals in the marine ecotoxicological test with A. lixula.

  8. MINIATURIZED SEDIMENT PROCEDURES FOR ASESSING TOXICITY USING MARINE AND FRESHWATER AMPHIPODS AND EMBRYO/LARVAL FISH

    EPA Science Inventory

    Sediment toxicity tests are needed that can be conducted with less sediment volume and fewer organisms. Bench scale remediation techniques often produce less sediment than is required to perform the standardized sediment methods and the excess sediments that are generated present...

  9. Developmental toxicity and molecular responses of marine medaka (Oryzias melastigma) embryos to ciguatoxin P-CTX-1 exposure.

    PubMed

    Yan, Meng; Leung, Priscilla T Y; Ip, Jack C H; Cheng, Jin-Ping; Wu, Jia-Jun; Gu, Jia-Rui; Lam, Paul K S

    2017-04-01

    Ciguatoxins are produced by toxic benthic dinoflagellates and cause ciguatera fish poisoning worldwide, but the toxic effects on developing marine fish have not been well investigated. The Pacific ciguatoxin (P-CTX-1), is a potent sodium channel agonist, which is one of the most toxic members among all CTXs. This study evaluated the toxic effects of microinjecting purified Pacific ciguatoxin-1 (P-CTX-1) on embryonic development of marine medaka Oryzias melastigma. A lower 96h-LD50 value was estimated for eleuthero-embryos (1.32ngg(-1)) than that for embryos (1.71ngg(-1)), indicating that P-CTX-1 is more lethal to newly hatched medaka larvae. P-CTX-1 induced detrimental effects during embryonic development, including hatching failure, abnormalities in physical development (caudal fin malformation and spinal deformities), internal damage (green coloration of the gall bladder and hemorrhaging), immune dysfunction, and altered muscle physiology (bradycardia and hyperkinetic twitching). The results of a transcriptional expression analysis of genes related to the stress/immune responses, cardiac and bone development, and apoptosis supported the observed developmental abnormalities. This study advanced the understanding of P-CTX-1 mediated toxic mechanisms in the development of early life stages of a fish, and thus contributed to the toxicity assessment of CTXs in marine ecosystems.

  10. Effects of Specific Dosages of Magnesium and Zinc on the Teratogenicity of Cadmium, Nickel, and Cobalt in Xenopus Embryos, as Assessed by the Fetax Test

    PubMed Central

    Boga, Ayper; Erdogan, Seref; Sertdemir, Yasar

    2008-01-01

    The objective of this study was to determine if exposure to divalent cations, Cd2+, Ni2+, and Co2+ would lead to malformations in Xenopus laevis embryos, and whether addition of Mg2+ and Zn2+; separately and in combination, would reduce their toxicity and teratogenicity on the embryos of Xenopus laevis as assessed by 96-h FETAX tests. Results indicate that exposure to Cd2+, Ni2+ or Co2+ lead to an increase in toxicity and teratogenicity in embryos, whereas Mg2+, Zn2+, or a combination of them reduced the toxic and terato-genic effects of these divalent cations. Modulation of Cd2+, Ni2+ or Co2+ toxicity and teratogenicity by Mg2+ and Zn2+, varied with the metal. Zn2+ was observed to be a better suppressor of Co2+ toxicity and teratogenicity than Mg2+. In contrast, Ni2+, and Cd2+ teratogenicity was reduced more prominently by Mg2+. On the other hand, combination of Mg2+ and Zn2+ showed potentialization effect on all divalent cation toxicity and teratogenicity. We concluded that Mg2+ and Zn2+ reduced the toxicity and teratogenicity of Cd2+, Ni2+, Co2+. PMID:18648570

  11. Comparative toxicities of benzene, chlorobenzene, and dichlorobenzenes to sea urchin embryos and sperm

    SciTech Connect

    Pagano, G.; Cipollaro, M.; Corsale, G.; Esposito, A.; Giordano, G.G.; Ragucci, E.; Trieff, N.M.

    1988-04-01

    The leukemogenicity and myelotoxicity of benzene are well-known and the major cause of benzene's banning from most industrial applications. Various benzene derivatives such as alkylbenzenes and chlorobenzenes, however, continue to be used as chemical intermediates, solvents, pesticides, etc. in spite of incomplete knowledge of their chronic toxicity. This study was designed to obtain comparative data on developmental, genetic and reproductive toxicities of benzene (B), chlorobenzene (CB) and dichlorobenzenes (o-, m-, and p-DCB) in the sea urchin bioassay. This test system, permits observation of a number of biological endpoints on mitotic activity, embryogenesis and fertilization, and thus provides multi-parametric toxicological data on xenobiotics.

  12. Test systems to identify reproductive toxicants.

    PubMed

    Riecke, K; Stahlmann, R

    2000-09-01

    Experience with drugs and other xenobiotics indicates that both animal testing and epidemiological studies are necessary to provide adequate data for an estimation of risks that might be associated with exposure to a chemical substance. In this review, the pros and cons of test systems for reproductive toxicity are discussed. Usually, several studies are performed to cover the different phases of the reproductive cycle. In the preclinical development of drugs, the three so-called 'segment testing protocols' have been used for several decades now. More recently, new testing concepts have been accepted internationally which include more flexibility in implementation. Several examples of compounds with the potential for reproductive toxicity are presented in more detail in a discussion of some pitfalls of the tests for fertility (phthalates and fluoroquinolones), teratogenicity (acyclovir and protease inhibitors) and postnatal developmental toxicity (fluoroquinolones). In addition, important aspects of kinetics and metabolism as a prerequisite for a rational interpretation of results from toxicological studies are briefly discussed. In vitro assays are useful for supplementing the routinely used in vivo approaches or for studying an expected or defined effect, but they are not suitable for revealing an unknown effect of a chemical on the complex reproductive process.

  13. Estimation of toxicity using the Toxicity Estimation Software Tool (TEST)

    EPA Science Inventory

    Tens of thousands of chemicals are currently in commerce, and hundreds more are introduced every year. Since experimental measurements of toxicity are extremely time consuming and expensive, it is imperative that alternative methods to estimate toxicity are developed.

  14. Developmental toxicity of the common UV filter, benophenone-2, in zebrafish embryos.

    PubMed

    Fong, Henry C H; Ho, Jeff C H; Cheung, Angela H Y; Lai, K P; Tse, William K F

    2016-12-01

    Benozophenone (BP) type UV filters are extensively used in the personal care products to provide protection against the harmful effects of UV radiation. BPs are one of the primary components in the UV filter family, in which benophenone-2 (BP2) is widely used as a UV filter reagent in the sunscreen. Humans used these personal care products directly on skin and the chemicals will be washed away to the water system. BP2 has been identified as one of the endocrine disruptor chemicals, which can inference the synthesis, metabolism, and action of endogenous hormones. Environmentally, it has been found to contaminate water worldwide. In this study, we aimed to unfold the possible developmental toxicology of this chemical. Zebrafish are used as the screening model to perform in situ hybridization staining to investigate the effects of BP2 on segmentation, brain regionalization, and facial formation at four developmental stages (10-12 somite, prim-5, 2 and 5 days post-fertilization). Results showed 40 μM (9.85 mg L(-1)) or above BP2 exposure in zebrafish embryos for 5 days resulted in lipid accumulation in the yolk sac and facial malformation via affecting the lipid processing and the expression of cranial neural crest cells respectively. To conclude, the study alarmed its potential developmental toxicities at high dosage exposure.

  15. Development of chrysin loaded poloxamer micelles and toxicity evaluation in fish embryos.

    PubMed

    Sassa-Deepaeng, Tanongsak; Pikulkaew, Surachai; Okonogi, Siriporn

    Poloxamer micelles promise safety and efficacy for many water insoluble drugs. Chrysin has been reported to have anticancer, anti-inflammatory, antioxidant, and anti-aromatase activities but its water insoluble properties limit its pharmaceutical application. In the present study, chrysin loaded poloxamer micelles were developed. Two types of poloxamers, Pluronic F-68 and Pluronic F-127 were compared. It was found that chrysin loaded Pluronic F-68 micelles (CS-P68) and chrysin loaded Pluronic F-127 micelles (CS-P127) obviously increase the aqueous solubility of chrysin. The results also indicated that the type of polymer and ratio of drug to polymer affected size and desirable characteristics of the micelles. The micelle system of CS-P68 and CS-P127 formed at drug to polymer ratios of 1:4 and 1:2, respectively, was found to be the most suitable monodispersed system with a nanosize-range diameter. The in vivo study in zebrafish eggs indicates that the toxicity of CS-P68 and CS-P127 is a dose response. CS-P68 and CS-P127 at a drug dose of 10 ng/mL or less is safe for zebrafish embryo growth. The results of this study indicate enhanced water solubility of chrysin. Chrysin loaded poloxamer micelles are promising for further use in in vivo studies in mammalian animals and humans.

  16. Assessing the toxicity of chemical compounds associated with land-based marine fish farms: the sea urchin embryo bioassay with Paracentrotus lividus and Arbacia lixula.

    PubMed

    Carballeira, C; De Orte, M R; Viana, I G; Delvalls, T A; Carballeira, A

    2012-08-01

    In aquaculture, disinfection of facilities, prevention of fish diseases, and stimulation of fish growth are priority goals and the most important sources of toxic substances to the environment, together with excretory products from fish. In the present study, embryos of two species of sea urchin (Paracentrotus lividus and Arbacia lixula) were exposed to serial dilutions of six antibiotics (amoxicillin (AMOX), ampicillin, flumequine (FLU), oxytetracycline (OTC), streptomycin (ST), and sulfadiazine [SFD]) and two disinfectants (sodium hypochlorite (NaClO) and formaldehyde [CH(2)O]). Alterations in larval development were studied, and the effective concentrations (ECs) were calculated to evaluate the toxicity of the substances. Both species showed similar sensitivities to all substances tested. Disinfectants (EC(50) = 1.78 and 1.79 mg/l for CH(2)O; EC(50) = 10.15 and 11.1 mg/l for NaClO) were found to be more toxic than antibiotics. AMOX, OTC, and ST caused <20 % of alterations, even at the highest concentrations tested. FLU was the most toxic to P. lividus (EC(50) = 31.0 mg/l) and SFD to A. lixula (EC(50) = 12.7 mg/l). The sea urchin bioassay should be considered within toxicity assessment-monitoring plans because of the sensitivity of larvae to disinfectants.

  17. Toxicity of polychlorinated diphenyl ethers in hydra attenuata and in rat whole-embryo culture. Master's thesis

    SciTech Connect

    Becker, M.C.

    1991-05-01

    Polychlorinated diphenyl ethers (PCDEs) are a class of biaryl compounds that have little commercial application, but appear to be widespread in the environment. They have been found in wood preservative waste dumpsites and in fly ash from municipal waste incinerators. They have been detected in bird eggs and tissues, fish, and other edible marine organisms in the United States, Canada, and Europe. There are limited reports in the extant literature on the toxicity of PCDEs. This study was designed to evaluate the toxicity of selected PCDEs in cultures of Hydra attenuata and post-implantation rat whole embryos. The toxicity of several closely related polychlorinated biphenyls (PCBs) was evaluated in both cultures and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was evaluated in whole embryo culture. Embryonic growth and development parameters (yolk sac diameter, crown-rump length, somite count, and DNA and protein content) and gross morphology were determined. Findings indicated that these chemicals were neither embryotoxic nor teratogenic. Thus, the PCDEs, which elicit other diverse toxic and biochemical responses in rodents, are relatively inactive in these bioassays for developmental toxicity.

  18. Toxicity of a mancozeb containing formulation and Cd-sulphate to chicken embryos after administration as single compounds or in combination.

    PubMed

    Keseru, M; Fejes, S; Budai, P; Várnagy, L

    2003-01-01

    Environmental pollution of metal modelled by cadmium-sulphate and a 80% mancozeb containing fungicide formulation (Dithane M-45) were studied on chicken embryos after administration as a single compounds or in combination. The test materials were injected into the air-chamber in a volume of 0.1 ml/egg on day 0 of incubation. The concentration of cadmium-sulphate was 0.01%. The applied concentration of Dithane M-45 fungicide was 0.2%. Evaluation was done on day 19 of the hatching period. The individual administration of cadmium-sulphate and the 80% mancozeb containing fungicide formulation did not cause a significant reduction in body weight as compared to the control data. Embryonic mortality increased at all individual treated groups and reached almost a 35% rate. After the individual administration of pesticide, the number of chicken embryos with developmental anomalies did not differ markedly from the control. After the combined administration of cadmium-sulphate and the 80% mancozeb containing fungicide formulation (Dithane M-45) on day 0 of the hatching period embryonic mortality markedly increased. 88% of the treated embryos were dead. Results from the combined administration of cadmium-sulphate and an 80% mancozeb containing fungicide formulation (Dithane M-45) caused higher embryomortality with respect to individual toxicity test of cadmium-sulphate and fungicide in our study.

  19. Ocular Toxicity Testing of Lunar Dust

    NASA Technical Reports Server (NTRS)

    Meyers, Valerie E.

    2010-01-01

    This slide presentation reviews the use of ocular testing to determine the toxicity of lunar dust. The OECD recommendations are reviewed. With these recommendations in mind the test methodology was to use EpiOcular, tissues derived from normal human epidermal keratinocytes, the cells of which have been differentiated on cell culture inserts to form a multi-layered structure, which closely parallels the corneal epithelium and to dose the tissue with 100 mg dust from various sources. The in-vitro study provides evidence that lunar dust is not severely corrosive or irritating, however, in vitro tests have limitations, and in vivo tests provides a more complete scenario, and information, it is recommended that in vivo tests be performed.

  20. Integrative assessment of marine pollution in Galician estuaries using sediment chemistry, mussel bioaccumulation, and embryo-larval toxicity bioassays.

    PubMed

    Beiras, R; Fernández, N; Bellas, J; Besada, V; González-Quijano, A; Nunes, T

    2003-08-01

    An integrative assessment of environmental quality was carried out in selected sites along the Galician coast (NW Iberian Peninsula) combining analytical chemistry of seawater and sediments, bioaccumulation in the marine mussel, and embryo-larval sediment toxicity bioassays, in order to link biological and chemical criteria for the assessment of coastal pollution. Maximum values of Hg and Cu in seawater, sediment and mussels, were found in the inner part of Ria of Pontevedra, while maximum levels of organics (polychlorinated biphenyls, hexachlorobenzene and aldrin) were found in mussels from A Coruña. Outstanding values of Cu, Pb and Zn have been found in seawater and sediment from a single site, P3, which also was the most toxic in the embryo-larval bioassays performed with four different phyla of marine organisms: mollusks, echinoderms, arthropods and chordates. Sediment quality effects range-median values provided a valuable reference to predict biological effects from sediment chemistry data, while effects range-low values were too conservative. Sediment toxicity could also be predicted by using a toxic-unit model based on published EC50 values for trace metals and mobilization factors independently obtained from measurements of metal contents in sediments and their elutriates. When chemical and toxicological data are independently used to arrange sampling sites by using non-metric multidimensional scaling, a remarkable degree of concordance between both types of configurations could be observed.

  1. Comparative toxicities of aluminum and zinc from sacrificial anodes or from sulfate salt in sea urchin embryos and sperm.

    PubMed

    Caplat, Christelle; Oral, Rahime; Mahaut, Marie-Laure; Mao, Andrea; Barillier, Daniel; Guida, Marco; Della Rocca, Claudio; Pagano, Giovanni

    2010-09-01

    The toxicity of aluminum or zinc from either sacrificial anodes (SA) or their sulfate salts (SS) was evaluated in sea urchin (Paracentrotus lividus) embryos or sperm exposed to Al(III) or Zn(II) (SA or SS, 0.1-10 microM), scoring developmental defects (DDs), fertilization rate (FR), and mitotic abnormalities. A significant DD increase was observed in SS, but not SA Al(III)- and Zn(II)-exposed embryos vs. controls. Both Al(III) and Zn(II), up to 10 microM, from SA and SS, inhibited mitotic activity and induced mitotic aberrations in exposed embryos. SA-Al(III)-exposed sperm displayed a significant FR increase, unlike Al(III) sulfate overlapping with controls. Both SA-Zn(II) and Zn(II) sulfate sperm exposure resulted in a significant FR increase. The offspring of SA-Al(III)-exposed sperm displayed a significant DD decrease, unlike Al(III) sulfate exposure. Zinc sulfate sperm exposure resulted in a significant increase in offspring DDs, whereas SA-Zn(II) sperm exposure decreased DDs. Together, exposures to SA-dissolved Al(III) or Zn(II) resulted in lesser, if any toxicity, up to hormesis, compared to SS. Studies of metal speciation should elucidate the present results.

  2. Protective effects of levamisole, acetylsalicylic acid, and α-tocopherol against dioxin toxicity measured as the expression of AhR and COX-2 in a chicken embryo model.

    PubMed

    Gostomska-Pampuch, Kinga; Ostrowska, Alicja; Kuropka, Piotr; Dobrzyński, Maciej; Ziółkowski, Piotr; Kowalczyk, Artur; Łukaszewicz, Ewa; Gamian, Andrzej; Całkosiński, Ireneusz

    2017-04-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxins) are classed as persistent organic pollutants and have adverse effects on multiple functions within the body. Dioxins are known carcinogens, immunotoxins, and teratogens. Dioxins are transformed in vivo, and interactions between the products and the aryl hydrocarbon receptor (AhR) lead to the formation of proinflammatory and toxic metabolites. The aim of this study was to determine whether α-tocopherol (vitamin E), acetylsalicylic acid (ASA), and levamisole can decrease the amount of damage caused by dioxins. Fertile Hubbard Flex commercial line chicken eggs were injected with solutions containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or containing TCDD and the test compounds. The chicken embryos and organs were analyzed after 7 and 13 days. The levels at which AhR and cyclooxygenase-2 (COX-2) proteins (which are induced during inflammation) were expressed were evaluated by performing immunohistochemical analyses on embryos treated with TCDD alone or with TCDD and the test compounds. TCDD caused developmental disorders and increased AhR and COX-2 expression in the chicken embryo tissues. Vitamin E, levamisole, ASA, and ASA plus vitamin E inhibited AhR and COX-2 expression in embryos after 7 days and decreased AhR and COX-2 expression in embryos after 13 days. ASA, levamisole, and ASA plus vitamin E weakened the immune response and prevented multiple organ changes. Vitamin E was not fully protective against developmental changes in the embryos.

  3. Toxicity of Uranium Adsorbent Materials using the Microtox Toxicity Test

    SciTech Connect

    Park, Jiyeon; Jeters, Robert T.; Gill, Gary A.; Kuo, Li-Jung; Bonheyo, George T.

    2015-10-01

    The Marine Sciences Laboratory at the Pacific Northwest National Laboratory evaluated the toxicity of a diverse range of natural and synthetic materials used to extract uranium from seawater. The uranium adsorbent materials are being developed as part of the U. S. Department of Energy, Office of Nuclear Energy, Fuel Resources Program. The goal of this effort was to identify whether deployment of a farm of these materials into the marine environment would have any toxic effects on marine organisms.

  4. 16 CFR 1500.40 - Method of testing toxic substances.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Method of testing toxic substances. 1500.40... testing toxic substances. The method of testing the toxic substances referred to in § 1500.3(c) (1)(ii)(C... with additional strips and should fit snugly around the trunk of the animal. The ends of the sleeve...

  5. Exposure to ultraviolet radiation late in development increases the toxicity of oil to mahi-mahi (Coryphaena hippurus) embryos.

    PubMed

    Sweet, Lauren E; Magnuson, Jason; Garner, T Ross; Alloy, Matthew M; Stieglitz, John D; Benetti, Daniel; Grosell, Martin; Roberts, Aaron P

    2016-11-16

    The Deepwater Horizon oil spill in 2010 overlapped with the spawning of many pelagic fish species in the Gulf of Mexico, including mahi-mahi (Coryphaena hippurus). Polycyclic aromatic hydrocarbons (PAHs) released during the spill have been shown to cause photo-induced toxicity under ultraviolet (UV) radiation. In the present study, mahi-mahi embryos were exposed to high-energy water accommodated fractions of source and naturally weathered oils for up to 48 h. The timing of co-exposure with UV radiation varied between an early development exposure for 8 h or a late development exposure for 8 h. The UV co-exposure had a photo-induced toxic effect on hatching success for all oil types and exposure scenarios. A more sensitive developmental window to photo-induced toxicity was observed when UV exposure occurred late in development. Source Oil B was over 6-fold more toxic, and Massachusetts source oil was 1.6-fold more toxic when the embryos were co-exposed to UV light late in development. Furthermore, weathered oil from the surface co-exposure with UV late in development resulted in bradycardia in the mahi-mahi. The present study provides evidence that the developmental window when UV co-exposure occurs has a significant effect on the degree of photo-induced toxicity of oil and that UV co-exposure may exacerbate long-term cardiac effects in developing fish. Environ Toxicol Chem 2016;9999:1-7. © 2016 SETAC.

  6. Teratogenic and toxic effects of Lingzhi or Reishi medicinal mushroom, Ganoderma lucidum (W.Curt.:Fr.) P. Karst. (higher Basidiomycetes), on zebrafish embryo as model.

    PubMed

    Dulay, Rich Milton R; Kalaw, Sofronio P; Reyes, Renato G; Alfonso, Noel F; Eguchi, Fumio

    2012-01-01

    This paper highlights the teratogenic and toxic effects of Ganoderma lucidum (Lingzhi or Reishi mushroom) extract on zebrafish embryos. Hatchability, malformations, and lethality rate of zebrafish embryos were assessed to provide valuable information regarding the potential teratogenic activity of G. lucidum. Hatching was completed 48 h post treatment application (hpta) at 1% or lower concentrations of extract and embryo water. The hatching rate of embryos treated with 5% or higher concentrations was significantly lower (p> 0.05) than the control. Tail malformation was the most marked morphological abnormality in embryos at 72 hpta, which was obviously caused by 1% extract (55.56% tail malformation) and was observed in all embryos exposed to 5% of extract. Growth retardation was evident in embryos exposed to 5%, 10%, and 20%. However, lethal effect of extract of G. lucidum was dependent on dose and time of exposure. Mortality rates of embryos treated with 5% (44.44%) or higher concentrations of the extract was significantly higher (p > 0.05) than that of the control embryos at 72 hpta. These results suggest that G. lucidum extract has lethal and sub-lethal effects on zebrafish embryos.

  7. TOXICITY TESTS FOR SEDIMENT QUALITY ASSESSMENTS

    EPA Science Inventory

    Toxic sediments have contributed to a wide-variety of environmental problems around the world. The observed effects include direct toxic effects to aquatic life, bio-magnification of toxicants in the food chain, and economic impacts. This chapter discusses the use of toxicity...

  8. Embryo-Fetal Developmental Toxicity Studies with Pregabalin in Mice and Rabbits.

    PubMed

    Morse, Dennis C

    2016-04-01

    Pregabalin was evaluated for potential developmental toxicity in mice and rabbits. Pregabalin was administered once daily by oral gavage to female albino mice (500, 1250, or 2500 mg/kg) and New Zealand White rabbits (250, 500, or 1250 mg/kg) during organogenesis (gestation day 6 through 15 [mice] or 6 through 20 [rabbits]). Fetuses were evaluated for viability, growth, and morphological development. Pregabalin administration to mice did not induce maternal or developmental toxicity at doses up to 2500 mg/kg, which was associated with a maternal plasma exposure (AUC0-24 ) of 3790 μg•hr/ml, ≥30 times the expected human exposure at the maximum recommended daily dose (MRD; 600 mg/day). In rabbits, treatment-related clinical signs occurred at all doses (AUC0-24 of 1397, 2023, and 4803 μg•hr/ml at 250, 500, and 1250 mg/kg, respectively). Maternal toxicity was evident at all doses and included ataxia, hypoactivity, and cool to touch. In addition, abortion and females euthanized moribund with total resorption occurred at 1250 mg/kg. There were no treatment-related malformations at any dose. At 1250 mg/kg, compared with study and historical controls, the percentage of fetuses with retarded ossification was significantly increased and the mean number of ossification sites was decreased, which correlated with decreased fetal and placental weights, consistent with in utero growth retardation. Therefore, the no-effect dose for developmental toxicity in rabbits was 500 mg/kg, which produced systemic exposure approximately 16-times human exposure at the MRD. These findings indicate that pregabalin, at the highest dose tested, was not teratogenic in mice or rabbits.

  9. Comparing rat and rabbit embryo-fetal developmental toxicity data for 379 pharmaceuticals: on systemic dose and developmental effects.

    PubMed

    Theunissen, Peter T; Beken, Sonia; Beyer, Bruce; Breslin, William J; Cappon, Gregg D; Chen, Connie L; Chmielewski, Gary; de Schaepdrijver, Luc; Enright, Brian; Foreman, Jennifer E; Harrouk, Wafa; Hew, Kok-Wah; Hoberman, Alan M; Y Hui, Julia; Knudsen, Thomas B; Laffan, Susan B; Makris, Susan L; Martin, Matthew; McNerney, Mary Ellen; Siezen, Christine L; Stanislaus, Dinesh J; Stewart, Jane; Thompson, Kary E; Tornesi, Belen; Van der Laan, Jan Willem; Weinbauer, Gerhard F; Wood, Sandra; Piersma, Aldert H

    2016-10-21

    A database of embryo-fetal developmental toxicity (EFDT) studies of 379 pharmaceutical compounds in rat and rabbit was analyzed for species differences based on toxicokinetic parameters of area under the curve (AUC) and maximum concentration (Cmax) at the developmental lowest adverse effect level (dLOAEL). For the vast majority of cases (83% based on AUC of n = 283), dLOAELs in rats and rabbits were within the same order of magnitude (less than 10-fold different) when compared based on available data on AUC and Cmax exposures. For 13.5% of the compounds the rabbit was more sensitive and for 3.5% of compounds the rat was more sensitive when compared based on AUC exposures. For 12% of the compounds the rabbit was more sensitive and for 1.3% of compounds the rat was more sensitive based on Cmax exposures. When evaluated based on human equivalent dose (HED) conversion using standard factors, the rat and rabbit were equally sensitive. The relative extent of embryo-fetal toxicity in the presence of maternal toxicity was not different between species. Overall effect severity incidences were distributed similarly in rat and rabbit studies. Individual rat and rabbit strains did not show a different general distribution of systemic exposure LOAELs as compared to all strains combined for each species. There were no apparent species differences in the occurrence of embryo-fetal variations. Based on power of detection and given differences in the nature of developmental effects between rat and rabbit study outcomes for individual compounds, EFDT studies in two species have added value over single studies.

  10. Integrated chip-based physiometer for automated fish embryo toxicity biotests in pharmaceutical screening and ecotoxicology.

    PubMed

    Akagi, Jin; Zhu, Feng; Hall, Chris J; Crosier, Kathryn E; Crosier, Philip S; Wlodkowic, Donald

    2014-06-01

    Transgenic zebrafish (Danio rerio) models of human diseases have recently emerged as innovative experimental systems in drug discovery and molecular pathology. None of the currently available technologies, however, allow for automated immobilization and treatment of large numbers of spatially encoded transgenic embryos during real-time developmental analysis. This work describes the proof-of-concept design and validation of an integrated 3D microfluidic chip-based system fabricated directly in the poly(methyl methacrylate) transparent thermoplastic using infrared laser micromachining. At its core, the device utilizes an array of 3D micromechanical traps to actively capture and immobilize single embryos using a low-pressure suction. It also features built-in piezoelectric microdiaphragm pumps, embryo-trapping suction manifold, drug delivery manifold, and optically transparent indium tin oxide heating element to provide optimal temperature during embryo development. Furthermore, we present design of the proof-of-concept off-chip electronic interface equipped with robotic servo actuator driven stage, innovative servomotor-actuated pinch valves, and embedded miniaturized fluorescent USB microscope. Our results showed that the innovative device has 100% embryo-trapping efficiency while supporting normal embryo development for up to 72 hr in a confined microfluidic environment. We also showed data that this microfluidic system can be readily applied to kinetic analysis of a panel of investigational antiangiogenic agents in transgenic zebrafish lines. The optical transparency and embryo immobilization allow for convenient visualization of developing vasculature patterns in response to drug treatment without the need for specimen re-positioning. The integrated electronic interfaces bring the lab-on-a-chip systems a step closer to realization of complete analytical automation.

  11. Exposure Science for Chemical Prioritization and Toxicity Testing

    EPA Science Inventory

    Currently, a significant research effort is underway to apply new technologies to screen and prioritize chemicals for toxicity testing as well as to improve understanding of toxicity pathways (Dix et al. 2007, Toxicol Sci; NRC, 2007, Toxicity Testing in the 21st Century; Collins ...

  12. Comparison of bulk sediment and sediment elutriate toxicity testing methods

    EPA Science Inventory

    Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

  13. Assessment of toxic interactions of heavy metals in multi-component mixtures using sea urchin embryo-larval bioassay.

    PubMed

    Xu, Xue; Li, Yan; Wang, Yuan; Wang, Yonghua

    2011-02-01

    The toxicities of copper, lead, zinc and cadmium ions and various concentrations of mixtures of them were studied using sea urchin (Strongylocentyotus intermedius) embryo-larval bioassay. Toxic unit analysis was used to determine type of joint action for each mixture combination (binary, ternary and quaternary). For the majority of the binary combinations, the interactions were of synergistic nature, but in ternary or quaternary mixtures, the joint action was mainly concentration additive, while antagonism was only observed for two mixtures (Cu+Pb and Zn+Cd) among all the 11 combinations. Two prevailing theoretical models: the concentration addition (CA) model and the independent action (IA) model were used to predict the mixture toxicities. The weak correlation obtained (R≃0.55) indicated that the hypotheses of mode of action involved in the two models to some extent failed to describe the behavior of the mixture system. Then a novel bio-concentration factor-based model was developed and was successful to predict the toxicities of mixtures, with an obtained R of 0.92. This model indicated that in a mixture system of heavy metals, the joint toxicity was mainly determined by the combined action of bio-concentrations of metals other than the simply similar (CA) or dissimilar (IA) modes of action of the mixture components.

  14. Albendazole sulphoxide enantiomers in pregnant rats' embryo concentrations and developmental toxicity.

    PubMed

    Capece, B P S; Navarro, M; Arcalis, T; Castells, G; Toribio, L; Perez, F; Carretero, A; Ruberte, J; Arboix, M; Cristòfol, C

    2003-05-01

    Three single oral doses (8.5, 10, and 14 mg/kg) of a racemic formulation of albendazole sulphoxide (ABZSO) were administered to pregnant rats on day 10 of gestation. Mother plasma and embryo concentrations of ABZSO enantiomers and albendazole sulphone (ABZSO(2)) were determined 9 h after administration. The (-)-ABZSO enantiomer showed higher peak concentrations in both maternal plasma and embryo than the (+) enantiomer. An increase in embryo concentrations of ABZSO enantiomers and ABZSO(2) was only observed when dose rose to 14 mg/kg. There was an increase in resorption when the dose increased, but significant differences were only found in the higher dose group when compared with the other groups. The incidence of external and skeletal malformations (mostly of the tail, vertebrae and ribs) rose significantly in the 10 mg/kg group, producing almost 20% and 90% of malformed fetuses, respectively, and gross external and skeletal abnormalities in the thoracic region and limbs were also found.

  15. Use of the rat postimplantation embryo culture to assess the embryotoxic potency within a chemical category and to identify toxic metabolites.

    PubMed

    Janer, G; Verhoef, A; Gilsing, H D; Piersma, A H

    2008-10-01

    The implementation of in vitro alternatives in the safety evaluation of chemicals in the animal intensive area of reproductive toxicity testing is highly desirable, but has been limited by issues around predictivity and applicability domains. The validation of alternatives may gain from a category approach, in which, rather than validating a test for the universe of chemicals, its predictive value is assessed for each class of chemicals for which the test represents relevant end point(s). We studied the embryotoxicity in rodent postimplantation whole embryo culture (WEC) of a series of phthalates and their metabolites. Phthalate diesters are widely applied industrial chemicals, their monoester derivatives being considered as their embryotoxic metabolites. The relative in vitro potency of three out of four monophthalates was found to mimick that of corresponding diphthalates tested in vivo. The phthalate that deviated from this ranking, monoethylhexylphthalate (MEHP), showed a relatively high in vitro toxicity as compared to in vivo data. This deviation could be explained through kinetic differences among phthalates, as shown between MEHP and monobutylphthalate. In addition, in vitro testing of specific secondary MEHP metabolites showed that they were all less potent than MEHP. This finding confirmed that MEHP in vitro embryotoxicity is most likely the best correlate to DEHP in vivo embryotoxicity. This study shows that a category approach in the assessment of the validation of in vitro alternatives is feasible, and can be improved when kinetic considerations are taken into account.

  16. Perspectives on testing for toxic agents.

    PubMed Central

    Nelson, N

    1987-01-01

    A series of observations and comments are made with respect to several areas of toxicology: these are briefly discussed. Some innovative areas receive discussion as representing substantial progress made in the field of toxicology in recent years. Topics included raise a number of questions: what agents should we test, and how should we go about selecting them; what is the importance of allowing for genetic diversity in carrying out tests that are meaningful for humans; and what is the relevance of studies in pharmacokinetics in the laboratory to humans. Human studies, because of ethical considerations, must be indirect, through access to available autopsy and surgical human tissues. Also, drug trials and clinical studies must be exploited. Cancer testing and evaluation is briefly commented on. Systemic toxicity is considered in respect to possible improved ways of determining the "NOEL," that is, the no-observed-effect level. Suggestions for improving study of mixtures of chemicals are considered. The rapid advances in molecular biology have significantly strengthened our ability to trace the action of chemicals in the body from exposure to disease. It is very important that training in toxicology be based on a sound disciplinary training in one of the classic fields of the biomedical sciences, such as biochemistry, pharmacology, molecular biology. It is concluded that advances in the past decade have made the practice of toxicology a much more scientific endeavor, especially in its use of the latest developments in basic biomedical sciences. PMID:3319572

  17. 16 CFR 1500.40 - Method of testing toxic substances.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... that does not require animals, are presented in the CPSC's animal testing policy set forth in 16 CFR... number of test animals. The method of testing the toxic substances referred to in § 1500.3(c)(1)(ii)(C... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Method of testing toxic substances....

  18. 16 CFR 1500.40 - Method of testing toxic substances.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... not require animals, are presented in the CPSC's animal testing policy set forth in 16 CFR 1500.232. A... test animals. The method of testing the toxic substances referred to in § 1500.3(c)(1)(ii)(C) and (c)(2... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Method of testing toxic substances....

  19. Sodium cholate-templated blue light-emitting Ag subnanoclusters: in vivo toxicity and imaging in zebrafish embryos.

    PubMed

    Chandirasekar, Shanmugam; Chandrasekaran, Chandramouli; Muthukumarasamyvel, Thangavel; Sudhandiran, Ganapasam; Rajendiran, Nagappan

    2015-01-28

    We report a novel green chemical approach for the synthesis of blue light-emitting and water-soluble Ag subnanoclusters, using sodium cholate (NaC) as a template at a concentration higher than the critical micelle concentration (CMC) at room temperature. However, under photochemical irradiation, small anisotropic and spherically shaped Ag nanoparticles (3-11 nm) were obtained upon changing the concentration of NaC from below to above the CMC. The matrix-assisted laser desorption ionization time-of-flight and electrospray ionization mass spectra showed that the cluster sample was composed of Ag4 and Ag6. The optical properties of the clusters were studied by UV-visible and luminescence spectroscopy. The lifetime of the synthesized fluorescent Ag nanoclusters (AgNCs) was measured using a time-correlated single-photon counting technique. High-resolution transmission electron microscopy was used to assess the size of clusters and nanoparticles. A protocol for transferring nanoclusters to organic solvents is also described. Toxicity and bioimaging studies of NaC templated AgNCs were conducted using developmental stage zebrafish embryos. From the survival and hatching experiment, no significant toxic effect was observed at AgNC concentrations of up to 200 μL/mL, and the NC-stained embryos exhibited blue fluorescence with high intensity for a long period of time, which shows that AgNCs are more stable in living system.

  20. The red tide toxin, brevetoxin, induces embryo toxicity and developmental abnormalities.

    PubMed Central

    Kimm-Brinson, K L; Ramsdell, J S

    2001-01-01

    Brevetoxins are lipophilic polyether toxins produced by the red tide dinoflagellate Gymnodinium breve, and their neurotoxic effects on adult animals have been documented. In this study, we characterized adverse developmental effects of brevetoxin-1 (PbTx-1) using an exposure paradigm that parallels the maternal oocyte transfer of toxin. Medaka fish (Oryzias latipes) embryos were exposed to PbTx-1 via microinjection of toxin reconstituted in a triolein oil droplet. Embryos microinjected with doses of 0.1-8.0 ng/egg (ppm) of brevetoxin-1 exhibited pronounced muscular activity (hyperkinesis) after embryonic day 4. Upon hatching, morphologic abnormalities were commonly found in embryos at the following lowest adverse effect levels: 1.0-3.0 ppm, lateral curvature of the spinal column; 3.1-3.4 ppm, herniation of brain meninges through defects in the skull; and 3.4-4.0 ppm, malpositioned eye. Hatching abnormalities were also commonly observed at brevetoxin doses of 2.0 ppm and higher with head-first, as opposed to the normal tail-first, hatching, and doses > 4.1 ng/egg produced embryos that developed but failed to hatch. Given the similarity of developmental processes found between higher and lower vertebrates, teratogenic effects of brevetoxins have the potential to occur among different phylogenetic classes. The observation of developmental abnormalities after PbTx-1 exposure identifies a new spectrum of adverse effects that may be expected to occur following exposure to G. breve red tide events. PMID:11335186

  1. THE USE OF EMBRYOS OF PALAEMONETES PUGIO IN EVALUATING THE DEVELOPMENTAL TOXICITY OF COMPOUNDS

    EPA Science Inventory

    The grass shrimp, Palaemonetes pugio, is a common, well distributed species along the eastern coast of America that is an important part of the food web. The embryos of P. pugio have shown sensitivity to the water-soluble fraction of Number 2 fuel oil, which indicates they may be...

  2. Albendazole causes stage-dependent developmental toxicity and is deactivated by a mammalian metabolization system in a modified zebrafish embryotoxicity test.

    PubMed

    Mattsson, Anna; Ullerås, Erik; Patring, Johan; Oskarsson, Agneta

    2012-08-01

    The zebrafish embryotoxicity test has previously been combined with an external metabolic activation system (MAS) to assess developmental toxicity of metabolites produced by maternal metabolism. Due to toxicity of MAS the exposure was limited to one early and short period. We have modified the method and included additional testing time points with extended exposure durations. Using the anthelmintic drug albendazole as a model substance, we demonstrated stage-dependent toxic effects at three windows of zebrafish embryo development, i.e. 2-3, 12-14 and 24-28h post fertilization, and showed that MAS, by metabolic deactivation, reduced the toxicity of albendazole at all time points. Chemical analysis confirmed that albendazole was efficiently metabolized by MAS to the corresponding sulfoxide and sulfone, which are non-toxic to zebrafish embryos. To conclude, the modified zebrafish embryotoxicity test with MAS can be expanded for assessment of metabolites at different developmental stages.

  3. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    SciTech Connect

    Greeley Jr, Mark Stephen; Elmore, Logan R; McCracken, Kitty

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the current

  4. A dietary embryo/fetal developmental toxicity study of arruva, an R,R-monatin salt isomer, in Crl:CD(SD) rats.

    PubMed

    Brathwaite, W A; Casterton, P L; Nikiforov, A I; Rihner, M O; Sloter, E D; Hlywka, J J

    2013-12-01

    R,R-Monatin is an intensely sweet substance originally identified in the root bark of Sclerochiton ilicifolius. R,R-Monatin salt, commonly known as "arruva", has potential for use as a high-potency sweetener food ingredient. Previously, arruva was concluded to present no toxicologically relevant effects to Crl:CD(SD) rats and Crl:CD-1(ICR) mice fed up to 35,000 ppm arruva in the diet for 90 days. In the present study, groups of mated Sprague-Dawley rats (25 Crl:CD(SD) females/group) were exposed continuously to 0 (control), 15,000, 30,000, or 50,000 ppm arruva in the diet during gestation days 6-21. There were no fetal malformations or developmental variations that were attributable to arruva at any exposure level, nor were there any test article-related effects on intrauterine survival. Maternal toxicity, evidenced by lower mean body weights, body weight gains and feed efficiency, was observed at 50,000 ppm. A developmental effect, in the form of lower mean fetal body weight, was noted in the 50,000 ppm group in the presence of maternal toxicity. Therefore, the dietary no-observed-adverse-effect level (NOAEL) for maternal and embryo/fetal developmental toxicity of arruva in pregnant rats during gestation days 6-21 was 30,000 ppm (equivalent to 2564 mg/kg bw/day) based on reductions in maternal and fetal body weights.

  5. Developmental toxicity, uptake and distribution of sodium chromate assayed by frog embryo teratogenesis assay-Xenopus(FETAX).

    PubMed

    Bosisio, Stefano; Fortaner, Salvador; Bellinetto, Sonia; Farina, Massimo; Del Torchio, Riccardo; Prati, Mariangela; Gornati, Rosalba; Bernardini, Giovanni; Sabbioni, Enrico

    2009-09-01

    The embryotoxicity and teratogenicity of Cr(VI) on the survival and morphology of the anuran Xenopus laevis have been assessed by frog embryo teratogenesis assay-Xenopus (FETAX). The lethal median (LC(50)) and teratogenic median (TC(50)) concentration values of Cr(VI) were 890 microM and 260 microM, respectively. The calculated teratogenic index (TI) value was 3.42, suggesting that hexavalent chromium has a teratogenic potential. Malformations of embryos included lifting of the body, coiling of the tail and body oedema. Furthermore, the chromium salt caused significant growth retardation at 25 microM exposure concentrations. The use of radiolabelled (51)Cr(VI) allowed the determination of the time course uptake of Cr in Xenopus exposed to concentrations ranging from 0.025 to 500 microM. The evaluation of its distribution into the body (head-abdomen-tail) was evaluated at different exposure times. Chromium is taken up at 24 h by Xenopus embryos for all concentrations tested. At 48 h post fertilization (stage of larva) the amount of Cr accumulated by the two-day-old larva ranged from 0.42 to 580 pg mg(-1) wet weight at 0.025 and 500 microM respectively. These amounts were lower than those at 24 h (2.77 to 11016 pg mg(-1) wet weight embryo) reaching values of the same order of magnitude at 120 h (five-days-old larva). Since at 48 h Xenopus development leads to a swimming embryo, the observed uptake at 24 h could be the result of the binding of Cr to jelly coat compounds surrounding the embryo body as confirmed by gel filtration experiments on (51)Cr-jelly coat. The interaction of Cr with jelly coat is in agreement with the role of jelly coat in protecting the embryo against pathogen and chemical toxins to ensure fertilization. This work further supports the hypothesis that Cr contamination of surface waters could contribute to explain the reported worldwide depletion of frog population.

  6. Bacterial and enzymatic bioassays for toxicity testing in the environment.

    PubMed

    Bitton, G; Koopman, B

    1992-01-01

    Microbioassays using bacteria or enzymes are increasingly applied to measure chemical toxicity in the environment. Attractive features of these assays may include low cost, rapid response to toxicants, high sample throughput, modest laboratory equipment and space requirements, low sample volume, portability, and reproducible responses. Enzymatic tests rely on measurement of either enzyme activity or enzyme biosynthesis. Dehydrogenases are the enzymes most used in toxicity testing. Assay of dehydrogenase activity is conveniently carried out using oxidoreduction dyes such as tetrazolium salts. Other enzyme activity tests utilize ATPases, esterases, phosphatases, urease, luciferase, beta-galactosidase, protease, amylase, or beta-glucosidase. Recently, the inhibition of enzyme (beta-galactosidase, tryptophanase, alpha-glucosidase) biosynthesis has been explored as a basis for toxicity testing. Enzyme biosynthesis was found to be generally more sensitive to organic chemicals than enzyme activity. Bacterial toxicity tests are based on bioluminescence, motility, growth, viability, ATP, oxygen uptake, nitrification, or heat production. An important aspect of bacterial tests is the permeability of cells to environmental toxicants, particularly organic chemicals of hydrophobic nature. Physical, chemical, and genetic alterations of the outer membrane of E. coli have been found to affect test sensitivity to organic toxicants. Several microbioassays are now commercially available. The names of the assays and their basis are: Microtox (bioluminescence), Polytox (respiration), ECHA Biocide Monitor (dehydrogenase activity), Toxi-Chromotest (enzyme biosynthesis), and MetPAD (enzyme activity). An important feature common to these tests is the provision of standardized cultures of bacteria in freeze-dried form. Two of the more recent applications of microbioassays are in sediment toxicity testing and toxicity reduction evaluation. Sediment pore water may be assayed directly or

  7. Effect of water hardness on peracetic toxicity to zebrafish, Danio rerio, embryos

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of peracetic acid (PAA) in aquaculture has been suggested as an alternative therapeutic agent as use of previous therapeutants becomes restricted. Few data are available concerning fish toxicity by PAA or factors that affect this toxicity. The aim of this study was to investigate the influ...

  8. Application of half-embryo test to irradiated apples and cherries

    NASA Astrophysics Data System (ADS)

    Kawamura, Yoko; Miura, Aya; Sugita, Takiko; Yamada, Takashi; Saito, Yukio

    1995-09-01

    The half-embryo test was applied to irradiated apples and cherries. The optimum incubation temperature for apples and cherries was 30°C and 25°C, respectively. Benzyladenine stimulated the shooting of cherry half-embryos, therefore, they were incubated with 10 μM benzyladenine. The irradiation of apples and cherries caused obvious changes in the growth of the half-embryos. A dose of 0.15 kGy or more almost totally retarded shoot elongation. If shooting is less than 50%, the apples and cherries are identified as "irradiated". An assessment could be made after I to 4 days and the detection limit of the irradiation dose is 0.15 kGy.

  9. Toxicity testing of trinitrotoluene-contaminated soil composts

    SciTech Connect

    Honeycutt, M.E.; McFarland, V.A.; Jarvis, A.S.

    1997-10-01

    The Mutatox{trademark} assay and earthworm acute toxicity test were employed to evaluate the efficacy of composting in reducing the toxicity of TNT-contaminated soils. The Mutatox assay is a proprietary bacterial bioluminescence test that determines the mutagenic potential of sample extracts. The earthworm acute toxicity test was chosen because it exposes the organisms to the unaltered contaminant/solid matrix. Rockeye soil, a TNT-contaminated soil collected from a military installation, was composted using two methods. This yielded five samples, Rockeye, Compost A composting. Soil extracts were prepared for Mutatox using the sonification method. Ten serial dilution samples were tested soils/artificial soil were tested in the earthworm toxicity test. In the Rockeye soil samples, a toxic response was shown in both test methods. Mutatox indicated no toxicity in Composts A and B after composting but did not show a positive mutagenic response in the lower serial dilutions. The LC50s for Compost A and B after composting in the earthworm toxicity test were 35.3% and 100%, respectively. Using Mutatox and the earthworm toxicity test together provides a sensitive means of monitoring the effectiveness of various composting techniques for remediating TNT-contaminated soils.

  10. Biologically Relevant Exposure Science for 21st Century Toxicity Testing

    EPA Science Inventory

    High visibility efforts in toxicity testing and computational toxicology including the recent NRC report, Toxicity Testing in the 21st Century: a Vision and Strategy (NRC, 2007), raise important research questions and opportunities for the field of exposure science. The authors ...

  11. Environmental levels of Zn do not protect embryos from Cu toxicity in three species of amphibians.

    PubMed

    Weir, Scott M; Flynn, R Wesley; Scott, David E; Yu, Shuangying; Lance, Stacey L

    2016-07-01

    Contaminants often occur as mixtures in the environment, but investigations into toxicity usually employ a single chemical. Metal contaminant mixtures from anthropogenic activities such as mining and coal combustion energy are widespread, yet relatively little research has been performed on effects of these mixtures on amphibians. Considering that amphibians tend to be highly sensitive to copper (Cu) and that metal contaminants often occur as mixtures in the environment, it is important to understand the interactive effects that may result from multiple metals. Interactive effects of Cu and zinc (Zn) on amphibians have been reported as antagonistic and, conversely, synergistic. The goal of our study was to investigate the role of Zn in Cu toxicity to amphibians throughout the embryonic developmental period. We also considered maternal effects and population differences by collecting multiple egg masses from contaminated and reference areas for use in four experiments across three species. We performed acute toxicity experiments with Cu concentrations that cause toxicity (10-200 μg/L) in the absence of other contaminants combined with sublethal concentrations of Zn (100 and 1000 μg/L). Our results suggest very few effects of Zn on Cu toxicity at these concentrations of Zn. As has been previously reported, we found that maternal effects and population history had significant influence on Cu toxicity. The explanation for a lack of interaction between Cu and Zn in this experiment is unknown but may be due to the use of sublethal Zn concentrations when previous experiments have used Zn concentrations associated with acute toxicity. Understanding the inconsistency of amphibian Cu/Zn mixture toxicity studies is an important research direction in order to create generalities that can be used to understand risk of contaminant mixtures in the environment.

  12. Toxicity evaluation of β-diketone antibiotics on the development of embryo-larval zebrafish (Danio rerio).

    PubMed

    Wang, Huili; Che, Baoguang; Duan, Ailian; Mao, Jingwen; Dahlgren, Randy A; Zhang, Minghua; Zhang, Hongqin; Zeng, Aibing; Wang, Xuedong

    2014-10-01

    This study evaluated the effects of β-diketone antibiotics (DKAs) on the development of embryo-larval zebrafish (Danio rerio). When exposure to DKAs, developmental malformations, such as hatching delay, curved body axis, pericardial edema, uninflated swim bladder and yolk sac edema, were observed at 120 h postfertilization (hpf). The estimated 120 hpf nominal concentrations of no observed effect concentration and lowest observed effect concentration for DKAs were 18.75 and 37.50 mg/L, respectively, suggesting that DKAs have much lower toxicity than other persistent pollutants. Following DKA exposure, embryonic heart rates were significantly reduced as compared to the controls at 48 and 60 hpf. The peak bending motion frequency appeared 1 h earlier than in control embryos. The 2.34 and 9.38-mg/L treatment groups had a higher basal swim rate than control groups at 120 hpf in both light and light-to-dark photoperiod experiments. The occurrence of high speed swim rates was enhanced approximately threefold to sevenfold in the 2.34 and 9.38 mg/L treatments compared to the control. Glutathione (GSH) concentrations in the 2.34 and 9.38-mg/L treatments were significantly higher than the control at 72 hpf, suggesting that GSH production was induced at the end of the hatching period. When exposed to DKAs, zebrafish superoxide dismutase enzyme (SOD) activities were significantly inhibited in the early embryonic period, demonstrating that the clearing ability in zebrafish was lower than the generation rate of free radicals. In summary, the combined DKAs were developmentally toxic to zebrafish in their early life stages and had the ability to impair individual behaviors that are of great importance in the assessment of their ecological fitness.

  13. Selection of cryoprotectants based on their toxic effects on oyster gametes and embryos.

    PubMed

    Nascimento, Iracema A; Leite, Maria Bernadete N L; Sampaio de Araújo, Milena Maria; Sansone, Giovanni; Pereira, Solange A; do Espírito Santo, E Maristela

    2005-08-01

    Cryopreservation is a valuable tool for aquaculture by providing continuous seed production, regardless of the spawning seasons. This study aimed to select the least toxic among the cryoprotectants dimethyl sulfoxide (Me2SO), propylene glycol (PG), and methanol (MET) based on their toxicological effects on Crassostrea rhizophorae gametes and trochophores. They were exposed for 10, 20, and 30 min to a range of concentrations of those cryoprotectants. The endpoint was EC15-24 h (effective concentration which causes abnormalities in 15% of the population exposed to the cryoprotectants for 24 h), recently determined as the chronic value (the concentration at which chronic effects are first observed) for C. rhizophorae embryonic phases. There were no significant differences (p>0.05) among the exposure times in Me2SO toxic effects to either gametes or trochophores. For MET, the increase in exposure time resulted in higher toxicity for gametes, but not for trochophores, while for PG there was a significant (p>0.05) increase in toxicity with the increase of exposure for trochophores and spermatozoa, but not for oocytes. For gametes, MET was the most toxic among the cryoprotectants, while PG was the most toxic for trochophores.

  14. Assessing differences in toxicity and teratogenicity of three phthalates, Diethyl phthalate, Di-n-propyl phthalate, and Di-n-butyl phthalate, using Xenopus laevis embryos.

    PubMed

    Gardner, Steven T; Wood, Andrew T; Lester, Rachel; Onkst, Paitra E; Burnham, Nathaniel; Perygin, Donna H; Rayburn, James

    2016-01-01

    Phthalates, compounds used to add flexibility to plastics, are ubiquitous in the environment. In particular, the diethyl (DEP), di-n-propyl (DnPP), and di-n-butyl (DBP) phthalates were found to exert detrimental effects in both mammalian and non-mammalian studies, with toxic effects varying according to alkyl chain length. Embryos of Xenopus laevis, the African clawed frog, have been used to assess toxicity and teratogenicity of several compounds and serves as a model for assessing adverse and teratogenic effects of ortho-phthalate esters. The purpose of this study was to develop a model for comparison of developmentally toxic effects of ortho-phthalate esters using Xenopus embryos. In this study developing Xenopus laevis embryos were exposed to increasing concentrations of DEP, DnPP, and DBP using the 96-h Frog Embryo Teratogenesis Assay-Xenopus (FETAX), with 96-h lethal concentrations, effective concentrations to induce malformations, teratogenic indices, and concentrations to inhibit growth determined. DEP, DnPP, and DBP showed enhanced toxicity with increasing ester length. Developing Xenopus laevis exposed to DEP, DnPP, and DBP showed similar malformations that also occurred at lower concentrations with increasing alkyl chain length. Teratogenic risk did not change markedly with alkyl chain length, with data showing only DBP to be teratogenic.

  15. Temperature-based rapid toxicity test using Ceriodaphnia dubia.

    PubMed

    Jun, B H; Lee, S I; Ryu, H D; Kim, Y J

    2006-01-01

    Toxicants, which may cause the inhibition to the biological process in sewage/wastewater treatment plant, need to be monitored within short time to prevent from serious damage. A new method, Temperature-based rapid toxicity test (TempTox test) using Ceriodaphnia dubia, was developed and compared with the standard 48 hr acute bioassay (Std. 48-hr test). Inorganic toxicants of cadmium, zinc, copper, cyanide, chromium (III), chromium (VI) and organic toxicants of phenol, PCP and pesticides of BPMC, Diazinon, Fenitrothion were tested for TempTox test and Std. 48-hr test. Because the TempTox test is based on just temperature control, C. dubia neonates were exposed to toxicants under high temperature (35.5 degrees C) condition without any complicated pretreatment. After given exposure time of 1, 1.25, 1.5 hours, the number of the live (no toxic effect) or the dead (toxic effect) was counted with eye without the aid of any microscope and median effective concentrations (EC50 values) were determined. From the results for all toxicants, the TempTox test was proved to be as sensitive as the Std. 48-hr test with shorter-time of just 1.25-1.5 hours. Moreover, the TempTox test was further much more sensitive than alternative bioassays such as the 1-hour l.Q. test and 30-minute Microtox. The TempTox test showed a high applicability of toxicity bioassay for real sewage/wastewater treatment plant by its easiness, rapidity and sensitivity. Finally, the prototype for short-term TempTox test was introduced.

  16. Rapid in vivo testing of drug response in multiple myeloma made possible by xenograft to turkey embryos

    PubMed Central

    Farnoushi, Y; Cipok, M; Kay, S; Jan, H; Ohana, A; Naparstek, E; Goldstein, R S; Deutsch, V R

    2011-01-01

    Background: The best current xenograft model of multiple myeloma (MM) in immune-deficient non-obese diabetic/severe-combined immunodeficient mice is costly, animal maintenance is complex and several weeks are required to establish engraftment and study drug efficacy. More practical in vivo models may reduce time and drug development cost. We recently described a rapid low-cost xenograft model of human blood malignancies in pre-immune turkey. Here, we report application of this system for studying MM growth and the preclinical assessment of anticancer therapies. Methods: Cell lines and MM patient cells were injected intravenously into embryonic veins on embryonic day 11 (E11). Engraftment of human cells in haematopoietic organs was detected by quantitative real-time polymerase chain reaction, immunohistochemistry, flow cytometry and circulating free light chain. Results: Engraftment was detected after 1 week in all embryos injected with cell lines and in 50% of those injected with patient cells. Injection of bortezomib or lenalinomide 48 h after cell injection at therapeutic levels that were not toxic to the bone marrow dramatically reduced MM engraftment. Conclusion: The turkey embryo provides a practical, xenograft system to study MM and demonstrates the utility of this model for rapid and affordable testing therapeutics in vivo. With further development, this model may enable rapid, inexpensive personalised drug screening. PMID:22045188

  17. Assessing contaminant sensitivity of endangered and threatened aquatic species: Part III. Effluent toxicity tests

    USGS Publications Warehouse

    Dwyer, F.J.; Hardesty, D.K.; Henke, C.E.; Ingersoll, C.G.; Whites, D.W.; Augspurger, T.; Canfield, T.J.; Mount, D.R.; Mayer, F.L.

    2005-01-01

    Toxicity tests using standard effluent test procedures described by the U.S. Environmental Protection Agency were conducted with Ceriodaphnia dubia, fathead minnows (Pimephales promelas), and seven threatened and endangered (listed) fish species from four families: (1) Acipenseridae: shortnose sturgeon (Acipenser brevirostrum); (2) Catostomidae; razorback sucker (Xyrauchen texanus); (3) Cyprinidae: bonytail chub (Gila elegans), Cape Fear shiner (Notropis mekistocholas) Colorado pikeminnow (Ptychocheilus lucius), and spotfin chub (Cyprinella monacha); and (4) Poecillidae: Gila topminnow (Poeciliopsis occidentalis). We conducted 7-day survival and growth studies with embryo-larval fathead minnows and analogous exposures using the listed species. Survival and reproduction were also determined with C. dubia. Tests were conducted with carbaryl, ammonia-or a simulated effluent complex mixture of carbaryl, copper, 4-nonylphenol, pentachlorophenol and permethrin at equitoxic proportions. In addition, Cape Fear shiners and spotfin chub were tested using diazinon, copper, and chlorine. Toxicity tests were also conducted with field-collected effluents from domestic or industrial facilities. Bonytail chub and razorback suckers were tested with effluents collected in Arizona whereas effluent samples collected from North Carolina were tested with Cape Fear shiner, spotfin chub, and shortnose sturgeon. The fathead minnow 7-day effluent test was often a reliable estimator of toxic effects to the listed fishes. However, in 21 % of the tests, a listed species was more sensitive than fathead minnows. More sensitive species results varied by test so that usually no species was always more or less sensitive than fathead minnows. Only the Gila topminnow was consistently less sensitive than the fathead minnow. Listed fish species were protected 96% of the time when results for both fathead minnows and C. dubia were considered, thus reinforcing the value of standard whole

  18. Assessing contaminant sensitivity of endangered and threatened aquatic species: part III. Effluent toxicity tests.

    PubMed

    Dwyer, F J; Hardesty, D K; Henke, C E; Ingersoll, C G; Whites, D W; Augspurger, T; Canfield, T J; Mount, D R; Mayer, F L

    2005-02-01

    Toxicity tests using standard effluent test procedures described by the U.S. Environmental Protection Agency were conducted with Ceriodaphnia dubia, fathead minnows (Pimephales promelas), and seven threatened and endangered (listed) fish species from four families: (1) Acipenseridae: shortnose sturgeon (Acipenser brevirostrum); (2) Catostomidae; razorback sucker (Xyrauchen texanus); (3) Cyprinidae: bonytail chub (Gila elegans), Cape Fear shiner (Notropis mekistocholas) Colorado pikeminnow (Ptychocheilus lucius), and spotfin chub (Cyprinella monacha); and (4) Poecillidae: Gila topminnow (Poeciliopsis occidentalis). We conducted 7-day survival and growth studies with embryo-larval fathead minnows and analogous exposures using the listed species. Survival and reproduction were also determined with C. dubia. Tests were conducted with carbaryl, ammonia--or a simulated effluent complex mixture of carbaryl, copper, 4-nonylphenol, pentachlorophenol and permethrin at equitoxic proportions. In addition, Cape Fear shiners and spotfin chub were tested using diazinon, copper, and chlorine. Toxicity tests were also conducted with field-collected effluents from domestic or industrial facilities. Bonytail chub and razorback suckers were tested with effluents collected in Arizona whereas effluent samples collected from North Carolina were tested with Cape Fear shiner, spotfin chub, and shortnose sturgeon. The fathead minnow 7-day effluent test was often a reliable estimator of toxic effects to the listed fishes. However, in 21 % of the tests, a listed species was more sensitive than fathead minnows. More sensitive species results varied by test so that usually no species was always more or less sensitive than fathead minnows. Only the Gila topminnow was consistently less sensitive than the fathead minnow. Listed fish species were protected 96% of the time when results for both fathead minnows and C. dubia were considered, thus reinforcing the value of standard whole

  19. Toxicity Tests for Ensuring Succesful Industrial Wastewater Treatment Plant Operation

    NASA Astrophysics Data System (ADS)

    Cěbere, B.; Faltiņa, E.; Zelčāns, N.; Kalniņa, D.

    2009-01-01

    Industrial wastewaters are complex and can be polluted by non-biodegradable end toxic organic compounds and are a serious threat to the environment. Chemical procedure alone cannot provide sufficient information. A complete evaluation of wastewaters should include ecotoxicological tests too, especially concerning the complex wastewaters. In the literature review the authors attempted to establish which is the more promising and suitable aquatic toxicology test for sewage treatment plant influent toxicity monitoring. A variety of types of organisms representing different trophic levels and many different species are used for aquatic toxicity testing. Toxicity characterization would be needed both for influents and effluents of wastewater treatment plant. For the purpose of screening biological wastewater treatment influent, toxicity to activated sludge microorganisms is important and toxicology tests here used are respirometry and bioluminescence toxicology tests. Respirometry toxicity tests are easy, fast and inexpensive compared to other approaches. Bioluminescence has been widely used, the most thoroughly investigated test system is the Microtox. The toxicity tests have also been compared by different authors. International, national and regional authorities use these tools to meet various regulatory and legislative requirements. Importance of biotesting has been emphasized also in EU legislation.

  20. Developmental toxicity of thyroid-active compounds in a zebrafish embryotoxicity test.

    PubMed

    Jomaa, Barae; Hermsen, Sanne A B; Kessels, Maurijn Y; van den Berg, Johannes H J; Peijnenburg, Ad A C M; Aarts, Jac M M J G; Piersma, Aldert H; Rietjens, Ivonne M C M

    2014-01-01

    Zebrafish embryos were exposed to concentration ranges of selected thyroid-active model compounds in order to assess the applicability of zebrafish-based developmental scoring systems withinan alternative testing strategy to detect the developmental toxicity ofthyroid-active compounds. Model compounds tested included triiodothyronine (T3), propylthiouracil (PTU), methimazole (MMI), sodium perchlorate (NaClO4) and amiodarone hydrochloride (AMI), selected to represent different modes of action affecting thyroid activity. Tested time windows included 48-120 hours post fertilization (hpf), 0-72 hpf and 0-120 hpf. All tested compounds resulted in developmental changes, with T3 being the most potent. The developmental parameters affected included reflective iridophores, beat and glide swimming, inflated swim bladders, as well as resorbed yolk sacs. These effects are only evident by 120 hpf and therefore an existing General Morphology Score (GMS) system was extended to create a General Developmental Score(GDS) that extends beyond the 72 hpfscoring limit of GMS and includes additional parameters that are affected by exposure to model thyroid-active compounds. Moreover, the GDS is cumulative as it includes not only the scoring of developmental morphologies but also integrates developmental dysmorphologies. Exposures from 48-120 hpf did not provide additional information to exposures from 0-120 hpf. The results indicate that the zebrafish GDS can detect the developmental toxicity of thyroid toxicants and may be of use in an integrated testing strategy to reduce, refine and in certain cases replace animal testing.

  1. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... acute toxicity of chemical substances and mixtures (“chemicals”) subject to environmental effects test... per volume of nutrient medium or test solution in a specified period of time. (5) Static system means a test container in which the test solution is not renewed during the period of the test. (c)...

  2. The Use of Physarum for Testing of Toxicity/Mutagenicity

    DTIC Science & Technology

    1984-04-19

    1974) studied toxic and mutagenic effects of bisulfite in synchronous cultures of the flagellate, Chlorella pyrenoidosa. Dixon et al. (1979) have...AFAMRL-TR-84-007 . 0 . THE USE OF PHYSARUM FOR TESTING OF TOXICITY /MUTAGENICITY JOYCE MOHBERG GOVERNORS STATE UNIVERSITY SCIENCE DIVISION PARK FOREST...approved for publication. FOR THE COMMANI)ER BRUCE 0. STUART, PhD Director Toxic Hazards Division Air Force Aerospace Medical Research Laboratory SECURITY

  3. Toxicity of pristine graphene in experiments in a chicken embryo model.

    PubMed

    Sawosz, Ewa; Jaworski, Slawomir; Kutwin, Marta; Hotowy, Anna; Wierzbicki, Mateusz; Grodzik, Marta; Kurantowicz, Natalia; Strojny, Barbara; Lipińska, Ludwika; Chwalibog, André

    2014-01-01

    Evaluation of the potential cytotoxicity of graphene is a key factor for medical applications, where flakes or a surface of graphene may be used as bioactive molecules, drug carriers, or biosensors. In the present work, effects of pristine graphene (pG) on the development of a living organism, with an emphasis on morphological and molecular states of the brain, were investigated using a chicken embryo model. Fertilized chicken eggs were divided into the control group and groups administered with pG suspended in milli-Q water at concentrations of 50 μg/L, 100 μg/L, 500 μg/L, 1,000 μg/L, 5,000 μg/L, and 10,000 μg/L (n=30 per group). The experimental solutions were injected in ovo into the albumin and then the eggs were incubated. After 19 days of incubation, the survival, weight of the body and organs, and blood serum biochemical indices were measured. The brain samples were collected for microscopic examination of brain ultrastructure and measurements of gene and protein expression. Survival of embryos was significantly decreased after treatment with pG, but the body and organ weights as well as biochemical indices were not affected. In all treatment groups, some atypical ultrastructures of the brain were observed, but they were not enhanced by the increasing concentrations of pG. Expression of proliferating cell nuclear antigen at the messenger ribonucleic acid level was downregulated, and the number of proliferating cell nuclear antigen-positive nuclei was significantly reduced in the 500-10,000 μg/L groups compared with the control group, indicating a decreased rate of deoxyribonucleic acid synthesis in the brain. The present results demonstrate some harmful effects of the applied pG flakes on the developing organism, including brain tissue, which ought to be considered prior to any medical applications.

  4. EVALUATION OF ALTERNATIVE REFERENCE TOXICANTS FOR USE IN THE EARTHWORM TOXICITY TEST

    EPA Science Inventory

    The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However,the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants...

  5. On the performance of acute toxicity tests using the National Reference Toxicant Database

    SciTech Connect

    Zaidhk, B.

    1995-12-31

    The US National Reference Toxicant Database was used to compile data from 158 Ceriodaphnia dubia, and 187 fathead minnow acute toxicity tests. The data are analyzed using the EPA flow-chart for acute toxicity tests to determine the distribution of test methods selected. The data are reanalyzed using maximum likelihood estimation assuming probit, logit and Gompertz tolerance distributions and non-parametrically using the Spearman-Karber method with and without trimming. The results of these analyses are compared with respect to mean square error for the parametric methods and confidence intervals for the point estimate for all analyses.

  6. Toxicity of Polychlorinated Diphenyl Ethers in Hydra Attenuata and in Rat Whole Embryo Culture

    DTIC Science & Technology

    1991-05-01

    those reported by Ewald et aL, (1976) who demonstrated that the toxicity of PCBs to Euglena gracilis is inversely proportional to the percent...biphenyls to Euglena gracilis: Cell population growth, carbon fixation, chlorophyll level, oxygen consumption, and protein and nucleic acid synthesis

  7. Extrapolation of toxic indices among test objects

    PubMed Central

    Tichý, Miloň; Rucki, Marián; Roth, Zdeněk; Hanzlíková, Iveta; Vlková, Alena; Tumová, Jana; Uzlová, Rút

    2010-01-01

    Oligochaeta Tubifex tubifex, fish fathead minnow (Pimephales promelas), hepatocytes isolated from rat liver and ciliated protozoan are absolutely different organisms and yet their acute toxicity indices correlate. Correlation equations for special effects were developed for a large heterogeneous series of compounds (QSAR, quantitative structure-activity relationships). Knowing those correlation equations and their statistic evaluation, one can extrapolate the toxic indices. The reason is that a common physicochemical property governs the biological effect, namely the partition coefficient between two unmissible phases, simulated generally by n-octanol and water. This may mean that the transport of chemicals towards a target is responsible for the magnitude of the effect, rather than reactivity, as one would assume suppose. PMID:21331180

  8. Early life-stage toxicity test methods for gulf toadfish (Opsanus beta) and results using chlorpyrifos

    SciTech Connect

    Hansen, D.J.; Goodman, L.R.; Cripe, G.M.; Macauley, S.F.

    1986-02-01

    Gulf toadfish (Opsanus beta) were continuously exposed as embryos, sac fry, and juveniles to technical chlorpyrifos in two 49-day early life-stage toxicity tests. Survival was significantly (alpha = 0.05) reduced only in 150 micrograms/liter. However, toadfish exposed to chlorpyrifos concentrations from 3.7 to 150 micrograms/liter weighted significantly less than control fish: 9% lower in 3.7 micrograms/liter to 62% lower in 150 micrograms/liter. The 96-hr LC50 for juvenile fish was 520 micrograms/liter. Concentrations of chlorpyrifos in toadfish and bioconcentration factors increased with increasing exposure concentration, a condition not generally observed with other marine fishes and other test chemicals. These results demonstrated the procedures for, and the practicality of, early life-stage tests with this marine species. We recommend the use of the gulf toadfish for comparative toxicity testing and for evaluating the toxicity of substances in conjunction with ontogenetical, physiological, and histological investigations of this considerably studied genus. We do not recommend it for routine effects testing.

  9. Sensitivity or artifact? -- IQ Toxicity Test -- effluent values

    SciTech Connect

    Hayes, K.R.; Novotny, A.N.; Batista, N.

    1995-12-31

    Several complex effluents were DAPHNIA MAGNA IQ TOXICITY TESTED -- (1.25 hours) and conventionally tested with Daphnia magna (48 hours). In many samples the IQ Technology yielded low EC50 values while the 48 hour exposures yielded no acute toxicity. Possible explanations have been suggested for this occurrence such as: genotoxicity, mutagenicity, substrate interference, and enzyme satiation. To identify the causative agent(s) of this response a Toxicity Identification Evaluation was performed on one of the samples. To define the nature of the response, THE SOS-CHROMOTEST KIT and THE MUTA-CHROMOPLATE KIT were utilized to characterize genotoxicity and mutagenicity respectively. The sample did not test positive for genotoxicity but tested positive for mutagenicity only after activation with S9 enzymes, suggesting the presence of promutagens. Additional work needs to be performed to correlate IQ TOXICITY TEST sensitivity with positive MUTA-CHROMOPLATE response.

  10. A field validation of two sediment-amphipod toxicity tests.

    PubMed

    Ferraro, Steven P; Cole, Faith A

    2002-07-01

    A field validation study of two sediment-amphipod toxicity tests was conducted using sediment samples collected subtidally in the vicinity of a polycyclic aromatic hydrocarbon (PAH)-contaminated Superfund site in Elliott Bay (WA, USA). Sediment samples were collected at 30 stations with a 0.1 m2 grab from which subsamples were taken for sediment toxicity testing and geochemical and macrofaunal analyses. Standard 10-d sediment-amphipod toxicity tests were conducted with Rhepoxynius abronius and Leptocheiros plumulosus. Sediments were analyzed for 33 PAHs, pentachlorophenol, polychlorinated biphenyls, acid-volatile sulfide, simultaneously extracted metals (Cd, Cu, Zn, Pb, Ni), total organic carbon, and grain size. Sediment temperature, oxygen-reduction potential, water depth, and interstitial water salinity were also measured. Polycyclic aromatic hydrocarbons, quantified as total PAH toxic units (TU(PAH)), were confirmed to be an important common causal agent of the changes in the two toxicity test (% survival R. abronius, % survival L. plumulosus) and five macrofaunal community (number of species, S; numerical abundance, A: total biomass, B: Swartz's dominance index, SDI; Brillouin's index, H) endpoints. Two other macrofaunal community metrics (the complement of Simpson's index, 1 - SI, and McIntosh's index, MI) were less sensitive to TU(PAH) than the two toxicity test endpoints. The sensitivities of R. abronius and L. plumulosus to TU(PAH) were statistically indistinguishable. Field validations were conducted by testing the association between or among each toxicity test endpoint, each of seven macrofaunal community metrics (S, A, B, SDI, H, 1 - SI, MI), and TU(PAH) by (1) Spearman's coefficient of rank correlation, (2) Kendall's coefficient of concordance, (3) G tests of independence, and (4) regression analysis. Some field validations based on multivariable tests of association (e.g., points 2 and 3) among toxicity test, field, and stressor endpoints produced

  11. Draft Test Guideline: Whole Sediment Acute Toxicity Invertebrates, Marine

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  12. Draft Test Guideline: Fish Acute Toxicity Mitigated By Humic Acid

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  13. Draft Test Guideline: Whole Sediment Acute Toxicity Invertebrates, Freshwater

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  14. Optimization of Hyalella azteca IQ Toxicity Test{trademark} for prediction of 28-day sediment toxicity tests

    SciTech Connect

    Novotny, A.N.; Ezzard, C.L.; Douglas, W.S.; Home, M.T.

    1995-12-31

    The IQ Toxicity Test, which is a rapid screening toxicity test consisting of the observation of in-vivo inhibition of an enzymatic process using a fluorescent substrate, has proven successful for the determination of 24 and 48-hour EC50`s of D. magna, C. dubia, D. pulex and M. bahia. The application of this concept to utilize the freshwater amphipod Hyalella azteca may be an excellent way in which to reduce the standard 28-day chronic sediment toxicity test to possibly one hour`s time. This study incorporates an additive experimental design to explore the effects of and interactions between five specific variables: size of the amphipod, exposure time to the toxicant, concentration of substrate, exposure time to the substrate, and length of time starved prior to testing. The results of the IQ toxicity test were compared to those of a 28-day chronic sediment toxicity test. Preliminary data indicate that there is an optimal combination of these variables which results in a concise, reproducible toxicity test for use with Hyalella azteca, and would potentially be applicable to other freshwater amphipods in the future.

  15. 76 FR 38170 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-29

    ... AGENCY Toxic Substances Control Act Chemical Testing; Receipt of Test Data AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: This notice announces EPA's receipt of test data on 12 chemicals listed in the Toxic Substance Control Act (TSCA) section 4 test rule titled ``Testing of...

  16. Marine and estuarine porewater toxicity testing -- species and end point comparisons

    SciTech Connect

    Carr, R.S.; Chapman, D.C.; Biedenbach, J.M.; Robertson, L.

    1994-12-31

    As part of their continuing development and evaluation of the porewater toxicity test approach for assessing the quality of marine and estuarine sediments, a variety of studies involving species and endpoint comparisons as well as validation studies have recently been conducted. The results from numerous extensive sediment quality assessment surveys have demonstrated that porewater toxicity tests are considerably more sensitive than the standard solid-phase tests and invariably exhibit a higher degree of concordance with sediment quality assessment guidelines than the standard tests. Species that have been evaluated for use in testing marine and estuarine pore water include a life-cycle test with the polychaete Dinophilus gyrociliatus, survival and hatching success with embryo-larval stages of red drum Sciaaenops ocellatus, survival of nauplii stages of the harpacticoid copepod Longipedia sp., and three different assays (fertilization, embryological development, and cytogenetic) with the sea urchin Arbacia punctulata. The different species and end points have been compared using sediment pore water from a variety of contaminated sites. Although the results of tests with the different species and end points were often comparable, in general, the sea urchin embryological development assay appears to be the most sensitive porewater test evaluated thus far in their laboratory.

  17. The Toxicity Estimation Software Tool (T.E.S.T.)

    EPA Science Inventory

    The Toxicity Estimation Software Tool (T.E.S.T.) has been developed to estimate toxicological values for aquatic and mammalian species considering acute and chronic endpoints for screening purposes within TSCA and REACH programs.

  18. THE TOXCAST PROGRAM FOR PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS

    EPA Science Inventory

    The United States Environmental Protection Agency (EPA) is developing methods for utilizing computational chemistry, high-throughput screening (HTS) and various toxicogenomic technologies to predict potential for toxicity and prioritize limited testing resources towards chemicals...

  19. Bacterial and enzymatic bioassays for toxicity testing in the environment

    SciTech Connect

    Bitton, G.; Koopman, B. )

    1992-01-01

    Microbioassays using bacteria or enzymes are increasingly applied to measure chemical toxicity in the environment. Attractive features of these assays may include low cost, rapid response to toxicants, high sample throughput, modest laboratory equipment and space requirements, low sample volume, portability, and reproducible responses. Enzymatic tests rely on measurement of either enzyme activity or enzyme biosynthesis. Dehydrogenases are the enzymes most used in toxicity testing. Assay of dehydrogenase activity is conveniently carried out using oxidoreduction dyes such as tetrazolium salts. Other enzyme activity tests utilize ATPases, esterases, phosphatases, urease, luciferase, beta-galactosidase, protease, amylase, or beta-glucosidase. Recently, the inhibition of enzyme (beta-galactosidase, tryptophanase, alpha-glucosidase) biosynthesis has been explored as a basis for toxicity testing. Enzyme biosynthesis was found to be generally more sensitive to organic chemicals than enzyme activity.107 references.

  20. Neutral red uptake cytotoxicity tests for estimating starting doses for acute oral toxicity tests.

    PubMed

    Stokes, William S; Casati, Silvia; Strickland, Judy; Paris, Michael

    2008-05-01

    In vitro cytotoxicity assays can be used as alternative toxicity tests to reduce the total number of animals needed for acute oral toxicity tests. This unit describes two methods for determining the in vitro cytotoxicity of test substances using neutral red uptake (NRU) and using the in vitro data to determine starting doses for in vivo acute oral systemic toxicity tests, e.g., the up-and-down procedure or the acute toxic class method. The use of the NRU methods to determine starting doses for acute oral toxicity tests may reduce the number of animals required, and for relatively toxic substances, this approach may also reduce the number of animals that die or require humane euthanasia due to severe toxicity. An interlaboratory validation study has demonstrated that the methods are useful and reproducible for these purposes. Two standardized protocols provide details for performing NRU tests with rodent and human cells.

  1. Arsenic (III, V), indium (III), and gallium (III) toxicity to zebrafish embryos using a high-throughput multi-endpoint in vivo developmental and behavioral assay.

    PubMed

    Olivares, Christopher I; Field, Jim A; Simonich, Michael; Tanguay, Robert L; Sierra-Alvarez, Reyes

    2016-04-01

    Gallium arsenide (GaAs), indium gallium arsenide (InGaAs) and other III/V materials are finding increasing application in microelectronic components. The rising demand for III/V-based products is leading to increasing generation of effluents containing ionic species of gallium, indium, and arsenic. The ecotoxicological hazard potential of these streams is unknown. While the toxicology of arsenic is comprehensive, much less is known about the effects of In(III) and Ga(III). The embryonic zebrafish was evaluated for mortality, developmental abnormalities, and photomotor response (PMR) behavior changes associated with exposure to As(III), As(V), Ga(III), and In(III). The As(III) lowest observable effect level (LOEL) for mortality was 500 μM at 24 and 120 h post fertilization (hpf). As(V) exposure was associated with significant mortality at 63 μM. The Ga(III)-citrate LOEL was 113 μM at 24 and 120 hpf. There was no association of significant mortality over the tested range of In(III)-citrate (56-900 μM) or sodium citrate (213-3400 μM) exposures. Only As(V) resulted in significant developmental abnormalities with LOEL of 500 μM. Removal of the chorion prior to As(III) and As(V) exposure was associated with increased incidence of mortality and developmental abnormality suggesting that the chorion may normally attenuate mass uptake of these metals by the embryo. Finally, As(III), As(V), and In(III) caused PMR hypoactivity (49-69% of control PMR) at 900-1000 μM. Overall, our results represent the first characterization of multidimensional toxicity effects of III/V ions in zebrafish embryos helping to fill a significant knowledge gap, particularly in Ga(III) and In(III) toxicology.

  2. Hypersalinity toxicity thresholds for nine California ocean plan toxicity test protocols.

    PubMed

    Voorhees, Jennifer P; Phillips, Bryn M; Anderson, Brian S; Siegler, Katie; Katz, Scott; Jennings, Lydia; Tjeerdema, Ron S; Jensen, Joanna; de la Paz Carpio-Obeso, Maria

    2013-11-01

    Currently, several desalination facilities have been proposed to operate or are actually operating in California. These facilities' use of reverse osmosis (RO) may discharge hypersaline reject brine into the marine environment. The risks, if any, this brine would pose to coastal receiving waters are unknown. To test the toxicity of hypersaline brine in the absence of any additional toxic constituents, we prepared brine and tested it with the seven toxicity test organisms listed in the 2009 California Ocean Plan. The most sensitive protocols were the marine larval development tests, whereas the most tolerant to increased salinities were the euryhaline topsmelt, mysid shrimp, and giant kelp tests. Reject brines from the Monterey Bay Aquarium's RO desalination facility were also tested with three species. The effects of the aquarium's brine effluent on topsmelt, mussels, and giant kelp were consistent with those observed in the salinity tolerance experiments. This information will be used by regulators to establish receiving water limitations for hypersaline discharges.

  3. Relative developmental toxicity of short-chain chlorinated paraffins in Zebrafish (Danio rerio) embryos.

    PubMed

    Liu, Lihua; Li, Yifan; Coelhan, Mehmet; Chan, Hing Man; Ma, Wanli; Liu, Liyan

    2016-12-01

    Short-chain chlorinated paraffins (SCCPs) are ubiquitous in the environment and might cause adverse environmental and human health effects. Little is known about the relative toxicity of different SCCP compounds especially during development. The objective of this study was to characterize and compare effects of seven SCCP groups at environmentally relevant levels, using a zebrafish (Danio rerio) model. Observations on malformation, survival rates at 96 h post fertilization (hpf), and hatching rates at 72 hpf indicated that the C10- groups (C10H18Cl4, 1,2,5,6,9,10-C10H16Cl6 and C10H15Cl7) were more toxic than the C12- groups (C12H22Cl4, C12H19Cl7 and 1,1,1,3,10,12,12,12-C12H18Cl8) and Cereclor 63L. The C10- groups were also more potent than C12- groups and Cereclor 63L in decreasing thyroid hormone levels. Among the three compounds within the C10- group, the compounds with less chlorine content had stronger effects on sub-lethal malformations but less effects on triiodothyronine (T3) and tetraiodothyronine (T4). Only C10H18Cl4 significantly decreased the mRNA expression of tyr, ttr, dio2 and dio3 at a dose-dependent manner suggesting that the specific mode of actions differ with different congeners. The mechanisms of disruption of thyroid status by different SCCPs could be different. C10H18Cl4 might inhibit T3 production through the inhibition effect on dio2. These results indicate that SCCP exposure could alter gene expression in the hypothalamic-pituitary-thyroid (HPT) axis and thyroid hormone levels. The mechanisms of disruption of thyroid status by different SCCPs could be different. Our results on the relative developmental toxicities of SCCPs will be useful to reach a better understanding of SCCP toxicity supporting environmental risk evaluation and regulation and used as a guidance for environmental monitoring of SCCPs in the future.

  4. Rice seed toxicity tests for organic and inorganic substances

    USGS Publications Warehouse

    Wang, W.

    1994-01-01

    Plant seed toxicity tests can be used to evaluate hazardous waste sites and to assess toxicity of complex effluents and industrial chemicals. Conventional plant seed toxicity tests are performed using culture dishes containing filter paper. Some reports indicate that filter papers might interfere with the toxicity of inorganic substances. In this study, a plastic seed tray was used. Rice was used as the test species. A comparison of results in the literature and this study revealed that variation of test species, methods, exposure duration, and other factors may affect the test results. The results of this study showed that the order of decreasing toxicity of metal ions was Cu>Ag>Ni>Cd>Cr(VI)>Pb>Zn>Mn>NaF for rice. The test results were similar to those reported in the literature for lettuce Ag>Ni>Cd,Cu>Cr (VI)>Zn>Mn, millet Cu,Ni>Cd>Cr(VI)>Zn>Mn, and ryegrass Cu>Ni>Mn>>Pb>Cd>Zn> Al>Hg>Cr>Fe. The order of decreasing toxicity of organic herbicides was paraquat, 2,4-D>>glyphosate>bromacil.

  5. Harmonization of standard toxicity test methods used in North America

    SciTech Connect

    Ingersoll, C.G.; Dwyer, F.J.; Ankley, G.T.

    1995-12-31

    Over the past two years, Environment Canada (EC) and the US Environmental Protection Agency (EPA) have developed standard methods for conducting toxicity and bioaccumulation tests with freshwater, estuarine, and marine sediments. Existing ASTM methods were used as a basis to harmonize these methods for conducting testing with either field-collected or laboratory-spiked sediments. For freshwater toxicity tests, methods are described by EC and EPA for the amphipod Hyalella azteca and the midges Chironomus tentans and C. riparius. Endpoints include 10- to 14-d survival of growth. Methods are also described by EPA for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus. For estuarine and marine toxicity tests, methods are described for several amphipods (i.e., Rhepoxynius abronius, Ampelisca abdita, Eohaustorius estuarius, Leptocheirus plumulosus). Endpoints include 10-d survival and reburial. EC is also developing methods for conducting toxicity tests with Atlantic, Pacific, and Arctic Canadian species of polychaetes. Methods are described by EPA for conducting 28-d bioaccumulation tests with a variety of mollusks (i.e., Macoma spp.) and polychaetes (i.e., Nereis spp.). Slight inconsistencies in methods between freshwater and estuarine/marine testing or between EC and EPA testing include: (1) static vs. flow-through conditions, (2) sieving of sediment, (3) types and quantity of food, (4) age of test organisms, or (4) duration of the test and required endpoints. Additional research is in progress to: (1) develop chronic toxicity tests with amphipods and midges measuring survival, growth, or reproduction, (2) develop whole-sediment toxicity identification evaluation (TIE) procedures, (3) refine sediment spiking procedures, and (4) field-validate laboratory tests.

  6. Test chambers and test procedures for in situ toxicity testing with zooplankton

    SciTech Connect

    Pereira, A.M.M; Da Maia Soares, A.M.V.; Goncalves, F.; Ribeiro, R.

    1999-09-01

    Ecotoxicity assessment is usually done by classical tests under controlled conditions. However, field situations may not be accurately predicted by laboratory testing. In situ testing is a pertinent way for assessing the ecological relevance of laboratory bioassays. The objectives of this study were to develop an in situ test chamber and respective test protocols suitable for ecotoxicity testing with zooplankton and to evaluate the use of laboratory protocols (water column and solid phase) by comparing results obtained under controlled conditions with in situ results at an aquatic system receiving acid mine drainage. At the most contaminated stations and at the reference stations, good agreement was found between in situ and classical setting. At intermediate stations, in situ toxicity was generally higher than that in classical tests. Sample collection and preservation probably altered actual toxicity, thus emphasizing the need for caution in estimating or extrapolating field effects from laboratory results.

  7. 76 FR 38169 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-29

    ... AGENCY Toxic Substances Control Act Chemical Testing; Receipt of Test Data AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: This notice announces EPA's receipt of test data on five chemicals listed in the Toxic Substances Control Act (TSCA) section 4 test rule titled ``In Vitro...

  8. Ameliorative effects of sodium chloride on acute copper toxicity among Cope's gray tree frog (Hyla chrysoscelis) and green frog (Rana clamitans) embryos.

    PubMed

    Brown, Maria G; Dobbs, Emily K; Snodgrass, Joel W; Ownby, David R

    2012-04-01

    Urban stormwater runoff is composed of a mixture of components, including polycyclic aromatic hydrocarbons, metals, deicing agents, and many others. The fate of these chemicals is often in stormwater detention ponds that are used by amphibians for breeding. Among aquatic organisms, the toxic mechanism for many metals involves interference with active Na(+) and Cl(-) uptake. Addition of cations has been shown to reduce the toxicity of metals among some aquatic organisms through competitive inhibition, but no studies have investigated the interaction between NaCl and Cu among amphibian embryos and larvae. To determine the degree to which NaCl may ameliorate the toxicity of Cu to amphibian embryos and larvae, the authors exposed Hyla chrysoscelis (Cope's gray treefrogs) and Rana (Lithobates) clamitans (green frogs) to seven levels of Cu and NaCl in fully factorial experiments. When exposure was in artificial hard water, Cu was highly toxic to both species (96-h median lethal concentration [LC50] of 44.7 µg/L and 162.6 µg/L for H. chrysoscelis and R. clamitans, respectively). However, approximately 500 mg/L of NaCl eliminated Cu toxicity over the range of Cu concentrations used in the experiments (maximum 150 µg Cu/L for H. chrysoscelis and 325 µg Cu/L for R. clamitans). The current results suggest that NaCl is likely responsible for the toxic effects of NaCl and metal mixtures that might be typical of runoff from road surfaces in northern latitudes.

  9. Validation test with embryonic and larval stages of Chordodes nobilii (Gordiida, Nematomorpha): sensitivity to three reference toxicants.

    PubMed

    Achiorno, Cecilia L; de Villalobos, Cristina; Ferrari, Lucrecia

    2010-09-01

    Chordodes nobilii is a parasite whose pre- and postparasitic stages are found in different types of freshwater bodies. Due to the peculiarities of its life cycle, it acts as a link between freshwater bodies and terrestrial ecosystems. There is little toxicological information on the group Gordiida. It is only known that embryos and larvae of C. nobilii are sensitive to glyphosate and malathion at relevant concentrations in the environment. On this basis, the aims of this study were to characterize the sensitivity of the pre-parasitic stages of C. nobilii to three reference toxicants: sodium dodecyl sulfate (SDS), cadmium chloride and potassium dichromate (Cr(6+)), and to validate a previous experimental protocol for ecotoxicological risk assessment. The protocol involved acute exposure of early embryonic stages and larvae to the three toxicants for 96 h and 48 h, respectively. Embryo development was inhibited only by Cr(6+) which presented a IC(50) of 0.71 mg Cr(6+)L(-1). The development of the eggs exposed to SDS and those exposed to cadmium chloride showed no differences as compared to that of controls. However, the infective capacity of larvae derived from the eggs exposed to the three toxicants was lower than that of controls. Larval survival was affected even at the lowest concentration of the three toxicants assayed. In relation to other freshwater organisms, C. nobilii can be characterized as an organism medium to highly sensitive to the toxicants tested.

  10. A new biological test of water toxicity-yeast Saccharomyces cerevisiae conductometric test.

    PubMed

    Dolezalova, Jaroslava; Rumlova, Lubomira

    2014-11-01

    This new biological test of water toxicity is based on monitoring of specific conductivity changes of yeast Saccharomyces cerevisiae suspension as a result of yeast fermentation activity inhibition in toxic conditions. The test was verified on ten substances with various mechanisms of toxic effect and the results were compared with two standard toxicity tests based on Daphnia magna mobility inhibition (EN ISO 6341) and Vibrio fischeri bioluminescence inhibition (EN ISO 11348-2) and with the results of the S. cerevisiae lethal test (Rumlova and Dolezalova, 2012). The new biological test - S. cerevisiae conductometric test - is an express method developed primarily for field conditions. It is applicable in case of need of immediate information about water toxicity. Fast completion is an advantage of this test (time necessary for test completion is about 60min), the test is simple and the test organism - dried instant yeast - belongs among its biggest advantages because of its long-term storage life and broad availability.

  11. The Nicotine-Evoked Locomotor Response: A Behavioral Paradigm for Toxicity Screening in Zebrafish (Danio rerio) Embryos and Eleutheroembryos Exposed to Methylmercury

    PubMed Central

    Mora-Zamorano, Francisco X.; Svoboda, Kurt R.; Carvan, Michael J.

    2016-01-01

    This study is an adaptation of the nicotine-evoked locomotor response (NLR) assay, which was originally utilized for phenotype-based neurotoxicity screening in zebrafish embryos. Zebrafish embryos do not exhibit spontaneous swimming until roughly 4 days post-fertilization (dpf), however, a robust swimming response can be induced as early as 36 hours post-fertilization (hpf) by means of acute nicotine exposure (30–240μM). Here, the NLR was tested as a tool for early detection of locomotor phenotypes in 36, 48 and 72 hpf mutant zebrafish embryos of the non-touch-responsive maco strain; this assay successfully discriminated mutant embryos from their non-mutant siblings. Then, methylmercury (MeHg) was used as a proof-of-concept neurotoxicant to test the effectiveness of the NLR assay as a screening tool in toxicology. The locomotor effects of MeHg were evaluated in 6 dpf wild type eleutheroembryos exposed to waterborne MeHg (0, 0.01, 0.03 and 0.1μM). Afterwards, the NLR assay was tested in 48 hpf embryos subjected to the same MeHg exposure regimes. Embryos exposed to 0.01 and 0.03μM of MeHg exhibited significant increases in locomotion in both scenarios. These findings suggest that similar locomotor phenotypes observed in free swimming fish can be detected as early as 48 hpf, when locomotion is induced with nicotine. PMID:27123921

  12. Economical test methods for developmental neurobehavioral toxicity.

    PubMed Central

    Bignami, G

    1996-01-01

    The assessment of behavioral changes produced by prenatal or early postnatal exposure to potentially noxious agents requires both the designing of ad hoc tests and the adaptation of tests for adult animals to the characteristics of successive developmental stages. The experience in designing tests is still more limited than in the adaptation of tests, but several tests have already proven their usefulness; some examples are the suckling test, the homing test, and evaluations of dam-pup and pup-pup interactions. Functional observational batteries can exploit the development at specified postnatal ages of several reflexes and responses that are absent at birth in altricial rodent species with a short pregnancy such as the rat and the mouse. In neonates, the assessment of early treatment effects can rely not only on deviations from normal responding but also on changes in the time of appearance of otherwise normal response patterns. The same applies to other end points such as responses to pain and various types of spontaneous motor/exploratory activities, including reactivity to a variety of drug challenges that can provide information on the regulatory systems whose development may be affected by early treatments. In particular, the analysis of ontogenetic dissociations (i.e., differential early treatment effects depending jointly on developmental stage at the time of exposure, age of testing, and response end point) can be of considerable value in the study of treatments' mechanisms of action. Overall, it appears that behavioral teratological assessments can be effectively used both proactively, i.e., in risk assessment prior to any human exposure, and reactively. In the latter case, these assessments could have special value in the face of agents suspected to produce borderline changes in developing humans, whose innocuousness or noxiousness can be difficult to establish in the absence of hard evidence of teratogenicity. PMID:9182035

  13. Interpretation of coastal sediment quality based on trace metal and PAH analysis, benthic foraminifera, and toxicity tests (Sardinia, Western Mediterranean).

    PubMed

    Schintu, Marco; Buosi, Carla; Galgani, François; Marrucci, Alessandro; Marras, Barbara; Ibba, Angelo; Cherchi, Antonietta

    2015-05-15

    An integrated approach for the assessment of coastal sediment quality was utilised in three areas of Sardinia (Western Mediterranean, Italy). Sediments were analysed for trace metals and polycyclic aromatic hydrocarbons (PAHs), while benthic foraminifera were used as bioindicators. Furthermore, the embryo-toxicity test was used to provide ecologically relevant information using rapid and cost-effective screening tools. The aim was to evaluate the usefulness of coupling different analytical tools. The results revealed the presence of polluted sediments in areas exposed to petrochemical industries, smelters or military settlements. However, while foraminifera have presented similar indications for chemical analysis of contamination levels in the different areas, the toxicity test exhibited a poor relationship with the contaminants measured individually. The results raise questions concerning the bioavailability of contaminants released by sediments in the water column. Overall, the toxicity rate was significant in many samples in comparison with other sites studied in other Mediterranean regions.

  14. Expression of storm water runoff toxicity in three test organisms

    SciTech Connect

    Katznelson, R.; Markel, R.P.

    1995-12-31

    Storm water toxicity was monitored at numerous locations in the San Francisco Bay Area, using the EPA protocol for short-term chronic toxicity tests with freshwater organisms in the ``screening`` mode. Toxicity to Selenastrum capricomutum and Pimephales promelas was prevalent in samples collected at industrial catchments but was rarely detected in samples collected from other land use catchments. On the other hand, Ceriodaphnia dubia responded in most samples collected from industrial, commercial, residential, and transportation corridor catchments. In further analyses of C. dubia test results, the median time to lethality (LT{sub 50}) was derived to allow comparisons of the relative intensity of toxicity, and the number of offspring per female per reproductive day (OFRD) was calculated to allow separation of mortality from reproductive effects. This approach revealed that most of the moderately toxic (LT{sub 50} of 5--7 days) storm water samples collected from catchments of mixed land use (stream stations) did not inhibit reproduction, and that most storm water samples collected from transportation corridors did inhibit reproduction. Toxicity identification evaluations (TIE) indicated that diazinon is the major cause of toxicity in many stream samples, suggesting an explanation for the differential sensitivity observed in different species.

  15. Freeze concentration of ambient waters for toxicity testing.

    PubMed

    deBruyn, A M; Rasmussen, J B

    2001-08-01

    We have developed a method to concentrate aqueous samples for toxicity testing. This method relies on the phenomenon of freezing exclusion, whereby solutes are rejected from the interstices of a growing ice crystal. Tenfold freeze concentration gave excellent recoveries of inorganic and organic analytes, phenol and ZnSO4 toxicity from spiked natural waters, and toxicity of both pre- and postdischarge municipal wastewater. Simultaneous 10-fold concentration of strong mineral or humic ambient matrices did not substantially modify the expressed toxicity of phenol or ZnSO4, and it did not seem to generate spurious toxicity to the marine bioassay organism used (Vibrio fischeri). Hundredfold freeze concentration permitted the quantification of low levels of ambient toxicity in a wide variety of natural waters using a rapid, inexpensive microbioassay. Precipitation of matrix elements may limit the degree of concentration that can be achieved with highly mineralized or strongly humic waters. This approach is well suited to ambient toxicity testing, because it is nonspecific and has low potential for solvent contamination. Furthermore, the low temperatures involved minimize volatilization and degradation of organic contaminants.

  16. Comparative toxicity of metal oxide nanoparticles (CuO, ZnO and TiO2) to developing zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Vicario-Parés, Unai; Castañaga, Luis; Lacave, Jose Maria; Oron, Miriam; Reip, Paul; Berhanu, Deborah; Valsami-Jones, Eugenia; Cajaraville, Miren P.; Orbea, Amaia

    2014-08-01

    Increasing use of nanomaterials is resulting in their release into the environment, making necessary to determine the toxicity of these materials. With this aim, the effects of CuO, ZnO and TiO2 nanoparticles (NPs) on zebrafish development were assessed in comparison with the effects caused by the ionic forms (for copper and zinc), bulk counterparts and the stabilizer used for rutile TiO2 NPs. None of the NPs caused significant embryo mortality. CuO NPs were the most toxic affecting hatching and increasing malformation prevalence (≥1 mg Cu/L), followed by ZnO NPs that affected hatching at ≥5 mg Zn/L and stabilized TiO2 NPs that caused mortality and decreased hatching at 100 mg Ti/L. Exposure to the stabilizer alone provoked the same effect. Thus, toxicity of the TiO2 NP suspension can be linked to the surfactant. For all the endpoints, the greatest effects were exerted by the ionic forms, followed by the NPs and finally by the bulk compounds. By autometallography, metal-bearing deposits were observed in embryos exposed to CuO and ZnO NPs, being more abundant in the case of embryos exposed to CuO NPs. The largest and most abundant metal-bearing deposits were detected in embryos exposed to ionic copper. In conclusion, metal oxide NPs affected zebrafish development altering hatching and increasing the prevalence of malformations. Thus, the use and release of metal oxide NPs to the environment may pose a risk to aquatic organisms as a result of the toxicity caused by NPs themselves or by the additives used in their production.

  17. Evaluation of alternative reference toxicants for use in the earthworm toxicity test

    SciTech Connect

    Yeardley, R.B. Jr.; Lazorchak, J.M.; Pence, M.A.

    1995-07-01

    The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However, the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants was evaluated. Reference toxicants were rated in relation to the following criteria: (a) reproducibility, (b) low human health hazard, (c) feasibility of measurement, and (d) chemical stability. Potassium chloride (KCl) and ammonium chloride (NH{sub 4}Cl) were evaluated as possible alternatives to the one currently in common use, 2-chloroacetamide. Potassium chloride rated the best for the combination of the four criteria, followed by NH{sub 4}Cl and 2-chloroacetamide. Coefficients of variation (C.V.s) from control charts of six definitive tests were use to measure reproducibility. The best reproducibility (lowest C.V.) was shown by KCl, followed by NH{sub 4}Cl and 2-chloroacetamide. Toxicants ranked KCl < NH{sub 4}Cl {much_lt} 2-chloroacetamide in terms of health hazard; and KCl = NH{sub 4}Cl > 2-chloroacetamide in terms of measurement feasibility. Both 2-chloroacetamide and NH{sub 4}Cl changed in concentration during testing. Evidence is also presented that 2-chloroacetamide degrades rapidly during testing, and that, as dead worms decay, ammonification may be adding another toxicant, ammonia, to tests.

  18. Oral Toxicity Study and Skin Sensitization Test of a Cricket

    PubMed Central

    Ryu, Hyeon Yeol; Lee, Somin; Ahn, Kyu Sup; Kim, Hye Jin; Lee, Sang Sik; Ko, Hyuk Ju; Lee, Jin Kyu; Cho, Myung-Haing; Ahn, Mi Young; Kim, Eun Mi; Lim, Jeong Ho; Song, Kyung Seuk

    2016-01-01

    Crickets have been attracting considerable interest in the field of nutrition and toxicology due to the global exhaustion of food resulting from a growing population. The cricket is normally eaten in several countries after roasting, similar to the grasshopper; however, safety evaluation data on cricket powder is limited. Here, we performed general toxicity studies of cricket powder including a single, 2-week repeated dose range evaluation test, a 13-week repeated oral dose toxicity test in Sprague-Dawley rats, a single oral dose toxicity test in Beagle dogs, and a skin sensitization test in guinea pigs following the Organization for Economic Cooperation and Development test guidelines 406 and 408 in addition to Good Laboratory Practice. To investigate the NOAEL and target organs of cricket powder, Sprague-Dawley rats were allocated to 4 groups: vehicle control, 1,250 mg/kg, 2,500 mg/kg, 5,000 mg/kg dose test groups and cricket powder was administered over 13 weeks after single dose and dose range finding studies in rats based on the results of the single oral administration toxicity study in rats and Beagle dogs. The results of the study showed that the NOAEL of cricket powder was over 5,000 mg/kg for both sexes of rats without adverse effects in a 13-week repeated oral toxicity study and there was no skin hypersensitivity reaction. Therefore, our results reveal that crickets can be widely used as a new substitute food or nutrient resource. PMID:27123167

  19. A COMPARISON OF BULK SEDIMENT TOXICITY TESTING METHODS AND SEDIMENT ELUTRIATE TOXICITY

    EPA Science Inventory

    Bulk sediment toxicity tests are routinely used to assess the level and extent of contamination in natural sediments. While reliable, these tests can be resource intensive, requiring significant outlays of time and materials. The purpose of this study was to compare the results ...

  20. Predictive modeling of developmental toxicity using EPA’s Virtual Embryo

    EPA Science Inventory

    Standard practice in prenatal developmental toxicology involves testing chemicals in pregnant laboratory animals of two species, typically rats and rabbits, exposed during organogenesis and evaluating for fetal growth retardation, structural malformations, and prenatal death just...

  1. Rapid Field Toxicity Test for Water Supplies

    DTIC Science & Technology

    1994-02-28

    four hours to allow toxins to react with the cells, bioluminescent bacteria , and for the cells to regain their ight-producing powers. In 1993, the...chart bioluminescent bacteria . recorder, where it is depicted as a cumulative curve (Fig. 5). Mud testing uses the suspended particulate phase (SPP, Fig...in perfect Correlation with the bioluminescent bacteria assay agreement. Correlation of E50 with LC50 is shown (Fig. 10) is good below an EC50 (half

  2. The influence of time on lead toxicity and bioaccumulation determined by the OECD earthworm toxicity test.

    PubMed

    Davies, Nicola A; Hodson, Mark E; Black, Stuart

    2003-01-01

    Internationally agreed standard protocols for assessing chemical toxicity of contaminants in soil to worms assume that the test soil does not need to equilibrate with the chemical to be tested prior to the addition of the test organisms and that the chemical will exert any toxic effect upon the test organism within 28 days. Three experiments were carried out to investigate these assumptions. The first experiment was a standard toxicity test where lead nitrate was added to a soil in solution to give a range of concentrations. The mortality of the worms and the concentration of lead in the survivors were determined. The LC50s for 14 and 28 days were 5311 and 5395 microgPb g(-1)soil respectively. The second experiment was a timed lead accumulation study with worms cultivated in soil containing either 3000 or 5000 microgPb g(-1)soil. The concentration of lead in the worms was determined at various sampling times. Uptake at both concentrations was linear with time. Worms in the 5000 microg g(-1) soil accumulated lead at a faster rate (3.16 microg Pb g(-1)tissue day(-1)) than those in the 3000 microg g(-1) soil (2.21 microg Pb g(-1)tissue day(-1)). The third experiment was a timed experiment with worms cultivated in soil containing 7000 microgPb g(-1)soil. Soil and lead nitrate solution were mixed and stored at 20 degrees C. Worms were added at various times over a 35-day period. The time to death increased from 23 h, when worms were added directly after the lead was added to the soil, to 67 h when worms were added after the soil had equilibrated with the lead for 35 days. In artificially Pb-amended soils the worms accumulate Pb over the duration of their exposure to the Pb. Thus time limited toxicity tests may be terminated before worm body load has reached a toxic level. This could result in under-estimates of the toxicity of Pb to worms. As the equilibration time of artificially amended Pb-bearing soils increases the bioavailability of Pb decreases. Thus addition of

  3. THE ROLE OF INORGANIC ION IMBALANCE IN AQUATIC TOXICITY TESTING

    EPA Science Inventory

    Effluent toxicity testing methods have been well defined, but to a large part have not attempted to segregate the effects of active ionic concentrations and ion imbalances upon test and species performances. The role that various total dissolved solids in effluents have on regula...

  4. POREWATER CHEMISTRY: EFFECTS OF SAMPLING, STORAGE, HANDLING, AND TOXICITY TESTING

    EPA Science Inventory

    As a general principle, it is nearly impossible to remove a porewater sample from sediment, use it in a toxicity testing vessel with test organisms, and prevent changes in the chemistry of the natural and anthropogenic organic and inorganic constituents. The degree of change in t...

  5. Federal Register: Toxic Substances; 1,2- Dichloropropane; Testing Requirements

    EPA Pesticide Factsheets

    The EPA (also Agency) is issuing a final test rule under section 4(a) of the Toxic Substances (TSCA) that requires manufacturers and processors of 1,2-dichloropropane (DCP CAS Number 78-87—5) to test this chemical.

  6. Development of a Chronic Toxicity Testing Method for Daphnia pulex

    DTIC Science & Technology

    2015-08-01

    11 Addition of 4d old D. pulex to 50 mL beakers for remainder of chronic test to assess survival and reproduction ...15 Reproduction ...protocol was developed specifically for the use of a D. pulex three-brood chronic toxicity test measuring survival and reproduction as endpoints. This

  7. Toxicity of acid-sulphate soil leachate and aluminium to the embryos and larvae of Australian bass (Macquaria novemaculeata) in estuarine water.

    PubMed

    Hyne, R V; Wilson, S P

    1997-01-01

    The toxicity of leachate water from acid-sulphate soil to the early life stages of Australian bass, Macquaria novemaculeata, incubated in seawater was evaluated. Acid-sulphate soil leachate water (pH> or =6.8) delayed the hatching of fertilised eggs, but after 48 h the per cent hatching was normal. In comparison, acidic saline water (25 per thousand salinity) at pH 4.0 or less prevented embryos from hatching. The survival of yolk-sac larvae exposed to acid-sulphate soil leachate water at a concentration of 32% in seawater and an initial pH of 7.2, was significantly different to controls after 96 hours. In corresponding tests with only acidified saline water (20 per thousand salinity), pH levels equal to or below 5.0 killed yolk-sac larvae after 96 h exposure. Aluminum showed a pH dependent toxicity to yolk-sac larvae, with added aluminium as low as 200 microg litre(-1) having a significant effect on larval survival at pH 5.5, and concentrations of 600-800 microg litre(-1) having a significant effect on larval survival at an initial pH range of 6.0 < pH < 6.8. It was concluded that significant mortality of the early life stages of Australian bass would occur if they are exposed to acid-sulphate soil leachate that results in a pH in the receiving estuarine water below 5.5, or when the pH is below 6.8 and aluminium is present at a total concentration of 800 microg litre(-1) or greater.

  8. Results of chronic toxicity tests conducted on selected A-area outfalls, June-August 1996

    SciTech Connect

    Specht, W.L.

    1997-07-01

    In anticipation of possible toxicity testing requirements in the SRS`s new (1996) NPDES permit, toxicity tests were performed at selected A-Area NPDES outfalls in order to determine if the outfalls were toxic. Chronic definitive toxicity tests were conducted on Ceriodaphnia dubia using water collected from nine locations during the summer of 1996. Six of the nine locations were toxic.

  9. Comparison of ethanol toxicity to Daphnia magna and Ceriodaphnia dubia tested at two different temperatures: static acute toxicity test results

    SciTech Connect

    Takahashi, I.T.; Cowgill, U.M.; Murphy, P.G.

    1987-08-01

    Ethanol is a commonly used solvent in toxicity testing, yet there are few studies in the literature devoted to its toxicity to zooplankton. The purpose of this study was to compare the response of Daphnia magna Straus 1820 and Ceriodaphnia dubia J. Richard 1894 to ethanol. Two temperatures were selected because most toxicity data involving D. magna has been carried out at 20/sup 0/C while all discussions concerning C. dubia appear to relate to temperatures oscillating around 25/sup 0/C. Thus, the response of these two organisms to ethanol was examined at 20/sup 0/C and at 24/sup 0/C.r

  10. Acetyl L-carnitine targets adenosine triphosphate synthase in protecting zebrafish embryos from toxicities induced by verapamil and ketamine: An in vivo assessment.

    PubMed

    Guo, Xiaoqing; Dumas, Melanie; Robinson, Bonnie L; Ali, Syed F; Paule, Merle G; Gu, Qiang; Kanungo, Jyotshna

    2017-02-01

    Verapamil is a Ca(2)(+) channel blocker and is highly prescribed as an anti-anginal, antiarrhythmic and antihypertensive drug. Ketamine, an antagonist of the Ca(2)(+) -permeable N-methyl-d-aspartate-type glutamate receptors, is a pediatric anesthetic. Previously we have shown that acetyl l-carnitine (ALCAR) reverses ketamine-induced attenuation of heart rate and neurotoxicity in zebrafish embryos. Here, we used 48 h post-fertilization zebrafish embryos that were exposed to relevant drugs for 2 or 4 h. Heart beat and overall development were monitored in vivo. In 48 h post-fertilization embryos, 2 mm ketamine reduced heart rate in a 2 or 4 h exposure and 0.5 mm ALCAR neutralized this effect. ALCAR could reverse ketamine's effect, possibly through a compensatory mechanism involving extracellular Ca(2)(+) entry through L-type Ca(2)(+) channels that ALCAR is known to activate. Hence, we used verapamil to block the L-type Ca(2)(+) channels. Verapamil was more potent in attenuating heart rate and inducing morphological defects in the embryos compared to ketamine at specific times of exposure. ALCAR reversed cardiotoxicity and developmental toxicity in the embryos exposed to verapamil or verapamil plus ketamine, even in the presence of 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester, an inhibitor of intracellular Ca(2)(+) release suggesting that ALCAR acts via effectors downstream of Ca(2)(+) . In fact, ALCAR's protective effect was blunted by oligomycin A, an inhibitor of adenosine triphosphate synthase that acts downstream of Ca(2)(+) during adenosine triphosphate generation. We have identified, for the first time, using in vivo studies, a downstream effector of ALCAR that is critical in abrogating ketamine- and verapamil-induced developmental toxicities. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  11. Acetyl L-carnitine targets adenosine triphosphate synthase in protecting zebrafish embryos from toxicities induced by verapamil and ketamine: An in vivo assessment

    PubMed Central

    Guo, Xiaoqing; Dumas, Melanie; Robinson, Bonnie L.; Ali, Syed F.; Paule, Merle G.; Gu, Qiang; Kanungo, Jyotshna

    2016-01-01

    Verapamil is a Ca2+ channel blocker and is highly prescribed as an anti-anginal, antiarrhythmic and antihypertensive drug. Ketamine, an antagonist of the Ca2+-permeable N-methyl-D-aspartate-type glutamate receptors, is a pediatric anesthetic. Previously we have shown that acetyl L-carnitine (ALCAR) reverses ketamine-induced attenuation of heart rate and neurotoxicity in zebrafish embryos. Here, we used 48 h post-fertilization zebrafish embryos that were exposed to relevant drugs for 2 or 4 h. Heart beat and overall development were monitored in vivo. In 48 h post-fertilization embryos, 2 mM ketamine reduced heart rate in a 2 or 4 h exposure and 0.5 mM ALCAR neutralized this effect. ALCAR could reverse ketamine’s effect, possibly through a compensatory mechanism involving extracellular Ca2+ entry through L-type Ca2+ channels that ALCAR is known to activate. Hence, we used verapamil to block the L-type Ca2+ channels. Verapamil was more potent in attenuating heart rate and inducing morphological defects in the embryos compared to ketamine at specific times of exposure. ALCAR reversed cardiotoxicity and developmental toxicity in the embryos exposed to verapamil or verapamil plus ketamine, even in the presence of 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester, an inhibitor of intracellular Ca2+ release suggesting that ALCAR acts via effectors downstream of Ca2+. In fact, ALCAR’s protective effect was blunted by oligomycin A, an inhibitor of adenosine triphosphate synthase that acts downstream of Ca2+ during adenosine triphosphate generation. We have identified, for the first time, using in vivo studies, a downstream effector of ALCAR that is critical in abrogating ketamine- and verapamil-induced developmental toxicities. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. PMID:27191126

  12. Baker's yeast assay procedure for testing heavy metal toxicity

    SciTech Connect

    Bitton, G.; Koopman, B.; Wang, H.D.

    1984-01-01

    Baker's yeast (Saccharomyces cerevisiae) is microorganism which is commercially available and sold as packaged dry pellets in any food store at low cost. Studies have been undertaken on the effects of organic xenobiotics as well as heavy metals on yeast metabolism. This type of study has been generally useful in examining the mechanism(s) of chemical toxicity. However, a rapid and quantitative toxicity test using S. cerevisiae as the test organism has not been developed. The purpose of this study was to develop a toxicity assay for heavy metals, using commercial dry yeast as the test microorganism. This rapid and simple procedure is based on the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride (INT) to INT-formazan by the yeast electron transport system. The scoring of active cells following exposure to heavy metals was undertaken according to the MINT (malachite green-INT) method developed by Bitton and Koopman.

  13. In vitro developmental toxicity test detects inhibition of stem cell differentiation by silica nanoparticles

    SciTech Connect

    Park, Margriet V.D.Z. Annema, Wijtske; Salvati, Anna; Lesniak, Anna; Elsaesser, Andreas; Barnes, Clifford; McKerr, George; Howard, C. Vyvyan; Lynch, Iseult; Dawson, Kenneth A.; Piersma, Aldert H.; Jong, Wim H. de

    2009-10-01

    While research into the potential toxic properties of nanomaterials is now increasing, the area of developmental toxicity has remained relatively uninvestigated. The embryonic stem cell test is an in vitro screening assay used to investigate the embryotoxic potential of chemicals by determining their ability to inhibit differentiation of embryonic stem cells into spontaneously contracting cardiomyocytes. Four well characterized silica nanoparticles of various sizes were used to investigate whether nanomaterials are capable of inhibition of differentiation in the embryonic stem cell test. Nanoparticle size distributions and dispersion characteristics were determined before and during incubation in the stem cell culture medium by means of transmission electron microscopy (TEM) and dynamic light scattering. Mouse embryonic stem cells were exposed to silica nanoparticles at concentrations ranging from 1 to 100 {mu}g/ml. The embryonic stem cell test detected a concentration dependent inhibition of differentiation of stem cells into contracting cardiomyocytes by two silica nanoparticles of primary size 10 (TEM 11) and 30 (TEM 34) nm while two other particles of primary size 80 (TEM 34) and 400 (TEM 248) nm had no effect up to the highest concentration tested. Inhibition of differentiation of stem cells occurred below cytotoxic concentrations, indicating a specific effect of the particles on the differentiation of the embryonic stem cells. The impaired differentiation of stem cells by such widely used particles warrants further investigation into the potential of these nanoparticles to migrate into the uterus, placenta and embryo and their possible effects on embryogenesis.

  14. Improved bacterial growth test for rapid water toxicity screening

    SciTech Connect

    Slabbert, J.L.

    1986-10-01

    Bacteria have several attributes which make them attractive as test organisms for the rapid screening of chemical pollution in natural waters. They have relatively short life cycles and, therefore, respond rapidly to environmental change. The degree of toxicity of chemicals to bacteria is normally established by measuring viability or growth. A very sensitive test has been described measuring cell multiplication inhibition of Pseudomonas putida, results being obtained after a 16 h incubation period. Because of their short generation time it is possible, however, that bacteria are capable of manifesting measurable growth within a shorter incubation period. In the present study P. putida was cultured under modified test conditions aiming at an equally sensitive but more rapid growth test. Subsequent to initial tests, using different growth media, a toxicity test procedure was developed which uses a medium with low complexing capacity, a standardized inoculum and a 6 h incubation period.

  15. DEVELOPMENTAL TOXICITY OF METHANOL: PATHOGENESIS IN CD-1 AND C57BL/6J MICE EXPOSED IN WHOLE EMBRYO CULTURE

    EPA Science Inventory

    BACKGROUND: Methanol causes axial skeleton and craniofacial defects in both CD-1 and C57BL/6J mice during gastrulation, but C57BL/6J embryos are more severely affected. We evaluated methanol-induced pathogenesis in CD-1 and C57BL/6J embryos exposed during gastrulation in whole em...

  16. Resolving some practical questions about Daphnia acute toxicity tests

    SciTech Connect

    Barera, Y.; Adams, W.J.

    1981-10-01

    Acute toxicity tests were performed with six age groups of Daphnia magna, ranging from less than or equal to6 h to 216 h, and with five chemicals, selected on the basis of their physical and chemical properties as well as their acute toxicity to D. magna. The age of the daphnids did not significantly alter the 48-h EC/sub 50/ values for the chemicals tested. The maximum difference observed in the 48-h EC/sub 50/ values between the 6-h and 216-h age groups was a factor of 3.9 for linear alkylbenzene sulfonate (LAS). For purposes of standardization, it appears that D. magna up to 48 h of age at the beginning of the test can be used to conduct acute toxicity tests with most chemicals. The results of static acute toxicity tests conducted with butylbenzyl phthalate (BBP) and D. magna in the presence and absence of several commonly used solvents indicate that the acute toxicity of this chemical is not altered by the use of a solvent carrier. The 48-h EC/sub 50/ value for BBP without a solvent was 1.0 mg/L, compared with a range of 1.6 to 2.2 mg/L when acetone, dimethylformamide, ethanol, or triethylene glycol were used as solvent carriers. The acute toxicities of the solvents in the absence of BBP were also determined for D. magna. The values ranged from 9.3 to 52.4 g/L. The results of static acute tests performed with D. magna and BBP in the presence of various concentrations of daphnid foods (algae or trout chow), indicate that the 48-h EC/sub 50/ values increase proportionally with an increase in food concentrations. These results suggest that acute toxicity tests with D. magna should be conducted in the presence of food with chemicals with a high Ksigma if the results are to be used to select the test concentrations for a chronic study with daphnids. The type of food and the concentration used in the acute test should be the same as those used in a chronic test.

  17. Control group response variability in short-term toxicity tests

    SciTech Connect

    Gast, L.C.; Shimp, C.; Wang, Q.; Shukla, R.; Fulk, F.

    1995-12-31

    The US EPA`s National Reference Toxicant Database (NRTDB) has afforded an excellent opportunity to examine and document variability in responses within control groups (i.e. zero concentration of the toxicant.) The NRTDB has compiled acute and chronic reference toxicant test results for eight species and currently contains results for 32 laboratories and generally eight to ten tests for a species within each laboratory. The Ceriodaphnia dubia Survival and Reproduction test and the Pimephales promelas (fathead minnow) Survival and Growth test are the most frequently represented chronic tests with 331 and 144 sets of test data, respectively. For this presentation, Ceriodaphnia dubia reproduction data, expressed as total numbers of young in the test period, and fathead minnow survival and growth data were analyzed using a variance components model. The information regarding the control population is useful in examining the sources of inter and intralaboratory variability of chronic testing. In addition, this control population response variability information will be valuable for characterizing what can be termed as ``practically equivalent responses`` between a control and an effluent. The preliminary analysis indicates considerable between-test variability; however, this variability is not consistent across laboratories. Results of further exploration on this issue will be presented.

  18. Developmental toxicity testing of biopharmaceuticals in nonhuman primates: previous experience and future directions.

    PubMed

    Martin, Pauline L; Weinbauer, Gerhard F

    2010-12-01

    Developmental toxicity studies for pharmaceutical safety testing are designed to evaluate potential adverse effects of drug treatment on pregnancy and on the developing embryo/fetus. Biopharmaceuticals present specific challenges for developmental toxicity testing because the pharmacology of these molecules, which are frequently human-specific proteins, is often restricted to humans and nonhuman primates (NHPs). For those species-restricted molecules, the only option for the evaluation of potential effects on development of the human biopharmaceutical is to use NHPs. This article reviews each of the stages of development in cynomolgus macaques (the most frequently used NHP) and the potential exposure of the embryo, fetus, and infant following administration of a biopharmaceutical during pregnancy and lactation. Because the purpose of the NHP developmental studies is to identify potential human risks, a comparison between macaque and human development and potential exposure has been made when possible. Understanding the potential exposure of the conceptus relative to critical periods in development is essential to designing a scientifically based study that adequately addresses human risks. Some options for NHP study designs, including the option of combining end points into a single study, and the pros and cons of each of the study options have been reviewed. Developmental studies for biopharmaceuticals in NHPs need to be optimally designed on a case-by-case basis taking into consideration the pharmacology of the molecule, the type of molecule (antibody or non-antibody), the potential exposure relative to the development of potential target organs, the clinical use, and the ethical considerations associated with the use of NHPs.

  19. In vitro cytotoxicity testing for prediction of acute human toxicity.

    PubMed

    Barile, F A; Dierickx, P J; Kristen, U

    1994-06-01

    This study was designed to compare the cytotoxic concentrations of chemicals, determined with three independent in vitro cytotoxicity testing protocols, with each other and with established animal LD50 values, and against human toxic concentrations for the same chemicals. Ultimately, these comparisons allow us to evaluate the potential of in vitro cell culture methods for the ability to screen a variety of chemicals for prediction of human toxicity. Each laboratory independently tested 50 chemicals with known human lethal plasma concentrations and LD50 values. Two of the methods used monolayer cell cultures to measure the incorporation of radiolabeled amino acids into newly synthesized proteins and cellular protein content, while the third technique used the pollen tube growth test. The latter is based on the photometric quantification of pollen tube mass production in suspension culture. Experiments were performed in the absence or presence of increasing doses of the test chemical, during an 18- to 24-h incubation. Inhibitory concentrations were extrapolated from concentration-effect curves after linear regression analysis. Comparison of the cytotoxic concentrations confirms previous independent findings that the experimental IC50 values are more accurate predictors of human toxicity than equivalent toxic blood concentrations (HETC values) derived from rodent LD50s. In addition, there were no conclusive statistical differences among the methods. It is anticipated that, together, these procedures can be used as a battery of tests to supplement or replace currently used animal protocols for human risk assessment.

  20. Acute toxicity testing in cultures of mouse neuroblastoma cells.

    PubMed

    Walum, E; Peterson, A

    1983-01-01

    Cultured mouse neuroblastoma cells (C1300) may be used as models for nerve cells since they have a number of properties in common with their normal counterparts in vivo. In order to test the possibility of using C1300 cells as alternative to experimental animals when testing for acute toxicity, cells (clone 41A3) were exposed to a number of common chemicals (CH3HgCl, CdCl2,HgCl2 ppDDT, n-butanol, benzene, dioxan, n-propanol, aceton and t-butanol). The toxic effect was quantified by measuring the degree of cell detachment in the cultures. The concentrations of chemicals that caused 25% of the total cell number to detach (TD25) were used for comparison with LD50 values. In spite of the very simplified situation in culture, where the toxicity of a substance is little or not at all influenced by factors like penetration, storage, metabolism and excretion a good correlation (corr. coeff. 0,98) was obtained between TD25 values and LD50 values. Good correlations between in vitro and in vivo tests have also been reported by others. One possible explanation to these findings could be simplified in vivo toxicokinetics of these substances when tested in high doses for general effects like animal death. If so, simple in vitro tests may be used for predicting acute toxicity of certain groups of substances.

  1. Guidelines for developmental toxicity testing of chemicals in Japan

    SciTech Connect

    Tanimura, T.

    1985-11-01

    With the definition of teratogenicity expanded in terms of the developmental stages when an agent acts and the types of developmental anomalies induced, the concept of developmental toxicity has been established. The examination of functional developmental disorders including behavior has become one of the most important items for the evaluation of developmental toxicity of chemicals, especially pharmaceutical drugs. The guidelines for developmental toxicity testing of drugs in Japan stress the need for examination of growth and development including behavior and fertility on the postweaning offspring. The outline of the Japanese guidelines is presented and it is emphasized that studies should be done as research and include self evaluation of the scientific truth of the experiment and extrapolation to humans. In addition, the activities of the Behavioral Teratology Meeting, a satellite meeting to the Japanese Teratology Society, are introduced and enquete surveys of the Japan Pharmaceutical Manufacturers Association and collaborative studies for the standardization of learning tests in Japan are briefly presented.

  2. Functional toxicology: tools to advance the future of toxicity testing

    PubMed Central

    Gaytán, Brandon D.; Vulpe, Chris D.

    2014-01-01

    The increased presence of chemical contaminants in the environment is an undeniable concern to human health and ecosystems. Historically, by relying heavily upon costly and laborious animal-based toxicity assays, the field of toxicology has often neglected examinations of the cellular and molecular mechanisms of toxicity for the majority of compounds—information that, if available, would strengthen risk assessment analyses. Functional toxicology, where cells or organisms with gene deletions or depleted proteins are used to assess genetic requirements for chemical tolerance, can advance the field of toxicity testing by contributing data regarding chemical mechanisms of toxicity. Functional toxicology can be accomplished using available genetic tools in yeasts, other fungi and bacteria, and eukaryotes of increased complexity, including zebrafish, fruit flies, rodents, and human cell lines. Underscored is the value of using less complex systems such as yeasts to direct further studies in more complex systems such as human cell lines. Functional techniques can yield (1) novel insights into chemical toxicity; (2) pathways and mechanisms deserving of further study; and (3) candidate human toxicant susceptibility or resistance genes. PMID:24847352

  3. Sediment acute toxicity testing utilizing short-term bioassays

    SciTech Connect

    Campbell, M.G.

    1991-01-01

    The purpose of this study was to investigate the usefulness of two new bioassays for acute toxicity assessments of sediments. A bacterial bioassay based on inhibition of alpha-glucosidase biosynthesis in Bacillus licheniformis and a 48-hour lethality bioassay employing the benthic cladoceran, Chydorus sphaericus. were evaluated by direct comparisons with standard bioassays, using sediment samples collected from various sites in Florida. This study showed that the bioassay based on inhibition of alpha-glucosidase biosynthesis in Bacillus licheniformis was useful in the acute toxicity screening of sediment elutriates. In regards to Escambia County, Florida samples, the assay was comparable with the Microtox assay and was especially sensitive for samples containing metals. To determine an appropriate procedure for assessing hydrophobic contaminants of sediments in the B. licheniformis bioassay, two extracting procedures were compared. Based on the responses in the Microtox bioassay, shaking sediment samples in methylene chloride produced extracts that were significantly higher in toxicity than extracts obtained by sonication for eight of the ten sediment samples tested. Comparisons of methanol and dimethyl sulfoxide (DMSO) as exchange solvents revealed that there was generally no significant difference between these solvents in terms of toxicity in the Microtox assay. Solvent extracts prepared by shaking and exchanged into methanol showed lower toxicity in the B. licheniformis bioassay than in the Microtox assay. Observed sediment toxicity in both bioassays was expressed in terms of the equivalent dry weight concentration of sediment causing 50% inhibition of the assay organism.

  4. Comparisons of Sediment Test Volumes for Freshwater Solid Phase Sediment Toxicity Tests

    EPA Science Inventory

    Laboratory tests with benthic macroinvertebrates are commonly used to assess the potential toxicity of contaminated sediments, and detailed standard test procedures have been developed for various species. For freshwater, two benthic organisms, Hyalella azteca and Chironomus dil...

  5. The use of mrp1-deficient (Danio rerio) zebrafish embryos to investigate the role of Mrp1 in the toxicity of cadmium chloride and benzo[a]pyrene.

    PubMed

    Tian, Jingjing; Hu, Jia; Chen, Mingli; Yin, Huancai; Miao, Peng; Bai, Pengli; Yin, Jian

    2017-03-02

    Previous studies in our lab have revealed that both P-glycoprotein (Pgp) and multi-resistance associated protein (Mrp) 1 played important roles in the detoxification of heavy metals and polycyclic aromatic hydrocarbon (PAH) in zebrafish embryos. This paper aims to extend this research by using mrp1-deficient model to illustrate the individual function of Mrp1. In this respect, CRISPR/Cas9 system was employed to generate a frameshift mutation in zebrafish mrp1 causing premature translational stops in Mrp1. Significant reduction on the efflux function of Mrps was found in mutant zebrafish embryos, which correlated well with the significantly enhanced accumulation and toxicity of cadmium chloride (CdCl2) and benzo[a]pyrene (BαP), indicating the protective role of the corresponding protein. The different alteration on the accumulation and toxicity of Cd(2+) and BαP could be attributed to the fact that Cd(2+) and its metabolites were mainly excreted by Mrp1, while BαP was primarily pumped out by Pgp. More importantly, the compensation mechanism for the absence of Mrp1, including elevated glutathione (GSH) level and up-regulated expression of pgp and mrp2 were also found. Thus, mrp1-deficient zebrafish embryo could be a useful tool in the investigation of Mrp1 functions in the early life stages of aquatic organisms. However, compensation mechanism should be taken into consideration in the interpretation of results obtained with mrp1-deficient fish.

  6. Effects of Ru(CO)3Cl-glycinate on the developmental toxicities induced by X-ray and carbon-ion irradiation in zebrafish embryos.

    PubMed

    Zhou, Rong; Song, Jing'e; Si, Jing; Zhang, Hong; Liu, Bin; Gan, Lu; Zhou, Xin; Wang, Yupei; Yan, Junfang; Zhang, Qianjing

    The inhibitory effects of carbon monoxide (CO), generated by Ru(CO)3Cl-glycinate [CO-releasing molecule (CORM-3)], on developmental toxicity in zebrafish embryos induced by ionizing radiation with different linear energy transfer (LET) were studied. Zebrafish embryos at 5h post-fertilization were irradiated with X-ray (low-LET) and carbon-ion (high-LET) with or without pretreatment of CORM-3 1h before irradiation. CORM-3 pre-treatment showed a significant inhibitory effect on X-ray irradiation-induced developmental toxicity, but had little effect on carbon-ion irradiation-induced developmental toxicity. X-ray irradiation-induced significant increase in ROS levels and cell apoptosis could be modified by CORM-3 pretreatment. However, embryos exposed to carbon-ion irradiation showed significantly increase of cell apoptosis without obvious ROS generation, which could not be attenuated by CORM-3 pretreatment. CORM-3 could inhibit apoptosis induced by ionizing radiation with low-LET as an effective ROS scavenger. The expression of pro-apoptotic genes increased significantly after X-ray irradiation, but increased expression was reduced markedly when CORM-3 was applied before irradiation. Moreover, the protein levels of P53 and γ-H2AX increased markedly after X-ray irradiation, which could be modified by the presence of CORM-3. The protective effect of CORM-3 on X-ray irradiation occurred mainly by suppressing ROS generation and DNA damage, and thus inhibiting the activation of P53 and the mitochondrial apoptotic pathway, leading to the attenuation of cell apoptosis and consequently alleviating X-ray irradiation-induced developmental toxicity at lethal and sub-lethal levels.

  7. Scanning respirometer for toxicity tests using micro-organisms

    NASA Astrophysics Data System (ADS)

    Zhang, Min-Quan; Li, Xiang-Ming; Wong, Yuk-Shan; Kwan, FolkYear

    1995-09-01

    A novel respirometer is developed for microbial toxicity tests. The respirometer is based on luminescent quenching of oxygen to measure the concentration of dissolved oxygen in cell vessels and evaluate the toxicity of chemicals by monitoring the effect of toxicants on cell respiration of micro-organisms. The oxygen sensing element is ruthenium complex absorbed on the surface of silica particles followed by immobilizing on a silicone rubber film. The oxygen sensing film is coated on the inner bottom of a transparent cell vessel. A sensing device scanning under the cell vessel is used for remote monitoring of the oxygen concentration inside the cell vessels so that a large number of samples can be handled in one batch. The sensing device includes the excitation light sources and an optical cable connected to a filter and a photomultiplier tube for detecting the luminescence in the cell vessel which can then be related to the dissolved oxygen concentration inside the cell vessel. The movement of the sensing device and data acquisition are controlled by a personal computer. The toxicity of heavy metals to activated sludge, soil bacteria and E. coli were tested using the present device. The scanning respirometer provides a new alternative for fast and large scale screening and monitoring of toxicants using micro-organisms.

  8. The Third FRAME Toxicity Committee: working toward greater implementation of alternatives in toxicity testing.

    PubMed

    Combes, Robert D; Balls, Michael; Bansil, Lee; Barratt, Martin; Bell, David; Botham, Philip; Broadhead, Caren; Clothier, Richard; George, Elizabeth; Fentem, Julia; Jackson, Michael; Indans, Ian; Loizou, George; Navaratnam, Vyra; Pentreath, Victor; Phillips, Barry; Stemplewski, Henry; Stewart, Jane

    2004-06-01

    FRAME (the Fund for the Replacement of Animals in Medical Experiments; http://www. frame.org.uk) is a scientific charity, which has, for over 30 years, been advocating and conducting its own research on the application of the Three Rs (reduction, refinement and replacement) to animal experimentation. FRAME develops and validates scientifically based replacement alternative methods to facilitate their acceptance by scientists and regulators. As part of these activities, FRAME established a FRAME Toxicity Committee in 1979, and a report of its work was published in 1982, and discussed in the proceedings of a subsequent meeting, published in 1983. A Second Toxicity Committee formed in 1988, reported its work in 1990, which was discussed in the proceedings of a subsequent conference, published in 1991. The work of these committees was extremely successful and influential in laying the foundation for later activities in alternatives research. A Third FRAME Toxicity Committee was formed in 1999, since much progress had been achieved in the previous decade, especially with regard to the successful validation of several non-animal replacement methods and the start of their regulatory acceptance. Moreover, some new test methods are on the point of being validated, and many new techniques and discoveries are impacting on toxicity testing. Also, interest in reduction and refinement in toxicology has increased. However, there is considerable scope and need for the further implementation of the Three Rs in toxicity testing, especially due to recent plans for the large-scale testing of high-production volume, hormonally-active and existing chemicals, and the increasing use of transgenic animal models. The new committee comprises 18 experts from industry, academia, animal welfare, legislative and regulatory bodies, with one observer from the UK Government Home Office. The main objective is to review progress made in the application of the Three Rs in the development and safety

  9. Controlling type-1 error rates in whole effluent toxicity testing

    SciTech Connect

    Smith, R.; Johnson, S.C.

    1995-12-31

    A form of variability, called the dose x test interaction, has been found to affect the variability of the mean differences from control in the statistical tests used to evaluate Whole Effluent Toxicity Tests for compliance purposes. Since the dose x test interaction is not included in these statistical tests, the assumed type-1 and type-2 error rates can be incorrect. The accepted type-1 error rate for these tests is 5%. Analysis of over 100 Ceriodaphnia, fathead minnow and sea urchin fertilization tests showed that when the test x dose interaction term was not included in the calculations the type-1 error rate was inflated to as high as 20%. In a compliance setting, this problem may lead to incorrect regulatory decisions. Statistical tests are proposed that properly incorporate the dose x test interaction variance.

  10. Assessment of toxicity test endpoints for freshwater mussel larvae (glochidia).

    PubMed

    Fritts, Andrea K; Barnhart, M Christopher; Bradley, Megan; Liu, Na; Cope, W Gregory; Hammer, Edward; Bringolf, Robert B

    2014-01-01

    The objectives of the present study were to determine if the viability of freshwater mussel larvae (glochidia) is an ecologically relevant endpoint for toxicity tests and to define the appropriate duration of those tests. The authors assessed 1) how viability (the shell closure response to sodium chloride) compares with infectivity (ability to attach to a host fish and successfully metamorphose to the juvenile stage), and 2) the decline of viability and infectivity over time after glochidia were released from female mussels. Glochidia of 7 mussel species were isolated from females, placed in water, and subsampled daily for 2 d to 5 d. Viability, when ≥90%, was generally a good predictor of infectivity; however, when viability was <90%, infectivity was often disproportionately low, especially for glochidia collected near the end of the brooding period. Viability and infectivity declined more rapidly in natural water and sediment compared to reconstituted water. Following 24-h exposure to a toxicant (sodium chloride or copper), infectivity of the viable glochidia did not differ among concentrations of toxicants. The results indicate that viability is a valid proxy for infectivity and an ecologically relevant endpoint for standard toxicity tests with freshwater mussels for any test duration with control viability >90%.

  11. A FIELD VALIDATION OF TWO SEDIMENT-AMPHIPOD TOXICITY TESTS

    EPA Science Inventory

    A field validation study of two sediment-amphipod toxicity tests was conducted using sediment samples collected subtidally in the vicinity of a polycyclic aromatic hydrocarbon (PAH)-contaminated Superfund site in Elliott Bay, WA, USA. Sediment samples were collected at 30 stati...

  12. Development of a Reproductive Toxicity Test Using Xenopus.

    DTIC Science & Technology

    2000-05-01

    of the present study was to develop and validate a reproductive toxicity test using Xenopus laevis which measures effects on gametogenesis...reproductive performance, and development fitness of the progeny. Sexually mature female and male Xenopus laevis were exposed to varying concentrations of

  13. Static renewal tests using Pimephales promelas (fathead minnows). Clinch River-Environmental Restoration Program (CR-ERP) study, ambient water toxicity

    SciTech Connect

    Simbeck, D.J.

    1993-12-31

    Clinch River-Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of October 21--28, 1993. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Due to serious reproduction/embryo abortion problems with the TVA daphnid cultures, TVA conducted tests during this study period using only fathead minnows. Surface water samples were collected by TVA Field Engineering personnel from Poplar Creek Mile 2.9, Mile 4.3, and Mile 5.1 on October 20, 22, and 25. Samples were split and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival or growth) in testing conducted by TVA. Attachments to this report include: Chain of custody forms -- originals; Toxicity test bench sheets and statistical analyses; and Reference toxicant test information.

  14. Toxicity of parathion on embryo and yolk-sac larvae of gilthead seabream (Sparus aurata l.): effects on survival, cholinesterase, and carboxylesterase activity.

    PubMed

    Arufe, M Isabel; Arellano, Juana M; Albendín, Gemma; Sarasquete, Carmen

    2010-12-01

    This study was conducted to examine the acute toxicity of the organophosphorus pesticide (OP) parathion on embryos and yolk-sac larvae of gilthead seabream (Sparus aurata), and to investigate the effects of this compound on cholinesterase and carboxylesterase activity of seabream larvae in the phase of endogenous feeding. The 72-h LC50 for yolk-sac larvae (0.523 mg L⁻¹) was about two-fold lower than the 48-h LC50 for embryos (1.005 mg L⁻¹). Parathion significantly inhibited the activity of ChE and CaE activity in yolk sac larvae but there were not significant differences in the sensitivity of both esterases to parathion as inferred by their 72-h IC50 values. Larvae exposed to parathion for 72 h showed a 70% inhibition of the whole body acetylcholinesterase at approximately the LC50.

  15. Joint toxic actions of organic flocculating polymers: Impact on Whole Effluent Toxicity testing. Part 3

    SciTech Connect

    Fort, D.J.; Stover, E.L.

    1996-11-01

    Most states and/or US Environmental Protection Agency (EPA) regions have adopted narrative water quality criteria requiring various forms of Whole Effluent Toxicity (WET) testing as a component of the National Pollutant Discharge Elimination System (NPDES) discharge criteria. Because polymers and inorganic coagulant aids are commonly used in conjunction with one another for wastewater treatment, an assessment of potential interactions between the two types of additives was warranted. Thus, joint-compound interaction studies with both the polymer and FeCl{sub 3} or Al{sub 2}(SO{sub 4}){sub 3} were conducted to determine the effect of co-treatment on WET. Results from these studies clearly demonstrated that the toxicity of these additives during combined treatment was much more dramatic than for each compound individually and that individual toxic assessment would not account for the total magnitude of toxicity induced during combined treatment. Combinations of flocculating polymers with different physical/chemical characteristics (i.e., chemical structure, molecular weight, hydrophobicity, molar refractivity, and charge density) are also commonly used in wastewater treatment. Thus, joint-polymer action studies with several polymer mixtures were performed. Polymers used in these studies included cationic polyquaternary amine (PQA), cationic epichlorohydrin/dimethylamine (EPI/DMA), anionic polyacrylamide (A-PAM), and non-ionic polyacrylamide (N-PAM) polymers. Results from these studies are presented in this manuscript. Overall, results from these studies indicated that the type of polymer mixture was important in determining the joint toxic actions of the flocculating polymers.

  16. When can embryos learn? A test of the timing of learning in embryonic amphibians.

    PubMed

    Sehr, Evie K; Beasley, Lindsay N; Wilson, Kurtis W; Gall, Brian G

    2016-04-01

    Learning is crucial to the survival of organisms across their life span, including during embryonic development. We set out to determine when learning becomes possible in amphibian development by exposing spotted salamander (Ambystoma maculatum) embryos to chemical stimuli from a predator (Ambystoma opacum), nonpredator (Lithobates clamitans), or control at developmental stages 16-21 or 36-38 (Harrison 1969). Once exposures were completed and embryos hatched, we recorded the number of movements and time spent moving of individuals in both groups and all treatments. There was no significant difference in number of movements or time spent moving among any of the treatments. The groups that were exposed to predator stimuli and a blank control at stages 36-38 were also tested to determine whether there was a difference in refuge preference or difference in survivorship when exposed to a predator (marbled salamander). There was no difference in survival or refuge preference between individuals; however, all individuals preferred vegetated over open areas regardless of treatment type. We discuss hypotheses for the absence of embryonic learning in this species and suggest it may be the result of the intensity of the predator-prey interaction between the predator, large marbled salamander larvae, and the prey, spotted salamander larvae.

  17. Construction and test of an artificial uterus for ex situ development of shark embryos.

    PubMed

    Nick, Otway; Megan, Ellis

    2012-01-01

    An artificial uterus (AU) was constructed from clear and opaque acrylic and life-support and monitoring systems were attached. The dwarf ornate wobbegong shark (Orectolobus ornatus) was used to test the AU because recent research has shown that during pregnancy the uterine fluid composition changes with mid- to late-term embryos immersed in seawater. An artificial uterine fluid comprising filtered, autoclaved seawater was placed in the AU. Eight, sexually mature female O. ornatus were captured from the wild and held in captivity. Subsequent ultrasound examinations confirmed pregnancy in three of these females. Six late-term embryos (three males and three females) were removed surgically from one euthanized female and placed in the AU. Their condition was monitored for 18 days before "birth" on September 26, 2008. The subsequent survival and growth of the AU pups was compared with naturally born wobbegong pups in captivity over a 140-day monitoring period. The development in the AU did not have detrimental effects as there was no postpartum mortality and there were marked increases in total length and weight that did not differ significantly between the two groups.

  18. The impact of toxicity testing costs on nanomaterial regulation.

    PubMed

    Choi, Jae-Young; Ramachandran, Gurumurthy; Kandlikar, Milind

    2009-05-01

    Information about the toxicity of nanoparticles is important in determining how nanoparticles will be regulated. In the U.S., the burden of collecting this information and conducting risk assessment is placed on regulatory agencies without the budgetary means to carry out this mandate. In this paper, we analyze the impact of testing costs on society's ability to gather information about nanoparticle toxicity and whether such costs can reasonably be borne by an emerging industry. We show for the United States that costs for testing existing nanoparticles ranges from $249 million for optimistic assumptions about nanoparticle hazards (i.e., they are primarily safe and mainly require simpler screening assays) to $1.18 billion for a more comprehensive precautionary approach (i.e., all nanomaterials require long-term in vivo testing). At midlevel estimates of total corporate R&D spending, and assuming plausible levels of spending on hazard testing, the time taken to complete testing is likely to be very high (34-53 years) if all existing nanomaterials are to be thoroughly tested. These delays will only increase with time as new nanomaterials are introduced. The delays are considerably less if less-stringent yet risk-averse perspectives are used. Our results support a tiered risk-assessment strategy similar to the EU's REACH legislation for regulating toxic chemicals.

  19. Indicators of Ceriodaphnia dubia chronic toxicity test performance and sensitivity

    SciTech Connect

    Rosebrock, M.M.; Bedwell, N.J.; Ausley, L.W.

    1994-12-31

    The North Carolina Division of Environmental Management has begun evaluation of the sensitivity of test results used for measuring chronic whole effluent toxicity in North Carolina wastewater discharges. Approximately 67% of 565 facilities required to monitor toxicity by an NPDES permit perform a Ceriodaphnia dubia chronic, single effluent concentration (pass/fail) analysis. Data from valid Ceriodaphnia dubia chronic pass/fail tests performed by approximately 20 certified biological laboratories and submitted by North Carolina NPDES permittees were recorded beginning January 1992. Control and treatment reproduction data from over 2,500 tests submitted since 1992 were analyzed to determine the minimum significant difference (MSD) at a 99% confidence level for each test and the percent reduction from the control mean that the MSD represents (%MSD) for each certified laboratory. Initial results for the 20 laboratories indicate that the average intralaboratory percent MSD ranges 12.72% (n = 367) to 34.91% (n = 7) with an average of 23.08%. Additionally, over 3,800 tests were analyzed to determine the coefficient of variation (CV) for control reproduction for each test and the average for each certified biological laboratory. Preliminary review indicates that average interlaboratory control reproduction CV values range from 10.59% (n = 367) to 31.08% (n = 572) with a mean of 20.35%. The statistics investigated are indicators of intra/interlaboratory performance and sensitivity of Ceriodaphnia chronic toxicity analyses.

  20. EP-toxicity testing of mercury removal resin grout

    SciTech Connect

    Mersman, K.E.

    1984-07-18

    To determine which category a waste will fit into, the EPA requires a classification test. The test, EP-toxicity, consists of a physical integrity test followed by an extraction. For the case of the mercury removal resin grout, the mercury concentration in the extract cannot exceed 0.2 mg/L if the waste is to be classified as ``solid waste.`` Otherwise, the waste is classified as ``hazardous.`` Simulated process solutions were used to load the mercury removal resin. The resin was solidified with the addition of cement and water using a formulation based on grout formulations typically used to solidify power reactor ion exchange resins. Envirodyne Engineers of St. Louis, Missouri, an EPA sanctioned laboratory, performed the EP-toxicity test for the two samples. One sample was a blank which was made with unloaded resin. For the formulation tested, the EP-toxicity test results showed that the mercury removal resin grout does not fit into the ``hazardous waste`` category.

  1. An evaluation of the whole effluent toxicity test method

    SciTech Connect

    Osteen, D.V.

    1999-12-17

    Whole effluent toxicity (WET) testing has become increasingly more important to the Environmental Protection Agency (EPA) and the States in the permitting of wastewater discharges from industry and municipalities. The primary purpose of the WET test is to protect aquatic life by predicting the effect of an effluent on the receiving stream. However, there are both scientific and regulatory concerns that using WET tests to regulate industrial effluents may result in either false positives and/or false negatives. In order to realistically predict the effect of an effluent on the receiving stream, the test should be as representative as possible of the conditions in the receiving stream. Studies (Rand and Petrocelli 1985) suggested several criteria for an ideal aquatic toxicity test organism, one of which is that the organism be indigenous to, or representative of, the ecosystem receiving the effluent. The other component needed in the development of a predictive test is the use of the receiving stream water or similar synthetic water as the control and dilution water in the test method. Use of an indigenous species and receiving water in the test should help reduce the variability in the method and allow the test to predict the effect of the effluent on the receiving stream. The experience with toxicity testing at the Savannah River Site (SRS) has yielded inconclusive data because of the inconsistency and unreliability of the results. The SRS contention is that the WET method in its present form does not adequately mimic actual biological/chemical conditions of the receiving streams and is neither reasonable nor accurate. This paper discusses the rationale for such a position by SRS on toxicity testing in terms of historical permitting requirements, outfall effluent test results, standard test method evaluation, scientific review of alternate test species, and concerns over the test method expressed by other organizations. This paper presents the Savannah River Site

  2. COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES

    EPA Science Inventory

    The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

  3. Sun light mediated synthesis of gold nanoparticles as carrier for 6-mercaptopurine: Preparation, characterization and toxicity studies in zebrafish embryo model

    SciTech Connect

    Ganeshkumar, Moorthy; Sastry, Thotapalli Parvathaleswara; Sathish Kumar, Muniram; Dinesh, Murugan Girija; Kannappan, Sudalyandi; Suguna, Lonchin

    2012-09-15

    Highlights: ► Gold nanoparticles prepared using eco-friendly method with good in vitro stability. ► Can be used as drug delivery system. ► Did not show any toxicity in zebrafish embryo. ► More toxic to cancer cells when compared to N-Au-Mp and Mp. -- Abstract: The objective of this study is to synthesize green chemistry based gold nanoparticles by sun light irradiation method. The prepared gold nanoparticles (AuNPs) were modified using folic acid and then coupled with 6-mercaptopurine. These modified nanoparticles were used as a tool for targeted drug delivery to treat laryngeal cancer. In the present study, novel bionanocomposites containing nutrient agar coated gold nano particles (N-AuNPs) coupled with 6-mercaptopurine (drug) (N-AuNPs-Mp), folic acid (ligand) (N-AuNPs-Mp-Fa) and rhodamine (dye) (N-AuNPs-Rd), a fluorescent agent, were prepared and characterized by IR, UV, TEM, Particle size analysis and in vitro stability. The toxicity and fluorescence of N-Au was studied using zebrafish embryo model. The in vitro cytotoxicity of free Mp, N-Au-Mp and N-Au-Mp-Fa against HEp-2 cells was compared and found that the amount of Mp required to achieve 50% of growth of inhibition (IC{sub 50}) was much lower in N-Au-Mp-Fa than in free Mp and N-Au-Mp.

  4. Use of neomysis mercedis (crustacea: mysidacea) for estuarine toxicity tests

    SciTech Connect

    Brandt, O.M.; Fujimura, R.W.; Finlayson, B.J. )

    1993-03-01

    The mysid Neomysis mercedis was examined as a test organism for use in acute toxicity tests at intermediate salinities characteristic of estuarine waters. Several sensitive invertebrate species are available for marine assessments (mysids) and freshwater tests (cladocerans), but few are available for estuarine toxicity tests. Observations in the laboratory indicate that Neomysis mercedis can be reared successfully at a temperature of 17[degrees]C, a salinity of 2%, and a population density less than 5/L. Brine shrimp nauplii Artemia salina, algae, and commercial foods were used to sustain mysid cultures. Neomysis mercedis is vivaparous and can complete its life cycle in 3-4 months. Neomysis mercedis is as sensitive as or more sensitive to toxicants than the marine mysid Mysidopsis bahia and the freshwater cladocerans Daphnia magna, Ceriodaphnia dubia, and Simocephalus serrulatus. The mean 96-h LC50 values (concentrations lethal to half the test animals) for N. mercedis, in increasing order, were 0.20 [mu]g/L for thiobencarb, and for malathion, 14 [mu]g/L for carbofuran, 150 [mu]g/L for copper sulfate, 280 [mu]g/L for thiobencarb, and 1,600 [mu]g/L for molinate. Neonates (5 d postrelease) were generally more sensitive than older juveniles. Coefficients of variation (100[center dot]SD/mean) of LC50 values varied from 21 to 35%. 37 refs., 2 figs., 7 tabs.

  5. Prospects for the development of validated screening tests that measure developmental toxicity potential: view of one skeptic.

    PubMed

    Mirkes, P E

    1996-06-01

    Humans are exposed to a variety of potential developmental toxicants. This fact, combined with the knowledge that human development can be disrupted by "environmental" agents, has led to the development of methods designed to identify potential developmental toxicants. Currently, the principal method used to screen drugs and chemicals that are potential human developmental toxicants is the segment II study (i.e., a study in which prospective drugs and chemicals are tested in pregnant animals). Because of the cost and time involved in such studies and the pressure to reduce the number of animals used in such testing, alternative methods for developmental toxicity testing have been sought. This has resulted in a number of in vitro tests whose aim is to screen large numbers of agents quickly and inexpensively. Although numerous in vitro tests of developmental toxicity have been developed during the last 15 years, no one system or combination of tests have been validated for the purpose intended. Nonetheless, two systems--the limb bud/CNS micromass, and the chick embryo neural retina cell culture (CERC)--continue to be advanced as viable in vitro developmental toxicology tests. The purpose of this commentary is to evaluate the prospects for the development of an in vitro test system(s) that can screen the universe of drugs and chemicals and reliably identify those that require further study and those that do not. The conclusion of this investigator is that the prospects for validating such in vitro tests are not promising. This conclusion is based primarily on the lack of basic knowledge regarding the relevance of end points assayed in the micromass and CERC test systems to those end points known or thought to be critical for normal development.

  6. Effect of test conditions on relative toxicity rankings of fifteen materials

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Fifteen materials were evaluated for relative toxicity of pyrolysis effluents, using different test conditions in the USF methodology. Wool fabrics were consistently among the most toxic materials, and polystyrene and polychloroprene flexible foam were consistently among the least toxic materials.

  7. Using transgenic Caenorhabditis elegans in soil toxicity testing.

    PubMed

    Graves, Amber L; Boyd, Windy A; Williams, Phillip L

    2005-05-01

    Soil bioassays are important tools for evaluating toxicological effects within the terrestrial environment. The American Society for Testing and Materials E2172-01 Standard Guide outlines a method for conducting laboratory soil toxicity tests using the nematode Caenorhabditis elegans. This method is an efficient tool for extracting C. elegans from soil samples and can be carried out after a 24-h exposure period using relatively small amounts of soil. Drawbacks of this method include problems with (1) recovery of nematodes from soils containing a high percentage of organic matter, and (2) distinguishing indigenous nematode species from nematodes added for the laboratory test. Due in part to these issues, C. elegans has not been extensively accepted for use in soil testing. To address these concerns and improve upon the American Society for Testing and Materials method, this project focused on using transgenic strains of C. elegans carrying a GFP-expressing element. Lethality and behavior tests revealed that the transgenic nematodes respond similarly to the wild-type N2 strain, indicating that they can be used in the same manner in soil testing. The GFP marker is easily identifiable not only within soils containing a large amount of organic matter, but also in field-collected soils containing indigenous nematodes. These results support the use of transgenic GFP C. elegans in soil bioassays as a tool to further the reliability of laboratory toxicity tests.

  8. In situ toxicity testing with locally collected Daphnia

    SciTech Connect

    Snyder-Conn, E.

    1993-07-01

    Daphnia middlendorffiana from local tundra ponds were transplanted into five reserve pits (sumps with used drilling wastes and precipitation) at drill sites in the Prudhoe Bay oil field. Concurrently, Daphnia were transplanted into tundra ponds adjacent to the reserve pits (near ponds), into more distant but connected ponds (distant ponds), and into control ponds to evaluate the toxicity of the fluids along contaminant gradients. Twenty adult Daphnia were placed in eight waxed flow-through containers and exposed to the conditions of each test site. In each exposure container, the ratios of the number of dead Daphnia to the total number of adult Daphnia, the number of young Daphnia to the total number of adult Daphnia, the number of molting Daphnia to the total number of adult Daphnia, and the number of released ephippia to the total number of adult Daphnia were determined. The results not only indicate the utility of in situ testing of invertebrate toxicity but suggest that under certain conditions in situ tests may be more sensitive than traditional laboratory toxicity tests.

  9. Toxicity testing and instream biological monitoring in evaluating municipal effluents

    SciTech Connect

    Krier, K.; Pontasch, K.

    1995-12-31

    Twelve streams receiving municipal wastewater treatment plant effluents were evaluated in riffle areas above and below the outfall using the Environmental Protection Agency`s Rapid Bioassessment Protocols (RBPs) for benthic macroinvertebrates. Eight of the sites evaluated using RBP 1 exhibited stream health in the downstream riffles equaling or exceeding the upstream riffles. RBP 1 results suggested possible impacts at the remaining four sites, and these sites were more intensely evaluated using RBPs 2 and 3, acute effluent toxicity tests with Daphnia magna, and quantification of periphytic chlorophyll a and ash free dry weight (AFDW). Results from RBP 2 indicated three of the four sites evaluated have similar taxonomic richness above and below the outfall, while one site is heavily impacted by organic pollutants. Toxicity tests with 100% effluent resulted in no mortality with any of the four effluents tested. Relative to the respective upstream sites, chlorophyll a was significantly increased at one downstream site and significantly reduced at another. AFDW was similar above and below the outfalls in all streams. These results suggest that laboratory toxicity tests may not always be adequate predictors of instream biological effects.

  10. Antioxidant, Antimicrobial Activity and Toxicity Test of Pilea microphylla

    PubMed Central

    Modarresi Chahardehi, Amir; Ibrahim, Darah; Fariza Sulaiman, Shaida

    2010-01-01

    A total of 9 plant extracts were tested, using two different kinds of extracting methods to evaluate the antioxidant and antimicrobial activities from Pilea microphylla (Urticaceae family) and including toxicity test. Antioxidant activity were tested by using DPPH free radical scavenging, also total phenolic contents and total flavonoid contents were determined. Toxicity assay carried out by using brine shrimps. Methanol extract of method I (ME I) showed the highest antioxidant activity at 69.51 ± 1.03. Chloroform extract of method I (CE I) showed the highest total phenolic contents at 72.10 ± 0.71 and chloroform extract of method II (CE II) showed the highest total flavonoid contents at 60.14 ± 0.33. The antimicrobial activity of Pilea microphylla extract was tested in vitro by using disc diffusion method and minimum inhibitory concentration (MIC). The Pilea microphylla extract showed antibacterial activity against some Gram negative and positive bacteria. The extracts did not exhibit antifungal and antiyeast activity. The hexane extract of method I (HE I) was not toxic against brine shrimp (LC50 value was 3880 μg/ml). Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in food industry. PMID:20652052

  11. Non-animal Replacements for Acute Toxicity Testing.

    PubMed

    Barker-Treasure, Carol; Coll, Kevin; Belot, Nathalie; Longmore, Chris; Bygrave, Karl; Avey, Suzanne; Clothier, Richard

    2015-07-01

    Current approaches to predicting adverse effects in humans from acute toxic exposure to cosmetic ingredients still heavily necessitate the use of animals under EU legislation, particularly in the context of the REACH system, when cosmetic ingredients are also destined for use in other industries. These include the LD50 test, the Up-and-Down Procedure and the Fixed Dose Procedure, which are regarded as having notable scientific deficiencies and low transferability to humans. By expanding on previous in vitro tests, such as the animal cell-based 3T3 Neutral Red Uptake (NRU) assay, this project aims to develop a truly animal-free predictive test for the acute toxicity of cosmetic ingredients in humans, by using human-derived cells and a prediction model that does not rely on animal data. The project, funded by Innovate UK, will incorporate the NRU assay with human dermal fibroblasts in animal product-free culture, to generate an in vitro protocol that can be validated as an accepted replacement for the currently available in vivo tests. To date, the project has successfully completed an assessment of the robustness and reproducibility of the method, by using sodium lauryl sulphate (SLS) as a positive control, and displaying analogous results to those of the original studies with mouse 3T3 cells. Currently, the testing of five known ingredients from key groups (a surfactant, a preservative, a fragrance, a colour and an emulsifier) is under way. The testing consists of initial range-finding runs followed by three valid runs of a main experiment with the appropriate concentration ranges, to generate IC50 values. Expanded blind trials of 20 ingredients will follow. Early results indicate that this human cell-based test holds the potential to replace aspects of in vivo animal acute toxicity testing, particularly with reference to cosmetic ingredients.

  12. Hyalella IQ Toxicity Test{trademark} as a predictor of whole sediment toxicity with diversely contaminated sediments

    SciTech Connect

    Douglas, W.S.; Hayes, K.R.

    1994-12-31

    The IQ TOXICITY TEST{trademark} is a toxicity screening test that evaluates the organism`s galactosidase enzyme system functionality as a predictor of acute toxicity. Organisms are exposed to a potentially toxic solution for approximately one hour. Following the exposure, the organisms are exposed to a slurry of a galactoside sugar tagged with a fluorescent marker (methylumbelliferyl galactoside) for 15--20 minutes. A black light can then be used to examine whether the hemolymph of the organism contains free umbelliferone, which brightly fluoresces. The organisms are then scored as ``on`` or ``off`` with respect to free umbelliferone. This endpoint can then be used to calculate an EC50, which is comparable to a whole effluent, pure compound, or sediment toxicity test. Slightly different methodologies are used for different toxicity test organisms. The objective of this presentation is to discuss the use of the IQ{trademark} methodology with porewater extract exposures of the amphipod Hyalella azteca as a predictor of results of whole sediment toxicity tests. The results of over thirty 10 and 28-day whole sediment toxicity tests and the concurrent Hyalella azteca 10 TOXICITY TESTS{trademark} are compared and discussed. The use of screening tests as a reduced cost method for initial site assessment will be discussed.

  13. Technical considerations regarding toxicity testing of commercial bioremediation agents

    SciTech Connect

    Bidwell, J.R.; Cavender, R.C.; Cherry, D.S.; Merski, A.T.; Cianciarulo, F.L.

    1995-12-31

    The toxicological evaluation of commercial bioremediation agents (CBAs) for use on oil spills is under consideration by the USEPA. Currently, acute and chronic bioassays are conducted with the CBA alone and with CBA that has been diluted with the water soluble fraction (WSF) of a crude oil. Endpoints are expressed as a concentration of the CBA. This approach may not address the toxicological issue of CBA use since it (1) does not determine if the CBA affects toxicity of the oil itself, and (2) does not consider temporal aspects associated with byproducts of oil degradation. The present study was conducted to address these issues. A CBA was mixed with unweathered crude oil from 1 to 42 days. The WSF of the mixture was then drawn off and acute bioassays were conducted with silverside minnows, Menidia beryllina, and mysid shrimp, Mysidopsis bahia. For silversides, 96-hr LC50 values ranged from 42.7% WSF after 1 day mixing to 10.5% after 42 days. Toxicity increased sharply between days 4 and 7 when the 96-hr LC50 dropped from 39.0 to 18.2% WSF. A similar trend occurred for mysid shrimp. The presence of the CBA caused a more rapid increase in the toxicity of the oil as compared to bioassays in which oil was mixed alone and then tested. These data indicate that the interaction of CBAs with oil, and associated temporal trends in toxicity, are important aspects to consider in hazard evaluation of these products. The current proposed CBA toxicity testing protocol does not effectively address these issues.

  14. Sperm DNA integrity testing: big halo is a good predictor of embryo quality and pregnancy after conventional IVF.

    PubMed

    Tandara, M; Bajić, A; Tandara, L; Bilić-Zulle, L; Šunj, M; Kozina, V; Goluža, T; Jukić, M

    2014-09-01

    Sperm DNA integrity is a sperm functional parameter of male fertility evaluation. Two parameters of sperm DNA integrity were observed: DNA damage expressed as DNA fragmentation index (DFI) and percentage of the DNA undamaged spermatozoa expressed as big halo. Halosperm test was used for sperm DNA integrity determination. The aim of this study was to evaluate which DNA integrity parameter is better as an embryo quality and pregnancy prognostic parameter after the conventional IVF. We evaluated two embryo groups (positive and negative group) according to the 3rd day cumulative embryo score. Big halo and DFI, as we expected, showed good correlation (r = -0.69; p < 0.001). Receiver operating characteristic (ROC) analyses show that DFI and big halo are significant (p < 0.001) as prognostic parameters of embryo quality. ROC curves comparison of DFI and big halo revealed the AUC value for big halo to be significantly higher (DFI AUC = 0.71 vs. big halo AUC = 0.83; p = 0.025) than for DFI. Big halo was found to be the only independent predictor of embryo quality. Sperm DNA integrity both parameters are good prognostic parameters of embryo quality after the conventional IVF where big halo seems to be better. ROC analyses show DFI and big halo as significant prognostic parameters for achieved pregnancy (AUC ± SE for DFI was 0.67 ± 0.06 and 0.75 ± 0.06 for big halo). To our knowledge, this is the first study demonstrating the correlation between sperm DNA undamaged rate expressed as big halo parameter and semen characteristics as well as the influence on fertilization rate, embryo quality and pregnancy in conventional IVF.

  15. Improving the reliability of aquatic toxicity testing of hydrophobic chemicals via equilibrium passive dosing - A multiple trophic level case study on bromochlorophene.

    PubMed

    Stibany, Felix; Ewald, Franziska; Miller, Ina; Hollert, Henner; Schäffer, Andreas

    2017-01-28

    The main objective of the present study was to improve the reliability and practicability of aquatic toxicity testing of hydrophobic chemicals based upon the model substance bromochlorophene (BCP). Therefore, we adapted a passive dosing format to test the toxicity of BCP at different concentrations and in multiple test systems with aquatic organisms of various trophic levels. At the same time, the method allowed for the accurate determination of exposure concentrations (i.e., in the presence of exposed organisms; Ctest) and freely dissolved concentrations (i.e., without organisms present; Cfree) of BCP in all tested media. We report on the joint adaptation of three ecotoxicity tests - algal growth inhibition, Daphnia magna immobilization, and fish-embryo toxicity - to a silicone O-ring based equilibrium passive dosing format. Effect concentrations derived by passive dosing methods were compared with corresponding effect concentrations derived by standard co-solvent setups. The passive dosing format led to EC50-values in the lower μgL(-1) range for algae, daphnids, and fish embryos, whereas increased effect concentrations were measured in the co-solvent setups for algae and daphnids. This effect once more shows that passive dosing might offer advantages over standard methods like co-solvent setups when it comes to a reliable risk assessment of hydrophobic substances. The presented passive dosing setup offers a facilitated, practical, and repeatable way to test hydrophobic chemicals on their toxicity to aquatic organisms, and is an ideal basis for the detailed investigation of this important group of chemicals.

  16. Applicability of subchronic toxicity test with Hyalella azteca for toxicity identification evaluation programs

    SciTech Connect

    Putt, A.E.; Jop, K.M.

    1995-12-31

    A series of screening tests including the short-term chronic exposure of Ceriodaphnia dubia to sediment pore waters, 10-day exposures of Chironomus tentans and Hyalella azteca to bulk sediments and a bioaccumulation study with Lumbriculus variegatus were performed as part of an ecological risk assessment of Plow Shop Pond, Fort Devens, Massachusetts. Chronic endpoints such as reproduction and growth indicated sediment toxicity, however, a toxicity identification evaluation program was initiated to further define the source and extent of the toxicity. A short-term chronic exposure with C. dubia was a logical choice for the TIE, however, since amphipods are epibenthic organisms, they are a better surrogate of sediment dwelling organisms than a water column species such as C. dubia. Observations performed during H. azteca culture suggested that this species of amphipod could thrive in the water column for up to three weeks. Therefore, 7-day old H. azteca were exposed to pore water samples under static-renewal conditions for 10 days. Survival and growth (i.e., dry weight) were determined at the termination of each exposure. Laboratory control group performance consistently averaged a {>=}90% survival and {>=}43 {micro}g of dry weight per amphipod. Growth of amphipods used in each exposure generally exceeded two times the initial body weight after 10 days of exposure. Previous studies have indicated that the growth and reproductive response of H. azteca are positively correlated for a given set of exposure conditions. The results of these 10-day subchronic exposures with H. azteca provide a consistent and reliable measure of the chronic sediment toxicity with a benthic invertebrate for toxicity identification evaluation programs.

  17. Developmental toxicity, EROD, and CYP1A mRNA expression in zebrafish embryos exposed to dioxin-like PCB126.

    PubMed

    Liu, Han; Nie, Fang-Hong; Lin, Hong-Ying; Ma, Yi; Ju, Xiang-Hong; Chen, Jin-Jun; Gooneratne, Ravi

    2016-02-01

    Dioxin-like PCB126 is a persistent organic pollutant that causes a range of syndromes including developmental toxicity. Dioxins have a high affinity for aryl hydrocarbon receptor (AhR) and induce cytochrome P4501A (CYP1A). However, the role of CYP1A activity in developmental toxicity is less clear. To better understand dioxin induced developmental toxicity, we exposed zebrafish (Danio rerio) embryos to PCB126 at concentrations of 0, 16, 32, 64, and 128 μg L(-1) from 3-h post-fertilization (hpf) to 168 hpf. The embryonic survival rate decreased at 144 and 168 hpf. The fry at 96 hpf displayed gross developmental malformations, including pericardial and yolk sac edema, spinal curvature, abnormal lower jaw growth, and non-inflated swim bladder. The pericardial and yolk sac edema rate significantly increased and the heart rate declined from 96 hpf compared with the controls. PCB126 did not alter the hatching rate. To elucidate the mechanism of PCB126-induced developmental toxicity, we conducted ethoxyresorufin-O-deethylase (EROD) in vivo assay to determine CYP1A enzyme activity, and real-time PCR to study the induction of CYP1A mRNA gene expression in embryo/larval zebrafish at 24, 72, 96, and 132 hpf. In vivo EROD activity was induced by PCB126 at 16 μg L(-1) concentration as early as 72 hpf but significant increases were observed only in zebrafish exposed to 64 and 128 μg L(-1) doses (p < 0.005) at 72, 96, and 132 hpf. Induction of CYP1A mRNA expression was significantly upregulated in zebrafish exposed to 32 and 64 μg L(-1) at 24, 72, 96, and 132 hpf. Overall, the severe pericardial and yolk sac edema and reduced heart rate suggest that heart defects are a sensitive endpoint, and the general trend of dose-dependent increase in EROD activity and induction of CYP1A mRNA gene expression provide evidence that the developmental toxicity of PCB126 to zebrafish embryos is mediated by activation of AhR.

  18. Using single-species toxicity tests, community-level responses, and toxicity identification evaluations to investigate effluent impacts

    SciTech Connect

    Maltby, L.; Clayton, S.A.; Yu, H.; McLoughlin, N.; Wood, R.M.; Yin, D.

    2000-01-01

    Whole effluent toxicity (WET) tests are increasingly used to monitor compliance of consented discharges, but few studies have related toxicity measured using WET tests to receiving water impacts. Here the authors adopt a four-stage procedure to investigate the toxicity and biological impact of a point source discharge and to identify the major toxicants. In stage 1, standard WET tests were employed to determine the toxicity of the effluent. This was then followed by an assessment of receiving water toxicity using in situ deployment of indigenous (Gammarus pulex) and standard (Daphnia magna) test species. The third stage involved the use of biological survey techniques to assess the impact of the discharge on the structure and functioning of the benthic macroinvertebrate community. In stage 4, toxicity identification evaluations (TIE) were used to identify toxic components in the effluent. Receiving-water toxicity and ecological impact detected downstream of the discharge were consistent with the results of WET tests performed on the effluent. Downstream of the discharge, there was a reduction in D. magna survival, in G. pulex survival and feeding rate, in detritus processing, and in biotic indices based on macroinvertebrate community structure. The TIE studies suggested that chlorine was the principal toxicant in the effluent.

  19. Produced water toxicity tests accurately measure the produced water toxicity in marine environments?

    SciTech Connect

    Douglas, W.S.; Veil, J.A.

    1996-10-01

    U.S. Environmental Protection Agency (EPA) Region VI has issued a general permit for offshore oil and gas discharges to the Gulf of Mexico that places numerical limits on whole effluent toxicity (WEI) for produced water. Recently proposed EPA general permits for other produced water discharges in Regions VI and X also include enforceable numerical limits on WET. Clearly, the industry will be conducting extensive produced water WET testing. Unfortunately, the WET test may not accurately measure the toxicity of the chemical constituents of produced water. Rather the mortality of test organisms may be attributable to (1) the high salinity of produced water, which causes salinity shock to the organisms, or (2) an ionic imbalance caused by excesses or deficiencies of one or more of seawater`s essential ions in the test chambers. Both of these effects are likely to be mitigated in actual offshore discharge settings, where the receiving water will be seawater and substantial dilution will be probable. Thus, the additional salinity of produced water will be rapidly assimilated, and the proper marine ionic balance will be quickly restored. Regulatory authorities should be aware of these factors when interpreting WET test results.

  20. Field assessments in conjunction with whole effluent toxicity testing

    SciTech Connect

    La Point, T.W.; Waller, W.T.

    2000-01-01

    Whole effluent toxicity (WET) tests are widely used to assess potential effects of wastewater discharges on aquatic life. This paper represents a summary of chapters in a 1996 Society of Environmental Toxicology and Chemistry-sponsored workshop and a literature review concerning linkages between WET testing and associated field biomonitoring. Most published studies thus far focus primarily on benthic macroinvertebrates and on effluent-dominated stream systems in which effluents demonstrate little or no significant acute toxicity. Fewer studies examine WET test predictability in other aquatic ecosystems (e.g., wetlands, estuaries, large rivers) or deal with instream biota such as fish and primary producers. Published results indicate that standards for the usual WET freshwater test species, Ceriodaphnia dubia and Pimephales promelas, may not always protect most of the species inhabiting a receiving stream. Although WET tests are useful in predicting aquatic individual responses, they are not meant to directly measure natural population or community responses. Further, they do not address bioconcentration or bioaccumulation of hydrophobic compounds; do not assess eutrophication effects in receiving systems; and lastly, do not reflect genotoxic effects or function to test for endocrine-disrupting chemicals. Consequently, a more direct evaluation of ecosystem health, using bioassessment techniques, may be needed to properly evaluate aquatic systems affected by wastewater discharges.

  1. Decreased Dissolution of ZnO by Iron Doping Yields Nanoparticles with Reduced Toxicity in the Rodent Lung and Zebrafish Embryos

    PubMed Central

    Xia, Tian; Zhao, Yan; Sager, Tina; George, Saji; Pokhrel, Suman; Li, Ning; Schoenfeld, David; Meng, Huan; Lin, Sijie; Wang, Xiang; Wang, Meiying; Ji, Zhaoxia; Zink, Jeffrey I.; Mädler, Lutz; Castranova, Vincent; Lin, Shuo; Nel, Andre E.

    2014-01-01

    We have recently shown that the dissolution of ZnO nanoparticles and Zn2+ shedding leads to a series of sub-lethal and lethal toxicological responses at cellular level that can be alleviated by iron-doping. Iron-doping changes the particle matrix and slows the rate of particle dissolution. To determine whether iron doping of ZnO also leads to lesser toxic effects in vivo, toxicity studies were performed in rodent and zebrafish models. First, we synthesized a fresh batch of ZnO nanoparticles doped with 1–10 wt % of Fe. These particles were extensively characterized to confirm their doping status, reduced rate of dissolution in an exposure medium and reduced toxicity in a cellular screen. Subsequent studies compared the effects of undoped to doped particles in the rat lung, mouse lung and the zebrafish embryo. The zebrafish studies looked at embryo hatching and mortality rates as well as the generation of morphological defects, while the endpoints in the rodent lung included an assessment of inflammatory cell infiltrates, LDH release and cytokine levels in the bronchoalveolar lavage fluid. Iron doping, similar to the effect of the metal chelator, DTPA, interfered in the inhibitory effects of Zn2+ on zebrafish hatching. In the oropharyngeal aspiration model in the mouse, iron doping was associated with decreased polymorphonuclear cell counts and IL-6 mRNA production. Doped particles also elicited decreased heme oxygenase 1 expression in the murine lung. In the intratracheal instillation studies in the rat, Fe-doping was associated with decreased polymorphonuclear cell counts, LDH and albumin levels. All considered, the above data show that Fe-doping is a possible safe design strategy for preventing ZnO toxicity in animals and the environment. PMID:21250651

  2. Integral toxicity test of sea waters by an algal biosensor.

    PubMed

    Tonnina, Daniele; Campanella, Luigi; Sammartino, Maria Pia; Visco, Giovanni

    2002-04-01

    An integral toxicity test, based on an algal biosensor and suitable to be used in sea water, is presented. The biosensor was designed and built by coupling a Clark oxygen electrode as transducer and the marine alga Spirulina subsalsa as biological mediator; it constitutes the "core" in a lab-scale prototype of a flow apparatus suitable to continuously monitor, in sea water, the photosynthetic activity of the alga and, from its variation, the marine pollution from the toxicological point of view. Inorganic pollutants (heavy metals) were tested in previous researches while organic ones (chlorophenols, pesticides and surfactants) are the object of the present paper.

  3. Use of DNA strand damage (Comet assay) and embryo hatching effects to assess contaminant exposure in blue crab (Callinectes sapidus) embryos

    SciTech Connect

    Lee, R.F.; Steinert, S.A.; Nakayama, K.; Oshima, Y.

    1999-07-01

    After fertilization, blue crab eggs are embedded in a sponge which is attached to the female abdomen during embryo development. Embryos after 9 stages in the egg sac hatch into a swimming zoea stage (stage 10). The authors have developed a bioassay where embryo development is monitored in culture plates with and without toxicants in the water. Toxicant effects are based on determining the percentage of embryos which hatch to zoea. Hatching EC{sub 50} (toxicant concentration at which 50% of the embryos fail to hatch) for a number of pesticides, organometallics and metals were determined. The test takes from 2 to 6 days depending on the embryo stage selected for the study. In addition to embryo development effects the prevalence of DNA single-strand breaks in individual embryo cells were determined using the single cell gel electrophoresis method (Comet assay). A good correlation between DNA strand breakage and embryo defects was found after exposure to genotoxic contaminants. Thus, the bioassay linking DNA damage to embryo hatching effects is rapid, sensitive and mechanistically relevant.

  4. Sulfidation as a natural antidote to metallic nanoparticles is overestimated: CuO sulfidation yields CuS nanoparticles with increased toxicity in medaka (Oryzias latipes) embryos.

    PubMed

    Li, Lingxiangyu; Hu, Ligang; Zhou, Qunfang; Huang, Chunhua; Wang, Yawei; Sun, Cheng; Jiang, Guibin

    2015-02-17

    Sulfidation is considered as a natural antidote to toxicity of metallic nanoparticles (NPs). The detoxification contribution from sulfidation, however, may vary depending on sulfidation mechanisms. Here we present the dissolution-precipitation instead of direct solid-state-shell mechanism to illustrate the process of CuO-NPs conversion to CuS-NPs in aqueous solutions. Accordingly, the CuS-NPs at environmentally relevant concentrations showed much stronger interference on Japanese medaka (Oryzias latipes) embryo hatching than CuO-NPs, which was probably due to elevated free copper ions released from CuS-NPs, leading to significant increase in oxidative stress and causing toxicity in embryos. The larval length was significantly reduced by CuS-NPs, however, no other obviously abnormal morphological features were identified in the hatched larvae. Co-introduction of a metal ion chelator [ethylene diamine tetraacetic acid (EDTA)] could abolish the hatching inhibition induced by CuS-NPs, indicating free copper ions released from CuS-NPs play an important role in hatching interference. This work documents for the first time that sulfidation as a natural antidote to metallic NPs is being overestimated, which has far reaching implications for risk assessment of metallic NPs in aquatic environment.

  5. Bioavailability of fluoranthene in freshwater sediment toxicity tests

    SciTech Connect

    Suedel, B.C.; Rodgers, J.H. Jr. ); Clifford, P.A. )

    1993-01-01

    To examine equilibrium-partitioning model predictions of interstitial water concentrations of fluoranthene as part of the equilibrium-partitioning (EqP) approach to sediment quality criteria development, the bioavailability (toxicity) of fluoranthene-amended sediment to Hyalella azteca, Daphnia magna, and Chironomus tentans was determined. Fluoranthene was added to three freshwater sediments with similar organic carbon content. Predicted interstitial water concentrations from the equilibrium-partitioning model were similar to measured interstitial water concentrations for WRFS and TR sediment, but the model underpredicted measured values for LF sediment by a factor of two. EC50s for Daphnia magna, Hyalella azteca, and Chironomus tentans in interstitial water were a factor of two to five greater for LF than for WRFS and TR sediments. Factors other than organic carbon content of sediments probably contributed to the variability in bioavailability of fluoranthene. Based on 10-d sediment toxicity tests with Hylella azteca, Daphnia magna, and Chironomus tentans, organic carbon-normalized sediment concentrations were better predictors of toxicity than interstitial water and bulk sediment fluoranthene concentrations. In 10-d aqueous-phase tests with fluoranthene, Chironomus tentans and Hyalella azteca were twice as sensitive as Daphnia magna.

  6. A category approach to predicting the developmental (neuro) toxicity of organotin compounds: the value of the zebrafish (Danio rerio) embryotoxicity test (ZET).

    PubMed

    Beker van Woudenberg, Anna; Wolterbeek, André; Te Brake, Lindsey; Snel, Cor; Menke, Aswin; Rubingh, Carina; de Groot, Didima; Kroese, Dinant

    2013-11-01

    Zebrafish embryos were exposed to different organotin compounds during very early development (<100h post fertilization). Morphology, histopathology and swimming activity (in a motor activity test) were the endpoints analyzed. DBTC was, by far, the most embryotoxic compound at all time points and endpoints studied. In fact, we observed a clear concordance between the effects observed in our zebrafish embryo model, and those observed with these compounds in full rodent in vivo studies. All organotin compounds classified as developmental (neuro) toxicants in vivo, were correctly classified in the present assay. Together, our results support the ZET model as a valuable tool for providing biological verification for a grouping and a read-across approach to developmental (neuro) toxicity.

  7. Miniaturized embryo array for automated trapping, immobilization and microperfusion of zebrafish embryos.

    PubMed

    Akagi, Jin; Khoshmanesh, Khashayar; Evans, Barbara; Hall, Chris J; Crosier, Kathryn E; Cooper, Jonathan M; Crosier, Philip S; Wlodkowic, Donald

    2012-01-01

    Zebrafish (Danio rerio) has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP). The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale.

  8. Miniaturized Embryo Array for Automated Trapping, Immobilization and Microperfusion of Zebrafish Embryos

    PubMed Central

    Akagi, Jin; Khoshmanesh, Khashayar; Evans, Barbara; Hall, Chris J.; Crosier, Kathryn E.; Cooper, Jonathan M.; Crosier, Philip S.; Wlodkowic, Donald

    2012-01-01

    Zebrafish (Danio rerio) has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP). The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale. PMID:22606275

  9. Establishing relative sensitivities of various toxicity testing organisms to ammonia

    SciTech Connect

    Karle, L.M.; Mayhew, H.L.; Barrows, M.E.; Karls, R.K.

    1994-12-31

    The toxicity of ammonia to various organisms was examined to develop a baseline for mortality in several commonly used testing species. This baseline data will assist in choosing the proper test species and in interpreting results as they pertain to ammonia. Responses for two juvenile fish species, three marine amphipods, and two species of mysid shrimp were compared for their sensitivity to levels of ammonia. All mortality caused by ammonia in the bottom-dwelling Citharichthys stigmaeus occurred within 24 h of exposure, whereas mortality in the silverside, Menidia beryllina, occurred over the entire 96-h test duration. Responses to ammonia varied among the amphipods Rhepoxynius abronius, Ampelisca abdita, and Eohaustorius estuarius. R. abronius and A. abdita showed similar sensitivity to ammonia at lower concentrations; A. abdita appeared more sensitive than R. abronius at levels above 40 mg/L. Concentrations of ammonia required to produce significant mortality in the amphipod E. estuarius were far higher than the other species examined (> 100 mg/L NH{sub 3}). A comparison of ammonia toxicity with two commonly used invertebrates, Holmesimysis sculpts and Mysidopsis bahia, suggest that these two species of mysid have similar sensitivities to ammonia. Further studies with ammonia that examine sensitivity of different organisms should be conducted to assist regulatory and environmental agencies in determining appropriate test species and in interpreting toxicological results as they may be affected by levels of ammonia.

  10. Current and future needs for developmental toxicity testing.

    PubMed

    Makris, Susan L; Kim, James H; Ellis, Amy; Faber, Willem; Harrouk, Wafa; Lewis, Joseph M; Paule, Merle G; Seed, Jennifer; Tassinari, Melissa; Tyl, Rochelle

    2011-10-01

    A review is presented of the use of developmental toxicity testing in the United States and international regulatory assessment of human health risks associated with exposures to pharmaceuticals (human and veterinary), chemicals (agricultural, industrial, and environmental), food additives, cosmetics, and consumer products. Developmental toxicology data are used for prioritization and screening of pharmaceuticals and chemicals, for evaluating and labeling of pharmaceuticals, and for characterizing hazards and risk of exposures to industrial and environmental chemicals. The in vivo study designs utilized in hazard characterization and dose-response assessment for developmental outcomes have not changed substantially over the past 30 years and have served the process well. Now there are opportunities to incorporate new technologies and approaches to testing into the existing assessment paradigm, or to apply innovative approaches to various aspects of risk assessment. Developmental toxicology testing can be enhanced by the refinement or replacement of traditional in vivo protocols, including through the use of in vitro assays, studies conducted in alternative nonmammalian species, the application of new technologies, and the use of in silico models. Potential benefits to the current regulatory process include the ability to screen large numbers of chemicals quickly, with the commitment of fewer resources than traditional toxicology studies, and to refine the risk assessment process through an enhanced understanding of the mechanisms of developmental toxicity and their relevance to potential human risk. As the testing paradigm evolves, the ability to use developmental toxicology data to meet diverse critical regulatory needs must be retained.

  11. A Simple "in Vitro" Culture of Freshwater Prawn Embryos for Laboratory Investigations

    ERIC Educational Resources Information Center

    Porntrai, Supaporn; Damrongphol, Praneet

    2008-01-01

    Giant freshwater prawn ("Macrobrachium rosenbergii" De Man) embryos can be cultured "in vitro" to hatching in 15% (v/v) artificial seawater (ASW). This technique can be applied as a bioassay for testing toxicity or for the effects of various substances on embryo development and can be used as a simple and low-cost model for…

  12. What food and feeding rates are optimum for the Chironomus dilutus sediment toxicity test method?

    EPA Science Inventory

    Laboratory tests with benthic macroinvertebrates conducted using standard toxicity test procedures are used to assess the potential toxicity of contaminated sediments. Results are compared across sites or for batches of samples, and the performance of organisms in control treatme...

  13. Combinatorial QSAR modeling of chemical toxicants tested against Tetrahymena pyriformis.

    PubMed

    Zhu, Hao; Tropsha, Alexander; Fourches, Denis; Varnek, Alexandre; Papa, Ester; Gramatica, Paola; Oberg, Tomas; Dao, Phuong; Cherkasov, Artem; Tetko, Igor V

    2008-04-01

    Selecting most rigorous quantitative structure-activity relationship (QSAR) approaches is of great importance in the development of robust and predictive models of chemical toxicity. To address this issue in a systematic way, we have formed an international virtual collaboratory consisting of six independent groups with shared interests in computational chemical toxicology. We have compiled an aqueous toxicity data set containing 983 unique compounds tested in the same laboratory over a decade against Tetrahymena pyriformis. A modeling set including 644 compounds was selected randomly from the original set and distributed to all groups that used their own QSAR tools for model development. The remaining 339 compounds in the original set (external set I) as well as 110 additional compounds (external set II) published recently by the same laboratory (after this computational study was already in progress) were used as two independent validation sets to assess the external predictive power of individual models. In total, our virtual collaboratory has developed 15 different types of QSAR models of aquatic toxicity for the training set. The internal prediction accuracy for the modeling set ranged from 0.76 to 0.93 as measured by the leave-one-out cross-validation correlation coefficient ( Q abs2). The prediction accuracy for the external validation sets I and II ranged from 0.71 to 0.85 (linear regression coefficient R absI2) and from 0.38 to 0.83 (linear regression coefficient R absII2), respectively. The use of an applicability domain threshold implemented in most models generally improved the external prediction accuracy but at the same time led to a decrease in chemical space coverage. Finally, several consensus models were developed by averaging the predicted aquatic toxicity for every compound using all 15 models, with or without taking into account their respective applicability domains. We find that consensus models afford higher prediction accuracy for the

  14. Sediment toxicity testing of Lake Orta after liming

    SciTech Connect

    Baudo, R.; Beltrami, M.; Rossi, D.; Gronda, A.; Abdel-Monem, A.M.; Burton, G.A.

    1995-12-31

    Lake Orta has been severely polluted by industrial effluents containing Cu, NH{sub 3}, Cr., Ni, and Zn. Ammonia oxidation caused a pH drop below 4. More than 60 papers have described the adverse chemical and biological changes which occurred in Lake Orta in the past several decades. In 1989, CaCO{sub 3} (10,900 tons) was added to the lake as a remedial action. The treatment was effective, improving water quality and allowing some original plankton, benthic, and fish populations to return. However, Cu and Cr are still present in the top 10 cm of sediment. The toxicity of the sediment was evaluated using multiple assays: Microtox (solid phase and pore water), Brachionus calyciflorus and Thamnocephalus platyurus Toxkits (pore water), seed germination and root elongation (solid phase and pore water). In addition, in situ and laboratory tests were conducted with Hyalella azteca and an indigenous species of Daphnia. Assays responses varied yet showed surficial sediments to be toxic. Toxicity increased with sediment in pre-liming deposition zones. Recovery of the ecosystem is evident, however the contaminated sediments may impede further improvement.

  15. Fish embryo tests with Danio rerio as a tool to evaluate surface water and sediment quality in rivers influenced by wastewater treatment plants using different treatment technologies.

    PubMed

    Thellmann, Paul; Köhler, Heinz-R; Rößler, Annette; Scheurer, Marco; Schwarz, Simon; Vogel, Hans-Joachim; Triebskorn, Rita

    2015-11-01

    In order to evaluate surface water and the sediment quality of rivers connected to wastewater treatment plants (WWTPs) with different treatment technologies, fish embryo tests (FET) with Danio rerio were conducted using native water and sediment samples collected upstream and downstream of four WWTPs in Southern Germany. Two of these WWTPs are connected to the Schussen River, a tributary of Lake Constance, and use a sand filter with final water purification by flocculation. The two others are located on the rivers Schmiecha and Eyach in the area of the Swabian Alb and were equipped with a powdered activated carbon stage 20 years ago, which was originally aimed at reducing the release of stains from the textile industry. Several endpoints of embryo toxicity including mortality, malformations, reduced hatching rate, and heart rate were investigated at defined time points of embryonic development. Higher embryotoxic potentials were found in water and sediments collected downstream of the WWTPs equipped with sand filtration than in the sample obtained downstream of both WWTPs upgraded with a powdered activated carbon stage.

  16. Tests for oil/dispersant toxicity: In situ laboratory assays

    SciTech Connect

    Wright, D.A.; Coelho, G.M.; Aurand, D.V.

    1995-12-31

    As part of its readiness program in oil spill response, the Marine Pollution Control Unit (MPCU), Department of Transport, U.K. conducts annual field trials in the North Sea, approximately 30 nautical miles from the southeast coast of England. The trials take the form of controlled releases of crude oil or Medium Fuel/Gas Oil mix (MFO), with and without the application of Corexit 9527 dispersant. In 1994 and 1995 the authors conducted a series of in situ toxicity bioassays in association with these spills with included 48h LC50 tests for turbot (Scophthalmus maximus) and oyster (Crassostrea gigas) larvae, a 48 h oyster (C. gigas) embryonic development test and two full life-cycle assays using the copepods Acartia tonsa and Tisbe battagliai. Tests were also conducted in the Chesapeake Bay laboratory using estuarine species including the copepod Eurytemora affinis and the inland silverside Menidia beryllina. Here, the authors report on the results of these assays, together with 1996 in situ toxicity data resulting from Norwegian field trials in the northern North Sea.

  17. Organotypic liver culture models: Meeting current challenges in toxicity testing

    PubMed Central

    LeCluyse, Edward L.; Witek, Rafal P.; Andersen, Melvin E.; Powers, Mark J.

    2012-01-01

    Prediction of chemical-induced hepatotoxicity in humans from in vitro data continues to be a significant challenge for the pharmaceutical and chemical industries. Generally, conventional in vitro hepatic model systems (i.e. 2-D static monocultures of primary or immortalized hepatocytes) are limited by their inability to maintain histotypic and phenotypic characteristics over time in culture, including stable expression of clearance and bioactivation pathways, as well as complex adaptive responses to chemical exposure. These systems are less than ideal for longer-term toxicity evaluations and elucidation of key cellular and molecular events involved in primary and secondary adaptation to chemical exposure, or for identification of important mediators of inflammation, proliferation and apoptosis. Progress in implementing a more effective strategy for in vitro-in vivo extrapolation and human risk assessment depends on significant advances in tissue culture technology and increasing their level of biological complexity. This article describes the current and ongoing need for more relevant, organotypic in vitro surrogate systems of human liver and recent efforts to recreate the multicellular architecture and hemodynamic properties of the liver using novel culture platforms. As these systems become more widely used for chemical and drug toxicity testing, there will be a corresponding need to establish standardized testing conditions, endpoint analyses and acceptance criteria. In the future, a balanced approach between sample throughput and biological relevance should provide better in vitro tools that are complementary with animal testing and assist in conducting more predictive human risk assessment. PMID:22582993

  18. Toxicity testing: creating a revolution based on new technologies.

    PubMed

    Bhogal, Nirmala; Grindon, Christina; Combes, Robert; Balls, Michael

    2005-06-01

    Biotechnology is evolving at a tremendous rate. Although drug discovery is now heavily focused on high throughput and miniaturized screening, the application of these advances to the toxicological assessment of chemicals and chemical products has been slow. Nevertheless, the impending surge in demands for the regulatory toxicity testing of chemicals provides the impetus for the incorporation of novel methodologies into hazard identification and risk assessment. Here, we review the current and likely future value of these new technologies in relation to toxicological evaluation and the protection of human health.

  19. Discovering less toxic ionic liquids by using the Microtox® toxicity test.

    PubMed

    Hernández-Fernández, F J; Bayo, J; Pérez de los Ríos, A; Vicente, M A; Bernal, F J; Quesada-Medina, J

    2015-06-01

    New Microtox® toxicity data of 16 ionic liquids of different cationic and anionic composition were determined. The ionic liquids 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, [BMPyr(+)][TFO(-)], 1-butyl-1-methylpyrrolidinium chloride, [BMPyr(+)][Cl(-)], hydroxypropylmethylimidazolium fluoroacetate, [HOPMIM(+)][FCH2COO(-)], and hydroxypropylmethylimidazolium glycolate [HOPMIM(+)][glycolate(-)] were found to be less toxic than conventional organic solvent such as chloroform or toluene, accoding the Microtox® toxicity assays. The toxicity of pyrrolidinium cation was lower than the imidazolium and pyridinium ones. It was found that the inclusion of an hydroxyl group in the alkyl chain length of the cation also reduce the toxicity of the ionic liquid. To sum up, the Microtox® toxicity assays can be used as screening tool to easily determined the toxicity of a wide range of ionic liquids and the toxicity data obtained could allow the obtention of structure-toxicity relationships to design less toxic ionic liquids.

  20. Zebrafish Embryo as an In Vivo Model for Behavioral and Pharmacological Characterization of Methylxanthine Drugs.

    PubMed

    Basnet, Ram Manohar; Guarienti, Michela; Memo, Maurizio

    2017-03-09

    Zebrafish embryo is emerging as an important tool for behavior analysis as well as toxicity testing. In this study, we compared the effect of nine different methylxanthine drugs using zebrafish embryo as a model. We performed behavioral analysis, biochemical assay and Fish Embryo Toxicity (FET) test in zebrafish embryos after treatment with methylxanthines. Each drug appeared to behave in different ways and showed a distinct pattern of results. Embryos treated with seven out of nine methylxanthines exhibited epileptic-like pattern of movements, the severity of which varied with drugs and doses used. Cyclic AMP measurement showed that, despite of a significant increase in cAMP with some compounds, it was unrelated to the observed movement behavior changes. FET test showed a different pattern of toxicity with different methylxanthines. Each drug could be distinguished from the other based on its effect on mortality, morphological defects and teratogenic effects. In addition, there was a strong positive correlation between the toxic doses (TC50) calculated in zebrafish embryos and lethal doses (LD50) in rodents obtained from TOXNET database. Taken together, all these findings elucidate the potentiality of zebrafish embryos as an in vivo model for behavioral and toxicity testing of methylxanthines and other related compounds.

  1. Zebrafish Embryo as an In Vivo Model for Behavioral and Pharmacological Characterization of Methylxanthine Drugs

    PubMed Central

    Basnet, Ram Manohar; Guarienti, Michela; Memo, Maurizio

    2017-01-01

    Zebrafish embryo is emerging as an important tool for behavior analysis as well as toxicity testing. In this study, we compared the effect of nine different methylxanthine drugs using zebrafish embryo as a model. We performed behavioral analysis, biochemical assay and Fish Embryo Toxicity (FET) test in zebrafish embryos after treatment with methylxanthines. Each drug appeared to behave in different ways and showed a distinct pattern of results. Embryos treated with seven out of nine methylxanthines exhibited epileptic-like pattern of movements, the severity of which varied with drugs and doses used. Cyclic AMP measurement showed that, despite of a significant increase in cAMP with some compounds, it was unrelated to the observed movement behavior changes. FET test showed a different pattern of toxicity with different methylxanthines. Each drug could be distinguished from the other based on its effect on mortality, morphological defects and teratogenic effects. In addition, there was a strong positive correlation between the toxic doses (TC50) calculated in zebrafish embryos and lethal doses (LD50) in rodents obtained from TOXNET database. Taken together, all these findings elucidate the potentiality of zebrafish embryos as an in vivo model for behavioral and toxicity testing of methylxanthines and other related compounds. PMID:28282918

  2. [Toxic and teratogenic effects of the ammonium salt of fosamine on the development of quail and chick embryos].

    PubMed

    Lutz-Ostertag, Y

    1983-01-01

    The effects of a commercial spray preparation of ammonium salt ppf fosamine (a defoliant) on quail and chick eggs have been studied. The results lead us to conclude that under the stated conditions the product has little embryotoxicity. However, it does have teratogenic effects on the steal and on the cervical, dorsal and posterior axial skeleton. The observed malformations are more severe and appear more frequently in quail than in chick embryos.

  3. A SURROGATE SUBCHRONIC TOXICITY TEST METHOD FOR WATERS WITH HIGH TOTAL DISSOLVED SOLIDS

    EPA Science Inventory

    Total dissolved solids (TDS) are often identified as a toxicant in whole-effluent toxicity (WET) testing. The primary test organism used in WET testing, Ceriodaphnia dubia, is very sensitive to TDS ions, which can be problematic when differentiating the toxicity of TDS from those...

  4. Study of Charge-Dependent Transport and Toxicity of Peptide-Functionalized Silver Nanoparticles Using Zebrafish Embryos and Single Nanoparticle Plasmonic Spectroscopy

    PubMed Central

    Lee, Kerry J.; Browning, Lauren M.; Nallathamby, Prakash D.; Xu, Xiao-Hong Nancy

    2013-01-01

    Nanomaterials possess unusually high surface area-to-volume ratios, and surface-determined physicochemical properties. It is essential to understand their surface-dependent toxicity in order to rationally design biocompatible nanomaterials for a wide variety of applications. In this study, we have functionalized the surfaces of silver nanoparticles (Ag NPs, 11.7 ± 2.7 nm in diameters) with three biocompatible peptides (CALNNK, CALNNS, CALNNE) to prepare positively (Ag-CALNNK NPs+ζ), negatively (Ag-CALNNS NPs−2ζ), and more negatively charged NPs (Ag-CALNNE NPs−4ζ), respectively. Each peptide differs in a single amino acid at its C-terminus, which minimizes the effects of peptide sequences and serves as a model molecule to create positive, neutral and negative charges on the surface of the NPs at pH 4–10. We have studied their charge-dependent transport into early-developing (cleavage-stage) zebrafish embryos and their effects on embryonic development using dark-field optical microscopy and spectroscopy (DFOMS). We found that all three Ag-peptide NPs passively diffused into the embryos via their chorionic pore canals, and stayed inside the embryos throughout their entire development (120 h), showing charge-independent diffusion modes and charge-dependent diffusion coefficients. Notably, the NPs create charge-dependent toxic effects on embryonic development, showing that the Ag-CALNNK NPs+ζ (positively charged) are the most biocompatible while the Ag-CALNNE NPs–4ζ (more negatively charged) are the most toxic. By comparing with our previous studies of the same sized citrated Ag and Au NPs, the Ag-peptide NPs are much more biocompatible than the citrated Ag NPs, and nearly as biocompatible as the Au NPs, showing the dependence of nanotoxicity upon the surface charges, surface functional groups and chemical compositions of the NPs. This study also demonstrates powerful applications of single NP plasmonic spectroscopy for quantitative analysis of single NPs

  5. Study of charge-dependent transport and toxicity of peptide-functionalized silver nanoparticles using zebrafish embryos and single nanoparticle plasmonic spectroscopy.

    PubMed

    Lee, Kerry J; Browning, Lauren M; Nallathamby, Prakash D; Xu, Xiao-Hong Nancy

    2013-06-17

    Nanomaterials possess unusually high surface area-to-volume ratios and surface-determined physicochemical properties. It is essential to understand their surface-dependent toxicity in order to rationally design biocompatible nanomaterials for a wide variety of applications. In this study, we have functionalized the surfaces of silver nanoparticles (Ag NPs, 11.7 ± 2.7 nm in diameter) with three biocompatible peptides (CALNNK, CALNNS, CALNNE) to prepare positively (Ag-CALNNK NPs(+ζ)), negatively (Ag-CALNNS NPs(-2ζ)), and more negatively charged NPs (Ag-CALNNE NPs(-4ζ)), respectively. Each peptide differs in a single amino acid at its C-terminus, which minimizes the effects of peptide sequences and serves as a model molecule to create positive, neutral, and negative charges on the surface of the NPs at pH 4-10. We have studied their charge-dependent transport into early developing (cleavage-stage) zebrafish embryos and their effects on embryonic development using dark-field optical microscopy and spectroscopy (DFOMS). We found that all three Ag-peptide NPs passively diffused into the embryos via their chorionic pore canals, and stayed inside the embryos throughout their entire development (120 h), showing charge-independent diffusion modes and charge-dependent diffusion coefficients. Notably, the NPs create charge-dependent toxic effects on embryonic development, showing that the Ag-CALNNK NPs(+ζ) (positively charged) are the most biocompatible while the Ag-CALNNE NPs(-4ζ) (more negatively charged) are the most toxic. By comparing with our previous studies of the same sized citrated Ag and Au NPs, the Ag-peptide NPs are much more biocompatible than the citrated Ag NPs, and nearly as biocompatible as the Au NPs, showing the dependence of nanotoxicity upon the surface charges, surface functional groups, and chemical compositions of the NPs. This study also demonstrates powerful applications of single NP plasmonic spectroscopy for quantitative analysis of single

  6. Non-animal methodologies within biomedical research and toxicity testing.

    PubMed

    Knight, Andrew

    2008-01-01

    Laboratory animal models are limited by scientific constraints on human applicability, and increasing regulatory restrictions, driven by social concerns. Reliance on laboratory animals also incurs marked - and in some cases, prohibitive - logistical challenges, within high-throughput chemical testing programmes, such as those currently underway within Europe and the US. However, a range of non-animal methodologies is available within biomedical research and toxicity testing. These include: mechanisms to enhance the sharing and assessment of existing data prior to conducting further studies, and physicochemical evaluation and computerised modelling, including the use of structure-activity relationships and expert systems. Minimally-sentient animals from lower phylogenetic orders or early developmental vertebral stages may be used, as well as microorganisms and higher plants. A variety of tissue cultures, including immortalised cell lines, embryonic and adult stem cells, and organotypic cultures, are also available. In vitro assays utilising bacterial, yeast, protozoal, mammalian or human cell cultures exist for a wide range of toxic and other endpoints. These may be static or perfused, and may be used individually, or combined within test batteries. Human hepatocyte cultures and metabolic activation systems offer potential assessment of metabolite activity and organ-organ interaction. Microarray technology may allow genetic expression profiling, increasing the speed of toxin detection, well prior to more invasive endpoints. Enhanced human clinical trials utilising micro- dosing, staggered dosing, and more representative study populations and durations, as well as surrogate human tissues, advanced imaging modalities and human epidemiological, sociological and psycho- logical studies, may increase our understanding of illness aetiology and pathogenesis, and facilitate the development of safe and effective pharmacologic interventions. Particularly when human tissues

  7. Sugars exert a major influence on the vitrification properties of ethylene glycol-based solutions and have low toxicity to embryos and oocytes.

    PubMed

    Kuleshova, L L; MacFarlane, D R; Trounson, A O; Shaw, J M

    1999-03-01

    A systematic approach was taken to assess the vitrification properties of ethylene glycol-based solutions supplemented with carbohydrates. Solutions were prepared by weight (gravimetrically) using ethylene glycol as the cryoprotectant, 0.9% NaCl in water, and six different sugars: d-glucose, d(-)-fructose, d-sorbitol, sucrose, d(+)-trehalose, and raffinose. Sugars were added on a molal basis (0. 1, 0.5, and 1 m). Characteristics of the solutions were measured during warming by differential scanning calorimetry using a cooling rate of 100 degrees C/min and a warming rate of 10 degrees C/min. In the absence of carbohydrates a 59 wt% EG-saline solution formed a stable glass. When EG was replaced by an equimolal concentration of glucose, fructose, or sorbitol (monosaccharides) at 0.1, 0.5, or 1.0 m there was no change in the total solute concentration at which vitrification occurred, but the glass transition (Tg) occurred at a higher temperature than in EG-saline alone. When EG was replaced by an equimolal concentration of sucrose or trehalose (disaccharides) both the Tg and the lowest total solute concentration required for vitrification became progressively higher as the molecular weight, or the ratio of sugar to EG in the solutions, increased. At the highest tested disaccharide concentration (1 m) vitrification was achieved at a total solute concentration of 65 wt% (sucrose) and 67 wt% (trehalose). The polysaccharide raffinose significantly modified the vitrification properties of ethylene glycol solutions. When 0.5 or 0.1 m raffinose replaced EG on an equimolal basis the glass transition point was raised more than with either the monosaccharides or the disaccharides. Raffinose allowed vitrification at a total solute concentration of 67 wt% (0.5 m) and 63 wt% (0.1 m). The maturation of immature mouse oocytes, and the development of embryos in media containing 5-7 mM of any sugar was comparable to controls, indicating that they are not toxic. Exposure of freshly

  8. Assessment of the individual and mixture toxicity of cadmium, copper and oxytetracycline, on the embryo-larval development of the sea urchin Paracentrotus lividus.

    PubMed

    Gharred, Tahar; Jebali, Jamel; Belgacem, Mariem; Mannai, Rabeb; Achour, Sami

    2016-09-01

    Multiple pollutions by trace metals and pharmaceuticals have become one of the most important problems in marine coastal areas because of its excessive toxicity on organisms living in this area. This study aimed to assess the individual and mixture toxicity of Cu, Cd, and oxytetracycline frequently existing in the contaminated marine areas and the embryo-larval development of the sea urchin Paracentrotus lividus. The individual contamination of the spermatozoid for 1 h with the increasing concentrations of Cd, Cu, and OTC decreases the fertility rate and increases larvae anomalies in the order Cu > Cd > OTC. Moreover, the normal larva frequency and the length of spicules were more sensitive than the fertilization rate and normal gastrula frequency endpoints. The mixture toxicity assessed by multiple experimental designs showed clearly that concentrations of Cd, Cu, and OTC superior to 338 μg/L, 0.56 μg/L, and 0.83 mg/L, respectively, cause significant larva malformations.

  9. Microbially mediated O-methylation of bisphenol A results in metabolites with increased toxicity to the developing zebrafish (Danio rerio) embryo.

    PubMed

    McCormick, Jessica M; Van Es, Theo; Cooper, Keith R; White, Lori A; Häggblom, Max M

    2011-08-01

    Bisphenol A (BPA) is used in the manufacture of plastics, and has been identified in various environmental matrices, including human serum and breast milk. The prevalence of BPA in the environment and the potential exposure to humans underscores the need to more fully understand the fate of BPA in the environment and the resulting effects and toxicity to humans and other organisms. Here we demonstrate that Mycobacterium species, including Mycobacterium vanbaalenii strain PYR-1, are able to O-methylate BPA to its mono- and dimethyl ether derivatives (BPA MME and BPA DME, respectively). The O-methylation of BPA results in metabolites with increased toxicity as shown from differences in survival and occurrence of developmental lesions in developing zebrafish embryos exposed to BPA, BPA MME, and BPA DME. The mono- and dimethyl ether derivatives were more toxic than BPA, resulting in increased mortality at 5 (LC(50) = 0.66 and 1.2 mg L(-1)) and 28 (LC(50) = 0.38, <0.5 mg L(-1)) days post fertilization. Furthermore, exposure to either of the O-methylated metabolites resulted in an increase in the incidence of developmental lesions as compared to BPA exposure. These data illustrate a new mechanism for microbial transformation of BPA, producing metabolites warranting further study to understand their prevalence and effects in the environment.

  10. The toxicity of creosote-treated wood to Pacific herring embryos and characterization of polycyclic aromatic hydrocarbons near creosoted pilings in Juneau, Alaska.

    PubMed

    Duncan, Danielle L; Carls, Mark G; Rice, Stanley D; Stekoll, Michael S

    2016-10-14

    Polycyclic aromatic hydrocarbons (PAHs) from creosote exposure in the laboratory resulted in deleterious effects in developing Pacific herring (Clupea pallasi) embryos, and potentially toxic concentrations of PAHs were measured using passive water samplers at 1 of 3 harbor field sites in Juneau, Alaska, USA. Aqueous total PAH concentrations of 4.6 μg/L and 8.4 μg/L from creosote exposure resulted in skeletal defects and ineffective swimming in hatched larvae in the laboratory (10% effective concentrations) and were the most sensitive parameters measured. Hatch rates also suffered from creosote exposure in a dose-dependent manner: at exposures between 5 μg/L and 50 μg/L total PAH, 50% of the population failed to hatch. Comparisons between laboratory and field deployed passive samplers suggested that for at least 1 harbor in Juneau, concentrations sufficient to induce teratogenic effects were found directly on creosoted pilings, within 10 cm of them, and sometimes at a distance of 10 m. Total PAH concentrations generally decreased with distance from creosoted pilings. Creosote pilings contribute to the PAH load within a marina and can rise to PAH concentrations that are harmful to fish embryos, but at a scale that is localized in the environment. Environ Toxicol Chem 2016;9999:1-9. © 2016 SETAC.

  11. Validation and sensitivity comparisons of micro-scale toxicity tests for the evaluation of freshwater sediment toxicity

    SciTech Connect

    Riebel, P.; Bureau, J.; Blaise, C.; Michaud, J.R.

    1995-12-31

    A three-year study is currently underway to develop a representative and cost-effective battery of toxicity tests for evaluating freshwater sediment and porewater toxicity. Among the tests currently being evaluated are the following: Microtox{trademark} chronic test, Microtox{trademark} solid-phase test, Microtox{trademark} liquid phase test, Thamnotoxkit F{trademark}, Rotoxkit F{trademark}, Daphnia magna IQ test{trademark}, Sediment Toxkit, SOS Chromotest, a Selenastrum capricornutum short exposure assay, and trout hepatocyte assays. Conventional sediment tests with Chironomus tentans, Hyalella azteca and Lumbriculus variegatus, as well as benthic macroinvertebrate community assessments and sediment chemical characterizations are being conducted at two contaminated sites. Toxicity test reproducibility, sensitivity, practicality, cost and ecological relevance are discussed.

  12. PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY IN MEDAKA (ORYZIAS LATIPES) EMBRYOS: RELEVANCE TO ENVIRONMENTAL RISK IN CONTAMINATED SITES

    EPA Science Inventory

    The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoa...

  13. Thymoquinone therapy abrogates toxic effect of cadmium on rat testes.

    PubMed

    Fouad, A A; Jresat, I

    2015-05-01

    The protective effect of thymoquinone was investigated against cadmium-induced testicular toxicity in rats. Testicular toxicity was induced by a single intraperitoneal (i.p.) injection of cadmium chloride (2 mg kg(-1) ). Thymoquinone treatment (10 mg kg(-1)  day(-1) , i.p.) was applied for five consecutive days, starting 3 days before cadmium administration. Thymoquinone significantly attenuated the cadmium-induced decreases in serum testosterone, and testicular reduced glutathione and superoxide dismutase activity and significantly decreased the elevations of testicular malondialdehyde, nitric oxide and cadmium ion levels resulted from cadmium chloride administration. Also, thymoquinone ameliorated the cadmium-induced testicular tissue injury observed by histopathological examination. In addition, thymoquinone significantly decreased the cadmium-induced expression of inducible nitric oxide synthase, tumour necrosis factor-α, cyclooxygenase-2, nuclear factor-κB and caspase-3 in testicular tissue. It was concluded that thymoquinone, through its antioxidant and anti-inflammatory activities, may represent a potential candidate to protect the testes against the detrimental effect of cadmium exposure.

  14. Toxicity testing of neurotoxic pesticides in Caenorhabditis elegans.

    PubMed

    Meyer, Dean; Williams, Phillip L

    2014-01-01

    The use of pesticides is ubiquitous worldwide, and these chemicals exert adverse effects on both target and nontarget species. Understanding the modes of action of pesticides, as well as quantifying exposure concentration and duration, is an important goal of clinicians and environmental health scientists. Some chemical exposures result in adverse effects on the nervous system. The nematode Caenorhabditis elegans (C. elegans) is a model lab organism well established for studying neurotoxicity, since the components of its nervous system are mapped and known, and most of its neurotransmitters correspond to human homologs. This review encompasses published studies in which C. elegans nematodes were exposed to pesticides with known neurotoxic actions. Endpoints measured include changes in locomotion, feeding behavior, brood size, growth, life span, and cell death. From data presented, evidence indicates that C. elegans can serve a role in assessing the effects of neurotoxic pesticides at the sublethal cellular level, thereby advancing our understanding of the mechanisms underlying toxicity induced by these chemicals. A proposed toxicity testing scheme for water-soluble chemicals is also included.

  15. Fractionating nanosilver: importance for determining toxicity to aquatic test organisms.

    PubMed

    Kennedy, Alan J; Hull, Matthew S; Bednar, Anthony J; Goss, Jennifer D; Gunter, Jonas C; Bouldin, Jennifer L; Vikesland, Peter J; Steevens, Jeffery A

    2010-12-15

    This investigation applied novel techniques for characterizing and fractionating nanosilver particles and aggregates and relating these measurements to toxicological endpoints. The acute toxicity of eight nanosilver suspensions of varying primary particle sizes (10-80 nm) and coatings (citrate, polyvinylpyrrolidone, EDTA, proprietary) was assessed using three aquatic test organisms (Daphnia magna, Pimephales promelas, Pseudokirchneriella subcapitata). When 48-h lethal median concentrations (LC50) were expressed as total silver, both D. magna and P. promelas were significantly more sensitive to ionic silver (Ag(+)) as AgNO(3) (mean LC50 = 1.2 and 6.3 μg/L, respectively) relative to a wide range in LC50 values determined for the nanosilver suspensions (2 -126 μg/L). However, when LC50 values for nanosilver suspensions were expressed as fractionated nanosilver (Ag(+) and/or <4 nm particles), determined by ultracentrifugation of particles and confirmed field-flow-fractograms, the LC50 values (0.3-5.6 μg/L) were comparable to the values obtained for ionic Ag(+) as AgNO(3). These results suggest that dissolved Ag(+) plays a critical role in acute toxicity and underscores the importance of characterizing dissolved fractions in nanometal suspensions.

  16. Toxicity assessment and vitellogenin expression in zebrafish (Danio rerio) embryos and larvae acutely exposed to bisphenol A, endosulfan, heptachlor, methoxychlor and tetrabromobisphenol A.

    PubMed

    Chow, Wing Shan; Chan, Winson Ka-Lun; Chan, King Ming

    2013-07-01

    Organochlorine pesticides and brominated flame retardants, such as tetrabromobisphenol A and polybrominated diphenyl ethers, pose an environmental hazard owing to their persistence, low solubility and estrogenic effects, and concerns have been raised regarding their effects on aquatic biota. In the present study, zebrafish embryos and larvae were used as a model to investigate the sublethal and lethal effects of three different organochlorine pesticides, namely methoxychlor, endosulfan and heptachlor, as well as the flame retardant tetrabromobisphenol A, and its precursor compound bisphenol A. Preliminary data for chemical exposure tests were obtained by determining the 96 h median effective concentration EC50 (hatching rate) and 96 h median lethal concentration LC50 . Quantitative polymerase chain reaction was used to investigate the gene expression levels of the biomarker vitellogenin (vtg1) after 96 h exposures to 10, 25, 50 and 75% of the 96 h EC50 value for embryos and 96 h LC50 value for larvae. The use of vtg1 mRNA induction in zebrafish embryos and larvae was found to be a sensitive biomarker of exposure to these organic compounds, and was helpful in elucidating their adverse effects and setting water quality guidelines.

  17. Formulated sediment for use in whole-sediment toxicity testing

    SciTech Connect

    Kemble, N.E.; Dwyer, F.J.; Hardesty, D.K.; Ingersoll, C.G.

    1995-12-31

    A formulated control sediment was developed to provide consistent and acceptable biological endpoints for a variety of species used in whole sediment toxicity testing. In an attempt to develop such a sediment the authors conducted multiple tests to evaluate: (1) {alpha}-cellulose as an organic carbon source, (2) various TOC concentrations, (3) various grain sizes, (4) different food types, and (5) overlying waters. Studies were conducted with the amphipod Hyalella azteca the midges Chironomus riparius, Chironomus tentans and the oligochaete Lumbriculus variegatus in 10 d exposures and H. azteca in 28 d exposures. Sediment from West Bearskin Lake Minnesota was used as a control sediment with each species in each test. Survival of test organisms in all of the 10-d experiments, with the exception of C. riparius, was above the acceptable levels for a control sediment. Survival in the formulated sediments also was not significantly different when compared to the control sediment. Amphipod survival in the 28-d exposures was low; however, the use of reconstituted water in combination with the formulated sediment may have been a problem. The authors are currently evaluating various types of overlying water with formulated sediments and sublethal endpoints in each of the exposures (i.e., growth, sexual maturation or head capsule width).

  18. An interlaboratory comparison of sediment elutriate preparation and toxicity test methods

    EPA Science Inventory

    Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

  19. AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF SEVEN TECHNOLOGIES DETECTING TOXICITY IN DRINKING WATER (R2)

    EPA Science Inventory

    Rapid toxicity technologies can detect certain toxins and with testing it can be determined their susceptibility to interfering chemical in controlled experimental matrix. Rapid toxicity technologies do not identify or determine the concentrations of specific contaminants, but s...

  20. Toxicity testing of organic chemicals in groundwater polluted with landfill leachate

    SciTech Connect

    Baun, A.; Kloeft, L.; Bjerg, P.L.; Nyholm, N.

    1999-09-01

    A method for assessment of toxicity of nonvolatile organic chemicals contaminants in groundwater polluted with landfill leachate has been evaluated. The biotests utilized were composed of an algal growth inhibition test (Selenastrum capricornutum), a daphnia immobilization test (Daphnia magna), and a bacterial genotoxicity test (umuC, Salmonella typhimurium). The feasibility of the selected biotests was investigated for a series of groundwater samples collected along pollution gradients downstreams of two landfills in Jutland, Denmark. Two different approaches were used, direct toxicity testing of whole groundwater samples, and toxicity testing of concentrates obtained by solid-phase extraction. Direct testing of whole groundwater samples produced toxic responses, but the complex sample matrix masked the toxicity of the organic chemical contaminants of interest. Solid-phase extraction was used successfully as an on-site method that eliminated ion toxicity and produced biotest responses that reflected the toxicity of the nonvolatile organic chemical contaminants in the groundwater.

  1. Evaluation of municipal waste incinerator fly ash toxicity and the role of cadmium by two aquatic toxicity tests

    SciTech Connect

    Kaneko, Hidehiro

    1996-12-31

    Fly ash from a municipal solid waste incinerator in Japan is regulated under the hazardous waste regulation Waste under Special Control, according to the Amendment of the Waste Disposal and Public Cleansing Law, because it contains high concentrations of heavy metals which are available for leaching. To evaluate the toxicity of fly ash, a fly ash leachate was prepared according to the Japanese standard leaching procedure. The chemical analysis of the leachate showed that possibly one of the most toxic substances was cadmium. The toxicity of the leachate and the cadmium was determined by algal assay and a Daphnia acute toxicity test. The results showed that the leachate was about seven times more toxic to the growth of algae and 20 to 30 times more toxic to the survival of Daphnia than expected from its cadmium concentration. The toxicity interaction between cadmium and the other constituents in the leachate was also examined. The toxicity of cadmium showed an additive effect with the other constituents in the leachate in algal assay. In the Daphnia test, however, cadmium showed an antagonistic effect.

  2. Current developments in reproductive toxicity testing of pesticides.

    PubMed

    Cooper, Ralph L

    2009-09-01

    A protocol to evaluate the potential developmental and reproductive effects of test chemicals has been developed by the Life Stages Task Force of the International Life Sciences Institute (ILSI)/Health and Environmental Sciences Institute (HESI) Agricultural Chemical Safety Assessment (ACSA) Technical Committee. Since the original publication, several international groups have provided public comment on conducting the test. The extended one-generation reproductive toxicity test is now under consideration as a potential test guideline. The protocol uses a flexible approach that is markedly different from the current multigenerational guidelines. It encourages the use of toxicokinetics when setting the doses, evaluates more than one rat per sex per litter in the F1 offspring and does not necessarily require mating of the F1 to produce an F2 (F1 mating may be triggered by the presence of effects in the P0 and developing F1 rats). A number of additional reproductive endpoints, and the neurotoxicity and immunotoxicity cohorts are included. The ACSA protocol was developed with the goal of assuring that the methods are scientifically appropriate and the toxicological endpoints and exposure durations are relevant for risk assessment. Compared to existing testing strategies, the proposed approach uses substantially fewer animals, provides additional information on the neonate, juvenile and pubertal animal, and includes an estimation of human exposure potential for making decisions about the extent of testing required. In this paper, the evolution of the protocol since the 2006 publication is discussed. These changes reflect the collective input of a U.S. expert panel of government and industrial scientist convened in 2007 and discussions of an OECD expert group held in Paris, France (October, 2008).

  3. Aquatic toxicity testing for multicomponent compounds with special reference to preparation of test solution

    SciTech Connect

    Tadokoro, H.; Maeda, M.; Kawashima, Y.; Kitano, M.; Hwang, D.F.; Yoshida, T. )

    1991-02-01

    An adequate method of determining the toxicity of a compound consisting of multiple components, such as creosote, coal tar, and coal tar pitch, was studied for different test solution preparation methods, i.e., direct dosing without filtration, diluting the stock solution of saturated concentration, and dispersing with acetone. Killifish, Oryzias latipes, as a freshwater fish; red sea bream, Pagrus major, as a saltwater fish; and daphnia, Daphnia magna, as a representative crustacean, were used for testing. The chemical analysis of each preparation of test solution with gas chromatography revealed an entirely different profile of the components. The highest toxicity was obtained with preparation by acetone dispersion. That was followed by the preparations with direct dosing method and with the method of dilution of saturated concentration stock solution. Considering the results obtained, the direct dosing method with a suitable settling time may provide useful information enabling extrapolation of the test results to the natural environment for complex multicomponent compounds.

  4. Characterization of toxicants in urban road dust by Toxicity Identification Evaluation using ostracod Heterocypris incongruens direct contact test.

    PubMed

    Khanal, Rajendra; Furumai, Hiroaki; Nakajima, Fumiyuki

    2015-10-15

    The current study involves characterization of organic compounds, heavy metals, and ammonia as potential toxicants in one arterial road (St. 3) and two highway (St. 7 and 8) urban road dust (URD) collected in Tokyo, Japan. URD toxicity was evaluated by Toxicity Identification Evaluation using the ostracod Heterocypris incongruens direct contact test. URDs were treated with resins (10% XAD-4, 20% SIR-300 and 20% SIR-600) to determine the reduction in mortality after treatment. The mortality of ostracods exposed to St. 3 URD (baseline 80%) was significantly (p<0.05) reduced to 0% and 47% after XAD-4 and SIR-300 treatment respectively. This reduction led us to suspect hydrophobic organic compounds and heavy metals as potential toxicants. Subsequent elution of the recovered XAD-4 with polar (methanol, acetone) and non-polar (dichloromethane) solvents confirmed the dominance of relatively polar hydrophobic organic toxicants. The dissolved concentration of Cu and Zn after SIR-300 treatment exceeded the 50% lethal concentration (LC50) for ostracods, which led us to suspect Cu and Zn as other probable toxicants. The concentration of Zn in a SIR-300 acidic elutriate, recovered after the termination of toxicity test, confirmed Zn as one of the toxicants in St. 3. The baseline mortality (100%) of St. 7 was significantly reduced (23%) by SIR-300 treatment. This indicated the presence of heavy metals as the probable toxicant. However, the concentration of dissolved heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the overlying water was below previously reported LC50 values for each metal in St. 7. Recovery of Zn concentrations exceeding the LC50 in the St. 7 SIR-300 elutriate led us to suspect a dietary exposure route of Zn to the ostracod during the direct contact test. The overall results indicate that the toxicant types can vary widely depending on the road sampled.

  5. Towards sensible toxicity testing for nanomaterials: proposal for the specification of test design

    NASA Astrophysics Data System (ADS)

    Potthoff, Annegret; Weil, Mirco; Meißner, Tobias; Kühnel, Dana

    2015-12-01

    During the last decade, nanomaterials (NM) were extensively tested for potential harmful effects towards humans and environmental organisms. However, a sound hazard assessment was so far hampered by uncertainties and a low comparability of test results. The reason for the low comparability is a high variation in the (1) type of NM tested with regard to raw material, size and shape and (2) procedures before and during the toxicity testing. This calls for tailored, nanomaterial-specific protocols. Here, a structured approach is proposed, intended to lead to test protocols not only tailored to specific types of nanomaterials, but also to respective test system for toxicity testing. There are existing standards on single procedures involving nanomaterials, however, not all relevant procedures are covered by standards. Hence, our approach offers a detailed way of weighting several plausible alternatives for e.g. sample preparation, in order to decide on the procedure most meaningful for a specific nanomaterial and toxicity test. A framework of several decision trees (DT) and flow charts to support testing of NM is proposed as a basis for further refinement and in-depth elaboration. DT and flow charts were drafted for (1) general procedure—physicochemical characterisation, (2) choice of test media, (3) decision on test scenario and application of NM to liquid media, (4) application of NM to the gas phase, (5) application of NM to soil and sediments, (6) dose metrics, (S1) definition of a nanomaterial, and (S2) dissolution. The applicability of the proposed approach was surveyed by using experimental data retrieved from studies on nanoscale CuO. This survey demonstrated the DT and flow charts to be a convenient tool to systematically decide upon test procedures and processes, and hence pose an important step towards harmonisation of NM testing.

  6. Towards sensible toxicity testing for nanomaterials: proposal for the specification of test design

    PubMed Central

    Potthoff, Annegret; Weil, Mirco; Meißner, Tobias; Kühnel, Dana

    2015-01-01

    During the last decade, nanomaterials (NM) were extensively tested for potential harmful effects towards humans and environmental organisms. However, a sound hazard assessment was so far hampered by uncertainties and a low comparability of test results. The reason for the low comparability is a high variation in the (1) type of NM tested with regard to raw material, size and shape and (2) procedures before and during the toxicity testing. This calls for tailored, nanomaterial-specific protocols. Here, a structured approach is proposed, intended to lead to test protocols not only tailored to specific types of nanomaterials, but also to respective test system for toxicity testing. There are existing standards on single procedures involving nanomaterials, however, not all relevant procedures are covered by standards. Hence, our approach offers a detailed way of weighting several plausible alternatives for e.g. sample preparation, in order to decide on the procedure most meaningful for a specific nanomaterial and toxicity test. A framework of several decision trees (DT) and flow charts to support testing of NM is proposed as a basis for further refinement and in-depth elaboration. DT and flow charts were drafted for (1) general procedure—physicochemical characterisation, (2) choice of test media, (3) decision on test scenario and application of NM to liquid media, (4) application of NM to the gas phase, (5) application of NM to soil and sediments, (6) dose metrics, (S1) definition of a nanomaterial, and (S2) dissolution. The applicability of the proposed approach was surveyed by using experimental data retrieved from studies on nanoscale CuO. This survey demonstrated the DT and flow charts to be a convenient tool to systematically decide upon test procedures and processes, and hence pose an important step towards harmonisation of NM testing. PMID:27877848

  7. [Comprehensive Toxicity Evaluation and Toxicity Identification Used in Tannery and Textile Wastewaters].

    PubMed

    Huang, Li; Chen, Wen-yan; Wan, Yu-shan; Zheng, Guo-juan; Zhao, Yuan; Cai, Qiang

    2015-07-01

    To better evaluate the toxicity of tannery and textile effluents from various emission stages, the research attempted battery of toxicological bioassays and toxicological indices. The bioassays employed Microtox test, zebra fish embryo-larval test and algae (Chlorella vulgaris) test. Meanwhile, toxicological indices including Toxicity Unit (TU), Average Toxicity (AvTx), Toxic Print (TxPr), Most Sensitive Test (MST) and Potential Ecotoxic Effects Probe (PEEP) were applied. The results illustrated that PEEP was the most comprehensive index to take account of the emissions and toxic potential of effluents. PEEP values showed that the reduction rates of toxicity in tannery and textile effluents were 36. 8% and 23. 2%, respectively. Finally, based on the Microtox toxicity test, toxicants in textile effluent were identified through the toxicity identification evaluation (TIE) studies. The results indicated that the main toxicant of textile effluent was non-polar organic pollutants, followed by filterable compounds, heavy metals, oxidizing substances and volatile components.

  8. Custom-designed nanomaterial libraries for testing metal oxide toxicity.

    PubMed

    Pokhrel, Suman; Nel, André E; Mädler, Lutz

    2013-03-19

    Advances in aerosol technology over the past 10 years have enabled the generation and design of ultrafine nanoscale materials for many applications. A key new method is flame spray pyrolysis (FSP), which produces particles by pyrolyzing a precursor solution in the gas phase. FSP is a highly versatile technique for fast, single-step, scalable synthesis of nanoscale materials. New innovations in particle synthesis using FSP technology, including variations in precursor chemistry, have enabled flexible, dry synthesis of loosely agglomerated, highly crystalline ultrafine powders (porosity ≥ 90%) of binary, ternary, and mixed-binary-and-ternary oxides. FSP can fulfill much of the increasing demand, especially in biological applications, for particles with specific material composition, high purity, and high crystallinity. In this Account, we describe a strategy for creating nanoparticle libraries (pure or Fedoped ZnO or TiO₂) utilizing FSP and using these libraries to test hypotheses related to the particles' toxicity. Our innovation lies in the overall integration of the knowledge we have developed in the last 5 years in (1) synthesizing nanomaterials to address specific hypotheses, (2) demonstrating the electronic properties that cause the material toxicity, (3) understanding the reaction mechanisms causing the toxicity, and (4) extracting from in vitro testing and in vivo testing in terrestrial and marine organisms the essential properties of safe nanomaterials. On the basis of this acquired knowledge, we further describe how the dissolved metal ion from these materials (Zn²⁺ in this Account) can effectively bind with different cell constituents, causing toxicity. We use Fe-S protein clusters as an example of the complex chemical reactions taking place after free metal ions migrate into the cells. As a second example, TiO₂ is an active material in the UV range that exhibits photocatalytic behavior. The induction of electron-hole (e⁻/h⁺) pairs followed by

  9. Hepatotoxicity and subchronic toxicity tests of Morinda citrifolia (noni) fruit.

    PubMed

    West, Brett J; Su, Chen X; Jensen, C Jarakae

    2009-10-01

    Morinda citrifolia (noni) fruit juice has been approved as a safe food in many nations. A few cases of hepatitis in people who had been drinking noni juice have been reported, even though no causal link could be established between the liver injury and ingestion of the juice. To more fully evaluate the hepatotoxic potential of noni fruit juice, in vitro hepatotoxicity tests were conducted in human liver cells, HepG2 cell line. A subchronic oral toxicity test of noni fruit was also performed in Sprague-Dawley (SD) rats to provide benchmark data for understanding the safety of noni juice, without the potential confounding variables associated with many commercial noni juice products. Freeze-dried filtered noni fruit puree did not decrease HepG2 cell viability or induce neutral lipid accumulation and phospholipidosis. There were no histopathological changes or evidence of dose-responses in hematological and clinical chemistry measurements, including liver function tests. The no-observed-adverse-effect level (NOAEL) for freeze-dried noni fruit puree is greater than 6.86 g/kg body weight, equivalent to approximately 90 ml of noni fruit juice/kg. These findings corroborate previous conclusions that consumption of noni fruit juice is unlikely to induce adverse liver effects.

  10. Toxicity testing: the search for an in vitro alternative to animal testing.

    PubMed

    May, J E; Xu, J; Morse, H R; Avent, N D; Donaldson, C

    2009-01-01

    Prior to introduction to the clinic, pharmaceuticals must undergo rigorous toxicity testing to ensure their safety. Traditionally, this has been achieved using in vivo animal models. However, besides ethical reasons, there is a continual drive to reduce the number of animals used for this purpose due to concerns such as the lack of concordance seen between animal models and toxic effects in humans. Adequate testing to ensure any toxic metabolites are detected can be further complicated if the agent is administered in a prodrug form, requiring a source of cytochrome P450 enzymes for metabolism. A number of sources of metabolic enzymes have been utilised in in vitro models, including cell lines, primary human tissue and liver extracts such as S9. This review examines current and new in vitro models for toxicity testing, including a new model developed within the authors' laboratory utilising HepG2 liver spheroids within a co-culture system to examine the effects of chemotherapeutic agents on other cell types.

  11. Genetically Defined Strains in Drug Development and Toxicity Testing.

    PubMed

    Festing, Michael F W

    2016-01-01

    There is growing concern about the poor quality and lack of repeatability of many pre-clinical experiments involving laboratory animals. According to one estimate as much as $28 billion is wasted annually in the USA alone in such studies. A decade ago the FDA's "Critical path" white paper noted that "The traditional tools used to assess product safety-animal toxicology and outcomes from human studies-have changed little over many decades and have largely not benefited from recent gains in scientific knowledge. The inability to better assess and predict product safety leads to failures during clinical development and, occasionally, after marketing." Repeat-dose 28-days and 90-days toxicity tests in rodents have been widely used as part of a strategy to assess the safety of drugs and chemicals but their repeatability and power to detect adverse effects have not been formally evaluated.The guidelines (OECD TG 407 and 408) for these tests specify the dose levels and number of animals per dose but do not specify the strain of animals which should be used. In practice, almost all the tests are done using genetically undefined "albino" rats or mice in which the genetic variation, a major cause of inter-individual and strain variability, is unknown and uncontrolled. This chapter suggests that a better strategy would be to use small numbers of animals of several genetically defined strains of mice or rats instead of the undefined animals used at present. Inbred strains are more stable providing more repeatable data than outbred stocks. Importantly their greater phenotypic uniformity should lead to more powerful and repeatable tests. Any observed strain differences would indicate genetic variation in response to the test substance, providing key data. We suggest that the FDA and other regulators and funding organizations should support research to evaluate this alternative.

  12. Quality Testing of Three Species of Tephritid Fruit Flies After Embryo Cryopreservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluates characteristics commonly used to define insect quality or fitness by using a complement of three species of tephritid fruit flies obtained from cryopreserved embryos. The Mexican, Anastrepah ludens, Caribbean, A. suspense, and Mediterranean, Certatitis capitata, fruit flies were...

  13. Quality testing of three species of Tephritid fruit flies after embryo cryopreservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluates characteristics commonly used to define insect quality or fitness by using a complement of three species of tephritid fruit flies obtained from cryopreserved embryos. The Mexican, Anastrepah ludens, Caribbean, A. suspense, and Mediterranean, Certatitis capitata, fruit flies were...

  14. Toxicity of lead and zinc to developing mussel and sea urchin embryos: critical tissue residues and effects of dissolved organic matter and salinity.

    PubMed

    Nadella, Sunita R; Tellis, Margaret; Diamond, Rachael; Smith, Scott; Bianchini, Adalto; Wood, Chris M

    2013-08-01

    Lead (Pb) EC50 values in the very sensitive early development phases (48-72h post-fertilization) of the mussels Mytilus galloprovincialis and Mytilus trossolus and sea urchin Strongylocentrotus purpuratus in 100% sea water were: M. trossolus - 45 (95% C.I.=22-72) μgL(-1); M. galloprovincialis - 63 (36-94) μgL(-1); S. purpuratus - 74 (50-101) μgL(-1). Salinity thresholds for normal development varied: M. trossolus>21ppt; M. galloprovincialis>28ppt; S. purpuratus≥30ppt. Addition of two spectroscopically distinct dissolved organic matters (DOM) from fresh water (Nordic Reservoir) and sea water (Inshore) moderately decreased the toxicity of Pb to both mussels, but not in a concentration-dependent fashion, with only an approximate doubling of EC50 over the range of 1.4-11.2mgCL(-1). Independent Pb binding capacity determinations for DOC explained the lack of a relationship between DOM concentration and toxicity. Salinity had no effect on Pb toxicity down to 21ppt in M. trossolus, and low salinity (21ppt) did not enhance the protective effect of DOC. Both DOMs increased the toxicity of Pb in developing sea urchin embryos, in contrast to mussels. Relative to Pb, the organisms were 6-9 fold less sensitive to Zn on a molar basis in 100% seawater with the following Zn EC50s: M. trossolus - 135 (103-170) μgL(-1); M. galloprovincialis - 172 (126-227) μgL(-1), S. purpuratus - 151 (129-177) μgL(-1). Nordic Reservoir and Inshore DOM (2-12mgCL(-1)) had no significant effect on Zn toxicity to mussels, in accord with voltammetry data showing an absence of any strong ligand binding for Zn by DOMs. As with Pb, DOMs increased Zn toxicity to urchin larvae. Critical Tissue Residues (CTR) based on whole body concentrations of Pb and Zn were determined for M. galloprovincialis at 48h and S. purpuratus at 72h. The median lethal CTR values (LA50s), useful parameters for development of saltwater Biotic Ligand Models (BLMs), were approximately 4-fold higher on a molar basis for Zn than

  15. Novel transcriptome assembly and comparative toxicity pathway analysis in mahi-mahi (Coryphaena hippurus) embryos and larvae exposed to Deepwater Horizon oil

    NASA Astrophysics Data System (ADS)

    Xu, Elvis Genbo; Mager, Edward M.; Grosell, Martin; Hazard, E. Starr; Hardiman, Gary; Schlenk, Daniel

    2017-03-01

    The impacts of Deepwater Horizon (DWH) oil on morphology and function during embryonic development have been documented for a number of fish species, including the economically and ecologically important pelagic species, mahi-mahi (Coryphaena hippurus). However, further investigations on molecular events and pathways responsible for developmental toxicity have been largely restricted due to the limited molecular data available for this species. We sought to establish the de novo transcriptomic database from the embryos and larvae of mahi-mahi exposed to water accommodated fractions (HEWAFs) of two DWH oil types (weathered and source oil), in an effort to advance our understanding of the molecular aspects involved during specific toxicity responses. By high throughput sequencing (HTS), we obtained the first de novo transcriptome of mahi-mahi, with 60,842 assembled transcripts and 30,518 BLAST hits. Among them, 2,345 genes were significantly regulated in 96hpf larvae after exposure to weathered oil. With comparative analysis to a reference-transcriptome-guided approach on gene ontology and tox-pathways, we confirmed the novel approach effective for exploring tox-pathways in non-model species, and also identified a list of co-expressed genes as potential biomarkers which will provide information for the construction of an Adverse Outcome Pathway which could be useful in Ecological Risk Assessments.

  16. Novel transcriptome assembly and comparative toxicity pathway analysis in mahi-mahi (Coryphaena hippurus) embryos and larvae exposed to Deepwater Horizon oil

    PubMed Central

    Xu, Elvis Genbo; Mager, Edward M.; Grosell, Martin; Hazard, E. Starr; Hardiman, Gary; Schlenk, Daniel

    2017-01-01

    The impacts of Deepwater Horizon (DWH) oil on morphology and function during embryonic development have been documented for a number of fish species, including the economically and ecologically important pelagic species, mahi-mahi (Coryphaena hippurus). However, further investigations on molecular events and pathways responsible for developmental toxicity have been largely restricted due to the limited molecular data available for this species. We sought to establish the de novo transcriptomic database from the embryos and larvae of mahi-mahi exposed to water accommodated fractions (HEWAFs) of two DWH oil types (weathered and source oil), in an effort to advance our understanding of the molecular aspects involved during specific toxicity responses. By high throughput sequencing (HTS), we obtained the first de novo transcriptome of mahi-mahi, with 60,842 assembled transcripts and 30,518 BLAST hits. Among them, 2,345 genes were significantly regulated in 96hpf larvae after exposure to weathered oil. With comparative analysis to a reference-transcriptome-guided approach on gene ontology and tox-pathways, we confirmed the novel approach effective for exploring tox-pathways in non-model species, and also identified a list of co-expressed genes as potential biomarkers which will provide information for the construction of an Adverse Outcome Pathway which could be useful in Ecological Risk Assessments. PMID:28295044

  17. Comparison of mathematically-predicted toxic equivalents (TEQs) and bioassay-derived dioxin-equivalents (TCDD-EQs) in heron embryos

    SciTech Connect

    Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D. ||

    1995-12-31

    Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from an uncontaminated site (Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, WI; Bair and West Marin Islands, San Francisco Bay, CA). Hepatic microsomal monooxygenases were induced up to 85-fold relative to the reference site, and was associated with concentrations of total PCBs and 11 PCB congeners that are presumed to express toxicity through the Ah receptor. TEQs [mathematically predicted; summed product of PCB congener concentrations using 5 different sets of toxic equivalency factors (TEFs)] were compared to TCDD-EQS [derived by bioassay; ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells]. Although TEQs were up to 15-fold greater than TCDD-EQs, the pattern among sites was consistent and TEQs were highly correlated with TCDD-EQS. TEFs based on single congener mammalian studies yielded TEQs that greatly exceeded values from the H4IIE bioassay of field sample. TEFs generated from avian egg injection studies yielded TEQs that most closely approximated bioassay-derived TCDD-EQS. Cytochrome P450 parameters were related to TEQs and TCDD-EQS; adjusted r{sup 2} often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data document the general predictive value of TEQs and TCDD-EQs for P450 induction in field collected samples, but also indicate the need for development of TEFs for the species and biological end point of concern.

  18. Reproducibility of a life-cycle toxicity test with Daphnia magna

    SciTech Connect

    Parkhurst, B.R.; Forte, J.L.; Wright, G.P.

    1981-01-01

    Standardized chronic life-cycle toxicity testing procedures for aquatic species are described. The reproducibility of chronic toxicity and points using the static-renewal method with Daphnia magna are investigated. The objectives were to determine if the lowest rejected concentrations tested (LRCTs) obtained for six different toxicity criteria in static-renewal tests with acridine were reproducible over time and to determine the relative sensitivity and variability of the toxicity criteria. Two of the six toxicity criteria, numbers of young per brood and the young produced per female, were found to be reliable and sensitive for estimating the LRCT for acridine to D. magna. (RJC)

  19. Comparison of prehatch C-start responses in rainbow trout and lake trout embryos by means of a tactile stimulus test

    USGS Publications Warehouse

    Wright, P.J.; Noltie, Douglas B.; Tillitt, D.E.

    2003-01-01

    The C-start in teleost fishes, a type of startle response, mediates the ability to respond to abrupt, unexpected stimuli and is characterized by a short-latency, C-type fast start acceleration. In prehatch fish embryos, the C-start appears necessary for mechanical breakdown of the egg chorion and successful hatching by way of increased embryo movement and distribution of the hatching enzymes. In later stages, the C-start plays an important role in predator avoidance. Using tactile stimulation, we evaluated the C-start response in rainbow trout Oncorhynchus mykiss at 170 degree-days, when 6.6% of embryos exhibited C-starts, and lake trout Salvelinus namaycush embryos at 320 degree-days, when 23% of embryos exhibited C-starts. Triplicate groups of embryos were later tested at three developmental stages: early (220 and 360 degree-days for rainbow trout and lake trout, respectively), middle (260 and 480 degree-days, respectively), and late (320 and 560 degree-days, respectively). The proportion of trout embryos exhibiting C-start increased through time, such that 100% had responded by the late stage, just prior to hatching. C-starts could be obtained by repeated stimulation, and the relative activity of the embryos (based on the number of flexures per stimulus) also increased over time. Rainbow trout and lake trout showed very similar C-start responses at parallel developmental stages, and these patterns of response were similar to those reported in other fish species.

  20. Integrated testing strategies for toxicity employing new and existing technologies.

    PubMed

    Combes, Robert D; Balls, Michael

    2011-07-01

    We have developed individual, integrated testing strategies (ITS) for predicting the toxicity of general chemicals, cosmetics, pharmaceuticals, inhaled chemicals, and nanoparticles. These ITS are based on published schemes developed previously for the risk assessment of chemicals to fulfil the requirements of REACH, which have been updated to take account of the latest developments in advanced in chemico modelling and in vitro technologies. In addition, we propose an ITS for neurotoxicity, based on the same principles, for incorporation in the other ITS. The technologies are deployed in a step-wise manner, as a basis for decision-tree approaches, incorporating weight-of-evidence stages. This means that testing can be stopped at the point where a risk assessment and/or classification can be performed, with labelling in accordance with the requirements of the regulatory authority concerned, rather than following a checklist approach to hazard identification. In addition, the strategies are intelligent, in that they are based on the fundamental premise that there is no hazard in the absence of exposure - which is why pharmacokinetic modelling plays a key role in each ITS. The new technologies include the use of complex, three-dimensional human cell tissue culture systems with in vivo-like structural, physiological and biochemical features, as well as dosing conditions. In this way, problems of inter-species extrapolation and in vitro/in vivo extrapolation are minimised. This is reflected in the ITS placing more emphasis on the use of volunteers at the whole organism testing stage, rather than on existing animal testing, which is the current situation.

  1. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  2. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  3. Effects of the Particulate Matter2.5 (PM2.5) on Lipoprotein Metabolism, Uptake and Degradation, and Embryo Toxicity

    PubMed Central

    Kim, Jae-Yong; Lee, Eun-Young; Choi, Inho; Kim, Jihoe; Cho, Kyung-Hyun

    2015-01-01

    Particulate matter2.5 (PM2.5) is notorious for its strong toxic effects on the cardiovascular, skin, nervous, and reproduction systems. However, the molecular mechanism by which PM2.5 aggravates disease progression is poorly understood, especially in a water-soluble state. In the current study, we investigated the putative physiological effects of aqueous PM2.5 solution on lipoprotein metabolism. Collected PM2.5 from Seoul, Korea was dissolved in water, and the water extract (final 3 and 30 ppm) was treated to human serum lipoproteins, macrophages, and dermal cells. PM2.5 extract resulted in degradation and aggregation of high-density lipoprotein (HDL) as well as low-density lipoprotein (LDL); apoA-I in HDL aggregated and apo-B in LDL disappeared. PM2.5 treatment (final 30 ppm) also induced cellular uptake of oxidized LDL (oxLDL) into macrophages, especially in the presence of fructose (final 50 mM). Uptake of oxLDL along with production of reactive oxygen species was accelerated by PM2.5 solution in a dose-dependent manner. Further, PM2.5 solution caused cellular senescence in human dermal fibroblast cells. Microinjection of PM2.5 solution into zebrafish embryos induced severe mortality accompanied by impairment of skeletal development. In conclusion, water extract of PM2.5 induced oxidative stress as a precursor to cardiovascular toxicity, skin cell senescence, and embryonic toxicity via aggregation and proteolytic degradation of serum lipoproteins. PMID:26615830

  4. Results of acute and chronic toxicity tests conducted at SRS NPDES outfalls, July--October 1991

    SciTech Connect

    Specht, W.L.

    1992-01-01

    Acute (48 hour LC50) and chronic (7-day reproductive impairment) toxicity tests were conducted on Ceriodaphnia dubia in water collected from 53 NPDES outfalls. All tests were conducted at the in-stream waste concentration. only 12 of the 53 outfalls showed no evidence of toxicity. Twenty-eight of the outfalls were acutely toxic, often producing 100% mortality during the first day of exposure. Fourteen outfalls had no discharge at the time of sampling and could not be tested. Three outfalls were not tested because their toxicity has been adequately characterized in other investigations. Elevated concentrations of total residual chlorine are suspected to be responsible for the observed toxicity of many NPDES outfalls, particularly the sanitary wastewater treatment plants. Chemical data from previous studies indicate that metals may also be present in toxic concentrations at many outfalls. Toxicity identification and reduction options are discussed.

  5. Reproductive toxicity of bisphenol A and cadmium in Potamopyrgus antipodarum and modulation of bisphenol A effects by different test temperature.

    PubMed

    Sieratowicz, Agnes; Stange, Daniela; Schulte-Oehlmann, Ulrike; Oehlmann, Jörg

    2011-10-01

    An OECD initiative for the development of mollusc-based toxicity tests for endocrine disrupters and other chemicals has recommended three test species with respective test designs for further standardisation. Preparing a subsequent pre-validation study we performed a reproduction test with Potamopyrgus antipodarum, determining the concentration range of the selected test substances, bisphenol A (BPA) and cadmium (Cd). At 16 °C, the recommended test temperature, the number of embryos in the brood pouch was increased by BPA and decreased by Cd (NOEC: 20 μg BPA/L and 1 μg Cd/L). Coinstantaneous BPA tests at 7 °C and 25 °C demonstrated a temperature dependency of the response, resulting in lower NOECs (5 μg/L respectively). As expected, reproduction in control groups significantly varied depending on temperature. Additional observations of the brood stock showed seasonal fluctuations in reproduction under constant laboratory conditions. The recommended temperature range and test conditions have to be further investigated.

  6. Early Evolution of the Toxicity Identification Evaluation Process: Contributions from the USEPA Effluent Testing Program

    EPA Science Inventory

    As part of its whole effluent testing program, the USEPA developed an effects-directed analysis (EDA) approach to identifying the cause of toxicity in toxic effluents or ambient waters, an EDA process termed a “Toxicity Identification Evaluation” (TIE), which is the focus of this...

  7. Methods For Collecting , Culturing And Performing Toxicity Tests With Daphnia ambigua

    SciTech Connect

    Specht, Winona L.

    2005-07-01

    Toxicity tests conducted on water collected from impacted locations in SRS streams often failed chronic toxicity tests and sometimes failed acute toxicity tests (Specht 1995). These findings prompted SRS to determine the cause of the failures. Some SRS NPDES outfalls were also failing chronic toxicity tests, even though no toxicant could be identified and when TIEs were performed, none of the TIE treatments removed the toxicity. Ultimately, it was determined that the failures were due to the low hardness of SRS surface waters, rather than to the presence of a toxicant. The species of cladoceran that the EPA recommends for toxicity testing, Ceriodaphnia dubia, is stressed by the very low hardness of SRS waters. SRS developed an alternate species toxicity test that is similar to the EPA test, but uses an indigenous cladoceran, Daphnia ambigua (Specht and Harmon, 1997; Harmon et al., 2003). In 2001, SCDHEC approved the use of D. ambigua for toxicity testing at SRS, contingent upon approval by EPA Region 4. In 2002, EPA Region 4 approved the use of this species for compliance toxicity testing at SRS. Ultimately, the use of this species demonstrated that SRS effluents were not toxic, and most toxicity testing requirements were removed from the NPDES permit that was issued in December 2003, with the exception of one round of chronic definitive testing on outfalls A-01, A-11, and G-10 just before the next NPDES permit application is submitted to SCDHEC. Although the alternate species test was developed at SRS (1996-1998), the culture was transferred to a contract toxicity testing lab (ETT Environmental) located in Greer, SC in 1998. ETT Environmental became certified by SCDHEC to perform toxicity tests using D. ambigua in 2002, and at this time is the only laboratory certified by SCDHEC to perform tests with this species. Because of the expense associated with maintaining the D. ambigua culture for several years when no toxicity testing is required, SRS decided to suspend

  8. Design and Analysis of Chronic Aquatic Tests of Toxicity with Daphnia magna.

    DTIC Science & Technology

    1981-12-01

    toxicity with Daphnia magna and statistical issues involved in the planning of such tests. All procedures are illustrated with examples based on real...keywords: Daphnia Magna ; Chronic aquatic toxicity tests; Statistical analysis; Graphical data display; Tests of hypothesis; Confidence intervals; Dose

  9. Effects of food and water quality on culturing and toxicity testing of Ceriodaphnia dubia: Final report

    SciTech Connect

    Cooney, J.D.; DeGraeve, G.M.; Moore, E.L.; Palmer, W.D.; Pollock, T.L.

    1988-05-01

    Effects of Food and Water Quality on Culturing and Toxicity Testing of Ceriodaphnia dubia. Tests of eight diets for culturing Ceriodaphnia have identified two foods that support high and consistent survival and reproduction. Use of these foods can contribute to the precision of EPA recommended effluent toxicity tests.

  10. Rapid toxicity testing based on mitochondrial respiratory activity

    SciTech Connect

    Haubenstricker, M.E. ); Holodnick, S.E.; Mancy, K.H. ); Brabec, M.J. )

    1990-05-01

    The need exists for rapid and inexpensive methods to determine the health effects of environmental contaminants on biological systems. One of the current research approaches for assessing cytotoxicity is to monitor the respiratory activity of the mitochondrion, a sensitive, nonspecific subcellular target site. Detected changes in mitochondrial function after the addition of a test chemical could be correlated to toxic effects. Mitochondrial respiration can be characterized by three indices: state 3 and state 4 respiratory rates, and the respiratory control ratio (RCR). State 4, the idle or resting state, results when coupled mitochondrial respire in a medium containing inorganic phosphate and a Kreb's cycle substrate in the absence of a phosphate acceptor such as adenosine diphosphate (ADP). In the presence of ADP the respiration rate increases to a maximum (state 3), accompanied by phosphorylation of ADP to adenosine triphosphate (ATP). The ratio of state 3 to state 4, or RCR, indicates how tightly the oxidative phosphorylation process is coupled. The synthesis of ATP by mitochondria is influenced by a number of compounds, most of which are either uncouplers or inhibitors.

  11. Implementing Lecane quadridentata acute toxicity tests to assess the toxic effects of selected metals (Al, Fe and Zn).

    PubMed

    Guzmán, Félix Torres; González, Francisco Javier Avelar; Martínez, Roberto Rico

    2010-03-01

    An environmental study revealed that three metals (Al, Fe and Zn) are common in the San Pedro River (SPR) (Aguascalientes, Mexico). Regrettably, in many samples the concentrations of these metals exceeded the maximum allowed toxicant concentrations levels as defined in by Mexican legislation. The highest concentrations of the three metals were found during the 2005 dry season, with elevated Al concentrations present along the entire river. Not surprisingly, the highest concentrations for all three metals came from locations adjacent to industrial areas. Estimates of the contribution of these metals to total toxicity revealed that these three metals are important contaminants of the river and responsible for most of the lethal toxicity found in environmental samples. To assess the importance of these reports, we conducted acute toxicity tests to determine LC50 for Al, Fe and Zn on the freshwater rotifer Lecane quadridentata. This permitted us to estimate the contribution of these metals to total toxicity during 2005-2006. Based on LC50 values, all three metals should be considered very toxic, with the zinc LC50 value (0.12 mg L(-1)) making it the most toxic metal for L. quadridentata. This approach can be applied to other sites with similar concentrations of these metals.

  12. Comparison of an Ampelisca abdita growth rate test with other standard amphipod sediment toxicity tests

    SciTech Connect

    Schafer, K.; Weston, D.P.

    1995-12-31

    Amphipod crustaceans are often used to measure the toxicity of bulk sediments. Acute lethal bioassays are commonly employed, but this study investigated the potential for using a chronic growth bioassay with Ampelisca abdita. A potential advantage of this method is that the growth rate could be a more sensitive measure of contamination than mortality. Growth rates for A. abdita in sediments spiked with cadmium and crude oil were compared to mortality rates in A. abdita, Eohaustorius estuaries, and Rhepoxynius abronius in sediments with the same concentrations of contaminants. A. abdita was more sensitive to cadmium than the other two species. For crude oil, there was a significant shift in size distribution from the control even at concentrations as low as 150 mg/kg of oil. The standard acute lethal tests for all species, on the other hand, did not show significant mortality until at least 1,600 mg/kg. The results confirm that growth rates are a more sensitive indicator of toxicity, and to at least the three contaminants tested, A. abdita is as sensitive as E. estuarius and R. abronius. This study also confirmed the reported high mortality rates of E. estuaries in San Francisco Bay sediments. The causes of this high mortality are unknown but give further reason for using A. abdita for toxicity tests in this region.

  13. Lethal and sublethal toxicity of the industrial chemical epichlorohydrin on Rhinella arenarum (Anura, Bufonidae) embryos and larvae.

    PubMed

    Hutler Wolkowicz, Ianina R; Aronzon, Carolina M; Pérez Coll, Cristina S

    2013-12-15

    Lethal and sublethal toxicity of the major chemical used in epoxide compounds, epichlorohydrin (ECH) was evaluated on the early life cycle of the common South American toad, Rhinella arenarum (Anura, Bufonidae). The stages evaluated were (according to Del Conte and Sirlin): early blastula (S.3-S.4), gastrula (S.10-S.12), rotation (S.15), tail bud (S.17), muscular response (S.18), gill circulation (S.20), open mouth (S.21), opercular folds (S.23) and complete operculum (S.25). The LC50 and EC50 values for lethal and sublethal effects were calculated. The early blastula was the most sensitive stage to ECH both for continuously and pulse-exposures (LC50-24h=50.9 mg L(-1)), while S.20 was the most resistant (LC50-24h=104.9 mg L(-1)). Among sublethal effects, early blastula was also the most sensitive stage (LOEC-48 h=20 mg L(-1)) and it has a Teratogenic Index of 2.5, which indicates the teratogenic potential of the substance. The main abnormalities were persistent yolk plugs, cell dissociation, tumors, hydropsy, oral malformations, axial/tail flexures, delayed development and reduced body size. ECH also caused neurotoxicity including scarce response to stimuli, reduction in the food intake, general weakness, spasms and shortening, erratic or circular swimming. Industrial contamination is considered an important factor on the decline of amphibian populations. Considering the available information about ECH's toxicity and its potential hazard to the environment, this work shows the first results of its developmental toxicity on a native amphibian species, Rhinella arenarum.

  14. Application of toxicity tests into discharges of the pulp-paper industry in Turkey.

    PubMed

    Sponza, Delia Teresa

    2003-01-01

    The aim of this study was to investigate the acute toxicity of pulp-paper industry wastewater using traditional and enrichment toxicity tests and to emphasize the importance of toxicity tests in wastewater discharge regulations. Enrichment toxicity tests are novel applications and give an idea of whether there is potential toxicity or growth-limiting and -stimulating conditions. Different organisms were used such as bacteria (floc and coliform bacteria), algae (Chlorella sp.), protozoa (Vorticella sp.), and fish (Lepistes sp.) to represent four trophic levels. Furthermore, chemical oxygen demand (COD) fractionation results were compared with these tests to assess the effect of COD subcategories on the determination of possible toxicity. The pulp-paper industry results revealed acute toxicity to at least two organisms in 6 of 20 effluent samples. The toxicity test results were assessed with chemical analyses such as COD, biochemical oxygen demand (BOD), color, absorbable organic halogen (AOXs), and phenol. It was observed that the toxicity of the effluents could not be explained by using physicochemical analyses in four cases for the pulp-paper industry. The results clearly indicate that bioassay tests provide additional information on the toxicity potential of industrial discharges and effluents.

  15. Field validation of 10-day freshwater sediment toxicity tests using Hyalella azteca and Chironomus tentans

    SciTech Connect

    Becker, D.S.; Bigham, G.N.

    1995-12-31

    Two of the toxicity tests commonly used to evaluate freshwater sediments are the 10-day amphipod (Hyalella azteca) and chironomid (Chironomus tentans) tests. EPA and ASTM have recently developed standardized protocols for these tests. Although both tests are considered sensitive indicators of sediment toxicity, little information exists on how well test results correspond to adverse biological effects in the field. In this study, the lethal and sublethal (i.e., biomass) responses of the two toxicity tests were compared with alterations of benthic macroinvertebrate assemblages (i.e., benthic effects) at 56 stations in Onondaga Lake, New York. The lake has received municipal and industrial discharges for more than 100 years, and sediment chemical concentrations range widely throughout the lake. Toxicity results for Onondaga Lake were compared with reference conditions using the t-test, and benthic effects were determined using classification analysis of log-transformed taxa abundances. In general, a relatively high level of agreement was found between results of the toxicity tests and alterations of benthic assemblages. Significant (P < 0.05) correlations were found between all toxicity test endpoints and taxa richness of benthic assemblages. In addition, significant concordance (P {le} 0.01, binomial test) was found between toxicity designations for the 56 stations based on toxicity tests and toxicity designations based on benthic effects. Despite the general level of agreement among the various biological indicators, chironomid biomass and benthic effects were found to be the most sensitive indicators of toxicity, whereas amphipod survival and biomass were the least sensitive indicators. This study suggests that results of the 10-day amphipod and chironomid toxicity tests are highly predictive of adverse biological effects in the field.

  16. Use of multidimensional scaling in the selection of wastewater toxicity test battery components.

    PubMed

    Ren, Shijin; Frymier, Paul D

    2003-04-01

    In aquatic toxicity testing, no single test species is sensitive to all toxicants. Therefore, test batteries consisting of several individual assays are becoming more common. The organisms in a test battery should be representative of the entire system of interest. The results of the assays should be complementary to other components in the test battery to avoid redundancy. With the aid of multidimensional scaling (MDS), a multivariate statistical method, we examined the toxicity data of five bioassays (the continuous Shk1, Polytox, activated sludge respiration inhibition, Nitrosomonas, and Tetrahymena assays) that could serve as test battery components for the assessment of wastewater toxicity to activated sludge. MDS mapped the five assays into a two-dimensional space and showed that the Nitrosomonas assay should be included in test batteries plus one of the remaining four assays for assessing wastewater toxicity to activated sludge.

  17. Applicability of ambient toxicity testing to national or regional water-quality assessment

    USGS Publications Warehouse

    Elder, John F.

    1990-01-01

    Comprehensive assessment of the quality of natural waters requires a multifaceted approach. Descriptions of existing conditions may be achieved by various kinds of chemical and hydrologic analyses, whereas information about the effects of such conditions on living organisms depends on biological monitoring. Toxicity testing is one type of biological monitoring that can be used to identify possible effects of toxic contaminants. Based on experimentation designed to monitor responses of organisms to environmental stresses, toxicity testing may have diverse purposes in water-quality assessments. These purposes may include identification of areas that warrant further study because of poor water quality or unusual ecological features, verification of other types of monitoring, or assessment of contaminant effects on aquatic communities. Toxicity-test results are most effective when used as a complement to chemical analyses, hydrologic measurements, and other biological monitoring. However, all toxicity-testing procedures have certain limitations that must be considered in developing the methodology and applications of toxicity testing in any large-scale water-quality-assessment program. A wide variety of toxicity-test methods have been developed to fulfill the needs of diverse applications. The methods differ primarily in the selections made relative to four characteristics: (1) test species, (2) endpoint (acute or chronic), (3) test-enclosure type, and (4) test substance (toxicant) that functions as the environmental stress. Toxicity-test approaches vary in their capacity to meet the needs of large-scale assessments of existing water quality. Ambient testing, whereby the test organism is exposed to naturally occurring substances that contain toxicant mixtures in an organic or inorganic matrix, is more likely to meet these needs than are procedures that call for exposure of the test organisms to known concentrations of a single toxicant. However, meaningful

  18. A test strategy for the assessment of additive attributed toxicity of tobacco products.

    PubMed

    Kienhuis, Anne S; Staal, Yvonne C M; Soeteman-Hernández, Lya G; van de Nobelen, Suzanne; Talhout, Reinskje

    2016-08-01

    The new EU Tobacco Product Directive (TPD) prohibits tobacco products containing additives that are toxic in unburnt form or that increase overall toxicity of the product. This paper proposes a strategy to assess additive attributed toxicity in the context of the TPD. Literature was searched on toxicity testing strategies for regulatory purposes from tobacco industry and governmental institutes. Although mainly traditional in vivo testing strategies have been applied to assess toxicity of unburnt additives and increases in overall toxicity of tobacco products due to additives, in vitro tests combined with toxicogenomics and validated using biomarkers of exposure and disease are most promising in this respect. As such, tests are needed that are sensitive enough to assess additive attributed toxicity above the overall toxicity of tobacco products, which can associate assay outcomes to human risk and exposure. In conclusion, new, sensitive in vitro assays are needed to conclude whether comparable testing allows for assessment of small changes in overall toxicity attributed to additives. A more pragmatic approach for implementation on a short-term is mandated lowering of toxic emission components. Combined with risk assessment, this approach allows assessment of effectiveness of harm reduction strategies, including banning or reducing of additives.

  19. Pyrrolizidine Alkaloids: Testing for Toxic Constituents of Comfrey.

    ERIC Educational Resources Information Center

    Vollmer, John J.; And Others

    1987-01-01

    Discusses the possibilities of toxins present in medicinal herbs. Describes an experiment in which toxic constituents can be selectively detected by thin-layer chromatography and NMR spectroscopy. (TW)

  20. Comparison of mathematically-predicted toxic equivalents (TEQs) and bioassay-derived dioxin-equivalents (TCDD-EQs) in heron embryos

    USGS Publications Warehouse

    Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D.

    1995-01-01

    Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from an uncontaminated site (Chincoteague National Wildlife Refuge,VA) and three polluted sites (Cat Island, Green Bay, WI; Bair and West Marin Islands, San Francisco Bay, CA). Hepatic microsomal monooxygenases were induced up to 85-fold relative to the reference site, and was associated with concentrations of total PCBs and 11 PCB congeners that are presumed to concern.to express toxicity through the Ah receptor. TEQs [mathematically predicted; summed product of PCB congener concentrations using 5 different sets of toxic equivalency factors (TEFs)] were compared to TCDD-EQs [derived by bioassay; ethoxyresorufin-O-dealkylase activity of treated H411E rat hepatoma cells]. Although TEQs were up to 15-fold greater than TCDD-EQs, the pattern among sites was consistent and TEQs were highly correlated with TCDD-EQs. TEFs based on single congener mammalian studies yielded TEQs that greatly exceeded values from the H411E bioassay of field sample. TEFs generated from avian egg injection studies yielded TEQs that most closely approximated bioassay-derived TCDD-EQs. Cytochrome P450 parameters were related to TEQs and TCDD-EQs; adjusted r2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data document the general predictive value of TEQs and TCDD-EQs for P450 induction in field collected samples, but also indicate the need for development of TEFs for the species and biological end point of concern.

  1. COMPARATIVE TOXICITY TESTING OF SELECTED BENTHIC AND EPIBENTHIC ORGANISMS FOR THE DEVELOPMENT OF SEDIMENT QUALITY TEST PROTOCOLS

    EPA Science Inventory

    Sediment contamination has resulted in the need to develop an appropriate suite of toxicity tests to assess ecotoxicological impacts on estuarine ecosystems. Existing Environmental Protection Agency (EPA) protocols recommend a number of test organisms, including amphipods, polych...

  2. Developmental and interactive effects of arsenic and chromium to developing Ambystoma maculatum embryos: Toxicity, teratogenicity, and whole-body concentrations.

    PubMed

    Gardner, Steven; Cline, George; Mwebi, Nixon; Rayburn, James

    2017-01-01

    Anthropogenic activity has contributed to elevated environmental concentrations of arsenic (As) and chromium (Cr). The spotted salamander, Ambystoma maculatum, may be useful for identifying developmental effects produced by exposure to these contaminants as adults breed and larvae develop in water that may contain As or Cr. Three sample sets among 700 developing larvae were exposed to a range of As, Cr, or 2.5:1 mixture of As:Cr concentrations, respectively. From these 700 larvae, samples containing approximately 24 larvae showed different patterns of whole-body As and Cr from individual and mixture exposure. Whole-body As concentrations were 20.27 and 45.4 µg/g dry weight for larvae exposed to 20 mg/L As and 25:10 mg/L As:Cr, respectively, while whole-body Cr concentrations were 24.8 and 22 µg/g dry weight for larvae exposed to 20 mg/L Cr and 25:10 As:Cr, respectively. Observed malformations included edema, tail kinking, facial deformities, and abnormal bending. Twelve-day lethal concentrations for As and Cr in Ambystoma maculatum larvae were 261.17 mg/L and 71.93 mg/L, respectively, while 12-d effective concentrations to induce malformations were 158.82 and 26.05 mg/L, giving teratogenic indices of 1.64 and 2.76 for individual metal exposure. Exposure to a mixture of As and Cr resulted in a response addition and yielded lower lethal and effective concentration values with a teratogenic index of 2.78, indicating that these contaminants are developmentally toxic at lower concentrations when exposed as a mixture. Data demonstrate that As and Cr affect development of amphibian larvae, and that Ambystoma maculatum may be a useful indicator of environmental toxicity for these metals.

  3. Environmental concentrations of the cocaine metabolite benzoylecgonine induced sublethal toxicity in the development of plants but not in a zebrafish embryo-larval model.

    PubMed

    García-Cambero, J P; García-Cortés, H; Valcárcel, Y; Catalá, M

    2015-12-30

    Several studies have found cocaine and its main active metabolite benzoylecgonine (BE) in the aquatic environment and drinking water, derived from its consumption by humans as well as the inability of water treatment processes to eliminate it. A few studies have already investigated the ecotoxicology of BE to aquatic invertebrates, but none has still addressed the effects of BE on aquatic vertebrates or vascular plants. The goal of this publication is to provide information on the toxicity of environmental concentrations of BE during animal and vascular plant development, in order to contribute to a better understanding of the potential risk of this substance for the environment. BE induced alterations in mitochondrial activity and DNA levels of fern spores at environmental concentrations (1 ng L(-1)), which could disrupt gametophyte germination. However, BE at concentrations ranging from 1 ng L(-1) to 1 mg L(-1) did not disturb morphogenesis, hatching, heartbeat rate or larval motility in a zebrafish embryo-larval model. Adverse effects on ferns agree with the allelophathic role described for alkaloids and their unspecific interference with plant germination. Therefore, the anthropogenic dispersion of alkaloid allelochemicals may pose a risk for biodiversity and irrigated food production that should be further investigated.

  4. Evaluation of three soil toxicity tests used to monitor acceptable endpoints

    SciTech Connect

    Brinkmann, M.; Stroo, H.; Leuschner, A.; Leuteritz, D.; Stromberg, M.; Brourman, M.

    1995-12-31

    Three terrestrial toxicity tests were used to evaluate the efficacy of biological treatment of creosote and pentachlorophenol impacted soils at a Superfund site. Microtox, 5-day lettuce seed, and 14-day earthworm toxicity tests were performed on 10 soil samples at the beginning and end of 3 months of land treatment. Secondary endpoints of root length and earthworm weight loss were also evaluated. EC50 and LC50 values were calculated using a Trimmed Logit Statistical Program and compared to toxicity of 10 background samples collected from the site. Results for initial soils demonstrated toxicity with three of the five endpoints. End treatment results showed no measurable toxicity using all endpoints. Toxicity testing results are critical for obtaining regulatory approval for the full-scale treatment system. Post treatment closure requirements for the site will be based on bioassay results. Evaluation of the three tests used showed the Microtox test to be the most sensitive to this type of toxicity. Lettuce seed germination results were the least sensitive of the three primary endpoints chosen. Of the secondary endpoint criteria, root length demonstrated reliable EC50 values and showed toxicity trends similar to Microtox and earthworm tests. The earthworm weight loss endpoint was not a useful toxicity measurement at 14 days.

  5. Anodonta imbecillis copper sulfate reference toxicant test, Clinch River - Environmental Restoration Program (CR-ERP)

    SciTech Connect

    Simbeck, D.J.

    1997-06-01

    Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12-21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained in a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values.

  6. Factors affecting toxicity test endpoints in sensitive life stages of native Gulf of Mexico species.

    PubMed

    Echols, B S; Smith, A J; Rand, G M; Seda, B C

    2015-05-01

    Indigenous species are less commonly used in laboratory aquatic toxicity tests compared with standard test species due to (1) limited availability lack of requisite information necessary for their acclimation and maintenance under laboratory conditions and (2) lack of information on their sensitivity and the reproducibility of toxicity test results. As part of the Natural Resource Damage Assessment aquatic toxicity program in response to the Deepwater Horizon Oil incident (2010), sensitive life stages of native Gulf of Mexico species were evaluated in laboratory toxicity tests to determine the potential effects of the spill. Fish (n = 5) and invertebrates (n = 2) selected for this program include the following: the Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), spotted sea trout (Cynoscion nebulosus), cobia (Rachycentron canadum), red porgy (Pagrus pagrus), blue crab (Callinectes sapidus), and the common moon jellyfish (Aurelia aurita). Initially in the program, to establish part of the background information, acute tests with reference toxicants (CdCl2, KCl, CuSO4) were performed with each species to establish data on intraspecies variability and test precision as well as identify other factors that may affect toxicity results. Median lethal concentration (LC50) values were calculated for each acute toxicity test with average LC50 values ranging from 248 to 862 mg/L for fish exposures to potassium chloride. Variability between test results was determined for each species by calculating the coefficient of variation (%CV) based on LC50 values. CVs ranged from 11.2 % for pompano (96-h LC50 value) to 74.8 % for red porgy 24-h tests. Cadmium chloride acute toxicity tests with the jellyfish A. aurita had the lowest overall CV of 3.6 %. By understanding acute toxicity to these native organisms from a compound with known toxicity ranges and the variability in test results, acute tests with nonstandard species can be better interpreted and used

  7. Chronic toxicity bioassay with ceriodaphnia dubia': (1) An evaluation of a toxicity test-based approach for determining the sources of chronic toxicity; and (2) an evaluation of culture/dilution waters and diet as determinants of test outcomes

    SciTech Connect

    Francisco, D.E.; Elias, M.C.; LaRocca, C.A.; DiGiano, F.A.; Maerker, M.J.

    1993-08-01

    In order to limit the discharge of toxic materials in toxic amounts to the waterways of the United States, the U. S. Environmental Protection Agency (EPA) has developed a 7-day survival and reproduction toxicity bioassay test using the freshwater cladoceran, Ceriodaphnia dubia. The North Carolina Division of Environmental Management has developed a less expensive modification of this test called the NC Ceriodaphnia Mini-Chronic Pass/Fail Toxicity Test. These tests are used to monitor discharges from wastewater treatment plants. Failure to satisfy the requirements (evidence of either acute or chronic toxicity) of the discharge permit constitutes an effluent violation. Effluent violations require that studies be conducted to determine the means to eliminate the violation. The present investigation had three basic objectives: (1) to develop and test a toxicity test-based method for locating the sources of toxic materials discharged into a collection system; (2) to investigate the effect of culture/dilution water on the health of C. dubia and reproducibility of the NC Ceriodaphnia Mini-Chronic Pass/Fail Toxicity Test; and (3) to investigate the effect of 3 diets on the health and robustness of C. dubia.

  8. Strategies for integrating transcriptional profiling into high throughput toxicity testing (SOT Symposium Workshop presentation)

    EPA Science Inventory

    Presentation Description: The release of the National Research Council’s Report “Toxicity Testing in the 21st Century: A Vision and a Strategy” in 2007 initiated a broad-based movement in the toxicology community to re-think how toxicity testing and risk assessment are performed....

  9. New technologies and approaches in toxicity testing and risk assessment (ESOT)

    EPA Science Inventory

    The release of the National Research Council’s Report “Toxicity Testing in the 21st Century: A Vision and a Strategy” in 2007 initiated a broad-based movement in the toxicology community to re-think how toxicity testing and risk assessment are performed. Multiple efforts in the ...

  10. A comparison of relative toxicity rankings by some small-scale laboratory tests

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Small-scale laboratory tests for fire toxicity, suitable for use in the average laboratory hood, are needed for screening and ranking materials on the basis of relative toxicity. The performance of wool, cotton, and aromatic polyamide under several test procedures is presented.

  11. The Adverse Outcome Pathway: A conceptual framework to support toxicity testing in the 21st century

    EPA Science Inventory

    The field of regulatory toxicity testing is at a turning point. The U.S. National Research Council (NRC) envisioned a shift away from traditional toxicity testing and towards a focused effort to explore and understand pathways perturbed by biologically active substances or their ...

  12. Allium-test as a tool for toxicity testing of environmental radioactive-chemical mixtures

    NASA Astrophysics Data System (ADS)

    Oudalova, A. A.; Geras’kin, S. A.; Dikareva, N. S.; Pyatkova, S. V.

    2017-01-01

    Bioassay-based approaches have been propagated to assess toxicity of unknown mixtures of environmental contaminants, but it was rarely applied in cases of chemicals with radionuclides combinations. Two Allium-test studies were performed to assess environmental impact from potential sources of combined radioactive-chemical pollution. Study sites were located at nuclear waste storage facilities in European and in Far-Eastern parts of Russia. As environmental media under impact, waters from monitor wells and nearby water bodies were tested. Concentrations of some chemicals and radionuclides in the samples collected enhanced the permitted limits. Cytogenetic and cytotoxic effects were used as biological endpoints, namely, frequency and spectrum of chromosome aberrations and mitotic abnormalities in anatelophase cells as well as mitotic activity in Allium root tips. Sample points were revealed where waters have an enhanced mutagenic potential. The findings obtained could be used to optimize monitoring system and advance decision making on management and rehabilitation of industrial sites. The Allium-test could be recommended and applied as an effective tool for toxicity testing in case of combined contamination of environmental compartments with radionuclides and chemical compounds.

  13. Chlormequat chloride retards rat embryo growth in vitro.

    PubMed

    Xiagedeer, Bayindala; Wu, Shuang; Liu, Yingjuan; Hao, Weidong

    2016-08-01

    Chlormequat chloride is the most widely used plant growth regulator in agriculture to promote sturdier growth of grain crops by avoidance of lodging. Therefore, human exposure to chlormequat chloride is very common, but its developmental toxicity has not been studied. Thus, we investigated the developmental toxicity of chlormequat chloride by applying rat whole embryo culture (WEC) model, limb bud micromass culture and 3T3 fibroblast cytotoxicity test. Chlormequat chloride at 150μg/ml (0.93mM) retarded the rat embryo growth without causing significant morphological malformations and at 500μg/ml (3.1mM) caused both retardation and morphological malformation of the embryos. However, the proliferation and differentiation of limb bud cells were not affected by chlormequat chloride at as high as up to 1000μg/ml (6.2mM) applied. This concentration of chlormequat chloride did not affect the cell viability as examined by 3T3 fibroblast cytotoxicity test either, suggesting that cellular toxicity may not play a role in chlormequat induced inhibition of rat embryo growth. Collectively, our results demonstrated that chlormequat chloride may affect embryo growth and development without inhibiting cell viability.

  14. Preimplantation Genetic Diagnosis: Prenatal Testing for Embryos Finally Achieving Its Potential

    PubMed Central

    Stern, Harvey J.

    2014-01-01

    Preimplantation genetic diagnosis was developed nearly a quarter-century ago as an alternative form of prenatal diagnosis that is carried out on embryos. Initially offered for diagnosis in couples at-risk for single gene genetic disorders, such as cystic fibrosis, spinal muscular atrophy and Huntington disease, preimplantation genetic diagnosis (PGD) has most frequently been employed in assisted reproduction for detection of chromosome aneuploidy from advancing maternal age or structural chromosome rearrangements. Major improvements have been seen in PGD analysis with movement away from older, less effective technologies, such as fluorescence in situ hybridization (FISH), to newer molecular tools, such as DNA microarrays and next generation sequencing. Improved results have also started to be seen with decreasing use of Day 3 blastomere biopsy in favor of polar body or Day 5 trophectoderm biopsy. Discussions regarding the scientific, ethical, legal and social issues surrounding the use of sequence data from embryo biopsy have begun and must continue to avoid concern regarding eugenic or inappropriate use of this technology. PMID:26237262

  15. Terrestrial isopods -- a good choice for toxicity testing of pollutants in the terrestrial environment

    SciTech Connect

    Drobne, D.

    1997-06-01

    Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the digestive glands. These responses are able to provide accurate indications of sublethal toxicity. Toxicity tests with terrestrial isopods could be much more reliable through the use of positive controls. A positive control with a reference toxicant could also be supplemented by a reference endpoint. The most suitable reference endpoint is change of food consumption rate. Toxicity testing with terrestrial isopods is a very promising method for fast, routine, and inexpensive laboratory determination of the relative toxicities of chemicals in the terrestrial environment.

  16. Population growth rate determinants for Arbacia: Evaluating ecological relevance of toxicity test endpoints

    SciTech Connect

    Nacci, D.; Gleason, T.; Munns, W.R. Jr.

    1995-12-31

    A population dynamics model for the sea urchin, Arbacia punctulata, was recently developed incorporating life stage endpoints frequently measured in acute and chronic toxicity studies. Model elasticity analysis was used to demonstrate that population growth rate was influenced most by adult survival and least by early life stage success, calling into question the ecological relevance of results from standardized Arbacia fertilization and larval development toxicity tests. Two approaches were used to continue this evaluation. Actual and hypothetical dose-response curves for toxicant exposures over multiple life stages were used to evaluate contributions to population growth rate of stage-specific toxicant effects. Additionally, relationships between critical life stages were developed from laboratory data for Arbacia. The results of this analysis underscore the importance of understanding both endpoint sensitivity to toxicants and sensitivity of population growth rate to test endpoints in determining the ecological relevance of toxicity tests results.

  17. Improving Toxicity Assessment of Pesticide Mixtures: The Use of Polar Passive Sampling Devices Extracts in Microalgae Toxicity Tests

    PubMed Central

    Kim Tiam, Sandra; Fauvelle, Vincent; Morin, Soizic; Mazzella, Nicolas

    2016-01-01

    Complexity of contaminants exposure needs to be taking in account for an appropriate evaluation of risks related to mixtures of pesticides released in the ecosystems. Toxicity assessment of such mixtures can be made through a variety of toxicity tests reflecting different level of biological complexity. This paper reviews the recent developments of passive sampling techniques for polar compounds, especially Polar Organic Chemical Integrative Samplers (POCIS) and Chemcatcher® and the principal assessment techniques using microalgae in laboratory experiments. The progresses permitted by the coupled use of such passive samplers and ecotoxicology testing as well as their limitations are presented. Case studies combining passive sampling devices (PSD) extracts and toxicity assessment toward microorganisms at different biological scales from single organisms to communities level are presented. These case studies, respectively, aimed (i) at characterizing the “toxic potential” of waters using dose-response curves, and (ii) at performing microcosm experiments with increased environmental realism in the toxicant exposure in term of cocktail composition and concentration. Finally perspectives and limitations of such approaches for future applications in the area of environmental risk assessment are discussed. PMID:27667986

  18. Evaluation of a chronic toxicity test based upon the use of luminescent bacteria

    SciTech Connect

    Bulich, A.; Huynh, H.; Ulitzur, S.

    1995-12-31

    The authors have previously reported on the initial development of a new chronic toxicity test which utilizes the Microtox strain of luminescent bacteria as the test organism. These freeze-dried luminescent bacteria, following inoculation into a special growth medium, initiate a series of reproductive cycles and numerous metabolic pathways resulting in the production of light. Toxic materials which inhibit any aspect of the organisms` reproductive cycle or light production are detected in low levels. Critical test parameters associated with this test were evaluated and the resulting information summarized herein. These parameters include the following: (1) Data calculation methods and software used to capture, analyze, and present test data. (2) Evaluation of test data from 70 copper sulfate experiments with resulting information about test precision, sensitivity, and variability of light production from control cuvettes. 3. An analysis and summary of comparative test data from over 50 effluent samples which were co-tested with the Ceriodaphnia dubia 7 day chronic toxicity test and the Microtox 22 hour chronic toxicity test. (4) Luminescent bacteria chronic toxicity test data from whole effluent samples compared with corresponding test data from whole sediment toxicity test methods.

  19. Development and application of a marine sediment porewater toxicity test using algal spores

    SciTech Connect

    Hooten, R.; Carr, R.S.

    1995-12-31

    An acute pore water toxicity test protocol using germination and growth of marine macroalgae as endpoints was developed to indicate the presence of toxic compounds in marine/estuarine and sediment porewater samples. Zoospores collected from Ulva fasciata and U. lactuca were used as test organisms. Preliminary results with sodium dodecyl sulfate (SDS, a reference toxicant) indicate that zoospores germination and growth of embryonic gametophytes are as sensitive as the sea urchin fertilization and embryological development toxicity tests. Algal germination and growth data for copper, mercury and other metals will be presented. The results of tests utilizing this algal assay with sediment pore water from contaminated sediments will be compared with more traditional sediment toxicity test methods.

  20. Assessing Contaminant Sensitivity of Endangered and Threatened Aquatic Species: Part III. Effluent Toxicity Tests

    EPA Science Inventory

    This paper reports on the results of chronic toxicity tests conducted with common surrogate species, and several threatened and endangered species for which there were excess artificially propagated stock to allow direct testing.

  1. ASSESSING CONTAMINANT SENSITIVITY OF ENDANGERED AND THREATENED SPECIES: EFFLUENT TOXICITY TESTS

    EPA Science Inventory

    Toxicity tests using standard effluent test procedures were conducted (EPA 1994) with Ceriodaphnia dubia and fathead minnows and four endangered fish species: bonytail chub (Gila elegans), Colorado squawfish (Ptychocheilus lucias ), razorback sucker (Xyrauchen texanus) and Gila t...

  2. Application of simple and low-cost toxicity tests for ecotoxicological assessment of industrial wastewaters.

    PubMed

    Aydin, Mehmet Emin; Aydin, Senar; Tongur, Süheyla; Kara, Gülnihal; Kolb, Marit; Bahadir, Müfit

    2015-01-01

    The objective of this study was to identify and to apply appropriate biotests having the advantages of being highly sensitive, easy to run, relatively inexpensive and able to substitute fish toxicity tests due to ethical reasons of animal welfare. To perform an ecotoxicological assessment of industrial wastewaters, different microbiotests were conducted to substitute the fish toxicity test with Lebistes reticulatus through Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, Lemna minor and Lepidium sativum representing different trophic levels in the aquatic and terrestrial ecosystems. Also, Algaltox F(TM) with Pseudokirchneriella subcapitata and Protox F(TM) with Tetrahymena thermophila tests were carried out. However, they could not be applied successfully for the wastewater samples. Wastewater samples from seven different industrial zones comprising different industries were subjected to characterization through measuring their physical-chemical parameters and their toxicity versus the above-mentioned organisms. T. platyurus, D. magna and L. reticulatus were the most sensitive test organisms investigated for the wastewaters. Considering toxic unit values, generally wastewater samples were toxic according to Thamnotox F(TM), Daphtox F(TM) and fish toxicity tests. As an important outcome, it was concluded that Daphtox F(TM) and Thamnotox F(TM) could be a good alternative for the fish toxicity test, which is so far the sole toxicity test accepted by the Turkish Water Pollution Control Regulation.

  3. A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

    USGS Publications Warehouse

    Burton, G. Allen; Ingersoll, Christopher G.; Burnett, LouAnn C.; Henry, Mary; Hinman, Mark L.; Klaine, Stephen J.; Landrum, Peter F.; Ross, Phillipe; Tuchman, Marc

    1996-01-01

    The significance of sediment contamination is often evaluated using sediment toxicity (bioassay) testing. There are relatively few “standardized” test methods for evaluating sediments. Popular sediment toxicity methods examine the extractable water (elutriate), interstitial water, or whole (bulk) sediment phases using test species spanning the aquatic food chain from bacteria to fish. The current study was designed to evaluate which toxicity tests were most useful in evaluations of sediment contamination at three Great Lake Areas of Concern. Responses of 24 different organisms including fish, mayflies, amphipods, midges, cladocerans, rotifers, macrophytes, algae, and bacteria were compared using whole sediment or elutriate toxicity assays. Sediments from several sites in the Buffalo River, Calumet River (Indiana Harbor), and Saginaw River were tested, as part of the U.S. Environmental Protection Agency's (USEPA) Assessment and Remediation of Contaminated Sediments (ARCS) Project. Results indicated several assays to be sensitive to sediment toxicity and able to discriminate between differing levels of toxicity. Many of the assay responses were significantly correlated to other toxicity responses and were similar based on factor analysis. For most applications, a test design consisting of two to three assays should adequately detect sediment toxicity, consisting of various groupings of the following species: Hyalella azteca, Ceriodaphnia dubia, Chironomus riparius, Chironomus tentans, Daphnia magna, Pimephales promelas, Hexagenia bilineata, Diporeia sp., Hydrilla verticillata, or Lemna minor.

  4. Effect of the test media and toxicity of LAS on the growth of Isochrysis galbana.

    PubMed

    Garrido-Perez, M C; Perales-VargasMachuca, J A; Nebot-Sanz, E; Sales-Márquez, D

    2008-11-01

    In this paper, the toxicity of linear alkylbenzene sulfonate (LAS) was evaluated in the marine microalga Isochrysis galbana using data of growth inhibition toxicity tests at 96-h exposure time. Toxicity was examined in standard conditions and by means of the modification of two variables of the test media: (1) the dilution water and (2) the content of nutrients in the test medium. For this purpose, a total of 10 toxicity test were designed: five dilution waters, four natural marine waters and one synthetic seawater; each in two different nutritive conditions, saturated nutrient concentration (SC) by the addition of modified f/2 nutritive medium, and natural nutrient concentration (NC), i.e., without the addition of f/2. At threshold toxicity levels, the dilution waters used in the test and the nutrient concentrations did not affect the toxicity of LAS. At IC50 concentrations, the toxicity of LAS is influenced by both variables: under SC conditions, the toxic effect of LAS diminishes, obtaining in all the tests IC50 > 10 mg/L LAS. Under NC conditions, IC50 concentrations ranging between 3.15 and 9.26 mg/L LAS have been obtained.

  5. [Toxicity tests and their application in safety assessment of water quality].

    PubMed

    Xu, Jian-Ying; Zhao, Chun-Tao; Wei, Dong-Bin

    2014-10-01